Edwards Limited

Martin Ernst Tollner

Barrie Dudley Brewster

Paul David Flower

Mark Spitteler

A pump insert () for supporting a rotor () of a pump comprises an annular resilient support () for engaging the body () of the pump, the support () extending about a rolling bearing () having an inner race () for engaging the rotor (), an axially preloaded outer race () fixed to the support (), and a plurality of rolling elements () located between the races. During assembly, the rolling bearing () can be accurately positioned within the support () so that there is a very low tolerance stack-up when the insert () is fitted to the rotor (). Consequently, the position of the rotor () will hardly change, if at all, when the rolling bearing () is replaced during servicing of the pump.

Vacuum pump

The present invention provides a vacuum pump () which comprises a turbo-molecular pumping mechanism () in series with a Siegbahn pumping mechanism (). A first pump inlet () is provided through which gas can pass through both the turbo-molecular pumping mechanism and the Siegbahn pumping mechanism. Additionally, an inter-stage (inlet) is provided through which gas can enter the pump at a location between the turbo-molecular pumping mechanism and the Siegbahn pumping mechanism and pass only through the Siegbahn pumping mechanism. There are flow channels () in a first plurality of stages () of the Siegbahn pumping mechanism which are in fluid communication with the inter-stage inlet () and gas entering the pump through the inter-stage inlet is pumped in parallel along said flow channels.

A vacuum pump comprises a housing, a drive shaft supported by a beating arrangement for rotation relative to the housing about an axis, and a pumping mechanism comprising a stator component mounted on the housing and a disk-shaped rotor component mounted on the drive shaft axially proximate the stator component. The bearing arrangement comprises a bearing supported in both radial and axial directions by a resilient support, comprising inner and outer annular portions connected by a plurality of flexible members, so that there is a fixed relation between the inner race of the bearing and the outer portion of the resilient support to determine the axial clearance between the rotor and stator components of the pumping mechanism.

The present invention relates to a method of setting the pressure in a chamber of a vacuum system to a required pressure, the system comprising a pressure control system including a pump for evacuating gas from the chamber and a flow controller for allowing the flow of gas into the chamber, the method comprising setting an initial flow into and/or out of the chamber for achieving a pressure above the required pressure so as to increase the rate of pressure increase, the initial flow occurring over a transient period which does not allow the pressure to exceed the required pressure, and setting a preset flow into and/or out of the chamber after the transient period has elapsed for achieving and maintaining the required pressure.

Pressure control method

A method of operating apparatus for controlling the pressure in a process chamber (), the apparatus comprising a first pump unit () having an inlet in fluid connection with an outlet of said process chamber, and a second pump unit () having an inlet in fluid connection with an outlet of the first pump unit via a flow control unit () comprising a variable flow control device () having variable conductance for controlling outlet fluid pressure at the outlet of the first pump unit, the method comprises controlling speed of the first pump unit to increase the range of chamber pressures over which control of the outlet fluid pressure produces changes in said chamber pressure without exceeding the thermal limit and/or motor stall limit of the first pump unit.

Growing community of inventors

Eastbourne, United Kingdom

Martin Ernst Tollner