JPH0942401A - Toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent trunnion and gall of a link by fitting an outer peripheral part on the penetrating hole of the link, forming a recessed spherical surface on an inner circumference, engaging the penetrating hole fit to a rotary shaft part to the formed spherical surface, and a forming a respective clearance between a shoulder part where the off set axial part of a trunnion is opposed to the rink and the link. SOLUTION: A pair of actuators are driven in axial directions which are different from each other, one trunnion is raised, and the other one is made fall down, a power roller 1 is slantly rotated, a change gear ratio is changed, and it is displaced in the axial direction while rotating according to slant rotation of the power roller 1. Links 4, 5 for connecting a pair of trunnions 3, 3 are slid and inclined, a sphere coupler constituted by a spherical surface engaged to a spherical surface ring is interposed, relative rotation is enabled to an optimal axial circumference, and oscillating motion is smoothly carried out while rotating the trunnion around the axis. A prescribed clearance δ is formed between a shoulder part where the off set axial part of the trunnion is opposed to the link and the link, and thereby, it is avoid to be brought in contact the link and the shoulder with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a connection structure between a trunnion and a link of a toroidal type continuously variable transmission used for a vehicle or the like.

[0002]

2. Description of the Related Art As a structure of a link for supporting a trunnion of a toroidal type continuously variable transmission, Japanese Patent Application Laid-Open No. 4-35136 is known.
No. 0 is known.

To explain this, as shown in FIG. 7, a pair of power rollers 1 and 1 sandwiched by a pair of input / output disks (not shown) having toroidal grooves formed on the opposite surfaces are An eccentric shaft 2, the base end of which is supported by a pair of trunnions 3 and 3 which are arranged so as to sandwich the rotating shaft of the disc.
It is rotatably supported by 2.

The power rollers 1 and 1 have trunnions 3 and 3
By changing the tilt angle according to the axial displacement of, the arbitrary gear ratio is set steplessly.

The trunnions 3 and 3 disposed on the left and right sides of the rotary shaft in the plane orthogonal to the rotary shaft of the input / output disk form rotary shaft portions 3a and 3b at the upper and lower ends thereof, respectively. An offset shaft portion 3c offset by a predetermined amount in the radial direction is formed between the rotary shaft portions 3a and 3b.
The eccentric shaft 2 is supported at its base end by an offset shaft portion 3c so as to be orthogonal to the rotation axis of the trunnion 3.

The rotating shaft 3b at the lower end of the trunnion 3 is
The trunnions 3, 3 are connected to a rod 6b of a hydraulic cylinder 6 that can expand and contract in the axial direction and rotate about the axis. The rollers 1 and 1 rotate in accordance with the tilt.

On the other hand, the upper and lower rotating shaft portions 3a and 3b of the trunnions 3 and 3 are mutually connected via links 4'and 5'which are swingable in a plane orthogonal to the rotating shaft of the input / output disk. It is connected and supports the axial force applied to the trunnions 3, 3.

Through holes are formed at both longitudinal ends and central portions of the links 4 ', 5', and the rotary shaft portions 3a, 3b of the trunnions 3, 3 are inserted through the through holes at both ends, while the central portions are inserted. The through holes of the parts are fitted with the link support members 116 and 120, which project from the casing 10 toward the rotary shaft of the input / output disk in the vertical direction in the figure, respectively.

Here, the left and right hydraulic cylinders 6, 6 are synchronously driven in opposite directions, and the links 4 ', 5'swing about the link support members 116, 120 as fulcrums. For this reason, spherical bearings 110 and 112 are interposed between the rotary shafts 3a and 3b and the through holes at both ends of the links 4'and 5 ', so that the links 4'and 5'are inclined with respect to the trunnion 3. Tolerate.

A needle bearing 200 is interposed between the inner circumferences of the spherical bearings 110, 112 and the rotary shaft portions 3a, 3b to smoothly rotate the trunnion 3 about its axis.

[0011]

By the way, in the toroidal type continuously variable transmission as described above, since the spherical bearing 110 is only engaged with the through hole of the link 4 ', as shown in FIG. The shoulder portion 30 formed as a horizontal plane according to the offset amount of the shaft portion 3c has a lower surface 4 of the link 4'at a neutral position where the link 4'and the trunnion 3 are orthogonal to each other.
By making surface contact with 0, the trunnion 3 is positioned in the vertical direction (vertical direction in the drawing). The link 5'and the rotating shaft portion 3b side are similarly connected.

However, when the tilt angles of the power rollers 1, 1 are changed, the hydraulic cylinders 6, 6 are synchronously driven in opposite directions of the trunnions 3, 3, so that, for example, the trunnion 3 on the left side in the figure is used. Similarly, when the trunnion 3 on the right side is driven in the contracting direction, the link 4 ′ swings upward in the figure as shown in FIG. 9, and the lower surface 40 and the shoulder 30 of the trunnion 3 are in point contact with each other. As shown in FIG. 10, when the left trunnion 3 is contracted and the other trunnion is driven to extend, the end of the shoulder 30 and the lower surface 40 are in point contact with each other. Since the trunnion 3 rotates accordingly, the lower surface 40 and the shoulder portion 3 which are in point contact with each other.
Twist occurs between the trunnion 3 and the trunnion 3 and the resistance when the trunnion 3 is displaced in the axial direction increases, and the wear of the trunnion 3 and the links 4'and 5'increases. There was a problem of doing.

In order to prevent the spherical bearing 110 from coming off from the rotary shaft portion 3a, as shown in FIG.
2 and the snap ring 111 have to be provided, which causes a problem that not only the number of parts increases but also the number of assembling steps increases and productivity decreases.

Therefore, the present invention has been made in view of the above problems, and it is possible to reduce the number of parts and improve productivity while preventing galling of the trunnion and the link to ensure durability and responsiveness. To aim.

[0015]

According to a first aspect of the present invention, a toroidal groove is formed on surfaces facing each other, and an input disk and an output disk are coaxially arranged, and the input disk and the output disk. A pair of tiltable power rollers sandwiched between surfaces facing each other and a pair of trunnions disposed in a plane orthogonal to the rotation axes of the input and output disks and displaceable in the axial direction and around the axis. And a rotary shaft portion formed on both ends of the trunnion, an offset shaft portion offset from the rotary shaft by a predetermined amount between the rotary shaft portions of the trunnion, and a rotary shaft portion sandwiched between opposed surfaces of the input disc and the output disc. And a pair of power rollers rotatably supported by eccentric shafts fixed to the offset shafts of the pair of trunnions, and through holes formed at both ends. The rotating shafts of the pair of trunnions are connected to each other through a link, and the pair of trunnions are driven in opposite axial directions, respectively, with a link having a support member fixed to the casing and swingably supported at substantially the center. In a toroidal type continuously variable transmission including an actuator, a sphere having a through hole fitted to the rotating shaft portion,
While fitting the outer periphery to the through hole of the link, a spherical ring that forms a concave spherical surface on the inner periphery and engages with the spherical body, and a shoulder portion and a link where the offset shaft portion of the trunnion faces the link And a predetermined gap δ formed therebetween.

In a second aspect based on the first aspect, a roller bearing is provided between the inner periphery of the through hole formed at both ends of the link and the outer periphery of the spherical ring.

In a third aspect, the first or second aspect is provided.
In the invention described above, the gap δ is set to a predetermined ratio with respect to the total stroke amount of the actuator.

[0018]

Therefore, the first invention drives the pair of actuators in opposite axial directions to raise one trunnion and lower the other trunnion, tilting the power roller to change the gear ratio, The trunnion is displaced in the axial direction while rotating according to the tilt of the power roller. The link connecting the pair of trunnions swings about the link support member as a fulcrum in response to the opposite axial movements of the trunnion, and the link tilts with respect to the trunnion in response to this swing, but the end of the link A spherical joint made up of a sphere engaged with a spherical ring is mounted on the rotating shaft part of the trunnion and the trunnion to allow relative rotation about an arbitrary axis, and the trunnion is rotated while rotating the trunnion about the axis. The relative swing motion with the link can be smoothly performed, and at this time, the offset shaft portion provided between the rotating shaft portions of the trunnion has a predetermined gap between the shoulder portion and the link facing the link. Therefore, even if the link swings with respect to the trunnion, contact between the link and the shoulder can be avoided, and the trunnion can be driven smoothly.

Further, according to the second aspect of the invention, since the roller bearing is interposed between the inner circumference of the through hole formed at both ends of the link and the outer circumference of the spherical ring, the trunnion shaft accompanying the tilting of the power roller is provided. The peripheral displacement can be smoothly performed by the roller bearing, and the swing of the link with respect to the trunnion can be smoothly performed by the spherical ring and the spherical body.

According to the third aspect of the invention, since the gap δ between the shoulder of the trunnion and the link is set to a predetermined ratio with respect to the total stroke of the actuator, the actuator extends from the most extended position to the most retracted position. In between, the contact between the shoulder and the link can be avoided, and the trunnion can be driven smoothly.

[0021]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, a case where the present invention is applied to the toroidal type continuously variable transmission shown in FIG. 7 of the conventional example is shown, and the spherical bearings 110 and 112 shown in FIG. It is replaced with a spherical joint made up of a spherical body 7 and a concave spherical ring 8 and further has links 4 and 5 that form a predetermined gap δ with the shoulder portion 30 of the trunnion 3. This is the same as the example, and the same components are denoted by the same reference symbols and redundant description is omitted.

The links 4, 5 connecting the left and right trunnions 3, 3 are provided with through holes at both ends and the central part in the longitudinal direction in the same manner as the conventional example. The through holes 4L, 4C, and 4R are the same as the link 5 in that order.
Through holes 5L, 5C, and 5R are formed in the through holes.

The through holes 4L, 4R of the link 4 are inserted through the rotary shafts 3a, 3a at the upper ends of the trunnions 3, 3, while
Similarly, the through holes 5L and 5R of the link 5 are inserted through the rotating shaft portions 3b and 3b at the lower end.

Through hole 4 formed at the center of link 4
Columnar link support members 12 and 13 projecting from the upper surface of the actuator cover 11 forming the inner peripheral upper surface and the inner peripheral bottom surface of the casing 10 toward the rotation axis of the input / output disk respectively pass through C and 5C. To be done. The actuator cover 11 is a piston 6a of the hydraulic cylinders 6, 6.
Is formed and is coupled to the casing 10.

Between each through hole of the links 4 and 5 and the trunnion 3 and the link supporting members 12 and 13, a spherical joint as shown in FIG. 2 is interposed.

This spherical joint has a cylindrical spherical ring 8
The inner circumference 8a is formed by a concave spherical surface having a predetermined inner diameter, and the inner circumference is engaged with a spherical body 7 having a predetermined outer diameter having a through hole 7b, which is formed by a convex spherical surface. Outer circumference 7a of sphere 7
Is in sliding contact with the inner circumference 8a of the spherical ring 8, and the spherical body 7 is held on the inner circumference of the spherical ring 8 without using any special retaining means, while the relative rotation between the spherical body 7 and the spherical ring 8 is made around an arbitrary axis. It can be carried out.

Such a spherical joint has links 4, 5
Of the through holes 4L, 4C, 4R, 5L, 5C, 5R and the trunnion 3 and the link support members 12 and 13 by press fitting or the like, and the trunnions 3 and 3 are connected by the links 4 and 5. 5 is rotatable about the supporting members 12 and 13 as fulcrums.

For example, at the connecting position of the through hole 4L and the rotary shaft portion 3a, the outer circumference 8 of the spherical ring 8 is provided on the inner circumference of the through hole 4L.
b is fitted by press-fitting or the like, and the through hole 7b of the spherical body 7 is fitted by press-fitting or the like in the rotary shaft portion 3a.

Here, the spherical joint is, as shown in FIG. 3, a neutral position of the trunnion 3, that is, the trunnion 3.
And the links 4 and 5 are orthogonal to each other, the lower surface 40 of the link 4
It is fixed at a position where a predetermined gap δ is formed between the shoulder 30 and the shoulder 30. A spherical joint is arranged so that the gap δ is formed on the link 5 side as well, and only the link 4 side will be described below in order to simplify the description.

The gap δ is set to a predetermined value or a predetermined ratio so that the lower surface 40 does not come into contact with the shoulder portion 30 at the most extended position or the most contracted position of the hydraulic cylinder 6. It is set so as to be a predetermined ratio K or more with respect to the total stroke amount L. This ratio K
Is appropriately set according to the lever ratio of the link, the total stroke amount, and the like.

The configuration is as described above. Next, the operation will be described.

When changing the tilt angle of the power roller 1, the left and right hydraulic cylinders 6, 6 shown in FIG. 1 are driven in opposite directions, for example, the trunnion 3 on the left side in the figure is driven upward. , The right trunnion 3 is driven downward to change the tilt angle of the power roller 1 supported by the eccentric shaft 2.

At this time, the links 4 and 5 connecting the left and right trunnions 3 and 3 swing around the link support members 12 and 13 connected via the spherical joints, as shown in FIGS. The ends of the links 4 and 5 use the spherical joint as the axis,
The axial positioning of the trunnions 3 and 3 can be performed while rotating relative to the trunnion 3.

As shown in FIGS. 4 and 5, as the trunnion 3 is raised or lowered, the shoulder portion 30 and the lower surface 4 of the link 4 are moved.
Although the gap δ with respect to 0 changes, since the gap δ is set to a predetermined ratio K or more with respect to the total stroke amount L, δ ≠ 0 even at the most extended position and the most contracted position of the hydraulic cylinder 6, so that Unlike the conventional example, the shoulder portion 30 and the lower surface 40 of the link 4 are not in sliding contact with each other, so that the drive resistance of the trunnion 3 which rotates while displacing in the axial direction can be reduced as compared with the above-described conventional example, and the responsiveness of shifting is improved. It is possible to improve wear resistance of the trunnion 3 and the links 4 and 5 and improve durability.

Further, the spherical body 7 of the spherical joint does not fall off from the inner circumference of the spherical ring 8, and the spherical joint is press-fitted to interpose between the links 4, 5 and the trunnion 3 and the link supporting members 12, 13. Since it is mounted, it is possible to reduce the number of parts and the number of assembling steps to improve the productivity and the manufacturing cost without requiring a locking means such as a snap ring unlike the conventional example.

FIG. 6 shows the second embodiment. The outer circumference 8b of the spherical ring 8 and the through hole 4 of the link 4 of the first embodiment are shown.
Roller bearings 20 are provided on the inner circumferences of L, 4R and through holes 5L, 5R of the link 5, respectively, and the other points are the same as in the first embodiment.

The roller bearing 20 is prevented from falling off by the retainer 20 interposed between the roller bearing 20 and the inner circumference of the through hole 4L, and the roller bearing 20 further facilitates the rotation of the trunnion 3 accompanying the tilting of the power roller 1. The drive resistance of the trunnion 3 can be further reduced, and the responsiveness of the toroidal type continuously variable transmission can be improved.

[0039]

As described above, according to the first aspect of the present invention, a link for connecting a pair of trunnions has a spherical joint formed by a spherical body engaged with a spherical ring at an end portion of the link and a rotating shaft portion of the trunnion. It becomes possible to rotate the trunnion about the axis by rotating the trunnion around the axis, and to smoothly perform the relative swing motion between the trunnion and the link. Since a predetermined gap is formed between the link and the shoulder where the offset shaft that is provided faces the link, avoid contact between the link and the shoulder even if the link swings with respect to the trunnion. Therefore, it is possible to reduce the drive resistance of the trunnion to improve the response at the time of shifting and prevent wear of the link and the trunnion to improve the durability as compared with the conventional example. Furthermore, since the spherical ring and the spherical body are fixed by being fitted into the through hole of the link and the rotating shaft portion of the trunnion, respectively, the retaining means as in the conventional example is not required, and the number of parts and the number of assembly steps are increased. Can be reduced and productivity can be improved.

Further, according to the second aspect of the invention, since the roller bearing is interposed between the inner periphery of the through hole of the link and the outer periphery of the spherical ring, the displacement of the trunnion around the axis due to the tilting of the power roller is prevented from occurring. It is possible to pivotally support the trunnion, thereby further reducing the drive resistance of the trunnion and improving the responsiveness of the shift.

According to the third aspect of the invention, since the gap δ between the shoulder of the trunnion and the link is set to a predetermined ratio with respect to the total stroke amount of the actuator, the maximum extension position to the maximum contraction position of the actuator are set. In between, the contact between the shoulder and the link can be avoided, and the trunnion can be driven smoothly.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a toroidal type continuously variable transmission showing an embodiment of the present invention.

2A and 2B show a spherical joint, in which FIG. 2A is a front view and FIG. 2B is a radial cross-sectional view.

FIG. 3 is an enlarged side view of the trunnion and the link in the neutral position.

FIG. 4 is an enlarged side view of the trunnion and the link showing a case where the trunnion is raised.

FIG. 5 is an enlarged side view of the trunnion and the link showing a case where the trunnion is lowered.

FIG. 6 is a sectional view of a link and a spherical joint showing a second embodiment.

FIG. 7 is a sectional view of a main part of a conventional toroidal type continuously variable transmission.

FIG. 8 is a side enlarged view of a trunnion and a link in a neutral position, similarly showing a conventional example.

FIG. 9 is a side enlarged view of the trunnion and the link, which also shows a conventional example and shows a case where the trunnion is raised.

FIG. 10 is a side enlarged view of the trunnion and the link showing a case where the trunnion is lowered, similarly showing the conventional example.

[Explanation of symbols]

 1 power roller 2 eccentric shaft 3 trunnion 3a, 3b rotating shaft part 3c offset shaft part 4 link 5 link 6 hydraulic cylinder 7 spherical body 7a outer circumference 7b through hole 8 spherical ring 8a inner circumference 8b outer circumference 12, 13 link support member

Claims (3)

[Claims] 1. A toroidal groove is formed on the surfaces facing each other, and is tilted by being sandwiched between the input disk and the output disk arranged coaxially and the facing surfaces of the input disk and the output disk. A pair of free power rollers, a pair of trunnions disposed in a plane orthogonal to the rotation axes of the input and output disks, and displaceable in the axial direction and around the axis, and formed at both ends of the trunnion. And a pair of trunnions that are sandwiched between the rotating shaft portion, an offset shaft portion that is offset from the rotating shaft by a predetermined amount between the rotating shaft portion of the trunnion, and the facing surfaces of the input disc and the output disc. Rotation of a pair of power rollers rotatably supported by an eccentric shaft fixed to the offset shaft portion of the and a pair of trunnions through through holes formed at both ends. A toroidal type provided with a link that connects the shafts and that is swingably supported in a substantially central part by a support member fixed to the casing, and actuators that respectively drive the pair of trunnions in opposite axial directions. In a continuously variable transmission, a spherical body having a through hole fitted to the rotary shaft portion and an outer circumference fitted to the through hole of the link are formed, while a concave spherical surface is formed on the inner circumference to engage with the spherical body. And a predetermined gap δ formed between the link and a shoulder portion where the offset shaft portion of the trunnion faces the link, and a toroidal type continuously variable transmission. 2. The toroidal type stepless according to claim 1, wherein a roller bearing is interposed between an inner circumference of a through hole formed at both ends of the link and an outer circumference of the spherical ring. transmission. 3. The toroidal type continuously variable transmission according to claim 1, wherein the gap δ is set to a predetermined ratio with respect to the total stroke amount of the actuator.