CN1801585A

CN1801585A - Stepping motor

Info

Publication number: CN1801585A
Application number: CNA2006100025216A
Authority: CN
Inventors: 笠原贵
Original assignee: Nidec Copal Corp
Current assignee: Nidec Precision Corp
Priority date: 2005-01-06
Filing date: 2006-01-06
Publication date: 2006-07-12
Anticipated expiration: 2026-01-06
Also published as: CN1801585B; JP2006191754A; JP4703192B2; KR100923561B1; KR20060080862A

Abstract

To provide a stepping motor which enables further downsizing. This stepping motor 1 has such a merrit that the diameter of a casing 25 can be made small since it is constituted so that a pair of stators 7A and 7B may catch a rotor 5 in the direction of its axis L. Furthermore, this motor can enlarge the internal space of the casing 25 in the direction of its axis L since it has such constitution that both ends of the casing 25 are opened so that yokes 11A and 11B may be exposed from the open ends of the casing 25. Accordingly, even if motors are of the same size, this motor can raise its output while keeping the size since the coils 9A and 9B and the rotor 5 within the casing 25 can be enlarged in the direction of its axis L. Adopting the casing 25 of such both ends open type will be extremely effective for the further downsizing of a small PM-type stepping motor which is used for drive of the lens of a cemera, the drive of the pickup lens of a media-related apparatus, etc.

Description

Stepping motor

Technical field

The lens that the present invention relates to be used for camera drive, PM (permanent magnet) the type stepping motor of the driving of the pick-up head lens of medium relevant device etc.

Background technology

In the past, as the technology in this field, had the Japan Patent spy and opened the 2003-009497 communique.The stepping motor of putting down in writing in this communique comprises: the periphery alternating magnetization at axle (rotating shaft) is the rotor of the N utmost point and the S utmost point; Be configured on the axis direction of axle, clip a pair of magnetic pole unit (stator) of rotor.This magnetic pole unit is by constituting with respect to magnet and coil of establishing and the yoke of accommodating this coil on the axis direction of axle.Can realize being suitable for needing the stepping motor of minor diameters such as lens driving of the camera of regulation torque by such configuration relation.

[patent documentation 1] Japan Patent spy opens the 2003-009497 communique

In the above-mentioned existing stepping motor, rotor and magnetic pole unit are enclosed in the framework, the two end cap upper cover of framework.But, a pair of stator is clamped rotor on axis direction motor, although aspect miniaturization, have the swedged advantage of energy, for the motor that makes same diameter improves output, existence must prolong the profile of motor on axis direction problem.

Summary of the invention

The object of the present invention is to provide the stepping motor of the further miniaturization of a kind of energy.

Stepping motor of the present invention, in framework, dispose and be fixed on the rotating shaft and rotor that the N utmost point and S utmost point alternating magnetization form, with on the axis direction of rotating shaft, be housed in the yoke and a pair of stator that forms with rotor and the coil established, it is characterized in that, a pair of stator disposes relatively with the form of clamping rotor on axis direction, both ends open on the axis direction of framework, yoke is exposed from the open end of framework.

This stepping motor is clamped rotor with a pair of stator on axis direction form constitutes, and has the advantage that can reduce the framework diameter.And this motor has the structure that its framework both ends open, yoke are exposed from the open end of framework, so the framework inner space can be enlarged along axis direction.Therefore, even the motor of same size also can make the coil of framework inside and rotor maximize, thereby raising output under the situation of original size can kept on axis direction.Adopting the framework of such both ends open type, is extremely effective for the further miniaturization of PM (permanent magnet) the type stepping motor that the lens that are used for camera drive, the driving of the pick-up head lens of medium relevant device etc. is small-sized.

In addition, be provided with notch part at the both ends of the framework that is made of nonmagnetic material, yoke is configured in the framework and the part of yoke is exposed from notch part, implements welding yoke is fixed on framework for good from notch part.By adopting the framework of both ends open type, as long as the welding position that the so simple operation of breach just can be guaranteed framework and yoke simply is set at the both ends of framework.By this notch part, weld while can confirm the position relation of framework and yoke, can improve the reliability and the operation of assembling.Such welding becomes possibility by the both ends open that makes framework.

Coil is made of air core coil, and the one or both ends of the tubular reel that disposes in the hollow part of air core coil preferably are not provided with flange part.By eliminating a side flange part at least, coil can be expanded to axis direction from reel.This means coil is maximized, thus, can under the situation of keeping the miniature motor size, improve output.

In addition, coil is surrounded by inboard yoke and outside yoke, and rotating shaft is kept by bearing, the sleeve of being located at bearing that rotating shaft connected preferably towards axis direction extend and with inboard yoke and outside yoke crimping.That is, the sleeve of being located at bearing integratedly is fixed on inboard yoke and the outside yoke, thereby does not need to be used for fixing the cap of bearing at the two ends of framework, the framework inner space can be enlarged along axis direction.And, because had sleeve with inboard yoke and outside yoke crimping, so inboard yoke is connected reliably with outside yoke by bearing.

Adopt further miniaturization of the present invention.

Description of drawings

Fig. 1 is the exploded perspective view of an example of expression stepping motor of the present invention.

Fig. 2 is the stereogram of the state after the stepping motor assembling of presentation graphs 1 finishes.

Fig. 3 is the longitudinal sectional view of expression stepping motor.

Fig. 4 is welding state is before implemented in expression to stepping motor a stereogram.

Fig. 5 is the amplification view that the major part of framework notch part is located in expression.

Fig. 6 is the front view of expression flange part.

Fig. 7 is the cutaway view of the connection status of expression framework and flange part.

Embodiment

Below, be elaborated with reference to the best example of accompanying drawing to stepping motor of the present invention.

As Fig. 1～shown in Figure 3, small-sized stepping motor 1 is cylindric, and its external diameter is about 4mm, total length is about 8mm, has realized miniaturization, and the lens that are used for camera drive, the driving of the pick-up head lens of medium relevant device etc.This stepping motor 1 have by on the periphery of rotating shaft 3 along the circumferential direction uniformly-spaced alternating magnetization be the rotor 5 that the permanent magnet of the N utmost point and the S utmost point constitutes, on the axis L of rotating shaft 3 direction, a pair of

stator

7A, 7B are configured in the front and back of rotor 5.Disposing packing ring 4a, the 4b that is installed on the rotating shaft 3 between the stator 7A of one end face of rotor 5 and front side and between the other end of the rotor 5 of rear side and the stator 7B.

Front side stator 7A constitutes magnetic circuit by coil 9A, the yoke 11A that accommodates coil 9A.Yoke 11A is made of outside yoke 13A made of iron and inboard yoke 15A, outside yoke 13A and the inboard yoke 15A sleeve 31a by being used for the bearing 31 that rotating shaft 3 is rotatably mounted with and magnetic circuit is connected.Outside yoke 13A has from the edge part of discoideus base portion 14A and extends 4 magnetic pole tooth 17A that constitute the broach shape along axis direction, and inboard yoke 15A has from the edge part of discoideus base portion 16A and extends 4 magnetic pole tooth 19A that constitute the broach shape along axis direction.

Yoke 11A disposes near yoke 11A, the base portion 14A of outside yoke 13A and the base portion 16A of inboard yoke 15A be in respectively with axis L direction on the outside of coil 9A and inboard parallel, magnetic pole tooth 17A and magnetic pole tooth 19A are roughly alternately disposing on the same circumference with the form that surrounds rotor 5.In the motor 1 that so constitutes, coil 9A and rotor 5 and establish on axis L direction, thereby can reduce the external diameter of stepping motor 1.

And terminal unit 21A is configured in the foreign side of stator 7A, the coiling 9a that stretches out from coil 9A be connected from the outstanding terminal 23A of the resin clamp dog shape 22A of portion of terminal unit 21A.This coil 9A is an air core coil, and by the resinous reel 20A maintenance integrally formed with the block 22A of portion of terminal unit 21A.Electric current is from the terminal 23A supply coil 9A of external power source by terminal unit 21A.

Then, the structure of stator 7B is identical with stator 7A, so stator 7B is made simple explanation.The stator 7B of rear side constitutes magnetic circuit by coil 9B, the yoke 11B that accommodates coil 9B.Yoke 11B is made of outside yoke 13B made of iron and inboard yoke 15B, and outside yoke 13B is connected with magnetic circuit by the sleeve 33a of bearing 33 with inboard yoke 15B.Outside yoke 13B and inboard yoke 15B have 4 magnetic pole tooth 17B and the 4 magnetic pole tooth 19B that extend formation broach shape from the edge part of discoideus base portion 14B and base portion 16B along axis L direction.

And terminal unit 21B is configured in the foreign side of stator 7B, the coiling 9b that stretches out from coil 9B be connected from the outstanding terminal 23B of the resin clamp dog shape 22B of portion of terminal unit 21B.This coil 9B is an air core coil, and by the resinous reel 20B maintenance integrally formed with the block 22B of portion of terminal unit 21B.

So among a pair of stator 7A in front and back, the 7B that constitutes, it is relative with the outer peripheral face of rotor 5 that

magnetic pole tooth

17A, 19A, 17B, 19B are configured to, and the magnetic pole tooth 17 of stator 7A is inconsistent on axis L direction with the magnetic pole tooth 17B of stator 7B, and predetermined angular staggers.The magnetic pole tooth 19A of stator 7A and the magnetic pole tooth 19B of the stator 7B predetermined angular that also staggers.Switch the sense of current that flows to

coil

9A, 9B by

terminal unit

21A, 21B successively, can make the rotation of rotor 5 step-like, rotating shaft 3 is stepping ground rotation thereupon also.

And stepping motor 1 has a pair of

stator

7A, 7B and accommodates the non magnetic framework 25 of rotor 5.This framework 25 forms cross section C font by stainless steel material, has the upwardly extending peristome 25c in axis L side.The reason that forms peristome 25c on framework 25 is: for the block 22A of portion, the 22B that makes

terminal unit

21A, 21B exposes towards the outside; In order when assembling stepping motor 1, easily

terminal unit

21A, 21B to be inserted along axis L direction from open end 25a, the 25b of framework 25; For

terminal unit

21A, 21B are located in a circumferential direction.

And, framework 25 is formed the result of cross section C font, the both ends open of framework 25 on axis L direction, base portion 14A, the 14B of

outside yoke

13A, 13B exposes from open end 25a, the 25b of framework 25.By adopting the framework 25 of such both ends open type, the inner space of framework 25 can be enlarged along axis L direction.Therefore, even the motor of same size also can make coil 9A, the 9B of framework 25 inside and rotor 5 maximize on axis L direction, so keeping raising output under the situation of original size.This for the lens that are used for camera drive, the further miniaturization of PM (permanent magnet) the type stepping motor of the driving of the pick-up head lens of medium relevant device etc. is extremely effective.

And, as Fig. 1, Fig. 4 and shown in Figure 5, the notch part S of 2 コ fonts being set in each end of the framework 25 that constitutes by nonmagnetic material, each notch part S forms outside yoke 13A, the magnetic pole tooth 17A of 13B on framework 25, the part of 17B is exposed.By adopting such notch part S, implement welding Y (with reference to Fig. 2) while can confirm

magnetic pole tooth

17A, 17B from notch part S, can easily make framework 25 combine (with reference to Fig. 2) with magnetic pole tooth 17A, the 17B of outside yoke 13A, 13B.Therefore, can improve the reliability and the operation of stepping motor 1 assembling.

As the effort of the output of further raising stepping motor 1, as Fig. 1 and shown in Figure 5, coil 9A is made of air core coil, and the reel 20A of tubular inserts in the hollow part 9c of air core coil 9A, and only the end at reel 20A is provided with flange part 20a.That is, removed former should 2 in the flange part one.Its result can maximize coil 9A with coil 9A along the expansion of axis L direction, thus, improves output when keeping the miniature motor size.

In order to realize that coil 9A further expands, also one-sided flange part 20a can be removed, but flange part 20a also is the coupling part of block 22A of portion and reel 20A that for assembling operation, reel 20A is best and terminal unit 21A is integrated on terminal unit 21A.In addition, configuration insulation film F as thin as a wafer between the base portion 14A of coil 9A and outside yoke 13A, coil 9A and reel 20A fix by binding agent.

For coil 9B, also identical with coil 9A, reel 20B inserts in the hollow part 9d of air core coil 9B, and only the end at reel 20B is provided with flange part 20b.

And as Fig. 1 and shown in Figure 3, rotating shaft 3 is kept freely by the 31b of the disc-shaped body portion rotation of bearing 31.On this bearing 31, be provided with the sleeve 31a that extends from body 31b along axis L direction, on the end of the base portion 16A of the end of the base portion 14A of yoke 13A and inboard yoke 15A, outside yoke 13A was connected by sleeve 31a with inboard yoke 15A outside sleeve 31a was crimped on.Bearing 31 is fixed on the yoke 15A by means such as welding or riveted joints.This bearing 31 need have sliding concurrently, so utilize the structure of implementing the good plating of lubrification on the pure iron surface.By adopting such bearing 31, the cap that does not need rigid bearing to use at the two ends of framework 25 can easily be expanded the inner space of framework 25 along axis L direction.

For the bearing 33 of stator 7B side, also the bearing 31 with stator 7A side is identical, the explanation that the Therefore, omited is detailed.

More than best example of the present invention is illustrated, but the present invention is not limited to above-mentioned example.As Figure 6 and Figure 7, sometimes flange part 40 can be set on stepping motor 1 as required.This occasion, the front end on the axis L of framework 25 direction is provided with tab 41, and each tab 41 is outstanding along axis L direction, and inserts and be located in the patchhole 40a of flange part 40.Open such riveted joint by the front end of implementing tab 41, flange part 40 is securely fixed on the framework 25.Tab 41 also can be weldingly fixed on the flange part 40.

Claims

1. stepping motor, in framework, dispose: be fixed on the rotating shaft and rotor that the N utmost point and S utmost point alternating magnetization form, on the axis direction of described rotating shaft, be housed in the yoke and a pair of stator that forms with described rotor and the coil established, it is characterized in that

A pair of described stator disposes relatively with the form of clamping described rotor on described axis direction, the both ends open on the axis direction of described framework, and described yoke is exposed from the open end of described framework.

2. stepping motor as claimed in claim 1, it is characterized in that, both ends in the described framework that is made of nonmagnetic material are provided with notch part, described yoke is configured in the described framework and the part of described yoke is exposed from described notch part, implements welding so that described yoke is fixed on the described framework from described notch part.

3. stepping motor as claimed in claim 1 is characterized in that described coil is made of air core coil, and the one or both ends of the tubular reel that disposes in the hollow part of described air core coil are not provided with flange part.

4. stepping motor as claimed in claim 1, it is characterized in that, described coil is surrounded by inboard yoke and outside yoke, described rotating shaft is kept by bearing, be located on the described bearing that described rotating shaft connects sleeve towards described axis direction extend and with described inboard yoke and the yoke crimping of the described outside.