A hydraulic pump includes a cylinder block, a plurality of pistons, a swash plate, a first pressing unit, and a second pressing unit. The cylinder block has a plurality of cylinder bores and is disposed so as to be rotatable. Each of the plurality of pistons is retained in associated one of the cylinder bores so as to be movable. The swash plate is configured for controlling the amount of movement of the plurality of pistons in accordance with the size of the tilt angle. The first pressing unit is configured for pressing the swash plate in such a direction as to reduce the tilt angle of the swash plate. The second pressing unit is configured for pressing the swash plate in such a direction as to increase the tilt angle of the swash plate by a pressure supplied from the outside of the hydraulic pump.

A hydraulic pump includes a cylinder block, a plurality of pistons, a swash plate, a first pressing unit, and a second pressing unit. The cylinder block has a plurality of cylinder bores and is disposed so as to be rotatable. Each of the plurality of pistons is retained in associated one of the cylinder bores so as to be movable. The swash plate is configured for controlling the amount of movement of the plurality of pistons in accordance with the size of the tilt angle. The first pressing unit is configured for pressing the swash plate in such a direction as to reduce the tilt angle of the swash plate. The second pressing unit is configured for pressing the swash plate in such a direction as to increase the tilt angle of the swash plate by a pressure supplied from the outside of the hydraulic pump.

In accordance with at least one aspect of this disclosure, a variable displacement pump system can include, a variable displacement pump disposed in a main line and configured to supply pressure to receive a low pressure fluid and to output a high pressure fluid. The main line can connect a hydraulic fluid source to a plurality of system actuators, where the variable displacement pump is disposed in the main line between the hydraulic fluid source and the plurality of system actuators to pressurize the hydraulic fluid.

In accordance with at least one aspect of this disclosure, a variable displacement pump system can include, a variable displacement pump disposed in a main line and configured to supply pressure to receive a low pressure fluid and to output a high pressure fluid. The main line can connect a hydraulic fluid source to a plurality of system actuators, where the variable displacement pump is disposed in the main line between the hydraulic fluid source and the plurality of system actuators to pressurize the hydraulic fluid.

An axial piston machine has a swash plate and an adjusting device having an adjusting cylinder and a double-acting adjusting piston which is longitudinally movable in the adjusting cylinder and includes a piston and a piston rod, which is fixedly connected to the piston and is articulated to the swash plate. The joint between the adjusting piston and the swash plate is a movable swivel joint having a joint body receptacle on one part and a joint body on the other part of the adjusting piston and the swash plate. The joint body is closely guided in the joint body receptacle in the direction of movement of the adjusting piston, is rotatable about an axis of rotation running parallel to the pivot axis of the swashplate, and is movable with a directional component perpendicular to the direction of movement of the adjusting piston and perpendicular to the axis of rotation.

An axial piston machine has a swash plate and an adjusting device having an adjusting cylinder and a double-acting adjusting piston which is longitudinally movable in the adjusting cylinder and includes a piston and a piston rod, which is fixedly connected to the piston and is articulated to the swash plate. The joint between the adjusting piston and the swash plate is a movable swivel joint having a joint body receptacle on one part and a joint body on the other part of the adjusting piston and the swash plate. The joint body is closely guided in the joint body receptacle in the direction of movement of the adjusting piston, is rotatable about an axis of rotation running parallel to the pivot axis of the swashplate, and is movable with a directional component perpendicular to the direction of movement of the adjusting piston and perpendicular to the axis of rotation.

What is suggested is a micromembrane pumping device for pumping a fluid, having: a pump chamber to which an inlet valve, an outlet valve, and a membrane device for varying a volume of the pump chamber are associated, wherein the membrane device has a plate-shaped actuator for deforming the membrane device; and influencing means for influencing the plate-shaped actuator and the volume of the pump chamber; wherein the membrane device has a plate-shaped membrane body limiting the pump chamber; wherein the plate-shaped actuator is arranged on a side of the plate-shaped membrane body facing away from the pump chamber; wherein the plate-shaped actuator is mounted to and electrically insulated from the plate-shaped membrane body by an electrically insulating glue layer; wherein at least one embedded portion of a support body at or in which a deformation sensor for detecting a deformation of the membrane device is arranged, is arranged within the glue layer to detect the volume of the pump chamber; wherein the influencing means, the plate-shaped actuator and the deformation sensor form a closed-loop control circuit for regulating a volume flow.

A valve piston pump body device of water flosser includes a front bracket shell equipped with a back bracket shell. A pump body is installed at the middle-upper end of the cavity between the front bracket shell and the back bracket shell. A motor is installed at the middle-lower end of the cavity between the front bracket shell and the back bracket shell. The rotating shaft at the upper end of the motor is equipped with motor teeth. A first metal shaft is arranged in the hole of the cavity between the front bracket shell and the back bracket shell. A driving gear is installed on the first metal shaft and the driving gear and the motor teeth are mutually engaged. A one-way valve piston device is used.

Systems and methods for controlling a pump system for use in negative pressure wound therapy are described herein. In some embodiments, a method for controlling a pump system includes causing provision of negative pressure, via a flow path, to a wound dressing configured to be positioned over a wound, the flow path configured to fluidically connect the pump system to the wound dressing, measuring a first pressure value in the flow path at a first time, measuring a second pressure value in the flow path at a second time, calculating a first rate of pressure change using the first and second pressure values, and in response to determining that the calculated first rate of pressure change satisfies a threshold rate of change, providing an indication that the wound dressing is full, wherein the method is performed under control of a controller of the pump system.

Systems and methods for controlling a pump system for use in negative pressure wound therapy are described herein. In some embodiments, a method for controlling a pump system includes causing provision of negative pressure, via a flow path, to a wound dressing configured to be positioned over a wound, the flow path configured to fluidically connect the pump system to the wound dressing, measuring a first pressure value in the flow path at a first time, measuring a second pressure value in the flow path at a second time, calculating a first rate of pressure change using the first and second pressure values, and in response to determining that the calculated first rate of pressure change satisfies a threshold rate of change, providing an indication that the wound dressing is full, wherein the method is performed under control of a controller of the pump system.