A fluid pump includes a cam plate that defines an interior cam surface having an eccentric portion and a narrow portion. A hub rotates within the interior cam surface and has a piston cavity that is in communication with an inlet port and an outlet port. A piston member is operably received within the piston cavity to define a suction phase within the eccentric portion and a pressure phase within the narrowed portion. The piston member is biased outward by rotational operation of the hub. During the suction phase, the piston member is biased away from the piston cavity to define a flow cavity that draws fluid from the inlet port. During the pressure phase, the piston member is biased by the narrowed portion into the flow cavity to push the fluid from the flow cavity toward the outlet port.

A pump may generally include a frame including a reservoir. The reservoir stores a hydraulic fluid. The pump may also include a motor assembly supported by the frame and a pump assembly operably driven by the motor assembly. The pump assembly is in fluid communication with the reservoir and configured to dispense the hydraulic fluid out of the frame. The pump assembly includes a first piston and a second piston, wherein the first piston dispenses hydraulic fluid out of the frame between a first pressure and a second pressure greater than the first pressure, and the second piston dispenses hydraulic fluid out of the frame between the first pressure and a third pressure, the third pressure being greater than the second pressure.

A hydraulic pump includes a work port, a high-flow piston, multiple high-pressure pistons, and an unloading valve. The work port couples to a fluid supply line of a hydraulic tool. The high-flow piston supplies fluid along a first flow path to the work port. The high-pressure pistons supply fluid along a second flow path to the work port. The unloading valve is fluidly coupled to the first flow path and the second flow path, and actuatable between an open state and a closed state. The unloading valve is configured to (i) permit fluid to flow from the high-flow piston to the work port in the open state, (ii) inhibit fluid from flowing from the high-flow piston to the work port in the closed state, and (iii) actuate from the open state to the closed state when a pressure of the fluid in the second flow path exceeds a threshold pressure.

A pressure adjustment apparatus including a pump, a selector valve coupled to the pump, and a chamber in selective fluid communication with the pump through the selector valve is disclosed. The pump includes a pump body that defines a variable volume therein, the pump body further defining a first aperture and a second aperture therethrough. The selector valve includes a first check valve disposed in a first fluid channel of a plurality of fluid channels, the first check valve being oriented to permit flow through the first fluid channel only in a first flow direction, the first flow direction being a flow direction out of the variable volume, and a second check valve disposed in a second fluid channel of the plurality of fluid channels, the second check valve being oriented to permit flow through the second fluid channel only in a second flow direction.

The valve for the minimum waste concrete pump, object of the present invention, comprises a valve for the minimum waste concrete pump that comprises a double-piston alternative-type pump valve provided with an inlet conduit (20) and a discharge conduit (30) installed inside the valve container (10) and arranged next to a concrete reception hopper located above the container, allowing to pump concrete and other pasty substances, such as: sludge, mining residues, grout, mortar, dirty water, and similar. The embodiment of the valve generates the minimum of waste retained after the equipment operation, improving the durability and efficiency of use of the pumps, besides reducing the cleaning time, resulting in a great reduction of operational costs, avoiding the unnecessary displacement of the pump equipment to the central. In addition, this new embodiment results in a valve performing a linear translation movement that reduces component wear and minimizes the need for maintenance on the equipment, as its embodiment does not require constant lubrication.

An electric pump device includes a single motor, a pump that discharges fluid from a discharge port with driving force of the motor, and a flow passage switch that includes outlets configured to be in communication with the discharge port and switches an outlet of the outlets that is in communication with the discharge port with driving force of the motor.

A pump may generally include a frame including a reservoir. The reservoir stores a hydraulic fluid. The pump may also include a motor assembly supported by the frame and a pump assembly operably driven by the motor assembly. The pump assembly is in fluid communication with the reservoir and configured to dispense the hydraulic fluid out of the frame. The pump assembly includes a first piston and a second piston, wherein the first piston dispenses hydraulic fluid out of the frame between a first pressure and a second pressure greater than the first pressure, and the second piston dispenses hydraulic fluid out of the frame between the first pressure and a third pressure, the third pressure being greater than the second pressure.

A pressure adjustment apparatus including a pump, a selector valve coupled to the pump, and a chamber in selective fluid communication with the pump through the selector valve is disclosed. The pump includes a pump body that defines a variable volume therein, the pump body further defining a first aperture and a second aperture therethrough. The selector valve includes a first check valve disposed in a first fluid channel of a plurality of fluid channels, the first check valve being oriented to permit flow through the first fluid channel only in a first flow direction, the first flow direction being a flow direction out of the variable volume, and a second check valve disposed in a second fluid channel of the plurality of fluid channels, the second check valve being oriented to permit flow through the second fluid channel only in a second flow direction.

A pressure adjustment apparatus including a pump, a selector valve coupled to the pump, and a chamber in selective fluid communication with the pump through the selector valve is disclosed. The pump includes a pump body that defines a variable volume therein, the pump body further defining a first aperture and a second aperture therethrough. The selector valve includes a first check valve disposed in a first fluid channel of a plurality of fluid channels, the first check valve being oriented to permit flow through the first fluid channel only in a first flow direction, the first flow direction being a flow direction out of the variable volume, and a second check valve disposed in a second fluid channel of the plurality of fluid channels, the second check valve being oriented to permit flow through the second fluid channel only in a second flow direction.

An electric pump device includes a single motor, a pump that discharges fluid from a discharge port with driving force of the motor, and a flow passage switch that includes outlets configured to be in communication with the discharge port and switches an outlet of the outlets that is in communication with the discharge port with driving force of the motor.