1. Group test results
Data of fatigue test results obtained by group method of shot peened gear and non shot peened gear.
According to Chauvenet criterion, the suspicious data of each group were selected and processed. Among them, the test data of each group of shot peened gear are valid, and the data of non shot peened gear are suspicious under the load of 35 kn and 33 kn.
Where, XP is the logarithmic life when the survival rate is p; up is the standard normal deviation; s is the standard deviation; NP is the life when the survival rate is p.
According to the above formula, the fatigue life pairs under different survival rates are obtained.
2. Lifting test results
The fatigue strength limit results of the two processes are tested by the lifting method.
Fatigue limit loads with different survival rates.
3. Root stress calculation
According to the formula in GB / T 14230-1993, the actual root stress under each load is calculated.
In the formula, σ’f is the actual root stress; ft is the nominal tangential force on the dividing circle of the end face; YFe is the tooth shape coefficient of point e under the load; yse is the stress correction coefficient of point e under the load; B is the tooth width; m is the modulus; YST is the stress correction coefficient of the gear; y δ relt is the sensitivity coefficient of the relative root fillet; yrrelt is the condition coefficient of the relative root surface; YX is the calculation bending coefficient Dimensional factor of flexural strength.
According to the above formula, the stress value of the dedendum under each test load is calculated.