A hydraulic pump includes a work port configured to supply fluid to a hydraulic tool. A high-flow piston supplies fluid along a first flow path to the work port and plurality of high-pressure pistons supplies fluid along a second flow path to the work port. An unloading valve is positioned along the first flow path and actuates from an open state to a closed state when a pressure level of the fluid in the second flow path exceeds a first threshold pressure. A controller allows a user to select a mode of operation. The controller sets a second threshold pressure of the hydraulic pump based on the selected mode of operation, and the second threshold pressure corresponds to an end operation of the hydraulic tool.

Provided is a variable displacement pump which sucks and discharges a working fluid by moving a piston with a stroke in response to an inclination angle of a swash plate, the variable displacement pump including: a control piston which includes a columnar piston portion pressing the swash plate and adjusts the inclination angle of the swash plate between a maximal inclination angle in which a discharge capacity of the working fluid becomes maximal and a minimal inclination angle in which the discharge capacity of the working fluid becomes minimal; a piston accommodation portion which is formed in the housing and accommodates the piston portion; and a pressed portion which is disposed between the swash plate and the piston portion and is pressed toward the swash plate by the piston portion, in which when the inclination angle of the swash plate is an intermediate inclination angle in which the discharge capacity of the working fluid becomes an intermediate amount between the maximal amount and the minimal amount, a contact point between the piston portion and the pressed portion is located at a center portion including an axis center of the piston portion in an end surface on the side of the swash plate in the piston portion.

Provided is a variable displacement pump which sucks and discharges a working fluid by moving a piston with a stroke in response to an inclination angle of a swash plate, the variable displacement pump including: a control piston which includes a columnar piston portion pressing the swash plate and adjusts the inclination angle of the swash plate between a maximal inclination angle in which a discharge capacity of the working fluid becomes maximal and a minimal inclination angle in which the discharge capacity of the working fluid becomes minimal; a piston accommodation portion which is formed in the housing and accommodates the piston portion; and a pressed portion which is disposed between the swash plate and the piston portion and is pressed toward the swash plate by the piston portion, in which when the inclination angle of the swash plate is an intermediate inclination angle in which the discharge capacity of the working fluid becomes an intermediate amount between the maximal amount and the minimal amount, a contact point between the piston portion and the pressed portion is located at a center portion including an axis center of the piston portion in an end surface on the side of the swash plate in the piston portion.

A fluid flow meter comprising a fluid pump to displace fluid with pumping strokes of one or more pumping stroke types wherein each of the one or more stroke types displaces a known volume of fluid, a sensor functionally associated with a fluid reservoir and adapted to generate a signal indicative of a fluid pumping condition within the fluid reservoir, which fluid reservoir is integral or functionally associated with the pump, and circuitry to trigger one or a sequence of strokes of the pump in response to a signal from the sensor.

A fluid flow meter comprising a fluid pump to displace fluid with pumping strokes of one or more pumping stroke types wherein each of the one or more stroke types displaces a known volume of fluid, a sensor functionally associated with a fluid reservoir and adapted to generate a signal indicative of a fluid pumping condition within the fluid reservoir, which fluid reservoir is integral or functionally associated with the pump, and circuitry to trigger one or a sequence of strokes of the pump in response to a signal from the sensor.

A fluid flow meter comprising a fluid pump to displace fluid with pumping strokes of one or more pumping stroke types wherein each of the one or more stroke types displaces a known volume of fluid, a sensor functionally associated with a fluid reservoir and adapted to generate a signal indicative of a fluid pumping condition within the fluid reservoir, which fluid reservoir is integral or functionally associated with the pump, and circuitry to trigger one or a sequence of strokes of the pump in response to a signal from the sensor.

A hydraulic pump assembly for a vehicle is provided, comprising an electrical motor, a hydraulic pump driven by the electrical motor, and a centrifugal regulator connected with a pressure overflow valve connected to the oil outlet of the hydraulic pump, characterized in that the pump assembly further comprises at least two input check valves and at least two output check valves arranged such that a first pressure outlet port is formed when the motor is rotating in a first direction, and a second pressure outlet port is formed when the motor is rotating in an opposite direction.

A hydraulic pump includes a work port configured to supply fluid to a hydraulic tool. A high-flow piston supplies fluid along a first flow path to the work port and plurality of high-pressure pistons supplies fluid along a second flow path to the work port. An unloading valve is positioned along the first flow path and actuates from an open state to a closed state when a pressure level of the fluid in the second flow path exceeds a first threshold pressure. A controller allows a user to select a mode of operation. The controller sets a second threshold pressure of the hydraulic pump based on the selected mode of operation, and the second threshold pressure corresponds to an end operation of the hydraulic tool.

A hydraulic pump includes a work port configured to supply fluid to a hydraulic tool. A high-flow piston supplies fluid along a first flow path to the work port and plurality of high-pressure pistons supplies fluid along a second flow path to the work port. An unloading valve is positioned along the first flow path and actuates from an open state to a closed state when a pressure level of the fluid in the second flow path exceeds a first threshold pressure. A controller allows a user to select a mode of operation. The controller sets a second threshold pressure of the hydraulic pump based on the selected mode of operation, and the second threshold pressure corresponds to an end operation of the hydraulic tool.

A method of operating a hydraulic pump to provide fluid to a hydraulic tool for performing a work operation on a workpiece includes operating a high-flow piston to supply fluid from a tank to a work port via a first flow path and operating a high-pressure piston to supply fluid from the tank to the work port via a second flow path. An unloading valve is actuated to selectively couple the first flow path and the second flow path based on a first threshold pressure. An end of the work operation is determined based on a second threshold pressure.