Hysteresis magnet coupling for roots type pumps.

摘要

A hysteresis magnet coupling for a Roots type pump comprises a magnet plate holding member (1) connected to either a pump shaft (3a) or a driving shaft (2), and a hysteresis plate holding member (2) connected to the other of the two shafts. A diaphragm (5) of a non-magnetic material is interposed between the magnetic plate (1a) and the hysteresis plate (2a) and hermetically sealed at its peripheral portion to a pump housing (6). The diaphragm (5) prevents heat generated at the hysteresis plate from transferring to the magnet plate, thereby permitting a stabilized operation of the pump.