The main factors to be considered in the design of hypoid gear with few teeth are meshing restriction conditions, cutting conditions and strength balance conditions. The meshing restriction conditions have been analyzed before and are relatively easy to meet. The latter is mainly reflected in that after the transmission ratio reaches a certain value, the surface cone of the large wheel of hypoid gear will interfere with the cutter head. Therefore, the surface cone angle of the large wheel of hypoid gear is generally limited to 85 °, At the same time, the strength of hypoid gear small wheel is obviously weaker than that of hypoid gear large wheel due to the increase of transmission ratio. In order to meet the above design conditions, it can be realized by deliberately increasing the pitch cone angle of the large and small wheels of the hypoid gear. Here, the influence of relevant geometric factors is analyzed by geometric parameter orthogonal method.
Orthogonal experiment is a commonly used experimental optimization method. It uses orthogonal table to arrange and analyze multiple factors, and uses mathematical statistics to analyze the experimental results.
The characteristic of orthogonal experiment is that it selects a part of all experimental factors for experimental design and analysis, and represents the results of all experiments through the results of some experiments. It does not have a comprehensive experiment, and it also makes a detailed analysis of various factors and the interaction between various factors. Sometimes there will be mixed interactions. Although the orthogonal test does not analyze the comprehensive factors one by one, it can play the effect of all tests, find the optimal level combination in all tests through this part of tests, and reduce the number of tests or trial calculations.
Orthogonal test is to select several levels of several factors from all the factors of the test. After these factors and levels are arranged through certain geometric figures, if the level of all factors in this area is tested, it is a comprehensive test. If a part is selected for the test, it is an orthogonal test design.
Through the method of orthogonal test, the main geometric parameters of hypoid gear are analyzed by orthogonal test. In order to distinguish from the real physical test, it is referred to as “orthogonal test”.