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.

Progressing cavity devices and systems are provided. In one embodiment, a stator of a progressing cavity device includes metal plates with apertures that are rotationally offset to form a winding rotor conduit for receiving a rotor of the progressing cavity device. A layer of elastomer can be provided on edges of the apertures of the metal plates in the winding rotor conduit, and the stator can also include a gas breakout port through the metal plates to enable gas between the metal plates to escape the stator. Additional systems, devices, and methods are also disclosed.

A steel piston with an oil gallery, and process for forming a steel piston oil gallery channel, which corresponds to the complex shape of the combustion bowl in the piston crown. The oil gallery channel is first forged to the basic shape that corresponds to the shape of the walls of the combustion bowl. Machine-turning surfaces in the oil gallery channel can be machine-finished as desired. Surfaces in the oil gallery which cannot be machined with conventional turning operations, such as recesses and protrusions into the channel, are left in the original forged condition.

A sliding component for an internal combustion engine includes: a sliding component main body that includes a plurality of concave portions formed in a predetermined portion thereof; and a coating layer that covers a portion of the sliding component main body, in which the plurality of concave portions are not formed.

Disclosed are hollow pistons made from a single piece of starting material and methods of manufacturing hollow pistons from the single piece of starting material.

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.

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.

A piston for an internal combustion engine including a cooling gallery and a complex combustion surface is provided. The piston includes an upper crown member joined to a lower member, for example by hybrid induction welding. A complex combustion bowl is formed in the upper crown member by forging. The combustion bowl includes at least one protrusion, and typically a plurality of protrusions spaced from one another. After the forging step and before the joining step, portions of an undercrown surface located opposite the spaces between the protrusions are machined, and portions located directly opposite the protrusions are left as-forged. The crown member is joined to the lower member, for example by hybrid induction welding.

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.

A steel piston with an oil gallery, and process for forming a steel piston oil gallery channel, which corresponds to the complex shape of the combustion bowl in the piston crown. The oil gallery channel is first forged to the basic shape that corresponds to the shape of the walls of the combustion bowl. Machine-turning surfaces in the oil gallery channel can be machine-finished as desired. Surfaces in the oil gallery which cannot be machined with conventional turning operations, such as recesses and protrusions into the channel, are left in the original forged condition.