JP2005299804A - Belt continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt continuously variable transmission with a secondary shaft and an intermediate shaft each having a smaller size in the extension portion in the axial direction and a case having improved rigidity. <P>SOLUTION: The belt continuously variable transmission comprises a primary pulley 35 provided on a primary shaft SP, a secondary pulley 36 provided on a secondary shaft SS, a belt B wound on both pulleys, and a final speed reducer 10 including a reduction gear device and a differential device. Herein, power is transmitted to the differential device via an intermediate shaft 50 arranged between the secondary shaft SS and the differential device. The intermediate shaft 50 has a single gear 53 for meshing with both of a gear 47 of the secondary shaft and an input gear 58 of the differential device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a belt type continuously variable transmission, and in particular, a belt type configured to transmit power between two variable pulleys by a belt and to control a gear ratio by changing a belt winding radius. The present invention relates to a continuously variable transmission.

  In general, a stepped or continuously variable transmission is provided on the output side of the engine for the purpose of operating the engine under optimum conditions according to the traveling state of the vehicle. An example of such a continuously variable transmission is a belt-type continuously variable transmission. This belt-type continuously variable transmission has two rotating shafts of a primary shaft and a secondary shaft that are arranged in parallel, and a primary pulley and a secondary pulley that are separately attached to each rotating shaft. Both the primary pulley and the secondary pulley are configured by combining a fixed sheave integrated with a rotating shaft and a movable sheave, and a V-shaped groove is formed between the fixed sheave and the movable sheave.

  Further, a belt is wound around the groove of the primary pulley and the groove of the secondary pulley, and a hydraulic chamber for generating a holding pressure in the axial direction is separately provided on the movable sheave. By separately controlling the hydraulic pressure in each hydraulic chamber, the groove width of the primary pulley is controlled to change the belt wrapping radius and the gear ratio is changed, while the groove width of the secondary pulley is changed. The belt tension is controlled.

  In such a belt-type continuously variable transmission, an intermediate shaft serving as a third shaft is provided in parallel with the secondary shaft, and a differential case (see FIG. Hereinafter, the power is transmitted to a differential case (see Patent Document 1).

  By the way, in the transaxle described in Patent Document 1 above, two large and small gears are provided in an axially separated form on the intermediate shaft, and the gear on the large diameter side meshes with the gear provided on the secondary shaft. At the same time, a gear on the small diameter side is meshed with a ring gear provided in the differential case to constitute a reduction gear device.

  In the belt type continuously variable transmission as described above, since the hydraulic chamber is provided on the outer peripheral side of the rotating member, the hydraulic pressure generated by centrifugal force, so-called centrifugal hydraulic pressure, acts on the hydraulic chamber, There is a problem that the oil pressure of the oil becomes higher than the oil pressure that is the control target and the control accuracy is lowered. An example of a belt-type continuously variable transmission as a measure for solving such inconvenience due to centrifugal hydraulic pressure is also described in Patent Document 1.

  In the belt-type continuously variable transmission described in Patent Document 1, a first hydraulic chamber that presses the movable sheave in the axial direction, and a pressing force in a direction opposite to the pressing force of the first hydraulic chamber on the movable sheave. A second hydraulic chamber for applying pressure is formed, and an oil passage forming member is disposed in a path of an oil passage communicated with the second hydraulic chamber. Further, the oil passage forming member is attached to the secondary shaft, bearings and partition walls are disposed on both sides thereof, and an oil passage is provided in the secondary shaft. The second portion is provided by a notch provided in the oil passage forming member. The hydraulic chamber is configured to communicate with the oil passage.

JP 2001-323978 A

  By the way, in the belt-type continuously variable transmission described in Patent Document 1, the output from the secondary shaft is transmitted to the differential device via two large and small gears axially separated from the intermediate shaft. Because it is configured, the degree of freedom of selection of the reduction ratio is great, but on the other hand, since the two gears are provided separated in the axial direction, the problem is that the axial length of the intermediate shaft must be lengthened was there. Further, since the large-diameter side gear is provided on the far side from the belt type continuously variable transmission due to the arrangement of the two large and small gears constituting the reduction gear device, the gear meshes with the large-diameter side gear. Accordingly, the shaft length of the secondary shaft is also increased, and as a result, the axial dimension of the extension portion of the secondary shaft and the intermediate shaft in the transaxle is increased, and the torque converter housing space is increased. There was also a problem of being restricted.

  The present invention has been made against the background of the above circumstances, and it is possible to reduce the axial dimension of the extension portion of the secondary shaft and the intermediate shaft, and to increase the rigidity of the case. The object is to provide a step transmission.

  In order to achieve the above object, a belt-type continuously variable transmission according to an aspect of the present invention includes a primary pulley provided on a primary shaft, a secondary pulley provided on a secondary shaft, a belt wound around both pulleys, A final reduction gear including a reduction gear device and a differential device is provided, and power is transmitted to the differential device via an intermediate shaft disposed between the secondary shaft and the differential device. In the belt-type continuously variable transmission, the intermediate shaft is provided with a single gear that meshes with both the gear provided on the secondary shaft and the input gear to the differential gear. .

  Here, it is preferable that one of the bearings supporting the secondary shaft and one of the bearings supporting the intermediate shaft are supported by the same member at a position overlapping in the axial direction.

  Further, one of the bearings supporting the secondary shaft includes at least two hydraulic chambers, an outer diameter side and an inner diameter side, that generate a belt clamping pressure acting on the movable sheave of the secondary pulley, in an axial direction from the movable sheave. In the partition member having an axially extending portion that slides to be independently configured with the axially extending portion that is extended to the outer peripheral portion, it is provided on the outer peripheral portion of the cylindrical portion that is press-fitted to the secondary shaft. Is preferred.

  Further, the outer diameter side hydraulic chamber is formed between an axially extending portion on the outermost diameter side of the movable sheave, an axially extending portion on the inner diameter side of the movable sheave, and the partition member. It is preferable that a drain hole is formed in a positional relationship that communicates in the vicinity of a predetermined gear ratio when the movable sheave moves between the axially extending portion on the outermost diameter side and the partition member.

  According to an aspect of the present invention, the intermediate shaft disposed between the secondary shaft and the differential device has a single gear that meshes with both the gear provided on the secondary shaft and the input gear to the differential device. This gear is decelerated and power is transmitted from the secondary shaft to the differential gear. As a result, since the intermediate shaft can be shortened in the axial direction, it is possible to reduce the size, and it is possible to increase the space for accommodating the torque converter.

  Further, according to the embodiment in which one of the bearings supporting the secondary shaft and one of the bearings supporting the intermediate shaft are supported by the same member at a position overlapping in the axial direction, the rigidity of the case which is the same member is increased. Can be increased.

  Further, one of the bearings supporting the secondary shaft has at least two hydraulic chambers, an outer diameter side and an inner diameter side, which generate a belt clamping pressure acting on the movable sheave of the secondary pulley, in an axial direction from the movable sheave. In the partition member having an axially extending portion that slides on the axially extending portion independently of the extended axially extending portion, the outer peripheral portion of the press-fitting cylindrical portion to the secondary shaft is provided. Accordingly, the press-fitting cylindrical portion of the partition wall member to the secondary shaft is supported by the bearing and is prevented from being separated from the secondary shaft, so that oil leakage from the hydraulic chamber on the inner diameter side is prevented.

  Further, the outer diameter side hydraulic chamber is formed between an outermost diameter side axially extending portion of the movable sheave, an inner diameter side axially extending portion thereof, and the partition member. According to the form in which the drain hole is formed in a positional relationship that communicates in the vicinity of a predetermined gear ratio when the movable sheave moves between the axially extending portion on the outermost diameter side and the partition member. It is possible to easily prevent the remaining hydraulic oil from being generated.

  Here, a preferred embodiment of the belt type continuously variable transmission according to the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a skeleton diagram of a transaxle 1 of a belt-type continuously variable transmission according to the present invention applied to an FF vehicle (an engine front front wheel drive vehicle). A transaxle 1 shown in FIG. 1 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 transaxle 1 has a transaxle body 3 that is disposed on the side of an engine 2 that is placed horizontally and connected to a crankshaft SC of the engine 2. The transaxle body 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 (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 a 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 starts, the lockup clutch 20 is operated, and the power transmitted from the engine 2 to the front cover 12 is mechanically and directly transmitted to the input shaft SI. . 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 includes the above-described primary shaft (drive-side rotating shaft) SP that extends substantially coaxially with the input shaft SI, and a secondary shaft that is a secondary shaft arranged in parallel with the primary shaft SP. (Driven 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 fixed sheave 37 and the movable sheave 38 face each other, and a substantially V-shaped pulley groove 39 is formed between them. Further, the movable sheave 38 is movable in the axial direction of the primary shaft SP with respect to the fixed sheave 37, and the continuously variable transmission 9 moves the movable sheave 38 in the axial direction of the primary shaft SP to move with the movable sheave 38. A hydraulic actuator 40 is provided to approach and separate the fixed sheave 37.

  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 is also movable in the axial direction of the secondary shaft SS with respect to the fixed sheave 41, and the continuously variable transmission 9 moves the movable sheave 42 in the axial direction of the secondary shaft SS to move with the movable sheave 42. A hydraulic actuator 45 that moves the fixed sheave 41 toward and away from the fixed sheave 41 is provided.

  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 is extended beyond the bearing 33. A reduction drive gear 47 is fixed to an extension of the secondary shaft SS, and power is transmitted from the belt-type continuously variable transmission 9 to the final reduction gear 10 via 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 pinion gear 60 is engaged with two side gears 61. A front drive shaft 62 is separately connected to each side gear 61, and a wheel (front wheel) FW is fixed to each front drive shaft 62. ing.

  Here, an embodiment of the transaxle 1 including the belt type continuously variable transmission 9 described above will be described in more detail with reference to FIG. FIG. 2 is a cross-sectional view showing a specific configuration example of the transaxle 1 including the belt-type continuously variable transmission 9 including the primary pulley 35 and the secondary pulley 36 and the final reduction gear 10.

  The primary pulley 35 is provided on the outer periphery of the primary shaft SP, and is substantially disposed between a bearing 31 attached to the transaxle case 5 side and a bearing 32 attached to the transaxle rear cover 6. The primary shaft SP is rotatable about the axis A1, and an oil passage SPA is formed in the primary shaft SP in the axial direction. The oil passage SPA is communicated with a hydraulic circuit of the hydraulic control device. Further, the primary shaft SP is provided with an oil passage SPB extending in the radial direction toward the outer peripheral surface thereof and communicating with the oil passage SPA. The oil passage SPB is disposed at a position near the end of the primary shaft SP.

  On the other hand, the movable sheave 38 includes an inner cylindrical portion 38A that slides along the outer peripheral surface of the primary shaft SP, and a radial direction portion 38B that is continuous from the end on the fixed sheave 37 side of the inner cylindrical portion 38A toward the outer peripheral side. The outer cylindrical portion 38C is continuous with the outer peripheral end of the radial direction portion 38B and extended in the axial direction toward the bearing 32. An oil passage 38D that penetrates obliquely from the inner peripheral surface to the outer peripheral surface is formed at the boundary between the inner cylindrical portion 38A and the radial direction portion 38B. The oil passage 38D and the oil passage SPB are communicated with each other through a spline portion described later formed on the outer peripheral surface of the primary shaft SP.

  As shown in FIG. 2, a plurality of splines (teeth) 38 </ b> S (a total of 30 in this embodiment) are formed on the inner peripheral surface of the movable sheave 38. A plurality of spline grooves SPG that mesh with the splines 38S of the movable sheave 38 are formed on the outer peripheral surface of the primary shaft SP that slidably supports the movable sheave 38. The spline 38S of the movable sheave 38 and the spline groove SPG of the primary shaft SP are formed such that the tooth surface or the groove surface forms an involute curve. Thus, in the belt-type continuously variable transmission 9, the movable sheave 38 can be moved in the axial direction with respect to the primary shaft SP by the spline 38S and the spline groove SPG, while the relative movement in the circumferential direction of the primary shaft SP. It is considered impossible.

  Further, the belt type continuously variable transmission 9 includes a cylinder member 270 that is an annular partition member. As can be seen from FIG. 2, the cylinder member 270 includes a first radial portion 270A extending in the radial direction of the primary shaft SP, and a first cylindrical portion extending substantially parallel to the axis of the primary shaft SP from the first radial direction portion 270A. 270B, a second radial direction portion 270C extending in the radial direction of the primary shaft SP from the first cylindrical portion 270B along the back surface of the movable sheave 38, and an axis line approximately from the second radial direction portion 270C via the curved portion. It has 2nd cylindrical part 270D extended in parallel.

  A small-diameter portion at the tip of the primary shaft SP is press-fitted into a center hole formed in the first radial direction portion 270A of the cylinder member 270, and the cylinder member 270 uses a lock nut 280 to form a step portion of the primary shaft SP. It is fixed between. The first cylindrical portion 270B of the cylinder member 270 is rotatably supported by a bearing 32 fixed to the transaxle rear cover 6 by an annular bearing retainer 281 and a bolt BO. Thus, in the belt type continuously variable transmission 9, the primary shaft SP is rotatably supported by the bearing 32 via the cylinder member 270 (first cylindrical portion 270B).

  A seal member 272 is disposed on the outer edge portion of the outer cylindrical portion 38C of the movable sheave 38 so as to be in sliding contact with the inner peripheral surface of the second radial direction portion 270C of the cylinder member 270. On the other hand, on the outer peripheral side of the axial end portion of the inner cylindrical portion 38A of the movable sheave 38, a second sliding portion described later that slidably contacts the inner peripheral side of the first cylindrical portion 270B of the cylinder member 270. 38F is formed. Thus, the inner cylinder part 38A, the radial direction part 38B, the outer cylinder part 38C, and the cylinder member 270 of the movable sheave 38 define the first hydraulic chamber 40A that constitutes the hydraulic actuator 40 described above. On the other hand, the first hydraulic direction portion 270A, the first cylindrical portion 270B of the cylinder member 270, the axial end portion of the inner cylindrical portion 38A of the movable sheave 38 and the primary shaft SP, and the second hydraulic pressure constituting the hydraulic actuator 40 described above. A chamber 40B is defined. By controlling the hydraulic pressure in the first hydraulic chamber 40A and the second hydraulic chamber 40B, the movable sheave 38 is moved with respect to the fixed sheave 37 to change the wrapping radius of the belt B. Can be obtained.

  The movable sheave 38 is provided with a first sliding portion 38E and the above-described second sliding portion 38F that are spaced apart in the axial direction of the primary shaft SP. Of the two sliding portions of the movable sheave 38, the first sliding portion 38E is provided on the fixed sheave 37 side in the axial direction of the primary shaft SP with respect to the spline 38S and on the inner peripheral surface of the movable sheave 38. In contact with the outer peripheral surface of the primary shaft SP. On the other hand, as described above, the second sliding portion 38F is spaced apart from the first sliding portion 38E in the axial direction, and on the outer peripheral surface of the axial end portion of the inner cylindrical portion 38A of the movable sheave 38. Is provided. And the 2nd sliding part 38F contacts the internal peripheral surface of the 1st cylindrical part 270B of the cylinder member 270 instead of the primary shaft SP, as FIG. 2 shows.

  Further, the secondary pulley 36 is disposed between the bearing 33 and the bearing 34 via a cylinder member described later on the outer periphery of the secondary shaft SS. The secondary shaft SS is rotatable about an axis B1 parallel to the axis A1, and two oil passages SSA and SSB are formed in the secondary shaft SS in the axial direction. The oil passages SSA and SSB are communicated with a hydraulic circuit of a hydraulic control device. Furthermore, an oil passage SSC that extends in the radial direction toward the outer peripheral surface of the secondary shaft SS and communicates with the oil passage SSA is provided. Furthermore, an oil passage SSD that extends in the radial direction toward the outer peripheral surface of the secondary shaft SS and communicates with the oil passage SSB is provided. Furthermore, a step SSE is formed between the opening portion of the oil passage SSD on the outer periphery of the secondary shaft SS and the bearing 33.

  The movable sheave 42 of the secondary pulley 36 includes a cylindrical portion 42A as a first axially extending portion on the innermost inner diameter side, and a radial direction portion 42B continuous to an end portion on the fixed sheave 41 side on the outer periphery of the cylindrical portion 42A. And. An annular cylinder member 290 as a partition member is provided between the step SSE and the bearing 33.

  The cylinder member 290 includes a first cylindrical portion 290A press-fitted into the outer peripheral portion of the secondary shaft SS, a first radial direction portion 290B, and the radial end portion 42B side of the movable sheave 42 from the outer peripheral end of the first radial direction portion 290B. The second cylindrical portion 290C as the first axially extending portion on the innermost diameter side extended toward the inner side, and the second radial direction as a flange portion extending radially from the end of the second cylindrical portion 290C A third cylinder as a second axially extending portion that is continuous to the outer peripheral side of the portion 290D and the second radial direction portion 290D and extends in a direction protruding toward the radial direction portion 42B of the movable sheave 42 A portion 290E, an inclined portion 290F that is spaced apart from the back surface of the movable sheave 42 and that is inclined in the outer diameter direction and extends from the end portion of the third cylindrical portion 290E; and an outer peripheral side of the inclined portion 290F. And And a fourth cylindrical portion 290G of the third axial extension that extends toward the radial portion 42B of the movable sheave 42.

  An axial spline groove 42S is formed on the inner peripheral surface of the cylindrical portion 42A of the movable sheave 42, and an axial spline groove SSG is formed on the outer peripheral surface of the secondary shaft SS. A plurality of spline grooves 42S and spline grooves SSG are formed at predetermined intervals in the circumferential direction. The secondary shaft SS and the movable sheave 42 are positioned so that each spline groove 42S and each spline groove SSG have the same phase in the circumferential direction, and a plurality of rollers 100 straddling both the grooves are disposed. ing. As with the primary shaft SP, the secondary shaft SS and the movable sheave 42 can move relative to each other in the axial direction, but cannot move relative to each other in the circumferential direction. Yes.

  On the other hand, the movable sheave 42 is provided with an annular member 295 on the back surface thereof. The annular member 295 includes a radial direction portion 295A fixed to the radial direction portion 42B of the movable sheave 42, and an inner diameter side cylinder as a second axially extending portion extending from the inner peripheral end toward the cylinder member 290 side. Part 295 </ b> B and an outer diameter side cylindrical part 295 </ b> C as a third axially extending part extending from the outer peripheral end toward the cylinder member 290 side. Here, a resin-made seal ring 295D is attached to the outer peripheral side of the inner diameter side cylindrical portion 295B, and is movable relative to the inner peripheral surface of the third cylindrical portion 290E of the cylinder member 290 in the axial direction. The seal surface is formed in the contact part. Further, a resin-made seal ring 295E is similarly attached to the outer peripheral side of the outer diameter side cylindrical portion 295C, and is movable relative to the inner peripheral surface of the fourth cylindrical portion 290G of the cylinder member 290 in the axial direction. And a sealing surface is formed at the contact portion.

  The outer peripheral surface of the cylindrical portion 42A of the movable sheave 42 and the inner peripheral surface of the second cylindrical portion 290C of the cylinder member 290 are fitted so as to be slidable or relatively movable, and the end surface of the cylindrical portion 42A and the partition member A first hydraulic chamber PCI-1 on the inner diameter side is formed in a space surrounded by the cylinder member 290 and the outer peripheral surface of the secondary shaft SS. The first hydraulic chamber PCI-1 on the inner diameter side is communicated with the oil passage SSD through a spline portion. On the other hand, as described above, the inner cylindrical portion 295B of the annular member 295 fixed to the movable sheave 42 is slidably fitted to the inner peripheral surface of the third cylindrical portion 290E of the cylinder member 290. Thus, a second hydraulic chamber PCI-2 on the inner diameter side is formed in a space surrounded by the outer peripheral surface of the cylindrical portion 42A of the movable sheave 42, the inner peripheral surface of the inner diameter side cylindrical portion 295B of the annular member 295, and the cylinder member 290. Has been. The second hydraulic chamber PCI-2 on the inner diameter side is also communicated with the above-described oil passage SSD via an oil passage 42C formed in the cylindrical direction 42A of the movable sheave 42 in the radial direction. A compression spring 292 that urges the movable sheave 42 in the direction in which the belt clamping pressure is generated is provided in the second hydraulic chamber PCI-2 on the inner diameter side.

  On the other hand, in the space surrounded by the outer peripheral surface of the inner diameter side cylindrical portion 295B of the annular member 295 fixed to the movable sheave 42, the inner peripheral surface of the outer diameter side cylindrical portion 295C of the annular member 295, and the cylinder member 290, A hydraulic chamber PCO on the outer diameter side is formed. The outer diameter side hydraulic chamber PCO is formed in a substantially radial direction continuously to the boundary portion between the cylindrical portion 42A and the radial direction portion 42B of the movable sheave 42 and the inner diameter side cylindrical portion 295B of the annular member 295. It communicates with the oil passage 42D. The oil passage 42D communicates with the oil passage SSC via an annular groove 42E formed on the inner peripheral side of the movable sheave 42.

  Further, an annular groove 295F having a predetermined width is formed on the outer peripheral surface of the outer diameter side cylindrical portion 295C of the annular member 295, and at the same time, the outer diameter side cylindrical portion 295C is annularly connected to the seal ring 295E. A drain hole 295G is formed in the radial direction adjacent to the groove 295F. In addition, a drain hole 290H is formed in the fourth cylindrical portion 290G of the cylinder member 290 in the same radial direction. As will be described later, the drain holes 290H and 295F are positions that communicate with each other via the annular groove 295F when the movable sheave 42 is moved to a large groove width, in other words, when the capacity of the hydraulic chamber PCI on the inner diameter side is small. It is said that.

  As described above, the first cylindrical portion 290A of the cylinder member 290 is press-fitted into the outer periphery of the secondary shaft SS, and at the same time, the reduction drive gear 47 is spline-fitted and fastened and fixed by the nut 184. Thus, the inner ring of the bearing 33 is press-fitted into the outer peripheral portion of the first cylindrical portion 290 </ b> A of the cylinder member 290 and is sandwiched between the first radial direction portion 290 </ b> B of the cylinder member 290 and the reduction drive gear 47. Further, the cylinder member 290, the bearing 33, and the reduction drive gear 47 are sandwiched and fixed in the axial direction of the secondary shaft SS by the nut 184 and the step SSE. The outer ring of the bearing 33 is supported by the transaxle case 5.

  Further, in the present embodiment, the reduction driven gear 53 is formed integrally with the intermediate shaft 50 that is an intermediate shaft, and meshed with the reduction drive gear 47. The intermediate shaft 50 is rotatably supported by a bearing 51 and a bearing 52 that are also supported by the transaxle case 5 at a position overlapping the bearing 33 in the axial direction, and a reduction driven gear 53 is provided on the outer periphery of the differential case 55. The ring gear 58 is engaged. As described above, the bearing 33 and the bearing 51 are supported by the transaxle case 5 in a positional relationship in which they are overlapped in the axial direction, so that the case rigidity can be increased.

  Here, the control and operation of the secondary pulley 36 and the hydraulic actuator 45 of the belt type continuously variable transmission 9 in the above-described embodiment will be described. When the oil pressures of the outer diameter side hydraulic chamber PCO and the inner diameter side first and second hydraulic chambers PCI-1 and PCI-2 are discharged through the drain holes and oil passages, they are given to the belt B. The movable sheave 42 is pressed to the bearing 33 side by the applied tension. This state is shown above the axis B1 in FIG.

  From the above state, control is performed from the hydraulic circuit to the first hydraulic chamber PCI-1 on the inner diameter side through the oil passage SSB and the oil passage SSD, and further to the second hydraulic chamber PCI-2 on the inner diameter side through the oil passage 42C. When the hydraulic pressure is supplied and the hydraulic pressures of the first and second hydraulic chambers PCI-1 and PCI-2 on the inner diameter side rise, the control hydraulic pressure is applied to the end face of the cylindrical portion 42A of the movable sheave 42 and the inner diameter of the movable sheave 42. The movable sheave 42 is pressed in the axial direction toward the fixed sheave 41 side. Then, by the movement of the movable sheave 42, the drain hole 290H formed in the fourth cylindrical portion 290G of the cylinder member 290 and the drain hole 295G formed in the outer diameter side cylindrical portion 295C of the annular member 295 are passed through the annular groove 295F. Almost simultaneously with the release of the communication, the supply of the control oil pressure from the hydraulic circuit via the oil passage SSA, the oil passages SSC and 42D is started, and the outer diameter side hydraulic chamber PCO is also supplied with the first and The control hydraulic pressure is supplied together with the second hydraulic chambers PCI-1 and PCI-2. As described above, the communication between the drain hole 290H of the fourth cylindrical portion 290G of the outer diameter side hydraulic chamber PCO and the drain hole 295G of the annular member 295 at the position corresponding to the predetermined gear ratio of the movable sheave 42 is made to correspond. Thus, the width of the groove 44 of the secondary pulley 36 is reduced while the supply of the control hydraulic pressure is controlled. Based on the tension applied to the belt B and the pressing force based on the control oil pressure of the first and second hydraulic chambers PCI-1 and PCI-2 on the inner diameter side and the outer diameter side hydraulic chamber PCO, The width of the groove 44 is controlled. The state shown below the axis B1 in FIG. 2 corresponds to a state where the width of the groove 44 is the narrowest and the gear ratio is large.

  Here, when the movable sheave 42 moves from the state shown below the axis B1 in FIG. 2 where the width of the groove 44 is the narrowest and the gear ratio is large to the side where the gear ratio is small, the control hydraulic pressure is increased. The mode of switching and supplying and the positional relationship with the drain hole will be further described. In the state where the gear ratio is large, the oil passage 42D of the movable sheave 42 and the oil passage SSC formed in the radial direction as the pressure oil supply hole and the oil passage SSA of the secondary shaft SS form the annular groove 42E. The outer diameter side hydraulic chamber PCO communicates with the oil passage of the hydraulic circuit. On the other hand, the drain hole 295G formed in the outer diameter side cylindrical portion 295C of the annular member 295 and the adjacent annular groove 295F as the drain hole and the drain hole 290H formed in the fourth cylindrical portion 290G of the cylinder member 290 are shafts. The directional positions are relatively displaced and are closed to each other. From this state, when the movable sheave 42 moves toward the side where the gear ratio is small, both drain holes in the closed state communicate and open. At this time, the supply of the control hydraulic pressure from the oil passage 42D is stopped by a command from a hydraulic control device (not shown).

The positional relationship between the movable sheave 42 and the drain hole will be further described. In this embodiment, the supply of the control hydraulic pressure is stopped at a position where the speed ratio γ is slightly larger than a predetermined value (for example, γ1). On the other hand, the drain hole is formed so as to shift from the closed state to the open state when the speed ratio is a predetermined value γ1. Thus, the supply of the control hydraulic pressure is not continued unnecessarily after the drain starts.
By stopping the supply of the control hydraulic pressure, the hydraulic oil having the control hydraulic pressure is not supplied to the outer diameter side hydraulic chamber PCO, and the first and second inner diameter sides are within the range where the gear ratio is smaller than the predetermined value γ1. The clamping pressure by the movable sheave 42 is generated only by the control oil pressure supplied to the hydraulic chambers PCI-1 and PCI-2. Thus, the influence of the centrifugal hydraulic pressure is reduced with a simple configuration by generating the clamping pressure only by the hydraulic chamber on the inner diameter side where the influence of the centrifugal force is small.

  Even when the belt member 42A receives a belt reaction force from the cylindrical portion 42A as the first axially extending portion on the innermost inner diameter side of the movable sheave 42, the cylinder member 290 as the partition wall member has the first cylindrical portion. 290A is press-fitted into the outer peripheral portion of the secondary shaft SS, the bearing 33 is press-fitted into the outer peripheral portion of the first cylindrical portion 290A, and the diameter of the cylindrical portion 42A of the movable sheave 42 is slidably disposed. Since it is configured to have the second radial direction portion 290D that is a flange portion extending in the direction, the rigidity of the portion where the maximum force is applied from the movable sheave 42 is sufficiently ensured. As a result, since the first cylindrical portion 290A of the cylinder member 290 is not separated from the secondary shaft SS, there is no oil leakage from the first hydraulic chamber PCI-1 on the inner diameter side, and the first cylinder portion 290A of the cylinder member 290 Since the movement of the three cylindrical portions 290E in the outer diameter direction is prevented, a decrease in sealing performance with the cylindrical portion 295B as the axially extending portion of the movable sheave 42 is suppressed.

It is a skeleton figure which shows the transaxle to which the belt type continuously variable transmission of this invention is applied. It is sectional drawing which shows embodiment of the belt-type continuously variable transmission of this invention.

Explanation of symbols

SP primary shaft SS secondary shaft 35 primary pulley 36 secondary pulley 37 primary side fixed sheave 38 primary side movable sheave 41 secondary side fixed sheave 42 secondary side movable sheave 42A cylindrical portion (extension portion in the first axial direction on the innermost diameter side)
SSA, SSB, SSC, SSD Oil passage 42C, 42D Oil passage (pressure oil supply hole)
290 cylinder member 290H drain hole 295 annular member 295G drain hole 295F annular groove PCO outer diameter side hydraulic chamber PCI inner diameter side hydraulic chamber PCI-1 first inner diameter side hydraulic chamber PCI-2 second inner diameter side hydraulic chamber

Claims (4)

A primary pulley provided on a primary shaft, a secondary pulley provided on a secondary shaft, a belt wound around both pulleys, a reduction gear device and a final reduction device including a differential device, the secondary shaft and the differential device In the belt-type continuously variable transmission configured to transmit power to the differential through an intermediate shaft disposed between
A belt type continuously variable transmission, wherein the intermediate shaft is provided with a single gear that meshes with both a gear provided on the secondary shaft and an input gear to the differential.   2. The belt-type continuously variable belt according to claim 1, wherein one of the bearings supporting the secondary shaft and one of the bearings supporting the intermediate shaft are supported by the same member at a position overlapping in the axial direction. transmission.   One of the bearings that supports the secondary shaft extends from the movable sheave in the axial direction with at least two hydraulic chambers, an outer diameter side and an inner diameter side, that generate belt clamping pressure acting on the movable sheave of the secondary pulley. In the partition member having an axially extending portion that slides on the axially extending portion to be independently configured with the existing axially extending portion, the partition member is provided on the outer peripheral portion of the press-fitting cylindrical portion to the secondary shaft. The belt type continuously variable transmission according to claim 1 or 2.   The outer diameter side hydraulic chamber is formed between an outermost diameter side axially extending portion of the movable sheave, an inner diameter side axially extending portion, and the partition member, and the outermost side of the movable sheave. The drain hole is formed in a positional relationship that communicates in the vicinity of a predetermined gear ratio when the movable sheave moves between the radially extending portion on the radial side and the partition member. The belt type continuously variable transmission described.

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