A single circular arc gear is called a Novikov gear or a W-N gear. The engagement is performed by the contact of the concave and convex gear surfaces. The pinion is the convex gear and the driven gear is the concave gear. These gears are used in the gearboxes of the Westland Lynx and the Ka-family of helicopters. They can reduce the height of the gearbox when compared to the planetary gears which increases reliability and decreases weight. Circular arc gears allow for a large single drive ratio of up to 1:9. Circular Arc Gearing only has small periodic dynamic loads and it is easy to form a elastic fluidic oil film. This decreases spalling and scoring on the gears. Due to the large equivalent curvature radius, the gear surface has a higher load capability. It can also increase the life of the bearings and housing, and using parallel shaft drive can reduce the radial forces.
Sources
- dingApplicationProbingAdvanced2011
Backlinks
[[Circular Arc Gear Transmission]]
[[Kamov Helicopters]]
[[Lynx Helicopter Transmission]]
Planetary Gearbox