JP3843597B2 - Toroidal continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toroidal continuously variable transmission that can be applied to a power transmission section of a vehicle or the like and that continuously shifts and outputs to an output shaft via a power roller that can tilt the rotation of an input shaft.
[0002]
[Prior art]
Conventionally, as a toroidal continuously variable transmission, a toroidal transmission comprising an input disk driven by an input shaft, an output disk disposed opposite to the input disk and connected to the output shaft, and a power roller frictionally contacting both disks 2. Description of the Related Art A toroidal continuously variable transmission in which one set or a plurality of sets are arranged on the same shaft is known. In this toroidal-type continuously variable transmission, the rotation of the input disk can be changed steplessly and transmitted to the output disk by changing the tilt angle of the power roller.
[0003]
Such a toroidal continuously variable transmission is called a so-called double-cavity toroidal continuously variable transmission in which two sets of toroidal transmission portions are arranged on the same shaft as shown in FIGS. There is something to be done. 2 is a schematic view of a double cavity type toroidal continuously variable transmission, and FIG. 3 is a cross-sectional view showing details of one toroidal transmission portion of the double cavity type toroidal continuously variable transmission shown in FIG.
[0004]
In the double cavity type toroidal continuously variable transmission shown in FIG. 2, two sets of toroidal transmission units 1 and 2 are arranged side by side on the main shaft 3. The toroidal transmission unit 1 is disposed between the input disk 4, the output disk 5 disposed opposite to the input disk 4, the input disk 4 and the output disk 5, and friction on the toroidal curved surfaces of both disks 4, 5. It is comprised from the power roller 6 to engage. Similar to the toroidal transmission unit 1, the toroidal transmission unit 2 is disposed between the input disk 7, the output disk 8 disposed opposite to the input disk 7, and between the input disk 7 and the output disk 8. The power roller 9 is frictionally engaged with the 7 and 8 toroid curved surfaces. Each toroidal transmission unit 1, 2 is provided with two power rollers 6, 9. Each of the power rollers 6 and 9 can rotate around its own rotation axis 10 and can tilt around a tilting axis 11 (perpendicular to the paper surface) perpendicular to the rotation axis 10.
[0005]
The input shaft 13 is disposed on the same axis as the main shaft 3, and power from the engine is input to the input shaft 13 via the torque converter 12. In the toroidal transmission units 1 and 2, the input disks 4 and 7 can be displaced in the axial direction of the main shaft 3 via the ball spline 17 and can rotate integrally with the main shaft 3. A loading cam 14 provided with a cam roller 15 is disposed at the tip of the input shaft 13, and the cam action causes the toroidal transmission 1 to move the input disk 4 to the power roller 6 according to the magnitude of the input torque. Thrust force to press is generated. As shown in FIG. 3, since a thrust bearing 16 is interposed between the main shaft 3 and the loading cam 14, the main shaft 3 can rotate relative to the loading cam 14, but is integral in the axial direction. It is connected to. When the thrust force is generated, the main shaft 3 is pulled toward the input shaft 13 by the reaction, and the input disk 7 is pressed against the power roller 9 in the toroidal transmission unit 2. Therefore, the thrust force sandwiches the power rollers 6 and 9 between the input disks 4 and 7 and the output disks 5 and 8, and gives a frictional engagement force corresponding to the magnitude of the transmission torque. A part of the rotational force from the loading cam 14 is transmitted to the input disk 4 of the toroidal transmission 1 through the cam roller 15, and the rotation of the input disk 4 is transmitted to the output disk 5 through the rotation of the power roller 6. . On the other hand, the remainder of the rotational force from the loading cam 14 is transmitted to the input disk 7 of the toroidal transmission unit 2 via the ball spline 17 and the main shaft 3, and the rotation of the input disk 7 passes through the rotation of the power roller 9 to the output disk. 8 is transmitted.
[0006]
In the toroidal transmission units 1 and 2, the power rollers 6 and 9 are tilted around the tilt shaft 11, so that the rotation of the input disks 4 and 7 is stepless to the output disks 5 and 8 according to the tilt angle θ. To be transmitted. The power rollers 6 and 9 are rotatably and swingably supported with respect to a trunnion (not shown), and can cope with the axial displacement of the main shaft 3 generated according to the thrust force.
[0007]
At the neutral position where the rotational axis 10 of the power rollers 6 and 9 intersects the axis of the main shaft 3, the tilt angle θ of the power rollers 6 and 9 is maintained at that time, and the gear ratio is the value at that time. keeping. When the trunnion is moved in the axial direction of the tilting shaft 11 during torque transmission, the power rollers 6 and 9 are also displaced in the tilting shaft direction accordingly, and the power rollers 6 and 9 and the input disks 4 and 7 and the output disk are displaced. The contact position with 5 and 8 is displaced from the contact position at the neutral position. As a result, the power rollers 6 and 9 receive a tilting force from both disks, and tilt about the tilting shaft 11 occurs in a direction and speed according to the moving direction and the moving amount of the tilting shaft 11. . When such tilting occurs, the radius drawn by the friction contact points with the power rollers 6 and 9 on the input disks 4 and 7 and the radius drawn by the friction contact points with the power rollers 6 and 9 on the output disks 5 and 8 The stepless speed change is performed by changing the ratio. In the tilt control of the power rollers 6 and 9, the trunnion tilt axial displacement is controlled by the operation of an actuator (not shown) so that the target speed ratio is achieved by a controller (not shown).
[0008]
The output disks 5 and 8 are respectively spline-fitted with a hollow shaft portion 40 extending integrally on both sides from the gear body 22 of the output gear 21 so as to transmit torque from the power rollers 6 and 9 and to rotate together. is doing. The spline fitting portion 42 is configured by meshing a spline formed on the outer periphery of the hollow shaft portion 40 with a spline formed on the inner periphery of the fitting hole 43 of the output disk 5. The output gear 21 is rotatably supported with respect to the casing 19 via an angular bearing 23 having an inner ring 24a and an outer ring 24b. The output gear 21 is rotatably arranged with respect to the main shaft 3. Hereinafter, the support of the output disks 5 and 8 will be described with respect to the output disk 5 of the toroidal transmission 1, but the same applies to the output disk 8.
[0009]
The roller bearing 46 that rotatably supports the main shaft 3 is disposed on the inner peripheral portion of the output disk 5 facing the input disk 4 on the front end 45 side. The roller bearing 46 is a bearing that allows a slight axial movement of the main shaft 3. Further, the output disk 5 is positioned in the thrust direction by abutting at the abutting portion 29 via the spacer 28 on the back surface 18 on the output gear 21 side. The spacer 28 is in contact with the inner ring 24 a of the bearing 23. The output disk 5 is fitted in the inner peripheral portion near the back surface 18 by the spigot fitting portion 41 with the outer peripheral surface of the hollow shaft portion 40 of the output gear 21 to determine the radial position. The output disk 5 receives a thrust force as indicated by an arrow A and a radial force as indicated by an arrow B from the power roller 6. The thrust force indicated by arrow A is supported from the bearing 23 to the casing 19 via the spacer 28, and the radial force indicated by arrow B is supported from the bearing 23 to the casing 19 via the hollow shaft portion 40 from the spigot fitting portion 41. Is done.
[0010]
The torque transmitted to the output disks 5 and 8 is extracted from the chain transmission device 20, that is, the output gear 21, through the chain 26 and the sprocket 25 to the counter shaft 27 (FIG. 2) as the output shaft. A disc spring 49 is interposed between the loading cam 14 and the input disk 4 in order to press the input disks 4 and 7 against the power rollers 6 and 9 even when no input torque is applied. The main shaft 3 is formed with an oil passage 47 formed so as to extend in the axial direction, and an oil passage 48 penetrating in a radial direction from the oil passage 47 in order to supply lubricating oil to each contact portion and rotating portion. Yes.
[0011]
Regarding the support of the output disk, there is a toroidal continuously variable transmission disclosed in Japanese Patent Laid-Open No. 3-92655, Japanese Patent Laid-Open No. 5-39830, or Japanese Patent Laid-Open No. 8-61453. In these toroidal-type continuously variable transmissions, the input shaft is supported so as to be able to move slightly in the axial direction with respect to the transmission cover, and is rotatably supported. While being supported rotatably via a bearing, it is serrated to a boss portion of an output gear disposed between the output disks so as to be rotatable relative to the input shaft. The output gear is rotatably supported on the transmission cover via a ball bearing with respect to the casing. Japanese Patent Laid-Open No. Hei 6-147282 discloses that a pair of input disks or output disks arranged opposite to each other from each other are fitted to each other so as to fit each other into one disk. A toroidal continuously variable transmission that is configured as a rigid body and prevents both disks from falling is disclosed.
[0012]
The conventional toroidal type continuously variable transmission as described above has the following problems. That is, in the toroidal-type continuously variable transmission, when the contact point between the power rollers 6 and 9 and the input disks 4 and 7 and the output disks 5 and 8 changes, the gear ratio changes. Looking at the support of the output disk 5, in the thrust direction, there is no particular restriction other than being abutted against the output gear 21 by the abutting portion 29 by the pressing force from the power roller 6, etc., and the inlay fitting in the radial direction It is only regulated by the department. The diameter of the abutting portion 29 of the back surface 18 of the output disk 5 is substantially equal to the diameter D of the spigot fitting portion 41 and is very small compared to the outer diameter of the output disk 5 in terms of layout. Further, the spigot fitting portion 41 between the output disk 5 and the output gear 21 exists in the vicinity of the abutting portion 29, and the fitting length L is also shorter than the diameter D of the fitting portion. Further, the fitting of the spigot fitting portion 41 and the spline fitting portion 42 is a gap fitting from the viewpoint of assembly workability, and the spline fitting portion 42 is fitted in a gap larger than that of the spigot fitting portion 41. It has become.
[0013]
Therefore, for example, when a force is applied to tilt the output disks 5 and 8 from the power rollers 6 and 9, the output disks 5 and 8 are in contact with the output gear 21 at the approaching portion 29 and the inlay portion 30 that are close to each other. The action which prevents trying to incline is poor. A bearing 46 disposed between the main shaft 3 and the output disks 5 and 8 is positioned substantially at the center of the long main shaft 3 to rotatably support the main shaft 3. It is difficult to expect to position the radial position with high accuracy. Since the spline fitting part 42 is farther from the abutting part 29 than the spigot fitting part 41 and the gap in the spline fitting part 42 is larger than the gap in the spigot part 41, the output disks 5 and 8 are easily tilted. is there. Because of the support structure of the output disks 5 and 8, the geometrical arrangement of the output disks 5 and 8 and the power rollers 6 and 9 changes, and the transmission ratio changes, and the originally intended transmission ratio cannot be obtained. Or a stable gear ratio cannot be obtained. Further, due to repeated contact between the back surfaces of the output disks 5 and 8 and the spacers 28, fretting wear occurs at the contact portions, and the support of the output shaft of the main shaft is supported via the output disk. As a result, there is a problem in that the support rigidity and assembly accuracy of the spindle are likely to be lowered.
[0014]
[Problems to be solved by the invention]
Therefore, in a toroidal-type continuously variable transmission, the support range of the output disk with respect to the output gear is widened to make it easier to counter the inclination of the output disk when an external force is applied to the output disk. There is a problem to be solved in that it is prevented from tilting with respect to the output gear.
[0015]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem, and to prevent the output disk from tilting with respect to the output gear by widening the axial fitting range of the output disk with respect to the output gear. It is an object of the present invention to provide a toroidal continuously variable transmission that prevents a type continuously variable transmission from shifting unintentionally and can stably maintain a predetermined speed ratio.
[0016]
According to the present invention, a first input disk to which torque of an input shaft is transmitted via a loading cam, and the first input disk are fixed to one end so as to be integrally fixed in the rotational direction and movable in the axial direction. An attached main shaft, a second input disc fixed to the other end of the main shaft, first and second output discs arranged opposite to the input discs and rotatable relative to the main shaft, the input A power roller disposed between the disk and the output disk and transmitting the output disk to the output disk by continuously changing the rotation of the input disk in accordance with a tilt angle with respect to the both disks; An output gear, and an output shaft connected to the output gear, the output gear being disposed between the output disks and the main shaft from the gear main body. And a hollow shaft portion that fits in a fitting hole of each output disk, and the hollow shaft portion extends over substantially the entire length of the fitting hole of the output disk. The present invention relates to a continuously variable transmission.
[0017]
In the toroidal type continuously variable transmission, the main shaft is supported on the inner peripheral surface of the hollow shaft portion via a bearing so as to be relatively rotatable.
[0018]
Further, in the toroidal continuously variable transmission, the fitting portion in which the output disk and the hollow shaft portion are fitted is formed on an inlay fitting portion located on the gear body side of the output gear and on the input disc side. It is comprised from the spline fitting part located.
[0019]
Further, in the toroidal continuously variable transmission, each output disk is abutted against the gear body of the output gear via a spacer.
[0020]
Since the toroidal continuously variable transmission according to the present invention is configured as described above, it operates as follows. That is, the hollow shaft portion provided along the main shaft from the gear body and fitted in the fitting hole of each output disk extends over substantially the entire length of the fitting hole of each output disk. The fitting hole is supported by the hollow shaft portion over substantially the entire area in the axial direction. For example, when the output disk tends to tilt due to the pressing force from the power roller, the hollow shaft generates a reaction force that opposes the tilt of the output disk over a wide range, so the tilt of each output disk is greatly suppressed. Is done. The amount that the power roller disposed between the input disk and the output disk is manipulated with respect to the power roller in order to transmit the rotation of the input disk to the output disk by continuously changing the rotation of the input disk is the tilt angle with respect to both disks. It is. By suppressing the tilt of the output disk, the positional relationship between the power roller and the output disk does not change, and as a result, the tilt angle does not change to an unintended angle. Therefore, the gear ratio of the toroidal type continuously variable transmission is accurately controlled according to the tilt angle, and a stable gear ratio is maintained when a constant gear ratio is obtained.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a toroidal type continuously variable transmission according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a main part of an embodiment of a toroidal continuously variable transmission according to the present invention. The toroidal type continuously variable transmission shown in FIG. 1 shows the related configuration of the main shaft, output disk, and output gear, and other structures not shown are the conventional toroidal type continuously variable transmission shown in FIG. 2 and FIG. The same components are denoted by the same reference numerals as those used in FIGS. 2 and 3.
[0022]
In the embodiment of the toroidal-type continuously variable transmission according to the present invention shown in FIG. 1, only the toroidal transmission unit 1 is shown, but as shown in FIG. 2, two toroidal transmission units 1 and 2 are provided. It is. However, since both the toroidal transmission parts 1 and 2 are symmetrically arranged, only the toroidal transmission part 1 will be described below. The hollow shaft portion 30 extending along the main shaft 3 from the gear main body 22 of the output gear 21 fitted so as to be rotatable relative to the main shaft 3 has a substantially entire length in the axial direction range of the fitting hole 33 of the output disk 5. It extends across. Accordingly, the output disk 5 is supported by the hollow shaft portion 30 that extends long in the axial direction of the main shaft 3.
[0023]
A fitting portion between the output disk 5 and the hollow shaft portion 30 of the output gear 21 includes an inlay fitting portion 31 on the gear body 22 side of the output gear 21 and a spline fitting portion on the input disk 4 side facing the output disk 5. 32. The spigot fitting portion 31 is configured by fitting between a spigot fitting surface 34 on the hollow shaft portion 30 side and a spigot fitting surface 35 on the fitting hole 33 side of the output disk 5 and is relatively precise. It is fitted by a large gap. In addition, the spline fitting portion 32 is connected to the spline 36 formed on the outer periphery of the hollow shaft portion 30 and the spline 37 formed on the inner periphery of the fitting hole 33 of the output disk 5, thereby generating an output. Torque can be transmitted between the disk 5 and the output gear 21. The hollow shaft portion 30 extends over substantially the entire length of the fitting hole 33 of the output disk 5, and a rolling surface 38 for the roller bearing 39 is formed on the inner peripheral surface of the distal end of the hollow shaft portion 30. The main shaft 3 is rotatably supported by the output gear 21 via a roller bearing 39. The portion of the hollow shaft portion 30 closest to the gear body 22 is a bearing fitting portion 30a into which the inner ring 24a of the bearing 23 is fitted.
[0024]
Thus, the output disk 5 is supported by the output gear 21 in a wide range in the axial direction of the fitting hole 33. That is, the hollow shaft portion 30 extends to the vicinity of the opening on the input disk 4 side of the fitting hole 33 and supports the output disk 5 even at a location away from the spigot fitting portion 31. When the output disk 5 is inclined with the spigot fitting portion 31 as a fulcrum, the spline fitting portion 32 far from the spigot fitting portion 31 immediately counters the inclination of the output disc 5. Therefore, when an external force such as a pressing force from the power roller 6 acts on the output disk 5, the inclination of the output disk 5 with respect to the output gear 21 is significantly less than the inclination of the output disk in the conventional toroidal continuously variable transmission. Thus, the positional relationship between the output disk 5 and the power roller 6 does not change. As a result, the gear ratio can be controlled in accordance with the tilt angle θ of the power roller 6, and when the constant gear ratio is to be maintained, the gear ratio can be stably maintained without fluctuation. .
[0025]
Further, since the inclination of the output disk 5 with respect to the output gear 21 can be prevented, the back surface 18 which is the side surface of the output disk 5 on the output gear 21 side and the spacer 28 are always in close contact with each other. Therefore, it is possible to prevent the occurrence of fretting wear caused by the back surface 18 of the output disk 5 repeatedly contacting and separating from the spacer 28 as seen in a conventional toroidal type continuously variable transmission. Further, since the main shaft 3 is supported by the casing 19 from the bearing 39 through the hollow shaft portion 30 and the bearing 23, the main shaft 3 is output via the bearing 46 like the conventional toroidal continuously variable transmission. 5, and the number of parts interposed between the main shaft 3 and the casing 19 is reduced with respect to the support of the main shaft 3 as compared with the case where the main shaft 3 is supported by the casing 19 via the output gear 21 and the bearing 23. Thus, the support rigidity of the main shaft 3 with respect to the casing 19 and the assembly accuracy can be improved.
[0026]
【The invention's effect】
As described above, the toroidal type continuously variable transmission according to the present invention has a wide axial fitting region of the output disk with respect to the output gear, so that the inclination of the output disk with respect to the output gear is greatly suppressed. Accordingly, since the positional relationship between the output disk and the power roller does not change due to the inclination of the output disk, the toroidal continuously variable transmission does not shift to an unintended gear ratio, and the tilt angle of the power roller Therefore, it is possible to control the gear ratio accurately according to the above, and when the gear ratio is kept constant, a stable gear ratio can be maintained. Further, there is no problem such as fretting wear between the output disk and the spacer. Furthermore, in order to support the main shaft with respect to the casing, the number of parts interposed between the main shaft and the casing can be reduced, and the support rigidity and assembly accuracy of the main shaft can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a toroidal continuously variable transmission according to the present invention.
FIG. 2 is a diagram showing an example of a conventional toroidal continuously variable transmission.
FIG. 3 is an enlarged sectional view showing a part of a conventional toroidal-type continuously variable transmission.
[Explanation of symbols]
1, 2 Toroidal transmission 3 Main shaft 4, 7 Input disc 5, 8 Output disc 6, 9 Power roller 11 Tilt shaft 13 Input shaft 14 Loading cam 19 Casing 21 Output gear 22 Gear body 28 Spacer 29 Butting portion 30 Hollow shaft Part 31 spigot fitting part 32 spline fitting part 33 fitting hole 34, 35 spigot fitting surface 36, 37 spline 39 bearing

Claims (4)

A first input disk to which torque of the input shaft is transmitted via a loading cam; a main shaft attached to one end so that the first input disk is integrally fixed in the rotational direction and movable in the axial direction; A second input disk fixed to the other end of the main shaft; first and second output disks disposed opposite to the input disks and rotatable relative to the main shaft; the input disk and the output A power roller that is arranged between the disk and that continuously changes the rotation of the input disk according to a tilt angle with respect to the two disks and transmits the rotation to the output disk; an output gear connected to the two output disks; And an output shaft transmission-coupled to the output gear, the output gear extending along the main shaft from the gear body and the gear body disposed between the output disks. A hollow shaft portion that fits into the fitting hole of each output disk, and the hollow shaft portion extends over substantially the entire length of the fitting hole of the output disk. transmission. The toroidal continuously variable transmission according to claim 1, wherein the main shaft is supported on an inner peripheral surface of the hollow shaft portion via a bearing so as to be relatively rotatable. The fitting portion in which the output disk and the hollow shaft portion are fitted includes an spigot fitting portion located on the gear body side of the output gear and a spline fitting portion located on the input disk side. The toroidal continuously variable transmission according to claim 1 or 2, comprising: The toroidal continuously variable transmission according to any one of claims 1 to 3, wherein each of the output disks is abutted against the gear body of the output gear via a spacer.

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