JP2007068303A - Geared motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a geared motor in which strength of a torque limiter can be ensured even when the radial dimension is limited and durability can be enhanced. <P>SOLUTION: In the geared motor 7, the torque limiter 50 consists of an output shaft 19 delivering the rotational output of a DC motor 11 on the post-stage of a planet holder 34, a roller pin 55 held in a plurality of holes 191 of an output shaft side cylindrical section 190 and containable in a groove 341 extending in the axial direction on the outer circumferential surface of a holder side cylindrical section 340, and a coil spring 57 held around the output shaft side cylindrical section 190 in order to bias the roller pin 55 toward the inside of the groove 341. Consequently, strength of the torque limiter 50 can be ensured even when the radial dimension is limited and durability can be enhanced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a geared motor in which rotation of a motor is transmitted to an output shaft via a speed reduction mechanism.

In a drive device for opening and closing a toilet seat and a toilet lid of a Western-style toilet, a geared motor is used in which a rotational output of a motor is transmitted to an output shaft connected to the toilet seat and the like by being decelerated by a reduction mechanism. In such a geared motor, since it is often arranged in a cylindrical case, a planetary gear speed reduction mechanism suitable for being housed in such a case is often employed as the speed reduction mechanism.

However, since the planetary gear speed reduction mechanism generally does not have a large reduction ratio, when a large speed reduction ratio such as 1 / hundred hundred is required for the speed reduction mechanism, a plurality of planetary gear speed reduction mechanisms are arranged in the motor axis direction. Must be connected in series and stored in a case. Furthermore, a torque limiter for preventing an excessive force from being applied to the speed reduction mechanism even when an external force is applied during driving of the output shaft must be connected in series in the motor axial direction and housed in the case. In particular, when the torque limiter is to be housed in a relatively small diameter case such as a drive device for opening and closing a toilet seat or toilet lid of a Western-style toilet, the strength of the torque limiter is insufficient and there is a problem in durability. is there. As a result, there is a problem that even if there is no problem in the planetary gear speed reduction mechanism, a problem occurs in the torque limiter, resulting in a malfunction.

  In view of the above problems, the present invention provides a geared motor that can ensure the strength of the torque limiter and can improve durability even when there is a dimensional restriction in the radial direction. There is.

  In order to solve the above problems, in the present invention, a motor, a speed reduction mechanism, an output shaft through which the rotational output of the motor is transmitted through the speed reduction mechanism, and a power transmission path from the motor to the output shaft are transmitted. In the geared motor having a torque limiter at a midway position, the torque limiter is disposed on the same axis as the input side member to which the rotational output of the motor is input, and the input side member. An output side member that is a rear stage and outputs the rotation output of the motor, and is held on one side of the input side member and the output side member, and on the other side of the input side member and the output side member A pin that can be accommodated in a groove extending in the axial direction on the outer peripheral surface, and a biasing member that is held on one of the input side member and the output side member and biases the pin toward the groove Characterized in that it consists of.

  In the present invention, it is preferable that the speed reduction mechanism includes the planetary gear speed reduction mechanism, wherein the planetary holder of the planetary gear speed reduction mechanism is the input side member and the output shaft is the output side member. With this configuration, the planetary holder of the planetary gear speed reduction mechanism constituting the speed reduction mechanism can also be used as the input side member, and the output shaft can also be used as the output side member, thereby reducing the number of parts and the number of assembly steps. Can do.

  In the present invention, it is preferable that the speed reduction mechanism includes a mysterious planetary gear speed reduction mechanism, and the torque limiter is disposed in a rear stage including a planetary holder of the mysterious planetary gear speed reduction mechanism. With this configuration, the mysterious planetary gear reduction mechanism can obtain a large reduction ratio, but when an external force is applied during driving of the output shaft, an excessive force of the output shaft causes the upstream side of the mysterious planetary gear reduction mechanism to Cannot communicate to Therefore, the torque limiter is disposed at the rear stage including the planet holder of the mysterious planetary gear reduction mechanism, that is, on the output shaft side including the planet holder of the mysterious planetary gear reduction mechanism.

  In the present invention, the reduction mechanism includes a mysterious planetary gear reduction mechanism or a planetary gear reduction mechanism, and the planetary holder of the mysterious planetary gear reduction mechanism or the planetary holder of the planetary gear reduction mechanism is formed in a cylindrical shape, The outer peripheral surface has a groove extending in the axial direction in which the pin can be accommodated, and the first sliding portion formed in the engaging portion of the output side member slides on the inner peripheral surface. Preferably, the groove has an engagement hole having one sliding surface, and the groove and the engagement hole are formed at positions overlapping in the motor axial direction. If comprised in this way, shortening to the motor axial direction can be carried out only by the length which the groove | channel and the engagement hole overlapped in the motor axial direction.

  In the present invention, it is preferable that the first sliding portion is formed in a part of the engaging portion in the motor axial direction. If comprised in this way, a sliding loss can be suppressed compared with the case where the 1st sliding surface is formed in the whole motor axial direction.

  In the present invention, the torque limiter is disposed on the same axis as the input side member to which the rotational output of the motor is input and the input side member, so that the dimension of the torque limiter in the radial direction is effective. Therefore, it can arrange | position with restraint. In addition, the output side member that is the latter stage of the input side member and outputs the rotation output of the motor, and is held by either one of the input side member and the output side member, and the other side of the input side member and the output side member A pin that can be housed in a groove extending in the axial direction on the outer peripheral surface of the outer peripheral surface, and an urging member that is held on either one of the input side member and the output side member that urges the pin toward the groove. Therefore, even when there is a dimensional restriction in the radial direction, the strength of the torque limiter can be ensured and durability can be improved.

  A geared motor to which the present invention is applied will be described with reference to the drawings.

(overall structure)
FIG. 1 is an explanatory diagram of a Western-style toilet using a geared motor to which the present invention is applied as a toilet seat unit. FIG. 2 is a sectional view of a geared motor to which the present invention is applied. 3 (a), (b
), (C), and (d) are cross-sectional views taken along lines AA, BB, CC, and DD, respectively, in FIG.

1 includes a toilet body 2, a water tank 3, a toilet lid 6, a toilet seat unit 4, and the like. The toilet seat unit 4 includes a toilet seat 5 and a geared motor 7 that drives the toilet seat 5 to open and close.
And.

In FIG. 2, the geared motor 7 has a columnar shape as a whole, and is generally a cylindrical shape whose outer diameter is substantially constant in the DC motor 11 and the motor axial direction L from the base end side to the tip end side. The case body 16 and the cover 15 are arranged in this order. From the cover 15, the front-end | tip part of the output shaft 19 protrudes toward the front end side, and the front-end | tip part of this output shaft 19 is connected with the toilet seat 5 shown in FIG. The case body 16 includes a first case body 13 disposed on the DC motor 11 side and a second case body 1 fixed to the end portion on the front end side of the first case body 13.
4, and a cover 15 is fixed to the end of the second case body 14 on the front end side.
In the DC motor 11, a connecting plate 12 is attached to a screw 111 on an output side end surface of the motor body.
The base case side end portion of the first case 16 is fixed to the connecting plate 12 with screws 112.

(Configuration of deceleration mechanism)
In the geared motor 7 of this embodiment, a speed reduction mechanism 40 for reducing the rotational output of the DC motor 11 and transmitting it to the output shaft 19 is disposed inside the case 16. It is comprised by the mysterious planetary gear reduction mechanism 20 and the planetary gear reduction mechanism 30 which are explained in full detail below.

As shown in FIG. 2 and FIGS. 3 (a) and 3 (b), first, the mysterious planetary gear reduction mechanism 20 is
The input gear 21 to which the driving force from the DC motor 11 is transmitted on the center side, the planetary gear 22 disposed around the input gear 21 and driven by the input gear 21, and the planetary gear 22 can be rotated by the plate 26. A planetary holder 27 having a shaft portion 25 supported on the planetary gear 2 and the planetary gear 2.
2, the planetary gear 22 is held between the input gear 21 and the planetary gear 22 around the planetary gear 22. The fixed internal gear 23 regulates the rotation of the planetary gear 22, and the motor axial direction L with respect to the fixed internal gear 23 around the planetary gear 22. And a movable internal gear 24 which is disposed adjacent to and driven by the planetary gear 22. In this embodiment, the two planetary gears 22 are arranged at symmetrical positions with the input gear 21 interposed therebetween.

In such a strange planetary gear reduction mechanism 20, if the number of teeth of the input gear 21 is Z1, the number of teeth of the planetary gear is Z2, the number of teeth of the fixed internal gear 23 is Z3, and the number of teeth of the movable internal gear 24 is Z4, The reduction ratio is the following equation: Reduction ratio = [(Z3 + Z1) / Z1] × [Z4 / (Z3-Z4)]
In comparison with the planetary gear reduction mechanism 30, a large reduction ratio can be obtained. For example, the number of teeth is as follows: Number of teeth of the input gear 21 Z1 = 10
Number of teeth of planetary gear Z2 = 12
Number of teeth Z3 of fixed internal gear 23 = 36
Number of teeth of movable internal gear 24 Z4 = 34
If set to, the reduction ratio is 78.2. That is, in the mysterious planetary gear reduction mechanism 20,
Since the number of planetary gears 22 and the difference between the number of teeth Z3 of the fixed internal gear 23 and the number of teeth Z4 of the movable internal gear 24 are set to be equal, if the number of planetary gears 22 is 2, the teeth of the fixed internal gear 23 The difference between the number Z3 and the number of teeth Z4 of the movable internal gear 24 is 2, and a large reduction ratio can be obtained.

In this embodiment, the input gear 21 is constituted by a motor pinion fixed to the tip of the motor shaft 110 of the DC motor 11. The fixed internal gear 23 is formed on the inner peripheral surface of the first case body 13. The movable internal gear 24 has a cup shape having a cylindrical body 241 adjacent to the fixed internal gear 23 on the front end side in the motor axial direction L, and has an internal tooth on the inner peripheral surface of the cylindrical body 241. It has the tooth | gear part formation part 242 in which was formed. The outer peripheral surface of the cylindrical body 241 is a sliding portion 243 that slides and rotates on a sliding surface 131 formed on the inner peripheral surface of the first case body. The sliding portion 243 is formed at a position overlapping the tooth portion forming portion 242 in the cylindrical body portion 241 in the motor axial direction L. In the movable internal gear 24, a cylindrical portion 42 extends from the center of the bottom surface toward the tip, and the inside of the cylindrical portion 42 is a shaft hole into which a metal support shaft 45 is fitted and fixed. Yes.

Here, the support shaft 45 is fixed to the movable internal gear 24, and the base end side of the support shaft 45 is connected to the input gear 21.
It fits in the hole opened on the tip side. Further, the distal end side of the support shaft 45 is fitted in a hole opened on the proximal end side of the planetary holder 34 of the planetary gear reduction mechanism 30 described later.

In the planetary gear reduction mechanism 30, the sun gear 31 is formed on the outer peripheral surface of the cylindrical portion 42 of the movable internal gear 24, and the planetary gear 32 is disposed around the sun gear 31. In the present embodiment, the reduction mechanism 40 has a large torque at the subsequent stage, and accordingly, the planetary gear reduction mechanism 30 is required to have a large strength. Therefore, three planetary gears 32 are used. These planetary gears 32 are supported by a support plate 36 in a state in which the planetary gears 32 are rotatable around the axis of the shaft 33 fixed to the planetary holder 34. On the outside of the planetary gear 32, the fixed internal gear 3 that holds the planetary gear 32 between the sun gear 31 and restricts the rotation of the planetary gear 32.
The fixed internal gear 35 is fixed to the inner peripheral surface of the second case body 13 with a predetermined detent structure. In this embodiment, since the reduction ratio of the planetary gear reduction mechanism 30 is 5, the reduction ratio of the entire reduction mechanism 40 is 391.

(Configuration of torque limiter, etc.)
As shown in FIGS. 2 and 3C, the output shaft 19 is mechanically connected to the planetary holder 34 of the planetary gear reduction mechanism 30, and the rotation of the planetary holder 34 is transmitted to the output shaft 19. Is done. Here, between the planetary holder 34 and the output shaft 19, the planetary holder 34 is connected to the DC motor 1.
A torque limiter 50 is configured which uses an input side member to which a rotation output of 1 is inputted and uses the output shaft 19 itself as an output side member.

In constructing such a torque limiter 50, in this embodiment, FIG. 2 and FIG.
As shown in d), first, a plurality of grooves 341 extending in the motor axial direction L are formed in a semicircular shape in cross section on the outer peripheral surface of the holder side cylindrical portion 340 protruding toward the front end side in the planetary holder 34. Each of these grooves 341 is fitted with a round bar-shaped roller pin 55. Further, a flange portion 195 that extends in the radial direction is formed at a midway position in the motor axial direction L of the output shaft 19. The flange portion 195 extends to the base end side and surrounds the holder-side cylindrical portion 340. A cylindrical portion 190 is formed.

Here, the output shaft side cylindrical portion 190 is formed with a plurality of holes 191 extending in the motor axial direction L so as to penetrate the output shaft side cylindrical portion 190 in the radial direction. A part of the roller pin 55 accommodated in the formed groove 341 is also fitted in the hole 191 formed in the output shaft side cylindrical portion 190. In this state, the roller pin 55 can move in the radial direction. That is, as shown by a solid line in FIG. 3D, the roller pin 55 is fitted in the groove 341 formed in the holder-side cylindrical portion 340, and in FIG. As shown by the dotted line, the state is such that it can be completely moved into the hole 190 formed in the output shaft side cylindrical portion 19 by escaping from the groove 341. However, a coil spring 57 as an urging member is mounted around the output shaft side cylindrical portion 190, and the coil spring 57 urges the roller pin 55 toward the groove 341. In addition, the flange portion 195 extends to the base end side and slides on a first sliding surface 342 formed in an engagement hole 343 formed at the center of the holder side cylindrical portion 340. An engaging portion 193 in which the portion 192 is formed is formed.

In this way, the torque limiter 50 is configured with the rotation center axis of the motor shaft 110 of the DC motor 11, the rotation center axis of the planetary holder 34, and the rotation center axis of the output shaft 19 being arranged on the same axis. is there.

In such a torque limiter 50, when the load applied to the output shaft 19 is small when the planetary holder 34 rotates, the roller pin 55 connects the planetary holder 34 and the output shaft 19. The rotation of 34 is also transmitted to the output shaft 19. On the other hand, when a large load is applied to the output shaft 19 when the planet holder 34 rotates, the roller pin 55 escapes from the groove 341 of the planet holder against the spring force of the coil spring 57 and the planet holder 34 and the output shaft. Since the connection with the planetary holder 34 is released, the torque limiter 50 is idled even if the planetary holder 34 rotates, and the rotation of the planetary holder 34 is not transmitted to the output shaft 19. At that time, roller pin 5
5 enters another groove 341 adjacent in the circumferential direction, and the planetary holder 34 and the output shaft 19 are connected again.

A potentiometer 81 is configured between the second case 16 and the output shaft 19. The potentiometer 81 holds the substrate 82 on the second case 16 side, and the detection result is output to the outside via the connector 83. It has become so. An O-ring 17 is disposed between the outer peripheral surface of the output shaft 19 and the second case 16, and an O-ring 18 is also disposed between the cover 15 and the output case 16. These O-rings 17 and 18 are for protecting the potentiometer 81 from grease and oil.

(Main effects of this form)
In the geared motor 7 configured as described above, the torque limiter 50 is disposed on the same axis as the planetary holder 34 to which the rotation output of the DC motor 11 is input, and the planetary holder 34. Can be disposed while effectively suppressing the dimension in the radial direction. Moreover, the output shaft 19 that outputs the rotation output of the DC motor 11, which is a subsequent stage of the planetary holder 34, is held in the plurality of holes 191 of the output shaft side cylindrical portion 190, and is Since the roller pin 55 that can be accommodated in the groove 341 extending in the axial direction and the coil spring 57 that is held around the output shaft side cylindrical portion 190 that urges the roller pin 55 toward the groove 341, the diameter is increased. Even when there is a dimensional restriction in the direction, the strength of the torque limiter 50 can be ensured and the durability can be improved. In addition, since the torque limiter 50 is constituted by the output shaft 19 of the planetary holder 34, the number of parts and the number of assembling steps can be reduced.

Furthermore, in this embodiment, the groove 341 and the engagement hole 343 formed on the outer peripheral surface of the holder side cylindrical portion 340 are formed at positions overlapping in the motor axial direction. Therefore, the length in the motor axial direction can be shortened by the length in which the groove 341 and the engagement hole 343 overlap in the motor axial direction.
In the present invention, since the first sliding portion 192 is formed in a part of the engaging portion 193 in the motor axial direction, compared to the case where the sliding portion is formed in the entire motor axial direction L, Sliding loss can be suppressed.

[Other embodiments]
In the above embodiment, in the planetary holder 34, a plurality of grooves 341 are formed on the outer peripheral surface of the holder-side cylindrical portion 340 in a semicircular cross section, and the round bar-shaped roller pins 55 are fitted into these grooves 341. An output shaft side cylindrical portion 190 of the output shaft 19 is formed so as to surround the holder side cylindrical portion 340, and a hole 191 is formed in the output shaft side cylindrical portion 190 so as to penetrate in the radial direction. Is retained. Further, a coil spring 57 as an urging member is mounted around the output shaft side cylindrical portion 190, and the roller pin 55 is urged toward the groove 341 by the coil spring 57. do not have to. Specifically, contrary to the above embodiment, a plurality of grooves are formed in a semicircular cross section on the outer peripheral surface of the output shaft side cylindrical portion, and a round bar-shaped roller pin 55 is fitted into these grooves. On the other hand, a holder side cylindrical portion of the planetary holder 34 is formed so as to surround the output shaft side cylindrical portion, a hole for holding the roller pin 55 is formed in the holder side cylindrical portion, and a coil spring 57 is provided around the holder side cylindrical portion. You may comprise so that it may mount | wear.

  Further, the speed reduction mechanism 40 is constituted by the mysterious planetary gear speed reduction mechanism 20 and the planetary gear speed reduction mechanism 30, but it is not always necessary to be constituted by the mysterious planetary gear speed reduction mechanism 20 and the planetary gear speed reduction mechanism 30. For example, it may be constituted by one planetary gear reduction mechanism 30 or may be constituted by one wonder planetary gear reduction mechanism 30. Further, it may be constituted by two wonder planetary gear reduction mechanisms 20 or may be constituted by two planetary gear reduction mechanisms 20. The position detection of the motor output shaft 19 is not limited to the potentiometer 81, and sensors such as a magnetic sensor and an optical sensor, or switches such as a leaf switch, a reed switch, and a micro switch may be used. In addition, an assist spring may be provided for the output shaft 19 so that an urging force may be applied to the output shaft 19 when the toilet seat is driven in the opening direction that requires large torque. Furthermore, the geared motor 7 is not limited to the toilet seat 5 but may be used to open and close the toilet lid 6, and may further be used to open and close various members other than the western toilet 1.

It is explanatory drawing of the western style toilet which used the geared motor to which this invention was applied for the toilet seat unit. It is sectional drawing of the geared motor to which this invention is applied. 3A, 3B, 3C, and 3D are cross-sectional views taken along lines AA, BB, CC, and DD in FIG. 2, respectively.

Explanation of symbols

7 Geared motor 11 DC motor (motor)
19 Output shaft (output side member)
20 Mysterious planetary gear reduction mechanism 30 Planetary gear reduction mechanism 34 Planetary holder (input side member)
40 Deceleration mechanism 50 Torque limiter 55 Roller pin (pin)
57 Coil spring (biasing member)
191 Engagement part 192 First sliding part 241 Cylindrical body part 341 Groove 342 First sliding surface 343 Engagement hole

Claims (5)

In a geared motor having a motor, a speed reduction mechanism, an output shaft through which the rotation output of the motor is decelerated and transmitted via the speed reduction mechanism, and a torque limiter in the middle of a power transmission path from the motor to the output shaft ,
The torque limiter is disposed on the same axis as the input side member to which the rotation output of the motor is input, and outputs the rotation output of the motor at a subsequent stage of the input side member. An output side member;
A pin that is held on one side of the input side member and the output side member and can be accommodated in a groove extending in the axial direction on the outer peripheral surface of the other side of the input side member and the output side member; A geared motor comprising: a biasing member that is held on either one of the input side member and the output side member and biases the pin toward the groove.   2. The planetary gear reduction mechanism according to claim 1, wherein the planetary gear reduction mechanism is included in the reduction mechanism, and the planetary holder of the planetary gear reduction mechanism is the input side member, and the output shaft is the output side member. And geared motor.   3. The magic mechanism according to claim 1, wherein the speed reduction mechanism includes a mysterious planetary gear speed reduction mechanism, and the torque limiter is disposed in a subsequent stage including a planetary holder of the mysterious planetary gear speed reduction mechanism. Geared motor.   3. The strange planetary gear reduction mechanism or the planetary gear reduction mechanism is included in the reduction mechanism according to claim 1 or 2, and the planetary holder of the strange planetary gear reduction mechanism or the planetary holder of the planetary gear reduction mechanism is formed in a cylindrical shape. In addition, the outer peripheral surface has a groove extending in the axial direction in which the pin can be accommodated, and the first sliding portion formed in the engaging portion of the output side member slides on the inner peripheral surface. A geared motor comprising an engagement hole having a first sliding surface that moves, wherein the groove and the engagement hole are formed at positions overlapping in a motor axial direction. 5. The geared motor according to claim 4, wherein the first sliding portion is formed in a part of the engaging portion in a motor axial direction.

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