JP2018071386A - Electric double-cylinder piston pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent or restrain backflow during switching a supply/exhausting port as much as possible.SOLUTION: The electric double-cylinder piston pump comprises: a hopper 1 provided with a transport pipe 3 and two supply/discharge ports 11, 21; an oscillation pipe 2 housed in the hopper 1 and alternately communicating the transport pipe 3 with the supply/discharge ports 11, 21; an electric actuator 5 for oscillating the oscillation pipe 2 to a position for alternately communicating with the supply/discharge ports 11, 21; two right and left piston cylinders 10, 20 respectively connected to the two supply/discharge ports 11, 21, sucking pressure-fed fluid in the hopper 1 when not communicated with the oscillation pipe 2, and emitting the sucked pressure-fed fluid when communicated with the oscillation pipe 2; plural ball spring devices 15, 25 provided coaxially with axial lines CL1, CL2 so that the respective piston cylinders 10, 20 can be driven; and slotless motors 19, 29 provided coaxially with the axial lines CL1, CL2 and driving the respective ball spring devices 15, 25.SELECTED DRAWING: Figure 1

Description

  The present invention is suitable for the pumping of low slump concrete and earth and sand with poor fluidity in construction and civil engineering works, or the pumping of dehydrated sludge with low water content generated in treatment plants such as human waste treatment plants and sewage treatment plants. The present invention relates to an oscillating tube type double cylinder piston pump that can be used.

FIG. 5 shows an example of an oscillating tube type double cylinder piston pump driven by hydraulic pressure.
As shown in the figure, a hydraulically driven double cylinder piston pump includes a hopper 101, a swing pipe 102 that is swingably accommodated in the hopper 101, and a hydraulic cylinder device 105 that swings the swing pipe 102. , And two piston cylinders 110 and 120 that are alternately connected to the swing pipe 102, and the hydraulic cylinder device 105 and the piston cylinders 110 and 120 are operated using oil as a medium.

  However, the hydraulically driven oscillating tube type double cylinder piston pump operates the hydraulic cylinder device and the piston cylinder using oil as a medium. Therefore, during the winter when the temperature is low, warm-up operation is required until the oil temperature rises. is there. In addition, in order to move the hydraulic cylinder device and the piston cylinder, a hydraulic unit and hydraulic piping composed of hydraulic equipment such as a hydraulic pump, a hydraulic valve, and an accumulator are also required, which requires a large facility space.

  Further, it is necessary to perform the standby operation of the hydraulic pump even when the hydraulically driven piston cylinder is inoperative. Therefore, there exists a problem that driving efficiency is bad. In addition, there is a problem that oil leakage occurs from the connecting portion of the hydraulic piping and the hydraulic equipment. Furthermore, there is a problem that the operation noise is high when the hydraulic pump or hydraulically driven oscillating pipe is switched.

  On the other hand, for example, Patent Document 1 discloses a technique for electrifying a double cylinder piston pump that drives a piston cylinder using an electric motor and a ball screw device instead of a hydraulically driven piston cylinder. According to the technology described in the same document, there is no problem of oil leakage due to the electrification of the piston cylinder, the hydraulic unit and the hydraulic piping are not required, the warm-up operation is not required, noise is reduced, and the operation efficiency is improved. Can do.

JP 2003-193961 A

  By the way, in the oscillating tube type double cylinder piston pump for dewatering cake pumping used in a sewage treatment plant, a high discharge pressure exceeding 8 MPa is required due to the long-distance pumping of the dewatering cake having poor fluidity. A large thrust exceeding 30 t is also required for the cylinder thrust.

Here, in the case of an oscillating tube type double cylinder piston pump, the moment when the discharge side and the suction side communicate with each other occurs when switching between discharge and suction because of the structure in which the oscillating tube is used for switching between discharge and suction.
At the moment when the discharge side and the suction side communicate with each other, the high pressure liquid on the discharge side flows backward to the suction side. Therefore, it is necessary to suppress the backflow by shortening the time during which the discharge side and the suction side communicate with each other as much as possible. For this purpose, it is necessary to install the two piston cylinders as close as possible to each other with the axis lines CL1 and CL2 in order to perform switching between discharge and suction as smoothly as possible.

  However, if the structure is such that the piston cylinder and the electric motor are connected in series on the same axis, when a commonly used brushless motor is used, the stator structure of the brushless motor is arranged in the circumferential direction facing the rotor inside the core. Since a plurality of slots are provided at regular intervals and an insulating coil is wound around each slot, a width corresponding to the slot for winding the insulating coil in the radial direction is required.

  Further, when a brushless motor is used, if the electric motor is lengthened in the axial direction, it is not easy to wind an insulating coil in a long slot in the axial direction. For this reason, it is difficult to generate a large torque with a limited motor outer diameter in a commonly used brushless motor, and it is necessary to manufacture a high-pressure oscillating pipe type double cylinder piston pump that requires a large thrust. There are still issues to be solved.

  Accordingly, the present invention has been made paying attention to such a problem, and is an oscillating tube type electric double cylinder piston pump capable of preventing or suppressing as much as possible a backflow when switching between discharge and suction. It is an issue to provide.

  In order to solve the above-mentioned problems, an electric double cylinder piston pump according to a first aspect of the present invention includes a hopper to which a transport pipe is connected and two supply / exhaust ports are provided, and a hopper in the hopper. An oscillating tube that is movably accommodated to alternately communicate the transport pipe with the two supply / exhaust ports, and an electric actuator that oscillates the oscillating tube to a position alternately communicating with the two supply / exhaust ports; , Connected to the two supply / exhaust ports, respectively, sucks the pressurized fluid in the hopper when not communicating with the rocking tube, and discharges the sucked pressurized fluid when communicating with the rocking tube. Two left and right piston cylinders, two ball screw devices installed coaxially with respect to the axis so that each piston cylinder can be driven, and each ball screw device installed coaxially with the axis. Do One of the slotless motor, characterized in that it comprises a.

  According to the electric double cylinder piston pump according to the first aspect, two ball screw devices are installed coaxially with respect to the axes of the two left and right piston cylinders, and are further installed coaxially with each ball screw device. Since it is driven by two slotless motors, there is no slot compared to a brushless motor that is generally used by driving the ball screw device coaxially with each piston cylinder by a coaxial slotless motor. High efficiency because there is no cogging torque and no iron loss. Since the slotless motor has a simple structure in which the stator coil is provided inside the core, the radial space can be utilized to the maximum. For this reason, the axes of the piston cylinders can be arranged as close as possible to achieve a compact configuration. Therefore, the backflow at the time of switching between discharge and suction can be prevented or suppressed as much as possible.

  In addition, the slotless motor can be manufactured with a long stator in the axial direction, so even when it is constrained in the radial direction, such as an oscillating pipe type double cylinder piston pump, it is large even when laid out on the same axis. The ball screw device can be driven by torque. Therefore, according to the electric double cylinder piston pump according to the first aspect of the present invention, the electric double cylinder piston pump can be electrified without using hydraulic pressure, the operation efficiency is good, the installation space is small, and the backflow when switching between discharge and suction is possible. Excellent in preventing or suppressing.

  In order to solve the above-mentioned problem, an electric double cylinder piston pump according to the second aspect of the present invention includes a hopper to which a transport pipe is connected and two supply / exhaust ports are provided, and the hopper Oscillatingly housed in such a manner that the transport pipe communicates with the two supply / exhaust ports alternately, and an electric motor that oscillates the oscillating pipe at positions alternately communicating with the two supply / exhaust ports. A pressure-feed fluid that is connected to the actuator and the two supply / exhaust ports, respectively, sucks the pressure-feed fluid in the hopper when not communicating with the swing tube, and sucks the pressure-feed fluid that is sucked when communicated with the swing tube. Two left and right piston cylinders for discharging, a plurality of ball screw devices installed symmetrically with respect to the axis thereof so that each piston cylinder can be driven, and a plurality of slotless motors respectively driving each ball screw device Prepare And wherein the door.

According to the electric double cylinder piston pump according to the second aspect, a plurality of ball screw devices are installed symmetrically with respect to the axis of the two left and right piston cylinders, and each ball screw device is driven by a plurality of slotless motors. Therefore, by driving the ball screw device with a slotless motor, as in the first aspect, there is no cogging torque and no iron loss compared to a brushless motor that is generally used. Efficiency. Furthermore, the radial space can be maximized.
For this reason, the axes of the piston cylinders can be arranged as close as possible to achieve a compact configuration. Therefore, the backflow at the time of switching between discharge and suction can be prevented or suppressed as much as possible. Furthermore, by installing a plurality of ball screw devices symmetrically with respect to the axis of the two left and right piston cylinders and driving each ball screw device with a slotless motor, the piston can be driven with a large torque proportional to the number of ball screw devices. Can be driven.

  In order to solve the above problems, an electric double cylinder piston pump according to a third aspect of the present invention includes a hopper to which a transport pipe is connected and two supply / exhaust ports are provided, and the hopper Oscillatingly housed in such a manner that the transport pipe communicates with the two supply / exhaust ports alternately, and an electric motor that oscillates the oscillating pipe at positions alternately communicating with the two supply / exhaust ports. A pressure-feed fluid that is connected to the actuator and the two supply / exhaust ports, respectively, sucks the pressure-feed fluid in the hopper when not communicating with the swing tube, and sucks the pressure-feed fluid that is sucked when communicated with the swing tube. Two piston cylinders for discharging left and right, a plurality of ball screw devices installed symmetrically with respect to the axis thereof so that each piston cylinder can be driven, and a plurality of electric motors respectively driving each ball screw device , One of the In the ton cylinder, the electric motor that drives the one piston cylinder is provided on the piston cylinder side of the ball screw device, and the other piston cylinder has the electric motor that drives the other piston cylinder, The ball screw device is provided on the side opposite to the piston cylinder.

  According to the electric double cylinder piston pump according to the third aspect, a plurality of ball screw devices are installed vertically symmetrically with respect to the axes of the two left and right piston cylinders, and a plurality of electric motors for driving the ball screw devices are provided. The one piston cylinder has an electric motor for driving the one piston cylinder provided on the piston cylinder side of the ball screw device, and the other piston cylinder has an electric motor for driving the other piston cylinder. Since it is provided on the side opposite to the piston cylinder of the apparatus, even when a brushless motor generally used as an electric motor is employed, the radial space can be utilized to the maximum. For this reason, the axes of the piston cylinders can be arranged as close as possible to achieve a compact configuration. Therefore, the backflow at the time of switching between discharge and suction can be prevented or suppressed as much as possible.

  Here, in the electric double cylinder piston pump according to any one aspect of the present invention, the electric actuator is a swinging slotless motor, and the swinging slotless motor is at least five times the rated torque of the motor body. It is preferable to rock the rocking tube with torque. With such a configuration, a slotless motor that does not have a slot and does not generate a magnetic saturation phenomenon is used to drive switching between discharge and suction, and the oscillating tube is oscillated with a torque more than five times the rated torque. Therefore, it is suitable for reducing the size of the electric actuator.

  In particular, the electric double cylinder piston pump according to any one aspect of the present invention, such as a dewatering cake pressure feed pump used in a sewage treatment plant, has a high pressure swing that requires a large thrust exceeding 8 MPa. Even when it is used as a moving tube type double cylinder piston pump, it can be electrified without using hydraulic pressure, has high operating efficiency, has a small installation space, and can solve problems of noise and oil leakage.

  As described above, according to the present invention, it is possible to prevent or suppress backflow as much as possible when switching between discharge and suction.

It is explanatory drawing of 1st embodiment of the rocking | fluctuation pipe type electric double piston pump which concerns on 1 aspect of this invention, Comprising: The same figure (a) is a top view, (b) is a front view, (c) is A-. It is A sectional drawing, and the same figure (a) and (b) shows the cross section along an axis line. It is explanatory drawing of 2nd embodiment of the rocking-tube type electric double piston pump which concerns on 1 aspect of this invention, Comprising: The same figure (a) is a top view, (b) is a front view, (c) is (b) ) In the right side view, and FIGS. 4A and 4B show cross sections along the axis. It is explanatory drawing of 3rd embodiment of the rocking | fluctuation pipe type electric double piston pump which concerns on 1 aspect of this invention, Comprising: The same figure (a) is a top view, (b) is a front view, (c) is (b) ) In the right side view, and FIGS. 4A and 4B show cross sections along the axis. FIG. 4 is an explanatory diagram of an oscillating tube type electric double piston pump driven by a brushless motor with a slot according to a fourth embodiment of the oscillating tube type electric double piston pump according to one aspect of the present invention. ) Is a plan view, (b) is an AA sectional view, (c) is a BB sectional view, (d) is a right side view of (c), and in FIG. A cross section is shown. It is explanatory drawing of the conventional rocking pipe type double piston pump by a hydraulic drive, The same figure (a) is a top view, (b) is a front view, (c) is ZZ sectional drawing, Figures (a) and (b) show a cross section along the axis.

  Embodiments of an oscillating tube type electric double piston pump according to an aspect of the present invention will be described below with reference to the drawings as appropriate. The drawings are schematic. For this reason, it should be noted that the relationship between the thickness and the planar dimension, the ratio, and the like are different from the actual ones, and the dimensional relationship and the ratio are different between the drawings. Further, the following embodiments exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, and arrangement of components. Etc. are not specified in the following embodiments.

[First embodiment]
As shown in FIG. 1, the oscillating tube type electric double cylinder piston pump of the first embodiment includes a base 8 and a hopper 1 attached to the front surface of the base 8. A transport pipe 3 is connected to the front surface of the hopper 1. At the lower part of the rear surface of the hopper 1, two supply / discharge ports 11 and 21 are provided on the left and right sides. In the hopper 1, an oscillating tube 2 bent in a substantially S shape is accommodated so as to be oscillated. One end of the swing tube 2 communicates with the transport tube 3 on the front surface of the hopper 1. A swing shaft 4 having a horizontal axis is fixed to an upper portion of the middle portion of the swing tube 2.

  The base end side of the swing shaft 4 is attached to the swinging electric actuator 5 at a position that penetrates the rear wall 1k of the hopper 1 and protrudes to the outside. The electric actuator 5 includes a speed reducer 6 and a slotless motor body 7. The slotless motor main body 7 has a simple structure in which a stator coil is simply provided inside the core, and has no slot so that a magnetic saturation phenomenon does not occur. Moreover, since there is no slot, there is no cogging torque and there is no iron loss, so that the efficiency is high.

  The speed reducer 6 is one that can swing the swing shaft 4 in the left-right direction with a torque that is five times or more the rated torque of the slotless motor body 7. Even when used as a high-pressure oscillating pipe type double cylinder piston pump that requires a large thrust exceeding 8 MPa, the oscillating pipe 2 is oscillated left and right around the oscillating shaft 4 to Each swing position can be held. The other end of the oscillating tube 2 is alternately connected to the two supply / exhaust ports according to the respective left / right oscillating positions, and can communicate with the two supply / exhaust ports 11, 21 alternately via the seal ring 9. It has become.

  Two piston cylinders 10 and 20 respectively communicating with the two supply / exhaust ports 11 and 21 are installed on the base 8 on the outer surface on the rear side of the hopper 1 with the axes CL1 and CL2 being parallel to each other. Each piston cylinder 10, 20 is driven so as to suck the pressure-feed fluid in the hopper 1 when not communicating with the rocking tube 2 and to discharge the sucked pressure-feed fluid when communicating with the rocking tube 2. Is done.

  Specifically, the first piston cylinder 10 includes a first cylinder body 12, a first ball screw device 15 connected coaxially with the axis CL 1 at the rear end of the first cylinder body 12, and a rear of the first ball screw device 15. A first slotless motor 19 connected coaxially with the axis CL1 is provided at the end. The first slotless motor 19 has a simple structure in which a stator coil is provided on the inner side of the core, and there is no slot so that a magnetic saturation phenomenon does not occur. In addition, since there is no slot, there is no cogging torque and there is no iron loss, so the efficiency is high.

  The first cylinder body 12 includes a hollow cylindrical first cylinder 13 and a first piston 14 slidably fitted to the first cylinder 13. The first piston 14 includes a piston head 14a that slides in the axial direction in the first cylinder 13, and a hollow cylindrical piston rod 14c that is coupled to the rear end of the piston head 14a via a coupling 14b. And have.

  The first ball screw device 15 includes a hollow cylindrical housing 16, a cylindrical nut 17 slidably disposed on the inner peripheral surface of the housing 16 so as to be slidable in the axial direction of the housing 16, and an inner periphery of the nut 17. The screw shaft 18 is screwed onto the surface via a number of rolling balls. The rear end of the screw shaft 18 is coaxially connected to the drive shaft of the first slotless motor 19. Between the front end of the housing 16 and the piston rod 14c, a bearing 16j that smoothly supports the sliding movement of the piston rod 14c by a large number of rolling elements is interposed.

  The nut 17 of the first ball screw device 15 is coaxially connected to the axis CL1 at the rear end of the piston rod 14c, and the screw shaft 18 of the first ball screw device 15 is driven by the first slotless motor 19. As a result, the nut 17 slides and the first piston 14 slides in the axial direction. Here, the hollow cylindrical piston rod 14c is connected to the hollow cylindrical portion so that the screw shaft 18 can be accommodated, and when the nut 17 is retracted, the screw shaft 18 can be accommodated in the piston rod 14c.

  The second piston cylinder 20 has the same configuration as the first piston cylinder 10. That is, the second piston cylinder 20 includes a second cylinder main body 22, a second ball screw device 25 connected coaxially with the axis CL <b> 2 at the rear end of the second cylinder main body 22, and a rear end of the second ball screw device 25. And a second slotless motor 29 connected coaxially with the axis CL2. The second slotless motor 29 has a simple structure in which a stator coil is provided on the inner side of the core, and there is no slot so that a magnetic saturation phenomenon does not occur. In addition, since there is no slot, there is no cogging torque and there is no iron loss, so the efficiency is high.

  The second cylinder body 22 has a hollow cylindrical second cylinder 23 and a second piston 24 slidably fitted on the second cylinder 23. The second piston 24 includes a piston head 24a that slides in the second cylinder 23 along the axial direction, and a hollow cylindrical piston rod 24c that is coupled to the rear end of the piston head 24a via a coupling 24b. And have.

  The second ball screw device 25 includes a hollow cylindrical housing 26, a cylindrical nut 27 slidably disposed on the inner peripheral surface of the housing 26 so as to be slidable in the axial direction of the housing 26, and an inner periphery of the nut 27. The screw shaft 28 is screwed onto the surface via a number of rolling balls. The rear end of the screw shaft 28 is connected to the drive shaft of the second slotless motor 29 coaxially with the axis CL2. Between the front end of the housing 26 and the piston rod 24c, a bearing 26j that smoothly supports the sliding movement of the piston rod 24c by a large number of rolling elements is interposed.

  A nut 27 of the second ball screw device 25 is connected coaxially to the axis CL2 at the rear end of the piston rod 24c, and the screw shaft 28 of the second ball screw device 25 is driven by the second slotless motor 29. As a result, the nut 27 slides and the second piston 24 is slidable in the axial direction. Here, the hollow cylindrical piston rod 24c is connected to the hollow cylindrical portion so that the screw shaft 28 can be accommodated. When the nut 27 is retracted, the screw shaft 28 can be accommodated in the piston rod 24c.

Next, the operation and effect of the electric double cylinder piston pump of the first embodiment will be described.
In the electric double cylinder piston pump of the first embodiment, when the pressure-fed fluid in the hopper 1 is pumped, the swinging pipe 2 is swung left and right by the swinging electric actuator 5, and two piston cylinders The first piston 14 and the second piston 24 in the motors 10 and 20 are moved forward and backward alternately by driving the slotless motors 19 and 29.

  As a result, the fluid to be fed in the hopper 1 is sucked into the corresponding piston cylinder 10 or 20 from one of the supply / discharge ports 11 or 21. At this time, the other supply / exhaust port 21 or 11 has the corresponding piston cylinder 20 or 10 communicating with the oscillating pipe 2, and the fluid to be fed that has been sucked inside is pumped by the advance of the piston 14 or 24. Then, it is discharged from the rocking tube 2 to the transport tube 3.

  Therefore, according to this electric double cylinder piston pump, the swing pipe 2 is swung left and right by driving the electric actuator 5 in accordance with the forward and backward movement of the pistons 14 and 24 in the two piston cylinders 10 and 20. Thus, the fluid to be fed in the hopper 1 can be continuously discharged from the rocking tube 2 through the transport tube 3.

  Here, in this type of double cylinder piston pump, the oscillating pipe is immersed in the fluid to be fed in the hopper. For this reason, the resistance when switching the supply / exhaust port by swinging the swing tube left and right is large. Especially in the hopper, such as pumping low slump concrete and earth and sand with poor fluidity in construction and civil engineering work, or pumping dehydrated sludge with low water content generated at treatment plants such as human waste treatment plants and sewage treatment plants. The resistance at the time of switching varies greatly depending on the properties of the fluid to be fed and the length of the oscillating tube.

  On the other hand, according to the electric double cylinder piston pump of the first embodiment, two ball screw devices 15 and 25 are installed coaxially with respect to the axis lines CL1 and CL2 of the two left and right piston cylinders 10 and 20, and each ball Since the screw devices 15 and 25 are configured to be driven by two slotless motors 19 and 29, respectively, the slotless motors 19 and 29 have no slots as compared with a brushless motor that is generally used. There is no cogging torque and there is no iron loss, so it is highly efficient. Furthermore, since each slotless motor 19 and 29 has a simple structure in which a stator coil is provided inside the core, the radial space can be utilized to the maximum.

  Further, each slotless motor 19, 29 can be manufactured with a long stator in the axial direction, so that even if there is a restriction in the radial direction, such as a oscillating pipe type double cylinder piston pump, a large torque can be obtained. Thus, the ball screw devices 15 and 25 can be driven.

  Further, two ball screw devices 15 and 25 are installed coaxially with respect to the axis lines CL1 and CL2 of the two left and right piston cylinders 10 and 20, and each ball screw device 15 and 25 is coaxial with each axis line CL1 and CL2. Are driven by two slotless motors 19 and 29, respectively, so that the axial lines CL1 and CL2 of the two piston cylinders 10 and 20 can be arranged as close as possible to each other and can be configured compactly. Therefore, the backflow at the time of switching between discharge and suction can be prevented or suppressed as much as possible.

  Further, a slotless motor (slotless motor main body 7) that does not have a slot and does not generate a magnetic saturation phenomenon is used as the electric actuator 5 for switching between discharge and suction. Since the switching valve is operated with a torque more than five times the rated torque of the slotless motor main body 7 as a configuration having the slotless motor main body 7, the electric actuator 5 can be downsized while being treated in a sewage treatment plant. Like the dewatering cake pressure feed pump used, even a high-pressure oscillating pipe double cylinder piston pump that requires a large thrust, with a discharge pressure exceeding 8 MPa, can be electrified without using hydraulic pressure. It has good operating efficiency, small installation space, and can solve problems of noise and oil leakage.

  As described above, according to the electric double cylinder piston pump of the first embodiment, the backflow at the time of switching between discharge and suction can be prevented or suppressed as much as possible. The electric double cylinder piston pump according to the present invention is not limited to the first embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the first embodiment, the two piston cylinders 10 and 20 can be driven, the two ball screw devices 15 and 25 installed coaxially with the axis CL1 and CL2, and the axes CL1 and CL2 The example provided with the two slotless motors 19 and 29 that are coaxially installed and drive the ball screw devices 15 and 25 has been described. However, the arrangement and the number of the ball screw devices and the slotless motors that drive the ball screw devices are described. Is not limited to this. Hereinafter, other embodiments will be described. In other embodiments, the same or corresponding components as those in the first embodiment are given the same reference numerals or corresponding reference numerals (combinations of the same numerals and different alphabets), and the description thereof. Are omitted as appropriate.

[Second Embodiment]
As in the first embodiment, the electric double cylinder piston pump of the second embodiment includes a hopper 1 to which a transport pipe 3 is connected and two supply / discharge ports 11 and 21 are provided, as shown in FIG. The swing pipe 2 accommodated in the hopper 1 and alternately communicating the transport pipe 3 with the two supply / discharge ports 11 and 21, and the position where the swing pipe 2 communicates with the two supply / discharge ports 11 and 21 alternately The fluid to be fed in the hopper 1 is sucked and communicated with the oscillating tube 2 when not connected to the oscillating tube 2 and connected to the electric supply and discharge ports 11 and 21 respectively. Sometimes the left and right piston cylinders 10 and 20 for discharging the sucked fluid to be fed and the plurality of ball screw devices 15A installed symmetrically with respect to the axis lines CL1 and CL2 so that the piston cylinders 10 and 20 can be driven. , 15B, 25A, 25 When provided with the ball screw device 15A, 15B, 25A, slotless motor 19A for driving the 25B, 19B, 29A, and 29B.

  That is, in the electric double cylinder piston pump of the second embodiment, the first piston cylinder 10 is provided with two ball screw devices 15A and 15B symmetrically with respect to the axis CL1, and each ball screw device 15A. , 15B are disposed behind the first piston cylinder 10 coaxially with the screw shafts 18A, 18B of the ball screw devices 15A, 15B.

  The second piston cylinder 20 is provided with two ball screw devices 25A and 25B symmetrically with respect to the axis CL2, and the slotless motors 29A and 29B for driving the ball screw devices 25A and 25B are provided. These are arranged behind the second piston cylinder 20 coaxially with the screw shafts 28A and 28B of the ball screw devices 25A and 25B.

  In the second embodiment, the piston rods 14c and 24c of the pistons 14 and 24 are formed of solid round bars, as shown in FIG. . The rear ends of the piston rods 14c and 24c are fixed to the center of the connecting rod 33, and the nuts 17A and 17B of the ball screw devices 25A and 25B are fixed above and below the connecting rod 33, whereby each nut The pistons 14 and 24 are slidably driven integrally with 17A and 17B (note that the structure on the second piston cylinder 20 side is the same as that on the first piston cylinder 10 side and is not shown).

  According to the electric double cylinder piston pump of the second embodiment, two ball screw devices 15A, 15B, 25A, 25B are installed vertically symmetrically with respect to the axis lines CL1, CL2 of the two left and right piston cylinders 10, 20, Since the ball screw devices 15A, 15B, 25A, and 25B are respectively driven by the slotless motors 19A, 19B, 29A, and 29B, the cogging torque is compared with the generally used brushless motor, as in the first embodiment. It is highly efficient because there is no iron loss. Furthermore, the radial space can be maximized. Therefore, as in the first embodiment, the axes CL1 and CL2 of the piston cylinders 10 and 20 can be arranged as close as possible to achieve a compact configuration. Therefore, the backflow at the time of switching between discharge and suction can be prevented or suppressed as much as possible.

  Furthermore, according to the electric double cylinder piston pump of the second embodiment, in addition to the same effects as those of the first embodiment, two symmetrically with respect to the axes CL1 and CL2 of the two left and right piston cylinders 10 and 20 ( 4) ball screw devices 15A, 15B, 25A, 25B are installed, and the ball screw devices 15A, 15B, 25A, 25B are driven by the slotless motors 19A, 19B, 29A, 29B, respectively. The piston cylinders 10 and 20 can be driven with a large torque proportional to the number of devices.

[Third embodiment]
The third embodiment is an example in which a ball screw device and a slotless motor for driving the ball screw device are further added to the second embodiment.
That is, in the electric double cylinder piston pump of the third embodiment, the first piston cylinder 10 has six vertically symmetrical with respect to the axis CL1 with respect to the two left and right piston cylinders 10 and 20 (three on the top and three on the bottom). 3) and the ball screw devices 15A-F are driven by the slotless motors 19A-F, respectively, and the second piston cylinder 20 is vertically symmetrical with respect to its axis CL2. 6 (three on the top and three on the bottom) are installed, and each of the ball screw devices 25A-F is driven by the slotless motors 29A-F, respectively.

  According to the electric double cylinder piston pump of the third embodiment, six (total 12) ball screw devices 15A to F and 25A to F are installed symmetrically in the vertical direction, and each of the ball screw devices 15A to F and 25A to F. Is driven by the slotless motors 19A to 19F and 29A to 29F, the piston cylinders 10 and 20 can be driven with a larger torque proportional to the number of ball screw devices as in the second embodiment.

  In the above embodiment, the second embodiment shows an example in which two ball screw devices are arranged vertically symmetrically (4 in total on the left and right), and in the third embodiment, 6 ball screws are symmetrically arranged on the left and right (total on the left and right). 12) The example in which the ball screw device is arranged is shown. However, the present invention is not limited to this, and when driving the piston cylinder with a large torque proportional to the number of ball screw devices, for example, four ( A total of 8 ball screw devices can be arranged on the left and right, and, for example, eight ball screw devices can be arranged symmetrically in the vertical direction (16 on the left and right). The same applies to the arrangement and number of each slotless motor.

[Fourth embodiment]
Further, in each of the above-described embodiments, an example in which a slotless motor is used as the electric motor that drives each ball screw device has been described. However, the present invention is not limited to this, and backflow at the time of switching between discharge and suction is possible. If the layout can be prevented or suppressed, a general slotless brushless motor may be used as the electric motor.

  That is, as shown in FIG. 4, the electric double cylinder piston pump of the fourth embodiment is accommodated in the hopper 1 to which the transport pipe 3 is connected and the two supply / discharge ports 11 and 21 are provided. Oscillating pipe 2 that alternately communicates the transport pipe 3 with the two supply / exhaust ports 11, 21, and an electric actuator that oscillates the oscillating pipe 2 to a position where it alternately communicates with the two supply / exhaust ports 11, 21. 5 and 2 are connected to the two supply / discharge ports 11 and 21, respectively, to suck the pressurized fluid in the hopper 1 when not communicating with the oscillating tube 2 and sucked when the fluid is communicated with the oscillating tube 2. The left and right piston cylinders 210 and 220 that discharge the body, and a plurality of piston cylinders 210 and 220 that are capable of driving the piston cylinders 210 and 220 and that are vertically symmetrical with respect to the axis lines CL1 and CL2 (two in this example (four in total)) ) Ball screw device 215 Comprises B, 225A, and B, the ball screw device 215A, B, 225A, an electric motor that drives the B, brushless motor 219A slotted, B, 229A, and B.

  Here, in the fourth embodiment, one second piston cylinder 220 is provided with slotted brushless motors 229A, B for driving the second piston cylinder 220 on the second piston cylinder 220 side, and the other second piston cylinder 220 is provided with the other second piston cylinder 220. The one piston cylinder 120 is provided with brushless motors 219 </ b> A and 219 with slots for driving the first piston cylinder 120 on the side opposite to the first piston cylinder 120.

  According to the electric double cylinder piston pump of the fourth embodiment, while installing a plurality of ball screw devices 215A, B, 225A, B symmetrically with respect to the axis lines CL1, CL2 of the two left and right piston cylinders 210, 220, The second piston cylinder 220 is provided with slotless brushless motors 229A, B for driving the second piston cylinder 220 on the second piston cylinder 220 side, and the first piston cylinder 120 drives the first piston cylinder 120. Since the slotless brushless motors 219A and 219B are provided on the side opposite to the first piston cylinder 120, even if a brushless motor generally used as an electric motor is employed, the radial space Can be used to the maximum. Therefore, as shown in FIG. 5A, the two left and right piston cylinders 210 and 220 can be configured compactly by arranging the axial lines CL1 and CL2 as close as possible. Therefore, the backflow at the time of switching between discharge and suction can be prevented or suppressed as much as possible.

DESCRIPTION OF SYMBOLS 1 Hopper 2 Oscillation pipe 3 Transport pipe 4 Oscillation shaft 5 Electric actuator 6 Reducer 7 Slotless motor main body 8 Base 9 Seal ring 10 First piston cylinders 11 and 21 Supply / exhaust port 12 First cylinder main body 13 First cylinder 14 First piston 14a Piston head 14b Coupling 14c Piston rod 15 Ball screw device 16 Housing 17 Nut 18 Screw shaft 19 First slotless motor 20 Second piston cylinder 22 Second cylinder body 23 Second cylinder 24 Second piston 24a Piston head 24b coupling 24c piston rod 25 ball screw device 26 housing 27 nut 28 screw shaft 29 second slotless motor 33 connecting rod CL1, CL2 axis

Claims (4)

  A hopper connected to the transport pipe and provided with two supply / exhaust ports; a swing pipe accommodated in the hopper so as to be swingable and alternately communicating the transport pipe with the two supply / discharge ports; An electric actuator that swings the swing pipe to a position that alternately communicates with the two supply / exhaust ports, and a cover in the hopper that is connected to the two supply / discharge ports and is not in communication with the swing pipe. Left and right piston cylinders for sucking the pumped fluid and discharging the sucked fluid to be pumped when communicating with the oscillating pipe, and each piston cylinder are installed coaxially with respect to the axis thereof An electric double cylinder piston pump comprising: two ball screw devices; and two slotless motors installed coaxially with respect to the axis to drive each ball screw device.   A hopper connected to the transport pipe and provided with two supply / exhaust ports; a swing pipe accommodated in the hopper so as to be swingable and alternately communicating the transport pipe with the two supply / discharge ports; An electric actuator that swings the swing pipe to a position that alternately communicates with the two supply / exhaust ports, and a cover in the hopper that is connected to the two supply / discharge ports and is not in communication with the swing pipe. Left and right two piston cylinders for sucking the pumped fluid and discharging the sucked fluid to be pumped when communicating with the oscillating pipe, and a plurality of piston cylinders installed symmetrically with respect to the axis so that each piston cylinder can be driven An electric double cylinder piston pump comprising: a ball screw device according to claim 1; and a plurality of slotless motors that respectively drive the ball screw devices. A hopper connected to the transport pipe and provided with two supply / exhaust ports; a swing pipe accommodated in the hopper so as to be swingable and alternately communicating the transport pipe with the two supply / discharge ports; An electric actuator that swings the swing pipe to a position that alternately communicates with the two supply / exhaust ports, and a cover in the hopper that is connected to the two supply / discharge ports and is not in communication with the swing pipe. Left and right two piston cylinders for sucking the pumped fluid and discharging the sucked fluid to be pumped when communicating with the oscillating pipe, and a plurality of piston cylinders installed symmetrically with respect to the axis so that each piston cylinder can be driven A ball screw device and a plurality of electric motors for driving each ball screw device,
One piston cylinder has the electric motor for driving the one piston cylinder provided on the piston cylinder side of the ball screw device, and the other piston cylinder has the electric motor for driving the other piston cylinder. The electric double cylinder piston pump is provided on the opposite side to the piston cylinder of the ball screw device.   The electric actuator is a rocking slotless motor, and the rocking slotless motor rocks the rocking tube with a torque that is five times or more the rated torque of the motor body. The electric double cylinder piston pump described in the item.

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