CN215186332U

CN215186332U - Induction motor

Info

Publication number: CN215186332U
Application number: CN202121475289.4U
Authority: CN
Inventors: 孟庆一; 刘书香; 刘康; 王崤君; 黄玉森; 张大柯
Original assignee: Nanyang Explosion Proof Suzhou Special Equipment Co ltd
Current assignee: Nanyang Explosion Proof Suzhou Special Equipment Co ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2021-12-14
Anticipated expiration: 2031-06-30

Abstract

The utility model discloses an induction motor, it relates to the motor field. The technical scheme is characterized by comprising a motor shaft, a first end cover and a second end cover, wherein a first insulating bearing is arranged between the motor shaft and the first end cover, and a second insulating bearing is arranged between the second end cover and the motor shaft; the first insulating bearing comprises a first bearing outer ring provided with an insulating coating; the outer end face of the first end cover is provided with a grounding hole extending to the end face of the first bearing outer ring, and a grounding piece which is not in contact with the end face of the first bearing outer ring is arranged in the grounding hole; and the end surface of the outer ring of the first bearing is provided with an insulation breaking point opposite to the end part of the grounding part. The utility model discloses can realize the ground connection of motor shaft under the condition of installing two insulation bearing, the counter shaft voltage releases to the life of extension bearing and motor.

Description

Induction motor

Technical Field

The utility model relates to a motor field, more specifically says, it relates to an induction motor.

Background

The working principle of the motor is that a rotating magnetic field is generated by utilizing an electrified coil and acts on a rotor to form magnetoelectric power rotating torque.

Due to the asymmetry of the motor core and coil and the deflection of the rotor slots, an alternating voltage in the axial extension direction is generated in the motor operation. The frequency of the voltage may be the same as the power supply frequency or may be the same as the slip frequency or a multiple thereof.

The shaft voltage is the main source of the bearing current, which damages both the sliding bearing and the rolling bearing, and in order to prevent the generation of the bearing current, the bearings at one end or both ends of the induction motor are usually insulated. Since the frequency converter generates high frequency harmonics, both bearings need to be insulated in a variable frequency controlled induction motor.

To the induction motor that insulating bearing was installed to one end, the motor shaft is connected through uninsulated bearing and casing and can be realized ground connection, but accomplish the equipment back at the motor, and whether insulating bearing's insulating coating received the damage then unable detection.

For the variable frequency control induction motor with the insulating bearings arranged at the two ends, after the motor is assembled, whether the insulating coating of the insulating bearing is damaged or not can be detected, but a motor shaft cannot be grounded, so that the shaft voltage cannot be released; when the shaft voltage increases to a certain value, it also has an effect on the bearing or the motor.

SUMMERY OF THE UTILITY MODEL

Not enough to prior art exists, the utility model aims to provide an induction motor, its ground connection that can realize the motor shaft under the condition of installing two insulation bearings releases counter shaft voltage to the life of extension bearing and motor.

In order to achieve the above purpose, the utility model provides a following technical scheme:

an induction motor comprises a motor shaft, a first end cover and a second end cover, wherein a first insulating bearing is arranged between the motor shaft and the first end cover, and a second insulating bearing is arranged between the second end cover and the motor shaft;

the first insulating bearing comprises a first bearing outer ring provided with an insulating coating;

the outer end face of the first end cover is provided with a grounding hole extending to the end face of the first bearing outer ring, and a grounding piece which is not in contact with the end face of the first bearing outer ring is arranged in the grounding hole;

and the end surface of the outer ring of the first bearing is provided with an insulation breaking point opposite to the end part of the grounding part.

Further, the motor shaft includes axle extension end and non-axle extension end, first end cap is close to the axle extension end, the second end cap is close to non-axle extension end.

Further, the grounding piece and the grounding hole comprise a threaded fit.

Further, the end face of the first bearing outer ring forms a bare metal area at the insulation damage point, and the diameter of the metal area is smaller than the inner diameter of the grounding hole.

To sum up, the utility model discloses following beneficial effect has:

1. under the condition that the insulating bearings are arranged at the two ends, the shaft voltage on the motor shaft is released by utilizing the matching of the insulation failure point and the grounding piece, so that the service lives of the bearings and the motor can be prolonged;

2. the structure is simple, the operation is convenient and safe;

3. after the frequency conversion control induction motor is assembled, whether the insulating coatings of the front and rear insulating bearings are damaged or not can be detected, hidden dangers are avoided through pre-detection, and therefore the purposes of reducing bearing vibration, noise, abnormal sound and scrapping caused by electric corrosion of the motor due to shaft current in the using process are achieved, and the service life of the motor is prolonged.

Drawings

Fig. 1 is a schematic structural view of an induction motor according to embodiment 1;

fig. 2 is a sectional view of an induction motor in embodiment 1;

fig. 3 is an enlarged schematic view of a portion a in fig. 2.

In the figure: 1. a motor shaft; 11. a shaft extension end; 12. a non-axially extending end; 2. a first insulating bearing; 21. a first bearing outer ring; 211. an insulation breakdown point; 3. a second insulating bearing; 4. a first end cap; 41. a ground hole; 411. a threaded bore section; 412. a smooth hole section; 5. a second end cap; 6. and a grounding screw.

Detailed Description

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

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications to the present embodiment without inventive contribution as required after reading the present specification, but all of them are protected by patent laws within the scope of the claims of the present invention.

Example (b):

an induction motor, referring to fig. 1 to 3, comprises a motor shaft 1 and a housing, wherein the housing comprises a first end cover 4 and a second end cover 5, a first insulating bearing 2 is arranged between the motor shaft 1 and the first end cover 4, and a second insulating bearing 3 is arranged between the second end cover 5 and the motor shaft 1; the first insulating bearing 2 comprises a first bearing outer ring 21 provided with an insulating coating, and the outer ring of the second insulating bearing 3 is also provided with the insulating coating in the embodiment; of course, in other alternative embodiments, the first insulating bearing 2 and the second insulating bearing 3 may also adopt other structural forms to realize insulation, such as an insulating sleeve and the like, and are not limited herein; the outer end face of the first end cover 4 is provided with a grounding hole 41 extending to the end face of the first bearing outer ring 21, and a grounding piece which is not in contact with the end face of the first bearing outer ring 21 is arranged in the grounding hole 41; the end face of the first bearing outer ring 21 is provided with an insulation breaking point 211 opposite to the end part of the grounding part; in the embodiment, the first insulating bearing 2 and the second insulating bearing 3 are used for avoiding the generation of shaft current, and the shaft voltage on the motor shaft 1 is released by the cooperation of the insulation breaking point and the grounding piece, so that the service life of the motor can be prolonged.

Referring to fig. 1 to 3, the motor shaft 1 includes a shaft-extending end 11 and a non-shaft-extending end 12, specifically, the first end cap 4 is close to the shaft-extending end 11, and the second end cap 5 is close to the non-shaft-extending end 12 in this embodiment; the sealing performance requirement of the second end cover 5 is high, so that the grounding hole 41 is arranged on the first end cover 4 in the embodiment, and the influence of punching on the second end cover 5 on the sealing performance can be avoided; of course, in other alternative embodiments, if it is ensured that the sealing performance is not affected, the second end cap 5 may be perforated, which is not limited herein.

Referring to fig. 1 to 3, the grounding member includes a threaded engagement with the grounding hole 41; specifically, the grounding member in this embodiment is a grounding screw 6, and the grounding hole 41 includes a threaded hole section 411 therein, which is engaged with the grounding screw 6; in this embodiment, the grounding hole 41 further includes a unthreaded hole section 412 connected to the threaded hole section 411, and the installation of the unthreaded hole section 412 can reduce the length of the threaded fit, so as to facilitate the rotation of the grounding screw 6; the end part of the grounding screw 6 close to the insulation failure point 211 is provided with a tip, and the release of shaft voltage on the motor shaft 1 is realized by utilizing the tip discharge effect; in the embodiment, the end surface of the first bearing outer ring 21 forms a bare metal area at the insulation failure point 211, and the diameter of the metal area is smaller than the inner diameter of the grounding hole 41 to ensure that the metal area does not contact with the first end cap 4.

Claims

1. An induction motor comprises a motor shaft, a first end cover and a second end cover, wherein a first insulating bearing is arranged between the motor shaft and the first end cover, and a second insulating bearing is arranged between the second end cover and the motor shaft;

the method is characterized in that:

2. The induction machine of claim 1, wherein: the motor shaft includes axle extension end and non-axle extension end, first end cap is close to the axle extension end, the second end cap is close to the non-axle extension end.

3. The induction machine of claim 1, wherein: the grounding piece and the grounding hole are in threaded fit.

4. The induction machine of claim 1, wherein: and a naked metal area is formed on the end surface of the first bearing outer ring at the insulation failure point, and the diameter of the metal area is smaller than the inner diameter of the grounding hole.