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Helical Gears 101

November 27, 2019

Helical Gears 101

Chosen for their ability to provide reduced friction, heat, and noise in comparison to other gear types, helical gears are defined by their unique profiles which feature an array of unique cuts on the gear edge. Each tooth serves the purpose of interlocking with the teeth of the opposite helical-type gear that feature teeth that run in the opposite direction.


Helical gear configurations operate like any other gear where rotation is achieved through the interlocking of teeth – but are more restrained and gradual than other gear types. This is largely due to the way in which their teeth interact in relation to axis rotation. The axis can either be fixed parallel or crossed at a 90-degree angle.


Various Advantages


  • Ideal for carrying higher load applications due to the increased number of teeth in contact
  • Capable of transferring motion and power in both parallel and straight angle axes
  • Load is distributed evenly across axes, resulting in less wear and tear over time
  • Angled teeth come into contact slowly and gradually, resulting in reduced noise and smoother operation


Common Types


There are three main classifications of helical gears: crossed-axis, parallel-axis, and double helical-type gears. Crossed-axes are the most basic of the three classifications, and provide a wedging motion due to the high degree of slide action at the sides of the teeth. Parallel-axis helical types are defined by an infinite number of thin, staggered spur gears – resulting in each tooth getting skewed at the side much like a cylindrical helix. Double helical type gears are defined by their right/left side helix configuration.


Common Applications


Helical gears offer great utility in the automotive manufacturing industry. They are commonly found in vehicle transmissions due to their smooth operation and reduced noise level. Vehicle transmissions are essential in the configuration of the gear ratio that operates between the engine and driving wheels to change in accordance with how fast the vehicle is going. Many industrial equipment configurations that require quiet high-speed operations also feature helical-type gears.