Study of Test for and Evaluation of HMT for a Tractor

Purpose: In this study, we provided test items for the reliability evaluation of hydromechanical transmission (HMT) for a tractor and attempted to improve the quality of products through a test evaluation. Furthermore, we attempted to secure technological competitiveness by conducting comparative tests with products from advanced companies.BRMethods: Understand the internal structure of HMT and analyze the principle of operation to provide test items related to performance, functions, and life. For life testing, apply the accelerated life model to reduce the testing time. Establish test methods and evaluation criteria for each test item by considering the operating conditions of the tractor.BRResults: We provided HMT test items that could be used to effectively evaluate product quality, and they consisted of two functions, three functions, and one lifetime. The HMT operational load was calculated from tractor operational conditions, and the accelerated test model was applied to provide an accelerated test cycle and a test time that guaranteed a lifetime of 5,000 h.BRConclusion: Test equipment appropriate for test evaluation and for performing performance, function, and life tests was constructed, and the test results were analyzed to verify the reliability of HMT and to demonstrate the suitability of the proposed test items.