Development of a General Function Oriented Method to Design Flank Modifications of Beveloids under Consideration of Producibility

• Applicant: Professor Dr.-Ing. Christian Brecher
• Subject Area: Engineering Design, Machine Elements, Product Development ; Metal-Cutting and Abrasive Manufacturing Engineering
• Term: from 2015 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 274876554

A particular gear type which becomes more and more important is the beveloid gear, also known as conical involute gear. This is manly due to their ability to realize small crossing angles between shafts and they can be produced economically on conventional gear grinding machines. Beveloid gears have been used in marine applications, for example, for many years. In recent years the use of beveloid gears in the automotive sector has increased. Here the beveloid gear is used, for example in four wheel drives to transmit torque and rotation from the output of the gearbox to a front axle that may not be parallel.The running behavior of gears is generally characterized by load carrying capacity and noise vibration harshness (NVH). Conventional flank modifications, like crownings and angle modifications, can be used to optimize the running behavior. For beveloid gears this optimization reaches its limits. Due to the geometry and positioning of beveloid gears it is not possible to realize full line contact instead of point contact by using standard modifications. Line contact leads to a better load distribution on the tooth flanks which leads to decreased Hertzian stresses. In existing designs for realizing line contact the machinability of the flank modifications is not regarded. Furthermore there exist no methods to measure and tolerate these topological modifications.For spur and helical gears exist methods to manufacture topological flank modifications. But the process stability and profitability of this manufacturing method is low. Thus standard manufacturing processes like the continuous generating grinding are preferred to match economical and technical requirements. Additionally there exists no function oriented method to tolerate topological flank modifications. Ergo the full potential of topological flank modifications is not completely utilized.Hence, regarding the actual state of the art, the aim of this research project is to develop and verify a general function oriented method to design flank modifications of beveloids under consideration of producibility. The definition of existing flank modifications is extended in that way that topological modifications are defined locally for each point of the flank. The purpose of this method is the optimization of the beveloid gears running behavior (load carrying capacity and NVH), regarding the constraints of standard manufacturing processes.

• DFG Programme: Research Grants