Shaft Revolution Indicator Equipment
Abstract
The subject equipment was set up and subjected to as many of the tests required for shaft systems as possible. Particular attention was given to the indicator while it was under test for shock and vibration integrity. The usual inspection of the equipment, as to design, material and workmanship concluded the test. (a) The test results indicate that the equipment requires further development to improve its shock and vibration integrity. Under shock the maximum indicator error attained was 14 r.p.m., and under vibration the error increased to 160 r.p.m. The pointer failed to return to zero when the transmitter was stopped. One of the indicator "Lord" rubber mountings was torn away during these tests. (b) The transmitter, although of a rugged design, does not function properly when inclined 30 degrees from normal. The unidirectional driving gear does not mesh properly with the transmitter shaft under this condition. Also, a better seal should be provided for the shafts extending through the partition between the gear and contact chambers to prevent leakage of the lubricant. The use of a rubber gasket for the gear chamber cover is questionable. (c) It appears possible that this type of indicator can be made to comply with the accuracy requirements for shaft r.p.m. repeaters, but not for master indicators. The temperature compensation feature is considered effective as there was no increase in error over an ambient temperature range of 0 deg C to 65 deg C. The pointer oscillates considerably when the indicator is deliberately rocked by hand, and although the oscillation might not occur with the normal motion of a ship, it is believed that the pointer movement should be more damped. (d) The indicator driving motor requires a current of 0.85 amperes for reliable operation while causing the pointer to indicate 400 r.p.m. The voltage required to maintain this current varied from 12.4 volts at 24 deg C to 14.2 volts at 65 deg C.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 24, 1939
- Accession Number
- AD1158812
Entities
People
- J. R. Coomes
- J. S. Bryant
Organizations
- United States Naval Research Laboratory