JP5994582B2 - Toroidal continuously variable transmission - Google Patents

Description

  The present invention relates to an improvement of a toroidal type continuously variable transmission of a half toroid type that is used as a transmission for an automobile or a transmission for adjusting the operating speed of various industrial machines such as pumps. Specifically, it is possible to prevent a large difference in the traction coefficient of the traction section for each power roller and realize a structure with high transmission efficiency.

  The use of a toroidal continuously variable transmission as a transmission for an automobile is described in many publications such as Patent Documents 1 to 5 and partially implemented, and is well known. 2 to 3 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 2a and 2b are disposed around the portions near both ends of the input rotating shaft 1, and the input surfaces are arranged in a state where the inner side 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, the output gear 4 which is the first transmission gear described in the claims is fixed at the axially central portion, and patented at both axial ends. A pair of output disks 5 and 5, which are elements described in claims, are supported by spline engagement so as to be able to rotate in synchronization with the output cylinder 3. In this state, the inner side surfaces of the two output disks 5 and 5, each of which is a toroidal curved surface, are opposed to the inner side surfaces of the two input disks 2 a and 2 b. The output gear 4 meshes with a transmission gear 6 which is a second transmission gear described in the claims, so that the rotation of the output disks 5 and 5 can be taken out.

  Further, a plurality of power rollers 7 and 7 each having a spherical convex surface are sandwiched between the input disks 2a and 2b and the output disks 5 and 5. The power rollers 7 and 7 are rotatably supported by trunnions 8 and 8, respectively, and rotate with the rotation of the two input disks 2a and 2b, while the two outputs from the two input disks 2a and 2b. Power is transmitted to the disks 5 and 5. That is, when the toroidal-type continuously variable transmission is operated, one input disk 2a (left side in FIG. 2) is rotationally driven by the drive shaft 9 via the pressing device 10. As a result, the pair of input disks 2a and 2b supported at both ends of the input rotating shaft 1 rotate in synchronization while being pressed in directions approaching each other. This rotation is transmitted to the output disks 5 and 5 through the power rollers 7 and 7 and is taken out from the output gear 4.

  When changing the gear ratio between the input disks 2a, 2b and the output disks 5, 5, the hydraulic actuators 18, 18 provided at the ends of the trunnions 8, 8 The trunnions 8, 8 are displaced in the axial direction of the tilting shafts 12a, 12b provided concentrically with each other at both ends. Then, a tangential force acting on each traction portion which is a rolling contact portion between the circumferential surface of each of the power rollers 7 and 7 supported by each of the trunnions 8 and 8 and the side surface of each of the disks 2a, 2b and 5 In addition, a component force other than the rotation direction of the disks 2a, 2b, and 5 is generated, and the trunnions 8 and 8 swing around the tilt shafts 12a and 12b by the component force. When the trunnions 8 and 8 are swung until the desired gear ratio is obtained, the trunnions 8 and 8 with respect to the axial directions of the tilt shafts 12a and 12b are returned to the neutral positions. The gear ratio is held at the desired value. Incidentally, during operation of the toroidal continuously variable transmission, a force called 2Ft is applied to each trunnion 8, 8 from each power roller 7, 7, and this force 2Ft constitutes each actuator 18, 18 above. Pistons 19 and 19 are supported. That is, the difference ΔP between the hydraulic pressures in the pair of hydraulic chambers 20a and 20b provided with the pistons 19 and 19 sandwiched between the actuators 18 and 18 (the hydraulic pressure on the low pressure side is released). Therefore, the product of the high pressure side hydraulic pressure) and the pressure receiving area S of each piston 19, 19 is proportional to the force 2Ft (2Ft （ΔP · S). Since these points are well known in the technical field of toroidal-type continuously variable transmissions, detailed description thereof will be omitted.

  Further, in Patent Document 1, as shown in FIG. 4, by using an integrated output disk 5a, the entire toroidal continuously variable transmission can be reduced in size and weight, and the pressure device 10a can be hydraulic. Structures using the formula are described. In the second example of this conventional structure, teeth are formed directly on the outer peripheral edge of the output disk 5a, and the outer peripheral edge portion of the output disk 5a is used as the output gear 4a. The output gear 4a is engaged with a transmission gear (not shown in FIG. 4) so that the rotation of the output disk 5a can be taken out. The structure shown in FIG. 4 is different from the structure shown in FIGS. 2 to 3 in other parts. However, since these differences are not related to the gist of the present invention, the detailed explanation is as follows. Omitted.

  In any structure, during operation of the toroidal-type continuously variable transmission, the disks 2a, 2b, 5, 5a and the power rollers 7, 7 are elastically deformed. The positions of these power rollers 7 and 7 with respect to the axial direction of 5a change. In the case of the first example of the conventional structure shown in FIGS. 2 to 3, the power rollers 7 and 7 are eccentric shafts in which the base half and the front half are eccentric with respect to the trunnions 8 and 8. 11 and 11 and the power rollers 7 and 7 are displaced in the axial direction of the respective disks 2a, 2b, 5, and 5a by supporting them through a plurality of sets of rolling bearings including radial bearings and thrust bearings. Is allowed to do. However, as a structure for appropriately maintaining the position of each power roller in the axial direction of each disk, regardless of the elastic deformation of each constituent member, the structure described in Patent Document 2 is also conventionally known. Are known. Since the structure of the embodiment of the present invention to be described later uses the structure described in the cited document 2, the structure described in the cited document 2 will be described with reference to FIGS. The trunnion 8a constituting the toroidal continuously variable transmission described in Patent Document 2 includes at least input and output disks between a pair of tilting shafts 12a and 12b concentrically provided at both ends. 2a, 2b, 5 and 5a (see FIGS. 2 and 4), a support beam portion 14 having a cylindrical convex surface 13 on the inner side (upper side in FIGS. 6 to 8) in the radial direction (up and down direction in FIGS. 6 to 8). Is provided.

  As shown in FIGS. 6 to 8, the central axis A of the cylindrical convex surface 13 is parallel to the central axis B of the two tilting shafts 12a and 12b and is more than the central axis B of the two tilting shafts 12a and 12b. In the radial direction of each of the disks 2 and 5, it exists outside (the lower side of FIGS. 6 to 8). Further, a concave portion 17 having a partially cylindrical surface is formed across the outer surface in the radial direction on the outer surface of the outer ring 16 constituting the thrust ball bearing 15 provided between the support beam portion 14 and the outer surface of the power roller 7. It is provided in the state. And this recessed part 17 and the cylindrical convex surface 13 of the said support beam part 14 are engaged, The said outer ring | wheel 16 is rock | fluctuated regarding the axial direction of each said disk 2a, 2b, 5, 5a with respect to the said trunnion 8a. Supports displacement.

  A support shaft 21 is fixed to the center of the inner surface of the outer ring 16 integrally with the outer ring 16, and the power roller 7 is rotatably supported around the support shaft 21. Furthermore, a pair of stepped surfaces 22 and 22 facing each other are provided on the inner surface of the trunnion 8a at a continuous portion between both end portions of the support beam portion 14 and the pair of tilting shafts 12a and 12b. . Then, these stepped surfaces 22 and 22 and the outer peripheral surface of the outer ring 16 constituting the thrust ball bearing 15 are brought into contact with or in close proximity to each other, and the traction force applied to the outer ring 16 from the power roller 7 These step surfaces 22 and 22 can be supported.

According to the structure shown in FIGS. 5 to 8 described above, as described in Patent Document 2, the power roller 7 is displaced in the axial direction of each of the disks 2a, 2b, 5, 5a, and each of the components A structure that can appropriately maintain the contact state between the peripheral surface of the power roller 7 and each of the disks 2a, 2b, 5, and 5a regardless of the elastic deformation amount of the member can be configured easily and at low cost.
That is, when it is necessary to displace the power roller 7 in the axial direction of each of the disks 2 a, 2 b, 5, 5 a, the outer ring 16 swings and displaces around the central axis A of the cylindrical convex surface 13. Based on this oscillating displacement, a portion of the peripheral surface of the power roller 7 that is in rolling contact with one axial side surface of each of the disks 2a, 2b, 5, 5a is the disk 2a, 2b, 5, 5a. It is displaced in the axial direction, and the contact state is properly maintained.

  Regardless of the structure, a toroidal continuously variable transmission is formed through the output gears 4 and 4a provided at the center in the axial direction of the output discs 5 and 5a provided around the intermediate portion of the input rotary shaft 1 which is an inner disc. In the case of a structure for putting torque in and out, the output disks 5 and 5a are displaced in the radial direction based on the gear reaction force applied to the output gears 4 and 4a. This gear reaction force is a combination of the reaction force in the direction opposite to the transmitted torque (tangential direction) and the radial reaction force generated based on the friction between the tooth surfaces. For example, FIG. The output gear 4 and the transmission gear 6 shown are applied in a direction inclined with respect to the arrangement direction (the direction connecting the rotation centers of the two gears 4 and 6).

  Regardless of the direction in which the gear reaction force is applied, the radial position of the output gears 4 and 4a is shifted in the radial direction with respect to the neutral position based on the gear reaction force. As a result, the surface pressures of the traction portions, which are the rolling contact portions of the peripheral surfaces of the power rollers 7, 7 and the disks 2a, 2b, 5, 5a, are not the same. Specifically, the surface pressure of each traction portion increases on the side where the gear reaction force acts, and the surface pressure of each traction portion decreases on the opposite side. As a result, there is a large difference in the traction coefficient μt (= Ft / Fc), which is the ratio of the tangential force Ft and the normal force Fc (cold surface pressure), between the side where the gear reaction force acts and the opposite side. . If the traction coefficient μt is different for each traction section, it is disadvantageous in terms of ensuring the transmission efficiency of the toroidal continuously variable transmission. Specifically, when the pressing force generated by the pressing devices 10 and 10a tends to be insufficient, excessive slip tends to occur in a traction portion having a high traction coefficient μt. On the other hand, if the pressing force generated by the pressing devices 10 and 10a is increased so that excessive slip does not occur even in a traction portion with a high traction coefficient μt, the surface pressure of the traction portion with a low traction coefficient μt becomes excessive. The rolling resistance increases at the traction portion. Any phenomenon is undesirable because it reduces the transmission efficiency of the toroidal-type continuously variable transmission.

  In addition, there are Patent Documents 3 to 6 as publications describing techniques related to the implementation of the present invention. Among them, Patent Document 3 relates to a power roller unit in which a trunnion and a power roller are combined through a plurality of sets of rolling bearing units, from the center of the tilting shaft to the center of the traction portion on the peripheral surface of the power roller. It describes a method that can accurately measure the assembly height as a distance. Patent Documents 4 to 6 describe techniques for forming fine grooves on the peripheral surface in order to increase the traction coefficient of the traction portion related to the peripheral surface of the power roller.

JP 2008-82360 A JP 2008-25821 A Japanese Patent Laid-Open No. 10-30700 JP 2008-303965 A JP 2008-303922 A JP 2009-287739

  The present invention was invented to realize a toroidal type continuously variable transmission with high transmission efficiency by preventing the occurrence of a large difference in the traction coefficient of the traction section for each power roller in view of the circumstances as described above. It is.

The toroidal type continuously variable transmission according to the present invention includes a pair of outer disks, an inner disk, a first transmission gear, and a gear transmission device in the same manner as the previously known toroidal continuously variable transmissions. And a plurality of trunnions, a plurality of power rollers, and a pressing device.
A pair of the outer disks are rotated in a state where the axial side surfaces of the rotating disks are opposed to each other at two positions separated from each other in the axial direction in the rotating shaft. Rotation synchronized with the shaft is supported freely.
In addition, the inner disk rotates relative to the rotating shaft around the middle portion of the rotating shaft, with both axial side surfaces having a circular arc cross section facing one axial side surface of both outer disks. It is supported freely, and is formed as a single unit or by combining a pair of elements.
In addition, the first transmission gear is provided at the center in the axial direction of the inner disk and rotates in synchronization with the inner disk.
The gear transmission device includes a second transmission gear meshed with the first transmission gear, and transmits torque between the inner disk and another rotational shaft arranged in parallel with the rotational shaft. .
Each trunnion has a pair of cavities in the axial direction, each pair of cavities located between both axial side surfaces of the inner disk and one axial side surface of the outer disks. On the opposite sides with respect to the direction, a swinging displacement centering on a tilting shaft that is twisted with respect to the rotating shaft is provided freely.
Each power roller is rotatably supported on the inner side surface of each trunnion, and each circumferential surface formed as a spherical convex surface is formed on both axial sides of the inner disk and axial pieces of the outer disks. It is in contact with the side.
Further, the pressing device is provided between the rotating shaft and one of the two outer disks, and presses the one outer disk toward the other outer disk of the two outer disks. To do.

In particular, in the toroidal-type continuously variable transmission according to the present invention, the peripheral surface of each power roller in a state where torque is not transmitted between the disks or in a state where torque transmitted is low (low torque transmission state). The traction coefficient is generated based on the meshing of the first and second gears, and is different from each other between the power rollers existing at different positions with respect to the action direction of the gear reaction force applied to the inner disk. Make it.
Then, when the torque increases and the inner disk is displaced in the radial direction based on the gear reaction force, the difference in traction coefficient between the traction parts is reduced (ideally, the difference is zero). ).
That is, in the low torque transmission state, the traction coefficient of each traction portion that is a rolling contact portion between the peripheral surface of each power roller and the side surface of each disk that is present on the side on which the gear reaction force acts is expressed as the gear. The traction coefficient is set higher than the traction coefficient of the traction portion between the peripheral surface of each power roller and the side surface of each disk existing on the side opposite to the side on which the reaction force acts.
In the present invention, the state in which each power roller is present on the side on which the gear reaction force acts or on the opposite side is not necessarily the direction in which the gear reaction force acts and the installation position of each power roller. It doesn't have to match. In short, this gear reaction force acts on the one side in the direction of increasing the surface pressure of a part of the traction parts, and on the other side, the surface pressure of the remaining traction part is lowered. The condition of the present invention is satisfied as long as it acts in the direction.

  Specifically, when implementing the present invention as described above, for example, the configuration of the invention described in claims 2 to 7 can be adopted. In each of these inventions, the assembly height of each power roller unit is regulated. Each of these power roller units is a unit in which a trunnion and a power roller are combined through a plurality of sets of rolling bearing units. The assembly height of each of these power roller units refers to the power supported by these trunnions from the center of one pair of tilting shafts for each trunnion provided concentrically at both ends of each trunnion. The distance to the center of the traction part about the roller circumference. The assembly height of such a power roller unit can be measured with high accuracy by, for example, the method described in Patent Document 3.

In the case of the invention described in claim 2, the assembly height of each of the power roller units arranged on the side opposite to the side on which the gear reaction force acts is set as the gear height. The assembly height of each of the power roller units disposed on the reaction force acting side is set higher.
On the other hand, in the case of the invention described in claims 3 to 7, the assembly heights of the respective power roller units are made equal to each other.
In the case of the invention described in claim 3, each power roller unit arranged on the side on which the gear reaction force acts is arranged on the side opposite to the side on which the gear reaction force acts on. Rather than the central axis of each disk.
In the case of the invention described in claim 4, the power rollers are arranged on the peripheral surface of the power rollers constituting the power roller units disposed on the side opposite to the side on which the gear reaction force acts. A fine groove is formed to increase the traction coefficient of each traction portion with respect to the peripheral surface.
Also, in the case of the invention described in claim 5, the power roller unit is arranged on the side opposite to the side on which the gear reaction force acts, and is supplied to each traction portion relating to the peripheral surface of each power roller constituting the power roller unit. The amount of traction oil is set to be larger than the amount of traction oil supplied to each traction portion related to the peripheral surface of each power roller that constitutes each power roller unit arranged on the side where the gear reaction force acts.
In the case of the invention described in claim 6, the radius of curvature of the generatrix shape of the peripheral surface of each power roller constituting each power roller unit arranged on the side opposite to the side on which the gear reaction force acts is set. The radius of curvature of the generatrix shape of the peripheral surface of each power roller constituting each power roller unit arranged on the side on which the gear reaction force acts is made smaller.
Furthermore, in the case of the invention described in claim 7, a hydraulic actuator is provided for displacing each power roller unit arranged on the side where the gear reaction force acts in the axial direction of each tilt shaft. Pressure receiving area of the piston that constitutes a hydraulic actuator for displacing each power roller unit arranged in a direction opposite to the side on which the gear reaction force acts in the axial direction of each tilting shaft Make it wider than the area.

  In the case of the toroidal-type continuously variable transmission of the present invention configured as described above, the traction coefficient of each traction section is set to an appropriate value or with the inner disk displaced in the radial direction with a large torque transmission. A value close to this appropriate value can be obtained. For this reason, it is possible to prevent an excessive slip from occurring in a traction portion having a high traction coefficient μt, or an increase in rolling resistance in the traction portion due to an excessive surface pressure of the traction portion having a low traction coefficient μt. As a result, transmission efficiency can be improved in all traction sections, and transmission efficiency as a whole toroidal type continuously variable transmission can be improved.

The fragmentary sectional view which shows one example of the toroidal type continuously variable transmission for demonstrating this invention. Sectional drawing which shows the principal part which shows the 1st example of the toroidal type continuously variable transmission conventionally known and used as the object of this invention. AA sectional drawing of FIG. The principal part sectional drawing which shows the 2nd example of the toroidal type continuously variable transmission conventionally known and used as the object of this invention. The perspective view which shows the structure according to the power roller unit integrated in the toroidal type continuously variable transmission of FIG. Similarly, the orthographic projection shown in the state seen from the circumferential direction of each disk. Sectional drawing shown in the state similarly seen from the same direction as FIG. BB sectional drawing of FIG.

[First example of embodiment]
A first example of an embodiment of the present invention corresponding to claims 1 and 2 will be described with reference to FIG. The feature of the present invention including this example is that a large gear reaction force applied to the inner disk from the first transmission gear such as the output gear 4a fixed at the axial center of the inner disk such as the output disk 5a. Regardless of this, there is a difference in the dimensions, properties, operating conditions, etc. of each part in order to efficiently transmit power in each traction part of the toroidal type continuously variable transmission. The absolute values of these differences are the bending rigidity of the input rotary shaft 1 that supports the output gear 4a around the intermediate portion, the magnitude of the torque transmitted by the toroidal continuously variable transmission, the pitch circle diameter of the output gear 4a, and It depends on various requirements such as gear modules. However, in any case, the dimensional difference is a small value of about several tens of μm to several hundreds of μm, and other conditions hardly appear in the drawings. FIG. 1 itself is basically a structure obtained by combining the structure described in Patent Document 1 and the structure described in Patent Document 2, and the features of the present invention are read from the drawing. I can't do that. However, referring to FIG. 1 is important in understanding the present invention. Therefore, referring to FIG. 1 and FIGS. 2 to 3 as necessary, this example and other embodiments will be described. explain.

  In the case of this example, a downward gear reaction force is applied to the output disk 5a based on the meshing of the output gear 4a and the transmission gear 6 (see FIG. 2) as shown by the arrow α in FIG. It shall act. Therefore, in the case of the toroidal type continuously variable transmission of this example, each power roller 7 is in a state where the torque is not transmitted between the disks 2a, 2b, 5a or the transmitted torque is low (low torque transmission state). , 7 are made different from each other between the power rollers 7 and 7 existing at different positions with respect to the direction of the action of the gear reaction force.

  For this reason, in the case of this example, the assembly height of the power roller units 23 and 23 each combining the trunnion 8a and the power roller 7 through a plurality of sets of rolling bearings is regulated. The assembly height of each of these power roller units 23, 23 is supported by the trunnion 8a from the center of a pair of tilting shafts 12a, 12b (see FIG. 3) concentrically provided at both ends of the trunnion 8a. The distance to the center of the traction part about the peripheral surface of the power roller 7 is said. In the case of this example, the assembly height H of each of the power roller units 23 and 23 arranged on the upper side in FIG. 1, which is the side opposite to the side on which the gear reaction force acts, is applied to the gear reaction force. The assembly height h of each of the power roller units 23 and 23 arranged on the lower side of FIG. 1 is higher (H> h). Such adjustment of the assembly heights H and h of the power roller units 23 and 23 is, for example, at least one of the trunnion 8a, the outer ring 16 or balls 24 and 24 of the thrust ball bearing 15, and the power roller 7. Adjustment is made by changing the dimension of one type of member in the axial direction of the power roller 7. The adjusted assembly heights H and h are measured by the method described in Patent Document 3 as described above.

  According to the structure of this example as described above, in the low torque transmission state, the power rollers 7 constituting the power roller units 23 and 23 arranged on the upper side (reaction side of the gear reaction force) in FIG. , 7, the surface pressure (normal force Fc) of the traction portion is higher than the surface pressure of the traction portion on the lower side of FIG. In the case of this example, the magnitude of torque (tangential force Ft) to be transmitted by each traction unit is the same. Accordingly, the traction coefficient μt (= Ft / Fc) of the upper traction portion is reduced by the amount that the surface pressure (normal normal force Fc) of each traction portion is larger on the upper side and smaller on the lower side in FIG. It becomes smaller than the traction coefficient μt of the part.

  From this state, when the torque transmitted between the disks 2a, 2b, 5a increases, the output disk 5a is displaced downward in FIG. 1 with respect to the radial direction based on the gear reaction force. As a result, the surface pressure of the traction part of each of the power rollers 7 and 7 disposed on the upper side in FIG. The surface pressure of the traction section increases. Then, the traction coefficient of each of these traction sections increases for the upper traction section in FIG. 1 and decreases for the lower traction section. As a result, the traction coefficient difference between the traction units can be reduced (ideally the difference is zero).

  Thus, in the case of the toroidal-type continuously variable transmission of this example, the traction coefficient of each of the traction portions is set to an appropriate value or a value with the output disk 5a being displaced in the radial direction with a large torque transmission. A value close to this appropriate value can be obtained. For this reason, it is possible to prevent an excessive slip from occurring in a traction portion having a high traction coefficient μt, or an increase in rolling resistance in the traction portion due to an excessive surface pressure of the traction portion having a low traction coefficient μt. As a result, transmission efficiency can be improved in all traction sections, and transmission efficiency as a whole toroidal type continuously variable transmission can be improved. If the difference between the assembly heights H and h of the respective power roller units 23 and 23 is appropriately regulated so that the difference in the traction coefficient μt between the traction portions is minimized in the state where the usage frequency is the highest, The efficiency of the toroidal type continuously variable transmission can be improved, and it can contribute to the improvement of fuel efficiency of a vehicle equipped with the toroidal type continuously variable transmission.

[Second Example of Embodiment]
Next, a second example of the embodiment of the present invention corresponding to claims 1 and 3 will be described. In the following embodiments, the assembly heights of the power roller units 23 and 23 are made equal to each other. Instead, in the case of this example, each of the power roller units 23 and 23 arranged on the upper side of FIG. 1 which is the reaction side of the gear reaction force is replaced with the lower side of FIG. The power roller units 23 and 23 arranged on the side are arranged closer to the center axis of the disks 2a, 2b and 5a. Therefore, the positions of the circular holes 26 and 26 (see FIG. 3) formed in the support plates 25 and 25 for supporting the tilt shafts 12a and 12b provided at both ends of the trunnions 8a and 8a are different. Make it. More specifically, the circular holes 26 and 26 for supporting the upper power roller units 23 and 23 in FIG. 1 are made more than the circular holes 26 and 26 for supporting the lower power roller units 23 and 23. Approach the input rotation shaft 1 side.

In the case of this example, the power rollers 7 constituting the power roller units 23 and 23 arranged on the upper side (reaction side of the gear reaction force) in FIG. , 7 is made higher than the surface pressure of the traction portion on the lower side (the gear reaction force acting side) of FIG.
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]
Next, a third example of the embodiment of the invention corresponding to claims 1 and 4 will be described. In the case of this example, fine grooves are formed on the peripheral surfaces of the power rollers 7 and 7 constituting the power roller units 23 and 23 arranged on the upper side of FIG. . And the traction coefficient of each traction part regarding the peripheral surface of each power roller 7 and 7 arrange | positioned at the reaction side of these gear reaction force is made high. On the peripheral surfaces of the power rollers 7 and 7 constituting the power roller units 23 and 23 arranged on the lower side of FIG. 1 which is the working side of the gear reaction force, fine grooves as described above are formed. And keep the surface smooth.

By forming fine grooves on the peripheral surfaces of the power rollers 7 and 7, the traction portions which are rolling contact portions between the peripheral surfaces of the power rollers 7 and 7 and the side surfaces of the disks 2a, 2b and 5a are provided. The fact that the traction coefficient is high is as described in Patent Documents 4-6. Therefore, in the case of this example, in the low torque transmission state, the traction relating to the power rollers 7 and 7 constituting the power roller units 23 and 23 arranged on the upper side (reaction side of the gear reaction force) in FIG. The traction coefficient of the portion becomes higher than the traction coefficient of the lower traction portion of FIG. Then, the output disk 5a is displaced downward in FIG. 1 with respect to the radial direction based on the gear reaction force accompanying the increase in the transmission torque, and is located on the reaction side of the gear reaction force. , 7, even when the surface pressure of the traction section is reduced, excessive slippage is prevented from occurring in each of these traction sections.
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 Example of Embodiment]
A fourth example of the embodiment of the present invention corresponding to claims 1 and 5 will be described. In the case of this example, each power roller unit 23, 23 arranged on the lower side in FIG. 1 where the gear reaction force acts and on the upper side in FIG. The amounts of traction oil supplied to the traction portions related to the peripheral surfaces 7 and 7 are different from each other. Specifically, each traction portion related to the circumferential surface of each of the power rollers 7 and 7 constituting each of the power roller units 23 and 23 disposed on the lower side of FIG. The circumference of each power roller 7, 7 constituting each power roller unit 23, 23 arranged on the upper side in FIG. 1, which is the side opposite to the side on which the gear reaction force acts than the amount of traction oil to be supplied. Increase the amount of traction oil supplied to each traction section on the surface. It should be noted that the amount of traction oil supplied in this way can be easily changed by changing the diameter of the nozzle for spraying the traction oil to each traction section.

The traction coefficient of each of the traction portions changes according to the amount of traction oil (oil film thickness) existing in each of the traction portions. In other words, the amount of traction oil supplied to the traction portion on the reaction side of the gear reaction force is made larger than the traction portion on the reaction side of the gear reaction force, thereby cooling the traction portion on the reaction side of the gear reaction force. The traction coefficient of the traction part on the reaction side of the gear reaction force is made higher than that on the operation side of the gear reaction force. Further, if a sufficient amount of traction oil can be supplied to each of these traction portions, the traction coefficient of the traction portion is ensured, and the side on which the gear reaction force acts as the output gear 5a is displaced based on the gear reaction force. Torque can be transmitted without causing excessive slippage even if the surface pressure of each traction portion decreases on the opposite side.
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.

[Fifth Example of Embodiment]
A fifth example of the embodiment of the present invention corresponding to claims 1 and 6 will be described. In the case of this example, the generatrix shape of the peripheral surface of each power roller 7, 7 constituting each power roller unit 23, 23 arranged on the upper side in FIG. 1, which is the side opposite to the side on which the gear reaction force acts, is provided. The radius of curvature is larger than the radius of curvature of the generatrix shape of the peripheral surfaces of the power rollers 7 and 7 constituting the power roller units 23 and 23 arranged on the lower side of FIG. Make it smaller. Therefore, in the case of this example, the area of the contact ellipse existing in the traction portion which is the rolling contact portion between the peripheral surface of each of the power rollers 7 and 7 and the side surface of each of the disks 2a, 2b and 5a is the gear reaction force. 1 is smaller on the reaction side of FIG. 1 and larger on the lower side of the action side. For this reason, even if the surface pressure of each traction portion decreases on the side opposite to the side on which the gear reaction force acts as the output gear 5a is displaced based on the gear reaction force, a sufficient surface pressure can still be secured. Thus, torque can be transmitted without causing excessive slippage in the traction section.
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.

[Sixth Example of Embodiment]
A sixth example of the embodiment of the present invention corresponding to claims 1 and 7 will be described. In the case of this example, pistons 19 constituting hydraulic actuators 18, 18 for displacing the trunnions 8 a, 8 a constituting the power roller units 23, 23 in the axial direction of the tilt shafts 12 a, 12 a, The pressure receiving areas 19 (see FIG. 3) are made different from each other in accordance with the direction of action of the gear reaction force. Specifically, the pressure receiving area of the pistons 19 and 19 of the actuators 18 and 18 for displacing the upper trunnions 8a and 8a in FIG. It is made narrower than the pressure receiving area of the pistons 19 and 19 of the actuators 18 and 18 for displacing the lower trunnions 8a and 8a in FIG.

In the case of this example, the tangential force 2Ft applied to each power roller can be kept small on the side where the surface pressure of each traction portion decreases during transmission of large torque (the reaction side of the gear reaction force). As a result, it is possible to prevent a large difference in the traction coefficient between the traction portion where the gear reaction force acts and the traction portion where the gear reaction force does not act, and the transmission efficiency as a whole toroidal type continuously variable transmission Can be improved.
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.

  When the toroidal continuously variable transmission is used as an automatic transmission for an automobile, for example, the direction in which the toroidal continuously variable transmission transmits torque is reversed between acceleration and deceleration (when the engine brake is activated). . Further, in the case of a continuously variable transmission configured by combining a toroidal continuously variable transmission and a planetary gear type transmission, the torque that passes through the toroidal continuously variable transmission even during the same acceleration (or deceleration) The direction of may be reversed. And if the direction of the torque passage is reversed, the direction of action of the gear reaction force also changes. Therefore, in any case, the traction coefficient of all traction units cannot be optimized. Therefore, when carrying out the present invention, the dimensions and properties of each part or the supply state of traction oil are regulated so that the traction coefficient of all traction parts can be optimized in the operating state with the highest appearance frequency. .

DESCRIPTION OF SYMBOLS 1 Input rotating shaft 2a, 2b Input disk 3 Output cylinder 4, 4a Output gear 5, 5a Output disc 6 Transmission gear 7 Power roller 8, 8a Trunnion 9 Drive shaft 10, 10a Pressing device 11 Eccentric shaft 12a, 12b Tilt shaft DESCRIPTION OF SYMBOLS 13 Cylindrical convex surface 14 Support beam part 15 Thrust ball bearing 16 Outer ring 17 Concave part 18 Actuator 19 Piston 20a, 20b Hydraulic chamber 21 Support shaft 22 Step surface 23 Power roller unit 24 Ball 25 Support plate 26 Circular hole

Claims (7)

Of the rotating shafts, two positions that are separated from each other in the axial direction are supported so as to freely rotate in synchronization with the rotating shaft, with the respective axial side surfaces facing each other having arcuate cross sections. A pair of outer disks;
Around the intermediate portion of the rotating shaft, the axially opposite side surfaces having a circular arc cross section are opposed to the axially one side surfaces of both outer disks, and are integrally supported to freely rotate relative to the rotating shaft. Or an inner disk formed by combining a pair of elements;
A first transmission gear provided at the axially central portion of the inner disk and rotating in synchronization with the inner disk;
A gear transmission device including a second transmission gear meshed with the first transmission gear, and transmitting torque between the inner disk and another rotational shaft arranged in parallel with the rotational shaft;
One pair for each pair of cavities located between both axial side surfaces of the inner disk and one axial side surface of the outer disks with respect to the axial direction, respectively, opposite to each other with respect to the radial direction of each of these disks, A plurality of trunnions provided freely with swing displacement about a tilting shaft that is twisted with respect to the rotating shaft;
A plurality of powers that are rotatably supported on the inner side surface of each trunnion and have a spherical convex surface contacted with both axial side surfaces of the inner disk and one axial side surface of the outer disks. Laura,
A pressing device provided between the rotating shaft and one outer disk of the two outer disks, and pressing the one outer disk toward the other outer disk of the two outer disks; In toroidal type continuously variable transmissions,
Generated based on the meshing of the first and second transmission gears , and with respect to the acting direction of the gear reaction force applied to the inner disk, the peripheral surface of each power roller present on the side on which the gear reaction force acts and the Traction coefficient of each traction part which is a rolling contact part with the side surface of each disk, and a traction part between the peripheral surface of each power roller and the side surface of each disk existing on the side opposite to the side on which the gear reaction force acts The torque is not transmitted between the disks, or a difference is provided when the transmitted torque is low, and the torque increases, and the inner disk moves in the radial direction based on the gear reaction force. A toroidal continuously variable transmission characterized in that, in a displaced state, a difference in traction coefficient between the traction sections is reduced.   A unit in which a trunnion and a power roller are combined via a plurality of sets of rolling bearing units is referred to as a power roller unit, and a pair of tilting shafts are provided for each trunnion provided concentrically at both ends of each trunnion. When the distance from the center to the center of the traction part on the peripheral surface of each power roller supported by these trunnions is the assembly height of each power roller unit, this gear reaction force The assembly height of each of the power roller units disposed on the side opposite to the side on which the gear acts is higher than the assembly height of the power roller units disposed on the side on which the gear reaction force acts. Toroidal continuously variable transmission.   A unit in which a trunnion and a power roller are combined via a plurality of sets of rolling bearing units is referred to as a power roller unit, and a pair of tilting shafts are provided for each trunnion provided concentrically at both ends of each trunnion. When the distance from the center to the center of the traction portion on the peripheral surface of each power roller supported by these trunnions is the assembly height of each power roller unit, the assembly height of each power roller unit is made equal to each other. The power roller units arranged on the side opposite to the side on which the gear reaction force acts are arranged closer to the central axis of each disk than the power roller units arranged on the side on which the gear reaction force acts The toroidal type continuously variable transmission according to claim 1.   A unit in which a trunnion and a power roller are combined via a plurality of sets of rolling bearing units is referred to as a power roller unit, and a pair of tilting shafts are provided for each trunnion provided concentrically at both ends of each trunnion. When the distance from the center to the center of the traction portion on the peripheral surface of each power roller supported by these trunnions is the assembly height of each power roller unit, the assembly height of each power roller unit is made equal to each other. In order to increase the traction coefficient of each traction portion related to the peripheral surface of each power roller on the peripheral surface of each power roller constituting each of the power roller units disposed on the side opposite to the side on which the gear reaction force acts The toroidal type continuously variable transmission according to claim 1, wherein a fine groove is formed.   A unit in which a trunnion and a power roller are combined via a plurality of sets of rolling bearing units is referred to as a power roller unit, and a pair of tilting shafts are provided for each trunnion provided concentrically at both ends of each trunnion. When the distance from the center to the center of the traction portion on the peripheral surface of each power roller supported by these trunnions is the assembly height of each power roller unit, the assembly height of each power roller unit is made equal to each other. The gear reaction force acts on the amount of traction oil to be supplied to each traction portion related to the peripheral surface of each power roller constituting each power roller unit disposed on the side opposite to the side on which the gear reaction force acts. Each of the power rollers on the peripheral surface of each of the power rollers constituting the power roller unit disposed on the side. It was larger than the amount of traction oil supplied to the action section, toroidal-type continuously variable transmission according to claim 1.   A unit in which a trunnion and a power roller are combined via a plurality of sets of rolling bearing units is referred to as a power roller unit, and a pair of tilting shafts are provided for each trunnion provided concentrically at both ends of each trunnion. When the distance from the center to the center of the traction portion on the peripheral surface of each power roller supported by these trunnions is the assembly height of each power roller unit, the assembly height of each power roller unit is made equal to each other. The radius of curvature of the generatrix shape of the peripheral surface of each power roller that constitutes each power roller unit arranged on the side opposite to the side on which the gear reaction force acts is arranged on the side on which the gear reaction force acts The power roller unit is made smaller than the radius of curvature of the generatrix shape of the peripheral surface of each power roller constituting each power roller unit. Placing the toroidal type continuously variable transmission.   A unit in which a trunnion and a power roller are combined via a plurality of sets of rolling bearing units is referred to as a power roller unit, and a pair of tilting shafts are provided for each trunnion provided concentrically at both ends of each trunnion. When the distance from the center to the center of the traction portion on the peripheral surface of each power roller supported by these trunnions is the assembly height of each power roller unit, the assembly height of each power roller unit is made equal to each other. The pressure reaction area acts on the pressure receiving area of a piston that constitutes a hydraulic actuator for displacing each power roller unit arranged on the side where the gear reaction force acts in the axial direction of each tilt shaft. A hydraulic actuator for displacing each power roller unit disposed on the opposite side to the side to be moved in the axial direction of each tilting shaft. It was larger than the pressure receiving area of the piston constituting the Chueta, toroidal type continuously variable transmission according to claim 1.

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