JP4560769B2 - Belt type continuously variable transmission - Google Patents

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 mounted on a primary shaft (drive side rotating shaft) and a secondary shaft (driven side rotating shaft) arranged in parallel to each other, a primary pulley mounted 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. In addition, each movable sheave is movable in the axial direction with respect to the corresponding rotating shaft and immovable in the circumferential direction via a ball and a ball groove (ball spline). 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. For the primary pulley and the secondary pulley, a hydraulic chamber is provided for moving each movable sheave closer to and away from the corresponding fixed sheave. The hydraulic pressure in each hydraulic chamber is controlled separately, whereby the groove width of the pulley is changed to change the belt winding radius, the transmission ratio is set to a desired value, and the belt tension is adjusted. .

  In such a belt type continuously variable transmission, an arrangement in which a bearing is arranged on the outer peripheral side of a cylinder member forming the hydraulic chamber of the pulley as described above is disclosed in, for example, Patent Document 1 (particularly, FIG. 2).

  Further, Patent Document 2 discloses a belt-type continuously variable transmission in which a hydraulic chamber (cylinder chamber) is formed at an axial end portion of a movable sheave.

Japanese Patent Application Laid-Open No. 7-198010 Japanese Utility Model Application No. 3-48148 (Japanese Utility Model Application No. 1-110262 Microfilm)

  By the way, combining the configuration in which the bearing is arranged on the outer peripheral side of the cylinder member described in Patent Document 1 and the configuration in which the hydraulic chamber is formed at the axial end of the movable sheave described in Patent Document 2, It is also conceivable to configure the outer peripheral side of the axial end portion to slide toward the inner peripheral side of the cylinder member. However, with such a configuration, the cylinder member itself receives the reaction force of the force applied from the belt to the movable sheave. Therefore, in order to increase the strength of the cylinder member, it is necessary to increase the size or thickness. There is a problem that the cost is increased and the weight is increased.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a belt type continuously variable transmission that can suppress an increase in the size or thickness of a cylinder member.

  The belt-type continuously variable transmission according to the present invention is a belt-type continuously variable transmission in which a bearing is provided on the outer peripheral side of a cylinder member that forms a hydraulic chamber for a movable sheave arranged slidably in the axial direction on the outer periphery of a rotating shaft. A hydraulic chamber is formed between the axial end of the movable sheave and the cylinder member, and is formed on an outer peripheral side of the axial end of the movable sheave; The bearing is arranged in such a relationship that at least a part of the sliding portion that comes into contact with the inner peripheral side exists in the axial configuration range of the bearing within the movable range of the movable sheave.

  Here, it is preferable that an inner ring of the bearing is press-fitted on the outer peripheral side of the cylinder member, and the inner peripheral side of the cylinder member is processed into a sliding portion after the press-fitting.

  In this belt type continuously variable transmission, a hydraulic chamber is formed between the axial end of the movable sheave and the cylinder member. Furthermore, when the movable sheave moves in the axial direction within the movable range, at least a part of the sliding portion that is formed on the outer peripheral side of the axial end portion of the movable sheave and contacts the inner peripheral side of the cylinder member is Since the bearing is arranged in the relationship existing in the axial configuration range, the reaction force of the force applied from the belt can be received not by the cylinder member but by the bearing. Therefore, it is possible to suppress an increase in size or thickness of the cylinder member.

  Further, according to the form in which the inner ring of the bearing is press-fitted to the outer peripheral side of the cylinder member, and the inner peripheral side of the cylinder member is processed and formed in the sliding portion after the press-fitting. Even if the cylinder member is deformed by press fitting, the accuracy of the sliding portion can be secured.

  Hereinafter, preferred embodiments of a belt type continuously variable transmission according to the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic configuration diagram showing a part of 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.

  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, and a forward / reverse switching mechanism 8 and a belt type continuously variable transmission according to the present invention are disposed inside the transaxle case 5 and the transaxle rear cover 6. A (CVT) 9 and a final reduction gear (differential device) 10 are 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 included in the belt-type continuously variable transmission 9, and the power transmission path between the carrier 30 and the input shaft SI is connected using the forward clutch CR. Blocked. 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, a belt type continuously variable transmission 9 according to the present invention includes a primary shaft (driving side rotating shaft) SP that extends substantially coaxially with the input shaft SI, and a secondary shaft that is 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.

  As shown in FIG. 1, a shaft 48 supported by bearings 46 and 47 is connected to the secondary shaft SS of the belt type continuously variable transmission 9. A counter driven gear 49 is fixed to the shaft 48, and power is transmitted from the belt type continuously variable transmission 9 to the final reduction gear 10 via the counter driven gear 49. The final reduction gear 10 includes an intermediate shaft 50 that is arranged in parallel with the secondary shaft SS. The intermediate shaft 50 is supported by bearings 51 and 52, and a counter driven gear 53 that meshes with the counter driven gear 49 of the secondary shaft SS and a final drive gear 54 are fixed to the shaft 50.

  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 formed on the outer periphery thereof. The ring gear 58 meshes with the final drive gear 54 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 the main part of the belt-type continuously variable transmission 9 according to the present invention described above. FIG. 2 shows the configuration related to the primary pulley 35 and the primary shaft SP of the continuously variable transmission 9. Is shown. The primary shaft SP is rotatable about an axis, 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 oil passages SPB and SPC that extend in the radial direction toward the outer peripheral surface thereof and communicate with the oil passage SPA. The oil passage SPB and the oil passage SPC are provided at different positions in the axial direction. Specifically, the oil passage SPB is disposed closer to the end of the primary shaft SP than the oil passage SPC. Yes. An oil passage SPD that is opened between the movable sheave 38 and the fixed sheave 37 and supplies oil that lubricates the contact portion of the belt B is also extended in the radial direction toward the outer peripheral surface 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. The inner cylinder portion 38A is formed with an oil passage 38D penetrating from the inner peripheral surface to the outer peripheral surface. The oil passage 38D and the oil passage SPC communicate with each other through an annular notch formed on the outer peripheral surface of the primary shaft SP.

  As shown in FIG. 2, a plurality of spline grooves (teeth) 38 </ b> S are formed on the inner peripheral surface of the inner cylindrical portion 38 </ b> A of the movable sheave 38. On the other hand, a plurality of spline grooves (teeth) SPG are formed on the outer peripheral surface of the primary shaft SP that slidably supports the movable sheave 38. The spline grooves 38S and SPG are formed at predetermined intervals in the circumferential direction, and the primary shaft SP and the movable sheave 38 are positioned so that the grooves 38S and SPG have the same phase in the circumferential direction. A plurality of balls 100 straddling both the grooves 38S and SPG are disposed. The primary shaft SP and the movable sheave 38 can be smoothly moved relative to each other in the axial direction by the spline grooves 38S, SPG and the ball 100, but the primary shaft SP and the movable sheave 38 are not relatively moved in the circumferential direction. It is considered possible. Reference numeral 100A denotes a snap ring for preventing the ball 100 from falling off, which is attached to an annular groove provided on an inner peripheral surface of the axial end portion of the inner cylindrical portion 38A of the movable sheave 38, and 100B denotes a primary shaft SP. It is a snap ring for preventing the ball 100 from falling off, which is mounted in an annular groove provided on the outer peripheral surface.

  Further, the belt type continuously variable transmission 9 includes a cylinder member 70 that is an annular partition member. As can be seen from FIG. 2, the cylinder member 70 includes a first radial direction portion 70A extending in the radial direction of the primary shaft SP, and a cylindrical portion 70B extending substantially parallel to the axis of the primary shaft SP from the first radial direction portion 70A. And a second radial portion 70C extending in the radial direction of the primary shaft SP along the back surface of the movable sheave 38 from the tubular portion 70B.

  A small-diameter portion at the front end of the primary shaft SP is press-fitted into a center hole formed in the first radial direction portion 70 </ b> A of the cylinder member 70, and the cylinder member 70 uses a lock nut 80 to form a step portion of the primary shaft SP. It is fixed between. The cylindrical portion 70B of the cylinder member 70 is rotatably supported by a bearing 32 fixed to the transaxle rear cover 6 by an annular bearing retainer 81 and a bolt BO. Thereby, in the belt-type continuously variable transmission 9, the primary shaft SP is rotatably supported by the bearing 32 via the cylinder member 70 (cylindrical portion 70B), as will be described in detail later.

  Further, a seal member 72 is arranged on the outer edge portion of the second radial direction portion 70 </ b> C of the cylinder member 70 so as to be in sliding contact with the inner peripheral surface of the outer cylinder portion 38 </ b> C formed on the outer periphery of the movable sheave 38. 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 38F, which will be described later, slidably contacts the inner peripheral side of the cylindrical portion 70B of the cylinder member 70. Is formed. Thus, the inner cylinder portion 38A, the radial direction portion 38B, the outer cylinder portion 38C, and the cylinder member 70 of the movable sheave 38 define the first hydraulic chamber 40A that constitutes the hydraulic actuator 40 described above. On the other hand, the second hydraulic chamber 40B constituting the hydraulic actuator 40 described above is constituted by the first radial direction portion 70A of the cylinder member 70, the cylindrical portion 70B, the axial end portion of the inner cylindrical portion 38A of the movable sheave 38 and the primary shaft SP. 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 cylindrical part 70B of the cylinder member 70 instead of the primary shaft SP, as FIG. 2 shows.

  Here, the positional relationship between the second sliding portion 38F and the above-described bearing 32 will be described in more detail with reference to FIG. In the present embodiment, the bearing 32 which is a ball bearing has an inner ring 32A formed on the outer peripheral side of the cylindrical portion 70B as well as the stepped portion 70BS formed on the outer peripheral side of the cylindrical portion 70B of the cylinder member 70. It is sandwiched and held by a snap ring SR mounted in the annular groove 70BG. Here, in the bearing 32, the inner ring 32A is press-fitted to the step part 70BS in the cylindrical part 70B of the cylinder member 70, and after the press-fitting, the inner peripheral side of the cylindrical part 70B of the cylinder member 70 is processed and the sliding part Is formed. Now, assuming that the axial width of the inner ring 32A is D, this is the axial configuration range of the bearing according to the present invention. The axial configuration range means a range in which force can be directly received by the bearing 32. On the other hand, the sliding surface of the second sliding portion 38F has an L length or width in the axial direction.

  In FIG. 3, a solid line indicates a position where the movable sheave 38 moves to the rightmost side, that is, a position where the movable sheave 38 approaches the fixed sheave 37 and narrows the pulley groove, which is indicated by a broken line. In contrast, what is shown is a position where the movable sheave 38 has moved to the leftmost side, that is, a position where the movable sheave 38 is spaced apart from the fixed sheave 37 to widen the pulley groove. Accordingly, the movable range of the movable sheave 38 is between the rightmost position and the leftmost position of the movable sheave 38. Therefore, in the present embodiment, at least part of the second sliding portion 38F that contacts the inner peripheral side of the cylindrical portion 70B of the cylinder member 70 is configured in the axial direction of the bearing 32 within the movable range of the movable sheave 38. A relationship that exists within the range is set. That is, for example, at the rightmost position of the movable sheave 38, the second sliding portion 38F overlaps the axial configuration range of the bearing 32 by the width OR, and at the leftmost position of the movable sheave 38, the second sliding portion 38F The sliding portion 38F overlaps the axial configuration range of the bearing 32 by the width OL. Therefore, the range indicated by hatching in FIG. 3 is always in contact with at least a part of the second sliding portion 38F.

  Thus, the reaction force of the force applied from the belt B to the movable sheave 38 can be directly received not only by the cylindrical portion 70B of the cylinder member 70 but also by the bearing 32, so that the cylinder member 70 can be made larger or thicker accordingly. It is possible to suppress fleshing.

[Second to Fourth Embodiments]
Hereinafter, belt type continuously variable transmissions according to second to fourth embodiments of the present invention will be described with reference to FIG. The same elements as those described in relation to the first embodiment described above are denoted by the same reference numerals, and redundant description is omitted.

  In the belt type continuously variable transmission shown in FIGS. 4A, 4B, and 4C, a bearing 32R made of a roller bearing is used instead of the bearing 32 made of a ball bearing used in the first embodiment. Is a feature. When the roller bearing 32R is used in this way, as described above, after the inner ring is press-fitted into the outer peripheral side of the cylindrical part 70B of the cylinder member 70, the cylindrical part 70B that may have been deformed along with this press-fitting. When processing the inner peripheral side of the outer ring, the outer ring and the rollers as the rolling elements and the inner ring can be easily disassembled. Therefore, the machining can be performed without the outer ring and the rolling element, and the biting of a foreign object during the machining can be avoided.

  In the second embodiment shown in FIG. 4 (A), the rotating shaft of the roller as a rolling element is an inclined roller bearing 32R-1 inclined with respect to the rotating shaft of the outer ring, and the third embodiment shown in FIG. 4 (B). In the embodiment, the roller rotation shaft and the outer ring rotation shaft are normal roller bearings 32R-2, and in the fourth embodiment shown in FIG. 4 (C), the inner ring is omitted and the roller is directly connected. The deformation roller bearing 32R-3 is in contact with the cylindrical portion 70B of the cylinder member 70. According to the fourth embodiment, the diameter of the bearing can be reduced.

  In each of the above embodiments, the present invention has been described as being applied to a primary pulley or a primary shaft. However, the present invention is not limited to this, and a secondary pulley or a secondary shaft is used. It goes without saying that it can be applied.

1 is a schematic configuration diagram showing a part of a vehicle to which a continuously variable transmission according to the present invention is applied. It is a principal part expanded sectional view which shows 1st Embodiment of the continuously variable transmission by this invention. FIG. 3 is a cross-sectional view for explaining the continuously variable transmission shown in FIG. 2. It is a principal part expanded sectional view which shows other embodiment of the continuously variable transmission by this invention, (A) is 2nd Embodiment, (B) is 3rd Embodiment, (C) is 4th Embodiment. .

Explanation of symbols

9 belt type continuously variable transmission 32 bearing 32A inner ring 35 primary pulley 36 secondary pulley 37 fixed sheave 38 movable sheave 38S spline 38A inner cylinder 38E first sliding portion 38F second sliding portion 40A first hydraulic chamber 40B first Two hydraulic chambers 70 Cylinder member 70B Cylindrical part SP Primary shaft SS Secondary shaft

Claims (2)

A belt-type continuously variable transmission in which a bearing is provided on the outer peripheral side of a cylinder member that forms a hydraulic chamber for a movable sheave that is slidably disposed in the axial direction on the outer periphery of a rotating shaft,
A hydraulic chamber is formed between the axial end of the movable sheave and the cylinder member, and a predetermined shaft that contacts the inner peripheral side of the cylinder member on the outer peripheral side of the axial end of the movable sheave is formed a sliding portion having a length in the direction, at least a portion of the axial length of the sliding portion, in the axial direction movable range of the movable sheave, the relationship that exists within the axial structure range of the bearing Thus, the belt-type continuously variable transmission, wherein the bearing is arranged.   The inner ring of the bearing is press-fitted into the outer peripheral side of the cylinder member, and the inner peripheral side of the cylinder member is processed into a sliding portion after the press-fitting. The belt-type continuously variable transmission according to 1.

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