JP2018091490A - Power roller unit for toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a structure capable of stabilizing shift operation and facilitating securement of durability.SOLUTION: An outer ring of a thrust rolling bearing is supported in an oscillation displaceable manner, by engaging a concave part provided on an outside surface of the outer ring with a cylindrical convex surface of a support beam part of a trunnion. Or, by engaging a concave groove 27 formed in a circumferential direction and a projection 28 formed on the cylindrical convex surface to the concave part, displacement of the outer ring on an axial direction of a central axis of the cylindrical convex surface is restricted. Further, by crowning both end parts in the circumferential direction on both outside surfaces of the projection 28, inclined convex surface parts 29, 29 are provided at both end parts in the circumferential direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a generator (generator) used in, for example, an automatic transmission for a vehicle (automobile), an automatic transmission for a construction machine (construction machine), an aircraft (a fixed wing aircraft, a rotary wing aircraft, an airship, etc.), etc. The present invention relates to an improvement of a power roller unit incorporated in a half-toroidal toroidal continuously variable transmission that is used as an automatic transmission for adjusting the operating speed of various industrial machines such as automatic transmissions and pumps.

  The use of a half-toroidal toroidal continuously variable transmission as a transmission for an automobile is described in many publications such as Patent Documents 1 to 4 and partially implemented, and is well known. Further, a structure in which a toroidal type continuously variable transmission and a planetary gear mechanism are combined to widen the adjustment range of the gear ratio is also described in many publications such as Patent Document 5 and has been widely known. 7 to 8 show a first example of a toroidal-type continuously variable transmission described in these patent documents and widely known in the past. In the case of the first example of this conventional structure, a pair of input disks 2 and 2 are disposed around the portions near both ends of the input rotation shaft 1 in a state where the inner surfaces, each of which is a toroidal curved surface, face each other. The rotation synchronized with the rotating shaft 1 is supported. An output tube 3 is supported around the intermediate portion of the input rotary shaft 1 so as to be rotatable with respect to the input rotary shaft 1. Further, on the outer peripheral surface of the output cylinder 3, an output gear 4 is fixed at the center in the axial direction, and a pair of output disks 5 and 5 are connected to both ends in the axial direction by spline engagement. Supports the rotation synchronized with. In this state, the outer surfaces of the output disks 5 and 5, each of which is a toroidal curved surface, are opposed to the inner surfaces of the input disks 2 and 2.

  Further, a plurality of power rollers 6, 6 each having a spherical convex surface are sandwiched between the input disks 2, 2 and the output disks 5, 5. The power rollers 6 and 6 are rotatably supported by trunnions 7 and 7, respectively. The trunnions 7 and 7 are tilted with respect to the central axes of the disks 2 and 5, respectively. The shafts 8 and 8 are supported so as to be swingable and displaceable. That is, each of the trunnions 7 and 7 includes a pair of tilting shafts 8 and 8 provided concentrically with each other at both axial ends, and a supporting beam existing between the tilting shafts 8 and 8. These tilting shafts 8 and 8 are pivotally supported with respect to the support plates 10 and 10 via radial needle bearings 11 and 11, respectively.

  Each of the power rollers 6 and 6 includes support shafts 12 and 12 in which the base half portion and the tip half portion are eccentric to each other on the inner surface of the support beam portions 9 and 9 constituting the trunnions 7 and 7, respectively. Via a plurality of rolling bearings, the support shafts 12 and 12 are supported so as to be able to rotate around the front half of each of the support shafts 12 and 12 and to be slightly oscillated and displaced around the base half of each of the support shafts 12 and 12. ing. Between the outer side surfaces of the power rollers 6 and 6 and the inner side surfaces of the support beam portions 9 and 9 constituting the trunnions 7 and 7, each is a part of the plurality of rolling bearings. The thrust ball bearings 13 and 13 and the thrust needle bearings 14 and 14 are provided in order from the power rollers 6 and 6 side. Of these, the thrust ball bearings 13, 13 allow the power rollers 6, 6 to rotate while supporting a load in the thrust direction applied to the power rollers 6, 6. Each of the thrust ball bearings 13, 13 includes a plurality of balls 18 between an inner ring raceway 15 formed on the outer side surface of each of the power rollers 6, 6 and an outer ring raceway 17 formed on the inner side surface of the outer ring 16. , 18 are provided to be able to roll. The thrust needle roller bearings 14, 14 support thrust loads applied to the outer rings 16, 16 constituting the thrust ball bearings 13, 13 from the power rollers 6, 6. The front half of each of the support shafts 12 and 12 is allowed to swing around the base half of each of the support shafts 12 and 12.

  During operation of the toroidal-type continuously variable transmission as described above, one input disk 2 (left side in FIG. 7) is rotationally driven by the drive shaft 19 via the pressing device 20. As a result, the pair of input disks 2 and 2 supported at both ends of the input rotating shaft 1 rotate synchronously while being pressed in a direction approaching each other. The rotation is transmitted to the output disks 5 and 5 through the power rollers 6 and 6 and is taken out from the output gear 4. When changing the gear ratio between the input rotary shaft 1 and the output gear 4, the trunnions 7, 7 are displaced in the axial direction of the tilt shafts 8, 8 by hydraulic actuators 21, 21. . As a result, the direction of the tangential force acting on the rolling contact portion (traction portion) between the outer peripheral surface of each of the power rollers 6 and 6 and the inner surface of each of the disks 2 and 5 changes (to the rolling contact portion). Side slip occurs). As the direction of the force changes, the trunnions 7 and 7 swing around their tilt shafts 8 and 8, and the outer peripheral surfaces of the power rollers 6 and 6 and the disks 2 and 8. The contact position with the inner surface of 5 changes. The outer peripheral surface of each of these power rollers 6 and 6 is in rolling contact with the radially outward portion of the inner surface of both input disks 2 and 2 and the radially inward portion of the inner surface of both output disks 5 and 5. By doing so, the gear ratio between the input rotary shaft 1 and the output gear 4 is increased. On the other hand, the outer peripheral surface of each of the power rollers 6, 6 is radially inward of the inner side surfaces of the input disks 2, 2 and the radially outer side of the inner surfaces of the output disks 5, 5. If it is brought into rolling contact with the portion, the gear ratio between the input rotary shaft 1 and the output gear 4 becomes the deceleration side.

  When the toroidal type continuously variable transmission as described above is operated, the members used for power transmission, that is, the input and output disks 2 and 5 and the power rollers 6 and 6 are connected to the pressing device 20. It is elastically deformed based on the pressing force generated. In accordance with this elastic deformation, the input and output disks 2 and 5 are displaced in the axial direction. The pressing force generated by the pressing device 20 increases as the torque transmitted by the toroidal continuously variable transmission increases, and the amount of elastic deformation of the members 2, 5, 6 increases accordingly. Therefore, in order to properly maintain the contact state between the inner surface of each of the input and output disks 2 and 5 and the outer peripheral surface of each of the power rollers 6 and 6 regardless of the fluctuation of the torque, each of the trunnions 7 and 7, a mechanism for displacing the power rollers 6 and 6 in the axial direction of the disks 2 and 5 is required. In the case of the above-described first example of the conventional structure, the tip half of each of the support shafts 12 and 12 that support the power rollers 6 and 6 is also oscillated and displaced about the base half as well. The power rollers 6 and 6 are displaced in the axial direction of the disks 2 and 5.

  In the first example of the conventional structure as described above, the structure for displacing the power rollers 6 and 6 in the axial direction of the disks 2 and 5 is complicated. However, it is inevitable that the cost will increase. As a technique for solving such a problem, Patent Document 3 describes a structure as shown in FIGS. Since the present invention improves the second example of the conventional structure shown in FIGS. 9 to 14, the second example of the conventional structure will be described next. The feature of the second example of this conventional structure is the structure of the portion that supports the trunnion 7a so that the power roller 6a can be displaced in the axial direction of the input and output disks 2, 5 (see FIG. 7). The basic structure and operation of the toroidal type continuously variable transmission as a whole are the same as those of the first example of the conventional structure shown in FIGS.

  The trunnion 7a constituting the second example of the conventional structure exists between a pair of tilting shafts 8a and 8b concentrically provided at both ends, and between these tilting shafts 8a and 8b, and at least A support having a cylindrical convex surface 22 on the inner side (upper side of FIGS. 10, 13, and 14) of the input and output disks 2 and 5 (see FIG. 7) in the radial direction (vertical direction of FIGS. 10, 13, and 14). And a beam portion 23. The two tilting shafts 8a and 8b are supported on the support plates 10 and 10 (see FIG. 8) via the radial needle bearings 11a and 11a, respectively, so that they can swing and be displaced in the axial direction.

  Further, as shown in FIGS. 10 and 13, the center axis A of the cylindrical convex surface 22 is parallel to the center axis B of the both tilt axes 8a and 8b, and the center axis B of the both tilt axes 8a and 8b. Rather than the outer side (the lower side of FIGS. 10, 13, 14) in the radial direction of the disks 2, 5. Further, a concave portion 24 having a partially cylindrical surface is radially crossed on the outer surface of the outer ring 16a constituting the thrust ball bearing 13a provided between the support beam portion 23 and the outer surface of the power roller 6a. It is provided in the state. And this recessed part 24 and the cylindrical convex surface 22 of the said support beam part 23 are engaged, and the said outer ring 16a is rockable displacement about the axial direction of each said disks 2 and 5 with respect to the said trunnion 7a. I support it.

  Further, a support shaft 12a is fixed to the center of the inner surface of the outer ring 16a integrally with the outer ring 16a, and the power roller 6a is rotatable around the support shaft 12a via a radial needle bearing 25. I support it. Furthermore, a pair of stepped surfaces 26 and 26 facing each other are provided on the inner surface of the trunnion 7a at a continuous portion between both end portions of the support beam portion 23 and the pair of tilting shafts 8a and 8b. . Then, these stepped surfaces 26, 26 and the outer peripheral surface of the outer ring 16a constituting the thrust ball bearing 13a are brought into contact with or in close proximity to each other, and any traction force applied from the power roller 6a to the outer ring 16a is selected. These step surfaces 26 and 26 can be supported.

According to the toroidal type continuously variable transmission of the second example of the conventional structure configured as described above, the power roller 6a is displaced in the axial direction of each of the disks 2 and 5, and the amount of elastic deformation of each constituent member is increased. Regardless of the change, a structure capable of appropriately maintaining the contact state between the outer peripheral surface of the power roller 6a and the one side surface in the axial direction of each of the disks 2 and 5 can be configured simply and at low cost.
That is, during operation of the toroidal continuously variable transmission, the power rollers 6a are displaced in the axial direction of the disks 2 and 5 based on elastic deformation of the input and output disks 2 and 5 and the power rollers 6a. When necessary, the outer ring 16a of the thrust ball bearing 13a that rotatably supports each of the power rollers 6a is provided with a concave portion 24 having a partial cylindrical surface provided on the outer surface and a cylindrical convex surface 22 of the support beam portion 23. The sliding surface of the cylindrical convex surface 22 is oscillated and displaced about the central axis a. Based on this oscillating displacement, the portion of the outer peripheral surface of each power roller 6a that is in rolling contact with one axial side surface of each disk 2, 5 is displaced in the axial direction of each disk 2, 5; The contact state is properly maintained.

  As described above, the central axis A of the cylindrical convex surface 22 is larger in diameter than the central axes B of the tilting shafts 8a and 8b, which are the oscillation centers of the trunnions 7a during the shifting operation. Exists with respect to the direction. Therefore, the radius of the rocking displacement about the central axis A of the cylindrical convex surface 22 is larger than the rocking radius at the time of the speed change operation, and both the input disks 2 and 2 and the both output disks 5, 5 Has little effect on the change in the transmission ratio between (and can be neglected or remain within an easily modifiable range).

  In the case of the second example of the conventional structure shown in FIGS. 9 to 14, parts manufacturing, parts management, and assembly work are all easier than the first example shown in FIGS. Although easy to achieve, there is room for improvement in terms of stabilizing the shifting operation. The reason for this is that each step surface 26 is provided in a pair at each end of each support beam 23 so that the outer ring 16a can be smoothly moved and displaced about each support beam 23. , 26 to make the distance D between the outer rings 16a slightly larger than the outer diameter d (D> d). The outer rollers 16a and the power rollers 6a supported concentrically with the outer ring 16a have shafts of the support beam portions 23 corresponding to a difference (D−d) between the distance D and the outer diameter d. Displaceable in the direction.

On the other hand, during operation of a vehicle equipped with a toroidal-type continuously variable transmission, each power roller 6a receives a force in the opposite direction from each of the disks 2 and 5, for example, during acceleration and deceleration (when the engine brake is activated). ("2Ft", well known in the technical field of toroidal continuously variable transmissions). Then, the force 2Ft causes the power rollers 6a to be displaced in the axial direction of the support beam portions 23 together with the outer rings 16a. The direction of this displacement is the same as the displacement direction of each trunnion 7, 7 (see FIG. 8) by each actuator 21, 21 described above, and the shifting operation is started even when the displacement is about 0.1 mm. Create a possibility. When the shifting operation is started for such a reason, the shifting operation is not directly related to the driving operation, and the driver feels uncomfortable regardless of any correction. In particular, when a shift that is not intended by the driver as described above is performed in a state where the torque transmitted by the toroidal-type continuously variable transmission is low, a sense of discomfort given to the driver tends to increase.

  In order to suppress the occurrence of the speed change operation that is not directly related to the driving operation as described above, the difference (D−d) between the distance D and the outer diameter d is made small (for example, about several tens of μm). ) Can be suppressed. However, during the operation of the half-toroidal toroidal continuously variable transmission, each trunnion 7a is caused by a thrust load applied to each support beam portion 23 from the traction portion via each power roller 6a and each outer ring 16a. As exaggeratedly shown in FIG. 15, the side where each outer ring 16a is installed is elastically deformed in a direction in which it becomes concave. As a result of this elastic deformation, the distance between the step surfaces 26, 26 provided in pairs for each trunnion 7a is reduced. Even in such a state, in order to prevent the distance D between the two step surfaces 26 and 26 from becoming smaller than the outer diameter d of each outer ring 16a, the normal state (the state where each trunnion 7a is not elastically deformed). It is necessary to ensure a certain difference between the distance D and the outer diameter d. As a result, a shift operation that is not directly related to the driving operation as described above is likely to occur particularly during driving at a low torque, which tends to increase the sense of discomfort. In particular, as described in Patent Document 5, a toroidal continuously variable transmission, a planetary gear type transmission, and a clutch device are combined, and the clutch device is used to switch between a low speed mode and a high speed mode. In the case of the transmission, the direction of the torque passing through the toroidal type continuously variable transmission is reversed in the acceleration state as the two modes are switched. For this reason, as described above, a shifting operation not directly related to the driving operation occurs, and it is easy for the driver to feel uncomfortable.

  On the other hand, in Patent Document 3, a pair of outer side surfaces (side surfaces in the axial direction) formed on the inner side surface, which is a cylindrical convex surface of the support beam portion, is formed in a ridge that is parallel to each other and a concave portion on the outer ring side. A structure is also described in which the force 2Ft is supported by engaging a pair of concave grooves whose inner side surfaces (side surfaces in the axial direction) are parallel to each other. However, in the case of such a structure, along the elastic deformation of the trunnion, the outer surface of the ridge is formed at both ends in the circumferential direction (the rocking direction of the outer ring) of the engagement portion between the ridge and the groove. It was found from the simulation conducted by the present inventors that the surface pressure of the contact portion with the inner surface of the concave groove becomes excessively high. In such a state, if the outer ring swings and displaces with respect to the trunnion support beam portion, there is a possibility that the wear of the rubbing portion between the outer surface of the ridge and the inner surface of the concave groove may become significant. And the abrasion powder generated by this wear may contaminate the lubricating oil (traction oil) and make the lubrication state of each part poor, or the meshing part of the gears and the rolling contact part of the rolling bearing may be easily damaged. There is. Further, the gap between the outer surface of the ridge and the inner surface of the groove (the rattling of the engaging portion between the ridge and the groove) becomes large, and the speed change is not directly related to the driving operation. There is a possibility that the operation is likely to occur.

JP 2003-214516 A JP 2007-315595 A JP 2008-25821 A JP 2008-275088 A JP 2004-169719 A

  In view of the circumstances as described above, the present invention has been invented to realize a structure that can stabilize a speed change operation and can easily ensure durability.

A power roller unit for a toroidal continuously variable transmission according to the present invention includes a trunnion, a power roller, and a thrust rolling bearing.
Of these, the trunnion exists between a pair of tilting shafts concentrically provided at both ends and between these tilting shafts, and at least one side surface (perpendicular to the axial direction of these tilting shafts). A support beam portion having a cylindrical convex surface on a side surface in the radial direction in a state of being assembled to the toroidal type continuously variable transmission.
The power roller has a spherical convex outer peripheral surface and is rotatably supported on one side surface of the trunnion.
The thrust rolling bearing has an outer ring and a plurality of rolling elements. Of these, the outer ring is provided with an outer ring raceway on one side facing the power roller in the axial direction, and a concave portion having a partial cylindrical surface is provided on the other side facing the support beam part in the axial direction. . The outer ring is supported by the trunnion so as to be able to swing and swing about the central axis of the cylindrical convex surface by engaging the concave portion with the cylindrical convex surface of the support beam portion. Each of the rolling elements is provided between the outer ring raceway and an inner ring raceway provided on the power roller so as to freely roll.
Furthermore, the outer ring of the thrust rolling bearing engages a concave groove formed in the concave portion in a circumferential direction (a circumferential direction of the cylindrical convex surface, a width direction of the concave portion) and a protrusion formed on the cylindrical convex surface. By doing so, the trunnion can be oscillated and the displacement of the two tilting shafts in the axial direction is limited.

In particular, in the power roller unit for a toroidal type continuously variable transmission according to the present invention, both end portions in the circumferential direction of the inner surface of the concave groove facing each other with respect to the axial direction of the two tilting shafts, Among the outer side surfaces, when used (during a speed change operation of the toroidal type continuously variable transmission incorporating the power roller unit), a portion of the inner side surface of the concave groove facing (sliding contact) with both ends in the circumferential direction At least one of the portions is inclined in a direction away from the mating surface as it goes to both sides in the circumferential direction (swing direction).
In this case, for example, the crowning can be applied only to the one part, or the one part can be constituted by a complex curved surface whose curvature radius changes midway.

According to the power roller unit for a toroidal type continuously variable transmission of the present invention configured as described above, it is possible to realize a structure in which the speed change operation can be stabilized and the durability can be easily secured.
That is, both ends in the circumferential direction of the inner surface of the groove and the outer surfaces of the protrusion facing each other in the axial direction of the tilting axis are opposed to each other in the circumferential direction on the inner surface of the groove. Since at least one portion of the portion to be inclined in a direction away from the mating surface toward the both sides in the circumferential direction, the concave portion of the outer ring is engaged with the cylindrical convex surface of the trunnion, It is possible to prevent the surface pressure of the contact portion between the outer surface of the protrusion and the inner surface of the groove from becoming excessively high at both ends in the circumferential direction of the engaging portion between the protrusion and the groove. . Therefore, regardless of the rocking displacement of the outer ring with respect to the support beam portion, it is possible to prevent the wear from becoming significant at the frictional portion between the outer surface of the protrusion and the inner surface of the groove. As a result, it is easy to ensure the durability of the power roller unit for the toroidal type continuously variable transmission, and thus the entire toroidal type continuously variable transmission. Further, the dimensional relationship between the protrusions and the concave grooves can be properly maintained over a long period of time, and the shifting operation of the toroidal type continuously variable transmission can be stabilized over a long period of time.

The perspective view shown in the state which took out the trunnion among the power roller units for toroidal type continuously variable transmissions of the 1st example of embodiment of this invention. The perspective view (B) shown in the state seen from the direction different from (A) and (A) which similarly takes out and shows an outer ring | wheel. The main part enlarged perspective view (A) of the support beam part of the trunnion showing the part to be crowned, and the same figure (B) shown in the state viewed from the opposite direction with respect to the axial direction of the central axis of the tilting axis (B) . The schematic diagram for demonstrating the engagement state of a protrusion and a ditch | groove. Of the power roller unit for the toroidal type continuously variable transmission of the second example of the embodiment of the present invention, a perspective view (A) showing the outer ring taken out, and the axial direction of the tilting shaft is opposite to (A) The perspective view (B) shown in the state seen from the direction. The same figure as FIG. Sectional drawing which shows the 1st example of a conventional structure. Aa sectional drawing of FIG. The perspective view which looked at the trunnion which supported the power roller via the thrust ball bearing which shows the 2nd example of the conventional structure from the radial direction outer side of each disk. Similarly, the front view shown in the state seen from the circumferential direction of the disk. The top view seen from the upper part of FIG. The side view seen from the right side of FIG. Bb sectional drawing of FIG. Cc sectional drawing of FIG. FIG. 14 is a cross-sectional view seen from the same direction as FIG. 13, exaggeratingly showing a state where the trunnion is elastically deformed based on a thrust load applied from the power roller.

[First example of embodiment]
1 to 4 show a first example of an embodiment of the present invention. The feature of the present invention, including this example, is that a speed change operation can be stabilized and a structure that can easily ensure durability can be realized. The structure and operation of the other parts are the same as in the second example of the conventional structure shown in FIGS.

  The power roller unit for the toroidal type continuously variable transmission of this example includes a trunnion 7b, a power roller 6a (see FIGS. 9 to 13), and a thrust ball bearing 13a. Of these, the trunnion 7b exists between a pair of tilting shafts 8a and 8b concentrically provided at both ends and the tilting shafts 8a and 8b, and is assembled to the toroidal continuously variable transmission. In this state, a support beam portion 23a having a cylindrical convex surface 22a on the inner side (upper side in FIG. 1) in the radial direction of the input and output disks 2 and 5 (see FIG. 7) is provided.

  Further, the power roller 6a has a spherical convex surface on the outer peripheral surface, and swinging displacement about the central axis of the cylindrical convex surface 22a is formed on the inner surface of the support beam portion 23a via the thrust ball bearing 13a. And can be freely rotated around its own central axis.

  The thrust ball bearing 13a is provided between the inner surface of the support beam portion 23a of the trunnion 7b and the outer surface of the power roller 6a, and includes an outer ring 16b and a plurality of balls. Of these, the outer ring 16b is provided with a concave portion 24a having a partially cylindrical surface on the outer side surface in a state of crossing the outer side surface in the radial direction, and a support shaft 12a is fixed integrally with the outer ring 16b at the center of the inner side surface. doing. Then, the outer ring 16b engages the concave portion 24a with the cylindrical convex surface 22a of the support beam portion 23a, so that the outer ring 16b swings and displaces around the central axis of the cylindrical convex surface 22a with respect to the trunnion 7b. (The swing displacement in the axial direction of each of the disks 2 and 5 in the assembled state of the toroidal type continuously variable transmission) is supported. Then, the balls are rotatably arranged between an outer ring raceway 15a provided on the inner side surface of the outer ring 16b and an inner ring raceway provided on the inner side surface of the power roller 6a to constitute the thrust ball bearing 13a. At the same time, by providing a radial bearing between the inner peripheral surface of the center hole of the power roller 6a and the outer peripheral surface of the support shaft 12a, the power roller 6a is rotatably supported around the support shaft 12a. .

  In the case of this example, the concave portion 24a which is a cylindrical concave surface is provided with a concave groove 27 having a rectangular cross section formed in the circumferential direction of the concave portion 24a (width direction, swinging direction of the outer ring 16b), and the trunnion 7b. By engaging the cylindrical convex surface 22a of the support beam portion 23a constituting the ridge 28 formed in the circumferential direction of the cylindrical convex surface 22a, the both tilting of the outer ring 16b with respect to the trunnion 7b is achieved. The displacement of the shafts 8a and 8b in the axial direction is limited. The above configuration is the same as the structure described in Patent Document 3 described above.

  Particularly in the case of the structure of this example, both outer side surfaces of the protrusion 28 have a so-called partial crowning shape. That is, both end portions in the circumferential direction on both outer side surfaces of the ridge 28 (which varies depending on the application, vehicle type, magnitude of torque transmitted by the toroidal type continuously variable transmission, etc., for example, a toroidal type for a general passenger car) In the case of a step transmission, by applying a crowning process to the range of about 1/2 to 1/5 of the total length in the circumferential direction from both ends in the circumferential direction), The shape of the disks 2 and 5 viewed from the inside in the radial direction has a large radius of curvature (this varies depending on the application, vehicle type, magnitude of torque transmitted by the toroidal type continuously variable transmission, etc., for example, a toroidal for a general passenger car) In the case of the type continuously variable transmission, inclined convex surface portions 29 and 29 each having a partially convex arc shape (having a radius of curvature of about 100 to 1000 mm) are provided. Further, flat surface portions 30 and 30 parallel to both inner surface surfaces of the concave groove 27 are provided in the circumferential intermediate portion of both outer surfaces of the protrusion 28, and both the flat surface portions 30 and 30 and the inclined convex surfaces are provided. The parts 29 and 29 are smoothly continued. On the other hand, both inner side surfaces of the concave groove 27 are flat surfaces parallel to each other over the entire length.

  Since the power roller unit for the toroidal type continuously variable transmission of the present example configured as described above has both outer side surfaces of the protrusion 28 in a so-called partial crowning shape, during operation of the toroidal type continuously variable transmission, Even if the trunnion 7b is elastically deformed in a direction in which the side on which the outer ring 16b is installed is concave, the circumferential direction of the contact portion between the inner surface of the groove 27 and the outer surface of the protrusion 28 It is possible to prevent the surface pressure at both ends from becoming excessively high. Therefore, when the outer ring 16b is oscillated and displaced with respect to the support beam portion 23a, it is possible to prevent the abrasion of the rubbing portion between the inner side surface of the concave groove 27 and the outer side surface of the protrusion 28, and It is possible to prevent the wear powder from contaminating the lubricating oil. As a result, the lubrication state of each part to which the lubricating oil is supplied can be kept good for a long period of time, and the meshing part of the gears and the rolling contact part of the rolling bearing can be hardly damaged. It is possible to easily ensure the durability of the power roller unit for a step transmission, and thus the entire toroidal continuously variable transmission. In addition, since the dimensional relationship between the groove 27 and the protrusion 28 (the size of the gap between the inner surface of the groove 27 and the outer surface of the protrusion 28) can be maintained properly over a long period of time, When the torque transmission direction by the toroidal-type continuously variable transmission is reversed, it is possible to prevent an unintended shift operation from being performed for a long period of time and to prevent the driver from feeling uncomfortable.

  In the case where the present invention is carried out, both end portions in the circumferential direction of both outer side surfaces of the protrusion 28 may be constituted by a compound curved surface whose curvature radius changes midway. Further, both outer side surfaces of the protrusion 28 can be formed into a so-called full crowning shape having a single radius of curvature over the entire length. However, during the operation of the toroidal type continuously variable transmission, the concave groove 27 is formed in the circumferential intermediate portion of the outer side surfaces of the protrusion 28 from the surface supporting the force 2Ft applied to the power roller 6a. It is more preferable to provide flat surface portions 30 and 30 parallel to both inner side surfaces.

  Further, when the present invention is implemented, a cylindrical convex surface is formed over the entire circumference of the support beam portion as in the structure described in the above-mentioned Patent Document 3, and the cylindrical convex surface is entirely formed in the central portion in the axial direction. By engaging a pair of locking pieces, each of which is substantially semicircular, in the outer circumferential surface-side concave groove formed over the circumference, it is possible to provide circumferential protrusions on the cylindrical convex surface. In such a structure, when the inclined convex surface portion is provided on the outer surface of the ridge, the positional relationship between the outer ring and the trunnion on the outer surface of the ridge is the same as before the start of the shifting operation of the toroidal continuously variable transmission. In the same, neutral state, the inclined convex surface portion is provided at a portion facing the both ends in the circumferential direction of the inner surface of the concave groove formed in the concave portion of the outer ring. The swing angle of the outer ring with respect to the trunnion during the shifting operation of the toroidal continuously variable transmission (during use) is very small (depending on the application, vehicle type, magnitude of torque transmitted by the toroidal continuously variable transmission, etc. Although it is different, for example, in the case of a toroidal-type continuously variable transmission for a general passenger car, it is about 1 degree at the maximum). The portions facing the circumferential end portions of the inner surface are also in the neutral state and are substantially the same as the portions facing the circumferential end portions of the inner surface of the concave groove.

[Second Example of Embodiment]
5 to 6 show a second example of the embodiment of the present invention. In the case of this example, the shape of each disk 2, 5 (see FIG. 7) viewed from the radially outer side at both circumferential ends of both inner side surfaces of the concave groove 27a formed in the concave portion 24a of the outer ring 16c. Are provided with inclined concave surface portions 31 and 31 each having a partially concave arc shape with a large radius of curvature, and provided with flat surface portions 32 and 32 parallel to each other in the circumferential intermediate portion. The inclined concave surface portions 31 and 31 are smoothly continued. On the other hand, both outer side surfaces of the protrusion 28 formed in the circumferential direction on the cylindrical convex surface 22a of the support beam portion 23a constituting the trunnion 7b (see FIG. 1) are flat surfaces parallel to each other over the entire length. With such a configuration, even when the trunnion 7b is elastically deformed in a direction in which the outer ring 16c side is recessed during operation of the toroidal-type continuously variable transmission, the inner surface of the groove 27 and the The surface pressure at both ends in the circumferential direction of the contact portion with the outer surface of the protrusion 28 is prevented from becoming excessively high.
The configuration and operation of the other parts are the same as in the case of the first example of the embodiment described above.

DESCRIPTION OF SYMBOLS 1 Input rotating shaft 2 Input disk 3 Output cylinder 4 Output gear 5 Output disk 6, 6a Power roller 7, 7a, 7b Trunnion 8, 8a, 8b Tilt shaft 9 Support beam part 10 Support plate 11, 11a Radial needle bearing 12, 12a Support shaft 13, 13a Thrust ball bearing 14 Thrust needle bearing 15, 15a Inner ring raceway 16, 16a, 16b Outer race 17 Outer raceway 18 Ball 19 Drive shaft 20 Pressing device 21 Actuator 22, 22a Cylindrical convex surfaces 23, 23a, 23b Support beam Part 24, 24a Concave part 25 Radial needle bearing 26 Stepped surface 27, 27a Concave groove 28 Projection 29 Inclined convex part 30 Flat surface part 31 Inclined concave part 32 Flat surface part

Claims (1)

A trunnion having a pair of tilting shafts concentrically provided at both end portions, and a supporting beam portion that is present between the two tilting shafts and has a cylindrical convex surface on at least one side surface;
The outer peripheral surface is a spherical convex surface, and a power roller rotatably supported on one side surface of the trunnion;
An outer ring raceway is provided on one side surface in the axial direction, and a concave portion having a partial cylindrical surface is provided in the diametrical direction on the other side surface in the axial direction. By engaging this concave portion with the cylindrical convex surface of the support beam portion, the trunnion On the other hand, the outer ring supported so as to be able to swing and swing around the central axis of the cylindrical convex surface, and provided between the outer ring raceway and the inner ring raceway provided in the power roller, so as to be freely rollable. A thrust rolling bearing having a plurality of rolling elements,
The outer ring of this thrust rolling bearing can swing and displace with respect to the trunnion by engaging a groove formed in the circumferential direction in the recess with a protrusion formed on the cylindrical convex surface. In addition, in the power roller unit for toroidal type continuously variable transmission, the displacement in the axial direction of both tilting shafts is limited,
Of the both ends in the circumferential direction of the inner surface of the groove and the outer surfaces of the ridges, the opposite ends in the circumferential direction on the inner side of the groove are opposed to each other in the axial direction of the two tilt axes. A power roller unit for a toroidal continuously variable transmission, characterized in that at least one of the two is inclined in a direction away from the mating surface toward the both sides in the circumferential direction.

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