A tangentially cut rod packing ring is provided. The tangentially cut rod packing ring comprises a first ring formed from a plurality of segments. Each of the segments has a portion of two interfaces where each interface slidably engages an interface of an adjacent segment. One interface terminates at a leading surface. One interface has a stop surface. The leading surface is originally separated from the stop surface by a gap. As the interfaces slidably move, the gap lessens until the leading surface abuts the stop surface. The tangentially cut rod packing ring also comprises a second ring formed from a plurality of segments. The second ring has a first portion and a second portion. The first portion forms as shelf on which the first ring sits. The second portion surrounds the first ring. An elastic member in a groove on the outer surface of the second portion provides a compressive force on both the second ring and the first ring.

A piston pump, in particular a high-pressure fuel pump for an internal combustion engine, includes a pump housing, a pump piston, and a delivery chamber that is delimited at least by the pump housing and the pump piston. The piston pump further includes a seal configured to seal the delivery chamber and a separate guide element configured to guide the pump piston. The seal and the guide element are arranged between the pump piston and the pump housing. The seal is formed as a plastic ring with a substantially sleeve-shaped base portion.

The invention relates to a piston pump, in particular for injection systems for motorized two-wheeled vehicles and/or for motorized three-wheeled vehicles, having a compression chamber, a piston, an inlet valve, and an outlet valve. A fluid can flow into the compression chamber via the inlet valve, and the fluid can flow out of the compression chamber via the outlet valve. A region in the form of a channel, which is arranged fluidically upstream of the outlet valve, in particular directly upstream of the outlet valve, has a cross-section which is reduced compared to a compression chamber region at a distance from the outlet valve. The invention is characterized in that a piston end face facing the channel has a region which can be immersed into the channel.

The invention relates to a piston pump, in particular for injection systems for motorized two-wheeled vehicles and/or for motorized three-wheeled vehicles, having a compression chamber, a piston, an inlet valve, and an outlet valve. A fluid can flow into the compression chamber via the inlet valve, and the fluid can flow out of the compression chamber via the outlet valve. A region in the form of a channel, which is arranged fluidically upstream of the outlet valve, in particular directly upstream of the outlet valve, has a cross-section which is reduced compared to a compression chamber region at a distance from the outlet valve. The invention is characterized in that a piston end face facing the channel has a region which can be immersed into the channel.

A box lubricator that includes a pump with a piston housing and piston. The piston housing extends from a first end to a second end, and includes a bore extending through the piston housing from the first end of the piston housing to the second end of the piston housing. The piston housing also includes a recess disposed at the second end of the piston housing, the recess being concentric with the bore and comprising a diameter larger than a diameter of the bore. The piston is disposed inside the bore of the piston housing. At least one elastomeric seal is disposed inside the recess of the piston housing and around the piston. In some embodiments, a ball and socket joint connects the piston to the rocker arm assembly. In some embodiments, a fluid passage and a check valve are disposed inside the piston.

A box lubricator that includes a pump with a piston housing and piston. The piston housing extends from a first end to a second end, and includes a bore extending through the piston housing from the first end of the piston housing to the second end of the piston housing. The piston housing also includes a recess disposed at the second end of the piston housing, the recess being concentric with the bore and comprising a diameter larger than a diameter of the bore. The piston is disposed inside the bore of the piston housing. At least one elastomeric seal is disposed inside the recess of the piston housing and around the piston. In some embodiments, a ball and socket joint connects the piston to the rocker arm assembly. In some embodiments, a fluid passage and a check valve are disposed inside the piston.

A reciprocating pump assembly that includes a power end, first and second stay rods coupled to the power end, and a fluid end that includes a mounting flange coupled to the first and second stay rods and a packing nut assembly. The packing nut assembly includes a packing nut threadably engaged with the mounting flange and comprising a gear pattern, and a retention assembly that includes a collar, an alignment arm, a pawl, and a biasing assembly. The collar extends around the first stay rod. The alignment arm is coupled to the collar and shaped to contact the second stay rod. The pawl is pivotally coupled to the alignment arm or the collar and positioned to engage the gear pattern to allow the packing nut thread into the mounting flange and prevent the packing nut from unthreading. The biasing assembly biases the pawl into engagement with the gear pattern.

A fluid dispensing system includes a motor housing and a piston pump assembly connected to the motor housing. A motor is mounted within the motor housing. The piston pump assembly includes a pump housing, a cartridge having a first end that extends into a second end of the pump housing, a piston that extends into a first end of the pump housing and the first end of the cartridge, and a packing stack within the cartridge and adjacent an inner surface of the cartridge and through which the piston extends. The cartridge is configured to be removed from the pump housing, and removal of the cartridge removes the packing stack from within the pump housing while leaving the pump housing connected to the motor housing.

An electric submersible pumping system for use in pumping fluids from a wellbore includes a motor, a pump driven by the motor, and a fluid expansion module connected to the motor. The fluid expansion module includes a piston seal housing and a piston assembly contained within the piston seal housing. The piston assembly includes a piston body having an exterior surface, a plurality of seals connected to the exterior surface of the piston body and a pressure equalization system. The pressure equalization system reduces a pressure differential between fluid in an annular space between the plurality of seals and fluid surrounding the first piston assembly.

In a piston including a plurality of piston rings, a state where a difference in differential pressure between the piston rings is eased is maintained even after passage of time, and the life of the piston rings is extended. A piston includes a piston body in which a plurality of ring grooves is formed, and a plurality of piston rings respectively arranged in the ring grooves. In the piston, a leakage groove is formed on a low-pressure side surface of the ring groove, and in a state where the piston ring is abutted with the low-pressure side surface while being abutted with a cylinder, the leakage groove ensures communication between a high-pressure side space and a low-pressure side space with respect to the piston ring.