Feasibility study of negative lift circumferential type seal for helicopter transmissions
- Goldring, E. N.
- Oct 1, 1977.
- Physical Description:
- 1 electronic document
- Restrictions on Access:
- Unclassified, Unlimited, Publicly available. and Free-to-read Unrestricted online access
- A new seal concept, the negative lift circumferential type seal, was evaluated under simulated helicopter transmission conditions. The bore of the circumferential seal contains step type geometry which produces a negative lift that urges the sealing segments towards the shaft surface. The seal size was a 2.5 inch bore and the test speeds were 7000 and 14,250 rpm. During the 300 hour test at typical transmission seal pressure (to 2 psig) the leakage was within acceptable limits and generally less than 0.1 cc/hour during the last 150 hours of testing. The wear to the carbon segments during the 300 hours was negligible.
- NASA Technical Reports Server (NTRS) Collection.
- Document ID: 19780009447., Accession ID: 78N17390., and NASA-CR-135302.
- No Copyright.
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