According to conventional calculations based on DIN 3990 standard, values of safety factors against tooth breakage for all investigated gearings
The graphical method is the same in principle for all planetary gearing
problems but varies somewhat in the procedure to be followed depending upon whether the mechanism consists (a) of spur gears having the same circular pitch; (b) of spur gears having different circular pitches; or (c) of bevel gears.
The double-helical gearing
is said to eliminate axial loads on the bearings of both the shafts, which means that the rotor bearings are not subject to wear, which is not the case in conventional gear pumps, according to the company.
For several decades, worm gearing
has been used in steel mills, machine tools, conveyors, and similar heavy equipment.
The core of the Berstorff gear pump is a pair of gear shafts with double helical gearing
(figure 1), to prevent axial forces from acting on the bearings of both shafts.