JP3709418B2 - Toroidal continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toroidal continuously variable transmission applied to a vehicle or the like, and more particularly to an improvement in a bearing support structure for a power roller clamped between input and output disks.
[0002]
[Prior art]
In recent years, research and development of a continuously variable transmission for an automobile has been promoted in view of its smoothness, ease of driving, and improvement in fuel consumption.
Among them, a traction drive type toroidal continuously variable transmission (hereinafter referred to as toroidal type CVT) that transmits power by shearing an oil film is known.
[0003]
The toroidal type CVT can be classified into a full toroidal type and a half toroidal type according to its shape. Of the two types, the full toroidal CVT does not apply a thrust force to the power roller. On the other hand, in the half toroidal CVT, a thrust force is applied to the power roller, and a bearing is required to receive this force. This bearing performance has a significant effect on efficiency. However, the half-toroidal CVT has a tangent drawn to the two contact points of the disk and the power roller having an intersection, and the locus of the intersection is in the vicinity of the rotating shaft in the entire speed change range. The half toroidal CVT is selected in consideration of these advantages and disadvantages compared to the type CVT.
[0004]
The shifting operation of this half toroidal CVT generates a side slip force by giving a slight displacement to the trunnion, which is a power roller support member, in a direction perpendicular to the power roller rotating shaft and the disk rotating shaft, thereby obtaining a tilting force. It is a mechanism.
[0005]
As a bearing support structure of a power roller that is clamped so that power can be transmitted between the input / output disks of such a toroidal CVT, for example, the structure described in FIG. 4 of Japanese Patent Laid-Open No. 11-51139 is known. Yes.
[0006]
In this prior art publication, as shown in FIG. 8, a power roller sandwiched between input and output disks, a trunnion that rotatably supports the power roller by a support shaft, and a power roller and an outer ring. A plurality of rolling elements rolling in the raceway grooves provided in the power roller and the outer ring, and a plurality of pocket holes penetrating in the direction of the power roller rotation axis, and the rolling elements are placed in the raceway grooves. And a cage that holds the roll so as not to fall off.
[0007]
[Problems to be solved by the invention]
However, in the conventional power roller bearing support structure, as shown in FIG. 8, the inner wall thickness ti between the inner peripheral surface of the cage and the pocket hole, the outer peripheral surface of the cage and the pocket hole, Therefore, there is a problem that the rolling element pitch diameter, which is the diameter of a circle connecting the centers of the rolling elements, becomes small.
[0008]
As a result, if the rolling elements of the same size are not shortened in the circumferential direction, the number of rolling elements decreases when the rolling element pitch diameter is small, and the rolling fatigue life of the power roller and outer ring raceway groove is shortened. Become. On the other hand, in the case of the same size and the same number of rolling elements, there is a problem that the circumferential distance between adjacent rolling elements becomes shorter as the rolling element pitch diameter becomes smaller.
[0009]
In other words, considering the raceway grooves of the power roller and the outer ring from the viewpoint of rolling fatigue life, the larger the number of rolling elements, the better. In order to increase the number of rolling elements, it is necessary to increase the pitch diameter of the rolling elements. . On the other hand, when the outer diameter of the cage is increased, as shown in FIG. 10, it contacts the input / output disk. Therefore, if the outer thickness to is thicker than the inner thickness ti, the outer diameter is inevitably changed. The moving body pitch diameter is reduced.
[0010]
Therefore, in order to increase the pitch diameter of the rolling elements while maintaining the outer diameter of the cage, the outer wall thickness to is made thinner than the inner wall thickness ti. However, in the conventional power roller bearing support structure, Since the inner radial gap δi between the pocket hole and the rolling element and the outer radial gap δo between the pocket hole and the rolling element are the same gap, the pocket hole and the rolling element of the cage are shown in FIG. The positional relationship is as shown in FIG.
[0011]
Therefore, when the cage is eccentric in the radial direction due to vibration or the like, as shown in FIG. 11, the rolling element may collide with the outer thick portion having a small thickness and weak strength, and the cage strength is insufficient. There is a problem.
[0012]
Moreover, in a general bearing, as shown in FIG. 12, as a structure of the cage, an annular portion between the rolling element and the center of the bearing, and the annular portion connected to the rolling element are disposed between the rolling elements. What consists of a columnar part, ie, a thing with an outer wall thickness of zero, is known. However, this bearing has a problem that when the rolling element and the columnar part of the cage collide with each other suddenly, the columnar part is cantilevered, so that the stress at the base part becomes high and the strength is insufficient.
[0013]
The problem to be solved by the present invention is a power capable of exhibiting high cage strength even if the cage is eccentric in the radial direction due to vibration or the like while ensuring a large rolling element pitch diameter while maintaining the cage outer diameter as it is. An object of the present invention is to provide a toroidal continuously variable transmission having a roller bearing support structure.
[0014]
[Means for Solving the Problems]
In the invention according to claim 1 of the present invention, an input disk and an output disk that are coaxially arranged opposite to each other;
A power roller clamped between these input / output disks so that power can be transmitted;
Of the input disk or the output disk, a pressing means disposed on the back of one disk and pressing toward the other disk;
A power roller support member capable of tilting around a swing axis perpendicular to the pivot shaft while rotatably supporting the power roller;
A plurality of rolling elements that are sandwiched between the power roller and the outer ring and roll in raceway grooves provided in the power roller and the outer ring;
A toroidal continuously variable transmission having a plurality of pocket holes penetrating in the direction of the rotation axis of the power roller, and a retainer for holding the rolling elements so as not to fall off the raceway grooves in the pocket holes. ,
The inner wall thickness between the inner peripheral surface of the cage and the pocket hole is thicker than the outer wall thickness between the outer peripheral surface of the cage and the pocket hole,
In addition, the radial inner gap between the pocket hole and the rolling element is set smaller than the radial outer gap between the pocket hole and the rolling element.
[0015]
According to a second aspect of the present invention, in the toroidal continuously variable transmission according to the first aspect, the diameter of the circle connecting the centers of the pocket holes is larger than the rolling element pitch diameter which is the diameter of the circle connecting the centers of the rolling elements. This is characterized in that the pocket hole pitch diameter is increased.
[0016]
According to a third aspect of the present invention, in the toroidal continuously variable transmission according to the first aspect, the circumferential hole diameter of the pocket hole is a hole longer than the radial hole diameter of the pocket hole. .
[0017]
In invention of Claim 4, in the toroidal type continuously variable transmission of Claim 1, a ball is used as the rolling element,
The radius of curvature of the pocket hole on the inner diameter side of the cage is made smaller than other portions.
[0018]
Operation and effect of the invention
In the first aspect of the present invention, first, the cage is provided with a plurality of pocket holes by making the inner peripheral surface and the inner wall thickness thicker than the outer wall thickness of the outer peripheral surface. . In other words, considering the raceway grooves of the power roller and the outer ring from the viewpoint of rolling fatigue life, the larger the number of rolling elements, the better. In order to increase the number of rolling elements, it is necessary to increase the pitch diameter of the rolling elements. . On the other hand, when the outer diameter of the cage is increased, the cage comes into contact with the input / output disk. Therefore, the outer diameter of the cage cannot be increased unless the entire design including the input / output disk is changed.
On the other hand, by reducing the outer wall thickness, the rolling element pitch diameter can be increased even if the outer diameter of the cage remains unchanged.
Also, the rolling elements are held in the respective pocket holes of the cage, and when assembled, the rolling elements are fitted into the raceway grooves of the power roller and the raceway grooves of the outer ring, and the diameters of the pocket holes and the rolling elements when assembly is completed. The inner gap in the direction is set to be smaller than the outer gap in the radial direction between the pocket hole and the rolling element.
Therefore, even if the cage tries to be eccentric in the radial direction due to vibration or the like, the radial inner gap between the pocket hole and the rolling element is smaller than the outer gap, so the eccentric force is supported on the thicker inner diameter side that comes in contact first. As a result, the generated stress on the inner diameter side is low, and no breakage occurs, and a high cage strength can be exhibited.
[0019]
In the invention according to claim 2 of the present invention, the pocket hole pitch diameter, which is the diameter of the circle connecting the centers of the pocket holes, is larger than the rolling element pitch diameter, which is the diameter of the circle connecting the centers of the rolling elements. Is done.
That is, the raceway groove of the power roller and the raceway groove of the outer ring are set so that the rolling element pitch diameter is smaller than the pocket hole pitch diameter. That is, the rolling element pitch diameter is defined in advance by the raceway groove.
Therefore, when setting the pocket hole, if it is set to have a pocket hole pitch diameter larger than the rolling element pitch diameter, the shape of the pocket hole is not a complicated shape such as an ellipse, but a simple circular shape is charged. The configuration according to Item 1, that is, the configuration in which the radial inner clearance between the pocket hole and the rolling element is set smaller than the outer clearance can be realized, and the manufacturing cost can be suppressed.
[0020]
In the invention according to claim 3 of the present invention, the circumferential hole diameter of the pocket hole is made longer than the radial hole diameter of the pocket hole.
That is, when a radial load due to power transmission acts on the power roller, the power roller is displaced in the direction of the tilting axis with respect to the outer ring, so that the contact angle between the rolling element, the power roller and the raceway groove of the outer ring is on the circumference. Different values. At this time, the revolution speed of the rolling element changes depending on the contact angle, whereas the revolution speed of the cage is constant, so that a circumferential contact force is generated between the rolling element and the cage. .
Therefore, a circumferential clearance is secured between the rolling element and the pocket hole, and even if a radial load is applied to the power roller, generation of a circumferential contact force between the rolling element and the cage is prevented. can do.
On the other hand, since the gap between the rolling element and the cage is increased, the collision force between the rolling element and the cage due to vibration or the like is increased. However, since the radial inner clearance between the pocket hole and the rolling element is smaller than the outer clearance, even if the cage moves in the radial direction due to vibration or the like and the eccentric force acts, the eccentric force is increased on the thick inner diameter side. Can be supported.
[0021]
In the invention according to the fourth aspect of the present invention, a ball is used as the rolling element, and the radius of curvature of the pocket hole on the inner diameter side of the cage is made smaller than the other portions.
That is, when the cage is eccentric in the radial direction due to vibration or the like, the eccentric force is received by contact with the rolling element on the inner diameter side, but the radius of curvature of the pocket hole on the inner diameter side of the cage is smaller than other portions. This makes it possible to make this radius of curvature substantially coincide with the radius of curvature of the ball as the rolling element, thereby increasing the contact area and reducing the surface pressure between the inner diameter side of the pocket hole retainer and the ball. .
Therefore, the surface pressure between the inner diameter side of the cage hole in the pocket hole and the ball is reduced, and even if a large radial eccentric force or a high frequency eccentric force acts, the cage can be prevented from being worn or seized. Can do.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
The first embodiment is a toroidal-type continuously variable transmission corresponding to the inventions described in claims 1 and 2.
[0023]
[overall structure]
FIG. 1 is an overall configuration diagram showing a toroidal type continuously variable transmission according to the first embodiment. Reference numeral 10 denotes a toroidal type continuously variable transmission. A rotational driving force from an engine (not shown) is input via a torque converter 12. The The torque converter 12 includes a pump impeller 12a, a turbine runner 12b, a stator 12c, a lockup clutch 12d, an apply side oil chamber 12e, a release side oil chamber 12f, and the like, and an input shaft 14 passes through the center thereof.
[0024]
The input shaft 14 is connected to a forward / reverse switching mechanism 36, and the mechanism 36 includes a planetary gear mechanism 42, a forward clutch 44, a reverse brake 46, and the like. The planetary gear mechanism 42 includes a pinion carrier 42a that supports a double pinion, a ring gear 42b that meshes with the double pinion, and a sun gear 42c. The pinion carrier 42 a of the planetary gear mechanism 42 is connected to the torque transmission shaft 16, and the first continuously variable transmission mechanism 18 and the second continuously variable transmission mechanism 20 are connected to the torque transmission shaft 16 on the downstream side in the transmission case 22. Placed in tandem (dual cavity type). A control valve body is disposed on the base indicated by reference numeral 64.
[0025]
The first continuously variable transmission mechanism 18 has a pair of input disks 18a and output disks 18b whose opposing surfaces are formed in a toroidal curved surface, and is sandwiched between the opposing surfaces of the input / output disks 18a and 18b and transmits torque. A pair of power rollers 20c and 18d arranged symmetrically with respect to the shaft 16, a support member that supports the power rollers 20c and 18d so as to be tiltable, and a servo piston (FIG. 2) as a hydraulic actuator are provided. Similarly, the second continuously variable transmission mechanism 20 includes a pair of input disks 20a and output disks 20b whose opposing surfaces are formed in a toroidal curved surface, a pair of power rollers 20c and 20d, a support member thereof, and a servo piston (FIG. 2). Prepare.
[0026]
On the torque transmission shaft 16, the continuously variable transmission mechanisms 18 and 20 are arranged in opposite directions so that the output disks 18b and 20b face each other. The input disks 18a and 20a of the first continuously variable transmission mechanism 18 are torque converters. 12 is pressed toward the right side in the axial direction in the figure by a loading cam device 34 that generates a pressing force corresponding to the input torque 12. The loading cam device 34 has a loading cam 34 a and is supported on the shaft 16 via a slide bearing 38. The input disk 18a of the first continuously variable transmission mechanism 18 and the input disk 20a of the second continuously variable transmission mechanism 20 are pressed and urged toward the left in the axial direction by a disc spring 40. The loading cam device 34 and the disc spring 40 correspond to the pressing means described in the claims. The input disks 18a and 20a are supported by the transmission shaft 16 via the ball splines 24 and 26 so as to be rotatable and movable in the axial direction.
[0027]
In the above mechanism, each of the power rollers 20c and 20d is tilted so as to obtain a tilt angle corresponding to the gear ratio by an operation described later, and the input rotation of the input disks 18a and 20a is steplessly (continuously) shifted. Then, it is transmitted to the output disks 18b and 20b. The output disks 18b and 20b are spline-coupled with an output gear 28 fitted on the torque transmission shaft 16 so as to be relatively rotatable, and the transmission torque is a gear coupled to an output shaft (counter shaft) 30 via the output gear 28. The gears 28 and 30a constitute a torque transmission mechanism 32. Further, a transmission mechanism 48 including gears 52 and 56 provided on the output shafts 30 and 50 and an idler gear 54 meshing with the gears 52 and 56 is provided, and the output shaft 50 is connected to the propeller shaft 60.
[0028]
[Configuration of shift control system]
A shift control system for tilting the power rollers 18c, 18d, 20c, and 20d so as to obtain a tilt angle corresponding to the gear ratio will be described with reference to a schematic diagram shown in FIG.
[0029]
First, each of the power rollers 18c, 18d, 20c, and 20d is supported at one end of the trunnions 17a, 17b, 27a, and 27b (power roller support members) so as to be rotatable around the pivot shafts 15a, 15b, 25a, and 25b. Yes. At the other end of the trunnions 17a, 17b, 27a, 27b, servo pistons are provided as hydraulic actuators that move the trunnions 17a, 17b, 27a, 27b in the axial direction to tilt the power rollers 18c, 18d, 20c, 20d. 70a, 70b, 72a, 72b are provided.
[0030]
As a hydraulic control system for controlling the operation of the servo pistons 70a, 70b, 72a, 72b, a high oil passage 74 connected to the high oil chamber, a low oil passage 76 connected to the low oil chamber, A shift control valve 78 having a port 78a for connecting the side oil passage 74 and a port 78b for connecting the low side oil passage 76 is provided. A line pressure from a hydraulic pressure source having an oil pump 80 and a relief valve 82 is supplied to the line pressure port 78 c of the shift control valve 78. The speed change spool 78d of the speed change control valve 78 detects the axial direction and the tilt direction of the trunnion 17a and interlocks with a lever 84 and a recess cam 86 that feed back to the speed change control valve 78. The speed change sleeve 78e of the speed change control valve 78 is driven by the step motor 88 so as to be displaced in the axial direction.
[0031]
A CVT controller 110 is provided as an electronic control system for driving and controlling the step motor 88. The CVT controller 110 includes a throttle opening sensor 112, an engine rotation sensor 114, an input shaft rotation sensor 116, an output shaft rotation sensor (vehicle speed). Input information from the sensor 118 or the like is taken in.
[0032]
[Power roller bearing support structure]
The configuration of the bearing support structure of the power roller 20c selected as a representative from the power rollers 18c, 18d, 20c, and 20d will be described with reference to FIG. The same structure is adopted for the other power rollers 18c, 18d, and 20d.
[0033]
The trunnion 27a supports the power roller 20c so as to be rotatable about the pivot shaft 25a at the position of the power roller storage portion 90 that is recessed at one end. The trunnion 27a can be tilted around a swing axis that is orthogonal to the pivot shaft 25a.
[0034]
The power roller 20 c is rotatably supported on the outer ring 92 via a plurality of balls 91 and is rotatably supported on the pivot shaft 25 a via a radial bearing 93. The outer ring 92 is fixed to the pivot shaft 25a, and a thrust bearing 94 that allows the outer ring 92 to slide is interposed between the outer ring 92 and the power roller housing 90.
[0035]
The plurality of balls 91 are sandwiched between the power roller 20 c and the outer ring 92, and roll along the power roller side raceway groove 95 and the outer ring side raceway groove 96 formed in the power roller 20 c and the outer ring 92. . A retainer 97 is disposed between the power roller 20c and the outer ring 92. The retainer 97 has a plurality of pocket holes 98 penetrating in the direction of the power roller rotation axis at equal intervals. One ball 91 is rotatably held in each of the holes 98.
[0036]
The relationship among the ball 91, the raceway grooves 95 and 96, the retainer 97, and the pocket hole 98 will be described with reference to FIG.
[0037]
The diameter of a circle connecting the centers of a plurality of balls 91, and the rolling element pitch diameter dmb defined by the raceway grooves 95 and 96 is increased. Thereby, the number of balls 91 is increased from the current state. The outer diameter of the cage 97 is the same as the current state, but as shown in FIG. 4, it is the diameter of a circle connecting the centers of the pocket holes 98 of the cage 97 rather than the rolling element pitch diameter dmb. The pocket hole pitch diameter dmc is set to be large, and the center hole diameter of the retainer 97 is set to a small diameter at such a level that interference with the pivot shaft 25a does not cause a problem.
[0038]
As a result, only by changing the design of the ball 91, the raceway grooves 95 and 96, and the bearing portion by the cage 97, the inner wall between the inner peripheral surface of the cage 97 and the pocket hole 98 as shown in FIG. The thickness ti is made thicker than the outer wall thickness to between the outer peripheral surface of the cage 97 and the pocket hole 98, and the radial inner gap δi between the pocket hole 98 and the ball 91 is It was set to be smaller than the radial outer gap δo with respect to 91.
[0039]
Next, the operation will be described.
[0040]
[Gear ratio control action]
The toroidal CVT changes the gear ratio by tilting the power rollers 18c, 18d, 20c, and 20d. That is, when the speed change sleeve 78e is displaced by rotating the step motor 88, the hydraulic oil is guided to one servo piston chamber of the servo pistons 70a, 70b, 72a, 72b, and the hydraulic oil is discharged from the other servo piston chamber. The rotation centers of the power rollers 18c, 18d, 20c, and 20d are offset with respect to the rotation centers of the disks 18a, 18b, 20a, and 20b. By this offset, a tilting force is generated in the power rollers 18c, 18d, 20c, and 20d, and the tilting angle changes.
This tilting motion and offset are transmitted to the transmission spool 78d via the recess cam 86 and the lever 84, and stop at a balance position with the transmission sleeve 78e displaced by the step motor 88.
Note that the step motor 88 displaces the speed change sleeve 78e in accordance with a drive command from the CVT controller 90 that obtains the target speed ratio.
[0041]
[Bearing support of power roller]
[0042]
First, the cage 97 is provided with a plurality of pocket holes 98 having an inner peripheral surface and an inner wall thickness ti larger than an outer wall thickness to of the outer peripheral surface.
[0043]
That is, considering the raceway grooves 95 and 96 of the power roller 20c and the outer ring 92 from the viewpoint of rolling fatigue life, the larger the number of balls 91, the better. In order to increase the number of balls 91, the rolling element pitch diameter dmb is set to It needs to be bigger. On the other hand, when the outer diameter of the cage is increased, as apparent from FIG. 3, the cage comes into contact with the input / output disks 20a and 20b. The diameter cannot be increased.
[0044]
On the other hand, by reducing the outer wall thickness to, the rolling element pitch diameter dmb can be increased even if the outer diameter of the cage remains unchanged.
[0045]
Further, the balls 91 are respectively held in the pocket holes 98 of the cage 97, and the balls 91 are fitted into the power roller side raceway grooves 95 and the outer ring side raceway grooves 96 when assembled. Then, the pocket hole pitch diameter dmc which is the diameter of the circle connecting the centers of the pocket holes 98 of the cage 97 is set larger than the rolling element pitch diameter dmb which is the diameter of the circle connecting the centers of the plurality of balls 91. Thus, in the assembled state, the radial inner clearance δi between the pocket hole 98 and the ball is set to be smaller than the radial outer clearance δo between the pocket hole 98 and the ball 91.
[0046]
Therefore, even if the cage 97 tries to be eccentric in the radial direction due to vibration or the like, the radial inner gap δi between the pocket hole 98 and the ball 91 is smaller than the outer gap δo. Since the eccentric force is supported, the generated stress on the inner diameter side is low, and no breakage occurs, and a high cage strength can be exhibited.
[0047]
Further, since the rolling element pitch diameter dmb is defined in advance by the power roller side raceway groove 95 and the outer ring side raceway groove 96, the pocket hole pitch diameter dmc is larger than the rolling element pitch diameter dmb when the pocket hole 98 is set. If it is set, the inside clearance δi in the radial direction between the pocket hole 98 and the ball 91 is changed to the outside clearance δo by making the shape of the pocket hole 98 a simple circular shape without making it a complicated shape such as an ellipse. A configuration in which the setting is smaller can be realized.
[0048]
Next, the effect will be described.
(1) The inner wall thickness ti between the inner peripheral surface of the cage 97 and the pocket hole 98 is made thicker than the outer wall thickness to between the outer peripheral surface of the cage 97 and the pocket hole 98, and the pocket The radial inner clearance δi between the hole 98 and the ball 91 is set smaller than the radial outer clearance δo between the pocket hole 98 and the ball 91, so that the rolling element pitch diameter dmb is kept large with the cage outer diameter unchanged. However, even if the cage 97 is eccentric in the radial direction due to vibration or the like, high cage strength can be exhibited.
(2) Since the pocket hole pitch diameter dmc, which is the diameter of the circle connecting the centers of the pocket holes 98, is larger than the rolling element pitch diameter dmb, which is the diameter of the circle connecting the centers of the balls 91, the shape of the pocket holes 98 is simplified. By adopting such a perfect circular configuration, it is possible to realize a configuration in which the radial inner gap δi between the pocket hole 98 and the ball 91 is set smaller than the outer gap δo. As a result, the shape of the pocket hole 98 can be reduced. The manufacturing cost can be reduced as compared with the case of an elliptical shape or the like.
[0049]
(Embodiment 2)
The second embodiment is a toroidal continuously variable transmission corresponding to the invention described in claim 3.
[0050]
In the second embodiment, as shown in FIG. 5, a plurality of pocket holes formed in the retainer 97 are formed with pocket holes 98 ′ formed by holes whose circumferential hole diameter Lc is longer than the radial hole diameter Lr. It is a thing. Since other configurations are the same as those of the first embodiment, illustration and description thereof are omitted.
[0051]
To explain the operation, the power roller 20c has a radial load (thrust load) due to transmission of power in addition to an axial load (thrust load) due to the pressing force from the input / output disks 20a and 20b, as shown in FIG. Radial load) works. For this reason, the Herzt contact portion between the outer ring side raceway groove 96 and the ball 91 is elastically deformed, and the power roller 20c is displaced in the direction of the tilting axis with respect to the outer ring 92, so that the contact between the ball 91, the power roller 20c and the outer ring 92 is achieved. The angle α takes different values, for example, α1 and α2 in FIG. At this time, according to the literature, the revolution speed Nb of the ball 91 is
Nb = {1- (cos α / (dm / da))} · (Ni / 2)
dm: ball pitch diameter, da: ball diameter, Ni: power roller rotation speed, which varies depending on the contact angle α, while the revolution number of the cage 97 is constant. During the period 97, a circumferential contact force is generated.
[0052]
On the other hand, a circumferential clearance between the ball 91 and the pocket hole 98 ′ is ensured by setting the pocket hole 98 ′ to be a hole whose circumferential hole diameter Lc is longer than the radial hole diameter Lr. Even if a radial load is applied to the power roller 20c, it is possible to prevent the circumferential contact force between the ball 91 and the cage 97 from being generated.
[0053]
In this case, since the gap between the ball 91 and the pocket hole 98 ′ is increased, the collision force between the ball 91 and the cage 97 due to vehicle vibration or the like is increased.
However, in the second embodiment, since the radial inner gap δi between the pocket hole 98 ′ and the ball 91 is smaller than the outer gap δo, the cage 97 moves in the radial direction due to vibration or the like, and the eccentric force acts. However, since the eccentric force is supported on the thick inner diameter side, the cage 97 is not damaged.
[0054]
To explain the effect, in the second embodiment, the pocket hole 98 ′ is a hole in which the circumferential hole diameter Lc is longer than the radial hole diameter Lr. Therefore, even if a radial load acts on the power roller 20 c, Generation of circumferential contact force between 91 and the retainer 97 can be prevented.
[0055]
(Embodiment 3)
The third embodiment is a toroidal continuously variable transmission corresponding to the fourth aspect of the invention.
[0056]
In the third embodiment, as shown in FIG. 7, a ball 91 is used as a rolling element, the pocket hole 98 ″ has a radius of curvature ri on the inner diameter side of the cage smaller than the radius of curvature ro of the other part. Since other configurations are the same as those of the first embodiment, illustration and description thereof are omitted.
[0057]
Explaining the operation, when the cage 97 is eccentric in the radial direction due to vibration of the vehicle or the like, an eccentric force is received by contact with the ball 91 on the inner diameter side of the cage 97, but the pocket hole 98 "is retained. Since the radius of curvature ri on the inner diameter side of the vessel is smaller than the radius of curvature ro of the other part, this radius of curvature ri can be made substantially coincident with the radius of curvature of the ball 91 that is a rolling element, thereby increasing the contact area. The surface pressure between the cage inner diameter side of the pocket hole 98 ″ and the ball 91 can be lowered.
[0058]
The effect will be described. In the third embodiment, the ball 91 is used as a rolling element, and the pocket hole 98 ″ is a hole in which the radius of curvature ri on the inner diameter side of the cage is smaller than the radius of curvature ro of other portions. Even if the eccentric force in the radial direction or the eccentric force acts frequently, it is possible to prevent the retainer 97 from being worn or seized by the balls 91.
[0059]
(Other embodiments)
As mentioned above, although Embodiment 1-Embodiment 3 were demonstrated, about a specific structure, it is not limited to what was described in these Embodiment, It has the component of Claim 1. Anything is included in the present invention.
[0060]
For example, in the first to third embodiments, the example in which the power roller is rotatably supported by the shaft (pivot shaft) has been shown. However, the power roller can also be rotatably supported by the rolling element without using the shaft Can be applied.
[Brief description of the drawings]
1 is an overall system diagram showing a toroidal type continuously variable transmission according to a first embodiment;
FIG. 2 is a shift control system diagram showing the toroidal-type continuously variable transmission according to the first embodiment.
FIG. 3 is a sectional view showing a bearing support structure for a power roller in the toroidal-type continuously variable transmission according to the first embodiment.
4 is a view showing a cage and balls as rolling elements in the bearing support structure of Embodiment 1. FIG.
FIG. 5 is a view showing a cage and balls as rolling elements in the bearing support structure of the second embodiment.
FIG. 6 is an operation explanatory view showing a state in which a load received from a power roller is supported by a bearing portion in the bearing support structure of the second embodiment.
7 is a view showing a cage and balls as rolling elements in the bearing support structure of Embodiment 3. FIG.
FIG. 8 is a sectional view showing a bearing support structure for a power roller in a conventional toroidal-type continuously variable transmission.
FIG. 9 is a view showing a cage and a rolling element in a conventional bearing support structure.
FIG. 10 is a diagram showing a relationship between an input / output disk and a cage outer diameter, and a rolling element pitch diameter and a wall thickness in a conventional bearing support structure.
FIG. 11 is a diagram showing a collision between a rolling element and a cage on which an eccentric force acts in a conventional bearing support structure.
FIG. 12 is a view showing a bearing support structure known as a general bearing structure.
[Explanation of symbols]
20a input disk 20b output disk 20c power roller 25a pivot shaft 27a trunnion (power roller support member)
34 Loading cam device (pressing member)
40 Belleville spring (pressing member)
90 Power roller storage 91 Ball (rolling element)
92 Outer ring 93 Radial bearing 94 Thrust bearing 95 Power roller side raceway groove 96 Outer ring side raceway groove 97 Cage 98 Pocket hole ti Inner wall thickness to outer wall thickness δi Inner gap δo Outer gap

Claims (4)

An input disk and an output disk disposed coaxially and oppositely;
A power roller clamped between these input / output disks so that power can be transmitted;
Of the input disk or the output disk, a pressing means disposed on the back of one disk and pressing toward the other disk;
A power roller support member capable of tilting around a swing axis perpendicular to the pivot shaft while rotatably supporting the power roller;
A plurality of rolling elements that are sandwiched between the power roller and the outer ring and roll in raceway grooves provided in the power roller and the outer ring;
A toroidal continuously variable transmission having a plurality of pocket holes penetrating in the direction of the rotation axis of the power roller, and a retainer for holding the rolling elements so as not to fall off the raceway grooves in the pocket holes. ,
The inner wall thickness between the inner peripheral surface of the cage and the pocket hole is thicker than the outer wall thickness between the outer peripheral surface of the cage and the pocket hole,
A toroidal continuously variable transmission characterized in that the radial inner clearance between the pocket hole and the rolling element is set smaller than the radial outer clearance between the pocket hole and the rolling element. The toroidal continuously variable transmission according to claim 1,
A toroidal continuously variable transmission characterized in that a pocket hole pitch diameter, which is a diameter of a circle connecting the centers of the pocket holes, is made larger than a rolling element pitch diameter, which is a diameter of a circle connecting the centers of the rolling elements. The toroidal continuously variable transmission according to claim 1,
A toroidal continuously variable transmission characterized in that a circumferential hole diameter of the pocket hole is made longer than a radial hole diameter of the pocket hole. The toroidal continuously variable transmission according to claim 1,
Using balls as the rolling elements,
A toroidal continuously variable transmission characterized in that a radius of curvature of the pocket hole on the inner diameter side of the cage is made smaller than that of other portions.

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