基于发动机外特性的CVT速比控制方法研究

针对传统无级变速器速比控制中速比变化频繁,从而导致无级变速器效率低下、磨损严重等问题,研究了一种基于发动机外特性的速比控制方法,即在保证经济性与动力性的条件下限制无级变速器速比变化.理论研究和仿真分析结果表明,所提出的最佳经济区速比控制方法可以有效降低无级变速器速比调节频率,从而提高无级变速器效率与使用寿命.     

变速器速比分配的一个新模型

变速器速比分配的数学模型在模拟计算整车性能的过程中起着十分重要的作用。在对现有变速器速比分配模型进行分析的基础上,提出了变速器速比间隔成等比的数学模型。由于该模型只用一个参数来描述,所以极大地简化了整车性能的模拟计算。     

整车动力传动系统优化匹配试验

以6×4半挂牵引汽车匹配的280kW发动机为主体,通过配装不同速比的桥,根据变速器的直接档和超速档分别进行加速性和经济性试验,然后分析所得的动力性和经济性数据确定整车匹配优化方案,从而降低整车油耗,为客户节约运输成本。     

CVT轿车发动机建模及PID速比控制器设计

针对装备金属带式无级变速器轿车的发动机建立了其转矩模型和目标转速调节特性曲线。对无级变速器速比的取值范围进行了计算,并按照质量集中法简化了传动系的模型。设计了简单实用的PID速比控制器,并在simulink环境下对CVT整车模型起步、急加速和上坡工况进行了仿真分析。结果表明,实际速比对目标速比有很好的跟随效果。     

变速器比分配的一个新模型

变速器比分配的数学模型在模拟计算整车性能的过程中起着十分重要的作用。在对现在变速器速比分配模型进行了分析的基础上，提出了变速器速比间隔成等比的数学模型。由于该模型只用一个参数来描述，所以极大地简化了整车性能的模拟计算。     

基于DSP的汽车无级变速器电控系统的研究

在分析了金属带式无级变速器的变速原理后，设计了基于DSP的无级变速器的电控系统的硬件和软件。考虑到CVT传动系统的复杂化，设计了模糊自适应PID控制器，开发了基于速比反馈的速比控制系统。试验结果表明，所设计的控制系统是可行和实用的。     

国产轿车自动变速器维修技术讲座（二十）

三、AF13 篇 (一)基本参数与操作说明 1.基本参数 AF13自动变速器是日本Aisin　AW公司生产的产品,Aisin　AW 内部识别号为60-40LE。日本Aisin　AW公司生产的自动变速器为通用、欧宝、大宇等世界各大汽车厂家配套,其产品具有典型性。AF13自动变速器的主要规格参数如表1所示。 表1　　AF13自动变速器的主要规格参数 AF13 A- 自动变速器型号 F- 前轮驱动 13-最大输入扭矩130N·m1挡速比 2.807∶12挡速比 1.479∶13挡速比 1.000∶14挡速比 0.735∶1R 挡速比2.769∶1差速器速比4.048∶1自动变速器油型号 DEXRO…     

重型变速器换档沉重分析及解决方法

以某车型所用变速器项目为例,分析了重型变速器换档手感沉重的原因,重点研究了变速器速比和惯量对同步器换档力的影响,并提出了若干有效的解决办法,对相似应用有重要参考意义。     

自动变速器匹配对纯电动汽车能耗影响的研究

为研究不同自动变速器匹配对电动汽车能耗的影响,利用Simulink平台建立LF620纯电动汽车模型,并通过实车测试数据验证了模型的合理性。在此基础上以整车原地起步加速时间为动力性约束,以3种典型循环工况综合能耗最低为目标,对不同自动变速器速比和换挡控制策略进行优化。最后基于优化速比分析了不同自动变速器匹配对电动汽车能耗的影响。结果表明,相比于单挡变速器,使用两挡和3挡自动变速器可降低电动汽车对驱动电机的要求和整车能耗。另外,在传动效率相同的情况下,CVT的能耗要低于其他变速器。     

AVL-cruise在商用车速比匹配中的应用

文章通过传统速比计算方法算出速比,通过AVL-cruise软件验证所算速比和原速比的整车经济性、动力性水平,再结合实际需求对变速器速比进行选择,该方法对主机厂速比匹配有重要意义。     

Development of the Inner Spherical CVT for a motorcycle

An Inner Spherical CVT (ISCVT) transfers engine power by utilizing the traction force of the lubricant fluid film on the contact point between concave and convex spherical rolling bodies. Since the concave and the convex contact surfaces of the ISCVT are exactly spherical parts, they have a large circular (not elliptic) contact area, and the ISCVT mechanism has a larger torque capacity, less spin loss, and better stability than other traction drive mechanisms. The IVT (Infinitely Variable Transmission) performances also can easily be embodied in the ISCVT. In this work, we developed a prototype of the ISCVT for a motorcycle with a 125cc single cylinder engine having a maximum torque of 13.73 Nm at 8,000 rpm. The design parameters were determined, and the transmission performances were evaluated by optimal design procedure. The transmission efficiency, the life time, the maximum severe stresses on each part of the ISCVT, and the work needed for varying speed ratio were theoretically investigated, and the efficiency performances were experimentally measured. The manufactured prototype was installed in an actual motorcycle, which was fixed on the test-bench equipped with a dynamometer. The parasitic loss of the prototype and the cross-sectional road load performance were tested. The power efficiency of the simulated prototype was between 87∼92%, and the life span was more than 50,000 hours. The tested overall power efficiency was around 70∼92% under frequent driving conditions, which is an impressive performance in a motorcycle transmission despite the small difference from the simulation.     

串联式振动压路机行走驱动系统参数的选择计算

串联式振动压路机行走驱动系统的设计必须满足其在各种工况下的要求,并高效地利用发动机所提供的能量.本文通过对串联式振动压路机行走驱动系统参数的分析,提出合理选择各环节参数,如:分动箱传动比,液压泵排量和轮边减速比的计算方法.     

Performance Evaluation of Ball CVT and Comparison with Half Toroidal CVT

This study aims at finding an analytical model of ball continuously variable transmission (B-CVT) behavior and performance, based on the existing model of the half-toroidal traction drive. The geometrical and kinematical aspects of this model have been found. Then, force-moment equilibrium equations have been applied for a B-CVT. The contact behavior has been modeled using the isothermal elastohydrodynamic lubrication (EHL) theory, and spin and relative slip losses have been estimated for this CVT. Finally, the overall efficiencies of the B-CVT have been analyzed and compared with the halftoroidal traction drive. This study results have shown that B-CVT has higher torque efficiency and lower speed efficiency in comparison with half-toroidal CVT. Also, it has shown that the adjustment of axial forces in B-CVT leads to higher efficiency in lower input torques.     

Speed ratio control of a parallel layout double cavity half-toroidal CVT for four-wheel drive

A double cavity half-toroidal CVT has two variators, which gives a hint of a new four-wheel drive without a center differential gear unit by applying each of them to drive front and rear drive shafts independently. Torque re-circulation at cornering or different tire radii between front and rear tire is avoided by compensating the speed ratio of variator. The controller adjusts the attitude angle of power roller of the front variator against the rear by measuring the steering angle at cornering. This paper describes the speed ratio control system of the 4WD-CVT with speed ratio range of 1 : 8.7 and test results of vehicle motion mounted on a 3.2L RV.     

Multi-objective geometrical optimization of full toroidal CVT

The objective of this research is geometrical and kinematical optimization of full-toroidal continuously variable transmission (CVT) in order to achieve high power transmission efficiency and low mass. At first, a dynamic analysis is performed for the system. A computer model is developed to simulate elastohydrodynamic (EHL) contact between disks and roller and consequently, calculate CVT efficiency. The validity of EHL model is investigated by comparing output of this model and experimental data. Geometrical parameters are obtained by means of Particle Swarm Optimization algorithm, while the optimization objective is to maximize CVT efficiency and minimize its mass. The algorithm is run for different values of selected input parameters that are oil temperature, roller tilting angle (speed ratio). Optimization results show that optimized geometrical parameters are approximately constant for various values of input parameters. Also, it is observed that, increasing values of oil temperature and roller tilting angle (in clockwise direction), will decrease power transmission efficiency. An average power transmission efficiency of 86.7% is achieved over a wide range of input parameters, using optimized geometry.     

电动车两档变速器设计开发

设计了一款电动车用变速器,对驱动电机进行参数匹配设计。依据整车动力性和经济性的要求,对传动系统的速比进行了优化设计,制定了以电机高效运行为原则的换挡控制策略,并与采用固定速比减速器的电动汽车进行了对比验证试验,整车的能耗降低了6%,续驶里程延长了7%。     

Re-adhesion control for a railway single wheelset test rig based on the behaviour of the traction motor

A method for detecting wheel slip/slide and re-adhesion control of AC traction motors in railway applications is presented in this paper. This enables a better utilisation of available adhesion and could also reduce wheel wear by reducing high creep values. With this method, the wheel–rail (roller) creepage, creep force and friction coefficient can be indirectly detected and estimated by measuring the voltage, current and speed of the AC traction motor and using an extended Kalman filter. The re-adhesion controller is designed to regulate the motor torque command according to the maximum available adhesion based on the estimated results. Simulations under different friction coefficients are carried out to test the proposed method.     

轮毂液驱车辆助力模式温度补偿控制策略

轮毂液驱车辆是在传统重型商用车基础上加装一套轮毂液压驱动系统,使其在低附着路面下具有较高的牵引性能。在轮毂液驱车辆助力模式下,针对液压系统油液温度升高引起的系统泄漏量增加、控制精度降低等问题,提出一种温度补偿控制策略。根据考虑系统损失的流量连续性原理和轮速跟随思想,提出了基于温度补偿的多因素泵排量控制策略,并通过MATLAB/Simulink和AMESim联合仿真平台对该控制策略进行了验证。仿真结果表明：温度补偿策略补偿了系统的流量损失,满足了实际轮速跟随需求,提高了总牵引力。同时,通过HIL试验证明了温度补偿策略在实车上依然能达到仿真时的控制效果,对轮毂液驱车辆的实际开发具有理论指导意义。     

Performance optimization of CVT for two-wheeled vehicles

Continuously Variable Transmission (CVT) is one of the most promising automotive transmission technologies because of its continuously variable gear ratio and reduced shift shock. CVT is different from Manual Transmission and Automatic Transmission, and it is possible to operate the power source in its high efficiency region with CVT in the drive train. Several types of CVT exist that can be categorized based on the mechanism of power transmission, such as the belt pulley, traction drive, and hydrostatic types. This paper investigates the belt pulley CVT, which consists of a thrust actuator, driver pulley, belt, driven pulley, and preload spring of the output shaft. A complete CVT is constructed, and based on that a simulation program that analyzes the static performance of a CVT is implemented in Matlab/Simulink. From these simulation results, methods for improving the efficiency of the CVT are discussed. The coefficient of the torque capacity factor is proposed as affecting the matching between a power source and a CVT, and methods for improving the matching effect are also investigated.     

轮式铣刨机电辅助驱动系统速度匹配分析

以轮式铣刨机为研究对象，针对前桥驱动牵引力不足的情况进行后轮电辅助驱动，在对铣刨机辅助驱动运动学研究的基础上，设计了电辅助驱动速度匹配策略，建立了该铣刨机电辅助驱动的数学模型，并运用Simulink模块对其进行了仿真分析。结果表明：前、后轮速度匹配策略确实可行。