CN103715812A

CN103715812A - Motor end cover device capable of preventing shaft current

Info

Publication number: CN103715812A
Application number: CN201310735434.1A
Authority: CN
Inventors: 王必生
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-12-28
Filing date: 2013-12-28
Publication date: 2014-04-09

Abstract

The invention discloses a motor end cover device capable of preventing shaft current. The motor end cover device comprises end covers, an electric brush, a spring and a set screw, wherein the electric brush makes close contact with the inner ring of a bearing through the set screw and the spring to conduct electric charges, caused by various factors, accumulated on a rotor shaft, so that equal potential is formed between a stator and a rotor, namely between the inner ring of the bearing and the outer ring of the bearing, and the purpose of avoiding bearing electro-corrosion is achieved. The motor end cover device has the advantages that the subsequent maintenance cost of the bearing is reduced; the shaft current is avoided through a direct electric short circuit between a motor base, the end covers, the bearing and the rotor, so that the service life of the bearing is prolonged, and operation is guaranteed.

Description

Can prevent the motor end cover apparatus of shaft current

Technical field

The present invention relates to a kind of motor end cover apparatus, relate in particular to a kind of motor end cover apparatus that can prevent shaft current.

Background technology

When motor is manufactured, the reasons such as asymmetrical effect that the magnetic line of force that in the time of manufactured by electric machine iron core punching, cause in punching direction difference or the asymmetric gap of bed joint distributes, can in motor, produce the axle electromotive force along rotor shaft direction, when electromotive force is elevated to while being enough to puncture bearing film, just can pass through support, iron core, end cap, bearing holder (housing, cover), bearing, rotating shaft forms current circuit; Variable-frequency motor, due to harmonic wave and electric machine structure, also can cause between armature spindle and support and have potential difference, causes the inner generation current of the joining bearing of rotating shaft and support; The each several part magnetic circuit of motor is asymmetric, and the annular magnetic flux of appearance is responded to alternating voltage, and then forms low frequency shaft current; Phenomena produces shaft current, shaft current is very harmful to motor bearings, and it punctures oil film and causes rolling surface galvanic corrosion to burn to bearing, and often causes bearing burnt, this electric current has the effect of galvano-cautery to bearing, finally have a strong impact on useful life and the reliability of motor bearings.In order to prevent shaft current, in the structure of existing end cover for motor, mainly contain: the metal end that insulation bearing is housed in bearing chamber, this kind of end cap body do not possess insulation function, to rely on after the interior equipped insulation bearing of bearing chamber of end cap, utilize insulating barrier to there is anti-shaft current function, block the shaft current that motor produces in running, but insulation bearing is expensive, be subject to the obvious raising of manufacturing cost of motor and the restriction of load, operational environment etc., be often only applied on the motor product of specific (special) requirements; The structural member of handlebar bearing portions and motor insulate in a certain way, makes shaft current can not pass through bearing portions, but structure relative complex, and front and back bearings all will take the mode of insulation, has also increased cost simultaneously.

Summary of the invention

The present invention will achieve the goal and be to overcome above-mentioned weak point, and a kind of motor end cover apparatus that can prevent shaft current is provided.

The present invention solves the problems of the technologies described above adopted technical scheme: can prevent the motor end cover apparatus of shaft current,

Comprise end cap, brush, spring, holding screw, described brush by holding screw by the inner ring close contact of spring and bearing, with the electric charge gathering on the conduction armature spindle that various factors was produced, making between stator and rotor is to form equipotential between the inside and outside circle of bearing, reaches the object of avoiding bearing galvano-cautery.

Described end cap is provided with unthreaded hole and screw in the axial optional position of the bearing inner race end face with corresponding.

Described brush comprises brush head, brush is debated and conducting strip.

Compared with prior art, advantage of the present invention is simple, compact and reasonable for structure; Setting by brush makes the electric charge gathering between rotor and end cap directly by brush, be transmitted to the earth terminal of whole motor, and it is not only with low cost, successful, but also reduced the maintenance cost of later stage bearing; By making between support, end cap, bearing, rotor directly electrical short, to avoid the generation of shaft current, thereby improved bearing useful life, operation has obtained guarantee.

Accompanying drawing explanation

Fig. 1 is structure chart of the present invention.

Fig. 2 is the A place enlarged drawing of Fig. 1.

Fig. 3 is the end cover structure figure of A place of Fig. 1.

Fig. 4 is brush structure figure.

Embodiment

Below in conjunction with accompanying drawing, embodiment is described in further detail the present invention.

As shown in Figure 1, can prevent the motor end cover apparatus of shaft current, comprise end cap 2, brush 4, spring 5, holding screw 6, bearing 2 is nested into after the bearing guard of axle 1, and its outer ring is encased in the bearing chamber of end cap 2; As shown in Figure 2, Figure 3 and Figure 4, brush 4 is arranged in the unthreaded hole 21 of end cap 2, spring 5 is between brush head 41 and conducting strip 43, brush head 41 and conducting strip 43 are debated 42 by brush and are linked together, by holding screw 6, by the screw 22 engagement spinning with end cap 2, live conducting strip 43, make the inner ring close contact of brush 4 and bearing 3, with the electric charge gathering on the conduction armature spindle 1 that various factors was produced, making between stator and rotor is to form equipotential between the inside and outside circle of bearing, reaches the object of avoiding bearing galvano-cautery.

In above-described embodiment, as Fig. 2, shown in Fig. 3 and Fig. 4, end cap 2 makes the brush 4 inner ring endface position in bearing 3 all the time with unthreaded hole 21 and screw 22 that the axial optional position of corresponding bearing 3 inner ring end faces arranges, elastic force effect by spring makes the inner ring end face of brush 4 and bearing 3 constantly in close contact state, make the electric charge that gathers on armature spindle 1 through the inner ring of bearing 3 to brush head 41, by brush, debate 42 to conducting strip 43 again, by screw 6, pass through end cap 2 to the outer ring generation electrical short of bearing 3 again, avoid electric charge through in bearing 3, the situation of oil film between outer ring raceway and rolling element, ground connection by motor effectively discharges the electric charge on armature spindle 1, 3 useful lifes of bearing have effectively been improved, motor operation has obtained guarantee.

Claims

1. can prevent the motor end cover apparatus of shaft current, comprise end cap (2), brush (4), spring (5), holding screw (6), described brush (4) is passed through the inner ring close contact of spring (5) and bearing (3) by holding screw (6), with the electric charge gathering on the conduction armature spindle that various factors was produced, making between stator and rotor is to form equipotential between the inside and outside circle of bearing, reaches the object of avoiding bearing galvano-cautery.

2. the motor end cover apparatus that can prevent shaft current as claimed in claim 1, is characterized in that described end cap (2) is provided with unthreaded hole (21) and screw (22) in the axial optional position of the bearing with corresponding (3) inner ring end face.

3. the motor end cover apparatus that can prevent shaft current as claimed in claim 1, is characterized in that described brush (4) comprises brush head (41), brush is debated (42) and conducting strip (43).