JPH0140296Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field of invention] The present invention relates to an inner rotor type motor.

[Technical background of the invention]

In a small stepping motor, etc., as illustrated in FIG.
A motor is known that is fitted to both ends of a stator 4, respectively.

The stator 4 of this type of motor is formed of a stacked body of electromagnetic steel plates, but most of its outer periphery except for both ends is not covered by the pair of frames 3.

For this reason, the outer periphery of the stator 4 is painted, and the coating 5 is used to prevent the stator 4 from rusting.

[Problems with background technology]

However, it has been difficult to control the thickness of the coating pattern 5 at a constant level in terms of manufacturing. Therefore, frame 3
If the coating 5 sandwiched between the frame 3 and the stator 4 is too thick, it will be difficult to fit the frame 3 and the stator 4 together. Moreover, if the coating pattern 5 is too thin, not only will there be a problem in the rust prevention effect, but also the axes of the rotor 1 and the stator 4 will be misaligned due to the play that occurs in the fitting portion. If the axis mismatch occurs, the intervals between the salient pole teeth of the rotor 1 and the stator become uneven, making it impossible to achieve stable performance. Furthermore, the coating pattern 5 is weak in strength and easily peels off. If the coating pattern 5 peels off, it not only makes the appearance unsightly, but also impairs the rust prevention performance.

[Purpose of invention]

Therefore, the purpose of this invention is to reliably maintain rust prevention performance over many years of use, maintain a good appearance, be easy to assemble, and prevent axial misalignment between the rotor and stator. Our goal is to provide motors that can.

[Summary of the idea]

The present invention has a pair of frames, a rotor, and a stator, and each of the frames has an annular peripheral wall integrally around the end plate, and an inner corner of the tip of the peripheral wall. The frame has an annular fitting groove, and a bearing is attached to the center of the end plate, and the pair of frames are disposed with the ends of their peripheral walls facing each other, and both ends of the stator are directly fitted into the fitting grooves, the stator is disposed between the pair of frames, and a rotating shaft of the rotor disposed inside the stator is rotatably supported by the bearing. Implemented on the motor.

The present invention to achieve the above purpose is as follows:
A fitting groove shallower than the fitting groove is formed at the tip of the peripheral wall portion along the axial direction of the frame and connected to the outer periphery of the fitting groove, and a non-metallic barrier is formed on the outer periphery of the stator. A rust ring is attached to each of the stators with both ends exposed, and the exposed ends of the stator are directly fitted into fitting grooves of the pair of frames, and both ends of the rust prevention ring are fitted. is inserted into the annular groove, and the peripheral wall portion covers both ends of the rust prevention ring.

According to the motor of the present invention configured as described above, the outer peripheral portion of the stator that is not covered by the frame is covered with the anti-rust ring, and both exposed ends of the stator are covered with the frame, so that the outer peripheral portion of the stator Can be rust-proofed. Since the anti-corrosion ring is made of non-metallic material, it will not peel off unlike conventional coatings, and since it can be manufactured easily and consistently, there will be little variation in the anti-rust effect. Therefore, for these reasons, a sufficient stator rust prevention effect can be maintained over many years of use. Since the end of the rust prevention ring is inserted into the frame and covered with the peripheral wall of the frame, even if there are variations in the end position of the rust prevention ring and the length of the ring, the end of the rust prevention ring visibility is prevented. Therefore, it has a good appearance. Moreover, since the anti-rust ring does not peel off as described above, the good appearance will not be impaired even after many years of use. Furthermore, the fitting grooves of the frame are directly fitted to both ends of the stator that are not covered by the anti-rust ring, so that the anti-rust ring is not inserted into these fitting parts, making assembly easy. Of course, there is no factor other than the dimensional accuracy of the stator and frame, whose dimensions can be easily controlled, that would cause these axes to be inconsistent. In addition, since the above-mentioned fitting is performed closely, that is, without any gaps, the axes of the rotor and stator can be precisely aligned, and stable performance can therefore be achieved.

[Example of idea]

A first embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

In the figure, reference numeral 11 denotes a pair of frames having an annular peripheral wall portion 11b integrally provided around the end plate portion 11a.
These are arranged with the tips of the peripheral wall portions 11b facing each other. Furthermore, a bearing 12 is attached to the center of the end plate portion 11a, and a rotating shaft 14 of a rotor 13 is rotatably supported between these two bearings 12. The rotor 13 includes, for example, a rotating shaft 14, a magnet 15, and a pair of rotor cores 16 provided in contact with both sides of the magnet 15.
are formed by attaching them to each other. Although not shown in FIG. 2, a plurality of salient pole teeth are provided protruding from the outer periphery of the rotor core 16.

Further, 17 in the figure is a stator disposed inside and clamped to these frames 11. It goes without saying that the pair of frames 11 are connected with the stator 17 sandwiched therebetween. Stator 17
is formed by providing an excitation winding 19 on a stator core 18 which is formed by laminating and bonding a large number of electromagnetic steel plates, for example. Although not shown in FIG. 2, the stator core 18 has a plurality of salient pole teeth on its inner periphery, and the excitation winding 19 is wound around the salient pole teeth.

On the outer periphery of the stator 17, a non-metallic anti-corrosion ring 2 is provided with both ends of the stator 17 exposed.
0 is coated. In this example, the rust prevention ring 20
The case is shown in which the anti-rust ring 20 is made of a heat-shrinkable synthetic resin tube, and therefore, after being covered with the outer periphery of the stator 17, the anti-rust ring 20 is heated and shrinks to be installed. ing.

A fitting groove 21 that closely fits into the exposed end of the stator 17 is provided at the inner corner of the tip of the peripheral wall portion 11b of the pair of frames 11. Therefore, in this motor, the outer diameter dimension A of the stator 17 and the dimension B of the fitting groove 21 are approximately equal. Furthermore, an annular groove 22 is provided at the opening edge of the peripheral wall portion 11b of the pair of frames 11 so as to be connected to the outer periphery of the fitting groove 21. This annular groove 22 is formed shorter than the fitting groove 21 along the axial direction of the frame 11, and the end of the rust prevention ring 20 is inserted into the annular groove 22.
b is designed to cover the end of the rust-proofing ring 20.

The motor with the above structure rotates by an angle corresponding to the number of excitation phases due to the attractive and repulsive forces that act between the salient pole teeth between the rotor core 16 and the stator core 18 when the excitation phase is switched by energizing the excitation winding 19. It is something that will be done.

Further, the motor having the above structure is assembled by directly fitting the opening edges of the pair of frames 11 to both ends of the stator 17, but this fitting is done when the stator 17 is formed to have approximately equal dimensions A and B. and the fitting groove 21 of the frame 11. For this reason, the axial center of the stator 17, the axial center of the bearing 12 attached to the center of the frame 11, and therefore the axial center of the rotor 13 are assembled so that they exactly match. Therefore, the gap between the two salient pole teeth becomes constant, and stable performance can be achieved. Since the outer periphery of the stator 17 is covered with the anti-corrosion ring 20 and the peripheral wall portion 11b of the frame 11 which are brought into close contact with the outer periphery, the stator 17 can be reliably prevented from rusting. Furthermore, unlike a painted pattern, the rust prevention ring 20 can be easily manufactured to a certain thickness, shape, etc., and therefore, the reliability of the rust prevention effect is also high. Furthermore, frame 1
1 has an annular groove 22 and covers the end of the antirust ring 20, so that the appearance of the motor can be improved. In particular, in this embodiment, since the anti-corrosion ring 20 is a tube made of heat-shrinkable synthetic resin, although there are considerable variations in the end positions and length dimensions, the effects of these variations are not visually recognized. It prevents this from happening and looks good.

Moreover, since the anti-corrosion ring 20 is made of non-metal,
Because it is easy to manufacture, can be obtained at low cost, and is lightweight, it does not contribute to the increase in cost and weight of the entire motor, and the stator 1
It is easy to apply it to the outer periphery of 7.

Next, a second embodiment shown in FIG. 5 will be explained.

This embodiment is the same as the first embodiment described above, except that the anticorrosive ring 20 is made of synthetic rubber. Note that the anti-corrosion ring 20 protects the stator 17 with its elastic force.
In addition to being attached to the outer periphery, in this embodiment, it has a large number of fins 20a, and this anti-rust ring 20 is used as a mounting portion.

Therefore, the intended purpose of the present invention can also be achieved in this second embodiment. Note that in this embodiment, since the anti-corrosion ring 20 is made of synthetic rubber, it can provide an anti-slip effect when attaching the motor, etc. Furthermore, in this embodiment, if the fins 20a are made larger, an anti-vibration effect can be obtained.

Furthermore, although both of the above-mentioned embodiments are constructed as described above, in the present invention, the anti-rust ring 20 may be formed to protrude from the outer surface of the frame 11 except for its both ends. In this case, the anti-rust ring 20 can also serve as a frame protection material that prevents the frame 11 from hitting the motor mounting surface or the like and prevents the frame 11 from being damaged.

In addition, when implementing the present invention, the specific structure, shape, position, and material of the rotor, stator, bearing, frame, rust prevention ring, fitting groove, annular groove, etc. shall be It goes without saying that the present invention is not limited to the above embodiments and can be implemented in various ways.

[Effect of idea]

The present invention described above has an annular groove that is shallower in the axial direction of the frames than the annular fitting groove provided at the inner corner of the end portions of the peripheral wall portions of the pair of frames. A non-metallic anti-rust ring is attached to the outer periphery of the stator with both ends of the stator exposed, and the exposed ends of the stator are connected to the outer periphery of the fitting groove. By directly fitting each into the fitting groove of the frame, and inserting both ends of the rust preventive ring into the annular groove, and covering both ends of the rust preventive ring with the peripheral wall, it has been possible to achieve long-lasting results. It has a variety of excellent practical uses, such as being able to reliably maintain rust prevention performance over the course of use, maintaining a good appearance, being easy to assemble during manufacturing, and preventing misalignment of the rotor and stator axes. effective.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a conventional example. 2 to 4 show a small stepping motor according to the first embodiment of the present invention, in which FIG. 2 is a vertical side view, FIG. 3 is a partially enlarged sectional view, and FIG. 4 is a frame and stator. FIG. 2 is an exploded cross-sectional view showing the relationship between FIG. 5 is a longitudinal sectional side view showing a second embodiment of the present invention. 11... Frame, 11a... End plate portion, 11b
... Peripheral wall portion, 14 ... Rotating shaft, 12 ... Bearing, 1
3... Rotor, 17... Stator, 20... Antirust ring, 21... Fitting groove, 22... Annular groove.

Claims (1)

[Claims for Utility Model Registration] It has a pair of frames 11, a rotor 13, and a stator 17, and each frame 11 has an annular peripheral wall part 11b integrally around the end plate part 11a, and The peripheral wall portion 11b has an annular fitting groove 21 at the inner corner of the tip thereof, and a bearing 12 is attached to the center of the end plate portion 11a. 11b
are disposed with their tips facing each other, and both ends of the stator 17 are fitted into the fitting grooves 21, respectively, so that the stator 17 is connected to the pair of frames 1.
1, in which a rotary shaft 14 of the rotor 13 disposed inside the stator 17 is rotatably supported by the bearing 12.
A fitting groove 22 shallower than the fitting groove 21 is formed along the axial direction of the stator 17 and connected to the outer periphery of the fitting groove 21, and a non-metallic anti-rust ring 20 is attached to the outer periphery of the stator 17. Both ends of the stator 17 are exposed and covered, and the exposed ends of the stator 17 are directly fitted into the fitting grooves 21 of the pair of frames 11, and both ends of the rust prevention ring 20 are fitted. part into the annular groove 22, and the peripheral wall part 11b
A motor characterized in that both ends of the anti-corrosion ring 20 are covered with.