Force Sensing System.
DEPARTMENT OF THE NAVY WASHINGTON DC
Pagination or Media Count:
This patent discloses an apparatus for measuring thrust loading on a rotating shaft. A plurality of strain gages, electrically connected in parallel and series to form one arm of a Wheatstone bridge circuit, are mounted at equal intervals on a thin strap or band formed to surround the shaft with a predetermined hoop load. Lubricating material disposed between the shaft and the band prevents transfer of friction forces from the shaft to the band. As the thrust loading increases, shaft dilation girth increase causes the band to stretch and increase its stress. This hoop stress is measured by the strain gages mounted on the band, and is transmitted as the output signal produced by the bridge via radio telemetry or slip rings to a remote indicator. A second arm of the Wheatstone bridge circuit, to provide compensation for temperature effects, can be provided by an additional strain gage mounted on a block of material identical to that of the shaft which block is in turn mounted on the above thin strap or band.
- Marine Engineering