Gear honing is a highly productive process for the production of small and
medium sized gears and is used mainly in the serial production of the automotive
industry. The low robustness of the process is a particular challenge in gear
honing. The consequences range from an inadequate gear quality to an early breakage of the honing tool. In order to describe the processmachine interaction, the machining forces must be known.
Hard finishing technology, e.g. — honing — is used to manufacture high-performance gears. Gear honing is primarily used to hard finish small- and medium-sized automotive gears. And yet trials have shown that gears with a module larger than mn = 4 mm can also be honed efficiently, but problems often occur due to unstable process design. In this paper a model to improve the process design is described.
The honing of gears - by definition
- facilitates ease of operation, low noise and smoother performance in a transmission. Honing also contributes to
reduced friction in the powertrain. Both the intense cutting (roughing process) as well as the functionally fine- finishing of transmission gears can be performed in one setup, on one machine.
Gear tooth wear and micropitting are very difficult phenomena to predict
analytically. The failure mode of micropitting is closely correlated to the lambda ratio. Micropitting can be the limiting design parameter
for long-term durability. Also, the failure mode of micropitting can progress to wear or macropitting, and then go on to manifest more severe failure modes, such as bending. The results of a gearbox test and manufacturing process development program will be presented to evaluate super-finishing and its impact on micropitting.
Stringent NVH requirements, higher
loads and the trend towards miniaturization to save weight and space are forcing transmission gear designers to increasingly tighten the surface finish, bore size and bore-to-face perpendicularity
tolerances on the bores of transmission
In recent years, the demands for load capacity and fatigue life of gears constantly increased while weight and volume had to be reduced. To achieve those aims, most of today's gear wheels are heat treated so tooth surfaces will have high wear resistance. As a consequence of heat treatment, distortion unavoidably occurs. With the high geometrical accuracy and quality required for gears, a hard machining process is needed that generates favorable properties on the tooth surfaces and the near-surface material with high reliability.