JP3486992B2 - Toroidal type continuously variable transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention A toroidal type continuously variable transmission according to the present invention is used, for example, as an automobile transmission. 2. Description of the Related Art The use of a toroidal-type continuously variable transmission, as schematically shown in FIGS. The toroidal type continuously variable transmission supports an input side disk 2 concentrically with an input shaft 1 and an output side disk 4 at an end of an output shaft 3 as disclosed in, for example, Japanese Utility Model Laid-Open Publication No. 62-71465. Is fixed. An inner surface of a casing containing the toroidal-type continuously variable transmission or a support bracket provided in the casing swings around a pivot 5 which is twisted with respect to the input shaft 1 and the output shaft 3. Trunnions 6, 6 are provided. this
Each trunnion 6, 6 is apparent from FIG.
And a pair of pivots 5, 5 provided at each end.
Only the ends are supported and the middle is not supported.
It swings about both pivots 5,5. Each of the trunnions 6, 6 is shown in FIGS.
As shown in (1), it is made of a metal material having sufficient rigidity, and the pivots 5, 5 are provided on the outer surfaces of both ends. A circular hole 7 formed in the center of each trunnion 6
Supports the base end of the displacement shaft 8 (FIGS. 9 to 10) , and swings the trunnions 6 , 6 about the pivots 5, 5 to freely adjust the inclination angle of the displacement shaft 8. And Power rollers 9, 9 are rotatably supported around displacement shafts 8, 8 supported by the trunnions 6, 6, respectively. The power rollers 9, 9 are sandwiched between the input side and output side disks 2, 4. The inner surfaces 2a and 4a of the input side and output side disks 2 and 4 facing each other have a circular arc-shaped concave surface centered on the pivot 5. The peripheral surfaces 9a, 9a of the power rollers 9, 9 formed on the spherical convex surface,
The inner surfaces 2a and 4a are in contact with each other. A loading device 10 of the loading cam type is provided between the input shaft 1 and the input disk 2, and the input disk 2 is pressed toward the output disk 4 by the pressing device 10. ing. The pressure device 10 includes a cam plate 11 that rotates together with the input shaft 1 and a plurality (for example, four) of rollers 13, 13 held by a holder 12. One side of the cam plate 11 (FIGS. 9 to
10 is formed on the outer surface of the input side disk 2 (the left side in FIGS. 9 to 10). 15 are formed. Then, the plurality of rollers 13, 13 are
The input shaft 1 is rotatably provided about a radial axis with respect to the center of the input shaft 1. When the cam plate 11 rotates with the rotation of the input shaft 1 when using the toroidal type continuously variable transmission configured as described above, a plurality of rollers 13, 1
3 is pressed against the cam surface 15 on the outer surface of the input disk 2. As a result, the input side disk 2 is pressed by the plurality of power rollers 9, 9, and at the same time, based on the pressing of the pair of cam surfaces 14, 15 and the plurality of rollers 13, 13, The input side disk 2 rotates. Then, the rotation of the input side disk 2 is transmitted to the output side disk 4 via the plurality of power rollers 9, 9, and the output shaft 3 fixed to the output side disk 4 rotates. When changing the rotation speed between the input shaft 1 and the output shaft 3 and first reducing the speed between the input shaft 1 and the output shaft 3, as shown in FIG. As a result, the trunnions 6 are swung so that the peripheral surfaces 9a of the power rollers 9, 9 are closer to the center of the inner surface 2a of the input disk 2 and to the outer surface of the inner surface 4a of the output disk 4. At this time, the respective displacement shafts 8, 8 are inclined so as to abut each other. Conversely, when increasing the speed, the trunnions 6, 6 are swung as shown in FIG. 10 so that the peripheral surfaces 9a, 9a of the power rollers 9, 9, the inner surface 2a of the input side disk 2 And the inner surface 4a of the output disk 4
The respective displacement shafts 8, 8 are inclined so as to abut against the portion near the center of. If the angle of inclination of each of the displacement shafts 8, 8 is set between those in FIGS. 9 and 10, an intermediate speed ratio can be obtained between the input shaft 1 and the output shaft 3. FIG. 14 shows that each of the trunnions 6 is
A mechanism for tilting about the pivots 5, 5 is described in U.S. Pat. No. 4,928,542. The pivots 5 are formed by needle bearings 16
The support plate 17 is freely supported for rotation and slight displacement in the axial direction. At the time of gear shifting, pressure oil is fed into a hydraulic cylinder 18 supported by the support plate 17 to displace the trunnion 6 in the axial direction. Based on this displacement, the contact positional relationship between the peripheral surface 9a of the power roller 9 and the inner surfaces 2a, 4a (FIGS. 9 to 10) of the input and output disks 2, 4 changes, and the trunnion 6 is moved. It swings in any direction around the pivots 5,5. As is apparent from FIG. 14, the actual displacement shaft 8 is an eccentric shaft in which the base half and the front half are eccentric to each other. The base half is pivotally supported by the trunnion 6 and A power roller 9 is pivotally supported around the half. Further, a cylindrical surface portion 19 is formed at the maximum diameter portion of the outer peripheral surface of the power roller 9. Further, the outer peripheral edge of the outer ring 20 for pivotally supporting the power roller 9 with respect to the displacement shaft 8 and the outer peripheral edge of the retainer 22 holding the balls 21, 21 are formed on the outer peripheral surface 9a of the power roller 9. Are arranged inwardly of the spherical surface obtained by extending the length of each disk so that these outer peripheral edges do not interfere with the inner side surfaces 2a, 4a of both the input side and output side disks 2, 4. In order to put into practical use a toroidal type continuously variable transmission configured and operating as described above, it is necessary to suppress an increase in weight while
It is desired to improve performance. On the other hand, the trunnions 6, 6 for swingably supporting the power rollers 9, 9 are heavy in weight in order to secure sufficient rigidity. For this reason, the structure of the trunnions 6, 6 becomes important in reducing the weight and improving the performance of the toroidal-type continuously variable transmission. That is,
During the operation of the toroidal-type continuously variable transmission, a large thrust load is applied from one of the power rollers 9 to one surface of each of the trunnions 6 (the surface on which the power rollers 9 are installed). When the rigidity of the power rollers 9 and 9 is insufficient and the power rollers 9 and 9 are elastically deformed in a direction in which the one surface side is concave, the thrust ball bearings formed by the outer ring 20 and the balls 21 and 21 are biased. A load is applied, and the durability of the thrust ball bearing decreases. Therefore, it is necessary to sufficiently secure the rigidity of each of the trunnions 6, 6, but if the trunnions 6, 6 are simply enlarged to secure the rigidity,
However, the weight increases, and the practicality of the toroidal type continuously variable transmission is impaired. In view of such circumstances, Japanese Utility Model Application Laid-Open No. 6-1460.
No. 3 proposes a trunnion 27 having a shape as shown in FIGS. The trunnion 27 is made of a material having sufficient rigidity, such as steel, and has a base 28.
A pair of pivots 5 projecting from both end faces of the base 28,
5 is provided. The base 28 is formed by cutting off a part of a columnar material having a first central axis a.
That is, the concave portion 24 is provided by shaving the intermediate portion on one side of the material, and a circular hole 29 is formed in the intermediate portion of the concave portion 24. This circular hole 29 supports the base end of the displacement shaft for supporting the power roller. Also, at both ends of the base 28,
The portions deviated from the concave portions 24 are plate portions 25, 25 bent with respect to the main body portion 26 having the circular holes 29. Further, the other surface of the material is subjected to milling or the like to form a flat surface 30 parallel to the recess 24. On the outer surfaces of the pair of plate portions 25, 25, pivots 5, 5 are respectively provided to protrude. Each of the pivots 5, 5 formed integrally with the base portion 28 is parallel to the first central axis a and projects from the first central axis a in the direction in which the displacement shaft 8 projects (FIGS. 15 to 17). (A downward direction), and is formed in a columnar shape having a second central axis b. In the case of the trunnion 27 configured as described above, the weight of the trunnion 27 can be reduced while securing rigidity. In the case of the trunnion 27 as shown in FIGS. 15 to 17 constructed as described above, the trunnion 27 is compared with the conventional trunnion 6 as shown in FIGS. If it is the same rigidity, it becomes lighter. However, the base 28 and the inner surface 2 of both the input and output disks 2 and 4
a, because it is not a shape that fully considers prevention of interference with 4a,
In order to reduce the weight, it may be difficult to secure the rigidity. That is, during operation of the toroidal type continuously variable transmission,
In order to increase the gear ratio between the input side disk 2 and the output side disk 4, it is necessary to incline the trunnion 27 about the pivots 5, 5. In addition, even when the trunnion 27 is greatly inclined in this manner, the side edge of the base portion 28 that constitutes the trunnion 27 and the inner surface 2
a and 4a must not interfere with each other. On the other hand, the trunnion 27 described in the above-mentioned publication is not a shape in which prevention of such interference is particularly considered. Therefore, in order to prevent the interference even when the inclination angle of the trunnion 27 about the pivots 5 and 5 becomes large,
The width of the base 28 must be reduced. However, a decrease in the width of the base portion 28 leads to a decrease in the rigidity of the base portion 28, so that it is impossible to achieve both reduction in weight and securing of rigidity. The toroidal-type continuously variable transmission of the present invention has been invented in view of such circumstances. [0013] A toroidal-type continuously variable transmission according to the present invention is arranged concentrically with an input side disk and rotatably supported with respect to the input side disk. Only the both ends are supported by the output side disk and a pair of pivots which are in a twisted position with respect to the central axis of both the input side and the output side disk, and the intermediate part is not supported, and swings around these both pivots. The vehicle includes a trunnion, a displacement shaft supported by the trunnion, and a power roller rotatably supported by the displacement shaft and sandwiched between the input and output disks. Then, the inner surfaces of the input and output disks facing each other are concave surfaces having an arc-shaped cross section, and the peripheral surface of the power roller is a spherical convex surface. Let me. Also this
At the same time, at the middle of the outer surface of the trunnion,
Except for the circular holes for supporting the
There is no recessed part. In particular, in the toroidal type continuously variable transmission according to the present invention, a part of the trunnion is swung about the pivot and the inner side surfaces of the input side and the output side discs are moved together. The entire outer surface of the portion that enters into the inner surface is diametrically inner than the cylindrical surface in contact with each of the inner surfaces around the pivot. On the other hand, the outer surface of the portion of the remaining portion of the trunnion that does not enter between the inner surfaces of both the input and output disks regardless of the swing about the pivot .
A portion exists diametrically outside the cylindrical surface. With the toroidal-type continuously variable transmission of the present invention configured as described above, the operation itself when freely changing the speed ratio between the input shaft and the output shaft is the same as the conventional toroidal transmission described above. This is the same as in the case of the type continuously variable transmission. In particular, in the case of the toroidal-type continuously variable transmission of the present invention, the rigidity of the trunnion can be maximized in a limited installation space. Further, even if the trunnion is swung about the pivot, the side edge of the trunnion does not interfere with the inner surfaces of the input and output disks. Therefore, it is possible to obtain a toroidal type continuously variable transmission that is lightweight and has a large gear ratio. 1 to 7 show an embodiment of the present invention.
The toroidal-type continuously variable transmission according to the present invention is characterized by the shape of the trunnion, and the other parts are the same as those of the above-described conventional structure. Therefore, the following description will focus on the trunnion. A middle portion of the trunnion 31 made of a material having sufficient rigidity, such as steel, in the length direction (the left-right direction in FIGS. 2 and 4) is a base portion 32. Further, at both ends in the longitudinal direction of the base portion 32, bent portions 33, 33 which are bent at right angles in the same direction from the base portion 32 are formed. The base 3
A circular hole 34 is formed at a portion slightly closer to one end in the length direction (the left end in FIGS. 2 and 4) from the center of 2. This circular hole 34
In FIG. 14, a base half of the displacement shaft 8 as shown in FIG. 14 is pivotally supported, and a power roller 9 also as shown in FIG. In this state, the power roller 9
Is located substantially at the center of the base 32.
In the outer surface of the trunnion 31 (the upper surface in FIGS. 1 to 3).
Except for both ends of the outer surface of the base portion 32, which is an intermediate portion
Except for the circular hole 34, the power roller 9
There are no recessed parts. The inner surfaces of the bent portions 33, 33 facing each other are arc-shaped concave surfaces whose central portions in the width direction (vertical direction in FIG. 4) are concave. Thereby, each of the bent portions 33, 3
The bending rigidity of a continuous portion between the bent portions 33, 33 and the base portion 32 is ensured while preventing interference between the power roller 3 and the power roller 9. On the outer surfaces of the bent portions 33, 33, concentric pivots 5, 5 are formed. In order to reduce the weight of the trunnion 31 to the utmost,
In the center of the through holes 35a and 35b are formed in a range where the rigidity of each of the pivots 5 and 5 can be secured.
5 is formed in a cylindrical shape. Further, the base 32 constituting the trunnion 31 has a sectional shape as shown in FIG. That is, the surface half (the lower half in FIG. 3) from which the displacement shaft 8 protrudes is connected to the surface (the lower surface in FIG. 3) from which the displacement shaft 8 protrudes from the center in the thickness direction (vertical direction in FIG. 3). , The width of the inner half is gradually increased, and the opposite half (the upper half in FIG. 3) is defined as an outer half 37 that continues from the inner half. The outer half portion 37 has a large dimension in the thickness direction instead of a small width dimension. When such a trunnion 31 is assembled in a toroidal type continuously variable transmission, and the transmission ratio between the input side disk 2 and the output side disk 4 is increased, the trunnion 31 is largely inclined around the pivots 5, 5. Both end portions in the width direction of the inner half portion 36 enter a portion 38 between the inner side surfaces 2a and 4a of the input side and output side disks 2 and 4 shown by oblique lattice in FIG. On the other hand, in FIG. 1 including the outer half 37 ,
The outer surface portion of the range represented by the central angle S is the portion 38
Do not enter. In the illustrated embodiment in this order, the entire outer surface of the inner half 36, there the pivot shafts 5 each inner surface 2a around, diametrically inward of the cylindrical surface in contact with 4a. On the other hand, a part of the outer surface of the outer half portion 37, which is the remaining portion of the trunnion 31, is diametrically outer than the cylindrical surface in contact with the inner surfaces 2a, 4a around the pivots 5, 5. I do. In the case of the toroidal-type continuously variable transmission of the present invention configured as described above, the rigidity of the trunnion 31 provided in a limited installation space can be maximized. That is, the outer half portion 3 which does not enter the portion 38 between the side surfaces 2a, 4a.
7 is a trunnion 3 because the thickness can be sufficiently secured.
1 can be sufficiently secured. Therefore, the elastic deformation of the trunnion 31 can be suppressed to a very small value, and an unbalanced load can be prevented from being applied to the thrust bearing provided between the power roller 9 and the trunnion 31. Therefore, the durability of the thrust bearing can be sufficiently ensured. On the other hand, since the inner half portion 36 which enters the portion 38 between the inner side surfaces 2a and 4a is provided on the inner side in the diameter direction from the cylindrical surface, the inner half portion 36 is shown in FIGS. As shown, no matter in which direction the trunnion 31 is swung about the pivots 5, 5, both side edges of the trunnion 31 in the width direction and the inner surfaces 2a, 4a of the input and output disks 2, 4 are shown. Does not interfere. Therefore, it is possible to obtain a toroidal type continuously variable transmission that is lightweight and has a large gear ratio. Incidentally, in order to further reduce the size and weight of the toroidal type continuously variable transmission, in order to maximize the rigidity of the trunnion 31 installed in a limited space, the first embodiment shown in FIG. As in the second embodiment, a part of the outer surface of the outer half portion 37 of the trunnion 31 is positioned diametrically inside a cylindrical surface indicated by a chain line α in FIG. The cylindrical surface indicated by the chain line α is centered on the center axis of the pair of pivots 5 and is in contact with the base end of the displacement shaft 8 protruding from the outer half 37. Outer half 37
By regulating the shape in this way, and making a casing having a predetermined clearance with respect to the cylindrical surface indicated by the chain line α,
The trunnion 31 having the largest rigidity can be obtained as long as it can be stored in the casing. Further, in order to reliably prevent the inner surface 2a of the input side disk 2 from interfering with the trunnion 31 even during abnormal operation, as shown in the third embodiment shown in FIG. The portion that enters the portion 38 between the inner side surfaces 2a, 4a of the output side disks 2, 4 is positioned diametrically inside the cylindrical surface indicated by the chain line β in FIG. The cylindrical surface indicated by the chain line β has the center of the center axis of the pair of pivots 5 as its center, and has a radius r represented by the following equation (1). R = RLC --- (1) In the formula (1), R is the inner surface 2a of the input and output disks 2, 4,
The radius of curvature L of 4a is such that the height C of the cam surface 15 formed on the back surface of the input side disk 2 is such that the generatrix of the inner side surface 2a of the input side disk 2 is formed so as to constitute the loading device 10 of the loading cam type. 1 /
Exceeding four arcs is the amount of overhang of the protrusion existing on the outer peripheral edge portion of the input side disk 2. By arranging the inner half portion 36 inside the cylindrical surface having the radius r obtained by the equation (1) with the center axis of the pair of pivots 5 as its center, the input can be performed even during abnormal operation. Interference between the inner surface of the side disk 2 and the trunnion can be reliably prevented. The reason will be described. Generally, in a toroidal type continuously variable transmission, the output-side disk 4 is supported rotatably (displaceable in the axial direction), and the input-side disk 2 is supported rotatably and slightly displaceable in the axial direction.
During operation, the input disk 2 is strongly pressed toward the output disk 4 by the action of the pressure device 10. Due to this pressing, the input-side disc 2 slightly moves in the axial direction toward the output-side disc 4. In this state, the distance between the inner surfaces 2a and 4a of the disks 2 and 4 is reduced, and the inner surfaces 2a and 4a are
Interference with the outer surface. Normally, the height L of the cam surface 15 is regulated so that the rollers 13 constituting the pressure device 10 do not completely go over the mountain of the cam surface 15.
If an unexpectedly large excessive torque is applied to the cam plate 11 for some reason, there is a possibility that the roller 13 completely passes over the peak of the cam surface 15. In such a case, the edge of the projecting portion present at the outer peripheral edge of the input side disk 2 approaches the cylindrical surface indicated by the chain line β,
It approaches the outer half 37 of the trunnion 31. This is a state where the input side disk 2 and the trunnion 31 are closest to each other. Accordingly, if the outer surface exists inside the cylindrical surface indicated by the chain line β in FIG. 8, the possibility that the inner surfaces 2a, 4a and the outer surface of the inner half portion 36 interfere with each other is eliminated. still,
The amount of overhang C is such that the input side disk 2 has a circular shape, while the trunnion 31 is long in the front and back directions in FIG.
It is necessary to consider in order to prevent interference in three-dimensional directions. Of course, if there is no projection (if C = 0), there is no need to subtract the overhang amount. The toroidal-type continuously variable transmission according to the present invention is constructed and operates as described above. Therefore, the rigidity of the trunnion installed in a limited space is improved while securing a sufficient gear ratio. You can get the maximum. As a result, the weight and performance of the toroidal-type continuously variable transmission can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an end view of a trunnion, showing a first embodiment of the present invention. FIG. 2 is a sectional view taken along line AA of FIG. FIG. 3 is a sectional view taken along line BB of FIG. 2; FIG. 4 is a view as viewed from below in FIG. 2; FIG. 5 is a half sectional view of an input side disk and an output side disk. FIG. 6 is a half sectional view showing the relationship between the input side disk and the output side disk and the trunnion at the time of maximum deceleration and maximum acceleration; FIG. 7 is an end view of a trunnion pivotally supporting a power roller, showing a second embodiment of the present invention. FIG. 8 is a half sectional view showing the relationship between a pressing device, an input disk, and an output disk and a trunnion, showing a third embodiment of the present invention. FIG. 9 is a side view showing the basic configuration of the toroidal-type continuously variable transmission to which the present invention is applied, in a state at the time of maximum deceleration. FIG. 10 is a side view showing a state at the time of maximum speed increase. FIG. 11 is an end view of a conventionally used trunnion. FIG. 12 is a side view of the same. FIG. 13 is a partial perspective view of the same. FIG. 14 is a sectional view showing another example of the conventional structure. FIG. 15 is an end view of a conventionally proposed trunnion. FIG. 16 is a side view of the same. FIG. 17 is a partial perspective view of the same. [Description of Signs] 1 Input shaft 2 Input side disk 2a Inner surface 3 Output shaft 4 Output side disk 4a Inner surface 5 Pivot 6 Trunnion 7 Circular hole 8 Displacement shaft 9 Power roller 9a Peripheral surface 10 Pressurizing device 11 Cam plate 12 Holding Container 13 Roller 14 Cam surface 15 Cam surface 16 Needle bearing 17 Housing 18 Hydraulic cylinder 19 Cylindrical surface portion 20 Outer ring 21 Ball 22 Cage 24 Recess 25 Plate portion 26 Body portion 27 Trunnion 28 Base 29 Circular hole 30 Flat surface 31 Trunnion 32 Base 33 Bent portion 34 Circular holes 35a, 35b Through hole 36 Inner half 37 Outer half 38

Continuation of front page (56) References JP-A-6-307513 (JP, A) JP-A-59-133860 (JP, A) JP-A-6-280959 (JP, A) JP-A 1-275951 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 15/38

Claims (1)

(57) [Claim 1] An input side disk, an output side disk concentric with the input side disk and rotatably supported with respect to the input side disk, an input side, and an output side. A trunnion swinging around these two pivots, and a trunnion supported at the trunnions, with only the two ends being supported by a pair of pivots that are twisted with respect to the central axes of the two side discs and not the intermediate portion. A displacement shaft, and a power roller rotatably supported by the displacement shaft and sandwiched between the input side and the output side discs. There is a concave arcuate, as a spherical convex surface and the peripheral surface of the power roller, Rutotomoni abut the this peripheral surface and the inner surface, the Toranio
A circular hole for supporting the displacement axis
Except for the concave part facing the power roller
In the toroidal-type continuously variable transmission, the input side, along with the swing around the pivot axis in a part of the trunnion,
The entire outer surface of the portion that enters between the inner surfaces of the two output-side disks is diametrically inner than the cylindrical surface that is in contact with each of the inner surfaces around the pivot, and the pivot is formed by the rest of the trunnion. Regardless of the swing around the center, the input side,
A toroidal-type continuously variable transmission, wherein a part of an outer surface of a portion that does not enter between inner surfaces of both output side disks is present in a diameter direction outside of the cylindrical surface.