Continuously variable transmission

Abstract

A continuously variable transmission (1) is provided with a fixed pulley (31), a sliding pulley (32), a belt (V) sandwiched between the fixed pulley (31) and the sliding pulley (32), a rear cylinder (37) fixed to the fixed pulley (31) and having a peripheral wall portion (372) of pressure receiving chambers (R1, R2), and a bolt (B) provided at a position that comes into contact with the rear cylinder (37) when an oil pressure equal to or greater than a predetermined value is supplied to the oil chambers (R1, R2). When the rear cylinder (37) starts to deform, elastic deformation is permitted, and the rear cylinder (37) is brought into contact with the bolt (B) before plastic deformation occurs.

Description

[0001] This application is a divisional application of the Chinese invention patent application with the application date of September 9, 2019, application number 201980055835.8, invention name “Continuously Variable Transmission”, and the applicants are Jatco Co., Ltd. and Nissan Motor Co., Ltd. Technical Field

[0002] The invention relates to a continuously variable transmission. Background Art

[0003] Patent Document 1 discloses a continuously variable transmission in which a cylinder member constituting a wall of a pulley hydraulic chamber is provided on the inner side when viewed from the pulley surface side of a sliding pulley.

[0004] Due to abnormality of the actuator for supplying the pulley oil pressure, an unexpectedly high oil pressure may be supplied to the pulley chamber. However, usually, one of the following two countermeasures is taken.

[0005] (A) The original high oil pressure cannot be supplied to the pulley chamber.

[0006] For example, when the oil pressure exceeds a predetermined value, a valve for releasing the oil is provided to prevent the supply of the oil pressure exceeding the predetermined value to the pulley oil pressure chamber.

[0007] (B) Even if a predetermined hydraulic pressure or more is supplied, the cylinder components will not be deformed.

[0008] For example, the cylinder member has a thicker plate thickness in order to increase the rigidity of the cylinder member.

[0009] In either of the above methods, the idea is that the cylinder parts are not deformed in the first place, but case (A) causes an increase in the number of parts, and case (B) causes an increase in weight due to an increase in plate thickness.

[0010] Therefore, it is necessary to be able to suppress deformation of the cylinder member without increasing the number of parts and weight.

[0011] Prior art literature

[0012] Patent Literature

[0013] Patent Document 1: Japanese Patent Application Publication No. 2001-263463 Summary of the invention

[0014] The continuously variable transmission of the present invention comprises:

[0015] Fixed pulley;

[0016] Sliding pulley;

[0017] an annular member clamped on the fixed pulley and the sliding pulley;

[0018] a cylinder member fixed to the fixed pulley and having a cylinder portion constituting a wall of the pulley pressure receiving chamber;

[0019] The stopper member is provided at a position where it comes into contact with the cylinder member when a hydraulic pressure equal to or higher than a predetermined value is supplied to the pulley pressure receiving chamber.

[0020] According to the present invention, when the cylinder member is deformed by supplying oil pressure exceeding a predetermined value to the pulley pressure receiving chamber, the stopper member contacts the cylinder member, thereby suppressing deformation of the cylinder member without increasing the number of components or weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a diagram for explaining the main structure of the continuously variable transmission.

[0022] Figure 2 It is a diagram for explaining the primary pulley and the forward / reverse switching mechanism and their surroundings of the continuously variable transmission.

[0023] Figure 3 It is a diagram for explaining the main part of the primary pulley.

[0024] Figure 4 This is a diagram for explaining the grooves on the outer periphery of the rear cylinder. DETAILED DESCRIPTION

[0025] Hereinafter, an embodiment of the present invention will be described by taking a case of a belt-type continuously variable transmission 1 for a vehicle as an example.

[0026] Figure 1 It is a diagram for explaining the main structure of the continuously variable transmission 1 .

[0027] Figure 2 It is a diagram for explaining the primary pulley 3 and the forward / reverse travel switching mechanism 5 and their surroundings of the continuously variable transmission.

[0028] Figure 3 It is a diagram for explaining the main part of the primary pulley 3. Figure 3 (a) is a diagram for explaining the positional relationship between the slide pulley 32 and the rear cylinder 37 when the speed ratio of the speed change mechanism 2 is the lowest speed. Figure 3 (b) is a diagram for explaining the positional relationship between the slide pulley 32 and the rear cylinder 37 when the speed ratio of the speed change mechanism 2 is the highest speed.

[0029] Figure 4 It is a diagram for explaining the groove 38 on the outer periphery of the peripheral wall portion 372 of the rear cylinder 37. Figure 4 (a) Yes Figure 2 AA profile in Figure 4 (b) is from Figure 4 (a) is an expanded view of the peripheral wall portion 372 viewed in the direction of arrow AA. Figure 4 In (b), for convenience of explanation, the groove 38 is shown with hatching.

[0030] like Figure 1 As shown, in the belt-type continuously variable transmission 1 , the rotational driving force of an engine (not shown) is input to the forward / reverse switching mechanism 5 via a torque converter (not shown).

[0031] The forward / reverse switching mechanism 5 includes a planetary gear set 6 , a forward clutch 51 , and a reverse brake 52 .

[0032] In the forward / reverse switching mechanism 5, when the forward clutch 51 is engaged, the rotation input from the torque converter side is output to the speed change mechanism 2 as clockwise rotation. When the reverse brake 52 is engaged, the rotation input from the torque converter side is output to the speed change mechanism 2 as counterclockwise rotation.

[0033] The speed change mechanism 2 includes a pair of pulleys (a primary pulley 3 and a secondary pulley 4 ) and a belt V (an endless member) wound around the pair of pulleys.

[0034] In the speed change mechanism 2, by changing the winding radius of the belt V on a pair of pulleys (primary pulley 3, secondary pulley 4), the rotation input from the forward / reverse switching mechanism 5 is changed to a desired speed change and output to the final reduction mechanism (not shown).

[0035] The primary pulley 3 has a fixed pulley 31 (fixed pulley) and a sliding pulley 32 (movable pulley).

[0036] The fixed pulley 31 includes a shaft portion 311 disposed along the rotation axis X1 and a pulley portion 312 extending radially outward from the outer periphery of the shaft portion 311 .

[0037] The bearings 34A and 34B are respectively inserted and fixed to one end 311 a and the other end 311 b in the longitudinal direction of the shaft portion 311 .

[0038] One end 311 a and the other end 311 b of the shaft portion 311 are rotatably supported by the support hole 15 on the side cover 13 and the support portion 101 on the transmission case 10 via bearings 34A and 34B, respectively.

[0039] In this state, the gear carrier 64 (see Figure 2 ) is connected to the other end 311b of the shaft portion 311 in a non-rotatable manner.

[0040] The slide pulley 32 includes an annular base portion 321 externally inserted into the shaft portion 311 of the fixed pulley 31 , and a pulley portion 322 extending radially outward from the outer periphery of the annular base portion 321 .

[0041] The annular base portion 321 of the sliding pulley 32 is spline-fitted to the outer periphery of the shaft portion 311 , and the sliding pulley 32 is provided in a state where relative rotation with the fixed pulley 31 is restricted and movable in the axial direction (rotation axis X1 direction) of the shaft portion 311 .

[0042] The pulley portion 312 of the fixed pulley 31 and the pulley portion 322 of the sliding pulley 32 face each other with a gap therebetween in the direction of the rotation axis X1.

[0043] In the primary pulley 3 , a V-shaped groove 33 around which the belt V is wound is formed between the pulley surface 312 a of the fixed pulley 31 and the pulley surface 322 a of the slide pulley 32 .

[0044] like Figure 2 As shown, on the outer diameter side of the pulley portion 322, a cylindrical cylinder portion 323 is provided on a pressure receiving surface 322b on the opposite side of the pulley surface 322a.

[0045] The cylinder portion 323 is provided along the direction of the rotation axis X1 and is formed to have a predetermined length L1 in a direction away from the pulley portion 322 .

[0046] The outer peripheral portion 35 a of the front plunger 35 abuts against the inner periphery of the cylinder portion 323 .

[0047] The D-ring 9 is attached to the outer peripheral portion 35 a of the front plunger 35 , and the gap between the inner periphery of the cylinder portion 323 and the outer peripheral portion 35 a is sealed by the D-ring 9 .

[0048] The inner peripheral portion 35 b of the front plunger 35 abuts against the outer periphery of the annular base portion 321 of the slide pulley 32 from the radially outer side.

[0049] The D-ring 9 is attached to the inner peripheral portion 35 b of the front plunger 35 , and the gap between the outer periphery of the annular base 321 and the inner peripheral portion 35 b is sealed by the D-ring 9 .

[0050] In the primary pulley 3 , an oil chamber R1 to which operating oil pressure is supplied is formed between the front plunger 35 and the pulley portion 322 .

[0051] The annular base portion 321 is provided with a small diameter portion 324 at an end portion opposite to the pulley portion 322 .

[0052] The annular rear plunger 36 is pressed into the small diameter portion 324. The inner peripheral portion 36b of the rear plunger 36 is fixed in a state of being pressed into a step portion of the small diameter portion 324 on the pulley portion 322 side (right side in the figure).

[0053] In this state, the rear plunger 36 is set in a state where the relative rotation with the annular base 321 is restricted and cannot move in the direction of the rotation axis X1.

[0054] The outer peripheral portion 36 a of the rear plunger 36 abuts against the inner periphery of the cylindrical peripheral wall portion 372 of the rear cylinder 37 from the rotation axis X1 side.

[0055] The D-ring 9 is attached to the outer peripheral portion 36 a of the rear plunger 36 , and the gap between the inner periphery of the peripheral wall portion 372 and the outer peripheral portion 36 a is sealed by the D-ring 9 .

[0056] The rear cylinder 37 is composed of a disc portion 371 inserted outside the shaft portion 311 and a peripheral wall portion 372 surrounding the entire outer circumference of the disc portion 371 .

[0057] The shaft portion 311 is press-fitted into the inner circumference 371 b of the disc portion 371 , and the inner circumference 371 b of the disc portion 371 is held between the step portion 314 provided on the shaft portion 311 and the bearing 34A externally inserted on the shaft portion 311 .

[0058] The bearing 34A is positioned in the direction of the rotation axis X1 by a nut N screwed onto the outer periphery of the shaft portion 311 , and movement of the rear cylinder 37 adjacent to the bearing 34A in a direction away from the slide pulley 32 is restricted by the bearing 34A.

[0059] The peripheral wall portion 372 is formed with an outer diameter smaller than the inner diameter of the cylindrical cylinder portion 323 , and a front end portion 372 a of the peripheral wall portion 372 abuts against the front plunger 35 inside the cylinder portion 323 in the direction of the rotation axis X1 .

[0060] The front end portion 372 a of the peripheral wall portion 372 restricts movement of the front plunger 35 in a direction away from the pulley portion 322 (leftward in the figure).

[0061] The outer peripheral portion 35 a and the inner peripheral portion 35 b of the front plunger 35 are offset in the direction of the rotation axis X1 , and the outer peripheral portion 35 a is located closer to the pulley portion 322 of the slide pulley 32 than the inner peripheral portion 35 b .

[0062] The front end portion 372 a of the peripheral wall portion 372 abuts against a region on the outer peripheral portion 35 a side of the front plunger 35 in the direction of the rotation axis X1 .

[0063] In the primary pulley 3, a space surrounded by the rear plunger 36, the front plunger 35, and the peripheral wall portion 372 of the rear cylinder 37 serves as a second oil chamber R2 to which the operating oil pressure is supplied.

[0064] In the sliding pulley 32, the oil chamber R1 and the oil chamber R2 are adjacent to each other on the inner side (left side in the figure) viewed from the pulley surface 322a so as to sandwich the front plunger 35. The oil chamber R1 and the oil chamber R2 constitute a pulley pressure receiving chamber on the primary pulley 3 side.

[0065] Therefore, the pressure receiving area of ​​each pulley pressure receiving chamber (each oil chamber R1, R2) can be reduced, so that the outer diameter of the primary pulley 3 (pulley parts 322, 312) can be reduced.

[0066] The shaft portion 311 of the fixed pulley 31 is provided with an in-shaft oil passage 313 for supplying actuating oil pressure to the oil chambers R1 and R2 .

[0067] In the shaft portion 311, the shaft inner oil passage 313 opens at one end 311a toward the side cover 13 side (left side in the figure). The support cylinder 152 provided in the side cover 13 is loosely fitted on the side cover 13 side (left side in the figure) of the shaft inner oil passage 313. The cylindrical bushing 153 is externally fitted on the support cylinder 152, and the side cover 13 side of the shaft portion 311 is rotatably supported by the bushing 153 internally fitted in the shaft inner oil passage 313.

[0068] In this state, the seal ring S provided on the outer periphery of the bushing 153 seals the gap between the outer periphery of the bushing 153 and the inner periphery of the in-shaft oil passage 313 .

[0069] The support hole 15 of the bearing 34A is opened in the side cover 13 at the portion facing the transmission case 10. A recess 151 is formed in the center of the support hole 15 when viewed from the direction of the rotation axis X1 to avoid interference with the shaft portion 311 of the fixed pulley 31. The support cylinder 152 is provided in the center of the recess 151.

[0070] The oil pressure (oil OL) is supplied from the oil pressure control circuit (not shown) to the support cylinder 152 via the oil passage 131 in the side cover. The oil pressure supplied to the support cylinder 152 is supplied to the oil chambers R1 and R2 (pulley pressure receiving chambers) attached to the sliding pulley 32 through the shaft oil passage 313.

[0071] In the primary pulley 3, the sliding pulley 32 is displaced in the direction of the rotation axis X1 by adjusting the supply pressure to the oil chambers R1 and R2 (pulley pressure chambers) attached to the sliding pulley 32. As a result, the groove width of the V-shaped groove 33 between the pulley surfaces 312a and 322a changes according to the supply pressure of the oil OL, thereby changing the winding radius of the belt V of the primary pulley 3.

[0072] like Figure 1 As shown, the secondary pulley 4 includes a fixed pulley 41 (fixed pulley) and a sliding pulley 42 (movable pulley).

[0073] The fixed pulley 41 includes a shaft portion 411 (pulley shaft) disposed along the rotation axis X2 and a pulley portion 412 extending radially outward from the outer periphery of the shaft portion 411 .

[0074] The slide pulley 42 includes an annular base portion 421 externally inserted into the shaft portion 411 of the fixed pulley 41 , and a pulley portion 422 extending radially outward from the outer periphery of the annular base portion 421 .

[0075] The pulley portion 412 of the fixed pulley 41 and the pulley portion 422 of the sliding pulley 42 face each other with a gap therebetween in the direction of the rotation axis X2.

[0076] In the secondary pulley 4 , a V-shaped groove 43 around which the belt V is wound is formed between the pulley surface 412 a of the fixed pulley 41 and the pulley surface 422 a of the slide pulley 42 .

[0077] The shaft portion 411 of the fixed pulley 41 has bearings 44A and 44B externally inserted at one end portion 411 a and the other end portion 411 b in the direction of the rotation axis X2 .

[0078] The other end portion 411 b of the shaft portion 411 in the direction of the rotation axis X2 is rotatably supported by the support portion 102 on the transmission case 10 side via a bearing 44B.

[0079] One end portion 411 a of the shaft portion 411 in the direction of the rotation axis X2 is rotatably supported by the support hole 16 on the side cover 13 via a bearing 44A.

[0080] The support hole 16 of the bearing 44A opens in the side cover 13 at a portion facing the transmission case 10. A recess 161 is formed in the center of the support hole 16 to avoid interference with the shaft portion 411 of the fixed pulley 41 when viewed from the rotation axis X2.

[0081] A support tube 162 is provided in the center of the recessed portion 161 . The support tube 162 protrudes toward the transmission 10 side (right side in the figure), and the front end side of the support tube 162 is loosely fitted in the shaft oil passage 413 of the fixed pulley 41 .

[0082] A cylindrical bushing 163 is externally fitted on the support tube 162 , and the side cover 13 side of the shaft portion 411 is rotatably supported by the bushing 163 which is internally fitted in the in-shaft oil passage 413 .

[0083] In this state, the seal ring S provided on the outer periphery of the bushing 163 seals the gap between the outer periphery of the bushing 163 and the inner periphery of the in-shaft oil passage 413 .

[0084] The shaft oil passage 413 opens at one end 411a of the shaft 411. The shaft oil passage 413 extends linearly in the shaft 411 along the rotation axis X2 of the fixed pulley 41, and crosses the inner diameter side of the sliding pulley 42 inserted outside the shaft 411 in the rotation axis X2 direction.

[0085] An oil hole 414 is provided at the front end side (right side in the figure) of the in-shaft oil passage 413 so as to communicate with the in-shaft oil passage 413 and the outer periphery of the shaft portion 411 .

[0086] The support cylinder 162 is supplied with hydraulic pressure from a hydraulic control circuit (not shown) via the oil passage 132 in the side cover. The hydraulic pressure supplied to the support cylinder 162 is supplied to the oil chamber R3 located on the outer diameter side of the shaft portion 411 via the in-shaft oil passage 413 .

[0087] In the secondary pulley 4, the sliding pulley 42 is displaced in the direction of the rotation axis X2 by adjusting the supply pressure to the oil chamber R3 (pulley pressure chamber) attached to the sliding pulley 42. As a result, the groove width of the V-shaped groove 43 between the pulley surfaces 412a and 422a changes according to the supply pressure, thereby changing the winding radius of the belt V of the secondary pulley 4.

[0088] The pulley portion 422 of the slide pulley 42 is provided with a cylinder portion 423 on a pressure receiving surface 422 b opposite to a pulley surface 422 a .

[0089] The cylinder portion 423 is provided along the direction of the rotation axis X2 and is formed to have a predetermined length L2 in a direction away from the pulley portion 422 .

[0090] The outer peripheral portion 45 a of the plunger 45 abuts against the inner periphery of the cylinder portion 423 .

[0091] The D-ring 9 is attached to the outer peripheral portion 45 a of the plunger 45 , and the gap between the inner periphery of the cylinder portion 423 and the outer peripheral portion 45 a is sealed by the D-ring 9 .

[0092] A cylindrical fitting portion 451 is provided on the inner diameter side of the plunger 45. The fitting portion 451 is spline-fitted to the outer periphery of the shaft portion 411 of the fixed pulley 41. The fitting portion 451 of the plunger 45 is positioned between the bearing 44B and the step portion 411c of the shaft portion 411 in the direction of the rotation axis X2.

[0093] The plunger 45 extends the outer diameter side of the annular base portion 421 of the slide pulley 42 in a region adjacent to the fitting portion 451 in a direction approaching the pulley portion 422 (leftward in the figure), and then bends toward the outer diameter side.

[0094] In the plunger 45, one end of the spring Sp contacts the region 452 bent on the outer diameter side from the direction of the rotation axis X2. The other end of the spring Sp contacts the pressure-receiving surface 422b of the pulley portion 422. The spring Sp is set to be compressed in the direction of the rotation axis X2, and the sliding pulley 42 is pressed in the direction of reducing the groove width of the V-shaped groove 43 (the direction of changing the speed ratio of the speed change mechanism 2 to the highest gear side) by the force applied by the spring Sp.

[0095] like Figure 2 As shown, in the area of ​​the side cover 13 on the primary pulley 3 side, a boss portion 17 having a bolt hole 17 a is provided at a position adjacent to the support hole 15 of the bearing 34A.

[0096] A plurality of boss portions 17 are provided at predetermined intervals in the circumferential direction around the rotation axis X1.

[0097] The bolt hole 17 a is formed along the axis Xa and penetrates the side cover 13 in the thickness direction. Here, the axis Xa is an axis parallel to the rotation axis X1 of the primary pulley 3 .

[0098] An annular retainer 18 surrounding the support hole 15 of the bearing 34A is provided inside the side cover 13. The retainer 18 is formed with an inner diameter smaller than the opening diameter of the support hole 15 to prevent the bearing 34A from falling out of the support hole 15.

[0099] After retainer 18 is positioned on the transmission case 10 side surface of side cover 13, when bolt B is screwed into bolt hole 17a, shaft portion B1 of bolt B penetrates retainer 18 along axis Xa in side cover 13. Thus, retainer 18 is arranged at a position supporting the outer ring of bearing 34A.

[0100] like Figure 3 As shown in (a), in the side cover 13, the peripheral wall portion 372 of the rear cylinder 37 is located on the extension of the axis Xa passing through the center of the bolt hole 17a of the boss portion 17.

[0101] That is, the bolt B is arranged at a position overlapping with the peripheral wall portion 372 located at the outermost peripheral portion of the rear cylinder 37 when viewed from the axis Xa (rotation axis X1 ).

[0102] Furthermore, the front end Bx of the bolt B is provided to face the boundary portion 373 between the disc portion 371 and the peripheral wall portion 372 of the rear cylinder 37 in the direction of the axis Xa, with a gap CL1 being provided between the front end Bx and the boundary portion 373 .

[0103] According to the results of experiments and simulations, the gap CL1 is set to the width at which the boundary portion 373 of the rear cylinder 37 abuts the front end Bx of the bolt B when the rear cylinder 37 is deformed by supplying oil pressure exceeding a specified value in the sliding pulley pressure chamber (oil chamber R1, oil chamber R2).

[0104] The case where the oil pressure exceeding a predetermined value is supplied to the pulley pressure receiving chamber (oil chamber R1, oil chamber R2) is, as an example, a case where a valve failure or the like occurs in a control valve (not shown).

[0105] Furthermore, the abutment timing is set to the time before the deformation of the rear cylinder 37 exceeds the elastic deformation area and reaches the plastic deformation area (before yielding). This is because, if the plastic deformation area is reached, even if the oil pressure in the sliding pulley pressure chamber (oil chamber R1, oil chamber R2) is restored to normal pressure, the shape of the rear cylinder 37 cannot be restored to its original state.

[0106] Therefore, in the present embodiment, the gap CL1 is set in order to suppress the plastic deformation while allowing the elastic deformation of the rear cylinder 37 .

[0107] That is, after the rear cylinder 37 starts to deform, the bolt B as the stopper abuts against the rear cylinder 37, thereby preventing the rear cylinder 37 from plastically deforming. At least, the plastic deformation of the rear cylinder 37 is suppressed to a necessary minimum.

[0108] If the plastic deformation of the rear cylinder 37 can be suppressed, the thickness of the rear cylinder 37 (the circular plate portion 371 and the peripheral wall portion 372 ) can be reduced, thereby reducing the weight of the primary pulley 3 .

[0109] The outer periphery of the boundary portion 373 between the disc portion 371 and the peripheral wall portion 372 of the rear cylinder 37 is rounded to prevent the periphery of the boundary portion 373 from being damaged when the front end Bx of the bolt B abuts against the rear cylinder 37.

[0110] The peripheral wall portion 372 facing the front end Bx of the bolt B is provided with a groove 38 extending linearly along the rotation axis X1.

[0111] like Figure 4 As shown in (a) and (b), when viewed in the radial direction of the rotation axis X1, the groove 38 is formed to have a length Lx in the direction of the rotation axis X1 from the region overlapping the disc portion 371 to the vicinity of the front end portion 372a of the peripheral wall portion 372.

[0112] The groove 38 is formed to have a uniform width Wx over the entire length along the direction of the rotation axis X1.

[0113] The grooves 38 are provided at predetermined intervals (predetermined width Wx) in the circumferential direction around the rotation axis X1 on the outer periphery of the peripheral wall portion 372. The grooves 38 are provided along the entire circumference in the circumferential direction around the rotation axis X1.

[0114] On the outer periphery of the peripheral wall portion 372 , the region where the groove 38 is formed and the region where the groove 38 is not formed are formed to have the same width Wx in the circumferential direction, and the region where the groove 38 is formed and the region where the groove 38 is not formed are alternately arranged.

[0115] The front end portion 372a of the peripheral wall portion 372 is a contact portion that contacts the front plunger 35 in the direction of the rotation axis X1. A pressing force corresponding to the oil pressure supplied to the oil chamber R1 acts on the front plunger 35 side.

[0116] In the present embodiment, in order to ensure the rigidity and strength of the front end portion 372 a side, the groove 38 is formed within a range of the length Lx in the direction of the rotation axis X1 that reaches the vicinity of the front end portion 372 a of the peripheral wall portion 372 .

[0117] The groove 38 is used as a detection portion of the rotation speed sensor 120 and is used to reduce the weight of the rear cylinder 37 .

[0118] The rotation speed sensor 120 is provided near the disk portion 371 on the outer diameter side of the peripheral wall portion 372, and the rotation speed sensor 120 is provided with the detection surface 120a facing the peripheral wall portion 372. In this state, the detection surface 120a as the detection portion of the rotation speed sensor 120 is arranged facing the radial direction.

[0119] In the groove 38 , a region facing the detection surface 120 a is a first groove portion 381 that functions as a detected portion of the rotation speed sensor 120 , and a second groove portion 382 that is a region other than the first groove portion 381 is a lightening portion.

[0120] In the groove 38 , the first groove portion 381 and the second groove portion 382 are connected in series, and the first groove portion 381 is located close to the circular plate portion 371 .

[0121] Furthermore, the length La of the first groove portion 381 in the direction of the rotation axis X1 is shorter than the length Lb of the second groove portion 382 (La<Lb).

[0122] Here, in the primary pulley 3, the groove width (width in the direction of the rotation axis X1) of the V-groove 33 is changed by displacing the slide pulley 32 in the direction of the rotation axis X1 in conjunction with the change in the speed ratio of the variator 2.

[0123] Here, the groove width of the V-shaped groove 33 is the largest when the speed ratio is the lowest gear (see Figure 3 (a)), which is smallest in the highest gear (see Figure 3 (b)).

[0124] Furthermore, when the slide pulley 32 is displaced in the direction of the rotation axis X1 , the cylinder portion 323 of the slide pulley 32 is also displaced in the direction of the rotation axis X1 .

[0125] In the present embodiment, the length La of the first groove 381 is set so that the cylinder 323 displaced in the direction of the rotation axis X1 does not interfere with the rotation speed sensor 120 .

[0126] Therefore, the first groove 381 does not overlap with the cylinder 323 (pulley tube) in the radial direction of the rotation axis X1. That is, in this embodiment, the movement range of the cylinder 323 that is linked to the movement of the sliding pulley 32 in the direction of the rotation axis X1 does not overlap with the first groove 381 when viewed from the radial direction.

[0127] On the other hand, when the groove width of the V-shaped groove 33 is equal to or larger than a predetermined width, the second groove portion 382 overlaps the cylinder portion 323 in the radial direction.

[0128] In this way, the first groove portion 381 as the detected portion of the rotation speed sensor 120 does not overlap with the cylinder portion 323 in the radial direction in the region of the total speed ratio of the speed change mechanism 2, thereby avoiding interference between the rotation speed sensor 120 and the cylinder portion 323.

[0129] On the other hand, the second groove portion 382 is a region that does not function as a detected portion of the rotation speed sensor 120, and therefore radially overlaps with the cylinder portion 323 in the region of a predetermined speed ratio of the speed change mechanism 2. Furthermore, since the second groove portion 382 extends to a range that reaches the inner circumference of the cylinder portion 323, it further contributes to weight reduction by reducing the weight of the peripheral wall portion 372.

[0130] In addition, from the perspective of lightweighting, the second groove portion 382 preferably has a length that overlaps with the cylinder portion 323 in the area of ​​the total speed ratio, but can also be designed to overlap in the area of ​​a part of the speed ratio and not overlap in the area of ​​other parts of the speed ratio.

[0131] As described above, the continuously variable transmission 1 of the present embodiment has the following structure.

[0132] (1) The continuously variable transmission 1 has:

[0133] Fixed pulley 31;

[0134] Sliding pulley 32;

[0135] Belt V (annular member) clamped on the fixed pulley 31 and the sliding pulley 32;

[0136] The rear cylinder 37 (cylinder member) is fixed to the fixed pulley 31 and has a peripheral wall portion 372 (cylinder barrel portion) of oil chambers R1 and R2 (pulley pressure receiving chambers);

[0137] The bolt B (stopper) is provided at a position where it comes into contact with the rear cylinder 37 when a hydraulic pressure equal to or higher than a predetermined value is supplied to the oil chambers R1 and R2 (pulley pressure receiving chambers).

[0138] According to the above configuration, when the oil pressure exceeding a predetermined value is supplied to the oil chambers R1 and R2 (pulley pressure chambers) and the rear cylinder 37 is deformed, the bolt B (stopper member) contacts the rear cylinder 37 to suppress the deformation of the rear cylinder 37. Thus, the deformation of the rear cylinder 37 can be suppressed without increasing the number of parts and weight.

[0139] At this time, by setting the position of the bolt B and the thickness of the rear cylinder 37, after the deformation of the rear cylinder 37 begins and before the plastic deformation occurs, the rear cylinder 37 is brought into contact with the bolt B, thereby allowing the elastic deformation of the rear cylinder 37 while suppressing the plastic deformation.

[0140] In this way, the rear cylinder 37 can be prevented from being plastically deformed, or the plastic deformation can be suppressed to a necessary minimum.

[0141] Thus, when the supply of the oil pressure exceeding the predetermined value is released, the rear cylinder 37 quickly returns to its original shape, and thus, it is possible to appropriately prevent a malfunction caused by deformation of the rear cylinder 37 from occurring in the oil chambers R1 and R2.

[0142] Therefore, it is possible to reduce the thickness of the components of the rear cylinder 37, and it is possible to reduce the weight of the rear cylinder 37 only in the thinned portion.

[0143] Furthermore, since there is no need to separately prepare a safety valve (valve) for preventing an oil pressure exceeding a predetermined value from being supplied to the oil chambers R1 and R2 (pulley pressure receiving chambers), an increase in the number of components can be prevented.

[0144] The continuously variable transmission 1 of the present embodiment has the following structure.

[0145] (2) The bolt B as the stopper is arranged at a position overlapping the peripheral wall portion 372 located at the outermost peripheral portion of the rear cylinder 37 when viewed from the direction of the rotation axis X1.

[0146] It is not preferable that after the rear cylinder 37 comes into contact with the bolt B, the rear cylinder 37 further deforms according to this principle with the contact point with the bolt B serving as a fulcrum.

[0147] By providing the bolts B near the peripheral wall portion 372 located at the outermost peripheral portion of the rear cylinder 37, it is possible to appropriately prevent the rear cylinder 37 from further deforming according to the principle with the contact point with the bolts B as a fulcrum when the rear cylinder 37 is deformed.

[0148] In particular, the rear cylinder 37 is formed into a bottomed cylindrical shape by a cylindrical peripheral wall portion 372 arranged along the extension line of the bolt B, and a circular plate portion 371 that seals the opening of the peripheral wall portion 372 on the bolt B side. Furthermore, the front end Bx of the bolt B is arranged at a position opposite to the boundary portion 373 between the circular plate portion 371 and the peripheral wall portion 372 and with a gap CL1 between the boundary portion 373.

[0149] With the above configuration, the boundary portion 373 between the circular plate portion 371 and the peripheral wall portion 372 has higher rigidity and strength than other portions. Therefore, when the rear cylinder 37 is deformed, the boundary portion 373 is brought into contact with the bolt B, thereby better preventing the rear cylinder 37 from being deformed.

[0150] In addition, as long as the rear cylinder 37 can be prevented from being plastically deformed or the plastic deformation can be suppressed to the necessary minimum, the position where the bolt B in the rear cylinder 37 abuts may be other than the boundary portion 373 .

[0151] In addition, in the present embodiment, the stopper is exemplified as a bolt B, but it may be another member as long as it can prevent plastic deformation of the rear cylinder 37 by contacting with the rear cylinder 37. For example, a bulging portion may be provided on the inner periphery of the side cover 13, and the rear cylinder may contact with the bulging portion to suppress plastic deformation.

[0152] The continuously variable transmission 1 of the present embodiment has the following structure.

[0153] (3) When the oil pressure supplied to the oil chambers R1 and R2 (pulley pressure receiving chambers) is lower than a predetermined value, the rear cylinder 37 does not come into contact with the bolt B serving as the stopper.

[0154] The bolt B is a fixing element fixed to the side cover 13 (housing), and the rear cylinder 37 is a rotating element rotating together with the primary pulley 3 (pulley).

[0155] Therefore, if the rear cylinder 37 is always in contact with the bolt B as a stopper, interference will occur, which will cause noise. Therefore, in the normal case where the oil pressure supplied to the oil chambers R1 and R2 (pulley pressure chambers) is less than the specified value, by preventing the rear cylinder 37 from contacting the bolt B, the generation of noise can be appropriately prevented.

[0156] The continuously variable transmission 1 of the present embodiment has the following structure.

[0157] (4) When a predetermined value or more of oil pressure is supplied to the oil chambers R1 and R2 (pulley pressure receiving chambers), the rear cylinder 37 comes into contact with the bolt B as a stopper before plastic deformation occurs.

[0158] In the present invention, the rear cylinder 37 may be prevented from undergoing plastic deformation or the plastic deformation may be controlled to a necessary minimum, but it is preferred that the rear cylinder not undergo plastic deformation.

[0159] The above provision can also be expressed in other words as: "When the oil pressure exceeding the specified value is supplied to the pulley pressure chamber, the distance between the cylinder member and the stop member is set in such a way that the cylinder member abuts against the stop member before plastic deformation occurs."

[0160] In addition, a groove 38 extending in the direction of the rotation axis X1 is formed on the outer periphery of the peripheral wall portion 372 of the rear cylinder 37 , and a plurality of grooves 38 are provided at predetermined intervals in the circumferential direction around the rotation axis X1 .

[0161] Therefore, by providing a plurality of grooves 38 and allowing the region between adjacent grooves 38 to function as a reinforcing rib, it is possible to suppress large deformation of the peripheral wall portion 372 when the rear cylinder 37 abuts against the bolt B.

[0162] Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above and can be appropriately modified within the scope of the technical concept of the invention.

Claims

1. A continuously variable transmission, characterized in that: have: Fixed pulley; Sliding pulley; an annular member clamped on the fixed pulley and the sliding pulley; a cylinder member fixed to the fixed pulley and having a cylinder portion constituting a wall of the pulley pressure receiving chamber; A stop member is arranged at a position separated from the cylinder member by a gap so as to abut against the cylinder member when an oil pressure greater than a specified value is supplied to the pulley pressure chamber, and not abut against the stop member when the oil pressure supplied to the pulley pressure chamber is less than the specified value.

2. The continuously variable transmission according to claim 1, characterized in that: When the oil pressure equal to or higher than the predetermined value is supplied to the pulley pressure receiving chamber, the cylinder member comes into contact with the stopper member before being plastically deformed.

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