It is generally considered that spur gears are noisier than helical gears.

Acoustic waves, indeed, are generated by most planetary gearboxes having straight teeth because the "contact ratio" of the internal gears (number of teeth in contact) is generally below 2.0 in spur gear stages, and 2.0 is the limit after which a gear stage becomes quiet because 2 teeth are always in contact.

Thanks to the helix angle allowing more teeth to be contact at the same time, the contact ratio is generally higher than 2 in helical gearboxes, so they can be more silent.

On the other hand, helical gears generate high axial efforts to the internal components of the gearbox such as bearings or friction disks, so such construction can be prejudicial to a planetary gearbox life if some rules are not respected. The more helix angle, the more efforts on the bearings!

So we developed the PerfectPitch^TM concept:

• Reckon helical gearboxes all use the smallest helix angle possible, in order to provide a contact ratio of 2 in any reduction ratio while limiting the axial loads generated by helical gear components

• Every gearbox is tested for noise at up to 6,000 rpm (when compatible with max. allowed speed) before shipment

• We performed all gear calculation based on 20,000 hours of use minimum  with a servomotor at maximum rated torque or 2,000 hours at maximum acceleration torque.

• ​We always publish conservative torque ratings, using an application factor 1,25 as a minimum. The result might appear pessimistic, but Reckon wants every customer to be satisfied, rather than overrating products capacity.

• We use only carburized and quenched planet gears, as they allow tough operating conditions (sharp acceleration, emergency stops, fast reversals...)

• We source all bearings from premium suppliers (like the massive tappered rollers bearings in the X-Treme and Ultimate lines)

• We performed all bearing calculation based on combined maximal torques combined with maximal axial and radial forces over 20,000 hours

• We designed our planet carriers with cages (except for the Spirit line), so the gears are not free to displace axially or bend. The extra stiffness provided ensures that gears pitch-lines stay well-aligned during the acceleration phases instead of bending. Transmission load is distributed alongside the pitch-line of the gears rather than focused at gear teeth ends.