JP4524743B2 - Toroidal continuously variable transmission - Google Patents

Description

  The present invention relates to a toroidal continuously variable transmission that can be used for transmissions of automobiles and various industrial machines.

  FIG. 2 shows an example of a conventional toroidal continuously variable transmission that can be used as a transmission for an automobile. This toroidal type continuously variable transmission is a so-called double cavity type high torque toroidal type continuously variable transmission. Two input side disks 2 and 2 and two output side disks 3 and 3 are connected to the input shaft 1. It is attached to the outer periphery. An output gear 4 is rotatably supported on the outer periphery of the intermediate portion of the input shaft 1. Output side discs 3 and 3 are connected to cylindrical flange portions 4a and 4a provided at the center of the output gear 4 by spline engagement. The output gear 4 is supported in the housing case 14 via an intermediate wall (partition wall) 13 formed by coupling two members, and can thereby rotate about the axis O of the input shaft 1. On the other hand, displacement in the direction of the axis O is prevented.

  The input shaft 1 is rotationally driven by a drive shaft 22 via a loading cam type pressing device 12. Specifically, a loading cam type pressing device 12 is provided between the input side disk 2 and the input shaft 1 located on the left side in the drawing, and the input side disk 2 is connected to the output side disk by the pressing device 12. The input side disk 2 can be driven to rotate while being elastically pressed toward the disk 4. The pressing device 12 includes a loading cam (cam plate) 12 a that rotates together with the input shaft 1, and a plurality of (for example, four) rollers (rolling members) 12 b that are rotatably held by a cage 7. It is configured. A cam surface 113 that is uneven in the circumferential direction is formed on one side surface (the right side surface in FIG. 2) of the loading cam 12a. The same applies to the outer side surface (the left side surface in FIG. 2) of the input side disk 2. A cam surface 114 having a shape is formed. An angular ball bearing (angular bearing) 30 capable of supporting a thrust load is interposed between the end of the input shaft 1 and the loading cam 12a.

  The output side disks 3 and 3 are supported by needle bearings 5 and 5 interposed between the input shaft 1 so as to be rotatable about the axis O of the input shaft 1. Further, the input side disks 2 and 2 are supported on both ends of the input shaft 1 via ball splines 6 and 6 so as to rotate together with the input shaft 1. Also, as shown in FIG. 3, there is a power between the inner peripheral surfaces (concave surfaces) 2a, 2a of the input side disks 2, 2 and the inner peripheral surfaces (concave surfaces) 3a, 3a of the output disks 3, 3. A roller 11 is rotatably held.

  The input side disk 2 positioned on the right side in FIG. 2 has its back surface (the right side in FIG. 2) abutted against the loading nut 9 via a first disc leaf spring 10 having a large elasticity. 1 is substantially prevented from being displaced in the axial direction (left-right direction in FIG. 2). Further, a second disc leaf spring 8 is provided between the input side disk 2 located on the left side in FIG. 2 and the loading cam 12a. These disc springs 8 and 10 are provided on the inner peripheral surfaces 2a, 2a, 3a and 3a of the disks 2, 2, 3 and 3 and the peripheral surfaces (traction surfaces) 11a and 11a of the power rollers 11 and 11 (see FIG. 3). A pressing force is applied to the abutting portion.

  Therefore, in the continuously variable transmission configured as described above, when a rotational force is input from the drive shaft 22 to the input shaft 1, the loading cam 12a rotates with the rotation of the input shaft 1, and the cam surface 113 has a plurality of rollers. 12 b is pressed against the cam surface 114 formed on the outer surface of the input side disk 2. As a result, the input side disk 2 is pressed by the plurality of power rollers 11, and at the same time, the input side disk 2 rotates based on the pressing of the cam surfaces 113, 114 and the plurality of rollers 12b. Then, the rotation of the input side disk 2 is transmitted to the output side disk 4 at a constant speed ratio through the plurality of power rollers 11 and 11. The rotation of the output side disks 3 and 3 is transmitted from the output gear 4 to the output shaft 17 via the transmission gear 15 and the transmission shaft 16.

  By the way, as described above, in the toroidal-type continuously variable transmission having the above-described configuration, power is output by an output gear (hereinafter simply referred to as a gear) 4 sandwiched between the output side disks 3 (for example, patents). In this case, the gear 4 is supported on the housing case 14 by the intermediate wall 13 via the bearing 40 (see FIG. 2). An angular bearing is generally used as the bearing 40 that supports the gear 4. As the gear 4, a helical gear is generally used in order to ensure strength and reduce noise.

  A tangential force, separation force, and thrust force act on the helical gear by meshing. Therefore, if all these loads are received by the bearing 40 that supports the gear 4, the bearing 40 becomes too large, which is not preferable. Further, the angular bearing 40 is provided on the output side and rotates at a considerably high speed when the transmission gear ratio is increased, so that it is difficult to increase the size. For this reason, conventionally, a bearing arrangement has been considered in which a moment load is not received by the thrust force generated by the engagement of the gear 4 (see, for example, Patent Document 2). In this case, the moment load is supported by the radial bearing (needle bearing) 5 disposed on the inner peripheral side of the output side disk 3 as in the configuration described above.

JP-A-8-193646 JP 2001-193812 A

  Since the load supported by the needle bearing 5 is a moment load as described above, the load does not act evenly on the rollers constituting the needle bearing 5. For this reason, conventionally, the diameter of the roller cannot be set very small in order to prevent peeling of the roller. However, if the diameter of the roller to be set is limited in this way, when trying to increase the gear ratio, the mouth portion A of the disks 2 and 3 (the side where the bearing 5 is inserted, see FIG. 2). ) Is a contact point with the power roller 11, and the maximum gear ratio may be determined by the diameter of the roller. Therefore, in order to further increase the gear ratio, it is necessary to reduce the diameter of the rollers.

  Further, as can be seen from FIG. 2, the current continuously variable transmission is structurally configured such that when the gear falls, the output side disk 3 also falls. In addition, since the mouth A of the disks 2 and 3 is greatly deformed, an edge load is generated in a part of the needle bearing 5 and the surface pressure is excessive, thereby causing problems such as early peeling. There is. Therefore, it was necessary to provide a large crowning on the roller.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a toroidal continuously variable transmission capable of reducing the diameter of a roller of a needle bearing that supports a disk and widening a gear ratio. And

In order to achieve the above object, a toroidal continuously variable transmission according to claim 1 is a pair of an input shaft to which a rotational force from an engine is input and a pair coupled to the input shaft and rotating integrally with the input shaft. A pair of output side disks that receive the rotational force of the input side disk at a predetermined speed ratio via a power roller provided between the input side disk and the input side disk, and between the pair of output side disks A cylindrical flange portion provided at a center portion of the gear is inserted outside the input shaft, and both end portions of the flange portion of the pair of output side disks are respectively provided. inserted inside, continuously variable and both end portions of the flange portion and the pair of output side disks are connected so as to rotate integrally respectively, and outputting the rotational force through said gear A speed machine, with each one of the first radial needle bearing is interposed between the input shaft and the both end portions of the flange portion of the gear, between the output side disks and the input shaft A second radial needle bearing is inserted in each of the first and second radial needle bearings. The first and second radial needle bearings are fixed in grooves formed on the outer surface of the input shaft, and the first radial needle bearing is The gap between the output side disk and the input shaft at the inserted position is larger than the gap between the output side disk and the input shaft at the position where the second radial needle bearing is inserted. It is characterized by.

In the first aspect of the present invention, at least one first radial needle bearing is interposed between the gear and the input shaft, and each second disk is disposed between each output side disk and the input shaft. since the radial needle bearing is interposed, the number the number of radial needle bearing as compared with only conventional configuration radial needle bearing is provided between the input shaft and the output side disk, therefore, the radial needle The moment load acting on the bearing can be reduced. Therefore, it is possible to reduce the diameter of the roller while preventing the roller constituting the radial needle bearing from being peeled off. As a result, it is possible to increase the gear ratio. In addition, the first radial needle bearing inserted between the gear and the input shaft reduces the tilt of the output side disk, and the second radial needle inserted between the output side disk and the input shaft. Since the generation of edge load in the bearing is suppressed, the radial needle bearing can be downsized.
Further , since the first and second radial needle bearings are attached to the input shaft, the bearing attachment surfaces can be processed simultaneously on the gear side and the disk side. Therefore, the radial gap can be managed only by measuring the respective inner diameters of the gear and the output side disk, and therefore the measurement and assembly can be simplified. Further, since the first and second radial needle bearings are provided in the groove of the input shaft, it is possible to increase the mouth portion of the disk and increase the gear ratio.

In addition , a gap (radial gap) between the output side disk and the input shaft at the position where the first radial needle bearing is inserted is a gap between the output side disk and the input shaft at the position where the second radial needle bearing is inserted. Since the clearance is set larger than the clearance (radial clearance), the moment load acts on each radial needle bearing evenly. Therefore, it is possible to avoid an increase in size of one of the first and second radial needle bearings, and to make the first and second radial needle bearings common (use the same radial needle bearing). As a result, the roller constituting the radial needle bearing can be reduced in size.

In the toroidal continuously variable transmission according to the present invention, at least one first radial needle bearing is interposed between the gear and the input shaft, and each second disk is provided between each output side disk and the input shaft. Since the radial needle bearing is inserted, the diameter of the roller of the radial needle bearing can be reduced and the gear ratio can be widened.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The feature of the present invention resides in the support form of the output side disk and gear, and other configurations and operations are the same as the conventional configurations and operations described above. Therefore, only the features of the present invention will be mentioned below. The other parts are denoted by the same reference numerals as those in FIGS. 2 and 3, and detailed description thereof is omitted.

  FIG. 1 shows an embodiment of the present invention. As shown in the figure, in the present embodiment, a first radial needle bearing is provided between the gear 4 and the input shaft 1, specifically, between each flange portion 4 a on both sides of the gear 4 and the input shaft 1. 5A is inserted. Further, a second radial needle bearing 5B that is the same as the first radial needle bearing 5A, for example, is inserted between each output side disk 3 and the input shaft 1 respectively.

In this case, the gap (radial gap) X between the output side disk 3 and the input shaft 1 at the position where the first radial needle bearing 5A is inserted is the output at the position where the second radial needle bearing 5B is inserted. It is set larger than the gap (radial gap) Y between the side disk 3 and the input shaft 1. That is, the dimension X is larger than the dimension Y by the amount that the flange portion 4 a is inserted between the output side disk 3 and the input shaft 1.

  In the above configuration, the first and second radial bearings 5 </ b> A and 5 </ b> B are fixed in a groove 50 formed on the outer peripheral surface of the input shaft 1.

  As described above, in this embodiment, the radial bearings 5A and 5B are interposed between both the gear 4 and the output side disk 3 and the input shaft 1, and only between the output side disk 3 and the input shaft 1. Since the number of radial bearings 5A and 5B is larger than the conventional configuration as shown in FIG. 2 in which the radial bearing 5 is provided, the moment load acting on the radial bearings 5A and 5B is reduced. be able to. For this reason, it is possible to reduce the diameter of the roller while preventing the rollers constituting the radial bearings 5A and 5B from being peeled off. As a result, it is possible to increase the gear ratio. Further, the first radial bearing 5 </ b> A inserted between the gear 4 and the input shaft 1 reduces the tilt of the output side disk 3, and is inserted between the output side disk 3 and the input shaft 1. Since the generation of the edge load at the second radial bearing 5B is suppressed, the radial bearings 5A and 5B can be downsized.

  In this embodiment, since the radial gap X in which the first radial needle bearing 5A is inserted is set larger than the radial gap Y in which the second radial needle bearing 5B is inserted, the moment due to the thrust force is set. The load M acts evenly on the radial bearings 5A and 5B. Therefore, the tilting of the disk 3 due to the moment load M is suppressed, and one of the first and second radial bearings 5A and 5B can be prevented from becoming large, and the first and second radial bearings can be avoided. It is also possible to share 5A and 5B (use the same radial bearing). As a result, the rollers constituting the radial bearings 5A and 5B can be reduced in size.

  In the present embodiment, since the first and second radial bearings 5A and 5B are attached to the input shaft 1, the bearing attachment surfaces can be processed simultaneously on the gear 4 side and the disk 3 side. Therefore, the radial gaps X and Y can be managed only by measuring the respective inner diameters of the gear 4 and the output side disk 3, and therefore the measurement and assembly can be simplified. Further, since the first and second radial bearings 5A and 5B are provided in the groove 50 of the input shaft 1, it is possible to increase the mouth portion A of the disks 2 and 3 and to increase the speed ratio. become.

  The present invention can be applied to a full toroidal continuously variable transmission having no trunnion in addition to a half toroidal continuously variable transmission.

It is principal part sectional drawing of the toroidal type continuously variable transmission which concerns on embodiment of this invention. It is sectional drawing of the conventional toroidal type continuously variable transmission. It is sectional drawing which shows the power roller clamped between the input side disk and output side disk in the conventional toroidal type continuously variable transmission.

Explanation of symbols

1 Input shaft 2 Input side disk 4 Gear 5A, 5B Radial needle bearing 50 Groove X, Y Clearance

Claims (1)

Input via a power roller provided between the input shaft to which the rotational force from the engine is input, a pair of input side disks coupled to the input shaft and rotating integrally with the input shaft, and the input side disk A cylindrical flange portion provided at the center of the gear, comprising a pair of output side disks that receive the rotational force of the side disk at a predetermined gear ratio, and a gear provided between the pair of output side disks Is inserted outside the input shaft, and both end portions of the flange portion are inserted inside the pair of output side discs, respectively, and both end portions of the flange portion and the pair of output side discs are integrated with each other. In the toroidal continuously variable transmission that is connected so as to rotate at and outputs the rotational force via the gear,
A first radial needle bearing is interposed between both ends of the flange portion of the gear and the input shaft, and a second radial needle is interposed between each output side disk and the input shaft. Needle bearing is inserted,
The first and second radial needle bearings are fixed in grooves formed on an outer surface of the input shaft ;
The gap between the output side disk and the input shaft at the position where the first radial needle bearing is inserted is the gap between the output side disk and the input shaft at the position where the second radial needle bearing is inserted. A toroidal-type continuously variable transmission characterized by being larger than the gap between the two .

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