Transfer case

Abstract: The present invention is directed to an improved "on-demand" power transfer system of the type having a transfer mechanism incorporated into the driveline of a four-wheel drive vehicle. The transfer mechanism is arranged to deliver drive torque to the driven wheels so as to establish a two-wheel drive mode of operation. In addition, the transfer mechanism is equipped with a clutch assembly for selectively delivering drive torque to the non-driven wheels for establishing a four-wheel drive mode of operation. The transfer mechanism is further equipped with a rotary actuator mechanism for actuating the clutch assembly. The rotary actuator mechanism is preferably mounted directly to the transfer mechanism to substantially minimize the packaging requirements associated with the on-demand power transfer system while concomitantly enhancing in-service reliability and allowing pre-assembly of the transfer mechanism prior to final installation into the vehicle driveline. The power transfer system further includes sensors for detecting various dynamic and operational characteristics of the vehicle and generating sensor input signals indicative thereof, and a controller for controlling actuation of the rotary actuator means in response to the sensor input signals.

Abstract: A power transfer system is disclosed for a four-wheel drive vehicle operable for permitting a vehicle operator to select between various full-time and part-time four-wheel drive modes. The power transfer system includes a transfer case equipped with a dual-planetary gear reduction unit and a synchronized range shift mechanism operable for permitting the vehicle operator to shift on-the-fly for establishing full-time and part-time high-range and low-range four-wheel drive modes. The transfer case is also equipped with an electronically-controlled slip limiting/torque-biasing arrangement including an interaxle differential and a transfer clutch operable for controlling the magnitude of speed differentiation and torque biasing across the interaxle differential.

Abstract: Four wheel drive train including a transfer case adapted to provide full time four wheel drive. A differential is provided in the transfer case and includes both a viscous coupling and a viscous fluid operated mechanical clutch which may be operated to inhibit and prevent differentiation.

Abstract: An automated twin-clutch multi-speed transmission is disclosed for use in a four-wheel drive vehicle. The transmission includes a first engine clutch operable to establish a releasable drive connection between the engine and a first input shaft, a first motor/generator connected to the first input shaft, a second engine clutch operable to establish a releasable drive connection between the engine and a second input shaft, a second motor/generator connected to the second input shaft, a mainshaft, and a geartrain for selectively establishing a plurality of forward and reverse speed ratio drive connections between the input shafts and the mainshaft. The transmission further includes power-operated dog clutches for selectively engaging constant-mesh gearsets associated with the geartrain, and a transmission controller for controlling coordinated actuation of the first and second engine clutches, the first and second motor-generators, and the power-operated dog clutches to permit non-power interrupted (“powershift”) sequential gear changes automatically without input from the vehicle operator. An interaxle differential transfers drive torque from the mainshaft to the front and rear drivelines to establish a full-time four-wheel drive mode.