JP2002021962A - Toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of the conventional type continuously variable transmission that load per one point is large and the fatigue life is shortened because balls constituting a thrust bearing of a power roller with two rolling grooves come into contact at each one point. SOLUTION: In this toroidal type continuously variable transmission, a pivot shaft 8 is mounted on a trunnion 7 rocking between an input disc 2 and an output disc 4, an outer ring 9 and a power roller 5 are fitted to the pivot shaft 8, and plural balls 12 are engaged with rolling grooves 10, 11 formed in the outer ring 9 and the power roller 5. The balls 12 come into contact with the two rolling grooves 10, 11 at each two points, the outer periphery contact points Ga, Pa and the inner periphery contact points Gb, Pb in the cross direction of the groove, whereby the thrust load in the direction of the rotation axis Pc of the power roller 5 is dispersed so that the generated stress at the respective contact points Ga, Pa, Gb, Pb is held down so as to improve fatigue life.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toroidal type continuously variable transmission mainly used for a transmission of an automobile.

[0002]

2. Description of the Related Art A toroidal type continuously variable transmission has a swingable trunnion between an input disk and an output disk arranged coaxially, and a bearing is mounted on a pivot shaft rotatably mounted on the trunnion. In addition to mounting the outer ring, a power roller that contacts both disks is rotatably mounted on the pivot shaft, and between the outer ring and the power roller, a plurality of balls forming a bearing together with the outer ring, and holding of each ball It has a configuration with a vessel interposed. A plurality of sets of trunnions and power rollers are provided at equal intervals around both disks. Further, the bearing constituted by the outer ring, each ball and the like allows rotation of the power roller and receives a thrust load in the direction of the rotation axis of the power roller.

In the toroidal type continuously variable transmission, a power roller is brought into contact with both disks at a predetermined pressure, and the rotation of an input disk is transmitted to an output disk via the power rollers. Then, by swinging the power roller together with the trunnion, the contact position of the power roller is moved in the radial direction of both disks, thereby changing the speed ratio steplessly. Such a toroidal-type continuously variable transmission is described in, for example, JP-A-11-132301.

[0004]

However, in the conventional toroidal-type continuously variable transmission as described above, a rolling groove in which balls are engaged with each other is formed on opposing surfaces of an outer race and a power roller. 1 point for each rolling groove (2 points in total)
Therefore, there is a problem that the load per one point becomes large, and the fatigue life of the ball and the rolling groove becomes short, and it has been a problem to solve such a problem.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toroidal type continuously variable transmission capable of improving the fatigue life of balls and rolling grooves in a thrust bearing of a power roller. It is intended to provide.

[0006]

According to a first aspect of the present invention, there is provided a toroidal-type continuously variable transmission which is capable of swinging between a coaxially arranged input disk and an output disk, and a rotatable trunnion. A pivot shaft attached to the pivot shaft, an annular outer ring attached to the pivot shaft, a power roller rotatably attached to the pivot shaft and contacting both disks, and an annular ring formed on opposing surfaces of the outer ring and the power roller. A toroidal-type continuously variable transmission including a plurality of balls that receive a thrust load in the rotation axis direction of the power roller by engaging with the rolling grooves of the power roller. Are in contact with each other at two points, an outer peripheral contact point and an inner peripheral contact point in the groove width direction. And a first working line connecting, the configuration in which the second working line connecting the two contact points of the ball with respect to the rolling grooves of the power roller intersects on a rotary axis of the power roller,
According to a third aspect of the present invention, the cross section of the rolling groove has a shape having an inner peripheral side arc in which the ball is inscribed in the same manner as an outer peripheral side arc in which the ball is inscribed. An outer peripheral side contact point and an inner peripheral side contact point are provided on the outer peripheral side and the inner peripheral side of the power roller with respect to the ball center line. The radius of curvature of the arc on the side is 114% to 130% of the radius of the ball. According to a sixth aspect of the present invention, an inner circumference is defined with respect to a line connecting the intersection of the first action line and the second action line with the center of the ball. A contact angle formed by a line connecting the side contact point and the center of the ball is 30 to 55 degrees, and a contact angle formed by a line connecting the outer contact point and the center of the ball is 50 to 85 degrees. As 7, the curvature of the outer peripheral side arc forming the rolling groove is According to an eighth aspect of the present invention, a plurality of balls are arranged on a plurality of concentric circles centered on the rotation axis of the power roller. Means.

[0007]

In the toroidal-type continuously variable transmission according to the first aspect of the present invention, the rotation of the input disk is transmitted to the output disk via the power roller, and the power roller is swung together with the trunnion to swing the two disks together. The contact position of the power roller is moved in the radial direction to change the gear ratio steplessly. Further, a bearing constituted by an outer ring and each ball attached to the pivot shaft of the trunnion allows rotation of the power roller and receives a thrust load in the direction of the rotation axis of the power roller. At this time, in the toroidal continuously variable transmission, the ball is provided at two points of the outer peripheral contact point and the inner peripheral contact point in the groove width direction with respect to each of the rolling grooves provided on the opposing surfaces of the outer ring and the power roller. Contact each other with
Since there are four contact points in total, the thrust load is dispersed at each contact point, and the contact surface pressure and heat generation at each contact point can be suppressed low.

In the toroidal type continuously variable transmission according to a second aspect of the present invention, the first action line connecting two contact points of the ball with the rolling groove of the outer ring, and the two action lines of the ball with the rolling groove of the power roller. Since the second action line connecting the contact points intersects on the rotation axis of the power roller, the outer peripheral side contact point and the inner peripheral side contact point in the rolling groove of the outer ring, and the outer peripheral side in the rolling groove of the power roller The rotational speeds (angular velocities) of the ball at the four contact points in total, that is, the contact point and the inner peripheral contact point, are equal, and slippage between the contact points is prevented.

In the toroidal-type continuously variable transmission according to the third aspect of the present invention, since the cross-section of the rolling groove has the same shape as the outer peripheral side arc where the ball is inscribed, the outer peripheral side arc where the ball is inscribed. The contact surface pressure at the side contact point and the inner peripheral contact point is suppressed to an appropriate range, and the generated stress is also suppressed to a low level.

In the toroidal type continuously variable transmission according to a fourth aspect of the present invention, the outer peripheral side and the inner peripheral side of the power roller are arranged on the outer peripheral side and the inner peripheral side with respect to a ball center line parallel to the rotation axis of the power roller.
Since the outer peripheral side contact point and the inner peripheral side contact point are provided, the force generated in the radial direction on the ball between the outer peripheral side contact point and the inner peripheral side contact point is canceled.

In the toroidal-type continuously variable transmission according to the fifth aspect of the present invention, the radius of curvature of the arc on the outer peripheral side and the inner peripheral side forming the rolling groove is set to 114 to 130% of the radius of the ball. The clearance between the ball and the rolling groove is secured, and the contact surface pressure between the ball and the rolling groove is suppressed to an appropriate range. Note that the radius of curvature of each arc is one of the radius of the ball.
If it is smaller than 14%, the clearance between the ball and the rolling groove becomes small, so that the contact area between the balls and the rolling groove increases, and the calorific value increases. Further, if the radius of curvature of each arc is larger than 130% of the radius of the ball, the contact surface pressure between the ball and the rolling groove increases, causing problems such as an increase in heat generation and peeling of the rolling surface. Therefore, it is preferable that the radius of curvature of the arc be 114 to 130% of the radius of the ball.

In the toroidal-type continuously variable transmission according to a sixth aspect of the present invention, an inner peripheral contact point and a center of the ball are defined with respect to a line connecting an intersection of the first action line and the second action line with the center of the ball. Is 30 to 55 degrees, and the contact angle between the line connecting the outer peripheral contact point and the center of the ball is 50 to 85 degrees. Therefore, the input load to the ball (normal direction at the contact point) Load) can be kept low. If the contact angle of the inner contact point is smaller than 30 degrees, and thereby the contact angle of the outer contact point is smaller than 50 degrees, the outer contact point and the inner contact point are too far apart. And the input load to the ball at each contact point increases. Further, when the contact angle of the inner contact point is made larger than 55 degrees and thereby the contact angle of the outer contact point is made smaller than 85 degrees, the outer contact point and the inner contact point are too close to each other. When the ball is deformed, the contact area between the ball and the rolling groove increases, and the calorific value increases. Therefore, the contact angle of the contact point on the inner peripheral side should be 30 to 5
It is preferable that the contact angle is 5 degrees and the contact angle of the outer peripheral contact point is 50 to 85 degrees.

In the toroidal-type continuously variable transmission according to the seventh aspect of the present invention, since the curvature of the outer circumferential arc forming the rolling groove is made larger than the curvature of the inner circumferential arc, the outer circumferential contact with the ball is formed. The stress generated at the point and the stress generated at the inner circumferential contact point can be made substantially equal. In other words, as described in claim 6, when the contact angle of the inner contact point is 30 to 55 degrees and the contact angle of the outer contact point is 50 to 85 degrees, the outer peripheral arc and the inner peripheral Assuming that the radius of curvature of the arc is the same, and that the thrust load in the rotation axis direction of the power roller is uniformly applied to the outer contact point and the inner contact point, the outer contact point contacts the thrust load in the direction of the thrust load. Since the contact angle at the inner contact point is smaller than the angle, the input load on the ball is greater at the inner contact point than at the outer contact point,
The generated stress is also larger at the inner peripheral contact point. On the other hand, in the toroidal type continuously variable transmission, since the curvature of the outer circumferential arc forming the rolling groove is larger than the curvature of the inner circumferential arc (the radius of curvature is smaller), the input load on the ball is reduced. Is larger at the inner peripheral contact point than at the outer peripheral contact point, but the contact surface pressure between the ball and the rolling groove at the outer peripheral contact point becomes smaller, so the occurrence at the outer peripheral contact point and the inner peripheral contact point The stresses are almost equal.

In the toroidal type continuously variable transmission according to claim 8 of the present invention, since a plurality of balls are arranged on a plurality of concentric circles centered on the rotation axis of the power roller, the number of balls increases. Accordingly, the stress generated at each contact point is further reduced, and a large load can be received by making each ball the same size.

[0015]

According to the toroidal-type continuously variable transmission according to the first aspect of the present invention, the pivot shaft is mounted on the trunnion swinging between the input disk and the output disk, and the annular outer ring is mounted on the pivot shaft. In a toroidal-type continuously variable transmission in which a power roller is attached, and a plurality of balls are provided in an annular rolling groove formed on the opposing surfaces of the outer ring and the power roller, the outer ring and the power roller have respective rolling grooves. Since the ball is brought into contact with the outer peripheral contact point and the inner peripheral contact point in the groove width direction, the thrust load is dispersed at each contact point, and the ball contacts the rolling groove at one point. The contact surface pressure and the amount of heat generated at each contact point can be greatly reduced compared to the conventional one, which results in the fatigue life of the balls and rolling grooves in the thrust bearing of the power roller. It can be remarkably improved, can be realized and thus the continuously variable transmission lifetime of itself.

According to the toroidal-type continuously variable transmission according to the second aspect of the present invention, the same effects as those of the first aspect can be obtained, and the outer peripheral contact point and the inner circumference in the rolling groove of the power roller can be obtained. The rotational speeds (angular velocities) of the balls at the four contact points in total, ie, the side contact points, are made equal to prevent slippage between the contact points, thereby further improving the fatigue life. it can.

According to the toroidal-type continuously variable transmission according to the third aspect of the present invention, the same effects as those of the first and second aspects can be obtained, and at the outer peripheral contact point and the inner peripheral contact point. The contact surface pressure can be kept within an appropriate range, the generated stress can be kept low, and the fatigue life can be further improved.

According to the toroidal-type continuously variable transmission according to a fourth aspect of the present invention, the same effects as those of the first to third aspects can be obtained, and furthermore, the contact between the outer peripheral side contact point and the inner peripheral side contact point can be obtained. Since the forces generated in the radial direction with respect to the balls can be offset between them, the force applied to the retainer of each ball can be reduced.

According to the toroidal type continuously variable transmission according to the fifth aspect of the present invention, the same effects as those of the third and fourth aspects can be obtained, and the contact surface pressure between the ball and the rolling groove can be adjusted within an appropriate range. , The occurrence of peeling of the rolling contact surface can be prevented, and the generated stress and the amount of heat generation can be reduced to further improve the fatigue life.

According to the toroidal type continuously variable transmission according to the sixth aspect of the present invention, the same effects as those of the second to fifth aspects can be obtained, and the input load to the ball (normal direction at the contact point) ) Can be suppressed low, and the generated stress and the amount of heat generation can be reduced to further improve the fatigue life.

According to the toroidal-type continuously variable transmission according to claim 7 of the present invention, the same effect as in claim 6 can be obtained, and the stress generated at the contact point on the outer peripheral side with the ball and the inner peripheral side Since the stress generated at the contact point is almost uniform,
The contact life of both the outer peripheral contact point and the inner peripheral contact point can be equally extended.

According to the toroidal-type continuously variable transmission according to the eighth aspect of the present invention, the same effects as those of the first to seventh aspects can be obtained, and in addition, the number of balls increases at each contact point as the number of balls increases. In addition to reducing the generated stress, the same size of each ball allows the bearing to receive a large load, thereby achieving a longer life for the thrust bearing and the continuously variable transmission. And transmission torque can be improved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a toroidal type continuously variable transmission according to the present invention will be described below with reference to the drawings.

The toroidal type continuously variable transmission shown in FIG. 1A is used for a transmission of an automobile, and has an input disk connected to an input shaft 1 connected to an engine via a rotation transmission mechanism (not shown). And an output shaft 4 connected to the axle side via another rotation transmission mechanism, and an output disk 4 provided between the two disks 2 and 4 (two in this embodiment). Is interposed. The two disks 2 and 4 have a substantially conical shape, have concave curved rolling surfaces 2a and 4a, and are arranged coaxially with their small diameter sides facing each other.

Further, as shown in FIG. 1B, the continuously variable transmission includes a trunnion 7 swingable about a swing shaft 6 provided between the two disks 2 and 4, and a trunnion 7 7, a pivot shaft 8 rotatably mounted and protruding toward the center of the disks 2 and 4, and an annular outer ring 9 mounted on the pivot shaft 8. The power roller 5 is mounted on the pivot shaft 8. It is rotatably mounted.

On the opposing surfaces of the outer race 9 and the power roller 5, annular rolling grooves 10 and 11 are formed concentrically, and a plurality of rolling grooves 10 and 11 (in this embodiment) are formed. In this case, eight balls 12 are engaged. These balls 1
2 are held at equal intervals by an annular holder 13 as shown in FIG. The power roller 5 comes into contact with both disks 2 and 4 with a predetermined pressure. At this time, the outer ring 9 and each ball 12 allow the power roller 5 to rotate while the thrust in the rotation axis direction is allowed. It constitutes a thrust bearing that receives a load.

In the continuously variable transmission, the ball 12 is contacted with the outer peripheral contact points Ga and Pa and the inner peripheral contact point in the groove width direction with respect to the rolling grooves 10 and 11 of the outer ring 9 and the power roller 5. Gb and Pb are in contact at two points, that is, at a total of four points.

At this time, each contact point Ga, Pa, Gb, P
b is the rotation axis P of the power roller 5 as shown in FIG.
Power roller 5 with respect to the ball center line Bc parallel to c
Rolling grooves 1 of the outer race 9
The first action line L1 connecting the two contact points Ga and Gb of the ball 12 with respect to 0 and the second action line L2 connecting the two contact points Pa and Pb of the ball 12 with the rolling groove 11 of the power roller 5 have the power. The rollers 5 intersect on the rotation axis Pc.

Further, as shown in FIG. 4 as the second action line L2 on the power roller 5 side, the first action line L1 and the second action line L2
The angle of contact θb formed by the line Lc connecting the inner peripheral contact point Pb and the center Q2 of the ball 12 to the line Lc connecting the intersection Q1 of the ball 12 and the center Q2 of the ball 12 is in the range of 30 to 55 degrees. The contact angle θa formed by the line La connecting the outer peripheral contact point Pb and the center Q2 of the ball 12 is in the range of 50 to 85 degrees. Note that a similar angle setting is made on the outer ring 9 side.

Further, as shown in FIG. 3, each of the rolling grooves 10, 11 has an outer peripheral side arc 10a, 1 in which the ball 12 is inscribed.
1a, the inner peripheral side arc 10b in which the ball 12 is inscribed,
11b, and the radius of curvature of these arcs is 114 to 130% of the radius of the ball 12.
At this time, the outer peripheral side arcs 10a, 11
The curvature of “a” is larger than the curvature of the inner peripheral side arcs 10b and 11b (the radius of curvature is small).

The toroidal type continuously variable transmission having the above structure transmits the rotation of the input disk 2 to the output disk 4 via the power roller 5 and swings the power roller 5 together with the trunnion 7 so that the two disks 2 are rotated. , 4 in the radial direction to move the contact position of the power roller 5 to change the gear ratio steplessly.

At this time, in the continuously variable transmission, the thrust bearing constituted by the outer ring 9 and each ball 12 receives the thrust load in the direction of the rotation axis Pc while allowing the rotation of the power roller 5. Outer ring 9 and power roller 5
The ball 12 has four contact points at the respective contact points Ga, Pa, Gb and Pb with respect to the respective rolling grooves 10 and 11, so that the thrust load is dispersed at the respective contact points and the respective contact points G
The contact surface pressure and the calorific value at a, Pa, Gb, and Pb can also be kept low.

In the continuously variable transmission, the outer peripheral contact points Ga and Pa and the inner peripheral contact points Gb and Gb are disposed on the outer and inner peripheral sides of the power roller 5 with respect to the ball center line Bc.
Since Pb is provided, the component force (Fax, Fbx in FIG. 5) generated in the radial direction with respect to the ball 12 between the outer peripheral contact points Ga, Pa and the inner peripheral contact points Gb, Pb cancels out. As a result, the force applied to the retainer 13 is reduced, and the first action line L1 and the second action line L
2 on the rotation axis Pc of the power roller 5, the rotation speeds (angular velocities) of the ball 12 at the four contact points Ga, Pa, Gb, and Pb are equal, and each contact point Ga , Pa, Gb, and Pb are prevented from slipping.

Further, in the continuously variable transmission, the contact angle θb between the inner peripheral contact points Gb and Pb is set in a range of 30 to 55 degrees,
Since the contact angle θa of the outer peripheral side contact points Ga and Pa is in the range of 50 to 85 degrees, the input load (load in the normal direction at the contact point) Fa and Fb to the ball 12 shown in FIG.

This is because the contact angle θb between the inner contact points Gb and Pb is smaller than 30 degrees and the outer contact points Ga and Pa are smaller.
When the contact angle θa is smaller than 50 degrees, the outer peripheral contact points Ga, Pa and the inner peripheral contact points Gb, Pb are too far apart, and the ball 12 at the respective contact points Ga, Pa, Gb, Pb When the contact angle θb of the inner contact points Gb and Pb is set to be larger than 55 degrees and the contact angle θa of the outer contact points Ga and Pa is set to be smaller than 85 degrees. Since the outer contact points Ga, Pa and the inner contact points Gb, Pb are too close to each other, and when deformed, the contact area between the ball 12 and the rolling grooves 10, 11 increases, and the amount of heat generated increases. It is.

In FIG. 5, both action lines L1, L2
Assuming that the action angle formed by the second action line L2 (or the first action line L1) with respect to a line Lc connecting the intersection Q1 of the ball 12 and the center Q2 of the ball 12 is Ψ, as shown in FIG. As the angle increases, the angle contact angles θa and θb also increase. Further, as shown in FIGS. 7 and 8, each contact point Ga, Pa, G
b, Pb, the smaller the working angle Ψ, the more the force Fax, in the direction orthogonal to the direction of the rotation axis Pc of the power roller 5.
The increase / decrease ratio of Fbx or the forces Fay and Fby in the normal direction increases. Here, FIGS. 6 to 8 show the rotation axis P of the power roller 5.
The values when the distance R from c to the ball center Bc is 29 mm are shown. In this case, it is desirable that the operating angle Ψ be in the range of 11 to 14 degrees from FIGS.

When the operating angle Ψ is in the range of 11 to 14 degrees when the distance R is 29 mm, the contact angle θb of the inner peripheral contact points Gb and Pb is in the range of 30 to 55 degrees, and The contact angle θa between the side contact points Ga and Pa is 50 to 85.
In this case, the input load to the ball 12 is suppressed to be low. Note that the contact angle θa, θb is set in the above range since the working angle Ψ changes depending on the distance R as a matter of course.

Further, the continuously variable transmission has outer circumferential arcs 10a, 11a and inner circumferential arcs 10b, 11b in which the ball 12 is inscribed in the cross section of the rolling grooves 10, 11, and furthermore, Each of the arcs 10a, 11a, 10b,
Since the radius of curvature of 11b is set to 114 to 130% of the radius of the ball, the clearance between the ball 12 and the rolling grooves 10, 11 is ensured, and the ball 12 and the rolling groove 1 are secured.
The contact surface pressures of 0 and 11 are kept within an appropriate range, and the generated stress is also kept low.

Each of the arcs 10a, 11a, 10b, 1
If the radius of curvature of 1b is smaller than 114% of the radius of the ball 12, the clearance between the ball 12 and the rolling grooves 10, 11 is reduced, the contact area between the two is increased, the amount of heat generated is increased, and each arc 10a is increased. , 11a, 10b, and 11b have a radius of curvature larger than 130% of the radius of the ball 12, the contact surface pressure between the ball 12 and the rolling grooves 10, 11 increases, so that the amount of heat generated increases and the rolling surface separates. Problem occurs. Therefore, the arcs 10a, 11a, 10b, 11b
Is preferably 114 to 130% of the radius of the ball 12.

Further, in the continuously variable transmission, the curvature of the outer circumferential arcs 10a, 11a is changed to the inner circumferential arcs 10b, 11b.
Since the curvature is larger than b, the stresses generated at the contact points Ga, Pa, Gb, and Pb with respect to the ball 12 can be made substantially uniform.

That is, as described above, the inner peripheral contact point G
b, the contact angle of Pb is 30 to 55 degrees, and the outer peripheral side contact point G
Assuming that the contact angle between a and Pa is 50 to 85 degrees, if a thrust load is applied in a state where the radius of curvature of the outer circumferential arc and the inner circumferential arc is the same, as shown in FIG.
Since the contact angle θb of the inner contact points Gb and Pb is smaller than the contact angle θa of a and Pa, the input load on the ball is smaller than the outer contact points Ga and Pa.
b becomes larger (Fa <Fb), and the generated stress becomes larger at the inner peripheral side contact points Gb and Pb (σa <σb). On the other hand, in the continuously variable transmission, the outer peripheral side arcs 10a,
Since the curvature of 11a is larger than the curvature of the inner circumferential arcs 10b and 11b (the radius of curvature is smaller), the ball 12
Is larger at the inner peripheral contact points Gb and Pb than at the outer peripheral contact points Ga and Pa, but the contact surface pressure between the ball 12 and the rolling grooves 10 and 11 at the outer peripheral contact points Ga and Pa is higher. Both contact points Ga, Pa, Gb, P
The generated stress at b is substantially equal (σa = σb), and both contact portions of the outer contact points Ga and Pa and the inner contact points Gb and Pb are equally prolonged in life.

As described above, in the toroidal type continuously variable transmission of the above embodiment, the contact surface pressure and the generation at the contact points Ga, Pa, Gb and Pb between the ball 12 and the rolling grooves 10 and 11 are described. Stress and calorific value will be kept low,
The fatigue life of the power roller in the thrust bearing is significantly improved.

FIGS. 9 and 10 are views for explaining another embodiment of the toroidal type continuously variable transmission according to the present invention.
The same components as those in the previous embodiment are denoted by the same reference numerals, and detailed description is omitted.

The toroidal type continuously variable transmission of this embodiment is
The configuration is such that a plurality of balls 12 are arranged on a plurality (two in this embodiment) of concentric circles around the rotation axis Pc of the power roller 5. That is, two annular rolling grooves 1 are provided on the opposing surfaces of the outer race 9 and the power roller 5 respectively.
0, 10, 11, and 11 are formed concentrically, and eight balls 1 are provided in each of the outer and inner rolling grooves 10, 11.
2 are engaged. At this time, as shown in FIG. 10, between the balls 12 adjacent in the inner row, the balls 1 in the outer row
By arranging 2, the length in the radial direction is saved. Each of the balls 12 has the same diameter.

Although not shown in detail, each of the rolling grooves 10, 11 has a cross-sectional shape in which the outer and inner arcs are continuous (see FIG. 3) as in the previous embodiment.
The curvature radius of the arc and the magnitude relationship between the outside and inside curvatures are the same as in the previous embodiment. At this time, each of the outer and inner rolling grooves 10 and 11 has a portion inside the inner circumferential contact points Gb and Pb of the ball 12 in the outer rolling grooves 10 and 11, and the inner rolling grooves 10 and 11. 11, a portion outside the outer peripheral contact points Ga and Pa of the ball 12, that is, the ball 12
The rolling grooves 10 and 11 are continuous by omitting a portion that does not come into contact with the ball 12 so that the ball 12 shown in FIG.
Arrangement, and saves the length in the radial direction to realize the overall miniaturization.

Further, each contact point Ga, Pa, Gb, Pb of the ball 12 with respect to the rolling grooves 10, 11 is set with respect to the ball center line Bc parallel to the rotation axis Pc of the power roller 5.
Two contact points G of the ball 12 which are located on the outer peripheral side and the inner peripheral side of the power roller 5 and which contact the rolling groove 10 of the outer ring 9.
a, Gb, and two contact points Pa, Pb of the ball 12 with the rolling groove 11 of the power roller 5.
Is the rotation axis Pc of the power roller 5.
It crosses above. The rotation speeds at the four contact points Ga, Pa, Gb, and Pb on each ball 12 are made equal.

In the toroidal type continuously variable transmission having the above structure, the first and second lines of action L1 and L2 are crossed on the rotation axis Pc of the power roller 5 so that the balls 12 are identical. , The rotational speed at each of the four contact points Ga, Pa, Gb, and Pb becomes equal, and a larger load is applied by making each ball 12 the same size. As a result, the life of the thrust bearing can be prolonged and the transmission torque can be improved.

As in the above embodiment, when a plurality of rolling grooves are arranged concentrically around the rotation axis Pc of the power roller 5 and a plurality of balls 12 are provided in each rolling groove. It is more preferable that the ball 12 be contacted at four points in each rolling groove, but the ball 12 is contacted at four points in at least one rolling groove and the ball 12 is contacted at two points in the remaining rolling grooves. It is also possible to configure
Even with such a configuration, it is possible to reduce the stress generated at each contact point due to the increase in the number of balls 12.

[Brief description of the drawings]

FIG. 1 is a view for explaining an embodiment of a toroidal type continuously variable transmission according to the present invention, which is a sectional view (a) of the whole and a sectional view (b) based on line AA in FIG. is there.

FIG. 2 is a plan view illustrating an arrangement of balls of a thrust bearing in the continuously variable transmission shown in FIG.

FIG. 3 is a cross-sectional view of a main part for explaining a position of each contact point and a shape of a rolling groove.

FIG. 4 is an explanatory diagram showing a range of a working angle of each contact point.

FIG. 5 is an explanatory diagram showing an input load at each contact point.

FIG. 6 is a graph showing a relationship between a working angle and a contact angle.

FIG. 7 is a graph illustrating the relationship between the operating angle and the increase / decrease ratio of each component force at the inner circumferential contact point.

FIG. 8 is a graph illustrating the relationship between the operating angle and the increase / decrease magnification of each component force at the outer peripheral side contact point.

FIG. 9 is a sectional view showing another embodiment of the toroidal type continuously variable transmission according to the present invention.

FIG. 10 is a plan view illustrating the arrangement of balls of a thrust bearing in the continuously variable transmission shown in FIG.

[Explanation of symbols]

 2 Input disk 4 Output disk 5 Power roller 7 Trunnion 8 Pivot shaft 9 Outer ring 10 11 Rolling groove 10a 11a Outer side arc 10b 11b Inner side arc 12 Ball Bc Ball center line Ga Pa Outer side contact point Gb Pb Inner side contact Point L1 First action line L2 Second action line Pc Rotary axis of power roller θa Contact angle of outer contact point θb Contact angle of inner contact point

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Riki Kamitani F-term in Nissan Motor Co., Ltd. 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa 3J051 AA03 BA03 BB01 BD02 BE09 CB06 EC03 EC06 FA02 3J101 AA04 AA32 AA42 AA54 AA62 BA53 BA54 BA55 FA31 GA11

Claims (8)

[Claims] 1. A trunnion which can swing between an input disk and an output disk arranged coaxially, a pivot shaft rotatably mounted on the trunnion, an annular outer ring mounted on the pivot shaft, and a pivot shaft. A power roller rotatably mounted and in contact with both disks, and a plurality of power rollers that receive a thrust load in the rotation axis direction of the power roller by engaging with annular rolling grooves formed on the opposing surfaces of the outer ring and the power roller. A toroidal type continuously variable transmission provided with balls of the type described above, wherein the balls contact the rolling grooves of the outer ring and the power roller at two points, an outer contact point and an inner contact point in the groove width direction. A toroidal-type continuously variable transmission characterized by the following. 2. A first action line connecting two contact points of the ball with the rolling groove of the outer ring and a second action line connecting the two contact points of the ball with the rolling groove of the power roller. The toroidal-type continuously variable transmission according to claim 1, wherein the transmission intersects on an axis. 3. The toroidal mold according to claim 1, wherein a cross-section of the rolling groove has a shape having an inner circumferential arc in which the ball is inscribed, as well as an outer circumferential arc in which the ball is inscribed. Step transmission. 4. An outer peripheral side and an inner peripheral side of the power roller with respect to a ball center line parallel to a rotation axis of the power roller,
The toroidal-type continuously variable transmission according to any one of claims 1 to 3, wherein an outer peripheral side contact point and an inner peripheral side contact point are provided. 5. The toroidal-type continuously variable transmission according to claim 3, wherein the radius of curvature of the arc on the outer peripheral side and the inner peripheral side forming the rolling groove is 114 to 130% of the radius of the ball. Machine. 6. A contact angle formed by a line connecting an inner peripheral side contact point and the center of the ball to a line connecting the intersection of the first action line and the second action line to the center of the ball is 30 to 55 degrees. In addition, the contact angle formed by the line connecting the outer peripheral contact point and the center of the ball is 50
The toroidal-type continuously variable transmission according to any one of claims 2 to 5, wherein the angle is from 85 to 85 degrees. 7. The curvature of the outer circumferential arc forming the rolling groove is:
7. The toroidal-type continuously variable transmission according to claim 6, wherein the curvature is larger than the curvature of the inner circumferential arc. 8. The toroidal-type continuously variable transmission according to claim 1, wherein a plurality of balls are arranged on a plurality of concentric circles around a rotation axis of the power roller.