A pump with two independent motors is disclosed. The first motor is mechanically connected to a first rotor comprising a first plurality of teeth radiating from the center of the first rotor. The second motor is mechanically connected to a second rotor comprising a second plurality of teeth radiating from the center of the first rotor, wherein the first plurality meshes with the second plurality. A sealed case may house the first and second rotors, and the case may include a suction inlet and a pressure outlet. Rotating the rotors propels a liquid from the suction inlet to the pressure outlet. Because the motors are independent of each other, when one motor fails to rotate the other motor will rotate both rotors and maintain the propelling liquid from the suction inlet to the pressure outlet. The pump may be a gear pump or a rotary lobe pump.

An external gear pump includes a pump housing in which a pump chamber is formed, a primary gear having a plurality of external teeth housed in the pump chamber, a secondary gear having a plurality of external teeth that mesh with the plurality of external teeth of the primary gear in the pump chamber, a first electric motor configured to generate a torque for rotationally driving the primary gear, a second electric motor configured to generate a torque for rotationally driving the secondary gear, and a control unit configured to control the first and second electric motors. The control unit controls the first and second electric motors so that the torque generated by the first electric motor is greater than the torque generated by the second electric motor.

A fluid system includes a variable-speed and/or a variable-torque pump to pump a fluid, at least one proportional control valve assembly, an actuator that is operated by the fluid to control a load, and a controller that establishes a speed and/or torque of the pump and a position of the at least one proportional control valve assembly. The pump includes at least one fluid driver that provides fluid to the actuator, which can be, e.g., a fluid-actuated cylinder, a fluid-driven motor or another type of fluid-driven actuator that controls a load. Each fluid driver includes a prime mover and a fluid displacement assembly. The fluid displacement assembly can be driven by the prime mover such that fluid is transferred from the inlet port to the outlet port of the pump.

A hydraulic system includes a hydraulic gear pump with a first gear having a plurality of first gear teeth and a second gear having a plurality of second gear teeth. The hydraulic system also includes a control valve and a control circuit. The control circuit controls the pump to adjust at least one of a flow in the hydraulic system to a flow set point or a pressure in the hydraulic system to a pressure set point, and concurrently establishes an opening of the control valve to adjust at least one of the flow to the flow set point or the pressure to the pressure set point. The control circuit establishes a position of a first tooth relative to a position of a second tooth to seal a fluid path from the outlet of the hydraulic gear pump to the inlet of the hydraulic gear pump.

A fluid-driven actuator system includes a fluid-driven actuator and at least one proportional control valve and at least one pump connected to the fluid-driven actuator to provide fluid to operate the fluid-driven actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The fluid driven actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to adjust at least one of a flow in the fluid system to a flow set point and a pressure in the fluid system to pressure set point and a concurrently establishes an opening of the at least one proportional control valve to adjust at least one of the flow to the flow set point and the pressure to the pressure set point.

A fluid system includes a variable-speed and/or a variable-torque pump to pump a fluid, at least one proportional control valve assembly, an actuator that is operated by the fluid to control a load, and a controller that establishes a speed and/or torque of the pump and a position of the at least one proportional control valve assembly. The pump includes at least one fluid driver that provides fluid to the actuator, which can be, e.g., a fluid-actuated cylinder, a fluid-driven motor or another type of fluid-driven actuator that controls a load. Each fluid driver includes a prime mover and a fluid displacement assembly. The fluid displacement assembly can be driven by the prime mover such that fluid is transferred from the inlet port to the outlet port of the pump.

A fluid-driven actuator system includes a fluid-driven actuator and at least one proportional control valve and at least one pump connected to the fluid-driven actuator to provide fluid to operate the fluid-driven actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The fluid-driven actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to adjust at least one of a flow in the fluid-driven system to a flow set point and a pressure in the fluid-driven actuator system to a pressure set point and concurrently establishes an opening of the at least one proportional control valve to adjust at least one of the flow to the flow set point and the pressure to the pressure set point.

A pumping system and method for operating a pumping system including a motor coupled to a variable speed drive to drive a pump. A torque indicator corresponding to the torque presented to the drive is determined. The torque indicator may be used to detect a fault if it exceeds a baseline torque, or to detect a defective transducer, or to detect a system change by perturbing one parameter and comparing another to a predicted value.

A control method is used with a control system to control a screw pump. The control system includes an electric motor and a motor drive. The control method includes following steps. Firstly, a DC bus voltage is monitored. If the DC bus voltage is smaller than a first threshold value, a potential energy stored in the pump screw and released by a backspin action is converted into a regenerative electrical energy so as to maintain a normal operation of the motor drive. Then, the motor drive drives the electric motor to control the backspin action of the screw pump according to a backspin torque limit strategy. If the electrical power from the power source is not restored and the level of a reverse regenerative torque is smaller than a preset torque value, the backspin action of the screw pump is stopped freely.

A rotary-vane internal combustion engine of the cat and mouse or scissor type with coordinated rotation of two co-axial shafts with position sensors creating chambers of variable volume for intake, compression, power and exhaust strokes. A reversible electric generator motor on at least one of the shafts with an electronic control system for current, an energy storage unit and electrical load. The total work done and angular speed is calculated or empirically determined while an alternating accelerating or decelerating torque is applied for a continuous, uniform rotation cycle.