Lust CDA3000 - A.2.10 Efficiencies, Coefficients of Friction and Density

A-30
Engineering Guide CDA3000
Appendix A Formula bank
A.2.10Efficiencies,
coefficients of
friction and
density
Efficiencies of transmission elements
Transmission
element
Characteristic Efficiency
Wire cable
Each complete wrap of the cable reel (friction
or roller bearing supported)
η
= 0.91 - 0.95
V-belt
Each complete wrap of the V-belt pulley (nor-
mal belt tension)
η
= 0.88 - 0.93
Plastic belts
Each complete wrap; rollers on roller bearings
(normal belt tension)
η
= 0.81 - 0.85
Rubber belts
Each complete wrap; rollers on roller bearings
(normal belt tension)
η
= 0.81 - 0.85
Chains
Each complete wrap; chains on roller bearings
(depending on chain size)
η
= 0.90 - 0.96
Spindles
Trapezoidal threaded spindle
Recirculating ball spindle
η
= 0.30 - 0.70
η
= 0.70 - 0.95
Table 7.16 Efficiencies of transmission elements