Contact patterns in extremity
They present a major risk of rupture of gears and tires. The Hertzian pressure initially planned to cover 100% of the width, then increases so inversely proportional to the support width. This defect becomes really critical when the range does not exceed 30% of the width (pressure multiplied by 4). The increase in pressure can cause:
- The appearance of surface damage (pitting, chipping, seizing)
- Cracks or even tooth breakage (with high risk if the piece gets stuck between pinion and girth gear)
- An asymmetric wear generating a irreversible flatness defect in case of setting (loss of contact pattern if setting modification)
- On the teeth, a temperature difference higher than 4 degrees requires an adjustment.