RNN Rotary Seals

RNN™ Series Differentially Pumped Rotary Seal

Differentially pumped rotary seals (RNNs) provide 360° of continuous rotary freedom through the vacuum wall of a UHV system. The RNN has two stages of differential pumping isolated by graphite-impregnated, expanded, Teflon® seals on special sealing surfaces. A preloaded ball bearing set accurately controls the rotating stage position.

RNNs are available with a worm drive fine adjust option. This allows for easier and more accurate angle adjustment. RNNs are also available with anti-backlash stepping or synchronous motor drive.

RNNs with up to 12″ I.D. are listed. Larger I.D.s have been built with excellent performance. Please consult factory for special applications.

Specifications

• Models with clear inside diameters of 1.53″ to 12″ standard, larger sizes on request
• Bakeable to 150°C
• Stationary and rotation flanges, tapped
• Thickness approximately that of two ConFlat-type flanges
• 2 stage differentially pumped
• Base pressures in 10^-11 Torr range
• 0–360° scale with Vernier, standard

Typical Performance Specifications for RNN-400 and larger models

• Resolution:      <0.004°
• Repeatability:  <0.008°
• Backlash:        <0.035°

Readability Specifications

• Standard scale: 1.0°
• Mechanical counter: 0.1°
• Microstepped motor drive required for maximum resolution

Options

• Fine adjust worm drive
• Digital read-out on fine adjust, 0.1° read-out, mechanical, nonresetable
• Mechanical counter option available
• Anti-backlash stepping motor drive 0.018° per full step (0.0225°/full step on RNN-150/MS), with manual knob
• Custom pumpout tube lengths and crank shaft lengths on /FA units available

Payloads

The standard maximum payloads are listed below. Larger loads may be handled under specific applications. Please consult the factory for custom applications.

• The center of gravity of the payload is within “X” of the polar axis of the unit, where X is equal to 10% of the RNN I.D.
• The center of gravity of the payload is within “Y” distance of the rotating flange on the horizontal mounted units, where Y is the flange I.D.
• The overall maximum size “A” of the payload outside vacuum is:
  Vertical operation: 7 x flange O.D.    Horizontal operation: 5 x flange O.D.    Inverted operation: 7 x flange O.D.

Model No.	Vertical	Horizontal	Inverted
RNN-150	54 lbs	30 lbs	45 lbs
RNN-250	90 lbs	38 lbs	70 lbs
RNN-400	144 lbs	66 lbs	110 lbs
RNN-600	180 lbs	84 lbs	140 lbs
RNN-800	200 lbs	91 lbs	160 lbs
RNN-1000	370 lbs	160 lbs	280 lbs
RNN-1200	430 lbs	200 lbs	350 lbs