A rotary pump for a fluid metering system is provided. The rotary pump reciprocates, and is reversed by a signal from a limit switch that is deflected by an actuator arm on a rotating sleeve of the pump system.

A rotary pump for a fluid metering system is provided. The rotary pump reciprocates, and is reversed by a signal from a limit switch that is deflected by an actuator arm on a rotating sleeve of the pump system. The rotary pump includes a plunger and optional stopper formed from a two-shot molding process, and including seals overmolded onto the head of the plunger and the head of the optional stopper.

The present disclosure provides a two-dimensional motor combination piston pump by combining two independent two-dimensional piston pumps into one structure to achieve parallel outputting. The combination piston pump includes a two-dimensional motor and a two-dimensional piston pump. The outer rotator serves as the piston and the flow distribution mechanism of the two-dimensional piston pump. While operating, outer rotator rotates and moves axially. By combining two independent two-dimensional piston pumps into one structure to achieve parallel outputting, the combined piston pump has a greater work-to-weight ratio. The two-dimensional motor and the two-dimensional piston pump may share some structures in common, allowing the structure of the combination piston pump to be compact.

An electronic angle adjustment mechanism for a pump and a motor generally includes a base and a linear actuator. The base has an upper portion mounted to a motor, a lower portion mounted to a pump, and a hinge for pivotably moving the upper base portion in relation to the lower base portion. The linear actuator is mounted to on an attachment plate that also attaches the motor to the upper base portion. The linear actuator can drive a flexible member or connect to a gear wheel or worm screw to pivot about the hinge and change an angle between the upper and lower base portions.

A piston ring is used for a reciprocating compressor. In the piston ring, polytetrafluoroethylene and polyetheretherketone or polyimide account for 50% or more by mass in total. The piston ring does not contain polyphenylene sulfide. The piston ring has a tensile strength within a range of more than 15 MPa and less than 100 MPa.

A rotatable piston assembly for a reciprocating piston type hydraulic machine includes a rotatable piston configured for a controlled rotation and configured to reciprocate within a cylinder bore of the reciprocating piston type hydraulic machine.

A rotatable piston assembly for a reciprocating piston type hydraulic machine includes a rotatable piston configured for a controlled rotation and configured to reciprocate within a cylinder bore of the reciprocating piston type hydraulic machine.

A plunger pump includes a cylinder having a cylinder chamber, and a first through hole and a second through hole that open from an inner circumferential surface toward an outer circumferential surface of the cylinder chamber, and a plunger inserted in the cylinder chamber and configured to make a reciprocating motion with respect to the cylinder chamber. An inner circumferential portion of the cylinder has an inner circumferential surface, and a helical first groove portion on the inner circumferential surface, the helical first groove portion being configured to communicate with at least one of the first through hole and the second through hole.

A plunger pump includes a cylinder having a cylinder chamber, and a first through hole and a second through hole that open from an inner circumferential surface toward an outer circumferential surface of the cylinder chamber, and a plunger inserted in the cylinder chamber and configured to make a reciprocating motion with respect to the cylinder chamber. An inner circumferential portion of the cylinder has an inner circumferential surface, and a helical first groove portion on the inner circumferential surface, the helical first groove portion being configured to communicate with at least one of the first through hole and the second through hole.

The present disclosure provides generally for a fluid-dispensing device. More specifically, the present disclosure provides for a precision fluid-dispensing device that may deliver a predefined volume of fluid quickly and reliably. In some aspects, the precision fluid-dispensing device may be used to deliver a fluid to a receiving container, such as in a manufacturing line, as a non-limiting example. In some embodiments, the precision fluid-dispensing device may dispense very accurate volumes of fluid using the head pressure of the fluid from an elevated reservoir or pressurized fluid supply. In some implementations, the precision fluid-dispensing device may dispense fluid gently and quickly, which may allow for handling of fluids that may be sensitive to agitation or mixing.