Structural Performance Analysis Of Working Mechanism Of Hydraulic Excavator

For the bad working conditions of hydraulic excavator, working mechanism as the main component suffered force loading, the structural performance of which plays an important role in overall performance, operational reliability and safety of hydraulic excavator. As domestic manufacturing industry of excavator started late, the starting point is low, and the design method is backward. Therefore, in practical work, it often occurs that the excavator boom and stick crack and fail, and the region of excavation is unreasonable and excavator's vibration is violent. All of those make the domestic excavator lack of competitiveness and low market share, which severely restricts the development of domestic excavator industry. To this end, in conjunction with enterprise scientific research projects and practical requirements, this thesis deeply studies the structural performance of working mechanism of hydraulic excavator, and carries out relevant researches, like the analysis about the hydraulic dynamic performance of working device influenced by hydraulic cylinder and the overall structural performance of working device taking the consider of the influence of pin-contact.This thesis includes six chapters. Chapter One presents the research background and significance of the topic, and sums up the research work about the structural performance of the working mechanism of the hydraulic excavator at home and abroad and several modeling methods of performance analysis, and has made the main research contents of this thesis; Chapter Two discusses the working process of hydraulic excavator and the design requirements of the working mechanism of the excavator. Based on the force analysis of the excavator working mechanism, seven kinds of typical operating conditions of the analysis about the structural performance of the working mechanism are identified; Chapter Three analyzes the influence of modal performance of the working device caused by different modeling strategies of the hydraulic cylinder, and carries out the modal performance analysis under the typical operating conditions; In Chapter Four, the structural strength and stiffness of the boom, stick and bucket are separately analyzed under the typical operating conditions; In Chapter Five, the analysis model of the overall structure of the work mechanism is established considering the impact of pin-contact, and the results of the analysis are compared with the result of the individual component analysis. The advantages and disadvantages of the two analytical methods are analyzed. Considering lateral loads and uneven loads of the bucket teeth when the excavator works, the structural strength analysis of the overall structure of the working mechanism is made under the typical operating conditions such as uneven load and lateral force; as the end of this thesis, Chapter Six makes the conclusion and gives research work for the next step.