Toroidal type continuously variable transmission

Abstract

To provide a toroidal type continuously variable transmission that suppresses wear of a cam surface of a cam plate of a pressing device and can acquire pressing force necessary for design.SOLUTION: A toroidal type continuously variable transmission includes a pressing device 12 of which cam plate 7 includes a storage part 7a for storing a biasing member 8 and is configured such that both of the part forming the storage part 7a from a radial outside and part forming the storage part 7a from a radial inside abut on a support member 116 in an axial direction during torque transmission between an input side disc 2 and an output side disc.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a toroidal continuously variable transmission used in automobiles, aircraft, etc.

Background Art

[0002] Generally, as a transmission used in automobiles, etc., for example, a double-cavity toroidal continuously variable transmission is known. This double-cavity toroidal continuously variable transmission is configured as shown in FIGS. 3 and 4 as an example. That is, as shown in FIG. 3, an input shaft 1 is rotatably supported inside a casing 50, and two input-side disks 2, 2 and two output-side disks 3, 3 are attached to the outer periphery of the input shaft 1. Further, an output gear 4 is rotatably supported on the outer periphery of an intermediate portion of the input shaft 1. The output-side disks 3, 3 are connected to cylindrical flange portions 4a, 4a provided at the center of the output gear 4 by spline coupling.

[0003] The input shaft 1 is rotationally driven by a drive shaft 22 via a loading cam type pressing device (loading cam mechanism) 12 provided between the input-side disk 2 located on the left side in the figure and a cam plate (loading cam) 7. Further, the output gear 4 is supported in the casing 50 via an intermediate wall 13 formed by the coupling of two members. Thereby, while being able to rotate about the axis O of the input shaft 1, displacement in the direction of the axis O is blocked.

[0004] As shown in Figure 3, the output disks 3,3 are rotatably supported about the axis O of the input shaft 1 by needle bearings 5,5 interposed between them and the input shaft 1. The input disk 2 on the left side of the figure is supported by the input shaft 1 via a ball spline 6, and the input disk 2 on the right side of the figure is spline-coupled to the input shaft 1, so that these input disks 2 rotate together with the input shaft 1. A power roller 11 (see Figure 4) is rotatably sandwiched between the inner surfaces (concave surfaces; also called traction surfaces) 2a,2a of the input disks 2,2 and the inner surfaces (concave surfaces; also called traction surfaces) 3a,3a of the output disks 3,3.

[0005] A stepped portion 2b is provided on the inner circumferential surface 2c of the input-side disk 2 located on the right side in Figure 3. A stepped portion 1b provided on the outer circumferential surface 1a of the input shaft 1 abuts against this stepped portion 2b, and the back surface of the input-side disk 2 (right side in Figure 3) abuts against a loading nut 9 that is screwed onto a threaded portion formed on the outer circumferential surface of the input shaft 1. This effectively prevents displacement of the input-side disk 2 in the direction of axis O relative to the input shaft 1. In addition, a disc spring 8 is provided between the cam plate 7 and the flange portion 1d of the input shaft 1. This disc spring 8 applies a pressing force (preload) to the contact points between the concave surfaces 2a, 2a, 3a, 3a of each disk 2, 2, 3, 3 and the circumferential surfaces 11a, 11a of the power rollers 11, 11.

[0006] Figure 4 is a cross-sectional view along line AA in Figure 3. As shown in Figure 4, a pair of trunnions 15, 15 are provided inside the casing 50, which swing around a pair of pivots 14, 14 that are twisted relative to the input shaft 1. Note that the input shaft 1 is not shown in Figure 4. Each trunnion 15, 15 has a pair of bent wall portions 20, 20 formed at both ends in the longitudinal direction (up and down direction in Figure 4) of the support plate portion 16, which bends toward the inner surface of the support plate portion 16. These bent wall portions 20, 20 form a concave pocket portion P in each trunnion 15, 15 for housing the power roller 11. The pivots 14, 14 are provided concentrically on the outer surfaces of each bent wall portion 20, 20.

[0007] A circular hole 21 is formed in the center of the support plate portion 16, and a support shaft portion 23a, which forms the base end of the displacement shaft (pivot shaft) 23, is supported in this circular hole 21. By swinging each trunnion 15, 15 around each pivot 14, 14, the inclination angle of the displacement shaft 23 supported in the center of each trunnion 15, 15 can be adjusted. Furthermore, each power roller 11 is rotatably supported around the pivot shaft portion 23b, which forms the tip of the displacement shaft 23 protruding from the inner surface of each trunnion 15, 15, via radial needle bearings (needle-shaped roller bearings that receive the pressing load acting on the inner ring (power roller 11) of the thrust ball bearing 24 (described later) (supporting radial loads); cage and roller) 35, and each power roller 11, 11 is sandwiched between each input-side disk 2, 2 and each output-side disk 3, 3. Furthermore, the support shaft portion 23a and the pivot shaft portion 23b of each displacement axis 23, 23 are eccentric to each other.

[0008] Furthermore, the pivots 14, 14 of each trunnion 15, 15 are supported so as to be swingable and displaceable in the axial direction (up and down direction in Figure 4) relative to a pair of yokes 23A, 23B, and the horizontal movement of the trunnions 15, 15 is restricted by each yoke 23A, 23B. Each yoke 23A, 23B is formed into a rectangular shape by pressing or forging a metal such as steel. Four circular support holes 18 are provided at the four corners of each yoke 23A, 23B, and the pivots 14 provided at both ends of the trunnion 15 are swingably supported in each of these support holes 18 via radial needle bearings 30. In addition, a circular locking hole 19 is provided in the center of the width direction (left and right direction in Figure 4) of the yokes 23A, 23B, and the inner circumferential surface of this locking hole 19 is a cylindrical surface into which spherical posts 64, 68 are fitted. Specifically, the upper yoke 23A is pivotably supported by a spherical post 64 which is supported by a fixing member 52 in the casing 50, and the lower yoke 23B is pivotably supported by a spherical post 68 and the upper cylinder body 61 of the drive cylinder (cylinder body) 31 that supports it.

[0009] Furthermore, the displacement axes 23, 23 provided on each trunnion 15, 15 are positioned 180 degrees opposite each other with respect to the input shaft 1. In addition, the direction in which the pivot shaft portion 23b of each displacement axis 23, 23 is eccentric with respect to the support shaft portion 23a is the same direction as the rotation direction of both disks 2, 2, 3, 3 (up and down opposite directions in Figure 4). Moreover, the direction of eccentricity is approximately perpendicular to the orientation direction of the input shaft 1. Therefore, each power roller 11, 11 is supported so that it can be slightly displaced in the longitudinal direction of the input shaft 1. As a result, even if each power roller 11, 11 tends to be displaced in the axial direction of the input shaft 1 due to the elastic deformation of each component based on the thrust load generated by the loading cam type pressing device 12, no excessive force is applied to each component, and this displacement is absorbed.

[0010] Furthermore, between the outer surface (large end surface) 11b of the power roller 11 and the inner surface 16a of the support plate portion 16 of the trunnion 15, thrust rolling bearings, namely thrust ball bearings (thrust bearings) 24 and thrust needle bearings 25, are provided in order from the side of the outer surface 11b of the power roller 11. Of these, the thrust ball bearings 24 support the thrust load applied to each power roller 11 while allowing the rotation of each power roller 11. Each of these thrust ball bearings 24 consists of multiple balls (rolling elements) 26, 26, an annular cage 27 that holds these rolling elements 26, 26 so that they can roll, and an annular outer ring 28. In addition, the inner ring raceway surface 24a of each thrust ball bearing 24 is formed on the outer surface 11b of each power roller 11, and the outer ring raceway surface 24b is formed on the inner surface of each outer ring 28.

[0011] Furthermore, the thrust needle bearing 25 is sandwiched between the inner surface 16a of the support plate portion 16 of the trunnion 15 and the outer surface of the outer ring 28. Such a thrust needle bearing 25 supports the thrust load applied from the power roller 11 to each outer ring 28, while allowing these power rollers 11 and outer rings 28 to swing around the support shaft portion 23a of each displacement shaft 23.

[0012] Furthermore, drive rods (trunnion shafts) 29, 29 are provided at one end of each trunnion 15, 15 (the lower end in Figure 4), and drive pistons (hydraulic pistons) 33, 33 are fixed to the outer circumferential surface of the intermediate portion of each drive rod 29, 29. Each of these drive pistons 33, 33 is then oil-tightly fitted into a drive cylinder 31, which is composed of an upper cylinder body 61 and a lower cylinder body 62. These drive pistons 33, 33 and the drive cylinder 31 constitute a drive device 32 that displaces each trunnion 15, 15 in the axial direction of its pivot 14, 14.

[0013] In a toroidal continuously variable transmission configured in this way, the rotation of the input shaft 1 is transmitted to each input-side disk 2, 2 via a loading cam-type pressing device 12. The rotation of these input-side disks 2, 2 is then transmitted to each output-side disk 3, 3 via a pair of power rollers 11, 11, and the rotation of these output-side disks 3, 3 is then extracted by the output gear 4.

[0014] To change the rotational speed ratio between the input shaft 1 and the output gear 4, a pair of drive pistons 33, 33 are displaced in opposite directions. As these drive pistons 33, 33 are displaced, a pair of trunnions 15, 15 are displaced in opposite directions. For example, the power roller 11 on the left side of Figure 4 is displaced to the lower side of the figure, and the power roller 11 on the right side of the figure is displaced to the upper side of the figure.

[0015] As a result, the direction of the tangential force acting on the contact points between the circumferential surfaces 11a, 11a of each power roller 11, 11 and the inner surfaces 2a, 2a, 3a, 3a of each input-side disk 2, 2 and each output-side disk 3, 3 changes. Along with this change in the direction of the force, each trunnion 15, 15 swings (tilts) in opposite directions around the pivots 14, 14 pivotally supported by the yokes 23A, 23B.

[0016] As a result, the contact position between the circumferential surfaces 11a, 11a of each power roller 11, 11 and their respective inner surfaces 2a, 3a changes, and the rotational speed ratio between the input shaft 1 and the output gear 4 changes. Furthermore, when the torque transmitted between the input shaft 1 and the output gear 4 fluctuates and the amount of elastic deformation of each component changes, each power roller 11, 11 and the outer rings 28, 28 attached to these power rollers 11, 11 rotate slightly around the support shaft portions 23a, 23a of each displacement shaft 23, 23. Since thrust needle bearings 25, 25 are present between the outer surfaces of each outer ring 28, 28 and the inner surfaces of the support plate portions 16 constituting each trunnion 15, 15, the rotation is performed smoothly. Therefore, as described above, the force required to change the inclination angle of each displacement shaft 23, 23 is small.

[0017] Incidentally, the aforementioned pressing device 12, which is a loading cam mechanism that generates axial force for traction drive (pressing force necessary to generate traction force), has been known in various configurations for a long time (see, for example, Patent Document 1). For example, in the configuration example shown in Figure 5, it consists of the aforementioned cam plate (cam flange) 7 that rotates together with the input shaft 1, and a plurality of cam rollers (rolling elements) 12b that are held rotatably between the cam plate 7 and the input-side disk 2 (the input-side disk 2 on the left side of Figure 5) by a retainer 12a, and elastically presses the input-side disk 2 toward the output-side disk 4 while allowing the input-side disk 2 to rotate freely.

[0018] Furthermore, a cam surface 113, which has circumferential irregularities, is formed on one side of the cam plate 7 (the left side in Figure 5), and a cam surface 114 with a similar shape is formed on the outer surface of the input-side disk 2 (the right side in Figure 5). In addition, an angular contact inner ring raceway 115 is formed on one side of the inner bearing support member (inner ring member) 119, which is fitted to the end of the input shaft 1 and whose back surface abuts against a nut 90 screwed onto the input shaft 1. Multiple balls 118 are interposed between this inner ring raceway 115 and an angular contact outer ring raceway 117 formed on the inner circumferential surface of the outer bearing support member (outer ring member) 116. In other words, the bearing support members (inner and outer ring members) 116, 119 and the balls 118 constitute an angular contact ball bearing 120 that is interposed between the input shaft 1 and the cam plate 7 and can support thrust loads. Furthermore, a shim 190 is inserted in the gap between the stepped portion on the outer circumference of the input shaft 1 that supports the cam plate 7 and the inner bearing support member 119. [Prior art documents] [Patent Documents]

[0019] [Patent Document 1] Japanese Patent Publication No. 2005-172144 [Overview of the project] [Problems that the invention aims to solve]

[0020] In the aforementioned pressing device 12 shown in Figure 5, generally, when there is no load and no power (torque) is transmitted between the discs 2 and 3, or during initial operation when the transmitted torque is small and the pressing force is small, a gap C exists between the cam plate 7 and the outer bearing support member 116 of the angular contact ball bearing 120. Therefore, as the transmitted torque increases, the cam twists, and the cam plate 7 moves axially to narrow the gap C, and eventually the cam plate 7 and the outer bearing support member 116 come into contact.

[0021] Here, the cam plate 7 has a housing portion 7a formed radially inward, which is a housing space for accommodating the aforementioned disc spring 8 that applies pressing force (preload) to the contact portion between the concave surfaces 2a, 3a of each disc 2, 3 and the circumferential surface 11a of the power roller 11. As a result, the cam plate 7 has a radially outer portion 7A that is solid and has high rigidity (and therefore difficult to deform), and a radially inner portion 7B that is hollow due to the presence of the housing portion 7a and has low rigidity (and therefore easily deformable). Therefore, as described above, when the cam plate 7 and the outer bearing support member 116 come into contact, and as the torque T transmitted by the traction drive increases as shown in Figure 7(a), the axial force Fa increases, and the amount of deformation of the cam plate 7 becomes larger in the radially inner portion 7B than in the radially outer portion 7A, as shown by the arrows in Figure 5. As the amount of deformation increases towards the radially inward direction, the slippage between the cam roller 12b and the cam surface 113 of the cam plate 7 increases, resulting in wear (fretting wear) of the cam surface 113.

[0022] Furthermore, when the cam surface 113 wears down in this way, the degree of inclination of the cam surface 113 also increases as the cam surface 113 is abraded. In other words, the value of the cam lead Ld (Ld = 2πT / Fa) of the loading cam mechanism, which is a parameter that represents the magnitude of the inclination of the cam surface 113, increases. Consequently, the pressing force (axial force Fa) when the same torque T is applied will decrease compared to before wear, and therefore, there is a risk that the pressing force required by the design will not be able to be exerted. Generally, the axial force Fa increases along with the torque T as the cam roller 12b rolls up along the cam surface 113, but as shown in Figure 7(b), when fretting wear W occurs on the cam surface 113 (when the inclination of the cam surface 113 (cam lead Ld) increases), the cam roller 12b is unable to roll up along the cam surface 113 properly, and as a result, the axial force Fa does not increase even if the torque T increases.

[0023] In other words, with respect to the curve L1 in Figure 6 which shows the ideal relationship between the torque T and axial force Fa required to enable traction drive, the actual axial force Fa (=2πT / ld) when fretting wear W occurs on the cam surface 113 is as shown by the solid line L2. In the disc spring region where a gap C is created between the cam plate 7 and the outer bearing support member 116, the preload of the disc spring 8 is maintained as shown by the horizontal part L21 of line L2. In the torque cam region where the cam plate 7 and the outer bearing support member 116 come into contact and the cam roller 12b rolls up along the cam surface 133, the axial force Fa increases with increasing torque T until a predetermined torque T' is reached, as shown by the upward sloping straight inclination L22 of line L2. However, thereafter, as shown by the horizontal part L23 of line L2, the cam roller 12b does not roll up along the cam surface 113 due to wear W, so the axial force Fa does not increase even if the torque T increases.

[0024] The present invention has been made in view of the above circumstances, and aims to provide a toroidal type continuously variable transmission that can suppress wear on the cam surface of the cam plate of the pressing device and obtain the pressing force required in the design. [Means for solving the problem]

[0025] In order to achieve the above object, the present invention provides an input shaft, an input-side disk and an output-side disk that are arranged concentrically with the input shaft and are rotatable relative to each other with their inner surfaces facing each other, a power roller sandwiched between the input-side disk and the output-side disk, and an outer surface on the opposite side of the inner surface of the input-side disk or the output-side disk, which presses the input-side disk or the output-side disk in the axial direction so as to bring the input-side disk and the output-side disk closer to each other, and a cam plate that rotates together with the input shaft. A toroidal continuously variable transmission comprising a loading cam type pressing device having a rolling element that is rotatably held by a retainer between the cam plate and the outer surface of the input-side disk or the output-side disk is provided with a biasing member that applies a preload to the contact portion between the input-side disk and the output-side disk and the power roller, and a support member that supports the cam plate in the axial direction. The cam plate has a housing portion that forms a housing space for housing the biasing member, and both a portion that forms the housing portion from the radially outer side and a portion that forms the housing portion from the radially inner side are axially abutted against the support member during torque transmission between the input-side disk and the output-side disk.

[0026] According to the above configuration, the cam plate is partially hollow due to the presence of the housing portion for housing the biasing member, and thus is easily deformed in this hollow portion. However, during torque transmission between the input-side disk and the output-side disk, both the portion that forms the housing portion from the radially outer side and the portion that forms the housing portion from the radially inner side are axially abutted against the support member. Therefore, it is possible to make the deformation amount of the cam plate of the pressing device substantially uniform over the entire radial direction when the pressing force (axial force) acts (during traction drive). (It is possible to avoid the radially biased deformation such that the deformation amount becomes larger toward the radially inner side as in the conventional case described above). Therefore, the slip generated between the rolling element and the cam surface of the cam plate can be suppressed, and as a result, the wear (fretting wear) on the cam surface can be suppressed. Therefore, it becomes possible to obtain the required pressing force in terms of design.

[0027] In the above configuration, in the no-load state where power (torque) is not transmitted between the disks or during the initial operation where the transmission torque is small and the pressing force is small, there may be a gap between the cam plate and the support member. The key point is that during torque transmission between the input-side disk and the output-side disk, both the part of the cam plate that forms the accommodating portion from the radially outer side and the part of the cam plate that forms the accommodating portion from the radially inner side should be axially abutted against the support member. Also, in the above configuration, the support member may be of any type as long as it can support the cam plate axially. Therefore, in one embodiment, the support member may be, for example, the outer ring member and / or the inner ring member of an angular ball bearing that is inserted between the input shaft and the cam plate and can support the thrust load. Further, in the above configuration, the biasing member may be in any form as long as it can apply a preload to the contact portions between the input-side disk and the output-side disk and the power roller (specifically, for example, the contact portions between the concave surfaces of each disk and the circumferential surface of the power roller), and may be, for example, a disc spring or a coil spring.

Advantages of the Invention

[0028] According to the present invention, during torque transmission between the input-side disk and the output-side disk, the cam plate of the pressing device is such that both the part that forms the accommodating portion from the radially outer side and the part that forms the accommodating portion from the radially inner side are axially abutted against the support member. Therefore, wear of the cam surface of the cam plate can be suppressed, and the required pressing force in terms of design can be obtained.

Brief Description of the Drawings

[0029] [Figure 1] It is a cross-sectional view of a main part along the axial direction of a toroidal continuously variable transmission according to a first embodiment of the present invention. [Figure 2] It is a cross-sectional view of a main part along the axial direction of a toroidal continuously variable transmission according to a second embodiment of the present invention. [Figure 3] It is a cross-sectional view showing an example of a conventional toroidal continuously variable transmission. [Figure 4] This is a cross-sectional view along line AA in Figure 3. [Figure 5] This is a cross-sectional view along the axial direction showing an example of the configuration around the pressing mechanism of a conventional toroidal continuously variable transmission. [Figure 6] This is a torque-axial force diagram showing the effect of cam roller transfer surface wear on a toroidal continuously variable transmission. [Figure 7] (a) is a schematic diagram showing the pressing state between the cam plate and the support member when the torque transmitted by the traction drive is increased and the axial force becomes large, and (b) is a schematic diagram showing the state in which the cam roller rolls up along the cam surface of the cam plate. [Modes for carrying out the invention]

[0030] Embodiments of the present invention will be described below with reference to the drawings. The distinctive feature of the present invention lies in the contact configuration between the cam plate and the support member, and the other configurations and operations are the same as those of the conventional configurations and operations described above. Therefore, in the following, only the distinctive parts of the present invention will be mentioned, and the other parts will be denoted by the same reference numerals as in Figures 3 to 5, and their detailed descriptions will be omitted or simplified.

[0031] Figure 1 shows a cross-sectional view of the main part along the axial direction of a toroidal continuously variable transmission according to the first embodiment of the present invention. As described above in relation to Figures 3 and 4, the toroidal continuously variable transmission according to this embodiment comprises an input shaft 1, an input-side disk 2 and an output-side disk (not shown in Figure 1) arranged concentrically with the input shaft 1 with their inner surfaces facing each other and capable of freely rotating relative to each other, and a power roller (not shown in Figure 1) sandwiched between the input-side disk 2 and the output-side disk.

[0032] Furthermore, a loading cam-type pressing device 12 is positioned on the outer surface opposite to the inner surface of the input-side disk 2 or the output-side disk, particularly on the outer surface 2d of the input-side disk 2 in this embodiment. This pressing device 12 presses the input-side disk 2 in the axial direction to bring the input-side disk 2 and the output-side disk closer together, and consists of a cam plate (cam flange) 7 that rotates with the input shaft 1, and a plurality of cam rollers (rolling elements) 12b that are held rotatably between the cam plate 7 and the outer surface 2d of the input-side disk 2 by a retainer 12a. With this configuration, the pressing device 12 elastically presses the input-side disk 2 toward the output-side disk 4 while allowing the input-side disk 2 to rotate freely. In this embodiment, the cam plate 7 is formed from a hard metal material such as high-carbon chromium bearing steel or chromium-molybdenum steel.

[0033] Furthermore, a cam surface 113, which has circumferential irregularities, is formed on one side of the cam plate 7 (the left side in Figure 1), and a cam surface 114 with a similar shape is formed on the outer surface 12d of the input-side disk 2. In addition, an angular contact inner ring raceway 115 is formed on one side of the inner bearing support member (inner ring member) 119, which is fitted to the end of the input shaft 1 and whose back surface abuts against a nut 90 screwed onto the input shaft 1. Multiple balls 118 are interposed between this inner ring raceway 115 and an angular contact outer ring raceway 117 formed on the inner circumferential surface of the outer bearing support member (outer ring member) 116, which supports the cam plate 7 in the axial direction. In other words, the bearing support members (inner and outer ring members) 116, 119 and the balls 118 constitute an angular contact ball bearing 120 that is interposed between the input shaft 1 and the cam plate 7 and can support thrust loads. Furthermore, a shim 190 is inserted in the gap between the stepped portion on the outer circumference of the input shaft 1 that supports the cam plate 7 and the inner bearing support member 119.

[0034] Furthermore, the toroidal continuously variable transmission of this embodiment has a disc spring 8 (formed from, for example, a spring material for hot forming such as spring steel, and a spring material for cold and hot forming such as SUP, hard steel wire, piano wire, stainless steel wire) as a biasing member that applies pressing force (preload) to the contact portion between the inner surfaces of the input-side disc 2 and the output-side disc and the circumferential surface of the power roller. The cam plate 7 is formed by creating a housing portion 7a on the radially inward side near the input shaft 1 that houses this disc spring 8 (in this embodiment, it has a closed wall on the side of the input-side disc 2 and is open on the side of the outer bearing support member 116). When torque is transmitted between the input-side disc 2 and the output-side disc, both the portion of the cam plate 7 that forms the housing portion 7a from the radially outward side and the portion that forms the housing portion 7a from the radially inward side are in axial contact with the outer bearing support member 116.

[0035] Specifically, the cam plate 7 has a substantially cylindrical outer extension portion 7b and an inner extension portion 7c that extend axially substantially concentrically with respect to an annular housing portion 7a in a cross-section along the axial direction as shown in the figure. The cam plate 7 is configured such that, at least when torque is transmitted between the input-side disk 2 and the output-side disk, the end face 7ba of the outer extension portion 7b, which is located radially outward from the housing portion 7a and extends axially, and the end face 7ca of the inner extension portion 7c, which is located radially inward from the housing portion 7a and extends axially, both abut against the outer bearing support member 116 in the axial direction.

[0036] With this configuration, the amount of deformation of the cam plate 7 of the pressing device 12 when a pressing force (axial force) is applied (during traction drive) can be made almost uniform across the entire radial direction (unlike the conventional method described above, where the amount of deformation is greater towards the inside of the radial direction, this avoids radially biased deformation). Therefore, slippage between the cam roller 12b and the cam surface 113 of the cam plate 7 can be suppressed, and as a result, wear (fretting wear) on the cam surface 113 can be reduced. Thus, the pressing force required by the design can be obtained.

[0037] In this embodiment, the pressing device 12 may have a gap between the cam plate 7 and the outer bearing support member 116 when there is no load and no power (torque) is being transmitted between the discs, or during initial operation when the transmitted torque is small and the pressing force is small. In short, it is sufficient that both the outer extension 7b of the cam plate 7 that forms the housing portion 7a from the radially outer side and the inner extension 7c of the cam plate 7 that forms the housing portion 7a from the radially inner side are in axial contact with the outer bearing support member 116 when torque is being transmitted between the input disc 2 and the output disc.

[0038] Figure 2 shows a cross-sectional view of the main part along the axial direction of a toroidal continuously variable transmission according to the second embodiment of the present invention. In the first embodiment described above, both the outer extension 7b of the cam plate 7 that forms the housing portion 7a from the radially outer side and the inner extension 7c of the cam plate 7 that forms the housing portion 7a from the radially inner side were in axial contact with a common outer bearing support member 116. In this embodiment, however, when torque is transmitted between the input side disk 2 and the output side disk, the outer extension 7b of the cam plate 7 that forms the housing portion 7a from the radially outer side is in axial contact with the outer bearing support member 116, and the inner extension 7c of the cam plate 7 that forms the housing portion 7a from the radially inner side is in axial contact with the axial extension 119a of the inner bearing support member 119. In this embodiment, the axially extended portion 119a of the inner bearing support member 119, together with the inner extended portion 7c which extends axially with a shorter length than in the first embodiment, forms a housing space (housing portion 7a) for housing the disc spring 8. The other configurations are the same as in the first embodiment. Therefore, the same effects as in the first embodiment can be obtained, and the pressing force from the cam plate 7 acting both radially outward and radially inward can be distributed to the two bearing support members 116 and 119, thereby reducing the load on the angular contact ball bearing 120.

[0039] While embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. For example, in the embodiments described above, the pressing device is positioned on the outer surface opposite to the inner surface of the input disk and presses the input disk in the axial direction to bring the input disk and the output disk closer together. However, the pressing device may be positioned on the outer surface opposite to the inner surface of the output disk and presses the output disk in the axial direction to bring the input disk and the output disk closer together. Furthermore, in the embodiments described above, the present invention was explained using the case of application to a double-cavity half-toroidal continuously variable transmission as an example, but the present invention is not limited to this and can also be applied to single-cavity half-toroidal and full-toroidal toroidal continuously variable transmissions. Moreover, the applications of the toroidal continuously variable transmission of the present invention are not limited and can be applied to various fields such as automobiles and aircraft. Furthermore, within the scope without departing from the spirit of the invention, some or all of the embodiments described above may be combined, or some of the components of one of the embodiments described above may be omitted. [Explanation of Symbols]

[0040] 1 input axis 2 Input disk 2a Inside surface 3. Output disk 3a Inside surface 7 Cam plate 7a Storage area 7b Outer extension 7c Inner extension 8. Disc spring (biasing member) 11 Power Roller 12 Pressing device 12a retainer 12b Rolling element 116 Outer bearing support member 119 Inner bearing support member

Claims

1. An input shaft, and an input-side disk and an output-side disk that are arranged concentrically with the input shaft, with their inner surfaces facing each other and capable of freely rotating relative to each other. A power roller sandwiched between the input disk and the output disk, A loading cam type pressing device having a cam plate positioned on the outer surface of the input-side disk or the output-side disk opposite to the inner surface, which presses the input-side disk or the output-side disk in the axial direction to bring the input-side disk and the output-side disk closer together and which rotates with the input shaft, and a rolling element held rotatably between the cam plate and the outer surface of the input-side disk or the output-side disk by a retainer, In a toroidal continuously variable transmission equipped with, A biasing member that applies preload to the contact portion between the input-side disk and the output-side disk and the power roller, A support member that supports the cam plate in the axial direction, Equipped with, The toroidal type continuously variable transmission is characterized in that the cam plate has a housing portion that forms a housing space for housing the biasing member, and when torque is transmitted between the input side disk and the output side disk, both the portion that forms the housing portion from the radially outer side and the portion that forms the housing portion from the radially inner side are in axial contact with the support member.

2. The toroidal continuously variable transmission according to claim 1, characterized in that the support member is an outer ring member and / or inner ring member of an angular contact ball bearing interposed between the input shaft and the cam plate and capable of supporting thrust loads.

3. The toroidal type continuously variable transmission according to claim 1 or 2, characterized in that the biasing member is a disc spring or a coil spring.

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