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 PerfectPitchTM 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 axial efforts on the internal elements
  • 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 compared to some competitors data, but Reckon wants every customer to be satisfied, rather than overstating products capacity.
  • We use only carburized and quenched satellite gears, as they allow tough operating conditions (sharp acceleration, emergency stops, fast reversals...)
  • We source all bearings (like the massive angular contact bearings in the Booster range or the tappered rollers featured in the X-Treme and Ultimate ranges)
  • 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, so the gears are not free to displace axially or bend. The high stiffness provided ensures that gears pitch-lines stay well-aligned during the acceleration phases instead of bending. Efforts are distributed alongside the pitch-line rather than focused at teeth ends.
  • All our cages are held by 2 bearings, one at each side (except in the X-Treme), in order to increase stiffness. Good gearboxes are stiff!



Thanks to the PerfectPitchTM concept, Reckon low-backlash planetary gearboxes are quiet, reliable and calculated for a long lifetime in tough working conditions.


Related products

NEW Access line!

NEW Access line!

Access was developped to offer the lowest price on the market of low-backlash planetary gearboxes. Yet it features carburized and ground planets, 5 arc-min backlash, monobloc housing, NTN bearings and probably the best lubricant on the planet : our usual Sumico gear grease!

New torque ratings!

New torque ratings!

Internal gear design was improved on the X-Treme, Booster and Ultimate series, with an increase of power of up to 60%!

Silent and safe by design

Silent and safe by design

The PerfectPitch concept is a combination of features that we believe are necessary to provide silent, reliable planetary gearboxes.


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