A system for maintaining a high vacuum in a vacuum enclosure such as cryostat, for example, is described. The system includes a high-vacuum pump having an input that is connected to the cryostat and an output. A vacuum vessel is connected to the output of the high-vacuum pump. A second vacuum pump is connectable to the vacuum vessel. The system is operated such that the high-vacuum pump maintains the cryostat at a high vacuum and the second vacuum pump is periodically operated to maintain the pressure of the vacuum vessel below a threshold pressure. The second vacuum pump may be either permanently connected to, or removable from, the vacuum vessel. The vacuum vessel acts to maintain the output of the high-vacuum pump within a suitable pressure range. This removes the need for the output of the high-vacuum pump to be connected to a continuously operating, second-stage vacuum pump. Furthermore, the second vacuum pump is only required to be operated periodically in order to maintain the pressure in the vacuum vessel below the threshold pressure.

A pumping device intended to be connected to a process chamber (2) includes a dry primary vacuum pump, an auxiliary pump mounted so that the auxiliary pump bypasses a check valve on the vacuum pump, a first valve device connected to a purging device for purging the dry primary vacuum pump and intended to be connected to a gas supply, a second valve device mounted so that the second valve device bypasses a check valve upstream from the auxiliary pump, and a controller configured to control the first and second valve devices on the basis of an operating status of the process chamber in such a way that the first valve device is at least partially closed and the second valve device is open when the process chamber is operating at ultimate vacuum. Also a method for pumping of a process chamber by way of such a pumping device.

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.