Hydraulic system for engine starter and generator
AssigneeCummins Inc.
InventorJohn P. O'Brien
Life of this patent
Estimating the term…
Abstract
A hydraulic engine system includes a first hydraulic pump-motor coupled to an engine and a second hydraulic pump-motor coupled to an electric machine. A hydraulic link fluidly connects the first and the second hydraulic pump-motors. During a cranking operation mode, the electric machine operates as a motor and transfers power via the second hydraulic pump-motor, the hydraulic link and the first hydraulic pump-motor to provide cranking torque to the engine. During a generator operation mode, the power generated by the engine is transferred via the first hydraulic pump-motor, the hydraulic link, and the second hydraulic pump-motor to the electric machine, operating as a generator, to generate electricity.
Claims22
A hydraulic drive system coupled to an engine and to an electric motor-generator, comprising:
- a first hydraulic pump-motor mechanically coupled to the engine;
- a second hydraulic pump-motor mechanically coupled to the electric motor-generator;
- a hydraulic link carrying hydraulic fluid, the hydraulic link coupled between the first hydraulic pump-motor and the second hydraulic pump-motor, the hydraulic link configured to transfer hydraulic fluid between the first hydraulic pump-motor and the second hydraulic pump-motor;
- and
- a controller coupled to the first hydraulic pump-motor and the second hydraulic pump-motor, the controller configured to:
- initiate a cranking mode by operating the second hydraulic pump-motor as a pump, and operating the first hydraulic pump-motor as a motor, and
- initiate a generating mode by operating the first hydraulic pump-motor as a pump, and operating the second hydraulic pump-motor as a motor.
A controller communicably coupled to a first hydraulic pump-motor, which is mechanically coupled to an engine, and to a second hydraulic pump-motor, which is mechanically coupled to an electric motor-generator, the controller comprising:
- cranking initiation circuitry structured to operate the first hydraulic pump-motor as a motor and to operate the second hydraulic pump-motor as a pump to transfer energy from the electric motor-generator to a crank shaft of the engine via the second hydraulic pump-motor and the first hydraulic pump-motor;
- and
- generator initiating circuitry structured to operate the first hydraulic pump-motor as a pump and to operate the second hydraulic pump-motor as a motor to transfer energy from the engine to a drive shaft of the electric motor-generator via the first hydraulic pump-motor and the second hydraulic pump-motor.
An apparatus comprising:
- an internal combustion engine;
- a first hydraulic pump-motor coupled to the internal combustion engine;
- an electric motor generator;
- a second hydraulic pump-motor coupled to the electric motor generator;
- a hydraulic link fluidly coupling the first hydraulic pump-motor and the second hydraulic pump-motor;
- at least one accumulator coupled to the hydraulic link, the at least one accumulator configured to selectively store energy from, and provide energy to, the hydraulic link;
- and
- a controller comprising:
- a cranking initiation circuitry structured to operate the first hydraulic pump-motor as a motor and to operate the second hydraulic pump-motor as a pump to transfer energy from the electric motor-generator to a crank shaft of the internal combustion engine via the second hydraulic pump-motor and the first hydraulic pump-motor, and to operate the at least one accumulator to provide energy to the internal combustion engine via the hydraulic link and the first hydraulic pump-motor,
- a generator initiating circuitry structured to operate the first hydraulic pump-motor as a pump and to operate the second hydraulic pump-motor as a motor to transfer energy from the internal combustion engine to a drive shaft of the electric motor-generator via the first hydraulic pump-motor and the second hydraulic pump-motor.
Dependencies are inferred from the claim text.