JP2009079768A - Rotary equipment shaft-sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary equipment shaft-sealing device having reduced running cost while allowing the replacement of only a packing and the use of a rotating shaft several times in spite of positional wear of a packing by changing a packing contact position on the rotating shaft. <P>SOLUTION: The shaft-sealing device is arranged around the rotating shaft 3 at a joint position between a driving side casing 5 of a pump 1 to be rotated by an electric motor and a pump casing 6. In a center opening 11b of one seal member 11 out of two annular seal members 11, 12 mounted neighboring each other on the outer peripheral face of the rotating shaft 3, an annular recessed portion 11c is formed into which a lip packing 14 having an approximately L-shaped cross section can be fitted. The lip packing is fitted into the annular recessed portion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotating device such as a pump rotated by a driving device such as a single-shaft eccentric screw pump or a rotary pump, and a driving side casing having a driving shaft or a rotating shaft connected to the driving shaft, and a cover such as a pump side casing. A shaft for sealing the gap between the rotating shaft and the surrounding casing (non-rotating portion), which is disposed around the driving shaft or the rotating shaft (hereinafter simply referred to as the rotating shaft) at the joint with the driving casing. The present invention relates to a sealing device.

  As for this type of shaft seal device, for example, in the single-shaft eccentric screw pump 31, as shown in FIG. 7, one end face on the suction port 36 a side of the pump casing 36 is connected to an electric motor (not shown) and rotates. A drive-side casing 35 provided with a rotary shaft 33 for rotation is joined, and an annular seal member 32 having an annular projection 32a on the outer peripheral surface is mounted around the rotary shaft 33 penetrating the joint location. There is a structure in which a plurality of gland packings 34 are fitted adjacent to each other in the central opening 32 b of the seal member 32, and the gland packing 34 is pressed by a set screw 38 via a pressing metal fitting 37. .

  In FIG. 7, an upward suction port 36 a is provided near the center of the pump casing 36, a stator 39 is connected to the end surface on the opposite side of the drive side casing 35, and a discharge port portion 43 is connected to one end of the stator 39. Yes. A male threaded rotor 42 is fitted into the female threaded hole 39a of the stator 39, and one end of the rotor 42 and one end of the rotating shaft 33 are connected by a connecting rod 40 via a universal joint (universal joint) 41, respectively. Has been.

  As a conventional typical shaft seal device 50, as shown in FIG. 6, at a joint portion between the driven casing 6 such as a pump casing and the driving casing 5, the central portion can be rotated through the center. An annular seal member (fixed ring) 51 is fitted in one annular groove 51a in a state where an O-ring 52 is loaded in an annular recess 9 which is an annular space portion with the arranged rotary shaft 3, and this seal An annular recess 51c in which a substantially L-shaped lip packing 53 can be fitted is formed around the central opening 51b of the member 51, and the lip packing 53 is interposed between the recess 51c and the rotary shaft 3.

  However, any of the above-described conventional shaft seal devices has room for improvement in the following points. That is, in recent years, high pressure resistance has been required for the gland packing and the lip packing for reasons such as increasing the rotational speed of the pump and increasing the viscosity of the transferred liquid. Therefore, hard materials such as hard rubber and high-density polyethylene have been conventionally used as the packing material in addition to general soft rubber.

  When such a packing made of a hard material such as hard rubber or high-density polyethylene is used, the rotating shaft is heavily worn, and it is necessary to replace the rotating shaft and the packing in a short period of time, resulting in an increase in running cost. As apparent from FIG. 6, the shaft sealing position (seal position) A by the lip packing 53 on the rotating shaft 3 is specified in one place because of the structure. This is because once worn, the position (shaft seal position) A on which the lip packing 53 abuts cannot be changed to seal the shaft.

  The present invention has been made in view of the above-mentioned points. By making it possible to easily change the position on the rotating shaft where the packing contacts, only the packing is replaced, and the rotating shaft is worn at the contact position of the packing. Even so, it is intended to provide a shaft seal device for a rotating device that can be used a plurality of times by changing the position and can reduce running costs.

  In order to achieve the above-mentioned object, the shaft seal device for a rotating device according to the present invention is the above-mentioned at the joint between the driving side casing and the driven side casing such as the pump casing in the rotating device such as a pump rotated by the driving device. One of at least two annular seal members mounted adjacent to each other on the outer peripheral surface of the rotating shaft in a shaft sealing device of a rotating device arranged around a rotating shaft rotated by a driving device An annular recess capable of fitting a lip packing is formed around the central opening of the seal member, and the lip packing is fitted into the annular recess.

  According to the shaft seal device having the above configuration, when the surface of the rotating shaft is worn or worn by the lip packing fitted on one side, the seal member is replaced, and the lip packing is replaced with a new one. By moving the position of the lip packing on the rotating shaft, that is, the seal position, to a position where there is no wear or wear, the life of the rotating shaft is at least doubled and the shaft sealing action is restored to the state at the time of initial assembly. . Moreover, since the structure is simple and the manufacturing cost is not much different from the conventional one, the running cost can be greatly reduced and it is economical.

  According to a second aspect of the present invention, there are three annular seal members, one of which is provided with the annular recess, and the other two seal members are made thick (the length in the axial direction of the rotating shaft). It can comprise from the sealing member from which these differ.

  According to the shaft seal device having this configuration, the position of the lip packing on the rotating shaft can be changed three times at the time of initial assembly, at the time of reassembly and at the time of reassembly, so only by replacing the lip packing, The life of the rotating shaft can be extended three times.

  As is apparent from the above description, the shaft seal device for a rotary device according to the present invention has the following excellent effects.

  (1) The shaft seal device according to the first aspect allows the position on the rotating shaft where the packing contacts to be changed, so that the rotating shaft can be easily changed even if the contact position of the packing is worn. By changing it so that it can be used a plurality of times, the running cost can be reduced particularly when a lip packing made of a hard material such as hard rubber or high-density polyethylene is used, which is economical.

  In other words, when the contact position on the surface of the rotating shaft is worn or worn by the lip packing fitted on one side, the seal member is replaced, and the lip packing is replaced with a new one. Since the position of the lip packing can be moved to a position where there is no wear or wear, the life of the rotating shaft is at least doubled, and the shaft sealing action is restored to the initial assembly state. Moreover, the overall structure is simple and the production cost is almost the same as before, so the running cost can be greatly reduced.

  (2) The shaft seal device of claim 2 can change the position of the lip packing on the rotating shaft three times at the time of initial assembly, reassembly and reassembly, so only by replacing the lip packing, The life of the rotating shaft can be extended three times.

  Embodiments of a shaft seal device for a rotating device according to the present invention will be described below with reference to the drawings.

  1 is a front view schematically showing an embodiment of a pump provided with a shaft seal device according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view showing a part (shaft seal portion) of FIG. 2A shows the time of initial assembly, and FIG. 2B shows the time of reassembly.

  As shown in FIG. 1, the pump 1 provided with the shaft seal device 10-1 (FIG. 2) of this example is operated by a rotary shaft 3 connected to a drive shaft of an electric motor 2. The driving side casing 5 and the pump casing 6 to be supported are joined together. The pump casing 6 is provided with a suction port 7 at the top and a discharge port 8 at one end.

  As shown in FIG. 2 (a), one end surface of the drive side casing 5 and one end surface of the pump casing 6 are joined so as to face each other, and are fastened and fixed by bolts and nuts (not shown) or the like. In this joint location, both the casings 5 and 6 are formed in a cylindrical shape with the outer diameter enlarged in the radial direction, and an annular recess 9 is formed at the joint location of both the casings 5 and 6. In the recess 9, two annular seal members 11 and 12 are fitted in a state of being mounted on the rotary shaft 3. In the shaft seal device 10-1 of this example, the thicknesses of the two seal members 11 and 12 (length along the axial direction of the rotary shaft 3) are equal, and annular grooves 11a and 12a are formed on one surface, respectively. The O-ring 13 is loaded there. Both seal members 11 and 12 are made of metal material, soft rubber, synthetic resin, etc., and the central opening 11b of one seal member 11 has a larger diameter than the central opening 12b of the other seal member 12, An annular recess 11c having a substantially L-shaped cross section into which a lip packing 14 having a substantially L-shaped cross section can be fitted is formed near the end (right side in the figure) of the central opening 11b. In the case of this example, the lip packing 14 is made of hard rubber, and at the time of initial assembly, in the annular recess 9 of the casings 5 and 6, it is sealed on the pump casing 6 side, that is, the back side as viewed from the E direction. The member 11 is arranged, and subsequently the seal member 12 is arranged. A lip packing 14 is fitted into the annular recess 11 c of the seal member 11.

  In this state, there is a seal line (seal start line) at the position A on the left side from the joining position of the casings 5 and 6, and the liquid to be transported in the pump casing 6 enters the drive side casing 5 from the outer peripheral side of the rotary shaft 3. To be prevented. Thus, if an abrasion action occurs between the rotating shaft 3 and the lip packing 14 that rotate at high speed, and replacement becomes necessary after a certain period of use, reassembly is performed as follows. That is, the connection between the drive shaft of the electric motor 2 and the rotary shaft 3 is released, the rotary shaft is disconnected, the drive-side casing 5 is separated from the pump casing 6, and the seal members 11 and 12 are shown along the rotary shaft 3. Pull out to the right side. Then, the seal member 12 is first inserted to the left in the axial direction along the rotation shaft 3, the lip packing 14 is replaced with a new one, and the seal member 11 is inserted along the rotation shaft 3. Thereafter, the drive-side casing 5 is joined to the pump casing 6 and assembled in the reverse order of disassembly, and the rotary shaft 3 is connected to the drive shaft of the drive motor 2.

  As a result of reassembling in this way, the seal wire is changed from the joint location to the B position on the right side, and the portion where the rotating shaft 3 is not worn can be used as the seal wire. Therefore, the life of the rotating shaft 3 is doubled compared to the conventional one. In addition, when the new lip packing 14 is inserted along the rotary shaft 3, the worn outer peripheral surface of the rotary shaft 3 is not damaged.

  FIG. 3 is a sectional view showing another embodiment of the shaft seal device of the present invention. FIG. 3 (a) shows the initial assembly, FIG. 3 (b) shows the reassembly, and FIG. 3 (c) shows the reassembly. Each represents time. The shaft seal device 10-2 of this example is different from the shaft seal device 10-1 of the first embodiment described above in that a third annular seal member 15 as a backup spacer is added. That is, the third seal member 15 is a member that is necessary when the opening diameter of the inlet has to be increased due to reasons such as prevention of cast-holes and assembly during the production of the drive-side casing 5. This is used for changing the seal lines A to C.

  In the case of this example, as shown in FIG. 3, the width of the annular recess 9 formed at the joint portion between the casings 5 and 6 is increased according to the width of the third seal member 15 to be added. The third seal member 15 has a width almost half that of the other seal members 11 and 12, and the structure and material are completely the same as those of the seal member 12. The third seal member 15 has an annular groove 15a on one surface, and the annular groove. An O-ring 16 is loaded in 15a. Since other configurations are the same as those in the first embodiment, common members are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIGS. 3A to 3C, the shaft seal device 10-2 of the present example has a lip packing 14 on the rotating shaft 3 at the time of initial assembly, reassembly, and reassembly. Since the positions A to C of the seal line can be changed three times, the life of the rotary shaft 3 is tripled. Further, when reassembling and reassembling, the position of the lip packing 14 is shifted to the right side (the drive side casing 5 side) along the axial direction of the rotary shaft 3 to rotate the new lip packing 14. When inserted along the shaft 3, it is possible to prevent the outer peripheral surface of the rotating shaft 3 from being damaged.

  4A and 4B are sectional views showing a shaft seal device according to another embodiment in which the shaft seal effect is improved. FIG. 4A shows an initial assembly time, and FIG. 4B shows a re-assembly time.

  As shown in FIG. 4, the shaft seal device 10-3 of this example includes two types of seal members 17 and 18 into which a lip packing 14 having a substantially L-shaped cross section can be fitted. The seal member 17 is a pump casing. The annular recess 9A provided on the side 6 and the seal member 18 are loaded into the annular recess 9B provided on the drive casing 5 side, respectively, and a lubricant enclosing chamber is provided between the two recesses 9A and 9B. 19 is provided. Since the annular wall 5e on one side constituting the annular recess 9B has a shallow depth (hanging dimension), the fixed ring 23 is locked to one end in the recess 9B. The enclosure chamber 19 is joined to the casings 5 and 6 between the drive casing 5 and the pump casing 6, and openings 19 a are formed in the upper and lower sides, and the openings 19 a are formed in screw holes. The nipple 20 provided with a male screw portion 20a on the tip end side is screwed so as to be openable and closed. On both surfaces of the sealing members 17 and 18, annular grooves 17a and 18a are formed near the outer periphery, and O-rings 21 are loaded in the annular grooves 17a and 18a, respectively.

  Further, of the seal members 17 and 18, the annular recess into which the lip packing 14 can be fitted and the same outer diameter as the maximum outer diameter of the packing 14 are almost the same in the central opening 17 b of one seal member 17. An annular recess to which a backup spacer 22 made of a circular ring with a width can be fitted is formed in this order as one continuous recess 17d from one end (left side in the figure). In the central opening 18b of the other seal member 18, an annular recess 18c into which the lip packing 14 can be fitted is formed at the end opposite to the seal member 17 (right side in the figure).

  As shown in FIG. 4A, the shaft seal device according to this example having the above-described configuration is the most separated in the annular recesses 9A and 9B across the center line s on the rotating shaft 3, as shown in FIG. Seal lines A and B are formed at the positions, and a lubricant is sealed in substantially the middle portion thereof to exert a sealing action together with the two lip packings 14 on both sides, so that the sealing action is very high. In addition, when the outer peripheral surface of the rotating shaft 3 is worn at the positions of the lip packings 14 on both sides, the drive-side casing 5 and the enclosure chamber 19 are separated in order from the pump casing 6, and the seal members 17, 18 are switched left and right. Then, by inserting a new lip packing 14 and reassembling as shown in FIG. 4B, the seal line is placed at the closest position in the annular recesses 9A and 9B across the center line s on the rotating shaft 3. CD, that is, the lip packing 14 comes into contact. As a result, the position of the lip packing 14 on the rotating shaft 3 is completely displaced, so that a high sealing action is obtained in combination with the sealing action by the lubricant in the intermediate portion, and the life of the rotating shaft 3 is also doubled. Extend.

  FIG. 5 is a cross-sectional view showing an embodiment of the shaft seal device having the simplest structure with one seal member. FIG. 5 (a) shows the initial assembly, and FIG. 5 (b) shows the reassembly. .

  As shown in FIG. 5, the shaft seal device 10-4 of this example has a seal member 24 inserted in an annular recess 9 formed in the vicinity of the joint between the pump casing 6 and the drive-side casing 5. An annular recess 24c into which the lip packing 14 having a substantially L-shaped cross section can be fitted inward is formed at one end (left side in the figure) of the central opening 24b of the seal member 24, and the other end (see FIG. Lip packing 14 having a substantially L-shaped cross section and a backup spacer 25 made of a thin annular body having the same diameter and the same diameter as the maximum outer diameter of the packing 14 are adjacent to each other. A recess 24d is formed. Further, on both surfaces of the seal member 24, annular grooves 24a are formed near the outer peripheral portion, and O-rings 26 are loaded in the respective annular grooves 24a.

  In the shaft seal device of the present example configured as described above, the shaft seal is performed with the lip packing 14 and the backup spacer 25 fitted in the annular recess 24d as shown in FIG. The shaft is sealed with the lip packing 14 fitted in the annular recess 24c with the sealing member 24 turned upside down as shown in FIG. The position of the lip packing 14, that is, the seal position only changes from A to B, and the deviation (dimension difference) is small compared to the above embodiments, but the position of the lip packing 14 on the rotating shaft 3 changes. If the lip packing 14 is replaced, the life of the rotating shaft 3 is doubled.

  Although the shaft sealing device of the present invention has been described above with reference to a plurality of embodiments, the present invention can be implemented as follows.

  That is, in each of the above embodiments, the case where the rotating device is a pump is taken as an example. However, the rotating device is not limited to the pump. This method can be applied to seal the gap. Further, the lip packing 14 in the embodiment has a substantially L-shaped cross section, but the cross-sectional shape is not limited.

It is an outline front view showing the example of the pump provided with the shaft seal device concerning the example of the present invention. FIG. 2A is an enlarged cross-sectional view showing a part (shaft seal portion) of FIG. 1, FIG. 2A shows an initial assembly time, and FIG. 2B shows a reassembly time. FIG. 3A is a sectional view showing another embodiment of the shaft seal device of the present invention, FIG. 3A shows an initial assembly time, FIG. 3B shows a reassembly time, and FIG. 3C shows a re-assembly time. It represents. FIGS. 4A and 4B are cross-sectional views showing a shaft seal device according to another embodiment in which the shaft seal effect is improved. FIG. 4A shows an initial assembly time, and FIG. 4B shows a reassembly time. FIG. 5A is a cross-sectional view showing an embodiment of a shaft seal device having the simplest structure with one seal member according to the present invention. FIG. 5A shows an initial assembly, and FIG. 5B shows a reassembly. Represent each. It is sectional drawing which shows the conventional typical shaft-seal apparatus in rotary equipment. It is sectional drawing which shows the conventional common shaft seal apparatus in a uniaxial eccentric screw pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pump 2 Electric motor 3 Rotating shaft 5 Drive side casing 6 Pump casing (driven side casing)
7 suction port 8 discharge port 9, 9A, 9B annular recess 10-1 to 10-4 shaft seal device 11, 12, 17, 18, 24 seal member 11a, 12a annular groove 11b, 12b central opening 11c, 12c annular recess 13.21 O-ring 14 Lip packing 15.25 Backup spacer (seal member)
19 Lubricant enclosure 20 Nipple 23 Fixed ring

Claims (2)

A shaft seal device for a rotary device disposed around a rotary shaft that is rotated by the drive device at a joint between a drive-side casing and a driven-side casing such as a pump casing in a rotary device such as a pump rotated by the drive device. In at least two annular seal members mounted adjacent to each other on the outer peripheral surface of the rotating shaft, an annular recess capable of fitting a lip packing around the central opening of one seal member is formed, A shaft seal device for a rotary device, wherein a lip packing is fitted into the annular recess. The shaft seal device for a rotary device according to claim 1, wherein the number of the annular seal members is three, one of which is provided with the annular recess, and the other two seal members are seal members having different thicknesses.

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