Hydrostatic transmission assembly and system

A fluid-driven motor system comprising:

• a fluid-driven motor;
• at least one pump assembly conjoined with the fluid-driven motor, the at least one pump assembly to provide fluid to rotate the fluid-driven motor, each pump assembly including,
• a pump with at least one fluid driver comprising a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from an inlet port of the pump to an outlet port of the pump and to the fluid-driven motor to rotate the fluid-driven motor, and
• a control valve in fluid communication with the pump and disposed on a downstream side of the outlet port;
• and
• a controller that establishes at least one of a speed or a torque of the at least one prime mover so as to maintain at least one of a flow in the fluid-driven motor system at a flow set point or a pressure in the fluid-driven motor system at a pressure set point and concurrently establishes an opening of the control valve so as to maintain at least one of the flow in the fluid-driven motor system at the flow set point or the pressure in the fluid-driven motor system at the pressure set point,
• wherein the at least one fluid driver includes a first fluid driver with a first prime mover and a first fluid displacement member, and a second fluid driver with a second prime mover and a second fluid displacement member,
• wherein the first prime mover rotates the first fluid displacement member in a first direction to transfer the fluid to the hydraulic motor,
• wherein the second prime mover rotates the second fluid displacement member, independently of the first prime mover, in a second direction to transfer the fluid to the hydraulic motor, and
• wherein the first prime mover and the second prime mover are controlled so as to synchronize contact between the first and second fluid displacement members.

A method for controlling a fluid flow in a fluid system, the fluid system including a fluid pump having a casing and at least one control valve in fluid communication with the fluid pump, the fluid pump to provide fluid to a fluid-driven motor that controls a load, the fluid pump including at least one fluid driver, each fluid driver having a prime mover and a fluid displacement assembly with a fluid displacement member, the method comprising:

• initiating operation of the fluid pump to provide the fluid to the fluid-driven motor;
• rotating the fluid-driven motor using the fluid from the fluid pump;
• establishing at least one of a speed or a torque of the at least one prime mover so as to maintain at least one of a flow in the fluid system at a flow set point or a pressure in the fluid system at a pressure set point and concurrently establishing an opening of the at least one control valve so as to maintain at least one of the fluid flow in the fluid system at the flow set point or the pressure in the fluid system at the pressure set point,
• rotating a first prime mover of the at least one fluid driver to rotate a first fluid displacement member about a first axial centerline in a first direction to transfer a fluid from an inlet port to an outlet port;
• rotating a second prime mover of the at least one fluid driver, independently of the first prime mover, to rotate a second fluid displacement member about a second axial centerline in a second direction to transfer the fluid from the inlet port to the outlet port;
• and
• synchronizing contact between the first fluid displacement member and the second fluid displacement member to seal a fluid path between the outlet port and the inlet port such that a slip coefficient is 5% or less.