JP4998081B2 - Conical friction ring type continuously variable transmission - Google Patents

Description

  The present invention provides a conical friction ring-type continuously variable transmission that obtains a continuously variable transmission by interposing a ring between two parallel conical friction wheels (cones) and moving the ring in the axial direction. In particular, the present invention relates to a pressing device that applies a traction force necessary for torque transmission between the ring and the cone.

  Conventionally, a steel ring is interposed between two conical friction wheels (primary cone and secondary cone) to surround the primary cone, and power is transmitted from the primary cone to the secondary cone via the ring. In addition, there is known a conical friction ring type continuously variable transmission in which the ring changes the contact position of the two cones by moving the ring in the axial direction to continuously change the speed (Patent Document 1 and Patent Document 1). 2).

  In the conical friction ring type continuously variable transmission, a pressing device including a spring and a torque cam is disposed between the secondary cone and the secondary shaft, and the pressing device acts on the secondary cone and the secondary shaft by the torque cam. The axial force corresponding to the load torque, in combination with the axial force generated by the spring, acts so that the ring is pressed against both cones, thereby providing a traction force required for torque transmission.

  The torque cam generates an axial force based on the relative rotation between the secondary cone and the secondary shaft, so that a relative rotation is generated between the cam members respectively connected to the secondary cone and the secondary shaft. Torsion torque is applied. The torsional torque causes a hysteresis with respect to the pressing force of the pressing device, and adversely affects the accuracy of the pressing force corresponding to the transmission torque.

  For this reason, conventionally, a thrust bearing is interposed on the contact surface between the spring and the secondary pulley or the secondary shaft to prevent the occurrence of the hysteresis (see Patent Document 1).

International Publication No. WO2004 / 113766 A1 JP-A-10-331935

  The operating angle of the torque cam (the relative rotational amount of both cam members) is small, so the operating angle of the thrust bearing is also in a very small range, and the needle continues to hit the same location repeatedly. For this reason, a problem arises in the durability of the thrust bearing, and it is wasteful in terms of cost to use an expensive thrust bearing for the very small relative rotation.

  Therefore, the present invention provides a conical friction ring type continuously variable transmission that can reduce the influence of the hysteresis and maintain high pressing accuracy while not using the thrust bearing, and solves the above-described problems. It is intended to provide.

According to the first aspect of the present invention, the conical friction wheels (2, 10) are respectively disposed on the first shaft (4) and the second shaft (11) disposed in parallel, and both the conical friction wheels (2) are arranged. , 10), a ring (3) is interposed between the first shaft (4) and the second shaft (11) so as to be axially movable, and a torque is transmitted between the first shaft (4) and the second shaft (11). In the continuously variable transmission (1),
A torque cam (20) that generates an axial force by relative rotation based on the torque and a spring (13), and applies a traction force between the conical friction wheel (2, 10) and the ring (3). A pressing device (12 ₁ ) (12 ₂ ) for
The spring (13) is contracted between the relative rotating members (16, 17) of the torque cam (20) so that the cam members (16, 17) and the axis (XX) are aligned,
During the compression force of the spring (13) acts, the thrust receiving portion before Symbol compressive force acts on the central point contact (18 1, _{18 2)} provided,
The present invention provides a conical friction ring type continuously variable transmission.

In the invention according to claim 2 (see, for example, FIG. 2), the thrust receiving portion (18 ₁ ) is two plates (14, 15) in which the central portion (14a, 15a) of one surface bulges, and these The plates (14, 15) are in contact with each other at the central part of the bulged central part (14a, 15a).
The conical friction ring type continuously variable transmission according to claim 1.

The invention according to claim 3 (e.g. see FIG. 3), the spring (13), a number of disc springs (13 ₁ ...) becomes arranged along said axis, at least two of these disc springs Consists of disk-shaped members (13 ₂ , 13 ₃ ) with the central part (13 ₂ a, 13 ₃ a) projecting to one side,
The thrust receiving portion (18 ₂₎ is formed by mutually abutting in the center portion of the two disc-shaped member ₍₁₃ 2, 13 ₃₎ a central portion which the projecting ₍₁₃ 2 a, ₁₃ 3 a) ,
The conical friction ring type continuously variable transmission according to claim 1.

  According to the first aspect of the present invention, a pressing device including a torque cam and a spring is provided, and the torque cam causes relative rotation between the two cam members, and a torsional torque based on the relative rotation acts on the compression force acting line of the spring. However, since the compression force is received by the thrust receiving portion disposed in the vicinity of the axis of the torque cam member and the spring, a sufficient shaft corresponding to the traction force required between the conical friction wheel and the ring is sufficient. Even if it is a force, the axial force can be supported by a portion with a small torque in the vicinity of the axial line, and with a simple structure omitting a thrust bearing, the influence of hysteresis is reduced, and a highly accurate pressing force is achieved. Based on traction force can be obtained.

  According to the second aspect of the present invention, since the thrust receiving portion is composed of two plates with the central portion of one surface bulging, various springs can be used as the spring, and the plate can be a low friction material or the like. Any suitable material can be used, and the thrust force can be received with high accuracy.

  According to the third aspect of the present invention, the spring is composed of a large number of disc springs, and the thrust receiving portion is constituted by a part of these disc springs, so that it is possible to design inexpensively and rationally.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a continuously variable transmission U mounted in a vehicle includes a starting device 31, such as a torque converter or a multi-plate wet clutch, a forward / reverse switching device 32, and a conical friction ring type continuously variable transmission according to the present invention. 1 and a differential device 33, each of which is built in a case.

  The power generated by the engine 30 is supplied to the input shaft (first shaft) 4 of the conical friction ring-type continuously variable transmission 1 via a starter 31 and a forward / reverse switching device 32 disposed behind the starter 31. The power is transmitted, the gear is continuously shifted by the conical friction ring type continuously variable transmission 1, and is output to the secondary shaft 11. Further, the power is transmitted to the differential device 33 by the secondary gear 21 provided on the secondary shaft 11 and the mount gear 34 meshing therewith, and output to the left and right drive shafts 35 and 35.

  The conical friction ring type continuously variable transmission 1 includes a primary cone (first conical friction wheel) 2, a secondary cone (second conical friction wheel) 10, a primary cone 2, and a secondary cone 10. The ring 3 interposed therebetween and the pressing device 12 including a spring 13 and a torque cam 20 are included.

  The primary cone 2 is integrally connected to the primary shaft 4 connected to the forward / reverse switching device 32 and is rotatably supported by the case, and has a conical shape with a certain inclination angle. . In addition, a steel ring 3 is disposed between the primary cone 2 and the secondary cone 10 so as to surround the outer periphery thereof, and the ring 3 is provided so as to be movable in the axial direction by a ball screw or the like. ing.

  The secondary cone 10 has a hollow conical shape having the same inclination angle as that of the primary cone 2, and is inserted into a secondary shaft 11 provided in parallel with the primary shaft 4 in the direction opposite to the primary cone 2 in the axial direction. The case 5 is rotatably supported by bearings 22 and 23. A pressing device 12 according to the present invention is interposed between the secondary cone 10 and the secondary shaft 11.

  The pressing device 12 includes a spring 13 such as a disc spring and a torque cam 20, which are arranged in series in the transmission direction. The torque cam 20 includes first and second cam members 16 and 17 having wavy end face cams at opposing flange portions, and a plurality of balls 19 interposed and arranged between the both end face cams. The other cam member is configured to move in the axial direction with respect to one cam member by relative rotation of the cam member.

  The first cam member 16 is connected to the secondary cone 10 integrally in the rotational direction and the axial direction, and the second cam member 17 is connected to the secondary shaft 11 integrally in the rotational direction and the axial direction. The secondary cone 10 integrated with the first cam member 16 is rotatably supported with respect to the case 5 by bearings 22 and 23, but is movable by a predetermined amount in the axial direction. The secondary shaft 11 integrated with the cam member 17 is rotatably supported by the conical roller bearing 25 with respect to the case 5 and supports a thrust force in the axial direction, particularly in a direction away from the secondary cone 10.

  The spring 13 is accommodated in the hollow boss portion of the first cam member 16, and one end of the spring 13 abuts on the first cam member 16 and the other end abuts on the second cam member 17. The cam members are biased in a direction away from each other.

  Therefore, first, the pressing device 12 always urges the secondary cone 10 in the arrow A direction against the secondary shaft 11 to which the spring 13 is fixed in the axial direction. When torque is transmitted from the secondary cone 10 to the secondary shaft 11, the torque cam 20 rotates relative to the load torque acting on the secondary shaft 11, and is fixed in the axial direction based on the relative rotation. The secondary cone 10 is given a force in the direction of arrow A with respect to the secondary shaft 11. The force in the direction of arrow A acting on the secondary cone 10 by the spring 13 and the torque cam 20 is a narrow pressure that presses the ring 3 against both the cones 2 and 10 against the primary cone 2 that is prevented from moving in the axial direction. Acting, the frictional force necessary for torque transmission is applied between the ring 3 and the two cones 2 and 10 in the traction oil, and the power is transmitted between the cones 2 and 10.

  In the above description, the positive torque that transmits torque from the secondary cone 10 to the secondary shaft 11 has been described. However, even in reverse torque (reverse drive) that transmits torque from the secondary shaft to the secondary cone, such as engine brake, Since the end cam shapes of the first and second cam members 16 and 17 are wavy, an axial force in the direction of arrow A is generated similarly.

  The first cam member 16 and the second cam member 17 rotate relative to each other with a slight rotation angle in accordance with the load torque, and thus a torsional force is also generated in the spring 13 that contacts both the cam members. . In the present invention, the torsional force of the spring 13 is received by a thrust receiving portion having a simple structure without using a thrust bearing, and the hysteresis of the spring 13 is reduced. The embodiment will be described below with reference to FIGS.

Pressing device 12, as shown in FIG. 2, a spring 13 consisting of a number of disc springs ₁₃ 1 ... arranged in series, it consists of the torque cam 20, first cam member 16 of the torque cam 20, the outer splines 16c The shaft portion 16b has a cylindrical hollow spring support portion 16a, and the cam portion 16d has a corrugated cam formed on the end face. The shaft portion 16b is spline-engaged with the boss portion 10a of the secondary cone 10, and the stepped portion 16e is in contact with the end surface of the boss portion, and is configured integrally with the secondary cone 10 in the rotation direction and the axial direction. Also, a number of disc springs 13 ₁ ... hollow portion of the spring supporting portion 16a is accommodated.

The second cam member 17 of the torque cam 20 includes a boss portion 17c having an inner spline 17a and a cam portion 17d in which a wavy cam is formed on the end surface. The secondary shaft 11 is spline-engaged with the boss portion 17, And it is contact | abutted by the stopper member 17b and it connects with the rotation direction and the axial direction integrally. The tip of the boss portion 17 is in contact with the spring 13 via the thrust receiving portion 18 ₁ which will be described later, the spring 13 is interposed in compressed state between the first and second cam members 16 and 17 The A large number of balls 19 are interposed and arranged between the cam portions 16d and 17d facing each other, and an axial force is generated based on the relative rotation of both cam members 16 and 17.

  The first cam member 16 disposed coaxially with the secondary cone 10 and the second cam member 17 disposed coaxially with the secondary shaft 11 are disposed in common with the axis XX. The spring 13 is arranged with the axis XX in common.

Between the tip and the second cam member boss portion 17c of the spring 13, the thrust receiving portion 18 ₁ are arranged in a common said axis. The thrust receiving portion 18 ₁ comprises a first and second plates 14 and 15 are two plate-like members having the same shape, one side of the plate, the central portion 14a, 15a is a convex shape that bulges The other surface is a flat surface. And it interposes between the said spring 13 and the boss | hub part 17c so that one surface of a middle-high shape may face each other. Accordingly, the two plates 14 and 15 are in contact with each other at the bulged central portions 14a and 15a, and the corresponding contact portions substantially coincide with the axis line XX, in the vicinity of the axis line. constitute a thrust receiving portion 18 ₁ for receiving the compressive force of the spring 13.

Incidentally, the spring 13, the other is frictionally contact with the bottom portion of the spring support portion of the first cam member 16, a number of disc springs 13 ₁ to each other even in frictional contact, is rotated integrally with the first cam member. Also, a number of disc springs 13 _1, holes 13a are formed in the center portion and the first and second plates 14 and 15, holes 14b at a position deviated from the central portion, 15b is formed The holes 13a, 14b, and 15b communicate with each other to form an oil passage for lubrication and the like.

Therefore, the urging force of the spring 13, one of them being received by the second cam member 17 which is fixed in the axial direction through the thrust receiving portion 18 _1, acting on the secondary cone 10 through the first cam member 16 To do. Torsional force of the spring 13 based on the relative rotation of the torque cam 20, the thrust receiving portion 18 ₁ for point contact with the axis X-X near (including contact by minimum area) heart, i.e. the two plates 14 and 15 A large thrust force is not applied to the spring 13 because it is received at the center of the bulging (middle and high) central portions 14a and 15a. Thus, the pressing device 12 _1, even those that generate sufficient axial force corresponding to the traction force required between the primary cone 2 and the secondary cone 10 and the ring 3, easy omitting the thrust bearing With a simple structure, the influence of the hysteresis of the spring 13 can be reduced, and a traction force based on a highly accurate pressing force can be obtained.

In this embodiment, the two plates 14 and 15 are made of a hardened quenching member, and in particular, the bulging center portions 14a and 15a are made of high hardness or a self-lubricating member such as a sintered alloy. configured, it may further reduce the thrust force generated in the thrust receiving portion 18 _1. Further, the spring 13 is not limited to a disc spring, and other springs such as a coil spring may be applied.

FIG. 3 shows a pressing device 12 ₂ according to the second embodiment of the present invention, in which the first and second plates 14 and 15 in Embodiment 1 constituted by a disc spring. Hereinafter, parts different from the configuration of the first embodiment will be described.

As shown in FIG. 3, the tip of the first spring 13 comprising a plurality of disc springs 13 _1, which is provided in a compressed state the cam member 16, and the boss portion 17c of the second cam member 17, it is constituted by a disc spring between the thrust receiving portion 18 ₂ is interposed a. The first and second disc spring ₁₃ 2, 13 ₃ constituting the thrust receiving portion 18 ₂ is made of a substantially s Ku-shaped circular member so that the central portion ₁₃ 2 a of the one side, 13 ₃ a projects , the central portion of the protruding central portion 13 2 _a, 13 3 _a is disposed opposite to point contact each other to form the thrust receiving portion 18 _2.

In the present embodiment, as described above, it becomes possible to form in some spring 13 comprising a thrust receiving portion 18 ₂ of a number of disc springs can rational design inexpensive.

The transmission system figure of the traveling vehicle which concerns on this invention. Sectional drawing which shows the press apparatus used for the conical friction ring type continuously variable transmission which concerns on Example 1. FIG. Sectional drawing which shows the press apparatus which concerns on Example 2. FIG.

Explanation of symbols

1 Conical friction ring type continuously variable transmission 2 Primary cone (conical friction wheel)
3 Ring 4 Primary shaft (first axis)
10 Secondary cone (conical friction wheel)
11 Secondary shaft (second axis)
12, 12 ₁ , 12 ₂ pressing device 13 springs 13 ₁ , 13 ₂ , 133 ₃ disc spring 14 first plate 14a central portion 15 second plate 15a central portion 16 first cam member 17 second cam members 18, 18 ₁ , 18 ₂ Thrust receiving part 20 Torque cam XX Axis line

Claims (3)

A conical friction wheel is disposed on each of the first shaft and the second shaft disposed in parallel, and a ring is interposed between the two conical friction wheels so as to be axially movable. In a conical friction ring type continuously variable transmission that transmits torque between two shafts,
A torque cam that generates an axial force by relative rotation based on the torque and a spring, and a pressing device that applies a traction force between the conical friction wheel and the ring;
The spring is contracted between the relative rotating members of the torque cam so that the cam member and the axis are aligned,
While the compressive force of the spring is acting, a thrust receiving portion is provided that acts on the central portion where the compressive force is in point contact.
A conical friction ring type continuously variable transmission. The thrust receiving part is two plates in which the central part of one surface bulges, and these plates are in contact with each other at the central part of the bulged central part,
The conical friction ring type continuously variable transmission according to claim 1. The spring is formed by arranging a number of disc springs along the axis, and at least two of the disc springs are formed of a disk-like member with a central portion protruding in one side,
The thrust receiving portion is formed by abutting the two disk-shaped members with each other at a central portion of the protruding central portion.
The conical friction ring type continuously variable transmission according to claim 1.

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