Modeling and Analysis for Dynamic Performances of a Two-Layer Engine Front End Accessory Drive System with an Overrunning Alternator Decoupler

To investigate the rotation vibration dynamics of the pulleys and the tension arms, and to estimate the vibrations of the belts and the slip ratio between the belt and the pulleys in the engine front-end accessory drive systems, a systematic modelling and analytical method is proposed for engine front-end accessory drive systems; this can be used for modelling engine front-end accessory drive systems with different layouts and different numbers of tensioners, including automatic and fixed tensioners. In the modelling, the rotational pulleys are classified as fixed-axis pulleys and moveable-axis pulleys (such as the pulley in the tensioner). Moreover, the belt spans are classified as the belt spans between the two fixed pulleys, and the belt spans adjacent to the pulley of a tensioner. The equations of motion for each type of pulley and the tension calculation equations for each type of belt span are developed. In this way, the equations of motion for all the pulleys and the tensioner arms can be obtained easily, irrespective of the layout of the tensioners. To obtain the dynamic rotational vibration responses of an engine front-end accessory drive system by the conventional Runge–Kutta method, high-efficiency algorithms or methods are also proposed for calculating the tangent-point coordinates between a belt and the adjacent pulleys and the belt length of the contact arc on one pulley. The proposed modelling and analysis methods are validated by modelling different layouts of the engine front-end accessory drive systems with different types and numbers of tensioners, and also by comparisons between the calculated dynamic vibration responses of the pulleys and the belts and the real experimental data.

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Fatigue Life Analysis of an Automotive Tensioner Through Strain-Life Approach

Volume 10: ASME 2015 Power Transmission and Gearing Conference; 23rd Reliability, Stress Analysis, and Failure Prevention Conference ◽

10.1115/detc2015-47915 ◽

2015 ◽

Author(s):

Maryam Talimi ◽

Jean W. Zu

Keyword(s):

Fatigue Life ◽

Stress Analysis ◽

Drive System ◽

Life Assessment ◽

Fatigue Properties ◽

Fatigue Life Assessment ◽

Front End ◽

Life Analysis ◽

Fatigue Life Analysis ◽

Prediction Approach

In this paper, fatigue life assessment of a tensioner is studied through dynamic load analysis, stress analysis, and stress-life fatigue analysis approach. Tensioner is a critical part of an automotive front end accessory drive system, providing pre-tension to the belt. The front end accessory drive systems are responsible for transmitting power from the crankshaft to the accessory components. Due to the engine pulsation, components of the accessory drive including the tensioner are subjected to dynamic loads leading to fatigue failure. The fatigue life assessment of a mechanical component highly depends on loading, geometry, and material properties. In addition, the dynamic behavior of the front end accessory drive is complicated due to coupling between several modes of vibrations in belt, pulleys, and the tensioner arm. Duo to the complexity of the parameters involved and complicated dynamics, the fatigue life analysis of FEAD components is a challenging task. This paper includes three main parts, namely stress analysis, fatigue properties prediction, and life estimation. The dynamic analysis of a generic front end accessory drive system is performed in order to obtain effective loads on the tensioner. Stress state for the tensioner in case of different applied loading conditions is performed via a series of Finite Element (FE) analyses, and the critical region of the part is determined. Finally, fatigue life is estimated through strain-life approach. Modest work has been found in this area providing a comprehensive solution to the fatigue life investigation of power train components. The present study offers a comprehensive modeling approach which predicts the automative tensioner lifetime. The lifetime of any FEAD system components can be determined using the developed fatigue life prediction approach.

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Modeling and Analysis of Gear-Shifting Process of Motor-Transmission Coupled Drive System

Journal of Computational and Nonlinear Dynamics ◽

10.1115/1.4032100 ◽

2016 ◽

Vol 11 (2) ◽

Cited By ~ 10

Author(s):

Hongxu Chen ◽

Xiaoxiao Cheng ◽

Guangyu Tian

Keyword(s):

Rotational Speed ◽

Hybrid Electric Vehicles ◽

Drive System ◽

Bench Test ◽

Control Parameters ◽

State Variables ◽

Two Phase ◽

Performance Simulation ◽

Modeling And Analysis ◽

Input Shaft

Motor-transmission coupled drive system is attractive for battery and hybrid electric vehicles. In such a system, the motor rotor is directly connected to the transmission input shaft and the active-synchronization technique is implemented to assist the speed synchronization; therefore, the gear-shifting characteristics are different from those of traditional manual and automated mechanical transmissions. In this work, we present a methodology for modeling the gear-shifting process and analyzing its characteristics in a motor-transmission coupled drive system. We treat the engaging of sleeve and desired clutch gear as a two-phase process—sleeve first interacting with synchro ring and then with clutch gear, respectively, and investigate all possible interaction ways in each phase. The movement of each part is governed by multibody dynamics, and the speed jumps caused by shifting impacts are described using the Poisson coefficient of restitution. We then develop a hybrid automaton (HA) model to couple the continuous-time evolutions and the discrete transitions of state variables, which cover all interaction ways of sleeve, synchro ring, and clutch gear. Based on this model, we carry out simulations in matlab to analyze the effects of two control parameters—the relative rotational speed of sleeve and desired clutch gear, and the shifting force—on shifting performance. Simulation and bench test results show that the optimal control parameters are located in the domain where the relative rotational speed is negative with small absolute value, which means the sleeve will not be locked out by synchro ring and can engage with the desired clutch gear smoothly.

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Design and Implementation of SRM Drive System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.722.331 ◽

2013 ◽

Vol 722 ◽

pp. 331-335

Author(s):

Shou Jun Song ◽

Lu Sheng Wang ◽

Zhi Hui Zhang

Keyword(s):

Functional Module ◽

Drive System ◽

Control Methods ◽

Loop Control ◽

Switched Reluctance ◽

Reluctance Machine ◽

Program Flow ◽

Dynamic Performances ◽

Working Principle ◽

And Control

In this paper, the basic operating principles and control methods of switched reluctance machine (SRM) are described briefly. Then, the drive system of a 3-phase SRM is designed and implemented. The design process includes two main parts: hardware and software. In hardware design, the structure and working principle of digital control and power drive circuit are presented. In software design, the program flow chart is provided, and details of each functional module are given as well. Finally, many experiments are carried out to verify the dynamic performances of the system. The phase current under different control methods, speed variation curve under closed-loop control and the mechanical characteristics of the system are given. Experimental results show that the designed SRM drive system has good speed adjusting ability and strong robustness.

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