Compute the required basic dynamic load rating, C, for a ball bearing to carry a radial load of 650 lb from a shaft rotating at 600 rpm that is part of an assembly conveyor in a manufacturing plant.
Compute the required basic dynamic load rating, C, for a ball bearing to carry a radial load of 650 lb from a shaft rotating at 600 rpm that is part of an assembly conveyor in a manufacturing plant.
From Table 14–4, let’s select a design life of 30 000 hours. Then L_d is
L_d = (30 000 h)(600 rpm)(60 min/h) = 1.08 × 10^9 rev
From Equation (14–3),C=P_d(L_d/10^6)^{1/k}
C = (650 lb)(1.08 × 10^9/10^6)^{1/3} = 6670 lb
TABLE 14–4 Recommended Design Life for Bearings | |
Application | Design life L_{10}, h |
Domestic appliances, instruments, medical apparatus | 1000–2000 |
Aircraft engines | 1000–4000 |
Automotive | 1500–5000 |
Agricultural equipment, hoists, construction machines | 3000–6000 |
Elevators, industrial fans, multipurpose gearing, rotary crushers, cranes | 8000–15 000 |
Electric motors, industrial blowers, general industrial machines, conveyors | 20 000–30 000 |
Pumps and compressors, textile machinery, rolling mill drives | 40 000–60 000 |
Critical equipment in continuous, 24-h operation; power plants, ship drives | 100 000–200 000 |