A reciprocating rod pump system, comprising an articulating plunger assembly having a plurality of plunger segments, each having a pin end and a box end, and a ball and socket articulating connector formed between the pin end of one plunger segment and the box end of another plunger segment. The articulating connector is formed from a collar rigidly attached to the pin end, which defines a socket, the collar comprising an internal shoulder which abuts an external shoulder on the plunger pin end, such that the uppermost end of the collar does not contact the plunger segment, and a plunger nipple comprising a ball adapted to fit and rotate within the socket, and a shank which rigidly engages the box end thread of a plunger segment.

A pump rod has a head extending from a neck, and the head is received within a drive slot of a drive link. The head includes a projection, and has an area smaller than an area of the head. The projection contacts an inner surface of the drive slot. The drive link may include a projection aligned with a centerline of the drive link. The drive link projection contacts a head of the pump rod. The projections provide a reduced contact area between the pump rod and the drive link, thereby reducing any side-loading on the pump rod and increasing a lifespan of the wear parts.

A pump rod has a head extending from a neck, and the head is received within a drive slot of a drive link. The head includes a projection, and has an area smaller than an area of the head. The projection contacts an inner surface of the drive slot. The drive link may include a projection aligned with a centerline of the drive link. The drive link projection contacts a head of the pump rod. The projections provide a reduced contact area between the pump rod and the drive link, thereby reducing any side-loading on the pump rod and increasing a lifespan of the wear parts.

A drive system for a fluid displacement pump includes an electric motor, a drive coupled to the rotor at a first end of the electric motor, a pump including a fluid displacement member mechanically coupled to the drive, and a controller configured to control a level of power to the electric motor based on a pressure setting set by a user. The electric motor includes a stator and a rotor disposed on an axis. The drive coupled to the rotor converts the rotational output to a linear, reciprocating input to power a pump.

A pump rod has a head extending from a neck, and the head is received within a drive slot of a drive link. The head includes a projection, and has an area smaller than an area of the head. The projection contacts an inner surface of the drive slot. The drive link may include a projection aligned with a centerline of the drive link. The drive link projection contacts a head of the pump rod. The projections provide a reduced contact area between the pump rod and the drive link, thereby reducing any side-loading on the pump rod and increasing a lifespan of the wear parts.

The present disclosure relates to a water pumping device for a water flosser, which includes a mounting base, a transmission assembly, a connecting member, and a piston. The transmission assembly includes a first transmission member. The connecting member is disposed in the mounting base in a reciprocally movable manner in a first direction. The first transmission member is rotatable about a first rotation axis perpendicular to the first direction, and in mating connection with the connecting member. The first transmission member is eccentrically disposed with respect to the first rotation axis. During a rotation of the first transmission member about the first rotation axis, the first transmission member reciprocates in the first direction, so as to drive the connecting member to reciprocate in the first direction. The reciprocation of the connecting member in the first direction can drive the piston to reciprocate in the first direction.

A drive system for a fluid displacement pump includes an electric motor, a drive coupled to the rotor at a first end of the electric motor, a fluid displacement member mechanically coupled to the drive, and a pump frame mechanically coupled to the electric motor. The electric motor includes a stator and a rotor disposed on an axis. The drive coupled to the rotor converts the rotational output to a linear, reciprocating input to the fluid displacement member. The rotor is disposed about the stator to rotate about the stator.

There is provided a compressor including: a piston that reciprocates inside a cylinder; a valve plate that closes an end portion of the cylinder; a connecting rod that supports the piston; a crankshaft that applies a rotating force to an end portion of the connecting rod; and a crankcase that rotatably supports the crankshaft. The piston is an oscillating piston that reciprocates while oscillating inside the cylinder according to rotation of the crankshaft. A central axis of an inner diameter of the cylinder is disposed at a position shifted by an offset amount e with respect to a rotation center axis of the crankshaft. An upper surface of the piston is substantially parallel to a crankcase side surface of the valve plate in a state where the piston is at a top dead center.

Apparatus for compressing cryogenic fluid in at least one compression stage comprising at least one piston and at least one sleeve delimiting at least one compression chamber, a shaft that is able to move in translation along a longitudinal axis (A), the shaft being connected to the piston(s) or sleeve(s) and being able to move with an alternating movement in two opposite directions to ensure phases of compression and intake of fluid into the at least one compression chamber by moving the at least one piston and the at least one sleeve in a relative manner, characterized in that the shaft comprises a portion of reduced cross section in the longitudinal direction (A), said portion of reduced cross section separating two adjacent parts of the shaft, the shaft also comprising at least one linking element made of material that is less thermally conductive than the constituent material of the shaft, in particular a composite material, said at least one linking element having two ends connected respectively to the two adjacent parts of the shaft.

A medical plunger pump and a chamber structure thereof. The chamber structure includes a barrel, where the barrel is provided with at least one cylindrical chamber which includes a piston working section in which a piston is able to reciprocate and a joint section where the piston is connected to a push rod. The joint section includes a first arc section that protrudes from the piston working section, where a first end of the first arc section is smoothly connected to a side wall of the piston working section, and a second end of the first arc section is bent and extendable along an axis of the piston working section. The medical plunger pump includes the above-mentioned chamber structure.