CN201563020U - Motor stator and rotor anti-static discharge device - Google Patents

Abstract

The utility model discloses an anti-static discharge device for a stator and a rotor of a motor, which comprises a bearing boring mill, a discharge bearing installed on a motor main shaft, and a discharge device mounting end cover installed on a motor cabinet, wherein the discharge device mounting end cover is provided with an annular containing slot and a mounting hole communicated with the annular containing slot; the annular containing slot and the discharge bearing are arranged coaxially; the mounting hole is radially arranged along the annular containing slot, and internally provided with a guide rod and a conducting spring; the bearing boring mill is arranged in the annular containing slot, the inner side of the bearing boring mill is contacted with the discharge bearing, and the outer side thereof is connected with the guide rod; the guide rod is externally sheathed with a sleeve which is in threaded connection with the discharge device mounting end cover; and a conducting spring is arranged in the mounting hole, and supports between the bearing boring mill and the sleeve. The anti-static discharge device for the stator and the rotor of the motor has the advantage of simple and compact structure, durability and high reliability.

Description

Motor stator and rotor anti-static discharge device

technical field

The utility model relates to the field of motors, in particular to a device capable of preventing electrostatic discharge of a stator and rotor of a motor.

Background technique

The motor is a kind of equipment widely used in industrial and agricultural production at present; during the working process of the motor, charge accumulation will occur on the surface of the motor stator and rotor. When the charge accumulates to a certain extent, static electricity will occur between the motor stator and rotor. discharge phenomenon. The parts where electrostatic discharge usually occurs are motor bearings and motor encoders.

At present, steel bearings, liquid bearings (including hydrostatic bearings, dynamic pressure bearings and dynamic and static pressure bearings) and gas bearings are widely used in motor bearings. Although the lubricating oil film on the bearing surface has an insulating effect, under high-voltage electrostatic discharge conditions, the lubricating oil film Or the smallest part of the lubricating air film gap is easily broken down, forming a discharge circuit, resulting in electrical corrosion on the surface of the motor bearing and damage. When the end of the motor is equipped with devices such as encoders, the motor bearings are supported by ceramic bearings, liquid bearings and gas bearings. Due to the insulating effect of the ceramic ball and the fluid, electrostatic discharge is not easy to occur at the bearing part, but will be transferred between the encoder gear fixed on the motor rotor and the encoder seat fixed on the motor box, resulting in damage to the encoder . In recent years, the application of AC frequency conversion speed regulation technology in the field of motors has become very common. High-order electromagnetic harmonics caused by frequency conversion technology greatly increase the probability of induced static electricity on the stator and rotor of the motor. According to statistics, at present, bearing failures caused by electrostatic discharge have accounted for more than 10% of all bearing failures, and are growing continuously; while encoder failures caused by electrostatic discharge account for a higher probability of all encoder failures.

In order to avoid electrostatic discharge of the stator and rotor of the motor on bearings, encoders and other parts, the common solution is to ground the rotor of the motor, and use a conductive lubricant for the bearings. However, conductive lubricants often wear the bearing due to the metal particles contained in it, resulting in shortened bearing life. Another traditional way to avoid electrostatic discharge is to ground the rotating shaft through carbon brushes. However, carbon brushes are prone to pollution and the surrounding environment needs to be cleaned during replacement, which makes it very inconvenient to replace carbon brushes. Now a method of eliminating the induced voltage by shielding the stator winding of the motor is proposed to reduce the electrostatic discharge, but because of the high cost of this method, it is difficult to realize in engineering.

The utility model patent with the patent number ZL200310110580.3 discloses a device that can prevent electrostatic discharge of the stator and rotor of the motor. The device uses metal balls in direct contact with the main shaft. The main defects are: 1. The friction force at other contact points of the ball is greater than The friction at the contact point between the ball and the main shaft prevents the ball from rotating flexibly, which intensifies the friction between the main shaft and the ball, makes the noise louder and is easy to wear, requires frequent replacement of the ball or the main shaft, high maintenance costs, and inconvenient disassembly and assembly during replacement, which is time-consuming and laborious 2. Especially when the tilting pad bearing is used to support the main shaft, the radial runout of the main shaft is much larger than when the fixed pad bearing is used to support the main shaft, which will inevitably cause the contact between the main shaft and the balls to be unreliable.

The utility model patent with the patent number ZL200420034823.8 discloses a bearing strut type device that can prevent electrostatic discharge of the stator and rotor of the motor. Cut contact, resulting in a large radial dimension of the motor, which makes the overall structure of the motor not compact enough and takes up a lot of space; 2. When the motor rotates at high speed, the discharge bearing rotates at a higher speed, which causes the vibration frequency of the spring to be very fast. At the same time, the discharge bearing and the encoder are positioned The contact of the sleeve is tangential line contact, so the high-frequency vibration will easily cause the unreliable contact between the discharge bearing and the positioning sleeve of the encoder, and the reliability of the discharge device will decrease; 3. As a wearing part, the discharge bearing needs to be replaced frequently, and the discharge device It is installed inside the rear support seat of the motor, which not only makes the structure of the motor not compact, but also makes the installation, disassembly and replacement of the discharge bearing very inconvenient.

Utility model content

The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a motor stator and rotor anti-static discharge device with simple and compact structure, durable, high reliability and easy disassembly.

In order to solve the above technical problems, the utility model adopts the following technical solutions:

An anti-static discharge device for a stator and rotor of a motor, comprising a bearing pad, a discharge bearing installed on the motor shaft, and a discharge device installation end cover installed on the motor box, the discharge device installation end cover is provided with an annular The mounting hole and the mounting hole communicated with the annular mounting groove, the circular mounting groove and the discharge bearing are arranged coaxially, the mounting hole is arranged radially along the circular mounting groove, and the mounting hole is provided with a guide rod and a conductive Spring, the bearing pad seat is placed in the annular accommodation groove, the inner side of the bearing pad seat is in contact with the discharge bearing, and the outer side is connected with the guide rod. The guide rod is covered with a sleeve, and the sleeve is installed with the discharge device. Threaded connection, the conductive spring is arranged in the installation hole, and supported between the bearing pad seat and the sleeve.

The contact between the inner side of the bearing pad and the discharge bearing is surface contact.

There are more than two bearing tile seats, and they are arranged equidistantly along the circumference of the discharge bearing. The number of mounting holes on the installation end cover of the discharge device is equal to the number of bearing tile seats. The set guide rod is connected with the conductive spring.

The discharge bearing is installed on the encoder connecting shaft at the end of the main shaft of the motor, and the outer diameter D of the discharge bearing is smaller than the inner diameter d of the main shaft bearing.

Compared with the prior art, the utility model has the advantages of: the discharge bearing is directly installed on the motor shaft, which simplifies the structure of the discharge device, makes the installation of the discharge device more convenient, and reduces the occupation in the radial direction Space makes the motor structure simpler and more compact, easy to disassemble and replace, and at the same time avoids the direct contact of the balls with the main shaft, which improves the service life of the main shaft and the discharge device; When rotating, the bearing shoe and the discharge bearing can still easily maintain contact under the action of the spring, so that the discharge device is always in a stable discharge state, and the reliability of the discharge device is improved. There are more than two bearing pads, and they are arranged equidistantly along the circumference of the discharge bearing. When the radial runout of the motor shaft in a certain direction is large, even if the bearing pad in a certain direction is temporarily separated from the discharge bearing, However, the bearing pads in other directions must form closer contact with the discharge bearing, so as to ensure the reliability of the discharge device and completely eliminate electrostatic discharge. The discharge bearing is installed on the encoder connecting shaft at the end of the motor shaft. The angular velocity of the discharge bearing is equal to that of the motor shaft, but the outer diameter D of the discharge bearing is smaller than the inner diameter d of the main shaft bearing. Therefore, the linear velocity of the surface of the discharge bearing is smaller than that of the motor shaft. The utility model is suitable for discharging under the condition that the main shaft of the motor rotates at high speed (the rotating speed reaches more than 10000 RPM). The utility model not only can directly replace the original motor end cover with the discharge device installation end cover to realize the function of avoiding the electrostatic discharge of the motor stator and rotor, but also can directly process the annular positioning groove and the installation hole on the original motor end cover, which is very convenient to realize.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is the A direction view of Fig. 1;

Fig. 3 is a structural schematic diagram of installing the utility model on a motor whose main shaft is supported by a tilting pad bearing.

Each label in the figure means:

1. Motor shaft 2. Lock nut

3. Discharge bearing 4. Bearing pad seat

5. Guide rod 6. Conductive spring

7. Sleeve 8. Discharge device installation end cover

9. Motor box 10. Tilting pad bearing

11. Motor stator 12. Motor rotor

13. Encoder 14. Encoder connecting shaft

81. Annular accommodation groove 82. Mounting hole

Detailed ways

As shown in Fig. 1, Fig. 2 and Fig. 3, the motor stator and rotor anti-static discharge device of the present invention includes a bearing pad 4, a discharge bearing 3 and a discharge device installation end cover 8, and the discharge bearing 3 is set on the motor main shaft 1 , and the axial displacement is limited by a lock nut 2. When the discharge bearing 3 is worn out, the new discharge bearing 3 can be replaced only by removing the lock nut 2. In this embodiment, the discharge bearing 3 is installed on the encoder connecting shaft 14 with a smaller diameter at the tail of the motor main shaft 1. The angular velocity of the discharge bearing 3 is equal to that of the motor main shaft 1, but the outer diameter D of the discharge bearing 3 is smaller than the inner diameter d of the main shaft bearing. , so the surface linear velocity of the discharge bearing 3 is less than the surface linear velocity of the motor main shaft 1, so that the utility model is suitable for discharging under the condition of the high-speed rotation of the main shaft (the rotating speed reaches more than 10000 RPM). The discharge device installation end cover 8 is installed on the motor case 9 through fasteners. The discharge device mounting end cover 8 is provided with an annular accommodation groove 81 and an installation hole 82 communicating with the annular accommodation groove 81. The annular accommodation groove 81 is coaxially arranged with the discharge bearing 3, and the installation hole 82 is along the diameter of the annular accommodation groove 81. direction settings. The installation hole 82 is provided with a guide rod 5 and a conductive spring 6, and the bearing shoe seat 4 is placed in the annular accommodation groove 81. The inner side of the bearing shoe seat 4 is in contact with the discharge bearing 3, and the outer side is fixedly connected with the guide rod 5 through threads. In the example, the discharge bearing 3 is a rolling bearing, and the contact formed between the inner side of the bearing shoe seat 4 and the outer ring of the discharge bearing 3 is surface contact. The contact can still be easily maintained under the condition, so that the discharge device is always in a stable discharge state, and the reliability of the discharge device is improved. The guide rod 5 is provided with a sleeve 7, the sleeve 7 is threadedly connected with the discharge device installation end cover 8, the sleeve 7 and the guide rod 5 are clearance fit, and the guide rod 5 guides the movement of the bearing pad 4; the conductive spring 6 is set in the installation hole 82 and is supported between the bearing shoe seat 4 and the sleeve 7. On the one hand, the conductive spring 6 plays the role of conductive connection, and on the other hand, it buffers the radial runout of the motor spindle 1 through its damping effect. , keep the bearing pad 4 in contact with the discharge bearing 3 and the conductive spring 6 . Two or more bearing pads 4 can be provided, and they are equidistantly arranged along the circumference of the discharge bearing 3. The number of mounting holes 82 on the discharge device installation end cover 8 is equal to the number of bearing pads 4, and each bearing pad 4 is installed with the corresponding The guide rod 5 set in the hole 82 is connected with the conductive spring 6. In this embodiment, the bearing shoe seat 4 is provided with two pieces. The bearing pad 4 and the discharge bearing 3 form a short separation, but the bearing pad 4 in other directions must form a closer contact with the discharge bearing 3, thereby ensuring the reliability of the discharge device and completely eliminating electrostatic discharge. The utility model simplifies the structure of the discharge device by directly installing the discharge bearing 3 on the motor main shaft 1, makes the installation of the discharge device more convenient, reduces the occupied space in the radial direction, and makes the motor structure more compact. At the same time, the direct contact of the ball with the motor shaft 1 is avoided, thereby improving the service life of the motor shaft 1 and the discharge device. When renovating the existing motor, the end cover 8 of the discharge device can be used to directly replace the original motor end cover to realize the function of avoiding static discharge of the stator and rotor of the motor, or the annular accommodation groove 81 and the installation hole 82 can be directly processed on the original motor end cover , which is very convenient to implement.

The working principle of the utility model will be described in detail below in conjunction with the motor supporting the main shaft by the tilting pad bearing.

As shown in Figure 3, the motor rotor 12 is installed in the middle of the motor shaft 1, the motor stator 11 is installed in the middle of the motor box 9, the motor shaft 1 is supported inside the motor box 9 through the tilting pad bearing 10, and the encoder 13 is installed Located at the end of the motor main shaft 1, the discharge device installation end cover 8 of the utility model is installed on the end of the motor casing 9, the discharge bearing 3 is installed on the motor main shaft 1, and the discharge bearing 3 is located at the motor casing 9 and locked between nut 2. Since the motor rotor 12 is mounted on the motor shaft 1, the motor stator 11 is mounted on the motor case 9, and the motor case 9 is usually grounded, so as long as the motor shaft 1 and the motor case 9 are kept in electrical conduction, electrostatic discharge can be prevented , while the motor main shaft 1 is supported by a tilting pad bearing 10 , the fluid in the tilting pad bearing 10 has an insulating effect, so that the motor main shaft 1 cannot be directly connected to the motor casing 9 . After the motor stator and rotor anti-static discharge device of the present utility model is installed, the motor main shaft 1 is communicated with the motor casing 9 through the discharge bearing 3, the bearing pad seat 4, the conductive spring 6, the sleeve 7 and the discharge device installation end cover 8 in sequence. A discharge circuit, therefore, the static electricity on the motor stator 11 and the motor rotor 12 can be directly discharged through the grounding conductor, thereby avoiding the high-voltage electrostatic discharge phenomenon between the motor stator 11 and the motor rotor 12, and playing a role in electronic components such as the encoder 13 Protective effects.

The foregoing embodiments are only preferred implementations of the present utility model, and it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present utility model, some equivalent transformations can also be made, and these equivalent transformations should be It is regarded as the protection scope of the present utility model.

Claims (5)

1. antistatic discharge device for stator and rotor of electric machine, it is characterized in that comprising bearing liner seat (4), the electric discharge device that is installed in the discharge bearing (3) on the electric machine main shaft (1) and is installed on the motor case body (9) is installed end cap (8), described electric discharge device is installed the installing hole (82) that end cap (8) is provided with annular storage tank (81) and communicates with annular storage tank (81), described annular storage tank (81) and the coaxial setting of discharge bearing (3), described installing hole (82) radially is provided with along annular storage tank (81), be provided with guide post (5) and power spring (6) in the described installing hole (82), described bearing liner seat (4) places in the annular storage tank (81), bearing liner seat (4) is inboard to be contacted with discharge bearing (3), the outside is connected with guide post (5), the outer sleeve (7) that is arranged with of described guide post (5), described sleeve (7) is installed end cap (8) with electric discharge device and is threaded, described power spring (6) is located in the installing hole (82), and is supported between bearing liner seat (4) and the sleeve (7).

2. antistatic discharge device for stator and rotor of electric machine according to claim 1 is characterized in that: described bearing liner seat (4) is inboard to be the face contact with contacting of discharge bearing (3).

3. antistatic discharge device for stator and rotor of electric machine according to claim 1 and 2, it is characterized in that: described bearing liner seat (4) is provided with more than two, and along the circumferential equidistant placement of discharge bearing (3), installing hole (82) quantity that described electric discharge device is installed on the end cap (8) equates that with bearing liner seat (4) quantity each bearing liner seat (4) joins with interior set guide post (5) of corresponding installing hole (82) and power spring (6).

4. antistatic discharge device for stator and rotor of electric machine according to claim 1 and 2, it is characterized in that: described discharge bearing (3) is installed on the encoder connecting axle (14) of electric machine main shaft (1) afterbody, and described discharge bearing (3) outer diameter D is less than the main shaft bearing inner diameter d.

5. antistatic discharge device for stator and rotor of electric machine according to claim 3 is characterized in that: described discharge bearing (3) is installed on the encoder connecting axle (14) of electric machine main shaft (1) afterbody, and described discharge bearing (3) outer diameter D is less than the main shaft bearing inner diameter d.

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