Continuously variable transmission and vehicle
The pulley device with a torque cam mechanism and dual groove structure in CVT addresses noise issues while enhancing gear change responsiveness and fuel efficiency.
Patent Information
- Application Number
- JP2024042304
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-03-18
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2044-03-18
AI Technical Summary
Existing cam mechanisms in continuously variable transmissions (CVT) improve gear change responsiveness but generate hammering noise, reducing marketability.
A pulley device with a torque cam mechanism featuring a cam pin and cam groove structure that allows the movable sheave to move axially, incorporating a first and second groove portion to manage gear ratio changes based on load, thereby suppressing noise and enhancing power performance and energy efficiency.
The pulley device achieves smooth gear ratio transitions, reduces noise, and maintains power performance, contributing to improved fuel economy and energy efficiency.
Smart Images

Figure 0007775356000001 
Figure 0007775356000002 
Figure 0007775356000003
Abstract
Description
[Technical Field]
[0001] The present invention relates to a pulley device that can be applied mainly to a continuously variable transmission. [Background technology]
[0002] In recent years, research and development has been conducted into improving fuel efficiency, which contributes to energy efficiency, in order to ensure that more people have access to affordable, reliable, sustainable and advanced energy. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Patent Publication No. 2021-193315 Summary of the Invention [Problem to be solved by the invention]
[0004] Regarding the above-mentioned improvement in fuel economy, Patent Document 1 describes a technology in which a cam mechanism is provided on the drive pulley of a continuously variable transmission, and a movable sheave is moved by a pin abutting against the cam contour, thereby improving gear change responsiveness during acceleration and deceleration. A structure equipped with such a cam mechanism can improve gear change responsiveness during acceleration and deceleration, while also enabling a quicker shift to the top ratio under low loads compared to a structure without a cam mechanism, thereby enabling the engine speed to be maintained at a low level, thereby improving fuel economy. However, such a cam mechanism may generate hammering noise, which may reduce marketability.
[0005] The present invention aims, for example, to further improve the structure of a cam mechanism in a pulley device, and ultimately to contribute to ensuring power performance and energy efficiency while suppressing a decrease in marketability. [Means for solving the problem]
[0006] One aspect of the present invention iscontinuously variable transmission The above continuously variable transmission teeth, Installed on the output rotating shaft of the power source A continuously variable transmission that can be mounted on a vehicle, the continuously variable transmission comprising a driving pulley, a driven pulley, and a belt installed between the driving pulley, The drive pulley is A fixed sheave; a movable sheave that is axially movable relative to the fixed sheave; a weight roller mechanism for shifting the movable sheave to the top ratio side in accordance with the rotation speed of the output rotary shaft; a rotor provided around the output rotary shaft between the output rotary shaft and the movable sheave, and configured to rotate the movable sheave in the axial direction; in a first direction away from the fixed sheave a torque cam mechanism capable of generating a force to move the The torque cam mechanism a cam pin extending radially outward from the output rotary shaft; a cam groove forming structure having a cam groove in which the cam pin can slide; It is equipped with The cam groove is The movable sheave is driven by the rotation of the output rotary shaft. The aforementioned a first groove portion formed so that the cam groove forming structure receives a force from the cam pin in a first direction; a second groove portion connected to the first groove portion at one end of the first groove portion where the cam pin is located when the output rotation shaft is not rotating, and formed so that the cam groove forming structure receives a force from the cam pin in a second direction opposite to the first direction; Including and transmitting a force in the second direction from the cam pin to the second groove portion while the vehicle is substantially stopped. It is characterized by: [Effects of the Invention]
[0007] According to the present invention, it is possible to further improve the structure of the cam mechanism in the pulley device, and further to improve energy efficiency. [Brief explanation of the drawings]
[0008] [Figure 1] 1 is a schematic side view of a vehicle structure according to an embodiment; [Figure 2] 1 is a cross-sectional view showing an example of the structure of a continuously variable transmission (CVT). [Figure 3] FIG. 2 is an enlarged schematic view of the drive pulley and its surrounding area. [Figure 4] FIG. 4 is a schematic diagram for explaining the detailed structure of a torque cam mechanism. [Figure 5] FIG. 2 is an exploded schematic view of a torque cam mechanism. [Figure 6] 4A and 4B are schematic side views showing the positional relationship of each element in the torque cam mechanism at low and top ratios. DETAILED DESCRIPTION OF THE INVENTION
[0009] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be omitted.
[0010] <<Vehicle configuration examples>> FIG. 1 is a schematic side view of the structure of a vehicle 1 according to an embodiment. To facilitate understanding of the structure, the figure shows an X-axis, a Y-axis, and a Z-axis that are orthogonal to one another (the same applies to other figures described below). The X-axis corresponds to the front-rear direction, the Y-axis corresponds to the left-right direction, and the Z-axis corresponds to the up-down direction. In this specification, expressions such as front / rear, left / right (side), and up / down indicate relative positional relationships with respect to the vehicle body. For example, expressions such as "front" and "forward" correspond to the +X direction, and expressions such as "rear" and "rearward" correspond to the -X direction.
[0011] The vehicle 1 includes wheels 11, a power unit 12, and a driving operation mechanism 13. In this embodiment, the vehicle 1 is a two-wheeled vehicle that includes front wheels that are steered and rear wheels that are driven as wheels 11, and although the two-wheeled vehicle illustrated here is a scooter type, other examples include a saddle-ride type or a rider type. Furthermore, the number of wheels 11 is not limited to that in this example, and the vehicle 1 may be a four-wheeled vehicle, for example.
[0012] The power unit 12 includes a power source 121 and a power transmission mechanism 122. The power source 121 may be any known configuration capable of generating power, and in this embodiment, an internal combustion engine is used, but in other embodiments, an electric motor may be used. The power (rotation) of the power source 121 is transmitted to the rear wheels, which are drive wheels, via the power transmission mechanism 122. As will be described in detail later, the power transmission mechanism 122 includes a continuously variable transmission (CVT) 2, and power according to the gear ratio is transmitted to the rear wheels (see FIG. 2).
[0013] The driving operation mechanism 13 is mainly provided at a position accessible to the driver (rider) at the front of the vehicle, and is configured, for example, with multiple operators arranged on a handlebar that can change the direction of the front wheels, which are steered. Examples of the operators include an acceleration operator, a braking operator, and a direction indicator operator.
[0014] <<Configuration example of continuously variable transmission>> Fig. 2 is a cross-sectional schematic diagram showing an example of the structure of the CVT 2. In this embodiment, the CVT 2 includes pulley devices 21 and 22 arranged side by side in the X direction, and a belt 23 mounted thereon. Fig. 3 is an enlarged schematic diagram of the pulley device 21 and its surroundings.
[0015] <About the drive pulley> The pulley device 21 is provided on an output rotation shaft AX1 of the power source 121 and receives power from the power source 121. The pulley device 21 will be referred to as a drive pulley 21 in the following description to distinguish it from the pulley device 22. The output rotation shaft AX1 is a rotation shaft (crankshaft in this embodiment) on the power source 121 side in the power transmission mechanism 122, and will be referred to as a drive shaft AX1 in the following description.
[0016] The drive pulley 21 includes a fixed sheave 21a, a movable sheave 21b, a torque cam mechanism 21c, a ramp plate 21d, and a weight roller 21e.
[0017] The sheaves 21a and 21b are generally conical in shape and are arranged opposite each other (the sheaves 21a and 21b may also be referred to as pulley halves). The fixed sheave 21a is fixed to the drive shaft AX1. The movable sheave 21b is supported by the drive shaft AX1 so as to be movable in the axial direction (the direction of the drive shaft AX1; in this embodiment, the Y direction) relative to the fixed sheave 21a. The diameter of the belt 23 wound around and between the sheaves 21a and 21b is kept small while the movable sheave 21b is separated from the fixed sheave 21a, and increases as the movable sheave 21b approaches the fixed sheave 21a.
[0018] The torque cam mechanism 21c is mounted around the drive shaft AX1 between the drive shaft AX1 and the movable sheave 21b, and in this embodiment includes a cam pin 211, a cam pin fixing structure 212, a cam groove forming structure 213, and a cam pin sealing structure 214. The cam pin fixing structure 212 is cylindrically configured to surround the drive shaft AX1 and is fixed to the drive shaft AX1, and the cam pins 211 are engaged with and fixed to the cam pin fixing structure 212. As a result, the cam pins 211 are arranged to extend radially outward from the drive shaft AX1 (in a direction away from the drive shaft AX1). A head 211h of the cam pin 211 extends radially outward from the cam pin fixing structure 212, and this head 211h can be configured to be rotatable. A plurality of cam pins 211 (for example, three) can be arranged. The cam groove forming structure 213 is fixed to the drive shaft AX1 and is cylindrically configured to surround the cam pin fixing structure 212 that fixes the cam pin 211, and has a cam groove T1, and is arranged so as to be movable in the axial direction relative to the cam pin fixing structure 212. The cam pin 211 fixed to the cam pin fixing structure 212 has a head portion 211h that is slidable relative to the cam groove T1 of the cam groove forming structure 213. A plurality of cam grooves T1 (for example, three) can be provided corresponding to the cam pins 211. The cam pin sealing structure 214 is configured in a cylindrical shape so as to surround the cam groove forming structure 213 , and seals the cam pin 211 so that the cam pin 211 does not come off the cam pin fixing structure 212 .
[0019] Here, the cam groove T1 extends in a direction inclined with respect to the axial direction, and as a result, the cam groove forming structure 213 receives a force (thrust force) from the cam pin 211 that moves the movable sheave 21b in the axial direction (Y direction) due to the rotation of the drive shaft AX1. Although details will be described later, in this embodiment, the cam groove forming structure 213 receives a force from the cam pin 211 in a direction (-Y direction) that moves it away from the fixed sheave 21a. With this structure, the cam groove forming structure 213 receives a force in the axial direction from the cam pin 211 due to the rotation of the drive shaft AX1, and the torque cam mechanism 21c generates a force that moves the movable sheave 21b in the axial direction.
[0020] The ramp plate 21d is disposed on the opposite side of the fixed sheave 21a with respect to the movable sheave 21b, and together with the movable sheave 21b, forms a space for accommodating a weight roller 21e, which will be described later.
[0021] The weight roller 21e is disposed on the opposite side of the fixed sheave 21a with respect to the movable sheave 21b, and is housed in a space formed between the movable sheave 21b and the ramp plate 21d so as to be movable radially outward. The contact surface F21b of the movable sheave 21b that contacts the weight roller 21e is inclined with respect to a plane perpendicular to the axial direction (the XZ plane). Therefore, when the drive shaft AX1 rotates, the resulting centrifugal force causes the weight roller 21e to move radially outward, and generates a force in the direction (+Y direction) that moves the movable sheave 21b closer to the fixed sheave 21a. This causes the movable sheave 21b to be pressed toward the fixed sheave 21a. The movement of the weight roller 21e here is a concept that includes rolling and sliding, and the weight roller 21e rolls and / or slides on the contact surface F21b of the movable sheave 21b. Therefore, the contact surface F21b may be expressed as a rolling surface or a sliding surface.
[0022] <About the driven pulley> 2, the pulley device 22 receives power from the drive pulley 21 via a belt 23. The pulley device 22 will be referred to as a driven pulley 22 in the following description to distinguish it from the pulley device 21.
[0023] The driven pulley 22 includes a fixed sheave 22a, a movable sheave 22b, a torque cam mechanism 22c, and a biasing unit 22d.
[0024] Like the sheaves 21a and 21b described above, the sheaves 22a and 22b have a generally conical shape and are arranged opposite each other. The fixed sheave 22a is fixed to the driven shaft AX2. The movable sheave 22b is supported by the driven shaft AX2 so as to be movable in the axial direction (the direction of the driven shaft AX2, the Y direction) relative to the fixed sheave 22a. The diameter of the belt 23 wound around and between the sheaves 22a and 22b is maintained large while the movable sheave 22b is close to the fixed sheave 22a, and becomes smaller as the movable sheave 22b moves away from the fixed sheave 22a.
[0025] The torque cam mechanism 22c has the same function as the torque cam mechanism 21c, that is, it generates a force that moves the movable sheave 22b in the axial direction due to the rotation of the driven shaft AX2.
[0026] The biasing unit 22d biases the movable sheave 22b toward the fixed sheave 22a so that the movable sheave 22b approaches the fixed sheave 22a. Any known biasing means may be used for the biasing unit 22d, and a coil spring is typically used.
[0027] The rotation of the driven shaft AX2 is transmitted directly or indirectly to the rear wheels, which are the driving wheels. In other words, the driven shaft AX2 may be connected to the rotation axis of the rear wheels via another power transmission mechanism, or may substantially coincide with the rotation axis of the rear wheels.
[0028] <Gear ratio> In the configuration of the CVT 2 described above, the belt 23 is installed between the pulleys 21 and 22. For example, when the distance between the sheaves 21a and 21b of the drive pulley 21 becomes smaller (the diameter of the belt 23 wound around them becomes larger), the distance between the sheaves 22a and 22b of the driven pulley 22 becomes larger (the diameter of the belt 23 wound around them becomes smaller). Similarly, when the distance between the sheaves 21a and 21b of the drive pulley 21 becomes larger (the diameter of the belt 23 wound around them becomes smaller), the distance between the sheaves 22a and 22b of the driven pulley 22 becomes smaller (the diameter of the belt 23 wound around them becomes larger). With this configuration, the power of the power source 121 is transmitted to the rear wheel, which is the drive wheel, at a gear ratio according to the diameter of the belt 23 at the drive pulley 21 and the diameter of the belt 23 at the driven pulley 22. Because the diameter of the belt 23 is continuously variable at both the pulleys 21 and 22, the gear ratio is continuously changed and there are no gear stages (i.e., continuously variable transmission).
[0029] For example, when the vehicle 1 is stopped, the movable sheave 21b is spaced apart from the fixed sheave 21a (the diameter of the belt 23 in the drive pulley 21 is small) and the movable sheave 22b is close to the fixed sheave 22a (the diameter of the belt 23 in the driven pulley 22 is large), and the speed ratio of the CVT 2 is large at this time. The state in which the movable sheave 21b is farthest from the fixed sheave 21a and the movable sheave 22b is closest to the fixed sheave 22a is the state in which the speed ratio is largest (low ratio). Thereafter, as the vehicle 1 accelerates, the moving sheave 21b approaches the fixed sheave 21a and the moving sheave 22b moves away from the fixed sheave 22a, continuously decreasing the speed ratio of the CVT 2. The state in which the moving sheave 21b is closest to the fixed sheave 21a and the moving sheave 22b is farthest from the fixed sheave 22a is the state in which the speed ratio is lowest (top ratio).
[0030] The speed change (i.e., the movement of the movable sheaves 21b and 22b) can be determined by the axial forces generated by the torque cam mechanism 21c and weight roller 21e of the drive pulley 21, and the torque cam mechanism 22c and biasing unit 22d of the driven pulley 22. For ease of understanding, the force generated by the torque cam mechanism 21c of the drive pulley 21 is defined as F1 (-Y direction), and the force generated by the weight roller 21e is defined as F2 (+Y direction). Furthermore, the force generated by the torque cam mechanism 22c of the driven pulley 22 is defined as F3 (-Y direction), and the force generated by the biasing unit 22d is defined as F4 (-Y direction). In this case: If |F1+F2|=|F3+F4|, the gear ratio is maintained; If |F1+F2|>|F3+F4|, the top ratio is approached (continuous upshifts); If |F1+F2|<|F3+F4|, the gear ratio approaches a low ratio (shifts down continuously).
[0031] Furthermore, in the configuration of the CVT 2, the direction in which the force F1 of the torque cam mechanism 21c is generated is the -Y direction (the direction in which the movable sheave 21b moves away from the fixed sheave 21a). This allows for a gradual upshift when a high load is applied to the power source 121, for example, when climbing a slope, and thereby enables the vehicle 1 to travel while suppressing a decrease in power performance.
[0032] <<Example of torque cam mechanism configuration>> Fig. 4 is a schematic diagram for explaining the detailed structure of the torque cam mechanism 21c, and Fig. 5 is an exploded schematic diagram thereof. The cam groove forming structure 213 includes a cylindrical portion 2131 in which the cam groove T1 is formed, and a flange portion 2132 provided around one end of the cylindrical portion 2131. The flange portion 2132 is also provided with an attachment portion 2132a for attaching the cam groove forming structure 213 to the main body of the drive pulley 21. The attachment portion 2132a can be fastened with, for example, a bolt or the like.
[0033] The cam groove forming structure 213 is attached to the cam pin fixing structure 212 so as to be movable in the axial direction, and the cam pin fixing structure 212 passes through the cylindrical portion 2131. The cam pin 211 is attached by fitting to the cam pin fixing structure 212 to which the cam groove forming structure 213 is attached, and at this time, the cam pin 211 is slidably inserted through the cam groove T1. Thereafter, the cam pin sealing structure 214 is attached so as to cover the cam pin 211 and the cam groove forming structure 213. In this manner, the torque cam mechanism 21c is assembled.
[0034] As described above, cam groove T1 is formed so that cam groove forming structure 213 receives a force in the -Y direction (i.e., a force in the direction approaching a low ratio) from cam pin 211 due to rotation of drive shaft AX1. The portion of cam groove T1 that generates this effect is shown as first groove portion T11 in the drawing.
[0035] In this embodiment, a second groove portion T12 is further provided as another part of the cam groove T1. The groove portion T12 is connected to the groove portion T11 at one end ET11a of the groove portion T11 (see the enlarged view in FIG. 4). The end ET11a corresponds to the end of the groove portion T11 where the cam pin 211 should be located when the drive shaft AX1 is not rotating (i.e., at a low ratio). The groove portion T12 is formed so that the cam groove forming structure 213 receives a force from the cam pin 211 in the +Y direction (i.e., the direction that brings the movable sheave 21b closer to the fixed sheave 21a, or the direction that brings it closer to the top ratio). The other end opposite the end ET11a is referred to as end ET11b.
[0036] In this way, the grooves T11 and T12 are inclined with respect to the Y direction and extend in different directions so as to exert different functions. With this structure, when the drive shaft AX1 rotates, the groove T11 acts to move the gear ratio closer to a low ratio, and the groove T12 acts to move the gear ratio closer to a top ratio. As shown in the figure, the area between the grooves T11 and T12 is designated as a bent portion T13.
[0037] Figure 6 is a schematic side view showing the positional relationship of each element in the torque cam mechanism 21c at low and top ratios, and also shows a circumferential development of the cylindrical portion 2131 in which the cam groove T1 is formed to make the structure easier to understand.
[0038] The inclination of the groove portion T12 is suppressed compared to that of the groove portion T11. In other words, when the angle formed by the groove portion T11 with the Y direction is θ1 and the angle formed by the groove portion T12 with the Y direction is θ2, θ2<θ1, In this embodiment, as an example, the angle θ1 is set to 45 degrees and the angle θ2 is set to 5 degrees, but in other embodiments, the angle θ1 can be adjusted within a range of 30 to 60 degrees, and the angle θ2 can be adjusted within a range of 0 to 15 degrees.
[0039] Furthermore, the length of the groove T12 in the Y direction is shorter than that of the groove T11. That is, when the length of the groove T11 in the Y direction is L11 and the length of the groove T12 in the Y direction is L12, L12 <L11、 These values can be determined by the sizes of the cam pin 211 and the cam groove forming structure 213 as well as the required gear shifting characteristics. Groove portion T12 is formed relatively short, and in this embodiment, when the drive shaft AX1 is not rotating, the cam pin 211 is located in groove portion T12 and extends partially beyond bent portion T13 to the groove portion T11 side. Therefore, the width of groove portion T12 is approximately equal to the diameter of head portion 211h of cam pin 211, but the length of groove portion T12 is shorter than the diameter of head portion 211h of cam pin 211.
[0040] With this structure, when the vehicle 1 is started from a stopped state, the cam pin 211 moves relatively easily from the groove T12 to the groove T11 and then slides in the groove T11. If a high load is applied to the power source 121 while the cam pin 211 slides in the groove T11, the groove T11 acts to bring the power source 121 closer to the low ratio, so that a gradual upshift to the top ratio is achieved.
[0041] On the other hand, for example, when downshifting from a top ratio to a low ratio or while the vehicle is substantially stationary, cam pin 211 is located near groove T12 or end ET11a, and end T12 acts to move the CVT 21 closer to the top ratio. As a result, cam pin 211 presses movable sheave 21b against fixed sheave 21a, which in turn presses movable sheave 21b against belt 23 located between them. This provides a damping effect due to belt 23, and impact noise that may have been generated by cam pin 211 at end ET11a is suppressed compared to a conventional structure without groove T12. Therefore, this embodiment makes it possible to achieve the shifting characteristics of CVT 2 in a manner suited to the load, and also to suppress impact noise of cam pin 211 when in a low ratio.
[0042] In the torque cam mechanism 22c, a cam groove having a different shape from the cam groove T1 in the torque cam mechanism 21c is formed, but a description thereof will be omitted here.
[0043] 4 and 5 again, it is preferable that the end ET11b of the groove portion T11 does not overlap the attachment portion 2132a of the flange portion 2132 when viewed in the axial direction. It is even more preferable that the cam groove T1 does not overlap the attachment portion 2132a of the flange portion 2132 when viewed in the axial direction. With such a structure, access to the cam groove T1 is not obstructed by the attachment portion 2132a, and therefore, for example, the cam groove forming structure 213 can be formed and processed relatively easily.
[0044] In this embodiment, the number of each of the cam pins 211, the cam grooves T1 and the attachment portions 2132a is three, but the number of each of these is not limited to this example.
[0045] As described above, according to this embodiment, the torque cam mechanism 21c includes a cam pin 211 extending radially outward from the drive shaft AX1, and a cam groove forming structure 213 having a cam groove T1 in which the cam pin 211 can slide. The cam groove T1 includes groove portions T11 and T12 that extend in different directions and are connected to each other. Groove portion T11 is formed so that the cam groove forming structure 213 receives a force from the cam pin 211 in a direction that moves the movable sheave 21b away from the fixed sheave 21a (in a direction that moves closer to a low ratio) due to rotation of the drive shaft AX1. Groove portion T12 is connected to groove portion T11 at an end portion ET11a of groove portion T11, and is formed so that the cam groove forming structure 213 receives a force from the cam pin 211 in a direction that moves the movable sheave 21b closer to the fixed sheave 21a (in a direction that moves closer to a top ratio). According to this structure, the speed change characteristics of the CVT 2 to which the drive pulley 21 is applied can be realized in a manner according to the load, and the hitting noise of the cam pin 211 at a low ratio can be suppressed.
[0046] In the above description, for ease of understanding, each element is denoted by a name related to its function. However, each element is not limited to having the content described in the embodiment as its main function, and may have that function auxiliary to the content. Therefore, each element is not strictly limited to the expression, and the expression can be replaced with a similar expression. In the same spirit, the expression "apparatus" may be replaced with "unit," "component," "piece," "member," "structure," "assembly," etc., or may be omitted or added.
[0047] Furthermore, two or more selectable elements exemplified in the embodiments are not strictly limited to the examples and may be arbitrarily combined, for example, each of the two or more selectable elements may be additionally or alternatively selected. For example, when two elements A and B are arbitrarily combined, they may be expressed as "A and / or B" or "at least one of A and B" to indicate either A only, B only, or both A and B.
[0048] Summary of the embodiment [1] A pulley device (21) provided on an output rotary shaft (AX1) of a power source (121), a fixed sheave (21a); a movable sheave (21b) that is movable axially relative to the fixed sheave; a torque cam mechanism (21c) that is circumferentially provided on the output rotary shaft between the output rotary shaft and the movable sheave and that is capable of generating a force that moves the movable sheave in the axial direction, The torque cam mechanism a cam pin (211) extending radially outward from the output rotary shaft; a cam groove forming structure (213) having a cam groove (T1) in which the cam pin can slide; It is equipped with The cam groove is a first groove portion (T11) formed so that the cam groove forming structure receives a force from the cam pin in a first direction that separates the movable sheave from the fixed sheave due to rotation of the output rotation shaft; a second groove portion (T12) connected to the first groove portion at one end of the first groove portion where the cam pin is located when the output rotation shaft is not rotating, and formed so that the cam groove forming structure receives a force from the cam pin in a second direction opposite to the first direction; Contains A pulley device characterized by: According to these features, it is possible to realize the speed change characteristics of a continuously variable transmission to which the pulley device is applied in a manner that corresponds to the load, and it is also possible to suppress the impact noise of the cam pin at low ratios, thereby making it possible to provide an even more improved pulley device.
[0049] [2] The length (L12) of the second groove portion in the axial direction is shorter than the length (L11) of the first groove portion in the axial direction. The pulley device according to [1] above. According to this feature, a continuously variable transmission to which the pulley device is applied is not prevented from shifting from a low ratio to a top ratio.
[0050] [3] When the angle formed between the first groove portion and the axial direction is θ1 and the angle formed between the second groove portion and the axial direction is θ2, θ2<θ1 holds. The pulley device according to [2] above. According to such a feature, the effect of [2] above can be more suitably obtained.
[0051] [4] the cam groove further includes a bent portion (T13) between the first groove portion and the second groove portion, When the output rotary shaft is not rotating, the cam pin is located in the second groove portion and extends partially beyond the bent portion to the first groove portion side. The pulley device according to [3] above. According to such a feature, the effect of [3] above can be more suitably obtained.
[0052] [5] The cam groove forming structure is A cylindrical portion (2131) in which the cam groove is formed; A flange portion (2132) provided around one end of the cylindrical portion; Including, The flange portion is provided with an attachment portion (2132a) for attaching the cam groove forming structure to the pulley device body, When viewed in the axial direction, the other end of the first groove portion opposite to the one end and the mounting portion do not overlap each other. The pulley device according to any one of the above items [1] to [4], characterized in that: According to such a feature, the cam groove forming structure can be formed and processed relatively easily.
[0053] [6] When viewed in the axial direction, the cam groove and the mounting portion do not overlap each other. The pulley device according to [5] above. According to this feature, the effect of [5] above can be more suitably obtained.
[0054] [7] The rotor further includes a weight roller (21e) disposed on the opposite side of the movable sheave from the fixed sheave, and moving radially outward by centrifugal force caused by rotation of the output rotary shaft to press the movable sheave toward the fixed sheave. The pulley device according to any one of the above items [1] to [6], characterized in that: According to this feature, it is possible to appropriately shift from a low ratio to a top ratio in a continuously variable transmission to which the pulley device is applied.
[0055] [8] A drive pulley (21) that is the pulley device according to any one of the above [1] to [7]; A driven pulley (22), and a belt (23) stretched between the drive pulley and the driven pulley. A continuously variable transmission (2). That is, the pulley device can be widely applied to desired continuously variable transmissions.
[0056] [9] The continuously variable transmission (2) described in [8] above; Wheels (11) and A vehicle (1) characterized by: That is, the continuously variable transmission can be widely applied to desired vehicles.
[0057] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention. [Explanation of symbols]
[0058] 21: drive pulley (pulley device), 21a: fixed sheave, 21b: movable sheave, 21c: torque cam mechanism, 211: cam pin, 213: cam groove forming structure.
Claims
1. A continuously variable transmission that can be mounted on a vehicle, the continuously variable transmission comprising a drive pulley provided on an output rotation shaft of a power source and a driven pulley, and a belt installed between the drive pulley and the driven pulley, The drive pulley is A fixed sheave; a movable sheave that is axially movable relative to the fixed sheave; a weight roller mechanism for shifting the movable sheave to the top ratio side in accordance with the rotation speed of the output rotary shaft; a torque cam mechanism that is circumferentially provided on the output rotation shaft between the output rotation shaft and the movable sheave, and that is capable of generating a force that moves the movable sheave in a first direction that separates the movable sheave from the fixed sheave in the axial direction, The torque cam mechanism a cam pin extending radially outward from the output rotary shaft; a cam groove forming structure having a cam groove in which the cam pin can slide; It is equipped with The cam groove is a first groove portion formed so that the cam groove forming structure receives a force from the cam pin to move the movable sheave in the first direction due to rotation of the output rotation shaft; a second groove portion connected to the first groove portion at one end of the first groove portion where the cam pin is located when the output rotation shaft is not rotating, and formed so that the cam groove forming structure receives a force from the cam pin in a second direction opposite to the first direction; and transmitting a force in the second direction from the cam pin to the second groove portion while the vehicle is substantially stopped. A continuously variable transmission characterized by:
2. The length of the second groove portion in the axial direction is shorter than the length of the first groove portion in the axial direction.
2. The continuously variable transmission according to claim 1.
3. When the angle formed between the first groove portion and the axial direction is θ1 and the angle formed between the second groove portion and the axial direction is θ2, θ2<θ1 holds.
3. The continuously variable transmission according to claim 2.
4. the cam groove further includes a bent portion between the first groove portion and the second groove portion, When the output rotary shaft is not rotating, the cam pin is located in the second groove portion and extends partially beyond the bent portion to the first groove portion side.
4. The continuously variable transmission according to claim 3.
5. The cam groove forming structure is a cylindrical portion in which the cam groove is formed; a flange portion provided around one end of the cylindrical portion; Including, the flange portion is provided with an attachment portion for attaching the cam groove forming structure, When viewed in the axial direction, the other end of the first groove portion opposite to the one end and the mounting portion do not overlap each other.
2. The continuously variable transmission according to claim 1.
6. When viewed in the axial direction, the cam groove and the mounting portion do not overlap each other.
6. The continuously variable transmission according to claim 5.
7. The weight roller mechanism includes a weight roller disposed on the opposite side of the movable sheave from the fixed sheave, the weight roller moving radially outward by centrifugal force caused by rotation of the output rotary shaft and pressing the movable sheave toward the fixed sheave.
2. The continuously variable transmission according to claim 1.
8. The first groove portion acts to move the movable sheave closer to the low ratio side, The second groove portion acts to move the movable sheave closer to the top ratio side.
2. The continuously variable transmission according to claim 1.
9. A vehicle equipped with a continuously variable transmission according to any one of claims 1 to 8 and a wheel. A vehicle characterized by:
Citation Information
Patent Citations
V-belt continuously variable transmission
JP1987118149A
Bidirectional differential clutch of continuous transmission
JP1995042807A
V-belt type automatic transmission
JP2005315270A
Stepless speed variator including device which changes shift curve
JP2021193315A
Belt type continuously variable transmission for saddle-riding type vehicle and saddle-riding type vehicle
WO2006001410A1