Studies on Power Train and Durability of Small Powered Tractors (III)
Life of Gear
1977 Volume 38 Issue 4 Pages 489-496
Details
1977 Volume 38 Issue 4 Pages 489-496
To study the gear strength of small powered tractors, we theoretically calculated the gear strength, and measured the transmissibility of tractors both in the field and in bench tests, and estimated the bending-fatigue-limit of gears by progressive stress tests. The results obtained were as follows:
1. Increasing the output-shaft-load, the drive power differences between every shaft of tractor were measured.
2. The abrasion of small powered tractor gears suddenly increased when running hour reached 300hr. Especially, the high abrasion was occured for the gears which number of teeth was few and rotational speed was fast.
3. The static and fatigue-bending-strength of the gears was nearly in proportion to the tensile strength of steel gears.
4. The repetitive number of bending-fatigue-limits of small powered tractor gears was estimated to be about 1-3×106.
5. The fatigue coefficient of small powered tractor gears was 2.0-2.3.
6. The bending-fatigue-limit values, estimated by Prot and Henry methods, almost agreed with the results obtained by S-N curve. The bending-fatigue-limit of gears can easily be estimated by using only a few data of the progressive-stress-method.
