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Helical Gear: Spur- or helical gearing?

For years, there is a battle going on between suppliers of servo-gearboxes, with centrally the question of what is better, spur- or helical gearing? We were surprised when we saw at the Hannover Messe 2013 that two of our competitors, which offered for decades spur-gear gearboxes, suddenly had gone over to helical gearing! This puts their arguments to choose for spur gearing in a different light. What struck us even more is that one of those suppliers copied the input side of Apex Dynamics. The clamping ring for the motor is even a 1:1 copy ! Actually we are very pleased with our slogan ” Apex Dynamics runs faster! “, as we also run faster when it comes to innovation.

The A-series gearboxes from Apex Dynamics, AB , AD , AE , AF , AL, AN series, are all equipped with helical ( Spiral ) gearing. We have chosen this for the following reasons:

  • less vibration
  • less noise
  • No synchronization errors
  • Higher torques

This does not mean that in some cases a spur-gear gearbox will not do the job perfectly. And that’s why we deliver the Apex Dynamics PA , PB, PE , PG , PN and PS with spur gearing.

Actually the gearbox has basically different design criteria:

Designing a gearbox with helical gearing is way different as a gearbox with spur gearing. Think of absorbing axial forces, without compromising on the axle-loads and the efficiency of the gear. Since applications where a gearbox with helical gearing is used, the requested torques, dynamics , inertia, backlash and stiffness are in most cases higher. This means that the gearbox is more high-end with regards to all used materials, seals, lubrication and bearings to meet these demands .

This proves once more that the portfolio of Apex Dynamics is well matched:

  • The medium end gear with spur gearing ( P series )
  • The high end gear with helical gearing ( A series )

A tip: how do you determine whether a gear has spur or helical gearing?


A gearbox with spur gearing is howling at medium- or higher speeds. Think of a car, in the reverse gear the car is howling even at low speeds. In forward gear the car’s drive line is practically silent due to the use of helical gearing.

Which choice is best for you? That is, of course, depending on the application. We like to advise you objectively because we can offer both variants.

So spur or helical ….. Apex Dynamics runs faster !