Abstract: A toroidal type continuously variable transmission, includes: at least one pair of disks concentrically disposed on each other and rotatably supported independent from each other; a trunnion swingable about a pivot shaft; a displacement shaft including a support shaft portion and a pivot shaft portion that are parallel and eccentric to each other, the support shaft portion rotatably supported to the circular hole of the trunnion through a radial bearing, the pivot shaft portion being protruded from an inner surface of the middle portion of the trunnion; a power roller nipped between the concave surfaces of the pair of disks while being rotatably supported on an outer circumferential surface of the pivot shaft portion; and a thrust bearings located between the power roller and the inner surface of the middle portion of the trunnions. An eccentric quantity of the displacement shaft being a distance between the support shaft portion and the pivot shaft portion is within a range from 5 mm to 15 mm.

Abstract: In order to facilitate an assembling operation of a structure which is correctly operated with a proper positional relation, in a power roller unit for a toroidal type continuously variable transmission according to the present invention, a displacement shaft, a power roller, a radial needle bearing, a thrust ball bearing and a thrust needle bearing are pre-assembled to a trunnion. After dimensional relations and operation conditions of the constructural parts of the assembly or unit are ascertained, the assembly is assembled within a housing together with other unit, thereby completing the toroidal type continuously variable transmission.

Abstract: In the toroidal-type continuously variable transmission, the torque transmission shaft 15 includes a flange portion 29a formed in one end thereof, while a securing portion 43 is formed in the end-face side half section of the flange portion 29a so as to be able to secure a tool thereto when tightly fastening a loading nut 19 to a external thread portion 40 formed in the torque transmission shaft 15. And, the outer peripheral surface of the securing portion 43 is formed as a polygonally cylindrical shape having four or more flat surfaces. Also, after the torque transmission shaft 15 is heat-carburized and the surface of a cylindrical portion 44 formed in the torque transmission shaft 15 is removed, the external thread portion 40 is worked, which makes it possible not only to secure the hardness of the adjoining portions of the external thread portion 40 but also to control the hardness of the external thread portion 40 itself.

Abstract: In a toroidal-type continuously variable transmission, there is provided a thrust rolling bearing interposed between a power roller and a trunnion for supporting a thrust-direction load applied to the power roller. The thrust rolling bearing includes a plurality of rolling elements and a retainer rollably holding the plurality of rolling elements. The retainer defines a circular-ring-shaped main body and a plurality of pockets respectively formed in the main body for rollably holding the plurality of rolling elements. A clearance between the pocket and the rolling element is set in the range of 0.6 to 6.0% of the ball diameter of the rolling element.

Abstract: A power roller bearing of a toroidal-type continuously variable transmission unit that is used for a transmission of an automobile or the like comprises a power roller, an outer race, balls, a retainer, etc. Annular raceway grooves are formed individually on the respective opposite end faces of the outer race and the power roller. Treated-surface layers for enhancing the endurance of the power roller bearing are formed individually on the respective surfaces of the raceway grooves. The treated-surface layers include super-finished surfaces with the surface roughness of 0.05 Ra or less, formed individually on the raceway grooves, and low-friction layers formed individually on the super-finished surfaces. Alternatively, the treated-surface layers include residual compression stress layers formed on the respective surface layer portions of the raceway grooves by shot-peening.

Abstract: A toroidal type continuously variable transmission, includes: at least one pair of disks concentrically disposed on each other and rotatably supported independent from each other; a trunnion swingable about a pivot shaft; a displacement shaft including a support shaft portion and a pivot shaft portion that are parallel and eccentric to each other, the support shaft portion rotatably supported to the circular hole of the trunnion through a radial bearing, the pivot shaft portion being protruded from an inner surface of the middle portion of said trunnion; a power roller nipped between the concave surfaces of the pair of disks while being rotatably supported on an outer circumferential surface of the pivot shaft portion; and a thrust bearings located between the power roller and the inner surface of the middle portion of the trunnions. An eccentric quantity of the displacement shaft being a distance between the support shaft portion and the pivot shaft portion is within a range from 5 mm to 15 mm.

Abstract: The hardness of the outer peripheral surface of a small-diameter portion 47 and one side surface of a collar portion 52, which respectively rub against a belleville spring 39a, is set at HRc45 or higher, thereby enhancing the wear resistance of these surfaces. On the other hand, the hardness of a fastening tubular portion 51 is set at HRc3O or lower, thereby making it difficult for the fastening tubular portion 51 to be damaged or cracked when it is fastened.

Abstract: A toroidal type continuously variable transmission, includes: at least one pair of disks concentrically disposed on each other and rotatably supported independent from each other; a trunnion swingable about a pivot shaft; a displacement shaft including a support shaft portion and a pivot shaft portion that are parallel and eccentric to each other, the support shaft portion rotatably supported to the circular hole of the trunnion through a radial bearing, the pivot shaft portion being protruded from an inner surface of the middle portion of said trunnion; a power roller nipped between the concave surfaces of the pair of disks while being rotatably supported on an outer circumferential surface of the pivot shaft portion; and a thrust bearings located between the power roller and the inner surface of the middle portion of the trunnions. An eccentric quantity of the displacement shaft being a distance between the support shaft portion and the pivot shaft portion is within a range from 5 mm to 15 mm.

Abstract: There is disclosed a traction drive fluid which comprises a base oil blended with (A) an active phosphate ester base compound, (B) a boron-containing imide base dispersant (e.g. polyalkenyl succinimide treated with a boron compound) and (C) a boron-free imide base dispersant (e.g. polyalkenyl succinimide) in such blending amounts that the phosphorus content derived from the component (A) and the boron content derived from the component (B) are each 100 to 600 ppm, preferably 60 to 300 ppm by weight, and at least 60 ppm by weight, respectively based on the base oil, and the boron-free imide base dispersant (C) is blended so that the ratio by weight of the nitrogen in the component(C) to the boron in the component (B) is at least 1, preferably 1 to 6.

Abstract: In order to facilitate an assembling operation of a structure which is correctly operated with a proper positional relation, in a power roller unit for a toroidal type continuously variable transmission according to the present invention, a displacement shaft, a power roller, a radial needle bearing, a thrust ball bearing and a thrust needle bearing are pre-assembled to a trunnion. After dimensional relations and operation conditions of the constructural parts of the assembly or unit are ascertained, the assembly is assembled within a housing together with other unit, thereby completing the toroidal type continuously variable transmission.

Abstract: In the toroidal-type continuously variable transmission, the radial needle roller bearing includes a plurality of needle rollers, the two end portions of each of the needle rollers in the axial direction thereof are crowned, and the crowning amount is set such that, in the portion of the needle roller that is situated by 7-13% of the axial-direction length toward the axial-direction central portion of the needle roller from the axial-direction end face of the needle roller, the crowning amount is 0.1-0.4% of the outside diameter of the axial-direction central portion of the needle roller.

Abstract: The toroidal type continuously variable transmission includes: first and second disks concentrically disposed on each other and supported such that they can be rotated freely; a pair of trunnions; a pair of displacement shafts respectively including support shaft portions and pivot shaft portions; a plurality of power rollers interposed between and held by the first and second disks; a plurality of thrust ball bearings respectively for supporting their associated power rollers; and, a plurality of thrust needle bearings respectively interposed between the outer surfaces of outer rings respectively forming the thrust ball bearings and the inner surfaces of the trunnions. A retainer for retaining the thrust needle roller in a freely rollable manner is formed of a single plate, and is carbonitrided, while the surface hardness Hv of the retainer is set higher than or equal to 550.

Abstract: In order to facilitate an assembling operation of a structure which is correctly operated with a proper positional relation, in a power roller unit for a toroidal type continuously variable transmission according to the present invention, a displacement shaft, a power roller, a radial needle bearing, a thrust ball bearing and a thrust needle bearing are pre-assembled to a trunnion. After dimensional relations and operation conditions of the constructural parts of the assembly or unit are ascertained, the assembly is assembled within a housing together with other unit, thereby completing the toroidal type continuously variable transmission.

Abstract: A continuously variable transmission provided with a rotary shaft characterized in that a ball spline is formed between an inner peripheral surface of a first disc and an outer peripheral surface of an intermediate portion of a rotary shaft, a restraining members for limiting displacement of balls of a ball spline is provided on an inner side of the inner peripheral surface of the first disc, a small-diametered portion is formed on the outer peripheral surface of the intermediate portion of the rotary shaft and between the first disc and a second disc, and the restraining members is mountable through the small-diametered portion with the restraining members and the small-diametered portion axially aligned with each other.

Abstract: A cam disk for use in a loading cam mechanism of a toroidal type continuously variable transmission comprises a first projecting portion, a second projecting portion, a flange portion, a cam surface, a bearing raceway and a corner section. The cam disk has metal flows along the cam surface, metal flows along a surface of the raceway, and metal flows along a surface of the corner section. To produce the cam disk, material is shaped into a predetermined form through a first forging step using a first die unit, a second forging step using a second die unit, a third forging step using a third die unit, a finishing step, etc. The metal flows are also formed in these steps.

Abstract: An angular bearing of a dual cavity toroidal type continuously variable transmission, includes: a torque input shaft having a shaft-side raceway groove formed in an outer peripheral surface of a flange portion provided in an end thereof; a loading cam unit of a loading cam unit having a disc-side raceway groove formed in an inner peripheral surface of a jointing opening thereof, the loading cam unit located around the end of the torque input shaft; and a plurality of balls held between the shaft-side raceway groove and the disc-side raceway groove to bear thrust loads exerted on the cam disc, wherein each of an angular contact angle between the balls and the shaft-side raceway groove and an angular contact angle between the balls and the disc-side raceway groove is 60° or smaller, and each of a curvature radius of a groove surface of the shaft-side raceway groove and that of a groove surface of the disc-side raceway groove is from 52% to 55% of a diameter of the ball.

Abstract: An outer race of a thrust ball bearing supporting a thrust load applied to a power roller is rotatably supported around a displacement shaft. A portion in which the contact pressure between an outer race track and the rolling surface of a rolling member is high changes so that the fatigue of the outer race track does not progress locally. Also, the power roller and the outer race are subjected to predetermined treatment and working. Irrespective of a great thrust load applied during operation, stress is alleviated and the lubricating property of the portion of contact is made good to thereby prevent cracks or early wear from occurring.

Abstract: There is provided a trunnion for a toroidal continuously variable transmission in which the material is strengthened against the wear and plastic deformation of a trunnion. The trunnion includes a base portion having a body portion, which connects and supports a base end portion of a displacement shaft at a surface intermediate portion, and a pair of plate portions, in which an edge apart from the body portion is a tip end edge, and a pair of axis (shaft) portions protruding from the outside surfaces of the plate portions in opposite directions to each other. The toroidal continuously variable transmission is characterized in that at least the rolling surface of a radial needle bearing for supporting the tilted rotation of the trunnion has a hardness not lower than HRC55, and a core portion has a hardness not lower than HRC20 and not higher than HRC45.

Abstract: A power roller for a toroidal type continuous variable transmission system comprises a trunnion having a central shaft, a bearing outer race connected to the trunnion, one face of which is provided with a first track groove concentric with the central shaft, a power roller rotatably mounted on one end portion of the central shaft, the power roller having a face opposing to the one face of the bearing outer race, the face being provided with a second track groove concentric with the central shaft, a plurality of rolling elements retained between the bearing outer race and the power roller and capable of rotating within a track formed by the first track groove and the second track groove, and a disk-like cage coaxially disposed between the bearing outer race and the power roller and rotatable about the central shaft, the cage including a plurality of through pockets for accommodating the rolling elements therein so as to retain the rolling elements within the track, the pockets being arranged at regular interva

Abstract: Improved input and output discs for toroidal type continuously variable transmissions are obtained by select processing techniques to form hardened layers. Processing techniques include, e.g., carburizing, carbonitriding, and high-frequency induction hardening. Shot peening may be used to impart compressive residual surface stress to predetermined disc portions to enhance resistance to cracking.