Research On Measurement Method Of Machining Error For Oerlikon Tooth Spiral Bevel Gear

Spiral bevel gears are widely used in delicate parts in tractors, automobiles, aerospace technology and light industrial machineries, whose quality, performance, and service life are important indicators of economic efficiency. There is one type of constant-depth tooth spiral bevel gears being processed by the end face milling gear hob plate equipment with the method of continuous index, being called Oerlikon spiral bevel gear. Due to its equal face angle, bottom angle and pitch angle, the Oerlikon spiral bevel gear doesn’t need pressure angle correction from cutting tool, which reduces the machine tool’s adjustment and speeds up the adjustment of the contacting area. Because of these advantages, this type of spiral bevel gear is widely utilized in the automobile industries in Europe and North America. However, Oerlikon spiral bevel gear tooth surface structure is complex and its tooth trace doesn’t generate axial force during the process of driving, so it needs high precision requirements. As a result, the application of the Oerlikon spiral bevel gear is still restrained and the precise measurement of tooth surface tolerance is expecting improvement.Currently the methods used to measure the spiral bevel gear tooth mostly require contact with the gear. During the measuring process, the contact between the probe and the gear surface wears out the parts easily. This paper presents a pair of non-contact measurement methods on Oerlikon spiral bevel gear tooth surface deviation, it can be used to measure Oerlikon spiral bevel gear tooth surface deviation. The measurement principle is:First, establish a model of the tooth surface; Secondly, have the measurement path planed; theoretical coordinate and normal direction of grid nodes are calculated on the basis of the model.Using the mobile X_Y precision platform to drive laser displacement sensors to measure and simulate the real tooth surface on45measurement points; make use of surface matching and compensation theory, the tooth surface error of spiral bevel gear is reflected by the difference surface which is fitted by the deviation between real tooth surface and theoretical tooth surface, Finally extract spiral bevel gear tooth surface deviation. The main research contents of the paper are as follows:1. Define the non-contact measurement method according to the principle of spiral bevel gear cutting process, completing the design of the overall structure of the measuring system, present a detailed workflow about gear tooth surface measurement error.2. Design the mechanical structure of spiral bevel gear measuring system achieving the laser sensor probe and the gear moves in the space according to the measuring path, with the completion of45points of the tooth surface in the measurement process. Inclined positioning table with a fixed designed to achieve not only self-centering, but also a certain tilt angle to the horizontal plane, which can effectively avoid the laser blocking during the measurement.3. Selection and test many important parts in the structure, making them meet the measuring precision and mechanical requirements.4. According to the measurement method, complete the functional design of the software system, and conduct experiments for the main modules.5. Simulate tooth surface deviation measurement process for spiral bevel gear and analysis the main sources of errors.