JP2001027298A - Rotary shaft of toroidal type continuously variable transmission - Google Patents

Abstract

(57) [Problem] To provide a rotating shaft of a toroidal-type continuously variable transmission capable of shortening the length of the rotating shaft in the axial direction. SOLUTION: The rotating shaft 20 integrally rotates with an input disk of a toroidal type continuously variable transmission having an input disk and an output disk, and has a flat surface 70 which is parallel to each other when viewed from an end surface side of the rotating shaft 20. It has a part 50 and a spline groove 51 formed near the collar part 50. The spline groove 51 is formed along the axial direction of the rotating shaft 20, and accommodates a ball for fixing the input disk and the rotating shaft 20 in the rotating direction. Each spline groove 5
1 is a center 70 in the width direction of each flat surface 70 of the brim portion 50.
It is formed at a position corresponding to each flat surface 70 so as to direct a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary shaft provided on a disk of a toroidal type continuously variable transmission used for a transmission mechanism of an automobile or the like.

[0002]

2. Description of the Related Art Conventionally, a continuously variable transmission called a so-called CVT has been put into practical use as a transmission used for a vehicle or the like. As an example of the continuously variable transmission, a toroidal type continuously variable transmission has been developed. The toroidal-type continuously variable transmission includes an input disk, an output disk, a power roller provided between the two disks, a loading cam mechanism for pressing the input disk toward the output disk, and the like. The input disk is movable in the axial direction with respect to the rotation axis (so-called CVT axis), but is fixed in the rotation direction, so that the input disk and the rotation axis rotate integrally.

In order to fix an input disk and a rotating shaft in a rotating direction, a ball spline 100 as shown in FIG.
Has been adopted. The ball spline 100 includes a spline groove 102 formed along an axial direction of a rotating shaft 101 as an input shaft, a spline groove 104 formed in an input disk 103, and these spline grooves 102, 1
The ball 105 is constituted by a ball 105 housed in the ball bearing 04. Since the spline groove 102 is processed by a rotary cutter such as a disk-shaped cutter and a grindstone for polishing, an arc-shaped cut-up surface corresponding to the outer diameter of the cutter and the grindstone is formed at both longitudinal ends of the spline groove 102. 106 are formed.

[0004] On one end side of the rotating shaft 101, a flange 111 for supporting the thrust bearing 110 is formed near the ball spline 100. The thrust bearing 110 is provided between a cam disk 113 which is a component of the loading cam mechanism 112 and the rotating shaft 101.

[0005] A loading nut 116 is screwed into a screw portion 115 formed on the other end side of the rotating shaft 101, and the disc spring 117 is fixed by the nut 116. When the nut 116 is fastened to the screw portion 115, the collar 11
1 is fixed by a jig such as a socket, thereby preventing the rotation shaft 101 from rotating. Therefore, the collar portion 111 has a hexagonal shape (rotating shaft 1) similar to a bolt head.
01 when viewed from the end face direction).

Further, as described in Japanese Patent Application Laid-Open No. 8-61453 or Japanese Patent Application No. 9-276913, a cam disk constituting a loading cam mechanism is
A toroidal-type continuously variable transmission in which a rotation axis (CVT axis) is prevented from rotating by a ball spline has also been proposed. In this case as well, the spline grooves provided on the rotating shaft are processed by a disk-shaped cutter and a grindstone similarly to the spline grooves 102, and further, a brim portion exists near the spline grooves.

[0007]

In order to reduce the size of the toroidal-type continuously variable transmission, it is desirable to make the length of the rotating shaft 101 as short as possible. In order to shorten the rotating shaft 101, it is necessary to reduce the distance between the flange 111 and the spline groove 102. However, if the distance between the collar 111 and the spline groove 102 is reduced, a cutter or a grindstone used for processing the spline groove 102 may interfere with the collar 111. Collar 111
When the tool interferes with a rotating tool such as a cutter or a grindstone, the rotating tool is damaged, and the collar 111 is unnecessarily shaved. For this reason, at present, the distance between the flange 111 and the spline groove 102 cannot be sufficiently reduced.

Accordingly, an object of the present invention is to provide a rotating shaft of a toroidal type continuously variable transmission that can minimize the distance between a spline groove and a flange.

[0009]

According to the present invention, there is provided a rotary shaft of a toroidal type continuously variable transmission having an input disk, an output disk, a cam disk, and the like, wherein the rotary shaft has an end face. A flange portion having at least two flat surfaces parallel to each other as viewed from above, and formed near the flange portion along the axial direction of the rotating shaft and for preventing rotation of the input disk or cam disk. And a spline groove for accommodating a member, wherein the spline groove is formed at a position facing a center in the width direction of the flat surface.

[0010] The spline groove is processed by a rotating disk-shaped cutter and a grindstone as in the prior art.
In the present invention, the spline groove is formed so as to be directed to the central portion in the width direction of the flat surface of the collar portion, that is, the portion where the distance from the center of the rotating shaft to the outer peripheral edge of the collar portion is shortest. The spline groove can be brought as close as possible to the collar portion within a range where the rotating tool does not interfere with the collar portion.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a variator section (Variator) constituting a main section of a double-cavity half-toroidal type continuously variable transmission 10. The transmission 10 includes an input disk 12a and an output disk 13a forming a first cavity 11, and an input disk 12b and an output disk 13b forming a second cavity 14.

A pair of power rollers 15 are provided between the first input / output disks 12a and 13a. The outer peripheral surface of the power roller 15 is in contact with the traction surface of each of the disks 12a and 13a. Second input / output disk 12
A pair of power rollers 15 is also provided between b and 13b. These power rollers 15 are rotatably attached to trunnions 17 by power roller bearings 16. The trunnions 17 are each a trunnion shaft 1
It is swingable about 8.

The first input disk 12a is attached to a rotating shaft (CVT shaft) 20 functioning as an input shaft so as to be relatively movable in the direction of the axis P while being prevented from rotating by a first ball spline 21. ing. The second input disk 12b is attached to the rotation shaft 20 so as to be relatively movable in the direction of the axis P while being prevented from rotating by the second ball spline 22. Therefore, the input disks 12a and 12b rotate integrally with the rotating shaft 20. The rotating shaft 20 is connected to a driving shaft 25 rotated by a driving source such as an engine via a bearing 26 so as to be relatively rotatable.

The output disks 13a and 13b are provided between the input disks 12a and 12b. The first output disk 13a faces the first input disk 12a,
The second output disk 13b is the second input disk 12b
Facing. These output disks 13a, 13b
Is rotatably supported on the rotating shaft 20 via bearings 30 and 31. Output disks 13a, 13
b are connected by a connecting member 32 and rotate in synchronization with each other. The connecting member 32 is provided with an output gear 33. The output gear 33 rotates in conjunction with an output shaft (not shown).

A loading cam mechanism 40 functioning as a pressing mechanism is provided on the back side of the first input disk 12a. The loading cam mechanism 40 includes a cam disk 41 and a roller 42. Cam disk 41
Is rotatably supported on the rotating shaft 20 via a thrust bearing 43. A cam surface 4 is provided on each of the opposed portions of the cam disk 41 and the input disk 12a.
4 and 45 are formed, and a roller 42 is provided between the cam surfaces 44 and 45.
Is sandwiched.

When the drive shaft 25 rotates while the rollers 42 are sandwiched between the cam surfaces 44 and 45, the cam disk 41 rotates and the first input disk 12 rotates.
a is pressed toward the first output disk 13a, and the first input disk 12a rotates together with the cam disk 41. In addition, since the reaction force received by the cam disk 41 is applied to the rotating shaft 20 via the thrust bearing 43, the second input disk 12b is pressed toward the second output disk 13b. The rotational force of the engine transmitted from the drive shaft 25 to the cam disk 41 rotates the input disks 12a and 12b,
a and 12b are transmitted to the output disks 13a and 13b via the power roller 15 so that the output gear 33 is rotated.
Will rotate.

As shown in FIG. 2, the rotating shaft 20 has a cylindrical shaft main body 20a extending in the direction of the axis P thereof.
On one end side of the shaft main body 20a, a flange portion 50 that spreads in a flange shape is provided on the outer peripheral side. Further, a first spline groove 51 constituting the first ball spline 21 is formed near the flange 50. In FIG.
0 and a part of the spline groove 51 are shown in an enlarged manner.

As shown in FIG. 1, a first input disk 1
2a, a spline groove 52 is formed at a position corresponding to the spline groove 51. These spline grooves 51,
A ball 53 that functions as a member for fixing the input disk 12a and the rotating shaft 20 in the rotation direction is housed in the 52. Therefore, the input disk 12a is
, And can move in the direction of the axis P.

A screw portion 60 is formed on the other end of the rotating shaft 20. A loading nut 61 is attached to the screw portion 60.
(Shown in FIG. 1) are screwed. A second spline groove 62 that forms the second ball spline 22 is formed near the screw portion 60. A spline groove 63 is formed at a position corresponding to the second spline groove 62 on the second input disk 12b. These spline grooves 62,
The input disk 12b and the rotating shaft 20 are fixed in the rotating direction by the ball 64 being accommodated in the 63, and
The input disk 12b can move in the direction of the axis P of the rotating shaft 20. The input disk 12b is urged toward the cam disk 41 by an elastic member 65 such as a disc spring. The elastic member 65 is fixed by the loading nut 61.

The flange 50 has a substantially regular hexagonal shape when viewed from the end face of the rotating shaft 20 (the direction along the axis P). That is, as shown in FIG. 4 and the like, the brim portion 50 has at least two sides parallel to each other (in the case of the illustrated example, a total of 6
Surface). When tightening the loading nut 61 to the screw portion 60, the collar portion 50 having the flat surface 70 can prevent the rotation of the rotary shaft 20 by a jig such as a socket fitted to the collar portion 50.

The first spline grooves 51 located near the flange 50 are provided at six locations at equal pitches in the circumferential direction of the rotating shaft 20 in accordance with the number of flat surfaces 70 (six in the illustrated example). ing. Each spline groove 51 extends in the direction of the axis P of the rotating shaft 20. Each spline groove 51
Is a rotary tool G such as a disk-shaped cutter and a grindstone (FIG. 3)
(Only part of which is shown) is rotated. Therefore, at both ends of the spline groove 51, arc-shaped cut-out surfaces 51a and 51b having a radius of curvature corresponding to the outer diameter of the rotary tool G are formed outside the effective length of the spline.

As shown in FIG. 4, each spline groove 51
Is the center 70a in the width direction of each flat surface 70, respectively.
(Only a part is displayed). That is, in the case of this embodiment, the spline grooves 5
Each spline groove 51 is formed at a position where the center C1 of one 1 substantially matches the line segment passing through the center 70a of the flat surface 70 (the center C2 of the flat surface 70).

As described above, each spline groove 51 has the lowest height H1 near the center 70a in the width direction of the flat surface 70 of the flange 50, that is, from the center C of the rotating shaft 20 to the outer peripheral edge of the flange 50. It is formed so as to point to a location. By providing the spline groove 51 at such a position,
The spline groove 51 can be brought as close as possible to the collar portion 50 as long as the rotary tool G does not interfere with the collar portion 50.

Assuming that the spline groove 51 is formed at a position pointing toward the corner 71 where the flat surfaces 70 intersect, the outer peripheral edge of the collar 50 passes through the spline groove 51 from the center C of the rotating shaft 20. Distance H2 to
Is considerably larger than the shortest distance H1 described above. For this reason, when the rotary tool G is brought close to the collar 50, the rotary tool G interferes with the corner 71 of the collar 50 as shown by a two-dot chain line in FIG. In order to avoid this interference, the distance from the flange 50 to the spline groove 51 needs to be relatively long.

However, if the spline groove 51 is formed at a position where the center C1 of the spline groove 51 substantially coincides with the center C2 of the flat surface 70 as in the above embodiment,
As shown in FIGS. 3 and 4, the distance H1 from the center C of the rotating shaft 20 to the outer peripheral edge of the collar portion 50 through the spline groove 51 is determined from the center C of the rotating shaft 20 to the corner portion 7.
The height becomes lower than the height H2 up to 1 by ΔH, so that the rotary tool G can be brought closer to the collar portion 50 by that amount.

The second spline groove 62 is also processed by a rotary tool such as a cutter or a grindstone. However, since there is no collar near the spline groove 62, when the second spline groove 62 is machined by the rotary tool, there is no problem that the rotary tool interferes with the collar.

FIG. 5 shows a second embodiment of the present invention. In this embodiment, the center C1 of the spline groove 51 is
Has a slight angle θ with respect to the center C2 of the flat surface 70.
This is an example of only leaning. Thus, the spline grooves 51
Even if the center C1 of the flat surface 70 and the center C2 of the flat surface 70 are displaced by the angle θ, the distance from the center C of the rotating shaft 20 to the flat surface 70 if the deviation angle θ is approximately within ± 5 degrees. H3 can be kept low. Therefore, also in this case, it is possible to bring the spline groove 51 as close as possible to the collar portion 50 within a range where the collar portion 50 does not interfere with the rotary tool G. When this angle θ exceeds ± 5 degrees, the rotation axis 2
The distance H3 from the center of 0 to the flat surface 70 becomes too large, so that the rotary tool G and the flange 50 easily interfere with each other.

FIGS. 6 and 7 show a rotating shaft 80 according to a third embodiment of the present invention. This rotary shaft 80 is a CVT shaft used for a toroidal type continuously variable transmission described in the above-mentioned Japanese Patent Application Laid-Open No. 8-61453 or a power split layout CVT described in Japanese Patent Application No. 9-217699. It is. A cam disk constituting a loading cam mechanism is fixed to the rotation shaft 80 in the rotation direction by a ball spline. As in the first embodiment, a spline groove 51 is formed in the vicinity of the flange portion 50, as in the first embodiment.
Each spline groove 51 is formed such that the center C1 of each spline groove 51 substantially matches the center C2 of the flat surface 70 as shown in FIG. In the case of the power split layout described above, since the distance between the ball spline groove and the flange portion is short, the effect of the present invention is more effectively exhibited. In addition, as in the fourth embodiment shown in FIG.
In the rotation shaft 80, the center C1 of the spline groove 51
However, it may be inclined by the angle θ with respect to the center C2 of the flat surface 70.

The number of flat surfaces 70 of the collar 50 is not limited to six. In short, if a spline groove is formed at a position facing the center in the width direction of each flat surface in a rotating shaft having a flange portion having at least two flat surfaces parallel to each other (so-called parallel two-surface width), The same effect as the above embodiment can be obtained. For example, the number of spline grooves may be three.

In practicing the present invention including these embodiments, the elements constituting the present invention, such as the number, shape and size of the flat surface of the flange of the rotating shaft and the spline grooves, are appropriately modified. Needless to say, it can be implemented. In the above embodiment, the double-cavity half-toroidal continuously variable transmission has been described. However, the present invention can be similarly applied to a single-cavity half-toroidal continuously variable transmission.

[0031]

According to the present invention, a rotary tool such as a cutter or a grindstone used for processing a spline groove can be brought as close as possible to the collar portion without interfering with the collar portion of the rotating shaft. , And the rotation axis can be shortened.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a half toroidal type continuously variable transmission showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the axial direction of a rotating shaft used in the half-toroidal type continuously variable transmission shown in FIG.

FIG. 3 is an enlarged sectional view showing a part of the rotation shaft shown in FIG. 2;

FIG. 4 is a cross-sectional view of the rotation shaft taken along line F4-F4 in FIG.

FIG. 5 is a sectional view taken along a radial direction of a rotating shaft according to a second embodiment of the present invention.

FIG. 6 is a sectional view taken along the axial direction of a rotating shaft according to a third embodiment of the present invention.

FIG. 7 is a cross-sectional view of the rotation shaft taken along line F6-F6 in FIG. 6;

FIG. 8 is a sectional view taken along a radial direction of a rotating shaft showing a fourth embodiment of the present invention.

FIG. 9 is a sectional view of a part of a conventional half toroidal type continuously variable transmission.

[Explanation of symbols]

 12a, 12b Input disk 13a, 13b Output disk 20 Rotating shaft 21 Ball spline 50 Collar 51 Spline groove 53 Ball (member for preventing rotation) 70 Flat surface

Claims (2)

[Claims] 1. A rotary shaft of a toroidal-type continuously variable transmission having an input disk, an output disk, a cam disk, and the like, wherein at least two flat surfaces parallel to each other as viewed from an end face side of the rotary shaft are formed. A spline groove formed in the vicinity of the flange portion along the axial direction of the rotating shaft and accommodating a member for preventing rotation of the input disk or the cam disk; A rotary shaft of a toroidal-type continuously variable transmission, wherein a groove is formed at a position facing a center of the flat surface in a width direction. 2. The flange portion has a substantially regular hexagon shape having six flat surfaces as viewed from the end face side of the rotary shaft, and each spline groove is formed in a circumferential direction of the rotary shaft corresponding to each flat surface. The rotary shaft of a toroidal-type continuously variable transmission according to claim 1, wherein the rotary shaft is formed at a constant pitch.