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US 4,555,978 AGranted
Multiple displacement motor driven power drive unit
AssigneeSundstrand Corporation
InventorsWesley A. Burandt, Allyn M. Aldrich
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AssigneeSundstrand Corporation
InventorsWesley A. Burandt, Allyn M. Aldrich
Estimating the term…
A multiple displacement motor driven power drive unit having two separate hydraulic systems each with a variable displacement hydraulic motor having its output connected to a torque summing gear train. A control provides for operation of one or the other of the motors at full displacement while the other motor is at zero displacement and free-wheels. There is a manual mechanical control operation with both motors simultaneously set at one-half of full displacement and driving the torque summing gear train. The change in motor displacements to one-half full displacement accomplishes velocity summing within the hydraulics. The multiple displacement motor driven power drive unit accomplishes the power efficiency of a multiple motor driven power drive unit utilizing a speed summing gear train with fixed displacement motors, but without the complexities associated with the use of a speed summing gear train and brakes.
A multiple displacement motor driven power drive unit utilizing a torque summing gear train having an output for driving a member and plural motor inputs and wherein the unit operates with the power efficiency of a velocity summing gear train driven by plural motors comprising, a pair of variable displacement hydraulic motors in separate independent hydraulic circuits and each connected to an input side of said torque summing gear train, each of said variable displacement hydraulic motors having an adjustable wobbler plate for setting motor displacement at or between zero and full displacement, interconnecting means fixing the relation between said wobbler plates whereby when one wobbler plate is at full displacement-setting position the other wobbler plate is at zero displacement-setting position, and means for establishing three different conditions of said interconnecting means wherein in two of said conditions one or the other of the wobbler plates is at full displacement-setting position and in the third condition both of the wobbler plates are positioned to set one-half of full displacement of the motors.
A multiple displacement motor driven power drive unit for driving a member comprising, a pair of variable displacement hydraulic motors having their output shafts operatively connected to said member, each of said motors having an adjustable device for setting motor displacement, means interconnecting said adjustable devices and having three operative settings, said operative settings including a first setting wherein one motor is at full displacement and the other motor is at zero displacement, a second setting in which the displacement of the motors is reversed, and a third setting wherein both motors are at one-half full displacement, and means for controlling the operative setting of said interconnecting means.
A multiple displacement motor driven power drive unit for driving a member comprising, a torque summing gear train connected to said member, a pair of variable displacement hydraulic motors each having an output shaft connected to said torque-summing gear train and a wobbler plate positionable to set the displacement of the associated motor, an independent hydraulic circuit for each motor, means for setting either of said motors to full displacement and supplying pressure fluid thereto while simultaneously setting the other of said motors to zero displacement and blocking supply of pressure fluid to said other motor to have the motor at full displacement drive the member while said other motor free-wheels, and means for setting both motors at one-half of full displacement and supplying pressure fluid to both motors to have both motors drive the member through the torque-summing gear train, and said means for setting displacement of the motors includes a link connecting the wobbler plates of the motors and a control piston operatively connected to the link.
A multiple displacement motor driven power drive unit comprising:
Dependencies are inferred from the claim text.