Despite the development and availability of a number of newly engineered, rugged materials intended for plastic gear applications, some engineers/designers continue to believe metal is better.
The deformation of the gear teeth due to load conditions may cause premature tooth meshing. This irregular tooth contact causes increased stress on the tooth flank. These adverse effects can be avoided by using defined flank modifications, designed by means of FE-based tooth contact analysis.
The purpose of this paper is to present a method of designing and specifying gear teeth with much higher bending and surface contact strength (reduced bending and surface contact stresses). This paper will show calculation procedures, mathematical solutions and the theoretical background equations to do this.
This article presents an analysis of asymmetric tooth gears considering the effective contact ratio that is also affected by bending and contact tooth deflections. The goal is to find an optimal solution for high performance gear drives, which would combine high load capacity and efficiency, as well as low transmission error (which affects gear noise and vibration).
The increasing demands in the automotive
industry for weight reduction, fuel
efficiency and a reduced carbon footprint need to be addressed urgently. Up until now, widely used conventional steels have lived up to expectations. However, with more stringent emissions standards,
demands on materials are increasing.
Materials are expected to perform better, resulting in a need for increased fatigue strength. A possibility to increase torque
on current generations without design
changes can be achieved by selecting suitable materials.
In terms of the tooth thickness, should we use the formulation with
respect to normal or transverse coordinate system? When normalizing
this thickness in order to normalize the backlash (backlash parameter),
we should divide by the circular pitch. Thus, when normalizing, should
this circular pitch be defined in the normal or traverse coordinate
system, depending on which formulation has been used? Is the backlash
parameter always defined with respect to the tangential plane or
normal plane for helical gears?
Introduction
The standard profile form in cylindrical
gears is an involute. Involutes are
generated with a trapezoidal rack — the
basis for easy and production-stable
manufacturing (Fig. 1).