JP2006029562A - Belt continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the deformation of a movable sheave near its back face resulting from the press of a movable side member into the movable sheave for defining a liquid chamber where the movable sheave is moved relative to a fixed sheave. <P>SOLUTION: This continuously variable transmission 9 comprises the fixed sheave 37 and the movable sheave 38 constituting a primary pulley 35 and a belt B wound on the fixed sheave 37 and the movable sheave 38. A movable cylinder 70 is pressed into a diameter enlarged portion of the movable sheave 38 in the axial direction, and the movable cylinder 70 defines an oil chamber 40a together with a piston 80 fixed to the fixed sheave 37 where the movable sheave 39 is moved relative to the fixed sheave 37. The movable cylinder 70 includes an engaging protrusion 74 for positioning the movable cylinder 70 relative to the movable sheave 38 in the axial direction to prevent the contact with the back face of the movable sheave 38 during press into the diameter enlarged portion 38a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a belt-type continuously variable transmission that can obtain a desired gear ratio by changing a winding radius of a belt.

  Conventionally, a belt type continuously variable transmission is known as a transmission for a vehicle. This type of belt-type continuously variable transmission is provided on a primary shaft (drive side rotating shaft) and a secondary shaft (driven side rotating shaft) arranged in parallel with each other, a primary pulley provided on the primary shaft, and a secondary shaft. Secondary pulley. Each of the primary pulley and the secondary pulley includes a fixed sheave and a movable sheave movable with respect to the fixed sheave. A substantially V-shaped pulley groove is formed between the fixed sheave and the movable sheave, and an endless belt is wound around the pulley grooves of the primary pulley and the secondary pulley. Further, an oil chamber is provided for the primary pulley and the secondary pulley for approaching and separating each movable sheave from the corresponding fixed sheave.

  Further, the belt type continuously variable transmission as described above has a movable cylinder movable together with the movable sheave and a piston (fixed plunger) fixed to the fixed sheave and defining an oil chamber together with the movable cylinder. Is known (see, for example, Patent Documents 1 and 2). In this belt type continuously variable transmission, from the viewpoint of reducing the manufacturing cost, increasing the versatility of the movable sheave, and further improving the maintainability, the movable cylinder is press-fitted in the axial direction with respect to the movable sheave. It is positioned and fixed by contacting the back surface. Further, as a belt-type continuously variable transmission having the movable cylinder (cylinder member) as described above, the movable cylinder and the back surface of the movable sheave are brought into local contact with each other in order to design the stress of the movable cylinder with high accuracy. (See, for example, Patent Document 3).

Japanese Patent No. 3055747 Japanese Patent No. 3116035 Japanese Patent Laid-Open No. 11-6549

  However, in the conventional belt-type continuously variable transmission configured as described above, the movable cylinder is press-fitted into the movable sheave, and the movable cylinder is brought into contact with the rear surface of the movable sheave so that the vicinity of the rear surface of the movable sheave. There was a risk that the deformation would increase.

  Therefore, the present invention can suppress deformation in the vicinity of the back surface of the movable sheave caused by press-fitting the movable side member that defines the liquid chamber for moving the movable sheave relative to the fixed sheave into the movable sheave. The purpose is to provide a belt type continuously variable transmission.

  A belt-type continuously variable transmission according to the present invention includes a fixed sheave and a movable sheave, and a belt wound around the fixed sheave and the movable sheave, and moves the movable sheave relative to the fixed sheave to wrap around the belt. In a belt-type continuously variable transmission that can obtain a desired gear ratio by changing the shaft, a movable side member that is press-fitted in the axial direction with respect to the movable sheave, and a fixed side that is fixed to the movable sheave. A movable member that is press-fitted into the movable sheave so that the fixed-side member that defines the liquid chamber for moving the movable sheave relative to the fixed sheave in cooperation with the member and the back surface of the movable sheave and the movable-side member do not come into contact with each other. Positioning means for positioning the side member in the axial direction is provided.

  The belt type continuously variable transmission according to the present invention is provided with positioning means for axially positioning the movable side member press-fitted into the movable sheave so that the back surface of the movable sheave and the movable side member do not come into contact with each other. Thereby, when the movable side member is press-fitted into the movable sheave, the transmission of the load to the vicinity of the back surface of the movable sheave can be suppressed, so that the deformation near the back surface of the movable sheave due to the press-fitting can be suppressed.

  In this case, the movable side member includes a fitting portion fitted into the movable sheave, and an annular portion that extends outward from one end portion of the fitting portion and faces the back surface of the movable sheave. It is preferable that an engaging portion that engages with the movable sheave is formed as the positioning means. Further, the engaging portion is preferably extended (protruded) inward from the other end portion of the fitting portion, and may be extended in the radial direction from the other end side region of the inner peripheral surface of the fitting portion. .

  Furthermore, the movable side member is preferably a cylinder that defines a liquid chamber, while the fixed side member is preferably a piston that defines the liquid chamber together with the cylinder. The movable side member may be a piston that defines a liquid chamber, while the fixed side member may be a cylinder that defines a liquid chamber together with the piston.

  ADVANTAGE OF THE INVENTION According to this invention, the deformation | transformation of the back surface vicinity of a movable sheave resulting from press-fitting the movable side member which defines the liquid chamber for moving a movable sheave with respect to a fixed sheave to a movable sheave can be suppressed. A belt-type continuously variable transmission can be realized.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing a vehicle to which a belt type continuously variable transmission according to the present invention is applied. A vehicle 1 shown in FIG. 1 is configured as a so-called FF vehicle (front engine front drive: front-wheel drive vehicle in front of the engine), and includes an engine 2 as a drive source. As the engine 2, a gasoline engine, a diesel engine, an LPG engine, a hydrogen engine, a bi-fuel engine, or the like can be adopted. Here, a description will be given assuming that a gasoline engine is used as the engine 2.

  As shown in FIG. 1, the vehicle 1 has a transaxle 3 that is disposed on the side of a horizontally placed engine 2 and connected to a crankshaft SC of the engine 2. The transaxle 3 includes a transaxle housing 4, a transaxle case 5, and a transaxle rear cover 6. The housing 4 is disposed on the side of the engine 2, and the case 5 is fixed to the opening end of the housing 4 on the side opposite to the engine 2. The rear cover 6 is fixed to the opening end of the case 5 on the side opposite to the housing 4. A torque converter 7 is disposed inside the transaxle housing 4. Inside the transaxle case 5 and the transaxle rear cover 6, a forward / reverse switching mechanism 8, a belt type continuously variable transmission according to the present invention ( CVT) 9, a final reduction gear 10 including a reduction gear device and a differential gear is arranged.

  The torque converter 7 includes a drive plate 11 and a front cover 12 fixed to the crankshaft SC of the engine 2 via the drive plate 11. As shown in FIG. 1, a pump impeller 14 is attached to the front cover 12. The torque converter 7 includes a turbine runner 15 that can rotate while facing the pump impeller 14.

  The turbine runner 15 is fixed to an input shaft SI that extends substantially coaxially with the crankshaft SC. Further, a stator 16 is disposed inside the pump impeller 14 and the turbine runner 15, and the rotation direction of the stator 16 is set only in one direction by the one-way clutch 17. A hollow shaft 18 is fixed to the stator 16 via a one-way clutch 17, and the above-described input shaft SI is inserted into the hollow shaft 18. A lockup clutch 20 is attached to the end of the input shaft SI on the front cover 12 side via a damper mechanism 19.

  The pump impeller 14, the turbine runner 15, and the stator 16 described above define a hydraulic fluid chamber, and this hydraulic fluid chamber is operated from an oil pump 21 disposed between the torque converter 7 and the forward / reverse switching mechanism 8. Liquid is supplied. Then, when the engine 2 is operated and the front cover 12 and the pump impeller 14 are rotated, the turbine runner 15 starts to be dragged by the flow of the hydraulic fluid. Further, the stator 16 converts the flow of the hydraulic fluid into a direction that assists the rotation of the pump impeller 14 when the rotational speed difference between the pump impeller 14 and the turbine runner 15 is large.

  Thus, the torque converter 7 operates as a torque amplifier when the rotational speed difference between the pump impeller 14 and the turbine runner 15 is large, and operates as a fluid coupling when the rotational speed difference between the two becomes small. When the vehicle speed reaches a predetermined speed after the vehicle 1 starts, the lockup clutch 20 is operated so that the power transmitted from the engine 2 to the front cover 12 is mechanically and directly transmitted to the input shaft SI. Become. Further, the fluctuation of the torque transmitted from the front cover 12 to the input shaft SI is absorbed by the damper mechanism 19.

  The oil pump 21 between the torque converter 7 and the forward / reverse switching mechanism 8 has a rotor 22, and the rotor 22 is connected to the pump impeller 14 via a hub 23. The hub 23 is spline-fitted to the hollow shaft 18, and the main body 24 of the oil pump 21 is fixed to the transaxle case 5 side. Accordingly, the power of the engine 2 is transmitted to the rotor 22 via the pump impeller 14, thereby driving the oil pump 21.

  The forward / reverse switching mechanism 8 has a planetary gear mechanism 25 of a double pinion type. The planetary gear mechanism 25 includes a sun gear 26 attached to an end of the input shaft SI on the continuously variable transmission 9 side, a ring gear 27 disposed concentrically on the outer peripheral side of the sun gear 26, and a plurality of pinion gears that mesh with the sun gear 26. 28, a plurality of pinion gears 29 that mesh with both the ring gear 27 and the pinion gear 28, and a carrier 30 that holds the pinion gears 28 so as to be capable of rotating, and holds the pinion gears 28 in an integrally revolving state around the sun gear 26. Including.

  The carrier 30 of the forward / reverse switching mechanism 8 is fixed to a primary shaft SP that is a primary shaft included in the belt-type continuously variable transmission 9, and the power transmission path between the carrier 30 and the input shaft SI includes a forward clutch CL. Connected or disconnected. The forward / reverse switching mechanism 8 has a reverse brake BR that controls the rotation and fixation of the ring gear 27.

  On the other hand, the belt-type continuously variable transmission 9 according to the present invention includes the above-described primary shaft (drive-side rotating shaft) SP extending substantially coaxially with the input shaft SI and a secondary shaft (parallel to the primary shaft SP) ( And a driven side rotation shaft) SS. The primary shaft SP is rotatably supported by the bearings 31 and 32, and the secondary shaft SS is rotatably supported by the bearings 33 and 34. The primary shaft SP is equipped with a primary pulley 35, and the secondary shaft SS is equipped with a secondary pulley 36.

  The primary pulley 35 includes a fixed sheave 37 that is integrally formed on the outer periphery of the primary shaft SP, and a movable sheave 38 that is slidably mounted on the outer periphery of the primary shaft SP. The movable sheave 38 includes an enlarged diameter portion 38a that is used for positioning of the movable cylinder 70 described later, and a thin portion 38b that defines a back surface of the movable sheave 38 and a belt sliding surface 38c. A plurality of splines (not shown) are formed on the inner peripheral surface of the movable sheave 38, and a plurality of splines that mesh with the splines of the movable sheave 38 are formed on the outer peripheral surface of the primary shaft SP that slidably supports the movable sheave 38. Grooves are formed. Thus, the movable sheave 38 can be moved in the axial direction with respect to the primary shaft SP by the spline and the spline groove, while the rotation of the movable sheave 38 with respect to the primary shaft SP is restricted. The fixed sheave 37 and the movable sheave 38 face each other, and a substantially V-shaped pulley groove 39 is formed between them. The movable sheave 38 is movable in the axial direction of the primary shaft SP with respect to the fixed sheave 37. The continuously variable transmission 9 moves the movable sheave 38 in the axial direction of the primary shaft SP to A hydraulic actuator 40 for moving the movable sheave 38 toward and away from the movable sheave 38 is provided.

  Similarly, the secondary pulley 36 also includes a fixed sheave 41 that is integrally formed on the outer periphery of the secondary shaft SS, and a movable sheave 42 that is slidably mounted on the outer periphery of the secondary shaft SS. The fixed sheave 41 and the movable sheave 42 face each other, and a substantially V-shaped pulley groove 44 is formed between them. The movable sheave 42 includes a diameter-expanded portion 42a used for positioning of the movable cylinder 75 described later, and a thin portion 42b that defines a back surface of the movable sheave 42 and a belt sliding surface 42c. The movable sheave 42 is also movable in the axial direction of the secondary shaft SS with respect to the fixed sheave 41. The continuously variable transmission 9 moves the movable sheave 42 in the axial direction of the secondary shaft SS to move the fixed sheave 41 and the movable sheave 41. And a hydraulic actuator 45 for moving the door 42 toward and away from the head 42.

  Around the pulley groove 39 of the primary pulley 35 and the pulley groove 44 of the secondary pulley 36, a belt B composed of a number of metal pieces and a plurality of steel rings is wound. Then, the hydraulic pressures by the hydraulic actuators 40 and 45 are separately controlled, whereby the groove widths of the primary pulley 35 and the secondary pulley 36 are changed, and the winding radius of the belt B is changed. As a result, the speed ratio of the continuously variable transmission 9 is set to a desired value, and the tension of the belt B is adjusted. The bearing 34 that supports the secondary shaft SS is fixed to the transaxle rear cover 6, and a parking gear PG is provided between the bearing 34 and the secondary pulley 36.

  Further, as shown in FIG. 1, the secondary shaft SS of the belt-type continuously variable transmission 9 extends beyond the bearing 33, and a reduction drive gear 47 is fixed to the extended portion of the secondary shaft SS. ing. Power is transmitted from the belt-type continuously variable transmission 9 to the final reduction gear 10 through the reduction drive gear 47. The final speed reducer 10 includes an intermediate shaft 50 that is an intermediate shaft disposed so as to be parallel to the secondary shaft SS. The intermediate shaft 50 is supported by bearings 51 and 52, and the intermediate shaft 50 is provided with a reduction driven gear 53 that meshes with the reduction drive gear 47 of the secondary shaft SS as a part of the reduction gear device.

  Further, the final reduction gear 10 has a hollow differential case 55. The differential case 55 is rotatably supported by bearings 56 and 57, and a ring gear 58 is provided on the outer periphery thereof. The ring gear 58 meshes with the reduction driven gear 53 of the intermediate shaft 50. Further, the differential case 55 supports a pinion shaft 59 therein, and two pinion gears 60 are fixed to the pinion shaft 59. Each of the pinion gears 60 is engaged with two side gears 61. Each side gear 61 is connected to a front drive shaft 62 separately. A wheel (front wheel) FW is fixed to each front drive shaft 62. ing.

  FIG. 2 is an enlarged cross-sectional view showing a main part of the belt-type continuously variable transmission 9 according to the present invention included in the vehicle 1 described above. The figure shows the primary pulley 35 and the primary shaft SP of the continuously variable transmission 9. A related configuration is shown. As shown in FIG. 2, the continuously variable transmission 9 includes an annular movable cylinder (movable side member) 70. The movable cylinder 70 includes a fitting portion 71 that is press-fitted and fixed in the axial direction of the primary shaft SP with respect to the enlarged diameter portion 38a formed in the movable sheave 38, and one end portion of the fitting portion 71 (on the right side in FIG. 2). Of the annular portion 72, that is, the opposite end of the annular portion 72 from the outer peripheral end of the annular portion 72. And an outer cylindrical portion 73 extending substantially in parallel with the primary shaft SP.

  A piston 80 is fixed to the primary shaft SP. The piston 80 has a base portion 81 that extends in the radial direction of the primary shaft SP, and an outer peripheral portion 82 that extends outward from the base portion 81 along the back surface of the movable sheave 38. The base portion 81 of the piston 80 is positioned and fixed together with the bearing 32 in a recess formed in the primary shaft SP, and the outer peripheral portion 82 of the piston 80 is sandwiched between the annular portion 72 of the movable cylinder 70 and the movable sheave 38. Opposite the back. The outer edge of the outer peripheral portion 82 is in sliding contact with the inner peripheral surface of the outer cylindrical portion 73 of the movable cylinder 70. Further, a seal ring 83 for sealing a gap with the inner peripheral surface of the outer cylindrical portion 73 is disposed on the outer edge of the outer peripheral portion 82. As a result, an oil chamber 40 a constituting the hydraulic actuator 40 described above is defined by a part of the movable cylinder 70, the piston 80 and the movable sheave 38.

  On the other hand, a through-hole extending in the axial direction from one end to the other end is formed inside the primary shaft SP, and this through-hole is an internal flow through which hydraulic oil used for moving the movable sheave 38 circulates. Used as road SPa. The primary shaft SP is formed with two radial oil passages (not shown) communicating with the internal flow passage SPa at predetermined intervals in the axial direction. Further, the movable sheave 38 is formed with one oil passage that can communicate with the two radial oil passages of the primary shaft SP. Thus, the oil chamber 40a defined by the movable cylinder 70, the piston 80, and a part of the movable sheave 38 has an oil path of the movable sheave 38 and one of the two radial oil paths of the primary shaft SP. , And communicates with the internal flow path SPa of the primary shaft SP.

  The working oil is supplied to the internal passage SPa of the primary shaft SP through an oil passage formed in the transaxle rear cover 6. The movable cylinder 70 and the movable sheave 38 are fixed by controlling the hydraulic pressure in the oil chamber 40a via the internal flow path SPa of the primary shaft SP, any one of the radial oil passages and the oil passage of the movable sheave 38. The belt B is moved together with the sheave 37 to change the wrapping radius of the belt B, whereby a desired gear ratio can be obtained.

  Now, as described above, the movable cylinder 70 that defines the oil chamber 40a in cooperation with the piston 80 is press-fitted into the enlarged diameter portion 38a of the movable sheave 38, thereby being fixed to the movable sheave 38. Become. However, when the movable cylinder 70 is press-fitted into the movable sheave 38 as described above, if the movable cylinder 70 (annular portion 72) and the back surface of the movable sheave 38 are brought into contact with each other, the thin portion 38b on the outer peripheral side of the movable sheave 38 is used. There is a risk that the load due to press-fitting is transmitted to the thin portion 38b, thereby deforming the thin portion 38b.

  In view of such a point, in the continuously variable transmission 9 according to the present invention, the movable cylinder 70 is in contact with the movable sheave 38 on the primary shaft so that the back surface of the movable sheave 38 and the annular portion 72 of the movable cylinder 70 do not contact each other. Positioned in the axial direction of the SP. In other words, in the present embodiment, the movable sheave 71 is positioned as a movable sheave from the other end of the fitting portion 71 of the movable cylinder 70 (the left end in FIG. 2, that is, the end opposite to the fixed sheave 37). An engaging protrusion 74 extends inward (in the radial direction) so as to engage with an end face of the enlarged-diameter portion 38a of 38. As shown in FIG. 2, the length L1 between the surface of the engaging projection 74 on the fixed sheave 37 side and the surface of the annular portion 72 on the fixed sheave 37 side is the length L1 of the enlarged diameter portion 38a of the movable sheave 38. The length is set shorter than the length L2 between the end surface and the back surface of the movable sheave 38 (L1 <L2).

  As a result, when the movable cylinder 70 is press-fitted into the enlarged diameter portion 38a of the movable sheave 38, the engagement projection 74 and the end surface of the enlarged diameter portion 38a eventually come into contact with each other, whereby the movable cylinder 70 is movable. It is positioned and fixed with respect to the sheave 38. Accordingly, the back surface of the movable sheave 38 and the annular portion 72 of the movable cylinder 70 do not contact each other, and a gap G is defined between the back surface of the movable sheave 38 and the annular portion 72.

  As a result, in the continuously variable transmission 9 according to the present invention, when the movable cylinder 70 is press-fitted into the movable sheave 38 of the primary pulley 35, transmission of a load to the vicinity of the back surface of the movable sheave 38 and the thin portion 38b can be suppressed. It is possible to suppress deformation near the back surface of the movable sheave 38 due to the press-fitting, and further deformation of the belt sliding surface 38c of the movable sheave 38. In addition, since the gap G is defined between the back surface of the movable sheave 38 and the annular portion 72, when the continuously variable transmission 9 is overhauled, for example, when the movable cylinder 70 or the piston 80 is replaced, It is possible to remove the movable cylinder 70 and the like from the movable sheave 38 by inserting a jig into the gap G. Thereby, workability | operativity at the time of decomposition | disassembly of the continuously variable transmission 9 can be improved.

  FIG. 3 is an enlarged cross-sectional view showing a main part of the belt-type continuously variable transmission 9, which shows a configuration related to the secondary pulley 36 and the secondary shaft SS of the continuously variable transmission 9. As shown in FIG. 3, the continuously variable transmission 9 includes an annular movable cylinder (movable side member) 75 for the secondary pulley 36 as well. The movable cylinder 75 includes a fitting portion 76 that is press-fitted and fixed in the axial direction of the primary shaft SP with respect to the enlarged-diameter portion 42a formed in the movable sheave 42 of the secondary pulley 36, and one end portion of the fitting portion 76 ( An annular portion 77 extending outward (generally in the radial direction of the secondary shaft SS) from the left end portion in FIG. 3, that is, the end portion on the fixed sheave 41 side, and the fixed sheave 41 from the outer peripheral end of the annular portion 77. And an outer cylindrical portion 78 extending substantially in parallel with the secondary shaft SS toward the opposite side.

  A piston 85 is fixed to the secondary shaft SS. The piston 85 has a base portion 86 that extends in the radial direction of the secondary shaft SS, and an outer peripheral portion 87 that extends outward from the base portion 86 along the back surface of the movable sheave 42. The base portion 86 of the piston 85 is positioned and fixed with respect to the secondary shaft SS, and the outer peripheral portion 87 of the piston 85 faces the back surface of the movable sheave 42 with the annular portion 77 of the movable cylinder 75 interposed therebetween. The outer edge of the outer peripheral portion 87 is in sliding contact with the inner peripheral surface of the outer cylindrical portion 78 of the movable cylinder 75. Further, a seal ring 88 for sealing a gap with the inner peripheral surface of the outer cylindrical portion 78 is disposed on the outer edge of the outer peripheral portion 87.

  Thereby, the movable cylinder 75, the piston 85, and a part of the movable sheave 42 define an oil chamber 45a that constitutes the hydraulic actuator 45 described above. Then, by controlling the hydraulic pressure in the oil chamber 45a, the movable cylinder 75 and the movable sheave 42 can be moved together with respect to the fixed sheave 41, and the winding radius of the belt B can be changed. As shown in FIG. 3, a balance plate 90 for defining a balance chamber behind the piston 85 is fixed to the outer cylindrical portion 78 of the movable cylinder 75, and the secondary shaft SS includes An oil receiver 91 that defines an oil passage for guiding hydraulic oil to the balance chamber is fixed.

  Also in the secondary pulley 36, the movable cylinder 75 is positioned in the axial direction of the secondary shaft SS with respect to the movable sheave 42 so that the back surface of the movable sheave 42 and the annular portion 77 of the movable cylinder 75 do not contact each other. That is, from the other end of the fitting portion 76 of the movable cylinder 75 (the right end in FIG. 3, that is, the end opposite to the fixed sheave 41), the diameter-enlarged portion of the movable sheave 42 serves as positioning means. An engaging projection 79 extends inward (in the radial direction) so as to engage with the end face of 42a. As shown in FIG. 3, the length L10 between the surface of the engaging projection 79 on the fixed sheave 41 side and the surface of the annular portion 77 on the fixed sheave 41 side is equal to the end surface of the enlarged diameter portion 42a of the movable sheave 42. It is set shorter than the length L20 between the movable sheave 42 and the back surface (L10 <L20).

  As a result, when the movable cylinder 75 is press-fitted into the enlarged diameter portion 42a of the movable sheave 42, the engagement projection 79 and the end surface of the enlarged diameter portion 42a eventually come into contact with each other, whereby the movable cylinder 75 is movable. It is positioned and fixed with respect to the sheave 42. Therefore, the back surface of the movable sheave 42 and the annular portion 77 of the movable cylinder 75 do not contact each other, and a gap G0 is defined between the back surface of the movable sheave 42 and the annular portion 77.

  As a result, in the continuously variable transmission 9 according to the present invention, even when the movable cylinder 75 is press-fitted into the movable sheave 42 of the secondary pulley 36, transmission of a load to the vicinity of the back surface of the movable sheave 42 and the thin portion 42b can be suppressed. Thus, it is possible to suppress deformation near the back surface of the movable sheave 42 due to press fitting, and further deformation of the belt sliding surface 42c of the movable sheave 42. Further, when the continuously variable transmission 9 is overhauled, the movable cylinder 75 and the like can be removed from the movable sheave 42 by inserting a jig into the gap G0.

  Further, in the secondary pulley 36, as shown in FIG. 3, a spring (coil spring) 89 is disposed between the enlarged diameter portion 42 a of the movable sheave 42 and the piston 85. The end of the spring 89 on the fixed sheave 41 side is positioned with respect to the movable sheave 42 by the tip of the engaging projection 79 of the movable cylinder 75. As described above, when the spring 89 is disposed between the movable sheave 42 and the movable cylinder 75, the engagement projection 79 of the movable cylinder 75 is extended inward, and the tip (inner end portion) of the engagement projection 79 is extended. ), The thickness (the difference between the inner diameter and the outer diameter) T of the enlarged diameter portion 42a of the movable sheave 42 can be increased as much as possible. As a result, the diameter-enlarged portion 42a of the movable sheave 42 can be strengthened. Therefore, when the movable cylinder 75 is press-fitted into the movable sheave 42, the deformation of the diameter-enlarged portion 42a of the movable sheave 42 (Inward bulging) can be suppressed. It goes without saying that such a configuration can be applied to the primary pulley 35.

  By the way, between the fixed sheave 37 and the movable sheave 38 constituting the primary pulley 35 and between the fixed sheave 41 and the movable sheave 42 constituting the secondary pulley 36, the movable sheaves 38 and 42 with respect to the fixed sheaves 37 and 41. There is a slight gap in the relationship of allowing the sliding. For this reason, when the belt B is wound around the primary pulley 35 and the secondary pulley 36, the movable sheaves 38 and 42 are slightly inclined with respect to the fixed sheaves 37 and 41 due to the tension of the belt B. Will slide against. For this reason, the surface pressure at either end of the inner peripheral surfaces (sliding surfaces) of the movable sheaves 38 and 42 may locally increase, and the sliding portions may be unevenly worn.

  In consideration of such a phenomenon, in the continuously variable transmission 9 of the present embodiment, as shown in FIG. 2, the end portion of the inner peripheral surface (sliding surface) of the movable sheave 38 constituting the primary pulley 35. Among them, a curved surface portion 38r is formed at the end portion on the fixed sheave 37 side. The primary shaft SP is formed with a curved concave portion SPr at the end of the sliding range of the movable sheave 38 (end on the fixed sheave 37 side). Similarly, a curved surface portion 42r is formed at the end portion on the fixed sheave 41 side of the end portion of the inner peripheral surface (sliding surface) of the movable sheave 42 constituting the secondary pulley 36, as shown in FIG. Yes. The secondary shaft SS has a curved concave portion SSr formed at the end of the sliding range of the movable sheave 42 (the end on the fixed sheave 41 side).

  As described above, the curved portions 38r and 42r are formed on the movable sheaves 38 and 42, or the concave portions SPr and SSr are formed on the primary shaft SP and the secondary shaft SS. Even if sliding with respect to the fixed sheaves 37 and 41 with a slight inclination with respect to the fixed sheaves 37 and 41, the surface pressure at the ends of the inner peripheral surfaces (sliding surfaces) of the movable sheaves 38 and 42 is local. It is possible to suppress the increase. Therefore, in the continuously variable transmission 9, it is possible to prevent the movable sheaves 38, 42, the primary shaft SP, and the secondary shaft SS from being unevenly worn.

  Here, the angle α (see FIG. 4) formed by the curved surface portions 38r, 42r with respect to the inner peripheral surfaces (sliding surfaces) of the movable sheaves 38, 42 is the maximum inclination of the movable sheaves 38, 42 with respect to the fixed sheaves 37, 41. It is preferable that the angle be greater than or equal to the angle. As a result, the surface pressure at the end portions of the inner peripheral surfaces of the movable sheaves 38 and 42 can be reduced, and uneven wear of the movable sheaves 38 and 42 and the like can be satisfactorily suppressed.

  Further, when the belt B is located at the innermost side during the operation of the continuously variable transmission 9, the curved surfaces 38r and 42r of the movable sheaves 38 and 42, as shown in FIG. It is preferable that the movable sheaves 38, 42 are formed so as not to contact the belt sliding surfaces 38c, 42c). Thereby, even if the movable sheaves 38 and 42 are slightly inclined with respect to the fixed sheaves 37 and 41, and the belt sliding surfaces 38c and 42c are inclined, the surface pressure of the elements constituting the belt B is locally increased. Can be suppressed. Further, in a state where the curved surface portions 38r and 42r of the movable sheaves 38 and 42 and the sliding surface of the belt B are not in contact with each other, a minute amount is provided between the belt sliding surfaces 38c and 42c and the sliding surface of the belt B. Since the gap g is formed, the lubricating medium (hydraulic oil) can be circulated between the movable sheaves 38 and 42 and the belt B using the gap g.

  For the same reason, the recesses SPr and SSr of the primary shaft SP and the secondary shaft SS do not come into contact with the sliding surface of the belt B when the belt B is positioned on the innermost side during the operation of the continuously variable transmission 9. It may be formed as follows. Further, the curved surface portions 38r and 42r may be smoothly continuous with the inner peripheral surfaces (sliding surfaces) of the movable sheaves 38 and 42. That is, the curved surface portions 38r and 42r do not have to be smoothly continuous with the belt sliding surfaces 38c and 42c, as shown in FIG.

  On the other hand, as shown in FIG. 2, between the fixed sheave 37 (41) and the movable sheave 38 (42), a plurality of both are slidable in the axial direction and the relative rotation of both is restricted. When the ball 100 is arranged, it is preferable not to provide a curved surface portion at the end of the inner peripheral surface (sliding surface) of the movable sheave 38 adjacent to the ball 100. That is, a groove in which the snap ring 101 for restricting the movement of the ball 100 is disposed is formed at the end of the inner peripheral surface of the movable sheave 38 close to the ball 100. Therefore, by omitting the curved surface portion from the end portion of the inner peripheral surface of the movable sheave 38 adjacent to the ball 100, it is possible to sufficiently secure the strength of the groove in which the snap ring 101 is disposed. When a plurality of balls 100 are arranged between the fixed sheave 37 (41) and the movable sheave 38 (42), the above-described increase in surface pressure due to the inclination of the movable sheaves 38 and 42 with respect to the fixed sheaves 37 and 41 is compared. Therefore, even if the curved surface portion is omitted, excessive uneven wear of the movable sheaves 38 and 42 can be suppressed.

  FIG. 6 is an enlarged sectional view showing a modification of the continuously variable transmission according to the present invention. In the continuously variable transmission 9A shown in FIG. 6, the movable piston 800 is press-fitted and fixed with respect to the enlarged diameter portion 38a of the movable sheave 38 constituting the primary pulley 35, while the cylinder 700 is fixed to the primary shaft SP. Yes. In this case, the movable piston 800 includes a fitting portion 801 that is press-fitted and fixed in the axial direction of the primary shaft SP with respect to the enlarged diameter portion 38a, and one end portion of the fitting portion 801 (the right end portion in FIG. And an annular portion 802 extending outward (generally in the radial direction of the primary shaft SP) from the end of the fixed sheave 37 side. The cylinder 700 has a base portion 701 extending in the radial direction of the primary shaft SP, an annular portion 702 extending outward from the base portion 701, and the primary shaft SP from the outer peripheral end of the annular portion 702 toward the fixed sheave 37. And an outer cylindrical portion 703 extending in parallel.

  The annular portion 702 of the cylinder 700 faces the back surface of the movable sheave 38 with the movable piston 800 interposed therebetween. Further, the outer edge of the annular portion 802 of the movable piston 800 is in sliding contact with the inner peripheral surface of the outer cylindrical portion 703 of the cylinder 700. Further, a seal ring 803 for sealing a gap with the inner peripheral surface of the outer cylindrical portion 703 is disposed on the outer edge of the annular portion 802 of the movable piston 800. Accordingly, the oil chamber 40a constituting the hydraulic actuator 40 is defined by the movable piston 800, the cylinder 700, and a part of the movable sheave 38.

  6, the movable piston 800 is positioned in the axial direction of the primary shaft SP with respect to the movable sheave 38 so that the back surface of the movable sheave 38 and the annular portion 802 of the movable piston 800 do not contact each other. The That is, from the other end of the fitting portion 801 of the movable piston 800 (the left end in FIG. 6, that is, the end opposite to the fixed sheave 37), the diameter-enlarged portion of the movable sheave 38 serves as positioning means. An engaging protrusion 804 extends inward (in the radial direction) so as to engage with the end face of 38a. As shown in FIG. 6, the length L11 between the surface of the engaging projection 804 on the fixed sheave 37 side and the surface of the annular portion 802 on the fixed sheave 37 side is equal to the end surface of the enlarged diameter portion 38a of the movable sheave 38. It is set shorter than the length L21 between the back surface of the movable sheave 38 (L11 <L21).

  As a result, when the movable piston 800 is press-fitted into the enlarged diameter portion 38a of the movable sheave 38, the engagement protrusion 804 and the end face of the enlarged diameter portion 38a eventually come into contact with each other, whereby the movable piston 800 is movable. It is positioned and fixed with respect to the sheave 38. Therefore, the back surface of the movable sheave 38 and the annular portion 802 of the movable piston 800 do not contact each other, and a gap G1 is defined between the back surface of the movable sheave 38 and the annular portion 802. As a result, in the continuously variable transmission 9A of FIG. 6, when the movable piston 800 is press-fitted into the movable sheave 38, transmission of a load to the vicinity of the back surface of the movable sheave 38 and the thin portion 38b can be suppressed. It is possible to suppress deformation near the back surface of the movable sheave 38 and further deformation of the belt sliding surface 38c of the movable sheave 38.

  As described above, when the movable piston 800 as the movable side member is press-fitted into the movable sheave 38, the engagement protrusion 804 as the positioning means may be provided to the movable piston 800. Needless to say, the configuration of FIG. 6 can be applied to the secondary pulley 36.

  FIG. 7 is an enlarged sectional view showing another modified example of the belt type continuously variable transmission according to the present invention. In the continuously variable transmission 9B shown in FIG. 7, the movable piston 800B is press-fitted and fixed with respect to the enlarged diameter portion 38a of the movable sheave 38B constituting the primary pulley 35, while the cylinder 700 is fixed to the primary shaft SP. . In this case, as shown in FIGS. 7 and 8, at least one engagement protrusion 804B extending in the radial direction is formed on the inner peripheral surface of the fitting portion 801 of the movable piston 800B. In the present embodiment, two engagement protrusions 804B are formed at intervals of 180 ° in the cylinder side region (the other end side region) on the inner peripheral surface of the fitting portion 801. Further, as shown in FIGS. 7 and 9, at least one engagement recess 38x that engages with the engagement protrusion 804B of the movable piston 800B is provided in the cylinder side region (the other end side region) of the enlarged diameter portion 38a. (In the present embodiment, two are formed in the circumferential direction at intervals of 180 °).

  As shown in FIG. 7, the length L12 between the end surface of the engaging protrusion 804B (the end surface on the fixed sheave 37 side) and the surface on the fixed sheave 37 side of the annular portion 802 is the engagement recess 38x of the movable sheave 38B. Is set to be shorter than the length L22 between the end surface (the end surface on the fixed sheave 37 side) and the back surface of the movable sheave 38B (L12 <L22). Thus, when the movable piston 800B is press-fitted into the enlarged diameter portion 38a of the movable sheave 38B in a state where the engagement protrusion 804B is engaged with the engagement recess 38x, the end surface of the engagement protrusion 804B and the engagement recess are eventually formed. The end surfaces of 38x abut against each other, whereby the movable piston 800B is positioned and fixed with respect to the movable sheave 38B.

  Therefore, the back surface of the movable sheave 38B and the annular portion 802 of the movable piston 800B do not contact each other, and a gap G2 is defined between the back surface of the movable sheave 38 and the annular portion 802. As a result, also in the continuously variable transmission 9B of FIG. 7, when the movable piston 800B is press-fitted into the movable sheave 38B, transmission of a load to the vicinity of the back surface of the movable sheave 38B and the thin portion 38b can be suppressed. It is possible to suppress deformation near the back surface of the movable sheave 38B and further deformation of the belt sliding surface 38c of the movable sheave 38B.

  Needless to say, the configuration of FIG. 7 can be applied to the secondary pulley 36. Further, it goes without saying that the configuration of FIG. 6 can also be applied to the movable cylinders of the primary pulley and the secondary pulley described with reference to FIGS.

1 is a schematic configuration diagram of a vehicle including a belt type continuously variable transmission according to the present invention. It is an expanded sectional view which shows the principal part of the belt-type continuously variable transmission shown by FIG. It is an expanded sectional view which shows the principal part of the belt-type continuously variable transmission shown by FIG. It is an expanded sectional view of the belt type continuously variable transmission shown in FIG. It is an expanded sectional view of the belt type continuously variable transmission shown in FIG. It is an expanded sectional view which shows the modification of the belt-type continuously variable transmission by this invention. FIG. 6 is an enlarged cross-sectional view showing another modification of the belt type continuously variable transmission according to the present invention. It is a front view which shows the movable piston contained in the belt-type continuously variable transmission of FIG. It is a rear view which shows the movable sheave contained in the belt type continuously variable transmission of FIG.

Explanation of symbols

9, 9A, 9B Belt type continuously variable transmission 35 Primary pulley 36 Secondary pulleys 37, 41 Fixed sheaves 38, 38B, 42 Movable sheaves 38a, 42a Expanded diameter portions 38c, 42c Belt sliding surfaces 38x Engaging recesses 38r, 42r Curved surfaces Portions 39, 44 Pulley grooves 40, 45 Hydraulic actuators 40a, 45a Oil chambers 70, 75 Movable cylinders 71, 76 Fitting portions 72, 77 Annular portions 73, 78 Outer cylindrical portions 74, 79 Engaging projections 80, 85 Piston 81 , 86 Base part 82, 87 Outer peripheral part 83, 88 Seal ring 89 Spring 700 Cylinder 701 Base part 702 Annular part 703 Outer cylindrical part 800, 800B Movable piston 801 Fitting part 802 Annular part 803 Seal ring 804, 804B Engagement protrusion B Belt G, G0, G1, G2 Clearance SP Primary shaft SS Secondary shaft SPr, SSr Recess

Claims (4)

A fixed sheave and a movable sheave, and belts wound around the fixed sheave and the movable sheave, and moving the movable sheave with respect to the fixed sheave to change a winding radius of the belt to achieve a desired speed change. In the belt type continuously variable transmission that can obtain the ratio,
A movable-side member press-fitted in the axial direction with respect to the movable sheave;
A fixed side member that is fixed to the fixed sheave and that defines a liquid chamber for moving the movable sheave relative to the fixed sheave in cooperation with the movable side member;
A belt type continuously variable transmission comprising: positioning means for positioning the movable side member press-fitted into the movable sheave in the axial direction so that the back surface of the movable sheave and the movable side member do not contact each other. .   The movable side member includes a fitting portion fitted into the movable sheave, and an annular portion that extends outward from one end portion of the fitting portion and faces the back surface of the movable sheave. The belt type continuously variable transmission according to claim 1, wherein an engaging portion that engages with the movable sheave is formed as the positioning means.   The belt according to claim 1 or 2, wherein the movable side member is a cylinder that defines the liquid chamber, and the fixed side member is a piston that defines the liquid chamber together with the cylinder. Type continuously variable transmission. 3. The belt according to claim 1, wherein the movable side member is a piston that defines the liquid chamber, and the fixed side member is a cylinder that defines the liquid chamber together with the piston. Type continuously variable transmission.

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