JP2019074162A - Stepless speed change device for vehicle - Google Patents

Abstract

To solve the problem that a belt type stepless speed change device for vehicle employs a structure which positions a seal ring, holding an oil passage in a shaft for supplying hydraulic oil to a variable sheave in an oil-tight state, in a groove formed in an outer periphery of a sleeve inserted into the shaft, but a decrease in productivity resulting from cutting processing of the groove causes a rise in cost.SOLUTION: A first step part 66 is provided between an end part-side internal diameter Is1 and an inner-side internal diameter Is2 of a shaft 29, a second step part 68 is provided by an end part-side external diameter O|1 and an inner-side external diameter O|2 of a sleeve 59, and a seal ring 62 is held between the first step part 66 and second step part 68. Consequently, position precision of the seal ring 62 can be secured, and the sleeve is processed only by forging without using cutting processing so as to improve productivity and thereby lower costs.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a continuously variable transmission for a vehicle, and relates to an oil tight structure of a continuously variable transmission for a vehicle in which a seal ring for holding a hydraulic oil which enables movement of a movable sheave in an oil tight manner is disposed. It is a thing.

  In a continuously variable transmission for a vehicle, a fixed sheave integrally formed with a shaft and a movable sheave splined relative to the shaft in an axially-relatively movable manner and relatively non-rotatable around the shaft in a state facing the fixed sheave An oil passage is formed inside the shaft, and hydraulic pressure of hydraulic fluid is supplied to the hydraulic actuator of the movable sheave via the opening in the shaft, thereby providing the movable sheave of the movable sheave. Movement is taking place. In the continuously variable transmission for vehicle described in Patent Document 1, an oil passage is provided inside the shaft, and an oil hole formed inside the shaft and opened at an end surface is cylindrical from the end of the shaft. A sleeve is inserted, and an annular seal ring is disposed in a groove formed on the outer periphery of the sleeve, whereby the shaft and the sleeve are kept oil-tight. Further, by holding the sleeve at a predetermined position relative to the shaft, the position of the seal ring is also maintained at a predetermined predetermined position relative to the shaft.

JP, 2008-223903, A

  In the oil-tight structure of Patent Document 1, when the sleeve is processed by forging, since it is difficult to demold the sleeve in the axial direction due to the presence of the groove, the metal divided at a plane passing through the central axis of the sleeve You need to use a type. However, in forging using a divided mold, the seal ring may be damaged by the burr generated in the portion corresponding to the mating surface of the divided mold, which may cause deterioration of the sealing performance. In order to avoid the deterioration of the sealing performance, the groove in which the seal ring is disposed is formed by expensive cutting after the sleeve is processed into a cylindrical shape by forging.

  The present invention has been made against the background described above, and the object of the present invention is to position the seal ring without forming the groove requiring cutting on the outer periphery of the sleeve. An object of the present invention is to provide a structure of a continuously variable transmission for a vehicle, which is maintained at a predetermined position set in advance with respect to a shaft.

  According to the first aspect of the present invention, (a) a fixed sheave integrally formed with the shaft and a spline which is axially movable relative to the shaft and opposed to the shaft so as not to be relatively rotatable in a state facing the fixed sheave A pair of variable sheaves, each having a fitted movable sheave, and a transmission belt wound around the pair of variable sheaves, and an oil passage open at one end surface of the shaft inside the shaft A continuously variable transmission for a vehicle comprising: a sleeve inserted into the oil passage; and a seal ring disposed between the shaft and the sleeve, wherein (b) the shaft includes the sleeve A first step is formed by the inner diameter of the end of the shaft through which the shaft is inserted and the inner diameter of the inner side of the shaft below the inner diameter of the end of the shaft, and the sleeve An outside diameter of the end of the sleeve inserted into the end of the shaft and an outside diameter of the inside of the sleeve inserted into the inside of the shaft smaller than an outside diameter of the end of the sleeve; As a result, a second step portion is formed, and the seal ring is held between the first step portion and the second step portion.

  A pair of variable sheaves each having a fixed sheave integrally formed with a shaft and a movable sheave splined relative to the shaft axially oppositely movable and non-rotatably rotatable relative to the shaft in a state facing the fixed sheave And a transmission belt wound around the pair of variable sheaves, and an oil passage opened at one end surface of the shaft inside the shaft, and a sleeve inserted into the oil passage and the shaft A continuously variable transmission for a vehicle comprising a seal ring disposed between the sleeve and the sleeve, wherein the shaft has an inner diameter on an end side of the shaft through which the sleeve is inserted and an end of the shaft. A first step portion is formed by the inner diameter of the inner side of the shaft which is smaller than the inner diameter of the portion side, and the sleeve is provided with the sleeve inserted to the end side of the shaft. A second step portion is formed by the outer diameter of the end of the sleeve and the outer diameter of the inner side of the sleeve inserted to the inner side of the shaft below the outer diameter of the end of the sleeve. The seal ring is held between the stepped portion and the second stepped portion. In this way, by not forming a small outer diameter portion sandwiched by the large outer diameter portion of the sleeve, it is possible to demold the sleeve in the axial direction during forging of the sleeve, and the axial division is performed. There is no need to use a mold. By this, it is possible to perform processing for holding the seal ring by forging processing without using cutting processing, and it is possible to improve productivity and reduce costs. Further, a seal ring is held between a first stepped portion formed by the shaft and a second stepped portion formed by the sleeve, whereby the position of the seal ring disposed relative to the shaft Is kept at a predetermined position set in advance.

It is a figure showing typically an example of the continuously variable transmission to which the present invention is applied. It is sectional drawing explaining the structure of the movable sheave of the variable sheave of the continuously variable transmission of FIG. 1, a fixed sheave, and its periphery part. It is a part of the configuration of the primary sheave shown in FIG. 2 and has a structure in which the oil passage is kept oil-tight by arranging a seal ring between the first step of the shaft and the second step of the sleeve. It is the figure which expanded and showed. FIG. 6 is a view corresponding to FIG. 3, showing an enlarged conventional structure in which the oil passage is kept oil-tight by arranging an annular seal ring in a groove formed on the outer periphery of the sleeve. is there. FIG. 5 is an enlarged view of a groove formed on an outer periphery of the conventional sleeve of FIG. 4; (A) is the figure which showed the surface of a sleeve parallel to the axis including the groove of a sleeve, and (b) is the arrow seen from the a side centering on the sleeve's axis. FIG. 5 is an enlarged view of a state of being kept oil-tight by a seal ring disposed in a groove of the conventional sleeve of FIG. 4; FIG. 4 shows two different inner diameters forming the first step of the shaft of FIG. 3 and two different outer diameters forming the second step of the sleeve;

  Preferably, a cross section of the seal ring is rectangular, and a circumferential thickness of an axis of the shaft of the seal ring is greater than the first stepped portion of the shaft. In this way, the hydraulic oil can be appropriately supplied to the seal ring, and the oil passage can be kept oiltight.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a view schematically showing a continuously variable transmission 10 (corresponding to the continuously variable transmission for a vehicle according to the present invention, hereinafter referred to as continuously variable transmission 10) in the present embodiment. The continuously variable transmission 10 has a primary pulley 18 (corresponding to the variable sheave of the present invention, hereinafter referred to as the primary pulley 18) provided on the outer peripheral side of the input shaft 14 and a secondary pulley 20 provided on the output shaft 16 Power transmission is performed via the frictional force (belt clamping force) between each of the pulleys 18 and 20 and the transmission belt 28. In the primary pulley 18, the hydraulic pressure supplied to the primary hydraulic actuator 42 is adjusted and controlled by a hydraulic control circuit (not shown) for supplying hydraulic pressure to the primary pulley 18, whereby the primary stationary sheave 34 and the primary movable sheave A primary thrust (= primary pressure × pressure receiving area) to change the V groove width between 40 is applied. Also, in the secondary pulley 20 (corresponding to the variable sheave according to the present invention, hereinafter referred to as the secondary pulley 20), the hydraulic pressure supplied to the secondary pulley 20 is supplied to the primary hydraulic actuator 44 by a hydraulic control circuit not shown. By controlling the pressure of the hydraulic pressure, control is performed to change the V groove width between the secondary fixed sheave 36 and the secondary movable sheave 38, and a secondary thrust (= secondary pressure × pressure receiving area) is applied. In the continuously variable transmission 10, the primary thrust (primary pressure) and the secondary thrust (secondary pressure) are controlled to change the V groove widths of the primary pulley 18 and the secondary pulley 20, and the engagement diameter of the transmission belt 28 The effective diameter is changed, and the gear ratio (= primary sheave rotational speed / secondary sheave rotational speed) is changed, and between the pulleys 18 and 20 and the transmission belt 28 so that the transmission belt 28 does not slip. Frictional force is controlled. The pulleys 18 and 20 and the transmission belt 28 are rotatably held by the case 12.

  FIG. 2 is a cross-sectional view showing primary pulley 18 in FIG. Although the primary pulley 18 will be representatively described below, the present invention can be applied to the secondary pulley 20 as well. The primary pulley 18 is rotatably supported by the case 12 via a bearing 22. A V-shaped V-groove 26 is formed between the disk-shaped primary side fixed sheave 34 integrally formed on the shaft 25 (hereinafter referred to simply as the fixed sheave 34 when it is not necessary to distinguish from the secondary side) The shaft 25 is supplied with a primary-side movable sheave 40 (hereinafter referred to simply as the movable sheave 40 if it is not necessary to distinguish from the secondary side) that is relatively non-rotatable and axially-relatively movable. Hydraulic actuator 42 that changes the groove width of the V groove 26 by moving the movable sheave 40 in the direction of the first axis C1 in accordance with the hydraulic pressure to move the fixed sheave 34 and the movable sheave 40 axially toward or away from each other. And have. The shaft 25 is rotatably supported around a first axis C1 by bearings 22 whose outer peripheral ends are fitted to the case 12. The inner diameter of the movable sheave 40 is formed with a groove having an involute curve on the side surface, and an involute spline fitting (hereinafter, spline fitting and a groove formed on the movable sheave 40 and a groove formed on the outer diameter of the shaft 25) As a result, the movable sheave 40 and the shaft 24 can not rotate relative to each other and can move relative to each other.

  The fixed sheave 34 of the primary pulley 18 is a disk-shaped member that protrudes radially from the outer peripheral surface of the shaft 25. The stationary sheave 34 is formed with a conical tapered surface 46 which is formed in a direction away from the movable sheave 40 in the radial direction. The movable sheave 40 of the primary pulley 18 has a boss portion 40a whose inner peripheral portion is spline-fit so as to be relatively movable in the axial direction relative to the shaft 25 and relatively non-rotatable about the first axis C1; And an outer periphery extending in parallel with the first axis C1 in a direction away from the fixed sheave 34 in the axial direction from a disc portion 40b radially projecting from an end portion on the fixed sheave 34 side in the axial direction of It is comprised from the cylinder part 40c. The disc portion 40b is formed with a conical tapered surface 48 which is formed in a direction away from the fixed sheave 34 as it goes in the radial direction, and a back surface portion 40d on the back surface side. A V-groove 26 is formed by the tapered surface 48 formed on the movable sheave 40 and the tapered surface 46 formed on the fixed sheave 34.

  The hydraulic actuator 42 includes a bottomed cylindrical cylinder member 50 fixed to a shaft 25 disposed at a back surface position opposite to the tapered surface 48 of the movable sheave 40. The cylinder member 50 is fixed so as not to move in the axial direction by fastening the nut 30 between the step 49 of the shaft 25 and the nut 30 via the disc-like sheet 32. The cylinder member 50 has a wall portion 50a whose inner peripheral portion is fixed between the step 25 of the shaft 25 and the bearing 22 via the seat 32, and an outer cylindrical portion 40c of the movable sheave 40 from the outer peripheral portion of the wall portion 50a. The cylindrical portion 50 b is provided so as to continuously protrude in the circumferential direction on the outer peripheral side of the movable sheave 40 and is in contact with the outer peripheral surface of the outer cylindrical portion 40 c of the movable sheave 40 via a seal member. An oil pressure chamber 52 is formed which is a space surrounded by the cylinder member 50, the back surface 40d of the movable sheave 40, and the shaft 24 in an oil tight manner. The hydraulic chamber 52 is an oil passage formed by the case 12 and not shown, and a first oil passage 54 formed in a cylindrical shape in the shaft 24 (corresponding to the oil passage of the present invention. Hereinafter, the first oil passage 54, a second oil passage 56 formed to communicate the inner circumferential side and the outer circumferential side of the shaft 24, and a third oil passage 57 formed in the movable sheave 40 and communicated with the second oil passage 56. The hydraulic pressure pressure-fed from an oil pump (not shown) is appropriately adjusted and supplied by a hydraulic control circuit (not shown). The hydraulic chamber 52 is kept oil-tight by a seal member installed in a seal groove 60 b formed in the outer cylindrical portion 40 c of the movable sheave 40. In the first oil passage 54, a sleeve 59 mounted with a seal member is inserted through the end of the shaft 24 of the first oil passage 54, and the case 12 is press-fitted to the inner diameter side of the sleeve 59. It is kept oiltight.

  FIG. 3 is an enlarged view of a rectangular region enclosed by a broken line in FIG. 2, that is, the end side of the first oil passage 54 formed in a cylindrical shape inside the shaft 25. A sleeve 59 installed inside the first oil passage 54, a case 12 pressed into the sleeve 59, and a part of the shaft 25 are shown. A seal ring 62 having a rectangular cross section is disposed between a first stepped portion 66 formed on the inner periphery of the shaft 25 and a second stepped portion 68 formed on the outer periphery of the sleeve 59.

  FIG. 4 shows an enlarged view of a conventional sleeve 58, shaft 24 and case 12 corresponding to the rectangular area shown dashed in FIG. A seal groove 60a is formed on the outer periphery of the sleeve 58 installed inside the first oil passage 54, and a seal ring 62 is arranged in the seal groove 60a. The seal groove 60a of the sleeve 58 is formed by cutting after processing the outer shape of the sleeve 58 by forging or the like, and by requiring cutting, the productivity at the time of processing the sleeve 58 is reduced and the processing cost is reduced. It has caused an increase.

  FIG. 5A is a side view parallel to the first axis C1 of the sleeve 58 including the seal groove 60a formed in the sleeve 58. As shown in FIG. 5 (b) is a view as seen from the side A shown in FIG. 5 (a), and the inner peripheral surface of the sleeve 58 and the bottom surface of the seal groove 60a are two on the inside of the outer periphery of the sleeve 58. It is shown as a circle. There is a restriction in forming the shape of the sleeve 58, that is, the small outer diameter seal groove 60a sandwiched by the large outer diameter portion of the sleeve 58 by forging which is an inexpensive processing method. In such a shape of the sleeve 58, since it is not possible to unmold the forging die in the direction of the first axis C1, in order to form the seal groove 60a on the outer periphery of the sleeve 58, 2 in a plane parallel to the first axis C1. It is necessary to use the type to be split, ie type split. When forging is performed divided into two molds, burrs are generated on the mating surfaces of the two molds. If burrs are generated in the seal groove 60a, the seal ring 62 may be damaged and sealing performance may be reduced, so the seal groove 60a can not be processed integrally with the sleeve 58.

  FIG. 6 is an enlarged view of a rectangular area surrounded by a dotted line in FIG. 4, in which the hydraulic oil is applied to the hydraulic oil indicated by hatching, and the first oil passage 54 has a rectangular cross section. The oil-tight state is shown by the ring 62. The seal groove 60a is a surface formed on the end side of the shaft 24 of the seal groove 60a, that is, A surface As, and a surface of the seal groove 60a on the inner side of the shaft 24, that is, B surface Bs and a bottom surface of the seal groove 60a. Is formed from the surface forming Ct, that is, C surface Cs. The first oil passage 54 is kept oiltight by the seal ring 62 being in close contact with the inner peripheral surface I1 of the shaft 24 and the A surface As. The hatched lines indicate the hydraulic oil in the first oil passage 54. As shown in FIG. 6, the surface on the inner side of the shaft 24 of the seal groove 60a, that is, the B surface Bs is not used to keep the first oil passage 54 oiltight. However, the B surface Bs is used as positioning for holding the seal ring 62 near the predetermined position with respect to the shaft 24.

  FIG. 7 shows a shaft 25 having a step, ie, a first step portion 66, formed in the inner diameter shown in FIG. 3, and a sleeve 59, having a step, ie, a second step portion 68, formed on the outer shape. The shaft 25 has a first step 66 formed by the inner diameter Is1 of the end of the shaft 25 through which the sleeve 59 is inserted and the inner diameter Is2 of the inner side of the shaft 25 smaller than the inner diameter Is1 of the end of the shaft 25 There is. In the sleeve 59, a second step portion 68 is formed by the outer diameter Ol2 of the inner side of the sleeve 59 installed on the inner side of the shaft 59 and the outer diameter Ol1 of the sleeve 59 installed on the end side of the shaft 25. It is done. A seal ring 62 is held between the first step 66 and the second step 68. The first stepped portion 66 formed by the shaft 25 corresponds to the B surface Bs of the seal groove 60a of the sleeve 58, and the second stepped portion 68 formed by the sleeve 59 corresponds to A of the seal groove 60a of the sleeve 58. It corresponds to the surface As. Thereby, when the hydraulic pressure is applied to the hydraulic oil, the seal ring 62 contacts the first inner peripheral surface I1 of the shaft 25 and the second step portion 68 of the sleeve 59, whereby the first oil passage 54 becomes oil-tight Be kept Further, the first step portion 66 formed on the shaft 25 is used as a positioning for holding the seal ring 62 in the vicinity of a predetermined position with respect to the shaft 25 similarly to the B surface Bs of the seal groove 60a of the sleeve 58. It is used.

  As described above, according to this embodiment, the shaft 25 can be moved relative to the fixed sheave 34 integrally formed with the shaft 25 and the fixed sheave 34 in the direction of the first axis C2 and around the first axis C1. A pair of variable sheaves 18, 20 each having a movable sheave 40 non-rotatably splined and a transmission belt 28 wound around the pair of variable sheaves 18, 20; A continuously variable transmission having an oil passage 54 opened at one end surface of the shaft 25 and a sleeve 59 inserted into the oil passage 54 and a seal ring 62 disposed between the shaft 25 and the sleeve 59 10, the shaft 25 is smaller than the inner diameter Is1 at the end of the shaft 25 through which the sleeve 59 is inserted and the inner diameter Is1 at the end of the shaft 25. The first step portion 66 is formed by the inner diameter Is2 on the inner side, and the sleeve 59 has an outer diameter Ol2 at the end of the 59 sleeve inserted into the end of the shaft 25 and an outer diameter at the end of the sleeve 59 A second stepped portion 68 is formed by the outer diameter Ol1 of the inner side of the sleeve 59 inserted to the inner side of the shaft 25 below the Ol2, and the seal ring 62 is formed between the first stepped portion 66 and the second stepped portion 68. Is held. In this way, by not forming a small outer diameter portion sandwiched by the large outer diameter portion of the sleeve 59, it is possible to remove the die in the axial direction of the sleeve in forging of the sleeve and to divide the sleeve in the axial direction There is no need to use a mold that has been By this, it is possible to perform processing for holding the seal ring by forging processing without using cutting processing, and it is possible to improve productivity and reduce costs. Further, the seal ring 62 is disposed on the shaft 25 by holding the seal ring 62 between the first step portion 66 formed by the shaft 25 and the second step portion 68 formed by the sleeve 59. The position 62 is kept at a preset predetermined position.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is also applicable in other aspects.

  In the above embodiment, the oil passage 54 is structured to be kept oil-tight by the sleeve 59, the case 12 and the seal ring 62, but the invention is not limited thereto. For example, the end of the sleeve 59 on the case 12 side The oil passage 54 may be made oiltight by pressing a disc-like member into the end of the sleeve 59 on the case 12 side or fitting a member covering the end of the sleeve 59 on the case 12 side to the part. it can.

  In the above embodiment, the fixed sheave 34 is integrally formed with the shaft 25. However, the fixed sheave 34 may be integrally formed by a mechanical method if it is not necessary to be integrally molded and rigidity can be secured. That's fine.

The above description is only one embodiment, and the present invention can be implemented in variously modified and improved modes based on the knowledge of those skilled in the art.

10: Belt-type continuously variable transmission for vehicles (continuously variable transmission for vehicles)
18, 20: Primary pulley, secondary pulley (variable sheave)
25: shaft 28: transmission belt 34, 36: fixed sheave 38, 40: movable sheave 54: first oil passage (oil passage)
59: Sleeve 62: Sealing 66: Transmission belt 66: First stepped portion 68: Second stepped portion Is1: Inner diameter Is2 at the end of the shaft: Inner diameter Ol1 at the inner side of the shaft: Outer diameter Ol2 at the end of the sleeve : Outer diameter of the inner side of the sleeve

Claims (1)

A pair of variable sheaves each having a fixed sheave integrally formed with a shaft and a movable sheave splined relative to the shaft axially oppositely movable and non-rotatably rotatable relative to the shaft in a state facing the fixed sheave And a transmission belt wound around the pair of variable sheaves, and an oil passage opened at one end surface of the shaft inside the shaft, and a sleeve inserted into the oil passage and the shaft A continuously variable transmission for a vehicle comprising: a seal ring disposed between the sleeve and the sleeve;
A first step portion is formed on the shaft by an inner diameter on the end of the shaft through which the sleeve is inserted and an inner diameter on the inner side of the shaft below the inner diameter on the end of the shaft
The inner diameter of the sleeve is smaller than the outer diameter of the end of the sleeve inserted into the end of the shaft and the outer diameter of the outer diameter of the end of the sleeve. A second step portion is formed by the outer diameter of
A continuously variable transmission for a vehicle, wherein the seal ring is held between the first stepped portion and the second stepped portion.

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