JPS62250856A - Step motor - Google Patents

Abstract

PURPOSE:To enhance the positioning accuracy in the circumferential and axial directions and to facilitate the assembly at the same time, by inserting a stator into the positioning hole of a coil frame and by putting a coil block between the expanded edge of the stator and a housing. CONSTITUTION:A rotor, a cylindrical coil block 3, numerous stator segments 4 and a stator block 5 are housed in a cup-shaped housing 1 of a step motor. In the coil block 3 two coil frames 31 and 32 are combined where coil strands are wound. Positioning holes 33 in the circumferential direction of a stator segment 4 are formed to coil frames 31 and 32. An edge 41 of a stator segment 4 is expanded, inserted into a hole 33 of the coil frame 31 and surrounded by coils 34 and 35. The coil block 3 is put between an edge 41 of the stator 4 and the bottom face of a housing 1 to get secured.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a step motor.

[Background technology]

A step motor is equipped with a rotor in which a large number of opposing magnetic poles are arranged alternately in the circumferential direction, and a large number of stators are arranged in the circumferential direction at regular intervals from the magnetic poles of the rotor. Unless the positional accuracy and the dimensional accuracy of the gap between the magnetic poles of the rotor and the stator are improved, characteristics such as step angle accuracy will deteriorate. Therefore, conventionally, the stator is held in the housing with a jig, etc.
The housing was fixed by filling it with resin or the like. Therefore, assembly time is required and costs are high.

[Purpose of the invention]

In view of the above circumstances, it is an object of the present invention to provide a step motor that does not require assembling man-hours and has good characteristics.

[Disclosure of the invention]

In order to achieve the above object, the present invention provides a rotor having a magnetic pole section in which a large number of opposing magnetic poles are arranged alternately in the circumferential direction, and a rotor having a magnetic pole section that is arranged circumferentially at a constant interval on both sides of the magnetic poles of the rotor in the axial direction. The coil frame includes a first stator and a second stator arranged in large numbers, a coil block wound around a coil frame, and a housing for storing these. A hole for positioning in the circumferential direction is formed, and a first stator with one end expanded is inserted into the hole and fixed to the housing at the other end, and the other expanded end and the housing are connected to each other. The gist is a step motor with a coil block sandwiched between them.

An embodiment of this will be explained in detail below with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of a step motor according to the present invention. As shown in the figure, this step motor includes a rotor 2, a cylindrical coil block 3, a number of stator pieces (first stator) 4, and a stator block 5 housed in a cup-shaped housing l. . The housing 1 is made of a magnetic material, and holes 11 into which the stator pieces 4 are inserted are formed radially on the bottom surface thereof. A bearing 6 is press-fitted and fixed in the center of the bottom surface. A flange 12 is formed around the opening of the housing 1 . The rotor 2 includes a rotor shaft 21 through which a disc-shaped magnet 22 and bushes 23 and 24 are inserted. The disc-shaped magnet 22 is attached to the rotor shaft 21 by bushings 23,24.
Fixed. The peripheral edge of the disc-shaped magnet 22 is magnetized so that N and Si are alternately deposited regularly on both sides (the upper and lower surfaces of the disc) at regular intervals. The coil block 3 includes two coil frames 31.3 around which coil wires are wound.
2 are combined. As shown in FIG. 4, the coil frame 31 has two winding portions 31a on diagonal lines around which coil wires are wound. The two winding portions 31a are connected by a collar portion 31b formed at one end thereof.

A hole 33 is formed in the coil frame 31 to position the stator piece 4 in the circumferential direction. The coil frame 32 is also the coil frame 3
It is the same as 1. By wrapping the coil cotton around the coil frames 31 and 32, turning one side of the coil frames inside out and shifting them by 90'', the cylindrical coil block 3 is obtained.In this way, the coil block 3 Two coil frames 3 around which coil wires are wound
1.32, the coil frame can be easily wound.

The stator piece 4 has one end 41 widened and is inserted into the hole 33 of the coil frame 31, and the coil 34, 35
It is now surrounded by Other end 4 of stator piece 4
2 is fitted into the hole 11 of the housing 1. The other end of the stator piece 4 is caulked and fixed to the bottom surface of the housing 1. The coil block 3 is sandwiched between one end 41 of the stator piece 4 and the bottom surface of the housing 1, and is fixed so as not to float up. As described above, since the stator piece 4 is inserted into the hole 33 of the coil frame and fixed to the housing 1, the coil frame positions the stator piece 4 and prevents it from falling down, and the positional accuracy of the stator piece 4 in the circumferential direction is improved. improves. Further, since one end portion 41 of the stator piece is expanded, the stator piece 4 is positioned in the axial direction by the upper surface of the coil frame, and the positional accuracy of the stator piece 4 in the axial direction is also improved. Note that the method for fixing the stator piece 4 to the bottom surface of the housing l is not limited to caulking, but may also be an adhesive method.

The stator block 5 is placed on a protrusion 13 provided on the inner peripheral surface of the housing 1 and closes the opening of the housing 1. On the lower surface of the stator block 5, a large number of convex second stators 51 are provided radially. The second stator 51 and the other end 41 of the stator piece 4 face each other and are magnetically connected by the housing 1 and the stator block 5. A bearing 7 is press-fitted and fixed in the center of the stator block 5. The rotor 2 is rotatable about its axis by having its rotor shaft 21 passed through and supported by bearings 6.7. The disk-shaped magnets 22 of the rotor 2 are arranged between the other end 41 of the stator piece 4 and the second stator 51 so as to be spaced from them at fixed intervals G and G' in the axial direction, respectively. . A part of the housing opening peripheral wall has a
A notch 14 is formed through which the lead wires 36 of the coils 34, 35 are drawn out.

FIG. 3 shows the state in which the coil block 3 and the stator piece 4 are attached to the housing 1, viewed from above. As shown in the figure, the stator piece 4 inserted into the coil frame 31 and the stator piece 4 inserted into the coil frame 32 are
They are separated by 2πxl (n is an integer) ±(π/2). below,
π stands for electrical angle. Considering the case of a 30-pole two-phase step motor, the stator piece 4 inserted into the coil frame 31 and the stator piece 4 inserted into the coil frame 32 are π/
Since they are arranged offset by 2, the positional relationship between the coil 34 of the coil frame 31 and the coil 35 of the coil frame 32 is 90'' (since there are 30 poles, 2π=360'/l 5=2
4°, yr/2-6', n=4, 2π×4-(
π/2)=90°. ). The stator pieces 4 inserted through the coil frame 31 and the coil 32 have an electrical angle of 2π.
-(π/6) away. This pinch is usually 2π×
Normally, it is set to n, but the reason why it is set to 2π-(π/6) is to reduce the torque (detent torque) when no current is flowing. The above has described the arrangement of the stator pieces 4 in the circumferential direction, but the second
The stator 51 also has the same arrangement as the stator pieces 4.

FIG. 5 is a principle diagram showing the relationship between the rotor and stator (stator piece and second stator) using a two-pole step motor, and a rectangular wave pulse as shown in FIG. 6(a) is applied to the coil 34. , the rotor 1 is made to rotate by applying a rectangular wave pulse whose phase is shifted by π/2 as shown in FIG. 6 (bl) to the coil 35.
In the case of a pole, one step is 66.1 periods and 6'X4=2
Rotate 4 degrees.

The step motor according to the present invention is not limited to the above embodiment.

〔Effect of the invention〕

As described above, the step motor according to the present invention includes a rotor having a magnetic pole portion in which a large number of opposing magnetic poles are arranged alternately in the circumferential direction, and a constant interval on both sides of the magnetic poles of the rotor in the axial direction. The coil frame includes a first stator and a second stator arranged in large numbers in the circumferential direction, a coil block wound around a coil frame, and a housing for storing these items, and the coil frame includes a coil block surrounded by coils. A hole is formed for positioning the first stator in the circumferential direction, and the first stator with one end expanded is inserted into the hole and fixed to the housing at the other end, and the first stator with the expanded other end Since the coil block is sandwiched between the part and the housing, the positional accuracy of the first stator in the circumferential direction and the axial direction is improved. Therefore, the positional accuracy of the stator with respect to the rotor's magnetic poles and the dimensional accuracy of the gap between the rotor's magnetic poles and the stator are improved, and characteristics such as step angle accuracy are improved. Moreover,
This eliminates the need for the conventional work of holding the stator in the housing with a jig or the like, filling the housing with resin, etc., and fixing it, thereby reducing the number of assembly steps.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of an embodiment of a step motor according to the present invention, and FIG. 2 is a longitudinal sectional view of the embodiment.
Figure 3 is a plan view showing the state in which the coil block and stator piece are attached to the housing of the above embodiment;
The figure is a perspective view of the coil frame of the above embodiment with a part thereof cut away, Figure 5 is a principle diagram showing the relationship between the rotor and stator using a two-pole step motor, and Figure 6 (a). b
) is a waveform diagram showing the pulses applied to different coils. ■... Housing 2... Rotor 3... Coil block 4... Stator piece (first stator) 2
2...Disc-shaped magnet (magnetic pole section of rotor) 31.
32... Coil frame 33... Hole for positioning the first stator in the circumferential direction 41... One end of the stator piece
42...Other end of stator piece 51...Second stator 2R 31 No. 41!1a Fig. 5

Claims (2)

[Claims] (1) A rotor having a magnetic pole portion made up of a large number of opposing magnetic poles arranged alternately in the circumferential direction, and a first stator in which a large number of magnetic poles are arranged circumferentially at regular intervals on both sides of the rotor's magnetic poles in the axial direction. and a second stator, a coil block wound around a coil frame, and a housing for storing these items, and the coil frame includes a first stator surrounded by coils.
A hole for positioning the stator in the circumferential direction is formed, and a first stator with one end expanded is inserted into the hole and fixed to the housing at the other end, and the first stator with the expanded other end and the housing A step motor with a coil block sandwiched between. (2) The step motor according to claim 1, wherein the coil block is constructed by combining a plurality of wound coil frames.