An orbital scroll wrap and a fixed scroll wrap of a scroll compressor include respective scroll start portions each having a bulbous shape defined by connecting an involute start point of an outer-surface involute curve and an involute start point of an inner-surface involute curve to each other with a plurality of arcs. At least one of the scroll start portions has a tiered shape wherein an n number (where n≥2) of tiers each having the bulbous shape are stacked in an axial direction of a main shaft. Letting involute-start-point angles of the outer-surface involute curves in respective tiers of the scroll start portion having the tiered shape be φos(1), φos(2), φos(3), . . . , and φos(n) in order from tip to base of the scroll start portion, the following is satisfied: φos(1)>φos(2)>φos(3)> . . . >φos(n); and 0.3π<φos(1)-φos(n)<0.7π.

A plurality of external teeth of an inner rotor are formed such that an intake-side clearance is larger than a discharge-side clearance. The intake-side clearance denotes a minimum value of a clearance between an external tooth and an internal tooth defining an inter-teeth chamber which communicates with an intake port and in which an amount of change in volume during rotation of the inner rotor by a unit angle is maximized. The discharge-side clearance denotes a minimum value of a clearance between an external tooth and an internal tooth defining the inter-teeth chamber which at least partially overlaps with a partition wall a first discharge port and a second discharge port when the amount of change in volume per unit angle is maximized.

The present invention relates to a vane rotary compressor wherein the volume of a compression room is reduced and a fluid is compressed when a rotor rotates. According to one embodiment of the present invention, the present invention provides the vane rotary compressor for maximizing the rotational moment of a vane by extending a weight part at a front end part of the curved blade type vane so as to remove the hitting noise due to the delay of the rotational operation of the vane when the rotor is rotated, and increasing the performance by reducing the internal leak.

An electrical motor vehicle vacuum pump arrangement includes a housing assembly, a pump apparatus arranged therein, a drive motor, and a sound dampener. The housing assembly includes an inlet and an outlet opening arrangement. The pump apparatus includes a pump rotor housing with an inlet- and an outlet-side face wall, and a pump rotor housing part arranged therebetween. The inlet- and the outlet-side face wall and the pump rotor housing part enclose a pump rotor chamber with a pump rotor arranged therein. The drive motor is arranged in the housing assembly. The drive motor includes a motor rotor and a motor stator. The sound damper includes a first and a second sound damping chamber, and a sound dampener element. The first sound damping chamber is connected to the pump rotor chamber and to the second sound damping chamber. The second sound damping chamber is connected to the outlet opening arrangement.

A rotary internal combustion engine including a rotor assembly where at least a first and a second of the combustion chambers have unequal theoretical volumetric ratios. Also, a rotary internal combustion engine including first and second rotor assemblies where at least one of the combustion chambers of the first rotor assembly and at least one of the combustion chambers of the second rotor assembly have unequal effective volumetric compression ratios and/or unequal effective volumetric expansion ratios.

Method for delivering a gas/liquid mixture fluid via a screw spindle pump that has a housing in which a drive spindle and a running spindle are accommodated. The spindles delimit together with the housing multiple pump chambers. A respective one of the pump chambers that is initially open toward the respective fluid inlet is closed off. The resulting closed-off pump chamber is moved axially toward the fluid outlet and, there, upon attainment of an opening rotation angle, is opened toward the fluid outlet. The drive spindle is driven so that the pressure in the respective pump chamber prior to and/or upon attainment of the opening rotation angle is increased in relation to the suction pressure of the screw spindle pump by at most 20% or by at most 10% of a difference in pressure between the suction pressure and the pressure in the region of the fluid outlet.

Disclosed is a compressor having a torque load reducing unit for moving a center of weight to which a gas force is applied. As the torque load reducing unit is formed at an oval-shaped roller, a distance between a rotation center of the roller and an operation point to which a gas force is applied becomes short. This can reduce a torque load to the roller, and can enhance compression efficiency.

Sealing in rotary positive displacement machines based on trochoidal geometry that comprise a helical rotor that undergoes planetary motion within a helical stator is described. Seals can be mounted on the rotor, the stator, or both. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides advantages with respect to sealing in the rotary machine. In multi-stage embodiments, the rotor-stator geometry remains substantially constant or varies along the axis of the rotary machine.

A vane pump includes: a rotor configured to rotate under rotational force from a rotary shaft while supporting multiple vanes and including a curved surface portion with an arc shape centered on the rotary shaft and a rotor recess depressed from the curved surface portion toward a rotation center; a cam ring disposed so as to surround the rotor and including an inner peripheral surface facing the curved surface portion of the rotor; and an inner plate disposed on one end of the cam ring in an axial direction of the rotary shaft so as to cover an opening of the cam ring and including a suction inner recess depressed toward the rotation center relative to the curved surface portion of the rotor.

This internal gear pump accommodates: a ring-shaped internally toothed gear provided with internal teeth, and an externally toothed gear provided with external teeth which internally mesh with the internal teeth of the internally toothed gear, said externally toothed gear being eccentrically disposed inside the internally toothed gear. The number of internal teeth is one greater than the number of external teeth. In any one of the external teeth and the internal teeth, a tooth tip section and a meshing section are formed by a curve having one continuous curvature. The curve is formed by an equation with which the maximum curvature is at the apex of the tooth tip, and the curvature gradually reduces towards the tooth bottom section.