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.

The present invention proposes a large industrial vacuum sealer system. The system comprises the following working steps: after materials are placed, a box base moves upwards to be jointed with a box cover in a sealing manner; the first valve 120 is switched on; a rotary vane pump starts roughly pumping the air; next, a roots pump starts working; when the pressure reaches a preset value, the first valve 120 is switched off; valves 110 and the second valve 130 are switched on; diffusion pumps start working; after the air is pumped out completely, all pumps stop working. A box body comprises the box cover and the box base, wherein the box body is fixedly mounted. The box base is driven by air cylinders to move along a rail. In the present invention, a light curtain sensor is mounted between the box cover and the box base.

A motor-driven Roots pump includes a housing, a drive shaft and a driven shaft that have axial lines parallel with each other, and a gear chamber. The housing includes a first partition that has a first defining surface, a second partition having a second defining surface, and a relief recess. An addendum circle of the drive gear and an addendum circle of the driven gear intersect with each other at a first intersection point. A plane that includes both the axial lines is defined as an imaginary plane. The first intersection point is located on a side of the imaginary plane on which the drive gear and the driven gear start meshing with each other. An opening of the relief recess is opposed to the first intersection point and is arranged in a region on a side of the imaginary plane on which the first intersection point is located.

A robot suction hand mountable on an industrial robot and configured to hold a workpiece by suction using a suction unit. The robot suction hand includes: a vacuum pump incorporated in the robot suction hand. The vacuum pump has a housing in which an intake port and an exhaust port are formed, and configured to intermittently take in air from the intake port and intermittently discharge air from the exhaust port. The robot suction hand includes a suction path that communicates with the suction unit and the intake port and a first member made of a porous material. The first member covers the exhaust port.

A vacuum pump comprises rotor elements arranged in a suction chamber. An outlet duct is connected to an exhaust pipe. For the purpose of silencing, sound expansion spaces are provided in the outlet duct, which are integrated into the pump housing. Alternatively or in addition to these sound expansion spaces, sound expansion spaces may be provided in an inlet duct which is used for the inlet of gas ballast, said sound expansion spaces being preferably likewise integrated into the pump housing.

A seal member includes pushing projections that project from a seal body toward at a groove inner-side circumferential surface and are arranged at intervals in a circumferential direction of the seal body. The pushing projections push the seal body against the groove inner-side circumferential surface and a groove outer-side circumferential surface between the groove inner-side circumferential surface and the groove outer-side circumferential surface. This reduces the gap between the groove outer-side circumferential surface and the seal member in the seal accommodating groove. Thus, salt water is unlikely to collect in the gap between the groove outer-side circumferential surface of the seal accommodating groove and the seal member. This improves the corrosion resistance of the housing and the seal member.

A pneumatic system installed on a vehicle and method of using the system to preheat compressor oil and/or components of the system to promote operation in cold weather conditions. The pneumatic system includes a compressor that generates compressed air in which oil is entrained, a separation tank that separates the oil from the air prior to the oil being returned to the compressor, and a heating element located within the separation tank and contacting the oil within the separation tank. Engine coolant of an engine cooling system of the vehicle flows through the heating element and the heating element transferring heat from the engine coolant to the oil within the separation tank to increase the temperature of the oil.

A blower may include a blower housing that may include a plurality of rotor chambers and a plurality of rotors. The plurality of rotors may be substantially identical and each may include a twist angle and a helix angle. The rotors and the blower housing may be configured to create internal fluid compression when the rotors are rotating at a first rotational speed and not to create internal fluid compression when the rotors are rotating at a second rotational speed. The rotors and the blower housing may be configured to create the internal fluid compression without backflow slots in the blower housing. The twist angle may include the angular displacement of lobes of the plurality of rotors between axial ends of the plurality of rotors. The helix angle may be a function of the twist angle and a pitch diameter of the plurality of rotors.

Disclosed is a system for treating exhaust fluid from semiconductor manufacturing equipment in which cleaning gases decomposed by a plastic apparatus alternately flow towards a front rotor region (a main rotor unit) and a rear rotor region (a subsidiary rotor unit) of a booster pump and then flow towards a dry pump, and thus uniformly react with process byproducts present throughout the whole area in a vacuum pump including the booster pump and the dry pump so as to improve removal efficiency of the process byproducts. Further, the retention time of the cleaning gases decomposed by the plasma apparatus in the vacuum pump is increased by adjusting the pressure in the pump with the rotational speed of a motor, and thus the reaction time of the cleaning gases with the process byproducts is increased, so as to further improve removal efficiency of the process byproducts, such as SiO.sub.2 powder.

A non-lubricated system for pumping a gas, includes a stationary stator with a housing that includes a rotor cavity and at least one rotatable rotor element incorporated within the rotor cavity. The stator includes at least one self-supporting sealing element, incorporated within the rotor cavity between an end face of at least one of the rotor elements and an interior wall of the housing to form a seal along the corresponding end face. At least one self-supporting sealing element is provided with an abradable coating on at least one side facing the rotor.