CN214412498U

CN214412498U - Current grounding device of permanent magnet synchronous motor shaft

Info

Publication number: CN214412498U
Application number: CN202120402676.9U
Authority: CN
Inventors: 徐延平
Original assignee: Individual
Current assignee: Taizhou Trillion Force Motor Co ltd
Priority date: 2021-02-24
Filing date: 2021-02-24
Publication date: 2021-10-15
Anticipated expiration: 2031-02-24

Abstract

The utility model discloses a synchronous motor shaft current earthing device of permanent magnetism, wherein there are red copper pigtail, OT opening copper nose binding post, copper bolt and copper packing ring. The device is copper pigtail and motor shaft excircle sliding contact, and copper pigtail both ends fixed connection OT opening copper nose binding post, binding post compress tightly on the motor housing bottom plate with copper bolt and copper packing ring together and constitute the axle current earthing device of this motor. The device reliably forms a short circuit loop between the motor rotating shaft and the motor shell, eliminates the generation of shaft voltage, namely shaft current, avoids the electric ablation of the shaft current on the motor bearing and parts, and protects the motor bearing and parts. The utility model has the advantages of reasonable design, it is simple, the ground connection is reliable, installation, maintenance, convenient to use, longe-lived, it is with low costs, stopped motor shaft electric current and produced the damage to motor bearing and part, improved the safe and reliable nature of going of motor operation, prolonged the life of motor.

Description

Current grounding device of permanent magnet synchronous motor shaft

Technical Field

The utility model relates to a permanent magnet synchronous motor field, concretely relates to permanent magnet synchronous motor shaft current earthing device.

Background

The motor is electrical equipment widely used in various industries of national economy, the usage amount is large, the operation time is long, and the motor operatesIn the process, a common problem exists in a high-voltage motor, a high-power low-voltage motor, a variable-frequency power supply motor and a generator, a loop is formed by a motor shaft to a shell to generate potential difference, namely shaft voltage, and when the voltage is high to a certain degree, the density of the shaft current exceeds 1.2A/mm²Then, the insulation performance of the lubricating grease is destroyed, the shaft voltage generated instantly breaks through an oil film to generate discharge, a shaft current is formed, once the shaft current is formed, a typical low-voltage large-current loop is formed, and the bearing is locally burnt by ablation at high temperature instantly. The surface of the rolling ball (roller) and the raceway of the bearing inner ring is provided with burn of a washboard-shaped strip-shaped groove, so that noise and vibration are generated, and the bearing is completely damaged in a short time. Under certain conditions, shaft current even can burn components such as a motor shaft extension and a coupler, and even more, the shaft current sometimes does not damage a bearing of the motor and also can damage a transmission device or a bearing of a load machine connected with the motor, so that great influence is brought to on-site safety production, and great economic loss is directly and indirectly caused to a user enterprise by shutting down and replacing the bearing.

The utility model has the following contents:

in order to solve axle current in case form, just constitute typical low-voltage heavy current return circuit, make the problem of bearing local ablation burn at the high temperature that produces in the twinkling of an eye, the utility model discloses a PMSM motor shaft current earthing device, including the copper pigtail, OT opening copper nose binding post, copper bolt, copper packing ring, motor shaft and motor housing bottom plate, the copper pigtail directly hangs and forms sliding contact around on the motor shaft excircle, and the both ends of copper pigtail all are fixed with OT opening copper nose binding post, and two OT opening copper nose binding posts compress tightly the axle current earthing device who constitutes this motor on motor housing bottom plate with copper bolt and copper packing ring together.

Preferably, the copper braid is directly hung on the excircle of the motor shaft to form maximum area sliding contact and has certain tension.

Preferably, the copper braid and OT opening copper nose connecting terminal is made of red copper, and the copper bolt and the copper washer are made of brass.

The utility model discloses permanent magnetism synchronous motor shaft current earthing device has solved the present generally used motor shaft and has stretched end installation ground connection carbon brush, adopted insulating bearing, insulating pad and insulating bolt, packing ring, chooseed for use special lubricating grease, used non-conductive shaft coupling etc. its structure is complicated, and the ground connection reliability is poor, and installation, maintenance, use are inconvenient, and the carbon brush life-span needs frequent change, technical problem with high costs.

The utility model provides a novel motor shaft current earthing device, the effect of its innovation technical measure, production adopts following method to realize:

1. on a motor shaft generating shaft current, a red copper braid with good conductivity is directly in sliding contact with the outer circle of the motor shaft, an OT opening copper nose wiring terminal with good conductivity is tightly and fixedly connected with the red copper braid to form a reliable conductive wire, and a copper bolt and a copper gasket are pressed on a motor shell bottom plate together to form the shaft current grounding device of the motor.

2. The threaded hole for installing the copper bolt is processed on the base plate of the motor shell, the sliding contact part of the outer circle of the motor shaft and the red copper braid is ground, the surface roughness is small, the sliding abrasion with the red copper braid is small, and the service life of the device is long.

3. A copper bolt and a copper washer which are good in electric conduction are adopted to tightly press the OT opening copper nose wiring terminal on a base plate of the motor shell, and certain tension is applied to the red copper braid while the copper bolt and the copper washer are tightly pressed, so that a motor rotating shaft and the motor shell form a good short circuit loop, and shaft voltage, namely shaft current is prevented from being generated.

The shaft current grounding device is not only suitable for a self-starting permanent magnet synchronous motor, but also suitable for other permanent magnet motors, a high-voltage asynchronous motor, a high-power low-voltage asynchronous motor, a variable-frequency power supply motor and a generator.

Compared with the prior art, the utility model have following advantage:

the structure design is reasonable, the grounding reliability is very good, the installation and the maintenance are convenient, the service life is long, and the cost is lower.

Drawings

FIG. 1 is a general assembly view of a current grounding device of a permanent magnet synchronous motor shaft;

FIG. 2 is an enlarged view of a portion of the current grounding device A of the permanent magnet synchronous motor shaft of FIG. 1;

fig. 3 is a partially enlarged view of a portion of the current grounding device B of the shaft of the permanent magnet synchronous motor of fig. 1.

The parts in the above figures are numbered as follows:

1. red copper braid

2. OT opening copper nose connecting terminal

3. Copper bolt

4. Copper gasket

5. Motor shaft

6. Motor shell bottom plate

Detailed Description

The present invention will be described with reference to the accompanying drawings.

FIG. 1 general assembly drawing of current grounding device of permanent magnet synchronous motor shaft

The red copper braid 1 is directly hung and wound on the excircle of a motor shaft 5 to be in sliding contact with the excircle of the motor shaft, two ends of the red copper braid are tightly and fixedly connected with the OT opening copper nose wiring terminal 2 to form a reliable conductive wire, the OT opening copper nose wiring terminal 2 is tightly pressed on a bottom plate 6 of a motor shell by a copper bolt 3 and a copper gasket 4, and certain tension is applied to the red copper braid 1 while the conductive wire is tightly pressed.

FIG. 2 is a partial enlarged view of a current grounding device of a permanent magnet synchronous motor shaft

The enlarged partial view of A is the front view, the enlarged partial view of B is the side view, and the both ends of red copper pigtail 1 and OT opening copper nose binding post 2 are closely fixed together, and copper bolt 3 and copper packing ring 4 compress tightly OT opening copper nose binding post 2 on motor housing bottom plate 6, exert certain tension for red copper pigtail 1 when compressing tightly.

Claims

1. The utility model provides a synchronous motor shaft current earthing device of permanent magnetism which characterized in that: including copper pigtail (1), OT opening copper nose binding post (2), copper bolt (3), copper washer (4), motor shaft (5) and motor casing bottom plate (6), copper pigtail (1) directly hangs and forms sliding contact around on motor shaft (5) excircle, and the both ends of copper pigtail (1) all are fixed with OT opening copper nose binding post (2), two OT opening copper nose binding post (2) compress tightly the axle current earthing device who constitutes this motor on motor casing bottom plate (6) together with copper bolt (3) and copper washer (4).

2. The permanent magnet synchronous motor shaft current grounding device of claim 1, further comprising: the copper braid (1) is directly hung on the excircle of the motor shaft (5) to form maximum area sliding contact and has certain tension.

3. The permanent magnet synchronous motor shaft current grounding device of claim 1, further comprising: the copper braid (1) and the OT opening copper nose wiring terminal (2) are made of red copper, and the copper bolt (3) and the copper washer (4) are made of brass.