Abstract: In an assembly of a toroidal continuously variable transmission, a sheath member (41) is temporarily fitted on a male screw (3A) so that a step between a spline part (21A) and a male screw (3A) of a CVT shaft (3) does not catch on an output disk (18, 20) when the CVT shaft (3) is passed through the output disk (18, 20). The outer diameter of the sheath member (41) is gradually reduced in a tapering shape from an outer diameter equal to that of the spline part (21A).

Abstract: An input disk (19) of a toroidal continuously variable transmission (19) is connected to a rotation shaft (3) via a ball spline structure. Plural power rollers gripped between the input disk (19) and an output disk (20) are disposed at a predetermined angular interval around the rotation shaft (3). A group or groups of spline units (21) forming the ball spline structure respectively comprise pairs of spline grooves (21A) and balls (21B) held inside these grooves. The input disk (19) exerts a thrust load on the power rollers (30) and their reaction force causes the input disk (19) to deform. By forming the ball spline structure from a group or groups of the spline units (21) in which the spline units (21) are disposed at the same angular interval as the power rollers (30),this deformation is prevented from causing the rotation shaft to suffer rotational vibration.

Abstract: A preloading mechanism (16) of a toroidal continuously variable transmission applies a predetermined preload to disks (1a, 1b, 2a, 2b) by belleville springs (9a, 9b). The input disk (1b) displaces in such a compressing direction of the belleville spring (9a) as the speed ratio increases. The displacement of the input disk (1b) is limited by a spacer (50), so the clearance (S) of the belleville springs (9a, 9b) is never zero and a large force is prevented from acting on the belleville springs (9a, 9b).

Abstract: The invention relates to a power roller used for a toroidal-type continuously variable transmission. This power roller has on its first side a groove for receiving a bearing, and the surface of the groove (bearing surface) has a carbon concentration which is not lower than that of the back surface of a second side opposed to the first side. The power roller has a hardened outer layer having first and second portions which are respectively defined by the bearing surface and the back surface. The first portion of the hardened outer layer has an effective depth which is not shallower than that of the second portion thereof. The power roller is prepared by the sequential steps of surface-hardening, quenching, and grinding. The surface-hardening process is one of carburizing and carbonitriding.

Abstract: A method of manufacturing a traction roller for a continuously variable transmission comprises placing a layer on a hollow cylindrical material having the volume substantially equal to the traction roller, performing axial pressure forging of the cylindrical material to obtain a work having the axial length substantially equal to that of the traction roller, performing axial die forging of the work to form side wall and outer peripheral surface of the traction roller, and grinding the work subjected to die forging to obtain a finished product of the traction roller.

Abstract: A loading cam for continuously variable transmissions includes cam rollers contacting an input disk and a cam flange to press the input disk in the axial direction of a main shaft of the transmission upon shifting, a holding member engaged with the cam flange to hold the cam rollers, and a cover attached to the holding member. The cover cooperates with the holding member to define a passage for supplying lubricating oil for the cam rollers.

Abstract: A toroidal-type continuously variable transmission is constructed such that an action line of a load on a ball or rolling element is inclined with respect to a power roller rotation axis so that a point of intersection of the action line and the power roller rotation axis is positioned farther than an outer ring support surface of a power roller support member with respect to an inner ring of the power roller.

Abstract: A slip control is effected by effecting a switch to a slip control ratio change control when a wheel slip exceeds a predetermined value. The usual ratio control in a continuously variable transmission is reinstated upon completion of the slip control ratio change control smoothly owing to modification of shift speed or provision of delay.

Abstract: A continuously variable traction roller transmission comprises a driving gear which is of the helical gear type, and has an angle of torsion with the direction set to generate a force for biasing a second output disk to a second input disk at least in the forward run state of a motor vehicle and when torque is transmitted from an engine.

Abstract: A thrust cam device is located at a back side of an input disc to bias the input disc toward an output disc in accordance with a torque applied thereto. The thrust cam device includes a drive cam, a back surface of the input disc, groups of cam rollers each being between respective cam surfaces of the drive cam and input disc, and a cam holder disposed between the drive cam and the input disc for rotatably holding the cam rollers. A disc spring is compressed between the input disc and the drive cam for constantly biasing the input disc toward the output disc. The input disc, the cam holder and the drive cam have respectively positioning holes which can be aligned. The positioning hole of the input disc is threaded. Upon requirement of preassembly of the thrust cam device, the input disc, the cam holder and the drive cam are turned to certain positions wherein the positioning holes are aligned, and a bolt is inserted into the aligned positioning holes and screwed into the threaded positioning hole.

Abstract: A continuously variable transmission is disclosed which comprises a torque transmitting device to which an engine torque is applied, the torque transmitting device being coaxially arranged on a first axis; a planetary gear mechanism to which a torque from the torque transmitting device is applied, the planetary gear mechanism being coaxially arranged on the first axis; a continuously variable type speed change device to which a torque from the planetary gear mechanism is applied, the speed change device being coaxially arranged on the first axis; an output shaft coaxially arranged on the first axis; a countershaft coaxially arranged on a second axis which is in parallel with the first axis; first gears for transmitting a torque from the speed change device to the countershaft; and second gears for transmitting a torque from the countershaft to the output shaft. The planetary gear mechanism is so arranged as to lower the torque applied thereto and transmit the lowered torque to the speed change device.

Abstract: A friction roller type continuously variable transmission comprises an input shaft, a first transmission mechanism, a second transmission mechanism, a thrust cam device and a hydraulically operated control device. The thrust cam device biases respective input discs of the first and second transmission mechanisms toward respective output discs of the same in accordance with a torque possessed by the input shaft. The biasing for the second input disc is indirectly made through the input shaft. The control device varies the speed change ratio of each transmission mechanism. A feedback control mechanism is employed, which is incorporated with the second transmission mechanism for feeding back the existing condition of the second transmission mechanism to the control device.

Abstract: A ratio change control for a transmission, in which an increase in feedback control term is restrained when a gearing mechanism takes over a drive between an input shaft, and an output shaft or when a transition in drive from the gearing mechanism to a continuously variable transmission mechanism has not been completed. Specifically, the feedback control term is set to zero.

Abstract: A continuously variable traction roller transmission comprises a loading nut having one end portion which abuts on a stopper formed by one end face of a ball spline, disc springs arranged between an input disc and the loading nut, and a preliminary pressure adjusting member arranged between the input disc and the disc springs.

Abstract: A hydraulic control system for a continuously variable traction roller transmission comprises a shift control valve for controlling hydraulic pressure within a hydraulic cylinder apparatus. The shift control valve includes a sleeve and a spool received therein for relative motion, which assume a normal state when a gear ratio commanded corresponds to a rotational displacement of rotation shanks of roller support members wherein the hydraulic cylinder apparatus provides a predetermined force to the rotation shanks in an axial direction thereof so as to preserve a rotational displacement of the rotation shanks. The sleeve has a plurality of bores for discharging hydraulic fluid to be supplied to the hydraulic cylinder apparatus.

Abstract: A control system for a hybrid transmission of a motor vehicle comprises a vehicle speed sensor and a control unit. In the control unit, a deceleration is calculated. When the deceleration is greater than the predetermined deceleration value under a condition where the vehicle speed is less than a predetermined vehicle speed value, a switch is effected from a torque delivery path through a continuously variable transmission mechanism to a torque delivery path through a gearing mechanism. Thus, there occurs no slip between a V-belt and a driver pulley in the continuously variable mechanism upon acceleration immediately after rapid deceleration.

Abstract: A system for controlling a continuously variable transmission is disclosed, in which a shift actuator is controlled in a feed-back manner with a feed-back gain such that a deviation between target and current values related to a reduction ratio reduces toward zero, and the feed-back gain is altered in response to a current torque detected.

Abstract: A system for controlling a continuously variable transmission. A target value of an input revolution speed or a reduction ratio is modified in response to a current engine torque. A shift actuator is controlled such that a deviation between current and modified target values reduces to zero.

Abstract: A hybrid continuously variable transmission includes a gearing mechanism and a continuously variable transmission mechanism which altenatively take over a drive. According to a ratio change control system, the continuously variable transmission mechanism is prevented from shifting operation until a transition from a drive owing to the gearing mechanism to a drive owing to the continuously variable transmission mechanism is completed.

Abstract: In a continuously variable traction roller transmission, a combination of a precess cam and a generally L-shaped link is used for converting a rotational movement of a traction roller supporting member to an axial movement of a spool of a speed change control valve. The cam surface of the precess cam is convexed to achieve an optimum characteristic of speed change ratio.