Abstract
In order to obtain lighter, more compact, and more effective turbine-driven propulsion gears, it is necessary to know the actual load carrying capacity of reduction gears as close as possible.
This paper describes some results of the load tests performed on the large size models of reduction gears, by means of a gear testing machine having the center distance 720mm. All of the test gears were five and double-helical. Three pairs were failed by pinion tooth breakages.
Non-modified-shaved gears was failed after K=350psi load run. At that time, it had operated at that load for 10×107 load cycles. Pittings were appeared after the tests were over.
Modified-shaved gears was failed after K=400psi load run, and it had operated at that load for 5×107 load cycles: However, it did carry over K=350psi load before failing. Similarly, shaved and honed gears carried K=350psi load successfully. Pittings appeared at loads K=250-350psi.
In addition, this paper deals with the tooth load distributions by measuring actually the stress in the root fillet, temperature difference between gear and pinion, and temperature distributions in the tooth face.
As a result of these tests, so many important influence factors such as design features, materials, and manufacturing process as they relate to the load carrying capacity of reduction gears, can be evaluated more accurately.
