Assessment of Worm Gearing for Helicopter Transmissions
Abstract
This report assesses a high-efficiency hydrostatic worm gear drive for helicopter transmissions. The example given is for a large cargo helicopter with three 4000-kW engines and a transmission reduction ratio of 110. The report also contains an efficiency calculation, a description of the test stand for evaluating and feasibility of worm gear hydrostatic mesh, a weight calculation, and a comparison with conventional helicopter transmission of the same power and transmission reduction ratio. Gear trains are extensively used in mechanical systems, but in no other transport vehicle is the relative weight of the transmission as great as in the helicopter. The transmission system is the helicopter's most complex and expensive assembly and requires the most labor-intensive maintenance. In addition, the weight of the transmission is comparable to that of the fuselage. Any substantial progress in the quality of helicopters will most likely come through improvements in their transmission systems. Worm gearing is very attractive for use in helicopter transmission because it can transmit torque from the horizontal engine shaft to the vertical rotor shaft, reducing the revolutions by any ratio necessary in one stage.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1990
- Accession Number
- ADA228257
Entities
People
- Lev Chaiko
Organizations
- National Aeronautics and Space Administration