JP2010216516A - Friction transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the size and weight of a transmission case by avoiding the application of a large force to the transmission case, and avoid an increase in the cost, consumed power, and size of an actuator by eliminating the actuator generating a large pressing force. <P>SOLUTION: In this friction transmission device, a pair of counter rollers 9, 10 which are disposed to face each other so as to hold a first roller 1 and a second roller 2 in the state that are separated from each other are connected to each other and supported by a connection support member 14. The counter rollers 9, 10 are pressingly brought into contact with the first roller 1 and the second roller 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  According to the present invention, a first roller and a second roller, which are provided in a vehicle or the like and are rotatably supported, are brought into press contact with each other, and the frictional transmission force generated at the contact portion causes one of the two rollers. The friction transmission device for transmitting power to the other roller, in particular, rotating the other roller by simultaneously pressing and contacting the counter roller with the other roller separated from the one roller. The present invention relates to a friction transmission device that reverses the direction with respect to the rotational direction by pressing contact with one roller.

  As a conventional friction transmission device as described above, for example, a vehicle friction transmission transmission device disclosed in Patent Document 1 disclosed by the applicant of the present application is known. The vehicle friction transmission transmission device includes a first roller and a first roller transmission device. A plurality of roller pairs with two rollers are provided with different reduction ratios, and a pair of these roller pairs is selectively pressed and contacted to perform forward drive speed change. In the vehicle friction transmission, the plurality of pairs of rollers are separated from each other, and the counter roller is pressed and contacted with the pair of rollers by driving the actuator, so that the second roller is reversely rotated with respect to the forward drive. Thus, the backward drive is obtained without providing a separate reverse rotation mechanism.

JP 2007-333123 A

  By the way, as a result of further research on the above-described conventional friction transmission device, the present inventor has found that it is desirable to improve the following. That is, when the roller pair is made of metal, the ratio of the transmission force to the pressing force, that is, the traction coefficient is usually 0.1 or less, so the pressing force becomes a very large value, and this large pressing force is generated. A large force also acts on the actuator support. However, since the transmission case that fixes and supports the actuator is usually made of a light alloy such as aluminum, the case size increases and the case weight increases to ensure sufficient strength. In addition, since an actuator that generates a large pressing force is required, the cost, power consumption, and size of the actuator increase.

  A friction transmission device according to the present invention that advantageously solves the above-described problems is achieved by connecting and supporting a pair of counter rollers opposed to each other so as to sandwich the first roller and the second roller that are separated from each other by a connection support member. The counter rollers are brought into pressure contact with the first roller and the second roller, respectively.

  According to the friction transmission device of the present invention, since the pair of counter rollers sandwiching the first roller and the second roller are connected and supported by the connection support member, the first roller and the second roller acting on the pair of counter rollers The force component in the opposite direction of the large pressing force from the roller serving as the driving roller and the large pressing reaction force from the roller serving as the driven roller cancels out inside the connecting support member. Can be avoided and the size and weight of the transmission case can be kept compact. In addition, since an actuator with a large output, such as the actuator of the conventional device, is not required to generate the pressing force, it is possible to avoid an increase in cost, power consumption, and size of the actuator.

It is explanatory drawing which shows typically the structure of the friction transmission gearbox for vehicles as 1st Embodiment of the friction transmission apparatus of this invention seeing from the axial direction of each roller. It is sectional drawing which shows typically the structure of the friction transmission gearbox of the said 1st Embodiment. It is explanatory drawing which shows typically arrangement | positioning of each roller axis line of the friction transmission gearbox of the said 1st Embodiment. It is explanatory drawing which shows typically the structure of the friction transmission transmission apparatus for vehicles as 2nd Embodiment of the friction transmission apparatus of this invention seeing from the axial direction of each roller. It is explanatory drawing which shows the operating state of the friction transmission gearbox of the said 2nd Embodiment. It is explanatory drawing which shows typically the structure of the friction transmission gearbox for vehicles as 3rd Embodiment of the friction transmission apparatus of this invention seeing from the axial direction of each roller. It is explanatory drawing which shows typically the structure of the vehicle friction transmission transmission apparatus as 4th Embodiment of the friction transmission apparatus of this invention seeing from the axial direction of each roller. It is explanatory drawing which shows the operating state of the friction transmission gearbox of the said 4th Embodiment. It is explanatory drawing which shows the operating state of the friction transmission gearbox of the said 4th Embodiment. It is explanatory drawing which shows typically the structure of the friction transmission transmission apparatus for vehicles as 5th Embodiment of the friction transmission apparatus of this invention seeing from the axial direction of each roller.

  Hereinafter, five types of embodiments of the friction transmission device of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram schematically showing the configuration of a vehicle friction transmission device as a first embodiment of the friction transmission device of the present invention when viewed from the axial direction of each roller, and FIG. FIG. 3 is a cross-sectional view schematically showing the configuration of the friction transmission transmission according to the embodiment, and FIG. 3 is an explanatory view schematically showing the arrangement of each roller axis of the friction transmission transmission according to the first embodiment.

  The friction transmission for a vehicle according to the first embodiment of the present invention is used for a vehicle drive system. As shown in FIG. 1, the drive roller 1 and the second roller 1 are respectively supported as a first roller rotatably supported. The driven rollers 2 as rollers are brought into pressure-contact with each other, and a driving force from a driving source (not shown) is transmitted from the driving roller 1 to the driving wheel (not shown) through the driven roller 2 during acceleration of the vehicle by the friction force generated at the contact portion. When the vehicle runs on the coast, the driving force from the driving wheels is transmitted from the driven roller 2 to the driving source through the driving roller 1.

  Specifically, the drive roller 1 and the driven roller 2 are configured as shown in FIGS. That is, the drive roller 1 is configured by integrally forming the first speed drive roller 11, the second speed drive roller 12, the third speed drive roller 13, and the drive roller support shaft portions 17 and 18. The roller diameter is 1st speed driving roller 11 <2nd speed driving roller 12 <3rd speed driving roller 13 and is driven between the driving roller support shafts 17 and 18 in order from the left in FIG. A roller 11, a second speed driving roller 12, and a third speed driving roller 13 are arranged.

  The driven roller 2 includes a first speed driven roller 21, a second speed driven roller 22, a third speed driven roller 23, and an eccentric driven roller shaft 24. The roller diameters are: 1-speed driven roller 21> 2-speed driven roller 22> 3-speed driven roller 23, and on the eccentric driven roller shaft 24 in order from the left in FIG. A speed driven roller 22 and a third speed driven roller 23 are arranged.

  The first speed driving roller 11 and the first speed driven roller 21, the second speed driving roller 12 and the second speed driven roller 22, and the third speed driving roller 13 and the third speed driven roller 23 constitute a roller pair, respectively. These three roller pairs are set with different gear ratios.

  As shown in FIG. 2, the eccentric driven roller shaft 24 is provided with a first support bearing 3 and a second support bearing 4 that rotatably support both end portions thereof, and the drive roller support shaft portions 17 and 18 are provided with them. Are provided with drive roller support bearings 5 and 6 for rotatably supporting them. The first support bearing 3 and the second support bearing 4 are respectively supported by two support members 7 arranged in a transmission case (not shown), and a driving roller is supported on a cam inclined surface 7a provided on these support members 7. By bringing the bearings 5 and 6 into contact with each other, a pressing force is applied to the three roller pairs.

  As shown in FIG. 2, the drive roller support bearings 5 and 6 have cam followers 5a and 6a as outer rings and needles 5b and 6b as rolling elements, while the cam inclined surface 7a is as shown in FIG. Further, the cam followers 5a and 6a of the drive roller support bearings 5 and 6 are formed on the cam inclined surface 7a. After contacting the rollers of any of the roller pairs, the rollers that are in contact with each other are moved along the cam inclined surface 7a by the reaction force of the transmission force between the roller pairs that are in contact with each other, so that the rollers in contact with each other are pressed. It is composed.

  As shown in FIGS. 2 and 3, the three driven rollers 21, 22, and 23 are arranged on the driven roller rotation axes 21 a, 22 a, and 23 a that are eccentric with respect to the rotation axes 2 a at both ends of the eccentric driven roller shaft 24. Servo for rotating the eccentric driven roller shaft 24 through an irreversible input type reduction mechanism (not shown) such as a worm gear set, for example, at one end portion of the eccentric driven roller shaft 24. A motor 8 (transmission actuator) is provided.

  At the time of a shift command, the servo motor 8 rotates the eccentric driven roller shaft 24 to rotate the rotation axis of one driven roller corresponding to the shift position before the shift among the driven roller rotation axes 21a, 22a, and 23a. The gear ratio is set differently by moving the rotation axis of one driven roller corresponding to the speed-change position after shifting out of the driven roller rotation axes 21a, 22a, and 23a closer to the drive roller rotation axis 1a. Of the three pairs of rollers, a pair of rollers that press the rollers in contact with each other can be switched.

  The first-speed driven roller 21, the second-speed driven roller 22, and the third-speed driven roller 23 are movable in the radial direction by the first connecting portion 31 and the second connecting portion 32, and in the rotational direction. Are connected together. The driving force is input to the transmission from either one of the drive roller support shafts 17 and 18, and the driving force output from the transmission is output from the first-speed driven roller 21 and the second-speed driven roller 22. It is taken out from any one of the three-speed driven rollers 23 in the radial direction or the axial direction.

  As shown in FIG. 1, the transmission according to the first embodiment further includes two counter rollers 9 and 10, a connection support member 14 that supports the counter rollers 9 and 10, and the counter rollers 9 and 10. The actuator 10 which moves 10 together as follows is provided. Here, the support shafts of the counter rollers 9 and 10 are rotatably supported by the connecting support member 14 at both ends via the counter roller bearings 15 and 16, and thereby the counter which is the center of rotation of the counter rollers 9 and 10. The roller rotation axes 9a and 10a extend in parallel to each other and in parallel with the drive roller rotation axis 1a and the driven roller rotation axis 2a, and are arranged at different positions from the drive roller rotation axis 1a and the driven roller rotation axis 2a. . For example, the connection support member 14 is formed so as to go around from the outside of the counter rollers 9 and 10 so as to be positioned on both sides in the axial direction of the counter rollers 9 and 10, so that both end portions of the support shafts of the counter rollers 9 and 10 are formed. Can be supported.

  Further, the counter rollers 9 and 10 are driven by the actuator through a member such as a fork-like member that engages with them, and move together in the axial direction of the counter roller rotation axes 9a and 10a. Aligned in the radial direction with respect to 21, and aligned in the radial direction with respect to the first speed roller pair 11, 21 and the axial position (reverse position) facing each other so as to sandwich the first speed roller pair 11, 21 therebetween Instead, it is selectively located at any one of the axial position (forward position) deviated from the first speed roller pair 11, 21 to the side opposite to the second speed roller pair 12, 22 side. On the other hand, the connection support member 14 is disposed in the transmission case so that it can freely move within a certain range in a direction orthogonal to the axial direction of the counter roller rotation axis 9a, 10a.

  However, in the transmission of the first embodiment, when the vehicle travels forward, the two counter rollers 9 and 10 are driven by the actuator and are aligned with the first-speed roller pair 11 and 21 in the radial direction. The shaft is moved to an axial position (forward position) deviated, and the eccentric driven roller shaft 24 is rotated by the servo motor 8 to drive a desired one of the driven roller rotational axes 21a, 22a, and 23a. By driving close to the roller rotation axis 1a and fixing it, the rollers of the desired roller pair among the three pairs of rollers set with different speed ratios are brought into pressure contact with each other, and the driving force from the driving source is applied to the driving wheel. Then, the eccentric driven roller shaft 24 is further rotated by the servo motor 8 to change the roller pair that presses and contacts the rollers, thereby changing the gear ratio.

  On the other hand, when the vehicle is traveling backward, the servo motor 8 rotates the eccentric driven roller shaft 24 so that all of the driven roller rotation axes 21a, 22a, and 23a are fixed apart from the drive roller rotation axis 1a. For each of the pair of rollers, a neutral state in which the rollers are separated from each other is set, and in the neutral state, the two counter rollers 9 and 10 are driven together by the actuator, and the first speed roller pair 11 and 21 are moved together. It is moved to an axial position (retraction position) aligned in the radial direction.

  The counter rollers 9 and 10 aligned in the radial direction with respect to the first-speed roller pair 11 and 21 are in contact with the first-speed driving roller 11 and the first-speed driven roller 21 as shown in FIG. The roller 11 transmits driving force to the counter rollers 9 and 10, and the first-speed driving roller 11 receiving the reaction force of the driving force moves along the cam inclined surface 7a in the approaching direction to the first-speed driven roller 21. Then, the counter rollers 9 and 10 are pressed against the counter rollers 9 and 10, and the counter rollers 9 and 10 are moved toward the first speed driven roller 21 by the pressing force and pressed against the first speed driven roller 21. Of the pressing force from the first-speed drive roller 11 and the pressing reaction force from the first-speed driven roller 21 acting on the counter rollers 9 and 10, the force component that presses the counter rollers 9 and 10 away from each other is , Both of which are added to the connection support member 14 and cancel each other as internal forces in the connection support member 14.

  Further, the counter roller 9 positioned on the side where the rotation direction of the first-speed drive roller 11 faces the first-speed driven roller 21 rotates the first-speed drive roller 11 when contacting the first-speed roller pair 11, 21. As a result, a wedge action is generated that is drawn toward the first speed roller pair 11 and 21 and pressed against the first speed roller pair 11 and 21.

  By these actions, the first-speed drive roller 11 transmits a reverse drive force to the first-speed driven roller 21 through the counter rollers 9 and 10 to the first-speed driven roller 21 and advances the first-speed driven roller 21 forward. Rotate in the opposite direction to the direction of travel.

  Therefore, according to the transmission of the first embodiment, the pair of counter rollers 9 and 10 sandwiching the first-speed drive roller 11 and the first-speed driven roller 21 are connected and supported by the connection support member 14. The force components in the opposite directions of the large pressing force from the first-speed drive roller 11 and the large pressing reaction force from the first-speed driven roller 21 against the counter rollers 9 and 10 are canceled out inside the connection support member 14. Therefore, it is possible to avoid a large force from acting on the transmission case, and to reduce the size and weight of the transmission case in a compact manner. In addition, since the driving force is transmitted by sandwiching the roller pair 11 and 21 between the pair of counter rollers 9 and 10, an actuator with a large output like the actuator of the conventional device is not required for generating the pressing force. It is possible to avoid an increase in cost, power consumption and size.

  FIG. 4 is an explanatory view schematically showing a configuration of a vehicle friction transmission device as a second embodiment of the friction transmission device of the present invention when viewed from the axial direction of each roller, and FIG. It is explanatory drawing which shows the operating state of the friction transmission transmission apparatus of embodiment. The friction transmission apparatus according to the second embodiment is different from the previous embodiment only in the support structure of the pair of counter rollers 9 and 10, and has the same configuration as the previous embodiment in other points. Only the support structure of the pair of counter rollers 9 and 10 different from the previous embodiment and the function and effect thereof will be described.

  That is, in this second embodiment, the U-shaped connecting support member 17 that opens downward in the drawing is generally extended in the direction of the cam inclined surface 7a, specifically in FIG. As shown in FIG. 5, the rotation axis 1a of the first-speed drive roller 11 and the rotation axis 21a of the first-speed driven roller 21 are perpendicular to the rotation axis 21a (the extending direction of the paper surface of FIG. 5). The connecting support member 17 is provided with slopes 17a and 17b that are closer to each other as it goes upward, and the slopes 17a and 17b provide counter roller bearings 15 and 17b. 16 are supported. For example, the connection support member 17 is formed so as to wrap around from the outside of the counter rollers 9 and 10 so as to be positioned on both sides in the axial direction of the counter rollers 9 and 10. Can be supported.

  Here, the inclined surface 17 a is a straight line B connecting the rotation axis 1 a of the first-speed drive roller 11 and the rotation axis 9 a of the counter roller 9, the rotation axis 21 a of the first-speed driven roller 21, and the rotation axis 9 a of the counter roller 9. Similarly, the inclined surface 17b has an inclination angle perpendicular to the straight line D that bisects the angle formed by the straight line C connecting the two and the rotation axis 1a of the first-speed drive roller 11 and the rotation axis 9a of the counter roller 10. And a straight line connecting the rotation axis 21a of the first-speed driven roller 21 and the rotation axis 10a of the counter roller 10 has an inclination angle orthogonal to a straight line that bisects the angle.

Since the support bearings 15 and 16 of the counter rollers 9 and 10 are in rolling contact with the inclined surfaces 17a and 17b, a force can be generated only in a direction perpendicular to the inclined surfaces 17a and 17b. Therefore, considering the balance of forces by setting the inclination angles of the inclined surfaces 17a and 17b as described above, the first-speed drive roller 11, the first-speed driven roller 21 and the counter roller 9 are shown in FIG. pressing force acting on the contact portion of the two places is the same size as F _c1, and the pressing force acting on the contact portion of the two places with a first-speed driving roller 11 and the first speed driven roller 21 and the counter roller 10 is also the same size as the F _c2 . From the moment balance, the transmission forces at the two contact portions on the same counter roller are equal, so the transmission forces at the two contact portions on the counter roller 9 have the same magnitude F _t1 . transmission force of the contact portion becomes the same size F _t2. Thereby, the ratio of the transmission force and the pressing force can be made equal at the two contact portions on the same counter roller. If this ratio is different, it is necessary to apply a pressing force to the contact portion where a larger pressing force is required. Therefore, the pressing force is excessive for the other contact portion, leading to an increase in loss. According to the second embodiment, such excessive pressing force can be eliminated.

Further, in the second embodiment, the positional relationship and the roller radius of the rotation axis of each roller are the friction coefficient of the contact portion between the first-speed driving roller 11 and the first-speed driven roller 21 and the counter rollers 9 and 10. Is an angle α between a straight line perpendicular to the straight line A connecting the rotation axis 1a of the first-speed drive roller 11 and the rotation axis 21a of the first-speed driven roller 21 and the cam inclined surface 7a, and μ = tan α. The angle formed by the straight line A and the straight line B connecting the rotation axis 1a of the first-speed drive roller 11 and the rotation axis 9a of the counter roller 9 is δ ₁ , and the straight line A and the first speed the angle between the straight line C connecting the rotation axis 9a of the rotation axis 21a and the counter roller 9 for use driven roller 21 and epsilon _1, further the straight line a and the axis of rotation 1a and counter first-speed driving roller 11 roller Angle of [delta] ₂ of the straight line connecting the rotational axis 9a of 0, and the straight line A, connects the rotational axis 10a of the rotation axis 21a and the counter roller 10 for the first speed driven roller 21 the angle between the straight line ε when a ₂ is set so as to balance equation is satisfied the following forces.

これをμについて解くと、（２）式になる。

（２）式の右辺の分子は図５の右方へ向かう力、右辺の分母は図５の下方へ向かう力である。 When the pressing force of the counter roller 9 is F _c1 , the transmission force of the counter roller 9 is F _t1 , the pressing force of the counter roller 10 is F _c2 , and the transmission force of the counter roller 10 is F _t2 , the relationship between the pressing force and the friction force Therefore, the equation (1) is established.

Solving this for μ yields equation (2).

In the expression (2), the numerator on the right side is the force toward the right in FIG. 5, and the denominator on the right side is the force in the downward direction in FIG.

これら（２），（３）式を連立させると、（４）式になる。

Moreover, the balance of the force in the left-right direction in FIG.

When these equations (2) and (3) are combined, equation (4) is obtained.

  Therefore, according to the second embodiment, in addition to the same effects as the first embodiment, the two contact portions on the counter roller 9 and the two contact points on the counter roller 10 can be obtained. The ratio of the transmission force and the pressing force in all of the parts becomes equal to each other, and the power can be transmitted with the minimum necessary pressing force.

  FIG. 6 is an explanatory view schematically showing the configuration of a vehicle friction transmission transmission device as a third embodiment of the friction transmission device of the present invention when viewed from the axial direction of each roller. The transmission device differs from the previous second embodiment only in that the connection support member 17 is supported by the support member 7 via the roller 18 so as to be linearly movable, and the other points are the same as in the second embodiment. Therefore, only the configuration different from that of the second embodiment and the function and effect thereof will be described below.

  That is, in the third embodiment, the central plane of the U-shaped connection support member 17 is a plane provided on the support member 7 and is substantially extended in the extending direction of the cam inclined surface 7a via the roller 18, specifically. Is linearly movable in a direction perpendicular to the rotation axis 1a of the first-speed drive roller 11 and the rotation axis 21a of the first-speed driven roller 21 and perpendicular to the straight line connecting the rotation axes 1a and 21a. I support it.

  Since the load in the direction orthogonal to the offset direction (upward load in FIG. 6) acting on the connecting support member 17 is also somewhat large, if it is supported by the transmission case 19 as in the second embodiment, the load on the transmission case 19 However, in this third embodiment, the support member 7 receives the load in the orthogonal direction via the roller 18 and supports it as an internal force.

  Therefore, according to the third embodiment, in addition to the same effects as those of the second embodiment, all the loads can be canceled within the support member 7 and the connection support member 17. It is not necessary to support all the force acting on the support member 17 with the transmission case 19, and it is possible to avoid a large force acting on the transmission case 19.

  FIG. 7 is an explanatory view schematically showing the configuration of a vehicle friction transmission transmission device as a fourth embodiment of the friction transmission device of the present invention when viewed from the axial direction of each roller. The transmission device differs from the second embodiment only in that the thick plate-like connection support member 19 is supported at one end of the eccentric driven roller shaft 24 via a bearing so as to be swingable. Since the configuration is the same as that of the second embodiment, only the configuration different from that of the second embodiment and the effects thereof will be described below.

  That is, in this fourth embodiment, a plate-like connection support member 19 having inclined surfaces 19a, 19b similar to the inclined surfaces 17a, 17b of the U-shaped connection support member 17 in the opening is provided via an eccentric driven roller. At one end of the shaft 24, the shaft 24 is supported so as to be swingable around the driven roller rotation axis 21a. On the other hand, the support bearings 5 and 6 of the first-speed drive roller 11 are separated from the connection support member 19 and supported by the cam slope 7a of the support member 7, and the profile of the cam slope 7a is 1 It is substantially concentric with the speed driven roller 21.

  Further, in the fourth embodiment, as shown in FIG. 8, the first-speed drive is driven in the positive drive direction of the first-speed drive roller 11 (clockwise direction indicated by the arrow in FIG. 8) of the counter rollers 9 and 10. When the roller 11 and the first-speed driven roller 21 are brought into contact with each other, that is, when the first-speed roller pair 11 and 21 are in contact with each other, the first-speed drive roller 11 rotates in the positive drive direction to move between the first-speed roller pair 11 and 21. The outer diameter of the counter roller 9 located on the side where the wedge action is drawn toward the first-speed roller pair 11, 21 is generated and the first-speed drive roller 11 and the first-speed driven roller 21 are pushed out. That is, it is larger than the outer diameter of the counter roller 10 pushed out between the first-speed roller pair 11 and 21 by the rotation of the first-speed drive roller 11 in the positive drive direction when contacting the first-speed roller pair 11 and 21. To have.

  Therefore, according to the fourth embodiment, in addition to the effects similar to those of the second embodiment, the connection support member 19 swings concentrically with the first-speed driven roller 21, so that the cam The counter rollers 9 and 10 are appropriately moved to follow the movement of the first-speed drive roller 11 along the inclined surface 7a, and the respective rotation axes 1a and 21a of the first-speed drive roller 11 and the first-speed driven roller 21 are moved. The relative position of the rotation axes 9a and 10a of the counter rollers 9 and 10 can be minimized, and as a result, there are two contact portions on the counter roller 9 and two contact portions on the counter roller 10. The ratio of the transmission force and the pressing force in all can be kept equal to each other.

このとき、カウンタローラ９，１０の半径が等しいとすると、右辺のＦ_C2の係数が１より大きくなるので、Ｆ_C1＞Ｆ_C2 となり、カウンタローラ９に働く荷重の方が大きくなる。すなわち、カウンタローラ９の方が、接触面圧が高くなり、強度が低下する。 Moreover, in this 4th Embodiment, as shown in FIG. 8, since the pressing force and transmission force similar to 2nd Embodiment shown in FIG. 5 are acting, (1) on the left side of (2) Formula Substituting equation (4) into the right side of equations (2) and rearranging results in the following equation (5).

At this time, if the radii of the counter rollers 9 and 10 are equal, the coefficient of F _{C2 on} the right side is larger than 1, so that F _C1 > F _C2 and the load acting on the counter roller 9 becomes larger. That is, the counter roller 9 has a higher contact surface pressure and lower strength.

Here, FIG. 9 shows calculated values of the pressing force F _c1 / F _c2 with respect to the radius R 1 of the counter roller 9. As the radius R1 is increased, _Fc1 is relatively decreased, and the radius of curvature of the roller surface is increased. Therefore, the surface pressure of the roller surface can be lowered by Hertz's formula.

  Therefore, according to the fourth embodiment, since the radius R2 of the counter roller 10 is R1> R2, the surface pressure of the counter roller 9 on the pull-in side where the surface pressure increases among the counter rollers 9, 10 is reduced, The life of the counter roller 9 on the drawing side can be extended.

  FIG. 10 is an explanatory view schematically showing the configuration of a vehicle friction transmission transmission device as a fifth embodiment of the friction transmission device of the present invention when viewed from the axial direction of each roller. The transmission is provided with an opening 19c in place of the inclined surface 19a in a plate-like connection support member 19 that also serves as the support member 7 and is disposed in the transmission case, and is adjacent to the opening 19c. The actuator 20 is provided, and the cam inclined surface 19d similar to the cam inclined surface 7a is provided at the central portion of the connection support member 19, which is different from the previous fourth embodiment. In other respects, the configuration is the same as that of the fourth embodiment. Therefore, only the configuration different from that of the fourth embodiment and the function and effect thereof will be described below.

  That is, in the fifth embodiment, the bearing 15 of the counter roller 9 is inserted into the opening 19c of the connection support member 19, and the bearing 15 is pressed by the actuator 20 made of a hydraulic cylinder or the like. 9 is pressed against the first-speed drive roller 11 and the first-speed driven roller 21.

  In the previous fourth embodiment, when the transmission torque is increased and the pressing force is increased, the Hertz deformation of the contact portion between the rollers and the elastic deformation of the support member 7 are also increased. 11 moves in the direction of the counter roller 10 on the cam surface 7a. At this time, since the counter roller 10 is simply pressed, it is sufficient to support the movement of the first-speed drive roller 11. However, the counter roller 9 is in a direction away from the inclined surface 19 a, so that the connection support member 19 is swung. Possible support is needed. In contrast, in the fifth embodiment, the counter roller 9 is moved by the actuator 20 so as to follow the movement of the first-speed drive roller 11.

  Therefore, according to the fifth embodiment, the opposing components of the support force of the actuator 20 and the support force of the counter roller 10 are canceled out, so that the same operational effects as those of the previous fourth embodiment can be achieved. In addition, although it is necessary to provide the actuator 20 as compared with the fourth embodiment, a bearing for supporting the coupling support member 19 so as to be swingable and a support portion thereof are not required. The entire device can have a simple structure.

  Although the present invention has been described based on the illustrated embodiment, the present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope of the claims. For example, in the above-described embodiment, The counter rollers 9 and 10 are moved in the axial direction between the forward movement position and the backward movement position by the actuator through the members engaged with them, but by moving the coupling support member in the axial direction, The counter rollers 9 and 10 can also be moved in the axial direction between the forward movement position and the backward movement position. Further, in the above-described embodiment, the roller pair of the driving roller 1 and the driven roller 2 is three pairs, but the friction transmission device may be two pairs or four or more pairs. And this invention can also be comprised as a friction transmission device without a speed-change function by making only one pair of roller pairs of the driving roller 1 and the driven roller 2.

  Thus, according to the friction transmission device of the present invention, since the pair of counter rollers sandwiching the first roller and the second roller are connected and supported by the connection support member, the first roller and the second roller acting on the pair of counter rollers Of these, the large pressing force from the roller serving as the driving roller and the large pressing reaction force from the roller serving as the driven roller cancel out the force components in opposite directions within the connecting support member. The force can be avoided and the size and weight of the transmission case can be kept compact. In addition, since an actuator with a large output, such as the actuator of the conventional device, is not required to generate the pressing force, it is possible to avoid an increase in cost, power consumption, and size of the actuator.

1 Drive roller (first roller)
1a, 2a, 9a, 10a, 21a, 22a, 23a Rotation axis 1b, 1c Drive roller support shaft 2 Driven roller (second roller)
3, 4, 5, 6, 15, 16 Bearing 5a, 6a Cam follower 5b, 6b Needle 7 Support member 7a, 19d Cam slope 8 Servo motor 9, 10 Counter roller 11 First speed drive roller 12 Second speed drive roller 13 3 Speed drive roller 14, 17, 19 Connecting support member 17a, 17b, 19a, 19b Slope 18 Roller 19c Opening 20 Actuator 21 First speed driven roller 22 Second speed driven roller 23 Third speed driven roller 24 Eccentric driven roller shaft

Claims (7)

The first roller and the second roller, which are rotatably supported, are brought into pressure contact with each other, and the power transmitted from one of the first roller and the second roller to the other by the frictional transmission force generated at the contact portion. In the friction transmission device that transmits
A pair of counter rollers that are arranged to face each other so as to sandwich the two rollers in a state where the first roller and the second roller are separated from each other;
A connection support member for connecting and supporting the pair of counter rollers;
A friction transmission device comprising: The connection support member supports the counter roller on a slope,
The slope has a first straight line connecting between the axis of the first roller and the axis of the counter roller, and a second straight line connecting between the axis of the second roller and the axis of the counter roller. 2. The friction transmission device according to claim 1, wherein the friction transmission device is set in a direction perpendicular to a third straight line that divides an angle formed by a half.   3. The friction transmission device according to claim 1, wherein the connection support member supports the counter roller such that an axis of the counter roller responds to movement of an axis of the first roller. 4.   Of the pair of counter rollers, the counter roller on the drawing side with respect to the first roller and the second roller in the positive drive direction of the first roller has an outer diameter of the first roller and the second roller. 4. The friction transmission device according to claim 1, wherein the friction transmission device is larger than the outer diameter of the counter roller on the pushing side.   5. The friction transmission device according to claim 4, wherein the connection support member includes an actuator that moves the axis of the counter roller in response to movement of the axis of the first roller. 6. The friction transmission device includes a support member that supports the first roller and the second roller,
The friction transmission device according to claim 4, wherein the connection support member is supported by the support member so as to respond to movement of an axis of the first roller.   6. The friction transmission device according to claim 1, wherein the connection support member swings around the axis of the second roller so as to respond to movement of the axis of the first roller. .

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