Electric continuously variable transmission

Abstract

To improve assemblability of an electric continuously variable transmission.SOLUTION: An electric continuously variable transmission includes: a driving pulley 46; a driven pulley 48; a transmission belt 49; and an actuator 50 which applies the axial force to a movable sheave 52 of the driving pulley 46 to change a groove width. The actuator 50 includes a feed screw mechanism 73 which converts rotational power of a motor 56 into axial power of the driving pulley 46. A transmission case 15a includes: a case body 42 which is open to one side in an axial direction; and a case cover 43 which covers the one side in the axial direction of the case body 42 and to which the actuator 50 is attached from the case outer side. The case cover 43 has an opening 43d which is closed by an actuator body 50a, which is formed separately from the feed screw mechanism 73, of the actuator 50. The feed screw mechanism 73 is supported so as to be insertable into or removable from the opening 43d.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an electric continuously variable transmission.

Background Art

[0002] In recent years, in order to enable more people to access affordable, reliable, sustainable, and advanced energy, research and development have been conducted on improving fuel efficiency, which contributes to energy efficiency. In a belt-type continuously variable transmission adopted in saddle-riding type vehicles such as motorcycles, the centrifugal weight is used to change the speed ratio according to the rotational speed. However, in order to further improve fuel efficiency, it is preferable to perform shift control considering more conditions rather than shifting only according to the rotational speed. For example, Patent Document 1 describes an electric belt-type continuously variable transmission including a drive pulley supported by an input shaft, a driven pulley supported by an output shaft, a transmission belt wound around both pulleys, and an actuator driven by a control device to apply an axial force to one of the two pulleys to change the groove width.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in this technology related to improving fuel efficiency, there was a problem in terms of assembly. That is, in this technology, there is a ball joint structure between the shaft end of the actuator and the drive member that changes the pulley groove width. When assembling the actuator to the vehicle body side, with the pulley and the drive member assembled to the vehicle body side, the shaft of the integrally assembled actuator was inserted into the case through the opening of the transmission case, and the shaft end was assembled to the drive member. However, since the opening of the transmission case is blocked by the actuator, the work area cannot be seen when assembling the actuator shaft to the drive member, which presented a challenge in terms of ease of assembly.

[0005] This invention aims to improve the ease of assembly of an electric continuously variable transmission in order to solve the above-mentioned problems. Ultimately, this will contribute to energy efficiency. [Means for solving the problem]

[0006] As a means of solving the above problems, a first aspect of the present invention provides an electrically powered stepless motor comprising: a drive pulley (46) supported on an input shaft (12); a driven pulley (48) supported on an output shaft (47); a transmission belt (49) wrapped around the drive pulley (46) and the driven pulley (48); a transmission case (15a) housing the drive pulley (46), the driven pulley (48), and the transmission belt (49); and an actuator (50) attached to the transmission case (15a) and driven by a control device, which applies axial force to a movable sheave (52) of a controlled pulley (46), with one of the drive pulley (46) and the driven pulley (48) designated as the controlled pulley (46), thereby changing the groove width. In the transmission, the actuator (50) comprises a motor (56) that generates rotational power and a lead screw mechanism (73) that converts the rotational power of the motor (56) into axial power of a controlled pulley (46). The transmission case (15a) comprises a case body (42) that opens toward one axial side and a case cover (43) that covers one axial side of the case body (42) and to which the actuator (50) is attached from the outside of the case. The case cover (43) has an opening (43d) that is closed by an actuator body (50a) which is separate from the lead screw mechanism (73) in the actuator (50), and the lead screw mechanism (73) is supported so as to be insertable and detachable within the opening (43d). With this configuration, the actuator's lead screw mechanism is separate from the actuator body and is supported so as to be insertable and removable within the opening of the case cover. This allows one end of the lead screw mechanism to be connected to the controlled pulley while the case body is open, before attaching the case cover to the transmission case body. Subsequently, the other end of the lead screw mechanism is inserted into the opening while the case cover is attached to the case body, and then the actuator body is attached to the case cover. This closes the opening of the case cover and connects the other end of the lead screw mechanism to the actuator body outside the transmission case. In this way, the actuator's feed screw mechanism can be assembled to the controlled pulley before the case cover is attached to the case body. This makes the assembly of the electric continuously variable transmission easier compared to the case where the feed screw mechanism is assembled to the controlled pulley after the case cover is attached.

[0007] A second aspect of the present invention is, in the first aspect described above, the lead screw mechanism (73) comprises a shaft (74) arranged parallel to the axial direction with respect to a drive pulley (46) and a driven pulley (48), which rotates around an axis by the driving force of a motor (56), and a nut member (75) arranged coaxially with the shaft (74), through which the shaft (74) is inserted, which strokes in the axial direction by the rotational motion of the shaft (74), wherein the nut member (75) is supported so as to be insertable and removable within an opening (43d), and one end (74c) of the shaft (74) protruding from the nut member (75) is supported by the actuator body (50a). With this configuration, by supporting one end of the shaft with the actuator body, if the actuator body is attached after assembling the lead screw mechanism, the end of the shaft protruding from the nut member can be supported by the actuator body. This simplifies the assembly of the lead screw mechanism and the assembly of the electric continuously variable transmission.

[0008] A third aspect of the present invention is, in the second aspect described above, the other end (74b) of the shaft (74) is supported by the case body (42), and both ends (74b, 74c) of the shaft (74) are supported by the actuator body (50a) and the case body (42) via thrust supports (95, 97), respectively. With this configuration, both ends of the shaft are supported via thrust bearings, allowing the case cover and case body to receive the reaction force when the nut member is propelled.

[0009] A fourth aspect of the present invention is, in the second or third aspect described above, a pulley drive member (71) attached to a movable sheave (52) of a controlled pulley (46) and capable of applying axial thrust to the movable sheave (52), wherein the pulley drive member (71) and the nut member (75) of the feed screw mechanism (73) are connected via a ball joint (76), and the ball joint (76) comprises a connecting pin (77) fixed to the nut member (75), a ball housing (78) provided on the pulley drive member (71), and a ball bearing (79) housed within the ball housing (78) and supported by the connecting pin (77). With this configuration, the connecting pin of the ball joint is fixed to the nut member, and the ball housing is provided on the pulley drive member. Compared to the case where the ball housing is provided on the nut member, this configuration makes it possible to reduce the size of the nut member and simplify the assembly of the feed screw mechanism.

[0010] A fifth aspect of the present invention is, in the fourth aspect described above, the ball housing (78) is capable of inserting and removing a ball bearing (79) through an opening (78d) facing the nut member (75). With this configuration, the ball bearing can be easily installed inside the ball housing while it is assembled to the feed screw mechanism, by inserting and removing the ball bearing through the opening in the ball housing that faces the nut member.

[0011] A sixth aspect of the present invention, in the second or third aspect described above, comprises a nut member (75) having a cylindrical shape through which a shaft (74) is inserted, a nut body (81) having an internal thread (81a) formed on the inner circumference within a specified range from one axial end, a ball screw nut (82) that holds a plurality of steel balls arranged in a spiral shape and is inserted into the nut body (81) from one axial end of the nut body (81), and a fixing member (83) that is screwed into the internal thread (81a) inside the nut body (81) on the axial end side of the ball screw nut (82), and tightens and fixes the ball screw nut (82) that has bottomed out on a stepped portion (81b) inside the nut body (81). With this configuration, the ball screw nut is inserted into the nut body, and the ball screw nut is tightened and secured with the nut body and fixing member, allowing the nut body, ball screw nut, and fixing member to be handled as a single, integrated small assembly. [Effects of the Invention]

[0012] According to the present invention, the ease of assembly of an electric continuously variable transmission can be improved. [Brief explanation of the drawing]

[0013] [Figure 1] This is a left side view of a motorcycle according to an embodiment of the present invention. [Figure 2] This is a left side view showing the area around the power unit of the above-mentioned motorcycle. [Figure 3] This is a plan view including an expanded cross-section of the area around the drive pulley of the transmission of the power unit described above. [Figure 4] This is a cross-sectional view showing an enlarged unfolded section of Figure 3. [Figure 5] Figure 4 is a cross-sectional view showing an enlarged view of the area around the lead screw mechanism. [Figure 6] This is an exploded perspective view of the electrically operated continuously variable transmission of an embodiment. [Figure 7] Figure 6 is an exploded perspective view showing the external configuration of the transmission case. [Figure 8] Figure 6 is an exploded perspective view showing the internal configuration of the transmission case.

Best Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, directions such as front, rear, left, and right are the same as those of the vehicle described below unless otherwise specified. Also, at appropriate positions in the drawings used in the following description, an arrow FR indicating the front of the vehicle, an arrow LH indicating the left side of the vehicle, an arrow UP indicating the upper side of the vehicle, and a line CL indicating the center of the vehicle body left and right are shown. In the present embodiment, the term "intermediate" is intended to include not only the center between both ends of the object but also the inner range between both ends of the object.

[0015] <Overall Vehicle> FIG. 1 is a left side view of a motorcycle 在本発明の実施形態における自動二輪車1の左側面図である。自動二輪車1は、鞍乗り型車両の一例である。自動二輪車1は、フロア状のステップ(足置き)を有し、かつシート28前方に乗降用の跨ぎ空間K1を有するスクーター型の車両であるが、バータイプのステップを有する車両や、ニーグリップ部を有する車両であってもよい。自動二輪車1は、エンジン(原動機)11および伝動装置15を一体化して後輪(駆動輪)4とともに上下揺動可能としたユニットスイング式の車両であるが、エンジン11および伝動装置15の少なくとも一方を車体フレーム20に固定的に支持した車両であってもよい。

[0016] The motorcycle 1 includes a front wheel 3 steered by a handle 2 and a rear wheel 4 driven by a power unit 10 including a power source. Steering system components including the handle 2 and the front wheel 3 are steerably supported by a head pipe 21 located at the front end of the vehicle body frame 20. The front portion of the power unit 10 is supported by the front and rear intermediate portion of the vehicle body frame 20 via suspension links or the like so as to be vertically swingable. The rear end portion of the power unit 10 is supported by the rear portion of the vehicle body frame 20 via a reaction cushion 9 which is a buffer device.

[0017] The vehicle frame 20 includes a head pipe 21 that extends vertically and is inclined so that the upper part is positioned further rearward when viewed from the side; an upper down frame 22 that extends downward to the rear from the upper and lower middle part of the head pipe 21; a lower down frame 23 that extends downward from the lower part of the head pipe 21 and then bends to the rear; a seat rail 24 that extends upward to the rear from the longitudinal middle part of the upper down frame 22; and a center frame 25 that extends upward to the rear from the rear end of the lower down frame 23 and supports the longitudinal middle part of the seat rail 24 from below.

[0018] The body frame 20 is covered by a body cover 30. A seat 28 for the occupant is provided at the upper rear of the body cover 30. The vehicle body cover 30 comprises a pair of left and right step floors 31 on which the driver seated on the seat 28 places their feet, a center tunnel 32 extending in the longitudinal direction of the vehicle between the left and right step floors 31, a front body cover 33 connected to the front of the center tunnel 32 and the left and right step floors 31, and a rear body cover 34 connected to the rear of the center tunnel 32 and the left and right step floors 31. Above the center tunnel 32, a straddle space K1 is formed between the seat 28 and the steering wheel 2 to make it easier for the occupant to straddle the vehicle body.

[0019] A main stand 36, which supports the vehicle in an upright position, is supported on the underside of the power unit 10. Figure 1 shows the main stand 36 in its retracted state, flipped up towards the rear of the vehicle. A side stand 37, which supports the vehicle in an upright position tilted to the left, is supported on the lower left of the lower down frame 23. Figure 1 shows the side stand 37 in an upright position, supporting the vehicle in an upright position.

[0020] <Power Unit 10> Figure 2 is a left side view showing the area around the power unit 10 of the motorcycle 1. Figure 3 is a plan view including an unfolded section of the area around the drive pulley 46 of the V-belt type continuously variable transmission 16 of the power unit 10. Figure 4 is a cross-sectional view showing an enlarged unfolded section of Figure 3. As shown in Figures 2 to 4, the power unit 10 comprises a water-cooled single-cylinder engine (internal combustion engine) 11 and a transmission device 15 connected to the engine 11 and the rear wheel 4, which transmits the output of the engine 11 to the rear wheel 4. The transmission case 15a of the transmission device 15 is integrally coupled (for example, integrally formed) to the body (crankcase 13) of the engine 11.

[0021] Referring also to Figure 1, the engine 11 comprises a crankcase 13 supporting the crankshaft 12 and a cylinder 14 coupled to the front of the crankcase 13. An intake device 18A is connected to the upper part of the cylinder head of the cylinder 14, and an exhaust device 19A is connected to the lower part of the cylinder head. An air cleaner 18, connected to the intake device 18A, is supported on the upper part of the transmission case 15a. An exhaust muffler 19, connected to the exhaust device 19A, is supported on a rear arm (not shown) located to the right of the rear wheel 4.

[0022] The crankcase 13 is divided into left and right case halves in the left-right direction (only the left case half 13a is shown in Figures 3 and 4). The left and right case halves are joined together to form a crank chamber inside. The crank chamber houses the crank web and crank pin (neither shown) of the crankshaft 12. The piston is connected to the crank pin via a connecting rod (neither shown).

[0023] The left journal portion 12a of the crankshaft 12 is rotatably supported in the left case half 13a via the left main bearing 48b. Although not shown in the figure, the right journal portion of the crankshaft 12 is rotatably supported in the right case half via the right main bearing. Line C1 in the figure indicates the rotational axis of the crankshaft 12 (the central axis of the journal portion).

[0024] <Electric continuously variable transmission> Figure 6 is an exploded perspective view of an electrically operated continuously variable transmission according to an embodiment. Referring to Figures 2 to 4 and Figure 6, the transmission 15 comprises a V-belt type continuously variable transmission 16 housed in a transmission case 15a that continuously changes the speed of the rotational power transmitted from the crankshaft 12, and a reduction gear mechanism 17 housed in the rear of the transmission case 15a that reduces the output of the V-belt type continuously variable transmission 16 and transmits it to the axle 4a of the rear wheel 4. The line C4 in the figure indicates the central axis of the rear wheel axle 4a.

[0025] The transmission case 15a comprises a case body 42 that extends continuously from the left side (left case half 13a) of the crankcase 13 to the rear of the vehicle, a case cover 43 fastened to the outside of the case body 42 in the vehicle width direction and partitioning the transmission chamber 43a between it and the case body 42, and a gear cover (not shown) fastened to the inside of the rear of the case body 42 in the vehicle width direction and partitioning the gear chamber housing the reduction gear mechanism 17 between it and the case body 42. A V-belt type continuously variable transmission 16 is housed in the transmission chamber 43a. The case body 42 and the case cover 43 constitute an integrated transmission case 41 that forms the transmission chamber 43a.

[0026] The V-belt type continuously variable transmission 16 includes a drive pulley 46 located in the transmission chamber 43a and coaxially mounted to the left side (small diameter shaft portion 12b) of the crankshaft 12, which serves as the drive shaft, and a driven pulley 48 located in the transmission chamber 43a and mounted to a driven shaft 47 that protrudes from the transmission chamber 43a into the gear chamber. The axial directions of the crankshaft 12, drive pulley 46, and driven pulley 48 are parallel to the left-right direction (vehicle width direction) of the vehicle. Lines C2 and C3 in the figure indicate the central axes of the drive pulley 46 and driven pulley 48, respectively. The drive pulley 46 is coaxially positioned with the crankshaft 12.

[0027] An endless V-belt (transmission belt) 49 is wound around the drive pulley 46 and the driven pulley 48. The belt winding diameter of the drive pulley 46 changes due to the action of the centrifugal weight 66 and the drive of the actuator unit 50. The belt winding diameter of the driven pulley 48 changes in accordance with the change in the belt winding diameter of the drive pulley 46. The actuator unit 50 is equipped with an electric motor (hereinafter simply referred to as "motor") 56 as a drive source. The V-belt type continuously variable transmission 16 is combined with the actuator unit 50 and a control device (not shown) to constitute an electric continuously variable transmission. The actuator unit 50 controls the operation of the drive pulley 46 as the controlled pulley.

[0028] The drive pulley 46 comprises a fixed sheave 51 fixed to the crankshaft 12, and a movable sheave 52 positioned on the inside of the fixed sheave 51 in the vehicle width direction, with its umbrella-shaped face facing the fixed sheave 51, and supported by the crankshaft 12 so as to be movable in the axial direction. The movable sheave 52 is positioned between the left case half 13a of the crankcase 13 and the fixed sheave 51. A V-groove is formed between the fixed sheave 51 and the movable sheave 52, around which the V-belt 49 is wound. The movable sheave 52 has a movable sheave boss 52a through which the crankshaft 12 is inserted. The movable sheave boss 52a protrudes toward the left case half 13a from the umbrella-shaped sheave body that forms the face surface.

[0029] The V-belt type continuously variable transmission 16 includes a first shift mechanism 53 actuated by a centrifugal weight 66 and a second shift mechanism 54 actuated by an actuator unit 50. In response to the operation of the first shift mechanism 53 and the second shift mechanism 54, the movable sheave 52 of the drive pulley 46 is moved axially, changing the winding radius of the V-belt 49. The first shift mechanism 53 and the second shift mechanism 54 will be described in detail later.

[0030] The driven pulley 48 comprises a fixed sheave 57 supported on the driven shaft 47 so as not to move axially, and a movable sheave 58 supported so as to move axially. A V-belt 49 is wound around the V-groove between the fixed sheave 57 and the movable sheave 58. The movable sheave 58 moves axially toward and away from the fixed sheave 57. The movable sheave 58 is biased axially toward the fixed sheave 57.

[0031] A centrifugal clutch 59 is coaxially supported on the outer side of the driven shaft 47 in the vehicle width direction. The centrifugal clutch 59 disconnects and reconnects the power transmission between the driven pulley 48 and the driven shaft 47. The centrifugal clutch 59 disconnects and reconnects the rotational power transmission transmitted to the driven pulley 48. The rotation of the drive pulley 46 is transmitted to the driven pulley 48. When the drive pulley 46 increases the winding radius of the V-belt 49, the driven pulley 48 acts to move the movable sheave 58 away from the fixed sheave 57 against the biasing force, thereby decreasing the winding radius of the V-belt 49. This causes a change in speed between the two pulleys 46 and 48 of the V-belt type continuously variable transmission 16.

[0032] The centrifugal clutch 59 does not engage (transmit power) when the rotational speed of the driven pulley 48 is low, but engages to transmit the rotation of the driven pulley 48 to the driven shaft 47 when the driven pulley 48 rotates above a specified rotational speed. When the rotational speed of the driven pulley 48 and, consequently, the engine 11 exceeds a specified rotational speed, the centrifugal clutch 59 establishes a power transmission state.

[0033] The reduction gear mechanism 17 includes a drive gear fixed to or formed on the driven shaft 47 within the gear chamber, a final gear fixed to the axle 4a of the rear wheel 4, and an intermediate gear shaft positioned between the drive gear and the final gear (none of which are shown). The rotation of the driven shaft 47 is reduced in multiple stages by the reduction gear mechanism 17 and transmitted to the axle 4a of the rear wheel 4.

[0034] The first shift mechanism 53 includes a cam member 65 positioned between the fixed sheave 51 of the drive pulley 46 and the left case half 13a of the crankcase 13. The cam member 65 is disc-shaped and coaxial with the crankshaft 12. The small diameter shaft portion 12b, which is the left side of the crankshaft 12, has the cam member 65, sleeve 67, and fixed sheave 51 mounted on it in order from the left case half 13a. A nut 68 is screwed onto the left end of the small diameter shaft portion 12b, fastening each component mounted on the small diameter shaft portion 12b via a washer 68a. In this way, each component is fixed to the crankshaft 12. A movable sheave 52 is supported on the outer circumference of the sleeve 67 so as to be axially movable.

[0035] A centrifugal weight 66 is sandwiched between the cam surface 65a of the cam member 65 and the back surface of the movable sheave 52. The cam surface 65a is inclined to approach the movable sheave 52 as it moves radially outward from the rotation axis C1 of the crankshaft 12. The back surface of the movable sheave 52 is inclined to approach the cam member 65 as it moves radially outward from the rotation axis C1 of the crankshaft 12.

[0036] As the crankshaft 12 rotates, centrifugal force acts on the centrifugal weight 66, causing it to move radially outward. This creates an action that attempts to move the movable sheave 52 axially to the fixed sheave 51, following the inclination of the cam surface 65a and its back surface. By driving the actuator unit 50 in response to this action, it is possible to achieve gear shift control by the actuator unit 50 with minimal energy.

[0037] The second shift mechanism 54 comprises an actuator unit 50 and a pulley drive arm 71 mounted on the rear side (inward in the vehicle width direction) of the movable sheave 52 of the drive pulley 46. On the rear side of the movable sheave boss 52a, a cylindrical intermediate wall portion 52b is formed, rising axially from the radial middle portion of the rear side toward the left case half 13a side (inward in the vehicle width direction). A ball bearing 72 is mounted on the intermediate wall portion 52b. The inner ring of the ball bearing 72 is fitted onto the outer circumference of the intermediate wall portion 52b, and the inner circumference of the pulley drive arm 71 is fitted onto the outer ring. The movable sheave 52 and the pulley drive arm 71 are connected so that they can rotate relative to each other but cannot move relative to each other in the axial direction.

[0038] The actuator unit 50 includes a motor 56 that generates rotational power by having a drive shaft 56a parallel to the axial direction of both pulleys 46 and 48, a lead screw mechanism 73 that converts the rotational power of the motor 56 into axial power of the controlled pulley, and a gear mechanism 91 as a transmission mechanism positioned between the motor 56 and the lead screw mechanism 73. In the figure, line C5 indicates the central axis of the motor 56, and line C6 indicates the central axis of the lead screw mechanism 73.

[0039] The motor 56 of the actuator unit 50 is electrically driven and controlled by a control device (not shown). The actuator unit 50 designates the drive pulley 46 of the two pulleys 46 and 48 as the controlled pulley, and applies an axial force to the movable sheave 52 of the drive pulley 46, thereby moving the movable sheave 52 axially in cooperation with the centrifugal weight 66. By changing the groove width of the drive pulley 46 due to the axial movement of the movable sheave 52, the winding radius of the V-belt 49 changes, and the V-belt type continuously variable transmission 16 changes speed. Hereinafter, the assembly of the components of the actuator unit 50 excluding the lead screw mechanism 73 will be referred to as the actuator body 50a (see Figures 6 and 7).

[0040] The actuator unit 50 (actuator body 50a) includes a unit casing 55 that is attached to the case cover 43 from the outside in the vehicle width direction. A gear mechanism 91 is housed in the mechanism chamber partitioned between the unit casing 55 and the case cover 43. The gear mechanism 91 includes a drive gear 56b fixed or formed on the drive shaft 56a of the motor 56 within the mechanism chamber, a final gear 74a fixed to the shaft 74 of the lead screw mechanism 73, and a pair of intermediate gear shafts 92 and 93 positioned between the drive gear 56b and the final gear 74a. Hereinafter, of the pair of intermediate gear shafts 92 and 93, the one on the motor 56 side will be referred to as the first intermediate gear shaft 92, and the one on the shaft 74 side will be referred to as the second intermediate gear shaft 93. A pair of intermediate gears 92a and 92b are fixed or formed on the first intermediate gear shaft 92. A pair of intermediate gears 93a and 93b are fixed or formed on the second intermediate gear shaft 93.

[0041] One intermediate gear 92a on the first intermediate gear shaft 92 has a larger diameter than the drive gear 56b. When the drive gear 56b meshes with this intermediate gear 92a, the rotation of the drive gear 56b is reduced and transmitted to the first intermediate gear shaft 92. The other intermediate gear 92b has a smaller diameter than one intermediate gear 93a on the second intermediate gear shaft 93. When one intermediate gear 93a on the second intermediate gear shaft 93 meshes with this intermediate gear 92b, the rotation of the first intermediate gear shaft 92 is reduced and transmitted to the second intermediate gear shaft 93. The pair of intermediate gears 93a and 93b on the second intermediate gear shaft 93 are, for example, of the same diameter. The other intermediate gear 93b on the second intermediate gear shaft 93 has a smaller diameter than the final gear 74a on the shaft 74. When the final gear 74a meshes with this intermediate gear 93b, the rotation of the second intermediate gear shaft 93 is reduced and transmitted to the shaft 74. In this way, the rotation of the drive shaft 56a of the motor 56 is reduced in multiple stages and transmitted to the shaft 74 of the lead screw mechanism 73.

[0042] The first intermediate gear shaft 92 has an end that protrudes inward in the vehicle width direction from one of the intermediate gears 92a, which is located inward in the vehicle width direction, and this inward end is supported by the outer wall portion 43b of the case cover 43 via a bearing 92c. The first intermediate gear shaft 92 has the other intermediate gear 92b at its outer end in the vehicle width direction. The intermediate portion of the first intermediate gear shaft 92, located between the pair of intermediate gears 92a and 92b in the vehicle width direction, is supported by the casing body 55a of the unit casing 55 via a bearing 92d.

[0043] The second intermediate gear shaft 93 has an end that protrudes inward in the vehicle width direction from the first intermediate gear 93a, which is located inward in the vehicle width direction, and this inward end is supported by the casing body 55a of the unit casing 55 via a bearing 93c. The second intermediate gear shaft 93 has an end that protrudes outward in the vehicle width direction from the other intermediate gear 93b, which is located outward in the vehicle width direction, and this outward end is supported by the casing cover 55b of the unit casing 55 via a bearing 93d. Around the opening 43d that supports the feed screw mechanism 73 in the outer wall portion 43b of the case cover 43, a recess 43e is formed that opens outward in the vehicle width direction. The opening of the recess 43e is closed by the unit casing 55, forming a mechanism chamber that houses the gear mechanism 91.

[0044] Figure 5 is a cross-sectional view showing an enlarged view of the area around the feed screw mechanism 73 in Figure 4. Referring to Figures 4 and 5, the unit casing 55 and case cover 43 support the feed screw mechanism 73, which is the output mechanism of the actuator unit 50. The feed screw mechanism 73 includes a shaft 74 that is arranged parallel to the axial direction of both pulleys 46 and 48 and rotates around its axis by the output of the actuator unit 50, and a nut member (actuator) 75 that is separate from the unit casing 55 and case cover 43, is arranged coaxially with the shaft 74 and through which the shaft 74 is inserted, and strokes in the axial direction by the rotational motion of the shaft 74.

[0045] The shaft 74 extends with its axis centered on the central axis C6. The inner end 74b of the shaft 74 in the vehicle width direction is rotatably supported in the bearing portion of the case body 42 via a bearing 94 and a thrust bearing 95. The outer end 74c of the shaft 74 in the vehicle width direction is rotatably supported in the bearing portion of the unit casing 55 via a bearing 96 and a thrust bearing 97. The unit casing 55 includes a casing cover 55b that is removable from the casing body 55a. The bearing portion of the unit casing 55 is provided in the casing cover 55b.

[0046] The outer ring of the bearing 94 is press-fitted into the bearing portion of the case body 42. The outer circumference of a cup-shaped thrust bearing 95, which opens outward in the vehicle width direction, is press-fitted into the inner ring of the bearing 94. The inner end 74b of the shaft 74 in the vehicle width direction is inserted into the bottomed recess 95a of the thrust bearing 95 so as to be removable until it bottoms out. A flange portion 95b is formed on the outer circumference of the thrust bearing 95, which abuts the inner ring of the bearing 94 from the axial outside.

[0047] The outer ring of the bearing 96 is press-fitted into the bearing portion of the unit casing 55. The outer circumference of a cup-shaped thrust bearing 97, which opens inward in the vehicle width direction, is press-fitted into the inner ring of the bearing 96. The bottomed recess 97a of the thrust bearing 97 is removably fitted into the outward-projecting end 74c of the final gear 74a on the shaft 74 until it bottoms out. A flange portion 97b is formed on the outer circumference of the thrust bearing 97, which abuts the inner ring of the bearing 96 from the axially inward side.

[0048] The nut member 75 comprises a nut body (member body) 81 which is cylindrical through which the shaft 74 is inserted and has a female thread 81a formed on the inner circumference within a specified range from the outer end in the vehicle width direction; a ball screw nut 82 which holds a plurality of steel balls arranged in a spiral and is inserted into the nut body 81 from the outer end in the vehicle width direction of the nut body 81; and a fixing member 83 which is screwed into the female thread 81a inside the nut body 81 outside the ball screw nut 82 in the vehicle width direction and tightens and fixes the ball screw nut 82 which bottoms out to a stepped portion 81b inside the nut body 81. The nut member 75 is treated as a small assembly in which the nut body 81, ball screw nut 82 and fixing member 83 are assembled together as a single unit.

[0049] The nut member 75 is separate from the unit casing 55, and its outer circumference in the vehicle width direction is slidably supported in the axial direction on the inner circumference of an opening 43d formed in the outer wall portion 43b of the case cover 43. An annular sealing member 84 is held on the outer side of the opening 43d in the vehicle width direction in the outer wall portion 43b, in contact with the outer circumference of the nut member 75. The outer portion of the nut member 75 in the vehicle width direction forms an outer surface parallel to the axial direction up to the outer end in the vehicle width direction, and is axially insertable and detachable from the opening 43d. The inner portion of the nut member 75 in the vehicle width direction is slidably supported on the outer circumference of the shaft 74 at the inner end of an inner flange 85 formed on its inner circumference. An annular sealing member 86 is held on the inner side of the inner flange 85 in the vehicle width direction, in contact with the outer circumference of the shaft 74.

[0050] <Ball Joint 76> Referring to Figures 4 and 5, the nut member 75, which is the output member of the feed screw mechanism 73, is connected to the pulley drive arm 71 via a ball joint 76. The ball joint 76 comprises a connecting pin 77 fixed to one of the pulley drive member and nut member 75, a ball housing 78 formed on the other of the pulley drive member and nut member 75, and a ball bearing (spherical body) 79 housed within the ball housing 78 and supported by the connecting pin 77. In the figure, line C7 indicates the central axis of the connecting pin 77, line C8 indicates the central axis of the ball housing 78, and point CP indicates the center of the ball bearing 79 (the rotation center of the ball joint 76).

[0051] The ball joint 76 in Figures 4 and 5 shows the state in which the connecting pin 77 and the ball housing 78 have their axes C7 and C8 aligned (a state in which the connecting pin 77 is not tilted relative to the ball housing 78; hereinafter referred to as the upright state of the connecting pin 77). In this embodiment, the connecting pin 77 is fixed to the nut member 75, and the ball housing 78 is provided on the pulley drive member.

[0052] The connecting pin 77 comprises a support shaft portion 77a that fits into the connecting hole 79a of the ball bearing 79, and a flange portion 77b provided on the base end side of the support shaft portion 77a, which is formed to be larger in diameter than the ball bearing 79 and smaller in diameter than the counterbore portion 78b. A clip 77e can be attached to a groove portion 77d that runs along the circumferential direction on the tip side of the support shaft portion 77a. The clip 77e prevents the ball bearing 79, which is supported through the support shaft portion 77a, from coming loose.

[0053] The ball housing 78 is provided at the end of the pulley drive arm 71 opposite the movable sheave 52 in the radial direction, and has a cup shape that opens radially outward (towards the nut member 75) of the movable sheave 52. A recess is formed on the outer circumference of the nut member 75 on the inner side in the vehicle width direction, recessing radially inward from the nut member 75, and the fixed shaft portion 77c of the connecting pin 77 is press-fitted into this recess and fixed. The ball bearing 79, supported by the support shaft portion 77a of the connecting pin 77, is removably fitted and held within the ball housing 78 of the pulley drive arm 71 together with the support shaft portion 77a.

[0054] The ball housing 78 includes a cylindrical support wall portion 78a that is in contact with the ball bearing 79 directly or via an intermediate member, and a counterbore portion 78b formed on the opening 78d side of the support wall portion 78a and having an inner diameter larger than the inner diameter of the support wall portion 78a and the outer diameter of the flange portion 77b.

[0055] Between the inner circumferential surface of the support wall portion 78a and the inner circumferential surface of the counterbore portion 78b, a planar stepped portion 78c is formed perpendicular to the axial direction of the ball housing 78. The stepped portion 78c forms a stepped surface that faces the flange portion 77b of the connecting pin 77 in the axial direction. In the upright position of the connecting pin 77, the stepped surface and the end face of the flange portion 77b on the stepped surface side overlap each other when viewed from the axial direction, and face each other with a gap in the axial direction. The opening 78d of the ball housing 78 faces the pin fixing portion of the nut member 75 that fixes the connecting pin 77 in the axial direction.

[0056] When the connecting pin 77 is in its upright position, a gap is formed between the outer circumference of the flange portion 77b and the inner circumference of the counterbore portion 78b. The connecting pin 77 can be tilted relative to the ball housing 78 by a specified angle in any direction from its upright position. When the connecting pin 77 is tilted relative to the ball housing 78 from its upright position, the flange portion 77b and the stepped portion 78c approach each other on the tilted side, and the outer edge of the flange portion 77b can come into contact with the stepped portion 78c. The contact between the flange portion 77b and the stepped portion 78c limits the tilt of the connecting pin 77 to a specified angle.

[0057] From the upright position of the connecting pin 77 until its tilt is restricted by the stepped portion 78c, at least a portion of the flange portion 77b of the connecting pin 77 is inserted into the counterbore portion 78b through the opening 78d of the ball housing 78. This configuration causes the flange portion 77b to close the opening 78d of the ball housing 78, thereby preventing foreign matter from entering the ball housing 78 and preventing grease from leaking out of the ball housing 78.

[0058] The connecting pin 77 is held in the ball housing 78, which restricts the rotation of the nut member 75 around its axis C6. This prevents the nut member 75 from rotating along with the shaft 74, accurately converting the rotational power of the shaft 74 (and thus the rotational power of the motor 56) into thrust for the nut member 75, allowing the movable sheave 52 to move axially. Since the connecting pin 77 can swing within a range where it does not contact the stepped portion 78c of the ball housing 78, it can absorb component tolerances of the actuator unit 50. It can also absorb vibrations of the pulley drive member caused by pulley vibrations, preventing the generation of vibration noise and improving the durability of the actuator 50. Since the maximum swing angle of the connecting pin 77 is defined by contact with the stepped portion 78c, the axial driving force of the lead screw mechanism 73 can be transmitted from the connecting pin 77 to the ball housing 78 with minimal loss while allowing the connecting pin 77 to swing.

[0059] <Assembly of the electric continuously variable transmission> Figure 7 is an exploded perspective view showing the external configuration of the transmission case 15a in Figure 6. Figure 8 is an exploded perspective view showing the internal configuration of the transmission case 15a in Figure 6. The procedure for assembling the electric continuously variable transmission will be explained below with reference to Figures 4 through 8.

[0060] First, the connecting pin 77, fixed to the nut member 75 of the feed screw mechanism 73, is inserted along the radial direction of the movable sheave 52 into the ball housing 78 of the pulley drive arm 71, which is attached to the movable sheave 52 and opens radially outward from the movable sheave 52. The small assembly of the movable sheave 52, pulley drive member, and feed screw mechanism 73 is housed in the transmission case 15a along the vehicle width direction, with the movable sheave 52 passing through the small diameter shaft portion 12b of the crankshaft 12 and being supported by the small diameter shaft portion 12b, and the feed screw mechanism 73 is supported by inserting the inner end 74b of the shaft 74 in the vehicle width direction into the thrust bearing 95 of the bearing portion of the case body 42.

[0061] The assembly described above can be easily performed with the transmission case 15a open (before the case cover 43 is installed). The movable sheave 52, pulley drive arm 71, and lead screw mechanism 73 can also be assembled by, for example, first assembling the movable sheave 52 and pulley drive arm 71 to the small diameter shaft portion 12b of the crankshaft 12, and then assembling the lead screw mechanism 73. In this case as well, since the assembly is performed with the transmission case 15a open, the workability of the assembly can be improved compared to when the assembly is performed after the case cover 43 is installed.

[0062] Next, the assembly of the driven pulley 48, centrifugal clutch 59, and V-belt 49 is inserted and assembled into the transmission case 15a along the vehicle width direction. The small assembly of the driven pulley 48 and centrifugal clutch 59 is housed in the transmission case 15a along the vehicle width direction, passing through the driven shaft 47 and supported by the driven shaft 47. On the drive pulley 46 side, the fixed sheave 51 is housed in the transmission case 15a along the vehicle width direction and supported by the small diameter shaft portion 12b of the crankshaft 12. After the fixed sheave 51 is assembled, a washer 68a and a nut 68 are attached to the end of the small diameter shaft portion 12b, and the fixed sheave 51 and other components are fastened and secured to the small diameter shaft portion 12b.

[0063] Next, the case cover 43 is attached to close the open portion on the outer side of the transmission case 15a in the vehicle width direction. At this time, the outer portion of the nut member 75 of the feed screw mechanism 73 in the vehicle width direction is inserted through the opening 43d of the case cover 43 and supported. The outer portion of the feed screw mechanism 73 in the vehicle width direction protrudes outward from the opening 43d of the case cover 43 in the vehicle width direction.

[0064] Next, the first intermediate gear shaft 92 is housed in the recess 43e around the opening 43d of the case cover 43, and then the actuator body 50a is attached to the recess 43e of the case cover 43 to close it. At this time, the casing cover 55b is removed and the casing body 55a is left open.

[0065] Next, the second intermediate gear shaft 93 and final gear 74a of the gear mechanism 91 are housed in the casing body 55a and assembled to the mating parts, thereby completing the assembly of the gear mechanism 91. After that, the casing cover 55b is attached to the opening of the casing body 55a to close it. At this time, the outer end 74c in the vehicle width direction of the shaft 74 is inserted into the thrust bearing 97 of the bearing portion of the casing cover 55b and supported. With this, the assembly of the electric continuously variable transmission is completed.

[0066] As described above, the electric continuously variable transmission in the above embodiment includes a drive pulley 46 supported on the input shaft (crankshaft 12), a driven pulley 48 supported on the output shaft (driven shaft 47), a transmission belt 49 wrapped around the drive pulley 46 and the driven pulley 48, a transmission case 15a housing the drive pulley 46, the driven pulley 48 and the transmission belt 49, and an actuator attached to the transmission case 15a and driven by a control device, which applies axial force to the movable sheave 52 of the drive pulley 46, treating one of the drive pulley 46 (drive pulley 46) as the controlled pulley, thereby changing the groove width. In an electrically operated continuously variable transmission comprising an actuator 50, the actuator 50 comprises a motor 56 that generates rotational power and a lead screw mechanism 73 that converts the rotational power of the motor 56 into axial power of a drive pulley 46. The transmission case 15a comprises a case body 42 that opens toward one axial side and a case cover 43 that covers one axial side of the case body 42 and to which the actuator 50 is attached from the outside of the case. The case cover 43 has an opening 43d that is closed by an actuator body 50a which is separate from the lead screw mechanism 73 in the actuator 50, and the lead screw mechanism 73 is supported so as to be insertable and detachable within the opening 43d.

[0067] With this configuration, the lead screw mechanism 73 of the actuator 50 is separate from the actuator body 50a and is supported so as to be insertable and removable within the opening 43d of the case cover 43. This makes it possible to connect one end of the lead screw mechanism 73 to the drive pulley 46 while the case body 42 is open, before attaching the case cover 43 to the case body 42 of the transmission case 15a. Subsequently, the case cover 43 is attached to the case body 42 while inserting the other end of the lead screw mechanism 73 into the opening 43d, and then the actuator body 50a is attached to the case cover 43. This closes the opening 43d of the case cover 43 and connects the other end of the lead screw mechanism 73 to the actuator body 50a outside the transmission case 15a. In this way, the lead screw mechanism 73 of the actuator 50 can be assembled to the drive pulley 46 before the case cover 43 is attached to the case body 42. This makes the assembly of the electric continuously variable transmission easier compared to the case where the lead screw mechanism 73 is assembled to the drive pulley 46 after the case cover 43 is attached.

[0068] In the above-described electric continuously variable transmission, the feed screw mechanism 73 comprises a shaft 74 arranged parallel to the axial direction of both pulleys 46 and 48 and rotating around its axis by the driving force of the motor 56, and an operating member (nut member 75) arranged coaxially with the shaft 74, through which the shaft 74 is inserted and which strokes in the axial direction by the rotational motion of the shaft 74. The nut member 75 is supported so as to be insertable and removable within the opening 43d, and one end 74c of the shaft 74 protruding from the nut member 75 is supported by the actuator body 50a. With this configuration, by supporting one end 74c of the shaft 74 with the actuator body 50a, if the actuator body 50a is attached after the lead screw mechanism 73 has been assembled, the one end 74c of the shaft 74 protruding from the nut member 75 can be supported by the actuator body 50a. This makes it easier to assemble the lead screw mechanism 73 and simplifies the assembly of the electric continuously variable transmission.

[0069] In the above-described electric continuously variable transmission, the other end 74b of the shaft 74 is supported by the case body 42, and both ends 74b and 74c of the shaft 74 are supported by the actuator body 50a and the case body 42 via thrust supports 95 and 97, respectively. With this configuration, both ends 74b and 74c of the shaft 74 are supported via thrust supports 95 and 97, respectively, so that the reaction force when the nut member 75 is thrust can be received by the case cover 43 and the case body 42.

[0070] In the above-described electric continuously variable transmission, a pulley drive member (pulley drive arm 71) is attached to the movable sheave 52 of the drive pulley 46 and is capable of applying axial thrust to the movable sheave 52. The pulley drive arm 71 and the nut member 75 of the feed screw mechanism 73 are connected via a ball joint 76. The ball joint 76 comprises a connecting pin 77 fixed to the nut member 75, a ball housing 78 provided on the pulley drive arm 71, and a ball bearing 79 housed within the ball housing 78 and supported by the connecting pin 77. With this configuration, the connecting pin 77 of the ball joint 76 is fixed to the nut member 75, and the ball housing 78 is provided on the pulley drive arm 71. Compared to the case where the ball housing 78 is provided on the nut member 75, this configuration makes it possible to reduce the size of the nut member 75 and to simplify the assembly of the feed screw mechanism 73.

[0071] In the above-described electric continuously variable transmission, the ball housing 78 allows the ball bearing 79 to be inserted into and removed from an opening 78d facing the nut member 75. With this configuration, the ball bearing 79 can be easily assembled into the ball housing 78 by inserting and removing it from the opening 78d of the ball housing 78 facing the nut member 75, while the ball bearing 79 is assembled to the feed screw mechanism 73 as a small assembly. If the ball bearing 79 is held in place in the ball housing 78 beforehand, it becomes difficult to insert the connecting pin 77 when the ball bearing 79 is tilted.

[0072] In the above-described electric continuously variable transmission, the nut member 75 comprises a member body (nut body 81) which is cylindrical in shape through which the shaft 74 is inserted and has a female thread 81a formed on the inner circumference within a specified range from one end in the axial direction; a ball screw nut 82 which holds a plurality of steel balls arranged in a spiral and is inserted into the nut body 81 from one end in the axial direction; and a fixing member 83 which is screwed into the female thread 81a inside the nut body 81 on the axial side of the ball screw nut 82 and tightens and fixes the ball screw nut 82 which bottoms out on the stepped portion 78c inside the nut body 81. With this configuration, the ball screw nut 82 is inserted into the nut body 81, and the ball screw nut 82 is tightened and secured with the nut body 81 and the fixing member 83, allowing the nut body 81, ball screw nut 82, and fixing member 83 to be treated as a single, integrated small assembly.

[0073] It should be noted that the present invention is not limited to the above embodiments. For example, the electric continuously variable transmission of this embodiment may be applied to saddle-type vehicles other than motorcycles. The saddle-type vehicles include all vehicles on which the driver straddles the vehicle body, and include not only motorcycles (including motorized bicycles and scooter-type vehicles) but also three-wheeled vehicles (including vehicles with one front wheel and two rear wheels, as well as vehicles with two front wheels and one rear wheel) or four-wheeled vehicles (such as four-wheeled buggies). Furthermore, it includes not only scooter-type vehicles with a straddling space but also vehicles with a straddling section. It may also be applied to vehicles that include an electric motor as the power source.

[0074] In an electrically operated continuously variable transmission, the operation of the driven pulley may be controlled by an actuator. Alternatively, the controlled pulley may be operated solely by the actuator without the use of centrifugal weights. In the actuator, the motor may be configured so that its axial direction is perpendicular to the vehicle width direction. Alternatively, the connecting pin may be fixed to the pulley drive member, and the ball housing may be provided on the nut member. Alternatively, the shaft of the lead screw mechanism may be the operating member. Furthermore, the configuration in the above embodiment is just one example of the present invention, and various modifications are possible without departing from the spirit of the invention, such as replacing the components of the embodiment with well-known components. [Explanation of Symbols]

[0075] 1. Motorcycle (saddle-type vehicle) 10 Power Units 11. Engine (Internal Combustion Engine) 12 Crankshaft (Input Shaft) 15 Transmission device 15a Transmission case 16 V-belt type continuously variable transmission 41 Gearbox 42 Case body 43 Case Cover 43d aperture 46. ​​Drive pulley (controlled pulley) 47 Driven shaft (output shaft) 48 Driven pulley 49 V-belt (power transmission belt) 50 Actuator Unit (Actuator) 50a Actuator Body 52 Movable sheave 56 Motor 71 Pulley drive arm (pulley drive component) 73 Lead screw mechanism 74 shaft 74b Other end 74c One end 75 Nut component 76 Ball joint 77 Connecting pins 78 Ball Housing 78d aperture 81 Nut body 81a Female thread 81b Stepped section 82 Ball screw nut 83 Fixing member 95,97 Thrust receiver

Claims

1. An electric continuously variable transmission comprising: a drive pulley (46) supported on an input shaft (12); a driven pulley (48) supported on an output shaft (47); a transmission belt (49) wrapped around the drive pulley (46) and the driven pulley (48); a transmission case (15a) housing the drive pulley (46), the driven pulley (48), and the transmission belt (49); and an actuator (50) attached to the transmission case (15a) and driven by a control device, which applies axial force to a movable sheave (52) of one of the drive pulley (46) and the driven pulley (48), thereby changing the groove width, wherein the device comprises: a drive pulley (46) supported on an input shaft (12); a driven pulley (48) supported on an output shaft (47); a transmission belt (49) wrapped around the drive pulley (46) and the driven pulley (48). The actuator (50) is A motor (56) that generates rotational power, The system includes a feed screw mechanism (73) that converts the rotational power of the motor (56) into axial power of the controlled pulley (46), The transmission case (15a) comprises a case body (42) that opens toward one axial side, and a case cover (43) that covers one axial side of the case body (42) and on which the actuator (50) is attached from the outside of the case. The case cover (43) has an opening (43d) that is closed by an actuator body (50a) which is separate from the feed screw mechanism (73) in the actuator (50). The feed screw mechanism (73) is supported so as to be insertable and removable within the opening (43d), The aforementioned feed screw mechanism (73) is A shaft (74) is arranged parallel to the axial direction of the drive pulley (46) and the driven pulley (48), and rotates around its axis by the driving force of the motor (56), The system includes a nut member (75) which is arranged coaxially with the shaft (74), through which the shaft (74) is inserted, and which strokes in the axial direction due to the rotational motion of the shaft (74), The nut member (75) is supported so as to be removable within the opening (43d), One end (74c) of the shaft (74) protruding from the nut member (75) is supported by the actuator body (50a), The other end (74b) of the shaft (74) is an electrically operated continuously variable transmission supported by the case body (42).

2. The electric continuously variable transmission according to claim 1, wherein both ends (74b, 74c) of the shaft (74) are supported by the actuator body (50a) and the case body (42) via thrust supports (95, 97), respectively.

3. The pulley drive member (71) is attached to the movable sheave (52) of the controlled pulley (46) and is capable of applying axial thrust to the movable sheave (52), The pulley drive member (71) and the nut member (75) of the feed screw mechanism (73) are connected via a ball joint (76). The electric continuously variable transmission according to claim 1 or 2, wherein the ball joint (76) comprises a connecting pin (77) fixed to the nut member (75), a ball housing (78) provided on the pulley drive member (71), and a ball bearing (79) housed within the ball housing (78) and supported by the connecting pin (77).

4. The electric continuously variable transmission according to claim 3, wherein the ball housing (78) allows the ball bearing (79) to be inserted into and removed from an opening (78d) facing the nut member (75).

5. The nut member (75) is A nut body (81) is cylindrical through which the shaft (74) is inserted, and has an internal thread (81a) formed on the inner circumference within a specified range from one end in the axial direction, A ball screw nut (82) is inserted into the nut body (81) from one axial end of the nut body (81), and holds multiple steel balls arranged in a spiral shape. The electric continuously variable transmission according to claim 1 or 2, further comprising: a fixing member (83) which is screwed into the female thread (81a) in the nut body (81) at one axial end of the ball screw nut (82) and which tightens and fixes the ball screw nut (82) that is bottomed out in the stepped portion (81b) within the nut body (81).

Images