JP2017002946A - Friction roller type reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction roller type reduction gear which surely synchronizes and operates a pair of loading cam mechanisms while having a both-side cam structure, suppresses the axial displacement of rollers other than a roller which is axially driven by the loading cam mechanisms, and is enhanced in power transmission efficiency.SOLUTION: A friction roller type reduction gear 100 comprises a sun roller 13, a ring roller 15, a plurality of intermediate rollers 17, a connecting part 21, and loading cam mechanisms 23A, 23B. Either of the sun roller 13 and the ring roller 15 has first and second roller elements 31, 33. The loading cam mechanism 23A, 23B are arranged at outside end face sides of the first and second roller elements in a pair, and have drive-side cam faces 83A, 83B, driven-side cam faces 81A, 81B, and rolling bodies 71A, 71B. There is arranged a connecting mechanism which connects the first roller element and the second roller element so as to be displaceable in an axial direction, and to be relatively non-rotatable.SELECTED DRAWING: Figure 1

Description

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

In recent years, electric vehicles, hybrid vehicles, electric four-wheel drive vehicles and the like have been widely used. As a driving method for these vehicles, there is a method in which a friction roller type speed reducer is combined with an electric motor, and the rotation of the motor output shaft is decelerated before being transmitted to driving wheels. This type of friction roller type speed reducer is described in Patent Document 1, for example.
As schematically shown in FIG. 13A, the friction roller type speed reducer of Patent Document 1 includes a sun roller 201, a ring roller 203 arranged concentrically with the sun roller 201, an outer peripheral surface of the sun roller 201, and the ring roller 203. And a plurality of intermediate rollers 205 that are rotatably supported and a loading cam mechanism 209. The sun roller 201 includes a pair of sun roller elements 207A and 207B. The loading cam mechanism 209 causes one sun roller element 207B to approach or separate from the other sun roller element 207A according to the transmission torque from the input shaft 211, and each of the sun roller elements 207A and 207B, the intermediate roller 205, and the ring roller 203 is Change the traction surface pressure.

  In the friction roller type speed reducer, the loading cam mechanism 209 is disposed on the side (outside) of the sun roller element 207B opposite to the sun roller element 207A. The loading cam mechanism 209 includes a sun roller element 207B on which the cam surface C1 is formed, a cam ring 215 that is disposed to face the outer end surface 213 of the sun roller element 207B, and on which the cam surface C2 is formed, and a ball 217. The cam surfaces C1 and C2 are formed to face the outer end surface 213 of the sun roller element 207B and the end surface 219 of the cam ring 215 on the sun roller element 207B side, respectively. A ball 217 is disposed between the cam surfaces C1 and C2. Each of the cam surfaces C1 and C2 has a shape in which the groove depth in the axial direction becomes gradually shallower toward both ends in the circumferential direction.

  In the loading cam mechanism 209 configured as described above, the ball 217 is positioned at the deepest portion of each of the cam surfaces C1 and C2 in the state shown in FIG. On the other hand, in the state shown in FIG. 13B in which rotational torque is applied to the input shaft 211, the balls 217 move to shallow portions of the cam surfaces C1 and C2. In this case, the distance Lc between the sun roller element 207B and the cam ring 215 is increased, and an axial thrust force that presses the sun roller element 207B toward the sun roller element 207A is generated. The sun roller element 207B receives the generated axial thrust and moves toward the sun roller element 207A. As a result, the distance between the sun roller elements 207A and 207B is reduced, and the outer peripheral surface of each sun roller element 207A and 207B, the outer peripheral surface of the intermediate roller 205, and the contact surfaces of the outer peripheral surface of the intermediate roller 205 and the inner peripheral surface of the ring roller 203 The contact surface pressure of the rolling contact portion of each roller is changed according to the magnitude of the torque that is transmitted, that is, the torque transmitted between the input shaft 211 and the output shaft 221.

  In addition to the one-side cam structure in which the loading cam mechanism 209 is provided only on one of the pair of sun roller elements 207A and 207B, as shown in the illustrated example, the loading cam mechanism is replaced with a pair of loading rollers. There has also been proposed a double-sided cam mechanism that is provided in a pair so as to sandwich the two.

JP2013-104545A

In the case where the friction roller type reduction gear has the above-described one-side cam structure, the number of components can be reduced, and the loading cam mechanism can be simplified. However, since only one loading roller (sun roller element 207B) of the pair of loading rollers is displaced in the axial direction, a structure for allowing the axial displacement of the intermediate roller 205 in contact with the loading roller is necessary.
Further, when the contact surface between the intermediate roller 205 and the ring roller 203 is tapered or arcuate, the contact state of the traction surface changes due to the axial displacement of the intermediate roller 205, and power transmission efficiency and durability performance are reduced. There was a concern.
Further, since the loading cam mechanism is a mechanism that generates axial thrust by the relative twist of the pair of cam surfaces C1 and C2, in the case of the one-side cam structure, the cam mechanism is actuated to cause the pair of loading rollers to be relatively twisted. Will occur. Therefore, a force for skewing the intermediate roller 205 is generated with a change in the transmission torque of the reduction gear. When skew occurs in the intermediate roller 205, slippage in the contact surface increases and power transmission efficiency decreases.

  On the other hand, in the case of the double-side cam mechanism, basically, the problem mentioned in the above-mentioned single-side cam mechanism does not occur. However, the pair of loading rollers may not operate at the same time due to minute processing errors of the cam surfaces C1 and C2. In that case, the loading roller exhibits the same behavior as the one-side cam mechanism described above, and the power transmission efficiency is reduced.

  In view of the above, the present invention has a double-sided cam structure, and operates a pair of loading cam mechanisms in a synchronized manner, thereby suppressing axial displacement of each roller other than the roller driven in the axial direction by the loading cam mechanism, thereby transmitting power. An object of the present invention is to provide a friction roller type speed reducer with improved efficiency.

The present invention has the following configuration.
(1) A sun roller connected concentrically with the input shaft and having a rolling contact surface on an outer peripheral surface; a ring roller disposed concentrically with the sun roller around the sun roller and having a rolling contact surface on an inner peripheral surface; and the sun roller; A plurality of intermediate rollers that are in rolling contact with the rolling contact surface of the ring roller and are supported rotatably about a rotation axis parallel to the input shaft; and a connecting portion that connects the ring roller to an output shaft; A friction roller type speed reducer comprising a sun roller, a ring roller, and a loading cam mechanism for changing each rolling contact surface pressure of the intermediate roller,
The ring roller has a first roller element and a second roller element arranged in parallel in the axial direction of the input shaft,
The rolling contact surfaces of the first roller element and the second roller element are arranged from an opposing end face where the first roller element and the second roller element face each other to an outer end face on the opposite side in the axial direction of the opposing end face. Toward the rotation axis center line of the intermediate roller is an inclined surface,
The loading cam mechanism is provided in a pair on the outer end face side of both the first roller element and the second roller element, and is arranged on the outer end face of the first roller element and the second roller element in the circumferential direction. In the circumferential direction, on the drive side cam surface provided along the side wall, and on the side wall portion disposed opposite to the outer end surface of the first roller element and the second roller element and fixed to the input shaft. A driven cam surface provided along, and a rolling element disposed between the driving cam surface and the driven cam surface,
The driving-side cam surface and the driven-side cam surface are each shaped such that the depth in the axial direction gradually changes in the circumferential direction and becomes shallower toward the circumferential end,
A friction roller type speed reducer comprising: a coupling mechanism that couples the first roller element and the second roller element to each other so as to be axially displaceable but not relatively rotatable.
(2) a sun roller connected concentrically with the input shaft and having a rolling contact surface on an outer peripheral surface; a ring roller disposed concentrically with the sun roller around the sun roller and having a rolling contact surface on an inner peripheral surface; and the sun roller; A plurality of intermediate rollers that are in rolling contact with the rolling contact surface of the ring roller and are supported rotatably about a rotation axis parallel to the input shaft; and a connecting portion that connects the ring roller to an output shaft; A friction roller type speed reducer comprising a sun roller, a ring roller, and a loading cam mechanism for changing each rolling contact surface pressure of the intermediate roller,
The sun roller has a first roller element and a second roller element arranged in parallel in the axial direction of the input shaft,
The rolling contact surfaces of the first roller element and the second roller element are arranged from an opposing end face where the first roller element and the second roller element face each other to an outer end face on the opposite side in the axial direction of the opposing end face. Toward the rotation axis center line of the intermediate roller is an inclined surface,
The loading cam mechanism is provided in a pair on the outer end face side of both the first roller element and the second roller element, and is arranged on the outer end face of the first roller element and the second roller element in the circumferential direction. In the circumferential direction on the driven cam surface provided along the side wall portion and the side wall portion disposed opposite to the outer end surface of the first roller element and the second roller element and fixed to the connecting portion. Driving side cam surface provided along the rolling side, and a rolling element disposed between the driving side cam surface and the driven side cam surface,
The driving-side cam surface and the driven-side cam surface are each shaped such that the depth in the axial direction gradually changes in the circumferential direction and becomes shallower toward the circumferential end,
A friction roller type speed reducer comprising: a coupling mechanism that couples the first roller element and the second roller element to each other so as to be axially displaceable but not relatively rotatable.

  According to the present invention, although a double cam structure is used, a pair of loading cam mechanisms are operated in a synchronized manner, and axial displacement of each roller other than the roller driven in the axial direction by the loading cam mechanism is suppressed. Transmission efficiency can be increased.

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 perspective view of the rocking | holding holder with which the intermediate roller was supported. It is a principal part expanded sectional view of the friction roller type reduction gear shown in FIG. It is a side view of the side by which the driven cam surface of the 1st cam ring was formed. FIG. 5 is a cross-sectional view of the first cam ring and the first roller element taken along line AA in FIG. 4, wherein (A) is a cross-sectional view showing a state in which the loading cam mechanism does not generate axial thrust, and (B). It is sectional drawing which shows the state which has generate | occur | produced the axial direction thrust. It is a perspective view of the 1st roller element and the 2nd roller element which show one example of composition of a connection mechanism. It is sectional drawing which shows the state with which the 1st roller element and the 2nd roller element were mutually connected. It is a perspective view of the 1st roller element and the 2nd roller element which show other examples of composition of a connection mechanism. It is a partial side view which shows the state with which the 1st roller element and the 2nd roller element were mutually connected. It is a perspective view of the 1st roller element which shows the other example of composition of a connection mechanism, the 2nd roller element, and a ring member. It is a partial side view which shows the state with which the 1st roller element and the 2nd roller element were mutually connected by the annular member. FIG. 2 is a schematic cross-sectional view of an essential part of a schematic friction roller type reduction gear provided with a loading cam mechanism on the sun roller side. It is a figure which shows the conventional loading cam mechanism, (A) is a schematic diagram which shows a mode that a ball | bowl is located in the deepest part of each cam surface, (B) moves a ball | bowl to the part where each cam surface became shallow. It is a schematic diagram which shows a mode that it does.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<Basic configuration of friction roller reducer>
FIG. 1 is a partial cross-sectional perspective view of a friction roller type speed reducer for explaining an embodiment of the present invention. The friction roller type speed reducer 100 includes a sun roller 13 connected to the input shaft 11, a ring roller 15, a plurality of (three in the illustrated example) intermediate rollers 17, a connecting portion 21 connected to the output shaft 19, A first loading cam mechanism 23A and a second loading cam mechanism 23B.

  The sun roller 13 is a solid structure roller integrally formed at one end of the input shaft 11. The outer peripheral surface 25 of the sun roller 13 is a concave curve having a single circular arc outer edge in the axial section, and serves as a rolling contact surface with the intermediate roller 17. The sun roller 13 rotates integrally with the input shaft 11 while being connected concentrically with the input shaft 11. As a result, the rotational torque from the input shaft 11 is transmitted to each intermediate roller 17.

  The ring roller 15 is disposed concentrically with the sun roller 13 around the sun roller 13. The inner peripheral surface 27 of the ring roller 15 serves as a rolling contact surface with the intermediate roller 17. The ring roller 15 having this configuration has a pair of first roller elements 31 and second roller elements 33 arranged in parallel in the axial direction of the input shaft 11.

  A plurality of intermediate rollers 17 are arranged in an annular space between the outer peripheral surface 25 of the sun roller 13 and the inner peripheral surface 27 of the ring roller 15. The outer peripheral surface 17 a of each intermediate roller 17 is in rolling contact with the rolling contact surfaces of the sun roller 13 and the ring roller 15. The intermediate roller 17 is supported by the swing holder 37 so as to be rotatable and movable in the axial direction about a support shaft (spinning shaft) 35 parallel to the input shaft 11.

  FIG. 2 is a perspective view of the swing holder 37 on which the intermediate roller 17 is supported. The swing holder 37 includes a holder body 39, a pair of swing shafts 41 protruding from the holder body 39 along the axial direction of the intermediate roller 17, and a radial direction of the swing shaft 41 from the holder body 39. It has a pair of arm parts 43 extended, and the above-mentioned support shaft (spinning shaft) 35 that is fixed to the tips of the pair of arm parts 43 and supports the intermediate roller 17.

  The swing shaft 41 of the swing holder 37 is supported by a carrier 45 as shown in FIG. The carrier 45 supports the swing holder 37 via the swing shaft 41 so as to be swingable. The carrier 45 is a fixed-side member connected to a fixed side such as a motor (not shown). The plurality of oscillating holders 37 are evenly arranged in the circumferential direction around the sun roller 13 so that the intermediate roller 17 can change the radial distance from the central axis of the sun roller 13 by the oscillating operation of the oscillating holder 37. Supported.

  A bottomed cylindrical connecting portion 21 having a cylindrical portion 47 and a bottom portion 49 is disposed on the outer periphery of the ring roller 15. The cylindrical portion 47 accommodates the ring roller 15 in the inner diameter portion, and fixes the ring roller 15 in the circumferential direction. The bottom 49 is connected to the output shaft 19. In the connecting portion 21 in the illustrated example, the bottom portion 49 and the output shaft 19 are integrally formed, and the ring roller 15 fixed to the cylindrical portion 47 is connected to the output shaft 19. Thereby, the connecting portion 21 rotates integrally with the ring roller 15.

  In the friction roller type speed reducer 100 configured as described above, the rotational torque input from the input shaft 11 is transmitted from the sun roller 13 to each intermediate roller 17 and further transmitted from each intermediate roller 17 to the ring roller 15 after being decelerated. . The ring roller 15 is connected to the output shaft 19 via the connecting portion 21, whereby the rotation of the input shaft 11 is decelerated and transmitted to the output shaft 19.

<Details of each part of friction roller reducer>
Next, the configuration of each part of the friction roller type speed reducer 100 will be described in detail. FIG. 3 is an enlarged cross-sectional view of a main part of the friction roller type speed reducer 100 shown in FIG.

  The inner peripheral surface 27 of the ring roller 15 includes a rolling contact surface 51 of the first roller element 31 and a rolling contact surface 53 of the second roller element 33. Each of the rolling contact surfaces 51 and 53 has a short distance from the opposing end surface 55 facing each other to the outer end surface 57 opposite to the opposing end surface 55 in the axial direction to the rotation axis center line L1 of the intermediate roller 17. It becomes an inclined surface. These inclined surfaces may be concave curved surfaces that form a single circular arc-shaped concave curve, in addition to the outer edge shape of the axial cross section being linear.

  A shaft hole 59 is formed along the axial direction of the intermediate roller 17, and the support shaft 35 is fitted into the shaft hole 59 via a needle bearing 61. The needle bearing 61 has a needle roller 63 and a cage 65 and rotatably supports the intermediate roller 17 on the support shaft 35. Further, the needle bearing 61 supports the intermediate roller 17 so as to be displaceable also in the axial direction.

  On the inner side of the cylindrical portion 47 of the connecting portion 21, in order from the bottom 49 side, a corrugated preload spring 67, a first cam ring 69A, a ball 71A as a rolling element, a first roller element 31, a second roller element 33, A ball 71B, a second cam ring 69B, and a retaining ring 73, which are rolling elements, are arranged.

  A concave groove 75 is formed in the inner peripheral portion of the cylindrical portion 47 along the axial direction. The concave grooves 75 are formed at a plurality of locations along the circumferential direction of the inner peripheral portion of the cylindrical portion 47. These concave grooves 75 accommodate radially projecting projections 77 and 79 formed on the outer periphery of the first cam ring 69A and the second cam ring 69B, respectively. The first cam ring 69A and the second cam ring 69B are accommodated. Fix in the direction of rotation.

  A ring groove (not shown) is formed along the circumferential direction on the inner peripheral surface of the opening side end opposite to the bottom 49 side of the cylindrical portion 47. A retaining ring 73 is inserted into the ring groove. The retaining ring 73 restricts the axial position of the second cam ring 69 </ b> B and prevents the second cam ring 69 </ b> B from coming off from the cylindrical portion 47.

  The protrusions 77 and 79 of the first cam ring 69A and the second cam ring 69B are engaged with the concave groove 75 of the cylindrical portion 47 in a state where there is no backlash in the rotational direction. Accordingly, smooth rotation torque can be transmitted between the cylindrical portion 47 and the first cam ring 69A and the second cam ring 69B.

  The preload spring 67 is attached to a notch formed by notching a part of the outer diameter side in an annular shape on the end surface of the first cam ring 69A on the bottom 49 side. The preload spring 67 applies preload to the first roller element 31 and the second roller element 33 when the rotational torque transmitted from the input shaft 11 is small, and the roller elements 31 and 33 and the intermediate roller 17 roll. The contact surface pressure is secured to a predetermined value or more.

<Loading cam mechanism>
In the loading cam mechanism, a first loading cam mechanism 23A is provided on the outer end face 57 side of the first roller element 31, and a second loading cam mechanism 23B is provided on the outer end face 57 side of the second roller element 33. That is, a pair of loading cam mechanisms are provided on both sides of the ring roller 15. The first loading cam mechanism 23A and the second loading cam mechanism 23B are configured by driven side cam surfaces 81A and 81B, driving side cam surfaces 83A and 83B, which will be described in detail later, and balls 71A and 71B as rolling elements, respectively. Then, the rolling contact surface pressures of the sun roller 13, the ring roller 15, and the intermediate roller 17 are changed.

  In this configuration, the driven cam surface 81A is formed on an end surface that is a side wall portion facing the first roller element 31 of the first cam ring 69A, and the driven cam surface 81B is the second cam ring 69B. It is formed on an end surface that becomes a side wall portion facing the roller element 33. The driving side cam surface 83A is formed on the end surface of the first roller element 31 facing the first cam ring 69A, and the driving side cam surface 83B is formed on the end surface of the second roller element 33 facing the second cam ring 69B. .

  The driven cam surfaces 81A and 81B and the drive cam surfaces 83A and 83B each have a shape in which the depth in the axial direction gradually changes in the circumferential direction and becomes shallower toward the circumferential end.

  FIG. 4 shows a side view of the first cam ring 69A on the side where the driven cam surface 81A is formed. The driven cam surface 81A is formed at equal intervals at a plurality of locations (three locations in the illustrated example) along the circumferential direction of the first cam ring 69A. The first roller element 31 (see FIG. 3) facing the first cam ring 69A has a driving cam surface 83A at a circumferential position corresponding to each driven cam surface 81A on the end surface facing the first cam ring 69A. Is formed. The driven cam surface 81A and the driving cam surface 83A have the same groove shape overlapping in the axial direction, and a ball 71A is disposed between the driven cam surface 81A and the driving cam surface 83A. Is done.

  Similarly, a driven cam surface 81B is formed on the second cam ring 69B, and a driving cam surface 83B is formed on the second roller element 33. The cam surfaces 81B and 83B are formed at equal intervals at a plurality of locations (three locations in the illustrated example) along the circumferential direction. The balls 71B are arranged between the driven cam surface 81B and the driving cam surface 83B.

  5A and 5B are cross-sectional views of the first cam ring 69A and the first roller element 31 taken along the line AA in FIG. 4, and FIG. 5A shows the axial thrust of the loading cam mechanisms 23A and 23B. Sectional drawing which shows the state which has not generate | occur | produced, (B) is sectional drawing which shows the state which has generate | occur | produced the axial direction thrust. As shown in FIG. 5A, each ball 71A is arranged at the deepest part of each cam surface 81A, 83A in a state where rotational torque is not applied to the input shaft 11 (see FIG. 3). In this state, the first cam ring 69A is pressed toward the first roller element 31 by the elastic force of the preload spring 67 shown in FIG. By this pressing force, as described above, the minimum necessary rolling contact surface pressure of each of the rollers 13, 15, and 17 is ensured, and slipping at a low load is prevented.

  In the first loading cam mechanism 23A, when the input shaft 11 is rotationally driven, the rotational torque from the input shaft 11 is transmitted to the first roller element 31 via the intermediate roller 17, as shown in FIG. Then, the first roller element 31 rotates relative to the first cam ring 69A. Then, the ball 71A moves to the shallow part of each of the cam surfaces 81A and 83A, and with this movement, the force in the direction separating the first roller element 31 from the first cam ring 69A, that is, the second roller element 33. An axial thrust F that presses toward the side is generated.

  Similarly, in the second loading cam mechanism 23B, when the input shaft 11 is rotationally driven, the balls 71B shown in FIG. 3 move on the cam surfaces 81B and 83B. With this movement, an axial thrust force that presses the second roller element 33 toward the first roller element 31 is generated.

  As described above, when the first loading cam mechanism 23A and the second loading cam mechanism 23B generate axial thrusts, the first roller element 31 and the second roller element 33 shown in FIG. Thus, the distance between the first roller element 31 and the second roller element 33 is reduced. Then, without changing the contact position between the inclined surfaces of the rolling contact surfaces 51 and 53, which are the inner peripheral surfaces of the first roller element 31 and the second roller element 33, and the outer peripheral surface 17a of the convex curved surface of the intermediate roller 17, The surface pressures of the rolling contact portions of the ring roller 15, the intermediate roller 17, and the sun roller 13 are increased. As a result, as the transmission torque increases, the surface pressure of the plurality of rolling contact portions existing between the input shaft 11 and the output shaft 19 increases.

  As described above, when the first loading cam mechanism 23A and the second loading cam mechanism 23B each generate axial thrust, the surface pressure of each rolling contact portion rises and each roller does not slip due to high surface pressure. Power is transmitted between them.

<Connection structure between first roller element 31 and second roller element 33>
(First configuration example)
The first roller element 31 and the second roller element 33 are rotated by the action of the first loading cam mechanism 23A and the second loading cam mechanism 23B by the rotational drive of the input shaft 11, and approach or separate from each other in the axial direction. Displace in the direction of The friction roller type speed reducer 100 having this configuration includes a coupling mechanism that couples the first roller element 31 and the second roller element 33 so that they can be displaced in the axial direction and cannot be rotated relative to each other.

  FIG. 6 is a perspective view of the first roller element 31 and the second roller element 33 showing one configuration example of the coupling mechanism. In the first roller element 31, at least one opening hole 91 is formed at a circumferential position that avoids the arrangement region of the driving cam surface 83A. On the other hand, at least one pin 93 is erected on the second roller element 33 on the end surface facing the first roller element 31 along the axial direction.

  The pin 93 is provided at a circumferential position corresponding to the opening hole 91 of the first roller element 31. The pin 93 is fixed to the second roller element 33 by being fitted into a lower hole 94 formed in the second roller element 33. In the illustrated example, an opening 91 is formed at an intermediate circumferential position between the arrangement regions of the driven cam surface 83 along the circumferential direction of the first roller element 31. In addition, a pin 93 is disposed on the second roller element 33 at the same circumferential position as the opening hole 91 described above. The pairs of the opening hole 91 and the pin 93 are formed at a total of three locations at equal intervals in the circumferential direction of the roller elements 31 and 33. In addition, although the number of arrangement | positioning of the opening hole 91 and the pin 93 is not restricted to this, it is preferable on maintaining balance that it arranges equally along the circumferential direction.

  FIG. 7 is a sectional view showing a state in which the first roller element 31 and the second roller element 33 are connected to each other. The pin 93 erected on the second roller element 33 is inserted into the opening hole 91 at the corresponding circumferential position of the first roller element 31. The outer diameter of the pin 93 is made smaller than the inner diameter of the opening hole 91 to such an extent that the pin 93 is not shaken in the circumferential direction in a state where the pin 93 is inserted into the opening hole 91. Thereby, the sliding resistance of the pin 93 in the opening hole 91 is reduced, and the axial displacement of the pin 93 is smoothly performed. That is, the pin 93 and the opening hole 91 serve as the above-described coupling mechanism, and the first roller element 31 and the second roller element 33 are coupled such that they can be displaced in the axial direction and cannot be rotated relative to each other.

  In the friction roller type speed reducer 100 having this configuration, the first roller element 31 and the second roller element 33 are integrated with each other by engaging the pin 93 of the second roller element 33 with the opening 91 of the first roller element 31. And rotate. For this reason, both rotation operation | movement can synchronize and generation | occurrence | production of the relative twist of the 1st roller element 31 and the 2nd roller element 33 can be prevented. Further, since the pin 93 in the opening hole 91 can be easily displaced in the axial direction, the first roller element 31 and the first roller element 31 and the second axial direction thrust from the first loading cam mechanism 23A and the second loading cam mechanism 23B can be used. The second roller element 33 is displaced axially evenly and stably.

  In the illustrated example, the opening hole 91 is a simple drilling hole, but a sliding bush may be press-fitted into the inner diameter portion of the opening hole 91 for the purpose of further improving the slidability of the pin 93. In that case, the axial slip in the sliding bush of the pin 93 becomes even lower resistance, and the axial displacement of the first roller element 31 and the second roller element 33 due to the axial thrust described above becomes more stable.

  By configuring the coupling mechanism as described above, the pair of first loading cam mechanism 23A and second loading cam mechanism 23B operate in synchronization with each other. Therefore, when the input shaft 11 rotates, the first roller element 31 and the second roller temporarily Even if the transmission torque of the element 33 varies, the pin 93 is not twisted. As a result, each of the roller elements 31 and 33 can be smoothly displaced in the axial direction, and a force that generates skew on the intermediate roller 17 does not act. Further, since no skew occurs in the intermediate roller 17 and the posture of the intermediate roller 17 is stabilized, it is possible to prevent the occurrence of slipping in the contact surface of each roller and the reduction in power transmission efficiency.

(Second configuration example)
Various modifications can be considered for the coupling mechanism between the first roller element 31 and the second roller element 33 described above. FIG. 8 is a perspective view of the first roller element 31A and the second roller element 33A showing another configuration example of the coupling mechanism. In the following description, the same members or the same parts are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  A square meshing clutch is formed on the end surfaces of the first roller element 31A and the second roller element 33A of this configuration that face each other. Specifically, the first roller element 31A is provided with a plurality of protrusions 95 along the circumferential direction on the end surface facing the second roller element 33A. The second roller element 33A is provided with a plurality of protrusions 97 along the circumferential direction on the end surface facing the first roller element 31A.

  The protrusion 97 is inserted into the recess 99 between the protrusions 95, and the protrusion 95 is inserted into the recess 101 between the protrusions 97. Both side surfaces in the circumferential direction of the projections 95 and 97 (both side walls in the circumferential direction of the recesses 99 and 101) are planes parallel to the axial direction, and when the projections 95 and 97 are inserted into the recesses 99 and 101, It becomes a sliding surface of the adjacent protrusion part 95 and the protrusion part 97. FIG. As a result, the first roller element 31A and the second roller element 33A are coupled so as to be capable of relative displacement in the axial direction but not to be relatively rotatable.

  FIG. 9 is a partial side view showing a state in which the first roller element 31A and the second roller element 33A are connected to each other. The protrusions 95 and the recesses 101 and the protrusions 97 and the recesses 99 mesh with each other to synchronize the rotation of the first roller element 31A and the second roller element 33A. The protrusions 95 and 97 and the recesses 99 and 101 are slidably engaged in the axial direction, and the first roller element 31A and the second roller element 33A can be smoothly displaced in the axial direction.

  By configuring the coupling mechanism as described above, the bonding area between the first roller element 31A and the second roller element 33A is increased, so that the same effect as described above can be obtained without the load being concentrated on a specific portion. In the case of this configuration, the number of parts can be reduced and the assembly process can be simplified.

(Third configuration example)
FIG. 10 is a perspective view of the first roller element 31B, the second roller element 33B, and the annular member 113 showing another configuration example of the coupling mechanism.
Splines 105 and 107 are formed on the outer diameter surface of the first roller element 31B and the second roller element 33B of this configuration, respectively. An annular member 113 is provided between the first roller element 31B and the second roller element 33B. A spline 111 that engages with the splines 105 and 107 of the roller elements 31B and 32B is formed on the inner surface of the annular member 113. As a result, the first roller element 31B and the second roller element 33B are coupled so as to be capable of relative displacement in the axial direction and not to be relatively rotatable.

  FIG. 11 is a partial side view showing a state in which the first roller element 31B and the second roller element 33B are connected to each other by the annular member 113. The spline 111 of the annular member 113 is simultaneously engaged with the spline 105 of the first roller element 31B and the spline 107 of the second roller element 33B. Although not shown, the annular member 113 is rotatably supported on its outer diameter surface and side surfaces by the inner diameter surface and protrusions in the cylindrical portion 47 of the connecting portion 21 shown in FIG.

  By configuring the coupling mechanism as described above, the same effects as described above can be obtained. Further, since splines are formed on the outer diameter surfaces of the first roller element 31B and the second roller element 33B, the entire circumference of the first roller element 31B and the second roller element 33B is supported by the annular member 113. Thus, the first roller element 31B and the second roller element 33B can be displaced in the axial direction with a more stable posture.

  Note that the splines 105, 107, and 111 may be other concave and convex engaging elements in addition to the illustrated rectangular splines.

  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 of seeking protection.

  For example, in the above configuration example, the loading cam mechanism is provided on the pair of ring rollers. However, the present invention is not limited to this, and the configuration may be such that the loading cam mechanism is provided on the pair of sun rollers. As an example, FIG. 12 shows a schematic cross-sectional view of a principal part of a friction roller type speed reducer provided with loading cam mechanisms 24A and 24B on the sun roller 13 side.

  The sun roller 13 includes a first roller element 14A and a second roller element 14B, and is supported on the input shaft 11 via a sleeve 121 so as to be freely displaceable in the axial direction. A pair of loading cam mechanisms 24A and 24B are provided on the outer end face 123 side of both the first roller element 14A and the second roller element 14B.

  In other words, the first cam ring 70A and the second cam ring 70B are arranged to face the outer end surfaces 123 of the first roller element 14A and the second roller element 14B, respectively. A driving cam surface 84A is formed on the end surface of the first cam ring 70A that serves as the side wall portion on the first roller element 14A side, and the driving cam is provided on the end surface that serves as the side wall portion of the second cam ring 70B on the second roller element 14B side. Surface 84B is formed. A driven cam surface 82A is formed on the outer end surface 123 of the first roller element 14A, and a driving cam surface 84B is formed on the outer end surface 123 of the second roller element 14B. A ball 72A is disposed between the driving cam surface 84A and the driven cam surface 82A, and a ball 72B is disposed between the driving cam surface 84B and the driven cam surface 82B. The first cam ring 70 </ b> A and the second cam ring 70 </ b> B are fixed to the input shaft 11 and are driven to rotate integrally with the input shaft 11. The first roller element 14A and the second roller element 14B are connected by the above-described connecting mechanism (in the illustrated example, the pin 93 and the opening hole).

  With the above configuration, the first roller element 14A and the second roller element 14B are coupled so that they can be displaced in the axial direction by the loading cam mechanisms 24A and 24B according to the rotation of the input shaft 11 and cannot be relatively rotated. Even in such a case, it is possible to obtain the same effect as the above-described loading cam mechanism.

  Further, although the friction roller type speed reducer 100 has been described as a configuration in which the ring roller 15 is rotationally driven without the intermediate roller 17 revolving around the sun roller 13, the present invention is not limited thereto. For example, the ring roller 15 may be fixed in the rotation direction, the intermediate roller 17 may be revolved around the sun roller 13, and the rotation of the carrier 45 that supports the intermediate roller 17 may be transmitted to the output shaft 19.

DESCRIPTION OF SYMBOLS 11 Input shaft 13 Sun roller 15 Ring roller 17 Intermediate roller 19 Output shaft 21 Connection part 23A, 24A 1st loading cam mechanism 23B, 24B 2nd loading cam mechanism 25 Outer peripheral surface 27 Inner peripheral surface 31 1st roller element 33 2nd roller element 35 Support shaft (spinning shaft)
51, 53 Rolling contact surface 55 Opposing end surface 57 Outer end surface 69A First cam ring 69B Second cam ring 71A, 71B, 72A, 72B Ball (rolling element)
81A, 81B, 82A, 82B Driven cam surface 83A, 83B, 84A, 84B Drive side cam surface 91 Opening hole (connection mechanism)
93 pin (connection mechanism)
95,97 Protrusion (coupling mechanism)
99,101 Recessed part (connection mechanism)
100 Friction roller type speed reducer 105, 107, 111 Spline (connection mechanism)

Claims (2)

A sun roller connected concentrically with the input shaft and having a rolling contact surface on the outer peripheral surface, a ring roller arranged concentrically with the sun roller around the sun roller and having a rolling contact surface on the inner peripheral surface, the sun roller and the ring roller A plurality of intermediate rollers that are in rolling contact with the rolling contact surface and are supported rotatably about a rotation shaft parallel to the input shaft, a connecting portion that connects the ring roller to an output shaft, the sun roller, A friction roller type speed reducer comprising: a ring roller; and a loading cam mechanism for changing each rolling contact surface pressure of the intermediate roller,
The ring roller has a first roller element and a second roller element arranged in parallel in the axial direction of the input shaft,
The rolling contact surfaces of the first roller element and the second roller element are arranged from an opposing end face where the first roller element and the second roller element face each other to an outer end face on the opposite side in the axial direction of the opposing end face. Toward the rotation axis center line of the intermediate roller is an inclined surface,
The loading cam mechanism is provided in a pair on the outer end face side of both the first roller element and the second roller element, and is arranged on the outer end face of the first roller element and the second roller element in the circumferential direction. In the circumferential direction, on the drive side cam surface provided along the side wall, and on the side wall portion disposed opposite to the outer end surface of the first roller element and the second roller element and fixed to the input shaft. A driven cam surface provided along, and a rolling element disposed between the driving cam surface and the driven cam surface,
The driving-side cam surface and the driven-side cam surface are each shaped such that the depth in the axial direction gradually changes in the circumferential direction and becomes shallower toward the circumferential end,
A friction roller type speed reducer comprising: a coupling mechanism that couples the first roller element and the second roller element to each other so as to be axially displaceable but not relatively rotatable. A sun roller connected concentrically with the input shaft and having a rolling contact surface on the outer peripheral surface, a ring roller arranged concentrically with the sun roller around the sun roller and having a rolling contact surface on the inner peripheral surface, the sun roller and the ring roller A plurality of intermediate rollers that are in rolling contact with the rolling contact surface and are supported rotatably about a rotation shaft parallel to the input shaft, a connecting portion that connects the ring roller to an output shaft, the sun roller, A friction roller type speed reducer comprising: a ring roller; and a loading cam mechanism for changing each rolling contact surface pressure of the intermediate roller,
The sun roller has a first roller element and a second roller element arranged in parallel in the axial direction of the input shaft,
The rolling contact surfaces of the first roller element and the second roller element are arranged from an opposing end face where the first roller element and the second roller element face each other to an outer end face on the opposite side in the axial direction of the opposing end face. Toward the rotation axis center line of the intermediate roller is an inclined surface,
The loading cam mechanism is provided in a pair on the outer end face side of both the first roller element and the second roller element, and is arranged on the outer end face of the first roller element and the second roller element in the circumferential direction. In the circumferential direction on the driven cam surface provided along the side wall portion and the side wall portion disposed opposite to the outer end surface of the first roller element and the second roller element and fixed to the connecting portion. Driving side cam surface provided along the rolling side, and a rolling element disposed between the driving side cam surface and the driven side cam surface,
The driving-side cam surface and the driven-side cam surface are each shaped such that the depth in the axial direction gradually changes in the circumferential direction and becomes shallower toward the circumferential end,
A friction roller type speed reducer comprising: a coupling mechanism that couples the first roller element and the second roller element to each other so as to be axially displaceable but not relatively rotatable.

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