L'invention concerne une pompe volumétrique.

Elle a pour objet une pompe volumétrique, comprenant un rotor tournant dans un stator avec un jeu donné, utilisée pour le pompage d'un gaz ou d'un mélange de gaz de masse moléculaire donnée, caractérisée en ce qu'elle comprend des moyens pour injecter, dans le jeu précité, un gaz de masse moléculaire plus élevée que celle du gaz ou du mélange de gaz pompé.

Applications aux pompes à palettes, aux pompes Roots, aux pompes à double vis cylindriques ou coniques, etc.

The present invention improves performance of a scroll fluid machine by effectively exhibiting a function of a tip seal installed at a tooth tip of a wall body even when a continuous slope is provided to the wall body. A slope in which the distance between opposing surfaces of opposing end plates continuously reduces from the outer peripheral surface toward the inner peripheral surface is provided, and a tip seal (7) that comes into contact with an opposing tooth bottom so as to seal a fluid is provided to a tip seal groove (3d) formed at a tooth tip of a wall body (3b) corresponding to the slope. A groove bottom (3d1) of the tip seal groove (3d) is formed into a shape in which the center portion (3d2) in the groove width direction is deepest. The tip seal (7) is formed such that the center portion (7a1), in the width direction, of the bottom (7a) of the tip seal (7) facing the groove bottom (3d1) projects farther than both side portions (7a2).

A compressor includes first and second scroll members (76; 78), first and second bearing housings (14;16), and a motor assembly (20). The first scroll member (76) includes a first end plate (80) and a first spiral wrap (82) extending from the first end plate (80). The second scroll member (78) includes a second end plate (86) and a second spiral wrap (88) extending from the second end plate (86) and intermeshed with the first spiral wrap (82) to define compression pockets (122) therebetween. The first bearing housing (14) supports the first scroll member (76) for rotation about a first rotational axis (A1). The second bearing housing (16) supports the second scroll member (78) for rotation about a second rotational axis (A2) that is parallel to and offset from the first rotational axis (A1). The motor assembly (20) is disposed axially between the first and second bearing housings (14;16) and includes a rotor (100) attached to the first scroll member (76). The rotor (100) surrounds the first and second end plates (80;86).

A back pressure space (77) of a vane groove (75) having completed communication with an intermediate-pressure supply groove (67) communicates with a first supply section (69a) until refrigerant pressure in each of compression chambers (33a, 33b, 33c) having been partitioned by vanes (25) of the vane grooves (75) reach the highest pressure, and then high pressure is supplied from the first supply section (69a). At a time point when the back pressure space (77) having completed communication with an intermediate-pressure supply groove (67) communicates with the first supply section (69a) of a high-pressure supply groove (69), the preceding back pressure space (77) adjacent to that back pressure space (77) on the downstream side of the rotation direction X completes communication with the first supply section (69a).

This compressor is provided with a drive shaft, a housing, a rotor, and cradles. The rotor is formed in an annular shape having cradle windows radially penetrating through in the radial direction. The rotor can rotate within the rotor chamber together with the drive shaft while being in sliding contact with the housing at the circumferential surface extending in the direction parallel to the axis. The cradles are provided in the cradle windows so as to be capable of pivoting about pivot axes. When pivoting, the cradles maintain the compression chambers in an airtight state by being in contact with the housing at both pivoting ends of the cradles, the pivoting ends extending along the direction parallel to the axis. The rotor chamber comprises an outer operation chamber which is located on the outside of the rotor, and an inner operation chamber which is located on the inside of the rotor. The cradles, and either the outer operation chamber and/or the inner operation chamber form the compression chambers, the volumes of which are varied by the rotation of the rotor.

Provides a screw compressor capable of preventing gas leaks through between, a casing and a gate rotor while preventing contact of the casing and the gate rotor with each other. With regard to a width of a seal surface 11 of the casing, a width Wd on a gas-outlet side of the screw rotor 2 is larger than a width Ws on a gas-inlet side of the screw rotor 2.

A motor-driven compressor has a compression mechanism, a rotary shaft, an electric motor, a motor drive circuit, a connecting terminal and a housing assembly. The compression mechanism, the electric motor, and the motor drive circuit are disposed along the axial direction of the rotary shaft in the housing assembly having first through third housings. The first housing is used for mounting the electric motor and the compression mechanism. The second housing has a terminal mounting portion for fixing the connecting terminal. The first and second housings have fastening portions at the radially peripheral portion thereof. The third housing is joined to the second housing to form an accommodation space for accommodating the motor drive circuit. The closed casing is formed by fastening the fastening portions of the first and second housings by means of a first bolt and connecting the second housing to the open end of the first housing.

In a scroll fluid machine, a stationary scroll fixed to a housing engages with an orbiting scroll to form a sealed chamber between the orbiting and stationary scrolls. Fluid in the sealed chamber is compressed or decompressed with revolution of the orbiting scroll with respect to the stationary scroll. A plurality of self-rotation preventing devices are provided on the orbiting scroll to prevent the orbiting scroll from rotating on its own axis. The self-rotation preventing device comprises an eccentric tube connected to a main shaft fitting in the housing, and an eccentric shaft fitted in a bearing plate. The eccentric tube is eccentrically revolved with respect to the main shaft thereby allowing engagement of the orbiting scroll with the stationary scroll to be adjusted.

In a cylinder (23) of a compression mechanism (20), an intake passage (40) passing through the cylinder (23) in the radial direction thereof is formed. There is provided in a sealed container (10) a coupling member (43) having a tip end face facing the periphery of the intake passage (40) in the outer face of the cylinder (23) and a base end to which an intake pipe (42) is mounted. The tip end face of the coupling member (43) serves as a flat sealed face. A concave groove (23a) is formed in a peripheral part around the intake passage (40) in the outer face of the cylinder (23) and an O ring (45) is fitted therein. The O ring (45) is pressed against the tip end face of the coupling member (43), sealing a gap between the cylinder (23) and the coupling member (43).

Grooves (20-27) in equal number are formed on the end surfaces (19a and 19b) of a roller (19), respectively, communicating portions (20a-27a) for establishing communication between the above-mentioned grooves and the inner periphery of the roller (19) are provided and sealing portions (20b, 20c, 20d, 20e and 20f-27b, 27c, 27d, 27e and 27f) each being decreased in a sectional area are formed. With this arrangement, the sectional areas are decreased relative to a direction of contamination of lubricant oil, so that a plurality of oil pressures can be obtained, thereby securing a constant clearance of the roller (19).

Leakage in a scroll wrap compressor is reduced by providing a roughened scroll wrap tip surface at the gap between the tip and the cooperating base so as to increase the frictional resistance to flow of fluid through the gap and to cause turbulence within the gap to further increase the resistance to the flow of fluid from the high pressure to the low pressure side across a scroll wrap tip. Various types of surfaces are shown for increasing the frictional resistance to flow such as knurling (16), grooving, cast cavities, metal particles and fibers and the like.