JP5905513B2 - Continuously variable transmission - Google Patents

Description

  The present invention relates to a continuously variable transmission that is configured by a belt or chain being stretched around a set of pulleys.

  A continuously variable transmission is known in which a belt or chain is stretched around a set of pulleys, and the groove widths of the primary pulley and the secondary pulley are mechanically operated by an actuator such as a motor.

  Patent Document 1 discloses a pulley width adjustment device for a continuously variable transmission that moves a movable pulley disk in an axial direction via a screw mechanism to change a pulley width between a fixed pulley disk and a movable pulley disk. ing.

JP 2003-139208 A

  In the continuously variable transmission described in Patent Document 1, the reaction force of the clamping force when the belt is clamped by the movable pulley is transmitted from the inner race to the outer race of the ball bearing and is input to the pulley width adjusting device. It is transmitted from the outer race to the inner race and is received by the nut of the rotating shaft.

  In such a configuration, since the reaction force of the belt clamping force is input not only in the radial direction but also in the thrust direction with respect to the ball bearing, the belt clamping force is limited by the allowable value of the ball bearing in the slalting direction. Therefore, the upper limit of the input torque of the continuously variable transmission is limited by the allowable value of the ball bearing.

  On the other hand, in order to increase the input torque of the continuously variable transmission, it is necessary to increase the allowable value of the ball bearing. However, the ball bearing increases in size and the weight and size of the continuously variable transmission increases. There is a problem.

  The present invention has been made in view of such problems, and an object thereof is to provide a continuously variable transmission that does not increase in weight or size.

According to an embodiment of the present invention, a set of pulleys, in which a groove is formed by a fixed sheave fixed to the rotating shaft and a movable sheave slidably provided in the axial direction of the rotating shaft, is provided. A continuously variable transmission having a continuously variable transmission mechanism configured by winding an endless belt around a groove of at least one of a pair of pulleys, wherein at least one of the pulleys advances and retracts a movable sheave by operation of an actuator The slide mechanism has a roller , and includes a slide block that rotates by the operation of the actuator, and a fixed block that has a cam surface with which the roller contacts and is locked to the case, and one end of the slide mechanism is The rotary shaft abuts on the movable sheave via the first bearing that receives the thrust force, the rotating shaft has an annular portion that rotates coaxially, and the other end of the slide mechanism receives the thrust force. Via a bearing, is supported on the annular portion, the actuator by changing the position in the circumferential direction with respect to the fixed block of the slide block, by abutting position to the cam surface of the roller is changed, the slide block axially And the movable sheave is advanced and retracted, and the first bearing, the second bearing, and the position where the roller and the cam surface come into contact with each other are stacked at substantially the same position in the axial direction .

  According to the above aspect, since the reaction force of the belt clamping force is received by the annular portion of the rotating shaft via the first bearing and the second bearing that receive the thrust force, it is compared with the bearing that receives the force in the radial direction. As a result, the allowable value of the belt clamping force increases. Therefore, the size and gravity of the first and second bearings are not increased, and the weight and size of the continuously variable transmission are not increased.

It is explanatory drawing which shows an example of a structure of the continuously variable transmission of 1st Embodiment of this invention. It is explanatory drawing of the secondary pulley of the continuously variable transmission mechanism of 1st Embodiment of this invention. It is explanatory drawing which shows the detail of the fixing | fixed part of 1st Embodiment of this invention. It is explanatory drawing which shows the detail of the fixing | fixed part of 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment>
FIG. 1 is an explanatory diagram showing a configuration of a drive device having a continuously variable transmission 1 according to a first embodiment of the present invention.

  The drive device includes an engine 5 and a continuously variable transmission 1. The rotation of the engine 5 is continuously shifted by the continuously variable transmission 1 and output.

  The rotation of the crankshaft 11 driven by the engine 5 is transmitted to the continuously variable transmission mechanism 4 via the torque converter 2 and the forward / reverse switching mechanism 3.

  The torque converter 2 includes a lockup clutch, and is controlled to a converter state and a lockup state (slip lockup) by hydraulic pressure.

  The forward / reverse switching mechanism 3 transmits the rotation of the turbine shaft 6 that is the output shaft of the torque converter 2 to the continuously variable transmission mechanism 4 in the forward (forward) direction, and transmits it in the reverse (reverse) direction. And a reverse brake.

  The continuously variable transmission 1 includes a continuously variable transmission mechanism 4. The continuously variable transmission mechanism 4 includes a primary pulley 15 connected to an input shaft 12 connected to the forward / reverse switching mechanism 3, a secondary pulley 16 connected to an output shaft 13 arranged in parallel with the input shaft 12, and a primary pulley. This is a belt-type continuously variable transmission mechanism that includes an endless belt (V-belt) 17 spanned between a pulley 15 and a secondary pulley 16.

  The primary pulley 15 includes a fixed pulley (fixed sheave) 15a, and a movable pulley (movable sheave) 15b that is arranged with a sheave surface facing the fixed pulley 15a and forms a V-groove with the fixed pulley. And a slide mechanism 21 provided on the back surface of the movable pulley 15b for displacing the movable pulley 15b in the axial direction.

  Similarly, the secondary pulley 16 includes a fixed pulley (fixed sheave) 16a, a movable pulley (movable sheave) 16b, and a slide mechanism 22 provided on the back surface of the movable pulley 16b to displace the movable pulley 16b in the axial direction. .

  When the movable pulleys 15 b and 16 b are displaced by the slide mechanisms 21 and 22, the width of the V-groove changes and the contact radius between the V belt 17 and each of the pulleys 15 and 16 changes, and the transmission ratio of the continuously variable transmission mechanism 4. Changes steplessly.

  The rotation of the secondary shaft 14 is transmitted to the wheels via the final reduction gear 18.

  The control device 40 controls the gear ratio of the continuously variable transmission mechanism 4 by controlling the slide mechanisms 21 and 22 of the primary pulley 15 and the secondary pulley 16, respectively.

  Next, the configuration of the slide mechanism 22 of the secondary pulley 16 will be described. Since the slide mechanism 21 of the primary pulley 15 has the same structure, the description thereof is omitted.

  FIG. 2 is a cross-sectional view for explaining the secondary pulley 16 of the present embodiment.

  A movable pulley 16 b is provided on the outer periphery of the output shaft 13. The movable pulley 16b is attached by a slide mechanism 22 so as to be slidable in the axial direction of the output shaft 13.

  The slide mechanism 22 includes a slide cam 51, a fixed cam 52, a ring portion 53, and an actuator 60.

  The slide cam 51 advances and retracts the movable pulley 16 b in the axial direction by the operation of the actuator 60. For example, the actuator 60 is an electric motor, and the rotation of the actuator 60 rotates the slide cam 51 via a worm gear or the like.

  A thrust bearing 71 (first bearing portion) is interposed between the slide cam 51 and the movable pulley 16b. The thrust bearing 71 is constituted by a thrust bearing in which needles or rollers that receive a force in the thrust direction are arranged in the circumferential direction.

  A ring portion 53 is provided on the outer periphery of the slide cam 51. The slide cam 51 and the ring portion 53 are fitted by an axial spline, and the slide cam 51 is configured to be slidable in the axial direction with respect to the operation of the ring portion 53. The ring portion 53 rotates the slide cam 51 by being rotated in the circumferential direction by the actuator 60.

  As will be described later with reference to FIG. 3, the fixed cam 52 is formed with a plurality of ribs 521 protruding from the outer peripheral side. The rib 521 is engaged with a rib receiving groove 9 a formed on the inner periphery of the case 9 to support the fixed cam 52 so as not to rotate with respect to the output shaft 13.

  A fixed nut 55 is screwed onto the output shaft 13, and a thrust bearing 72 is interposed between the fixed cam 52 and the fixed nut 55. Similar to the thrust bearing 71, the thrust bearing 72 is configured by a thrust bearing in which needles or rollers that receive a force in the thrust direction are arranged in the circumferential direction.

  The fixing nut 55 abuts on a stopper 131 formed on the output shaft 13, whereby the fixing nut 55 is positioned in the axial direction of the output shaft 13.

  The output shaft 13 is provided with a ball bearing 70 that supports the output shaft 13 on the case 9. In the ball bearing 70, the inner race 70 a is fitted to the output shaft 13 and the outer race 70 b is fitted to the case 9.

  With such a configuration, the rotation of the primary pulley 15 is transmitted to the fixed pulley 16 a and the movable pulley 16 b of the secondary pulley 16 that sandwiches the V belt 17 via the V belt 17 to rotate the output shaft 13.

  At this time, the fixed pulley 16 a, the movable pulley 16 b, and the fixed nut 55 rotate together with the output shaft 13. The slide cam 51 and the fixed cam 52 are supported by thrust bearings 71 and 72 and do not move with respect to the output shaft 13.

  The movable pulley 16b clamps the V belt 17 by the thrust generated by the slide cam 51. The reaction force of the holding force of the V belt by the slide cam 51 is transmitted to the thrust bearing 71, the slide cam 51, the fixed cam 52, and the thrust bearing 72, and the fixing nut 55 receives this reaction force. That is, in the secondary pulley 16, the thrust of the movable pulley 16 b is completed on the output shaft 13 and is not transmitted to the case 9 or the ball bearing 70 that supports the output shaft 13 on the case 9.

  Next, the movement of the movable pulley 16b by the slide mechanism 22 will be described.

  FIG. 3 is an explanatory diagram of the main points of the slide cam 51 and the fixed cam 52 of the present embodiment.

  A plurality of ribs 521 project from the outer periphery of the fixed cam 52. The rib 521 is engaged with a rib receiving groove 9 a formed on the inner periphery of the case 9, so that relative rotation with the case 9 is restricted.

  A cam surface 522 is formed on the upper surface side of the fixed cam 52, that is, on the side in contact with the slide cam 51. The cam surface 522 is equally divided into three, and each cam surface 522 is formed to protrude in the counterclockwise direction in the circumferential direction. Three rollers 511 are rotatably attached to the outer side of the slide cam 51 in the circumferential direction. The three rollers 511 of the slide cam 51 abut on the three cam surfaces 522 of the slide cam fixed cam 52, respectively.

  When the slide cam 51 rotates counterclockwise with respect to the fixed cam 52, the roller 511 raises the gradient of the cam surface 522. As a result, the slide cam 51 moves in a direction in which the movable pulley 16b approaches the fixed pulley 16a.

  On the other hand, when the slide cam 51 rotates in the clockwise direction with respect to the fixed cam 52, the roller 511 descends the gradient of the cam surface 522. As a result, the slide cam 51 moves in a direction in which the movable pulley 16b moves away from the fixed pulley 16a.

  With such a configuration, the slide cam 51 is moved in the axial direction by rotating the slide cam 51 with respect to the fixed cam 52 by rotating the ring portion 53 by the operation of the actuator 60, and the thrust cam 71 is interposed. By pressing the movable pulley 16b, the groove width between the movable pulley 16b and the fixed pulley 16a is changed.

  As described above, the continuously variable transmission mechanism 4 according to the embodiment of the present invention includes the fixed pulley 16a that is fixed to the rotating shaft (output shaft 13) and the movable pulley 16b that is slidable in the axial direction of the rotating shaft. A continuously variable transmission mechanism 4 comprising a set of pulleys (a primary pulley 15 and a secondary pulley 16) in which grooves are formed by the endless V belt 17 wound around the grooves of the set of pulleys. In the continuously variable transmission 1 provided, at least one of the pulleys (the primary pulley 15 or the secondary pulley 16) includes a slide mechanism 22 that moves the movable pulley 16b forward and backward by the operation of the actuator 60.

  One end of the slide mechanism 22 abuts on the movable pulley 16b via a first bearing (thrust bearing 71) that receives a thrust force, and the output shaft 13 has an annular portion (fixed nut 55) that rotates coaxially. The other end of the slide mechanism 22 is configured to be supported by the fixing nut 55 via a second bearing (thrust bearing 72) that receives a thrust force.

  As described above, in the continuously variable transmission 1 according to the first embodiment of the present invention, the slide mechanism 22 that presses the movable pulley 16b and clamps the V belt 17 receives the thrust force (the thrust bearing 71 and the thrust bearing 72). It is the structure which is received by the fixing nut 55 fixed to the output shaft 13 via these.

  Accordingly, the reaction force of the belt clamping force by the movable pulley 16b is received as a thrust force by the thrust bearing 71 and the thrust bearing 72 and is received by the fixing nut 55 of the output shaft 13, so that it is compared with a ball bearing that receives a force in the radial direction. Thus, the allowable value of the belt clamping force is increased even with the same size. Therefore, the increase in the weight and size of the continuously variable transmission can be suppressed without increasing the size and gravity of the thrust bearing 71 and the thrust bearing 72. This effect corresponds to claim 1.

  The slide mechanism 20 of the continuously variable transmission 1 includes a slide block 51 that rotates by the operation of the actuator 60 and a fixed block 52 that is locked to the case 9. When the actuator 60 changes the position of the slide block 51 in the circumferential direction with respect to the fixed block 52, the slide block 51 is displaced in the axial direction, and the movable pulley 16b is advanced and retracted.

  With such a configuration, the movable pulley 16b can be advanced and retracted by rotating the slide block 51 by the actuator 60 such as a motor. In particular, since the position of the movable pulley 16b is determined by the turning angle of the slide block 51 in the axial direction, it is not necessary to always supply hydraulic pressure as compared with the configuration in which the movable pulley 16b is advanced and retracted using hydraulic pressure. The energy efficiency for shifting the transmission 1 can be increased. This effect corresponds to the third aspect.

  The fixed block 52 has a rib 521 extending radially outward, and the fixed block 52 is locked to the case 9 by engaging the rib 521 with a rib receiver 9 a formed on the case 9. Therefore, the movable pulley can be moved back and forth with a simple configuration. This effect corresponds to claim 4.

Second Embodiment
Next, the structure of the continuously variable transmission 1 of 2nd Embodiment of this invention is demonstrated.

  FIG. 4 is a cross-sectional view for explaining the secondary pulley 16 of the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment, and the description is abbreviate | omitted.

  A universal nut 75 is fitted to the output shaft 13. The universal nut 75 is slidably attached to the axial direction of the output shaft 13. The movable pulley 16 b side of the universal nut 75 is in contact with the thrust bearing 72.

  The output shaft 13 is provided with a ball bearing 70 that supports the output shaft 13 on the case 9. The ball bearing 70 has an inner race (inner ring) 70 a fitted to the output shaft 13 and an outer race (outer ring) 70 b fitted to the case 9. The ball bearing 70 is fixed to the output shaft 13 by a fixing nut 76.

  The movable nut 16 of the universal nut 75 is in contact with the inner race 70 a of the ball bearing 70 on the side opposite to the movable pulley 16 b in the axial direction.

  With such a configuration, in the second embodiment of the present invention, the movable pulley 16b clamps the V-belt 17 by the thrust generated by the slide cam 51. The reaction force of the holding force of the V-belt by the slide cam 51 is transmitted to the thrust bearing 71, the slide cam 51, the fixed cam 52, the thrust bearing 72 and the universal nut 75, and the inner race of the ball bearing 70 fixed by the fixed nut 76. 70a receives this reaction force. Thus, similarly to the first embodiment, in the secondary pulley 16, the thrust of the movable pulley 16 b is completed at the output shaft 13 and is not transmitted to the case 9.

  Accordingly, as in the first embodiment, the reaction force of the belt clamping force by the movable pulley 16b is received as the thrust force by the thrust bearing 71 and the thrust bearing 72, and the inner race 70a of the ball bearing 70 of the output shaft 13 is fixed. Therefore, the allowable value of the belt clamping force is increased. Accordingly, the increase in the weight and size of the continuously variable transmission can be suppressed without increasing the size and gravity of the thrust bearing 71 and the thrust bearing 72. This effect corresponds to claim 2.

  The embodiment of the present invention has been described above, but the above embodiment is merely one example of application of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. is not.

  Although the secondary pulley 16 has been described as an example in the above embodiment, the present invention can be similarly applied to the primary pulley 15.

  In the above-described embodiment, the belt-type continuously variable transmission mechanism 4 in which the V-belt 17 is spanned between the pulleys has been described as an example, but the present invention is not limited thereto. Instead of the V belt 17, a continuously variable transmission mechanism in which a chain is stretched between pulleys may be used.

DESCRIPTION OF SYMBOLS 1 continuously variable transmission 4 continuously variable transmission mechanism 9 case 9a rib receiving groove 12 input shaft 13 output shaft 15 primary pulley 15a fixed pulley (fixed sheave)
15b Movable pulley (movable sheave)
16 Secondary pulley 16a Fixed pulley (fixed sheave)
16b Movable pulley (movable sheave)
17 Belt (V belt)
21, 22 Slide mechanism 51 Slide cam 52 Fixed cam 53 Ring part 55 Fixing nut (ring part)
60 Actuator 70 Ball bearing 70a Inner race (inner ring, ring part)
70b Outer race (outer ring)
71 Thrust bearing (first bearing)
72 Thrust bearing (second bearing)
76 Swivel nut (ring)

Claims (3)

A set of pulleys, each having a groove formed by a fixed sheave fixed to the rotating shaft and a movable sheave slidably provided in the axial direction of the rotating shaft, is provided in the groove of the set of pulleys. A continuously variable transmission having a continuously variable transmission mechanism configured by winding a belt,
At least one of the set of pulleys includes a slide mechanism that moves the movable sheave forward and backward by an operation of an actuator.
The slide mechanism is
A slide block having a roller and rotating by the operation of the actuator;
A fixing block having a cam surface against which the roller abuts and locked to the case;
One end of the slide mechanism presses the movable sheave through a first bearing that receives a thrust force,
The rotating shaft has an annular portion that is fixed to a radially outer side of the rotating shaft and rotates coaxially, and the other end of the slide mechanism is connected to the annular ring via a second bearing that receives a thrust force. Supported by the department ,
When the actuator changes the circumferential position of the slide block with respect to the fixed block, the contact position of the roller with the cam surface changes, so that the slide block is displaced in the axial direction, and the movable Advance and retract the sheave,
The first bearing, the second bearing, and a position at which the roller and the cam surface abut on each other are stacked at substantially the same position in the axial direction. Continuously variable transmission. The continuously variable transmission according to claim 1, wherein the annular portion is an inner ring of a bearing fixed to the rotating shaft,
A continuously variable transmission, wherein an outer ring of the bearing is supported by a case housing the continuously variable transmission mechanism. The continuously variable transmission according to claim 2,
The fixed block has a rib extending radially outward,
The continuously variable transmission , wherein the fixing block is locked to the case by engaging the rib with a rib receiver formed on the case .

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