JPH04248052A - Friction roller type continuously variable transmission - Google Patents

Abstract

PURPOSE:To maximize torque transmission capacity by providing a link balancing hydraulic cylinder device to a member on the movable side of supporting link members opposite to roller supporting members to support friction rollers. CONSTITUTION:Friction rollers 14, 16 are supported by means of roller supporting members 18, 20, setting the friction rollers to be frictionally contacted with an input disc 12 and an unindicated output disc. These roller supporting members 18, 20 are supported by supporting link members 26, 28 through bearings 18a and 18b, and 20a and 20b respectively. The supporting link member 26 makes a support by fitting a spherical post 36 of a housing 34 to a hole in an intermediate part, while the supporting link member 28 makes a support to a cover 40 which is integral with a housing 34 through a linear bearing 38. Both ends of the supporting link member 28 are connected to cylinders 66, 68 fitted to the housing 34, forming a hydraulic cylinder device for link balance by means of the cylinders 66, 68 and the respective pistons 70, 72 thereof. The hydraulic pressure of hydraulic oil passages is controlled by a hydraulic pressure control device, realizing balance of the mechanical system irrespective of the torque transmission direction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction wheel type continuously variable transmission.

0002

2. Description of the Related Art A conventional friction wheel type continuously variable transmission is disclosed in Japanese Patent Application Laid-open No. 155656/1983. The purpose of this is to equalize the traction coefficient at the contact surface between the pair of friction rollers and the disk. To balance the forces of the pair of friction rollers, one support link member of the trunnion is supported to the housing by a spherical post, and the other support link member is movably supported to the housing by a sliding post. In this state, in order to equalize the traction coefficients of the left and right friction rollers, the diameters of the pistons of the transmission hydraulic cylinders that apply an axial force to the trunnion are made different between the spherical post side and the sliding post side. That is, the diameter of the piston of the hydraulic cylinder on the spherical post side is made larger than that on the sliding post side. This makes it possible to equalize the traction coefficients of the pair of friction rollers when driven from the engine side.

0003

However, the conventional friction wheel type continuously variable transmission described above has a problem in that the traction coefficients are not equal under engine braking conditions, and the unbalance becomes even greater. In other words, in the normal driving state where torque is transmitted from the engine side to the output shaft side, the traction coefficient can be balanced as described in the above publication, but the driving torque is transmitted from the output shaft side to the engine side. (i.e.,
In engine brake condition), on the other hand, it is necessary to increase the diameter of the piston of the hydraulic cylinder on the sliding post side.
Since it is reversed as described above, the unbalance becomes larger. The present invention aims to solve these problems.

0004

[Means for Solving the Problems] The present invention solves the above problems by providing a link balancing hydraulic cylinder device for canceling the moment that tends to tilt the roller support member that occurs in proportion to the amount of unbalance. . That is, the present invention includes an input disk, an output disk,
a friction roller disposed in frictional contact with both disks within a toroidal groove formed by both disks;
A roller support member that rotatably supports the friction roller and is rotatable about a rotation shaft perpendicular to the axes of both disks and movable in the axial direction of the rotation shaft, and the roller support member is connected to the rotation shaft. It has a hydraulic cylinder device for speed change that can be driven in the axial direction of the roller support member, and a pair of support link members that respectively support both ends of both roller support members, and one of the pair of support link members is connected to the housing via a spherical post. This is intended for a friction wheel type continuously variable transmission in which the other of the pair of support link members is fixed and movable in the direction of the link axis, and the movable support link member is It is characterized in that a hydraulic cylinder arrangement for link balancing is provided, which is capable of exerting forces in both possible directions.

[0005]

[Operation] When rotational force is transmitted between the friction roller and the disk, a force acts on the roller support member to tilt it depending on the direction of transmission of the driving torque. This force acts on the movable support link member in the direction of its movement. The link balancing hydraulic cylinder system generates a force to counteract the force acting on the support link member. As a result, the unbalanced force acting on the support link member can be canceled by the link balancing hydraulic cylinder device, and the traction coefficient at the contact point between the pair of friction rollers and the disk can be balanced.

[0006]

Embodiment FIG. 1 shows a first embodiment. An input disk 12 is provided to rotate together with the input shaft 10. An output disk that rotates together with an output shaft (not shown) is arranged so as to face the input disk 12,
A toroid surface is formed between the input disk 12 and the output disk. Friction rollers 14 and 16 are arranged on this toroid surface. The friction roller 14 is rotatably supported by a roller support member 18 and is pressed against the input disk 12 and the output disk to be in frictional contact with them. Further, the friction roller 16 is also rotatably supported by the roller support member 20 and is pressed against the input disk 12 and the output disk to be in frictional contact with them. The roller support member 18 has spherical bearings 22 and 2 on its upper and lower shafts 18a and 18b, respectively.
4 to upper and lower support link members 26 and 28, respectively. Similarly, the roller support member 20 is also supported by support link members 26 and 28 via spherical bearings 30 and 32 on the upper and lower shafts 20a and 20b, respectively. The support link member 26 is supported by fitting a hole provided in the middle thereof into a spherical post 36 fixed to the housing 34. On the other hand, the support link member 28 is connected to the housing 34 via a linear bearing 38.
It is supported by a cover 40 that is integrated with. Housing 34
are provided with cylinders 42 and 44, and a cover 40.
are provided with cylinders 46 and 48. Cylinder 42 is located above shaft 18a, and cylinder 46 is located above shaft 18a.
It is located below b. Further, the cylinder 44 is connected to the shaft 20
a, and the cylinder 48 is located below the shaft 20b. The inner diameter dimensions of the cylinders 42, 44, 46 and 48 are the same. Fitted into the cylinders 42, 44, 46 and 48 are pistons 50, 52, 54 and 56, respectively. An oil chamber 91 formed by the cylinder 42 and the piston 50 and an oil chamber 93 formed by the cylinder 48 and the piston 56 are both connected to the oil passage 58. Further, an oil chamber 95 formed by the cylinder 44 and the piston 52 and an oil chamber 97 formed by the cylinder 46 and the piston 54 are both connected to the oil passage 6.
Connected to 0. These cylinders 42, 44, 4
6 and 48 and pistons 50, 52, 54 and 56 constitute a hydraulic cylinder device for shifting. The pistons 50, 52, 54 and 56 are connected to the shaft 18a through thrust bearings 51, 53, 55 and 57, respectively.
, the shaft 20a, the shaft 18b, and the shaft 20b.

Caps 62 and 64 are attached to each side of the housing 34, forming cylinders 66 and 68, respectively. Pistons 70 and 72 are fitted into the cylinders 66 and 68, respectively. Note that the piston 70 and the piston 72 have the same diameter. Pistons 70 and 72 are each connected to opposite ends of support link member 28. An oil chamber 98 formed by the cylinder 66 and the piston 70 is connected to the aforementioned oil passage 60, and an oil chamber 99 formed by the cylinder 68 and the piston 72 is connected to the aforementioned oil passage 58. There is. cylinders 66 and 68 and piston 7
0 and 72 constitute a link balancing hydraulic cylinder device. Note that the relationship between the diameters of the pistons 70 and 72 and the diameters of the pistons 50, 52, 54, and 56 is set as described below. The oil pressure of the oil passage 58 and the oil passage 60 is controlled by a hydraulic control device 74 as described below.

Next, the operation of this embodiment will be explained. The rotation of the input disk 12 is transmitted to an output disk (not shown) via friction rollers 14 and 16 in frictional contact therewith. The dynamical system at this time is schematically illustrated as follows:
It will look like Figure 2. When a clockwise torque T is input from the input disk 12, a tangential force F1 directed downward in the drawing acts on the friction roller 16, while a tangential force F2 directed upward in the drawing acts on the friction roller 14 (this The forces are supported by pistons 56 and 50, respectively). Therefore, a moment F1×D1 is applied to the friction roller 16 in accordance with the distance D1 between the point of application of the force to the friction roller 16 and the axes of the shafts 20a and 20b. Similarly, friction roller 1
A moment F2×D2 acts on 4. As a result, from the shaft 20a to the support link member 26 (D1/L1)×F1
A force is applied to the left in the figure. Note that L1 is the distance between the point of application of the force of the friction roller 16 and the support link member 26. Similarly, from the shaft 18a to the support link member 26 (D2
/L2)×F2, a force directed to the left in the figure acts. As a result, from the support link member 26 to the spherical post 36 (D/L)
The force ×(F1+F2) will act (in addition, D
1=D2=D, and L1=L2=L). Here, the diameters of the pistons 50, 52, 54, and 56 are all equal, so
The tangential force F1 and the tangential force F2 are equal, and if this is F, then the force applied to the spherical post 36 is 2×(D/L)×F.
The force will come into play. Since the force F is the product of the area S of the piston 50 etc. and the oil pressure P, the above force is 2×(D/L)×S×P. As a result, a force directed to the right in the figure that is equal to the above force is applied to the lower support link member 28.

This force is supported by piston 72. The same hydraulic pressure P as that applied to the piston 56 acts on the piston 72, but the area of the piston 72 is 2×(
D/L)×S, whereby the piston 72 exerts a force of 2×(D/L)×S×P on the support link member 28. Therefore, the dynamic system shown in FIG. 2 is in a completely balanced state, and the traction coefficient on the friction roller 16 side and the traction coefficient on the friction roller 14 side are equal.

Next, when a counterclockwise torque is input to the input disk 12, that is, when torque is transmitted from the output disk side to the input disk 12 side, a tangential force is generated by the pistons 52 and 54. As a result, a force is applied to the support link member 28 in the left direction in the figure, in a relationship opposite to that described above. This force is supported by piston 70. In this case as well, the dynamical system is in a completely balanced state, as in the case described above. Therefore, regardless of the direction of torque transmission, the dynamic system can always be balanced and the traction coefficients can be made equal.

FIG. 3 shows a second embodiment. In this second embodiment, the link balancing hydraulic cylinder device 110 is of a reciprocating piston type. That is, oil chambers 102 and 104 are formed on both sides of the piston, and these are connected to oil passages 58 and 60, respectively. The other configurations are basically the same as the first embodiment shown in FIG. In this second embodiment as well, the same effect as in the first embodiment described above can be obtained.

FIG. 4 shows a third embodiment. In this third embodiment, a force from a link balancing hydraulic cylinder device 130 is applied to the center portion of the support link member 28. That is, a hole into which the spherical body 112 fits is provided in the center of the support link member 28, and the spherical body 112 and another spherical body 114 are connected by a lever 116, and the lever 116 is rotatable about a fulcrum 118, so that the spherical body A force can be applied to 114 from the pistons 118 and 120 of the link balancing hydraulic cylinder device 130. This also makes it possible to obtain the same effect as in the first embodiment described above.

[0013]

As explained above, according to the present invention, a link balancing hydraulic cylinder device capable of applying a balancing force to the movable support link member is provided, so that the torque between the input disk and the output disk is reduced. Regardless of the transmission direction, it is possible to balance the dynamic system that makes up the friction wheel type continuously variable transmission, thereby equalizing the traction coefficient at the contact area of a pair of friction rollers and obtaining the maximum torque transmission capacity. be able to.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram schematically showing a dynamical system of the present invention.

FIG. 3 is a diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram showing a third embodiment of the present invention.

[Explanation of symbols]

10 Input shaft 12 Input disk 14 Friction roller 16 Friction roller 18 Roller support member 20 Roller support member 26 Support link member 28 Support link member 36 Spherical post 38 Linear bearing 42 Cylinder 44 Cylinder 46 Cylinder 48 Cylinder 50 Piston 52 Piston 54 Piston 56 Piston 66 Cylinder 68 Cylinder 70 Piston 72 Piston 74 Hydraulic control device

Claims (2)

[Claims] 1. An input disk, an output disk, a friction roller disposed in a toroidal groove formed by both disks so as to be in frictional contact with both disks, and a friction roller rotatably supported and a A roller support member rotatable around a rotation shaft perpendicular to the axis of the disk and movable in the axial direction of the rotation shaft; and a gear shift member capable of driving the roller support member in the axial direction of the rotation shaft. It has a hydraulic cylinder device and a pair of support link members that respectively support both ends of both roller support members, one of the pair of support link members is fixed to the housing via a spherical post, and one of the pair of support link members is fixed to the housing via a spherical post. On the other hand, in a friction wheel type continuously variable transmission supported movably in the direction of the link axis,
A friction wheel type continuously variable transmission characterized in that the movable support link member is provided with a link balancing hydraulic cylinder device capable of applying force in both directions to allow the support link member to move. 2. When the gear shifting hydraulic cylinder device is exerting a force F on the roller support member, the link balancing hydraulic cylinder device is applied to the movable support link member by 2×(
D/L)×F D: Distance between the point of application of the force of the friction roller and the axis of the roller support member L: Force of the distance between the point of application of the force of the friction roller and the axis of the support link member 2. The friction wheel type continuously variable transmission according to claim 1, further comprising a hydraulic control device for controlling the hydraulic pressure so as to act on the hydraulic pressure.