KR910007559Y1 - Small synchronous motor - Google Patents

Abstract

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Description

Small synchronous motor

1 is a central longitudinal sectional view showing one example of a small synchronous motor incorporating a reduction mechanism according to the present invention.

2 is an exploded perspective view showing an embodiment of the impact mitigating mechanism of the motor.

3 is a central longitudinal cross-sectional view of the assembled state of the impact mitigation mechanism of the embodiment.

4 is an exploded perspective view showing another embodiment of the impact mitigating mechanism.

(A)-(h) are sectional drawing which shows another Example of an elastic body.

6 is an explanatory view showing another embodiment of a method of arranging an elastic body.

7 (a), (b) is a curve diagram and a load curve diagram of the motor rotational speed of the present invention.

8 is a partial cutaway front view showing one embodiment of a conventional homogeneous small synchronous motor.

9 (a) and 9 (b) are curve diagrams and load curve diagrams of the rotational speed of the motor of FIG.

Tenth (a) and (b) are exploded perspective views and bottom views showing assembled examples of other conventional small synchronous motors.

* Explanation of symbols for main parts of the drawings

7: gear 8: axis of rotation

9: motor 23: protrusion

24: groove 27: elastic body

The present invention relates to a small synchronous motor incorporating a deceleration gear mechanism. More specifically, the present invention is directed to a small synchronous motor incorporating a deceleration gear mechanism including a shock absorbing mechanism for reducing load torque applied during operation. It is about.

Conventionally, a small synchronous motor and a so-called gear motor incorporating a deceleration gear mechanism are provided so as to transmit rotation of a rotor to an output shaft via a deceleration value array. Therefore, during operation, as shown in Fig. 9 (a), the rotation rises sharply and reaches a predetermined rotation speed (normal rotation) in a short time t. It is common to follow the occurrence of the transient peak (p) of the load torque as indicated by the load curve of. And since it operates reliably against the transient peak load p, a large power motor is needed, and it is difficult to miniaturize and there is a problem that cost increases. This also does not solve the problem of the peak appearance of the peak appearance of excessive load torque, which is insufficient in characteristics and has a defect in quality.

On the other hand, in order to solve this drawback, as shown in FIG. 8, the output gear 102 rotates freely in the output shaft 101 of the motor, and the support plate 103 which engages and interlocks with the output shaft 101 before and after the rotation thereof. A motor with a friction clutch, which is fitted as a spring washer 104 and constitutes a friction clutch for interlocking the output shaft 101 and the output gear 102 by a frictional force, has been put into practical use. By the action of the friction clutch, the rotation is delayed and slowed down so that the peak p of the oak is suppressed under excessive load, thereby preventing internal damage caused by external force.

In addition, as shown in FIGS. 10A and 10B, the gear 202 can be freely rotated with respect to the rotation shaft (output shaft) 201, while between the two disks 203 fixed to the rotation shaft 201. The through-hole 204 parallel to the rotating shaft 201 is provided in the tooth 202 at the same time as the tooth 202 is fitted, and the disk 203 is parallel to the rotating shaft 201 and the tooth 202 is provided. A pin 205 penetrating through the through hole 204 of the 204 is provided, and the through hole 204 between the pin 205 and the tooth 202 is filled with the polymer elastic body 206 to prevent the impact at the time of motor operation. In some cases, the elastic body 206 is absorbed and buffered (Japanese Patent Application No. 51-88512). According to this buffer mechanism, the rotation of the gear 202 is transmitted to the gear 202 → the polymer elastic body 206 → the attachment piece 205 → the disk 203 → the rotation shaft 201.

However, the friction clutch has a large dispersion of quality, and it is difficult to manage the friction torque, and also has a problem that the friction torque decreases when the friction clutch slides repeatedly due to wear of the inclined surface. For this reason, it is easy to set the relationship as friction torque> motor torque> load torque. However, when friction torque> motor torque, the rise in operation is suddenly increased as in FIG. As shown in Fig. 6A), the peak p of the transient load torque is generated.

When the torque relationship is moto torque> friction torque> load torque, the rise in operation becomes smooth in an ideal state, and a motor of friction torque without peak (p) of transient load torque is obtained, but when the torque relationship collapses. There is no idle or frictional effect and mobility is reduced. For this reason, the relationship between motor torque> transient load torque is required, and there is a drawback of using a large motor.

In addition, the same effect can be obtained by assembling the latch spring with the metal spring or the buffer spring using the coil spring instead of the spring washer of FIG. 8. There is a flaw.

In the case of the motor of FIG. 10, the shock absorbing mechanism is complicated and the number of parts is large, resulting in increased cost and difficulty in assembly. In particular, since the disk 203 is fixed to the rotating shaft 201, the shaft portion 201 is partially cut out (D cut 207) to form a complicated shape to form the jaw portion 208, which makes machining difficult and mechanical due to cohesion. It is easy to bring down the strength.

For this reason, it is not suitable when a brittle material such as ceramics is to be used for the output shaft 201 because the use under a high temperature atmosphere is considered, such as in a rotary motor of a microwave oven. In addition, it is also possible to reduce the number of parts by integrating a plurality of separated parts such as a polymer elastomer, but there are problems such as difficulty in processing parts. In addition, since the teeth 202 are fitted by the two disks 203 fixed to the rotating shaft 201, large play cannot be secured in the thrust direction. For this reason, it is difficult to employ a weight sensor that uses the movement of the output shaft of the motor, and there is a problem in that it is not possible to eliminate a motor attachment error or a mismatch in the thrust direction acting on the load side.

It is therefore an object of the present invention to provide a small synchronous motor incorporating a deceleration gear mechanism having a shock absorbing mechanism having a simple structure, a small number of parts, and a simple shaft shape.

In order to achieve the above object, the synchronous motor of the present invention comprises any one rotating member of the deceleration gear mechanism including a rotor and an output shaft between the driving side member and the driven side member. Each of the ipsilateral members is provided with a coupling portion provided to protrude or concave in the radial direction, and the coupling portions of both members are disposed to have a predetermined interval with respect to the circumferential direction, and between the coupling members of the two members in the circumferential direction of both members. It is intended to interpose an elastic body deformed by relative movement of.

Therefore, if the relative rotation acts between the driving side member and the driven side member simultaneously with the starting of the motor, the elastic body between the engaging portions of both members deforms and the shock during starting is absorbed, so that the increase in rotation is shown in FIG. As shown in the figure, it is gentle and there is no transient peak as shown in Fig. 7 (b).

Hereinafter, the embodiment of the present invention will be described in detail.

1 shows an embodiment of a small synchronous motor according to the present invention. This compact synchronous motor has a bobbin 11 in which a excitation coil 13 is wound in a cup-shaped case 1, and a rotor 9 having a magnet 10 attached to the center thereof is installed. ) And the output shaft 8 are connected via the output gear 7 and the reduction gears 4, 5, and 6, and are sealed by the cover plate 3.

At the bottom of the cup-shaped case 1, a plurality of yokes (not shown) are cut and raised upwards, arranged along the inner circumferential surface of the bobbin 11, and the lower end of the rotor shaft 14 is fixed.

The core plate 2 is provided in the cup-shaped case 1. A plurality of yokes (not shown) are cut out and placed in the core plate 2 so as to lie along the inner circumferential surface of the coil bobbin 11 and are assembled with the yoke. In addition, the core plate 2 is provided with a through hole 20 through which the drive pinion 9b formed integrally with the rotor 9 freely attached to the rotor shaft 14. In addition, rotation is freely fitted to the shaft 15 on which the drive pinion 9b and the reduction gear 4 to which it engages are fixed between the cover plate 3 and the core plate 2.

The shafts 18 and 16 are respectively fixed between the cover plate 3 and the core plate 2 and between the cover plate 3 and the case 1, and the reduction gears 5 and 6 are rotated. It fits freely, and the output gear 7 and the rotor 9 on the output shaft 8 are connected via the reduction gears 4, 5, and 6.

The rotor 9 is made of a hollow shaft portion 9a of a synthetic resin material and a magnetizing magnet 10 attached to the hollow shaft portion, and the pinion 9b is integrally formed on the hollow shaft portion 9a.

In the drawing, reference numeral 12 is a bobbin cover, 17 is a terminal, and 19 is a bearing.

The output shaft 8 is provided with a pin-shaped protrusion 23 in the radial direction and fitted into the groove 24 provided in the output gear 7. The groove 24 has a relation to engage at least with the protrusion 23 of the output shaft 8 in the original direction.

In the present embodiment, as shown in Fig. 2, the output gear 7 is bored with a + -shaped groove 24 penetrating the axial direction. In addition, the groove 24 may close one end to prevent the protrusion 23 from being separated. In the present embodiment, this groove 24 is formed in a + -shape perpendicular to each other, but may be one groove or a plurality of grooves. Of course, the pins as the protrusions 23 are also not limited to those shown in the drawings, but it is preferable that the pins are formed in a suitable shape or coefficient in correspondence with the shape, the coefficient, and the like of the grooves 24. In addition, the gear 7 and the shaft 8 are contacted at each corner portion 21 of the portion where the groove 24 intersects and is supported in the radial direction of the gear.

In addition, as the protrusions 23 formed on the output shaft 8, generally, a flat shape is suitable, but the present invention is not limited thereto, and is coupled to the groove 24 of the output gear 7 in the circumferential direction. It is possible to implement. For example, in the present embodiment, the output shaft 8 and the pin 23 are formed by drilling a hole 26 orthogonal to the shaft 8 in the output shaft 8 and pressing the pin 23 into the hole 26. I integrate it.

In addition, in the present embodiment, the thrust direction of the output shaft 8 is supported by another structure 22, for example, a gas or spring plate (for weight detection) of a microwave oven. Therefore, in the case of using it as a driving source of the rotary table of the microwave oven, it is possible to attach a sensor for measuring the weight of the food to be heated by using the axial movement of the shaft 8. In addition, since the output shaft is movable in the axial direction, it can be absorbed even when a thrust is applied on the load side or an attachment error in the thrust direction occurs when the motor is attached to the equipment used.

An elastic body 27 is provided between the pin 23 and the groove 24 that does not prevent relative movement between the pin 23 and the groove 24 in the axial direction. As the elastic body 27, an elastomer or a spring member made of a rubber such as rubber, polyurethane, or fluorine resin is usually employed. For example, the cylindrical body as shown in FIG. 2 or as shown in FIG. It is formed integrally with the groove shape. In the case of the cylindrical shape, the shape of the elastic body 27 is obtained by adopting various shapes as shown in Figs. 5 (a)-(h). It is preferable.

In the case of the integrated elastic body 27, a shape corresponding to the groove 24 of the gear 7 as shown in FIG. 4, for example, is integrally formed in a + shape to allow the pin-shaped protrusion 23 to pass through. Groove 28 is installed. In this case, since only the bottom part 29 exists in an axial direction, the plate of the output direction of the output side 8 can be enlarged compared with the shape of FIG. 2 which surrounds the perimeter of the projection 23 with the elastic body 27. As shown in FIG.

In addition, the shape of the integral elastic body 27 may be considered in various shapes depending on the fixing method and the shape of the groove 24. However, at least the gear between the protrusion 23 and the groove 24 of the output gear 7 may be used. If it is a structure or a shape interposed in the circumferential direction, it will not be specifically limited to a shape, a structure, etc.

In addition, in the embodiment of FIG. 4, the washer 30 formed of a polyethylene film or the like in order to reduce the friction between the integral elastic body 27 and the counterpart, for example, the case 1, which rotates and slides, has an output shaft 8. It is disposed coaxially and placed on the case 1.

In addition, the elastic body 27 does not need to surround the entire circumference of the protrusion 23. For example, in the case of a mold in which a motor rotates in a constant direction, as shown in FIG. 6, between the wall 25 and the protrusion 23 partitioning the groove 24 in the direction in which the protrusion 23 rotates at the time of starting. It is enough to install on. At this time, the elastic agent 27 may be integrated with the wall surface 25 that partitions the groove 24 of the tooth 7 in which the protrusion 23 collides by adhesion, duplex molding, insert molding, or the like. In the case where a spring member such as a leaf spring is employed as the elastic body 27, at least one end of the leaf spring may be embedded in the tooth side wall surface 25.

The motor 9 and the gears 4, 5, 6, and 7 are molded of plastic, metal, or the like. As a plastic material, a hard thermoplastic resin is generally employed. For example, polyacetal, polypropylene, vinyl chloride, nylon, and the like may be suitable. Among them, acetal resin having a strong and long fatigue life is most suitable. In addition, in the present specification, the plastic is made by containing various additives in various polymers or polymer materials, reinforced with various fibers such as glass fiber or carbon fiber, or fillers such as cotton, and composites with other materials. This includes taking over the subject. Of course, an elastomer (elastic polymer) may be employed as the tooth material.

When the small synchronous motor configured as described above is operated, the rotation of the rotor 9 is transmitted to the pinion 9b → deceleration gears 4, 5, 6 and output gear 7 and the elastic body ( The output shaft 8 is rotated through the 27). At this time, since the shock during operation is absorbed and relieved by the elastic body 27, the transient peak p is absorbed and the rotation gradually rises, so that the rotational characteristics and the degree of rotation shown in FIG. The torque characteristic as indicated by) is shown.

The above embodiment is one example of a suitable embodiment, but is not limited thereto, and various modifications can be made without departing from the spirit of the present invention.

For example, the elastic body 27 is interposed between the output side 8 and the coaxial gear 7 as well as any part of the reduction gear 4, 5, 6 or drive pinion 9b. It may be installed in the. In this case, at least one of the fixed shafts (15), (16), (18), or (14) in the above-described embodiment is used as the rotating shaft, and the rotating shaft and the corresponding reduction gears (4), (5), What is necessary is just to interpose the elastic body 27 between (6) or the drive pinion 9b. In addition, although the reduction gears 4, 5, and 6 are integrally comprised so that a large diameter gear and a small diameter gear may overlap in a rotation axis direction, this large diameter gear and a small diameter gear may be comprised separately, and the coupling part may be connected to both of them. It may be provided so that the elastic body 27 may be interposed between them. In addition, the hollow shaft portion 9a and the drive pinion 9b of the motor 9 may be constituted separately, and coupling portions may be provided on both of them so as to interpose the elastic body 27 therebetween. In each embodiment, the output gear 7 and the elastic body 27 are formed separately, but the output gear 7 and the elastic body 27 are integrally molded by double molding, or both members 7 are formed. And (27) may be formed of an elastic body.

The output shaft 8 and the protrusion 23 may be integrally molded with resin, ceramics, metal, or the like. In addition, the coupling portion provided on the driving side member and the driven side member is provided so that one side thereof protrudes in a radial direction and the other side is concave in a radial direction. You can choose.

As apparent from the above description, the small synchronous motor of the present invention includes a rotor and an output shaft, and any one of the reduction gear mechanisms interposed therebetween comprises a drive side member and a driven side member, and these drive side members. The radially protruding or concave coupling portions are formed in the and the side members, respectively, and the coupling portions of both members are disposed to have a predetermined distance with respect to the circumferential direction. By interposing the elastic body deformed by the movement, the impact applied excessively during operation is absorbed and relieved by the elastic body, so that rotational and torque characteristics without transient peaks can be obtained.

In addition, the impact mitigation system comprises one of the rotating members consisting of a driving side member and a driven side member, and the driving side member and the driven side member respectively protrude radially and concave in the driving side member, and at the same time, the engaging portion of both members is circumferentially formed. Since it is a simple and simple structure that is arranged and installed with a predetermined interval with respect to the intervening elastic body therebetween, the number of parts is small and assembling is easy compared with the conventional one, thereby reducing the manufacturing cost.

In addition, since the part shape is simple, the workability of the part is improved. In particular, since the shaft has a simple shape having only a projection, the output shaft can be formed of a brittle material such as ceramics, and is suitable for use in a high temperature atmosphere, for example, a drive motor for a microwave oven. In the molding as the brittle material, there is no problem of the stress concentration or the machining, because there is no tuck or mold release.

Claims (1)

In a small synchronous motor having a motor that rotates by energizing an excitation coil and an output shaft connected to the rotor via a decelerating gear train, and the output shaft follows the rotation of the rotor, the transmission path of the output shaft in the motor. One of the rotating members in the inner side is a driving side member and a driven side member, and the driving side member and the driven side member are formed with a protruding or concave coupling portion in the radial direction, respectively, and the coupling portions of both members have a predetermined distance with respect to the circumferential direction. It is arranged to be installed, and is also provided between the coupling member of the two members through the elastic body that is deformed by the relative movement of the two members in the circumferential direction, the coupling portion of the drive side member and the coupling portion of the driven side member can be rotated through the elastic body Small synchronous motor, characterized in that coupled to.