JP2013024322A - Toroidal continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a structure facilitated in manufacture of parts, management of parts and assembling work, easy to reduce costs, and can stabilize the speed changing operation.SOLUTION: A spacing between a pair of step surfaces 26a and 26b, which are provided per trunnion 7b, is gradually changed in the rocking direction of each outer ring 16b around each support beam part 23. Size of the spacing is set at a neutral value, at which displacement of each outer ring 16b in the axial direction of each support beam part 23 can be prevented in a part facing the outer peripheral surface of each outer ring 16b in a condition wherein a pushing device dose not generate the pushing force and each outer ring 16b exist at a neutral position. Further, in a condition wherein the pushing device generates the pushing force and each outer ring 16b is displaced by rocking around each support beam part 23, the size of the spacing is set at a value larger than the neutral value in a part facing the outer peripheral surface of each outer ring 16b.

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. FIGS. 11 to 12 show a first example of a toroidal type continuously variable transmission that is described in each of these patent documents and has been widely known. 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 trunnion 7, 7 is composed of a pair of tilting shafts 8, 8 provided concentrically with each other at both axial ends, and a support beam existing between these tilting shafts 8, 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. Among these, the thrust ball bearings 13 and 13 allow the rotation of the power rollers 6 and 6 while supporting the load in the thrust direction applied to the power rollers 6 and 6. Each thrust ball bearing 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. 11) 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. 13 to 18, 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. 11). 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. 14 and 17 to 18) in the radial direction (up and down direction in FIGS. 14 and 16 to 18) of the input and output disks 2 and 5 (see FIG. 11). And a beam portion 23. The two tilting shafts 8a and 8b are supported on the support plates 10 and 10 (see FIG. 12) via the radial needle bearings 11a and 11a, respectively, so as to be swingable.

  Further, as shown in FIGS. 14 and 17 to 18, the central axis A of the cylindrical convex surface 22 is parallel to the central axis B of the two tilting shafts 8a and 8b, and the center of these tilting shafts 8a and 8b. It exists on the outer side (the lower side of FIGS. 14 and 17 to 18) in the radial direction of each of the disks 2 and 5 with respect to the axis B. 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).

  Compared to the first example shown in FIGS. 11 to 12, the second example of the conventional structure shown in FIGS. 13 to 18 makes it easier to manufacture parts, manage parts, and assemble, thereby reducing costs. 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). Each outer ring 16a and each power roller 6a supported concentrically with each outer ring 16a have a difference (D−d) between the distance D and the outer diameter d, so Displaceable in the axial 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 and 7 (see FIG. 12) by each actuator 21 and 21 described above, and the shifting operation is started even if 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 operation of the half-toroidal toroidal continuously variable transmission, each trunnion 7a is caused by a thrust load applied from the traction portion to each support beam portion 23 via each power roller 6a and each outer ring 16a. As exaggeratedly shown in FIG. 19, the side where the outer rings 16a are installed is elastically deformed in the direction of being recessed. 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 stepped surfaces 26, 26 from being equal to or less 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.

  On the other hand, in Patent Document 3, the anchor piece locked to a part of the cylindrical convex surface provided on the support beam part side and the anchor groove formed on the inner surface of the concave part on the outer ring side are engaged with each other. A structure for supporting a force 2Ft is described. There is also a structure for supporting the force 2Ft by forming a plurality of balls between the rolling grooves each having an arcuate cross section formed in a portion where the cylindrical convex surface and the concave portion are aligned with each other. Have been described. However, in the case of the former structure, it is difficult to support and fix the anchor piece to the support beam portion with sufficient strength and rigidity to support the force 2Ft, and it is possible to reduce the cost and to provide sufficient reliability. It is difficult to secure. In the latter case, when the force 2Ft increases and the surface pressure of the rolling contact portion between the rolling surface of each ball and each rolling groove increases, an indentation is formed on the inner surface of each rolling groove. As a result, vibration may occur when each outer ring swings and displaces with respect to each trunnion.

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 was invented to realize a structure that facilitates parts production, parts management, and assembly work, facilitates cost reduction, and stabilizes the speed change operation. is there.

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, the same number of thrust rolling bearings, and a pressing device.
In particular, in the toroidal-type continuously variable transmission according to the present invention, the distance between the pair of step surfaces for each trunnion is gradually changed with respect to the swinging direction of each outer ring centering on each support beam. ing.
Further, the size of the interval is such that the pressing device does not generate a pressing force and each outer ring faces the outer peripheral surface of each outer ring in a state where each outer ring exists in a neutral position. The neutral value is a size that substantially prevents displacement in the axial direction of the beam portion.
Further, the outer peripheral surface of each outer ring in a state in which the outer ring is oscillated and displaced with the support beam portion as a center along with the elastic deformation of each disk and each power roller when the pressing device generates a pressing force. It is larger than the neutral value at the part facing the.
The phrase “substantially preventing displacement in the axial direction” refers to a state in which the power roller supported by each outer ring does not change in the axial direction of each support beam portion so as to start a shift operation. This speed change operation may be started even when each power roller is displaced about 0.1 mm in the axial direction. Therefore, the neutral value is equal to or larger than the diameter of the portion of the outer ring sandwiched between the stepped surfaces, but is less than a value larger by 0.1 mm than the diameter.

  When implementing the present invention as described above, for example, as in the second aspect of the present invention, the distance between the pair of stepped surfaces for each trunnion is made to coincide with the swinging direction of each outer ring. The width is made narrowest at the center in the width direction of each step surface. And the magnitude | size of the space | interval of this narrowest part is made into the said neutral value.

  Alternatively, as in the invention described in claim 3, with respect to the width direction of each of the step surfaces, the distance between the pair of step surfaces for each trunnion coincides with the swing direction of each outer ring. Change from one to the other. And the magnitude | size of the space | interval of the width direction intermediate part of each level | step difference surface is made into the said neutral value. In addition, the direction in which the pressing force is applied by the pressing device is a direction in which the outer rings are displaced in the direction in which the distance between the step surfaces is large based on the pressing force.

According to the toroidal-type continuously variable transmission of the present invention configured as described above, it is easy to manufacture parts, manage parts, and assemble work, easily reduce costs, and stabilize the speed change operation. realizable.
Of these, cost reduction is easy to achieve for the same reason as in the second example of the conventional structure shown in FIGS.

In addition, the stabilization of the speed change operation substantially prevents the displacement of the outer ring in the axial direction of the supporting beam portion of each trunnion by separating the gap between the pair of stepped surfaces provided for each trunnion, and this interval. Is gradually changed in accordance with the direction of the swing displacement of each outer ring centered on each of these support beam portions.
First, when each outer ring exists in the neutral position, the size of the interval is a neutral value that substantially prevents the axial displacement of each outer ring, so that the speed change operation can be stabilized.
On the other hand, the torque transmitted by the toroidal-type continuously variable transmission is increased, and the pressing force generated by the pressing device is increased. At the same time as the outer ring is displaced to the portion where the interval is increased, the interval is reduced along with the elastic deformation of the support beam portions.

Therefore, if the rigidity of each support beam part and the extent to which the interval changes are appropriately regulated, regardless of the change in the torque, the outer ring is displaced in the axial direction of the support beam part. It is possible to prevent substantially all the time, and to smoothly perform the swing displacement of the outer rings around the support beam portions. As a result, the shifting operation can be stabilized.
The rigidity of each support beam part and the degree to which the interval changes are controlled by the physical properties of the metal material constituting each trunnion, the shape and size of each trunnion, the magnitude of the torque to be transmitted, etc. In consideration of the above, based on the conventionally known elasticity theory or the like, it can be obtained by computer simulation or by experiment. If these computer simulations and experiments are used in combination, it is possible to prevent the stepped surfaces from pinching the outer rings and to prevent the outer rings from being displaced in the axial direction of the support beam portions. .

The perspective view which took out the trunnion and the outer ring | wheel which showed the 1st example of embodiment of this invention, and was seen from the radial inside of each disc. Similarly, an orthographic projection viewed from the inside in the radial direction. The a section enlarged view of FIG. The figure similar to FIG. 2 which shows the 2nd example of embodiment of this invention. The figure similar to FIG. 1 which shows the 3rd example. Similarly, an orthographic projection viewed from the inside in the radial direction. The b section enlarged view of FIG. Similarly, the schematic diagram for demonstrating the arrangement | positioning state of a trunnion, a power roller, and a press apparatus. Similarly, a schematic diagram for explaining the direction of the force acting on the contact portion between the step surface of the trunnion and the outer peripheral surface of the outer ring during operation of the toroidal-type continuously variable transmission. The figure similar to FIG. 6 which shows the 4th-5 examples of embodiment of this invention. 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. 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. Dd sectional drawing of FIG. Ee sectional drawing of FIG. FIG. 18 is a cross-sectional view seen from the same direction as FIG. 17, exaggeratingly showing a state where the trunnion is elastically deformed based on a thrust load applied from a power roller.

[First example of embodiment]
1-3 show a first example of an embodiment of the present invention corresponding to claims 1 and 2. The feature of this example is that the outer ring 16b constituting the thrust ball bearing 13a (see FIGS. 13 to 18) is provided to the support beam portion 23 of each trunnion 7b to stabilize the speed change operation. In this structure, the support beam portions 23 are not displaced in the axial direction while being supported so as to be able to swing. 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. 13 to 18 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, the distance between the pair of stepped surfaces 26a, 26a for each trunnion 7b is gradually changed with respect to the swinging direction of each outer ring 16b around each support beam portion 23. Yes. Specifically, each of the step surfaces 26a and 26a is a partially cylindrical convex curved surface. The step surfaces 26a and 26a are aligned with the rotational direction of the input and output disks 2 and 5 (see FIG. 11), and the width direction of each of the step surfaces 26a and 26a (the swinging direction of the outer ring 16b, It protrudes most at the center part in the left-right direction in FIG. 2 and is symmetrical with this center part as a boundary. Therefore, the distance between the pair of step surfaces 26a, 26a for each trunnion 7b is the narrowest at the center in the width direction of each of the step surfaces 26a, 26a.

  When the pressing device 20 (see FIG. 11) incorporated in the toroidal continuously variable transmission does not generate a pressing force, the disks 2, 5 and the power rollers 6a (FIGS. 13 to 18) are not elastically deformed. The power rollers 6a are not displaced in the axial direction of the disks 2 and 5. Accordingly, each outer ring 16b is in a neutral position. In this state, each of the outer rings 16b is located at the narrowest portion of the portion between the step surfaces 26a and 26a. In the case of this example, the distance D between the narrowest portions is slightly smaller than the outer diameter d of each outer ring 16b. Specifically, in a state where each outer ring 16b is disposed between the pair of stepped surfaces 26a, 26a for each trunnion 7b, each outer ring 16b swings around each support beam portion 23. Although it is allowed to be displaced dynamically, it is set to a size that substantially prevents displacement of each of the support beam portions 23 in the axial direction.

  More specifically, the distance D is not less than the outer diameter d and less than 0.1 mm larger than the outer diameter d {d ≦ D <(d + 0.1 mm)}. It should be noted that the magnitude relationship between the distance D and the outer diameter d does not reverse even if they are the same (the outer rings 16b are tightly fitted between the pair of stepped surfaces 26a, 26a). Preferably, a state of “outer diameter d” <“interval D” is secured. By restricting the value of the distance D to the neutral value set in the above-described range, the outer rings 16b can be displaced with respect to the support beam portions 23, and the axial displacement can be substantially reduced. (The axial displacement is suppressed to less than 0.1 mm). Whereas the neutral value of the distance D is restricted to the above range, the distance between the pair of stepped surfaces 26a, 26a other than the neutral value is the width direction of the stepped surfaces 26a, 26a. Gradually increases toward both ends. This degree of increase is based on the swing angle of each outer ring 16b based on the pressing force generated by the pressing device 20 and the distance between the step surfaces 26a, 26a based on elastic deformation of the support beam portions 23. Regulate in relation to the amount of shrinkage. Specifically, even when the swing angle and the interval change based on the pressing force, the relationship between the interval and the outer diameter d is within the above-described range (“interval” − “outer diameter d”). "= 0 to 0.1 mm).

According to the toroidal-type continuously variable transmission of the present example configured as described above, any part production, part management, and assembly work are performed for the same reason as in the second example of the conventional structure shown in FIGS. It becomes easy, and cost reduction can be easily achieved.
In particular, in the case of the toroidal type continuously variable transmission of this example, the distance between the step surfaces 26a, 26a provided for each trunnion 7b is regulated as described above, so that the shifting operation is stabilized. Can be planned.

  First, when the pressing force generated by the pressing device 20 is zero or very small, the elastic deformation amounts of the input and output disks 2 and 5 and the power rollers 6a are also determined by the elasticity of the support beam 23. The amount of deformation is also zero or slight, and each outer ring 16b is present at a neutral position that is the center in the width direction of each step surface 26a, 26a. In this state, since the difference between the distance D and the outer diameter d is less than 0.1 mm, the displacement of the outer rings 16b in the axial direction of the support beam portions 23 is substantially prevented, and a speed change operation is performed. Can be stabilized.

  On the other hand, when the torque transmitted by the toroidal continuously variable transmission increases and the pressing force generated by the pressing device 20 increases, the elastic deformation of the input and output disks 2 and 5 and the power rollers 6a occurs. As the amount increases, the power rollers 6 a are displaced in the axial direction of the disks 2 and 5. Then, along with this axial displacement, each outer ring 16b swings and displaces around each support beam 23, and the position of each outer ring 16b deviates from the neutral position. Specifically, each outer ring 16b is displaced toward a portion where the distance between the pair of stepped surfaces 26a, 26a is large. At the same time, the thrust load applied to each power roller 6a increases, and the amount of elastic deformation of each support beam portion 23 that supports this thrust load also increases. Then, the distance between the pair of stepped surfaces 26a, 26a tends to be reduced.

In short, when the transmission torque increases, each outer ring 16b is displaced to a portion where the distance between the pair of step surfaces 26a, 26a is large, and at the same time, the distance is reduced. In this way, the tendency of the interval between the outer rings 16b to change is reversed (cancelled), and the interval between the pair of stepped surfaces 26a and 26a that sandwich the outer ring 16b is the same. The outer ring 16b is slightly smaller (less than 0.1 mm) than the outer diameter d. As a result, it is possible to always substantially prevent the outer rings 16b from displacing in the axial direction of the support beam portions 23 regardless of the change in the transmission torque. Thus, it is possible to stabilize the speed change operation of the toroidal type continuously variable transmission by smoothly performing the swinging displacement of each outer ring 16b.
In the case of this example, the shape of each stepped surface 26a, 26a is symmetric with respect to the central portion in the width direction of each stepped surface 26a, 26a. Therefore, a plurality of stepped surfaces 26a, 26a are incorporated into a toroidal continuously variable transmission. The same shape can be used as the trunnion 7b (for example, both left and right in FIG. 12).

[Second Example of Embodiment]
FIG. 4 also shows a second example of an embodiment of the present invention corresponding to claims 1 and 2. In the case of this example, the shape of the stepped surfaces 26b and 26b provided for each trunnion 7c is a shape in which a pair of flat surfaces are combined. That is, the shape of each of the step surfaces 26b and 26b viewed from the inner surface side of each trunnion 7c is a pair of oblique sides that form an isosceles triangle with an apex angle slightly smaller than 180 degrees. . Since the configuration and operation of the other parts are the same as those in the first example of the above-described embodiment, redundant description is omitted.

[Third example of embodiment]
5 to 9 show a third example of the embodiment of the invention corresponding to claims 1 and 3. In the case of this example, the distance between the pair of stepped surfaces 26c, 26c for each trunnion 7d is set from one end with respect to the width direction of each of the stepped surfaces 26c, 26c coinciding with the swinging direction of each outer ring 16b. It is changed toward the other end. That is, the step surfaces 26c and 26c are inclined in directions opposite to each other with respect to the rotation direction of the input and output disks 2 and 5 (see FIG. 11), and the distance between the pair of step surfaces 26c and 26c. However, the distance from the upper left to the lower right in FIG. 5 and the width from the left to the right in FIG. 6 are increased. The distance D between the pair of stepped surfaces 26c and 26c in the width direction intermediate portion is set to a neutral value, that is, equal to or slightly smaller than the outer diameter d of each outer ring 16b (less than 0.1 mm). Only) is a big value.

  Also in the case of the structure of this example as described above, when the transmission torque of the toroidal-type continuously variable transmission is small, the difference between the neutral value D and the outer diameter d of each outer ring 16b is small. Shifting operation can be stabilized. As the transmission torque increases, the outer ring 16b is displaced to a portion where the distance between the pair of stepped surfaces 26c, 26c is large, and at the same time, the distance is reduced. Accordingly, it is possible to always substantially prevent the outer rings 16b from being displaced in the axial direction of the support beam portions 23 regardless of the change in the transmission torque. In addition, it is possible to stabilize the shifting operation of the toroidal type continuously variable transmission by smoothly swinging the outer ring 16b about the support beam portions 23.

  However, in the case of the structure of this example, the shape of each stepped surface 26c, 26c is asymmetric with respect to the rotation direction of each disk 2, 5, so that the installation direction of each trunnion 7d and the installation of the pressing device 20 are the same. It is necessary to properly regulate the position. Specifically, as shown in FIG. 8, the direction of the pressing force by the pressing device 20 is determined based on the pressing force of each outer ring 16 b and the distance between the pair of stepped surfaces 26 c and 26 c. The direction to be displaced in the larger direction. For example, in the case of a toroidal type continuously variable transmission in which the pressing device 20 is installed at the end as shown in FIG. 11, the distance between the pair of step surfaces 26c, 26c is set at the center. Place it so that it becomes wider as you go to. On the other hand, in the case of the structure in which the pressing device is arranged at the center, the gap between the pair of stepped surfaces 26c, 26c is arranged so as to become wider toward the end.

  In the case of the structure of this example as described above, it is necessary to prepare at least two types of trunnions 7d to be incorporated in the toroidal-type continuously variable transmission, in which the step surfaces 26c and 26c have different inclination directions. is there. Instead, in the case of the structure of this example, in addition to the easy processing of the stepped surfaces 26c, 26c, the outer ring 16b is moved from the initial stage when the pressing device 20 generates a pressing force. It can be more easily displaced to the side where the interval is wide. This point will be described with reference to FIG. During operation of the toroidal type continuously variable transmission, the force of 2 Ft is applied to each outer ring 16b from the power roller 6a (see FIGS. 13 to 18) in the rotation direction of each disk 2 and 5, and each outer ring 16b. A part of the outer peripheral surface is pressed against any one of the step surfaces 26c. As a result of this pressing, a component force f is generated in a direction in which each outer ring 16b is moved in the direction of inclination of the stepped surface 26c. The direction of this component force f is caused by elastic deformation of each of the disks 2, 5, etc. The direction coincides with the direction in which each outer ring 16b swings and displaces. For this reason, this oscillating displacement can be performed more smoothly. Since the configuration and operation of the other parts are the same as those in the first example of the above-described embodiment, redundant description is omitted.

[Fourth to fifth examples of embodiment]
FIG. 10 also shows fourth to fifth examples of the embodiment of the invention corresponding to claims 1 and 3. In both cases, the shape of the step surfaces 26d and 26e is changed to the convex surface of the partial cylindrical surface {the step surfaces 26d and 26d of FIG. 10A} or the concave surface {of FIG. 10B. Step surfaces 26e, 26e} are provided. The curvature radii, inclination angles, etc. of the curved surfaces constituting these stepped surfaces 26d, 26e are designed according to the amount of rocking displacement of the outer ring 16b, the amount of elastic deformation of the support beam portion 23, etc. as the transmission torque increases. Determine (according to computer simulation or experiment). Since the configuration and operation of the other parts are the same as in the third example of the above-described embodiment, overlapping description is omitted.

  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. Further, the pressing device is not limited to a mechanical loading cam device as shown in FIG. 11, but may be a hydraulic one.

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, 7c, 7d Trunnion 8, 8a, 8b Tilt axis 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 Inner ring raceway 16, 16a, 16b Outer race 17 Outer raceway 18 Ball 19 Drive shaft 20 Pressing device 21 Actuator 22 Cylindrical convex surface 23 Support beam portion 24 Recess portion 25 Radial needle bearing 26, 26a-26e Stepped surface

Claims (3)

At least one pair of disks, a plurality of trunnions, the same number of power rollers as each trunnion, the same number of thrust rolling bearings, and a pressing device,
Each of these discs is a toroidal curved surface having a circular arc cross section, with the axial one side surfaces facing each other, concentrically supported and freely supported by relative rotation,
Each trunnion exists between a pair of tilting shafts provided concentrically with each other at both ends, and between these tilting shafts, and at least the inner side surface in the radial direction of each disk A support beam portion having a cylindrical convex surface having a center axis that is parallel to the center axis of both tilting shafts and outside the center axis in the radial direction of each disk, and both ends of the support beam portion are mutually connected. Provided with a pair of stepped surfaces for each trunnion provided in a state of being opposed to each other, and with respect to the circumferential direction of the positions between the axial side surfaces of each disk in the axial direction, Oscillating displacement about the two tilting shafts in a twisted position with respect to the central axis of the disc is freely provided,
Each of the power rollers is rotatably supported on the inner side surface of each trunnion via a thrust rolling bearing, and each circumferential surface having a spherical convex surface is brought into contact with one axial side surface of each disk. And
Each thrust rolling bearing is provided between the support beam portion of each trunnion and the outer surface of each power roller, and an outer ring provided on each support beam portion side, and an inner ring of each outer ring. A plurality of rolling elements are provided between the outer ring raceway provided on the side surface and the inner ring raceway provided on the outer side surface of each of the power rollers, respectively.
The outer ring of each thrust rolling bearing engages the concave portion provided on the outer side surface of each outer ring with the cylindrical convex surface of each support beam portion, and the above described provided on both ends of each support beam portion. By arranging between each pair of stepped surfaces for each trunnion, with respect to each trunnion, the axial displacement of each disk is controlled in a state where the axial displacement of each support beam is restricted. Supported to enable displacement,
In the toroidal type continuously variable transmission, the pressing device presses the disks facing each other in a state of sandwiching the power rollers in a direction approaching each other.
The distance between the pair of stepped surfaces for each trunnion gradually changes with respect to the swinging direction of each outer ring around each support beam, and the size of this distance is determined by the pressing device. It is substantially impossible for the outer rings to be displaced in the axial direction of the support beam portions at the portions facing the outer peripheral surfaces of the outer rings in a state where the outer rings are in a neutral position without generating a pressing force. This is a neutral value to prevent, and the pressing device generates a pressing force, and each outer ring swings and displaces around each supporting beam portion with the elastic deformation of each disk and each power roller. A toroidal-type continuously variable transmission characterized by being larger than the neutral value at a portion facing the outer peripheral surface of each outer ring in a state.   The distance between the pair of stepped surfaces for each trunnion is the narrowest at the center in the width direction of each stepped surface, which corresponds to the swinging direction of each outer ring, and the distance between the narrowest portions. The toroidal continuously variable transmission according to claim 1, wherein the magnitude of the toroidal value is the neutral value.   The distance between the pair of stepped surfaces for each trunnion changes from one end to the other with respect to the width direction of each stepped surface, which coincides with the swinging direction of each outer ring. The width of the intermediate portion in the width direction of the step surface is the neutral value, and the acting direction of the pressing force by the pressing device is based on the pressing force, and the interval between the step surfaces is The toroidal-type continuously variable transmission according to claim 1, wherein the toroidal-type continuously variable transmission is a direction to be displaced in a large direction.

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