US Patent 11280340 Variable inlet conductance vacuum pump, vacuum pump arrangement and method

A vacuum pump, vacuum pump arrangement and method are disclosed. The vacuum pump includes at least one rotor; and a stator, an inlet for receiving gas during operation; and an exhaust for exhausting the gas. The vacuum pump includes a shaft extending through a centre of said pump and comprising a plate mounted on an end of the shaft towards the inlet. The vacuum pump includes control circuitry configured to control an axial position of the plate, a change in axial position of the plate providing a change in inlet conductance of gas to the vacuum pump. The plate is mounted such that it extends beyond the inlet in at least some axial positions of the rotor such that the plate is not on the same side of the inlet as the stator.