JP2002213551A - Toroidal type continuously variable transmission - Google Patents

Abstract

(57) [Problem] To provide a toroidal-type continuously variable transmission that can reduce the load on a support bearing that supports an input shaft, suppress loss in the support bearing, and improve efficiency. . An input shaft (1) and a pair of input disks (4) are provided so as to be immovable in an axial direction with respect to a case, and rotate around the input shaft in a state of facing the input disk. A pair of output disks 6 and 7 movably and axially movable, and a plurality of power rollers 8 and 9 which are rotatably contacted between the input disk and the output disk and transmit power by friction. An output gear 21 for taking out the rotational movement of the pair of output disks;
In a toroidal-type continuously variable transmission including a hydraulic pressing means provided on the input shaft, the direction of the axial reaction force of the output gear when the pressing force is generated by the hydraulic pressing means 16 is determined by the hydraulic pressure. The present invention is characterized in that the direction is such that the force generated by the pressing means in the axial direction of the input shaft is offset.

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 used as a transmission for an automobile.

[0002]

2. Description of the Related Art In a toroidal type continuously variable transmission, as shown in FIG. 3, a toroidal type continuously variable transmission in which a pressing force is generated by a hydraulic pressing means and an input disk is pressed to an output disk via a power roller. It is configured.

FIG. 3 shows a conventional double-cavity toroidal-type continuously variable transmission, in which one input shaft 1 has a front cavity 2 and a rear cavity 3 coaxially arranged. These cavities 2 and 3 have a pair of input disks 4 and 5 and a pair of output disks 6 and 7, and are provided between the input disk 4 and the output disk 6 and between the input disk 5 and the output disk 7. Power rollers 8, 9 that transmit power by friction are trunnions 8a, 9a.
, And are pivotally connected to each other.

The input disk 4 of the front side cavity 2
Are rotationally engaged with the input shaft 1 by a ball spline 10 and are movable in the axial direction. The input disk 5 of the rear cavity 3 is prevented from falling off by a flange 11 provided integrally with the input shaft 1.

[0005] A hydraulic cylinder 12 is provided on the input shaft 1, and the hydraulic cylinder 12 is rotatably supported by a support bearing 13. Hydraulic cylinder 12 has hydraulic chamber 1
The hydraulic chamber 14 communicates with a hydraulic supply source (not shown) through a hydraulic supply port 15 so that the hydraulic pressure generated in the portion of φD acts on the input shaft 1. The pressing means 16 is constituted.

Further, an output gear 17 fitted to the input shaft 1 is provided on the output disk 6 of the front side cavity 2 and the output disk 7 of the rear side cavity 3,
The output gear 17 is meshed with a driven gear 19 fitted on an output shaft 18 so that the output shaft 18 is transmitted to driving wheels of an automobile.

[0007]

However, in the toroidal-type continuously variable transmission constructed as described above, the input shaft 1 is pressed by the hydraulic pressing means 16, so that the force generated on the input shaft 1 is generated. In addition, the size of the support bearing 13 is increased because the support bearing 13 supports the above, and a reduction in efficiency due to a large loss of the support bearing 13 is a problem.

On the other hand, in a double-cavity toroidal-type continuously variable transmission, as shown in Japanese Patent No. 2861654, a drive gear rotating integrally with a front output disk and a rear output disk is formed by a helical gear. When the driving force is transmitted from the engine side, the direction of the torsion angle is generated in the forward running state of the vehicle to generate a force for pressing the rear output disk toward the rear input disk side. Have been. However, this assumes a loading cam as the pressing force generator, and corrects the pressing force reduced by the friction loss of the cavity of the input shaft.

The present invention has been made in view of the above circumstances, and has as its object to reduce the load on the support bearing of the input shaft, suppress the loss of the support bearing, and improve the efficiency. It is an object of the present invention to provide a toroidal-type continuously variable transmission that can reduce the size of the transmission in the axial direction and can be reduced in size.

[0010]

In order to achieve the above object, the present invention provides a case, an input shaft provided in the case, and the input shaft and one of the input shaft and the case. A pair of input disks, the input disks of which are immovably provided in the axial direction, and a pair of output disks which are rotatably and axially movable around the input shaft in a state facing the input disk. A plurality of power rollers that are rotatably rolled between the input disk and the output disk to transmit power by friction, an output gear that takes out the rotational movement of the pair of output disks, and that is provided on the input shaft. And a hydraulic pressing means provided with the hydraulic pressing means, wherein the direction of the axial reaction force of the output gear when a pressing force is generated by the hydraulic pressing means is determined by the hydraulic pressing means. Characterized by being in a direction to offset the force generated by the axial direction of the input shaft by means.

According to a second aspect, the output gear of the first aspect is
It is a helical gear having a torsion angle such that the axial reaction force cancels the force generated by the hydraulic pressure means in the axial direction of the input shaft.

According to the above configuration, when the pressing force is generated by the hydraulic pressing means, the torsional angle is such that the axial reaction force of the output gear cancels the force generated by the hydraulic pressing means in the axial direction of the input shaft. Is formed by a helical gear having Therefore, the load on the support bearing that supports the input shaft can be reduced.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a first embodiment. FIG. 1 is a longitudinal side view of a double-cavity half-toroidal type continuously variable transmission. FIG. 2 shows a relationship between a speed ratio and a force applied to a support bearing. This is a graph shown, and the same components as those of the related art are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 1, a case (not shown)
A hydraulic cylinder 12 is provided on the input side of the input shaft 1 provided inside the hydraulic cylinder.
It is rotatably supported by. Hydraulic cylinder 12
The hydraulic chamber 14 communicates with the rear side of the input disk 4 in the front side cavity 2 and constitutes a hydraulic pressure means 16.

The input shaft 1 and the front cavity 2
The input disk 4 is provided so as not to be movable in the axial direction with respect to the case, and the output disks 6 and 7 are provided so as to be movable in the axial direction. Further, an output gear 21 is fitted to the input shaft 1 between the output disk 6 in the front cavity 2 and the output disk 7 in the rear cavity 3. The output gear 21 is a driven gear 1 fitted to the output shaft 18.
9 are meshed, and the output shaft 18 is transmitted to the drive wheels of the automobile.

The output gear 21 determines the direction of the axial reaction force F of the output gear 21 when the pressing force is generated from the input side of the input shaft 1 by the hydraulic pressing means 16. In the direction of canceling the generated force in the axial direction. That is, the output gear 21 is formed by a helical gear having a torsion angle in which the axial reaction force F cancels the force generated by the hydraulic pressing means 16 in the axial direction of the input shaft 1. The load on the support bearing 13 that supports the input shaft 1 is reduced.

Therefore, when the input shaft 1 rotates, the input disk 4.5 rotates integrally. In this state, when hydraulic pressure is applied to the hydraulic chamber 14 of the hydraulic pressing means 16, the input disks 4,
5 through power rollers 8 and 9 to output discs 6 and 7
, And the output disks 6, 7 rotate integrally. The rotation of the output disks 6 and 7 is transmitted to the output shaft 18 via the output gear 21 and the driven gear 19.

At this time, the output gear 21 changes the direction of the axial reaction force F of the output gear 21 when the pressing force is generated from the input side of the input shaft 1 by the hydraulic pressing means 16.
Since the direction in which the force generated by the hydraulic pressure means 16 in the axial direction of the input shaft 1 is offset, the load on the support bearing 13 that supports the input shaft 1 can be reduced by the axial reaction force F.

Since the output disk 7 is not supported in the axial direction with respect to the input shaft 1, the reaction force F of the output gear 21 cannot theoretically be canceled in the cavity, and the support bearing at the shaft end of the input shaft 1 is not supported. The hydraulic pressure generated at the shaft end of the input shaft 1 is also supported by the support bearing 13 at the shaft end. Therefore, the reaction force F of the output disk 21 does not affect the front side cavity 2 and the rear side cavity 3.

According to the above configuration, since the load on the support bearing 13 can be reduced, the loss in the support bearing 13 can be suppressed, the efficiency can be improved, and the size of the support bearing 13 can be reduced (the axial dimension can be reduced). ) Can be achieved.

The reaction force F of the output gear 21 varies depending on the gear ratio. It is difficult to cancel the axial force applied to the support bearing 13 over the entire gear ratio. Therefore, as shown in FIG.
The torsion angle of the helical gear as the output gear 21 is set so that the force applied to the helical gear is minimized. The horizontal axis in FIG. 2 is the gear ratio, and the vertical axis is the reaction force. 2A shows the force generated on the input shaft 1 by the hydraulic pressure, B shows the reaction force of the output gear 21, C shows the force generated on the support bearing 13, and D shows the point at which the force generated on the support bearing 13 is canceled. is there. By setting the torsion angle of the helical gear as the output gear 21 so as to minimize the transmission ratio or the force applied to the support bearing 13 that is frequently used in this way, the efficiency is further improved and the support bearing 13 is used.
Can be reduced in size.

When the torsion angle of the helical gear of the output gear 21 is limited, the pressure receiving portion of the piston and the supply oil pressure may be adjusted, and the oil pressure is used for speed change control of a toroidal type continuously variable transmission. Use things. Since the oil pressure of the shift control system changes according to the load, it is convenient to cancel the force.

[0024]

As described above, according to the present invention, when the pressing force is generated by the hydraulic pressing means, the axial reaction force of the output gear is generated by the hydraulic pressing means in the axial direction of the input shaft. Is formed by a helical gear having a torsion angle in a direction that cancels out the load, so that the load on a support bearing that supports the input shaft can be reduced. Therefore, there is an effect that the loss in the support bearing can be suppressed, the efficiency can be improved, and the size of the support bearing can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a toroidal type continuously variable transmission showing a first embodiment of the present invention.

FIG. 2 is a graph showing a relationship between a gear ratio and a force applied to a support bearing.

FIG. 3 is a vertical side view of a conventional toroidal type continuously variable transmission.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Input shaft 2 ... Front side cavity 3 ... Rear side cavity 4, 5 ... Input disk 6, 7 ... Output disk 8, 9 ... Power roller 13 ... Support bearing 16 ... Hydraulic pressing means 21 ... Output gear

Claims (2)

[Claims] 1. A case, an input shaft provided in the case, a pair of input disks provided with the input shaft and one of the input disks immovable in the axial direction with respect to the case, A pair of output disks, which are rotatably and axially movable around the input shaft in a state facing the disks, are rotatably rolled between the input disk and the output disks, and are powered by friction. A plurality of power rollers, an output gear for taking out the rotational movement of the pair of output discs, and a hydraulic pressing means provided on the input shaft. The direction of the axial reaction force of the output gear when the pressing force is generated is set to a direction that cancels the force generated in the axial direction of the input shaft by the hydraulic pressing means. Toroidal-type continuously variable transmission to be butterflies. 2. The output gear is a helical gear having a torsion angle such that an axial reaction force of the output gear cancels a force generated in an axial direction of the input shaft by the hydraulic pressing means. The toroidal-type continuously variable transmission according to claim 1.