Abstract:Hydraulic motor reducers have been widely used in slewing and walking mechanisms of construction machinery.During the actual construction process of the machinery,due to the extremely poor working environment,the hydraulic motor reducer is prone to failure.In order to effectively predict the life of a reducer and study its performance degradation mechanism and failure mechanism,based on indepth analysis of its working conditions used in a pump truck,the design scheme of a test bed simulating working conditions of hydraulic motor reducers was discussed from the following three aspects:test bed layout,loading modes and clamping modes.A reversible threestage parallel shaft reducer was used as an accelerator to solve loading and installing problems;an oil pump was employed to achieve automatic load control;a mounting seat with mortisetenon connection for a test reducer was invented for fast and reliable clamping.Finally,a highpower reducer simulation testbed with different speeds and torques was designed.The results show that the test bed satisfies the design functional requirements,and the inertia moment of its output shaft is in accordance with the actual working conditions of the pump truck.