A novel rotating body, its material, and manufacturing method thereof, shortening a distance for cutting a bore surface in its axial direction, reducing processing costs, enabling lower-cost manufacture of inner rotor. A metallic rotating body 11 has a bore surface 12 for press-fitting a shaft thereinto, including a cutting-processed portion 13 at first end and an unprocessed portion 14 at second end. The processed portion 13 has an inner diameter formed smaller than the unprocessed portion 14. A chamfer 15 at first end of the bore surface 12 is cut, while a chamfer 6 at the second end not. A bore surface 2 of material 1 processed into the rotating body 11 includes a small-diameter portion 3 at first end and a large-diameter portion 4 at second end. A step 5 is formed between the small- and large-diameter portions 3, 4, with the chamfer 6 formed at second end.

A compressor includes a suction hole provided in a cylinder. The suction hole includes a plurality of portions being different in diameter and disposed from an outer circumferential side toward an inner circumferential side of the cylinder. The plurality of portions are reduced more in diameter toward the inner circumferential side of the cylinder. A central axis of an outer circumferential side suction hole of the plurality of portions intersects a central axis of the cylinder. A central axis of an inner circumferential side suction hole of the plurality of portions is parallel to the central axis of an outermost circumferential side portion and decentered from the central axis in an opposite direction to a direction of a spring hole.

A fixed scroll compressor body includes a scroll compressor body casting. The casting has a central body portion having a plate-like base with a spiral scroll rib projecting from the base at a right angle thereto. The spiral scroll rib includes a volume between the spiraled ribs for the compressing of refrigerant. The spiral scroll rib spirals from a central region of the plate-like base to an outer wall of the central body portion. The casting further includes a first inward-protruding portion that protrudes from the outer wall into the volume. A distance that the first inward-protruding portion protrudes into the volume is greater than a thickness of the first inward-protruding portion such that removal of the first inward-protruding portion results in a first intake opening in the outer wall. The first intake opening provides a path for a flow of refrigerant into the volume.

A vacuum booster assembly includes, but is not limited to, a booster housing defining a booster chamber and including a gas inlet and a gas outlet; a first rotor positioned within the booster chamber and adapted for rotation therein, the first rotor including a first shaft and at least two lobes defining a first lobe profile; and a second rotor positioned within the booster chamber and adapted for rotation therein, the second rotor including a second shaft and at least two lobes defining a second lobe profile, wherein the first and second rotors are formed from a metal having a coefficient of thermal expansion from about 1 (10.sup.6 in/in*K) to about 13 (10.sup.6 in/in*K), and wherein at least one of the outer surface of the first rotor, the outer surface of the second rotor, or the booster chamber includes a coating.

A crescent internal gear pump includes a front cover, an end cover, a ring gear and a pinion gear disposed within a gear housing in an eccentric, intermeshing relationship. The housing is disposed intermediate the front cover and the end cover. A crescent is disposed radially intermediate the ring gear and the pinion gear. The crescent partially extends into a correspondingly shaped slot in the end cover. The gear housing, the ring gear, and the pinion gear can have substantially the same thickness. A shim can be disposed intermediate the end cover and the gear housing for establishing a desired clearance therebetween.

The non-lubricated compressor (10) for compressing a gas, comprises: a stationary stator (12) with a housing (18) comprising a rotor cavity (20) delimited by a bottom wall (22), a top wall (24), and a lateral wall (26) connecting said bottom wall (22) and said top wall (24), a rotor element (14) arranged for rotation about an axis (z) within the rotor cavity (20) for compressing a gas therein, a self-supporting sealing element (16) arranged within the rotor cavity (20), wherein the sealing element (16) is made of an abradable carbon material, and comprises a wall portion (34) arranged on an inner surface of the lateral wall (26) of the rotor cavity (20).

The present invention discloses a compressor comprising: a fixed scroll including a suction communication passage that is formed so that refrigerant flowing through a suction pipe is guided to a compression chamber. The suction communication passage is formed so that the cross-sectional shape of the suction communication passage includes a step-like portion that is formed by multiple steps.

The present invention discloses a compressor comprising: a fixed scroll including a suction communication passage that is formed so that refrigerant flowing through a suction pipe is guided to a compression chamber. The suction communication passage is formed so that the cross-sectional shape of the suction communication passage includes a step-like portion that is formed by multiple steps.

Provided is a hollow rotor and method for making a hollow rotor for a gerotor system, the gerotor system including inner and outer rotors having interengaging lobed profiles. At least one of the inner or outer rotors comprises the hollow rotor, the hollow rotor including radially inner and outer walls radially spaced-apart in relation to a rotational axis of the rotor and walls extending between the radially inner and outer walls for closing axial ends of the hollow rotor. The radially inner and outer walls define therebetween a cavity, thus providing for a hollow or empty interior of the hollow rotor. At least one of the radially inner or outer walls forms a plurality of lobes circumferentially spaced-apart around the cavity.

A vacuum booster assembly includes, but is not limited to, a booster housing defining a booster chamber and including a gas inlet and a gas outlet; a first rotor positioned within the booster chamber and adapted for rotation therein, the first rotor including a first shaft and at least two lobes defining a first lobe profile; and a second rotor positioned within the booster chamber and adapted for rotation therein, the second rotor including a second shaft and at least two lobes defining a second lobe profile, wherein the first and second rotors are formed from a metal having a coefficient of thermal expansion from about 1 (10.sup.6 in/in*K) to about 13 (10.sup.6 in/in*K), and wherein at least one of the outer surface of the first rotor, the outer surface of the second rotor, or the booster chamber includes a coating.