JP2007040396A - Planetary gear type reduction gear with magnetic torque limiter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planetary gear type reduction gear with a magnetic torque limiter capable of being inexpensively manufactured and suitable for miniaturization. <P>SOLUTION: A planetary gear type reduction gear mechanism of multiple stages, and the magnetic torque limiter are provided between an input shaft 7 and an output shaft 14. The reduction gear mechanism of a first stage is composed of a sun gear 8 connected with a rotating shaft of a motor equivalent to the input shaft 7, a planetary gear 34, an internal gear 22 and a carrier 30, and the reduction gear mechanisms of a second stage or following, are composed of a sun gear 44 connected with the carrier 30 of the reduction gear mechanism of the stage just therebefore, a planetary gear 40, an internal gear 42 and a carrier 36. The magnetic torque limiter is constituted by mounting a permanent magnet or a semi-hard magnetic member 20 on the internal gear 22 as a component of the reduction gear mechanism before the reduction gear mechanism of the last stage, and mounting the other of permanent magnet and semi-hard magnetic member 20 on a fixing member 22 in a state that the permanent magnet and the semi-hard magnetic member 20 are opposite to each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a planetary gear type speed reducer with a magnet type torque limiter, in which a magnet type torque limiter is provided in a planetary gear type reduction mechanism portion at a stage close to the input shaft of a multistage planetary gear type speed reducer. is there.

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).
On the other hand, as the torque limiter, a frictional type that performs torque transmission / cutting by the frictional force of a friction member such as an O-ring, or a permanent magnet and a semi-rigid magnetic body as opposed to the present invention, A magnet type torque limiter having a configuration in which a permanent magnet magnetizes the semi-rigid magnetic body and transmits a rotational force proportional to the area of the magnetic hysteresis loop is used (for example, see Patent Documents 2 and 3).
The friction type torque limiter is configured so that the rotational force is transmitted between the manpower shaft side and the output shaft side for most of the operating time, and the rotation is cut off only when a large load is applied. It is advantageous when used for things. However, it is disadvantageous if the rotation is interrupted for most of its operating time and is transmitted only in certain special cases.
For example, in a paper feeding device 70 used in a copying machine or the like shown in FIG. 5, an upper roller 72 and a lower roller 74 are arranged to face each other with a predetermined gap, and the upper roller 72 is a one-way clutch or the like. The lower roller 74 is connected to the motor via a speed reducer with a torque limiter. When the paper is fed, the upper roller 72 is driven clockwise by the motor, and the lower roller 74 is driven clockwise by the motor (see FIG. 5A). A torque limiter (not shown) is provided between the shaft 80 of the reduction gear on the lower roller 74 side and the lower roller 74, and the slip torque of this torque limiter is set smaller than the rotational torque of the upper roller 72. Has been.
Therefore, when the sheet 76 is fed one by one between the rollers 72 and 74, the sheet 76 between the rollers 72 and 74 is caused by the frictional force with the upper roller 72 due to the clockwise rotational torque of the upper roller 72. The lower roller 74 is fed in the middle and left conveyance directions, and rotates in the counterclockwise direction by the rotational torque transmitted through the paper 76 from the upper roller 72 by the action of the torque limiter (see FIG. 5B).
If two sheets of paper are mistakenly conveyed and conveyed to the rollers 72 and 74 during the conveyance of the sheet, the frictional force between the surfaces of the sheets 76 and 78 contacting each other causes the friction between the sheets 76 and 78 and the rollers 72 and 74 contacting the sheets 76 and 78. Since the lower sheet 78 is smaller than the force, the lower sheet 78 slips with respect to the upper sheet 76, and the clockwise rotational torque on the upper roller 72 side transmitted to the lower roller 74 via the sheets 76 and 78 decreases. To do.
The reduction of the transmission rotational torque cancels the slip operation of the torque limiter on the lower roller 74 side, and the driving force of the motor is transmitted to the lower roller 74 via the shaft 80 of the speed reducer. The paper is rotated in a clockwise direction, and the lower paper 78 in contact therewith is sent in a direction opposite to the paper conveyance direction, that is, in the right direction in the figure, thereby preventing the simultaneous conveyance of a plurality of sheets (see FIG. 5C).
As described above, the torque limiter used in the paper feeding device 70 is normally in a slip state, and the slip is released in a special case. When a friction type torque limiter is used for such a thing, the friction member is interposed between the input shaft side and the output shaft side in most of the operating time, and the wear is severe. There is a problem of durability, which is disadvantageous.
On the other hand, if a magnet type torque limiter is used for such a thing, since the permanent magnet and the semi-hard magnetic body are not in contact with each other, the magnet type torque limiter has no problem of wear and is extremely advantageous.
JP 2003-130146 A JP-A-8-308209 JP-A-7-14254

When a planetary gear type reduction mechanism is provided in multiple stages, when a torque limiter is incorporated in the planetary gear type reduction mechanism, conventionally, a planetary gear type reduction mechanism is connected to a DC motor, and the output shaft of the final stage reduction mechanism of the reduction mechanism is connected. A configuration in which a torque limiter is assembled is common. 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.
That is, the reduction ratio becomes larger and the rotational torque becomes larger as the speed reduction mechanism becomes lower. 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.
When a magnet type torque limiter is used as in the present invention, the magnet type torque limiter has a configuration in which a permanent magnet magnetizes a semi-rigid magnetic body and transmits a rotational force proportional to the area of the magnetic hysteresis loop. Therefore, when the rotational torque to be transmitted / cut off is large, it is necessary to increase the area of the magnetic hysteresis loop, 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 reduction ratio in the final stage varies depending on the design, so the rotational torque also varies. Various designs for the limiter mechanism must also be prepared. That is, the torque limiter mechanism cannot be shared.
A first object of the present invention is to solve the problem of wear by incorporating a magnet type torque limiter mechanism in a planetary gear type reduction mechanism when a plurality of planetary gear type reduction mechanisms are provided.
The second object is to achieve downsizing in a configuration in which a plurality of planetary gear type reduction mechanisms are provided and a magnet type torque limiter mechanism is built in the planetary gear type reduction mechanism.
A third object is to make the torque limiter mechanism common.
The fourth object is to reduce the shaft blurring of the rotating part and to stably transmit / cut off the torque.

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 planetary gear type speed reduction mechanism configured between the input shaft and the output shaft, and a magnet type torque limiter configured between the input shaft and the output shaft. 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 rotating shaft of the motor corresponding to the input shaft, and the planetary gear meshes with the sun gear, An internal gear is meshed with a gear, and a carrier for pivotally supporting the planetary gear is provided. A reduction mechanism after the second stage is provided with a sun gear on the carrier of the speed reduction mechanism in the immediately preceding stage, and the planetary gear is provided on the sun gear. Meshing gears, the planetary gears An internal gear is meshed with a carrier for pivotally supporting the planetary gear, and the magnet torque limiter is permanently attached to an internal gear that is a component of at least one of the multiple speed reduction mechanisms. Either a magnet or a semi-hard magnetic body is provided, and either the permanent magnet or the semi-hard magnetic body is provided on the fixing member, and the permanent magnet and the semi-hard magnetic body are arranged to face each other.
The present invention also includes 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, an internal gear that meshes with the planetary gear, and the planetary gear. A planetary gear speed reduction mechanism configured between the input shaft and the output shaft, and a magnet type torque limiter configured between the input shaft and the output shaft. A 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 rotating shaft of the motor corresponding to the input shaft, meshing the planetary gear with the sun gear, and connecting the internal gear to the planetary gear. Meshed with a carrier for pivotally supporting 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 planetary gear is meshed with the sun gear, Meshing the planetary gear with the internal gear The magnet torque limiter is permanently attached to an internal gear that is a component of the speed reduction mechanism before the final speed reduction mechanism of the plurality of speed reduction mechanisms. Either a magnet or a semi-hard magnetic body is provided, and either the permanent magnet or the semi-hard magnetic body is provided on the fixing member, and the permanent magnet and the semi-hard magnetic body are arranged to face each other.
The present invention also includes 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, an internal gear that meshes with the planetary gear, and the planetary gear. A planetary gear speed reduction mechanism configured between the input shaft and the output shaft, and a magnet type torque limiter configured between the input shaft and the output shaft. A 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 rotating shaft of the motor corresponding to the input shaft, meshing the planetary gear with the sun gear, and connecting the internal gear to the planetary gear. Meshed with a carrier for pivotally supporting 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 planetary gear is meshed with the sun gear, Meshing the planetary gear with the internal gear The magnet torque limiter is a component of a speed reduction mechanism including a speed reduction mechanism closest to the shaft of the DC motor among the plurality of speed reduction mechanisms. Either a permanent magnet or a semi-hard magnetic body is provided on the gear, and either the permanent magnet or the semi-hard magnetic body is provided on the fixing member, and the permanent magnet and the semi-hard magnetic body are arranged to face each other. .
The present invention also includes 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, an internal gear that meshes with the planetary gear, and the planetary gear. A planetary gear speed reduction mechanism configured between the input shaft and the output shaft, and a magnet type torque limiter configured between the input shaft and the output shaft. A 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 rotating shaft of the motor corresponding to the input shaft, meshing the planetary gear with the sun gear, and connecting the internal gear to the planetary gear. Meshed with a carrier for pivotally supporting 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 planetary gear is meshed with the sun gear, Meshing the planetary gear with the internal gear The magnet type torque limiter is a speed reduction mechanism before the final speed reduction mechanism of the plurality of speed reduction mechanisms, and the shaft of the DC motor is provided. A permanent magnet or a semi-hard magnetic body is provided on an internal gear that is a component of a speed reduction mechanism including the speed reduction mechanism closest to the fixed member, and either the permanent magnet or the semi-hard magnetic body is provided on the fixing member, A permanent magnet and a semi-hard magnetic material are arranged to face each other.
In the present invention, the input shaft and the output shaft are supported by a bearing portion of the carrier.

According to the first aspect of the present invention, the problem of wear can be solved by incorporating the magnet type torque limiter mechanism in the multistage planetary gear type reduction mechanism.
In the invention of claim 2, the torque limiter function can be exhibited at a position where the rotational torque is small, as compared with the configuration in which the magnet type torque limiter is assembled to the output shaft of the final stage reduction mechanism of the multistage planetary gear type reduction mechanism. Therefore, the magnet type torque limiter mechanism can be configured in a small size.
In the third and fourth aspects of the invention, in the multi-stage planetary gear type reduction mechanism, the reduction ratio in the final stage varies depending on the design, and thus the rotational torque also varies. Since the torque limiter mechanism is configured using the internal gear, which is the component of the speed reduction mechanism including the nearest speed reduction mechanism, the part that transmits and cuts the rotation regardless of the number of stages of the planetary gear type speed reduction mechanism. Since the rotational torque is constant, only one type of magnet type torque limiter mechanism is required, and the magnet type torque limiter mechanism can be shared.
In the invention of claim 5, it is possible to reduce the shaft blurring of the rotating part and to stably transmit and interrupt the torque.

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 magnet type torque limiter is provided in the first stage of a two-stage speed reducer. In the figure, reference numeral 2 denotes a speed reducer, which is constituted by a DC motor. A cover 6 of the planetary gear speed reducer 4 with a magnet type 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.

Reference numeral 20 denotes a ring-shaped semi-hard magnetic body, and an outer peripheral surface thereof is fitted to an inner peripheral surface of the case 10 and is fixed to the case 10. Reference numeral 22 denotes an internal gear made of a ring-shaped permanent magnet, and the internal gear 22 is disposed to face the inner peripheral surface of the semi-hard magnetic body 20 with a predetermined slight gap in the radial direction. A hysteresis torque for fixing and holding the internal gear 22 on the side of the fixing member 11 acts between the intermediate member 22 and the semi-hard magnetic body 20.

Reference numerals 26 and 28 denote anti-sway members made of elastic O-rings, and one anti-sway member 26 is a latch formed on one side surface of the internal gear 22 in the axial direction and the inner diameter part of the case 10. The other steadying member 28 is disposed between the other side surface of the internal gear 22 and the locking surface of the cover 6, and the steadying members 26 and 28 are disposed on the fixing member 11. The internal gear 22 is held at a fixed position on the side. The steady rest members 26 and 28 also have a function as a sealing material, seal between the both side surfaces of the internal gear 22 and the wall surface on the side of the fixing member 11 facing the inner gear 22, and are made of a semi-hard magnetic body 20 and a permanent magnet. Oil or metal powder is prevented from entering the gap between the facing surfaces of the internal gear 22.

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.

The internal gear 22 has hysteresis between the internal gear 22 and the semi-hard magnetic body 20 when a load torque exceeding a predetermined magnitude is applied from the output shaft 14 side, such as when the output shaft 14 is stopped. The internal gear 22 is fixed with respect to the case 10 in a state where it slips and rotates in a non-contact state with respect to the case 10 against the magnetic holding force composed of torque, and this load torque does not reach a predetermined value. It is comprised so that a non-rotation state may be hold | maintained.

A tubular slide bearing 31 is fixed to a hole formed in the disk-shaped portion of the carrier 30, and the slide bearing 31 is a small-diameter portion of the output shaft 14 disposed on the same axis as the input shaft 7. Is fitted in a freely rotatable manner. 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. The internal gear 42 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 fixing member 11 side through a hysteresis torque with the semi-hard magnetic body 20. And it revolves around the axial center 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 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 in a non-contact state against the hysteresis torque with the semi-hard magnetic body 20. During the slip rotation, the internal gear 22 is prevented from moving in the axial direction, that is, from side to side by the steady members 26 and 28.

The DC motor is not overloaded by the slip rotation of the internal gear 22 in a non-contact state with respect to the semi-hard magnetic body 20. Similarly, when a load equal to or greater than slip torque is applied to the output shaft 14 from the outside in the reverse rotation direction, and the output shaft 14 rotates in the reverse direction, the rotational torque of the planetary gear 34 is the internal gear with the carrier pin 32 revolving in the reverse direction as a fulcrum. 22, and the rotational torque from the planetary gear 34 causes the internal gear 22 to slip and rotate against the semi-hard magnetic body 20 in a non-contact state against the hysteresis torque. Thereby, even if the output shaft 14 rotates reversely by the external rotational force, the DC motor is not overloaded.

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 semi-rigid magnetic body 20 slips and rotates in a non-contact state, the locus of the rotation is a perfect circle centered on the axis of the case 10. Thus, the surface of the internal gear 22 facing the semi-hard magnetic body 20 forms a substantially constant locus. Thereby, the space | interval with the internal peripheral surface of the semi-hard magnetic body 20 of the internal gear 22 does not change, Therefore, the transmission torque of the internal gear 22 is always constant, and no variation occurs.

  In the embodiment described above, the configuration is not limited to the configuration in which the anti-rest members 26 and 28 are opposed to each other on both sides in the axial direction of the internal gear 22, and only one of the anti-rest members 28 or 26 may be used. It is good also as a structure which makes a side surface contact the smooth surface perpendicular | vertical to an axial direction of the internal diameter part of the case 10 or the cover 6 which directly faces this one side surface. Moreover, it is good also as a structure which makes both the side surfaces of the internal gear 22 contact | connect these smooth surfaces directly. In carrying out the present invention, the internal gear 22 may be made of a semi-hard magnetic material, and the semi-hard magnetic material 20 may be a permanent magnet. Further, in this embodiment, the main body portion and the tooth portion of the internal gear 22 are integrally formed, but the teeth are formed by members separate from the main body portion made of a semi-hard magnetic body or a permanent magnet. It is good also as a structure which fixed together.

Next, another embodiment of the present invention will be described with reference to FIG.
FIG. 2 shows an embodiment in which a magnet type 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 the case includes a planet with a magnet type torque limiter. The cover 6 of the gear type reduction gear 4 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. Reference numeral 20a denotes a cylindrical semi-hard magnetic body, and an outer peripheral surface thereof is fitted to an inner peripheral surface of the case 10 and is fixed to the case. 22a is an internal gear made of a ring-shaped permanent magnet, and the internal gear 22a is disposed with a predetermined slight gap in the radial direction with respect to the inner peripheral surface of the semi-hard magnetic body 20, and the internal gear 22a. And the semi-hard magnetic body 20a are configured so that a hysteresis torque acts.

Reference numerals 26 and 28 denote anti-sway members made of elastic O-rings, and one anti-sway member 26 is a latch formed on one side surface of the internal gear 22a in the axial direction and the inner diameter part of the case 10. The other steadying member 28 is disposed between the other side surface of the internal gear 22a and the locking surface of the cover 6, and the steadying members 26 and 28 are disposed on the fixing member 11. The internal gear 22a is held at a fixed position on the side, and the facing portions between both side surfaces of the internal gear 22a and the fixing member 11 are sealed.

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. The internal gear 22a has a hysteresis between the internal gear 22a and the semi-hard magnetic body 20a 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. In a state in which the case 10 is slip-rotated in a non-contact state against the magnetic holding force due to the torque and the load torque does not reach a predetermined value, the internal gear 22 a Thus, a fixed non-rotating state is maintained.

A tubular slide bearing 31 is fixed to a hole formed in the disk-shaped portion of the carrier 30, and the slide bearing 31 is a small-diameter portion of the output shaft 14 disposed on the same axis as the input shaft 7. Is fitted in a freely rotatable manner. 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 the internal gear 22a is fixed to the fixing member 11 side through a hysteresis torque with the semi-hard magnetic body 20a. And it revolves around the axial center 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 is not slipped by the rotational torque from the planetary gears 34 and 40, and the internal gear 22a is not between the internal gear 22a and the semi-rigid magnetic body 20a. The state of being fixed to the fixing member 11 is held by the magnetic holding force acting on the.

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. Due to this rotational torque, the internal gear 22a slips and rotates against the semi-hard magnetic body 20 in a non-contact state against the hysteresis torque acting between the semi-hard magnetic body 20a. 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 rotational force of the planetary gear 40 and the rotational force of the other planetary gear 34, the internal gear 22a follows the inner peripheral surface of the case 10 against the hysteresis torque with the semi-hard magnetic body 20a. Then, the slip rotation is performed in a non-contact state, and this slip rotation is continued until the load applied to the output shaft 14 becomes the slip torque or less.

During slip rotation in a non-contact state of the internal gear 22a with respect to the fixed member 11, the planetary gear 34 rotates on the carrier pin 32 and rotates in the direction opposite to the slip rotation of the internal gear 22a. Revolutionary movements. It is possible to prevent the DC motor from being overloaded by the slip rotation of the internal gear 22a. During the slip rotation with the internal gear 22a in a non-contact state, the planetary gear 34 that rotates at a high speed in conjunction with the sun gear 8 rotates relative to the internal gear 22a. The planetary gear 34 has a fixing member for the internal gear 22a. 11 is decelerated by a revolving motion in a direction opposite to the slip rotational motion with respect to 11.

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 internal rotation. The gear 22a slips and rotates with respect to the fixed member 11 in a non-contact state. 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 half of the internal gear 22a The surface facing the hard magnetic body 20 forms a substantially constant locus. Thereby, the space | interval with the internal peripheral surface of the semi-rigid magnetic body 20a of the internal gear 22a does not change, Therefore, the transmission torque of the internal gear 22a is always constant, and no variation occurs.

Further, during slip rotation in a non-contact state along the inner peripheral surface of the semi-rigid magnetic body 20a of the internal gear 22a, both sides of the internal gear 22 are restricted from moving in the axial direction by the anti-rest members 26 and 28. , Horizontal movement is prevented. Similarly, when a load greater than slip torque is applied to the output shaft 14 in the reverse rotation direction and the output shaft 14 rotates in the reverse direction, the rotational torque of the planetary gears 40 and 34 is similarly set with the carrier pins 38 and 32 revolving in the reverse direction as fulcrums. The internal gear 22a acts on the internal gear 22a, and the rotational torque from the planetary gears 40 and 34 causes the internal gear 22a to perform slip rotation against the hysteresis torque acting on the semi-hard magnetic body 20a. Thereby, even if the output shaft 14 rotates reversely by the external rotational force, the DC motor is not overloaded.

Also in the present embodiment, as in the above-described embodiment, the configuration is not limited to the configuration in which the anti-rest members 26 and 28 are opposed to each other on both sides in the axial direction of the internal gear 22a. Alternatively, one side surface of the internal gear 22a may be directly brought into contact with the inner diameter portion of the case 10 facing the one side surface or the locking surface having a smooth surface perpendicular to the axial direction of the cover 6. Further, both side surfaces of the internal gear 22a may be directly brought into contact with the wall surface on the fixing member 11 side so as to be rotatable.

In carrying out the present invention, the internal gear 22a may be made of a semi-hard magnetic material, and the semi-hard magnetic material 20a may be a permanent magnet. Further, in the present embodiment, the internal gear 22a integrally constitutes the main body portion and the tooth portion, but as shown in FIG. 3, the main body portion of the internal gear 22a made of a permanent magnet or a semi-hard magnetic material. The tooth portion 22a ″ made of a metal material or the like 22a ′ may be constituted by another member and fixed integrally.

Next, another embodiment of the present invention will be described with reference to FIG.
FIG. 4 shows an embodiment in which a magnet type torque limiter is provided in the first stage and the second stage of a four-stage speed reducer. In the figure, reference numeral 2 denotes a speed reducer (DC motor). A cover 6 of the planetary gear speed reducer 4 with a 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. Reference numeral 20 b denotes a cylindrical semi-hard magnetic body, and the outer peripheral surface thereof is fitted to the inner peripheral surface of the case 10 and is fixed to the case 10.
Reference numeral 22b denotes an internal gear made of a cylindrical permanent magnet, and the outer peripheral surface of the internal gear 22b is arranged with a predetermined slight gap in the radial direction with respect to the semi-hard magnetic body 20b.

Reference numerals 26 and 28 denote anti-sway members made of elastic O-rings, and one anti-sway member 26 is a latch formed on one side surface of the internal gear 22b in the axial direction and the inner diameter part of the case 10. The other steadying member 28 is disposed between the other surface of the internal gear 22b and the locking surface of the cover 6, and the steadying members 26 and 28 are disposed on the fixing member. The internal gear 22b is held at a fixed position on the 11th side. 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 22b, 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 or reversely rotated by an external rotational force, the internal gear 22b The internal gear 22b slips and rotates in a non-contact state with respect to the case 10 against the hysteresis torque that acts between the semi-hard magnetic body 20b and the load torque does not reach a predetermined value. The internal gear 22b is configured to hold a non-rotating state fixed to the case 10 with a magnetic holding force by the hysteresis torque.

A tubular slide bearing 31 is fixed to a hole formed in the disk-shaped portion of the carrier 30, and the slide bearing 31 is a small-diameter portion of the output shaft 14 disposed on the same axis as the input shaft 7. Is fitted in a freely rotatable manner. 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 68 formed on a slide bearing 57 fixed to the carrier 56. The internal gear 64 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 22b. 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 68 rotates. Due to the rotation of the sun gear 68, the planetary gear 40 rotates about 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, when the output shaft 14 is stopped for some reason, for example, if a load exceeding 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, 60 increases with respect to the internal gear 22b. By this rotational torque, the internal gear 22b slip-rotates in a non-contact state against the semi-hard magnetic body 20b against the hysteresis torque acting between the semi-hard magnetic body 20b. Thereby, the rotation of the output shaft 14 is stopped, and the revolving motion of the planetary gears 62 and 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 22b, and by this revolving motion, the first carrier 30 rotates, and this rotation is transmitted to the planetary gear 60. It rotates around the carrier pin 58 of the second carrier 54. Due to the total rotational force of the rotational force of the planetary gear 60 and the rotational force of the other planetary gear 34, the internal gear 22b resists the hysteresis torque between the internal gear 22b and the semi-hard magnetic body 20b, and the inner periphery of the semi-hard magnetic body 20b. The slip rotation is performed in a non-contact state along the surface, and this slip rotation is continued until the load applied to the output shaft 14 becomes the slip torque or less.

During slip rotation in a non-contact state of the internal gear 22b with respect to the fixed member 11, the planetary gear 34 rotates on the carrier pin 32 and rotates in the direction opposite to the slip rotation of the internal gear 22b. Revolutionary movements. It is possible to prevent the DC motor from being overloaded by the slip rotation of the internal gear 22b in the non-contact state. During the slip rotation of the internal gear 22b, the relative rotational movement of the planetary gear 34 that rotates at a high speed in conjunction with the sun gear 8 relative to the internal gear 22b causes the planetary gear 34 to move relative to the semi-hard magnetic body 20b of the internal gear 22b. It is decelerated by a revolving motion in a direction opposite to the slip rotation motion in the non-contact state.

As a result, the relative rotational movement of the planetary gear 60 that has been decelerated at the rear stage relative to the internal gear 22b and the relative rotational movement of the planetary gear 34 relative to the internal gear 22b become the same speed, and the rotation of the two planetary gears 60 and 34 results in the internal rotation. The gear 22b rotates by slip relative to the fixed member 11. The planetary gears 34, 60 are firmly supported by the slide bearings 31, 55 at positions spaced apart from each other in the radial direction with respect to the axis of the case 10, that is, the central axes of the input shaft 7 and the output shaft 14.

Therefore, when the planetary gear 40 and the planetary gear 34 rotate and the internal gear 22b meshing with the slip rotates, the locus of the rotation becomes a perfect circle centered on the axis of the case 10, and the half of the internal gear 22b The surface facing the hard magnetic body 20b forms a substantially constant locus. Thereby, the space | interval with the internal peripheral surface of the semi-hard magnetic body 20b of the internal gear 22b does not change, Therefore, the transmission torque of the internal gear 22b is always constant, and no variation occurs. Further, during slip rotation in a non-contact state along the inner peripheral surface of the semi-rigid magnetic body 20b of the internal gear 22b, the internal gear 22b is restricted from movement in the axial direction by the anti-rest members 26 and 28 on both sides thereof. , Horizontal movement is prevented.

Similarly, when a load greater than slip torque is applied to the output shaft 14 in the reverse rotation direction and the output shaft 14 rotates in the reverse direction, the rotational torques of the planetary gears 60 and 34 are similarly supported by the carrier pins 58 and 32 revolving in the reverse direction. The internal gear 22b acts on the internal gear 22b, and the rotational torque from the planetary gears 60 and 34 causes the internal gear 22b to slip and rotate against the hysteresis torque acting between the semi-hard magnetic body 20b. Thereby, even if the output shaft 14 rotates reversely by the external rotational force, the DC motor is not overloaded.

  In the present embodiment as well, as in the above-described embodiment, the configuration is not limited to the configuration in which the anti-rest members 26 and 28 are opposed to each other on both sides in the axial direction of the internal gear 22b. Alternatively, one side surface of the internal gear 22b may be directly brought into contact with the inner diameter portion of the case 10 facing the one side surface or the locking surface having a smooth surface perpendicular to the axial direction of the cover 6. Further, both side surfaces of the internal gear 22b may be directly brought into contact with the wall surface on the fixing member 11 side so as to be freely rotatable.

In carrying out the present invention, the internal gear 22b may be composed of a semi-hard magnetic material, and the semi-hard magnetic material 20b may be a permanent magnet. Moreover, in this embodiment, although the internal gear 22b has comprised the main-body part and the tooth | gear part integrally, you may comprise the main-body part and tooth | gear part of the internal gear 22b by another member. In the above embodiment, the magnet type torque limiter mechanism is configured in the first or second stage internal gear of the planetary gear type speed reducer because the torque limiter effect is obtained as close to the input side as possible. It is advantageous and can be downsized. That is, since the torque on the input side is small, the magnet type torque limiter mechanism can be miniaturized.

In the embodiment shown in FIGS. 1 and 2, a carrier 30 that supports a planetary gear 34 that meshes with the internal gears 22, 22 a constituting the magnet type torque limiter is rotatably supported on both the input shaft 7 and the output shaft 14. In the embodiment shown in FIG. 4, the carrier that supports the planetary gear meshing with the internal gear constituting the magnet type torque limiter is rotatably supported by the output shaft, but the magnet type torque limiter is constituted. The carrier that supports the planetary gear meshing with the internal gear may be rotatably supported by the input shaft.

  The input shaft 7 and the output shaft 14 are coaxially opposed to each other, the input shaft 7 and the output shaft 14 are supported by a connecting member by bearings, and a planetary gear meshing with an internal gear constituting a magnet type torque limiter is supported. In the configuration in which the carrier is rotatably supported by the input shaft, the input shaft is supported by bearing on the fixed member side (cover 6 integral with the case 10), and the carrier is supported on the input shaft. By supporting the bearing, 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, since the internal gear meshing with the planetary gear also does not rotate eccentrically with respect to the fixed member side, the interval during the slip rotation between the internal gear and the fixed member side, that is, the semi-hard magnetic body, is kept constant and depends on the product. There will be no variation and it will be stable.

  In addition, a carrier that supports the planetary gear that is disposed so that the input shaft and the output shaft are concentrically opposed to each other, the input shaft and the output shaft are supported by a coupling member by bearings, and meshes with the internal gear that constitutes the magnet type torque limiter. 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 by 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 pivotally supported by the carrier pin of the carrier is not No eccentric rotation with respect to the fixed member side. That is, since the internal gear meshing with the planetary gear also does not rotate eccentrically with respect to the fixed member side, the interval during the slip rotation between the internal gear and the fixed member side, that is, the semi-hard magnetic body, is kept constant and depends on the product. There will be no variation and it will be stable.

  An input shaft and an output shaft are coaxially arranged opposite to each other, and the carrier that supports the planetary gear that meshes with the internal gear that constitutes the magnet type torque limiter by supporting the input shaft and the output shaft with a coupling member by bearings. In the configuration in which the output shaft is rotatably supported by the output shaft, 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 also does not rotate eccentrically with respect to the fixed member side, the interval during slip rotation between the internal gear and the semi-hard magnetic material is kept constant, and there is no variation due to the product. , Become stable.

It is sectional drawing of the planetary gear type reduction gear with a magnet type torque limiter concerning the present invention. It is sectional drawing which shows other embodiment of the planetary gear type reduction gear with a magnet type torque limiter which concerns on this invention. It is sectional drawing which shows other embodiment of the planetary gear type reduction gear with a magnet type torque limiter which concerns on this invention. It is sectional drawing which shows other embodiment of the planetary gear type reduction gear with a magnet type torque limiter which concerns on this invention. It is explanatory drawing of a prior art.

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 20 Semi-hard magnetic body 20a Semi-hard magnetic body 20b Semi-hard magnetic body 22 Internal gear 22a Internal gear 22b Internal gear 26 Stabilizing member 28 Stabilizing member 28 30 carrier 31 slide bearing 32 carrier pin 34 planetary gear 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 70 Paper feeder 72 Roller 74 Roller 76 Paper 78 Paper 80 Shaft

Claims (5)

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. A planetary gear type reduction mechanism configured between the input shaft and the output shaft, and a magnet type torque limiter configured between the input shaft and the output shaft. The first stage reduction mechanism is provided with a sun gear on the rotating shaft of the motor corresponding to the input shaft, the planetary gear is meshed with the sun gear, the planetary gear is meshed with the internal 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 in the immediately preceding stage, and the planetary gear is meshed with the sun gear. Mesh the gears, the planetary teeth The magnet type torque limiter is either a permanent magnet or a semi-rigid magnetic material on an internal gear that is a constituent element of at least one of the multi-stage reduction mechanisms. A planetary gear with a magnet type torque limiter, characterized in that one is provided, and either the permanent magnet or the semi-hard magnetic body is provided on the fixing member, and the permanent magnet and the semi-hard magnetic body are arranged to face each other. Type reducer. 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. A planetary gear type speed reduction mechanism configured between the input shaft and the output shaft, and a magnet type torque limiter configured between the input shaft and the output shaft. The first stage reduction mechanism is provided with a sun gear on the rotating shaft of the motor corresponding to the input shaft, the planetary gear is meshed with the sun gear, the planetary gear is meshed with the internal 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 in the immediately preceding stage, and the planetary gear is meshed with the sun gear. Mesh the gears, the planetary teeth The magnet type torque limiter is provided with a permanent magnet or semi-rigid on an internal gear that is a component of the speed reduction mechanism before the final speed reduction mechanism of the plurality of speed reduction mechanisms. Magnet type characterized in that either one of the magnetic bodies is provided, either the permanent magnet or the semi-rigid magnetic body is provided on the fixing member, and the permanent magnet and the semi-hard magnetic body are arranged to face each other. Planetary gear reducer with torque limiter. 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. A planetary gear type speed reduction mechanism configured between the input shaft and the output shaft, and a magnet type torque limiter configured between the input shaft and the output shaft. The first stage reduction mechanism is provided with a sun gear on the rotating shaft of the motor corresponding to the input shaft, the planetary gear is meshed with the sun gear, the planetary gear is meshed with the internal 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 in the immediately preceding stage, and the planetary gear is meshed with the sun gear. Mesh the gears, the planetary teeth The magnet type torque limiter is a permanent magnet for an internal gear which is a component of a speed reduction mechanism including a speed reduction mechanism closest to the shaft of the DC motor among the speed reduction mechanisms of the plurality of stages. Alternatively, either one of a semi-hard magnetic body is provided, the permanent member is provided with either the permanent magnet or the semi-hard magnetic body, and the permanent magnet and the semi-hard magnetic body are arranged to face each other. Planetary gear reducer with magnet type torque limiter. 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. A planetary gear type speed reduction mechanism configured between the input shaft and the output shaft, and a magnet type torque limiter configured between the input shaft and the output shaft. The first stage reduction mechanism is provided with a sun gear on the rotating shaft of the motor corresponding to the input shaft, the planetary gear is meshed with the sun gear, the planetary gear is meshed with the internal 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 in the immediately preceding stage, and the planetary gear is meshed with the sun gear. Mesh the gears, the planetary teeth The magnet type torque limiter is a speed reduction mechanism that is the speed reduction mechanism before the final speed reduction mechanism among the multiple speed reduction mechanisms, and is the closest speed reduction to the DC motor shaft. One of a permanent magnet and a semi-hard magnetic body is provided on an internal gear that is a component of a speed reduction mechanism including a mechanism, and either the permanent magnet or a semi-hard magnetic body is provided on the fixing member. A planetary gear speed reducer with a magnet type torque limiter, characterized in that a hard magnetic material is arranged oppositely. The planetary gear type reduction gear with a magnet type torque limiter according to any one of claims 1 to 4, wherein the input shaft and the output shaft are supported by a bearing portion of the carrier. Machine.

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