According to one embodiment, an exhaust system includes a first pump unit, a second pump unit, a shaft, and a motor. The first pump unit includes a first exhaust chamber, a first intake port, a first exhaust port, and a first rotor. The first intake port, the first exhaust port, and the first rotor are provided in the first exhaust chamber. The second pump unit includes a second exhaust chamber, a second intake port, a second exhaust port, and a second rotor. The second intake port, the second exhaust port, and the second rotor are provided in the second exhaust chamber. The shaft links the first rotor and the second rotor. The motor causes the first rotor, the second rotor, and the shaft to rotate.

A roots pump includes a housing, a rotor chamber, a pair of rotary shafts, and a pair of rotors. The rotor chamber includes a rotor chamber peripheral surface facing a pair of distal end portions of each of the rotors. Each of the pair of the distal end portions includes: a pair of rotor peripheral surfaces facing the rotor chamber peripheral surface with a first radial clearance; and a distal end peripheral surface that is formed between the pair of the rotor peripheral surfaces in the rotational direction and faces the rotor chamber peripheral surface with a second radial clearance greater than the first radial clearance. A width of the rotor chamber peripheral surface facing the distal end peripheral surface in the rotational direction is greater than a sum of a pair of predetermined widths of the rotor chamber peripheral surface facing the pair of the rotor peripheral surfaces.

Provided is an air compressor which helps to attain a proper discharge air temperature and which is superior in energy saving property. There are provided an air line connecting an air compressor, an oil separator, and an after cooler; an oil circulation line connecting the air compressor, the oil separator, and an oil cooler; a bearing oil supply line connecting one end of an intermediate branching portion disposed at an intermediate point of the oil circulation line between the oil cooler and the air compressor to a bearing oil supply portion of the air compressor; an intermediate portion oil supply line connecting the other end of the intermediate branching portion to an intermediate oil supply portion of the air compressor; a branching line supplying oil to the bearing oil supply portion and the intermediate oil supply portion; a blower sending air to the oil cooler and the after cooler; a bypass line connecting one end of a bypass branching portion disposed at an intermediate point of the oil circulation line between the oil separator and the oil cooler to the downstream side of the oil cooler of the bearing oil supply line; and a control valve controlling the inflow amount of the lubricating oil to the bypass line.

A screw compressor for a utility vehicle includes a housing. The housing is filled with oil. At least one pair of compressor screws are mounted in the housing and serve to compress air supplied to the screw compressor. In the assembled state, a heat exchanger is directly placed onto and installed on the housing, by which heat exchanger the temperature of the oil contained in the housing can be controlled.

A screw compressor for a utility vehicle includes a housing. The housing is filled with oil. At least one pair of compressor screws are mounted in the housing and serve to compress air supplied to the screw compressor. In the assembled state, a heat exchanger is directly placed onto and installed on the housing, by which heat exchanger the temperature of the oil contained in the housing can be controlled.

A rotary blower includes a housing and a pair of meshed rotors. The meshed rotors are disposed in the housing. Each rotor has a plurality of lobes. Each lobe includes a lobe tip seal insert mounted thereon. The lobe tip seal insert is disposed at a tip of the each lobe. Each lobe tip seal insert is constructed to seal against the housing and to prevent or reduce leakage between each lobe and the housing.

A dry-compressing vacuum pump, in particular a screw pump, has two rotor elements (14) which are arranged in a pump chamber (12) and which are each carried by a rotor shaft (22). Two shaft ends of the rotor shafts (22) project through a side wall (28) of the pump housing (10). On the two shaft ends (28) there is arranged in each case one toothed belt pulley (38). Furthermore, a drive device and an electric motor for driving the rotor shaft (22) are provided. According to the invention, the rotor shafts (22) are driven by means of a toothed belt (40). To be able to use a toothed belt for drive purposes, a rotational flank clearance between the two rotor elements (14) of greater than 0.75, in particular greater than 1, is provided.

A two-stage rotary compressor for gas, in particular air. The compressor comprises a bottom plate and a head enclosing between them two compression stages. The compressor is characterized in that an interconnection device is arranged between the two compression stages, said device being suited to establish a communication in series or in parallel, to be selected by the manufacturer, between said two compression stages.

The invention enables quick evacuation of a chamber to a specified target degree of vacuum while increasing selectivity of evacuation conditions. A vacuum-processing device contains a chamber 40 that enables a workpiece to be soldered in a vacuum environment, an operating part 20 that sets a condition for evacuating the chamber 40, a pump 23 that evacuates the chamber 40, and a control portion 61 that calculates the amount of decrease in the degree of vacuum when evacuating the chamber 40 using a predetermined pump output, sets the calculated value as a reference value and switches an evacuation property from the evacuation property including a lower pump output to the evacuation property including a higher pump output when the calculated amount of decrease in degree of vacuum in real time has become smaller than the reference value.

A system for noise and vibration management of a smoke evacuation system includes a pump that compresses air and produces a pressure differential within an airflow path. The pump may be a sealed, positive displacement pump. The system includes vibration absorption mechanisms disposed between inner and outer housings, as well as on the outside surface of the outer housing. Methods of controlling and regulating a motor of the system to preserve the lifespan of the motor and maintain consistent airflow rates throughout the smoke evacuation system include varying a supply of electrical current to the motor so that it can operate at variable performance levels. Orifices are opened and closed in order to relieve resistance pressures within the airflow path due to clogging and blockages.