Patent ID: 11891884
Assignee: TWIN DISC, INC.
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC E  F | IPC E  F

Claim 13:
14. A method of fracking a subterranean formation using a primary electric motor, the method including the steps of:
driving the primary electric motor with a starting motor;
driving a frac pump with an output of the primary electric motor to facilitate fracking the subterranean formation;
selectively delivering power from the primary electric motor to the frac pump using a transmission;
wherein the primary electric motor is a constant speed AC motor; and
wherein the starting motor is a hydraulic starting motor and the method further comprises the step of, in a starting mode, driving the hydraulic starting motor with a second electric motor, and rotating a motor shaft of the primary electric motor with the hydraulic starting motor to a first speed that corresponds to a fixed rated speed of the primary electric motor.