Disclosed is a pump system for a semiconductor chamber includes a housing having a front chamber and a rear chamber, a roots-type rotor provided to the front chamber of the housing, a screw-type rotor provided to the rear chamber, a shaft member coupled through the roots-type rotor and the screw-type rotor, and a driving motor provided to the outside of the housing in such a way as to be axially connected to the shaft member to provide power for driving the rotors. A fluid pipe is provided to the outside of the housing to connect the front chamber and the rear chamber. The fluid pipe is provided with a heater and/or a cooler to heat or cool the fluid flowing through the fluid pipe.

A housing unit of a Roots pump includes a rotor housing, which includes a peripheral wall, and a cover member, which closes an opening of the rotor housing. At least one of a mating surface of the peripheral wall or a mating surface of the cover member includes an annular first groove accommodating a seal member. The rotor housing includes a bulging portion including a second groove. The seal member incudes first projections, which project from an annular seal body, and a second projection, which projects further radially inward from the seal body than the first projections. Each first projection includes a distal end that contacts a side surface on a radially inner side or on a radially outer side of the first groove. The second projection is arranged in the second groove to determine the position of the seal body in the first groove.

A compressor design includes a male rotor (10) having one or more helical lobes (12) and a female rotor (14) having one or more helical grooves (16). The male rotor is mounted on a first shaft and the female rotor is mounted on a second shaft. The male rotor is positioned in a first section of a chamber and the female rotor is positioned in a second section of the chamber. Fluid enters the chamber at an inlet, and when the rotors are driven, the lobes of the male rotor fit into the grooves of the female rotor, causing compression and movement of the fluid towards an outlet or discharge end where the compressed fluid is discharged. The configuration of the lobe and groove helix, the lobe and groove profile, and the outer diameter of the rotors can be varied in different combinations to form different rotors.

A geared compressor includes a drive gear, a first intermediate gear, a second intermediate gear, a first impeller and a second impeller connected to a first driven gear, and a third impeller and a fourth impeller connected to a second driven gear. When viewed from an axial direction, a drive axis of the drive gear is disposed below a first intermediate axis of the first intermediate gear, a second intermediate axis of the second intermediate gear, a first driven axis of the first driven gear, and a second driven axis of the second driven gear in a vertical direction. The first impeller has a larger outer diameter than the second impeller, the third impeller, and the fourth impeller.

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.

The invention relates to a screw compressor comprising a compressor housing (11) having two rotor screws (1, 2) mounted axially parallel therein, which mesh with each other in a compression space (18), can be driven by a drive and are synchronized with each other in their rotational movement, wherein the rotor screws (1, 2) each have a single-part or multi-part base body (24) with two end faces (5a, 5b, 5c, 5d) and a profiled surface (12a, 12b) extending therebetween, and shaft ends (30) projecting beyond the end faces (5a, 5b, 5c, 5d), wherein at least the profiled surface (12a, 12b) is formed in multiple layers, comprising a first, inner layer (3) and a second, outer layer (4), wherein the first, inner layer (3) and the second, outer layer (4) both comprise or are formed from a thermoplastic synthetic material, wherein particles (25) or pores (32) supporting a running-in process are embedded in the second, outer layer (4) and the thermoplastic synthetic material defines a matrix for receiving the particles (25) or for forming the pores (32).

The invention relates to a rotor pair for a compressor block of a screw machine, wherein the rotor pair comprises a secondary rotor that rotates about a first axis and a main rotor that rotates about a second axis, wherein the number of teeth of the main rotor is 3 and the number of teeth of the secondary rotor is 4. The relative profile depth of the secondary rotor is at least 0.5, preferably at least 0.515, and at most 0.65, preferably at most 0.595. rk1 is an addendum circle radius drawn around the outer circumference of the secondary rotor and rf1 is a dedendum circle radius starting at the profile base of the secondary rotor, wherein the ratio of the axis distance of the first axis from the second axis and the addendum circle radius rk1 is at least 1.636, and at most 1.8, preferably at most 1.733.

The present application provides a screw compressor that comprises a first male rotor and a second male rotor, each of the first male rotor and the second male rotor having convex-helical teeth, the first male rotor and the second male rotor being rigidly connected together; a first female rotor and a second female rotor, each of the first female rotor and the second female rotor having concave-helical teeth, the first female rotor being arranged separately from and opposite to each other; wherein the convex-helical teeth of the first male rotor are engaged with the concave-helical teeth of the first female rotor, and the convex-helical teeth of the second male rotor are engaged with the concave-helical teeth of the second female rotor. The male rotors in the screw compressor are symmetrically so that the axial force exerted on the first male rotor counteract with the axial force exerted on the second male rotor.

The disclosure discloses a method for determining reasonable design area of roots pump rotor profile of roots pump and its application, and belongs to the field of mechanical design. According to the method of the disclosure, after a relation between the roots pump rotor profile and performance parameters is established, constraint conditions for avoiding a closed volume and undercutting are further determined, so that a reasonable design region of a roots pump rotor blade peak curve is determined. Reference is given when the roots pump rotor profile is designed, i.e., the rotor profile with the blade peak curve being not within the reasonable design region inevitably causes the problem of closed volume or undercutting in application, so that the design of the rotor profile that causes the closed volume or undercutting can be avoided when the roots pump rotor profile is designed. The problem that the design unreasonableness of the rotor profile is not found until the design is completed is solved, so that the design efficiency of the rotor profile is improved.

A blower assembly includes, but is not limited to, a blower housing defining a blower chamber and including a gas inlet and a gas outlet; a first rotor positioned within the blower 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 blower 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 blower chamber includes a coating.