JP5857473B2 - Toroidal continuously variable transmission - Google Patents

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 improvement of 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 freely supported. An output tube 3 is supported around the intermediate portion of the input rotary shaft 1 so as to freely rotate 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 rotation synchronized with the motor. In this state, the inner 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 about 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 these thrust ball bearings 13, 13 has 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 freely rollable. 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 peripheral surface of each of the power rollers 6 and 6 and the inner surface of each of the disks 2 and 5 changes (in the rolling contact portion). Side slip occurs). As the direction of the force changes, the trunnions 7 and 7 swing around their tilting shafts 8 and 8, and the 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 circumferential surfaces of the power rollers 6 and 6 are in rolling contact with the radially outer portions of the inner surfaces of the input disks 2 and 2 and the radially inner portions of the inner surfaces of the 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 peripheral surfaces of the power rollers 6 and 6 are arranged radially inwardly on the inner side surfaces of the input disks 2 and 2 and radially outwardly on the inner side surfaces of the output disks 5 and 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. Accordingly, 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 peripheral surface of each of the power rollers 6 and 6 regardless of the fluctuation of the torque, the trunnions 7 and 7 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.

  In the case of the first example of the conventional structure as described above, the structure for displacing each of the power rollers 6 and 6 in the axial direction is complicated, and parts manufacturing, parts management, and assembly work are all troublesome and costly. It is inevitable that the volume increases. 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 overall structure and operation of the toroidal type continuously variable transmission 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 in FIGS. 10 and 13 to 14) in the radial direction (up and down direction in FIGS. 10 and 13 to 14) of the input and output disks 2 and 5 (see FIG. 7). And a beam portion 23. Both the 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 as to be swingable.

  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 and 13 to 14) in the radial direction of the disks 2 and 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 peripheral surface of the power roller 6a and 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, a portion of the 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 the respective disks 2 and 5 during acceleration and deceleration (when the engine brake is activated) ( "2Ft", which is well known in the technical field of toroidal-type continuously variable transmissions, is added. 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). ), The difference between the distance D and the outer diameter d needs to be secured to some extent as shown in FIG. 16A, but as shown in FIG. There is a possibility that the power roller 6a is caught by the trunnion 7a.

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 easily reduce the cost and stabilize the speed change operation.

The toroidal-type continuously variable transmission of the present invention includes at least a pair of disks, a plurality of trunnions, the same number of power rollers as each trunnion, and the same number of thrust rolling bearings.
In particular, in the toroidal type continuously variable transmission of the present invention, a wedge-shaped member is provided between the trunnion and the outer ring. And even if the trunnion is elastically deformed, the trunnion can be supported without pinching the outer ring.

According to the toroidal type continuously variable transmission of the present invention configured as described above, it is possible to realize a structure that can easily reduce the cost and stabilize the speed change operation.
Of these, cost reduction is easy to achieve for the same reason as in the second example of the conventional structure shown in FIGS.
Moreover, the speed change operation can be stabilized by preventing the outer ring from being caught by elastic deformation of the trunnion by a wedge-shaped member provided between the trunnion and the outer ring.

The perspective view which shows one example of embodiment of this invention. The perspective view which isolate | separated the power roller unit from the trunnion in FIG. The front view of FIG. The top view which looked at the trunnion which isolate | separated the power roller of FIG. 2 from upper direction. The perspective view of a wedge member. The figure which shows operation | movement of a wedge member. (A) shows before operation, and (b) shows after operation. Sectional drawing which shows the 1st example of a conventional structure. Cc 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. The front view shown in the state seen from the circumferential direction of the disk in the 2nd example of conventional structure. The top view seen from the upper part of FIG. The side view seen from the right side of FIG. Dd sectional drawing of FIG. Ee sectional drawing of FIG. The sectional view seen from the same direction as Drawing 11 which exaggerates and shows the state where the trunnion was elastically deformed based on the thrust load added from a power roller. The figure which shows the clamping of the power roller by a trunnion.

  1 to 5 show an example of an embodiment of the present invention. The feature of this example is that the outer ring 16b constituting the thrust ball bearing 13a (see FIGS. 9 to 14) is provided to the support beam portion 23 of each trunnion 7b to stabilize the speed change operation. The trunnion is configured to prevent the outer ring from being pinched even if the trunnion is elastically deformed while supporting the rocking displacement relative to the outer ring. Since the structure and operation of the other parts are the same as those of the second example of the conventional structure shown in FIGS. 9 to 14 described above, the illustration and description of the equivalent parts are omitted or simplified. The explanation will be focused on.

  In the case of the structure of this example, a pair of wedge members 27 and 27 are provided between the trunnion 7 b and the outer ring 16 b and on both ends of the support beam portion 23. Further, as shown in FIG. 5, the wedge members 27, 27 are engaged with the cylindrical convex surface 22 of the support beam portion 23 of the trunnion 7b, and a concave portion 28 having a partial cylindrical surface similar to the outer ring, and the outer ring 16b. An inclined surface 30 that is in contact with an inclined surface 29 provided on the radial end surface of the trunnion 7b and that is inclined away from the support beam portion 23 from the center side of the support beam portion 23 of the trunnion 7b toward the both end sides thereof, A contact surface 31 that contacts the step surface 26a of the trunnion 7b is provided.

  By providing the wedge members 27 and 27 as described above, even when the trunnion is elastically deformed as shown in FIG. 16 during the operation of the toroidal type continuously variable transmission of this example, as shown in FIG. 6B. When the contact surfaces 31, 31 of the wedge members 27, 27 are pushed by the step surfaces 26a, 26a of the trunnion 7b, they slide to the center side of the trunnion 7b, and the outer ring 16b is moved to the power roller 6a side. Therefore, the outer ring 16b can be prevented from being caught by the trunnion 7b. In addition, the amount of movement of the power roller 6a and the amount of movement of the trunnion 7b toward the opposite side of the outer ring 16b due to elastic deformation cancel each other to some extent. Compared with the trunnion of the first example of the conventional structure.

  Further, the contact surface 30 of the wedge-shaped member 27 may be subjected to a surface treatment for reducing the friction coefficient, or the wedge-shaped member may be formed of a solid lubricant.

  Further, the concave portion 28 of the wedge-shaped member 27 may have a Gothic arch shape. By doing so, the inner surface of the concave portion 28 and the cylindrical convex surface 22 provided on the support beam portion 23 of the trunnion 7b Since contact is made at two positions in the circumferential direction of both surfaces, it is possible to secure a contact area between these both surfaces and to suppress wear on both surfaces.

  A pipe member 32 is provided between the support beam portion 23 of the trunnion 7b and the outer ring 16b. The pipe member 32 is oval and has a through hole 33 for allowing the lubricating oil to pass through in the center. A recess 35 for fitting one half of the pipe member 32 is formed in a part of the support beam portion 23 of the trunnion 7b in the downstream end opening portion of the upstream oil supply passage 34. A recess 37 for engaging the other half of the pipe member 32 is formed in the upstream end opening portion of the downstream oil supply passage 36 of 16b. In such a state that one half of the pipe member 32 is fitted in the recess 35 formed in the downstream end opening of the upstream oil supply passage 34, the other half is connected to the upstream end of the downstream oil supply passage 36. The recess 37 formed in the opening portion is engaged with a gap between the pipe member 32 and the recess 37 so that the displacement of the power roller 6a can be displaced by elastic deformation of the disks 2 and 5. In this manner, lubrication is supplied from the upstream oil supply passage 34 to the downstream oil supply passage 36 through the through hole 33 of the pipe member 32.

  The present invention can be implemented by a toroidal continuously variable transmission alone, or can be implemented as a continuously variable transmission in combination with a planetary gear mechanism as described in Patent Document 5.

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 Radial needle bearing 12 Support shaft 13 Thrust ball bearing 14 Thrust needle bearing 15 Inner ring raceway 16, 16a, 16b Outer ring 17 Outer ring raceway 18 Ball 19 Drive shaft 20 Press device 21 Actuator 22 Cylindrical convex surface 23 Support beam portion 24 Recess portion 25 Radial needle bearing 26, 26a Stepped surface 27 Wedge Member 28 Concave portion 29 Inclined surface 30 Inclined surface 31 Abutting surface 32 Pipe member 33 Through hole 34 Upstream oil supply passage 35 Concavity 36 Downstream oil supply passage 37 Concavity

Claims (1)

At least one pair of disks, a plurality of trunnions, the same number of power rollers as each of the trunnions, and the same number of thrust rolling bearings are provided, and each of these disks is a toroidal curved surface having an arc cross section. The trunnions are supported concentrically with each other so that relative rotation is freely possible with the axial side surfaces facing each other, and each trunnion is provided with a pair of tilts provided concentrically with each other at both ends. A rotating shaft and between the two tilting shafts, and at least the inner side surface in the radial direction of each disk is parallel to the central axis of the two tilting shafts and more than the central axis of the tilting shaft. And a support beam portion having a cylindrical convex surface having a central axis existing outside in the radial direction of each disk, and in the circumferential direction between the axial side surfaces of each disk in the axial direction. In each of the trunnions, the power rollers are provided at a plurality of locations so as to be freely oscillated and displaced about a tilting shaft that is twisted with respect to the central axis of each disk. The circumferential surface of each disk, which is rotatably supported through a thrust rolling bearing, is in contact with one side surface in the axial direction of each disk, and each thrust rolling bearing is connected to each trunnion. Provided between the support beam portion and the outer surface of each of the power rollers, an outer ring provided on the support beam portion side, an outer ring track provided on the inner side surface of each of the outer rings, A plurality of rolling elements are provided between the outer ring and the inner ring raceway provided on the outer surface of the power roller, and the outer ring of each thrust rolling bearing includes Outside A toroidal-type continuously variable step that is supported so as to be capable of rocking displacement in the axial direction of each disk with respect to each trunnion by engaging a concave portion provided in the cylindrical surface and a cylindrical convex surface of each support beam portion. In the transmission, a wedge-shaped member is provided between the trunnion and the outer ring, and the wedge-shaped member includes a partially cylindrical concave portion that engages with the cylindrical convex surface of the supporting beam portion of the trunnion. An inclined surface that is in contact with an inclined surface provided on a radial end surface of the outer ring of the thrust rolling bearing and is inclined so as to be separated from the support beam portion from the center side of the support beam portion of the trunnion toward the end side thereof; A toroidal continuously variable transmission, characterized in that a contact surface that contacts the step surface of the trunnion is provided .

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