Abstract: A hydrostatic transaxle is disclosed of the type having a central manifold (13) and right and left motor axle assemblies (15, 17). Each motor axle assembly includes a fluid motor (35) and a speed reduction gear set (51). The manifold defines a pair of aligned openings (81R, 81L) and disposed therein is a pair of elongated brake actuation members (83R, 83L), each member being axially moveable in its opening away from a central reference plane (RP). A cam means (95) defines right and left cam surfaces (107R, 107L) engaging the brake actuation members. Movement of the cam means forces the actuation members axially outward, until each engages friction pad (109), providing braking of a reaction plate (115) between the friction pad and a back up plate (119). The disclosed braking arrangement is simple and inexpensive, and achieves braking upstream of the reduction gear set, thus requiring less braking torque than would be required in the case of a conventional wheel brake. Also disclosed is an embodiment (FIG.

Abstract: A gear transmission for a vehicle in accordance with the present invention forms a first speed change range by disposing a back range gear and a second range gear on an output shaft adjacent to each other, disposing a back idle gear meshing always with the back range gear and a first range gear on a coaxial rotary shaft, engaging always the back idle gear with a gear disposed on an input shaft and engaging the first range gear with the second range gear on the input shaft. Accordingly, the speed change range of each of the first and second and back ranges can be constituted by two gear trains and the length in the axial direction can be reduced as a whole. Moreover, since the back range gear is always engaged with the back idle gear and the back idle gear is always engaged with the gear disposed on the input shaft, the angle of the face advance can be increased, chamfering of gears for sliding mesh becomes unnecessary and the gear strength of the back range gear train can be reinforced.

Abstract: A downshift control in an automatic transmission is disclosed wherein magnitude of servo activating hydraulic fluid pressure is temporarily decreased as a function of vehicle speed when the automatic transmission effects a downshift from a current gear ratio to a new gear ratio. Owing to this arrangement, a fluid operated frictional device associated with the current gear ratio is released quickly without any lag to allow quick increase in engine speed during the downshift with the throttle fully opened at a high vehicle speed, i.e., a power-on downshift at high vehicle speed.

Abstract: An automatic transmission for an automotive vehicle has a plurality of friction devices for selectively coupling a number of rotary elements in a planetary gear mechanism to one another, and a hydraulic circuit for controlling changeover of the friction devices. The hydraulic circuit includes a regulator valve for generating line pressure, a manual valve for selectively changing over the line pressure to the hydraulic circuit, a plurality of shift solenoids for directly controlling engaging hydraulic pressure of the friction devices by duty control when a shift is made, and a plurality of relay valves controlled by the solenoid valves, wherein the solenoid valves are duty-controlled independently of one another. With such an arrangement, one accumulator is sufficient and the number of valves can be reduced, so that the valve body can be made more compact. In addition, highly precise shock control is possible with regard to all shift conditions.

Abstract: An automatic transmission control system for an automotive vehicle comprising fluid pressure operated clutch and brake servos that establish and disestablish plural torque delivery paths between the engine of the vehicle and a driven member, the control system having a pressure regulator for maintaining an optimum pressure level, a throttle solenoid valve, ratio shift controlling solenoid valves and means for replacing the functions of the throttle solenoid valve and the shift controlling solenoid valves in the event that a control voltage failure or a valve malfunction should occur.

Abstract: An automatic transmission, in which a gear train including a plurality of planetary gear sets each composed of a sun gear, a carrier and a ring gear is accommodated in a casing so that the transmission of a drive force from an input shaft to an output shaft may be changed to set a plurality of gears. The automatic transmission includes a first brake connected to the carrier of the first one of the plural planetary gear sets for fixing the same to the casing; a first clutch arranged at the same side as is the connecting position of the carrier and the first brake means with respect to the first planetary gear set for connecting the carrier selectively to a rotating member such as the sun gear, carrier or ring gear of one of other planetary gear sets; and a second clutch arranged closer to the first planetary gear set than it is to the first clutch for connecting the sun gear of the first planetary gear set selectively to the rotating member.

Abstract: A central differential is composed of a planetary gear device. The planetary gear device comprises a first sun gear connected to an output shaft of a transmission, a carrier, a pinion set comprising first and second planetary pinions integral with each other and rotatably supported on the carrier, and a second sun gear. The first planetary pinion is engaged with the first sun gear, and the second planetary pinion is engaged with the second sun gear. The first and second planetary pinions are in the same phase, and a plurality of the pinion sets are equiangularly disposed around the first and second sun gears.

Abstract: A hydraulic pressure control system for an automatic transmission comprises a multiple transmission gear mechanism having a plurality of gear stages and frictional elements for switching power transmitting paths in the transmission gear mechanism. A hydraulic control mechanism controls engagement and disengagement of the frictional elements to establish one of the gear stages. A line pressure control valve controls line pressure of the hydraulic control mechanism, and a solenoid valve receives a control signal and controls a pilot pressure based on the control signal, allowing the line pressure control valve to control the line pressure. A frequency control device for increase a frequency of the control signal for the solenoid valve during a shift operation of the transmission. A responsive line pressure control is accomplished to reduce the torque shock during a shift operation of the transmission.

Abstract: A shift limiting valve (110) driven by a control solenoid valve controlled by an electronic control means (40) is installed between a manual shift valve (50) working in cooperation with speed-change operation of driver and shift valves (60) and (62) driven by solenoid valves (S1) and (S2) controlled by the electronic control means (40). The control solenoid valve is controlled by the electronic control means (40) to actuate the shift limiting valve (110) when a vehicle is moving forward at a specified or higher speed so that a planetary gear transmission (12) is not changed to a reverse drive stage even if the driver changes a drive mode to the reverse drive stage.

Abstract: A central differential for splitting output torque of a transmission is formed by a complex planetary device. The planetary device comprises an input sun gear operatively connected with an output shaft of the transmission, a plurality of output sun gears, a carrier, and a pinion member comprising a plurality of planetary pinions integral with each other and rotatably supported on the carrier. Fluid operated friction clutches are provided for selectively connecting one of the output sun gears to an output member of the central differential.

Abstract: In an automatic transmission, clutch-to-clutch powered downshifting is controlled by filling the on-coming clutch at a low pressure while ramping down the off-going clutch pressure until turbine speed is pulled up due to off-going clutch slippage, and then increasing the off-going pressure stepwise to compensate the change from static to dynamic coefficients of friction. Then the on-coming pressure is gradually ramped up and a closed-loop profile control period starts wherein the slip speed of the on-coming clutch is measured and controlled to a slip speed profile by controlling the off-going clutch pressure. When synchronization of the on-coming clutch is first detected, a closed-loop sync control period starts wherein the off-going pressure is controlled to minimize the slip and the on-coming pressure is ramped up at a steeper rate to begin clutch engagement during the sync control period.

Abstract: An improved method of scheduling ratio shifting in a vehicle transmission adaptively adjusts the normal shift schedule to avoid shift-related overheating of the torque transmitting devices of the transmission. In normal operation, transmission shifting is scheduled by comparing measured vehicle speed and engine throttle position values with predefined load data. In the background, the transmission controller determines the cumulative thermal energy stored in the torque transmitting devices. If excessive energy is indicated, the normal shift schedule is modified to allow extended operation in the lower speed ratios. When the cumulative energy indication returns to a normal level, normal shift scheduling is resumed.

Abstract: A process for continuously controlling the degree of locking of open differential drives in a driven axle of a multi-axle vehicle, in the case of which a nominal value .DELTA..sub.v soll of the differential speed at the wheels driven via the differential gear is determined as a function of the vehicle speed v.sub.F determined at the non-driven wheels and which records the wheel speed differential .DELTA..sub.v ist between the wheels driven via the differential gear, which wheel speed differential .DELTA..sub.v ist is readjusted by varying the locking effect on the nominal value .DELTA..sub.v soll of the differential speed always deviating from zero.

Abstract: A continuously variable transmission which effects a speed change by increasing and decreasing the width of a groove between a fixed pulley part and a movable pulley part. A belt ratio controller for the transmission uses oil pressure to increase and decrease the rotating radius of a belt wound on the pulley parts, the belt controller controlling the belt ratio to a target belt ratio value set based on the opening of the throttle when starting on a road having a small road surface friction coefficient.

Abstract: A system for controlling torque distributed to front wheels and rear wheels of a motor vehicle. A planetary gear device including a first sun gear connected to an output shaft of a manual transmission, first and second planet pinions integral with each other, a carrier provided to rotatably support the pinions and operatively connected to the front wheels, and a second sun gear operatively connected to the rear wheels is disposed to distribute the torque to front wheels and rear wheels. The first planetary pinion is engaged with the first sun gear, and the second planetary pinion is engaged with the second sun gear. A fluid operated multiple-disk clutch selectively connects two of the first sun gear, the carrier and the second sun gear so as to restrict the differential operation of the planetary gear device.

Abstract: For a predetermined period following the issuance of a shift command signal, the output of a engine speed signal is temporarily ignored. Upon the expiration of the predetermined time, the engine speed is sampled and if the rate of change thereof is above a given value, the initiation of the shift operation is deemed to have occurred.

Abstract: A gear train for changing the rotational speed of an input shaft to transmit the resultant rotation to an output shaft consists of single pinion type first and second planetary gear sets and a double pinion type third planetary gear set.

Abstract: A device for the remote control of engine functions comprising two control units, each control unit having a system consisting of an output shaft coupled with a first control potentiometer, a swiveling gear wheel segment which is coupled with the output shaft and which is connected to a push-pull cable the other end of which is connected to an operating lever of the engine, and adjusting motor coupled with the output shaft, an electronic control circuit for the adjusting motor, and a control mechanism connected to each control unit by means of an electric cable which is also connected to the electronic control circuit. The control mechanism has a second control potentiometer coupled to an operating handle, whereby the electronic control circuit compares the electric signals derived from the first and said control potentiometers and energizes the adjusting motors when the difference exceeds a given threshold value.

Abstract: A steplessly variable power transmission has a torque converter provided with an input member connected with an engine output member of an engine and an output member. A belt-pulley type of steplessly variable power transmitting mechanism is provided with primary pulley device, connected with the output member of the torque converter. A secondary pulley device, constituting an output member of the transmission, is also provided and a belt connects the primary pulley devices with the secondary pulley device for transmitting power between the primary and secondary pulley device with a predetermined pulley speed ratio. A hydraulic control system controls effetive diameters of the primary and secondary pulley devices to thereby change the speed ratio of the transmission steplessly. An output torque of the torque converter or a turbine torque of the torque converter, and the pulley speed ratio are calculated.

Abstract: A stepless hydrostatic mechanical transmission between a prime mover and a power output train in which an epicyclic differential is incorporated in the transmission and includes at least four shafts, a large and a small sun wheel, two planet wheels in mesh with the sun wheels, a web supporting the planet wheels and an annulus. Two main shafts constituting input and output shafts are connected with respectively different shafts of the epicyclic differential. Two hydrostatic machines are connected to the epicyclic differential such that in at least one working range of the power transmission the hydrostatic machines are adapted to be connected to the epicyclic differential and operated as pumps and motors.