Design criteria for closed type gear drive with soft teeth
Closed soft tooth face transmission: meet the fatigue strength of tooth surface, meet the root bending fatigue strength
1. closed soft tooth surface transmission: to ensure the tooth surface contact fatigue strength, meet the root bending fatigue strength;2. closed hard toothed surface or open gear drive: under the premise of ensuring the bending fatigue strength of tooth root, to meet the tooth surface contact fatigue strength
Therefore, the general should first according to the tooth surface contact fatigue strength condition, pitch diameter and the main geometric parameters (such as the calculation of gear center distance, tooth width etc.), then check the bending fatigue strength of gear teeth. When using the hardened (tooth surface hardness more than 350HBS), generally should first press the gear bending fatigue strength condition, determine the modulus gear and the main geometric parameters, and then check the tooth surface contact fatigue strength.
Closed hard toothed surface or open gear drive: meet the fatigue strength of tooth surface under the premise that the tooth root bending fatigue strength is guaranteed. The main failure modes of the closed drive are the pitting on the tooth surface and the bending fatigue fracture of the gear. When using a soft tooth surface (tooth surface hardness is less than or equal to 350HBS), the tooth surface contact fatigue strength is relatively low.
