Abstract: A device for control of a hydraulically actuatable shifting element of a motor vehicle transmission, having one clutch piston which defines, with a first surface, a hydraulically pressurizable piston space and, with a second surface of different size, a hydraulically pressurizable reset space and comprising a first clutch valve associated with the piston space, a second clutch valve associated with the reset space and a holding valve associated with the reset space. The valves can be moved according to a control pressure adjusted by a pressure adjuster, a change between a pressurization of the clutch piston on the piston space side and on the reset space, side being performed as a control function so that the clutch piston on its surface facing the reset space is pressurized in an unshifted state of the shifting element and is discharged in a shifted state of the shifting element.

Abstract: Second and third clutches are axially aligned so that the back side of the second clutch and the front side of the third clutch oppose each other, and a first clutch is positioned radially inward of the second and third clutches. Further, a clutch drum is extended so as to be used in common by the second and third clutches, the second clutch is engaged and disengaged from the axial front side by a second piston of a second oil pressure actuator, and the third clutch is engaged and disengaged from the axial rear side by a third piston of a third oil pressure actuator. The first through third clutches are positioned in a compact manner and can be independently operated.

Abstract: An ECT-ECU includes an abrupt turbine speed increase learning control circuit which prevents simultaneous release of both a frictional engagement element to be released and a frictional engagement element to be engaged, a tie-up learning control circuit which prevents simultaneous engagement of both the frictional engagement element to be released and the frictional engagement element to be engaged, a determination circuit that determines whether one of tie-up learning control and abrupt turbine speed increase learning control is necessary based on the turbine speed, and a control circuit that prohibits execution of the tie-up learning control unless the number of trips after the abrupt turbine speed increase learning control has been executed is at least equal to a predetermined number, when it has been determined that the tie-up learning control is necessary.

Abstract: A hydraulic control system for an automatic transmission includes a 3-4 shift valve that outputs a source pressure through a first path for shift speeds lower than a fourth shift speed established by directly connecting an input shaft with an output shaft of the automatic transmission, i.e., third shift speed. The hydraulic control system further includes a clutch apply control valve that outputs a source pressure through a second path at a shift speed higher than the fourth shift speed, i.e., fifth speed. The 3-4 shift valve and the clutch apply control valve serve to interrupt supply of the source pressure through the first path and the second path, respectively, in the fourth speed or the lock-up stage.

Abstract: A primary shift portion has a first predetermined speed ratio at a first shift-speed, a second predetermined speed ratio at a second shift-speed, a speed ratio of “1” at third and fifth shift-speeds, and a third predetermined speed ratio at fourth and sixth shift-speeds. A secondary shift portion has a predetermined reduction speed ratio at first, second, third, and fourth shift-speeds, and a speed ratio of “1” at fifth and sixth shift-speeds. The method realizes a 6-speed automatic transmission being capable of sequentially up- and down-shifting and a plurality of skip shifts with an existing 5-speed automatic transmission.

Abstract: The present invention comprises a vehicle speed monitoring device which enables a driver to enter a speed tolerance profile that represents the driver's personal travel speed preferences and which alerts the driver when the vehicle speed falls outside the speed tolerance profile. Specifically, the speed tolerance profile consists of a number of speed tolerance ranges, each associated with a particular posted speed limit. As the vehicle travels through various map zones, the applicable posted speed limit is determined using a customized GPS map. The device determines the vehicle location, speed and the posted speed limit and then compares the vehicle speed using a running average to see whether vehicle speed is within the driver's speed tolerance profile and if not, the device provides the driver with a visual and/or audible warning according to the driver's operational preferences.

Abstract: A method is proposed for controlling an automatic transmission driven by a prime mover in which a shift from a first transmission ratio to a second transmission ratio occurs in the form of a pull upshift or push downshift or a pull downshift or push upshift by a first clutch opening and a second clutch closing and an electronic transmission control device controls, via electromagnetic valves, the pressure curve of the first and of the second clutch during the shifting operation. The shifting operation is divided into various shifting phases, an engine intervention taking place in the load-transfer (LÜ) of the gradient-setting phase (GE), the sliding phase (GL), the gradient-reduction phase (GA) and the closing phase (S), an engine torque and/or a characteristic value that determines the engine torque being transferred from the transmission control device to an engine control device of the prime mover.

Abstract: In an automatic transmission, transient control of the working oil pressures for friction elements whose state is to be switched is normally carried out in accordance with a degree of shift development determined based on at least a vehicle speed. When the vehicle speed is too low to provide determination of the degree of shift development, transient control of the working oil pressures for the friction elements is carried out in accordance with elapsed time from shift instead of normal transient control.

Abstract: In a transmission which transmits a power from an electrical motor 1 to a countershaft 30 with a speed change, a drive side rotating member which is coupled to a main shaft 10 experiences a rotational change along with the main shaft 10 when a shift from a first speed ratio to a second speed ratio is executed, and an intermediate rotating member experiences a rotational change in a direction opposite to that of the drive side rotating member when the shift is executed. In this transmission, the ratio of the rotational inertia of the drive side rotating member to the rotational inertia of the intermediate rotating member equals the reciprocal of the ratio of the rotational change of the drive source to the rotational change of the intermediate rotating member, the rotational changes being experienced during the shift.

Abstract: An automatic transmission including an input shaft connected to an output shaft of an engine. A first clutch of a first planetary gear unit is positioned between the input and first output shafts while a third clutch of a third planetary gear unit is interposed between the second and third output shafts. Each of the first and third clutches are engaged by the action of flyweights operated by centrifugal force and disengaged by thrust exerted on helical gears of the planetary gear units. A second planetary gear unit includes a second clutch interposed between the first and the second output shafts. Control means control the second clutch so as to engage the first and the second output shaft or disengage the first and the second output shafts from each other and provide smooth shockless upshifting and downshifting of the automatic transmission.

Abstract: A structure in which a hydraulic-pressure control applied pressure for controlling each engagement element of an automatic transmission is realized by using an electric signal such that combinations of engagement which encounter a tie-up in case of a failure of the signal lead to interlocking are inhibited to prevent deterioration in the durability of each engagement element. An automatic transmission incorporates a planetary gear transmission mechanism using selective engagement of at least five engagement elements to realize six gear ratios, and a hydraulic-pressure control apparatus for controlling the engagement elements of the transmission mechanism. Valves are provided which inhibit combinations of engagement of two or more engagement elements of the five engagement elements for interlocking the transmission mechanism.

Abstract: A hydraulic control system for a continuously variable transmission includes a pressure regulator, a shift controller, a forward/reverse controller, and a torque converter operation controller. The pressure regulator includes a primary regulator valve for regulating hydraulic pressure supplied from an oil pump, a first solenoid valve, a secondary regulator valve, and a solenoid supply valve. The shift controller includes a shift ratio control valve, and a second solenoid valve controlling the shift ratio control valve. The forward/reverse controller includes a pressure control valve, a third solenoid valve controlling the pressure control valve, a manual valve, and first and second friction elements acting respectively as forward and reverse operational elements. The torque converter operation controller includes a torque converter feed valve receiving hydraulic pressure from the pressure regulator, a lock-up clutch control valve, and a fourth solenoid valve controlling the lock-up clutch control valve.

Abstract: In an automatic transmission, transient control of the working oil pressures for friction elements whose state is to be switched is normally carried out in accordance with a degree of shift development determined based on at least a vehicle speed. When the vehicle speed is too low to provide determination of the degree of shift development, transient control of the working oil pressures for the friction elements is carried out in accordance with elapsed time from shift instead of normal transient control.

Abstract: A hydraulic control device for an automatic transmission that can ensure power transmission when a failure occurs to the solenoid valve of the hydraulic control device, the hydraulic control device having a plurality of hydraulic servos for engaging and disengaging a plurality of friction engagement elements in accordance with the supply and discharge of a hydraulic pressure so as to prevent interlock from occurring to the transmission, a solenoid valve for generating a predetermined hydraulic pressure and supplying the predetermined hydraulic pressure to a hydraulic servo selected in correspondence with a target gear ratio and fail-safe means for supplying fail-safe hydraulic pressure to at least two hydraulic servos selected to attain an arbitrary gear ratio when a failure occurs to the solenoid valve and power transmission thereby becomes impossible.

Abstract: A method of shifting a transmission having both a hydrostatic portion, including a variable pump (15), and a hydraulic motor (29), and a mechanical transmission (33) portion, including a shift cylinder (37). The method includes relieving the output torque of the motor (29), shifting the mechanical transmission to neutral, and controlling the. displacement of the pump (15) to synchronize motor output speed with the required input speed to the desired gear ratio of the mechanical transmission (33). Then fluid flow to the shift cylinder (37) occurs to shift to the desired gear ratio. The shifting method includes a series of steps in which the feasibility of the prospective shift is determined, and only when the prospective shift can be completed, without detriment to the operation of the vehicle, will the shift be completed. As a result, the shifting between low gear and high gear can occur without bringing the vehicle to a stop each time.

Abstract: An electrohydraulic control device for power shift gearboxes, in particular in construction machinery, has switching elements (SE1, SE2, SE3) which can be actuated by a system pressure from an external pressurized medium source (1). Shift valves (SV1, SV2, SV3) are provided between the pressurized medium source (1) and the switching elements (SE1, SE2, SE3) and can each be actuated by pilot pressure. Each of the switching elements (SE1, SE2, SE3) can be actuated in a defined switching state by at least two actuated shift valves (SV1, SV2, SV3) and at least one non-actuated shift valve.

Abstract: A hydraulic control system for automatic transmission systems includes: an oil pump, a pressure control valve, a solenoid supply valve, a manual valve, a torque control regulator valve, a control switch valve, an N-D control valve, a 1st-2nd speed shift valve, a 2nd-3rd speed shift valve, a 3rd-4th speed shift valve, a second clutch valve, a third clutch valve, a fourth clutch valve, and an N-R control valve. Accumulators are provided to each supply line of first, second, third and sixth frictional elements to alleviate shock resulting from gear shifting and maintain stability in actuating hydraulic pressure.

Abstract: Improvements to a Shiftless, Continuously-Aligning Transmission (SCAT) to provide the turbine member of a torque converter with variable torque-increasing gearing and give it additional work advantage over a work load and eliminate a vast amount of slippage in the converter, the improvements embodying reactive planetary gears mechanically engaging the turbine to a sun gear of a planetary gear set; mobile ring gears controlled by a drive shell extending rearward and engaged to a mechanical ring gear modulator which controls the direction and speed of the planetary ring gears to vary the output torque being delivered by the converter; a two-section input turbine shaft; a clutch mechanism to engage the two turbine shaft sections; a clutchless, continuously engaged overdrive planetary unit; hydraulic controls; and electrical braking controls.

Abstract: A torque transmission unit is connectable to an internal combustion engine in order to drive a secondary unit with different transmission ratios in dependence upon the rotation rate of the internal combustion engine so that in the case of a low rotation rate of the internal combustion engine the transmission ratio is greater and in the case of a great rotation rate of the internal combustion engine the transmission ratio is less. The torque transmission unit comprises a planetary gear, a free-wheel and a clutch. By the clutch a part of the planetary gear can be coupled to or separated from another part of the planetary gear or a stationary support part, according to choice. The clutch is hydraulically actuable. The pressure for the hydraulic actuation of the clutch is delivered by a hydraulic pump which is integrated into the torgue transmission unit and is independent from the lubricant circuit of the internal combustion engine.

Abstract: A power transmission for driving a vehicle wherein a high-low speed changer is disposed between an engine and a primary speed change mechanism. The speed changer comprises a planetary gear mechanism provided between an input shaft and an output shaft, a speed increasing clutch for causing the gear mechanism to effect a speed increase, and a direct coupling clutch for coupling the input shaft to the output shaft via the gear mechanism without speed change. Since the torque transmitted to the speed change mechanism is small, the transmission can be compact in its entirety.

Abstract: A stepless transmission is provided with an input shaft having gear structure. A variator shaft also has gear structure. A variator is connected between the input shaft and the variator shaft. The variator alters the relative speeds of rotation between the input shaft and the variator shaft. An output shaft has gear structure that is operatively connected to the input shaft gear structure and the variator shaft gear structure. The speed and direction of rotation of the output shaft is related to the difference between the tangential velocities of the input shaft gear structure and the variator shaft gear structure acting on the output shaft gear structure. Structure for increasing the rotational speed delivered from the input shaft to the variator can be provided. Reduction structure for gearing down the rotational speed of the variator shaft gear structure can also be provided. Controls for the transmissions are also disclosed.