In modern automotive vehicles, gear noise becomes more and more of an issue. The main reason is the reduced masking noise of the engine, which vanishes completely in the case of an electric driveline. Improved gear quality unfortunately does not correlate with a better noise performance in any case. High gear quality makes sure that the gear flanks are inside tight tolerances and that all teeth are nearly identical. Even if the running behavior of such gear sets shows a very low sound pressure level, the noise perception for human ears may be annoying.
Mechanical power loss in gears is generated through sliding and rolling of the contact resulting in frictional work and elastic hysteresis generation of heat. This action is both a parasitic loss of energy from the drivetrain and a source of engineering costs to control system temperature to avoid heat-related failures of the gearbox components. Therefore, from both a cost and durability standpoint it is of great interest to minimize the frictional losses at the gear tooth contact interface.
Due to near-net shape production, additive-manufactured (AM) gears have a high potential to decrease costs and increase resource efficiency. The decreasing product life cycles as well as the increasing individualization of components demand high flexibility in manufacturing processes
Variable loads resulting from a working process, starting process, or operation near a critical speed will cause varying stresses at the gear teeth of a drive system. The magnitude and frequency of these loads depend upon the driven machine, the motor, the dynamic mass elastic properties of the system, and other effects.
Gear skiving offers great opportunities
for production with step-changing
productivity, particularly for internal gears,
whilst offering high-quality finishing
capabilities and being applicable on a
5-axis machine tool with its inherent
flexibility and multifunctionality.
The research presented in this paper extends the work done on CAD-based simulation approaches with an investigation of the surface topography of gears produced through gear skiving and the investigation of the cutting tool characteristics on the geometry of the produced gear. The study is complemented with the investigation of the cutting forces required in the machining process.
To increase cost efficiency in wind turbines, the wind industry
has seen a significant rise in power density and an increase in the overall size of geared components. Current designs for multimegawatt turbines demand levelized cost of energy (LCOE) reduction, and the gearbox is a key part of this process. Since fatigue failures nearly always occur at or near the surface, where the stresses are greatest, the surface condition strongly affects the gear life. Consequently, an improved surface condition effectively avoids major redesign or increased material cost due to an increase in part size. Additional finishing methods such as shot peening (SP) and superfinishing (SF) significantly increase the gear load capacity, but these effects have not yet been adequately considered in the current ISO 6336 standard or in any other gear standards. The combination of SP followed by SF will be described here as an “improved gear surface” (IGS).