JP2012112425A - Toroidal continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toroidal continuously variable transmission which has a gear-integrated disk having a gear section improved in durability.SOLUTION: This toroidal continuously variable transmission uses the gear-integrated disk 40 provided with a pair of output side disks and an output gear which are formed integrally with each other. A surface hardened zone 47 is provided to the outer peripheral section of the gear-integrated disk 40 with the gear section 41 by induction hardening. The depth of the surface hardened zone 47 from the outer peripheral surface of the gear integrated disk 40 extends to the deepest part 48 of the inner surface 3a of the gear-integrated disk. Therefore, stress concentration is prevented from occurring at the base end of a tooth 42. Consequently, the service life of the gear-integrated disk 40 can be extended.

Description

  The present invention relates to a toroidal continuously variable transmission that can be used for transmissions of automobiles and various industrial machines.

  For example, a double-cavity toroidal continuously variable transmission used as a transmission for an automobile is configured as shown in FIGS. As shown in FIG. 4, an input shaft (center shaft) 1 is rotatably supported inside the casing 50, and two input side disks 2, 2 and two outputs are provided on the outer periphery of the input shaft 1. Side disks 3 and 3 are attached. An output gear 4 is rotatably supported on the outer periphery of the intermediate portion of the input shaft 1. Output side disks 3 and 3 are connected to cylindrical flange portions 4a and 4a provided at the center of the output gear 4 by spline coupling.

  The input shaft 1 is rotationally driven by a drive shaft 22 via a loading cam type pressing device 12 provided between an input side disk 2 and a cam plate 7 located on the left side in the drawing. . The output gear 4 is supported in the casing 50 via a partition wall 13 formed by coupling two members, so that the output gear 4 can rotate around the axis O of the input shaft 1 while the axis O. Directional displacement is prevented.

  The output side disks 3 and 3 are supported by needle bearings 5 and 5 interposed between the input shaft 1 so as to be rotatable about the axis O of the input shaft 1. Further, the left input side disk 2 in the figure is supported on the input shaft 1 via a ball spline 6, and the right side input disk 2 in the figure is splined to the input shaft 1. Rotates with the input shaft 1. Further, the power roller 11 (see FIG. 5) is rotatable between the inner side surfaces (concave surfaces) 2a, 2a of the input side discs 2, 2 and the inner side surfaces (concave surfaces) 3a, 3a of the output side discs 3, 3. Is sandwiched between.

  A step 2b is provided on the inner peripheral surface 2c of the input disk 2 located on the right side in FIG. 4, and the step 1b provided on the outer peripheral surface 1a of the input shaft 1 is abutted against the step 2b. At the same time, the back surface (the right surface in FIG. 4) of the input side disk 2 is abutted against the loading nut 9. Thereby, the displacement of the input side disk 2 in the direction of the axis O with respect to the input shaft 1 is substantially prevented. Further, a disc spring 8 is provided between the cam plate 7 and the flange 1d of the input shaft 1, and this disc spring 8 is a concave surface 2a, 2a, 3a of each disk 2, 2, 3, 3. , 3a and the contact surface between the peripheral surfaces 11a and 11a of the power rollers 11 and 11 are applied with a pressing force.

  FIG. 5 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 5, a pair of trunnions 15, 15 that swing around a pair of pivots 14, 14 that are twisted with respect to the input shaft 1 are provided inside the casing 50. In addition, illustration of the input shaft 1 is abbreviate | omitted in FIG. Each trunnion 15, 15 is a pair of bent wall portions 20, 20 formed at both ends in the longitudinal direction (vertical direction in FIG. 5) of the support plate portion 16 so as to be bent toward the inner surface side of the support plate portion 16. have. The bent wall portions 20 and 20 form concave pocket portions P for accommodating the power rollers 11 in the trunnions 15 and 15. Further, the pivot shafts 14 and 14 are concentrically provided on the outer side surfaces of the bent wall portions 20 and 20, respectively.

  A circular hole 21 is formed in the center portion of the support plate portion 16, and a base end portion (first shaft portion) 23 a of the displacement shaft 23 is supported in the circular hole 21. Then, by swinging each trunnion 15, 15 about each pivot 14, 14, the inclination angle of the displacement shaft 23 supported at the center of each trunnion 15, 15 can be adjusted. In addition, each power roller 11 is rotatably supported around the tip end portion (second shaft portion) 23b of the displacement shaft 23 protruding from the inner surface of each trunnion 15, 15. 11 is sandwiched between the input disks 2 and 2 and the output disks 3 and 3. In addition, the base end part 23a and the front-end | tip part 23b of each displacement shaft 23 and 23 are mutually eccentric.

  The pivot shafts 14 and 14 of the trunnions 15 and 15 are supported so as to be swingable and displaceable in the axial direction (vertical direction in FIG. 5) with respect to the pair of yokes 23A and 23B, respectively. The horizontal movement of the trunnions 15 and 15 is restricted by 23B. Each yoke 23A, 23B is formed in 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 of the yokes 23 </ b> A and 23 </ b> B, and the pivot shafts 14 provided at both ends of the trunnion 15 swing through the radial needle bearings 30. It is supported freely. In addition, a circular locking hole 19 is provided in the central portion of the yokes 23A and 23B in the width direction (left-right direction in FIG. 4). 64 and 68 are fitted inside. That is, the upper yoke 23A is swingably supported by the spherical post 64 supported by the casing 50 via the fixing member 52, and the lower yoke 23B is supported by the spherical post 68 and the drive for supporting the same. The upper cylinder body 61 of the cylinder 31 is swingably supported.

  The displacement shafts 23 and 23 provided in the trunnions 15 and 15 are provided at positions 180 degrees opposite to the input shaft 1. Further, the direction in which the distal end portion 23b of each of the displacement shafts 23, 23 is eccentric with respect to the base end portion 23a is the same direction as the rotational direction of both the disks 2, 2, 3, 3 (in FIG. (Reverse direction). Further, the eccentric direction is a direction substantially orthogonal to the direction in which the input shaft 1 is disposed. Accordingly, the power rollers 11 and 11 are supported so that they 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 elastic deformation or the like of each component based on the thrust load generated by the pressing device 12, each component This displacement is absorbed without applying an excessive force to the member.

  Further, between the outer surface of the power roller 11 and the inner surface of the support plate portion 16 of the trunnion 15, a thrust ball bearing (thrust bearing) 24 that is a thrust rolling bearing is sequentially formed from the outer surface side of the power roller 11. A thrust needle bearing 25 is provided. Among these, the thrust ball bearing 24 supports the rotation of each power roller 11 while supporting the load in the thrust direction applied to each power roller 11. Each of such thrust ball bearings 24 includes a plurality of balls (hereinafter referred to as rolling elements) 26, 26, an annular retainer 27 that holds the rolling elements 26, 26 in a freely rolling manner, And an annular outer ring 28. Further, the inner ring raceway of each thrust ball bearing 24 is formed on the outer side surface (large end surface) of each power roller 11, and the outer ring raceway is formed on the inner side surface of each outer ring 28.

  The thrust needle bearing 25 is sandwiched between the inner surface 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 to each outer ring 28 from the power roller 11, while the power roller 11 and the outer ring 28 swing around the base end portion 23 a of each displacement shaft 23. Allow.

  Further, drive rods (trunnion shafts) 29 and 29 are provided at one end portions (lower end portions in FIG. 5) of the trunnions 15 and 15, respectively, and a drive piston ( Hydraulic pistons) 33, 33 are fixed. Each of these drive pistons 33 and 33 is oil-tightly fitted in a drive cylinder 31 constituted by an upper cylinder body 61 and a lower cylinder body 62. The drive pistons 33 and 33 and the drive cylinder 31 constitute a drive device 32 that displaces the trunnions 15 and 15 in the axial direction of the pivots 14 and 14 of the trunnions 15 and 15.

  In the case of the toroidal continuously variable transmission configured as described above, the rotation of the input shaft 1 is transmitted to the input side disks 2 and 2 via the pressing device 12. Then, the rotation of the input side disks 2 and 2 is transmitted to the output side disks 3 and 3 via the pair of power rollers 11 and 11, and the rotation of the output side disks 3 and 3 is further transmitted to the output gear 4. It is taken out more.

  When changing the rotational speed ratio between the input shaft 1 and the output gear 4, the pair of drive pistons 33, 33 are displaced in opposite directions. As the drive pistons 33 and 33 are displaced, the pair of trunnions 15 and 15 are displaced in directions opposite to each other. For example, the power roller 11 on the left side in FIG. 5 is displaced to the lower side in the figure, and the power roller 11 on the right side in the figure is displaced to the upper side in the figure. As a result, the peripheral surfaces 11a and 11a of the power rollers 11 and 11 act on contact portions of the input side disks 2 and 2 and the inner side surfaces 2a, 2a, 3a and 3a of the output side disks 3 and 3, respectively. The direction of the tangential force changes. As the force changes, the trunnions 15 and 15 swing (tilt) in opposite directions around the pivots 14 and 14 pivotally supported by the yokes 23A and 23B.

  As a result, the contact position between the peripheral surfaces 11a and 11a of the power rollers 11 and 11 and the inner surfaces 2a and 3a changes, and the gear ratio between the input shaft 1 and the output gear 4 changes. Further, 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, the power rollers 11 and 11 and the outer rings attached to the power rollers 11 and 11 will be described. 28 and 28 slightly rotate around the base end portions 23a and 23a of the displacement shafts 23 and 23, respectively. Since the thrust needle bearings 25 and 25 exist between the outer side surfaces of the outer rings 28 and 28 and the inner side surfaces of the support plate portions 16 constituting the trunnions 15 and 15, respectively, the rotation is performed smoothly. Is called. Therefore, as described above, the force for changing the inclination angle of each displacement shaft 23, 23 can be small.

  By the way, the output gear 4 is disposed between the pair of output side disks 3 and 3, and the pair of output side disks 3 and 3 and the output gear 4 are rotated together. For such a configuration, a pair of output side disks 3 and 3 are integrally provided in a shape in which the back surfaces are joined together, and gear teeth are provided on the outer peripheral portion of the pair of output side disks 3 and 3 integrated. Therefore, there is known a gear-integrated disc in which a pair of output-side discs 3 and 3 and an output gear 4 are integrally formed. The configuration of the input side disks 2 and 2 and the output side disks 3 and 3 can be reversed, and the input side disks 2 and 2 can be gear-integrated disks.

6A, a gear-integrated disc 40 in which a pair of output-side discs 3 and 3 and an output gear 4 are integrated is provided with a traction surface on each of the front and rear side portions. A through-hole 3b through which the input shaft 1 passes is formed at the center. In addition, a gear portion 41 that becomes the output gear 4 is formed on the outer peripheral portion of the gear-integrated disc 40. The gear portion 41 has a plurality of gear teeth 42 formed as the output gear 4, and teeth 42 Between each other is a tooth gap 43, and the bottom of the tooth gap 43 is a tooth bottom 44.

In this way, in the gear-integrated disc 40, surface hardening treatment is performed on the inner side surfaces 3a and 3a where the peripheral surface 11a of the para roller 11 is in rolling contact with the traction oil, and this surface hardening treatment includes induction hardening. . At this time, it has been proposed that the above-described gear portion 41 is also subjected to induction hardening (for example, see Patent Document 1).
In addition, in the induction hardening of the gear part 41, the hardness is prevented from becoming excessively high, and the toughness of the gear part 41 is ensured.
Further, the hardened surface layer 46 (hatched portion) by induction hardening at this time is located inside the proximal end portion of the teeth 42 of the gear portion 41 in the gear portion 41 as shown in FIGS. 6 (a) and 6 (b). Not reached. In the portion excluding the surface layer portion of the tooth 42, the surface hardened layer 46 is not reaching the tooth bottom 44. Note that the surface hardened layer 46 is formed deeper than the tooth bottom 44 because the surface layer portion of the tooth bottom 44 of the tooth gap 43 is exposed, but the base end of the tooth 42 as described above. The inside of the portion (depth portion corresponding to the tooth bottom 44) is in a state where no hardened layer is formed by induction hardening.

JP 2005-180498 A

  However, in the gear-integrated disc 40 of Patent Document 1, the surface hardened layer 46 is not formed inside the base end portion of the tooth 42 of the gear portion 41, and the surface hardened layer 46 is formed inside the tooth 42. The depth of the root 44 is not reached. In such induction hardening, stress concentration occurs at the depth position of the tooth bottom 44 of the tooth 42 during operation of the toroidal type continuously variable transmission, and there is a risk that the tooth bottom 44 may crack after many years of use. There is a possibility that the durability of the gear portion 41 may be lowered.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a toroidal continuously variable transmission capable of improving the durability of the gear portion of the gear-integrated disk.

  In order to achieve the above object, the toroidal continuously variable transmission according to claim 1 is characterized in that an input side disk and an output that are supported concentrically and rotatably with their respective inner surfaces facing each other. Side disk, and a power roller sandwiched between the input side disk and the output side disk, and at least one of the output side disk and the input side disk has gear teeth on the outer peripheral portion. In the toroidal-type continuously variable transmission that is provided as a gear-integrated disk integrated with the gear, and that is hardened on an outer peripheral portion that includes a traction surface that contacts the power roller and teeth of the gear. The outer peripheral portion of the integrated disc is hardened deeper than the depth along the radial direction of the gear integrated disc at the bottom of the gear. The features.

  According to the first aspect of the present invention, the outer peripheral portion of the gear-integrated disc that provides the gear teeth is hardened deeper than the depth of the gear tooth bottom. That is, in the outer peripheral portion of the gear-integrated disk including the inside of the gear teeth, the quenching radial depth is deeper than the tooth bottom. Thereby, the gear teeth are hardened substantially uniformly including the base end portion thereof, and it is possible to suppress the concentration of stress at the base end portion of the gear teeth. Therefore, the durability of the gear-integrated disk can be improved and the life can be extended.

  The toroidal continuously variable transmission according to claim 2 is the invention according to claim 1, wherein the outer peripheral portion of the gear-integrated disk is along the axial direction of the concave traction surface of the gear-integrated disk. In other words, quenching is performed to a depth along the radial direction substantially corresponding to the position of the deepest portion where the depth is deepest.

  In the invention according to claim 2, the boundary portion between the hardened surface layer by quenching of the gear and the uncured layer becomes deeper than the radial depth of the tooth bottom that becomes the base end portion of the tooth, It becomes possible to further suppress the stress concentration at the depth position of the bottom. As a result, the durability of the gear-integrated disk can be enhanced.

  The toroidal continuously variable transmission according to claim 3 is characterized in that in the invention according to claim 1 or claim 2, induction hardening is performed as the quenching.

  In the invention according to claim 3, when quenching is performed on the inner side surface (both side surfaces) of the gear-integrated disk and the tooth portion of the gear mainly by induction hardening, the following effects are obtained. Can be played. For example, separate the coils for induction hardening on the inner surface of the gear-integrated disk and the gear portion, and adjust the time for induction hardening and the frequency of the induction with each coil, making it easy to integrate the gear. Only the outer periphery of the disk can be adjusted so that the quenching depth is deeper.

  According to the toroidal-type continuously variable transmission of the present invention, in the gear-integrated disc, the depth of quenching of the gear portion is made deeper than the depth from the tooth tip to the tooth bottom, whereby the durability of the gear-integrated disc is improved. Thus, the life of the gear-integrated disk can be extended.

BRIEF DESCRIPTION OF THE DRAWINGS It is principal part sectional drawing which shows the gear integrated disk of the toroidal type continuously variable transmission of 1st Embodiment of this invention, (a) is principal part sectional drawing along the axial direction of the gear integrated disk, (B) is principal part sectional drawing along the direction orthogonal to the axial direction of a gear-integrated disc. It is principal part sectional drawing which shows the gear integrated disk and the induction hardening coil for demonstrating the induction hardening method of the said gear integrated disk. It is principal part sectional drawing which shows the gear integrated disc and the induction hardening coil for demonstrating another induction hardening method of the said gear integrated disc. It is sectional drawing which shows an example of the specific structure of the half toroidal type continuously variable transmission conventionally known. It is sectional drawing which follows the AA line of FIG. FIG. 6 is a cross-sectional view of a main part showing a gear-integrated disk of a conventional toroidal-type continuously variable transmission, where (a) is a cross-sectional view of the main part along the axial direction of the gear-integrated disk, It is principal part sectional drawing along the direction orthogonal to the axial direction of a body-shaped disk.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The feature of the present invention lies in the structure of a hardened surface layer formed by quenching a gear-integrated disc in which a pair of output-side discs are integrated and an output gear is integrally provided on the outer peripheral portion. Since the operation and operation are the same as those of the above-described conventional configuration and operation, only the characteristic portions of the present invention will be described below, and the other portions will be briefly described with the same reference numerals as those in FIG. Keep on.

  As shown in FIG. 1, in the toroidal type continuously variable transmission of this example, a gear-integrated disc 40 in which an output gear and an output-side disc are integrated is used. The gear-integrated disc 40 has the same shape as the conventional gear-integrated disc 40, and a pair of output-side discs are provided in a shape in which the back surfaces are joined to each other, and the teeth 42 of the output gear are provided on the outer peripheral portion. A gear portion 41 is provided.

  In the gear-integrated disc 40 of this embodiment, the depth of the hardened surface layer 47 is determined by induction hardening from the outer peripheral surface side provided in a wave shape from the teeth 42 and the tooth grooves 43 of the outer peripheral gear portion 41. It is deeper than the depth from the tip of 42 to the tooth bottom 44 which becomes the bottom of the tooth gap 43. In addition, the depth of the surface hardened layer 46 by induction hardening in the inner side surfaces 3a and 3a before and after the portion excluding the outer peripheral portion of the gear-integrated disk 40 can be the same as that in the prior art, for example.

In this embodiment, all the teeth 42 of the gear portion 41 are hardened by induction hardening to the inside thereof, and a hardened surface layer 47 is formed deeper than the depth of the tooth bottom 44 from the tip of the teeth 42. .
Here, the inner side surfaces 3a and 3a are formed in an arc shape in cross section, and the axial direction of the gear-integrated disc 40 is between the small diameter side end and the large diameter side end of the cross section of the inner side surfaces 3a and 3a. A deepest portion (groove bottom) 48 that is deepest along the line is provided. The deepest portion 48 is a portion closer to the end on the small diameter side than the end on the large diameter side.

In the cross-section along the axial direction of the gear-integrated disc 40 in FIG.
In this embodiment, a hardened surface layer 47 is formed by induction hardening from the outer peripheral surface of the gear-integrated disc 40 to a depth along the radial direction from the deepest portion 48. Further, the surface hardened layer 47 of the gear-integrated disc 40 is subjected to induction hardening on the outer peripheral side from the line segment connecting the deepest portions 48 of the front and rear inner side surfaces 3a and 3a to the surface hardened layer 47. It has become. In practice, the boundary portion on the inner peripheral side of the surface hardened layer 47 is not clearly and straight as shown in FIG. Further, the boundary portion on the inner peripheral side of the surface hardened layer 47 may be slightly on the outer peripheral side from the deepest portions 48 and 48. Conversely, the boundary portion on the inner peripheral side of the surface hardened layer 47 may be slightly on the outer peripheral side than the deepest portions 48 and 48.

  An induction hardening method for the gear-integrated disk 40 of such a toroidal type continuously variable transmission will be described. As shown in FIG. 2, a first coil 71 that performs induction hardening of the outer peripheral portion including the gear portion 41 of the gear-integrated disk 4, and an inner peripheral side from the first coil 71, that is, from the deepest portion 48 described above. Two second coils 72 arranged corresponding to the two inner side surfaces 3a and 3a on the inner peripheral side are used.

The first coil 71 is provided in a substantially U-shape (substantially C-shaped) so as to cover a portion on the outer peripheral side from the deepest portion 48 of the front and rear inner side surfaces 3a, 3a from the outer peripheral surface of the gear-integrated disc 40. Yes. The first coil 71 is arranged so that the distance from the gear-integrated disk 40 is substantially constant at any position. The gear portion 41 is arranged so that the distance from the tip of the tooth 42 is constant, and the tip of the tooth 42 and the root 44 have different distances to the first coil 71. It has become.
Further, the portion along the inner side surface 3a of the first coil 71 and the entire second coil 72 are arranged along the radial direction of the gear-integrated disc 40 when viewed in plan.

  The first coil 71 and the second coil 72 can be independently connected to and disconnected from the power source. The energization time of the high-frequency current to the first coil 71 and the second coil 72 It is possible to change the energizing time of the high frequency power source. The high frequency current supplied to the first coil 71 and the high frequency current supplied to the second coil 72 may be different in frequency.

  In induction hardening, on the half side of the gear-integrated disc 40, from the outer peripheral edge of the opening of the through hole 3b of the gear-integrated disc 40 to the outer peripheral surface, along the radial direction of the gear-integrated disc 40. The first coil 71 and the second coils 72 and 72 described above are arranged.

  At this time, the gear-integrated disk 40 is supported so as to be rotatable around its axis. At the time of induction hardening, for example, the gear-integrated disk 40 is rotated around the axis, and first, a high-frequency current is passed through the first coil 71, and then the second coil 72 is also passed after a preset time has elapsed. Apply high-frequency current. By rotating the gear-integrated disk 40, the first coil 71 and the second coil 72 along the radial direction on the half side of the gear-integrated disk 40 are substantially the whole except for the central portion of the gear-integrated disk 40. It is possible to subject the surface layer portion to induction hardening, and the arrangement of the induction hardening coil can be simplified. Thereby, the cost of the apparatus which performs induction hardening can be reduced.

  Also, the portion corresponding to the first coil 71 is induction-hardened longer than the portion corresponding to the second coil 72, so that the outer peripheral portion of the gear-integrated disc 40 is subjected to induction hardening over substantially the entire portion. And That is, as shown in FIGS. 1 and 2, a deep hardened surface layer 47 that extends from the outer peripheral surface to the deepest portion 48 is formed. The inner side surfaces 3a and 3a of the portion to be induction-hardened by the second coil 72 form a hardened surface layer 46 having the same thickness as the conventional one. That is, the surface hardened layer 46 is made thinner than the surface hardened layer 47.

  Further, the induction hardening of the gear-integrated disk 40 can be performed, for example, by arranging the induction hardening coils shown in FIG. In FIG. 3, the cross section of the three coils 73 and 74 arrange | positioned helically is shown. The spiral fourth coil 74 shown by the coil cross sections a, b, and c is for subjecting the inner peripheral side to the innermost side portion of the innermost surface 3a to induction hardening. The spiral third coil 72 indicated by the coil cross sections d, e, f, g, h, i is for subjecting the outer peripheral portion of the gear-integrated disk 40 to induction hardening.

Further, the spiral fourth coil 74 shown by the coil cross sections j, k, and l is for subjecting the inner peripheral side of the deepest portion 48 of the other inner surface 3a to induction hardening.
The third coil 73 and the fourth coil 74 are arranged at a predetermined distance from the surface of the gear-integrated disk 40, and the gear-integrated disks having coil cross sections a to c, d to i, and j to l. The intervals along the radial direction of 40 are substantially the same.
In FIG. 3, the coil cross sections a to l are shown only at the half side portion of the cross section of the gear-integrated disk 40, but the coils 73 and 74 are centered on the center of the gear-integrated disk 40. They are arranged in a substantially circular shape (spiral shape).

  The coil arrangement for induction hardening shown in FIG. 3 is more complicated than the case shown in FIG. 2, and the gear-integrated disk is placed inside the coils 73 and 74 unless the coils 73 and 74 are moved. Cannot be placed. However, there is no need to rotate the gear-integrated disc 40 during induction hardening, and the support mechanism for the gear-integrated disc 40 can be simplified.

  Also in this induction hardening coil arrangement, the outer periphery of the gear-integrated disk 40 by the third coil 73 is made longer than the time of quenching the inner side surfaces 3a, 3a by the fourth coil 74, so that the outer periphery is increased. The surface hardened layer 47 by induction hardening on the part side can be made thick, and the surface hardened layer 46 by induction hardening on the inner side surface 3 a can be made thinner than the above-mentioned surface hardened layer 47. In the induction hardening shown in FIGS. 2 and 3, the outer peripheral portion of the gear-integrated disc 40 is not subjected to induction hardening only from the outer peripheral surface side, but the deepest portion 48 of the two inner side surfaces 3a and 3a. Induction hardening is also applied from the outer peripheral portion. Thereby, shortening of the time at the time of performing induction hardening to the inner side of an outer peripheral part can be aimed at.

  In the gear-integrated disc 40 of the toroidal-type continuously variable transmission, the outer peripheral portion of the gear-integrated disc 40 in which the gear portion 41 is formed is deeper than the tooth bottom 44 of the gear portion 41, and the inside of the teeth 42 is also formed. The hardened surface 47 is formed by induction hardening. Furthermore, the depth of the surface hardened layer 47 reaches the position of the substantially deepest portion 48 of the inner side surface 3a.

  Thereby, stress concentration can be prevented from occurring due to the presence of a hardened portion and a non-hardened portion at the base end portion of the tooth 42 in the gear portion 41. Therefore, the durability of the gear-integrated disk 40 can be improved. That is, the life of the gear-integrated disk 40 can be extended.

  The input side disks 2 and 2 may be gear-integrated disks and may be induction hardened as described above.

  The present invention can be applied to various half-toroidal continuously variable transmissions such as a single cavity type and a double cavity type.

2 input side disk 3 output side disk 4 output gear 11 power roller 40 gear integrated disk 41 gear part 42 tooth 43 tooth groove 44 tooth bottom 46 surface hardened layer 47 surface hardened layer

Claims (3)

An input side disk and an output side disk that are supported concentrically and rotatably with their inner side surfaces facing each other, and a power roller sandwiched between the input side disk and the output side disk And
At least one of the output-side disk and the input-side disk is a gear-integrated disk integrated with the gear by providing gear teeth on an outer peripheral portion, and a traction surface that contacts the power roller, In the toroidal type continuously variable transmission in which the outer peripheral portion having gear teeth is quenched,
A toroidal continuously variable transmission, wherein the outer peripheral portion of the gear-integrated disc is hardened deeper than the depth of the gear tooth bottom along the radial direction of the gear-integrated disc.   The outer peripheral portion of the gear-integrated disc is quenched to a depth along the radial direction substantially corresponding to the position of the deepest portion deepest along the axial direction of the concave traction surface of the gear-integrated disc. The toroidal continuously variable transmission according to claim 1, wherein the toroidal continuously variable transmission is provided.   The toroidal continuously variable transmission according to claim 1 or 2, wherein induction hardening is performed as the hardening.

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