Mechanical Efficiency
Mechanical efficiency measures the effectiveness of a machine in transforming the energy and power that is input to the device into an output force and movement. Efficiency is measured as a ratio of the measured performance to the performance of an ideal machine:
| Transmission Elements | Efficiency | Wire Ropes | per complete wrap around drums (sleeve or anti-friction bearings) η = 0.91 – 0.95 |
|---|---|
| V-Belts | per complete wrap of the belt around the pulley (with normal belt tension) η = 0.88 – 0.93 |
| Polymer Belts | per complete wrap (rollers have anti-friction bearings) (with normal belt tension) η = 0.81 – 0.85 |
| Rubber Belts | per complete wrap (rollers have anti-friction bearings) (with normal belt tension) η = 0.81 – 0.85 |
| Chains | per complete wrap (gears have anti-friction bearings) (dependent on chain size) η = 0.90 – 0.96 |
| Spindles | (Acme) η = 0.30 – 0.70 |
| Spindles | (Ball) η = 0.70 – 0.95 |
| Gear Units | per stage of helical/bevel gears, oil lubricated, dependent on gear unit quality η = 0.97 – 0.98 for helical-worm or worm gear units consult the manufacturer’s information |