JP6941337B2 - Bearing member wear detector and rotating equipment - Google Patents

Description

The present invention relates to a bearing member wear detecting apparatus and rotating equipment.

Generally, a magnet coupling pump employs a bearing structure using a sleeve bearing. In this bearing structure, the wear state of the sleeve bearing is unknown unless it is disassembled. Further, even if the sleeve bearing is worn, it functions as a pump, so that it is difficult to notice abnormal wear. For this reason, depending on the wear state of the sleeve bearing, the amount of runout of the rotating parts supported by the sleeve bearing may increase, and a hole may be formed in contact with a partition wall such as a partition can. If a hole is made in the partition wall and the transfer liquid (chemical liquid) leaks out, it will corrode peripheral parts and cause great damage to the pump and the entire equipment. Therefore, it is desirable to detect the wear state of the sleeve bearing in advance. It was rare.

Patent Document 1 discloses a configuration in which a pressure detector detects a change in internal pressure due to a break in the seal inside the wear detection tube.
In Patent Document 2, an ultrasonic wave output from an ultrasonic sensor is reflected at the shaft end of a rotor shaft, and the reflected echo is detected to detect the distance to the shaft end of the rotor shaft. It is disclosed.
In Patent Document 3, the disconnection detector detects that the underwater bearing is worn and the rotating shaft comes into contact with the conducting wire to break the conducting wire, and it is determined that the amount of wear of the underwater bearing has reached a predetermined value. The configuration is disclosed.

Japanese Unexamined Patent Publication No. 2003-98043 Japanese Unexamined Patent Publication No. 5-44688 Japanese Unexamined Patent Publication No. 2008-75625

However, the configuration described in Patent Document 1 can be detected by breaking the seal, and cannot be used for a transfer liquid that is not desired to leak to the surroundings.
Further, in the configuration described in Patent Document 2, the distance to the shaft end of the rotor shaft is detected, and the inclination of the rotor shaft is not detected.
Further, in the configuration described in Patent Document 3, since it is premised that the conducting wire is cut by the inclination of the rotating shaft, there is a possibility that the inclination of the rotating shaft cannot be reliably detected.

The present invention, the state of wear of the bearing member for rotatably supporting the shaft member, before it becomes a serious condition, a simple and bearing member wear detecting device and a rotating equipment that can be reliably detected with an inexpensive configuration The challenge is to provide.

The present invention provides means for solving the above problems.
A swing force applying means for applying a force to a rotating shaft member rotatably supported by the bearing member in a direction orthogonal to the axis of the shaft member.
A runout amount detecting means for detecting a runout amount of the shaft member by applying a force by the runout force applying means, and a runout amount detecting means.
Provided is a bearing member wear detection device characterized by the above.

With this configuration, if the bearing member is worn, a force is forcibly applied to the shaft member by the runout force applying means, and the bearing member can be reliably swung. Therefore, it is possible to reliably detect the wear state, which was difficult in the past, even at the initial stage.

It is preferable to further include a wear state determining means for determining the wear state of the bearing member based on the detection signal of the runout detecting means.

With this configuration, the wear state of the bearing member can be automatically determined by the wear state determining means.

The shaft member includes a first magnet portion made of a magnetic material, and includes a first magnet portion.
The swing force applying means preferably includes a second magnet portion that attracts or repels the first magnet portion.

With this configuration, the shaft member can be swung in a non-contact manner by the first magnet portion and the second magnet portion.

The first magnet portion is composed of a plurality of permanent magnets in which a plurality of magnets are arranged in the circumferential direction so that the polarities on the outer peripheral side are alternately different.
The shake force applying means are arranged at positions symmetrical about the axis of the shaft member, the second magnet unit, that consists of a permanent magnet polarity of the opposing surfaces of said permanent magnets is different Is preferable.

It is preferable that the second magnet portion and the runout amount detecting means are arranged in the same plane orthogonal to the axis of the shaft member.

With this configuration, the amount of runout can be detected at a position where the shaft member is attracted or repelled by the magnet, so that the detection accuracy can be improved.

When the circumferential average value of the radial thickness in the initial state of the bearing member is d0 and the circumferential average value of the radial thickness estimated after the wear of the bearing member is d1, the wear state determination is performed. The means sets the period until the replacement time in a stepwise manner until the amount of runout of the shaft member detected by the runout amount detecting means reaches 2 × (d0-d1) with the threshold value as a reference (d0-d1). It is preferable to estimate that it is 2 × (d0−d1) or more to determine that it is time to replace the bearing member.

The bearing may be a sleeve bearing.

The present invention provides means for solving the above problems.
With any of the above bearing member wear detection devices,
A casing that houses the shaft member and the bearing member,
With
The casing provides a rotating device characterized by having a port to which the swing force applying means can be mounted.

It is preferable that the casing further has a port to which the runout amount detecting means can be mounted.

Further provided with an inner ring that is integrally attached to the outer circumference of the shaft member,
The bearing member includes a first bearing portion that rotatably supports the shaft member and a second bearing portion that rotatably supports the inner ring.
It is preferable that the runout amount detecting means is provided so as to be able to detect the runout amount of the shaft member in the first bearing portion or the runout amount of the inner ring in the second bearing portion.

An outer ring arranged between the casing and the inner ring,
A partition wall that separates the inner ring and the outer ring,
It is preferable to further provide.

The partition wall is preferably made of a non-magnetic material.

The inner ring has a plurality of magnets having different polarities on the inner peripheral side and the outer peripheral side and alternately having different polarities on the outer peripheral side in the circumferential direction.
The outer ring preferably has a plurality of magnets having different polarities on the inner peripheral side and the outer peripheral side and alternately having different polarities on the inner peripheral side in the circumferential direction.

The rotating device is preferably a uniaxial eccentric screw pump.

According to the present invention, since the force is forcibly applied to the shaft member by the swinging force applying means, the shaft member can be reliably swung if the bearing member is worn. Therefore, it is possible to accurately detect the wear state of the bearing member even at the initial stage.

It is a perspective view of the uniaxial eccentric screw pump which concerns on this embodiment. It is a vertical sectional view of FIG. It is a partially enlarged view of FIG. FIG. 3 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a cross-sectional view taken along the line BB of FIG.

Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings. In the following description, terms indicating a specific direction or position (for example, terms including "top", "bottom", "side", and "edge") are used as necessary, but the use of these terms is used. Is for facilitating the understanding of the invention with reference to the drawings, and the meaning of those terms does not limit the technical scope of the present invention. In addition, the following description is merely an example and is not intended to limit the present invention, its application, or its use. Furthermore, the drawings are schematic, and the ratio of each dimension is different from the actual one.

FIG. 1 shows a uniaxial eccentric screw pump 1 which is an example of a rotating device according to the present embodiment. The uniaxial eccentric screw pump 1 includes a pump portion 3 provided on one end side of the casing 2 and a pump device 4 provided on the other end side.

The casing 2 includes a pump casing 5 on the pump portion 3 side and a coupling casing 6 on the pump device 4 side. The pump casing 5 and the coupling casing 6 are connected via a flange member 7.

As shown in FIG. 2, the joint portion 8 is housed in the pump casing 5. The joint portion 8 rotatably connects the rotor 25 on the pump portion 3 side and the drive shaft 9 in the coupling casing 6. Further, a supply pipe 5a, which is an inflow port of a fluid supplied from a tank (not shown), is connected to the pump casing 5.

As shown in FIG. 3, a drive shaft 9 which is a shaft member is arranged in the coupling casing 6. The drive shaft 9 is made of metal such as stainless steel and is rotatably supported by a first sleeve bearing 10 which is a bearing member. A joint portion 8 in the pump casing 5 is connected to one end portion of the drive shaft 9. An inner ring 14 is integrated on the outer periphery of the other end side of the drive shaft 9.

The first sleeve bearing 10 is made of resin and is attached to the inner peripheral side of the flange member 7 via a tubular portion 12. The tubular portion 12 is composed of a small diameter portion 12a whose one end side (the side opposite to the joint portion 8) has a smaller outer diameter than the other end side. A second sleeve bearing 13 is attached to the small diameter portion 12a.

The second sleeve bearing 13 is also made of resin and is attached to the inner peripheral surface on the tip side of the inner ring 14. However, a gap is formed between the inner peripheral surface of the second sleeve bearing 13 and the outer peripheral surface of the small diameter portion 12a. When the first sleeve bearing 10 is worn by a dimension corresponding to this gap, the outer peripheral surface of the small diameter portion 12a comes into contact with the inner peripheral surface of the second sleeve bearing 13. That is, the support of the inner ring 14 by the second sleeve bearing 13 can be added to the support of the drive shaft 9 by the first sleeve bearing 10.

The inner ring 14 is made of a metal material (for example, titanium), and a driven magnet 15 is provided on the outer peripheral portion thereof. As shown in FIG. 4, in the driven magnet 15, a plurality of permanent magnets (here, eight) having different polarities on the inner peripheral side and the outer peripheral side of the inner ring 14 are arranged in the circumferential direction. Adjacent permanent magnets have different polarities on the outer peripheral side. The outer peripheral surfaces of the permanent magnets arranged at point-symmetrical positions centered on the axis of the inner ring 14 have the same polarity.

As shown in FIG. 3, a partition can 16 is attached as a partition wall to one end surface of the flange member 7 (the outer peripheral surface on one end side of the second tubular portion 12). The partition can 16 covers the drive shaft 9 and the inner ring 14, and separates the drive shaft 9 and the inner ring 14 from the pump device 4 side while forming a slight gap from the outer peripheral surface of the inner ring 14. An outer ring 17 is arranged on the outer peripheral side of the partition can 16.

The outer ring 17 has a cylindrical shape, and a drive magnet 18 is provided on the inner peripheral surface in the vicinity of the outer peripheral surface of the partition can 16 so as to face the driven magnet 15. As shown in FIG. 4, in the drive magnet 18, similarly to the driven magnet 15, a plurality of (here, eight) permanent magnets having different polarities on the inner peripheral side and the outer peripheral side are arranged on the outer peripheral side (here, eight) in the circumferential direction. And the inner circumference side) are arranged alternately with different polarities. One end side of the outer ring 17 has a smaller inner diameter and is integrated with the outer peripheral surface of the output shaft 30 of the pump device 4.

As shown in FIG. 5, the coupling casing 6 is formed with ports communicating inside and outside, that is, a sensor mounting hole 19 and a magnet mounting hole 20, respectively. The sensor mounting hole 19 and the magnet mounting hole 20 are formed so that their centers are located in the same plane orthogonal to the axial center of the coupling casing 6 (however, they may be deviated in the axial direction). It is preferably located in the same plane.) Further, here, the sensor mounting hole 19 is formed at a vertically upward position, and the magnet mounting hole 20 is formed at a position inclined by 45 ° with respect to the vertical direction. An overcurrent type gap sensor 21 can be attached to the sensor mounting hole 19 as a means for detecting the amount of runout, and a runout force applying magnet 22 (here, a neodymium magnet is used here) as a means for applying the runout force to the magnet mounting hole 20. ) Can be installed. Since the sensor mounting hole 19 and the magnet mounting hole 20 are used when detecting wear of the first sleeve bearing 10 and the second sleeve bearing 13, they are usually closed by a plug body (not shown).

Although not shown, the gap sensor 21 is configured to pass a high-frequency current through a coil inside the sensor head to generate a high-frequency magnetic field from the sensor head. Then, an eddy current is generated in the drive shaft 9 (inner ring 14) located in the high-frequency magnetic field generated from the sensor head, and the impedance of the coil changes. A control device 23, which is a wear state determining means, is connected to the gap sensor 21.

The control device 23 takes out as a voltage change of the built-in resonance circuit based on the impedance change of the coil of the gap sensor 21, and a memory high coder is actually used. As a result, the amount of runout indicating how much the rotating drive shaft 9 (inner ring 14) is swinging from the normal rotation position to the inner and outer circumferences is obtained. The control device 23 stores in advance a data table indicating how much the amount of runout should be before it is time to replace the first sleeve bearing 10. This amount of runout is a value at which the amount of wear may increase and the inner ring 14 may come into contact with the partition can 16. Here, the circumferential average value of the radial thickness of the first sleeve bearing 10 in the initial state is d0, and the radial direction when the first sleeve bearing 10 is worn until the inner ring 14 comes into contact with the partition can 16. When the circumferential average value of the thickness is d1, 2 × (d0-d1) is stored as a threshold value indicating the replacement time. Then, when the amount of runout from the initial value of the drive shaft 9 detected by the gap sensor 21 becomes 2 × (d0−d1) or more, it is possible to notify that it is time to replace the drive shaft 9. However, for example, it is preferable to set the threshold value in a plurality of stages so that notification such as "○○ days until the replacement time" can be notified. Actually, the process is executed based on the voltage value obtained from the impedance, instead of calculating the amount of runout.

The runout force applying magnet 22 has a rod shape and has different polarities between the insertion back side and the insertion front side, and is arranged in each magnet mounting hole 20 so that the insertion side end faces have opposite polarities between the runout force applying magnets 22. As a result, the polarities of the permanent magnets of the drive magnets 18 facing each other via the partition can 16 are the same on the insertion side end faces of the respective runout force applying magnets 22, and the repulsive force acts on one of them, and the other is different. Then the suction force acts.

As shown in FIG. 2, the pump unit 3 has a rotor 25 arranged in a stator 24, and an end stud 26 is arranged on one end side. The stator 24 is composed of an outer cylinder 27 and a stator main body 28 arranged in close contact with the inner surface thereof. The inner peripheral surface of the central hole of the stator 24 is n-row and has a single-stage or multi-stage female screw shape. The rotor 25 has a shaft body made of a metal material having a single-stage or multi-stage male screw shape with n-1 threads. The rotor 25 is arranged in the central hole of the stator 24 and forms a transfer space 29 connected in the longitudinal direction thereof.

Although not shown in detail, the pump device 4 rotates the output shaft 30 by driving a motor or the like.

Next, the operation of the uniaxial eccentric screw pump 1 having the above configuration will be described.

When the output shaft 30 is rotated by driving the pump device 4, the outer ring 17 integrated with the output shaft 30 also rotates. The driven magnet 15 of the inner ring 14 faces the drive magnet 18 provided on the inner peripheral surface side of the outer ring 17 via the partition can 16. As a result, the inner ring 14 rotates with the rotation of the outer ring 17, and the drive shaft 9 integrated with the inner ring 14 also rotates. As a result, the rotor 25 connected to the drive shaft 9 rotates to move the transfer space 29 in the stator 24, so that the fluid is conveyed.

Although the fluid is conveyed in this way, the first sleeve bearing 10 gradually wears due to the rotation of the drive shaft 9. When the first sleeve bearing 10 is worn to some extent, the small diameter portion 12a of the tubular portion 12 provided on the outer peripheral surface of the sleeve bearing 10 is rotatably supported by the second sleeve bearing 13 provided on the inner ring 14. That is, from the first stage in which the drive shaft 9 is supported only by the first sleeve bearing 10, the second sleeve bearing 13 further supports the small diameter portion 12a of the tubular portion 12 provided on the outer peripheral surface of the sleeve bearing 10. It will be a stage. Therefore, by shifting from the first stage to the second stage in which the amount of runout of the drive shaft 9 and the inner ring 14 due to wear gradually increases, the pace of increase in the amount of runout can be suppressed once. However, even if the first sleeve bearing 10 and the second sleeve bearing 13 are worn, the drive shaft 9 and the inner ring 14 rotate in a non-contact state using magnetic force, so that they are in a specific position (not necessarily the center). It may rotate without swinging so much.

Therefore, the wear state of the first sleeve bearing 10 and the second sleeve bearing 13 is periodically inspected. That is, the gap sensor 21 is attached to the sensor mounting hole 19 formed in the coupling casing 6, and the runout force applying magnet 22 is attached via the magnet mounting hole 20. Then, the pump device 4 is driven to rotate the drive shaft 9 at a constant speed.

A magnetic force in a direction orthogonal to the axial direction is applied to the drive shaft 9 and the inner ring 14 by the two vibration force applying magnets 22. Further, as the inner ring 14 rotates, the driven magnet 15 provided on the outer peripheral portion thereof sequentially confronts the swinging force applying magnet 22 with different polarities. As a result, when the drive shaft 9 and the inner ring 14 rotate, a force that reciprocates in the direction of action of the magnetic force (direction orthogonal to the axis) acts due to the magnetic force of the swing force applying magnet 22. Therefore, if the first sleeve bearing 10 and the second sleeve bearing 13 are worn, the drive shaft 9 and the inner ring 14 are forced to swing and rotate in the radial direction.

In FIG. 5, the two-dot chain line shows the maximum gap between the partition can 16 and the inner ring 14 at the position detected by the gap sensor 21 due to the magnetic force of the runout force applying magnet 22, and conversely, the outer peripheral surface of the inner ring 14 is on the opposite side. Indicates a state in which is in contact with the partition can 16.

The amount of runout of the drive shaft 9 and the inner ring 14 in the direction orthogonal to the axial direction is detected by the gap sensor 21 as a change in the impedance of the coil built in. The detected impedance is input to the control device 23.

The control device 23 calculates the amount of runout based on the input impedance. The amount of runout thus obtained changes according to the rotation of the drive shaft 9 and the inner ring 14. When the drive shaft 9 and the inner ring 14 rotate, the amount of runout changes at regular intervals. When the first sleeve bearing 10 and the second sleeve bearing 13 are worn, the peak value becomes large. Therefore, it is determined whether or not the peak value exceeds the threshold value stored in advance as described above. If the peak value exceeds the threshold value, the amount of wear of the first sleeve bearing 10 and the second sleeve bearing 13 becomes large, and it is presumed that the replacement time has come, and a notification to that effect is given. When a plurality of threshold values are set, it is possible to determine various wear states such as which stage is the first stage, the second stage, the replacement time, or the like.

Since the runout force applying magnet 22 is provided in this way, the drive shaft 9 and the inner ring 14 rotate at the specific positions even though the first sleeve bearing 10 and the second sleeve bearing 13 are worn. I can't keep doing it. Therefore, the amount of runout of the inner ring 14 can be accurately detected. In particular, since the inner ring 14 provided with the driven magnet 15 is forced to swing by the runout force applying magnet 22, the runout amount of the inner ring 14 can be accurately detected.

Further, since the runout force applying magnet 22 and the gap sensor 21 are arranged on the same plane orthogonal to the axial direction, the runout force applying magnet 22 exerts a magnetic force on the drive shaft 9 and the inner ring 14. The amount of runout can be detected at the same position. Therefore, the amount of runout can be detected more accurately than those not arranged in that way.

The present invention is not limited to the configuration described in the above embodiment, and various modifications can be made.

In the above embodiment, the partition can 16 which is a partition wall is arranged between the drive side and the driven side, and the drive side and the driven side are completely separated. However, the drive side and the driven side are directly connected to each other. Even in the power transmission mechanism, the above-mentioned configuration for detecting the wear of the bearing member can be adopted.

In the above embodiment, the drive shaft 9 is attracted or repelled by a permanent magnet, but other means such as an electromagnet may be adopted.

In the above embodiment, the runout amount of the inner ring 14 is detected by the gap sensor 21, but the runout amount of the drive shaft 9 may be detected. In this case, the gap sensor 21 may be configured to detect the runout of the drive shaft 9 instead of the inner ring 14.

In the above embodiment, eight permanent magnets are provided on the inner ring 14, but the number thereof may be appropriately changed as necessary (for example, the difference in the inner diameter dimension of the inner ring 14). Further, when the polarities on the outer peripheral side of the permanent magnets are different at the point-symmetrical positions centered on the axial center of the inner ring 14, the polarities on the insertion back end surface of the runout force applying magnet 22 to be mounted may be the same. ..

In the above embodiment, the control device 23 automatically determines the replacement time of the first sleeve bearing 10, but a person may actually see and determine the replacement time. Specifically, the replacement time may be determined by a person viewing the detected value, the detected waveform, etc. of the gap sensor 21 on a monitor or the like.

1 ... Uniaxial eccentric screw pump 2 ... Casing 3 ... Pump part 4 ... Pump device 5 ... Pump casing 6 ... Coupling casing 7 ... Flange member 8 ... Joint part 9 ... Drive shaft (shaft member)
10 ... 1st sleeve bearing (bearing member)
12 ... Cylinder 13 ... Second sleeve bearing (bearing member)
14 ... Inner ring (shaft member)
15 ... Driven magnet 16 ... Partition can 17 ... Outer ring 18 ... Drive magnet 19 ... Sensor mounting hole 20 ... Magnet mounting hole 21 ... Gap sensor (runout detection means)
22 ... Magnet for imparting runout force (means for imparting runout force)
23 ... Control device (wear state determination means)
24 ... Stator 25 ... Rotor 26 ... End stud 27 ... Outer cylinder 28 ... Stator body 29 ... Transfer space 30 ... Output shaft

Claims (12)

A swing force applying means for applying a force to a rotating shaft member rotatably supported by the bearing member in a direction orthogonal to the axis of the shaft member.
A runout amount detecting means for detecting a runout amount of the shaft member by applying a force by the runout force applying means, and a runout amount detecting means.
With
The shaft member includes a first magnet portion made of a magnetic material, and has a first magnet portion.
The swinging force applying means includes a second magnet portion that attracts or repels the first magnet portion, and is arranged at symmetrical positions about the axial center of the shaft member.
The first magnet portion is composed of a plurality of permanent magnets in which a plurality of magnets are arranged in the circumferential direction so that the polarities on the outer peripheral side are alternately different.
The second magnet portion is a bearing member wear detection device characterized in that the second magnet portion is composed of a permanent magnet having a different polarity of a surface facing the permanent magnet. The bearing member wear detecting device according to claim 1, further comprising a wear state determining means for determining a wear state of the bearing member based on a detection signal by the runout amount detecting means. The bearing member wear detecting device according to claim 1 or 2, wherein the second magnet portion and the runout amount detecting means are arranged on the same plane orthogonal to the axis of the shaft member. When the circumferential average value of the radial thickness in the initial state of the bearing member is d0 and the circumferential average value of the radial thickness estimated after the wear of the bearing member is d1, the wear state determination is performed. The means sets the period until the replacement time in a stepwise manner until the amount of runout of the shaft member detected by the runout amount detecting means reaches 2 × (d0-d1) with the threshold value as a reference (d0-d1). The bearing member wear detection device according to claim 2, wherein it is determined that it is time to replace the bearing member when it is estimated to be 2 × (d0-d1) or more. The bearing member wear detection device according to any one of claims 1 to 4, wherein the bearing member is a sleeve bearing. The bearing member wear detection device according to any one of claims 1 to 5.
A casing that houses the shaft member and the bearing member,
With
The casing is a rotating device having a port to which the swinging force applying means can be attached. The rotating device according to claim 6, wherein the casing further has a port to which the runout amount detecting means can be mounted. Further provided with an inner ring that is integrally attached to the outer circumference of the shaft member,
The bearing member includes a first bearing portion that rotatably supports the shaft member and a second bearing portion that rotatably supports the inner ring.
The claim is characterized in that the runout amount detecting means is provided so as to be able to detect the runout amount of the shaft member in the first bearing portion or the runout amount of the inner ring in the second bearing portion. The rotating device according to 6. An outer ring arranged between the casing and the inner ring,
A partition wall that separates the inner ring and the outer ring,
The rotating device according to claim 8, further comprising. The rotating device according to claim 9, wherein the partition wall is made of a non-magnetic material. The inner ring has a plurality of magnets having different polarities on the inner peripheral side and the outer peripheral side and alternately having different polarities on the outer peripheral side in the circumferential direction.
The rotation according to claim 9 or 10, wherein the outer ring has a plurality of magnets having different polarities on the inner peripheral side and the outer peripheral side and alternately having different polarities on the inner peripheral side in the circumferential direction. device. The rotating device according to any one of claims 6 to 11, wherein the rotary device is a uniaxial eccentric screw pump.

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