JP7431654B2 - toroidal continuously variable transmission - Google Patents

Description

The present invention relates to a toroidal continuously variable transmission.

BACKGROUND ART Toroidal continuously variable transmissions used in generators for automobiles, aircraft, etc. have been known. A toroidal continuously variable transmission includes an input disk, an output disk, and a power roller sandwiched between these disks. As the power roller rotates, power is transmitted from the input disk to the output disk. At this time, by changing the inclination of the power roller (that is, changing the radius of contact between the input disk and the output disk), the output can be steplessly decelerated or accelerated. Some toroidal continuously variable transmissions are equipped with a loading cam type pressing device to urge an input disk and an output disk toward each other. Patent Document 1 discloses this type of toroidal continuously variable transmission.

In the toroidal continuously variable transmission disclosed in Patent Document 1, a loading cam type pressing device is provided between an input disk and an input shaft. This pressing device includes a cam plate that rotates together with the input shaft, a plurality of rollers sandwiched between the input disk and the cam plate, and a support bearing that rotatably supports the cam plate on the rotating shaft. The support bearing is a thrust angular contact ball bearing, and includes an inner ring, an outer ring, and rolling elements sandwiched between the inner ring and the outer ring. The support bearing is assembled to the rotating shaft by fitting the inner ring onto the rotating shaft and screwing a nut into a portion of the rotating shaft that protrudes beyond the inner ring.

Japanese Patent Application Publication No. 2018-071609

In the toroidal continuously variable transmission disclosed in Patent Document 1, a nut is used to assemble the inner ring of the support bearing to the rotating shaft. Therefore, the rotating shaft must protrude from the inner ring by the amount by which the nut is screwed. Further miniaturization is required for toroidal continuously variable transmissions, and there is still room for improvement in terms of shortening the axial length of the rotating shaft.

In view of the above, the present invention provides a bearing that reduces the axial length of a rotating shaft in which a bearing that receives an axial load (for example, a thrust ball bearing or a thrust angular contact ball bearing) is assembled in a toroidal continuously variable transmission. We propose an assembly structure.

The toroidal continuously variable transmission according to one aspect of the present invention includes:
a rotating shaft;
a pair of disks arranged around the rotation axis and facing each other;
at least one power roller tiltably sandwiched between the pair of disks;
a bearing having an inner ring, an outer ring, and rolling elements sandwiched between the inner ring and the outer ring, and which is assembled to the rotating shaft and receives an axial load from at least one of the pair of disks;
a bolt having a head and a shaft, the shaft being screwed into the shaft end surface of the rotating shaft;
The bearing is characterized in that the inner ring is assembled to the rotating shaft by being sandwiched between the shaft end surface of the rotating shaft and the head of the bolt.

In the transmission configured as described above, the shaft end of the rotating shaft to which the bearing is assembled does not protrude in the axial direction beyond the inner ring of the bearing. Therefore, the axial length of the rotating shaft can be shortened compared to the conventional case where the shaft end of the rotating shaft projects from the inner ring of the bearing and a nut or retaining ring is provided on the projecting part. This can contribute to downsizing of the transmission.

According to the present invention, in a toroidal continuously variable transmission, it is possible to shorten the axial length of a rotating shaft to which a bearing that receives an axial load is assembled.

FIG. 1 is a sectional view of a drive mechanism-integrated power generation device including a toroidal continuously variable transmission according to an embodiment of the present invention. FIG. 2 is an enlarged view of the pressing device of the toroidal continuously variable transmission shown in FIG. 1 and its vicinity. FIG. 3 is an enlarged sectional view of the rotating shaft and the support bearing assembled thereto. FIG. 4 is an enlarged sectional view of the shaft end face of the rotating shaft and its vicinity. FIG. 5 is a cross-sectional view of the bolt.

Hereinafter, embodiments will be described with reference to the drawings.

FIG. 1 is a sectional view of a drive mechanism-integrated power generation device 1 including a toroidal continuously variable transmission 10 according to the present embodiment. As shown in FIG. 1, an integrated drive generator (IDG) is used as an AC power source for an aircraft, and includes a casing 2 that is attached to an engine of the aircraft. The casing 2 houses an input mechanism 3, a toroidal continuously variable transmission (hereinafter simply referred to as "transmission 10"), a power transmission mechanism 7, and a generator 5. Note that the transmission 10 does not need to be configured as a part of a power generation device integrated with a drive mechanism, and its application is not limited to aircraft.

[Schematic configuration of transmission 10]
The transmission 10 includes a transmission input shaft 11 and a transmission output shaft 12 that are arranged coaxially and are relatively rotatable. Hereinafter, the axes of the transmission input shaft 11 and the transmission output shaft 12 will be referred to as "rotation axis A1." Further, the direction in which the rotation axis A1 extends is referred to as the "axial direction X." The transmission input shaft 11 is connected to an engine rotating shaft (not shown) via the input mechanism 3. The input mechanism 3 includes a device input shaft 3a into which rotational power from an engine rotating shaft is input, and a gear 3b that rotates integrally with the device input shaft 3a. The transmission input shaft 11 is provided with a gear 6 that rotates integrally therewith. The transmission output shaft 12 is connected to the generator input shaft 5a of the generator 5 via the power transmission mechanism 7.

The rotational power taken out from the engine rotating shaft is input to the transmission input shaft 11 via the input mechanism 3, and the rotational power of the transmission input shaft 11 is transmitted to the input disk 13. The transmission 10 changes the speed of the rotation of a transmission input shaft 11 and outputs the same to a transmission output shaft 12 . The rotational power of the transmission output shaft 12 is transmitted to the generator input shaft 5a via the power transmission mechanism 7. When the generator input shaft 5a is rotationally driven, the generator 5 generates alternating current power. The gear ratio of the transmission 10 is set so as to maintain the rotational speed of the generator input shaft 5a at an appropriate value (a value corresponding to a frequency suitable for operating the electrical components of the aircraft) regardless of fluctuations in the rotational speed of the engine rotational shaft. Continuously changed.

The transmission 10 is, for example, a half toroidal type and a double cavity type, and includes two sets of input disks 13, 13 and output disks 14, 15. However, the transmission 10 is not limited to the double cavity type, and may be, for example, a single cavity type.

The input disks 13, 13 are fitted onto the transmission input shaft 11, and rotate integrally with the transmission input shaft 11 about the rotation axis A1. The output disks 14 and 15 are fitted onto the transmission output shaft 12 and rotate integrally with the transmission output shaft 12 about the rotation axis A1.

The input disk 13 has a concave surface 21a. The output disks 14, 15 have concave surfaces 31a. The input disk 13 and the output disk 14 are arranged to face each other in the axial direction X so that their concave surfaces 21a and 31a face each other. Similarly, the input disk 13 and the output disk 15 are arranged to face each other in the axial direction X so that their concave surfaces 21a and 31a face each other. An annular cavity is formed around the rotation axis A1 by the opposing concave surfaces 21a and 31a.

The transmission 10 is, for example, a central input type. The transmission output shaft 12 is inserted into the transmission input shaft 11 and protrudes from the transmission input shaft 11 on both sides in the axial direction X. The pair of input disks 13, 13 are central disks and are arranged back to back on the transmission input shaft 11. The pair of output disks 14 and 15 are outer disks, and are arranged outside of the pair of input disks 13 and 13 in the axial direction X. A gear 6 is disposed between the pair of input disks 13, 13, and is provided on the outer peripheral surface of the transmission input shaft 11 and rotates integrally with the transmission input shaft 11.

The displacement of the output disk 14 on one side toward the outside of the rotation axis A1 is restricted by a convex portion 12a provided at the end of the transmission output shaft 12. The output disk 15 on the other side is urged toward the input disk 13 by a preload spring 64, and is also urged toward the input disk 13 by a pressing device 17 during rotational driving. The output disk 15 is connected to the power transmission mechanism 7 via a pressing device 17 so as to be capable of transmitting power. The pressing device 17 will be explained in detail later.

The transmission 10 includes a plurality of power rollers 18 arranged in a cavity and a plurality of trunnions 19 that support the plurality of power rollers 18 in a tiltable manner. The trunnion 19 is supported by the casing 2 so as to be tiltable around the tilt axis A2 and displaceable in the direction of the tilt axis A2. The tilt axis A2 is in a torsional position with respect to the rotation axis A1. The power roller 18 is supported by a trunnion 19 so as to be rotatable around a rotation axis (not shown) perpendicular to the tilt axis A2. The trunnion 19 is connected to a hydraulic drive mechanism (not shown), and the hydraulic drive mechanism reciprocates the trunnion 19 together with the power roller 18 in the direction of the tilt axis A2.

[Configuration of pressing device 17]
FIG. 2 is an enlarged view of the pressing device 17 of the toroidal continuously variable transmission 10 shown in FIG. 1 and its vicinity. As shown in FIG. 2, the pressing device 17 includes a cam plate 61 and a roller unit 60.

The cam plate 61 is loosely fitted to the transmission output shaft 12 so as to face the back surface of the output disk 15 (the surface opposite to the concave surface 31a). The cam plate 61 integrally includes a hollow disk-shaped cam portion 611 and a cylindrical shaft portion 612 that protrudes from the outer peripheral edge portion of the cam portion 611 in the axial direction X.

The main surface of the cam portion 611 faces the back surface of the output disk 15. The main surface of the cam portion 611 is a first cam surface 613, and unevenness is repeatedly formed over the circumferential direction. A second cam surface 151 is provided on the back surface of the output disk 15 that faces the first cam surface 613 . The second cam surface 151 is also repeatedly formed with concavities and convexities in the circumferential direction so as to correspond to the first cam surface 613 .

The roller unit 60 is provided between the first cam surface 613, the second cam surface 151, and the axial direction X. The roller unit 60 includes a holder 62 and a plurality of rollers 63 held by the holder 62. Each roller 63 is sandwiched between a first cam surface 613 and a second cam surface 151, and its peripheral surface contacts both the first cam surface 613 and the second cam surface 151.

The retainer 62 holds a plurality of roller sets 63G arranged at approximately equal intervals in the circumferential direction around the rotation axis A1. One roller set 63G includes at least one roller 63 (three in this embodiment) arranged on the rotation axis extending in the radial direction. Each roller 63 of the roller set 63G is rotatable around the rotation axis of the roller set 63G.

The axial load that the pressing device 17 receives from the output disk 15 is supported by the support bearing 4 fixed to the transmission output shaft 12. The support bearing 4 is disposed on the back side of the cam plate 61 (ie, on the opposite side to the cam portion 611), and supports the cam plate 61 relative to the transmission output shaft 12 so as to be rotatable relative to the transmission output shaft 12. Specifically, the support bearing 4 includes an inner ring 41, an outer ring 42, and rolling elements 43 rotatably sandwiched between the inner ring 41 and the outer ring 42. The inner ring 41 is fixed to the transmission output shaft 12. The outer ring 42 is rotatable relative to the inner ring 41, and the outer ring 42 rotates integrally with the cam plate 61 about the rotation axis A1.

A preload spring 64 is arranged between the cam plate 61 and the support bearing 4. The preload spring 64 applies a pressing force in the axial direction X toward the output disk 15 to the cam plate 61 so that the output disk 15 is pressed (preloaded) toward the input disk 13 even when the transmission output shaft 12 is not rotating. It is something that is given. The preload spring 64 according to this embodiment is compressed in the axial direction X while being sandwiched between the cam portion 611 of the cam plate 61 and the outer ring 42 of the support bearing 4.

The outer ring 42 of the support bearing 4 has a spring contact portion 47 and a stopper portion 48 located radially outward from the spring contact portion 47. The spring contact portion 47 is located inside the cylinder shaft portion 612 in the radial direction, and is in contact with the preload spring 64 . In this embodiment, a shim plate 66 as an adjustment member is provided between the spring contact part 47 and the preload spring 64, and more specifically, the spring contact part 47 is in contact with the shim plate 66. . The shim plate 66 may be provided between the cam plate 61 and the preload spring 64. The stopper portion 48 faces the cylindrical shaft portion 612 of the cam plate 61 in the axial direction X with a slight gap G therebetween.

When the cam plate 61 is not rotating, the length of the gap G in the axial direction X is smaller than the amount of deformation in the axial direction X at the elastic limit of the preload spring 64. Therefore, when the cam plate 61 rotates and the output disk 15 and the cam plate 61 begin to be relatively displaced in the axial direction X so as to separate from each other due to the cam action, the cam plate 61 rotates while the preload spring 64 is within the elastic deformation range. 61 hits the stopper portion 48 and the gap G disappears. After the cam plate 61 hits the stopper portion 48, the pressing force against the output disk 15 due to the cam action increases as the rotational speed of the cam plate 61 increases. In this way, as the transmitted torque increases, the output disk 15 is pressed away from the cam plate 61 by the cam action, and the input disk 13 and the output disk 15 are urged toward each other, and the power roller 18 is sandwiched between the input disk 13 and the output disk 15 with sufficient contact pressure.

External teeth 614 are formed on the outer peripheral surface of the cylindrical shaft portion 612 of the cam plate 61 . The external teeth 614 mesh with internal teeth 711 provided on the first gear 71 of the power transmission mechanism 7, forming a dog clutch. When the cam plate 61 rotates in response to rotational force from the output disk 15 via the plurality of rollers 63, the rotation of the cam plate 61 is transmitted to the first gear 71 of the power transmission mechanism 7. The power transmission mechanism 7 transmits the output from the transmission 10 to the generator 5 and an oil pump unit (not shown).

[Configuration of power transmission mechanism 7]
As shown in FIG. 1, the power transmission mechanism 7 is composed of a plurality of gears including a first gear 71 to a fourth gear 74. The first gear 71 is a hollow gear. The first gear 71 has internal teeth 711 and external teeth 712. The inner teeth 711 mesh with the outer teeth 614 of the cam plate 61, and the outer teeth 712 mesh with the second gear 72.

The second gear 72 has main teeth 721 and auxiliary teeth 722. The main teeth 721 mesh with the external teeth 712 of the first gear 71 and the third gear 73. The secondary teeth 722 mesh with a gear (not shown) for transmitting the output of the transmission 10 to an oil pump unit (not shown). The third gear 73 meshes with the main teeth 721 of the second gear 72 and the fourth gear 74. The fourth gear 74 is fixed to the generator input shaft 5a of the generator 5.

[How to operate the transmission 10]
In the transmission 10 configured as described above, when the input disks 13, 13 are rotationally driven, the output disks 14, 15 are rotationally driven via the power roller 18, and the transmission output shaft 12 is rotationally driven. When the trunnion 19 and the power roller 18 are displaced in the direction of the tilt axis A2, the tilt angle of the power roller 18 around the tilt axis A2 is changed, and the gear ratio of the transmission 10 is continuously changed according to the tilt angle. be done. The power roller 18 is sandwiched between the concave surfaces 21a of the input disks 13, 13 and the concave surfaces 31a of the output disks 14, 15 in a state where it can be tilted around the tilt axis A2, and receives the rotational driving force of the input disk 13. The speed is changed at a speed change ratio according to the tilt angle and transmitted to the output disks 14 and 15. When the rotational torque of the output disks 14, 15 increases, the output disk 15 is pressed in a direction closer to the input disk 13 by the pressing device 17, and the pressure between the input disks 13, 13 and the output disks 14, 15 with respect to the power roller 18 increases. do.

When the output disk 15 rotates, the cam surface 151 forces the plurality of rollers 63 against the cam surface 613 of the cam plate 61 . As a result, the output disk 15 is pressed by the power roller 18, and at the same time, the cam plate 61 rotates based on the engagement between the pair of cam surfaces 151, 613 and the plurality of rollers 63. The rotation of the cam plate 61 is input to the power transmission mechanism 7 through engagement of the dog clutch (the external teeth 614 of the cam plate 61 and the internal teeth 711 of the first gear 71), and the generator input shaft 5a rotates.

[Assembling structure of support bearing 4]
Here, the assembly structure of the support bearing 4 to the transmission output shaft 12 will be described in detail. Hereinafter, the transmission output shaft 12 according to the present embodiment will be referred to as the "rotary shaft 9" for convenience of explanation. FIG. 3 is an enlarged sectional view of the rotating shaft 9 and the support bearing 4 assembled thereto. 4 is an enlarged sectional view of the shaft end face 91 of the rotating shaft 9 and its vicinity, and FIG. 5 is a sectional view of the bolt 8.

As shown in FIGS. 3 and 4, the rotating shaft 9 is a hollow shaft, and an oil passage 90 is formed inside. At least one shaft end surface 91 of the rotating shaft 9 is provided with an end opening 92 that opens toward the axial direction X. A female screw portion 93, a tapered portion 94, and an alignment portion 95 are formed in the rotating shaft 9 in this order from one shaft end surface 91 toward the opposite shaft end surface. The female threaded portion 93 has a hollow cylindrical shape, and a female thread 931 is formed on the inner peripheral surface of the female threaded portion 93 . The centering portion 95 has a hollow cylindrical shape that is thicker than the female screw portion 93 . That is, the inner diameter D95 of the aligning portion 95 is smaller than the inner diameter D93 of the female screw portion 93. The tapered portion 94 has an inner diameter that changes in the axial direction X so as to connect the female screw portion 93 and the alignment portion 95, which have different inner diameters.

As shown in FIG. 3, the support bearing 4 is an angular contact ball bearing, and includes an inner ring 41 having an inner ring raceway, an outer ring 42 having an outer ring raceway opposite to the inner ring raceway, and a rolling contact between the inner ring raceway and the outer ring raceway. It has a plurality of rolling elements 43 that are movably arranged. The outer ring 42 is rotatably fitted onto the transmission output shaft 12 and receives a pressing force in the axial direction X from the output disk 15 via the cam plate 61.

An inner ring 41 of the support bearing 4 is fixed to the rotating shaft 9. The inner ring 41 has a portion that bulges inward from the inner ring raceway that supports the rolling elements 43, and a shaft seat 413 facing in the axial direction X is formed in this portion. The inner diameter D41 of the inner ring 41 is the same as or larger than the inner diameter D92 of the end opening 92 of the rotating shaft 9, and smaller than the outer diameter D91 of the shaft end surface 91 of the rotating shaft 9 (D92≦D41<D91). Therefore, when the rotating shaft 9 and the inner ring 41 are aligned, at least a portion of the periphery of the end opening 92 of the rotating shaft 9 (shaft end surface 91) overlaps with the shaft seat 413 of the inner ring 41 in the axial direction X.

A flat bolt seat 414 is formed on the surface of the inner ring 41 opposite to the shaft seat 413. An annular annular protrusion 412 is formed around the bolt seat 414 and protrudes in the axial direction X.

As shown in FIGS. 3 and 5, the bolt 8 integrally includes a head 81, a shaft 83, and a neck 82 that connects the head 81 and the shaft 83. The head 81 is used to operate the bolt 8. Further, the head 81 sandwiches the inner ring 41 between the head 81 and the shaft end surface 91. The shaft portion 83 is inserted (screwed) into the rotating shaft 9 from the end opening 92 .

The head 81 has a short cylindrical shape. A plurality of operation holes 812 are formed in the main surface 811 of the head 81 . The plurality of operation holes 812 are arranged in an annular shape on the main surface 811. When screwing the shaft portion 83 of the bolt 8 into the shaft end surface 91 of the rotating shaft 9, a tool (not shown) having a plurality of pins that fit into the plurality of operation holes 812 is used.

The outer diameter of the head 81 corresponds to the inner diameter of the annular protrusion 412 of the inner ring 41. When the head 81 fits into the annular projection 412 and the outer peripheral surface of the head 81 and the inner peripheral surface of the annular projection 412 come into contact, the bolt 8 and the inner ring 41 are centered.

A flat seat surface 814 in the shape of a hollow disk is formed at the peripheral edge of the back surface 813 of the head 81 . The seat surface 814 seats on the bolt seat 414 of the inner ring 41.

The shaft portion 83 has a male screw portion 831 and a cylindrical portion 832 in order from the head 81 side. The male threaded portion 831 has a cylindrical shape and has an outer diameter D831 corresponding to the inner diameter D93 of the female threaded portion 93 of the rotating shaft 9 (D93≈D831). A male screw 833 is formed on the outer peripheral surface of the male screw portion 831 and is screwed into the female screw 931 .

The cylindrical portion 832 has a cylindrical shape and has an outer diameter D832 corresponding to the inner diameter D95 of the centering portion 95 of the rotating shaft 9 (D95≈D832). The cylindrical portion 832 is inserted into the alignment portion 95, and the outer circumferential surface of the cylindrical portion 832 and the inner circumferential surface of the alignment portion 95 come into contact with each other, thereby aligning the rotating shaft 9 and the bolt 8.

The neck portion 82 smoothly connects the back surface 813 of the head portion 81 and the end of the male threaded portion 831 of the shaft portion 83 . At the connection part between the neck part 82 and the head part 81, a "throat thick part 821" is provided at the corner. By providing the throat thick portion 821, the strength of the neck portion 82 is increased compared to a case where the throat thick portion 821 is not provided. A chamfered portion 411 is formed in the inner ring 41 by cutting out the volume of the corner of the inner peripheral edge of the inner ring 41 of the support bearing 4 so as to correspond to the protrusion of the throat thick portion 821. By making the inner ring 41 (chamfered portion 411) thinner in this way, a space is secured for giving the neck portion 82 of the bolt 8 a sufficient wall thickness, and the inner peripheral edge corner where stress tends to concentrate is secured. is removed, stress concentration is alleviated.

Since the inner ring 41 is thinned, the bolt 8 is configured to actively support the load that the inner ring 41 receives from the rolling elements 43. Specifically, the contact point P1 between the rolling element 43 and the inner ring 41 is located radially inward from the outer peripheral edge of the head 81 of the bolt 8 with respect to the rotation axis A1. Considering the contact angle of the support bearing 4, the head 81 and the neck 82 (particularly the throat thick part 821) of the bolt 8 can be the parts that support the pressing force transmitted from the inner ring 41. Note that the contact angle of the support bearing 4 is the angle between the straight line connecting the contact points of the rolling elements 43 and the outer ring 42 and the inner ring 41 and the radial direction. Therefore, the head portion 81 and the neck portion 82 are provided with sufficient wall thickness. Further, the chamfered portion 411 of the support bearing 4 and at least a portion of the throat thick portion 821 of the bolt 8 come into contact. This allows the bolt 8 to receive a load at the head 81 and neck 82.

A through hole 85 passing through the head 81, neck 82, and shaft 83 is provided in the axial center of the bolt 8. The inside of the through hole 85 communicates with an oil passage 90 within the rotating shaft 9. The through hole 85 has a small diameter hole portion 851 on the head 81 side, and a large diameter hole portion 852 having a larger diameter than the small diameter hole portion 851 on the shaft portion 83 side. The small diameter hole portion 851 functions as a throttle that provides resistance to the hydraulic oil that is about to be discharged from the oil passage 90 through the through hole 85 .

The rotating shaft 9 is provided with at least one oil hole 96 that communicates between the oil passage 90 in the shaft center and the outer periphery. When the rotating shaft 9 rotates, centrifugal force causes the hydraulic oil in the oil passage 90 to be ejected toward the outer circumferential side of the rotating shaft 9 through the oil hole 96, and parts mounted on the rotating shaft 9 are lubricated by the ejected hydraulic oil. The oil level in the oil passage 90 can rise to the oil level upper limit height. The upper limit height of the oil level in the oil passage 90 is determined by the inner diameter of the small diameter hole portion 851 of the through hole 85 of the bolt 8 . In other words, the smaller the inner diameter of the small diameter hole portion 851, the higher the oil level upper limit height becomes. When the oil level height in the oil passage 90 exceeds the upper limit oil level height, excess hydraulic oil is discharged to the outside through the through hole 85 of the bolt 8. As the oil level in the oil passage 90 becomes higher, the amount of hydraulic oil compressed within the oil passage 90 increases, so the centrifugal pressure applied to the hydraulic oil within the oil passage 90 increases, causing the oil to be ejected from the oil hole 96. The amount of oil increases. In this way, the amount of hydraulic oil jetted from the oil hole 96 can be adjusted by adjusting the diameter of the through hole 85 provided in the bolt 8 (in particular, the inner diameter of the small diameter hole portion 851).

[Assembling procedure for support bearing 4]
Here, the procedure for assembling the support bearing 4 to the rotating shaft 9 will be explained. First, the support bearing 4 is fitted onto the rotating shaft 9 in this order: the outer ring 42, the rolling elements 43, and the inner ring 41. Before fitting the inner ring 41, a shim 49 for preload adjustment may be placed on the end surface of the shaft end surface 91 of the rotating shaft 9. Next, the shaft portion 83 of the bolt 8 is inserted into the end opening 92 of the rotating shaft 9, and the bolt 8 is rotated to screw the male threaded portion 831 into the female threaded portion 93 of the rotating shaft 9. When the seat surface 814 of the bolt 8 comes into contact with the bolt seat 414 of the inner ring 41 and the bolt 8 no longer moves further into the rotating shaft 9 and no longer rotates, the support bearing 4 is assembled to the rotating shaft 9.

As shown in FIG. 3, in the support bearing 4 assembled to the rotating shaft 9 in the above procedure, the shaft seat 413 is pressed against the shaft end surface 91 of the rotating shaft 9 via the shim 49, and the bolt seat 414 is in pressure contact with the shaft end surface 91 of the rotating shaft 9. It is pressed against the seat surface 814 of No. 8. In this way, the inner ring 41 is compressed in the axial direction X between the rotating shaft 9 and the bolt 8, so that the inner ring 41 is assembled to the rotating shaft 9 in a relatively immovable manner.

Furthermore, the outer circumferential surface of the cylindrical portion 832 of the bolt 8 is in contact with the inner circumferential surface of the centering portion 95 of the rotating shaft 9, thereby aligning the bolt 8 and the rotating shaft 9. Furthermore, the outer circumferential surface of the head 81 of the bolt 8 is in contact with the inner circumferential surface of the annular protrusion 412 of the inner ring 41, thereby centering the bolt 8 and the support bearing 4. In this way, the rotating shaft 9 and the support bearing 4 are centered through the bolt 8.

As described above, the transmission 10 according to the present embodiment includes a rotating shaft 9 (transmission output shaft 12 in this embodiment), and a pair of disks 13 arranged around the rotating shaft 9 and facing each other. , 15, at least one power roller 18 tiltably sandwiched between a pair of disks 13, 15, and a power roller 18 that is assembled to the rotating shaft 9 to absorb an axial load from at least one of the pair of disks 13, 15. The bolt 8 has a head 81 and a shaft 83, and the shaft 83 is screwed into the shaft end surface 91 of the rotating shaft 9. The bearing 4 has an inner ring 41, an outer ring 42, and rolling elements 43 sandwiched between the inner ring 41 and the outer ring 42. The bearing 4 is characterized in that the inner ring 41 is assembled to the rotating shaft 9 by being sandwiched between the shaft end surface 91 of the rotating shaft 9 and the head 81 of the bolt 8.

According to the above configuration, the shaft end portion of the rotating shaft 9 to which the bearing 4 is assembled does not protrude further than the inner ring 41 of the bearing 4 in the axial direction. Therefore, the axial length of the rotary shaft 9 is shortened compared to the conventional case where the shaft end of the rotary shaft 9 protrudes from the inner ring 41 of the bearing 4 and a nut or a retaining ring is provided on the protruding portion. be able to. This can contribute to downsizing of the transmission 10.

In the transmission 10 according to the present embodiment, the shaft portion 83 of the bolt 8 includes a male threaded portion 831 having a male thread 833 formed on the outer circumferential surface, and a male threaded portion 831 provided on the distal end side of the male threaded portion 831. The cylindrical portion 832 has a smaller diameter than the threaded portion 831. The shaft end of the rotating shaft 9 has a cylindrical shape centered on the rotation axis A1, and has a female threaded portion 93 formed on the inner peripheral surface with a female thread 931 that engages with a male thread 833, and an inner peripheral surface. has an alignment portion 95 that contacts the outer peripheral surface of the cylindrical portion 832 .

According to the above configuration, the bolt 8 is screwed into the shaft end surface 91 of the rotating shaft 9, and the outer circumferential surface of the cylindrical portion 832 contacts the inner circumferential surface of the alignment portion 95, so that the rotating shaft 9 and the bolt 8 are connected to each other. alignment is performed.

Furthermore, in the transmission 10 according to the present embodiment, the inner ring 41 of the bearing 4 includes a bolt seat 414 on which a bearing surface 814 of the bolt 8 is seated, and an annular protrusion 412 provided around the bolt seat 414. , the outer peripheral surface of the head 81 of the bolt 8 and the inner peripheral surface of the annular protrusion 412 come into contact.

According to the above configuration, the bolt 8 is screwed into the shaft end surface 91 of the rotating shaft 9, the bearing surface 814 of the bolt 8 is seated on the bolt seat 414, and the outer circumferential surface of the head 81 of the bolt 8 and the annular protrusion 412 The bolt 8 and the bearing 4 are aligned by contacting the inner circumferential surfaces of the bolt 8 and the bearing 4.

Further, in the transmission 10 according to the present embodiment, the contact point P1 between the rolling elements 43 and the inner ring 41 is located radially inward from the outer circumferential edge of the head 81 of the bolt 8.

According to the above configuration, the axial load that the inner ring 41 receives can be received by the head 81 of the bolt 8. As a result, the inner ring 41 can be made thinner, and in this embodiment, the inner corner of the inner ring 41 is shaved to form a thin chamfered portion 411. Since the inner ring 41 is thinned, a throat thick portion 821 is provided between the head 81 and the neck 82 of the bolt 8, thereby increasing the thickness and increasing the strength.

In the transmission 10 according to the present embodiment, the rotating shaft 9 has an oil passage 90 extending in the axial direction X inside the rotating shaft 9, and the bolt 8 has a head 81 at the axial center of the bolt 8. It has a through hole 85 that passes through the shaft portion 83 and communicates with the oil passage 90 .

According to the above configuration, the oil level height of the oil passage 90 of the rotating shaft 9 can be adjusted by the inner diameter of the through hole 85 of the bolt 8. The hydraulic oil that exceeds the oil level is discharged to the outside from the oil passage 90 through the through hole 85 of the bolt 8. Depending on the oil level height of the oil passage 90 of the rotating shaft 9, the amount of hydraulic oil jetted from the oil passage 90 to the outer circumferential side through the oil hole 96 that radially penetrates the rotating shaft 9 can be adjusted. That is, depending on the size of the inner diameter of the through hole 85 of the bolt 8, the amount of hydraulic oil that is jetted from the rotating shaft 9 to the outer circumferential side through the oil hole 96 can be adjusted.

Although the preferred embodiments of the present invention have been described above, the present invention may include modifications to the specific structure and/or functional details of the above embodiments without departing from the spirit of the present invention. . The above configuration can be modified as follows.

For example, the transmission 10 is not limited to a central input type, but may be a central output type. In the case of the central output type, the positional relationship between the input disk 13 and the output disk 14 described above is reversed, the output disk becomes the center disk (second disk), and the input disk becomes the outer disk (first disk). In this case, the pressing device 17 is configured to press the input disk toward the output disk, and rotation is input to the cam plate 61 from a gear meshing with the external teeth 614.

4: Support bearing 8: Bolt 9: Rotating shaft 10: Toroidal continuously variable transmission 10: Transmission 13: Input discs 14, 15: Output disc 18: Power roller 41: Inner ring 42: Outer ring 43: Rolling element 63: Roller 81 : Head 82 : Neck 83 : Shaft 85 : Through hole 90 : Oil passage 91 : Shaft end surface 93 : Female thread part 95 : Aligning part 412 : Annular protrusion 413 : Shaft seat 414 : Bolt seat 814 : Seat surface 821 :Thick throat part 831 :Male thread part 832 :Cylindrical part 833 :Male thread 851 :Small diameter hole part 852 :Large diameter hole part 931 :Female thread A1 :Rotation axis P1 :Contact point

Claims (5)

a rotating shaft;
a pair of disks arranged around the rotation axis and facing each other;
at least one power roller tiltably sandwiched between the pair of disks;
a bearing having an inner ring, an outer ring, and rolling elements sandwiched between the inner ring and the outer ring, and which is assembled to the rotating shaft and receives an axial load from at least one of the pair of disks;
a bolt having a head and a shaft, the shaft being screwed into the shaft end surface of the rotating shaft;
The bearing is assembled to the rotating shaft by sandwiching the inner ring between the shaft end surface of the rotating shaft and the head of the bolt.
Toroidal continuously variable transmission. The shaft portion of the bolt has a male threaded portion having a male thread formed on an outer peripheral surface, and a cylindrical portion provided on a distal end side of the male threaded portion and having a smaller diameter than the male threaded portion,
The shaft end of the rotary shaft has a cylindrical shape centered on the rotation axis, and has a female threaded portion formed on the inner peripheral surface with a female thread that engages with the male thread, and an inner peripheral surface of the cylindrical portion. having an alignment part that contacts the outer circumferential surface;
The toroidal continuously variable transmission according to claim 1. The inner ring of the bearing has a bolt seat on which a bearing surface of the bolt is seated, and an annular protrusion provided around the bolt seat,
an outer circumferential surface of the head of the bolt and an inner circumferential surface of the annular protrusion are in contact with each other;
The toroidal continuously variable transmission according to claim 1 or 2. A contact point between the rolling element and the inner ring is located radially inward from an outer peripheral edge of the head of the bolt.
The toroidal continuously variable transmission according to any one of claims 1 to 3. The rotating shaft has an oil passage extending in the axial direction inside the rotating shaft,
The bolt has a through hole that passes through the head and the shaft at the axial center of the bolt and communicates with the oil passage.
The toroidal continuously variable transmission according to any one of claims 1 to 4.

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