Patent ID: 8890350

Claim:
An arrangement for driving a turbomachine having a rotor, the arrangement comprising: an input shaft rotationally coupled to the rotor; a motor generator device, the motor generator device having a motor mode of operation and a generator mode of operation; a differential gear device having a first portion rotationally and directly coupled to the input shaft and a second portion rotationally and directly coupled to the motor generator device; a hydraulic assembly having a third portion rotationally and directly coupled to the first portion opposite the motor generator device and a fourth portion rotationally and directly coupled to the second portion opposite the motor generator device, the hydraulic assembly having a plurality of pistons and a pair of wobbler plates coupled between the third portion and the fourth portion, the pair of wobbler plates being in a first position in the motor mode of operation, wherein the first position provides a maximum piston displacement in the plurality of pistons, wherein one of the pair of wobbler plates is configured to move to a second position during the motor mode of operation to limit a hydraulic pressure within the hydraulic assembly; wherein the pair of wobbler plates includes a first wobbler plate and a second wobbler plate, the first wobbler plate being configured to adjust a stroke of the first plurality of pistons and the second wobbler plate being configured to adjust the stroke of the second plurality of pistons; and a controller operably coupled to the input shaft, the motor generator device and the hydraulic assembly, wherein the controller includes a processor that is responsive to executable instructions when executed on the processor for moving the second wobbler plate to reduce a displacement of the second plurality of pistons to limit pressure levels within the hydraulic assembly.