A rotary positive displacement pump comprising a pair of forwardly-positioned sealing arrangements and a pair of forwardly-positioned sleeves are received within a cavity providing for easy maintenance of the pump when the seals need to serviced. Each of the sealing arrangement includes a dynamic seal and a static seal. The dynamic seal abuts a corresponding sleeve and hub while a static seal is established between the corresponding sleeve and rotor.

A fluid transfer pump that has a housing, a body portion movable within the housing between a first position and a second position, a gear coupled to the housing, a body cavity defined partially between the body portion and the housing, and an aperture defined in the housing that selectively provides a fluid to the body cavity. When the fluid is applied to the body cavity at or above a pilot pressure, the body portion is in the first position adjacent to the gear and when the fluid is applied to the body cavity at a fluid pressure lower than the pilot pressure, the body portion is in the second position and spaced from the gear.

A fluid transfer pump that has a housing, a body portion movable within the housing between a first position and a second position, a gear coupled to the housing, a body cavity defined partially between the body portion and the housing, and an aperture defined in the housing that selectively provides a fluid to the body cavity. When the fluid is applied to the body cavity at or above a pilot pressure, the body portion is in the first position adjacent to the gear and when the fluid is applied to the body cavity at a fluid pressure lower than the pilot pressure, the body portion is in the second position and spaced from the gear.

The present invention relates to a fixed displacement pump for use for conveying a hydraulic fluid in a closed hydraulic circuit, a closed hydraulic circuit, a construction machine and a method for operating a fixed displacement pump in a closed hydraulic circuit.

A commutator/manifold assembly controls a flow of hydraulic fluid in a hydraulic fluid system. The assembly includes a commutator having an offset design including an inner portion eccentrically encompassed within an outer portion, and offset commutator porting to control the hydraulic flow. A manifold includes manifold ports having a straight configuration by which walls defining the manifold ports run substantially along a longitudinal axis through an entirety of the manifold. The commutator is configured to rotate to sequentially align the commutator porting with differing portions of the manifold ports to control the flow. The commutator porting includes inner ports and outer ports that are isolated from each other by a commutator seal. A commutator ring has a guiding surface that guides rotation of the commutator. The rotation of the commutator provides a timed flow through the manifold ports straight through the manifold and without any directional flow restriction.

The invention relates to a system comprising an electric machine, where in the electric machine has a first shaft and a hydraulic unit, wherein the hydraulic unit has a second shaft, wherein the first shaft and the second shaft are connected to one another to form a shaft-hub connection, the shaft-hub connection has a central recess and the shaft-hub connection is connected fluidically to the interior of the hydraulic unit for lubrication.

A flexible impeller pump designed for use in dispensing a flowable food products. The flexible impeller pump includes a cover, impeller assembly and a pump body that are assembled to create the pump without other separate components. The components can be permanently connected to each other to create a disposable pump or can be disassembled for cleaning and reuse. The impeller assembly includes an impeller shaft and a flexible impeller molded over the impeller shaft to prevent separation. The impeller assembly is received within the pump body and the cover is secured to the pump body. The cover includes a seal that is molded over the pump body to prevent separation of the seal from the cover. The impeller shaft extends through the pump body and is coupled to a drive shaft of an electric motor that is operable to drive the impeller pump.

A gerotor pump assembly, and a system and method for operating a gerotor pump assembly, result in a lubrication strategy for operating in a loss-of-prime mode. An inner drive gear may be rotated in a first direction and in a second opposite direction about an axis of rotation. The inner drive gear has a number of projections extending outwardly therefrom. An outer driven gear surrounds the inner drive gear and defines a number of recessions along an inner surface configured to engage with the projections of the inner drive gear. The outer driven gear and the inner drive gear further define at least one dynamically-changing fluid cavity therebetween. The inner drive gear and the outer driven gear define an oil transfer volume clearance between a projection and a recession in a fully engaged position. Oil is maintained within the oil transfer volume clearance as the inner drive gear is rotated.

A pump bearing including a top face, a side face peripherally surrounding the top face, a bottom face opposed to the top face, a first bearing bore projecting from the top face to the bottom face, an edge defined where the top face meets the side face, and an asymmetric pressure balance groove defined within a portion of the edge of the top face and the side face defining first depth from the top face.

Seal systems are provided that use a variety of seals to seal fluid processing apparatuses, such as gear pumps, to facilitate the prevention of a leakage of fluids from the respective fluid processing apparatuses. Fluid apparatuses that use such seal systems are also provided. Methods of uses, making, and assembly of seal systems are further described herein.