Truck gearboxes are dimensioned for infinite life at max- imum torque regarding contact stresses and bending...
Truck gearboxes are dimensioned for infinite life at max- imum torque regarding contact stresses and bending stresses for all gear steps. Car gearboxes are dimen- sioned for finite life according to typical running con ditions. Maximum torque for the first gear can typically be maintained only 3 to 6 s for each acceleration before the maximum speed is reached. If a driver accelerates at full power 20 times per day for 20 years on the first gear, the required life is only 60 to 120 hr. The normal load spectrum gives a life of 200,000 km for 99% of the gearboxes. his 10-ton boat 50 km (the distance between his home and the harbor) during the 10-year life of the car. Cal- culate how much of the 200,000-km nominal life of the gearbox is consumed by the boat moving if the life is in- versely proportional to the load raised to the 3.2 power Assume that during the move the gearbox load is four times higher than normal. Ans. 42.25% of the gearbox life. A driver uses the car twice a year to move