A hydraulic torque converter, particularly for use in a motor vehicle between the prime mover and the transmission of the power train, employs a combination of a bypass clutch with one or more torsional vibration dampers which brings about savings in space and/or in the number of parts. In addition, the torque converter can stand long periods of use and is less prone to wear, adverse influences of abruptly developing stresses and/or other undesirable influences than conventional torque converters. Furthermore, the improved torque converter employs or can employ a bypass clutch and/or one or more torsional vibration dampers simpler and less expensive than but superior to those in conventional torque converters.

Hydraulic torque converter

The magnitude of torque which can be transmitted by a bypass clutch between the housing and the turbine of a torque converter between a prime mover, such as an engine, and an automatic transmission in the power train of a motor vehicle is selectively regulatable by a computerized regulating unit. The regulation involves the transmission of torque by the clutch in dependency upon the magnitude of the torque being transmitted by the output element of the engine and ascertaining as well as adaptively applying to the clutch a variable force so that the clutch can transmit a predetermined torque. This entails automatic selection of a minimum slip between a torque receiving and a torque transmitting part of the power train. Compensation, particularly long-range compensation, is carried out for the existence of possible differences between the predetermined and actual torques being transmitted by the clutch.

Method of and apparatus for transmitting torque in vehicular power trains

An adaptive electronic transmission control for an automatic transmission having multiple-ratio gearing establishing plural torque flow paths between a torque input member and a driven member, the relative motion of the elements of the gearing being controlled by a friction torque establishing member and an overrunning coupling connection between two gear elements of the gearing. A ratio shift is achieved by establishing a driving connection between a selected gearing element and a torque delivery shaft. The shift is achieved by controlling the capacity of the friction element using a fluid pressure actuator. Shift quality is optimized by establishing a bias pressure on a friction element accumulator and by using a feedback control system to control the rate of change of transmission ratio during the shift.

Adaptive electronic transmission control system and strategy for nonsynchronous automatic transmission

An adaptive pressure control method for synchronous downshifts in an automatic transmission that uses pressure actuated friction elements. The method uses characteristic parameters that determine downshift quality for both power-on downshifts and power-off downshifts. Selected measured variables are monitored to detect changes in the parameters. Adjustments for the friction elements are made in response to changes in the measured variables.

Adaptive pressure control method for synchronous downshifts in a multiple-ratio transmission

A multiple ratio transmission having a main gear unit with at least three forward driving ratios and a single reverse drive ratio and a simple planetary gear unit in series with the main gear unit, the simple planetary gear unit being downshifted and the main gear unit being upshifted on an upshift from a first intermediate ratio to a higher intermediate ratio, the simple planetary gear unit being upshifted and the main gear unit being downshifted on a downshift from the higher intermediate ratio to the first intermediate ratio.

Multiple ratio transmission with swap-shift controls

A control system for engaging and releasing a torque converter bypass clutch and for varying the torque capacity of the clutch by adjusting the torque converter torus chamber pressure in accordance with changing operating variables, the bypass clutch including a clutch release pressure chamber that is maintained at a calibrated pressure threshold valve whereby pressure clutch capacity control is achieved by controlling pressure differential in the converter.

Wilfried Franz-Xaver Schulz

Papers

Multiple ratio automatic transmission and torque converter