A supercharger includes a main housing, a front cover coupled to the main housing and having an inner portion received within the main housing, a drive coupling assembly arranged between an input shaft and a rotor shaft, and a coupling sleeve disposed about the drive coupling.

A rotor-chamber wall of a motor-driven Roots pump has a suction port and a discharge port. The side on which the discharge port is located with respect to a plane that includes both the rotational axis of a drive shaft and the rotational axis of a driven shaft is a first side. A first partition wall defines a gear chamber and has a first recess on the first side. A second partition wall defines the gear chamber and has a second recess. The first partition wall has a first oil supply passage that is configured to supply oil from the first recess to a first seal accommodating recess. The second partition wall has a second and a third oil supply passages. The second and the third oil supply passages are configured to supply oil from the second recess to a second and a third seal accommodating recesses, respectively.

[Object] To efficiently supply lubricant oil to a bearing member with a simple mechanism. [Solving Means] A vacuum pump includes a first housing, a second housing, a rotor shaft, a lubricant oil-stirring plate, and a bearing member. The second housing is attached to the first housing and forms a space that stores lubricant oil together with the first housing. The rotor shaft passes through the first housing. The lubricant oil-stirring plate is housed in the space and is attached to the rotor shaft. The bearing member is fixed to the first housing and rotatably supports the rotor shaft. The first housing includes a supply port that enables lubricant oil to be supplied to the bearing member. The second housing includes an inner-wall upper portion which the lubricant oil stirred by the lubricant oil-stirring plate hits against. The inner-wall upper portion of the second housing includes a recess portion that enables the lubricant oil to move above the supply port.

A vacuum system is disclosed. The vacuum system includes a first pump bay and a second pump bay enclosed by an enclosure. Each pump bay houses a motor and a vacuum pump driven by the motor. An inlet manifold and an exhaust manifold are in fluid communication with the first and second pump bays. The inlet manifold and the exhaust manifold are arranged to flow air through the pump bays to cool at least the vacuum pumps.

The invention relates to a volumetric compressor (100) including a container (51) for collecting the lubricant moved by an oil distribution disc (1). The compressor (100) further comprises at least two lubricant distribution channels (52), in which each lubricant distribution channel (52) extends from the collecting container (51) so that during operation, the lubricating oil flowing along the channel itself reaches a lubrication opening (82) of a lubrication duct (81) for a rolling bearing (90) of a rotor (80, 80). The lubrication opening (82) is arranged at a lower level with respect to the container (51).

The invention relates to a volumetric compressor (100) including a container (51) for collecting the lubricant moved by an oil distribution disc (1). The compressor (100) further comprises at least two lubricant distribution channels (52), in which each lubricant distribution channel (52) extends from the collecting container (51) so that during operation, the lubricating oil flowing along the channel itself reaches a lubrication opening (82) of a lubrication duct (81) for a rolling bearing (90) of a rotor (80, 80). The lubrication opening (82) is arranged at a lower level with respect to the container (51).

A leak detector is provided for leak-testing objects that are to be tested by spraying tracer gas, the leak detector including: a detection inlet configured to be connected to an object that is to be tested; a pumping device including a vacuum line connected to the detection inlet, a rough-vacuum pump connected to the vacuum line, and a turbomolecular vacuum pump connected to the vacuum line, a delivery of which is connected to the rough-vacuum pump; and a gas detector connected to the turbomolecular vacuum pump, the pumping device further including an ancillary pump connected to the rough-vacuum pump and being configured to lower an ultimate-vacuum pressure of tracer gas in the rough-vacuum pump. A leak detection method for leak-testing objects that are to be tested by spraying tracer gas is also provided.

A vacuum roots blower includes a rotor capable of being rotated to capture a gas from an inlet and further rotated to discharge the captured gas from an outlet. The captured gas is held within a pocket formed between lobes of the rotor and the adjacent housing within which the rotor is rotated. The vacuum roots blower includes a pressure relief system capable of delivering a pressure relief gas to the pocket. The pressure relief system includes a sonic passage structured to produce a choked flow condition as the pressure relief system fills the pocket with pressure relief gas. In one form the pressure relief gas can be a cooling gas, but other forms such as ambient air are also contemplated.

An air boost system for a two-cycle engine, such as an EMD engine, which operates with one or more roots blowers, or for similar engines that use gear-driven roots blowers or centrifugal blowers. At least one of the roots blowers is equipped with a variable transmission, which allows airflow into the engine to be varied in accordance with load or other engine operating conditions.

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.