JP2016044782A - Friction roller type reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction roller type reduction gear which can reduce the number of part items while maintaining the necessary rigidity of the reduction gear, can easily perform assembling work, and can assure performance at a reduction gear unit body.SOLUTION: A friction roller type reduction gear comprises a sun roller which is arranged concentrically with an input shaft, a ring roller, a plurality of intermediate rollers 19, and a connecting part which connects the ring roller and an output shaft. In the intermediate rollers 19, both end parts of a rotation shaft 31 are rotatably supported to an oscillation holder. The oscillation holder 32 is supported to a carrier 33 so as to allow oscillation displacement with an oscillation shaft 73 as a center. The carrier 33 is spigot-fit to a reduction gear attachment member, and a plurality of fixing penetration holes in which fastening members 35 for fixing the carrier to the reduction gear attachment member from the output shaft side are formed at a plurality of positions along a circumferential direction with the input shaft as a center. A pitch circle diameter D2 of an oscillation shaft center with the input shaft as a center is smaller than a pitch circle diameter D1 of a fastening member center.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a friction roller type speed reducer.

  In order to improve the convenience of electric vehicles that have begun to spread in recent years, there is a strong demand for improving the efficiency of electric motors in order to increase the travelable distance per charge. In order to improve the efficiency of the electric motor, it is desirable to use a small electric motor that rotates at high speed and to reduce the rotation of the motor output shaft before transmitting it to the drive wheels of the vehicle. In this case, the speed reducer connected to the motor output shaft has a very high operating speed and is likely to generate vibration and noise. Therefore, in order to suppress vibration and noise during operation, it is considered to use a friction roller type speed reducer. As a conventional friction roller type speed reducer, for example, one described in Patent Document 1 is known.

  As shown in FIG. 11, the friction roller type speed reducer 200 described in Patent Document 1 includes an input shaft 211, an output shaft 213, a sun roller 217, a ring roller 219, a plurality of intermediate rollers 221, and a loading. Cam mechanisms 223A and 223B, and a connecting portion 225 that connects the ring roller 219 and the output shaft 213 are provided. The sun roller 217 has a pair of sun roller elements 227A and 227B divided in the axial direction. The sun roller elements 227A and 227B are arranged concentrically with a gap between the input shaft 211 and are capable of axial movement and relative rotation with respect to the input shaft 211. The ring roller 219 is formed in an annular shape as a whole, and is arranged concentrically with the sun roller 217. In addition, the outer peripheral portion of the ring roller 219 is connected to the output shaft 213 via the connecting portion 225. Each of the plurality of intermediate rollers 221 is rotatably supported by a support shaft 231, and the outer peripheral surface thereof is in rolling contact with the outer peripheral surface of the sun roller 217 and the inner peripheral surface of the ring roller 219.

  The support shaft 231 of each intermediate roller 221 is individually supported by the swing holder 233. The swing holder 233 is supported by the carrier 237 so that the intermediate roller 221 can move (swing) in the radial direction of the input shaft 211. The carrier 237 is fixed to a motor body (not shown) by a plurality of fixing bolts 241 protruding to the input shaft 211 side.

JP2013-104545A

  In the above configuration, the reaction force of the rotational torque transmitted to the friction roller type speed reducer 200 is applied to the swing shaft that supports the swing holder 233 of the carrier 237 fixed to the motor body. For this reason, the carrier 237 needs to be fastened to the motor body with an axial force capable of maintaining the reaction force of the rotational torque, and the fixing bolt 241 is required to have high strength. However, as the rotational torque transmitted increases, the number and size of the fixing bolts 241 and the space for disposing the fixing bolts 241 increase, which hinders the reduction of the reduction gear. Moreover, the fastening operation | work with the carrier 237 and a motor main body becomes complicated, and the disadvantage that a number of parts increases arises.

  As shown in FIG. 12, when the friction roller type speed reducer 245 is fixed to the support wall of the motor housing 247, the outside of the friction roller type speed reducer 245 is covered with a connecting portion 225 connected to the output shaft. The friction roller type speed reducer 245 cannot be mounted from the output shaft 213 side. Therefore, the friction roller type speed reducer 245 is fastened with a nut or a fixing bolt 249 from the opposite side of the support wall to the speed reducer mounting surface. However, in that case, after the motor housing 247 and the friction roller type speed reducer 245 are fastened, the stator and the rotor are assembled to the motor housing 247, which complicates the assembly process and increases the number of parts. . In addition, there is a disadvantage that the performance of the motor alone cannot be measured and the performance of the motor alone cannot be guaranteed.

  On the other hand, as shown in FIG. 13, the parts of the friction roller type speed reducer 245 may be sequentially assembled to the motor assembly 251 to fix the friction roller type speed reducer 245 to the motor assembly 251. Specifically, after assembling the sun roller element 227A, the carrier assembly 253, the ring roller 219, and the sun roller element 227B in this order to the motor assembly 251, the preload is adjusted, and finally the connecting portion 225 and the output shaft 213 are assembled. It becomes a process. In this case, since it is necessary to fix a retaining ring for fixing the ring roller 219 to the connecting portion 225, a large work space is required between the motor assembly 251 and the end of the output shaft 213. In particular, in the configuration in which the loading mechanism is disposed on the ring roller 219 side, it is necessary to squeeze the preload spring and attach the retaining ring, which makes assembly work difficult. Further, there is a disadvantage that the performance cannot be measured with the friction roller type reduction gear 245 alone, and the performance cannot be guaranteed with the friction roller type reduction gear 245 alone.

  The present invention has been made in view of the above circumstances, and is a friction roller type reduction gear that can reduce the number of parts while maintaining the required strength of the reduction gear, simplify the assembly work, and guarantee the performance of the reduction gear alone. The purpose is to provide.

The present invention has the following configuration.
A sun roller disposed concentrically with the input shaft; a ring roller disposed concentrically with the sun roller on an outer peripheral side of the sun roller; and the input shaft between an outer peripheral surface of the sun roller and an inner peripheral surface of the ring roller. A plurality of intermediate rollers that are supported rotatably about a rotation shaft parallel to the outer periphery of the sun roller and that are in rolling contact with the outer peripheral surface of the sun roller and the inner peripheral surface of the ring roller, and a connecting portion that connects the ring roller to the output shaft; A friction roller type speed reducer comprising:
The intermediate roller is rotatably supported by a swing holder provided at both ends of the rotation shaft independently for each intermediate roller,
The swing holder has a swing shaft parallel to the rotation shaft at a circumferential position different from the rotation shaft with respect to a circumferential direction centering on the input shaft, and the swing displacement about the swing shaft is Supported by the carrier,
The carrier has an inlay fitting portion that is inlay-fitted to a speed reducer mounting member, and a fixing through-hole through which a fastening member for fixing the carrier to the speed reducer mounting member is inserted from the output shaft side Is formed at a plurality of positions along a circumferential direction centering on the input shaft,
A friction roller type speed reducer characterized in that a pitch circle diameter at the center of the swing shaft centering on the input shaft is smaller than a pitch circle diameter at the center of the fastening member.

  According to the present invention, the number of parts can be reduced while maintaining the required strength of the speed reducer, the assembly work can be simplified, and the performance of the speed reducer alone can be guaranteed.

It is a figure for demonstrating embodiment of this invention, and is a partial cross section perspective view of a friction roller type reduction gear. It is a principal part expanded sectional view of the friction roller type reduction gear shown in FIG. It is a top view of the cam ring which shows the cam groove of a loading cam mechanism. FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, showing a state (A) in which the loading cam mechanism does not generate thrust and a state (B) in which thrust is generated. It is a perspective view of the rocking | holding holder which supports an intermediate | middle roller. It is a disassembled perspective view of a carrier. It is a disassembled perspective view of the friction roller type reduction gear explaining the attachment method to the motor main body of a friction roller type reduction device. It is a perspective view of the back side of a carrier. It is the axial front view which looked at the carrier from the connecting plate side. It is the front view which looked at the friction roller type reduction gear from the output-shaft side to the axial direction. It is principal part sectional drawing of the conventional friction roller type reduction gear. It is explanatory drawing which shows a mode that the conventional friction roller type reduction gear is fixed to the support wall of a motor housing | casing. It is explanatory drawing which shows a mode that each part of the conventional friction roller type reduction gear is assembled | attached to a motor assembly one by one, and a friction roller type reduction gear is fixed to a motor assembly.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<Configuration of friction roller reducer>
FIG. 1 is a view for explaining an embodiment of the present invention, and is a partial cross-sectional perspective view of a friction roller type speed reducer, and FIG. As shown in FIGS. 1 and 2, the friction roller type speed reducer 100 includes a sun roller 15, a ring roller 17, a plurality of intermediate rollers 19, a ring roller 17, and an output shaft 13 that are arranged concentrically with the input shaft 11. And a loading cam mechanism 23.

  The sun roller 15 is a solid structure roller integrally formed with the input shaft 11 at one end of the input shaft 11 shown in FIG. The outer peripheral surface 15a of the sun roller 15 is formed in a concave curved surface in which the outer edge shape of the axial section is a single circular arc-shaped concave curve.

  The ring roller 17 is a pair of ring roller elements arranged in parallel in the axial direction, and includes a fixed ring roller element 27 and a movable ring roller element 29 movable in the axial direction. These ring roller elements 27 and 29 are arranged concentrically with the sun roller 15 on the outer peripheral side of the sun roller 15 in a state of being accommodated inside the cup-shaped connecting portion 21.

  The inner peripheral surfaces 27a and 29a of the fixed ring roller element 27 and the movable ring roller element 29 are formed from the opposite end faces 24 and 24 where the ring roller elements 27 and 29 face each other to the outer end faces 26 and 26 on the opposite side in the axial direction. It becomes the cyclic | annular inclined surface inclined so that an internal diameter may become small as it goes. These inclined surfaces become rolling contact surfaces on which the intermediate roller 19 rolls. The inner peripheral surfaces 27a and 29a are not limited to the inclined surfaces, but may be concave curved surfaces in which the outer edge shape of the axial cross section is a single arc-shaped concave curve.

  The plurality of intermediate rollers 19 are supported by a support shaft (spinning shaft) 31 via a needle bearing 22 so as to be rotatable and displaceable in the axial direction, respectively, and the outer peripheral surface 15 a of the sun roller 15 and the inner peripheral surface of the ring roller 17. 17a. Both ends of the support shaft 31 are supported by the swing holder 32. The swing holder 32 is supported by the carrier 33 so that the intermediate roller 19 can move (swing) in the radial direction of the input shaft 11. That is, the carrier 33 supports the swing holder 32 provided independently for each intermediate roller 19. The carrier 33 is fixed to a motor body (not shown) by a fastening member.

  The outer peripheral surface 19a of each intermediate roller 19 is a convex curved surface whose outer edge shape in the axial section is a single arc-shaped convex curve, and is in rolling contact with the outer peripheral surface 15a of the sun roller 15 and the inner peripheral surface 17a of the ring roller 17, respectively. .

  The connecting portion 21 is formed in a substantially disc shape and has a base end portion 37 whose central portion is connected to the output shaft 13, and an axial extension from the outer peripheral edge of the base end portion 37. And a cylindrical roller holding portion 39 for holding.

  Inside the roller holding portion 39, a corrugated preload spring 67, a cam ring 49, a ball 51 as a rolling element, a movable ring roller element 29, a fixed ring roller element 27, and a retaining ring 47 are provided from the base end portion 37 side. These members are inserted in this order, and these members are assembled to the roller holding portion 39.

  A plurality of concave grooves 43 are formed along the axial direction in the inner peripheral portion of the roller holding portion 39, and a ring groove 45 is formed in the circumferential direction at the end opposite to the base end portion 37. Has been.

  The concave groove 43 accommodates the protrusions 28 formed in a plurality of locations on the outer peripheral portion of the fixed ring roller element 27 and projecting in the radial direction. The protrusion 28 engages with the concave groove 43 of the roller holding portion 39 in a state where there is no rattling in the rotation direction, and enables transmission of rotational torque between the roller holding portion 39 and the ring roller 17.

  A retaining ring 47 is inserted into the ring groove 45. The retaining ring 47 restricts the axial position of the fixed ring roller element 27 and fixes the fixed ring roller element 27 to the roller holding portion 39.

  For example, the base end portion 37 of the connecting portion 21 is formed by cutting such as lathe processing, and the roller holding portion 39 is formed by plastic processing such as press molding. After the base end portion 37 and the roller holding portion 39 are formed as a single unit, they are joined to each other, so that the shaft centers can be aligned with high accuracy at low cost. Further, the base end portion 37 and the roller holding portion 39 are joined by beam welding. As a result, it is possible to perform heat bonding with a narrow bead and in a short time, and it is possible to suppress the occurrence of misalignment by minimizing thermal distortion.

  The cam ring 49 has a plurality of protrusions 61 that protrude radially outward from the outer peripheral portion thereof. The protrusion 61 of the cam ring 49 and the protrusion 28 of the fixed ring roller element 27 engage with the groove 43 of the roller holding portion 39, respectively.

  The cam ring 49 has a notch 63 formed on the outer end surface on the output shaft 13 side, in which a part on the outer diameter side is notched in an annular shape, and a preload spring 67 is attached to the notch 63.

  Since the sun roller 15 rotates at a high speed, there is a possibility that it becomes a vibration source of abnormal vibration if there is a slight deviation of the center of gravity. However, since the sun roller 15 of this configuration is integrally formed with the input shaft 11, the balance can be easily corrected and the occurrence of vibration can be reduced. Moreover, since the sun roller 15 has high rigidity and a high resonance frequency, occurrence of abnormal vibration due to resonance is reduced. Furthermore, the sun roller 15 having a solid structure reduces the amount of elastic deformation of the sun roller 15 when a radial load is applied. Thereby, the axial displacement amount of the intermediate roller 19 and the ring roller 17 becomes small, and the contact state of the rolling contact surface can be maintained in a good state as designed.

<Loading cam mechanism>
Next, the loading cam mechanism will be described.
The movable ring roller element 29, the cam ring 49, and the ball 51, which is a rolling element, constitute the loading cam mechanism 23 shown in FIG. The loading cam mechanism 23 changes the contact surface pressure of each rolling contact surface of the sun roller 15, the ring roller 17, and the intermediate roller 19.

  As shown in FIGS. 3 and 4, a plurality of (three in the illustrated example) first cam grooves 53 are formed on the outer end surface 26 of the movable ring roller element 29 along the circumferential direction. Similarly, a second cam groove 55 is formed for the cam ring 49. That is, the cam ring 49 is disposed facing the first cam groove 53, and a plurality of (three in the illustrated example) second cam grooves 55 are formed at circumferential positions corresponding to the first cam grooves 53. The balls 51 are sandwiched between the first cam groove 53 and the second cam groove 55, respectively.

  The first cam groove 53 and the second cam groove 55 have an axial groove depth that is deepest at the center in the circumferential direction, and gradually changes along the circumferential direction. It becomes shallower toward the end.

  In a state where the input shaft 11 is stopped, as shown in FIG. 4A, each ball 51 is located at the deepest part of each cam groove. In this state, the cam ring 49 is pressed toward the movable ring roller element 29 by the elastic force of the preload spring 67.

  When the input shaft 11 is driven to rotate, each ball 51 moves to a shallow portion of each cam groove 53, 55 as shown in FIG. As a result, an axial thrust force that presses the movable ring roller element 29 toward the fixed ring roller element 27 is generated. When the interval between the fixed ring roller element 27 and the movable ring roller element 29 is reduced by the axial thrust generated by the loading cam mechanism 23, the inner peripheral surface 17a of the ring roller 17 and the outer peripheral surface 19a of each intermediate roller 19 are reduced. As the surface pressure at the rolling contact portion increases, the surface pressure at the rolling contact portion between the outer peripheral surface 19a of each intermediate roller 19 and the outer peripheral surface 15a of the sun roller 15 also increases. As a result, the surface pressure of the plurality of rolling contact portions existing between the input shaft 11 and the output shaft 13 increases as the torque transmitted between the input shaft 11 and the output shaft 13 increases.

  Further, when the loading cam mechanism 23 generates axial thrust, the intermediate roller 19 is caused by the displacement of the movable ring roller element 29 in the axial direction due to elastic deformation of the traction components such as the ring roller 17 and elastic deformation of each contact point. It is displaced in the axial direction toward the fixed ring roller element 27 side.

<Structure that aligns the axis of each member>
As shown in FIG. 2, an annular first stepped portion 41 having an inner peripheral surface parallel to the output shaft 13 is formed on the inner surface of the base end portion 37 of the connecting portion 21 on the input shaft 11 side. Yes.

  Further, an annular outer peripheral surface that is formed concentrically with the center of the cam ring 49 and engages with the first stepped portion 41 of the base end portion 37 of the connecting portion 21 along the axial direction is formed on the outer end surface of the cam ring 49. A second stepped portion 65 is formed to protrude in the axial direction.

  The cam ring 49 and the connecting portion 21 are aligned with each other with high accuracy by fitting the first stepped portion 41 and the second stepped portion 65 together. Thereby, the movable ring roller element 29 is also in a state in which the axial center position is accurately aligned via the cam ring 49. The fixed ring roller element 27 is positioned in the radial direction by the intermediate roller 19. Since the intermediate roller 19 is positioned in the radial direction by the sun roller 15 concentric with the input shaft 11 and the input shaft 11 and the output shaft 13 are disposed concentrically, the sun roller 15, the ring roller 17, and the cam ring 49 are The axial center is in the state which matched exactly.

  In addition, the cam ring 49 is urged to the axially opposite side from the base end portion 37 by the preload spring 67, and the second stepped portion 65 is fitted to the first stepped portion 41 of the base end portion 37. . This fitting length is longer than the elastic deformation allowance of the preload spring 67. Accordingly, when the cam ring 49 is assembled to the base end portion 37, the preload spring 67 is prevented from being detached from between the cam ring 49 and the base end portion 37, and the assemblability of the speed reducer is improved.

<Supporting form of intermediate roller to carrier>
Next, the support form of each member of the friction roller type speed reducer 100 will be described in detail.
FIG. 5 is a perspective view of the swing holder 32 that supports the intermediate roller. The intermediate roller 19 is supported by the swing holder 32 at both ends of a support shaft 31 that is a rotating shaft. The same number of swing holders 32 as the intermediate rollers 19 are provided, and one intermediate roller 19 is supported by each swing holder 32. The swing holder 32 includes a pair of arm portions 71a and 71b that support both ends of the support shaft 31, and a base portion 75 that connects the arm portions 71a and 71b. A rocking shaft 73 parallel to the support shaft 31 is inserted through the base 75.

  FIG. 6 is an exploded perspective view of the carrier 33. The carrier 33 includes an annular bottom portion 77, a carrier body 81 having a column portion 79 erected at a plurality of locations (three locations in the illustrated example) that are equally spaced in the circumferential direction of one surface of the bottom portion 77, and a column portion. And a ring-shaped connecting plate 83 fixed to the distal end 79a of 79.

  Bolt insertion holes 85 for fixing the carrier 33 to the motor body are formed in the column portion 79 of the carrier body 81 at a plurality of locations (three locations in the illustrated example) along the axial direction.

  A swing holder 32 that supports the intermediate roller 19 is disposed between the column portions 79 arranged in the circumferential direction. The swing holder 32 swings on the carrier 33 by inserting a swing shaft 73 into a swing shaft hole 91 formed in the connecting plate 83 and a swing shaft hole (not shown) formed in the bottom 77. It is supported freely.

  A bolt fastening hole 87 is formed in the connecting plate 83 at a position corresponding to each bolt insertion hole 85 of the column portion 79, and a swing shaft hole 91 is formed at a position corresponding to the swing shaft 73 of the swing holder 32. Is formed.

  In other words, the swing holder 32 has a swing shaft 73 parallel to the support shaft 31 at a circumferential position different from the support shaft 31 in the circumferential direction around the input shaft 11, and the swing shaft 73 is the center. The carrier 33 is supported by the carrier 33 so as to be able to swing.

  The swinging holder 32 swings about the swinging shaft 73 with respect to the carrier 33, so that the intermediate roller 19 can protrude and retract in the radial direction of the carrier 33.

  The carrier body 81 and the connecting plate 83 are positioned relative to each other by pin fitting. That is, a pin hole 95 into which the pin 93 is inserted is formed in the tip end portion 79 a of the column portion 79 of the carrier body 81, and the pin 93 is located at a position corresponding to the pin hole 95 on the carrier body 81 side of the connecting plate 83. A pin hole (not shown) for inserting and inserting is formed.

  The carrier body 81 and the connecting plate 83 are pressed against each other in the axial direction with the pins 93 disposed between the corresponding pin holes 95, so that the pins 93 are press-fitted into the pin holes 95, and both are in the design position. Temporarily fixed. The bolt fastening hole 87 has an inner diameter that allows a bolt to be inserted to be inserted with a gap.

<Mounting method of friction roller type reducer>
FIG. 7 is an exploded perspective view of the friction roller type speed reducer 100 for explaining a method of attaching the friction roller type speed reducer 100 to the motor body 111. The friction roller type speed reducer 100 is fastened and fixed to a motor main body 111 that is a speed reducer mounting member by a fixing bolt 35 that is a fastening member.

  The friction roller type speed reducer 100 inserts fixing bolts 35 into a plurality of bolt insertion holes 113 formed through the base end portion 37 of the connecting portion 21 in the axial direction. It is concluded.

  At this time, the fixing bolt 35 is inserted into the bolt fastening hole 87 of the connecting plate 83 and the bolt insertion hole 85 of the carrier body 81, which are fixing through holes of the carrier 33 shown in FIG. Fastened to a screwing portion 115 formed on the main body 111. As a result, the temporarily fixed carrier 33 is fastened and fixed together by the fixing bolt 35, and high-precision alignment by the pin 93 and strong fastening by the fixing bolt 35 are simultaneously performed.

  Further, the carrier 33 is concentric with the rotating shaft (input shaft 11) by engaging a bottom portion (carrier-side inlay fitting portion) 77 with an inlay fitting portion 117 formed to protrude in the axial direction from the motor body 111. To be aligned. Inlay fitting is performed by positioning by fitting convex portions or concave portions, and the inlay fitting portion of this configuration is an annular shape provided on the front surface of the motor main body 111 on the rotating shaft arrangement side and centering on the rotating shaft. Are provided as protrusions. FIG. 8 is a perspective view of the back side of the carrier 33. The spigot fitting portion 117 is aligned with the outer peripheral surface 119 of the bottom 77 of the carrier 33 with the inner peripheral surface 121 of the annular projection that is the spigot fitting portion 117.

  The spigot fitting portion is not limited to the annular projection portion that is continuous in the circumferential direction, but is a projection portion that is discretely arranged along the circumferential direction or a recess portion that accommodates the outer peripheral surface 119. May be. Further, it may be engaged with the inner peripheral surface 125 of the center hole 123 of the bottom 77 shown in FIG. 8, or may be engaged with both the outer peripheral surface 119 and the inner peripheral surface 125. Furthermore, if the inlay fitting portion is configured to have an arc-shaped protrusion that fits in the radial direction and the circumferential direction at the bottom of the motor main body 111 and the carrier 33, the axial center alignment and rotation stop can be performed simultaneously. it can.

  The above-mentioned friction roller type reduction gear 100 is attached to the motor main body 111 in such a manner that each component is assembled and the adjusted friction roller type reduction gear 100 is connected to the motor main body 111 in the axial direction from the output shaft 13 side. It is a method to attach along. Therefore, the assembling work and the adjusting work can be simplified, and a particularly large space is not required at the time of assembling. Furthermore, performance measurement with a single motor and performance measurement with a single reduction gear can be easily performed.

<Relationship between fixing bolt and swinging shaft of swinging holder>
Next, the positional relationship between the fixing bolt 35 and the swing shaft of the swing holder 32 will be described.
FIG. 9 is an axial front view of the carrier 33 as viewed from the connecting plate 83 side. The fixing bolt 35 for fixing the carrier 33 to the motor body passes through the bolt fastening hole 87 and the bolt insertion hole 85 shown in FIG. 6 and is fastened to the motor body. In addition, a swing shaft 73 that supports the swing holder 32 is pivotally supported on the carrier 33 by a swing shaft hole 91 (the same applies to the bottom 77 side).

  The pitch circle diameter D1 at the center of the fastening member centered on the axis O of the fixing bolt 35 in the plan view in the axial direction and the pitch circle at the center of the swinging shaft centered on the axis O of the swinging shaft 73 of the swinging holder 32 The diameter D2 has a relationship of D1> D2. That is, the fixing bolt 35 is disposed radially outward from the axis O with respect to the swing shaft 73, and the fixing bolt 35 is disposed on the outer diameter side of the swing shaft 73.

  During the operation of the friction roller type speed reducer 100, the reaction force of the inter-roller transmission force acting on the intermediate roller 19 acts on the swing shaft 73 via the swing holder 32. As the transmission torque of the speed reducer increases, the reaction force of the rotational torque applied to the swing shaft 73 also increases. Even in this case, according to this configuration, the fixing bolt 35 serving as a fixing point is disposed outside the swing shaft 73 on which the reaction force acts. It can be made smaller than the reaction force acting on.

  Therefore, even if a large rotational moment about the axis O is generated in the carrier 33, the force acting on the fixing bolt 35 is less than the force acting on the swing shaft 73, and the holding required for the fixing bolt 35. The power can be reduced.

  Therefore, it is not necessary to increase the number and size of the fixing bolts 35 and the space for arranging the fixing bolts 35, and the number of parts can be reduced, the size and weight can be reduced, and the reduction gear can be reduced in size. Further, the assembly workability is improved by reducing the number of the fixing bolts 35.

  FIG. 10 is a front view of the friction roller type speed reducer 100 as viewed in the axial direction from the output shaft side. Bolt insertion holes 113 through which the fixing bolt 35 is inserted are formed at a plurality of positions in the base end portion 37 of the connecting portion 21. These bolt insertion holes 113 are arranged at a radial position that coincides with the pitch circle diameter D1 at the center of the fastening member described above, and at least circumferential positions that overlap the bolt fastening holes 87 and the bolt insertion holes 85 of the carrier 33 in the axial direction. ing.

  In the illustrated example, three fixing bolts 35 are evenly arranged around the output shaft 13 at every central angle of 120 degrees, and the three fixing bolts 35 overlap with the three fixing bolts 35 in the axial direction, and these three locations and the central angle. The bolt insertion holes 113 are respectively arranged at a total of six positions whose phases are shifted by 60 degrees.

  By matching the pitch circle diameter in which each bolt insertion hole 113 is disposed with the pitch circle diameter D1 at the center of the fastening member, and matching the phase in the circumferential direction between the bolt insertion hole 113 and the position of the fixing bolt 35 with each other. The interference between the fastening tool for the fixing bolt 35 and each part constituting the speed reducer such as the connecting portion 21 can be minimized, and damage to each part can be prevented.

  It is preferable that the bolt insertion hole 113 has an inner diameter larger than the head of the fixing bolt 35 and is arranged more than the number of the fixing bolts 35 in order to improve assembling workability. Further, the bolt insertion hole 113 may be other shapes such as an ellipse or a rectangle in addition to a circle.

  As described above, the present invention is not limited to the above-described embodiments, and those skilled in the art can make changes and applications based on combinations of the configurations of the embodiments, descriptions in the specification, and well-known techniques. This is also the scope of the present invention, and is included in the scope for which protection is sought.

11 Input shaft 13 Output shaft 15 Sun roller 17 Ring roller 19 Intermediate roller 21 Connecting portion 31 Support shaft (spinning shaft)
32 Oscillating holder 33 Carrier 35 Fixing bolt (fastening member)
73 Oscillating shaft 77 Bottom (Inlay fitting part)
85 Bolt insertion hole (fixing through hole)
87 Bolt fastening holes (fixing through holes)
91 Oscillating shaft hole 100 Friction roller type speed reducer D1 Pitch circle diameter at the center of the fastening member D2 Pitch circle diameter at the center of the oscillating shaft

Claims (1)

A sun roller disposed concentrically with the input shaft; a ring roller disposed concentrically with the sun roller on an outer peripheral side of the sun roller; and the input shaft between an outer peripheral surface of the sun roller and an inner peripheral surface of the ring roller. A plurality of intermediate rollers that are supported rotatably about a rotation shaft parallel to the outer periphery of the sun roller and that are in rolling contact with the outer peripheral surface of the sun roller and the inner peripheral surface of the ring roller, and a connecting portion that connects the ring roller to the output shaft; A friction roller type speed reducer comprising:
The intermediate roller is rotatably supported by a swing holder provided at both ends of the rotation shaft independently for each intermediate roller,
The swing holder has a swing shaft parallel to the rotation shaft at a circumferential position different from the rotation shaft with respect to a circumferential direction centering on the input shaft, and the swing displacement about the swing shaft is Supported by the carrier,
The carrier has an inlay fitting portion that is inlay-fitted to a speed reducer mounting member, and a fixing through-hole through which a fastening member for fixing the carrier to the speed reducer mounting member is inserted from the output shaft side Is formed at a plurality of positions along a circumferential direction centering on the input shaft,
A friction roller type speed reducer characterized in that a pitch circle diameter at the center of the swing shaft centering on the input shaft is smaller than a pitch circle diameter at the center of the fastening member.

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