Abstract: A method is disclosed for controlling a drill-free curve-CVT including a ring wheel, a set of planet wheels, and a sun wheel, wherein the ring and sun wheel are clamped together. The normal forces between the ring and sun wheel on the one hand and the planet wheels on the other hand are well defined when the transmission ratio is constant. The normal forces for constant ratio are called the static values. The method is configured so that during a continuous increase or decrease of the transmission ratio, any force component added to the static values of the first and/or the second normal force is either zero or smaller than a predefined force component to maintain a microslip condition of the rolling contacts between the planet wheels and the ring and sun wheels. This control of the forces is applied regardless of the speed of the ratio change.

Abstract: The invention relates to a continuously variable automatic transmission that modifies the transmission ratio thereof by means of the accumulation and conversion of potential and kinetic energy. The transmission, which is functionally formed around a device accumulating elastic potential energy (6) with a controlled (7) output (2), has an inflow system (5) suitable for distributing the energy that is absorbed, and an outflow system (9) suitable for delivering the potential energy that has been absorbed and converting it into kinetic energy. The accumulator of elastic potential energy is formed around an elastic spiral spring, the inlet thereof being arranged so as to only allow the inflow of energy and the outlet thereof so as to control the energy delivery.

Abstract: Components, subassemblies, systems, and/or methods for continuously variable transmissions (CVT) are provided. In one embodiment, a CVT has a number of spherical planets in contact with an idler assembly. Various idler assemblies can be used to facilitate to improve durability, fatigue life, and efficiency of a CVT. In one embodiment, the idler assembly has two rolling elements having contact surfaces that are angled with respect to a longitudinal axis of the CVT. In some embodiments, a bearing is operably coupled between the first and second rolling elements. The bearing is configured to balance axial force between the first and second rolling elements. In one embodiment, the bearing is a ball bearing. In another embodiment, the bearing is an angular contact bearing. In yet other embodiments, needle roller bearings are employed.

Abstract: A hydraulic circuit for controlling a continuously variable transmission includes: a lubrication line provided with a lubrication pump, and configured to supply oil from an oil tank to a lubrication target by using the lubrication pump; a high pressure line provided with a high pressure pump, branching from the lubrication line, and configured to supply, by using the high pressure pump, high-pressure oil to a hydraulic control section that controls oil pressure of the oil to be supplied to the continuously variable transmission; and a cooling return line branching from the high pressure line, and configured to return the oil to a downstream side of the lubrication pump in the lubrication line, a portion of the cooling return line forming a cooling path to cool a generator connected to the continuously variable transmission.

Abstract: A fast valve actuation system for an automatic vehicle transmission includes a pair of spring-biased shift valves. Solenoids control the application of pressurized hydraulic fluid to the head of each of the shift valves. Each shift valve has at least one port that is coupled to a fluid chamber of a torque transferring mechanism of an automatic transmission. The position of each of the shift valves determines whether its ports are connected with fluid pressure. Fluid passages connect the head of each shift valve to the spring pocket of the other shift valve.

Abstract: A toroidal traction drive has an axial loading system with a primary loading component and a non-linear cam roller loading component.

Abstract: A fast valve actuation system for an automatic vehicle transmission includes a pair of spring-biased shift valves. Solenoids control the application of pressurized hydraulic fluid to the head of each of the shift valves. Each shift valve has at least one port that is coupled to a fluid chamber of a torque transferring mechanism of an automatic transmission. The position of each of the shift valves determines whether its ports are connected with fluid pressure. Fluid passages connect the head of each shift valve to the spring pocket of the other shift valve.

Abstract: A continuously variable transmission is provided. The continuously variable transmission includes an input assembly, an output assembly, an input/output planetary ratio assembly and a torque feedback assembly. The input/output planetary ratio assembly is configured and arranged to set an input to output speed ratio. The input/output ratio assembly has a first portion that is in rotational communication with the input assembly and a second portion that is in rotational communication with the output assembly. The torque feedback control assembly provides an axial load force in response to a torque of a load coupled to the output assembly. Moreover, the torque feedback control assembly is coupled to provide torque feedback to the input/output planetary ratio assembly to at least in part control the input to output speed ratio of the input/output planetary ratio assembly.

Abstract: An apparatus and method are disclosed for controlling fluid flow to a variator which responsive to separate high and low pressure fluids to control an output torque thereof. A first trim valve may be responsive to a first control signal to supply a first fluid at a fluid outlet thereof. A second trim valve may be responsive to a second control signal to supply a second fluid at a fluid outlet thereof. A variator switching sub-system may controllably supply the high pressure fluid and the low pressure fluid to the variator. A multiplex valve may be fluidly coupled to the outlets of the first and second trim valves, and may supply the first fluid as the high pressure fluid to the variator switching sub-system during at least one predefined operating condition and may otherwise supply the second fluid as the high pressure fluid to the variator switching sub-system.

Abstract: An apparatus for controlling a variator having at least one roller between two torroidal disks may include at least one actuator responsive to fluid pressure at separate high side and low side fluid inlets thereof to control torque applied by the at least one roller to the disks. First and second variator switching valves may each receive a first fluid at a first pressure and a second fluid at a second lesser pressure. The first and second variator switching valves supply the first fluid to the high side fluid inlet and the second fluid to the low side fluid inlet during two of four different operational states together defined by the variator switching valves, and supply the second fluid to the high side fluid inlet and the first fluid to the low side fluid inlet during each of the remaining two of the four different operational states.

Abstract: A full-toroidal continuously variable transmission has a hydraulic actuator (20) for applying pressing force to a pair of disks (5, 15) through a roller (17). The hydraulic actuator (20) includes first and second oil chambers (23, 24). The pressing force of the hydraulic actuator (20) is produced by a pressure difference between the oil chambers (23, 24). A directional control valve (29; 29P; 29Q) connects a hydraulic pressure source (25; 25P; 25Q) to either of the oil chambers, and an oil tank (26) is connected to the other oil chamber. Each corresponding an intermediate section (27a; 27Pa, 27Qa) of a feeding path (27, 27P, 27Q) and intermediate section (28a; 28Pa; 28Qa) of a discharge path (28; 28P; 28Q) are connected by a communicational path (32; 32P; 32Q). A check valve (33; 33P; 33Q) for permitting a flow of operation oil only to the feeding path side (27, 27P, 27Q) is provided in the communication path (32; 32P; 32Q).

Abstract: A fail-to-neutral diagnostic technique for a transmission that includes a variator may include monitoring a state of a pressure differential valve fluidly coupled to a high side pressure applied to at least one actuator coupled to at least one corresponding roller of the variator and also fluidly coupled to a low side pressure applied to the at least one actuator, determining from the state of the pressure differential valve a variator torque sign corresponding to whether torque transferred by the at least one roller is positive or negative, determining an expected variator torque sign based on current operating conditions of the transmission, and commanding the transmission to a true neutral condition if the determined variator torque sign is different from the expected variator torque sign.

Abstract: The present invention relates to a stepless variable transmission device with parallel low gear wheel group, which is the first case that a low gear transmission wheel group equipped with a one-way transmission unit, which transmits with fixed speed ratio in same rotary direction, is installed between the input shaft and the output shaft of a stepless variable transmission device; and which is installed with the clutch device 212 with angular displacement difference and/or the clutch device 222 for eliminating the vibration produced by the hetero-shaft type stepless variable transmission device 100 and the low gear transmission wheel group 102, the both do not operate with fully same speed ratio, for overloaded transmission.

Abstract: The invention concerns an arrangement for control of a continuously variable transmission. The transmission includes a variator (10) having a movable torque transfer part (rollers 18) whose position corresponds to a variator drive ratio. A hydraulic actuator (28) is arranged to exert an adjustable force on the torque transfer part. The transmission further comprises a flow control arrangement which is arranged to receive as control inputs (a) the current position of the torque transfer part and (b) a demanded position for it. The demanded position may for example be determined by driver input. The flow control arrangement is adapted to supply through a supply outlet which communicates with the hydraulic actuator a flow of fluid which is modulated in accordance with an error between the two control inputs. The flow of fluid increases with increasing error.

Abstract: A continuously variable transmission is disclosed comprising a transmission input and output between which a variator (V) can be coupled, in either a low regime or a high regime, by gearing (R1, R2, R3, M). The relationship between variator ratio and overall transmission ratio is different in the two regimes. Incorporated in the gearing are first and second clutch means (L, H) both hydraulically actuated, for engaging and disengaging low and high regimes respectively. The gearing provides a synchronous ratio at which a change between low and high regimes, at constant variator ratio, provides no change in the overall transmission ratio. The transmission is provided with hydraulics which incorporate a shift valve (110) which controls application of hydraulic pressures to the first and second clutch means. A change in state of the shift valve (110) causes one clutch means to change from engaged to disengaged and the other to make the opposite transition.

Abstract: A pressing apparatus including two pressing apparatus parts for two gear members running together is proposed, with the second pressing apparatus part partially accommodating the force applied by the first pressing apparatus part.

Abstract: In a toroidal transmission with a continuously variable power transmission ratio, which is adjustable by displacement of a power transmission roller arranged between toric disks along an axis X-X under the control of an adjusting unit including a hydraulic piston, the adjusting unit has a bush which serves on the one hand to seal off the working space and, at the same time, forms two slide surfaces one for the piston and another for the guide bush, all in a small support space pivotally supporting a support member for the power transmission roller.

Abstract: A controller determines a target gear ratio from an accelerator opening and a vehicle speed. The controller determines the stroke of a trunnion on the basis of the difference between present inclination and a target inclination, thereby to control stroke by a hydraulic control valve. The stroke is corrected according to input/output disc pushing force.

Abstract: A variator assembly comprising a variator of the toroidal-race rolling-traction type. The assembly has input and output discs and rollers which are acted on by hydraulic roller control actuators. They are positioned between the discs to transmit torque from one disc to the other. Hydraulic end loading means supplied with fluid at an end load pressure to apply an end load to bias the discs and the rollers toward each other, thereby enabling the transmission of torque. Reaction pressure supply means are connected to the roller control actuators to cause them to apply an adjustable reaction force to the rollers. The assembly also has hydraulically influenced valve means which serve to compare an input related to the end load pressure with an input related to the reaction pressure and to control the end load pressure in dependence upon the comparison, thereby maintaining a relationship between the end load and reaction pressures.

Abstract: A toroidal-type continuously variable transmission includes three trunnions and power rollers in a single cavity. One of the trunnions is shifted by a pair of oil pressure actuators, each of a single-acting type. The remaining two trunnions are respectively shifted by separate oil pressure actuators, each of a double-acting type.

Abstract: In a toroidal continuously variable transmission (TCVT) control apparatus with a variator unit and a ratio control hydraulic system, an electronic TCVT control unit electronically feedback-controls a transmission ratio based on a deviation from a desired transmission ratio, and generates a normal-period command signal to be input to a step motor for compensating for the deviation. The control unit determines whether the deviation can be compensated for by electronically feedback-controlling the transmission ratio based on the deviation and generates an abnormal-period command signal to be input to the step motor to realize a step-motor displacement capable of shifting or diverging the transmission ratio to a speed-reduction side, while keeping a trunnion out of contact with a stopper in the direction of the trunnion axis, when the deviation cannot be compensated for by electronically feedback-controlling the transmission ratio based on the deviation.

Abstract: A speed change control valve (7) houses a spool (8) of comprising a land (83) which can face a supply port (7P) supplying an oil pressure, and lands (84, 85) which can respectively face a pair of drain ports (7D, 7D) formed on either side of the supply port (7P). Output ports (7L, 7H) which allow a first and second oil chamber of an hydraulic cylinder to communicate selectively with the supply port (7P) or the drain ports (7D) according to the displacement of a spool (8), are provided in the speed change control valve (7). In the neutral position of the spool (8), the lands (84, 85) respectively face the drain ports (7D), a width L1 of the land (83) is set to be equal to or greater than a width L1 of the supply port (7P), and a width L3 of the lands (84, 85) is set to a width at which the drain port (7D) can open.

Abstract: The trunnion (23) of a vehicle toroidal continuously variable transmission is displaced by a step motor (52) via a control valve (56) and oil pressure servo cylinder (50) in order to vary a speed ratio of the transmission. A controller (80) calculates a target value (z*) of a control variable (z) based on an accelerator pedal depression amount (APS) and output disk rotation speed (&ohgr;co) (S5). Further, a time-variant coefficient (f) showing the relation between the trunnion displacement (y) and variation rate ({dot over (&phgr;)}) of the gyration angle (&phgr;) of the power roller, is calculated (S10). The error between the speed change response of the transmission and a target linear characteristic can be decreased by determining a command value (u) to the step motor (52) under a control gain determined based on a time differential ({dot over (f)}) of the coefficient (f) (S20).

Abstract: In order to stabilize an operation for changing a speed change ratio, and to improve transmitting efficiency and endurance of structural parts of a toroidal continuously variable transmission, a relationship between the switching of a control valve and displacements of trunnions is such that initiation of the displacement of a trunnion having a feedback mechanism including a precess cam and a link arm is effected prior to initiation of the displacement of a trunnion not having a feedback mechanism.

Abstract: A rotary power transmission device is disclosed in which output/input speed ratio is automatically and continuously adjusted as a function of both demand torque and demand speed by translation of a traction wheel upon the faces of two coaxial counter-rotating drive plates which are in concurrent tangential enforced contact with the wheel, with wheel serving as output. Translation of wheel is accomplished by applying opposed forces of a hydraulically actuated piston and a compression spring. Magnitude of hydraulic pressure upon piston is defined by combined action of pump speed and restriction of a flow control valve. By causing pump speed to be proportional to input speed, and valve restriction to be a function of an environmental variable such as inclination of a vehicle equipped with the transmission, traction wheel position and thus speed ratio is automatically adjusted as a function of both demand torque and demand speed.

Abstract: The present invention relates to the supply of hydraulic actuation and cooling fluid to the roller actuation pistons and rollers provided in an IVT. The IVT assembly (10) includes a split casing (12a, 12b) and a manifold (28) that comprises one or more channels (30,32,60) formed in a surface of the casing formed by said split. The provision of said manifold in this position allows for easier manufacture and better performance.

Abstract: First oil chambers (80A) which drive a toroidal continuously variable transmission in a speed ratio decrease direction are connected to a first port (82B) of an oil pressure control valve (62) via a first passage (86A). Second oil chambers (80B) which drive the toroidal continuously variable transmission in a speed ratio increase direction are connected to a second port (82C) via a second passage (86B). The oil pressure control valve (62) selectively connects a pump port (82A, 82F, 82G) and a drain pot (82D, 82E, 82H) to the first and second ports (82B, 82C) according to the displacement of a spool (84). A damper (96, 98, 102, 108, 109, 114, 116, 120) is connected to one of the ports so as to exert a damping action on the oil passing through the oil pressure control valve (62).

Abstract: The amounts of displacement of trunnions installed in first and second cavities are made equal to each other irrespective of the amount of resilient deformation. Also, if the worst should happen, the stability of the running of an automobile is secured. The supply and discharge of pressure oil to first and second actuators for displacing the trunnions installed in the first and second cavities are effected by first and second control valves independent of each other. A value is included for controlling so that the difference between oil pressure fed into the first actuator and oil pressure fed into the second actuator may not become great.

Abstract: A continuously-variable-ratio transmission ("CVT"), especially of the toroidal-race rolling-traction type, in which the prime mover is connected to the ratio-varying component ("variator") by a torque converter or other starting device capable of slip. The CVT output is connected both to the variator output and also, by way of fixed ratio gearing and a one-way clutch, to the output of the starting device. At low speeds drive is transmitted from prime mover to the CVT output by way of the fixed ratio gearing in both forwards and reverse. In forward drive, as the speed of the variator output rises, operation of the one-way clutch causes the drive transmission path to change from the fixed ratio gearing to the variator output once the speed of the latter exceeds the former.

Abstract: A combined transmission assembly and monitoring system for indicating the operating condition of the transmission assembly includes a transmission assembly having an input shaft, an output shaft, and a plurality of components for connecting the output shaft for rotation at a predetermined speed relative to the input shaft, a sensor attached to a portion of the transmission assembly, the sensor being responsive to vibration of the portion of the transmission assembly for generating signals indicative of the sensed vibration, and a controller for receiving the signals from the sensor and generating an indication of the operating condition of the transmission assembly based on the vibration of the portion of the transmission assembly. Preferably the sensor is adapted to detect both the frequency and magnitude of vibration of the transmission assembly and to generate signals indicative of the sensed frequency and magnitude of vibration.