Toroidal continuously variable transmission

Abstract

Provided is a toroidal continuously variable transmission capable of preventing the application of bending stress to a variator shaft during rotation and the application of an eccentric load to each of support parts even when misalignment between the axis of a fitting hole formed in a post and the axis on which the variator shaft is supported occurs. A thrust bearing 12 which determines the position of an output side disc 10 in an axial direction and rotatably supports the output side disc 10 is fitted into a fitting hole 62b provided in a post 61, and a predetermined gap S is provided between the thrust bearing 12 and the fitting hole 62b in a direction perpendicular to the variator shaft 3. Therefore, even when misalignment between the axis of the fitting hole and the axis on which the variator shaft is supported occurs, the axes of the thrust bearing 12 and the variator shaft 3 can be aligned with each other in the predetermined gap S, thereby preventing the application of bending stress to the variator shaft 3 during rotation and the application of an eccentric load to each of support parts.

Claims

1. A toroidal continuously variable transmission comprising: a variator section which includes input side discs and an output side disc which are concentrically and rotatably supported by a variator shaft in a state where inner surfaces thereof oppose each other, and a plurality of power rollers which are provided between the input side discs and the output side disc and transmit rotational force of the input side discs to the output side disc at a predetermined gear ratio, the variator section being assembled into a casing; a post disposed perpendicular to the variator shaft; a thrust bearing which determines a position of the output side disc in an axial direction, rotatably supports the output side disc, and is fitted into a fitting hole provided in the post; and a predetermined gap provided between the thrust bearing and at least any one of the fitting hole and the output side disc in a direction perpendicular to the variator shaft, wherein one bearing ring of the thrust bearing is configured to be movable in the predetermined gap in the direction perpendicular to the variator shaft.

2. The toroidal continuously variable transmission according to claim 1, wherein the predetermined gap is set to a size capable of absorbing misalignment between an axis of the variator shaft and an axis of the thrust hearing.

3. The toroidal continuously variable transmission according to claim 2, wherein one bearing ring of the thrust bearing is able to be aligned in the predetermined gap.

4. The toroidal continuously variable transmission according to claim 1, wherein one bearing ring of the thrust bearing is able to be aligned in the predetermined gap.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 illustrates a toroidal continuously variable transmission of a first embodiment of the present invention, and is a sectional view thereof.

(2) FIG. 2 is an enlarged sectional view of the main parts of the toroidal continuously variable transmission.

(3) FIG. 3 illustrates a toroidal continuously variable transmission of a second embodiment of the present invention, and is an enlarged sectional view of the main parts thereof.

(4) FIG. 4 illustrates an example of a toroidal continuously variable transmission which is hitherto known, and is a sectional view thereof.

(5) FIG. 5 is an enlarged sectional view of the main parts of the toroidal continuously variable transmission.

(6) FIG. 6 is a sectional view taken along line A-A of FIG. 4.

DESCRIPTION OF EMBODIMENTS

(7) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment

(8) FIG. 1 is a sectional view of a toroidal continuously variable transmission according to the present embodiment and FIG. 2 is an enlarged sectional view of the main parts thereof. The toroidal continuously variable transmission illustrated in FIGS. 1 and 2 is different from the toroidal continuously variable transmission illustrated in FIGS. 4 to 6 in that a structure for preventing the application of bending stress to a variator shaft (input shaft) 3 during rotation and the application of an eccentric load to each of support parts is employed. Hereinafter, the difference will be described in detail, and like elements which are common are denoted by like reference numerals to omit or simplify the description thereof.

(9) As illustrated in FIG. 1, a variator section 1A is assembled into a casing 2. The variator section 1A includes input side discs 4A and 4B and an output side disc 10 which are concentrically and rotatably supported by a variator shaft 3 in a state where their inner surfaces oppose each other, and a plurality of power rollers 11 (see FIG. 3) which are provided between the input side discs 4A and 4B and the output side disc 10 and transmit the rotational force of the input side discs 4A and 4B to the output side disc 10 at a predetermined gear ratio.

(10) On the inside of the casing 2, a post 61 is disposed perpendicular to the input shaft (variator shaft) 3. The lower end portion of the post 61 is fastened and fixed to an upper cylinder body (body) 60 by a bolt 92. In addition, upper and lower yokes 23A and 23B are supported to oscillate by spherical posts 64 and 68 provided in the upper and lower sections of the post 61.

(11) On the upper side of the post 61, the spherical post 64 in the upper end portion of the post 61 is fastened and fixed to a connection plate 65 by a bolt 93.

(12) In the toroidal continuously variable transmission, after the variator section 1A illustrated in FIG. 1 is assembled, the assembled variator section 1A is accommodated in the casing 2 and one end portion of the input shaft (variator shaft) 3 is connected to a driving shaft 72 while the other end portion thereof is rotatably supported by a bearing 73.

(13) In the center portion of the post 61, an insertion hole 62 is formed as illustrated in FIG. 2. The insertion hole 62 includes a large-diameter hole 62a and a fitting hole 62b which has a smaller diameter than that of the large-diameter hole 62a.

(14) In addition, the thrust bearing 12 is inserted into the insertion hole 62, one bearing ring 12a of the thrust bearing 12 is fitted into the fitting hole 62b, and the other bearing ring 12b is inserted into the large-diameter hole 62a. An end portion 10b of the output side disc 10 is inserted into the large-diameter hole 62a of the insertion hole 62, and the other bearing ring 12b of the thrust bearing 12 is fitted to the end portion 10b.

(15) The thrust bearing 12 includes the pair of left and right bearing rings 12a and 12b.

(16) The bearing ring 12a has a ring shape with an L-shaped transverse section, and includes an annular ring portion 12a1 and a flange portion 12a2 formed at the outer peripheral portion of the ring portion 12a1.

(17) Similarly to the bearing ring 12a, the bearing ring 12b has a ring shape with an L-shaped transverse section, and includes an annular ring portion 12b1 and a flange portion 12b2 formed at the outer peripheral portion of the ring portion 12b1.

(18) The flange portion 12a2 and the flange portion 12b2 have the same shape while the ring portion 12a1 is thinner than the ring portion 12b1.

(19) The ring portion 12a1 is fitted into the fitting hole 62b. However, a predetermined gap S is provided between the outer peripheral surface of the ring portion 12a1 and the inner peripheral surface of the fitting hole 62b in a direction perpendicular to the input shaft (variator shaft) 3. Accordingly, the predetermined gap S is provided between the thrust bearing 12 and the fitting hole 62b in the direction perpendicular to the input shaft (variator shaft) 3.

(20) The predetermined gap S is set to a size such that misalignment between the axis of the input shaft (variator shaft) 3 and the axis of the thrust bearing 12 can be absorbed. That is, one bearing ring 12a of the thrust bearing 12 can be slightly moved in a vertical direction in FIG. 2 in the predetermined gap S for alignment.

(21) As described above, since one bearing ring 12a can be slightly moved in the vertical direction, the thrust bearing 12 can be slightly moved in the vertical direction in the gap S along with the output side disc 10 and the input shaft 3. Therefore, the axes of the thrust bearing 12 and the input shaft 3 can be aligned with each other.

(22) In addition, a spacer 13 is interposed between the flange portion 12a2 and the bottom surface of the large-diameter hole 62a.

(23) The outer peripheral surface of the ring portion 12b1 of the other bearing ring 12b of the thrust bearing 12 abuts the inner peripheral surface of the end portion 10b of the output side disc 10, and the flange portion 12b2 abuts the end portion 10b. Accordingly, the other bearing ring 12b of the thrust bearing 12 is fitted to the end portion 10b.

(24) In this embodiment, since the predetermined gap S is provided between the thrust bearing 12 and the fitting hole 62b formed in the post 61 in the direction perpendicular to the input shaft (variator shaft) 3, even when misalignment between the axis of the fitting hole 62b formed in the post 61 and the axis on which the input shaft (variator shaft) 3 is supported (the axis of the bearing 73 and the driving shaft 72) occurs during the assembly of the variator 1A as a module into the casing 2, the axes of the thrust bearing 12 and the input shaft (variator shaft) 3 can be aligned with each other in the predetermined gap S. Therefore, the application of bending stress to the input shaft (variator shaft) 3 during rotation and the application of an eccentric load to each of the support parts (the thrust bearings 12, the bearing 73 provided in the casing, the driving shaft 72, and the like) can be prevented.

Second Embodiment

(25) FIG. 3 illustrates a second embodiment and is a sectional view of main parts. The difference between a toroidal continuously variable transmission illustrated in this figure and the first embodiment illustrated in FIGS. 1 and 2 is the position where the predetermined gap S is provided. Hereinafter, the difference is described, and like elements which are common to those of the first embodiment are denoted by like reference numerals to omit or simplify the description thereof.

(26) In this embodiment, the thrust bearing 12 is reversed from left to right for use. That is, one bearing ring 12a is disposed on the left side, and the other bearing ring 12b is disposed on the right side.

(27) In this thrust bearing 12, the ring portion 12a1 is fitted to the inner peripheral surface of the end portion 10b of the output side disc 10, and the predetermined gap S is provided between the outer peripheral surface of the ring portion 12a1 and the inner peripheral surface of the end portion 10b in the direction perpendicular to the input shaft (variator shaft) 3. Accordingly, the predetermined gap S is provided between the thrust bearing 12 and the output side disc 10 in the direction perpendicular to the input shaft (variator shaft) 3.

(28) The predetermined gap S is set to a size such that misalignment between the axis of the input shaft (variator shaft) 3 and the axis of the thrust bearing 12 can be absorbed. That is, the output side disc 10 can be slightly moved in the vertical direction in FIG. 2 in the predetermined gap S with respect to one bearing ring 12a of the thrust bearing 12 for alignment.

(29) As described above, since the output side disc 10 can be slightly moved in the vertical direction with respect to one bearing ring 12a, the output side disc 10 and the input shaft 3 can be slightly moved in the vertical direction in the gap S. Therefore, the axes of the thrust bearing 12 and the input shaft 3 can be aligned with each other.

(30) In addition, the outer peripheral surface of the ring portion 12b1 of the other bearing ring 12b of the thrust bearing 12 abuts the inner peripheral surface of the fitting hole 62b, and the flange portion 12b2 abuts the bottom surface of the large-diameter hole 62a of the insertion hole 62 via the spacer 13. Accordingly, the other bearing ring 12b of the thrust bearing 12 is fitted into the fitting hole 62b.

(31) In this embodiment, since the predetermined gap S is provided between the thrust bearing 12 and the output side disc 10 in the direction perpendicular to the input shaft (variator shaft) 3, even when misalignment between the axis of the fitting hole 62b formed in the post 61 and the axis on which the input shaft (variator shaft) 3 is supported (the axis of the bearing 73 and the driving shaft 72) occurs during the assembly of the variator section 1A as a module into the casing 2, the axes of the thrust bearing 12 and the input shaft (variator shaft) 3 can be aligned with each other in the predetermined gap S. Therefore, the application of bending stress to the input shaft (variator shaft) 3 during rotation and the application of an eccentric load to each of the support parts (the thrust bearings 12, the bearing 73 provided in the casing, the driving shaft 72, and the like) can be prevented.

(32) In the embodiments described above, the predetermined gap S is provided between the thrust bearing 12 and any of the fitting hole 62b and the output side disc 10 in the direction perpendicular to the variator shaft. However, the gap S may also be provided between the thrust bearing 12 and both of the fitting hole 62b and the output side disc 10.

REFERENCE SIGNS LIST

(33) 1 toroidal continuously variable transmission 1A variator section 2 casing 3 input shaft 4A, 4B input side disc 10 output side disc 11 power roller 12 thrust bearing 61 post 62b fitting hole 72 driving shaft 73 bearing