摘要
本文设计一款集液压、机液和机械3种传动方式为一体的多功能动力传动装置。液压传动多用于起步作业,以满足平稳起步的要求;机液复合传动多用于作业工况,以满足无级调速的要求;机械传动多用于运输作业,以满足高效传动的要求;在满足传动要求的同时,动力输出轴可输出动力以驱动其它机构。从调速特性、换挡策略和效率特性3方面研究该多模式切换动力传动装置的传动性能优化问题。根据设计要求,对车辆系统进行动力学和运动学分析,得到动力传动装置的装配方案和相关参数,分析其调速特性。根据换挡品质评价指标,在整个调速过程中,对离合器和制动器共同参与的动力传动装置换挡策略进行研究,找出各元件的最佳切换时刻。根据经验公式得到液压系统效率,采用效率定义法计算多功能动力传动装置的效率;根据试验数据确定液压系统效率的拟合曲线,进而通过转化机构法确定机液复合传动系统的效率。结果表明:合理选择换挡元件的切换时序,可大大提升动力传动装置的换挡品质。液压系统在大排量、中高转速和中压区范围内有较好的效率特性,且可实现柔顺起步;机械传动效率较高,但对路况要求较高;机液复合传动一般在整个排量比和中高转速范围内,都具有较好的效率特性。
A multifunctional power transmission device integrating hydrostatic,hydro-mechanical and mechanical transmissions is designed in this paper.Hydrostatic transmission is mainly used in starting condition to meet the requirement of smooth start;hydro-mechanical compound transmission is mainly used in operation conditions for meeting the requirement of stepless speed regulation;and the mechanical transmission is mainly used in transportation operation with high transmission efficiency;while meeting transmission requirement,the power take off shaft can output power to drive other mechanisms.The transmission performance optimization of multi-mode switching power transmission device is studied from three aspects of speed regulation characteristic,shifting strategy and efficiency characteristic.According to the design requirements,the kinematics and kinetic analyses on the vehicle system is performed to obtain the assembly schemes and related parameters of power transmission device,with its speed regulation characteristic analyzed,and in the whole process of speed regulation,the shifting strategy of power transmission device,in which clutches and brakes are jointly involved,is studied,with the optimal switching moment for each element found out.The efficiency of hydraulic system is obtained by empirical formulas,and the efficiency of multifunctional power transmission device is calculated using efficiency definition method.The efficiency curves of hydraulic system are fitted based on test data,and the efficiency of hydro-mechanical compound transmission system is further determined by conversion mechanism method.The results show that the shifting quality of power transmission device can be greatly enhanced by properly selecting the switching sequence of shifting elements.Hydraulic system has better efficiency characteristic under the conditions of large displacement,medium-high speed and medium pressure,and can achieve smooth start;mechanical transmission has higher efficiency,but it also requests better road conditions;while hydro-mechanical compound transmission generally has relatively good efficiency characteristic in the range of whole displacement ratio and medium-high speeds.
作者
朱镇
蔡英凤
陈龙
夏长高
田翔
施德华
Zhu Zhen;Cai Yingfeng;Chen Long;Xia Changgao;Tian Xiang;Shi Dehua(Automotive Engineering Research Institute,Jiangsu University,Zhenjiang 212013)
出处
《汽车工程》
EI
CSCD
北大核心
2020年第10期1378-1385,1403,共9页
Automotive Engineering
基金
国家自然科学基金(51805222,U1764257)
中国博士后科学基金(2018M632247)
国家重点研发计划(2016YFD0700400)
江苏省战略性新兴产业发展重大专项(苏发改高技发(2016)1094号,(2015)1084号)资助
关键词
多功能动力传动装置
传动性能
调速特性
换挡策略
效率特性
multifunctional power transmission device
transmission performances
speed regulation characteristic
shifting strategy
efficiency characteristic