CN111211646A

CN111211646A - Brushless Motor

Info

Publication number: CN111211646A
Application number: CN201811392407.8A
Authority: CN
Inventors: 朱宇飞; 刘文俊; 王震宇
Original assignee: Suzhou Gala Tech Power Co ltd
Current assignee: Suzhou jiaxinchuang Microelectronics Co.,Ltd.
Priority date: 2018-11-21
Filing date: 2018-11-21
Publication date: 2020-05-29

Abstract

The invention discloses a brushless motor. The brushless motor includes a base, a rotating shaft and a bearing. The first end of the rotating shaft is matched with the base through the bearing. The bearing includes a first ring assembled with the rotating shaft and assembled with the base. The second ring, and the rolling body disposed between the first ring and the second ring, the first ring or/and the rolling body are insulators, and the second end of the rotating shaft is connected to the reducer through an insulating coupler. By setting the first ring or/and the rolling body of the bearing as an insulator, the discharge in the bearing is avoided, and the coupling between the rotating shaft and the reducer is insulated, so that the shaft voltage on the rotating shaft cannot be released to the reducer, avoiding the shaft voltage. The voltage causes damage to mechanisms such as bearings and gears, which improves the working condition and prolongs the service life of the mechanism.

Description

Brushless motor

Technical Field

The invention relates to the field of motors, in particular to a brushless motor.

Background

Under the conditions of magnetic imbalance and other reasons, shaft voltage is generated on a rotating shaft of the motor, the shaft voltage forms a loop between a base and a shell, shaft current is generated, and bearing current is generated. Generally, a certain gap exists between a rolling body of the bearing and an inner ring and an outer ring, lubricating oil is arranged in the bearing for lubrication, when the shaft voltage is higher than a certain threshold value, a lubricating oil isolating film in the bearing gap is broken down by high voltage electricity, and the electric arc discharge is generated when the electric potential of the inner ring of the bearing is too high relative to the electric potential of the outer ring, so that the bearing surface is damaged, and the service life of the bearing is terminated in advance.

The shaft voltage builds up on the rotor until the dielectric capacity of the motor bearing lubricant is exceeded, and a short pulse in the voltage discharge passes through the bearing to ground. The voltage is then again collected on the axis and the cycle replayed. This random and frequent electrical discharge has the effect of electrical discharge machining, causing pitting of the rolling elements and raceways of the bearing. Initially, these discharge sources create a "frosting" or "sandblasting" effect, the first symptom of bearing current damage being typically audible noise as the rolling elements ride over the pitted bearing races. Over time, this deterioration results in bearing races (known as "ripples") that have continued signs of severe damage to the bearing. Eventually, groove deterioration will lead to overall bearing failure.

In order to avoid bearing current damage to the bearing, an insulated bearing is adopted at present, but shaft voltage discharges to the ground through a gear meshing surface, damage is caused to the gear surface, and the gear fails in advance.

Disclosure of Invention

In order to solve the problem that the bearing current damages the bearing or the gear in the prior art, the invention aims to provide a brushless motor which reduces or eliminates the bearing current.

In order to achieve one of the above objects, an embodiment of the present invention provides a brushless motor, which includes a housing, a rotating shaft, and a bearing, wherein a first end of the rotating shaft is coupled to the housing through the bearing, the bearing includes a first ring assembled to the rotating shaft, a second ring assembled to the housing, and a rolling element disposed between the first ring and the second ring, the first ring or/and the rolling element is an insulator, and a second end of the rotating shaft is coupled to a speed reducer through an insulating coupler.

As a further improvement of an embodiment of the present invention, the first ring is an inner ring of the bearing, and the second ring is an outer ring of the bearing.

As a further development of an embodiment of the invention, the rolling elements are provided as ceramic balls.

As a further improvement of an embodiment of the present invention, the coupler includes a connecting shaft, one end of the connecting shaft is connected to the rotating shaft, the other end of the connecting shaft is connected to the speed reducer, and the connecting shaft has an insulating property.

As a further improvement of an embodiment of the present invention, an output end of the rotating shaft is inserted into the connecting shaft, and the connecting shaft is inserted into the speed reducer.

As a further improvement of an embodiment of the present invention, the connecting shaft is connected to the rotating shaft, and/or the speed reducer is connected by a spline.

As a further improvement of an embodiment of the present invention, the connecting shaft is provided as an insulating material.

As a further improvement of an embodiment of the invention, the coupler is provided as an insulated coupling.

As a further improvement of an embodiment of the present invention, the brushless motor is an inner rotor brushless motor, the stator includes a housing and a magnet, the housing is fixed on the base, the magnet is fixed inside the housing, and the rotor is arranged inside the magnet.

Compared with the prior art, the invention has the following beneficial effects: the first ring or/and the rolling body of the bearing are/is arranged to be an insulator, so that discharging in the bearing is avoided, the rotating shaft and the speed reducer are insulated through the coupler, shaft voltage on the rotating shaft cannot be released to the speed reducer, damage to the bearing, the gear and other mechanisms due to the shaft voltage is avoided, the working condition is improved, and the service life of the mechanism is prolonged.

Drawings

Fig. 1 is a front view of a brushless motor and a decelerator according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a brushless motor and speed reducer of an embodiment of the present invention;

FIG. 3 is a schematic structural view of a rotating shaft, a coupler and a reducer according to an embodiment of the present invention;

FIG. 4 is a cross-sectional view of a shaft, coupler and reducer of one embodiment of the present invention;

FIG. 5 is a front view of a spindle according to one embodiment of the present invention;

wherein, 1, a rotating shaft; 11. a first spline; 2. a speed reducer; 21. a second keyway; 3. a coupler; 31. a first keyway; 32. a second spline; 4. a bearing; 41. an inner ring; 42. a rolling body; 43. and an outer ring.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments shown in the drawings. These embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present invention.

An embodiment of the present invention provides a brushless motor, as shown in fig. 1 to 5, the brushless motor includes a base, a rotor and a stator are disposed on the base, a rotating shaft 1 is connected with the rotor, for an inner rotor brushless motor, the rotor is disposed inside, the rotating shaft 1 is disposed in the rotor, and the stator is disposed at the periphery of the rotor; for the outer rotor brushless motor, the stator is arranged at the inner side, the rotor is arranged at the periphery of the stator, the end part of the rotor is connected with the rotating shaft 1 and inserted into the stator, and the axis of the rotating shaft 1 and the axis of the stator are on the same line; the bearing 4 is arranged on the rotating shaft 1, the bearing 4 is connected with the base or other supporting mechanisms, and the bearing 4 is used for supporting the rotating shaft 1 to operate.

One end of the rotating shaft 1 is set to be an output end, the output end outputs the power of the brushless motor, the brushless motor is connected with the speed reducer 2, the bearing 4 has insulation, the coupler 3 is arranged between the output end and the speed reducer 2, and the coupler 3 has insulation.

Further, the bearing 4 includes a rolling body 42, an inner race 41, and an outer race 43, and the rolling body 42 is an insulator. In addition, when the rolling elements 42, the inner ring 41, and the outer ring 43 are all insulators, the object of the present invention can be achieved, or when only the rolling elements 42 are provided as insulators, it is possible to achieve a state in which the rolling elements 42 and the inner ring 41, and the rolling elements 42 and the outer ring 43 are insulated from each other, that is, current cannot be transmitted to other components through the inner ring 41 or the outer ring 43, and discharge in the bearing 4 is avoided, thereby protecting the bearing 4 from damage by the bearing current.

Further, the rolling bodies 42 are provided as ceramic balls. The insulated rolling elements 42 are provided as a ceramic material with high reliability because the ceramic has high compressive strength, high melting point, and excellent chemical stability at high temperature, thermal conductivity lower than that of a metal material, and in addition, the ceramic has good dimensional stability when temperature changes.

Further, the coupler 3 comprises a connecting shaft, one end of the connecting shaft is connected with the rotating shaft 1, the other end of the connecting shaft is connected with the speed reducer 2, and the connecting shaft has insulation property; the rotating shaft 1 is connected with the speed reducer 2 through a connecting shaft, and the shafts of the rotating shaft 1 and the speed reducer 2 are both generally made of metal, so that the purpose of the invention can be achieved by adding an insulating connecting shaft between the rotating shaft 1 and the speed reducer 2.

Further, the output end of the rotating shaft 1 is inserted into a connecting shaft, and the connecting shaft is inserted into the speed reducer 2, as shown in fig. 2 to 4, the rotating shaft 1 is inserted into the connecting shaft to drive the connecting shaft to rotate, and the connecting shaft is inserted into the speed reducer 2 to drive the speed reducer 2 to rotate.

Further, the connecting shaft is connected with the rotating shaft 1 and/or the speed reducer 2 through a spline; specifically, the splines comprise a first spline 11 and a second spline 32, the first spline 11 is arranged at the end part of the rotating shaft 1, the second spline 32 is arranged at the end part of the connecting shaft, a first key groove 31 matched with the first spline 11 is arranged in the connecting shaft, and a second key groove 21 matched with the second spline 32 is arranged in the speed reducer 2; the spline is provided for stabilizing the connection and transmission of the rotating shaft 1 with the coupler 3 and the speed reducer 2.

In addition, when the connecting shaft and the rotating shaft 1 and the speed reducer 2 are in interference fit or other forms of fit, if the rotating shaft 1 and the speed reducer 2 are inserted into the connecting shaft or the connecting shaft is respectively inserted into the rotating shaft 1 and the speed reducer 2, the transmission of current between the rotating shaft 1 and the speed reducer 2 can be separated by the connecting shaft, and the synchronous motion of the rotating shaft 1 and the speed reducer 2 can be realized, so that the purpose of the scheme can be realized.

Furthermore, the connecting shaft is made of insulating materials, namely the whole connecting shaft is made of the insulating materials; in addition, an insulating coating can be added on the outer side of a common material, or an insulating material is arranged on the upper part of the connecting shaft, so that the aim of the scheme can be fulfilled without generating current transmission at the position connected with the rotating shaft 1 or one side of the speed reducer 2.

Further, the coupler 3 is an insulation coupler, that is, the insulation coupler is adopted to connect the output end of the rotating shaft 1 with the speed reducer 2, so that the connection of the two shafts is realized, and the transmission of current is cut off.

Further, the brushless motor is an inner rotor brushless motor, the stator comprises a shell and a magnet, the shell is fixed on the base, the magnet is fixed on the inner side of the shell, and the rotor is arranged on the inner side of the magnet.

When the brushless motor is an outer rotor brushless motor, the stator and the rotor are exchanged, and the arrangement and the generated beneficial effects of the electric conductor are the same as those of the inner rotor brushless motor.

Compared with the prior art, the invention has the following beneficial effects:

(1) through the arrangement of the bearing 4 for insulation, the discharge in the bearing 4 is avoided, and the insulation between the rotating shaft 1 and the speed reducer 2 is avoided, so that the shaft voltage on the rotating shaft 1 cannot be released to the speed reducer 2, the damage of the shaft voltage to the bearing 4, a gear and other mechanisms is avoided, the working condition is improved, and the service life of the mechanism is prolonged;

(2) the insulating bearing 4 is adopted, for example, the bearing 4 with the rolling bodies 42 being ceramic balls is adopted, so that the material performance of the bearing 4 meets the use requirement, and the technical effect of the scheme is realized;

(3) the connecting shaft with insulativity is adopted to connect the rotating shaft 1 and the speed reducer 2, and the connecting shaft is provided with structures such as splines and the like, so that the stability and reliability of transmission are ensured, and meanwhile, the connecting shaft is provided with insulating materials, so that the purpose of insulating and protecting the speed reducer 2 is achieved.

The detailed description set forth above is merely a specific description of possible embodiments of the present invention and is not intended to limit the scope of the invention, which is intended to include within the scope of the invention equivalent embodiments or modifications that do not depart from the technical spirit of the present invention.

Claims

1. The utility model provides a brushless motor, including frame, pivot and bearing, its characterized in that, the first end of pivot is passed through the bearing with the frame connects, the bearing include with the first ring of pivot equipment, with the second ring of frame equipment, and set up first ring with rolling element between the second ring, first ring or/and the rolling element is the insulator, the second end of pivot connects the reduction gear through insulation coupler.

2. The brushless electric machine of claim 1, wherein the first ring is an inner race of a bearing and the second ring is an outer race of a bearing.

3. The brushless electric machine of claim 1, wherein the rolling elements are provided as ceramic balls.

4. The brushless motor of claim 1, wherein the coupler includes a connection shaft, one end of the connection shaft is connected to the rotation shaft, and the other end of the connection shaft is connected to the reducer, the connection shaft having an insulation property.

5. The brushless motor of claim 4, wherein the output end of the rotation shaft is inserted into the connection shaft, and the connection shaft is inserted into the decelerator.

6. The brushless electric machine of claim 5, wherein the connecting shaft is connected to the rotating shaft, and/or the reducer is connected by a spline.

7. The brushless electric machine of claim 4, wherein the connection shaft is provided as an insulating material.

8. The brushless electric machine of claim 1, wherein the coupler is provided as an insulated coupling.

9. The brushless electric machine of claim 1, wherein the brushless electric machine is configured as an inner rotor brushless electric machine, and the stator comprises a housing and a magnet, the housing being secured to the housing, the magnet being secured inside the housing, the magnet being disposed inside the rotor.