Gm Global Technolgoy Operations, Inc.

James C Polak

Donald Klemen

Carl A Lentz

Reece R Fuehrer

Walter Eric Palmer

Phillip J Ross

Robert H Schaefer

Harry Fackenthal

A clutch assembly has two pistons each having an apply chamber for independently controlling engagement of respective friction plates. An axially fixed wall is disposed adjacent the pistons opposite to the apply chambers. Fluid is admitted between the wall and the pistons such that during rotation of the clutch assembly, centrifugal pressure generated in the fluid in the apply chambers is counteracted by centrifugal pressure generated in the fluid between the wall and the pistons.

Clutch assembly with a pressure balance chamber

A preselected transmission has three friction clutches and one synchronized mechanical clutch assembly to provide five forward speed ratios. An additional mechanical clutch permits the addition of a reverse ratio. The clutches are combined with a gearing arrangement such that sequential or skip-shifting can be accomplished.

Multi-ratio transmission

A pump drive mechanism for use with a vehicle transmission includes a differential gear arrangement having members drivingly connected to the transmission input, the transmission output and the pump drive shaft. The connection to the pump drive shaft is via a one-way clutch. The transmission output is also connected to the pump drive shaft through a one-way clutch.

Pump drive mechanism

A retarder and friction brake system having vehicle service brakes and a shaft brake unit having a hydrodynamic retarder and friction brake. Manual brake controls provide for initial brake apply of the brake unit and then apply of the service brakes or independent apply of the service brakes. The brake unit has a dual chamber, hydrodynamic retarder with opposed bladed stators and a central rotor member having opposed bladed rotors mounted between the stator members for limited axial movement and rotation with a drum fixed to the shaft, and a friction brake having plates located concentrically within the retarder chambers on opposite sides of the rotor and splined to the drum and stators and a brake apply motor. In response to brake demand, the brake controls provide air pressure proportional to brake demand to the brake apply motor and fluid pressure proportional to brake demand and, in a low speed range limited to lower values with decreasing speed, to a brake chamber to provide a release pressure on the brake apply motor and flow through the constant restriction cooling passages in the brake plates to the retarder chambers for retarder braking and pumping through a cooler to provide with increasing speed in the low speed range, decreasing friction braking and increasing retarder braking having a total value proportional to brake demand, and in the higher speed range low friction braking and high retarder braking having a total value proportional to brake demand and increasing in a substantially straight line with increasing speed.

Retarder and friction brakes

A planetary gearing arrangement having a plurality of interconnected planetary gear sets controlled by friction drive establishing devices such as clutches and brakes for selectively establishing a plurality of forward drive ratios and a reverse drive ratio. The number of forward drive ratios available is one greater than the number of friction drive establishing devices. Each ratio change between the forward drives is accomplished by a single transition interchange of the friction drive establishing devices.

Planetary gearing arrangement for a transmission

A hydromechanical transmission in which the first and second drive ranges are input-split drives. In one embodiment the transmission includes a hydrostatic portion comprised of two hydraulically interconnected, variable displacement, hydraulic pump-motor units and two planetary gear sets which are controlled by a brake and a clutch to provide the two ranges. In another embodiment a third planetary gear set and a second clutch are added to provide increased torque coverage in first range and also provide a third drive range. In both embodiments the speed ratio within the drive ranges is varied by controlling the displacement ratio between the pump-motor units. The shifting from one drive range to another occurs at synchronous speeds, thereby reducing the shift energy absorption required in the clutches and brakes.

Input-split hydromechanical transmission

A planetary transmission having three substantially equal size simple planetary gear sets, two selectively operable clutches and three selectively operable brakes for providing four forward and two reverse speed ranges. The forward and reverse low ranges provide high torque multiplication for high tractive effort while the other forward ranges permit close step ratios for traveling speed operation of the vehicle.

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Indianapolis, IN, United States of America

James C Polak