Automobile gear transmission product development test refers to a series of tests required to check the design level and process rationality before the design finalization in the process of gear transmission product design and development. Through the test of processing prototype, verify and improve the product design and process level, find problems in time before mass production, and improve the quality and reliability of products.
The development test of automobile transmission is generally divided into bench test and vehicle test. The bench test is completed on various test benches in the laboratory, mainly including durability test and performance development test; The whole vehicle test is generally carried out after the bench test, which mainly verifies the service life, performance and reliability of the transmission under actual working conditions. This paper focuses on bench test. The bench development test includes two types: the first type is the verification pass test, such as the whole box durability test; The second type is the test to help find and solve problems, such as comprehensive performance test, contact spot test, lubrication performance test, vibration and noise test, shift performance test, etc.
1) The first type of test, such as the whole box durability test, is the most time-consuming and costly test, and needs rich load data, i.e. load spectrum as support. At present, the domestic advanced verification test process can simulate a variety of load conditions, and the time to complete this test is usually 4 ~ 6 months or even longer.
2) The second type of test is mainly performance test. The test time is short, and problems can be found in time. More importantly, through the second type of development test and basic test in the early stage, the one-time pass rate of full container durability can be greatly improved and the number of full container durability tests can be reduced.
The contact spot test can detect the load distribution on the gear tooth surface, and can be used to evaluate the accuracy of gear helix and tooth profile after gear assembly. The contact spot test before the whole box durability test can effectively evaluate and regulate the meshing quality of gears, improve the one-time pass rate of gear durability test and save test time and cost; The lubrication performance test before the full box durability test can effectively avoid the failure caused by insufficient bearing lubrication in the full box test, and also help to improve the passing rate of the full box durability test. At present, the test technologies such as contact spot and lubrication performance have gradually formed national standards and enterprise specifications, and the corresponding domestic test bench has been mature and applied (see Figure).
With the improvement of users’ attention to product comfort, vibration and noise tests have attracted more and more attention of enterprises. Especially in the automotive industry, international advanced enterprises spend 20% of their R & D expenses on solving the NVH problem of vehicles. There is a big gap between China and developed countries in this field. At present, the vibration and noise test system established in China has basically introduced foreign complete sets of equipment, and the core technology is controlled by others. However, it is gratifying that a few domestic R & D enterprises with strong R & D ability of test and test equipment have begun to independently develop test and test systems to solve NVH problems, including gear transmission error test bench and NVH test bench. The technical level of transmission error test-bed can fully meet the needs of automobile transmission enterprises. The development of NVH test-bed is also in the process of rapid improvement, which is expected to gradually replace imports.
At present, domestic automobile gear transmission enterprises have generally carried out the first type of development test. For the second type of development test, large automobile gear transmission enterprises have paid enough attention to it, and various test equipment have been popularized, while some enterprises need to improve their understanding of the importance of the second type of development test.