An automotive electrical oil pump which includes an oil displacement pumping unit with a pump rotor which rotates in a pump chamber to pump oil to an oil recipient, an electric driving motor which drives the pump rotor, an electrical connector plug which connects the electric driving motor to a power source, and a fluid connector. The fluid connector includes a pump inlet fluidically connected to a chamber inlet, a pump outlet fluidically connected to a chamber outlet, a first lateral circular ring opening which define the pump inlet or the pump outlet, and a second lateral circular ring opening or a circular front opening which defines the pump outlet or the pump inlet. The second lateral circular ring opening is provided separate from the first lateral circular ring opening. The pump outlet and the pump inlet are arranged coaxially to each other.

A rotary piston engine comprises a housing (1) spatially limiting a working chamber (2), an intake connection (4) for guiding gas into the working chamber (2), a pressure connection (6) for guiding the gas out of the working chamber (2), and a rotor assembly (4) having a first rotor (14) rotatably arranged in a first working sub-chamber (12) and a second rotor (21) cooperating with the first rotor (14) and rotatably arranged in a second working sub-chamber (13). The rotary piston engine also comprises a ventilation channel (8), formed in the housing (1) and connected to the working chamber (2) via a ventilation channel opening (9), for the temporally limited introducing of air into the working chamber (2), wherein the ventilation channel opening (9) is open at least in sections, in particular completely open, in a compression phase.

A vane pump that includes a first communication passage that extends along an outer periphery of the cam ring and that guides a fluid that has not flowed into the first suction port from the first inflow passage to the second suction port; a second communication passage that extends along the outer periphery of the cam ring on an opposite side of the first communication passage with respect to the rotor and that guides a fluid that has not flowed into the second suction port from the second inflow passage to the first suction port; and a rectifying portion that guides the fluid from the second inflow passage so that the fluid flows into the second suction port along the outer periphery of the cam ring.

In a general aspect, fluid flow in a gerotor system is enhanced. In some cases, a gerotor apparatus includes inner and outer gears. The outer gear includes inward-facing teeth and an inner surface that defines an inner profile of the outer gear. The inner gear includes outward-facing teeth and an outer surface that defines an outer profile of the inner gear. The inner gear and the outer gear reside in contact such that the inner profile of the outer gear seals against the outer profile of the inner gear at multiple distinct points. One or more cutouts are defined by the inner surface of the outer gear between a neighboring pair of the inward-facing teeth, by the outer surface of the inner gear between a neighboring pair of the outward-facing teeth, or both.

A gas meter with a rated maximum flow capacity of greater than 3,000 CFH (Cubic Feet per Hour)for example, between 3,500 CFH and 7,000 CFHis provided with 2-inch flange connectors. One or more undercuts are provided in the meter body to promote satisfactory performance in terms of, for example, differential pressures at the meter inlet and outlet.

In a general aspect, fluid flow in a gerotor system is enhanced. In some cases, a gerotor apparatus includes inner and outer gears. The outer gear includes inward-facing teeth and an inner surface that defines an inner profile of the outer gear. The inner gear includes outward-facing teeth and an outer surface that defines an outer profile of the inner gear. The inner gear and the outer gear reside in contact such that the inner profile of the outer gear seals against the outer profile of the inner gear at multiple distinct points. One or more cutouts are defined by the inner surface of the outer gear between a neighboring pair of the inward-facing teeth, by the outer surface of the inner gear between a neighboring pair of the outward-facing teeth, or both.

A gas meter with a rated maximum flow capacity of greater than 3,000 CFH (Cubic Feet per Hour)for example, between 3,500 CFH and 7,000 CFHis provided with 2-inch flange connectors. One or more undercuts are provided in the meter body to promote satisfactory performance in terms of, for example, differential pressures at the meter inlet and outlet.

In order to further improve the sound damping in a refrigerant compressor comprising a common housing, a screw-type compressor in a common housing has a compressor housing that is formed as part of the common housing with a first sound absorber unit which is arranged in the common housing. The first sound absorber unit is arranged adjacent a housing window, and the sound absorber unit comprises at least one chamber which is located between an inlet opening and an outlet opening and which widens out relative to the inlet opening and to the outlet opening in a direction transverse to a direction of flow.

A rotary piston compressor/pump/blower includes a housing spatially limiting a working chamber, an intake connection for guiding fluid into the working chamber, a pressure connection for guiding the fluid out of the working chamber, and a rotor assembly having a first rotor rotatably arranged in a first working sub-chamber and a second rotor cooperating with the first rotor and rotatably arranged in a second working sub-chamber. The rotary piston compressor/pump/blower also includes a ventilation channel, formed in the housing and connected to the working chamber via a ventilation channel opening, for the temporally limited introducing of air into the working chamber, wherein the ventilation channel opening is open at least in sections, in particular completely open, in a compression phase.

An oil pump includes: a shaft member; an inner rotor configured to rotate integrally with the shaft member; an outer rotor forming a rotor chamber into which oil is sucked from a suction passage and from which the oil is discharged toward a discharge passage, between the inner rotor and the outer rotor; a body member having a recess-shaped housing chamber in which each rotor is housed so as to be rotatable about an axis; and a cover member attached so as to close the housing chamber. The rotor chamber has first and second suction ports through each of which the oil to be sucked from the suction passage passes. The oil pump includes a straightening member branching the suction passage from a main path to the first suction port side and the second suction port side.