Gear pump

About: Gear pump is a research topic. Over the lifetime, 7490 publications have been published within this topic receiving 38837 citations. The topic is also known as: Gear pump.

Fully variable output hydraulic gear pump having an axially translatable gear

Abstract: A fully variable output hydraulic pump includes a main casing having a fluid pumping chamber extending therethrough, fluid input ports and fluid output ports. The fluid pumping chamber is shaped to receive a pair of cylindrically shaped gears inserted axially therethrough. A first rotatable gear and second rotatable gear are insertable through the pumping chamber. The first and second gears are rotatably supported by respective means which are axially translatable relative to each other. A means for sealing the area between the gears and the main casing effectively creates a sealed fluid pumping chamber. By translating one of said means for rotatably supporting the gears, the effective fluid pumping volume within the fluid pumping chamber may be altered to provide a fully variable output hydraulic pump.

Numerical Analysis of the Shaft Motion in the Journal Bearing of a Gear Pump

Abstract: This paper describes a numerical analysis of the dynamics of the shaft in the journal bearing of a gear pump. The modulus and direction of the load is a function of the relative position of the gears, causing a precession motion around an equilibrium position. The mean load is the function of the working pressure of the gear pump. The numerical analysis presented in this paper combines the equation of motion of the journal-gear set, based on the linearization of the fluid film load, with calculation of the load due to the pressure distribution on the gears. The damping and stiffness coefficients for the motion equation are calculated with the distributions around the shaft of the pressure and its derivatives. These distributions are calculated from the Reynolds equations using an in-house 2D finite element code with quadrangular elements; the equation of motion is solved with a fifth-order Runge-Kutta scheme. The results provide the stabilized position of the shaft for certain conditions, and allow limitation of the working pressure and the angular velocity of the pump in order to minimize, or to avoid, metal-metal contact and consequent wear of material. The results are compared with experiments and previously reported numerical results.

Concrete pump hydraulic system for conveying high-viscosity concrete

Abstract: The utility model discloses a concrete pump hydraulic system for conveying high-viscosity concrete, which comprises a pumping system and a stirring system. The pumping system comprises a main oil pump, a first safety valve, a pressure relief valve, a first electro-hydraulic reversing valve, a second electro-hydraulic reversing valve, a main oil cylinder connected with the first electro-hydraulic reversing valve, a swinging oil cylinder connected with the second electro-hydraulic reversing valve, a first proximity switch arranged at the final position of the stroke of a main oil cylinder piston rod and a second proximity switch arranged at the final position of the stroke of a swinging oil cylinder piston rod. The stirring system comprises a gear pump, a second safety valve connected with the gear pump, a manual reversing valve and a stirring motor connected with the manual reversing valve. The main oil pump and the gear pump are driven by a power device. The hydraulic system can ensure the concrete pump to lead a distribution valve to act successfully when in high-strength concrete construction, realizes high-efficiency conveying of the high-strength concrete, and meets construction requirements.

Electro-hydrostatic actuator with a failsafe system

Abstract: An electro-hydrostatic actuator unit that contains a sealed pressurized housing filled with a dielectric fluid. A bi-directional motor is immersed in the fluid and drives a gear pump for exchanging fluid via a control circuit between the chambers of a bi-directional hydraulic actuator in response to an input from a controller. The chambers are separated by a piston and a piston rod is connected to an external load such as a plunger type valve. A failsafe circuit is also provided which is arranged to override the control circuit in the event a failsafe condition is detected by the unit controller. The failsafe circuit contains a motor driven pump that provides high pressure fluid from the pressurized reservoir to an accumulator. Valves are arranged to shut down the control circuit and deliver fluid from the accumulator to one of the cylinder chambers to rapidly move the actuator to a desired failsafe position. Both motor drive pumps, the actuator, cylinder, and the controller are fully immersed in the fluid reservoir.

Hydrostatic self-regulating drive system

Abstract: A hydrostatic drive system has an internal combustion engine, a main pump driven by the engine and having a control element displaceable to vary the pump displacement, a control pump driven by the engine, an output motor having a control element displaceable to vary the motor displacement and having a rotary output, and conduits interconnecting the main pump and output motor for driving of the motor by the pump A speed-measuring pump is connected to the motor output and produces a pressure differential corresponding to the speed of the motor output A pump controller is powered by the control pump and connected to the pump control element for adjusting the pump displacement A motor controller is connected to the motor control element for adjusting the motor displacement An engine controller includes a first engine cylinder connected to the speed-measuring motor and operable thereby for adjusting the engine speed and a second engine cylinder connected to the control pump and operable thereby for affecting engine speed