Differentially Pumped Rotary Feedthrough - DPRF Series

Introduction to the DPRF Range

Differentially pumped rotary feedthroughs (DPRF’s) are of annular construction to enable a probe or similar device to be inserted into a UHV environment and rotated.

There are three versions of DPRF; coarse, manual high precision, and motorised high precision. The coarse version uses a steel bar to attain manual rotation, the high precision version uses a worm and wheel gearing to attain manual rotation, and the motorised version uses a stepper motor linked to the worm and wheel to obtain driven rotation. All of the DPRF’s have high thrust and radial load capacities; see technical information for more details.

The DPRF may be used in conjunction with an appropriate high precision translator (see the manipulation section later in this catalogue). In this case you have the option of including an internal bearing support tube as part of the rotating assembly. This is recommended when the item that is required to be rotated needs additional support. As an example, a DPRF coupled to an Omniax manipulator with a rotating support tube is used to hold and rotate the liquid helium cryostat in the Cryoax manipulator.

Method of Operation

The vacuum envelope is constructed from stainless steel and all non-demountable joints are welded.

The rotating member (1) is supported by two deep groove ball bearings (2) and is sealed to the housing by two separated PTFE ‘U’ seals (3), the sealing surfaces having a super polished sealing surface. The interspace between the two ‘U’ seals is connected to a 34 mm OD mini flange (4) projecting radially from the body. 

The differential pumping connection is made to this flange. An engraved protractor ring (5) is adjustable for rotary position. The precision and motorised DPRF's have a gear system (6 and 7) which drives the rotating housing either by means of a calibrated handwheel (8) or by means of a stepper motor.

Main components of the DPRF rotary feedthrough - Click to enlarge drawing