Page 20 - Gear Technology Solutions

and 0.4 presenting a realistic range for the application in automobiles, Values
above 0.4 will already restrict the back driving and present an unwanted high
engine brake effect.

1.6 Efficiency

The efficiency is calculated for coast and drive side (see Figure 4), using a
simplified approach similar to the traditional CAGE dimension sheet efficiency.
The new calculation in UNICAL considers the critical length sliding diameter of
pinions which shows in the result the distinct differences between straight
bevel gears, spiral bevel gears, hypoid gears and super reduction hypoids.

Figure 4: Special Methods Dimension-Sheet
part 4, efficiency

The mentioning of 30,000PSI, which is 12% of the allowable contact stress
endurance limit of average grade carburizing steel, has the intention to clarify
that the calculated efficiency values apply for operating conditions under light
load. In contrast to the traditional CAGE Dimension-Sheet, the new efficiency
calculation shows values for coast and drive side.

In case of a higher accuracy requirement of the efficiency values, it is
recommended to use the GEMS efficiency module which is based on the true
generated flank surfaces in connection with a precise Thermo-Elasto-
Hydrodynamic computation. The GEMS efficiency module creates a table with
efficiency values versus speed and torque which is also shown as a three-
dimensional graphic.

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