JP3656363B2 - Loading cam device for toroidal type continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a loading cam device incorporated in a toroidal type continuously variable transmission used as a transmission of an automobile, for example.
[0002]
[Prior art]
A toroidal-type continuously variable transmission, which has been studied mainly as a transmission for automobiles, is sandwiched between an input disk and an output disk, each of which has an arcuate concave cross section on the surfaces facing each other. It is structured to be combined with a freely rotatable power roller, and by adjusting the tilt angle of the rotation axis of the power roller, a rotational speed difference is generated between the input disk and the output disk to perform a speed change operation. I have to. At this time, since the peripheral surface of the power roller must abut against the input disk and the output disk without slipping in order to avoid driving force transmission loss, the torque in the input shaft direction applied to the power roller from the input disk Is adjusted so that an appropriate amount of frictional force is always generated between the input disk / power roller and between the power roller / output disk. For the adjustment, a loading cam device that can increase or decrease the pressing force in the input shaft direction according to the input torque is used.
[0003]
An example of this type of loading cam device is one disclosed in JP-A-1-299358. This loading cam device has a cam surface having a concavo-convex shape extending in the circumferential direction, is engaged with the torque input shaft, and rotates with the torque input shaft. An input disk that is provided on the surface of the cam disk that faces the cam surface and rotates relative to the torque input shaft, a substantially ring-shaped cage that is sandwiched therebetween, and a circumferential direction of the cage It is comprised from the rolling element each arrange | positioned in the opening part provided in multiple places. In addition, each rolling element is held in a state in which it can freely roll around the radial direction of the cage in the opening of the cage, and the side surfaces of each rolling element are the cam surfaces of the cam disk and the input disk. It is incorporated so as to come into contact with the unevenness.
[0004]
In the toroidal type continuously variable transmission incorporating the loading cam device having the above-described configuration, when the cam disk rotates, the input disk rotates synchronously via the rolling elements, and further, the output disk rotates reversely via the power roller. Accordingly, the rotational motion input to the torque input shaft is transmitted to the output disk as a rotational motion in the reverse direction and is extracted from the torque output shaft. At this time, the inclination angle of the rotation axis of the power roller is changed from the torque input shaft to the torque output shaft so that the peripheral surface of the power roller is in contact with the vicinity of the outer periphery of the input disk and the center of the output disk. Contrary to this, torque input is performed by changing the tilt angle of the rotating shaft of the power roller so that the peripheral surface of the power roller is in contact with the vicinity of the center of the input disk and the outer periphery of the output disk, respectively. Deceleration from the shaft to the torque output shaft is performed. Further, an intermediate gear ratio can be obtained almost steplessly by appropriately adjusting the inclination angle of the rotating shaft of the power roller.
[0005]
When a torque difference is generated between the cam disk and the input disk during the operation of such a toroidal type continuously variable transmission, the two disks rotate relative to each other with the rolling elements rolling. For this reason, a plurality of rolling elements are pressed against the cam surface of the input disk by the convex portion of the cam surface of the cam disk, the input disk is pressed against the power roller, and the power roller is further pressed against the output disk. / Friction force of appropriate magnitude is generated between the power roller and between the power roller and the output disk. In order to prevent seizure during pressing, lubricating oil is supplied between the cam surfaces of the cam disk and the output disk and the rolling elements.
[0006]
Further, in the loading cam device having the structure disclosed in Japanese Patent Laid-Open No. 1-299358, the outer diameter of the rolling element cage is reduced in order to reduce the area where the rolling element and the opening of the cage are in direct contact with each other. An abutting portion having a diameter smaller than the diameter of the rolling element is formed between the end surface in the direction and the peripheral edge of the opening of the cage that is in contact with the end surface. As a result, when the rolling element affected by the large centrifugal force generated by the high-speed rotation of the cam disk is strongly pressed against the peripheral edge of the opening on the cage outer diameter side, the rolling element and the cage opening are The frictional force acting between them is reduced. As a result, a torque difference is generated between the cam disk and the input disk, and the rolling elements roll smoothly when the two disks rotate relative to each other, and the magnitude of the pressing force applied to the input disk becomes more precise. Because of the control, the magnitude of the frictional force generated between the input disk / power roller and between the power roller / output disk is maintained appropriately, and no slip occurs. In this way, when the loading cam device having the structure disclosed in Japanese Patent Laid-Open No. 1-299358 is used, the transmission efficiency of the driving force is prevented from deteriorating and an appropriate gear ratio according to the torque difference can be obtained. .
[0007]
Furthermore, in the loading cam device having a structure disclosed in Japanese Patent Laid-Open No. 1-299358, the rolling elements held in the openings of the cage are formed by combining a plurality of rolling element elements having a narrow width in series (for example, Even in the case where the three rolling elements are configured, in order to reduce the frictional force generated between the adjacent rolling element, a diameter smaller than the diameter of the rolling element at the center of one end surface of each rolling element. The contact portion is formed. In the case of a rolling element formed by combining a plurality of such rolling element elements, the respective rolling element elements can be rotated independently of each other. There is an advantage that the difference in rotational speed can be absorbed.
[0008]
[Problems to be solved by the invention]
The loading cam device having the structure disclosed in Japanese Patent Laid-Open No. 1-299358 has a certain effect in that the follow-up performance of the speed change operation with respect to relatively small torque fluctuations continuously generated in a short time is improved. . However, in the above-described loading cam device, there is still direct contact between the rolling elements (or the rolling element located on the outermost periphery) and the opening of the cage, or between adjacent rolling element elements, For example, when an abrupt change occurs in the input torque, a large frictional force is generated on the end face of the rolling element (or rolling element). Such a frictional force acts as a resistance that prevents the rolling element from rolling, so that when the cam disk and the input disk rotate relative to each other, an appropriate pressing force corresponding to the torque difference between the two disks cannot be generated. The sliding of the roller is caused and the transmission efficiency of the driving force is deteriorated.
[0009]
Furthermore, in the above-described loading cam device, if direct contact between the rolling elements (or rolling element located on the outermost periphery) and the cage opening or direct contact between adjacent rolling element elements continues for a long time, The wear of the moving element end face and the peripheral edge of the opening of the cage proceeds, and the parts are easily damaged. In addition, such vibrations of equipment and parts caused by repeated direct contact not only cause an indirect cause of mechanical failure, but also cause discomfort to passengers such as automobiles due to noise. . For this reason, it is necessary to prevent direct contact between the cage openings and direct contact between adjacent rolling element elements.
[0010]
The present invention has been made under the circumstances as described above, and the object of the present invention is between the rolling elements (or the rolling element located on the outermost periphery) / the cage opening and between each adjacent rolling element. By eliminating the direct contact and reducing the frictional force generated on these end faces, the rolling of the rolling element when the cam disk and the input disk rotate relative to each other is made smooth and generated between both disks. It is an object of the present invention to provide a loading cam device for a toroidal type continuously variable transmission capable of generating an appropriate pressing force according to a torque difference.
[0011]
[Means for Solving the Problems]
The present invention relates to a cam disk that can be integrally rotated with respect to a torque input shaft and is locked and attached so that movement in the direction of the torque input shaft is restricted, and a cam disk that rotates relative to the torque input shaft. An input disk that is mounted to face the cam disk so as to be movable in the direction of the torque input shaft, and a substantially ring-shaped cage that is sandwiched between the cam disk and the input disk; The cam disk and the input disk, comprising: a plurality of cylindrical rollers that are rotatably held around the radial axis of the cage in openings formed at a plurality of locations in the circumferential direction of the cage. opposing surfaces is formed as a cam surface having an irregular shape over a circumferential direction, respectively, both mosquito of the plurality of cylindrical rollers the cam disc and the input disc Have been arranged so as to contact the surface, the by said plurality of cylindrical rollers in accordance with the torque difference the cam disk to occur between the input disk rolls between irregularities of both cam surfaces The present invention relates to a loading cam device for a toroidal-type continuously variable transmission in which a pressing force applied to an input disk changes in the input shaft direction, and the object of the present invention is to provide an end surface of each cylindrical roller in the outer diameter direction of the cage. This is achieved by providing a bearing between each of the openings. The above-described object of the present invention, said respective cylindrical roller was composed of rollers independently plurality of possible roll cylinder, the end surface of the cage outer diameter direction of the rollers each cylinder positioned in the outermost periphery This is achieved more effectively by providing bearings between the peripheral edges of the openings and between adjacent end faces of the cylindrical rollers . Furthermore, the above object of the present invention can be achieved more effectively by providing bearings between adjacent end faces of each cylindrical roller .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a front view showing an embodiment of a cage used in a loading cam device of a toroidal type continuously variable transmission according to the present invention. The present invention is characterized in that the rolling element (or a plurality of rolling element elements) is incorporated into the cage opening, and the other parts are equivalent to the loading cam device of the conventional toroidal continuously variable transmission. Can be configured. Therefore, below, the structure of the holder | retainer and rolling element (or several rolling element element) peculiar to this invention is demonstrated in detail.
[0013]
Four openings 2 are provided at equal intervals on the circumference of the substantially annular cage 1. Each opening 2 contains a roller-shaped rolling element 3, and each rolling element 3 is composed of three rolling element elements 3a having a narrow width that can be independently rolled. It is configured. A through-hole is bored on the peripheral edge of each opening 2 on the inner diameter side and outer diameter side of the cage, and in the center of each rolling element 3a, and both ends of the round bar-like pin 4 passed through the hole. The portion is caulked on the periphery of the opening 2 of the cage 1. Therefore, the pin 4 attached to each opening along the radial direction of the cage holds each rolling element 3a in the opening 2 and also functions as a rotation axis of each rolling element 3a. In addition, when each rolling element 3a is held using the pin 4 penetrating in this way and both ends of the pin 4 are caulked to the cage 1, each rolling element 3a and the cage 1 are preliminarily connected. Since they are integrated, the loading cam device can be easily incorporated in the assembly process of the toroidal type continuously variable transmission.
[0014]
In the loading cam device of the toroidal type continuously variable transmission according to the present invention, by providing bearings between the rolling element element / cage opening located on the outermost periphery and between adjacent rolling element elements, Rotational resistance is greatly reduced. FIG. 2 shows an opening when a bearing 5 is provided between an end surface in the outermost radial direction of the cage 1 of each rolling element 3a located on the outermost circumference and an outer peripheral side peripheral edge of the opening 2 of the cage 1. 2 is a partial view showing a configuration example near 2. FIG. FIG. 3 is a partial view showing a configuration example in the vicinity of the opening 2 when the bearing 5 is provided between the opposing end faces of the adjacent rolling element 3a. Further, FIG. 4 is a partial view showing a configuration example in which the bearings of FIG. 2 and FIG. 3 are used in combination, and between and adjacent to the rolling element 3a located on the outermost periphery and the opening 2 of the cage 1. Bearings 5 are respectively provided between the rolling element 3a. As these bearings, both rolling bearings and sliding bearings can be used.
[0015]
The loading cam device of the toroidal type continuously variable transmission of the present invention incorporating the cage 1 and the rolling element 3a configured as described above is a loading cam device incorporated in the above-described conventional toroidal type continuously variable transmission. Based on the same principle, the rotational movement of the torque input shaft is transmitted from the cam disk to the input disk while pressing the input disk in the direction of the torque input shaft. When relative rotation occurs between the cam disk and the input disk, the rolling element is rolled to apply a pressing force corresponding to the torque difference between the two disks to the input disk.
[0016]
In addition, in the loading cam device of the toroidal type continuously variable transmission according to the present invention, the cam disk rotates at a high speed and a strong centrifugal force acts on each rolling element 3a, and each rolling element 3a presses strongly in the outer circumferential direction of the cage 1. Even if rolling of each rolling element 3a occurs when the rolling element 3a is being moved, each rolling element 3a is in contact with the opening 2 of the cage 1 or another adjacent rolling element 3a via the bearing 5. For this reason, the frictional force acting on the end face of each rolling element 3a is drastically reduced as compared with the case of direct contact. Further, direct contact between the rolling element 3a located on the outermost periphery and the opening 2 of the cage 1 or between the adjacent rolling element 3a is completely eliminated.
[0017]
In addition, it is the former that the loss due to the frictional force is the largest among the rolling element 3a located on the outermost periphery and the opening 2 of the cage 1 and between the adjacent rolling element 3a. It is desirable to provide the bearing 5 at least in this part. Furthermore, if the bearing 5 is provided between the adjacent rolling element elements 3a, the above-described frictional force reducing effect appears even more.
[0018]
【The invention's effect】
As described above, according to the loading cam device of the toroidal-type continuously variable transmission of the present invention, the rolling element (or the rolling element located on the outermost periphery) / the opening of the cage and adjacent rolling element By providing the bearings between them, it is possible to significantly reduce the frictional force that becomes resistance to rolling of each rolling element or rolling element. As a result, rolling of the rolling element or rolling element when the cam disk and the input disk rotate relative to each other is performed smoothly, and an appropriate pressing force corresponding to the torque difference generated between the two disks is input. Since the power is supplied to the disc, the power roller does not slip and the transmission efficiency of the driving force can be improved.
[0019]
Further, in the loading cam device of the toroidal type continuously variable transmission according to the present invention, the rolling element (or the rolling element located on the outermost periphery) and the cage opening directly contact each other, or between adjacent rolling element. Therefore, the wear of the rolling element end face and the peripheral edge of the cage is not promoted, and the parts are not easily damaged. In addition, since vibration due to repeated direct contact does not occur, it does not cause an indirect cause of machine failure, and does not cause discomfort to passengers such as automobiles due to noise.
[Brief description of the drawings]
FIG. 1 is a front view showing a cage used in an embodiment of a loading cam device of a toroidal type continuously variable transmission according to the present invention.
FIG. 2 is an enlarged partial view showing the vicinity of an opening of a cage in an embodiment of a loading cam device for a toroidal-type continuously variable transmission according to the present invention.
FIG. 3 is an enlarged partial view showing the vicinity of an opening of a cage in a modification of the loading cam device of the toroidal type continuously variable transmission according to the present invention.
FIG. 4 is an enlarged partial view showing the vicinity of the opening of the cage in another embodiment of the loading cam device of the toroidal type continuously variable transmission according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cage 2 Opening part 3 Rolling element 3a Rolling element 4 Pin 5 Bearing

Claims (3)

A cam disk that is fixedly attached to the torque input shaft so as to be integrally rotatable with respect to the torque input shaft and restricted in movement in the direction of the torque input shaft; An input disk mounted to face the cam disk so as to be movable in the axial direction; a substantially annular retainer sandwiched between the cam disk and the input disk; and a circle of the retainer It is composed of a plurality of cylindrical rollers that are rotatably held around the radial axis of the cage in openings formed at a plurality of circumferential positions, and the cam disk and the input disk face each other. surface is formed as a cam surface having an irregular shape over a circumferential direction, respectively, the plurality of cylindrical rollers contact both cam surfaces of the cam disc and the input disc Have been arranged in so that, to the input disk by said plurality of cylindrical rollers in accordance with the torque difference the cam disk to occur between the input disk rolls between irregularities of both cam surfaces In the loading cam device of the toroidal type continuously variable transmission in which the pressing force applied in the input shaft direction changes, a bearing is provided between the end surface of each cylindrical roller in the outer diameter direction of the cage and the peripheral edge of each opening. A loading cam device for a toroidal type continuously variable transmission. Each of the cylindrical rollers is composed of a plurality of cylindrical rollers that can roll independently of each other, and the outer circumferential direction end surface of each of the cylindrical rollers located on the outermost periphery and the peripheral edge of each of the openings The loading cam device of the toroidal type continuously variable transmission according to claim 1, wherein bearings are respectively provided between the adjacent end surfaces of the cylindrical rollers . A cam disk that is fixedly attached to the torque input shaft so as to be integrally rotatable with respect to the torque input shaft and restricted in movement in the direction of the torque input shaft; An input disk mounted to face the cam disk so as to be movable in the axial direction; a substantially annular retainer sandwiched between the cam disk and the input disk; and a circle of the retainer It is composed of a plurality of cylindrical rollers that are rotatably held around the radial axis of the cage in openings formed at a plurality of circumferential positions, and the cam disk and the input disk face each other. surface is formed as a cam surface having an irregular shape over a circumferential direction, respectively, the plurality of cylindrical rollers contact both cam surfaces of the cam disc and the input disc Have been arranged in so that, to the input disk by said plurality of cylindrical rollers in accordance with the torque difference the cam disk to occur between the input disk rolls between irregularities of both cam surfaces In the loading cam device for a toroidal type continuously variable transmission in which the pressing force applied in the input shaft direction changes, a bearing is provided between the adjacent end faces of each cylindrical roller. Loading cam device for a step transmission.

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