A shunt-enhanced compression and pulsation trap (SECAPT) for a screw compressor assists internal compression (IC), reduces gas pulsation and NVH, and improves off-design efficiency, without using a slide valve and/or a serial pulsation dampener. The SECAPT includes an inner casing (e.g., an integral part of the compressor chamber) and an outer casing (e.g., surrounding part of the inner casing near the compressor discharge port) forming at least one diffusing chamber with a nozzle and a feedback region that provides a feedback flow loop between the compressor chamber and the compressor discharge port. The SECAPT automatically compensates cavity pressure to meet different outlet pressures (hence eliminating under-compression and/or over-compression when the discharge port opens), partially recovers potential energy associated with the under-compression (UC), and traps and attenuates gas pulsations and noise before the discharge port opens.

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.

A dry vacuum pump is provided, including two shafts, respectively supporting at least one pumping rotor being configured to synchronously rotate in reverse in order to convey a gas to be pumped from an intake of the dry vacuum pump to an outlet; and a synchronous motor configured to rotate one shaft of the two shafts, the synchronous motor including a rotor coupled to the shaft, a first stator with windings arranged around the rotor, and at least one second stator with windings arranged around the rotor, the windings of the stators being configured to be supplied individually or simultaneously in order to adapt a power of the synchronous motor to a pumping load. A method for controlling a synchronous motor of a vacuum pump is also provided.

A thermal abatement system comprises an axial inlet, radial outlet supercharger. A main case comprises at least two rotor bores, an inlet plane and an outlet plane. The inlet plane is perpendicular to the outlet plane. An inlet wall comprises an inner surface. Two rotor mounting recesses are in the inner surface, and the inlet wall is parallel to the inlet plane. An outlet is in the outlet plane. An inlet is in the inlet plane. At least two rotors are configured to move air from the inlet to the outlet. The main case comprises at least two backflow ports. An intercooler is connected to receive air expelled from the supercharger, to cool the received air, and to expel the cooled air to the at least two back flow ports.

A pumping unit is provided, including a primary vacuum pump of a multistage dry type, including at least four pumping stages fitted in series; and a two-stage Roots vacuum pump, including a first pumping stage and a second pumping stage fitted in series, the second pumping stage being fitted in series with and upstream of a first pumping stage of the primary vacuum pump in a direction of flow of gases to be pumped, in which a ratio of a volume displacement of the first pumping stage of the two-stage Roots vacuum pump to a volume displacement of the second pumping stage of the two-stage Roots vacuum pump is less than six, and in which a ratio of a volume displacement of the second pumping stage of the two-stage Roots vacuum pump to a volume displacement of the first pumping stage of the primary vacuum pump is less than six.

An internal combustion engine includes one or more pairs of non-meshing, externally timed rotors disposed within a housing in an expander module and a compressor module. Each rotor includes a cylindrical, center main body including a first end, a second end opposite the first end, an elongate portion extending between the ends and a first peripheral surface portion and a second peripheral surface portion and a bore extending through a center of the main body from the first end to the to second end. The rotors each have a groove extending along outer peripheral edge portions of the rotor. A pair of tip seals is disposed in the grooves. A pair of apex seals is disposed on the first peripheral surface portion and the second peripheral surface portion and an axially floating end plate is disposed at an end of the housing.

A heat exchanger for changing a temperature of a pumped gas flow and a pump comprising the heat exchanger is disclosed. The heat exchanger comprises: at least one tube configured to contain a flow of fluid; said at least one tube being at least partially embedded within a block of material; wherein said heat exchanger comprises mounting means configured to mount said heat exchanger adjacent to a gas port of a pump such that a least a portion of said heat exchanger extends into a path for gas flow flowing through said gas port; wherein the mounting means comprises a flange, the flange being configured to connect with the gas port of the pump, the block being mounted to the flange such that the block extends towards the rotor of the pump when the flange is connected with the gas port of the pump.

An exhaust gas recirculation pump system for an internal combustion engine includes an EGR gas source and an electric motor assembly. A roots device is coupled to the electric motor. The roots device includes a housing defining an internal volume wherein the housing includes a radial inlet port receiving the EGR gas source and an outlet port expelling the EGR gas from the housing. Rotors are disposed in the internal volume and connected to the electric motor. A transmission housing is attached to the housing. The transmission housing includes journals formed therein receiving bearings that support the rotors on only a single end of the rotors.

A power saving vacuum machine serves for improving vacuum ability of a condenser of a thermal power generator. The vacuum machine being installed after the condenser and includes a least one valve installed on the vacuum primary tube for sealing a vacuum primary tube to prevent air from entering into the condenser; a front stage pump has an inlet connected to an air inlet tube; at least one root vacuum pump including a main root vacuum pump; the main root vacuum pump including an inlet and a vent opening; the inlet of the main root vacuum pump being connected to a rear end of the vacuum primary tube. The at least one root vacuum pump may be only one pump which is the main root vacuum pump, or the at least one root vacuum pump is a plurality of root vacuum pumps which are connected serially.

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.