JP2013217459A - Reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a torque loss to improve the efficiency of torque transmission in a traction drive type reduction gear.SOLUTION: A traction drive type reduction gear is configured such that a rotating roller 14 and a planetary roller 21 which are indirectly brought into rotational contact with an input shaft 1 and a rotating ring 3 are incorporated between the input shaft 1 and the rotating ring 3, and when the input shaft 1 is rotated, the rotating ring 3 is rotated in the reverse direction according to the rotation of the rotating roller 14 and, at the same time, the revolution of the planetary roller 21 is transmitted to an output shaft 2 via a carrier 6, wherein the rotating roller 14 is brought into rolling contact with an inner wall of a recessed engagement part 8a of a cover (stationary member) 8 via a rolling bearing 16 in the rotation direction of the input shaft 1, and meanwhile, the planetary roller 21 is brought into rolling contact with the inner wall of a recessed engagement part 6a of the carrier 6 via a rolling bearing 23 in the revolution direction and, thereby, heat generation due to sliding between the respective members is prevented to suppress a torque loss.

Description

  The present invention relates to a speed reducer that decelerates rotation of an input shaft by a planetary mechanism and transmits it to an output shaft.

  In office machines such as printers, copiers, and facsimile machines, a small motor that rotates at high speed is generally used to reduce the size of the drive unit. Therefore, as a speed reducer built between the motor and the driven unit, A compact and large reduction ratio is required. In addition, since the office machine is used in an office, the reduction gear incorporated in the office machine is also required to have low noise.

  On the other hand, in Patent Document 1, an input shaft, an output shaft, a reversing mechanism and a planetary mechanism (first and second traction drives) of a bearing structure provided on the outer periphery of the input shaft, a reversing mechanism and a planetary mechanism. A cage that holds the ball that is in rolling contact with both the outer ring and the inner ring (pinched between the outer ring and the inner ring) so as to be able to rotate. The inner ring and the outer ring are connected to each other, and the cage of the reversing mechanism is a stationary member. (Case), the planetary mechanism retainer is fixed to the output shaft, and when the input shaft rotates, the reversing mechanism and the outer ring of the planetary mechanism are integrated in the opposite direction to the input shaft by the rotation of the reversing mechanism ball. A reduction gear (traction drive transmission) has been proposed in which the revolution of the ball of the planetary mechanism is transmitted to the output shaft through a cage.

  According to this configuration, the revolution of the ball of the planetary mechanism is partially offset by the reverse rotation of the outer ring, and the rotation of the output shaft is slowed accordingly, so that a large reduction ratio is obtained, and the reversing mechanism and the planetary mechanism are axially Since they are provided adjacent to each other, compactness can be ensured. In addition, since the traction drive system uses balls that are in rolling contact with both the outer ring and the inner ring for the reversing mechanism and the planetary mechanism, the noise is less than when using gears for each mechanism.

JP-A-9-189349

  By the way, the speed reducer described in Patent Document 1 is compact and has a large reduction ratio as described above, and has a low noise. However, the ball of the reversing mechanism is input by a fixed cage. Since the rotation around the axis is constrained, the planetary mechanism ball rotates while pushing and moving the cage in the direction of revolution, and heat is generated by sliding between the balls of the mechanism and the cage, resulting in torque loss. There is a problem that tends to be large.

  In addition, the revolution of the ball of the planetary mechanism is transmitted to the output shaft through the cage, and since the ball is generally incorporated into the pocket of the cage with a certain gap, due to the delay in the rotation transmission between the two, There is also a problem that the response of rotation transmission from the input shaft to the output shaft becomes slow.

  Therefore, an object of the present invention is to improve torque transmission efficiency by suppressing torque loss and improve responsiveness of rotation transmission from an input shaft to an output shaft in a traction drive type speed reducer.

  In order to solve the above-described problems, the present invention is provided between an input shaft, an output shaft, a rotating ring disposed radially outside the input shaft, and the input shaft and the rotating ring. A reversing mechanism having a plurality of rotation rollers that rotate and rotate in contact with the input shaft and the rotation ring in a state in which the surrounding revolution is constrained, and is provided between the input shaft and the rotation ring, and rotates between the input shaft and the rotation ring. A planetary mechanism having a plurality of planetary rollers that revolve around the input shaft while rotating in contact with the planetary roller, and a carrier that supports the planetary roller so as to rotate and is fixed to the output shaft, and the input shaft is rotated. When the rotation of the rotation roller rotates the rotation ring in the direction opposite to the input shaft, and the rotation of the planetary roller is transmitted to the output shaft through the carrier, the rotation roller is rotated in the rotation direction of the input shaft. Configuration for rolling contact on the stationary member (the first configuration) was employed at least one component which rolling contact with the planetary rollers to the carrier at its revolving direction (second configuration).

  That is, in a speed reducer using a reversing mechanism and a planetary mechanism as a traction drive system, the rotating roller of the reversing mechanism is brought into contact with a stationary member in the rotation direction of the input shaft, or the planetary roller of the planetary mechanism is used as a carrier in the revolving direction By making rolling contact, heat generation due to slippage between these members is prevented, and torque loss can be suppressed. Further, in the second configuration, the planetary roller can be assembled with the carrier without any gap, so that a delay in rotation transmission between the planetary roller and the carrier can be eliminated.

  In the case of adopting the first configuration, specifically, an engagement portion in which an inner ring of a rolling bearing is fitted and fixed to an outer periphery of one end portion of the rotation roller, and an outer ring of the rolling bearing is provided on the stationary member. It is preferable that the rotation roller is brought into contact with the stationary member via a rolling bearing by contacting the input shaft in the rotation direction of the input shaft. Alternatively, a plurality of projecting shafts parallel to the input shaft are provided on the stationary member, and an inner ring of a rolling bearing is fitted and fixed to an outer periphery of the projecting shaft, and an outer ring of the rolling bearing is attached to one end portion of the rotation roller. The rotation roller may be brought into contact with a stationary member via a rolling bearing.

  On the other hand, when the second configuration is adopted, specifically, an engagement in which an inner ring of a rolling bearing is fitted and fixed to an outer periphery of one end of the planetary roller, and an outer ring of the rolling bearing is provided on the carrier. The planetary roller may be brought into contact with the carrier via a rolling bearing by contacting the portion with the revolving direction of the planetary roller. Alternatively, the carrier is provided with a plurality of projecting shafts parallel to the input shaft, and the inner ring of the rolling bearing is fitted and fixed to the outer periphery of the projecting shaft, and the outer ring of the rolling bearing is attached to one end of the planetary roller in its revolving direction. By contacting, the planetary roller may be brought into rolling contact with the carrier via a rolling bearing.

  In each of the above-described configurations, a cage that holds the rotating roller or the planetary roller in a rollable manner is incorporated between the input shaft and the rotating ring, so that the posture of the rotating roller or the planetary roller is kept normal. , Can stabilize the operation.

  Further, if one end of the input shaft is fitted into an engagement hole provided on one end surface of the output shaft so as to be relatively rotatable, the rotation and rotation of the input shaft and the output shaft are suppressed. It can be made smoother.

  Furthermore, an outer cylinder that covers the outer peripheral surface of the rotating ring and the carrier and has a lid portion that allows the output shaft to pass therethrough, and a lid that closes the open end of the outer cylinder while allowing the input shaft to pass therethrough are provided. By making the unit into a unit, it is possible to improve the embeddability into a device such as an office machine. In this case, an input bearing portion is provided between the lid and the input shaft, an output bearing portion is provided between the lid portion of the outer cylinder and the output shaft, and the input shaft is provided in the vicinity of the output bearing portion. If one end of the input shaft is fitted into an engagement hole provided on one end surface of the output shaft so as to be relatively rotatable, the support structure of the input shaft becomes a double-supported structure, so that the tilt of the input shaft can be reliably prevented. The operation of the entire speed reducer can be further stabilized.

  As described above, the speed reducer according to the present invention employs a traction drive system for both the reversing mechanism and the planetary mechanism, and the rotation roller of the reversing mechanism is brought into rolling contact with the stationary member in the rotation direction of the input shaft. Since the roller is in contact with the carrier in its revolving direction, heat generation due to slippage between these members can be prevented, and as a result, torque loss is suppressed and torque transmission efficiency is improved. be able to. Further, when the planetary roller is brought into rolling contact with the carrier, there is no delay in rotation transmission between the planetary roller and the carrier, and the response of rotation transmission from the input shaft to the output shaft can be improved.

Longitudinal front view of the speed reducer of the first embodiment 1 is an exploded perspective view of FIG. Sectional view along line III-III in FIG. Sectional view along line IV-IV in FIG. Sectional view along line VV in FIG. Sectional view along line VI-VI in FIG. Longitudinal front view of the reducer according to the second embodiment 7 is an exploded perspective view of FIG. Sectional view along line IX-IX in FIG. Sectional drawing along the XX line of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 6 show a first embodiment. As shown in FIGS. 1 and 2, the speed reducer includes an input shaft 1 and an output shaft 2 that are arranged on the same axis, a rotary ring 3 that is arranged radially outside the input shaft 1, and an input shaft. 1 and a reversing mechanism 4 and a planetary mechanism 5 provided so as to be adjacent to each other in the axial direction between the rotating ring 3 and a carrier 6 having a plurality of concave engaging portions 6a that engage with the planetary mechanism 5 on one side surface. The outer cylinder 7 that covers the outer peripheral surfaces of the rotating ring 3 and the carrier 6 and has a lid portion 7a through which the output shaft 2 passes, and a disk-shaped lid 8 that closes the open end of the outer cylinder 7 while passing through the input shaft 1 Basically composed. Bearings (input bearing portion and output bearing portion) that rotatably support the input shaft 1 and the output shaft 2 between the lid 8 and the input shaft 1 and between the lid portion 7a of the outer cylinder 7 and the output shaft 2, respectively. ) 9, 10 are provided. And the cover 8 is fixed to the outer cylinder 7, and the whole reduction gear is unitized.

  The input shaft 1 and the output shaft 2 are in the vicinity of the bearing 10 of the output shaft 2, and one end of the input shaft 1 is inserted into an engagement hole 2 a provided at the center of the end surface of one end of the output shaft 2 through the bearing 11. Are fitted so that they can rotate relative to each other. As a result, the support structure of the input shaft 1 becomes a double-supported structure, and the tilt of the input shaft 1 is surely prevented, and the tilt of the output shaft 2 and the deflection deformation of the input / output shafts 1 and 2 are suppressed. The shafts 1 and 2 rotate smoothly, and the operation of the entire reduction gear, which will be described later, is stabilized. The output shaft 2 is integrally formed with the carrier 6 at one end thereof. The other end portions of the input / output shafts 1 and 2 are formed with flat portions 1a and 2b on the outer peripheral surfaces, respectively, and are opposed to engagement holes having a D-shaped cross section of the input side rotation member and the output side rotation member which are not shown. It is designed to be non-rotatable.

  The rotating ring 3 has an inner diameter on one end side (input side) smaller than an inner diameter on the other end side (output side), and the reversing mechanism 4 is provided between the one end side portion and the input shaft 1. The planetary mechanism 5 is provided between the other end portion and the input shaft 1.

  As shown in FIGS. 1 and 3, the reversing mechanism 4 includes an inner ring 12 that is fitted and fixed to the outer periphery of the input shaft 1, and an outer ring 13 that is fitted and fixed to the inner circumference on one end side of the rotating ring 3, The bearing structure includes a plurality of rotation rollers 14 disposed between the inner ring 12 and the outer ring 13 and a retainer 15 that holds the rotation rollers 14 so as to allow rolling. Then, the clearance (bearing internal clearance) between the rotation roller 14 and the inner ring 12 and the outer ring 13 is eliminated, the rotation roller 14 is brought into rolling contact with the inner ring 12 and the outer ring 13, and the rotation roller 14 and the inner and outer rings 12 and 13 are separated. So that traction occurs.

  Also, as shown in FIGS. 1, 2 and 4, one end of the rotating roller 14 is projected from the outer end surfaces of the inner ring 12 and the outer ring 13, and the inner ring 17 of the rolling bearing 16 is fitted and fixed to the outer periphery thereof. The outer ring 18 of the rolling bearing 16 is brought into contact with the inner walls of a plurality of concave engaging portions 8 a provided on the inner surface of the lid 8 in the rotational direction of the input shaft 1.

  As shown in FIGS. 1, 3, and 4, when the input shaft 1 rotates integrally with the inner ring 12, the rotation roller 14 to which the rotation of the input shaft 1 is transmitted via the inner ring 12 causes the rolling bearing 16 to move. Then, the lid 8 rotates in a state where the revolution around the input shaft 1 is restrained, and the rotating ring 3 is rotated integrally with the outer ring 13 in the direction opposite to the input shaft 1.

  As shown in FIGS. 1 and 5, the planetary mechanism 5 is fitted to the inner ring 19 fitted and fixed to the outer circumference of the input shaft 1 and the inner circumference on the other end side of the rotating ring 3, similarly to the reversing mechanism 4. It has a bearing structure comprising an outer ring 20 to be fixed together, a plurality of planetary rollers 21 arranged between the inner ring 19 and the outer ring 20, and a cage 22 that holds the planetary roller 21 in a rollable manner. . Then, a clearance (bearing internal clearance) between the planetary roller 21 and the inner ring 19 and the outer ring 20 is eliminated, the planetary roller 21 is brought into rolling contact with the inner ring 19 and the outer ring 20, and the planetary roller 21 and the inner and outer rings 19 and 20 are connected. So that traction occurs.

  Also, as shown in FIGS. 1, 2 and 6, one end of the planetary roller 21 protrudes from the outer end surfaces of the inner ring 19 and the outer ring 20, and the inner ring 24 of the rolling bearing 23 is fitted and fixed to the outer periphery thereof. The outer ring 25 of the rolling bearing 23 is brought into contact with the inner walls of a plurality of concave engaging portions 6 a provided on the inner surface of the carrier 6 in the revolving direction of the planetary roller 21.

  As shown in FIGS. 1, 5, and 6, when the input shaft 1 rotates, the planetary roller 21 is caused by traction generated between the input shaft 1 and the inner ring 19 integral with the input shaft 1 and the outer ring 20 integral with the rotation ring 3. While revolving, it revolves around the input shaft 1 in the same direction as the input shaft 1.

  Here, the retainers 15 and 22 of the reversing mechanism 4 and the planetary mechanism 5 serve to maintain the postures of the rotation roller 14 and the planetary roller 21 normally, and stabilize the rotation transmission operation. The outer peripheral surfaces of the inner rings 12 and 19 of the mechanisms 4 and 5 and the inner peripheral surfaces of the outer rings 13 and 20 are subjected to a crowning process in which both end portions in the axial direction are slightly reduced in diameter. As a result, the stress (edge stress) generated at the contact portion between the rotation roller 14 and the planetary roller 21 and the ends of the inner and outer rings 12, 13, 19, 20 can be kept low, and the bearing structure of each mechanism 4, 5 can be damaged early. Can be prevented.

  The concave engaging portions 8a and 6a of the lid 8 and the carrier 6 are formed in an oval shape in which the rolling bearings 16 and 23 are movable in the radial direction of the lid 8 and the carrier 6, respectively. It is designed to absorb dimensional tolerances and mounting play. A disc-like spacer 26 that is fitted on the outer periphery of the input shaft 1 is provided between the reversing mechanism 4 and the planetary mechanism 5.

  This speed reducer has the above-described configuration. When the input shaft 1 rotates, the reversing mechanism 4 rotates the rotating ring 3 in the opposite direction to the input shaft 1 and rotates the planetary roller 21 of the planetary mechanism 5 while rotating. Revolving in the same direction as the shaft 1, the revolution of the planetary roller 21 is transmitted to the output shaft 2 via the carrier 6. Accordingly, the revolution of the planetary roller 21 is partially offset by the reverse rotation of the rotating ring 3 to obtain a large reduction ratio, and the reversing mechanism 4 and the planetary mechanism 5 are provided side by side in the axial direction, so that compactness can be ensured. . The reduction ratio and the rotation direction of the output shaft 2 (revolution direction of the planetary roller 21) can be changed by appropriately setting the radial dimensions of the components of the reversing mechanism 4 and the planetary mechanism 5. Further, the reversing mechanism 4 and the planetary mechanism 5 have a traction drive system using a rotating roller 14 and a planetary roller 21 that are in rolling contact with both the input shaft 1 and the rotating ring 3, respectively. It is suitable for incorporation into a device that requires quietness such as a machine.

  In addition, the rotating roller 14 of the reversing mechanism 4 is brought into rolling contact with the lid 8 via the rolling bearing 16 in the rotation direction of the input shaft 1, and the planetary roller 21 of the planetary mechanism 5 is rotated via the rolling bearing 23 in its revolving direction. Since it is in rolling contact with the carrier 6, heat generation due to slippage between these members can be prevented, and torque loss is small. Therefore, high torque transmission efficiency can be obtained, and high-speed rotation input can be supported. Furthermore, since the entire speed reducer is unitized, there is also an advantage that it is excellent in assembling into a device such as an office machine. Further, since the planetary roller 21 is incorporated with the carrier 6 without any gap and there is no delay in the rotation transmission between them, the rotation transmission response from the input shaft 1 to the output shaft 2 is excellent.

  7 to 10 show a second embodiment. In this embodiment, the rolling contact structure of the rotating roller 14 to the lid 8 in the reversing mechanism 4 and the rolling contact structure of the planetary roller 21 to the carrier 6 in the planetary mechanism 5 are changed based on the first embodiment. is there.

  In the reversing mechanism 4 of the second embodiment, a plurality of projecting shafts 27 projecting in parallel with the input shaft 1 from the bottom surface of the recess 8b inside the lid 8 are provided, and the inner ring 29 of the rolling bearing 28 is provided on the outer periphery of each projecting shaft 27. The outer ring 30 of the rolling bearing 28 is brought into contact with one end of the rotating roller 14 in the rotational direction of the input shaft 1 by the fitting and fixing, so that the rotating roller 14 is brought into rolling contact with the lid 8 via the rolling bearing 28. Yes. Similarly, the planetary mechanism 5 is provided with a plurality of projecting shafts 31 projecting in parallel to the input shaft 1 from the bottom surface of the recess 6b inside the carrier 6, and the inner ring 33 of the rolling bearing 32 is fitted on the outer periphery of each projecting shaft 31. The outer ring 34 of the rolling bearing 32 is brought into contact with one end of the planetary roller 21 in its revolving direction, so that the planetary roller 21 is brought into rolling contact with the carrier 6 via the rolling bearing 32. Since the other configuration and rotation transmission operation are the same as those of the first embodiment, the same components as those of the first embodiment are basically denoted by the same reference numerals and description thereof is omitted.

  Also in the second embodiment, as in the first embodiment, the rotation roller 14 is in contact with the lid 8 via the rolling bearing 28, and the planetary roller 21 is in contact with the carrier 6 via the rolling bearing 32. No heat is generated due to slippage between these members, and high torque transmission efficiency is obtained.

  In each of the above-described embodiments, the inner ring and the outer ring that constitute the bearing structure of the reversing mechanism and the planetary mechanism are both a single part, but the inner ring is formed integrally with the input shaft, or the outer ring is a rotating ring. Alternatively, the rotating roller or the planetary roller may be in direct contact with the input shaft or the rotating ring.

  In addition, the rotation roller and the planetary roller are preferably brought into rolling contact with the lid and the carrier as in the respective embodiments, but either one of the rollers can be brought into sliding contact with the lid or the carrier.

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Output shaft 2a Engagement hole 3 Rotating ring 4 Reversing mechanism 5 Planetary mechanism 6 Carrier 6a Concave engaging part 7 Outer cylinder 7a Lid part 8 Lid (stationary member)
8a Concave engaging portion 12 Inner ring (reversing mechanism)
13 Outer ring (reversing mechanism)
14 Rotating roller 15 Cage 16, 23, 28, 32 Rolling bearings 17, 24, 29, 33 Inner ring (rolling bearing)
18, 25, 30, 34 Outer ring (rolling bearing)
19 Inner ring (planetary mechanism)
20 Outer ring (planetary mechanism)
21 Planetary roller 22 Cage 27, 31 Projection shaft

Claims (10)

  An input shaft, an output shaft, a rotating ring disposed radially outside the input shaft, and the input shaft and the rotating shaft provided between the input shaft and the rotating ring, in a state in which revolving around the input shaft is restricted. A reversing mechanism having a plurality of rotation rollers that rotate in rotation with a rotating ring, and provided between the input shaft and the rotating ring, and revolves around the input shaft while rotating in rotation with the input shaft and the rotating ring. A planetary mechanism having a plurality of planetary rollers; and a carrier that supports the planetary roller so as to rotate and is fixed to the output shaft. When the input shaft rotates, a rotation ring is formed by the rotation of the rotation roller. In a speed reducer that rotates in a direction opposite to an input shaft and transmits the revolution of the planetary roller to an output shaft through a carrier, the rotating roller is in rolling contact with a stationary member in the direction of rotation of the input shaft. Reduction gear.   An inner ring of a rolling bearing is fitted and fixed to the outer periphery of one end of the rotating roller, and an outer ring of the rolling bearing is brought into contact with an engaging portion provided on the stationary member in the rotation direction of the input shaft. The speed reducer according to claim 1, wherein the roller is in rolling contact with a stationary member via a rolling bearing.   A plurality of projecting shafts parallel to the input shaft are provided on the stationary member, an inner ring of a rolling bearing is fitted and fixed to the outer periphery of the projecting shaft, and an outer ring of the rolling bearing is rotated at one end of the rotating roller. 2. The speed reducer according to claim 1, wherein the rotation roller is brought into contact with a stationary member via a rolling bearing by making contact in a direction.   An input shaft, an output shaft, a rotating ring disposed radially outside the input shaft, and the input shaft and the rotating shaft provided between the input shaft and the rotating ring, in a state in which revolving around the input shaft is restricted. A reversing mechanism having a plurality of rotation rollers that rotate in rotation with a rotating ring, and provided between the input shaft and the rotating ring, and revolves around the input shaft while rotating in rotation with the input shaft and the rotating ring. A planetary mechanism having a plurality of planetary rollers; and a carrier that supports the planetary roller so as to rotate and is fixed to the output shaft. When the input shaft rotates, a rotation ring is formed by the rotation of the rotation roller. A reduction gear that rotates in a direction opposite to an input shaft and transmits the revolution of the planetary roller to an output shaft through a carrier, wherein the planetary roller is brought into rolling contact with the carrier in the revolution direction. Machine.   An inner ring of a rolling bearing is fitted and fixed to the outer periphery of one end portion of the planetary roller, and the outer ring of the rolling bearing is brought into contact with an engaging portion provided on the carrier in the revolving direction of the planetary roller, whereby the planetary roller is The speed reducer according to claim 4, wherein the speed reducer is in rolling contact with the carrier via a rolling bearing.   A plurality of projecting shafts parallel to the input shaft are provided on the carrier, and an inner ring of a rolling bearing is fitted and fixed to an outer periphery of the projecting shaft, and an outer ring of the rolling bearing is brought into contact with one end of the planetary roller in its revolving direction. The reduction gear according to claim 4, wherein the planetary roller is brought into rolling contact with the carrier via a rolling bearing.   The speed reducer according to any one of claims 1 to 6, wherein a cage that holds the rotating roller or the planetary roller so as to roll is incorporated between the input shaft and the rotating ring.   The speed reducer according to any one of claims 1 to 7, wherein one end portion of the input shaft is fitted into an engagement hole provided on one end surface of the output shaft so as to be relatively rotatable.   An outer cylinder that covers an outer peripheral surface of the rotating ring and the carrier and has a lid portion that allows the output shaft to pass therethrough, and a lid that closes an open end of the outer cylinder while allowing the input shaft to pass therethrough are provided. The speed reducer according to any one of claims 1 to 8.   An input bearing portion is provided between the lid and the input shaft, an output bearing portion is provided between the outer cylinder lid portion and the output shaft, and one end portion of the input shaft is disposed in the vicinity of the output bearing portion. The speed reducer according to claim 9, wherein the speed reducer is fitted in an engagement hole provided on one end surface of the output shaft so as to be relatively rotatable.

Images