二级膨胀往复式气动发动机设计与仿真  

Design and simulation of two-stage expansion reciprocating pneumatic engine

作　　者：潘孝斌[1] 谈乐斌[1] 顾辉[2] 

机构地区：[1]南京理工大学机械工程学院,江苏南京210094 [2]中国航天科工集团8511研究所,江苏南京210007

出　　处：《南京理工大学学报》2014年第4期439-444,共6页Journal of Nanjing University of Science and Technology

基　　金：中国博士后科学基金(2013M531359)

摘　　要：针对传统活塞往复式气动发动机中连杆对曲柄的作用力及方向不断变化,以及连杆对活塞侧向力使活塞摩擦力增加的缺点,提出了一种新型二级膨胀往复式气动发动机总体结构。应用单向轴承和齿轮传动,设计了具有双行程驱动膨胀做功的传动结构和气动控制回路。通过研究进排气过程与动力参数的相互作用关系,建立了两级耦合膨胀系统动力学模型,在MATLAB\SIMULINK下进行了仿真研究。仿真结果表明,在该文提供的结构参数下,动力性能满足设计要求,充气行程比是影响性能的主要因素。当充气行程比超过0.8时,输出功率因排气损耗增加而不再提升,在满足负载条件下,减小充气行程比有利于提高能量利用率,可达约77%。To overcome the defects of crank force changing constantly and piston friction adding because of the radial force on it in traditional crank-slider reciprocating pneumatic engine,a new type of two-stage expansion reciprocating pneumatic engine is proposed. A special transmission mechanism using unidirectional bearing and gear transmission, which can be bidirectionally driven by volume expansion,and the corresponding pneumatic circuits are designed. Through analyzing the relationship of intake and exhaust conditions and power performances,the two-level coupling expansion dynamic model is established and simulated with MATLAB／SIMULINK. The simulation results show that the performances of pneumatic engine can meet the design requirements and the charge ratio of stroke is a key factor. The output power doesn’t continually increase when it is over 0. 8 because of the fast piston＆amp;nbsp;velocity,the more exhaust loss. Therefore, the charge ratio of stroke should be controlled as low as under the condition of meeting the requirement of load. The energy efficiency can reach 77%.

关 键 词：气动发动机 往复式 二级膨胀 充气行程比 能量利用率 

分 类 号：TH138.9[机械工程—机械制造及自动化]