CN1066347A - Miniature motor - Google Patents

Abstract

A kind of miniature motor contains a band end hollow cylinder housing, permanent magnet, one to have the rotor of armature and commutator and one and is contained on the shell nozzle and has with the brush of commutator sliding contact and end frame with the terminal of brush electric connection, and rotor can be rotated to support on and is located on housing bottom and the bearing of holding on the frame.Permanent magnet is made by rubber or plastic magnet.A plurality of protuberances are located on the bottom and end frame of housing, by forcing protuberance to be pressed against on the end of permanent magnet this end of permanent magnet are out of shape partly so that permanent magnet is assembled on the interior perimeter surface of housing regularly.

Description

Miniature motor

The present invention briefly relates to the miniature motor that is used for audio and video equipment and auto electric member, is to assemble the miniature motor that reduces machine work and assembly cost reliably thereby be specifically related to its permanent magnet that forms magnetic field.

Fig. 1 is an end view that part is cut open, and the example that a present invention can use miniature motor thereon is shown.In Fig. 1, label 1 is for example housing of the shape of the such metal material of mild steel hollow cylinder that make and that be shaped as a band end of a usefulness.One for example is shaped as that the permanent magnet 2 of arc fan-shaped installs on the interior perimeter surface of housing 1 regularly.Label 3 is for example end framves on the thermoplastic resin material opening that make and that install to housing 1 of a usefulness.Label 4 is rotors, and this rotor contains an armature 5 and the commutator 6 in the face of permanent magnet 2, and can be rotated to support on the bearing 7 and 8 that is located at respectively on housing 1 and the end frame 3.

Label 9 is strip of sheet brush arms of making by such as the such electric conducting material of copper, and it has with the brush 10 of commutator 6 sliding contacts and is located in the end frame 3.Holding the input terminal 11 that is equipped with on the frame 3 with brush arm 9 electric connections, electric current can be fed on the armature 5 with commutator 6 by brush arm 9, brush 10 from the DC power supply (not shown) of an outside.

In above-mentioned structure,, produce a revolving force in the armature 5 in being in the magnetic field that forms by the permanent magnet 2 on the interior perimeter surface that is assembled to housing 1 regularly when electric current is fed on the armature 5.The result makes rotor 4 rotations, drives the various device that is connected on the rotor 4.

Miniature motor with said structure usually adopts and a kind ofly permanent magnet 2 is assembled on the interior perimeter surface of housing 1 regularly with holding the mode between the frame 3 by the bottom that permanent magnet 2 is clamped in vertically housing 1.

In the fixed form of this class, having a kind of is the protuberance that is provided with on end frame 3 with the axial end contact of permanent magnet 2, and permanent magnet 2 can be clamped by the bottom of protuberance and housing 1.In this case, can be provided with the next protuberance joint that is located on the end frame 3 of following of depression on the axial end of permanent magnet 2.(with reference to a day uncensored utility model application 103776/1990 of the present disclosure).

The another kind of mode that permanent magnet 2 is assembled to regularly on the interior perimeter surface of housing 1 is the triangle magnet clamping device that is provided with on end frame 3 with permanent magnet 2 contacts, and under end frame 3 sd sos a kind of situation, make the pinnacle of its triangle magnet clamping device be forced on the permanent magnet 2 and distortion clamps permanent magnet 2 in the housing 1 of packing into.(with reference to a day uncensored utility model application 116577/1989 of the present disclosure).

Another kind of again mode is on the inner face of end frame compressible protuberance to be set, and these protuberances are forced into and are attached on the rear end face of permanent magnet 2.(with reference to a day uncensored utility model application 120288/1980 of the present disclosure).

Except above-mentioned mechanism's fixed form, the mode that permanent magnet 2 is assembled on the housing 1 is regularly also used always frequently with adhesive.

The method of above-mentioned assembling permanent magnet 2 is effective to the miniature motor of the rigidity sintered magnet of use such as ferrimagnet with being used for fixing.But, in recent years, the demand of smaller and thinner miniature motor has been increased.But, can not make smaller and thinner permanent magnet at an easy rate with sintering method.In order to adapt to demand, usually adopt rubber magnet or plastic magnet to be used as permanent magnet 2 to smaller and thinner miniature motor.But, in the miniature motor that adopts rubber magnet or plastic magnet, come the clamping permanent magnet will make it be deformed into hourglass shape with excessive power, hindered rotor 4.Used weak chucking power then can cause the instability location of permanent magnet for fear of the magnet distortion with fixing.Depression is set on the axial end of permanent magnet can increase manufacturing procedure, thereby increases cost.

Secondly, the mode that compressible protuberance is set on end frame 3 can be located permanent magnet exactly vertically, but causes permanent magnet fine rotation along the circumferential direction through regular meeting.This will cause the phase shift with respect to brush, cause miniature motor to reduce quality.Use adhesive that the method that permanent magnet is assembled on the housing is regularly increased material with processing charges, not only increased manufacturing cost, and commutator has been had bad influence with the position that brush contacts from the gas that adhesive is emitted.

First purpose of the present invention provides a kind of its permanent magnet can locate and be assembled to regularly the interior miniature motor of housing exactly.

Second purpose of the present invention provides a kind of can the reduction and processes and the produced miniature motor of assembly fee.

Fig. 1 illustrates the end view that part that a present invention can use the example of miniature motor is thereon cut open.

Fig. 2 is the longitudinal sectional view that the major part of the first embodiment of the present invention is shown.

Fig. 3 is the longitudinal sectional view that the major part of the second embodiment of the present invention is shown.

Fig. 4 is the longitudinal sectional view that the major part of the third embodiment of the present invention is shown.

In the accompanying drawings, Fig. 2 is a longitudinal sectional view, and the first embodiment of the present invention is shown.Similar part indicates with the used same label of Fig. 1.In Fig. 2, label 12 is protuberances, is provided with a plurality of such protuberances 12 in the bottom of housing 1 along its inner circumferential surface.Label 13 is the protuberances that form needle-like, and the inner face of end frame 3 is provided with the protuberance 13 of the end face of a plurality of sensing permanent magnets 2.Protuberance 12 and 13 size and size can be come selected suitably according to the factor that composition, size, the shape of permanent magnet 2 are waited for, but these protuberances 12 preferably are shaped as like this, make them when following permanent magnet to contact permanent magnet 2 is out of shape partly or cut in the permanent magnet 2 with 13.

A kind of elastic caoutchouc magnet as permanent magnet 2 is by will mixing as adhesive with natural rubber such as the fine magnetic-particle of magnetic iron ore, and by extrude, kneading or other method of moulding be molded as that required shape makes.Should come selected suitably according to the magnetic properties that permanent magnet 2 is required as the elasticity that the mixed ratio by magnetic-particle and adhesive of the rubber magnet of permanent magnet 2 is determined.Except natural rubber, neoprene, butyl rubber, acrylonitrile-butadiene rubber, Oppanol, chlorosulfonated polyethylene, haloflex, or the like, all can be used as adhesive.Plastic magnet is by mixing with polyvinyl resin magnetic-particle and mixture being come out with injection moulding apparatus is molded as adhesive.In two kinds of situations, material known can be used as adhesive.

In above-mentioned structure, permanent magnet 2 in it embeds housing 1 and end frame 3 install on the housing 1 and clamped vertically reliably by protuberance 12 and 13 afterwards.On the other hand, protuberance 12 and 13 can prevent that permanent magnet 2 from along the circumferential direction moving, because protuberance 12 and 13 is partly cut in the permanent magnet 2.In this case, the limit deformation of permanent magnet 2 in so little degree, so that can on permanent magnet 2 obvious variation not appear, thereby just prevented that 2 pairs of rotors 4 of permanent magnet from disturbing.

Fig. 3 is the longitudinal sectional view that the major part of the second embodiment of the present invention is shown.Similar part indicates with same label shown in Figure 2.In Fig. 3, protuberance 13 is shaped as taper shape, pyramid or polygon pyramid, and is arranged to make the inward flange contact of its skewed surface with permanent magnet 2.

The effect of said structure is identical with first embodiment shown in Figure 2.In addition, said structure can also prevent to make outside expansion of inner surface of permanent magnet 2 cause undesirable interference is taken place rotor 4 owing to the power of axial support permanent magnet 2.

Fig. 4 is the longitudinal sectional view that the major part of the third embodiment of the present invention is shown.Similar part indicates with the used same label of first and second embodiment shown in Fig. 2 and 3.In Fig. 4, protuberance 13 is shaped as for example column, and is arranged to make protuberance 13 to stretch out with the end face contact with permanent magnet 2 from the inner surface of end frame 3 by this way, rather than with its inner circumference contact.The effect of said structure is similar with the situation of first embodiment.

This embodiment is that the cross section by permanent magnet 2 is that the fan-shaped or C shape of arc is described.But this embodiment also is applicable to the permanent magnet of hollow cylindrical.In the later case, present embodiment is more effective, because it has successfully limited the circumferential movement with the out of contior permanent magnet 2 of other modes.On the other hand, in the previous case, U-shaped spring or other device can be used between the permanent magnet 2 of adjacency to limit its circumferential movement.

The present invention with said structure and effect effectively permanent magnet is located reliably and the housing of packing in, and reduce processing and use with assembly fee.In addition, just prevented that without adhesive commutator and the gas of being emitted from adhesive round the position of brush from polluting, thereby kept high-caliber motor performance.

Claims (4)

1, a kind of miniature motor, contain one and be shaped as a housing band end hollow cylinder shaped and that have a permanent magnet within it on the perimeter surface, one contains one towards the armature of this permanent magnet and the rotor of a commutator, with on the opening that installs to this housing and have and be used for the brush of this commutator sliding contact with the end frame of the lead-out terminal of described brush electric connection, described rotor can be rotated to support on the bottom and the bearing on this end frame that is located at this housing respectively, it is characterized in that described permanent magnet made by rubber or plastic magnet, a plurality of bottom and described end framves that are used for the protuberance that this permanent magnet assembles regularly is arranged on described housing are out of shape so that this permanent magnet is assembled on the interior perimeter surface of this housing regularly this end of this permanent magnet by forcing described protuberance to be pressed against on the end of this permanent magnet partly.

2, by the described miniature motor of claim 1, it is characterized in that described protuberance is shaped as needle-like to cut the end face of described permanent magnet.

3, by the described miniature motor of claim 1, it is characterized in that described protuberance is shaped as taper, and make the interior end in contact of its inclined surface with described permanent magnet.

4, by the described miniature motor of claim 1, it is characterized in that described protuberance is shaped as column, and with the end face contact of described permanent magnet rather than with its inner circumference contact.