JP2007170547A - Planetary gear type reduction gear with torque limiter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust limiter torque simply and exhibit a torque limiter function always stably. <P>SOLUTION: An input shaft 7 and an output shaft 14 are supported on a fixed member 11. A planetary gear type reduction gear at at least one step provided with a sun gear 8, a planetary gear 34 meshing with the sun gear 8, an internal gear 22 meshing with the planetary gear 34, and a carrier 30 supporting the planetary gear 34, and a torque limiter are constituted between the input shaft 7 and the output shaft 14. The torque limiter has such a configuration that presses friction members 26, 28 against the internal gear 22 in the axial direction and holds the internal gear 22 on a fixed member 11 side by friction force among the friction members 26, 28 and the internal gear 22 pressed by them so as to slip and rotate. The torque limiter is provided with a spring force adjusting means for adjusting pressing force of a pressing means for pressing the friction members 26, 28 against the internal gear 22 by spring force. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a planetary gear type speed reducer with a torque limiter, and more particularly to a planetary gear type speed reducer provided with a torque limiter that uses a frictional resistance by acting a friction member on an internal gear in the axial direction.

2. Description of the Related Art A speed reduction mechanism that incorporates a planetary gear type speed reducer on the shaft of a DC motor and outputs based on a large reduction ratio is known.
Since the DC motor is configured to rotate the shaft by applying a current to the coil, it has a property that is weak against a large load from the shaft side. That is, if some load is applied to the shaft and the rotation of the motor shaft is stopped, the current applied to the coil increases, the motor becomes hot, seizure occurs, or the insulating material melts. There are problems such as short circuit and poor contact.

  In addition, when a reduction mechanism with a large reduction ratio is provided, the rotation speed of the output shaft of the reduction mechanism is significantly smaller than the rotation speed of the motor shaft. It will be big. In this state, when a large load is applied to the output shaft of the speed reduction mechanism, a large load is applied to the gear portion in the speed reduction mechanism, which may be damaged.

In order to solve the above problem, a planetary gear type speed reducer is incorporated in the shaft of the DC motor, and a torque limiter is interposed in the shaft, and if a load exceeding a predetermined value is applied to the output shaft of the speed reducer, its rotation Is considered to be a structure that does not transmit (see, for example, Patent Document 1). This patent document discloses a configuration in which an O-ring that is a friction member is interposed in the radial direction between the outer peripheral surface of the internal gear and the inner peripheral surface of the case that is a fixing member.
JP 2003-130146 A

  Generally, a planetary gear type speed reducer is provided with a sun gear on a rotation shaft of a motor corresponding to an input shaft, meshing the planetary gear with the sun gear, meshing the internal gear with the planetary gear, It is the structure which provided the carrier to support. When this planetary gear type reduction gear is configured with a torque limiter in which an O-ring that is a friction member is interposed in the radial direction between the outer peripheral surface of the internal gear and the inner peripheral surface of the case that is a fixing member, It is necessary that the axis of the inner peripheral surface of a case and the axis of the outer peripheral surface of the internal gear be completely coincident with each other.

If this does not match, when the outer peripheral surface of the internal gear is rotationally displaced relative to the inner peripheral surface of the case, the contact pressure of the O-ring will change, and the contact pressure at the bearing portion of the internal gear This is because this increases and this affects the transmission torque when the internal gear is rotationally displaced. However, it is extremely difficult to make the axial center of the inner peripheral surface of the case, which is a fixing member, completely coincide with the axial center of the outer peripheral surface of the internal gear, and it is extremely expensive in terms of structure and accuracy. I do not get.

Further, in the known ones disclosed in the above-mentioned patent document, since both end portions of the fixed internal gear and the movable internal gear are in contact with the case inner end surface, the resistance force due to frictional contact at this portion is received, This will cause the transmission torque to become unstable.
On the other hand, in the case where a plurality of planetary gear speed reduction mechanisms are provided, when a torque limiter is incorporated in the planetary gear type speed reduction mechanism, a generally conceivable configuration is to connect a reduction mechanism to a DC motor and to reduce the final speed of the speed reduction mechanism. A torque limiter is assembled to the output shaft of the mechanism.

However, this method has the following drawbacks. That is, when the rotational speed of the motor shaft is reduced, the rotational torque naturally increases as the reduction ratio increases. In other words, the later the speed reduction mechanism is, the higher the speed reduction ratio and the greater the rotational torque. When the torque limiter is assembled to the output shaft of the final stage speed reduction mechanism of the speed reduction mechanism, the rotation is transmitted or cut at the portion where the rotational torque is the largest. In the configuration in which torque transmission / cutting is performed by the frictional force of the friction member, if the rotational torque is large, a large frictional force is required for torque transmission, and as a result, the torque limiter mechanism must be large.

In addition, when a torque limiter is assembled to the output shaft of the final speed reduction mechanism of the speed reduction mechanism, the speed reduction ratio in the final stage varies depending on the design, so the rotational torque also varies. A variety of limiter mechanisms must also be prepared. That is, the torque limiter mechanism cannot be shared.

  In order to solve the above-mentioned problems, the applicant of the present application forms a torque limiter between the input shaft and the output shaft of the planetary gear type reduction gear, and the torque limiter is attached to the fixed member that supports the input shaft of the internal gear. The internal gear is disposed opposite to the fixed member via a friction member in the radial direction, the friction member is pressed in the axial direction against the internal gear, and the friction force Has developed a planetary gear type speed reducer with a torque limiter configured to hold an internal gear on the fixed member side (Japanese Patent Application No. 2005-178564).

In the invention according to this application, even if the axis of the inner peripheral surface of the case, which is a fixed member, and the axis of the outer peripheral surface of the internal gear do not completely coincide with each other with an inexpensive configuration, When the outer peripheral surface of the internal gear is rotationally displaced, the contact pressure of the friction member such as the O-ring does not change, and the contact pressure at the bearing portion of the internal gear does not affect the transmission torque, so that it is always stable. Thus, it is possible to provide a planetary gear type speed reducer with a torque limiter that exhibits a torque limiter function, thereby eliminating the problems of the prior art.

However, in the prior invention by the applicant of the present application, the diameter of the cross-section of the friction member such as the O-ring varies, and the spring force of the pressing means such as the coil spring varies, so the limiter torque of the torque limiter Variation will occur. Therefore, there is a problem that it is difficult to obtain an accurate limiter torque that meets the demands of the manufacturer and customer users.
The manufacturer also provides several types of friction members such as O-rings with different cross-sectional diameters according to various limiter torque specifications, and various types of pressing means such as coil springs with different spring forces. There is a problem that you must also prepare.
In addition, there is a problem that the limiter torque cannot be adjusted in accordance with the usage conditions on the customer side.
The object of the present invention is to improve the problems of the prior invention of the applicant of the present application.

In order to achieve the above object, the present invention provides a fixing member that supports an input shaft, an output shaft that is supported by the fixing member, a sun gear, a planetary gear that meshes with the sun gear, and an internal gear that meshes with the planetary gear. And a carrier for supporting the planetary gear, and at least one planetary gear type reduction mechanism configured between the input shaft and the output shaft, and a torque configured between the input shaft and the output shaft A limiter, and the torque limiter is arranged such that the internal gear is arranged with a gap in the radial direction with respect to the fixed member, and the internal gear is arranged to face the fixed member in the axial direction via a friction member. The friction member is pressed in the axial direction against the internal gear, and the internal gear is held on the fixed member side by a frictional force, and the friction member is directed to the internal gear on the fixed member side. Push pressed by spring force And means is provided with a spring force adjusting means for adjusting the pressing force of the pressing pressure means.
The present invention is characterized in that the pressing means is constituted by a coil spring.
Further, the present invention is characterized in that the pressing means is constituted by a leaf spring.
According to the present invention, the spring force adjusting means comprises a spring force adjusting body having a cam surface having a gradient along a circumferential direction on a surface facing the pressing means, and the spring force adjusting body is externally operated. The pressing means of the pressing means can be changed by rotating the spring force adjusting body by pressing the pressing means by the cam surface and rotating the spring force adjusting body. It is a feature.
In the present invention, the friction member is provided on both sides of the internal gear, the internal gear is disposed opposite to the fixed member via the friction member, and both sides of the internal gear are on the fixed member side. The friction member is brought into contact with the friction member, and the friction force between the friction member and the fixed member side and the friction force between the friction member and the internal gear pressed against the friction member are moved toward the fixed member side. It is characterized by having a configuration in which a gear is held.
In the present invention, the planetary gear type reduction mechanism is provided with a plurality of stages, and the first stage reduction mechanism is provided with a sun gear on the input shaft, meshing the planetary gear with the sun gear, and meshing the internal gear with the planetary gear. The second and subsequent speed reduction mechanisms are provided with a sun gear on the carrier of the speed reduction mechanism in the immediately preceding stage, and the next stage planetary gear is engaged with the sun gear. The inner gear is meshed with the planetary gear of the next stage, and a carrier is provided to pivotally support the planetary gear of the next stage, and the input shaft and the output shaft are coaxially arranged opposite to each other. A tubular bearing is inserted across both shafts, both shafts are connected to each other so as to be relatively rotatable, and a carrier supporting a planetary gear meshing with an internal gear constituting the torque limiter is connected to the input shaft or output shaft or Bearings are rotatable on both shafts It is characterized in that was supported.
According to the present invention, the friction member is a ring-shaped elastic member.
In the present invention, the planetary gear type reduction mechanism is provided with a plurality of stages, and the first stage reduction mechanism is provided with a sun gear on the input shaft, meshing the planetary gear with the sun gear, and meshing the internal gear with the planetary gear. The second and subsequent speed reduction mechanisms are provided with a sun gear on the carrier of the speed reduction mechanism in the immediately preceding stage, and the next stage planetary gear is engaged with the sun gear. The inner gear is meshed with the planetary gear of the next stage, and a carrier that supports the planetary gear of the next stage is provided, and the torque limiter is the last stage of the plurality of reduction mechanisms. An internal gear that is a component of the speed reduction mechanism before the speed reduction mechanism is disposed with a gap in the radial direction with respect to the fixed member, and a friction member is disposed opposite to the axial direction side of the internal gear, and the friction The member is pressed against the internal gear in the axial direction to generate friction. It is characterized in that it has a configuration which holds the internal gear to the stationary member side by the.
According to the present invention, the torque limiter is a component of a speed reduction mechanism that includes a speed reduction mechanism that is closest to the input shaft and that is a speed reduction mechanism that precedes the speed reduction mechanism of the last stage among the speed reduction mechanisms of the plurality of stages. An internal gear is arranged with a gap in the radial direction with respect to the fixed member, a friction member is arranged opposite to the axial direction side of the internal gear, and the friction member is pressed in the axial direction against the internal gear. The internal gear is held on the fixed member side by a frictional force.

  The present invention provides an accurate limiter torque that meets the requirements without preparing various types of friction members such as O-rings having different cross-sectional diameters or preparing various types of pressing means having different pressing forces. Can do. Further, the limiter torque can be easily adjusted according to the usage conditions on the customer side.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 shows an embodiment in which a torque limiter is provided in a one-stage speed reducer. In FIG. A cover 6 of a planetary gear speed reducer 4 with a torque limiter is fixed to the case of the speed reducer 2. The output shaft of the speed reducer 2 constitutes an input shaft 7 of the speed reducer 4, and a sun gear 8 is fixed to the input shaft 7.

Reference numeral 10 denotes a case made of a cylindrical body of the speed reducer 4. A bearing 12 is fixed to the inner diameter portion of the speed reducer 4, and the output shaft 14 is positioned on the coaxial extension line with the input shaft 7. It is supported rotatably. A disc-shaped cover 6 having a shaft hole is fixed to the case 10, and the cover 6 and the case 10 constitute a substantially cylindrical fixing member 11. A plurality of holding holes 16 extending in the axial direction of the fixing member 11 are formed in the outer circumferential portion of the cover 6 at substantially equal intervals in the circumferential direction, and the coils constituting the pressing means are formed in each holding hole 16. A spring 18 is inserted and arranged.

Reference numeral 20 denotes a ring-shaped pressing body, the inner peripheral surface of which is slidably fitted along the axial direction of the outer peripheral surface on one side of the cover 6, and the outer peripheral surface thereof is the inner peripheral surface of the case 10. It is slidably touching the surface. One surface of the pressing body 20 is in elastic contact with the coil spring 18 and is urged by the coil spring 18 in the left direction in the drawing, that is, in the axial direction of the fixing member 11. A pin hole is formed in the pressing body 20 in the axial direction, and a pin disposed on the cover 6 side is slidably inserted into the pin hole. With this configuration, the pressing body 20 is fixed to the fixing member 11. The rotation is locked.

Reference numeral 23 denotes a ring-shaped spring force adjusting body, the inner diameter portion of which is rotatably fitted to the outer peripheral surface of the tubular convex portion 6 a formed on the cover 6. At the boundary between the case 10 and the case of the deceleration device 2, the outer peripheral surface of the tubular convex portion 6 a, the end surface of the case of the deceleration device 2, the end surface of the cover 6 where the holding hole 16 opens, and the case 10 A concave groove 25 is formed in a ring shape with the end surface of the groove, and both side surfaces of the spring force adjusting body 23 are rotatably held between both wall surfaces of the concave groove 25. As shown in FIG. 2, three cam grooves 27 are formed on one side surface 23a of the spring force adjuster 23. The cam surface 27a has a slope with respect to the side surface 23a along the circumferential direction. However, they are formed with an angular difference of 120 degrees in the circumferential direction.

Each cam groove 27 has the same cam surface structure, and is arranged to face the holding holes 16 in the same number as the holding holes 16. The coil spring 18 in each holding hole 16 is elastically contacted with the cam surface 27a of the corresponding cam groove 27 substantially perpendicularly thereto. The contact position of each coil spring 18 with respect to the corresponding cam surface 27a is set to be the same with respect to the reference position A of each cam surface 27a. That is, in FIG. 3, the distances of the three coil springs 18 relative to the reference position A of the cam surfaces 27a are all set to be the same.

The step of the cam surface 27a of the cam groove 27 with respect to the side surface 23a of the spring force adjusting body 23 is configured to linearly increase in the circumferential direction as shown in FIG. . The slope of the cam surface 27a with respect to the side surface 23a of the spring force adjusting body 23 can be changed in various designs, and the depth of the cam surface 27a of the cam groove 27 is linearly displaced with respect to the side surface 23a. It is not specifically limited to. The spring force adjusting body 23 is provided with a tool insertion hole 29 and a screw hole 33 for a set screw 35 for rotating the spring force adjusting body 23, and one end of the screw hole 33 is formed at the spring force adjusting body 23. The other end is opened on the outer peripheral surface of the spring force adjusting body 23.

Reference numeral 22 denotes a ring-shaped internal gear, and the internal gear 22 is disposed with a gap in the radial direction with respect to the fixing member 11. That is, the outer peripheral surface of the ridge portion 24 formed on the outer peripheral portion of the main body of the internal gear 22 is inserted and disposed with a slight gap on the inner peripheral surface of the thin portion of the case 10. Reference numerals 26 and 28 denote friction members made of O-rings having elastic and friction surfaces, which are opposed to the axial side of the internal gear 22, that is, opposite to both side surfaces of the ridge portion 24, and the friction members 26 and 28 are Friction force between the friction members 26, 28 and the internal gear 22 pressed against the friction member 26, 28 by pressing against the internal gear 22 in the axial direction. Thus, the internal gear 22 is held on the fixing member 11 side.

The friction members 26 and 28 are formed between an engaging surface perpendicular to the axial direction formed on the inner diameter portion of the case 10 and one side surface of the ridge portion 24 and the other side surface of the ridge portion 24. It is compressed and arranged between the pressing body 20. The internal gear 22 is clamped in the axial direction of the internal gear 22 by friction members 26 and 28 due to the pressing force of the coil spring 18, and the axial force of the internal gear 22 is clamped. The fixing member 11 is held via the friction members 26 and 28.

Here, the axis of the internal gear 22 is the central axis thereof, and the axial direction of the internal gear 22 is a direction substantially parallel to the central axis, that is, the horizontal direction in FIG. . A carrier 30 is press-fitted and fixed to one end side of the output shaft 14, and a planetary gear 34 is rotatably supported on a carrier pin 32 projecting in an axial direction at an eccentric portion of the disk-like portion. One side of the planetary gear 34 meshes with the internal teeth of the internal gear 22, and the other side meshes with the sun gear 8.

When a load torque exceeding a predetermined magnitude is applied to the internal gear 22 from the output shaft 14 side, such as when the output shaft 14 is stopped, the internal gear 22 resists the friction holding force by the friction members 26 and 28. The internal gear 22 is configured to maintain a non-rotating state fixed with respect to the case 10 in a state where the case 10 slips with respect to the case 10 and the load torque does not reach a predetermined value. The frictional holding force for holding the internal gear 22 on the fixed member 11 side so as to be capable of slip rotation, that is, the limiter torque of the torque limiter can be adjusted by rotating the spring force adjusting body 23.

  In the above configuration, when the input shaft 7 rotates, the sun gear 8 rotates at the same speed, and this rotation is transmitted to the planetary gear 34. The planetary gear 34 rotates about the carrier pin 32 as a rotation axis and revolves along the internal gear 22 because the internal gear 22 is fixed to the fixed member 11 via the friction members 26 and 28. As the planetary gear 34 revolves, the carrier 30 rotates, and the output reduced at a predetermined reduction ratio is taken out from the output shaft 14.

On the other hand, when a load greater than a predetermined value, that is, a load greater than a slip torque (limiter torque) is applied to the output shaft 14 for some reason, the carrier 30 stops, and the rotational torque of the planetary gear 34 with the carrier pin 32 as a fulcrum Act on. Due to the rotational torque from the planetary gear 34, the internal gear 22 meshing with the planetary gear 34 slips and rotates along the inner peripheral surface of the case 10 against the holding friction holding force by the friction members 26 and 28. This slip rotation can prevent an overload from being applied to the speed-reduced device 2, that is, the DC motor.

  In order to adjust the limiter torque of the torque limiter to an appropriate value, the spring force adjusting body 23 is rotated by an external operation such as inserting a rod-like tool into the tool insertion hole 29 and operating this tool, The contact position of each coil spring 18 with respect to the cam surface 27a of the cam groove 27 is relatively moved. By the rotation of the spring force adjusting body 23, the amount of compression of each coil spring 18 in the axial direction changes according to the amount of displacement of the depth of the cam groove 27. With this change, the internal gear 22 is fixed. The frictional holding force, that is, the limiter torque that holds the member 11 so as to be capable of slip rotation changes.

After the limiter torque adjustment, the set screw 35 screwed into the screw hole 33 is rotated in the tightening direction, the tip of the set screw 35 is pressed against the outer peripheral surface of the tubular convex portion 6a of the cover 6, and the spring force adjusting body 23 is adjusted. Is fixed to the cover 6. The spring force adjusting body 23 is in close contact with the wall surface of the concave groove 25 due to the elastic force from the coil spring 18 and is not stressed in the rotational direction during use. There is no movement. Therefore, in the present invention, the rotation stopping mechanism for the spring force adjusting body 23 is not an essential configuration.

  In the above embodiment, the friction members 26, 28 are disposed opposite to each other on both sides in the axial direction of the internal gear 22. However, only one friction member 28 or 26 may be provided, and one side surface of the ridge portion 24 of the internal gear 22 may be directly The inner diameter portion of the case 10 facing the one side surface or the pressing member 20 may be configured to be in contact with a smooth surface perpendicular to the axial direction. In this case, it is advantageous to configure means for reducing the frictional force, such as interposing a bearing member or the like between the surface of the case 10 that directly contacts and one side surface of the protruding portion 24 of the internal gear 22.

In the above embodiment, the internal gear 22 is disposed with a gap in the radial direction with respect to the fixed member 11, and the internal gear 22 is axially disposed with respect to the fixed member 11 via the friction members 26 and 28. A configuration in which the friction members 26 and 28 are opposed to each other and pressed in the axial direction against the internal gear 22 and the internal gear 22 is held on the fixed member 11 side by a frictional force constitutes a torque limiter.
The coil spring 18 constitutes pressing means for pressing the friction members 26 and 28 against the internal gear 22 in the axial direction, and a spring force adjusting body 23 having a cam surface 27a that receives the elastic force of the pressing means. The spring force adjusting means for changing the spring force of the pressing means is configured.

Next, another embodiment of the present invention will be described with reference to FIG.
FIG. 5 shows an embodiment in which a torque limiter is provided in the first stage of the two-stage speed reducer. In the figure, reference numeral 2 denotes a speed reducer, which includes a cover 6 of the planetary gear type speed reducer 4 with the torque limiter. Is fixed. A sun gear 8 is fixed to an input shaft 7 that is an output shaft of the decelerator 2.

Reference numeral 10 denotes a case of the speed reducer 4. A bearing 12 is fixed to an inner diameter portion of the speed reducer 4, and an output shaft 14 is rotatably supported by the bearing 12. A cover 6 is fixed to the case 10, and the cover 6 and the case 10 constitute a fixing member 11. A plurality of holding holes 16 extending in the axial direction of the fixing member 11 are formed in the outer circumferential portion of the cover 6 at substantially equal intervals in the circumferential direction, and a coil spring 18 is inserted into each holding hole 16. Has been placed.

Reference numeral 20 denotes a ring-shaped pressing body, the inner peripheral surface of which is slidably fitted along the axial direction of the outer peripheral surface on one side of the cover 6, and the outer peripheral surface thereof is the inner peripheral surface of the case 10. It is slidably touching the surface. One surface of the pressing body 20 is in elastic contact with the coil spring 18 and is urged by the coil spring 18 in the left direction in the drawing, that is, in the axial direction of the fixing member 11.

A pin hole is formed in the pressing body 20 in the axial direction, and a pin disposed on the cover 6 side is slidably inserted into the pin hole. With this configuration, the pressing body 20 is fixed to the fixing member 11. The rotation is locked. Reference numeral 23 denotes a ring-shaped spring force adjusting body, the inner diameter portion of which is rotatably fitted to the outer peripheral surface of the tubular convex portion 6 a formed on the cover 6. At the boundary between the case 10 and the case of the deceleration device 2, the outer peripheral surface of the tubular convex portion 6 a, the end surface of the case of the deceleration device 2, the end surface of the cover 6 where the holding hole 16 opens, and the case 10 A concave groove 25 is formed in a ring shape with the end surface of the groove, and both side surfaces of the spring force adjusting body 23 are rotatably held between both wall surfaces of the concave groove 25.

As shown in FIG. 2, three cam grooves 27 are formed on one side surface 23a of the spring force adjuster 23. The cam surface 27a has a slope with respect to the side surface 23a along the circumferential direction. However, they are formed with an angular difference of 120 degrees in the circumferential direction. Each cam groove 27 has the same cam surface structure, and is arranged to face the holding holes 16 in the same number as the holding holes 16. The coil spring 18 in each holding hole 16 is elastically contacted with the cam surface 27a of the corresponding cam groove 27 substantially perpendicularly thereto.

The spring force adjusting body 23 is formed with a tool insertion hole and a screw hole for the set screw 35 for rotating the spring force adjustment body 23. The structure of the spring force adjusting means is the same as the structure of the spring force adjusting means of the first embodiment shown in FIG. Reference numeral 22 denotes a ring-shaped internal gear, and the internal gear 22 is disposed with a gap in the radial direction with respect to the fixing member 11. That is, the outer peripheral surface of the ridge portion 24 formed on the outer peripheral portion of the main body of the internal gear 22 is inserted and disposed with a slight gap on the inner peripheral surface of the thin portion of the case 10.

Reference numerals 26 and 28 denote friction members made of O-rings having elastic and friction surfaces, which are arranged opposite to the axial direction side of the internal gear 22, and the friction members 26 and 28 are urged by the urging force from the coil spring 18. Friction force between the friction members 26, 28 and the internal gear 22 pressed against the friction member 26, 28 by pressing against the internal gear 22 in the axial direction. Thus, the internal gear 22 is held on the fixing member 11 side.

The friction members 26 and 28 are formed between an engaging surface perpendicular to the axial direction formed on the inner diameter portion of the case 10 and one side surface of the ridge portion 24 and the other side surface of the ridge portion 24. It is compressed and arranged between the pressing body 20. The internal gear 22 is clamped in the axial direction of the internal gear 22 by friction members 26 and 28 due to the pressing force of the coil spring 18, and the axial force of the internal gear 22 is clamped. The fixing member 11 is held via the friction members 26 and 28.

Reference numeral 30 denotes a first carrier rotatably supported on the input shaft 7 and the output shaft 14, and a planetary gear 34 is rotatably supported on the carrier pin 32. One side of the planetary gear 34 meshes with the internal teeth of the internal gear 22, and the other side meshes with the sun gear 8. When a load torque exceeding a predetermined magnitude is applied to the internal gear 22 from the output shaft 14 side, such as when the output shaft 14 is stopped, the internal gear 22 resists the friction holding force by the friction members 26 and 28. The internal gear 22 is configured to maintain a non-rotating state fixed with respect to the case 10 in a state where the case 10 slips with respect to the case 10 and the load torque does not reach a predetermined value.

The friction holding force that holds the internal gear 22 in the non-rotating state on the fixed member 11 side, that is, the limiter torque of the torque limiter can be adjusted by rotating the spring force adjusting body 23. A tubular slide bearing 31 is fixed to the hole drilled in the disk-shaped portion of the carrier 30, and the slide bearing 31 is formed on the small diameter portion of the output shaft 14 that is disposed on the same axis as the input shaft. It fits freely. The center axis of the input shaft 7 and the output shaft 14 coincides with the axis of the inner peripheral surface of the case 10, and the carrier 30 is configured to be rotatable about the axis.

A sun gear 44 is integrally formed on the outer peripheral surface of the slide bearing 31. A second carrier 36 is fixed to the output shaft 14, and a planetary gear 40 is rotatably supported on the carrier pin 38. One side of the planetary gear 40 meshes with the internal teeth of an internal gear 42 integrally formed with the inner diameter portion of the case 10, and the other side meshes with the sun gear 44. Here, the internal gear 22 may be configured separately from the case 10 and fixed to the case 10 so as not to rotate.

  In the configuration described above, when the input shaft 7 rotates, the sun gear 8 rotates at the same speed, and this rotation is transmitted to the planetary gear 34. The planetary gear 34 rotates about the carrier pin 32 as a rotation axis, and the internal gear 22 is fixed to the fixed member 11 side via the friction members 26 and 28, so that the planetary gear 34 extends along the internal gear 22 and the case 10. Revolves around the inner peripheral axis. As the planetary gear 34 revolves, the carrier 30 rotates about the axis of the inner peripheral surface of the case 10 and the sun gear 44 rotates. Due to the rotation of the sun gear 44, the planetary gear 40 rotates around the carrier pin 38 as a rotation axis and revolves along the internal gear 42. As the planetary gear 40 revolves, the second carrier 36 rotates, and the output decelerated at a predetermined reduction ratio is taken out from the output shaft 14.

On the other hand, when a load greater than a predetermined value, that is, a slip torque or more is applied to the output shaft 14 for some reason, the revolving motion of the planetary gear 40 is prevented by this load, and the carrier 30 meshing with the planetary gear 40 via the sun gear 44. Stops, and the rotational torque of the planetary gear 34 acts on the internal gear 22 with the carrier pin 32 as a fulcrum. Due to the rotational torque from the planetary gear 34, the internal gear 22 meshing with the planetary gear 34 slips and rotates along the inner peripheral surface of the case 10 against the holding friction holding force by the friction members 26 and 28.

This slip rotation does not overload the DC motor. The planetary gear 34 is firmly supported by the slide bearing 31 at a position spaced apart from the axis of the case 10, that is, the central axis of the input shaft 7 and the output shaft 14 in the radial direction. Therefore, when the planetary gear 34 rotates and the internal gear 22 meshing with the slip rotates, the locus of this rotation becomes a perfect circle centered on the axis of the case 10, and the friction members 26 and 28 of the internal gear 22. Or the slip surface with the case 10 side forms a substantially constant locus. As a result, the contact pressure between the internal gear 22 and the friction members 26 and 28 or the case 10 side does not change, and therefore the transmission torque of the internal gear 22 is always constant and does not vary. .

  Also in this embodiment, as in the above embodiment, the friction members 26 and 28 are not limited to be arranged opposite to each other on both sides in the axial direction of the internal gear 22, and only one friction member 28 or 26 may be used. A configuration may be adopted in which one side surface of the ridge portion 24 of the internal gear 22 is directly brought into contact with an inner diameter portion of the case 10 facing the one side surface or a smooth surface perpendicular to the axial direction of the pressing body 20. In addition, the operation | movement which rotates the spring force adjustment body 23 and adjusts a limiter torque is the same as 1st Embodiment shown in FIG. 1, The description is abbreviate | omitted.

Next, another embodiment of the present invention will be described with reference to FIG.
FIG. 6 shows an embodiment in which a torque limiter is provided in the first stage and the second stage of a two-stage speed reducer. In the figure, reference numeral 2 denotes a speed reducer, and this case includes a planetary gear type speed reducer with a torque limiter. 4 cover 6 is fixed. A sun gear 8 is fixed to an input shaft 7 that is an output shaft of the decelerator 2. Reference numeral 10 denotes a case of the speed reducer 4. A bearing 12 is fixed to an inner diameter portion of the speed reducer 4, and an output shaft 14 is rotatably supported by the bearing 12.

A cover 6 is fixed to the case 10, and the cover 6 and the case 10 constitute a fixing member 11. A plurality of pin holding holes 68 extending in the axial direction of the fixing member 11 are formed at substantially equal intervals in the circumferential direction on the outer peripheral portion of the cover 6, and pins 70 are fitted into the pin holding holes 68. It is inserted and arranged. Reference numeral 20 denotes a ring-shaped pressing body, the inner peripheral surface of which is slidably fitted along the axial direction of the outer peripheral surface on one side of the cover 6, and the outer peripheral surface thereof is the inner peripheral surface of the case 10. It is slidably touching the surface.

One surface of the pressing body 20 is in elastic contact with a wave washer-like leaf spring 72 fitted and arranged on the outer peripheral surface of the cover 6, and the leaf spring 72 causes the left direction in the drawing, that is, the axis of the fixing member 11. Is biased in the direction. A pin hole is formed in the pressing body 20 in the axial direction, and a pin disposed on the cover 6 side is slidably inserted into the pin hole. With this configuration, the pressing body 20 has a fixing member 11 side. The rotation with respect to is locked.

Reference numeral 23 denotes a ring-shaped spring force adjusting body, the inner diameter portion of which is rotatably fitted to the outer peripheral surface of the tubular convex portion 6 a formed on the cover 6. The spring force adjusting body 23 has the same structure as the spring force adjusting body 23 in the first embodiment. At the boundary between the case 10 and the case of the to-be-decelerated device 2, the outer peripheral surface of the tubular convex portion 6a, the end surface of the case of the to-be-decelerated device 2, the end surface of the cover 6 and the case where the pin holding hole 68 opens. A concave groove 25 is formed in a ring shape with the ten end surfaces, and both side surfaces of the spring force adjusting body 23 are rotatably held between both wall surfaces of the concave groove 25.

As shown in FIG. 7, the one side surface 23a of the spring force adjusting body 23 has three cam grooves 27 formed with a cam surface 27a having a gradient with respect to the side surface 23a along the circumferential direction. However, they are formed with an angular difference of 120 degrees in the circumferential direction. Each cam groove 27 has the same cam surface structure, and is arranged to face the holding holes 68 in the same number as the number of the pin holding holes 68. The pin 70 in each holding hole 68 is in elastic contact with the cam surface 27a of the corresponding cam groove 27 substantially perpendicularly thereto. The contact position of each pin 70 with respect to the corresponding cam surface 27a is set to be the same with respect to the reference position of each cam surface 27a.

The cam groove 27 is the same as the cam groove 27 of the first embodiment. The spring force adjusting body 23 is provided with a tool insertion hole 29 and a screw hole 33 for a set screw 35 for rotating the spring force adjustment body 23. The other ends of the pins 70 that are elastically contacted with the cam surfaces 27a corresponding to the one ends are connected to the outer peripheral surface of the cover 6 via ring-shaped plates 74 that are slidably inserted in the axial direction. The plate spring 72 is elastically contacted. Reference numeral 22 a denotes a ring-shaped internal gear, and the internal gear 22 a is disposed with a gap in the radial direction with respect to the fixing member 11.

That is, the outer peripheral surface of the ridge portion 24a formed on the outer peripheral portion of the main body of the internal gear 22a is inserted and disposed with a slight gap on the inner peripheral surface of the thin portion of the case 10. Reference numerals 26 and 28 denote friction members made of O-rings having elastic and friction surfaces, which are opposed to the axial side of the internal gear 22a, and the friction members 26 and 28 are disposed on the internal gear 22a. By pressing in the axial direction, the frictional force between the friction members 26 and 28 and the fixing member 11 side and the frictional force between the friction members 26 and 28 and the internal gear 22a pressed against the friction member 26 are on the fixing member 11 side. The internal gear 22a is held.

The friction members 26 and 28 are formed between an engaging surface perpendicular to the axial direction formed on the inner diameter portion of the case 10 and one side surface of the ridge portion 24 and the other side surface of the ridge portion 24. It is compressed and arranged between the pressing body 20. The internal gear 22a is clamped in the axial direction of the internal gear 22a by the friction members 26 and 28 by the pressing force of the coil spring 18 by the friction members 26 and 28. The fixing member 11 is held via the friction members 26 and 28. Reference numeral 30 denotes a first carrier rotatably supported on the input shaft 7 and the output shaft 14, and a planetary gear 34 is rotatably supported on the carrier pin 32.

One side of the planetary gear 34 meshes with the internal teeth of the internal gear 22 a, and the other side meshes with the sun gear 8. When a load torque exceeding a predetermined magnitude is applied to the internal gear 22a from the output shaft 14 side such as when the output shaft 14 is stopped, the internal gear 22a resists the friction holding force by the friction members 26 and 28, The internal gear 22a is configured to maintain a non-rotating state fixed with respect to the case 10 in a state where the case 10 is slip-rotated with respect to the case 10 and the load torque does not reach a predetermined value.

The frictional holding force for holding the internal gear 22a toward the fixed member 11 side, that is, the limiter torque of the torque limiter, can be adjusted by rotating the spring force adjusting body 23. A tubular slide bearing 31 is fixed to the hole drilled in the disk-shaped portion of the carrier 30, and the slide bearing 31 is formed on the small diameter portion of the output shaft 14 that is disposed on the same axis as the input shaft. It fits freely. The center axis of the input shaft 7 and the output shaft 14 coincides with the axis of the inner peripheral surface of the case 10, and the carrier 30 is configured to be rotatable about the axis. A sun gear 44 is integrally formed on the outer peripheral surface of the slide bearing 31. A second carrier 36 is fixed to the output shaft 14, and a planetary gear 40 is rotatably supported on the carrier pin 38. One side of the planetary gear 40 meshes with the internal teeth of the internal gear 22 a, and the other side meshes with the sun gear 44.

  In the configuration described above, when the input shaft 7 rotates, the sun gear 8 rotates at the same speed, and this rotation is transmitted to the planetary gear 34. The planetary gear 34 rotates about the carrier pin 32 as a rotation axis, and revolves along the inner gear 22a and about the axis of the inner peripheral surface of the case 10. As the planetary gear 34 revolves, the carrier 30 rotates about the axis of the inner peripheral surface of the case 10 and the sun gear 44 rotates. Due to the rotation of the sun gear 44, the planetary gear 40 rotates about the carrier pin 38 as a rotation axis and revolves along the internal gear 22a. As the planetary gear 40 revolves, the second carrier 36 rotates, and the output decelerated at a predetermined reduction ratio is taken out from the output shaft 14.

During rotation of the input shaft 7 by driving the DC motor, the internal gear 22a has a rotational torque of the planetary gear 34 with the carrier pin 32 as a fulcrum and a carrier in the same rotational direction as the load applied to the output shaft 14. The rotational torque of the planetary gear 40 with the pin 38 as a fulcrum acts. As long as the load applied to the output shaft 14 does not exceed a predetermined magnitude, the internal gear 22a does not slip due to the rotational torque from the planetary gears 34, 40, and is retained by the holding force by the friction members 26, 28. 11 is held fixed.

On the other hand, if the output shaft 14 is stopped for some reason, for example, if a load greater than a predetermined value, that is, a slip torque or more, is applied to the output shaft 14, the rotational torque of the planetary gears 34, 40 with respect to the internal gear 22a increases. By this rotational torque, the internal gear 22a slips against the frictional force generated by the friction members 26 and 28. As a result, the rotation of the output shaft 14 is stopped, and the revolving motion of the planetary gear 40 is prevented. On the other hand, the rotation of the sun gear 8 is transmitted to the planetary gear 34, and the planetary gear 34 rotates.

When the planetary gear 34 rotates, the planetary gear 34 revolves with respect to the internal gear 22a. By this revolving motion, the first carrier 30 rotates, and this rotation is transmitted to the planetary gear 40. It rotates around the carrier pin 38 of the second carrier 36. Due to the total rotational force of the planetary gear 40 and the other planetary gear 34, the internal gear 22 a slips along the inner peripheral surface of the case 10 against the frictional force of the friction members 26 and 28. This slip rotation is continued until the load applied to the output shaft 14 becomes the slip torque or less.

During the slip rotation of the internal gear 22a, the planetary gear 34 revolves with respect to the internal gear 22a in a direction opposite to the slip rotation of the internal gear 22a while rotating about the carrier pin 32. It is possible to prevent the DC motor from being overloaded by the slip rotation of the internal gear 22a. During the slip rotation of the internal gear 22a, the relative rotational motion of the planetary gear 34 that rotates at a high speed in conjunction with the sun gear 8 with respect to the internal gear 22a is the slip rotation of the planetary gear 34 with respect to the fixing member 11 of the internal gear 22a. It is decelerated by the revolving motion in the opposite direction to the motion.

As a result, the relative rotational movement of the planetary gear 40, which has been decelerated at the subsequent stage, with respect to the internal gear 22a and the relative rotational movement of the planetary gear 34 with respect to the internal gear 22a become the same speed, and the rotation of the two planetary gears 40, 34 results in The gear 22 a slips with respect to the fixed member 11. The planetary gear 34 is firmly supported by the slide bearing 31 at a position spaced apart from the axis of the case 10, that is, the central axis of the input shaft 7 and the output shaft 14 in the radial direction.

Therefore, when the planetary gear 40 and the planetary gear 34 rotate and the internal gear 22a meshing with the slip rotates, the locus of this rotation becomes a perfect circle centered on the axis of the case 10, and the friction of the internal gear 22a The slip surfaces on the members 26 and 28 or the case 10 side form a substantially constant locus. As a result, the contact pressure between the internal gear 22a and the friction members 26, 28 or the case 10 side does not change, and therefore the transmission torque of the internal gear 22a is always constant and does not vary. .

In order to adjust the limiter torque of the torque limiter to an appropriate value, the spring force adjusting body 23 is rotated by an external operation, and the contact position of each pin 70 with the cam surface 27a of the cam groove 27 is moved. By the rotation of the spring force adjusting body 23, each pin 70 moves in the axial direction according to the amount of displacement of the depth of the cam groove 27. As the pin 70 moves in the axial direction, the plate 4 moves in parallel, the plate spring 72 is deflected evenly, the amount of deflection of the plate spring 72 changes, and the internal gear 22 is moved to the fixing member 11 side. The frictional holding force that is held so as to be able to rotate in slip, that is, the limiter torque changes.

After the limiter torque adjustment, the set screw 35 screwed into the screw hole 33 is rotated in the tightening direction, the tip of the set screw 35 is pressed against the outer peripheral surface of the tubular convex portion 6a of the cover 6, and the spring force adjusting body 23 is adjusted. Is fixed to the cover 6. The leaf spring 72 constitutes a pressing means for pressing the friction members 26 and 28 against the internal gear 22 a in the axial direction, and has a cam surface 27 a that receives the elastic force of the pressing means via the pin 70. The body 23 constitutes spring force adjusting means for changing the spring force of the pressing means. The pressing means and the spring force adjusting means shown in FIG. 7 can be applied to the embodiment shown in FIGS. Conversely, the configuration of the pressing unit and the spring force adjusting unit shown in FIGS. 1 and 5 may be adopted as the configuration of the pressing unit and the spring force adjusting unit of the present embodiment.

  Also in the present embodiment, as in the above embodiment, the friction members 26 and 28 are not limited to be disposed opposite to each other on both sides in the axial direction of the internal gear 22a, and only one friction member 28 or 26 may be used. A configuration may be adopted in which one side surface of the ridge portion 24a of the internal gear 22a is brought into direct contact with the inner surface of the case 10 facing the one side surface or the smooth surface perpendicular to the axial direction of the pressing body 20.

Next, another embodiment of the present invention will be described with reference to FIG.
FIG. 8 shows an embodiment in which a torque limiter is provided in the second stage of the two-stage speed reducer. In the figure, reference numeral 2 denotes a speed reducer, which includes a cover 6 of the planetary gear type speed reducer 4 with the torque limiter. Is fixed. A sun gear 8 is fixed to an input shaft 7 that is an output shaft of the decelerator 2.

Reference numeral 10 denotes a case of the speed reducer 4. A bearing 12 is fixed to an inner diameter portion of the speed reducer 4, and an output shaft 14 is rotatably supported by the bearing 12. A cover 6 is fixed to the case 10, and the cover 6 and the case 10 constitute a fixing member 11. A plurality of holding holes 16 extending in the axial direction of the fixing member 11 are formed in the outer circumferential portion of the cover 6 at substantially equal intervals in the circumferential direction, and a coil spring 18 is inserted into each holding hole 16. Has been placed. Reference numeral 21 denotes a ring-shaped internal gear, in which internal teeth are formed on the inner peripheral surface of the main body, and the outer peripheral surface of the main body is slidably fitted to the inner peripheral surface of the case 10.

One side surface of the internal gear 21 is elastically contacted with the coil spring 18 and is urged by the coil spring 18 in the left direction, that is, in the axial direction of the fixing member 11. A plurality of pin holes extending in the axial direction are formed in the main body of the internal gear 21 at substantially equal intervals in the circumferential direction, and the pins arranged in the pin holding holes on the cover 6 side are slidable in the pin holes. With this configuration, the rotation of the internal gear 21 relative to the fixed member 11 is locked.

Reference numeral 23 denotes a ring-shaped spring force adjusting body, the inner diameter portion of which is rotatably fitted to the outer peripheral surface of the tubular convex portion 6 a formed on the cover 6. At the boundary between the case 10 and the case of the deceleration device 2, the outer peripheral surface of the tubular convex portion 6 a, the end surface of the case of the deceleration device 2, the end surface of the cover 6 where the holding hole 16 opens, and the case 10 A concave groove 25 is formed in a ring shape with the end surface of the groove, and both side surfaces of the spring force adjusting body 23 are rotatably held between both wall surfaces of the concave groove 25.

On one side surface 23a of the spring force adjusting body 23, three cam grooves 27 each having a cam surface 27a having a gradient with respect to the side surface 23a are formed in the circumferential direction along the circumferential direction. It is formed with an angular difference of 120 degrees. Each cam groove 27 has the same cam surface structure, and is arranged to face the holding holes 16 in the same number as the holding holes 16. The coil spring 18 in each holding hole 16 is elastically contacted with the cam surface 27a of the corresponding cam groove 27 substantially perpendicularly thereto. The spring force adjusting body 23 is formed with a tool insertion hole and a screw hole for the set screw 35 for rotating the spring force adjustment body 23. The configuration of the spring force adjusting body 23 is the same as that of the spring force adjusting body 23 of the first embodiment shown in FIG.

Reference numeral 22 b denotes a ring-shaped internal gear, and the internal gear 22 b is disposed with a gap in the radial direction with respect to the fixing member 11. In other words, the outer peripheral surface of the main body of the internal gear 22b is fitted and arranged in the inner peripheral surface of the thin portion of the case 10 with a slight gap. Reference numerals 26 and 28 denote friction members made of O-rings having elastic and friction surfaces, which are opposed to the axial side of the internal gear 22b, and the friction members 26 and 28 are axial to the internal gear 22b. And the frictional force between the friction members 26 and 28 and the fixing member 11 side and the frictional force between the friction members 26 and 28 and the internal gear 22b pressed against the friction member 26, 28 toward the fixing member 11 side. The internal gear 22b is held.

The friction member 26 is compressively disposed between a locking surface perpendicular to the axial direction of a concave groove 27 formed in a ring shape on the inner diameter portion of the case 10 and one side surface of the internal gear 22b, and the friction The member 28 is compressed and disposed between the other side surface of the internal gear 22 b and the side surface of the main body of the internal gear 21. The internal gear 22b is pinched in the axial direction of the internal gear 22b by the friction members 26 and 28 by the pressing force of the coil spring 18 through the internal gear 21, and is clamped in the axial direction. It is held on the fixed member 11 side by the pressure via the friction members 26 and 28.

Reference numeral 30 denotes a first carrier rotatably supported on the input shaft 7 and the output shaft 14, and a planetary gear 34 is rotatably supported on the carrier pin 32. One side of the planetary gear 34 meshes with the internal teeth of the internal gear 21, and the other side meshes with the sun gear 8. When a load torque exceeding a predetermined magnitude is applied to the internal gear 22b from the output shaft 14 side, such as when the output shaft 14 is stopped, the internal gear 22b resists the friction holding force by the friction members 26 and 28, In a state where the case 10 is slip-rotated with respect to the case 10 and the load torque does not reach a predetermined value, the internal gear 22b is held in a non-rotating state with respect to the case 10 by the friction holding force by the friction members 26 and 28. It is configured. The friction holding force for holding the internal gear 22b in the non-rotating state on the fixed member 11 side, that is, the limiter torque of the torque limiter can be adjusted by rotating the spring force adjusting body 23.

A tubular slide bearing 31 is fixed to the hole drilled in the disk-shaped portion of the carrier 30, and the slide bearing 31 is formed on the small diameter portion of the output shaft 14 that is disposed on the same axis as the input shaft. It fits freely. The center axis of the input shaft 7 and the output shaft 14 coincides with the axis of the inner peripheral surface of the case 10, and the carrier 30 is configured to be rotatable about the axis. A sun gear 44 is integrally formed on the outer peripheral surface of the slide bearing 31. A second carrier 36 is fixed to the output shaft 14, and a planetary gear 40 is rotatably supported on the carrier pin 38. One side of the planetary gear 40 meshes with the internal teeth of the internal gear 22 b, and the other side meshes with the sun gear 44.

  In the configuration described above, when the input shaft 7 rotates, the sun gear 8 rotates at the same speed, and this rotation is transmitted to the planetary gear 34. The planetary gear 34 rotates about the carrier pin 32 as a rotation axis, and revolves along the internal gear 21 and about the axis of the inner peripheral surface of the case 10. As the planetary gear 34 revolves, the carrier 30 rotates about the axis of the inner peripheral surface of the case 10 and the sun gear 44 rotates. By the rotation of the sun gear 44, the planetary gear 40 rotates around the carrier pin 38 as a rotation axis and revolves along the internal gear 22b. As the planetary gear 40 revolves, the second carrier 36 rotates, and the output decelerated at a predetermined reduction ratio is taken out from the output shaft 14.

On the other hand, when the output shaft 14 is stopped for some reason, for example, when a load exceeding a predetermined value, that is, a load exceeding the slip torque, is applied to the output shaft 14, the revolving motion of the planetary gear 40 is blocked by this load. Thereby, the rotational torque of the planetary gear 40 acts on the internal gear 22b with the carrier pin 38 as a fulcrum. Due to the rotational torque from the planetary gear 40, the internal gear 22 b that meshes with the planetary gear 40 slips and rotates along the inner peripheral surface of the case 10 against the holding friction holding force by the friction members 26 and 28. This slip rotation does not overload the DC motor. In addition, the operation | movement which rotates the spring force adjustment body 23 and adjusts a limiter torque is the same as 1st Embodiment shown in FIG. 1, The description is abbreviate | omitted.

In the present embodiment as well, as in the above embodiment, the friction members 26 and 28 are not limited to be disposed opposite to each other on both sides in the axial direction of the internal gear 22b, and only one friction member 28 or 26 may be used. A configuration may be adopted in which one side surface of the internal gear 22 b is directly brought into contact with a smooth surface perpendicular to the axial direction of the inner diameter portion of the case 10 facing the one side surface or the smooth side surface of the internal gear 21.
The pressing means and spring force adjusting means in the present embodiment have the same configuration as the pressing means and spring force adjusting means in the first embodiment of FIG. 1, but the leaf spring 72 in the embodiment of FIG. 6 is used. The configuration of the pressing means and the spring force adjusting means may be employed.

Next, another embodiment of the present invention will be described with reference to FIG.
FIG. 9 shows an embodiment in which a torque limiter is provided in the second stage of the four-stage speed reducer. In the figure, reference numeral 2 denotes a speed reducer (DC motor). In this case, a planetary gear type speed reducer with a torque limiter is provided. 4 cover 6 is fixed. A sun gear 8 is fixed to an input shaft 7 that is an output shaft of the decelerator 2. Reference numeral 10 denotes a case of the speed reducer 4. A bearing 12 is fixed to an inner diameter portion of the speed reducer 4, and an output shaft 14 is rotatably supported by the bearing 12.

A cover 6 is fixed to the case 10, and the cover 6 and the case 10 constitute a fixing member 11. A plurality of holding holes 16 extending in the axial direction of the fixing member 11 are formed in the outer circumferential portion of the cover 6 at substantially equal intervals in the circumferential direction, and a coil spring 18 is inserted into each holding hole 16. Has been placed. Reference numeral 21 denotes a ring-shaped internal gear, in which internal teeth are formed on the inner peripheral surface of the main body, and the outer peripheral surface of the main body is slidably fitted to the inner peripheral surface of the case 10. One surface of the internal gear 21 is elastically contacted with the coil spring 18 and is urged by the coil spring 18 in the left direction, that is, in the axial direction of the fixing member 11.

A plurality of pin holes extending in the axial direction are formed in the main body of the internal gear 21 at substantially equal intervals in the circumferential direction, and the pins arranged in the pin holding holes on the cover 6 side are slidable in the pin holes. With this configuration, the rotation of the internal gear 21 relative to the fixed member 11 is locked. Reference numeral 23 denotes a ring-shaped spring force adjusting body, the inner diameter portion of which is rotatably fitted to the outer peripheral surface of the tubular convex portion 6 a formed on the cover 6. At the boundary between the case 10 and the case of the deceleration device 2, the outer peripheral surface of the tubular convex portion 6 a, the end surface of the case of the deceleration device 2, the end surface of the cover 6 where the holding hole 16 opens, and the case 10 A concave groove 25 is formed in a ring shape with the end surface of the groove, and both side surfaces of the spring force adjusting body 23 are rotatably held between both wall surfaces of the concave groove 25.

On one side surface 23a of the spring force adjusting body 23, three cam grooves 27 each having a cam surface 27a having a gradient with respect to the side surface 23a are formed in the circumferential direction along the circumferential direction. It is formed with an angular difference of 120 degrees. Each cam groove 27 has the same cam surface structure, and is arranged to face the holding holes 16 in the same number as the holding holes 16. The coil spring 18 in each holding hole 16 is elastically contacted with the cam surface 27a of the corresponding cam groove 27 substantially perpendicularly thereto.

The spring force adjusting body 23 is formed with a tool insertion hole and a screw hole for the set screw 35 for rotating the spring force adjustment body 23. The configuration of the spring force adjusting body 23 is the same as that of the spring force adjusting body 23 of the first embodiment shown in FIG.
Reference numeral 22 b denotes a ring-shaped internal gear, and the internal gear 22 b is disposed with a gap in the radial direction with respect to the fixing member 11. In other words, the outer peripheral surface of the main body of the internal gear 22b is fitted and arranged in the inner peripheral surface of the thin portion of the case 10 with a slight gap.

Reference numerals 26 and 28 denote friction members made of O-rings having elastic and friction surfaces, which are opposed to the axial direction side of the internal gear 22b, that is, both side surfaces thereof, and the friction members 26 and 28 are connected to the internal gear 22b. The fixing member is pressed by the frictional force between the friction members 26 and 28 and the fixing member 11 side and the friction force between the friction members 26 and 28 and the internal gear 22b pressed against the friction member 26, 28. The internal gear 22b is held on the 11 side. The friction member 26 is compressed and disposed between a locking surface 52 formed in the inner diameter portion of the case 10 and perpendicular to the axial direction and one side surface of the internal gear 22b. The other side surface of the gear 22b and the side surface of the main body of the internal gear 21 are compressed and arranged.

The internal gear 22b is pinched in the axial direction of the internal gear 22b by the friction members 26 and 28 by the pressing force of the coil spring 18 through the internal gear 21, and is clamped in the axial direction. Due to the pressure, the internal gear 21 is held on the fixed member 11 side via the friction members 26 and 28. Reference numeral 30 denotes a first carrier rotatably supported on the input shaft 7 and the output shaft 14, and a planetary gear 34 is rotatably supported on the carrier pin 32.

One side of the planetary gear 34 meshes with the internal teeth of the internal gear 21, and the other side meshes with the sun gear 8. When the output shaft 14 is stopped or the like, the internal gear 22b from the output shaft 14 side is given a load torque exceeding a predetermined magnitude against the friction holding force by the friction members 26 and 28, The internal gear 22b is configured to maintain a non-rotating state fixed with respect to the case 10 in a state where the case 10 is slip-rotated with respect to the case 10 and the load torque does not reach a predetermined value.

The friction holding force for holding the internal gear 22b in the non-rotating state on the fixed member 11 side, that is, the limiter torque of the torque limiter can be adjusted by rotating the spring force adjusting body 23. A tubular slide bearing 31 is fixed to the hole drilled in the disk-shaped portion of the carrier 30, and the slide bearing 31 is formed on the small diameter portion of the output shaft 14 that is disposed on the same axis as the input shaft. It fits freely. The center axis of the input shaft 7 and the output shaft 14 coincides with the axis of the inner peripheral surface of the case 10, and the carrier 30 is configured to be rotatable about the axis.

A sun gear 44 is integrally formed on the outer peripheral surface of the slide bearing 31. A second carrier 54 and a third carrier 56 are rotatably supported on the output shaft 14 via slide bearings 55 and 57, respectively, and a fourth carrier 36 is fixed to the output shaft 14. Yes. A planetary gear 60 is rotatably supported on the carrier pin 58 of the carrier 54. One of the planetary gears 60 meshes with the internal gear 22 b, and the other meshes with the sun gear 44 fixed to the tubular portion of the carrier 30.

A planetary gear 62 is rotatably supported on the carrier pin 61 of the carrier 56. One of the planetary gears 62 meshes with a ring-shaped internal gear 64 formed integrally with the inner diameter portion of the case 10, and the other meshes with a sun gear 66 formed on a slide bearing 55 fixed to the carrier 54. ing. A planetary gear 40 is rotatably supported on the carrier pin 38 of the carrier 36. One side of the planetary gear 40 meshes with the internal teeth of the internal gear 64, and the other side meshes with a sun gear 69 formed on a slide bearing 57 fixed to the carrier 56. Here, the internal gear 22b may be configured separately from the case 10 and fixed to the case 10 so as not to rotate.

  In the configuration described above, when the input shaft 7 rotates, the sun gear 8 rotates at the same speed, and this rotation is transmitted to the planetary gear 34. The planetary gear 34 rotates about the carrier pin 32 as a rotation axis and revolves along the internal gear 21. As the planetary gear 34 revolves, the carrier 30 rotates and the sun gear 44 rotates. Due to the rotation of the sun gear 44, the planetary gear 60 rotates around the carrier pin 58 as a rotation axis and revolves along the internal gear 22b. As the planetary gear 60 revolves, the second carrier 54 rotates and the sun gear 66 rotates.

Due to the rotation of the sun gear 66, the planetary gear 62 rotates around the carrier pin 61 as a rotation axis and revolves along the internal gear 64. As the planetary gear 62 revolves, the carrier 56 rotates and the sun gear 69 rotates. Due to the rotation of the sun gear 69, the planetary gear 40 rotates around the carrier pin 38 as a rotation axis and revolves along the internal gear 64. As the planetary gear 40 revolves, the fourth carrier 36 rotates, and the output decelerated at a predetermined reduction ratio is taken out from the output shaft 14.

On the other hand, if the output shaft 14 is stopped for some reason, for example, if a load exceeding a predetermined value, that is, a load exceeding the slip torque, is applied to the output shaft 14, the rotation of the carriers 36, 56, 54 is stopped by this load. Thereby, the rotational torque of the planetary gear 60 acts on the internal gear 22b with the carrier pin 58 as a fulcrum. Due to the rotational torque from the planetary gear 60, the internal gear 22b meshing with the planetary gear 60 slips and rotates along the inner peripheral surface of the case 10 against the pinching friction holding force by the friction members 26 and 28, and is excessively passed to the DC motor. The load is not applied. In addition, the operation | movement which rotates the spring force adjustment body 23 and adjusts a limiter torque is the same as 1st Embodiment shown in FIG. 1, The description is abbreviate | omitted.

The planetary gear 60 is firmly supported by the slide bearing 31 at a position spaced apart in the radial direction with respect to the axial center of the case 10, that is, the central axis of the input shaft 7 and the output shaft 14. Therefore, when the internal gear 22b meshing with the planetary gear 60 rotates due to the rotation of the planetary gear 60, the locus of this rotation becomes a perfect circle centered on the axis of the case 10, and the friction members 26, 28 of the internal gear 22b. Or the slip surface with the case 10 side forms a substantially constant locus. As a result, the contact pressure between the internal gear 22b and the friction members 26, 28 or the case 10 side does not change. Therefore, the transmission torque of the internal gear 22b is always constant and does not vary. .

  In the present embodiment as well, as in the above embodiment, the friction members 26 and 28 are not limited to be disposed opposite to each other on both sides in the axial direction of the internal gear 22b, and only one friction member 28 or 26 may be used. A configuration may be adopted in which one side surface of the internal gear 22 b is directly brought into contact with a smooth surface perpendicular to the axial direction of the inner diameter portion of the case 10 facing the one side surface or the smooth side surface of the internal gear 21.

In the above embodiment, the torque limiter mechanism is configured in the first gear or the second gear of the planetary gear type speed reducer because it is more advantageous to obtain the torque limiter effect as close to the input side as possible. It is because it can be downsized. That is, since the torque on the input side is small, the torque limiter mechanism can be downsized.

In the embodiment shown in FIGS. 5 and 6, the carrier 30 that supports the planetary gear 34 that meshes with the internal gears 22 and 22 a constituting the torque limiter is rotatably supported by both the input shaft 7 and the output shaft 14. In the embodiment shown in FIG. 9, the carrier 54 that supports the planetary gear 60 that meshes with the internal gear 22b that constitutes the torque limiter is rotatably supported on the output shaft 14, but as shown in FIG. The carrier 54 that supports the planetary gear 60 that meshes with the internal gear 22b that constitutes the torque limiter may be rotatably supported by the input shaft 7. The other configuration of FIG. 10 is the same as that of the embodiment shown in FIG.

  The input shaft and the output shaft are coaxially opposed to each other, the input shaft and the output shaft are supported by a coupling member by bearings, and the carrier that supports the planetary gear meshing with the internal gear constituting the torque limiter is used as the input shaft. In the configuration in which the bearing is supported rotatably, the input shaft is supported by the fixed member side (cover 6 integral with the case 10), and the carrier is supported by bearing on the input shaft. The carrier does not rotate eccentrically with respect to the fixed member side. Therefore, the revolution of the planetary gear pivotally supported by the carrier pin of the carrier does not rotate eccentrically with respect to the fixed member side. That is, the internal gear that meshes with the planetary gear also does not rotate eccentrically with respect to the fixed member side, so that the slip state of the friction member between the internal gear and the fixed member side is stable with no variation due to the product. Become.

  The input shaft and the output shaft are coaxially opposed to each other, the input shaft and the output shaft are supported by a connecting member by bearings, and the carrier that supports the planetary gear meshing with the internal gear constituting the torque limiter is supported by the carrier. In the configuration in which the carrier is supported by the connecting member so as to be rotatable on the input shaft and the output shaft, the input shaft and the output shaft are supported by the bearing member without eccentricity. Since the carrier is supported on the input shaft and the output shaft, the carrier does not rotate eccentrically with respect to the fixed member side. Therefore, the revolution of the planetary gear supported by the carrier pin of the carrier is fixed member. Does not rotate eccentrically with respect to the side. That is, the internal gear that meshes with the planetary gear also does not rotate eccentrically with respect to the fixed member side, so that the slip state of the friction member between the internal gear and the fixed member side is stable with no variation due to the product. Become.

  An input shaft and an output shaft are coaxially arranged opposite to each other, a carrier that supports the planetary gear that meshes with an internal gear that constitutes a torque limiter by supporting the input shaft and the output shaft with a coupling member and supporting the planetary gear is configured as described above. In this configuration, the input shaft and the output shaft are supported by the bearing member without eccentricity, that is, the output shaft does not rotate eccentrically with respect to the input shaft. And since the carrier is supported by the output shaft, the carrier does not rotate eccentrically with respect to the fixed member side, and therefore, the revolution of the planetary gear supported by the carrier pin of the carrier does not rotate with respect to the fixed member side. Does not rotate eccentrically.

That is, since the internal gear meshing with the planetary gear does not rotate eccentrically with respect to the fixed member side, the slip state of the friction member between the internal gear and the fixed member side is stable with no variation due to the product. Become.
The pressing means and spring force adjusting means in the embodiment shown in FIGS. 9 and 10 have the same configuration as the pressing means and spring force adjusting means in the first embodiment of FIG. 1, but the embodiment of FIG. The structure of the pressing means using the leaf spring 72 and the spring force adjusting means may be adopted.

It is sectional drawing of the planetary gear type reduction gear with a torque limiter which concerns on the 1st Embodiment of this invention. It is external appearance explanatory drawing of the spring force adjustment body used for 1st Embodiment. It is side surface explanatory drawing of the spring force adjustment body used for 1st Embodiment. It is explanatory drawing of a cam surface. It is sectional drawing of the planetary gear type reduction gear with a torque limiter which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the planetary gear type reduction gear with a torque limiter which concerns on the 3rd Embodiment of this invention. It is external appearance explanatory drawing which shows other embodiment of a spring force adjustment means. It is sectional drawing of the planetary gear type reduction gear with a torque limiter which concerns on the 4th Embodiment of this invention. It is sectional drawing of the planetary gear reducer with a torque limiter which concerns on the 5th Embodiment of this invention. It is sectional drawing of the planetary gear type reduction gear with a torque limiter which concerns on the 6th Embodiment of this invention.

Explanation of symbols

2 Reduced gear (DC motor)
4 Reduction gear 6 Cover 8 Sun gear 10 Case 11 Fixing member 12 Bearing 14 Output shaft 16 Holding hole 18 Coil spring 20 Press body 21 Internal gear 22 Internal gear 23 Spring force adjustment body 24 Convex part 25 Concave groove 26 Friction member 27 Cam Groove 27a Cam surface 28 Friction member 29 Hole 30 Carrier 31 Slide bearing 32 Carrier pin 33 Screw hole 34 Planetary gear 35 Set screw 36 Carrier 38 Carrier pin 40 Planetary gear 42 Internal gear 44 Sun gear 52 Locking surface 54 Carrier 55 Slide bearing 56 Carrier 57 Slide bearing 58 Carrier pin 60 Planetary gear 61 Carrier pin 62 Planetary gear 64 Internal gear 66 Sun gear 68 Pin holding hole 69 Sun gear 70 Pin 72 Leaf spring 74 Plate

Claims (9)

A fixed member that supports the input shaft, an output shaft that is supported by the fixed member, a sun gear, a planetary gear that meshes with the sun gear, an internal gear that meshes with the planetary gear, and a carrier that supports the planetary gear. Comprising at least one planetary gear speed reduction mechanism configured between the input shaft and the output shaft, and a torque limiter configured between the input shaft and the output shaft, the torque limiter comprising: The internal gear is disposed with a gap in the radial direction with respect to the fixed member, the internal gear is disposed to face the fixed member in the axial direction via a friction member, and the friction member is disposed on the internal gear. A pressing means for pressing the friction member toward the internal gear by a spring force on the fixed member side, wherein the internal gear is held on the fixed member side by pressing in the axial direction against the fixed member side, Adjust the pressing force of the pressing means. A planetary gear speed reducer with a torque limiter, characterized in that a spring force adjusting means for. 2. The planetary gear reducer with a torque limiter according to claim 1, wherein the pressing means is constituted by a coil spring. The planetary gear reducer with a torque limiter according to claim 1, wherein the pressing means is constituted by a leaf spring. The spring force adjusting means is constituted by a spring force adjusting body having a cam surface having a gradient along a circumferential direction on a surface facing the pressing means, and the spring force adjusting body can be rotated by an external operation. The pressing force of the pressing means can be changed by supporting the pressing means on the fixed member side, pressing the pressing means by the cam surface, and rotating the spring force adjusting body. The planetary gear type reduction gear with a torque limiter according to any one of claims 1 to 3. The friction members are provided on both sides of the internal gear, the internal gear is disposed opposite to the fixed member side via the friction member, and both sides of the internal gear are disposed on the fixed member side via the friction member. The internal gear is held on the fixed member side by the friction force between the friction member and the fixed member side and the friction force between the friction member and the internal gear pressed against the friction member. The planetary gear speed reducer with a torque limiter according to any one of claims 1 to 4, wherein the planetary gear type speed reducer has a torque limiter. The planetary gear type reduction mechanism is provided in a plurality of stages, and the first stage reduction mechanism is provided with a sun gear on the input shaft, meshing the planetary gear with the sun gear, meshing the internal gear with the planetary gear, and the planetary gear. The speed reduction mechanism after the second stage is provided with a sun gear on the carrier of the speed reduction mechanism at the immediately preceding stage, and the planetary gear of the next stage is meshed with the sun gear, A stage planetary gear is meshed with an internal gear, and a carrier for pivotally supporting the next stage planetary gear is provided. The input shaft and the output shaft are coaxially arranged opposite to each other and straddle both shafts. A tubular bearing is inserted and both shafts are connected to each other so as to be relatively rotatable, and a carrier supporting a planetary gear meshing with an internal gear constituting the torque limiter is rotatable on the input shaft, the output shaft, or both shafts. The bearing supported by It claims 1 to planetary gear type speed reducer with a torque limiter according to any one of claims 5, characterized in. The planetary gear reducer with a torque limiter according to any one of claims 1 to 6, wherein the friction member is a ring-shaped elastic member. The planetary gear type reduction mechanism is provided in a plurality of stages, and the first stage reduction mechanism is provided with a sun gear on the input shaft, meshing the planetary gear with the sun gear, meshing the internal gear with the planetary gear, and the planetary gear. The speed reduction mechanism after the second stage is provided with a sun gear on the carrier of the speed reduction mechanism of the immediately preceding stage, and the planetary gear of the next stage is meshed with the sun gear. An internal gear is meshed with a planetary gear of a stage, and a carrier is provided to pivotally support the planetary gear of the next stage, and the torque limiter is arranged in front of the final stage of the plurality of speed reduction mechanisms. An internal gear that is a component of the speed reduction mechanism is disposed with a gap in the radial direction with respect to the fixed member, a friction member is disposed opposite to the axial direction side of the internal gear, and the friction member is disposed on the internal gear. Against the axial direction, and by frictional force said A planetary gear speed reducer with a torque limiter according to any one of claims in claims 1 to 7, characterized in that it has a configuration which holds the internal gear in a fixed member side. The torque limiter includes an internal gear that is a speed reduction mechanism before the final speed reduction mechanism of the plurality of speed reduction mechanisms and that is a component of the speed reduction mechanism including the speed reduction mechanism closest to the input shaft. It is arranged with a gap in the radial direction with respect to the fixed member, a friction member is arranged opposite to the axial direction side of the internal gear, the friction member is pressed in the axial direction against the internal gear, and the frictional force The planetary gear type reduction gear with a torque limiter according to claim 8, wherein the internal gear is held on a fixed member side.

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