JP4258979B2 - Toroidal type continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toroidal continuously variable transmission used as a transmission for an automobile, for example.
[0002]
[Prior art]
For example, a double-cavity toroidal continuously variable transmission used as a transmission for an automobile is configured as shown in FIGS. That is, the input shaft 2 is rotatably supported inside the casing 1. A circular transmission shaft 3 is supported on the outer periphery of the input shaft 2 so that the input shaft 2 is concentric with the input shaft 2 so as to freely rotate relative to the input shaft 2.
[0003]
First and second input disks 4 and 5 are supported on both ends of the transmission shaft 3 via ball splines 6 with the inner side surfaces 4a and 5a facing each other. Accordingly, the first and second input disks 4 and 5 are rotatably supported on the inner side of the casing 1 concentrically and synchronously with each other.
[0004]
Around the intermediate portion of the transmission shaft 3, first and second output disks 7 and 8 are supported via a sleeve 9. The sleeve 9 has an output gear 10 integrally provided on an outer peripheral surface of an intermediate portion, has an inner diameter larger than the outer diameter of the transmission shaft 3, and a support wall 11 provided in the casing 1 by a pair of rolling bearings 12. It is supported so as to be rotatable concentrically with the transmission shaft 3.
[0005]
The first and second output disks 7 and 8 are splined to both ends of the sleeve 9 so that the inner side surfaces 7a and 8a face each other. Accordingly, the first input disk 4 and the first output disk 7 face the inner side surfaces 4a and 7a, and the second input disk 5 and the second output disk 8 face the inner side surfaces 5a and 8a. It is supported so that it can rotate freely.
[0006]
A pair of yokes 13a and 13b are supported on the inner surface of the casing 1 at the lateral positions of the first and second output disks 7 and 8 with both the disks 7 and 8 sandwiched from both sides. The pair of yokes 13a and 13b are formed in a rectangular shape by pressing or forging a metal such as steel. In order to swingably support pivots 16 provided at both ends of the trunnion 14 to be described later at the four corners of the yokes 13a and 13b, a circular support hole 18 is formed at a circular locking hole 19 at the center in the width direction. Is provided.
[0007]
The pair of yokes 13a and 13b are supported by the support posts 20a and 20b formed on the inner surface of the casing 1 at portions facing each other so as to be slightly displaceable. These support posts 20 a and 20 b are respectively a first cavity 21 that is a portion between the inner side surface 4 a of the first input disk 4 and the inner side surface 7 a of the first output disk 7, and the inner side surface 5 a of the second input disk 5. And the second cavity 22, which is a portion between the second output disk 8 and the inner surface 8 a of the second output disk 8.
[0008]
Therefore, with the yokes 13a and 13b supported by the support posts 20a and 20b, one end of each yoke 13a and 13b is at the outer peripheral portion of the first cavity 21, and the other end is at the outer peripheral portion of the second cavity 22. Each is facing.
[0009]
Since the first and second cavities 21 and 22 have the same structure, only the first cavity 21 will be described. A pair of trunnions 14 are provided. Concentric pivots 16 are provided at both ends of the trunnion 14, and the pivots 16 are supported at one end of the pair of yokes 13a and 13b so as to be swingable and displaceable in the axial direction. That is, it is supported by the radial needle bearing 26 inside the support hole 18 formed at one end of the yokes 13a and 13b. The radial needle bearing 26 includes an outer ring 27 having a spherical convex surface on the outer peripheral surface and a cylindrical surface on the inner peripheral surface, and a plurality of needles 28.
[0010]
A circular hole 30 is provided in each intermediate portion of the trunnion 14. A displacement shaft 31 is supported in each circular hole 30 portion. The displacement shaft 31 has a support shaft portion 33 and a pivot shaft portion 34 that are parallel to each other and eccentric. Of these, the support shaft portion 33 is supported inside the circular hole 30 via a radial needle bearing 35. Further, a power roller 36 is supported around the pivot shaft 34 via another radial needle bearing 38.
[0011]
The pair of displacement shafts 31 provided for each of the first and second cavities 21 and 22 are 180 degrees opposite to the input shaft 2 and the transmission shaft 3 for each of the first and second cavities 21 and 22. Is located. In addition, the direction in which each support shaft portion 34 of the displacement shaft 31 is eccentric with respect to each support shaft portion 33 is determined by the first and second input disks 4 and 5 and the first and second output disks 7 and 8. The rotation direction is the same direction. The eccentric direction is a direction substantially orthogonal to the arrangement direction of the input shaft 2. Therefore, the power roller 36 is supported so as to be slightly displaceable in the direction in which the input shaft 2 and the transmission shaft 3 are disposed. As a result, the power roller 36 tends to be displaced in the axial direction of the input shaft 2 and the transmission shaft 3 due to fluctuations in the amount of elastic deformation of the constituent members based on fluctuations in the torque transmitted by the toroidal continuously variable transmission. Even in this case, the displacement can be absorbed without applying an excessive force to the constituent members.
[0012]
Further, a thrust ball bearing 39 and a thrust bearing 40 such as a sliding bearing or a needle bearing are provided between the outer peripheral surface of the power roller 36 and the inner peripheral surface of the intermediate portion of the trunnion 14 in order from the outer surface of the power roller 36. ing. Of these, the thrust ball bearing 39 supports the rotation of the power roller 36 while supporting the load in the thrust direction applied to the power roller 36. The thrust bearing 40 supports the thrust load applied to the outer ring 41 of the thrust ball bearing 39 from the power roller 36 and allows the pivot shaft 34 and the outer ring 41 to swing around the support shaft 33. .
[0013]
Further, a drive rod 42 is coupled to one end of the trunnion 14, and a drive piston 43 is fixed to the outer peripheral surface of the intermediate portion of the drive rod 42. The drive piston 43 is oil-tightly fitted in the drive cylinder 44. The drive piston 43 constitutes an actuator for displacing the trunnion 14 in the axial direction.
[0014]
A loading cam type pressing device 45 is provided between the input shaft 2 and the first input disk 4. The pressing device 45 is spline-engaged with an intermediate portion of the input shaft 2 and supported in a state where displacement in the axial direction is prevented, and is freely rollable to a cam plate 46 that rotates together with the input shaft 2 and a retainer 47. And a plurality of rollers 48 held by the motor. Based on the rotation of the input shaft 2, the first input disk 4 is rotated while being pressed toward the second input disk 5.
[0015]
During operation of the toroidal type continuously variable transmission configured as described above, the rotation of the input shaft 2 is transmitted to the first input disk 4 via the pressing device 45, and the first input disk 4 and the second input disk are transmitted. The disk 5 rotates in synchronization with each other. The rotation of the first input disk 4 and the second input disk 5 is transmitted to the first and second output disks 7 and 8 via the power roller 36. The rotation of the first and second output disks 7 and 8 is taken out by the output gear 10.
[0016]
When the rotational speed ratio between the input shaft 2 and the output gear 10 is changed, a pair is provided for each of the first and second cavities 21 and 22 based on switching of control valves (not shown). Thus, the drive piston 43 is displaced by the same distance in the opposite directions for each of the cavities 21 and 22.
[0017]
Along with the displacement of these drive pistons 43, a total of four trunnions 14 are displaced in the opposite direction, and one power roller 36 is displaced downward and the other power roller 36 is displaced upward. As a result, the peripheral surface of each power roller 36 contacts the inner side surfaces 4a, 5a of the first and second input disks 4, 5 and the inner side surfaces 7a, 8a of the first and second output disks 7, 8. The direction of the tangential force acting on the part changes. As the direction of the force changes, the trunnion 14 swings in the reverse direction about the pivot 16 pivotally supported by the yokes 13a and 13b. As a result, the contact position between the peripheral surface of the power roller 36 and the first and second input disks 4 and 5 and the first and second output disks 7 and 8 changes, and the input shaft 2 and the output gear 10 are in contact with each other. Rotational speed ratio in between changes.
[0018]
However, the conventional toroidal-type continuously variable transmission configured as described above supports the trunnion 14 inside the casing 1 via support posts 20a and 20b and yokes 13a and 13b. Therefore, the number of parts increases, which not only complicates parts production, parts management, and assembly work, but also increases the height of the toroidal-type continuously variable transmission, which makes it difficult to reduce the size and weight.
[0019]
Therefore, for example, as shown in FIG. 4 of Japanese Patent Laid-Open No. 2000-9200, the yoke is directly fixed to the inside of the casing, and the pivots provided at both ends of the trunnion are vertically moved to the yoke via the ball spline. A structure that can be moved freely is developed.
[0020]
According to the above configuration, since the yoke is directly fixed to the casing, the number of parts can be reduced, the production of parts, the management of parts, and the assembly work can be simplified, and the height of the toroidal continuously variable transmission can be achieved. Small size, small size and light weight.
[0021]
[Problems to be solved by the invention]
However, the above-described toroidal-type continuously variable transmission disclosed in Japanese Patent Application Laid-Open No. 2000-9200 has a ball spline on the pivot shaft of the trunnion and has a structure that can move in the vertical direction. Further, the outer ring of the ball spline has a spherical surface so that it is not twisted when the trunnion is elastically deformed. Further, the trunnion can be tilted about the pivot axis by the needle bearing of the inner ring of the ball spline.
[0022]
Accordingly, the trunnion support structure is complicated and the number of parts is increased. Further, when a ball is incorporated into the upper ball spline, a hole must be formed in the casing, which causes a problem of reducing the rigidity of the casing. Further, in the ball spline that allows the trunnion to move in the vertical direction, the movement of the ball coexists with sliding and rolling depending on the position of the ball at the time of assembly. In general, when the rolling motion and the sliding motion have a friction coefficient that differs by at least an order of magnitude, and the slip coexists in the vertical movement, the vertical force is non-uniform in each trunnion.
[0023]
The present invention has been made paying attention to the above circumstances, and the object thereof is to eliminate the ball spline from the trunnion, to reduce the number of parts and to facilitate the assembly, and to make the movement of each trunnion in the vertical direction. An object is to provide a toroidal type continuously variable transmission which can be made uniform.
[0024]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a casing, an input disk and an output disk that are rotatably supported concentrically and independently of each other inside the casing, and the input disk. And a plurality of trunnions having an even number of pivots that are concentric or parallel to each other and are located at a torsional position perpendicular to the direction of the central axis of the output disk, and swing about the pivot axis, and A displacement shaft projecting from the inner surface of the trunnion, a plurality of power rollers sandwiched between the inner surfaces of the input disk and the output disk in a state of being rotatably supported by the displacement shaft, A toroidal-type continuously variable transmission including a support means that is directly fixed to the casing located on a side of a roller and supports the pivot; The stage, displaced freely supports pivot of the trunnions in the axial direction and tilting direction, axis of the trunnion, and supported via a needle bearing on the support means, the needle bearing inner ring and the outer ring is spherical It is supported by a spherical bearing .
[0026]
According to a second aspect of the present invention, the outer ring of the spherical bearing of the first aspect has a notch in a part of the spherical surface, and the inner ring is press-fitted from the notch and the inner and outer rings are integrally formed. And
[0027]
According to the said structure, the vertical motion of each trunnion is smooth, and it becomes possible to equalize force with each trunnion. Further, when the trunnion pivot is displaced in the vertical direction, it simultaneously rotates around the trunnion pivot, so that there is a slight slip but a rolling motion. Therefore, the frictional force is greatly reduced compared with a simple sliding motion, and synchronization / stability is improved at the time of shifting.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the same components as those in the prior art will be denoted by the same reference numerals and description thereof will be omitted.
[0029]
1 and 2 show a first embodiment, FIG. 1 is a cross-sectional view corresponding to line AA in FIG. 5, FIG. 2 shows an outer ring of a needle bearing, (a) is a plan view, and (b). Is a sectional view taken along line BB, and (c) is a sectional view taken along line CC.
[0030]
As shown in FIG. 1, an upper yoke 51 and a lower yoke 52 as support means are directly fixed to portions facing each other inside the casing 1. The upper yoke 51 and the lower yoke 52 are provided with needle bearings 53. The needle bearings 53 are supported by a spherical bearing 50, and support the pivot 16 of the trunnion 14 so as to be displaceable in the axial direction (vertical direction) and the tilting direction. ing.
[0031]
That is, the spherical bearing 50 has an inner ring 54 and an outer ring 55, and the inner and outer rings 54 and 55 are provided with spherical surfaces 54 a and 55 a that are spherically connected to each other. As shown in FIG. 2, a plurality of bolt holes 56 are provided at both ends of the outer ring 55, and the outer ring 55 is fixed to the upper yoke 51 and the lower yoke 52 by bolts 57 inserted through the bolt holes 56, respectively. Yes. In the present embodiment, the holes of the upper yoke 51 and the lower yoke 52 and the outer ring 55 of the spherical bearing 50 are accurately positioned with respect to the casing 1 by fitting about an intermediate fit. In addition, since the position of the spherical bearing 50 determines the position of each trunnion 14, the spherical bearing 50 can be accurately positioned with respect to the upper yoke 51 and the lower yoke 52 by a positioning pin or the like. Notches 58 are provided at two locations on the inner peripheral surface of the outer ring 55, and the inner and outer rings 54, 55 are integrated by press-fitting the inner ring 54 from the notch 58.
[0032]
The pivot 16 of the trunnion 14 is supported on the inner ring 54 of the spherical bearing 50. Since the pivot 16 is a rolling surface of the needle bearing 53, the hardness is increased by heat treatment such as induction hardening. Further, a lubricating oil passage 59 is provided in the upper yoke 51 and the lower yoke 52. The lubricating oil passage 59 communicates with the spherical bearing 50 and the needle bearing 53, and the outer ring 55 and the pivot 16 are provided with oil holes. The spherical bearing 50 and the needle bearing 53 are supplied with sufficient lubricating oil. Further, the lubricating oil passage 59 communicates with the radial needle bearing 35 of the trunnion 14.
[0033]
Further, since the trunnion 14 is freely displaceable in the vertical direction, a portion A between the lower surface of the outer ring 55 and the upper surface of the trunnion 14, a portion B between the upper surface of the outer ring 55 and the lower surface of the trunnion 14, and the lower surface of the outer ring 55 A gap corresponding to the upper and lower strokes of the trunnion 14 is provided in a portion C between the upper surface of the cable pulley 60 and a portion D between the safety cable pulley 60 and the lower yoke 52. Since the stroke amount of the trunnion 14 can be adjusted to the stroke amount of the drive piston 43, the gaps of the A, B, C, and D portions are designed to be slightly larger than the strokes E and F of the drive piston 43, and when the trunnion 14 is displaced in the vertical direction To prevent interference.
[0034]
The assembly order of the trunnion 14 portion of the toroidal-type continuously variable transmission configured as described above will be described. The upper yoke 51 and the inner and outer rings 54 and 55 of the spherical bearing 50 are integrally incorporated in the casing 1. Next, the pivot 16 of the trunnion 14 provided with the power roller 36 is assembled into the inner ring 54 of the spherical bearing 50. Finally, the lower yoke 52 integrated with the inner and outer rings 54 and 55 of the spherical bearing 50 is assembled from below the casing 1. Therefore, assembling is possible without making a hole in the casing 1 as in the prior art, and the rigidity of the casing 1 is not lowered.
[0035]
Conventionally, a ball spline that allows the trunnion to move in the vertical direction has both the sliding and rolling of the movement of the ball depending on the position of the ball during assembly. The ball spline that allows the trunnion to move in the vertical direction, the movement of the ball coexists with sliding and rolling depending on the position of the ball at the time of assembly, the vertical force in each trunnion was uneven, According to the toroidal-type continuously variable transmission configured as described above, each trunnion 14 has only one movement in the vertical direction, and the force can be made uniform by each trunnion 14. Further, when the pivot 16 of the trunnion 14 is displaced in the vertical direction, it simultaneously rotates around the pivot 16 of the trunnion 14, so that there is a slight slip but a rolling motion. Therefore, the frictional force is greatly reduced compared with a simple sliding motion, and synchronization / stability is improved at the time of shifting.
[0036]
FIG. 3 shows a second embodiment of the present invention, and the same components as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. In this embodiment, the upper yoke 51 and the lower yoke 52 and the outer ring 55 of the spherical bearing 50 are integrally formed, and it is possible to save the trouble of fixing the outer ring 55 to the upper yoke 51 and the lower yoke 52 with bolts 57 and to reduce the parts. The score can be reduced.
[0037]
FIG. 4 shows a third embodiment of the present invention. The same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the first embodiment, when the trunnion 14 is displaced in the vertical direction, the trunnion 14 slides between the pivot 16 and the needle bearing 53. However, in the present embodiment, the trunnion 14 is moved in the vertical direction. This displacement is made to slide between the needle bearing 53 and the inner ring 54 of the spherical bearing 50.
[0038]
【The invention's effect】
As described above, according to the present invention, the pivot shaft of the trunnion is supported by the supporting means so as to be freely displaceable in the axial direction and the tilting direction. Therefore, it is possible to reduce the number of parts and facilitate assembly. In addition, when the trunnion moves up and down, it simultaneously rotates around the trunnion axis, and it becomes a rolling motion, the frictional force is greatly reduced, the vertical movement of each trunnion can be made uniform, There is an effect that stability is improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a toroidal continuously variable transmission according to a first embodiment of the present invention and corresponding to the line AA in FIG. 5;
2A and 2B show an outer ring of a spherical bearing in the same embodiment, wherein FIG. 2A is a plan view, FIG. 2B is a cross-sectional view taken along line BB, and FIG. 2C is a cross-sectional view taken along line CC.
FIG. 3 is a sectional view showing a toroidal-type continuously variable transmission according to a second embodiment of the present invention and corresponding to the AA line in the figure.
FIG. 4 is a sectional view showing a support structure for a pivot shaft of a trunnion according to a third embodiment of the present invention.
FIG. 5 is a longitudinal side view of a conventional double cavity toroidal continuously variable transmission.
6 is a cross-sectional view taken along line AA in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Casing 2 ... Input shaft 4, 5 ... Input disc 7, 8 ... Output disc 14 ... Trunnion 16 ... Pivot 36 ... Power roller 50 ... Spherical bearing 51 ... Upper yoke 52 ... Lower yoke 53 ... Needle bearing 54 ... Inner ring 55 ... Outer ring

Claims (2)

A casing, an input disk and an output disk supported concentrically and independently of each other inside the casing, and a torsion that is perpendicular to the direction of the central axis of the input disk and the output disk A plurality of trunnions that exist at a position and have an even number of concentric or parallel pivots, swing around the pivots, displacement shafts that project from the inner surface of the trunnions, and freely rotate on these displacement shafts In a state of being supported by the plurality of power rollers, the plurality of power rollers sandwiched between the inner surfaces of the input disk and the output disk, and the pivot shaft that is directly fixed to the casing located on the side of each of the power rollers is supported. A toroidal-type continuously variable transmission provided with supporting means for
The pivot means of the trunnion is supported by the support means so as to be freely displaceable in the axial direction and the tilt direction ,
A toroidal continuously variable transmission characterized in that the pivot shaft of the trunnion is supported by the support means via a needle bearing, and the needle bearing is supported by a spherical bearing having an inner ring and an outer ring . 2. The toroidal type according to claim 1, wherein the outer ring of the spherical bearing has a notch in a part of the spherical surface, and the inner ring is press-fitted from the notch and the inner and outer rings are integrally formed. Continuously variable transmission.

Images