JP2018192461A - Shaft seal structure of powder device, powder device and shaft seal member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce leakage of powder and mixing of foreign matter into powder in a shaft seal of a powder device, reduce damage to the shaft seal structure, and facilitate maintenance of the shaft seal structure. To provide a structure, a powder device having a shaft-sealed structure thereof, and a powder handling method. SOLUTION: A container 11 for storing powder P, a rotating shaft 141 for non-contactly penetrating an outer wall 111 of the container 11, and a driving means M provided outside the container 11 for rotating the rotating shaft 141. The shaft sealing structure of the powder device 1 to have the bottom wall 161b provided with a circular shaft hole 161f through which the rotating shaft 141 passes non-contact and leads from the inside to the outside of the container 11, and the rotating shaft 141 and the shaft hole. Air supply means A, 151, 161e, 164 for sending gas from the outside to the inside of the container 11 are provided between the inner peripheral surface of the 161f, and a spiral groove 161g is formed on the inner peripheral surface of the shaft hole 161f. The shaft sealing structure of the powder device 1 is characterized in that the powder device 1 is provided. [Selection diagram] Fig. 2

Description

  The present invention relates to a shaft seal structure, a powder device, and a shaft seal member of a powder device, and more particularly to a shaft seal structure, a powder device, and a shaft seal member of a powder device that handles powder using a rotating shaft.

  Examples of a powder device that handles powder in a container using a rotating shaft include a screw conveyor (screw feeder) and a rotary feeder. The rotary shaft has various shapes and structures depending on the application, such as a screw blade or a disk-shaped blade. In such an apparatus, the rotating shaft is rotated by driving means such as a motor, and these driving means are generally provided outside the container.

  Therefore, the rotating shaft needs to penetrate the outer wall of the container. In such a configuration, in order to suppress wear, damage, and power loss of parts, a hole larger than the diameter of the rotating shaft is provided in the container, and the rotating shaft is often passed through the hole without contact with the outer wall of the container. . In this case, the problem is that the powder leaks from the gap between the rotating shaft and the inner wall of the hole.

  As a shaft seal structure for preventing powder leakage, for example, contact-type sealing means such as a gland packing is used. However, if powder enters between the rotating shaft and the gland packing or the shaft hole, the gland packing is likely to be worn and deteriorated. Therefore, it is necessary to frequently perform maintenance such as adjustment of the pressing force of the gland packing or replacement of the gland packing, which leads to an increase in cost when handling powder.

  In order to improve the shaft seal structure of the powder device, for example, in Patent Document 1, a first annular groove having a shaft sealing gas and a second annular groove having grease sealed therein are used as a gland packing. It is provided outside the casing to prevent the powder from being ejected outward (atmosphere) from the gap between the rotating shaft and the gland packing.

  In Patent Document 2, a bearing body attached to a box body that surrounds the rotation shaft outside the shaft hole through which the rotation shaft of the powder container penetrates, and a helical protrusion formed on the outer periphery of the rotation shaft in a portion passing through the shaft hole The powder leaking to the box side from the gap between the shaft hole and the rotating shaft is pushed back into the powder container by the spiral protrusion by the rotation of the rotating shaft.

  In Patent Document 3, in the rotary feeder, a partition plate having an insertion hole slightly larger than the rotation shaft is provided between the inside and the outside of the casing, and toward the inside of the casing in the gap between the insertion hole and the rotation shaft. Air is allowed to flow, and the granular material that is about to exit from the gap is pushed back into the casing.

No. 6-11096 Patent No. 5270965 JP-A-8-119457

  However, the shaft seal device of Patent Document 1 does not have a configuration that suppresses powder from entering the gap between the rotating shaft and the gland packing, and it is difficult to reduce the cost for maintenance of the gland packing. .

  The shaft seal structure of Patent Document 2 has protrusions formed on the rotating shaft, but (i) the structure is pushed back by the rotating force of the rotating shaft when the powder is pushed back, so the frictional force is large and the protrusions are worn. (Ii) The powder adheres to the inner peripheral surface of the shaft hole by the rotational force of the rotating shaft and bites between the rotating shafts, causing power loss, parts wear, scratches, and damage. (Iii) ) Since the rotating shaft is machined, it is difficult to remove the rotating shaft and the degree of machining is difficult (shaft shaving causes the shaft diameter to fluctuate and other accessory equipment must be resized), (iv) There is a problem such as high cost because it is necessary to prepare a rotating shaft according to the type.

  Further, in the configuration of Patent Document 3, since the air purge unevenness in the gap between the insertion hole and the rotation shaft is large, it is necessary to set the air amount based on a place where the flow rate is small, and it is necessary to supply a large amount of air. . In addition, the length of the gap between the insertion hole and the rotating shaft, i.e., it is necessary to push the granular material back with a stroke corresponding to the thickness of the partition plate. It is difficult to push back the incoming powder.

  Accordingly, the present invention provides a shaft seal structure for a powder device that can prevent powder from leaking from a container that handles the powder while reducing damage to the powder device, power loss at the rotating shaft, and maintenance costs, and powder. An object is to provide a device and a shaft seal member.

  The present invention has been completed by finding that the above problems can be solved by the following aspects.

(Aspect 1)
A shaft seal structure of a powder device comprising: a container for storing powder; a rotating shaft that penetrates the outer wall of the container in a non-contact manner; and a driving unit that is provided outside the container and rotates the rotating shaft. The container is connected between the bottom wall provided with a circular shaft hole that passes through the rotation shaft in a non-contact manner and communicates from the inside of the container to the outside, and the inner peripheral surface of the shaft hole and the rotation shaft. A shaft sealing structure of a powder device, wherein a spiral groove is formed on an inner peripheral surface of the shaft hole.

(Aspect 2)
The shaft sealing structure of the powder device according to aspect 1, wherein the spiral groove has a shape in which the width of the groove increases toward the rotation axis.

(Aspect 3)
In the cross section including the axis of the rotation axis, when the portion closest to the rotation axis between adjacent valleys of the spiral groove is a peak, the width of the peak in the cross section is the spiral. The shaft seal structure of the powder apparatus according to the second aspect, which is 1/5 or less of the pitch of the grooves.

(Aspect 4)
The shaft seal structure of the powder device according to the aspect 3, wherein the top of the mountain is a point in the cross section.

(Aspect 5)
5. The shaft seal of the powder device according to aspect 3 or 4, wherein the spiral groove has two inclined surfaces sandwiching the peak of the mountain, and an angle formed by the two inclined surfaces is 30 to 75 degrees in the cross section. Construction.

(Aspect 6)
A side wall extending outside the shaft hole in the projection in the direction of the center of rotation of the rotation shaft and extending from the bottom wall toward the outside of the container; and a gas introduction unit that passes through the side wall and communicates with the air feeding means. And a gas sealing means disposed between the rotating shaft and the side wall at a position farther from the container than the gas introduction part. Construction.

(Aspect 7)
The shaft seal structure of the powder apparatus according to aspect 6, further comprising a shaft seal member attached to the container, wherein the bottom wall, the side wall, and the gas introduction part are provided on the shaft seal member.

(Aspect 8)
The shaft sealing member is attached to the outside of the container, the container is provided with a through hole, and the rotating shaft passes through the through hole without contact with the inner peripheral surface of the through hole, and the shaft hole The shaft seal structure of the powder device according to aspect 7, wherein the through hole communicates with the powder device.

(Aspect 9)
The shaft seal structure of the powder device according to aspect 7 or 8, wherein the container and the shaft seal member are in contact with each other around the entire circumference of the shaft hole.

(Aspect 10)
A container for storing powder, a rotating shaft that penetrates the outer wall of the container in a non-contact manner, a driving means that is provided outside the container and rotates the rotating shaft, and the rotating shaft passes in a non-contact manner; Air supply means for sending gas from the outside to the inside of the container between the bottom wall provided with a circular shaft hole leading from the inside of the container to the outside, and the inner peripheral surface of the shaft hole and the rotating shaft And a spiral groove is formed on the inner peripheral surface of the shaft hole.

(Aspect 11)
A shaft seal attached to a powder device having a container for storing powder, a rotating shaft that penetrates the outer wall of the container in a non-contact manner, and a driving means that is provided outside the container and rotates the rotating shaft. A bottom wall provided with a circular shaft hole that is larger than the diameter of the rotating shaft and communicates from the inside of the container to the outside, and a gas sent from the outside to the inner peripheral surface of the shaft hole and the rotation A shaft sealing member comprising: a gas introducing portion that leads to a shaft; and a spiral groove formed on an inner peripheral surface of the shaft hole.

  ADVANTAGE OF THE INVENTION According to this invention, the shaft seal structure of the powder apparatus which can suppress that powder leaks from the container which handles powder, reducing the damage of the powder apparatus, the power loss in a rotating shaft, and a maintenance cost, Powder An apparatus and a shaft seal member can be provided.

It is a figure which shows the cross section of the powder transport apparatus as 1st Embodiment of this invention. It is sectional drawing of the shaft seal part of the powder transport apparatus as 1st Embodiment of this invention, and its periphery. Fig.3 (a) is the figure which looked at the shaft sealing member toward the upper left from the lower right in FIG. 1, FIG.3 (b) is AA sectional drawing in Fig.3 (a). It is the photograph which showed an example of the specific shape of a spiral groove. It is a 1st modification of the shaft seal part in 1st Embodiment of this invention. It is a 2nd modification of the shaft seal part in 1st Embodiment of this invention. It is an expansion schematic cross section for demonstrating the detail of the shaft seal structure of the powder transport apparatus as 1st Embodiment of this invention. It is a figure which shows the 1st modification of the helical groove | channel in 1st Embodiment of this invention. It is a figure which shows the 2nd modification of the helical groove | channel in 1st Embodiment of this invention. It is a figure which shows the powder mixing apparatus as 2nd Embodiment of this invention. It is a figure which shows the crushing apparatus as 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the scope of the present invention is not limited thereto.

  The powder apparatus in the present invention is a powder processing apparatus (for example, the first embodiment), a powder agitating apparatus (for example, the second embodiment) or the like, or a apparatus for generating powder. However, it is not limited thereto, and includes those in which powder is generated in a processing step such as a crushing apparatus (for example, the third embodiment). That is, the powder apparatus in the present invention refers to an apparatus that handles powder using a rotating shaft inside the apparatus or generates powder in processing a material using the rotating shaft.

  In the following embodiments, “powder” refers to a powdery solid, and includes any of powder, powder, particles, fine powder, fine powder, fine particles, and the like. Further, the material, shape, dimensions, etc. of the powder are not particularly limited.

  All of the devices in the following embodiments include a rotation shaft. Further, the “axis line” used in the following means a line serving as the rotation center of the rotation shafts 141, 241, and 341 described later in each embodiment unless otherwise specified. Further, the “shaft diameter” of the rotary shafts 141, 241, and 341 and the “hole diameter” of each hole having a circular shape refer to the diameter unless otherwise specified.

  1 to 3 and FIGS. 5 to 11 showing the respective embodiments, the z direction is the axial direction of the rotation shafts 141, 241, and 341, the r direction is the radial direction of the circle centering on the axis, and the θ direction is the rotation shafts 141, 241. , 341 indicates the direction of rotation. Further, the z, r, and θ directions indicate the same direction in each drawing in the same embodiment.

  In the following description, the direction of the z-axis arrow in the figure is the + z direction, the direction opposite to the z-axis arrow in the figure is the -z direction, and if the direction is not specified, the direction is z To do. Regarding the r direction, the direction away from the axis is defined as the + r direction, the direction approaching the axis is defined as the -r direction, and when the direction is not specified, it is defined as the r direction without a sign. Regarding the θ direction, when viewed in the direction of the z-axis arrow, the clockwise direction (the direction of the arrow in each figure) is the + θ direction, and the counterclockwise direction (the opposite direction of the arrow in each figure) is the −θ direction. Is not specified, the direction is the θ direction without any sign.

<1. Powder Transport Device (First Embodiment)>
FIG. 1 is a view showing a cross section of a powder transport apparatus 1 as a first embodiment of the present invention. In FIG. 1, the top and bottom and the left and right are the top and bottom and the left and right of the paper surface. Here, the downward direction of the paper surface is the direction in which gravity is applied. The powder transport apparatus 1 according to the present embodiment is an inclined screw conveyor that transports powder P. The powder transport device 1 includes a powder container 11, a powder introduction unit 12, a powder discharge unit 13, a screw 14, a motor M, an air pump A, hoses 151 and 152, a shaft seal unit 16, 17 and housings 181 and 182.

  The powder container 11 stores the powder P to be transported in the powder transport device 1. In the present embodiment, the powder container 11 is a container having a cylindrical outer wall extending in the longitudinal direction (z direction) of a rotating shaft 141 described later. In addition, the shape of the powder container 11 demonstrated here is the example, and the shape can be changed suitably according to use conditions. The outer wall of the powder container 11 constitutes the bottom bottom 111 constituting the bottom of the lower right (−z side) end of the cylinder, the side wall 112 forming the cylinder, and the bottom of the upper left (+ z side) end of the cylinder. And an upper bottom portion 113. The powder container 11 is connected to the powder introduction unit 12 on the lower right (−z) side of the side wall 112 and to the powder discharge unit 13 on the upper left (+ z) side of the side wall 112. The discharge hole 115 is provided. In addition, the powder container 11 is provided with through holes 111a and 113a in the lower bottom portion 111 and the upper bottom portion 113, respectively. In this embodiment, the through holes 111a and 113a are circular, and the centers of the through holes 111a and 113a are on the axis of the rotation shaft 141, but may be other shapes such as an ellipse or a polygon. Further, the lower bottom portion 111 is provided with a through hole 111b (FIG. 2) at a position corresponding to a through hole 161h (FIG. 3) of a shaft sealing member 161 described later, and the upper bottom portion 113 has a similar through hole. Is provided.

  The powder introduction unit 12 introduces the powder P into the powder container 11. As an introduction method, a hopper or the like is connected above the powder introduction part 12 and gravity is used, and air is flowed in the direction (+ z direction) from the device in the previous process toward the powder container 11 using a pump. However, the method is not limited to this.

  The powder discharger 13 discharges the powder P transported to the upper left (+ z) side of the powder container 11 from the powder container 11 to the outside by a screw 14 described later. Examples of the discharging method include a method of dropping the powder P from the powder discharging unit 13 or an air transport device, but are not limited thereto.

  The screw 14 has a rotating shaft 141 and a spiral blade 142. The shaft diameter of the rotating shaft 141 is smaller than the hole diameters of the through holes 111a and 113a. The rotary shaft 141 passes through the through hole 111a from the outside of the lower right side of the powder container 11 in a non-contact manner with the inner peripheral surface of the through hole 111a, enters the powder container 11, and passes through the through hole 113a of the through hole 113a. Passes out of contact with the inner peripheral surface and exits to the outside on the upper left side of the powder container 11. That is, the rotating shaft 141 penetrates the outer wall of the powder container 11 in a non-contact manner. The rotary shaft 141 further passes through a through hole 181 a of a lower right housing 181 described later, and a lower right (−z) side end 141 a of the rotary shaft 141 is connected to the motor M. One end 141b on the upper left (+ z) side of the rotating shaft 141 is inserted into a bearing 182a provided in the upper left housing 182 to be described later.

  In this embodiment, the spiral blade 142 is a spiral blade in the direction of a reverse screw (left-hand thread). The powder P introduced into the powder container 11 from the powder introduction part 12 rides on the spiral blade 142. With this configuration, when the screw 14 is rotated clockwise as viewed from the lower right side as shown in the drawing, that is, in the + θ direction, the powder P placed on the spiral blade 142 is moved from the lower right (−z) side to the upper left. Transported to the (+ z) side. The shape of the spiral blade 142 described here is an example in the present embodiment, and can be appropriately changed depending on the rotation direction of the screw 14, the nature of the powder P, the purpose of use, the design conditions, and the like.

  Further, in the present embodiment, the portion of the outer peripheral surface of the rotating shaft 141 of the screw 14 facing the gland packing 163 (described later with reference to FIG. 2) is the rotating shaft sleeve 143 that covers the rotating shaft 141 on the entire periphery. (FIG. 2) is provided. This is to suppress scratches and wear on the rotating shaft 141 due to friction between the rotating shaft 141 and sliding parts such as the gland packing 163. However, the present invention is not limited to this, and when the surface hardness of the rotary shaft 141 is high, scratches and wear of the rotary shaft 141 that occur until the replacement time of the screw 14 are within an allowable range, and the like, even if the rotary shaft sleeve 143 is not attached. It may be good.

  The motor M is a driving means for rotating the screw 14. In this embodiment, the motor M is provided outside the lower right (−z) side of the powder container 11. The drive means of the screw 14 is not limited to an electric motor, but may be an internal combustion engine, an external combustion engine, or a wind turbine, hydraulic power, or the like. In this embodiment, the screw 14 is directly connected to the motor M. However, power is transmitted from the motor M to the screw 14 via a speed reduction means such as a gear and a belt, a joint such as a universal joint, or other power transmission means. The structure which transmits may be sufficient.

  The air pump A is an air supply unit that is installed outside the powder container 11 and sends air to the shaft seals 16 and 17 from the outside. In this embodiment, the gas sent by the air pump A is air, but other gases such as nitrogen gas may be used in consideration of the properties of the powder P and the like. The air supply means is not limited to an air pump, and a blower, a compressor, or the like may be used, or an air supply line installed in a plant may be connected.

  The hose 151 connects the air pump A and a gas introducing portion 161e (described later with reference to FIG. 3) of the shaft sealing member 161 in the shaft sealing portion 16, and air sent from the air pump A is contained in the shaft sealing member 161. (Space S described later).

  The hose 152 connects the air pump A to the gas introducing portion of the shaft sealing member in the shaft sealing portion 17 (the shaft sealing portion 17 has the same configuration as the shaft sealing portion 16 (FIG. 2) and is not shown). Then, the air sent from the air pump A is sent to the shaft sealing member in the shaft sealing portion 17.

  The shaft sealing portion 16 suppresses the powder P from leaking out of the powder container 11 from the gap between the lower bottom portion 111 and the rotating shaft 141 of the screw 14. The shaft sealing portion 17 suppresses the powder P from leaking out of the powder container 11 from the gap between the upper bottom portion 113 and the rotation shaft 141 of the screw 14. The structure of the shaft seal portion 16 will be described later with reference to FIG. Since the shaft seal portion 17 has the same configuration as the shaft seal portion 16 in this embodiment, the description thereof is omitted.

  The housings 181 and 182 are respectively attached to the lower bottom portion 111 and the upper bottom portion 113 of the powder container 11 and cover the shaft seal portions 16 and 17. A circular through hole 181 a larger than the shaft diameter of the rotating shaft 141 of the screw 14 is provided on the bottom surface of the housing 181 on the lower bottom 111 (−z) side. The rotating shaft 141 passes through the through hole 181a without contacting the housing 181. In the present embodiment, the center of the through hole 181 a is on the axis of the rotation shaft 141.

  The housing 182 on the upper bottom 113 (+ z) side is provided with a bearing 182a. The bearing 182a rotatably supports the upper left end 141b of the rotating shaft 141. For the bearing 182a, for example, a ball bearing or the like is used, but the bearing 182a is not limited thereto as long as it can rotatably support the rotating shaft 141 of the screw 14.

<2. Shaft seal structure of powder transport device>
FIG. 2 is a view showing a cross-section of the shaft seal portion 16 and its periphery of the powder transport apparatus 1 as the first embodiment of the present invention. The shaft sealing portion 16 includes a shaft sealing member 161, a bolt 162a, a nut 162b, a gland packing 163, a lantern ring 164, a packing presser 165, a packing presser bolt 166a, and a spring 166b. Further, a side wall 161a (described later (FIG. 3A)) of the shaft sealing member 161 is interposed between a bottom wall 161b (described later (FIGS. 3A and 3B)) of the shaft sealing member 161 and a gland packing 163. A space S sandwiched between (b))) and the rotating shaft 141 is provided. As can be seen from FIG. 3A, a bolt hole 161d (similarly, the bolt 166a and the spring 166b in FIG. 2) and the gas introducing portion 161e are not on the same cross section, but for the sake of explanation, FIG. 2 shows on the same cross section.

  In the present embodiment, the shaft seal member 161 accommodates a gland packing 163 described later, and is detachably attached to the outside of the powder container 11. In the present embodiment, the shaft seal member 161 is a component different from the powder container 11. Therefore, it is possible to replace only the shaft seal member 161 according to the type of powder P, the use conditions of the apparatus, etc., or as a consumable, and the maintenance cost of the equipment can be reduced.

  3A is a view of the shaft sealing member 161 as viewed from the lower right to the upper left in FIG. 1 (in the direction of the z-axis arrow), and FIG. 3B is the view in FIG. It is AA sectional drawing. The shaft sealing member 161 includes a cylindrical side wall 161a extending in the axial direction (z direction) of the rotation shaft 141, a bottom wall 161b serving as a bottom surface of the cylinder, and one end of the side wall 161a on the powder container 11 (+ z) side. A flange 161c extending toward the outside (+ r direction) of the side wall 161a at one end on the powder container 11 (+ z) side is provided. In the present embodiment, the bottom wall 161b and the flange 161c form a continuous plane on the powder container 11 (+ z) side.

  The side wall 161a is outside the shaft hole 161f described later in the projection in the axis (z) direction. A bolt hole 161d is provided at the end of the side wall 161a on the motor M (−z) side toward the powder container 11 side (+ z direction). The bolt holes 161d are provided at four locations along a circumference (θ direction) centering on the axis of the rotation shaft 141. The bolt hole 161d is screwed with a packing presser bolt 166a described later. Here, the nominal diameter of the bolt hole 161d is a value smaller than the thickness of the side wall 161a. The number of bolt holes 161d can be changed as appropriate depending on the performance required for the shaft seal member 161 and the design conditions of peripheral components and the like. The thickness of the side wall 161a, the length in the axial direction (z direction), the nominal diameter of the bolt holes 161d, and the pitch are the strength required for the shaft seal member 161, the pressing force of the packing presser 165 described later, and the positional relationship with the peripheral components. It is determined as appropriate according to the design conditions.

  Further, the side wall 161 a has a gas introduction part 161 e that penetrates the side wall 161 a in the thickness direction (r direction) on the powder container 11 (+ z) side from a gland packing 163 described later and is connected to the hose 151. With this configuration, air sent from the air pump A passes through the hose 151, reaches the gas introduction part 161 e, and is guided to the space S. In this embodiment, the gas introduction part 161e is provided in two places which oppose on both sides of the rotating shaft 141, and two hose 151 connected to each gas introduction part 161e merges in the position which is not shown in figure. Yes. In addition, the number and position of the gas introduction part 161e are not restricted to this, It can change suitably by design conditions etc.

  The bottom wall 161b is provided with a circular shaft hole 161f that penetrates the bottom wall 161b. In the projection in the axis (z) direction, the shaft hole 161f is inside the side wall 161a. In the present embodiment, the center of the shaft hole 161 f is on the axis of the rotation shaft 141. The shaft hole 161 f communicates with the through hole 111 a of the powder container 11. The hole diameter of the shaft hole 161 f is larger than the shaft diameter of the rotating shaft 141 of the screw 14. Therefore, the rotating shaft 141 passes through the shaft hole 161f without contacting the inner peripheral surface of the shaft hole 161f (FIG. 2). With this configuration, the air guided to the space S is sent to the gap between the inner peripheral surface of the shaft hole 161f and the outer peripheral surface of the rotary shaft 141, and the inner peripheral surface of the shaft hole 161f and the outer peripheral surface of the rotary shaft 141. Between the outside and the inside of the powder container 11 from the outside toward the inside (+ z direction).

  A spiral groove 161g is formed on the inner peripheral surface of the shaft hole 161f. FIG. 4 is a photograph showing an example of a specific shape of the spiral groove 161g.

  In the present embodiment, the spiral groove 161g is provided in the right-handed direction in accordance with the rotation direction (+ θ direction) of the screw 14. In addition, when the screw 14 is reversely rotated (rotation in the −θ direction), the spiral groove 161g is preferably provided in the direction of the reverse screw (left screw). That is, it is preferable to align the direction of the spiral groove 161g and the rotation direction of the screw 14. According to this configuration, when the powder P having a large size in the spiral groove 161g contacts the rotating shaft 141 of the screw 14, the frictional force between the powder P and the rotating shaft 141 causes The force which pushes back the powder P into the powder container 11 works by using the spiral groove 161g as a guide. Further, the rotation of the rotating shaft 141 can be expected to further increase the flow velocity of the air flowing in the spiral groove 161g and to rectify the air.

  Details of the size of the spiral groove 161g, the positional relationship with the rotating shaft 141, and the size relationship between the diameter of the shaft hole 161f and the through hole 111a of the powder container 11 will be described later with reference to FIG. The thickness of the bottom wall 161b is preferably determined in consideration of not only the required strength but also the length of the shaft hole 161f necessary for pushing back the powder P by the airflow. The length of the shaft hole 161f is determined in consideration of the pitch of the spiral hole, the gap with the screw 14, the size of the powder P, and the like.

  The flange 161c is provided with four through holes 161h at equal intervals on a circumference centered on the axis of the rotation shaft 141. In the present embodiment, the through hole 161h is circular, and the hole diameter is larger than the nominal diameter of a bolt 162a described later. Note that the thickness and size of the flange 161c, and the number, arrangement, and hole diameter of the through holes 161h can be changed as appropriate according to design conditions such as the size of bolts 162a and dimensional tolerances of components described later. Further, the shape of the through hole is not limited to a circle, and may be a long hole extending along the θ direction.

  Returning again to FIG. The bolt 162 a and the nut 162 b fix the shaft sealing member 161 to the lower bottom portion 111 of the powder container 11. The bolt 162a passes through the through hole 111a provided in the lower bottom portion 111 and the through hole 161h provided in the flange 161c of the shaft seal member 161. The nut 162b is screwed with the bolt 162a outside the flange 161c of the shaft seal member 161 (on the motor M side). In this embodiment, bolts and nuts are used as an example of means for fixing the shaft seal member 161. However, the present invention is not limited to this, and claw fitting or the like may be used when a material such as plastic is used. In addition, when it is not necessary to replace the shaft seal member 161, or when the shaft seal member 161 may be replaced with the powder container 11, as a method for fixing the shaft seal member 161 to the powder container 11, other methods such as welding may be used. The shaft seal member 161 and the powder container 11 may be integrated.

  When the shaft sealing member 161 is attached to the powder container 11, the shaft sealing member 161 and the lower bottom portion 111 of the powder container 11 are in contact with each other around the through hole 111a and the shaft hole 161f. Further, the lower bottom portion 111 of the powder container 11 and the shaft sealing member 161 may be brought into contact with each other via a sealing material such as a gasket. With this configuration, it is possible to prevent the powder from entering the gap between the shaft seal member 161 and the powder container 11 and to prevent the powder from leaking outside through the gap between the shaft seal member 161 and the powder container 11. it can. Further, the air in the space S can be prevented from leaking to the outside through the gap between the shaft seal member 161 and the powder container 11, and the air can be efficiently sent between the through hole 111a and the shaft hole 161f. it can. The sealing material may be provided over the entire circumference of the through hole 111a and the shaft hole 161f, or may be partially provided at a necessary position in accordance with the shapes of the bottom wall 161b and the lower bottom portion 111 of the powder container 11. The sealing material is not particularly limited, such as metal, resin, rubber, etc., but seals the gap between the powder container 11 and the shaft seal member 161, and is easy to elastically deform so as not to damage these parts. What has the intensity | strength which can endure use is preferable. This configuration is a preferable example of the present embodiment, and a gap is partially provided between the shaft seal member 161 and the lower bottom portion 111 of the powder container 11 in consideration of usage conditions, manufacturing requirements, and the like. Also good.

  The gland packing 163 is a ring-shaped member or a member in which a string is formed in a spiral shape or a ring shape, and is disposed at a position (on the −z side) away from the powder container 11 from the spiral groove 161g and the gas introduction portion 161e. . The gland packing 163 can be elastically deformed. For example, a material such as hard rubber reinforced with fiber is used.

  The gland packing 163 is accommodated between the side wall 161 a of the shaft sealing member 161 and the rotary shaft sleeve 143 of the screw 14. The gland packing 163 contacts and presses the inner peripheral surface of the side wall 161a of the shaft sealing member 161 and the rotation shaft sleeve 143 of the screw 14 over the entire circumference of the rotation shaft 141. With this configuration, the gap between the side wall 161a of the shaft sealing member 161 and the rotating shaft 141 is closed by the gland packing 163 and the rotating shaft sleeve 143, and the air guided to the space S is opposite to the powder container 11 (motor M Side (-z direction)), and air can be efficiently fed between the through hole 111a and the shaft hole 161f. That is, in this embodiment, the gland packing 163 and the rotating shaft sleeve 143 are contact-type sealing means, and function as gas sealing means for preventing air from leaking.

  In the present embodiment, a plurality of gland packings 163 are accommodated in the axial direction (z direction) of the rotating shaft 141. The structure of the gland packing sealing in the present embodiment is an example thereof as long as it suppresses leakage of air (gas) introduced into the space S to the opposite side (−z side) of the powder container 11. The configuration is not limited to that described here. For example, in addition to the gland packing, an oil seal, a lip seal, and the like can be given, and a plurality of configurations may be used in combination.

  The lantern ring 164 is a ring-shaped member having an I-shaped cross section, between the side wall 161a of the shaft sealing member 161 and the rotating shaft 141, and between the bottom wall 161b of the shaft sealing member 161 and the gland packing 163, That is, it is arranged in the space S. The end of the lantern ring 164 on the powder container 11 (+ z) side is in contact with the bottom wall 161b of the shaft seal member 161, and the other end is on the motor M (−z) side with respect to the gas introduction part 161e. , Abuts on the gland packing 163.

  There is a gap between the lantern ring 164 and the rotating shaft 141. Further, the lantern ring 164 is provided with a through hole 164a that penetrates from the side wall 161a side to the rotating shaft 141 side. According to this configuration, a path (gas path) that guides the air guided to the space S between the through hole 111a and the shaft hole 161f and the rotating shaft 141 is formed. In addition, if it is a member (gas path formation member) which can form a gas path | route, it will not be restricted to a lantern ring. That is, a member having a configuration that allows gas to pass between the gas introduction portion 161e side and the rotary shaft 141 side while abutting against the gland packing 163 and the bottom wall 161b of the shaft seal member 161 and forming a space therebetween. I just need it.

  The packing presser 165 includes a cylindrical body 165a and a flange 165b that extends toward the outside (+ r) side of the body 165a at one end of the body 165a on the motor M side. The outer diameter of the body portion 165a is smaller than the inner diameter of the side wall 161a of the shaft seal member 161. The inner diameter of the body portion 165a is larger than the outer diameter of the rotating shaft sleeve 143. The portion of the body 165a on the powder container 11 side is inserted between the side wall 161a of the shaft sealing member 161 and the rotary shaft sleeve 143, and one end of the body 165a on the powder container 11 side is the motor M of the gland packing 163. Abuts one end.

  The flange 165b is provided with four through holes 165c at positions corresponding to the bolt holes 161d of the shaft seal member 161, respectively. A packing presser bolt 166a described later passes through the through hole 165c.

  The packing retainer bolt 166a passes through the through hole 165c of the seal retainer 165 and is screwed into the bolt hole 161d of the shaft seal member 161.

  The spring 166b is an elastic member, and one end (−z side) contacts the flange of the packing retainer bolt 166a, and the other end (+ z side) contacts the flange 165b of the packing retainer 165. Therefore, the spring 166b presses the packing presser 165 toward the powder container 11 (+ z direction), and the packing presser 165 presses the gland packing 163 toward the powder container 11 (+ z direction). Since the gland packing 163 is compressed in the direction of the rotating shaft 141 (z direction) by the packing presser 165 and the lantern ring 164, a force for extending in the radius (r) direction of the rotating shaft 141 acts.

  Therefore, by tightening the packing retainer bolt 166a, the force with which the gland packing 163 presses the rotary shaft sleeve 143 in the -r direction increases, and the force with which the air in the space S is sealed increases. The force for sealing the air in the space S can be adjusted by managing the tightening torque of the packing presser bolt 166a.

  The spring 166b pushes the packing presser bolt 166a toward the motor M side. Therefore, a frictional force is generated between the threaded portion (male thread) of the packing presser bolt 166a and the bolt hole 161d (female screw) of the shaft seal member 161, and the packing presser bolt 166a can be prevented from loosening.

<3. Modification of shaft seal>
FIG. 5 is a first modification of the shaft seal portion 16 in the first embodiment of the present invention. Here, the shaft seal member 161 is not used. The powder container 11 includes a side wall 161a, a bolt hole 161d, a gas introduction portion 161e, and a spiral groove 161g, and these configurations are the same as the configurations with the same reference numerals in FIGS. In this configuration, the bottom wall 161b corresponds to the lower bottom portion 111 of the powder container 11, and the shaft hole 161f corresponds to the through hole 111a of the powder container 11, and the inner peripheral surface of the through hole 111a. A spiral groove 161g is formed in the.

  In this configuration, since the spiral groove 161g can be provided until reaching the inside of the powder container 11, the spiral groove 161g can be lengthened without increasing the size of the apparatus. Or the part which the side wall 161a etc. protrudes from the powder container 11 can be made small, and size reduction of an apparatus can be performed. Further, in this configuration, the number of parts in the entire apparatus can be reduced, and the accuracy when the shaft seal member 161 is assembled to the powder container 11 need not be considered.

  FIG. 6 is a second modification of the shaft seal portion 16 in the first embodiment of the present invention. Here, a protruding portion 161 i is provided in which a part of the bottom wall 161 b including the shaft hole 161 f of the shaft sealing member 161 protrudes into the powder container 11. The inner peripheral surface of the through hole 111a of the powder container 11 faces or abuts the side surface of the protruding portion 161i. In FIG. 6, a clearance is provided between the inner peripheral surface of the through hole 111a and the side surface of the protruding portion 161i in consideration of the accuracy in processing of the component. However, the flange 161c is powdered over the entire periphery. The body container 11 is in contact with the lower bottom 111 of the body container 11. Therefore, a structure in which the lower bottom portion 111 of the powder container 11 and the shaft sealing member 161 are in contact with each other over the entire circumference of the shaft hole 161f is established, and a powder is formed between the powder container 11 and the shaft sealing member 161. The body can be prevented from leaking.

In this configuration, since the spiral groove 161g can be placed inside the powder container 11, the spiral groove 161g can be lengthened without increasing the size of the apparatus. Or the part which the shaft seal member 161 protrudes from the powder container 11 can be made small, and the apparatus can be reduced in size as a whole.
<4. Details of shaft seal structure of powder transport device>

  FIG. 7 is an enlarged schematic cross-sectional view for explaining details of the shaft seal structure of the powder transport device 1 as the first embodiment of the present invention. In the present embodiment and the modification described with reference to FIGS. 8 and 9, the crest 161 j is a rotation axis between the valleys adjacent to the spiral groove 161 g in a cross section including the axis of the rotation shaft 141. The part (point or line) closest to 141 is said (the same applies to modified examples described later). That is, the top 161j of the mountain is a continuation of this portion in three dimensions. If it is a point on the cross section, it is a three-dimensional line, and if it is a line on the cross section, it is a three-dimensional plane. The valley bottom 161k refers to a portion (a point or a line) that is farthest from the rotation axis 141 between adjacent peaks of the spiral groove 161g in the cross section including the axis of the rotation axis 141. That is, the valley bottom 161k is a continuation of this portion in three dimensions, and is a three-dimensional line if it is a point on the cross section, and a three-dimensional plane if it is a line on the cross section.

  In the present embodiment, the spiral groove 161g has a triangular shape in a shape where adjacent slopes intersect, that is, a cross section including the axis. Not limited to this, the cross section including the axis of the spiral groove 161g may have other shapes such as a trapezoid, a square, a semicircle, and a sine curve. However, the shape in which the width of the groove widens toward the rotating shaft 141 (axis) is easy to manufacture, the pressure loss of the air flowing through the spiral groove 161g can be suppressed, and the powder P is in the spiral groove 161g. It is also possible to suppress clogging. If the amount of the powder P clogged in the spiral groove 161g increases, it becomes difficult for air to flow into the spiral groove 161g, and the powder P cannot be efficiently pushed back into the powder container 11. Further, when the powder P is clogged in the spiral groove 161g, the powder P is also sandwiched between the spiral groove 161g and the rotary shaft 141, and the power loss when driving the screw 14, the rotary shaft 141 and the shaft seal member 161 may cause wear, scratches, and breakage.

  In the present embodiment, in the cross section including the axis line, the peak 161j of the mountain is the peak of the mountain and is three-dimensionally ridge-shaped and formed as a spiral line. Therefore, when the powder P reaches between the crest 161j and the rotating shaft 141, the powder P moves in either the powder container 11 side (+ z direction) or the motor M side (−z direction). However, the space between the surface of the spiral groove 161g and the outer peripheral surface of the rotating shaft 141 is widened. Therefore, it is possible to suppress the powder P from being sandwiched and deposited between the peak 161j of the mountain and the rotating shaft 141. And the power loss at the time of driving the screw 14 by the biting of the powder P, the abrasion of the rotating shaft 141 and the shaft seal member 161, a damage | wound, and damage can be suppressed.

  In the present embodiment, the inner peripheral surface of the through hole 111a of the powder container 11 coincides with a virtual cylinder C that contacts the valley bottom 161k of the spiral groove 161g. That is, the distance between the valley bottom 161k and the axis is equal to the distance between the inner periphery of the through hole 111a and the axis. The diameter of the through hole 111a may be made larger than the cylinder C in consideration of the accuracy of the mounting position, the dimensional tolerance of the parts, and the like.

  In FIG. 7, the width of the spiral groove 161g is w, the peak angle (= valley angle) is α, and the distance between the peak 161j and the rotation shaft 141 is d. Here, the width w of the spiral groove 161g is a distance between adjacent mountain peaks 161j. Moreover, the angle α of the mountain means an angle formed by the slopes adjacent to each other with the peak 161j or the valley bottom 161k sandwiched in the cross section including the axis.

  In the present embodiment, since the peak 161j is a point in the cross section including the axis, the width w of the spiral groove 161g is the same as the pitch. Therefore, the width w of the spiral groove 161g is preferably determined in consideration of the particle diameter of the powder P and an appropriate pitch for efficiently pushing back the powder P.

  The wider the width w of the spiral groove 161g, the lower the pressure loss that occurs when air enters the spiral groove 161g. Therefore, the powder P in the spiral groove 161g is efficiently pushed back without increasing the pressure of the air supplied by the air pump A. However, if the width w is wide, the particles that can enter the spiral groove 161g are large and many, and the air pressure required to push them back also increases. Furthermore, if the width w is wider than necessary, the flow velocity of the air flowing in the spiral groove 161g is lowered, and the force for pushing back the powder P may be weakened.

  Further, the wider the width w of the spiral groove 161g, the longer the pitch (= width w) of the spiral groove 161g. When the pitch of the spiral groove 161g is increased, the angle formed by the spiral groove 161g and the axis (z) direction is decreased. Therefore, the air sent from the gas introduction part 161e via the space S can be efficiently flowed into the spiral groove 161g, and the powder P in the spiral groove 161g can be pushed back with a large force. . Further, since the path length of the spiral groove 161g is shortened, the pressure loss of the air flowing through the spiral groove 161g can be reduced. However, in order to ensure a sufficient distance for pushing back the powder P, the bottom wall 161b (see FIG. 3 (a)) may need to be thickened.

  The narrower the width w of the spiral groove 161g, the narrower the air flow path of the spiral groove 161g. Therefore, the pressure loss that occurs when air enters the spiral groove 161g increases. Therefore, in order to push back the powder P in the spiral groove 161g, it is necessary to increase the output of the air pump A. On the other hand, if the helical groove 161g is too thin, the powder P tends to be clogged in the path.

  Further, the narrower the width w of the spiral groove 161g, the shorter the pitch (= width w) of the spiral groove 161g. When the pitch of the spiral groove 161g is shortened, the angle formed by the spiral groove 161g and the axis (z) direction is increased. Therefore, when air enters the spiral groove 161g, it becomes a resistance and a pressure loss occurs. Therefore, in order to push back the powder P, it is necessary to increase the pressure of the air supplied by the air pump A. On the other hand, if the pitch of the spiral grooves 161g is shortened, the path length of the spiral grooves 161g is increased, so that the powder P can be sufficiently pushed back even if the bottom wall 161b (FIG. 3A) is thin. .

  Considering the above, the width w of the spiral groove 161g is preferably 0.75 times or more, more preferably 1.0 or more times the particle size D50 of the powder P. More preferably, it is 2 times or more, and most preferably 1.5 times or more. Here, D50 is the particle size of particles having a cumulative size of 50% from the smallest in the mass-based particle size distribution of the powder P. In addition, not only D50 but the numerical value after D, that is, DX, indicates the particle size of particles having a cumulative X% from the smaller particle size in the mass-based particle size distribution.

  The width w of the spiral groove 161g is preferably 5 times or less, more preferably 4 times or less, and further preferably 3 times or less of the particle size D50 of the powder P. The width w is more preferably 2 times or less of the particle size D50 of the powder P, and most preferably 1.5 times or less. The preferable range of the value of the width w of the spiral groove 161g described here is for a general powder. Depending on the shape and properties of the powder P, the optimal value of the width w may not be within this range. is there.

  The angle α of the mountain will be described. If the angle α of the mountain is sufficiently large, it is possible to suppress the powder P from being caught in the spiral groove 161g, and consequently to prevent the powder P from being clogged in the path. However, if the angle α of the peak is too large, the air flowing through the spiral groove 161g tends to leak from the gap between the peak 161j of the peak and the rotating shaft 141, and the force for pushing back the powder P along the spiral groove 161g is weak. Become. Considering these, the angle α of the mountain is preferably 30 to 75 degrees, more preferably 45 to 75 degrees, and most preferably 60 degrees.

  As for the distance d between the peak 161j and the rotation shaft 141, the particle diameter of the powder P that can pass through the gap between the peak 161j of the spiral groove 161g and the rotation shaft 141 increases as the distance d increases. growing. The velocity component in the axis (z) direction of the particles passing through the gap is larger than the velocity component in the axis (z) direction of the particles passing through the spiral groove 161g. That is, the particles passing between the crest 161j and the rotation shaft 141 have a high speed toward the outside of the powder container 11 along the direction of the rotation shaft 141. Furthermore, the path for exiting the powder container 11 through the gap between the peak 161j and the rotating shaft 141 is much shorter than the path passing through the spiral groove 161g. Therefore, in order to reliably push back the particles passing through the gap between the crest 161j of the spiral groove 161g and the rotating shaft 141, it is necessary to flow a large amount of air through the gap. For this reason, the distance d is preferably shorter.

For example, the diameter of the portion of the rotating shaft 141 facing the spiral groove 161g is d1, the diameter of the virtual cylinder in contact with the peak 161j of the spiral groove 161g is d2, and the rotation shaft 141 and the peak 161j are between When the particle size of which may powders P through the the _{D 1,} it is considered that the _{D 1 ≧ d = (d2-} d1) / 2. Here, the value of _{D 1} is preferably determined in between the D50 D90, more preferably it is determined between the D60 of D80, still more preferably a D70.

However, the rotating shaft 141 may be fluttered during rotation (the distance between the outer peripheral surface of the rotating shaft 141 and the axis changes due to elastic deformation accompanying rotation). For this reason, the design value of the distance d is preferably determined in consideration of this. As an example, if the width of the flare of the rotating shaft 141 is Δd, D ₁ ≧ d = {(d2−d1 + Δd / 2)} / 2.

  In addition, since there is a deviation between parts due to tolerances (dimensional tolerances and geometrical tolerances) due to processing accuracy of parts, assembly accuracy, and the like, the distance between the axis of the rotary shaft 141 and the outer peripheral surface of the rotary shaft 141, and rotation The distance between the axis of the shaft 141 and the crest 161j of the spiral groove 161g is not always constant.

As an example, the tolerance of the distance between the axis of the rotating shaft 141 and the outer peripheral surface of the rotating shaft 141 is ± Δd _A , and the tolerance of the distance between the axis of the rotating shaft 141 and the peak 161j of the spiral groove 161g is ± Δd. _When considering these factors as _B, it is preferable that D ₁ ≧ d (nominal value) = {(d 2 −d 1 + Δd / 2)} / 2+ (Δd _A ² + Δd _B ² ) ^1/2. .

Further, in the case of designing so that the rotation shaft 141 and the spiral groove 161g do not contact and interfere in consideration of the above-described flare and tolerance, for example, d (nominal value)> (Δd _A ² + Δd _B ² ) ^1/2 + Δd / 2 is preferable.

  The performance of the shaft seal structure of the powder P affected by the values of the width w of the spiral groove 161g, the angle α of the peak, and the distance d between the peak 161j of the peak and the rotating shaft 141 will be described separately. It was. However, in the case of the shape as in the present embodiment, the width w of the spiral groove 161g, the angle α of the mountain, and the distance d are correlated with each other. Therefore, when actually designing the shaft seal structure, the use conditions and the like are taken into consideration. In addition, it may be based on a function including these values.

For example, as shown in FIG. 7, when the maximum diameter of the virtual sphere P _i capable of entering a spiral groove 161g and D _2, a geometrical calculation, the width w, mountain angle alpha, the distance d, derivable the relation diameter _{D 2.} In this relation, for example, when the constraint condition a diameter D _2, the greater mountain angle α is, the width w becomes large, i.e., the pitch of the helical groove 161g is lengthened. Incidentally, as the value of D ₂ is large, on the powder P can be prevented from clogging with the spiral groove 161g, since the flow path of the air of the helical groove 161g becomes thick, to reduce the pressure loss of the air it can. However, the value of D ₂ is too large, large quantities and large particles to enter the spiral groove 161 g, there is a possibility that the particles will exit to the outside of the powder container 11 is increased. Therefore, the value of D ₂ to be used for the above equation are D50, D70, etc., it is preferable to appropriately determined based on the particle size distribution of the powder P.

  In this way, after grasping the correlation of each value, considering the influence of each value on the performance of the shaft seal structure (as described above), a design for maximizing the effect of this embodiment Can contribute.

<5. Modification of spiral groove>
FIG. 8 is a diagram showing a first modification of the spiral groove 161g in the first embodiment of the present invention. In this modification, the peaks and valleys of the spiral groove 161g are rounded with respect to the shape of FIG. According to this configuration, since the peak of the spiral groove 161g is not sharp, it is easy to ensure the processing accuracy. Moreover, it can suppress that the peak of the spiral groove 161g deform | transforms easily. Furthermore, it is possible to prevent the crest of the spiral groove 161g from scratching other parts during assembly.

  The definition of the peak 161j is as described above. In this modification, the peak 161j is a point in the cross section including the axis (FIG. 8). In other words, the peak 161j of the mountain is a series of these points and is a three-dimensional spiral line. Similarly, according to the above definition, the valley bottom 161k is a point on the cross section and a three-dimensional spiral line.

  FIG. 9 is a diagram showing a second modification of the spiral groove 161g in the first embodiment of the present invention. In this modification, the peak of the spiral groove 161g is chamfered with respect to the shape of FIG. 7, and the valley bottom 161k is rounded. According to this configuration, the height of the crest 161j of the spiral groove 161g, that is, the distance d between the crest 161j and the rotating shaft 141 can be easily made constant during processing. Moreover, it can suppress that the peak of the spiral groove 161g deform | transforms easily.

  In this case, in the cross section including the axis (FIG. 9), the peak 161j is a line. That is, the top 161j of the mountain forms a spiral band having a surface that maintains a certain distance from the outer peripheral surface of the rotating shaft 141 in a three-dimensional manner. The width of the peak 161j in the cross section including the axis (FIG. 9) is defined as w1. When the width w1 is large, the powder is sandwiched between the peak 161j of the mountain and the rotating shaft 141, so that it is easy to deposit. For this reason, the width w1 of the peak 161j is preferably narrow.

  In consideration of the above, the width w1 of the peak 161j is preferably 1/5 or less, more preferably 1/10 or less of the pitch (= w + w1) of the spiral groove 161g. More preferably, it is 20 or less.

<6. Advantages of First Embodiment of the Present Invention>
According to 1st Embodiment of this invention demonstrated above, the shaft hole 161f and the rotating shaft 141 are non-contacting, ie, the rotating shaft 141 penetrates the powder container 11 non-contactingly. Therefore, damage to the powder transport apparatus 1 and maintenance cost due to the damage can be reduced. Moreover, the power loss in the rotating shaft 141 can also be suppressed.

  Further, the powder P entering between the shaft hole 161f and the outer peripheral surface of the rotating shaft 141 is pushed back to the inside of the powder container 11 by the air flowing between the shaft hole 161f and the outer peripheral surface of the rotating shaft 141. Therefore, it is possible to suppress the powder P from leaking between the shaft hole 161f and the outer peripheral surface of the rotating shaft 141. Therefore, the cost for cleaning the powder P leaked to the outside of the apparatus can be reduced, and wear and deterioration of the sliding member due to the powder P reaching the sliding member such as the gland packing 163 can be prevented. This can reduce the maintenance cost of parts.

  A spiral groove 161g is formed on the inner peripheral surface of the shaft hole 161f of the shaft sealing member 161. The path from the inside of the powder container 11 to the outside through the spiral groove 161g is longer than the path that does not pass through the spiral groove 161g. Therefore, a sufficient path length for pushing back the powder P is ensured, and the powder P is more reliably prevented from leaking from the powder container 11.

  And it is thought that the air sent between the gas introduction part 161e and the outer peripheral surface of the shaft hole 161f flows in the spiral groove 161g at a higher speed in the direction from the outside to the inside of the powder container 11. As a result, it is considered that the powder in the spiral groove 161 g is pushed back more strongly toward the inside of the powder container 11. In addition, the air flow is considered to be uniform in the spiral groove 161g, and a reduction in the amount of air that must be sent can be expected.

  Further, in the first embodiment of the present invention, in the gap between the rotating shaft 141 of the screw 14 and the shaft hole 161f of the shaft sealing member 161, the spiral groove 161g serving as a guide for air and powder P is outside ( It is arranged in the shaft hole 161f). Since the air and powder P flowing in the spiral groove 161g move around the rotating shaft 141, a force (centrifugal force) in a direction away from the axis of the rotating shaft 141 (+ r direction) acts. Conceivable. Therefore, it can be expected that the powder P and air flowing through the gap between the rotating shaft 141 and the shaft hole 161f are pressed against the spiral groove 161g and effectively guided along the spiral groove 161g.

  Further, since the force acts on the powder P in the direction away from the rotation shaft 141 by the centrifugal force, it is considered that the powder P in the spiral groove 161g can be prevented from adhering to the rotation shaft 141. . Therefore, it is possible to prevent power loss caused by the powder P being sandwiched between the spiral groove 161g and the rotating shaft 141 and scratches, wear, and breakage of the rotating shaft 141 and the shaft seal member 161.

  Furthermore, the following actions can be predicted for the movement of the air and powder P between the crest 161j of the spiral groove 161g and the rotating shaft 141 and the force. The air flow between the crest 161j of the spiral groove 161g and the rotating shaft 141 is different from the air in the spiral groove 161g. Therefore, it is considered that turbulent flow is generated at the boundary between these airs. And it is thought that it moves to the spiral groove | channel 161g by the turbulent flow to the powder P between the peak 161j and the rotating shaft 141.

  In addition to the above actions, the following actions can also be predicted. It is considered that the air flow in the spiral groove 161g is faster than the air flow between the crest 161j and the rotating shaft 141. In that case, the pressure of the air in the spiral groove 161g is lower than the pressure of the air between the crest 161j and the rotating shaft 141 (Bernoulli's theorem). Due to this pressure difference, the powder P between the peak 161j and the rotating shaft 141 is considered to be drawn into the spiral groove 161g.

  Due to these predicted effects, it is considered that the force applied to the powder P in the spiral groove 161g in the direction away from the rotating shaft 141 becomes stronger, and the powder P can be further prevented from adhering to the rotating shaft 141.

  As described above, according to the configuration of the present embodiment, it is possible to suppress the leakage of powder from the container that handles the powder while reducing the damage to the powder transport device 1, the power loss in the rotating shaft 141, and the maintenance cost. The shaft seal structure of the powder transport device 1, the powder transport device 1, and the shaft seal member 161 of the powder transport device 1 can be provided.

<7. Powder Mixing Device (Second Embodiment)>
FIG. 10 is a diagram showing a powder mixing apparatus 2 as a second embodiment of the present invention. In FIG. 10, the upper and lower sides and the left and right sides are the upper and lower sides and the left and right sides of the paper surface, and here, the downward direction on the paper surface is the direction in which gravity is applied. The powder mixing device 2 according to the present embodiment is a device for stirring and mixing the first powder P1 and the second powder P2. The powder mixing device 2 includes a powder container 21, a screw 24, a motor M, an air pump A, a hose 251, a shaft seal portion 26, and a housing 281. The particle diameters of the first powder P1 and the second powder P2 are not particularly limited, and in the present embodiment, there are two types of powder, but three or more types may be stirred and mixed. Good. The powder mixing device 2 described here is an example, and is not limited to this as long as it is a device that mixes two or more types of powders using a rotating shaft.

  The powder container 21 is a container for storing the first powder P1 and the second powder P2 that are mixed in the powder mixing device 2. In this embodiment, the powder container 21 is a container having a bottom portion 211 and a cylindrical side portion 212 extending upward (in the + z direction) from the bottom portion 211, and the upper portion is open. In addition, the shape of the powder container 21 demonstrated here is the example, and the shape can be changed suitably according to use conditions. Moreover, the structure of the powder container 21 is not restricted to this, It can also have a lid | cover or a ceiling above. In that case, for example, an inlet for powder P1 and P2 and an outlet for mixed powder (P1 + P2) can be provided on the lid or ceiling.

  A circular through hole 211 a is provided in the bottom 211 of the powder container 21. Further, for example, a powder outlet may be provided in the bottom 211 of the powder container 21.

  The screw 24 has a rotating shaft 241 and propeller blades 242 for mixing and stirring powder by rotation. The shaft diameter of the rotating shaft 241 is smaller than the through hole 211 a, and the rotating shaft 241 passes through the through hole 211 a from the outside of the lower side of the powder container 21 to the bottom portion 211 and enters the powder container 21. That is, the rotating shaft 241 penetrates the outer wall of the powder container 21 in a non-contact manner. The propeller blades 242 for mixing / stirring the screw 24 may be blades having a paddle shape or ribbon shape other than the propeller shape, and the first powder P1 and the second powder P2 are stirred and mixed. Any shape can be used. The rotating shaft 241 further passes through the through hole 281 a of the housing 281, and the lower (−z) end 241 a is connected to the motor M.

  The motor M is a driving means for rotating the screw 24, and is the same as in the first embodiment. When the motor M rotates the screw 24, the first powder P1 and the second powder P2 accommodated in the powder container 21 are stirred and mixed by the propeller blades 242. The drive means of the screw 24 is not limited to an electric motor, and may be an internal combustion engine, an external combustion engine, or a wind turbine, hydraulic power, or the like. Further, as described in the first embodiment, a power transmission unit may be interposed between the motor M and the screw 24.

  The air pump A is a unit that is installed outside the powder container 21 and sends air to the shaft seal portion 26 from the outside via the hose 251 and is the same as in the first embodiment, and thus the description thereof is omitted.

  The hose 251, the shaft seal portion 26, and the housing 281 are the same as the hose 151, the shaft seal portion 16 (FIGS. 2 to 9), and the housing 181 in the first embodiment, respectively, and the description thereof is omitted here.

  The powder mixing apparatus of the second embodiment is a vertical type, but a horizontal type powder mixing apparatus is also known, and it is clear that the shaft seal structure of the present invention can be similarly applied to a horizontal type powder mixing apparatus. It is.

<8. Crusher (Third Embodiment)>
FIG. 11 is a diagram showing a crushing device 3 as a third embodiment of the present invention. In FIG. 11, the left and right are the left and right sides of the paper surface, where the front side of the paper surface is the upward direction, the back direction of the paper surface is the downward direction, that is, the back direction of the paper surface is the direction in which gravity is applied. The crushing apparatus 3 according to the present embodiment is an apparatus for crushing the raw material RM to obtain a crushed material CM. In this apparatus, debris, dust, etc. that are contained in the raw material RM or that are generated during the crushing process or the like are referred to as powder P.

  The crushing device 3 includes a container 31, a raw material introduction part 32, a powder discharge part 33, a rotor 34, a motor M, an air pump A, hoses 351 and 352, shaft sealing parts 36 and 37, a housing 381. 382. Here, the raw material RM is not limited to a bulk material, but may be in the form of particles or powder. Therefore, the crushing includes not only crushing the bulk material, but also the operation of releasing only the agglomerated powder (secondary particles) to obtain primary particles or secondary particles with less aggregation. That is, here, crushing is an operation for obtaining a piece of material or particles smaller than the raw material.

  The container 31 stores the raw material RM introduced into the crushing device 3, the crushed crushed material CM, and the powder P. In the present embodiment, the container 31 is a container having a cylindrical outer wall extending in the direction of the rotation shaft 341 (z direction) described later. In addition, the shape of the container 31 demonstrated here is the example, and the shape can be changed suitably according to use conditions. The outer wall of the container 31 includes a left bottom 311 that forms the bottom of the left (−z side) end of the cylinder, a side 312 that forms the cylinder, and a right that forms the bottom of the right (+ z side) end of the cylinder. The bottom part 313 is comprised. The container 31 has a raw material introduction hole 314 connected to the raw material introduction portion 32 above the side portion 312 (before the paper surface), and a discharge hole 315 connected to the powder discharge portion 33 below the side portion 312 (back of the paper surface). And a fixed blade 316 on the inner wall of the side portion 312.

  The left bottom portion 311 and the right bottom portion 313 are respectively provided with circular through holes 311a and 313a through which a rotation shaft 341 of the rotor 34 described later passes. The configuration of the through holes 311a and 313a is the same as that of the through holes 111a and 113a in the first embodiment.

  In the present embodiment, the fixed blade 316 is a plate-like member having a blade portion 316a facing the direction of the rotor 34 (−r direction) and having a rotational direction (θ direction) as a thickness direction. In the present embodiment, the fixed blade 316 is configured as a pair opposed to each other across the rotor 34 on the outside of the rotor 34, but is not limited thereto, and may be a single location along the rotational direction (θ direction). Three or more locations may be provided. In the present embodiment, as an example, the blade portion 316a has a saw-like shape as shown in FIG.

  The raw material introduction unit 32 is a part for introducing the raw material RM into the container 31 from the upper side (front side of the paper) of the container 31. Specific examples of the structure of the raw material introduction unit 32 include, but are not limited to, a structure in which a hopper is provided on the raw material introduction hole 314 of the container 31.

  The powder discharge unit 33 is a part for discharging the generated crushed material CM from the container 31 to the outside. In the present embodiment, the crushed material CM is dropped from the container 31 by gravity. However, the present invention is not limited to this, and a method such as sucking out of the container 31 by negative pressure may be used.

  The rotor 34 has a rotation shaft 341 and a body portion 342. Since the structure of the rotating shaft 341 is the same as that of the rotating shaft 141 of 1st Embodiment, description is abbreviate | omitted. On the outer peripheral surface of the body portion 342, a plurality of grooves 342 a having a circumferential direction (θ direction) centered on the axis of the rotation shaft 341 as a longitudinal direction are provided in the axis (z) direction of the rotation shaft 341. A rotary blade 342b is attached to the groove 342a. The rotary blade 342b may be detachably attached using a bolt or the like, or may be integrated with the body 342 by adhesion, welding, or the like. The outer (+ r) side end of the rotary blade 342b protrudes outward (+ r) from the outer peripheral surface of the body 342, and has a shape corresponding to the blade 316a of the fixed blade 316. As an example of the shape of the outer (+ r) side end of the rotary blade 342b, when the rotor 34 rotates and the rotary blade 342b comes closest to the fixed blade 316, the outer (+ r) side end of the rotary blade 342b is The shape which opposes the blade part 316a of the fixed blade 316 with a certain gap is mentioned. With this configuration, when the rotor 34 rotates, the material that has entered between the outer peripheral surface of the rotary blade 342b and the blade portion 316a of the fixed blade 316 is crushed by shearing force to generate a crushed material CM.

  The motor M is a driving unit for rotating the rotor 34. Since the motor M is the same as that of the first embodiment, the description thereof is omitted. Further, as described in the first embodiment, a power transmission unit may be interposed between the motor M and the rotor 34.

  The air pump A is a unit that is installed outside the container 31 and sends air from the outside to the shaft seals 36 and 37 via the hoses 351 and 352, and since it is the same as in the first embodiment, description thereof is omitted.

  The hoses 351 and 352, the shaft seal portions 36 and 37, and the housings 381 and 382 are the same as the hoses 151 and 152, the shaft seal portions 16 (FIGS. 2 to 9) and 17, and the housings 181 and 182 in the first embodiment, respectively. Because of this structure, the description is omitted here. The shaft seal portions 36 and 37 are configured to push back the powder P generated mainly during the crushing process into the container 31, and the size of the spiral groove of the shaft seal member, the rotation of the spiral groove, and the like. The gap between the shaft 341 and the like are preferably designed according to the assumed size of the powder P. In other words, in the present embodiment, the shaft seal portions 36 and 37 prevent the dust or the like (powder P) contained in the raw material RM or generated during the crushing process from leaking outside the container 31. Provided.

  As a modification of the crushing device, for example, there is also a device that provides a plurality of rotors each equipped with a rotary blade and crushes the material in the meshed portion by applying a shearing force by meshing the rotary blades with each other. Conceivable. In such an apparatus, a shaft seal portion may be provided on each rotating shaft.

<9. Other Embodiments>
As mentioned above, although three embodiment of this invention was described, these are only some examples of many embodiments, and also a container using a rotating shaft, such as granulation, classification, drying, storage, filling, etc. It can be applied to an apparatus for processing the powder inside.

1: Powder transport device 11: Powder container 111a, 113a: Through hole 14: Screw 141: Rotating shaft 143: Rotating shaft sleeve 151, 152: Hose 16, 17: Shaft seal 161: Shaft seal member 161a: Side wall 161b : Bottom wall 161e: Gas introduction part 161f: Shaft hole 161g: Spiral groove 161i: Protruding part 161j: Peak of peak 163: Gland packing 164: Lantern ring w: Width of spiral groove w1: Width of peak of peak 2: Powder mixing device 21: Powder container 211a: Through hole 24: Screw 241: Rotating shaft 251: Hose 26: Shaft seal 3: Crushing device 31: Container 311a, 313a: Through hole 34: Rotor 341: Rotating shaft 36 37: Shaft seal M: Motor A: Air pump S: Space

Claims (11)

A container for storing powder;
A rotating shaft penetrating the outer wall of the container in a non-contact manner;
A shaft seal structure of a powder device, provided outside the container, and having a driving means for rotating the rotating shaft,
A bottom wall provided with a circular shaft hole that passes through the rotation shaft in a non-contact manner and communicates from the inside of the container to the outside;
An air supply means for sending gas from the outside of the container to the inside between the inner peripheral surface of the shaft hole and the rotary shaft;
A shaft sealing structure of a powder device, wherein a spiral groove is formed on an inner peripheral surface of the shaft hole.   2. The shaft seal structure of a powder device according to claim 1, wherein the spiral groove has a shape in which the width of the groove increases toward the rotation axis.   In the cross section including the axis of the rotation axis, when the portion closest to the rotation axis between adjacent valleys of the spiral groove is a peak, the width of the peak in the cross section is the spiral. The shaft seal structure of a powder device according to claim 2, wherein the shaft seal structure is 1/5 or less of the pitch of the grooves.   The shaft seal structure of a powder device according to claim 3, wherein in the cross section, the peak of the mountain is a point.   The shaft of the powder device according to claim 3 or 4, wherein the spiral groove has two inclined surfaces sandwiching the peak of the mountain, and an angle formed by the two inclined surfaces in the cross section is 30 to 75 degrees. Sealed structure.   A side wall extending outside the shaft hole in the projection in the direction of the center of rotation of the rotation shaft and extending from the bottom wall toward the outside of the container; and a gas introduction unit that passes through the side wall and communicates with the air feeding means. And a gas sealing means disposed between the rotating shaft and the side wall at a position farther from the container than the gas introduction part. Shaft seal structure.   The shaft seal structure of the powder device according to claim 6, further comprising a shaft seal member attached to the container, wherein the bottom wall, the side wall, and the gas introduction part are provided on the shaft seal member.   The shaft sealing member is attached to the outside of the container, the container is provided with a through hole, and the rotating shaft passes through the through hole without contact with the inner peripheral surface of the through hole, and the shaft hole The shaft seal structure of the powder device according to claim 7, wherein the through hole communicates with the shaft.   The shaft seal structure of a powder device according to claim 7 or 8, wherein the container and the shaft seal member are in contact with each other around the entire circumference of the shaft hole. A container for storing powder;
A rotating shaft penetrating the outer wall of the container in a non-contact manner;
A driving means provided outside the container and configured to rotate the rotating shaft;
A bottom wall provided with a circular shaft hole that passes through the rotation shaft in a non-contact manner and communicates from the inside of the container to the outside;
An air supply means for sending gas from the outside of the container to the inside between the inner peripheral surface of the shaft hole and the rotary shaft;
A powder device, wherein a spiral groove is formed on an inner peripheral surface of the shaft hole. A container for storing powder;
A rotating shaft penetrating the outer wall of the container in a non-contact manner;
A shaft sealing member attached to a powder device provided outside the container and having a driving means for rotating the rotating shaft,
A bottom wall provided with a circular shaft hole larger than the diameter of the rotating shaft and leading from the inside of the container to the outside;
A gas introduction part for guiding the gas sent from the outside between the inner peripheral surface of the shaft hole and the rotation shaft,
A shaft sealing member, wherein a spiral groove is formed on an inner peripheral surface of the shaft hole.