Continuously variable transmission

Abstract

A continuously variable transmission 100 comprising a movable drive pulley 110 that approaches or separates from a fixed drive pulley 102, and a lamp member 125 that is positioned on a second direction D2 side of the movable drive pulley 110, wherein: the lamp member 125 comprises a lamp plate 130 that is positioned on the second direction D2 side of the movable drive pulley 110 and has a lamp-side sliding surface 132 on which a weight 120 slides, and further comprises a boss part 135 that extends from the lamp plate 130 in a first direction D1, is integrated with the lamp plate 130, and is formed in a cylindrical shape; and the movable drive pulley 110 is externally fitted to the boss part 135 and slides along an outer-peripheral surface 135S of the boss part 135.

Description

Continuously variable transmission

[0001] The present invention relates to a continuously variable transmission that can be mounted on a saddle-type vehicle.

[0002] Conventionally, continuously variable transmissions that can be mounted on saddle-type vehicles such as motorcycles have been known. For example, in Patent Document 1, a fixed drive pulley that rotates integrally with a crankshaft rotated by a power source (e.g., an engine), a movable drive pulley that approaches or separates from the fixed drive pulley, a lamp plate that rotates integrally with the crankshaft, and a weight that is disposed between the lamp plate and the movable drive pulley and moves in the radial direction are disclosed. The movable drive pulley is movably provided on a boss portion fixed to the outer peripheral portion of the crankshaft and is configured to move along the outer peripheral surface of the boss portion.

[0003] Japanese Patent No. 7348427

[0004] By the way, in a conventional continuously variable transmission, with a weight, a boss portion, and a lamp plate attached to the movable drive pulley, it is assembled to the crankshaft, a V-belt is inserted, the fixed drive pulley is assembled to the tip of the crankshaft, and finally fastened with a nut to the tip of the crankshaft, so that the boss portion is fixed to the lamp plate. However, since the boss portion and the lamp plate are formed of two members, buckling may occur in the boss portion when the rotational driving force due to the rotation of the crankshaft is transmitted, and there is a possibility that sufficient axial force cannot be maintained.

[0005] The present invention has been made in view of such points, and an object thereof is to provide a continuously variable transmission capable of suppressing the occurrence of buckling in a boss portion on which a movable drive pulley is movably provided.

[0006] The continuously variable transmission according to the present invention has a drive pulley having a fixed drive pulley that rotates integrally with a crankshaft that rotates by a power source, and a movable drive pulley that is positioned opposite to the fixed drive pulley and moves toward or toward the fixed drive pulley along the crankshaft, and when the direction in which the movable drive pulley moves is defined as the direction of movement, the direction in which the movable drive pulley approaches the fixed drive pulley is defined as the first direction, and the direction in which the movable drive pulley moves toward the fixed drive pulley is defined as the second direction, a part of which is greater than the movable drive pulley The device comprises a ramp member located on the side of the second direction, and a weight sandwiched between the movable drive pulley and the ramp member and movable in the radial direction of the movable drive pulley, wherein the ramp member comprises a ramp plate located on the side of the second direction from the movable drive pulley and having a sliding surface on which the weight slides, and a boss portion extending from the ramp plate in the first direction, integrated with the ramp plate, and formed in a cylindrical shape, and the movable drive pulley is fitted onto the boss portion and configured to move along the outer circumferential surface of the boss portion.

[0007] In the continuously variable transmission according to the present invention, the boss portion and the ramp plate are integrated. In this embodiment, since the boss portion and the ramp plate are integrated, the number of fastening surfaces is reduced. As a result, buckling of the boss portion is suppressed when rotational driving force is transmitted due to the rotation of the crankshaft, and sufficient axial force can be maintained in the ramp member.

[0008] According to the present invention, it is possible to provide a continuously variable transmission that can suppress buckling of the boss portion on which the movable drive pulley is movably mounted.

[0009] Figure 1 is a schematic cross-sectional view showing the configuration of a continuously variable transmission and centrifugal clutch according to the first embodiment. Figure 2 is an enlarged cross-sectional view showing a part of the continuously variable transmission according to the first embodiment, showing a state in which the weight is located radially inward. Figure 3 is an enlarged cross-sectional view showing a part of the continuously variable transmission according to the first embodiment, showing a state in which the weight is located radially outward. Figure 4 is a perspective view of the movable drive pulley according to the first embodiment. Figure 5 is a plan view of the movable drive pulley according to the first embodiment. Figure 6 is a perspective view of the ramp plate according to the first embodiment. Figure 7 is a plan view of the ramp plate according to the first embodiment. Figure 8 is a perspective view of the weight according to the first embodiment. Figure 9 is a perspective view of the weight according to the first embodiment. Figure 10 is a perspective view of the weight according to the first embodiment. Figure 11 is a side view of the weight according to the first embodiment. Figure 12 is a plan view of the movable drive pulley and weight according to the first embodiment. Figure 13 is a perspective view of the movable drive pulley and weight according to the first embodiment. Figure 14 is a plan view of the ramp plate and weight according to the first embodiment. Figure 15 is a perspective view of the ramp plate and weight according to the first embodiment. Figure 16 is a plan view showing the positional relationship between the movable drive pulley, weight and ramp plate during acceleration according to the first embodiment. Figure 17 is a plan view showing the positional relationship between the movable drive pulley, weight and ramp plate during deceleration according to the first embodiment. Figure 18 is a plan view showing the positional relationship between the movable drive pulley, weight and ramp plate during deceleration according to a modified example. Figure 19 is a plan view showing the positional relationship between the movable drive pulley, weight and ramp plate during acceleration according to the second embodiment. Figure 20 is a plan view showing the positional relationship between the movable drive pulley, weight and ramp plate during deceleration according to the second embodiment.

[0010] Hereinafter, embodiments of the continuously variable transmission according to the present invention will be described with reference to the drawings. Naturally, the embodiments described herein are not intended to particularly limit the present invention. Furthermore, the same reference numerals are used for components and parts that perform the same function, and redundant explanations are omitted or simplified as appropriate.

[0011] <First Embodiment> The continuously variable transmission 100 of this embodiment is a device mainly used in saddle-type vehicles (for example, motorcycles such as scooters). As shown in Figure 1, the continuously variable transmission 100 is installed between a power source (for example, an engine or electric motor) and a centrifugal clutch 200 on the rear wheel side, which is the drive wheel. The continuously variable transmission 100 transmits rotational driving force to the centrifugal clutch 200 while continuously changing the reduction ratio with respect to the engine speed.

[0012] As shown in Figure 1, the continuously variable transmission 100 comprises a drive pulley 101, a weight 120, a ramp member 125, a V-belt 140, a driven pulley 150, and a sliding member 180. The weight 120 is an example of an intermediate member.

[0013] In the following description, the direction in which the movable drive pulley 110 of the continuously variable transmission 100 moves (the direction in which it approaches and moves away from the fixed drive pulley 102) is referred to as the direction of movement D, the direction in which the movable drive pulley 110 approaches the fixed drive pulley 102 is referred to as the first direction D1, and the direction in which the movable drive pulley 110 moves away from the fixed drive pulley 102 is referred to as the second direction D2. Furthermore, the radial direction refers to the radial direction of the movable drive pulley 110 and the ramp plate 130. Also, the direction in which the fixed drive pulley 102, the movable drive pulley 110, and the ramp plate 130 rotate is referred to as the rotation direction L (see Figure 4, etc.). However, the above directions are merely defined for the convenience of explanation and do not limit the installation configuration of the continuously variable transmission 100 in any way, nor do they limit the present invention in any way.

[0014] As shown in Figure 1, the drive pulley 101 is mounted on a crankshaft 90 that is rotated by a power source. The drive pulley 101 rotates directly by the rotational driving force of the power source. The drive pulley 101 has a fixed drive pulley 102 and a movable drive pulley 110 positioned opposite the fixed drive pulley 102.

[0015] As shown in Figure 1, the fixed drive pulley 102 rotates by sandwiching the V-belt 140 together with the movable drive pulley 110. The fixed drive pulley 102 is constructed by forming a metal material (for example, aluminum) into a conical cylindrical shape. The fixed drive pulley 102 includes a disc portion 103, a conical portion 106, and fins 107.

[0016] As shown in Figures 2 and 3, the disc portion 103 connects the fixed drive pulley 102 to the crankshaft 90 and supports the conical portion 106. The disc portion 103 is a flat plate formed in the shape of a ring. The fixed drive pulley 102 has a fitting hole 103H formed through it into which the crankshaft 90 is inserted. The inner circumferential surface 103A that forms the fitting hole 103H has a pulley-side spline portion 103S that spline-fits with the crankshaft 90. The pulley-side spline portion 103S is, for example, a plurality of grooves extending in the direction of movement D. The fitting hole 103H and the pulley-side spline portion 103S are provided on the disc portion 103. The disc portion 103 abuts against the end portion 135D1 in the first direction D1 of the boss portion 135 of the ramp member 125, which will be described later. The disc portion 103 is fixed to the crankshaft 90 in contact with the end portion 135D1. The disc portion 103 is fixed to the crankshaft 90 by a nut 105. As a result, the fixed drive pulley 102 always rotates integrally with the crankshaft 90.

[0017] As shown in Figure 2, the conical portion 106, together with the conical portion 112 of the movable drive pulley 110, sandwiches the V-belt 140. The conical portion 106 is formed in a tapered shape that slopes radially outward from the disc portion 103. The conical portion 106 slopes so that it moves away from the movable drive pulley 110 as it moves away from the disc portion 103 (towards the first direction D1). The conical portion 106 has a plurality of fins 107 formed on the surface 106D1 opposite to the surface 106D2 facing the movable drive pulley 110. The fins 107 are members for dissipating heat from the fixed drive pulley 102 to the outside. The fins 107 are arranged radially on the outside of the disc portion 103, centered on the axis of the crankshaft 90. The disc portion 103, the conical portion 106, and the fins 107 are integrally molded.

[0018] As shown in Figure 2, the movable drive pulley 110 rotates by sandwiching the V-belt 140 together with the fixed drive pulley 102. The movable drive pulley 110 is constructed by forming a metal material (for example, aluminum) into a conical cylindrical shape. The movable drive pulley 110 is fitted onto the boss portion 135 of the ramp member 125, which will be described later. The movable drive pulley 110 is configured to slide along the outer circumferential surface 135S of the boss portion 135. The movable drive pulley 110 has a center cylindrical portion 111, a conical portion 112, and a housing portion 113.

[0019] As shown in Figure 2, the center cylindrical portion 111 is the part into which the boss portion 135 of the lamp member 125 is inserted and which supports the conical portion 112. The center cylindrical portion 111 is formed in a cylindrical shape. The center cylindrical portion 111 is mounted on the boss portion 135 via a sliding member 180. The center cylindrical portion 111 is mounted on the sliding member 180 and the boss portion 135 so as to be movable in the direction of movement D and rotatable in the direction of rotation L. As a result, the movable drive pulley 110 is provided so as to be movable in the direction of movement D and rotatable in the direction of rotation L along the crankshaft 90, as shown in Figure 3. The movable drive pulley 110 is configured to move closer to or further away from the fixed drive pulley 102 along the crankshaft 90.

[0020] As shown in Figure 2, the conical portion 112, together with the conical portion 106 of the fixed drive pulley 102, sandwiches the V-belt 140. The conical portion 112 is formed in a tapered shape that slopes radially outward from the center cylindrical portion 111. The conical portion 112 is sloped so that it moves away from the fixed drive pulley 102 as it moves away from the crankshaft 90. The conical portion 112 has a surface 112D1 that faces the fixed drive pulley 102. The V-belt 140 is sandwiched between the surface 112D1 of the conical portion 112 of the movable drive pulley 110 and the surface 106D2 of the conical portion 106 of the fixed drive pulley 102.

[0021] As shown in Figure 2, the housing portion 113 is formed on the side of the conical portion 112 opposite to the side facing the fixed drive pulley 102. The housing portion 113 is a part that movably houses the weight 120 and the lamp-side protruding piece 133 of the lamp plate 130, which will be described later. As shown in Figures 4 and 5, the housing portion 113 is formed as a concave recess that protrudes from the second direction D2 side surface 112D2 of the conical portion 112. Three housing portions 113 are formed at equal intervals along the circumferential direction of the conical portion 112. The housing portions 113 are located radially outward from the center cylindrical portion 111. The three housing portions 113 are each formed in the same shape. The housing portion 113 includes a weight housing portion 118 and a protruding piece housing portion 116.

[0022] As shown in Figures 4 and 5, the weight housing portion 118 houses the weight 120 (see also Figures 12 and 13). The weight housing portion 118 is a recess that is recessed in the first direction D1. The weight housing portion 118 includes a pulley-side sliding surface 114, a weight receiving surface 115, and a radially inner surface 119. The pulley-side sliding surface 114, the weight receiving surface 115, and the radially inner surface 119 define the weight housing portion 118. The pulley-side sliding surface 114, the weight receiving surface 115, and the radially inner surface 119 define a part of the housing portion 113. The pulley-side sliding surface 114, together with the ramp-side sliding surface 132 of the ramp plate 130 (described later), is a surface that clamps the weight 120 in a radially movable state. The weight 120 slides on the pulley-side sliding surface 114. The pulley-side sliding surface 114 is a curved surface that extends radially. The pulley-side sliding surface 114 is inclined such that the radially outer portion is located closer to the ramp plate 130 (i.e., towards the second direction D2) than the radially inner portion. The pulley-side sliding surface 114 is continuous with the weight receiving surface 115 and the radially inner surface 119.

[0023] As shown in Figures 4 and 5, the weight receiving surface 115 is the part that receives the first end face 122C (see Figure 16) of the weight 120 sliding on the pulley-side sliding surface 114 and receives the rotational driving force of the ramp plate 130. The first end face 122C is an example of a surface on the downstream side in the rotation direction L. The weight receiving surface 115 extends from the surface 112D2 on the second direction D2 side of the conical portion 112 in the second direction D2. The weight receiving surface 115 is located downstream of the pulley-side sliding surface 114 in the rotation direction L. The weight receiving surface 115 extends in a direction intersecting the rotation direction L. The radially inner surface 119 extends from the surface 112D2 on the second direction D2 side of the conical portion 112 in the second direction D2. The radially inner surface 119 is located radially inward of the pulley-side sliding surface 114. The radial inner surface 119 is perpendicular to the weight receiving surface 115 in a plan view.

[0024] As shown in Figures 4 and 5, the movable drive pulley 110 is provided with a pulley-side groove 117. The pulley-side groove 117 is an example of a weight-clamping member-side groove. The pulley-side groove 117 accommodates the weight-side projection 124 of the weight 120, which will be described later (see Figures 12 and 13). The pulley-side groove 117 guides the movement of the weight 120. The pulley-side groove 117 is formed on the pulley-side sliding surface 114. At least a portion of the pulley-side groove 117 is located in the center of the pulley-side sliding surface 114 in the rotational direction L. The pulley-side groove 117 extends radially. The radially outer end of the pulley-side groove 117 opens in the direction of movement D (here, the second direction D2). The radially inner end of the pulley-side groove portion 117 does not open radially inward.

[0025] As shown in Figures 4 and 5, the protruding piece housing section 116 accommodates the ramp-side protruding piece 133 (see Figure 6) of the ramp plate 130. The protruding piece housing section 116 is a recess that is recessed in the first direction D1. The protruding piece housing section 116 is located upstream of the weight housing section 118 in the rotational direction L. The radial length of the protruding piece housing section 116 is longer than the radial length of the weight housing section 118. The protruding piece housing section 116 includes a bottom surface 116F, a downstream side surface 116A, a radial outer surface 116B, a radial inner surface 116C, and a housing surface 116E. The bottom surface 116F, the downstream side surface 116A, the radial outer surface 116B, the radial inner surface 116C, and the housing surface 116E define the protruding piece housing section 116. The bottom surface 116F, the downstream side surface 116A, the radially outer surface 116B, the radially inner surface 116C, and the housing surface 116E demarcate a part of the housing section 113. The downstream side surface 116A is continuous with the bottom surface 116F and is located downstream of the bottom surface 116F in the rotational direction L. The radially outer surface 116B is continuous with the bottom surface 116F and is located radially outward of the bottom surface 116F. The radially inner surface 116C is continuous with the bottom surface 116F and is located radially inward of the bottom surface 116F. The housing surface 116E is continuous with the bottom surface 116F and is located upstream of the bottom surface 116F in the rotational direction L. The housing surface 116E is located upstream of the ramp-side protruding piece 133 housed in the protruding piece housing section 116 in the rotational direction L.

[0026] As shown in Figure 1, a portion of the ramp member 125 is located on the second direction D2 side of the movable drive pulley 110. The ramp member 125 comprises a ramp plate 130 and a boss portion 135.

[0027] As shown in Figure 2, the ramp plate 130 is located on the second direction D2 side of the movable drive pulley 110. The ramp plate 130 presses the weight 120 toward the movable drive pulley 110 side (the first direction D1 side). The ramp plate 130 is positioned on the opposite side of the fixed drive pulley 102 from the movable drive pulley 110. The ramp plate 130 faces the movable drive pulley 110. The ramp plate 130 rotates integrally with the crankshaft 90. The ramp plate 130 is made of a metal material (for example, aluminum). As shown in Figures 6 and 7, the ramp plate 130 comprises a disc portion 131, a ramp-side sliding surface 132, and a ramp-side protruding piece 133.

[0028] As shown in Figures 6 and 7, the disc portion 131 is a flat plate formed in the shape of a ring. A through hole 131C is formed in the center of the disc portion 131, penetrating in the direction of movement D. The crankshaft 90 is integrally assembled with the through hole 131C. The ramp plate 130 always rotates integrally with the crankshaft 90.

[0029] As shown in Figures 6 and 7, the ramp-side sliding surface 132 is formed on the surface 131D1 of the disc portion 131 on the first direction D1 side. The ramp-side sliding surface 132, together with the pulley-side sliding surface 114 of the movable drive pulley 110, is a surface that clamps the weight 120 in a radially movable state. The weight 120 slides on the ramp-side sliding surface 132. The ramp-side sliding surface 132 is a plane that extends along the radial direction. The ramp-side sliding surface 132 is inclined such that the radially outer portion is located closer to the movable drive pulley 110 (i.e., towards the first direction D1) than the radially inner portion. Three ramp-side sliding surfaces 132 are formed at equal intervals along the circumferential direction of the disc portion 131.

[0030] As shown in Figure 2, the ramp-side protruding piece 133 is housed in the protruding piece housing 116. As shown in Figures 6 and 7, the ramp-side protruding piece 133 is formed on the surface 131D1 of the disc portion 131 on the first direction D1 side. Three ramp-side protruding pieces 133 are formed at equal intervals along the circumferential direction of the disc portion 131. The ramp-side protruding piece 133 extends from the surface 131D1 on the first direction D1 side in the first direction D1. The ramp-side protruding piece 133 is located upstream of the ramp-side sliding surface 132 in the rotation direction L. The ramp-side protruding piece 133 and the ramp-side sliding surface 132 are integrally molded. The ramp-side protruding piece 133 is located upstream of the weight 120 in the rotation direction L. The ramp-side protruding piece 133 is provided so as to be able to contact the weight 120. The ramp-side protruding piece 133 is provided so as to be able to contact the second end face 122D (see Figure 16), which will be described later, of the weight 120. When the ramp-side protruding piece 133 is housed in the protruding piece housing 116, it is configured to be movable in the rotational direction L relative to the protruding piece housing 116. The ramp-side protruding piece 133 presses against the second end face 122D of the weight 120 by the rotational driving force of the power source. The ramp-side protruding piece 133 indirectly presses against the movable drive pulley 110 via the weight 120 by the rotational driving force of the power source.

[0031] As shown in Figures 6 and 7, the ramp plate 130 is provided with a ramp-side recessed portion 137. The ramp-side recessed portion 137 is an example of a weight-clamping member-side recessed portion. The ramp-side recessed portion 137 accommodates the weight-side projection 124 of the weight 120, which will be described later (see Figures 14 and 15). The ramp-side recessed portion 137 guides the movement of the weight 120. The ramp-side recessed portion 137 is formed on the ramp-side sliding surface 132. At least a portion of the ramp-side recessed portion 137 is located in the center of the ramp-side sliding surface 132 in the rotational direction L. The ramp-side recessed portion 137 extends radially. The radially outer end of the ramp-side recessed portion 137 opens radially outward. The radially inner end of the ramp-side recessed portion 137 does not open radially inward. The radially inner end of the lamp-side groove portion 137 may be open radially inward.

[0032] As shown in Figure 2, the boss portion 135 extends from the ramp plate 130 in a first direction D1. The boss portion 135 is formed in a cylindrical shape. The boss portion 135 is integrated with the ramp plate 130. By integrating the boss portion 135 and the ramp plate 130, the seating surface is reduced, which can reduce the occurrence of buckling. In this embodiment, the boss portion 135 and the ramp plate 130 are integrally molded. The boss portion 135 and the ramp plate 130 are integrally molded, for example, by die-casting. The boss portion 135 and the ramp plate 130 may also be integrated by welding. Note that when the boss portion 135 and the ramp plate 130 are said to be integrated, it means that they are integrally molded or welded together, and does not include those that are connected to each other by fastening members such as bolts or screws. The boss portion 135 and the ramp plate 130 are formed from, for example, aluminum material. Since the boss portion 135 and the ramp plate 130 are molded from the same material, the occurrence of buckling can be reduced. The end portion 135D1 of the boss portion 135 in the first direction D1 is in contact with the fixed drive pulley 102. The crankshaft 90 is inserted into the boss portion 135. The inner circumferential surface 135T of the boss portion 135 is provided with a boss portion side spline portion 135X that spline-fits with the crankshaft 90. The length of the boss portion side spline portion 135X in the direction of movement D is half or less (for example, one-quarter or less) of the length of the boss portion 135 in the direction of movement D. A part of the boss portion side spline portion 135X is provided at the end portion of the inner circumferential surface 135T of the boss portion 135 in the first direction D1. The inner diameter of the boss portion side spline portion 135X and the inner diameter of the pulley side spline portion 103S are the same. The inner diameter of the spline portion 135X on the boss side and the inner diameter of the spline portion 103S on the pulley side may be different.

[0033] As shown in Figures 2 and 3, the weight 120 is sandwiched between the movable drive pulley 110 and the ramp plate 130. The weight 120 is mounted so as to be movable radially on the movable drive pulley 110. The weight 120 is housed in the housing portion 113 of the movable drive pulley 110. More specifically, the weight 120 is housed in the weight housing portion 118. The weight 120 is mounted so as to be able to transmit rotational driving force from the ramp plate 130 to the movable drive pulley 110 during acceleration (for example, when the engine speed increases). The weight 120 is configured to press against the movable drive pulley 110 and bring it closer to the fixed drive pulley 102. The weight 120 works in cooperation with the ramp plate 130 to press the movable drive pulley 110 toward the fixed drive pulley 102 (i.e., in the first direction D1). The weight 120 is configured to be radially movable during the process from when the engine is stopped (i.e., when the crankshaft 90 is not rotating) until the ramp plate 130 rotates and the weight 120 comes into contact with the ramp-side protruding piece 133 and the weight receiving surface 115. The weight 120 is configured to be radially movable by the centrifugal force acting on it. The ramp plate 130 rotates as the engine speed increases from the cranking speed (e.g., 50 rpm to 60 rpm) to the idling speed (e.g., 600 rpm to 800 rpm), causing the weight 120 to come into contact with the ramp-side protruding piece 133 and the weight receiving surface 115. When the weight 120 comes into contact with the ramp-side protruding piece 133 and the weight receiving surface 115, the rotational driving force from the ramp plate 130 is transmitted to the movable drive pulley 110. Furthermore, the engine speed when the lamp-side protruding piece 133 contacts the weight 120 and the weight 120 contacts the weight receiving surface 115 is lower than the engine speed when the movable drive pulley 110 begins to approach the fixed drive pulley 102. The weight 120 moves from an inner radial position (see Figure 2) to an outer radial position (see Figure 3) in response to an increase in the rotational speed of the movable drive pulley 110 (i.e., due to the centrifugal force accompanying the rotation of the movable drive pulley 110).When the weight 120 is in contact with the ramp-side projection 133 and the weight receiving surface 115, the weight 120 is configured to be movable along the pulley-side sliding surface 114 and the ramp-side sliding surface 132 from a radially inner position to a radially outer position. During acceleration, the weight-side projection 124 does not come into contact with the pulley-side groove 117 and the ramp-side groove 137. On the other hand, during deceleration (for example, when the engine speed decreases or when the brakes are applied), the weight 120 is provided to be able to transmit the rotational driving force from the movable drive pulley 110 to the ramp plate 130. During deceleration, as the centrifugal force acting on the weight 120 decreases, the weight 120 moves from a radially outer position to an radially inner position. During deceleration, the rotational speed of the movable drive pulley 110 exceeds the rotational speed of the ramp plate 130, and the weight-side projection 124 is configured to contact the pulley-side groove 117 and the ramp-side groove 137. The rotational driving force from the movable drive pulley 110 is transmitted to the ramp plate 130 by the weight-side projection 124 contacting the pulley-side groove 117 and the ramp-side groove 137.

[0034] As shown in Figures 8 to 11, the weight 120 comprises a weight body 121 and a body cover 122. The weight body 121 functions as a weight in the weight 120. The weight body 121 is constructed by forming a metal material into a cylindrical shape. The weight body 121 is fitted into the body cover 122 and integrated with it.

[0035] The main body cover 122 is formed from a resin material (for example, a polyamide resin). Because the main body cover 122 is made from a resin material, the sliding properties and wear resistance between the main body cover 122 and the movable drive pulley 110 and ramp plate 130 can be improved. The main body cover 122 abuts against the pulley-side sliding surface 114 and the ramp-side sliding surface 132. The main body cover 122 slides on the pulley-side sliding surface 114 and the ramp-side sliding surface 132. As shown in Figures 8 to 11, the main body cover 122 has a first sliding surface 122A, a second sliding surface 122B, a first end surface 122C (see Figure 12), a second end surface 122D, and a notch 122E.

[0036] As shown in Figures 8 to 11, the first sliding surface 122A is a surface that slides on the pulley-side sliding surface 114. The first sliding surface 122A is a curved surface with an arc-shaped cross-section. Because the first sliding surface 122A and the pulley-side sliding surface 114 are in line contact, the weight 120 can move smoothly on the pulley-side sliding surface 114. The second sliding surface 122B is a surface that slides on the ramp-side sliding surface 132. The second sliding surface 122B is a plane with a straight cross-section. The second sliding surface 122B prevents the weight 120 from rotating and moving on the pulley-side sliding surface 114. The first sliding surface 122A and the second sliding surface 122B are examples of weight-side sliding surfaces.

[0037] As shown in Figure 16, the first end face 122C is configured to be able to contact the weight receiving surface 115. The first end face 122C is the surface that presses against the weight receiving surface 115. The first end face 122C is a plane that covers one axial end of the weight body 121 (the downstream end in the rotation direction L). The first end face 122C is an example of the downstream surface in the rotation direction L. The second end face 122D is configured to be able to contact the ramp-side projection 133. The second end face 122D is the surface that is pressed by the ramp-side projection 133. The second end face 122D is a plane that covers the other axial end of the weight body 121 (the upstream end in the rotation direction L). The second end face 122D is an example of the upstream surface in the rotation direction L. As shown in Figure 8, the notch 122E is formed by cutting out a part of the first sliding surface 122A. The weight body 121 is inserted into the main body cover 122 through the notch 122E. The weight body 121 is exposed to the outside through the notch 122E.

[0038] As shown in Figures 8 to 11, the weight 120 is provided with a weight-side projection 124. The weight-side projection 124 extends radially. More specifically, the weight-side projection 124 extends radially when the weight 120 is housed in the weight housing 118. The weight-side projection 124 is formed on the first sliding surface 122A and the second sliding surface 122B. The weight-side projection 124 is formed at the center of the rotational direction L of the first sliding surface 122A and the center of the rotational direction L of the second sliding surface 122B. The weight-side projection 124 is formed on at least a portion of the radial direction of the first sliding surface 122A and the second sliding surface 122B. In this embodiment, a portion of the weight-side projection 124 is formed on a radial portion of the first sliding surface 122A, and another portion of the weight-side projection 124 is formed on a radial portion of the second sliding surface 122B. Alternatively, a portion of the weight-side projection 124 may be formed over the entire radial surface of the first sliding surface 122A. Another portion of the weight-side projection 124 may be formed over the entire radial surface of the second sliding surface 122B. As shown in Figures 12 and 13, the weight-side projection 124 is housed in the pulley-side groove 117. As shown in Figures 14 and 15, the weight-side projection 124 is housed in the ramp-side groove 137. The amount of projection of the weight-side projection 124 is shorter than the depth of the pulley-side groove 117 and the ramp-side groove 137. When the weight 120 is in its most radially inward position, the weight-side projection 124 is separated from the partition wall 137T (Figure 6) that defines the radially inward end of the ramp-side recessed groove 137 of the ramp plate 130.

[0039] As shown in Figure 2, the sliding member 180 is positioned between the outer circumferential surface 135S of the boss portion 135 and the movable drive pulley 110. The sliding member 180 is formed in a cylindrical shape. The movable drive pulley 110 slides along the outer surface of the sliding member 180. The sliding member 180 is provided over the entire length of the outer circumferential surface 135S of the boss portion 135 in the direction of movement D. The movable drive pulley 110 slides along the sliding member 180. At least the portion of the sliding member 180 that the movable drive pulley 110 slides over is made of resin (e.g., polyamide resin). Alternatively, the sliding member 180 may be made of metal (e.g., aluminum) and its surface may be coated with resin (e.g., polyamide resin).

[0040] As shown in Figure 1, the V-belt 140 transmits the rotational driving force transmitted to the drive pulley 101 to the driven pulley 150. The V-belt 140 is formed in an endless ring shape with a core wire covered in resin material. The V-belt 140 is positioned between the fixed drive pulley 102 and the movable drive pulley 110 of the drive pulley 101, and between the fixed driven pulley 151 and the movable driven pulley 154 of the driven pulley 150. The V-belt 140 is wrapped around the drive pulley 101 and the driven pulley 150.

[0041] As shown in Figure 1, the driven pulley 150 transmits the rotational driving force of the power source, which is transmitted from the drive pulley 101 via the V-belt 140, to the centrifugal clutch 200. The driven pulley 150 comprises a fixed driven pulley 151, a boss portion 152, and a movable driven pulley 154.

[0042] As shown in Figure 1, the fixed driven pulley 151 rotates while holding the V-belt 140 in place, together with the movable driven pulley 154. The fixed driven pulley 151 is constructed by forming a metal material (for example, aluminum) into a conical cylindrical shape. The fixed driven pulley 151 is fixed to the boss portion 152 with its convex side facing the movable driven pulley 154.

[0043] The boss portion 152 is a metal cylindrical component that rotates integrally with the fixed driven pulley 151. The boss portion 152 is attached to the drive shaft 153 so as to be relatively rotatable via a bearing. The drive shaft 153 is a metal shaft for driving the rear wheel of a motorcycle on which the continuously variable transmission 100 is mounted via a transmission (not shown). The rear wheel of the motorcycle is attached to one end (right side in the figure) of the drive shaft 153.

[0044] As shown in FIG. 1, the movable driven pulley 154 rotates while holding the V-belt 140 together with the fixed driven pulley 151. The movable driven pulley 154 is formed of a metal material (for example, an aluminum material) into a conical cylinder shape. The movable driven pulley 154 is provided so as to be movable in the moving direction D and rotatable in the rotational direction L with respect to the boss portion 152 in a state where the convex side surface faces the fixed driven pulley 151 side.

[0045] As shown in FIG. 1, a torque spring 155 is provided between the concave side surface of the movable driven pulley 154 and the drive plate 201 of the centrifugal clutch 200. The torque spring 155 presses the movable driven pulley 154 toward the fixed driven pulley 151. The torque spring 155 is, for example, a coil spring. The continuously variable transmission 100 changes the rotational speed of the drive shaft 153 continuously by changing the distance between the fixed drive pulley 102 and the movable drive pulley 110 and the distance between the fixed driven pulley 151 and the movable driven pulley 154.

[0046] As shown in FIG. 1, the centrifugal clutch 200 is provided at the end portion on the first direction D1 side of the boss portion 152 and the drive shaft 153. The centrifugal clutch 200 is a device that transmits or blocks the rotational driving force of a power source transmitted via the continuously variable transmission 100 to the drive shaft 153. The centrifugal clutch 200 includes a drive plate 201, a swing support pin 202, a clutch weight 203, and a clutch outer 206.

[0047] The drive plate 201 rotates integrally with the boss portion 152. The drive plate 201 is formed in a disc shape. Three swing support pins 202 are provided on the outer edge portion of the drive plate 201 in a standing state. The swing support pins 202 support the clutch weight 203 so as to be swingable.

[0048] The clutch weight 203 transmits or blocks the rotational driving force from the power source to the drive shaft 153 according to the rotational speed of the drive plate 201. The three clutch weights 203 are pulled radially inward by the connecting spring 204. The clutch shoe 205 increases the frictional force against the inner peripheral surface of the clutch outer 206. The clutch shoe 205 faces the inner peripheral surface of the clutch outer 206. According to the rotational speed of the drive plate 201, the clutch shoe 205 contacts or separates from the inner peripheral surface of the clutch outer 206.

[0049] The clutch outer 206 rotates integrally with the drive shaft 153. The clutch outer 206 transmits or blocks the rotational driving force from the power source to the drive shaft 153 when the clutch weight 203 contacts through the clutch shoe 205.

[0050] Next, the operation of the continuously variable transmission 100 of this embodiment will be described. When a motorcycle or the like is accelerating, the weight 120 moves from an inner position in the radial direction to an outer position in the radial direction. As shown in Figure 16, during acceleration, with the ramp-side protruding piece 133 in contact with the second end face 122D of the weight 120 and the first end face 122C of the weight 120 in contact with the movable drive pulley 110 (more specifically, the weight receiving surface 115), the weight 120 begins to move from an inner position in the radial direction to an outer position along the pulley-side sliding surface 114 (see Figure 13) and the ramp-side sliding surface 132 (see Figure 15). Then, the weight 120 moves to the outer position in the radial direction (see Figure 3). Here, during acceleration, the ramp-side protruding piece 133 contacts the second end face 122D of the weight 120, and the first end face 122C of the weight 120 contacts the movable drive pulley 110 (more specifically, the weight receiving surface 115), thereby transmitting the rotational driving force from the ramp plate 130 to the movable drive pulley 110 (see arrow FA in Figure 16). Furthermore, the pulley-side sliding surface 114 and the ramp-side sliding surface 132 that sandwich the weight 120 are formed such that the distance between them narrows from the inside to the outside in the radial direction. As a result, the movable drive pulley 110 moves toward the fixed drive pulley 102 side (i.e., toward the first direction D1 side) as the weight 120 moves toward the outside in the radial direction. As the movable drive pulley 110 approaches the fixed drive pulley 102, the V-belt 140 moves from the innermost part of the drive pulley 101 to the outermost part, and also moves from the outermost part of the driven pulley 150 to the innermost part.A predetermined direction LX is defined as the direction that intersects the radial direction when viewed from the axial direction of the crankshaft 90 (for example, the direction perpendicular to the radial direction in which the weight 120 moves when viewed from the axial direction of the crankshaft 90). During acceleration, the distance in the predetermined direction LX between the upstream surface 124D of the weight-side projection 124 in the rotational direction L and the surface 117D of the movable drive pulley 110 that is located upstream of the weight-side projection 124 in the rotational direction L and defines the pulley-side groove 117. When the distance is A, the distance in a predetermined direction LX between the downstream surface 124C of the weight-side projection 124 in the rotational direction L and the surface 137C of the ramp plate 130 that is located downstream of the weight-side projection 124 in the rotational direction L and defines the ramp-side groove 137 is B, and the distance in a predetermined direction LX between the upstream side surface 133D of the ramp-side projection piece 133, which is the upstream surface in the rotational direction L, and the housing surface 116E of the movable drive pulley 110 is C, then A and B are shorter than C.

[0051] As shown in Figure 17, when a motorcycle or the like is decelerating, the pulley-side groove 117 of the movable drive pulley 110 contacts the upstream surface 124D of the weight-side projection 124 in the direction of rotation L, and the downstream surface 124C of the weight-side projection 124 in the direction of rotation L contacts the ramp plate 130 (more specifically, the ramp-side groove 137), thereby transmitting the rotational driving force from the movable drive pulley 110 to the ramp plate 130 via the weight 120 (see arrow FD in Figure 17). For example, when back torque is applied from the rear wheel to the continuously variable transmission 100, the rotational driving force from the movable drive pulley 110 is transmitted to the crankshaft 90 via the weight 120 and the ramp plate 130. During deceleration, the upstream side surface 133D of the ramp-side projection 133 is separated from the housing surface 116E of the movable drive pulley 110. That is, a gap is formed between the upstream side surface 133D and the housing surface 116E. During deceleration, the downstream side surface 133C of the ramp-side protruding piece 133, which is the downstream side in the rotation direction L, is separated from the weight 120. During deceleration, the weight receiving surface 115 of the movable drive pulley 110 is separated from the weight 120. During deceleration, when Z is the distance in a predetermined direction LX between the first end face 122C of the weight 120 and the weight receiving surface 115 of the movable drive pulley 110, Y is the distance in a predetermined direction LX between the second end face 122D of the weight 120 and the downstream side surface 133C of the ramp-side projection piece 133, X is the distance in a predetermined direction LX between the downstream surface 124C of the weight-side projection 124 in the rotation direction L and the surface 117C of the movable drive pulley 110 that is located downstream of the weight-side projection 124 in the rotation direction L and defines the pulley-side groove portion 117, and W is the distance in a predetermined direction LX between the upstream surface 124D of the weight-side projection 124 in the rotation direction L and the surface 137D of the ramp plate 130 that is located upstream of the weight-side projection 124 in the rotation direction L and defines the ramp-side groove portion 137, Y and Z are shorter than X and W.

[0052] As described above, in the continuously variable transmission 100 of this embodiment, the boss portion 135 and the ramp plate 130 are integrated. In this embodiment, since the boss portion 135 and the ramp plate 130 are integrated, there is no need to fasten the boss portion 135 and the ramp plate 130 to each other with bolts or the like. As a result, buckling of the boss portion 135 is suppressed when rotational driving force is transmitted by the rotation of the crankshaft 90, and sufficient axial force can be maintained in the ramp member 125.

[0053] In the continuously variable transmission 100 of this embodiment, the ramp plate 130 and the boss portion 135 are integrally molded. According to the above embodiment, since the ramp plate 130 and the boss portion 135 are more firmly fixed together, buckling of the boss portion 135 can be further suppressed.

[0054] In the continuously variable transmission 100 of this embodiment, the ramp plate 130 and the boss portion 135 may be integrated by welding. According to the above embodiment, since the ramp plate 130 and the boss portion 135 are more firmly fixed, buckling of the boss portion 135 can be further suppressed.

[0055] In the continuously variable transmission 100 of this embodiment, the inner circumferential surface 135T of the boss portion 135 is provided with a boss portion side spline portion 135X that spline-fits with the crankshaft 90. According to the above embodiment, the boss portion 135 can be securely fixed by the crankshaft 90.

[0056] In the continuously variable transmission 100 of this embodiment, the length of the spline portion 135X on the boss side in the direction of movement D is less than or equal to half the length of the boss portion 135 in the direction of movement D. According to the above embodiment, the boss portion 135 can be reliably fixed to the crankshaft 90 using a boss portion 135 that is manufactured more simply and at lower cost.

[0057] In the continuously variable transmission 100 of this embodiment, the fixed drive pulley 102 abuts against the end 135D1 of the boss portion 135 in the first direction D1, the inner circumferential surface 103A of the fixed drive pulley 102 is provided with a pulley-side spline portion 103S that spline-fits with the crankshaft 90, and a part of the boss portion-side spline portion 135X is provided at the end of the inner circumferential surface 135T of the boss portion 135 in the first direction D1. According to the above embodiment, for example, it is sufficient to provide the boss portion-side spline portion 135X only around the end of the crankshaft 90 in the first direction D1, and it is not necessary to provide the boss portion-side spline portion 135X over a wider area of ​​the crankshaft 90.

[0058] In the continuously variable transmission 100 of this embodiment, the fixed drive pulley 102 abuts against the end 135D1 of the boss portion 135 in the first direction D1, and the inner circumferential surface 103A of the fixed drive pulley 102 is provided with a pulley-side spline portion 103S that spline-fits with the crankshaft 90, and the inner diameter of the boss portion-side spline portion 135X and the inner diameter of the pulley-side spline portion 103S are the same. According to the above embodiment, a crankshaft 90 that can be manufactured more simply and at lower cost can be used.

[0059] In the continuously variable transmission 100 of this embodiment, a sliding member 180 is provided, which is located between the outer circumferential surface 135S of the boss portion 135 and the movable drive pulley 110, is formed in a cylindrical shape, and slides against the movable drive pulley 110. According to the above embodiment, wear of the boss portion 135 can be suppressed.

[0060] In the continuously variable transmission 100 of this embodiment, the sliding member 180 is provided over the entire length of the outer peripheral surface 135S of the boss portion 135 in the direction of movement D, and the movable drive pulley 110 slides along the sliding member 180. According to the above embodiment, wear of the boss portion 135 can be suppressed more reliably.

[0061] In the continuously variable transmission 100 of this embodiment, the portion of the sliding member 180 that the movable drive pulley 110 slides over is made of resin at least. According to this embodiment, wear of the movable drive pulley 110 can be suppressed.

[0062] In the embodiment described above, the weight 120 had one weight-side projection 124, but it may have multiple weight-side projections 124. In this case, the multiple weight-side projections 124 are, for example, aligned in the rotational direction. The movable drive pulley 110 may have multiple pulley-side grooves 117, and the ramp plate 130 may have multiple ramp-side grooves 137. According to the above embodiment, during acceleration, the rotational driving force from the ramp plate 130 can be reliably transmitted by the movable drive pulley 110 via the multiple weight-side projections 124, the pulley-side grooves 117, and the ramp-side grooves 137, and during deceleration, the rotational driving force from the movable drive pulley 110 can be reliably transmitted by the ramp plate 130 via the multiple weight-side projections 124, the pulley-side grooves 117, and the ramp-side grooves 137.

[0063] In the embodiment described above, the movable drive pulley 110 was provided with a pulley-side groove 117 and the ramp plate 130 was provided with a ramp-side groove 137, but the embodiment is not limited to these. For example, as shown in Figure 18, the movable drive pulley 110 may be provided with a pulley-side stepped portion 317 and the ramp plate 130 may be provided with a ramp-side stepped portion 337. The pulley-side stepped portion 317 and the ramp-side stepped portion 337 are examples of stepped portions on the weight clamping member side. The pulley-side stepped portion 317 guides the movement of the weight 120. The pulley-side stepped portion 317 extends radially. The pulley-side stepped portion 317 is provided so as to be able to contact the upstream surface 124D of the weight-side projection 124 in the rotational direction L. The ramp-side stepped portion 337 guides the movement of the weight 120. The ramp-side stepped portion 337 extends radially. The step portion 337 on the ramp side is provided so as to be able to come into contact with the downstream surface 124C of the weight-side projection 124 in the rotational direction L.

[0064] <Second Embodiment> Figures 19 and 20 schematically show the movable drive pulley 210, weight 220, and ramp plate 230 of the continuously variable transmission 100 according to the second embodiment.

[0065] As shown in Figures 19 and 20, the movable drive pulley 210 is provided with a pulley-side projection 217. The pulley-side projection 217 is an example of a projection on the weight clamping member side. The pulley-side projection 217 is housed in the weight-side recessed groove 224 of the weight 220, which will be described later. The pulley-side projection 217 guides the movement of the weight 220. The pulley-side projection 217 is formed on the pulley-side sliding surface 114. At least a portion of the pulley-side projection 217 is located in the center of the pulley-side sliding surface 114 in the rotational direction L. The pulley-side projection 217 extends radially. The movable drive pulley 210 has the same configuration as the movable drive pulley 110, except that it is provided with a pulley-side projection 217 instead of a pulley-side recessed groove 117.

[0066] As shown in Figures 19 and 20, the ramp plate 230 is provided with a ramp-side projection 237. The ramp-side projection 237 is an example of a projection on the weight clamping member side. The ramp-side projection 237 is housed in the weight-side recessed groove 224 of the weight 220. The ramp-side projection 237 guides the movement of the weight 220. The ramp-side projection 237 is formed on the ramp-side sliding surface 132. At least a portion of the ramp-side projection 237 is located in the center of the rotational direction L of the ramp-side sliding surface 132. The ramp-side projection 237 extends radially. The ramp plate 230 has the same configuration as the ramp plate 130 except that it is provided with a ramp-side projection 237 instead of a ramp-side recessed groove 137.

[0067] As shown in Figures 19 and 20, the weight 220 is provided with a weight-side groove 224. The weight-side groove 224 extends radially. More specifically, the weight-side groove 224 extends radially when the weight 220 is housed in the weight housing 118. The weight-side groove 224 is formed on the first sliding surface 122A and the second sliding surface 122B. The weight-side groove 224 is formed at the center of the rotational direction L of the first sliding surface 122A and the center of the rotational direction L of the second sliding surface 122B. The weight-side groove 224 is formed on at least a portion of the first sliding surface 122A and the second sliding surface 122B in the radial direction. The weight-side groove 224 accommodates the pulley-side projection 217 and the ramp-side projection 237. The protrusions of the pulley-side projection 217 and the ramp-side projection 237 are shorter than the depth of the weight-side groove 224. The weight 220 has the same configuration as the weight 120, except that it has a weight-side groove 224 instead of a weight-side projection 124.

[0068] As shown in Figure 19, during acceleration, the ramp-side protruding piece 133 contacts the second end face 122D of the weight 220, and the first end face 122C of the weight 220 contacts the movable drive pulley 210 (more specifically, the weight receiving surface 115), thereby transmitting the rotational driving force from the ramp plate 230 to the movable drive pulley 210 (see arrow FA in Figure 19).

[0069] As shown in Figure 20, during deceleration, the downstream surface 217C of the pulley-side projection 217 of the movable drive pulley 210 in the direction of rotation L abuts against the weight-side groove 224, and the upstream surface 237D of the ramp-side projection 237 of the ramp plate 230 in the direction of rotation L abuts against the weight-side groove 224, thereby transmitting the rotational driving force from the movable drive pulley 210 to the ramp plate 230 via the weight 220 (see arrow FE in Figure 20). During deceleration, the upstream side surface 133D of the ramp-side projection 133 is separated from the housing surface 116E of the movable drive pulley 210.

[0070] Preferred embodiments of the present invention have been described above. However, the embodiments described above are merely illustrative, and the present invention can be implemented in various other forms.

[0071] In the embodiments described above, the movable drive pulleys 110 and 210 were configured to slide on the outer surface of the sliding member 180, but are not limited to this. The sliding member 180 may be configured to slide against the boss portion 135. That is, the boss portion 135 may be configured to slide on the inner circumferential surface of the sliding member 180. In this case, the sliding member 180 is fixed to the movable drive pulleys 110 and 210 and moves in the direction of movement D together with the movable drive pulleys 110 and 210. The length of the sliding member 180 in the direction of movement D is, for example, the same as the length of the center cylindrical portion 111 in the direction of movement D.

[0072] As shown in Figure 17, the continuously variable transmission 100 may be provided with a buffer member 300 upstream of the upstream side surface 133D of the ramp-side projection 133. The buffer member 300 is formed from an elastically deformable material (e.g., rubber). The buffer member 300 is an example of an intermediate member. During deceleration, the buffer member 300 is configured to contact the movable drive pulley 110 (more specifically the housing surface 116E) and the upstream side surface 133D. In Figure 17, the buffer member 300 is shown by a dashed line. According to the above embodiment, during deceleration, the buffer member 300 can prevent the upstream side surface 133D of the ramp-side projection 133 from contacting the housing surface 116E.

[0073] 90 Crankshaft 100 Continuously Variable Transmission 101 Drive Pulley 102 Fixed Drive Pulley 103A Inner Circumferential Surface 103S Splined Section on Pulley Side 110 Movable Drive Pulley 120 Weight 125 Ramp Member 130 Ramp Plate 135 Boss Section 135S Outer Circumferential Surface 135T Inner Circumferential Surface 135X Splined Section on Boss Side 180 Sliding Member

Claims

1. A drive pulley comprising: a fixed drive pulley that rotates integrally with a crankshaft that rotates by a power source; a movable drive pulley that is positioned opposite to the fixed drive pulley and moves toward or toward the fixed drive pulley along the crankshaft; a ramp member in which a portion is located on the second direction side of the movable drive pulley, when the direction in which the movable drive pulley moves is defined as the direction of movement, the direction in which the movable drive pulley approaches the fixed drive pulley is defined as the first direction, and the direction in which the movable drive pulley moves toward the fixed drive pulley is defined as the second direction; and a weight sandwiched between the movable drive pulley and the ramp member and movable in the radial direction of the movable drive pulley, wherein the ramp member comprises: a ramp plate located on the second direction side of the movable drive pulley and having a sliding surface on which the weight slides; and a boss portion extending from the ramp plate in the first direction, integrated with the ramp plate, and formed in a cylindrical shape. A continuously variable transmission in which the movable drive pulley is fitted onto the boss portion and is configured to move along the outer surface of the boss portion.

2. The continuously variable transmission according to claim 1, wherein the ramp plate and the boss portion are integrally molded.

3. The continuously variable transmission according to claim 1, wherein the ramp plate and the boss portion are integrated by welding.

4. The continuously variable transmission according to claim 1, wherein the inner circumferential surface of the boss portion is provided with a boss portion side spline portion that spline-fits with the crankshaft.

5. The continuously variable transmission according to claim 4, wherein the length of the spline portion on the boss side in the direction of movement is less than or equal to half the length of the boss portion in the direction of movement.

6. The continuously variable transmission according to claim 5, wherein the fixed drive pulley abuts against the end of the boss portion in the first direction, the inner circumferential surface of the fixed drive pulley is provided with a pulley-side spline portion that spline-fits with the crankshaft, and a part of the boss portion-side spline portion is provided at the end of the inner circumferential surface of the boss portion in the first direction.

7. The continuously variable transmission according to claim 4, wherein the fixed drive pulley abuts against the end of the boss portion in the first direction, the inner circumferential surface of the fixed drive pulley is provided with a pulley-side spline portion that spline-fits with the crankshaft, and the inner diameter of the boss-side spline portion and the inner diameter of the pulley-side spline portion are the same.

8. The continuously variable transmission according to claim 1, comprising a sliding member located between the outer circumferential surface of the boss portion and the movable drive pulley, formed in a cylindrical shape, and on which the boss portion or the movable drive pulley slides.

9. The continuously variable transmission according to claim 8, wherein the sliding member is provided over the entire outer surface of the boss portion in the direction of movement, and the movable drive pulley slides along the sliding member.

10. The continuously variable transmission according to claim 8, wherein at least the portion of the sliding member on which the boss portion or the movable drive pulley slides is made of resin.

11. The continuously variable transmission according to claim 1, wherein the end of the boss portion in the first direction is in contact with the fixed drive pulley.

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