JP3849332B2 - Manufacturing method of disk for toroidal type continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
A method for manufacturing a toroidal type continuously variable transmission disk according to the present invention includes, for example , an input side disk constituting a toroidal type continuously variable transmission used as a transmission for an automobile or a transmission for various industrial machines. Or to make an output side disk .
[0002]
[Prior art]
The use of a toroidal continuously variable transmission as schematically shown in FIGS. This toroidal continuously variable transmission, for example, as disclosed in Japanese Utility Model Laid-Open No. 62-71465, supports an input side disk 2 concentrically with an input shaft 1, and outputs arranged concentrically with the input shaft 1. An output side disk 4 is fixed to the end of the shaft 3. On the inner side of the casing in which the toroidal continuously variable transmission is housed, trunnions 6 and 6 that swing around pivots 5 and 5 that are twisted with respect to the input shaft 1 and the output shaft 3 are provided.
[0003]
That is, the trunnions 6 and 6 disposed in the portions deviating from the central axes of the two disks 2 and 4 have the pivots 5 and 5 on the outer surfaces of both ends, and the direction of the central axes of the two disks 2 and 4. Are provided at right angles to each other and concentrically with each other. In addition, the base portions of the displacement shafts 7 and 7 are supported at intermediate portions of the trunnions 6 and 6, and the trunnions 6 and 6 are swung around the pivot shafts 5 and 5, so that the respective displacements are displaced. The inclination angle of the shafts 7 and 7 can be freely adjusted. Power rollers 8 and 8 are rotatably supported around the displacement shafts 7 and 7 supported by the trunnions 6 and 6, respectively. Each of these power rollers 8 and 8 is sandwiched between inner surfaces 2a and 4a of the input side and output side disks 2 and 4 facing each other. Each of these inner side surfaces 2a, 4a has a concave surface obtained by rotating a circular arc with the pivot axis 5 as the center. And the peripheral surfaces 8a and 8a of each said power roller 8 and 8 formed in the spherical convex surface are made to contact | abut to the said inner surface 2a and 4a.
[0004]
A loading cam device 9 is provided between the input shaft 1 and the input side disc 2, and the input cam 2 is elastically pressed against the output side disc 4 by the loading cam device 9, The side disk 2 is rotatable. The loading cam device 9 includes a loading cam 10 that rotates together with the input shaft 1, and a plurality of (for example, four) rollers 12 and 12 that are rotatably held by a cage 11. On one side surface of the loading cam 10 (the right side surface in FIGS. 1 and 2), a cam surface 13 that is uneven in the circumferential direction is formed, and the outer surface of the input side disk 2 (the left side surface in FIGS. 1 and 2). ) Also has a cam surface 14 having a similar shape. The plurality of rollers 12 and 12 are supported so as to be rotatable about the radial axis with respect to the center of the input shaft 1.
[0005]
When the toroidal type continuously variable transmission configured as described above is used, when the loading cam 10 rotates as the input shaft 1 rotates, the cam surface 13 causes the plurality of rollers 12 and 12 to move outside the input side disk 2. The cam surface 14 formed on the side surface is pressed. As a result, the input-side disk 2 is pressed against the plurality of power rollers 8 and 8 and at the same time, based on the pressing force between the cam surfaces 13 and 14 and the plurality of rollers 12 and 12, the input disk 2 is pressed. The side disk 2 rotates. The rotation of the input side disk 2 is transmitted to the output side disk 4 via the plurality of power rollers 8, 8, and the output shaft 3 fixed to the output side disk 4 rotates.
[0006]
When changing the rotational speed ratio (transmission ratio) between the input shaft 1 and the output shaft 3, and when first decelerating between the input shaft 1 and the output shaft 3, the pivots 5 and 5 are used as the centers. Each trunnion 6, 6 is swung in a predetermined direction. The peripheral surfaces 8a and 8a of the power rollers 8 and 8 are formed in a portion near the center of the inner side surface 2a of the input side disc 2 and a portion near the outer periphery of the inner side surface 4a of the output side disc 4 as shown in FIG. The displacement shafts 7 and 7 are inclined so as to contact each other. On the other hand, when increasing the speed, the trunnions 6 and 6 are swung in the opposite directions around the pivots 5 and 5. As shown in FIG. 2, the peripheral surfaces 8a and 8a of the power rollers 8 and 8 are formed on the outer peripheral portion of the inner side surface 2a of the input side disc 2 and the central portion of the inner side surface 4a of the output side disc 4, respectively. The displacement shafts 7 and 7 are inclined so as to contact each other. If the inclination angle of each of the displacement shafts 7 and 7 is set intermediate between those shown in FIGS. 1 and 2, an intermediate transmission ratio can be obtained between the input shaft 1 and the output shaft 3.
[0007]
3 to 4 show an example of a more specific toroidal type continuously variable transmission described in the microfilm of Japanese Utility Model Application No. 63-69293 (Japanese Utility Model Laid-Open No. 1-173552). The input side disk 2 and the output side disk 4 are rotatably supported around needle-shaped input shafts 15 via needle bearings 16 and 16, respectively. That is, through-holes 17 and 17 having a circular cross-sectional shape are formed in the center of the input side disk 2 and the output side disk 4, and the inner side surface and the outer side surface of each of the disks 2 and 4 are axially directed (FIG. 3). In the left-right direction). The needle bearings 16 and 16 are provided between the inner peripheral surface of the through holes 17 and 17 and the outer peripheral surface of the intermediate portion of the input shaft 15. Further, retaining rings 19 and 19 are latched in locking grooves 18 and 18 formed on the inner peripheral surface of the through holes 17 and 17 on the inner surface side, and the needle bearings 16 and 16 are inserted into the through holes. The holes 17 and 17 prevent the discs 2 and 4 from coming out to the inner side surfaces 2a and 4a. The loading cam 10 is spline-engaged with the outer peripheral surface of the end portion (left end portion in FIG. 3) of the input shaft 15, and the outward flange-like flange portion 20 prevents movement away from the input side disk 2. ing. The loading cam 10 and the rollers 12 and 12 constitute a loading cam device 9 that rotates the input side disk 2 while pressing the input side disk 2 against the output side disk 4 based on the rotation of the input shaft 15. Yes. An output gear 21 is coupled to the output side disk 4 by keys 22 and 22 so that the output side disk 4 and the output gear 21 rotate in synchronization.
[0008]
Both ends of the pair of trunnions 6 and 6 are supported on the pair of support plates 23 and 23 so as to be freely swingable and displaceable in the axial direction (front and back direction in FIG. 3, left and right direction in FIG. 4). The displacement shafts 7 and 7 are supported in the circular holes 24 and 24 formed in the intermediate portions of the trunnions 6 and 6. Each of these displacement shafts 7 and 7 has support shaft portions 25 and 25 and pivot shaft portions 26 and 26 that are parallel to each other and eccentric, respectively. Of these, the support shaft portions 25 and 25 are rotatably supported inside the circular holes 24 and 24 via radial needle bearings 27 and 27. Further, the power rollers 8 and 8 are rotatably supported around the pivot shaft portions 26 and 26 via other radial needle bearings 28 and 28 corresponding to the bearings recited in the claims. .
[0009]
The pair of displacement shafts 7 and 7 are provided at positions opposite to the input shaft 15 by 180 degrees. The direction in which the pivot shafts 26 and 26 of the displacement shafts 7 and 7 are eccentric with respect to the support shafts 25 and 25 is the same with respect to the rotation direction of the input side and output side disks 2 and 4. The direction (the left-right reverse direction in FIG. 4) is used. The eccentric direction is a direction substantially perpendicular to the direction in which the input shaft 15 is disposed. Accordingly, the power rollers 8 and 8 are supported so as to be slightly displaceable in the direction in which the input shaft 15 is disposed. As a result, due to the elastic deformation of the constituent members based on the large load applied to the constituent members in the state of transmission of the rotational force, the power rollers 8 and 8 are moved in the axial direction of the input shaft 15 (see FIG. 3). Even when it tends to be displaced in the left-right direction (the front-back direction in FIG. 4), this displacement can be absorbed without applying an excessive force to each component.
[0010]
In addition, between the outer surface of each of the power rollers 8 and 8 and the inner surface of the intermediate portion of each of the trunnions 6 and 6, the thrust ball bearings 29 and 29 and the thrust are sequentially arranged from the outer surface side of the power rollers 8 and 8. Needle bearings 30 and 30 are provided. Of these, the thrust ball bearings 29 and 29 support the rotation of the power rollers 8 and 8 while supporting the load in the thrust direction applied to the power rollers 8 and 8. The thrust needle bearings 30 and 30 support the pivot shafts while supporting thrust loads applied to the outer rings 31 and 31 constituting the thrust ball bearings 29 and 29 from the power rollers 8 and 8. 26 and 26 and the outer rings 31 and 31 are allowed to swing around the support shaft portions 25 and 25.
[0011]
Further, drive rods 32 and 32 are coupled to one end portions (left end portions in FIG. 4) of the trunnions 6 and 6, respectively, and drive pistons 33 and 33 are fixed to the outer peripheral surfaces of the intermediate portions of the drive rods 32 and 32, respectively. Has been established. These drive pistons 33 and 33 are oil-tightly fitted in the drive cylinders 34 and 34, respectively.
[0012]
In the case of the toroidal type continuously variable transmission configured as described above, the rotation of the input shaft 15 is transmitted to the input side disk 2 via the loading cam device 9. Then, the rotation of the input side disk 2 is transmitted to the output side disk 4 through a pair of power rollers 8 and 8, and the rotation of the output side disk 4 is further taken out from the output gear 21. When changing the rotational speed ratio between the input shaft 15 and the output gear 21, 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 6 and 6 are displaced in the opposite directions. For example, the lower power roller 8 in FIG. The power rollers 8 are displaced to the left in the figure. As a result, the direction of the tangential force acting on the contact portion between the peripheral surfaces 8a, 8a of the power rollers 8, 8 and the inner side surfaces 2a, 4a of the input side disk 2 and the output side disk 4 changes. To do. The trunnions 6 and 6 swing in opposite directions around the pivots 5 and 5 pivotally supported by the support plates 23 and 23 as the force changes. As a result, as shown in FIGS. 1 and 2, the contact position between the peripheral surfaces 8a and 8a of the power rollers 8 and 8 and the inner surfaces 2a and 4a is changed. The rotational speed ratio with the output gear 21 changes.
[0013]
When the rotational force is transmitted between the input shaft 15 and the output gear 21 in this way, the power rollers 8 and 8 are connected to the input shaft 15 based on the elastic deformation of the constituent members. The displacement shafts 7 and 7 that are displaced in the axial direction and pivotally support the power rollers 8 and 8 are slightly rotated around the support shaft portions 25 and 25. As a result of this rotation, the outer side surfaces of the outer rings 31, 31 of the thrust ball bearings 29, 29 and the inner side surfaces of the trunnions 6, 6 are relatively displaced. Since the thrust needle bearings 30, 30 exist between the outer surface and the inner surface, the force required for the relative displacement is small. Therefore, as described above, the force for changing the inclination angle of each displacement shaft 7, 7 can be small.
[0014]
FIGS. 5 to 6 show the output-side disk 4 taken out of the toroidal type continuously variable transmission shown in FIGS. The through-hole 17 formed in the center of the output side disk 4 has a cylindrical surface portion 35, a spline portion 36, an outer ring raceway portion 37, and a second portion in order from the outer surface side (the right side in FIGS. 5 to 6). A cylindrical surface portion 38 is provided. Of these, the cylindrical surface portion 35 corresponds to the fitting portion described in the claims, and a part of the sleeve 39 (FIG. 3) fixed to the inner peripheral edge portion of the output gear 21 that rotates together with the output side disk 4. The sleeve 39 and the output side disk 4 are concentric with each other without looseness. When the keys 22 are provided, the keys 22 are provided between the cylindrical surface portion 35 and the sleeve 39. However, when the sleeve 39 and the output side disk 4 are spline-engaged, the keys 22 and 22 are unnecessary. On the other hand, when the keys 22 are provided, a key groove is provided instead of the spline portion. When the spline portion 36 is provided, the spline portion 36 engages with a male spline portion provided on a part of the outer peripheral surface of the sleeve 39 to prevent relative rotation between the sleeve 39 and the output side disk 4. To do. The structure for preventing the relative rotation between the sleeve 39 and the output side disk 4 is not limited to the spline engagement or the key engagement, but may be another engagement structure such as an uneven engagement extending in the axial direction. You can also. The locking groove 18 for locking the retaining ring 19 (FIG. 3) is provided between the outer ring raceway portion 37 and the second cylindrical surface portion 38. A residual compressive stress layer is preferably formed by shot peening on the output side disk 4 having such a shape (and the inner peripheral surface of the input side disk 2 if necessary). This reason will be described with reference to FIGS.
[0015]
During operation of the toroidal continuously variable transmission, the peripheral surfaces 8a and 8a of the power rollers 8 and 8 and the inner surfaces 2a and 4a of the input side and output side discs 2 and 4 are strongly abutted by the action of the loading cam device 9. . A strong force is applied to the contact portions of the surfaces 8a, 2a, and 4a in the direction indicated by the arrow in FIG. 7 during deceleration and in the direction indicated by the arrow in FIG. 8 during acceleration. Based on this strong force, both the input side and output side disks 2 and 4 are elastically deformed. For example, at the time of deceleration shown in FIG. 7, the portions near the outer diameter at the two positions opposite to the diameter direction of the inner side surface 4 a of the output side disk 4 are strongly pressed in the thrust direction. As a result, the output side disk 4 is elastically deformed from the state shown by the solid line in FIG. 9 to the state shown by the exaggerated line by the chain line. When the output side disk 4 is elastically deformed in this way, a tensile stress is applied to the second cylindrical surface part 38, particularly near the inner side surface 4a, of the through hole 17 provided in the central part of the output side disk 4.
[0016]
Since such tensile stress is repeatedly applied as the output side disk 4 rotates, the output side disk 4 is likely to be cracked in the second cylindrical surface portion 38 unless any countermeasure is taken. It becomes difficult to ensure durability. Therefore, if a residual compressive stress layer is formed by shot peening on the second cylindrical surface portion 38, which is closer to the inner surface 4a, of the inner peripheral surface of the output side disk 4, the tensile stress repeatedly applied. Regardless of this, cracks can be less likely to occur in the second cylindrical surface portion 38.
[0017]
[Problems to be solved by the invention]
As described above, when a residual compressive stress layer for preventing cracks is formed on the second cylindrical surface portion 38, shot peening is also applied to the outer ring raceway portion 37 adjacent to the second cylindrical surface portion 38. The surface roughness of the outer ring raceway portion 37 is deteriorated. As a result, the durability of the needle bearing 16 (FIG. 3) that includes the outer ring raceway portion 37 is impaired. When performing shot peening on the second cylindrical surface portion 38, if the outer ring raceway portion 37 is masked, it is possible to prevent the surface roughness of the outer ring raceway portion 37 from being deteriorated. It is actually very difficult to perform effective masking on the outer ring raceway portion 37 provided.
The manufacturing method of the toroidal type continuously variable transmission disk of the present invention was invented in view of such circumstances.
[0018]
[Means for solving the problems]
A toroidal type continuously variable transmission incorporating a disk that is the object of the manufacturing method of the present invention is, like the above-described conventional toroidal type continuously variable transmission, concentric with each other and rotatably supported independently of each other. A pair of concentric with each other at the twisted position that does not intersect the center axis of both the input side and output side disks but is perpendicular to the direction of the center axis of these both disks. A plurality of trunnions oscillating around a pivot axis, displacement shafts supported for each of the trunnions, and supported by the respective displacement shafts by bearings so that the inner surfaces of both the input side and output side disks are Ru and a clamping been power rollers during. Also , the inner surfaces of the input and output disks facing each other are concave surfaces each having a circular arc cross section, and the peripheral surfaces of the power rollers are spherical convex surfaces. It is in contact with the side .
Furthermore, in the case of the toroidal type continuously variable transmission disk that is the object of the manufacturing method of the present invention, the outer surface of the disk is arranged on the inner peripheral surface of at least one of the input side and output side disks. The outer ring raceway of the needle bearing provided between the fitting portion for externally fitting this disk to a member that rotates together with this disk and the outer peripheral surface of the rotary shaft inserted inside this disk, in order from the side surface side , The cylindrical surface portions are formed in series with each other.
In the case of the toroidal-type continuously variable transmission disk manufacturing method of the present invention, at least the inner surface of the disk among the inner peripheral surfaces of the disk provided with the fitting portion, the outer ring raceway, and the cylindrical surface portion. After forming the residual compressive stress layer by shot peening on the side portion, at least a part of the residual compressive stress layer of the outer ring raceway portion is left as it is in the residual compressive stress layer formed on the cylindrical surface portion. Is removed by grinding, and the outer ring raceway portion is made a smooth surface .
[0019]
[Action]
The operation of transmitting torque between the input side disk and the output side disk by the toroidal continuously variable transmission incorporating the disk manufactured by the manufacturing method of the present invention configured as described above, and both The action of changing the gear ratio between the disks is the same as that of the conventionally known toroidal type continuously variable transmission as described above.
In particular, in the case of a toroidal continuously variable transmission incorporating a disk manufactured by the manufacturing method of the present invention, a residual compressive stress layer is formed on the inner peripheral surface portion of the disk provided with a fitting portion, an outer ring raceway, and a cylindrical surface portion. Therefore, the durability of the disk can be ensured regardless of the tensile stress repeatedly applied to the inner peripheral surface portion based on the large thrust load applied from the power roller.
Furthermore, since the outer ring raceway portion is a smooth surface, the durability of the needle bearing that includes the outer ring raceway portion can be ensured.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The feature of the toroidal-type continuously variable transmission disk manufacturing method according to the present invention is that the properties of the inner peripheral surface of the output side disk 4 and the like provided with the fitting portion, outer ring raceway and cylindrical surface portion on the inner peripheral surface are appropriate. It is in the point to make . Since the structure and operation of the part other than this disk are the same as those of various toroidal type continuously variable transmissions that have been conventionally known or considered, including the conventional structure described above, the description of the equivalent part is omitted or omitted. For simplicity, the following description will focus on the features of the present invention.
[0021]
Similarly to the output side disk 4 constituting the conventional toroidal type continuously variable transmission described above, the output side disk 4 made by the manufacturing method of the present invention and constituting the toroidal type continuously variable transmission is shown in FIGS. It is configured as shown. That is, in the through-hole 17 formed in the center of the input side disk 4, the cylindrical surface portion 35 corresponding to the fitting portion described in the claims and the spline are sequentially formed from the outer surface side (the right side in FIGS. 5 to 6). A portion 36, an outer ring raceway portion 37, and a second cylindrical surface portion 38 corresponding to the cylindrical surface portion recited in the claims are provided. When the output side disk 4 is manufactured, a portion near the inner side surface 4a of the inner peripheral surface of the through hole 17 is subjected to shot peening from the opening on the second cylindrical surface portion 38 side, whereby a residual compressive stress layer is formed. to form. When this shot peening is performed, no masking is applied to any part of the inner peripheral surface of the through hole 17. Therefore, the residual compressive stress layer is formed not only on the second cylindrical surface portion 38 but also on the outer ring raceway portion 37. In contrast, when the output side disk 4 is manufactured by the toroidal type continuously variable transmission disk manufacturing method of the present invention, the residual compressive stress layer formed in the outer ring raceway portion 37 is formed by the shot peening. Later, it is removed by grinding and this outer ring raceway portion 37 is made a smooth surface . Of course, the residual compressive stress layer formed on the second cylindrical surface portion 38 is left as it is.
[0022]
In the case of a toroidal continuously variable transmission incorporating the output side disk 4 manufactured by the manufacturing method of the present invention configured as described above, a through hole 17 formed in the center of the output side disk 4 is provided. Among them, a residual compressive stress layer exists in the second cylindrical surface portion 38 where the largest tensile stress is applied in accordance with the operation of the toroidal continuously variable transmission. For this reason, it is related to the tensile stress repeatedly applied to the inner peripheral surface portion of the through-hole 17 based on the large thrust load applied from the power rollers 8 and 8 (FIGS. 3 to 4) with the operation of the toroidal type continuously variable transmission. Therefore, the durability of the output side disk 4 can be ensured.
Furthermore, since the outer ring raceway portion 37 has a smooth surface, the durability of the needle bearing 16 (FIGS. 3, 7 and 8) including the outer ring raceway portion 37 can be ensured.
Note that the disc that is a feature of the present invention is not limited to the output side disc as in the illustrated example, and may be an input side disc as long as the disc has a fitting portion, an outer ring raceway, and a cylindrical surface portion. .
[0023]
【The invention's effect】
Since the present invention is configured and operates as described above, it is possible to sufficiently secure the durability of the disk and the needle bearing for supporting the disk and contribute to the practical use of the toroidal continuously variable transmission.
[Brief description of the drawings]
FIG. 1 is a schematic side view showing a basic configuration of a toroidal-type continuously variable transmission incorporating a disc that is a target of a manufacturing method of the present invention in a state of maximum deceleration.
FIG. 2 is a schematic side view showing a state at the time of maximum acceleration.
FIG. 3 is a sectional view showing an example of a specific structure of a toroidal-type continuously variable transmission.
4 is a cross-sectional view taken along line AA in FIG.
FIG. 5 is a cross-sectional view showing only the output side disk taken out.
FIG. 6 is a half sectional view of the same.
FIG. 7 is a partial cross-sectional view of a toroidal continuously variable transmission for explaining the force applied to each disk during deceleration.
8 is a view similar to FIG. 7, showing a state at the time of acceleration. FIG.
9 is an exaggerated view of the deformation state of the output side disk based on the thrust load, and is a view showing only the output side disk taken out and viewed from the left side of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Input shaft 2 Input side disk 2a Inner side surface 3 Output shaft 4 Output side disk 4a Inner side surface 5 Pivot 6 Trunnion 7 Displacement shaft 8 Power roller 8a Circumferential surface 9 Loading cam apparatus 10 Loading cam 11 Cage 12 Rollers 13, 14 Cam surface 15 Input shaft 16 Needle bearing 17 Through hole 18 Locking groove 19 Retaining ring 20 Reel 21 Output gear 22 Key 23 Support plate 24 Circular hole 25 Support shaft portion 26 Pivot shaft portion 27 Radial needle bearing 28 Radial needle bearing 29 Thrust ball Bearing 30 Thrust needle bearing 31 Outer ring 32 Drive rod 33 Drive piston 34 Drive cylinder 35 Cylindrical surface portion 36 Spline portion 37 Outer ring raceway portion 38 Second cylindrical surface portion 39 Sleeve

Claims (1)

Both the input and output discs that are concentrically and independent of each other and rotatably supported, and do not intersect the central axes of these input and output discs, but perpendicular to the direction of the central axes of these discs A plurality of trunnions in a twisted position that swing around a pair of concentric pivots, a displacement shaft supported by each trunnion, and a bearing on each of these displacement shafts is freely rotatable And a power roller sandwiched between the inner side surfaces of both the input side and output side discs, and the inner side surfaces of the input side and output side discs facing each other, each having an arc-shaped cross section. and concave, as a spherical convex surface of the peripheral surface of the power rollers, is brought into contact with the respective peripheral surface and the inner surfaces constituting the toroidal type continuously variable transmission comprising, the input side, output side And at least one of the disk of the disk, the inner peripheral surface, in order from the outer surface side of the disk, a fitting portion for fitting outside the disk member that rotates with the disc, the disc The outer ring raceway of the needle bearing provided between the outer peripheral surface of the rotating shaft inserted through the inner side of the rotary shaft and the cylindrical surface portion are formed in series with each other. A residual compressive stress layer is formed by shot peening on at least a portion of the inner peripheral surface of the disc provided with the fitting portion and the outer ring raceway and the cylindrical surface portion. Among them, the portion formed on the cylindrical surface portion is left as it is, and at least a part of the residual compressive stress layer of the outer ring raceway portion is removed by grinding, and the outer ring raceway portion is flattened. Method for manufacturing a toroidal continuously variable transmission disc to the surface.

Images