Research Of Hydro-mechanical Composite Transmission Characteristics On Sanitation Work Vehicle

Hydraulic mechanical compound transmission(Hydro-mechanical Continuously Variable Transmission, referred HMCVT) is a new mechanical transmission which combines high-efficiency advantages of mechanical transmission with the advantage of the continuous velocity of the hydraulic transmission. This transmission has a continuous variable speed feature and can change the transmission ratio by the change of working conditions to make the engine always at the best power point or optimum fuel consumption point of the vehicle's power which has great significance of improving fuel economy. In order to improve the utilization of the sanitation vehicles during the job and energy transition, this paper proposes the research of the complex continuous transmission of the sanitation vehicles.First, the paper introduces the research achievements of complex transmission at home and aboard,doing the basic theory research of hydraulic machinery compound transmission. According to the actual demand and working conditions of sanitation trucks, pointing out the shortcomings of the formal sanitation truck transmissions and determine the direction of optimization sanitation truck transmission.Secondly,this paper research the twelve kinds of basic forms of input-split and output-split transmission. In deep study of characteristics of its hydraulic power split ratio and speed characteristic,combing the two types of drive from a tandem with a segmented form.analyzing the speed and power characterize of these two types.Finding out the advantages of both of these two types to determine the basic design of the sanitation vehicle.Then, combined with Isuzu basic chassis parameters and operating conditions of the sanitation vehicle, refine the transmission gear ratio, the parameters of center distance, etc., worked out closed loop speed control volume design and selection, and completed virtual design of transmission prototype.Finally, using AMESim software to build a physical model of complex HMCVT. After the simulation of the speed characteristics, load characteristics of the closed loop. Completed simulation of speed transmission characteristics, load characteristics, start feature and so on.Simulation results show that the transmission parameters designed match the theoretical results, able to withstand the impact of a step load. When changing at the start,should slowly to adjust the displacement ratio adjustment handle to make the stable adjustment of staring and driving come true.