三菱帕杰罗和猎豹吉普后桥防滑差速器的结构与维修

为了提高汽车在不良路面上的通过能力,三菱帕杰罗和猎豹吉普在后桥上安装有防滑差速器(也称摩擦片自锁差速器)。其优点是:在两驱动轮转速不等时,不需要进行人工操纵,便自动地向转速低的驱动轮多分配一些转矩,以提高汽车的通过性和操纵稳定性。结构如图1所示,三鞭帕杰罗和猎豹吉     

马自达故障六例

一、马自达323LX轿车摩擦片式差速器无法锁止故障现象一辆马自达323LX轿车行驶在泥泞的陡坡上,出现后桥一侧车轮打滑,汽车无法行驶的现象。故障分析与排除该车装置有摩擦片式差速器。它是普通锥齿轮差速器的变型,是通过增加差速器内的摩擦力来实现差速器锁止(即防滑)目的。为了增加差速器的内摩擦力,在半轴齿轮和差速器壳之间装有主从动摩擦片和推     

转矩式限滑差速器对后轮驱动汽车操纵稳定性影响的研究

采用7自由度车辆动力学模型,对装用JA1020LSD型转矩式限滑差速器的后轮驱动汽车进行了操纵稳定性研究。通过仿真分析和道路试验研究表明:装用限滑差速器后增加了后轮驱动车辆的不足转向趋势,即改善了操纵稳定性,但转向力矩略有增加。     

越野汽车蜗轮蜗杆式限滑差速器的研究

蜗轮蜗杆限滑差速器克服普通锥齿轮差速器平均分配转矩防滑性能差的缺点,有效地提高了汽车的通过性和安全性。首先对限滑差速器和普通锥齿轮差速器性能进行分析比较,然后介绍了蜗轮蜗杆差速器的结构、工作原理、转矩分配原理以及性能评价指标,最后以某越野汽车为实例对其蜗轮蜗杆差速器进行设计计算。     

预压弹簧摩擦片式防滑差速器的优化设计

针对某款SUV后驱动桥的轮间预压弹簧摩擦片式防滑差速器结构,在综合考虑各种附着系数道路行驶的条件下,提出了预压弹簧摩擦片式防滑差速器的优化设计数学模型,应用混合离散变量组合型法(MDCP)对所给出的实例进行优化,并对优化的结果进行了分析。     

导球式限滑差速器结构及工作原理

限滑差速器可提高汽车驱动性、通过性及操纵稳定性。简述了车用限滑差速器的分类及其优、缺点。导球式限滑差速器是近年新出现的一种结构简单的转矩敏感式限滑差速器。介绍了导球式限滑差速器的结构,论述了其差速运动及限制滑动的原理。     

转矩敏感式限滑差速器结构性能分析及其评价

介绍了限滑差速器的分类.着重对转矩敏感式限滑差速器的3种主流产品--锥盘式、轮齿式和摩擦片式差速器的结构与工作原理进行了探讨.在此基础上,提出了转矩式限滑差速器的性能评价参数和性能曲线,为对转矩式限滑差速器的进一步研究提供参考.     

独立驱动电动汽车机电耦合系统的研究

为解决独立驱动电动汽车防滑控制造成的动力性下降的问题,选用黏性联轴器作为机电耦合装置。对黏性联轴器转矩传递特性进行试验分析,之后在建立黏性联轴器与整车Simulink模型的基础上,对装有黏性联轴器和未装黏性联轴器的汽车进行动力性和操纵稳定性的仿真对比。结果表明,黏性联轴器不仅提高了独立驱动汽车的动力性和操纵稳定性,并起到辅助防滑的作用。     

托森差速器结构与性能

托森差速器作为一种新技术在４轮驱动轿车上的应用愈来愈受到重视。其特点是结构独特，原理简单。利用蜗轮蜗杆会传动的不可逆性和摩擦原理，使差速器根据其内部差动转矩的大小而自动地锁死或松开，极大地提高了汽车的转向通过性。     

托森差速器结构特征与工作原理浅析

根据蜗轮杆正、逆向传动的摩擦理论，论述了托森差速器高摩擦、低效率的特性。使其在差速工况条件下，提高了左、右驱动车轮的转矩比，从而改善了汽车通过性能。     

粘性液压联轴节特性分析与应用研究

系统地介绍了新型速度感应式限滑差速装置——粘性液压联轴节Visco-Lok，该装置存速度感应式限滑差速器基础上，在高转速差时通过加装剪切泵增大了限滑扭矩，提高了该工况下的牵引性，较好地实现了不同转速差下对车辆操纵稳定性、制动稳定性和牵引通过性的综合要求，并通过实车试验得到了验证。     

Optimisation of handling and traction in a rear wheel drive vehicle by means of magneto-rheological semi-active differential

This paper presents a semi-active differential, magneto-rheological fluid limited slip differential, which allows us to bias the torque between the driving wheels. It is based on the magneto-rheological fluid employment, by which it is possible to change, in a controlled manner, the internal friction torque and, consequently, the torque bias ratio. This device is an adaptive one and allows us to obtain an asymmetric torque distribution in order to improve vehicle handling. The device modelling and the control algorithm, realised for this activity, are described. The illustrated results highlight the advantages that are attainable regarding directional behaviour, stability, and traction.     

Quasi-steady-state linearisation of the racing vehicle acceleration envelope: a limited slip differential example

In the motorsport environment, passive limited slip differentials are a well-established means of improving the traction limitation imposed by the open differential. Torque sensing types are highly adjustable, and can alter both the stability and agility of the vehicle in the various cornering phases of a typical manoeuvre. In this paper, an adjustable clutch plate or ‘Salisbury’ differential model is presented, which can significantly alter its torque bias characteristics through adjustments in the drive/coast ramp angle, the number of friction faces and preload. To allow robust evaluation of differential parameter changes on ultimate vehicle performance and handling balance, a unified acceleration or ‘GG’ diagram framework is then described. This builds on traditional GG diagram approaches, by using nonlinear constrained optimisation to define both the vehicle acceleration limits and a ‘feasibility’ region within the performance envelope. By linearising a seven degrees of freedom vehicle model at multiple operating points, eigenvalue and yaw rate response analysis is then used to establish contours of stability and agility throughout the GG envelope. This brings new insights into the way in which handling balance changes below and up to the vehicle's acceleration limits.     

Optimal control of motorsport differentials

Modern motorsport limited slip differentials (LSD) have evolved to become highly adjustable, allowing the torque bias that they generate to be tuned in the corner entry, apex and corner exit phases of typical on-track manoeuvres. The task of finding the optimal torque bias profile under such varied vehicle conditions is complex. This paper presents a nonlinear optimal control method which is used to find the minimum time optimal torque bias profile through a lane change manoeuvre. The results are compared to traditional open and fully locked differential strategies, in addition to considering related vehicle stability and agility metrics. An investigation into how the optimal torque bias profile changes with reduced track-tyre friction is also included in the analysis. The optimal LSD profile was shown to give a performance gain over its locked differential counterpart in key areas of the manoeuvre where a quick direction change is required. The methodology proposed can be used to find both optimal passive LSD characteristics and as the basis of a semi-active LSD control algorithm.     

基于四轮轮边驱动电动车的路面附着系数估算方法

路面附着系数是影响车辆行驶安全性的重要因素,利用轮边驱动电动汽车驱动力矩可以对路面利用附着系数进行观测。当观测到μ-λ曲线接近于峰值点时,将该时刻的轮胎利用附着系数作为路面峰值附着系数,并根据识别的路面峰值附着系数进行驱动防滑控制。该方法能够有效防止轮胎滑转,提高车辆行驶稳定性。     

Judder analysis of electronically controlled limited slip differential

The electronically controlled limited slip differential system used on the new Skyline contributes to improvements in vehicle dynamics. One important performance parameter that is improved is the start-off acceleration when one drive wheel is on an ultra-low friction surface. There was concern, however, that larger LSD torque might cause drivetrain judder due to the negative μ-v slope of the wet multiplate clutch used in the system. An analysis based on natural mode calculations clarified the mechanism generating judder, and the results of stability calculations revealed measures for improvements. As a result, the problem of self-excited vibration was resolved.     

Lateral handling improvement with dynamic curvature control for an independent rear wheel drive EV

The integrated longitudinal and lateral dynamic motion control is important for four wheel independent drive (4WID) electric vehicles. Under critical driving conditions, direct yaw moment control (DYC) has been proved as effective for vehicle handling stability and maneuverability by implementing optimized torque distribution of each wheel, especially with independent wheel drive electric vehicles. The intended vehicle path upon driver steering input is heavily depending on the instantaneous vehicle speed, body side slip and yaw rate of a vehicle, which can directly affect the steering effort of driver. In this paper, we propose a dynamic curvature controller (DCC) by applying a the dynamic curvature of the path, derived from vehicle dynamic state variables; yaw rate, side slip angle, and speed of a vehicle. The proposed controller, combined with DYC and wheel longitudinal slip control, is to utilize the dynamic curvature as a target control parameter for a feedback, avoiding estimating the vehicle side-slip angle. The effectiveness of the proposed controller, in view of stability and improved handling, has been validated with numerical simulations and a series of experiments during cornering engaging a disturbance torque driven by two rear independent in-wheel motors of a 4WD micro electric vehicle.     

基于主动安全的轮间电控限滑差速器控制方法研究

论述了电控限滑差速器(ELSD)改善汽车动力学特性的原理,提出了基于提高汽车主动安全性的控制方法。该方法利用前馈与误差反馈控制相结合来控制车辆运动状态。反馈系数根据最优控制的方法确定。通过对所述控制系统的仿真研究,证明该系统在各种路面条件下均可明显改善汽车的操纵稳定性与主动安全性。