JP2007247911A - V-belt type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify/miniaturize a structure of a gear ratio variable mechanism by providing a driving pulley and a driven pulley with variable speed actuators driven by electric motors, in a V-belt type continuously variable transmission comprising a pulley fixed-half body fixed and supported on a rotating shaft, and a pulley movable half body axially movably supported on the rotating shaft in such a state that it is faced to the pulley fixed-half body and its rotation to the rotating shaft is inhibited, and holding a V-belt between the pulley fixed half body and the pulley movable half body. <P>SOLUTION: This V-belt type continuously variable transmission comprises a screw feeding mechanism composed of a rotatable/axially-unmovable screw portion rotatably supported on the rotating shaft in a state that its movement in the rotating shaft direction is inhibited, and rotated and driven by the electric motor through a reduction gear mechanism, and an unrotatable/axially movable screw portion held by the pulley movable half body movably in the rotating shaft direction in a state its rotation around the rotating shaft is inhibited, and fitted to the rotatable/axially unmovable screw portion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gear ratio variable mechanism for a V-belt continuously variable transmission.

  As an example of the prior art, the distance between the fixed half and the movable half of the drive pulley is controlled by a speed change actuator having an electric motor, and the distance between the fixed half and the movable half of the driven pulley is a gear. An example in which the setting is made in conjunction with a drive pulley via a mechanism is known (for example, see Patent Document 1). In this example, the interlocking mechanism is complicated.

JP 2001-330093 A (FIG. 6).

  The present invention eliminates the interlocking of the driving pulley and the driven pulley with the conventional complicated gear mechanism, and provides the transmission pulley driven by the electric motor on each of the driving pulley and the driven pulley, thereby simplifying the structure of the speed ratio variable mechanism. It is intended to reduce the size and size.

The present invention solves the above problems, and the invention according to claim 1
A pulley fixing half that is fixedly supported on the rotating shaft;
A pulley movable half that is supported so as to be movable in the axial direction in a state where rotation with respect to the rotation shaft is opposed to the pulley fixed half on the rotation shaft;
In a V-belt continuously variable transmission in which a V-belt is sandwiched between the pulley fixed half and the pulley movable half,
A rotatable axially non-movable screw portion that is rotatably supported by the rotary shaft in a state where movement in the rotational axis direction is prevented and is rotationally driven from the electric motor via a reduction gear mechanism;
A non-rotatable axially movable screw portion that is held by the movable pulley half so as to be movable in the rotational axis direction while being prevented from rotating about the rotational axis and is fitted to the rotatable axially nonmovable screw portion. The present invention relates to a V-belt type continuously variable transmission including a screw feed mechanism.

The invention according to claim 2 is the V-belt type continuously variable transmission according to claim 1,
An anti-rotation member is provided on the flange portion of the non-rotatable axially movable screw portion, and engages with an anti-rotation portion provided on the transmission case.

In the invention of claim 1,
Since the rotatable axially non-movable screw portion does not move in the axial direction, there is no need to increase the width of the final gear of the reduction gear mechanism that drives the screw portion, so the pulley movable half body drive mechanism is reduced in size. I can do it.

In the invention of claim 2,
A detent mechanism can be configured with a simple structure.

  FIG. 1 is a side view of a power unit 1 according to the present invention. This power unit is mounted on a motorcycle, and is supported by an overhead valve type four-stroke cycle two-cylinder water-cooled internal combustion engine 2 fixed to the vehicle and swingable up and down around a crankshaft 11. The transmission 3, the rear wheel support 4 and the rear wheel are integrated. An arrow F points to the front of the internal combustion engine 2.

  The internal combustion engine 2 of the power unit 1 includes a portion surrounded by a crankcase 6, a cylinder block 7, a cylinder head 8, and a cylinder head cover 9, and a cylinder oriented slightly upward at the front end of the crankcase 6. A block 7 is coupled, a cylinder head 8 is coupled to the front end of the cylinder block 7, and a cylinder head cover 9 is coupled to the front end of the cylinder head 8. A rear wheel shaft 60 is incorporated in the rear wheel support portion 4 and transmits the power of the internal combustion engine to the rear wheels.

FIG. 2 is a developed cross-sectional view of the AA cross section, the BB cross section, and the CC cross section of FIG. 1 drawn on one plane. The crankcase 6 includes a left crankcase 6L and a right crankcase 6R. The crankshaft 11 is rotatably supported by the journal bearing portions 10L and 10R of the left and right crankcases 6L and 6R. On the other hand, a piston 13 is slidably fitted in a cylinder hole 12 formed in the cylinder block 7. Both ends of the connecting rod 16 are pivotally supported by the crankshaft 11 and the piston 13 via the crankpin 14 and the piston pin 15, respectively.
When the piston 13 reciprocates, the crankshaft 11 rotates accordingly. A combustion chamber 20 is formed on the bottom surface of the cylinder head 8 facing the end surface of the piston 13, a spark plug 21 is mounted from the top of the cylinder head cover 9, and its tip faces the combustion chamber 20.

  The cylinder head 8 is formed with an intake port and an exhaust port connected to the combustion chamber 20. An intake valve that opens and closes the combustion chamber side opening of the intake port and an exhaust valve that opens and closes the combustion chamber side opening of the exhaust port are slidably fitted into the cylinder head 8. FIG. 2 shows an exhaust valve 27 for the right combustion chamber.

  In FIG. 2, a cam shaft 28 is supported between the cylinder head 8 and the cylinder head cover 9 in parallel with the crankshaft 11, and an intake valve and an exhaust valve are driven to open and close by the cam provided on the cam shaft 28. FIG. 2 shows an exhaust cam 29. The camshaft 28 is cranked by the crankshaft 11 by an endless chain 32 wound between a drive sprocket 30 provided at the right portion of the crankshaft 11 and a driven sprocket 31 provided at the right end of the camshaft 28. The shaft 11 is rotationally driven at a half rotational speed.

  A right crankcase cover 33 is provided outside the right crankcase 6R, and a generator 36 is constituted by a stator 34 fixed to the inner surface thereof and a rotor 35 fixed to the crankshaft 11 and surrounding the stator 34. Yes. A driven gear 37 provided adjacent to the generator 36 is a gear for receiving a rotational drive from a starter motor (not shown).

  The transmission case 38 that houses the transmission 3 in the power unit 1 includes a right transmission case 38R, a left transmission case 38L, and a partition wall 38S. The right transmission case 38R is rotatably supported on the left and right of the crankcase 6. On the left side of the crankcase, as shown in FIG. 5, the left crankcase 6L is rotatably supported by a ball bearing 40 held by a support metal 39 attached by a bolt 22, and on the right side of the crankcase, It is rotatably supported by connection hardware 43A and 43B supported by a roller bearing 42 held by a support hardware 41 attached to the right crankcase cover 33. The connection hardware 43A and 43B are integrated with bolts. A transmission case cover 23 is provided outside the left transmission case 38L.

  Both the left transmission case 38L and the partition wall 38S are coupled to the right transmission case 38R by bolts. The rear end portion of the transmission case 38 of the transmission 3 is a rear wheel support portion 4. The transmission 3 includes a V-belt type continuously variable transmission 45 and a gear reducer 46. The V-belt type continuously variable transmission 45 has a front half portion provided between the left transmission case 38L and the right transmission case 38R, and a second half portion provided between the left transmission case 38L and the partition wall 38S. The speed reducer 46 is provided between the partition wall 38S and the right transmission case 38R.

  The drive shaft of the V-belt continuously variable transmission 45 is the crankshaft 11 itself, and a drive pulley 47 of the V-belt continuously variable transmission 45 is provided at the left end of the crankshaft 11. The drive pulley 47 includes a fixed half 48 and a movable half 49. The driven shaft 50 of the V-belt type continuously variable transmission 45 is rotatably supported by the left transmission case 38L, the partition wall 38S, and the right transmission case 38R. A driven pulley 52 of a V-belt type continuously variable transmission 45 is provided on the driven shaft 50 via a centrifugal clutch 51. The driven pulley 52 includes a fixed half 53 and a movable half 54. An endless V-belt 55 is stretched between the driving pulley 47 and the driven pulley 52, and the rotation of the driving pulley 47 is transmitted to the driven pulley 52. When the rotational speed of the driven pulley 52 exceeds a predetermined rotational speed, the centrifugal clutch 51 provided between the driven pulley 52 and the driven shaft 50 is connected, and the driven shaft 50 starts to rotate.

  The gear reducer 46 is constituted by a gear group provided on three rotating shafts. The first shaft is the right half of the driven shaft 50 of the V-belt type continuously variable transmission 45 supported by the right transmission case 38R and the partition wall 38S, and a small diameter gear 56 is formed. The second shaft is an intermediate shaft 57 that is rotatably supported by the right transmission case 38R and the partition wall 38S, and the large-diameter gear 58 that meshes with the small-diameter gear 56 of the driven shaft 50 is integrally fitted. In addition, a small diameter gear 59 is formed adjacent thereto. The third shaft is a rear wheel shaft 60 that is rotatably supported by a partition wall 38S, a right transmission case 38R, and an arm 62 coupled to the connection hardware 43A. A large-diameter gear 61 that meshes with the small-diameter gear 59 of the intermediate shaft 57 is fitted to the rear wheel shaft 60. With this configuration, the torque of the driven shaft 50 is decelerated through the reduction gear group and transmitted to the rear wheel shaft 60. The rear wheel 5 is integrally fixed to the rear wheel shaft 60.

FIG. 3 is an enlarged cross-sectional view showing a state where the drive pulley 47 and its peripheral members are assembled to the crankshaft 11. The drive pulley 47 includes a drive pulley fixed half 48 and a drive pulley movable half 49. The left half of the crankshaft 11 is formed with a first small diameter portion 11A delimited by a step 11a and a step 11b, and a second small diameter portion 11B delimited by a step 11b and a crankshaft end surface portion 11c. .
A spline 11d is provided at the end of the first small diameter portion 11A, and a spline 11e is provided at the end of the second small diameter portion 11B.

  The inner ring of the ball bearing 63, the first support sleeve 64, and the guide sleeve 65 are fitted into the first small diameter portion 11A, and the second support sleeve 66 and the driving pulley are fixed to the second small diameter portion 11B. A half 48 is fitted. The sleeves 64, 65 and 66 are made of steel, and the driving pulley fixing half 48 is made of aluminum. Each of the above members is fastened to the screw hole at the end of the crankshaft 11 with a bolt 68 screwed through a washer 67, and is fixed so as not to move in the direction of the crankshaft 11. Of the above members, the guide sleeve 65 is fitted into the spline 11d of the first small-diameter portion 11A via the spline 65a on the inside thereof. The drive pulley fixing half 48 is fitted to the spline 11e of the second small diameter portion 11B via a spline 48a inside the center hole. Therefore, these members are fixed so as not to rotate relative to the crankshaft 11. The driving pulley fixing half 48 rotates with the crankshaft 11.

  The drive pulley movable half 49 includes an umbrella-shaped portion 49A that faces the fixed half, and a cylindrical portion 49B that surrounds the sleeves 64, 65, 66 and is integrally formed with the umbrella-shaped portion 49A. Yes. The umbrella portion 49A is made of an aluminum alloy, and the tubular portion 49B is made of steel. The umbrella-shaped portion 49A is integrally coupled to the flange portion of the cylindrical portion 49B by a rivet 44. A projecting spline 49Ba projecting inward is formed on the inner side of the cylindrical portion 49B of the driving pulley movable half 49, and is fitted to an outer spline 65b formed on the outer periphery of the guide sleeve 65. Since the outer spline 65b of the guide sleeve 65 is a long spline in the axial direction, the protruding spline 49Ba can slide in the axial direction in the guide groove. Accordingly, the drive pulley movable half 49 cannot be rotated relative to the crankshaft 11, but is held so as to be movable in the axial direction. The drive pulley movable half 49 receives torque from the crankshaft 11 and rotates together with the crankshaft 11 by the splines 11d, 65a, 65b, and 49Ba. Grease is applied to the groove of the outer spline 65b of the guide sleeve 65 to smooth the sliding of the protruding spline 49Ba of the movable half cylindrical portion 49B. Seals 69 are provided at both ends of the movable half-body cylindrical portion 49B to prevent the grease from leaking out and preventing dust from entering.

  4 is an enlarged cross-sectional view of only the shaft portion (excluding the ball bearing and the like) of the IV-IV cross section of FIG. The spline 11d of the crankshaft 11 and the inner spline 65a of the guide sleeve 65 meshing with each other are involute splines, and the projecting spline 49Ba that meshes with the outer spline 65b of the guide sleeve 65 is also an involute spline. A gap 70 is provided between the outer peripheral surface of the guide sleeve and the inner peripheral surface of the movable half cylindrical shaft portion 49B in order to enable movement of air and grease accompanying the movement of the protruding spline.

  In FIG. 3, a cylindrical ball bearing outer ring holding member 75 holds the outer ring of the ball bearing 63 attached to the crankshaft 11 so as not to move in the axial direction. A female thread cylindrical member 76 is integrated with the flange portion 75a on the outer periphery of the ball bearing outer ring holding member 75 by welding. An annular gear 77 is coupled to a flange portion 76 a on the outer periphery of the female screw cylindrical member 76 by a bolt 78. The ball bearing outer ring holding member 75, the female screw cylindrical member 76, and the annular gear 77 are integrated to form a female screw assembly 79, supported by the crankshaft 11 by the ball bearing 63, and in a state in which axial movement is impossible. Rotation independent of the axis 11 can be performed. The annular gear 77 of the female screw assembly 79 is rotationally driven by a small-diameter gear 102 of a second intermediate gear 104 that forms part of a transmission actuator 90 described later.

  An inner ring of a ball bearing 72 is mounted on the outer periphery of the cylindrical portion 49B of the movable half 49 of the driving pulley so as not to be relatively movable in the axial direction, and a male screw cylindrical member 80 is integrated with the outer ring of the ball bearing 72 on the inner periphery thereof. Is holding. The outer thread portion of the male thread cylindrical member 80 is engaged with the inner thread portion of the female thread cylindrical member. An anti-rotation member 81 is coupled to the flange portion 80 a at the end of the male screw cylindrical member 80 by a bolt 82. The male screw cylindrical member 80, the rotation preventing member 81, and the bolt 82 are integrated to form a male screw assembly 83. The protrusions 81b formed on both sides of the rotation stopper shaft 81a of the rotation stopper 81 are engaged with the rotation guide rail 84 provided on the right transmission case 38R shown in FIG. 6 (side view). is doing. As a result, when the female screw assembly 79 rotates, the male screw assembly 83 can only move in the direction of the crankshaft axis while preventing rotation around the crankshaft. The female screw assembly 79 and the male screw assembly 83 constitute a screw type feed mechanism.

  A front stopper 81 c is integrally formed on the arm portion of the rotation preventing member 81. This is for detecting the limit of the backward movement of the male screw assembly 83. A rear stopper 85 is attached to the rear end of the shaft portion 81 a of the rotation preventing member 81 with a bolt 86. This is for detecting the limit of forward movement of the male screw assembly 83. The anti-rotation member 81 and the anti-rotation guide rail 84 constitute an anti-rotation mechanism 88.

  The anti-rotation member 81 is formed with an extension 81d outside the shaft portion. The extension 81d is in contact with the tip of the bar-like member protruding from the end of the stroke sensor 87 for detecting the current position of the movable half. The stroke detection is performed by detecting the displacement of the rod-shaped member pushed out from the end of the stroke sensor 87 by a spring. The peripheral part of the rod-shaped member is covered with rubber bellows. The base of the stroke sensor 87 is connected to the right transmission case 38R.

FIG. 5 is a developed sectional view of the front half of the transmission 3. FIG. 6 is an arrangement diagram of gears and the like when the front half of the transmission is viewed from the side. The female screw assembly 79 is rotationally driven by a speed change actuator 90. The speed change actuator 90 includes an electric motor 91 and a gear reduction mechanism 92.
The rotation of the electric motor 91 is automatically controlled according to the vehicle speed, the throttle opening, and the rotational speed of the internal combustion engine. A reduction gear case 93 is attached to the right transmission case 38R. This case includes a right case member 93R, a left case member 93L, and an end case member 93E. A reduction gear chamber 94 is formed in a portion sandwiched between these case members. An electric motor 91 is attached to the right case member 93R of the reduction gear case 93 via the attachment plate 95, and a pinion 96 engraved on the rotation shaft of the motor enters the reduction gear chamber 94.

  A first intermediate gear 99 in which a large-diameter gear 97 meshing with the pinion 96 and a small-diameter gear 98 adjacent to the pinion 96 are integrally formed is rotatably supported by a reduction gear case 93 via a ball bearing 100.

  A second intermediate gear 104 in which a large-diameter gear 101 that meshes with the small-diameter gear 98 and a small-diameter gear 102 that is integrally adjacent to the small-diameter gear 98 are integrally fitted with the rotary shaft 103 is mounted on the reduction gear case 93. The bearing 105 is rotatably supported. The annular gear 77 of the female screw assembly 79 is meshed with the small-diameter gear 102.

  When the electric motor 91 rotates in the positive direction according to the control command, power is transmitted via the first and second intermediate gears 99 and 104, the female screw assembly 79 rotates, and the screw of the female screw cylindrical member 76 is rotated. The threaded portion of the male screw cylindrical member 80 of the non-rotatable male screw assembly 83 meshing with the portion receives thrust in the crankshaft direction from the threaded portion of the female screw cylindrical member 76, and the male screw assembly 83 is Move in the axial direction. The thrust received by the threaded portion of the male threaded cylindrical member 80 is transmitted to the movable half via the ball bearing 72, the drive pulley movable half 49 moves in the direction of the crankshaft axis, and the drive pulley fixed half 48 The interval is narrowed and the V-belt is moved in the outer circumferential direction. When the electric motor 91 rotates in the reverse direction in accordance with the control command, the interval between the drive pulley fixed half 48 and the drive pulley movable half 49 is widened by the reverse process, and the V-belt moves in the center direction. .

  FIG. 7 is a developed sectional view of the rear half of the transmission 3. The driven pulley 52 includes a driven pulley fixed half 53 and a driven pulley movable half 54. The driven pulley fixing half 53 includes an aluminum umbrella-shaped portion 53A and a steel tubular portion 53B. The driven pulley movable half 54 is also composed of an aluminum umbrella-shaped portion 54A and a steel tubular portion 54B. The umbrella-shaped portion of the fixed half 53 is fastened to the end of the cylindrical portion by a bolt 147, and the umbrella-shaped portion of the movable half 54 is integrally formed at the end of the cylindrical portion by casting.

  The driven shaft 50 is provided with step portions 50a, 50b and 50c. The cylindrical portion 53B of the driven pulley fixing half 53 is rotatable with respect to the driven shaft 50 by the ball bearing 110 provided on the outer periphery of the step portion 50a and the roller bearing 111 provided on the outer periphery of the step portion 50b. It is supported.

A cylindrical part 54B of the movable half is slidably fitted on the outer periphery of the cylindrical part 53B of the fixed half. Pins 112 are implanted at four locations on the outer periphery of the cylindrical portion 53B of the fixed half body. The cylindrical portion 54B of the movable half body is provided with cam grooves 113 that penetrate in the radial direction of the cylindrical portion 54B and extend at an inclination with respect to the axial direction at four locations in the circumferential direction. The head of the pin 112 is inserted.
As a result, the driven pulley movable half 54 is restricted by the pin 112 and can be moved relative to the driven pulley fixed half 53 in the axial direction, and the circumferential relative movement corresponding to the angle of the cam groove can be performed. Is possible.

  A cylindrical member 114 is fixed to the outer periphery of the cylindrical portion 54B of the driven pulley movable half 54 so as not to move in the axial direction, and covers the cam groove 113 of the cylindrical portion 54B. In order to assist the sliding of the driven pulley movable half 54 restricted by the pin 112, grease is applied to the cam groove 113, and seal materials for preventing oil leakage are provided inside both ends of the cylindrical member 114. It is provided. An inner ring of the ball bearing 115 is held on the outer periphery of the right end of the cylindrical member 114. An annular member 116 that abuts on the outer ring of the ball bearing 115 is provided.

  The inner ring of the ball bearing 117 is fixed to the stepped portion on the outer periphery of the left end of the cylindrical portion 53B of the driven pulley fixing half 53 by a nut 118. A male thread cylindrical member 120 is fixed to the outer ring of the ball bearing 117 so as not to move in the axial direction. The rotation of the male thread cylindrical member 120 is blocked by the ball bearing 117 with respect to the driven pulley 53. An anti-rotation member 121 is fixed to the male screw cylindrical member 120, and its end is fixed to the transmission case 38 (not shown). Therefore, the male screw cylindrical member 120 can remain stationary with respect to the transmission case 38 independently of the driven shaft 50 and the driven pulley 52 in both the axial direction and the rotational direction.

  The male screw cylindrical member 122 covers the male screw portion of the male screw cylindrical member 120 in a screwed state. An annular gear 123 is fixed to the flange portion 122 a of the female screw cylindrical member 122 by a bolt 124. A female screw assembly 125 is formed by the female screw cylindrical member 122, the annular gear 123, and the bolt 124.

  The annular gear 123 is rotated by being driven by a small-diameter gear 142 of a second intermediate gear 144, which will be described later, and the female screw portion of the female screw cylindrical member 122 receives thrust from the fixed male screw portion 120, and the female screw cylinder. The member 122 is driven in the axial direction while rotating. A disc spring 126 is interposed between the end of the female screw cylindrical member 122 and the annular member 116 fixed to the outer periphery of the ball bearing 115. Accordingly, the driven pulley movable half 54 is driven in the axial direction via the disc spring 126, the annular member 116, the ball bearing 115, and the cylindrical member 114 by the axial movement of the female screw cylindrical member 122. The male screw cylindrical member 120 and the female screw assembly 125 constitute a screw type feeding mechanism.

  The female screw assembly 125 is rotationally driven by a speed change actuator 130. The speed change actuator 130 includes an electric motor 131 and a gear reduction mechanism 132. The rotation of the electric motor 131 is automatically controlled according to the vehicle speed, the throttle opening, and the rotational speed of the internal combustion engine. The strain of the disc spring 126 is measured to detect the pressing force of the driven pulley movable half against the V-belt and fed back for control.

  A reduction gear case 133 is attached to the left transmission case 38L, and a reduction gear chamber 134 is formed. The electric motor 131 is attached to the reduction gear case 133 via the attachment plate 135, and a pinion 136 engraved on the rotation shaft of the motor enters the reduction gear chamber 134. A first intermediate gear 139 in which a large-diameter gear 137 meshing with the pinion 136 and a small-diameter gear 138 adjacent thereto is integrally formed is rotated via a ball bearing 140 to the left transmission case 38L and the reduction gear case 133. Supported as possible.

  A second intermediate gear 144 in which a large-diameter gear 141 that meshes with the small-diameter gear 138 and a small-diameter gear 142 that is integrally adjacent to the large-diameter gear 138 are fitted into the rotary shaft 143 is integrated into the left transmission case 38L. And a reduction gear case 133 is rotatably supported via a ball bearing 145. The small-diameter gear 142 is a gear having a long axial dimension, and can be engaged with the annular gear 123 of the female screw assembly 125 at an arbitrary position in the axial direction.

  FIG. 8 is an arrangement diagram of gears and the like when the rear half of the transmission is viewed from the side. In the state of FIG. 7, when the electric motor 131 rotates in the positive direction according to the control command, power is transmitted via the first and second intermediate gears 139 and 144 and meshes with the threaded portion of the male threaded cylindrical member 120. The internal thread assembly 125 rotates, the internal thread assembly 125 itself moves in the axial direction of the driven shaft 50, and the driven pulley is movable via the disc spring 126, the annular member 116, the ball bearing 115, and the cylindrical member 114. The half body 54 is pushed, the space | interval with the drive pulley fixed half body 53 is narrowed, and a V belt is moved to an outer peripheral direction. When the electric motor 131 rotates in the reverse direction in response to the control command, the interval between the driven pulley fixed half 53 and the driven pulley movable half 54 is increased by the reverse process to the above, and the V-belt moves in the center direction. . The left-side stopper 121a of the female screw assembly is provided at the other end of the anti-rotation member 121, and detects the limit of the leftward movement of the female screw assembly.

  An inner rotating member 51A of the centrifugal clutch 51 is fixed with a bolt 147 to the right end surface of the driven pulley fixing half. The outer rotating member 51B of the centrifugal clutch 51 is fitted to the driven shaft 50 through the spline 148 at a position facing the inner rotating member 51A so as not to be relatively rotatable. The outer periphery of the outer rotating member 51B covers the inner rotating member 51A. When the driven pulley reaches a predetermined number of rotations, the rotation is transmitted through the inner rotating member 51A and the outer rotating member 51B, and the driven shaft 50 starts rotating. As described with reference to FIG. 2, the rotation of the driven shaft 50 is decelerated via the gear of the gear reducer 46, transmitted to the rear wheel shaft 60, and the rear wheel 5 is driven.

As described in detail above, in the continuously variable transmission according to the present embodiment, the driving pulley and the driven pulley are stopped by the complicated gear mechanism as in the conventional art, and the driving pulley and the driven pulley are each driven by an electric motor. A variable speed actuator is provided to simplify the structure. The following effects are brought about by the configuration of the present embodiment.
(1) It is easy to secure the space for arranging the feed mechanism, and it is possible to secure the cooling performance of the electric motor.
(2) It is possible to effectively utilize the space on the outer surface side of the two umbrella-shaped portions facing each other of the driven pulley.
(3) The lateral pressure of the V belt can be adjusted, and the durability of the belt can be improved.
(4) Since the thrust can be adjusted by a simple structure comprising springs, it is possible to easily optimize the belt side pressure at all times.
(5) Pulley control according to the belt side pressure adjustment amount can be easily performed.

It is a side view of the power unit 1 which concerns on this invention. FIG. 2 is a developed cross-sectional view of the AA cross section, the BB cross section, and the CC cross section of FIG. 1 drawn on one plane. FIG. 4 is an enlarged cross-sectional view showing a state where the drive pulley 47 and its peripheral members are assembled to the crankshaft 11. It is an expanded sectional view of only the shaft part of the IV-IV section of FIG. FIG. 3 is a cross-sectional development view of the front half of the transmission 3. FIG. 3 is an arrangement diagram of gears and the like when the front half of the transmission is viewed from the side. 3 is a developed sectional view of the rear half of the transmission 3. FIG. FIG. 6 is an arrangement diagram of gears and the like when the rear half of the transmission is viewed from the side.

Explanation of symbols

, 11 ... Crankshaft, 45 ... V belt type continuously variable transmission, 47 ... Drive pulley, 48 ... Drive pulley fixed half, 49 ... Drive pulley movable half, 50 ... Drive shaft, 51 ... Centrifugal clutch, 52 ... Drive Pulley, 53 ... driven pulley fixed half, 54 ... driven pulley movable half, 55 ... endless V-belt, 76 ... female screw cylindrical member, 79 ... female screw assembly, 80 ... male screw cylindrical member, 83 ... male screw Assembly: 87 ... Stroke sensor, 90: Variable speed actuator, 91: Electric motor, 120 ... Male screw cylindrical member, 122 ... Female screw cylindrical member, 125 ... Female screw assembly, 126 ... Belleville spring, 130 ... Variable speed actuator, 131 ... Electric motor.

Claims (2)

A pulley fixing half that is fixedly supported on the rotating shaft;
A pulley movable half that is supported so as to be movable in the axial direction in a state where rotation with respect to the rotation shaft is opposed to the pulley fixed half on the rotation shaft;
In a V-belt continuously variable transmission in which a V-belt is sandwiched between the pulley fixed half and the pulley movable half,
A rotatable axially non-movable screw portion that is rotatably supported by the rotary shaft in a state where movement in the rotational axis direction is prevented and is rotationally driven from the electric motor via a reduction gear mechanism;
A non-rotatable axially movable screw portion that is held by the movable pulley half so as to be movable in the rotational axis direction while being prevented from rotating about the rotational axis and is fitted to the rotatable axially nonmovable screw portion. A V-belt type continuously variable transmission comprising a screw feed mechanism.   The V-belt type continuously variable transmission according to claim 1, wherein a non-rotating member is provided on a flange portion of the non-rotatable axially movable screw portion and engages with a non-rotating portion provided on a transmission case. Machine.

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