JPH03135355A - Structure of crow pawl type stator for pm type 2-phase stepping motor - Google Patents

Abstract

PURPOSE:To improve incorporating accuracy by a method wherein a resin ring is fitted to the outer periphery of a cylindrical pole teeth unit, made by combining a flat flange type yoke with a cup type yoke, and the resin ring is compressed into the direction of thrust under a condition that respective yokes are incorporated. CONSTITUTION:The cylindrical pole teeth unit 1 of flat flange type yokes A, B are combined with the cylindrical pole teeth unit 3 of cup type yokes C, D under non-contacting engaged condition and resin rings G, H are fitted to the peripheries of said pole teeth units 1, 3 while toroidal type coils E, F are mounted on the circumferences of the resin rings G, H. In such a constitution, the positioning of the direction of thrust is effected by the resin rings G, H. In this case, the resin rings G, H are compressed between the end faces of te cup type yokes C, D into the direction of the thrust while the flat flange type yokes A, B are positioned in the direction of the thrust utilizing the resin rings G, H as spacers. According to this method, the incorporating accuracy of 4 pieces of yokes may be increased sufficiently with a simple structure without inviting the increase of the cost of a stepping motor.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in the claw-pole stator structure of a PM (permanent magnet) type two-phase stepping motor.

(Prior Art) The claw-pole stator structure of the PM stepping motor is explained in detail in, for example, ``Easy Learning of Stepping Motors and How to Use'' published by Sogo Denshi Publishing.

FIGS. 4 and 5 show a typical conventional low-ball type stator structure of a PM type two-phase stepping motor.

In this stator structure, two flat flange type yokes A and B each have a flat flange 2 on the outside of a cylindrical pole toothed part 1, and two flat flange type yokes A and B each have a cup-shaped cylindrical part 4 on the outside of a cylindrical pole toothed part 3. It is equipped with a cup-shaped yoke C1D.

Flat flange type yoke A (B) and cup type yoke C (D
) are assembled so that the cylindrical pole tooth portions 1 and 3 of the two are in a non-contact meshing state, and a toroidal coil E (F) is installed around the pole tooth portion 1.3.

The flat flange-shaped yokes A and B are welded with their backs in contact with each other, and the cup-shaped yokes C and D are welded with their end surfaces of the cup-shaped cylindrical portions 4 in contact with each other.

A convex portion 2a is formed on the outer peripheral edge of the flat flange 2 of the flat flange type yokes A, B, and a concave portion 4a is formed on the end face of the cylindrical portion 4 of the cup type yokes C, D correspondingly. There is. Each yoke ASB, C.

When D is combined as described above, yoke A,
The convex part 2a of B fits into the concave part 4a of yokes C and D, and by this fitting, each yoke A, B, and C.

D is positioned in the radial direction. In addition, in this fitting structure, the convex portions 2a of the overlapping flat flanges 2 are sandwiched by the concave portions 4a of the yokes C and D in the thickness direction (the thrust direction of the stator), and by this sandwiching, the flat flange type yoke A , B are positioned in the thrust direction.

(Problems to be Solved by the Invention) In the conventional structure described above, the cup-shaped yokes C and D are joined at their edges to form a single body, but the flat flange-shaped yokes A and B installed between them are Concave portion 4a and convex portion 2a
Since it is only mated with yoke ASB and yoke C
, D, which causes a problem in that the yoke A1B rattles and generates vibration noise when the motor is operated. Particularly, the wobbling of the stator in the thrust direction is caused by an error in the dimensional accuracy of the depth of the four parts 4a, and it is very difficult to increase this dimensional accuracy in press sheet metal processing.

As a countermeasure to the above problem, yoke ASB is changed to yokes C and D.
They may be fitted together and joined together by welding or the like, but the increase in the number of welding steps results in a considerable increase in cost. Another measure is to combine the yokes A and B with the yokes C and D, and then caulk the convex portions 2a of the two stacked flat flanges 2 so as to separate them from each other.
There is a method to eliminate the gap in the thrust direction at the fitting part with a. However, this method is also very troublesome and results in a significant increase in cost.

This invention was made in view of the above-mentioned conventional problems, and the aim is to make it possible to assemble each of the four yokes with a sufficiently high precision by a simple improvement method that does not increase costs. It is in.

(Means for Solving the Problems) Therefore, in this invention, a resin ring is attached to the outer periphery of the cylindrical pole tooth part where a flat flange type yoke and a cup type yoke are combined, and a state in which each of the four yokes is assembled The dimensions were such that this resin ring was compressed in the thrust direction.

(Function) In the above structure, when the four yoke parts are assembled, the two resin rings are compressed in the thrust direction between the end faces of the cup-shaped yoke, and the flat flange-shaped yoke compresses the resin rings. Positioned as a spacer in the thrust direction.

(Embodiment) FIGS. 1 to 3 show the structure of an embodiment of the present invention. In this stator structure, two flat flange type yokes A and B each have a flat flange 2 on the outside of a cylindrical pole toothed part 1, and two cups have a cup-shaped cylindrical part 4 on the outside of a cylindrical pole toothed part 3. It is equipped with a shaped yoke C1D.

Flat 7 lunge type yoke A (B) and force/tube type yoke C (
In D), the cylindrical pole teeth 1 and 3 of the two are combined so that they are in a non-contact meshing state, and a resin ring G (H) is attached around the pole tooth 1.3, and
A toroidal coil E (F) is attached around the resin ring G (H).

The flat flange type yokes A and B are in contact with each other back to back, and the cup-shaped yokes C and D are welded with the end surfaces of the cup-shaped cylindrical portions 4 in contact with each other.

A convex portion 2a is formed on the periphery of the flat flange 2 of the lower flange type yokes A, B, and correspondingly, the cup type yokes C,
A recess 4a is formed in the end surface of the cylindrical portion 4 of D. When assembling each yoke ASB, C, and D, the convex portion 2a
is fitted into the four parts 4a, and each yoke A is fitted with this uneven fitting structure.
, B, C, and D are positioned in the radial direction.

What should be noted here is that in the present invention, the above-mentioned uneven fitting structure has a positioning function only in the radial direction,
The difference is that it does not have a positioning function in the thrust direction like the conventional one. In other words, the depth of the four parts 4a is set larger than the thickness of the convex part 2a, and in this fitting structure, the thickness direction (
A sufficiently large gap is actively created in the thrust direction).

Positioning in the thrust direction is done by a resin ring GSH. In other words, the resin rings G and H are cup-shaped yokes C,
The lower flange type yokes A and B are compressed in the thrust direction between the end faces of D, and the resin ring G.

It is positioned in the thrust direction using H as a spacer.

As shown in FIG. 3, one side of the inner periphery of the resin ring G (H) is formed into a tapered shape, making it easy to fit the pole tooth portion 1 into this inner periphery.

(Effect of the invention) As explained in detail above, according to the present invention, the simple 11
By using a resin ring that can be manufactured at low cost and fitting this ring into the cylindrical pole teeth of each yoke at the inner circumference of the coil, two lower flange shapes are formed within the two cup-shaped yokes. The yoke is positioned in the thrust direction. In other words, each part can be assembled with high precision using a compressed resin ring between the cup-shaped yokes as a spacer, without relying on the precision of the yoke produced by press sheet metal processing, which is difficult to achieve high dimensional accuracy. Sticking will no longer occur.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing a stator structure according to an embodiment of the present invention, and Fig. 2 shows the assembled state of the same embodiment.
3 is a sectional view of the resin ring in the same embodiment as above; FIG. 4 is an exploded perspective view of the conventional stator structure;
The figure is a cross-sectional view taken along the line v-V of the one shown in FIG. Cylindrical pole tooth flat flange 2a...Convex part/Cylindrical pole tooth part cup-shaped cylindrical part 4a...Concave part B...Lower flange type yoke D...Cup shaped yoke F...Coil H・・・Resin ring

Claims (1)

[Claims] Two flat flange type yokes A and B having a flat flange on the outside of the cylindrical pole tooth part, and two cup-shaped yokes having a cup-shaped cylindrical part on the outside of the cylindrical pole tooth part. C, D, flat flange type yoke A (B) and cup type yoke C (D)
The two cylindrical pole teeth are combined so that they mesh without contact, and a resin ring is attached around the pole teeth, and a toroidal coil is attached around the resin ring. The flat flange type yokes A and B are in contact with each other back to back, and the cup-shaped yokes C and D are joined with the end surfaces of the cup-shaped cylindrical portions in contact with each other.
The cup-shaped yokes C and D are positioned in the radial direction by a concave-convex fitting structure, and the two resin rings are compressed in the thrust direction between the end faces of the cup-shaped yokes C and D, and the flat flange-shaped yokes A, B
A claw pole stator structure of a PM type two-phase stepping motor, characterized in that the resin ring is positioned in the thrust direction using the resin ring as a spacer.