Design Of Air Spring Research Articles

Determining influential factors for an air spring fatigue life

AbstractThis paper presents an analysis of factors essential to air spring and undercarriage design to determine their influence on air spring fatigue life. Two sets of factors were chosen for the investigation: those relating to the design of the air spring itself (cord angle, diameter difference) and those relating to the design of the undercarriage (lever length, eccentricity, lever eccentricity, inclination). A full factorial experiment, whereby interactions between all the factors are investigated, would demand 729 experiments. Using Taguchi methods, the number of experiments required is dramatically reduced, using only 27 experiments to determine the influence of 6 factors and 3 interactions. Taguchi analysis shows here that factors inherent to air spring design have a much greater influence on fatigue life than those factors inherent to undercarriage design. Interaction between these factors has also revealed that there is no optimal cord angle for all air springs.

Remotely controlled compressed air spring—Design and implementation for distance education

AbstractDeveloping and using innovative teaching methods might be challenging for designers, teachers, and students. Current work covers the theory, simulation, and remote operation of a mechanical spring. Mechanical spring is presented as a mechatronic device that includes two pneumatic cylinders and accompanying equipment, and supporting software for remote control. This remote experiment enables simulation of different types of springs. The experiment was evaluated by three independent groups: Students, teachers, and independent evaluators. The results point out that developed remote experiment have a positive influence on the learning process.

Theoretical and Experimental Analysis of the Nonlinear Characteristics of an Air Spring With an Orifice

We herein propose a simple but accurate method for calculating the dynamic properties of an air spring that uses an orifice to produce a damping force. Air springs are commonly used in rail, automotive, and vibration isolation applications. However, because this type of air spring has nonlinear flow characteristics, accurate approaches have not yet been proposed. The restoring and damping forces in an air spring with an orifice damper vary with the amplitude of the body. This amplitude dependency has not been considered in previous studies. We herein propose a simple model for calculating the air spring constant and damping coefficient. However, this requires iterative calculation due to the nonlinearity of the air spring. The theoretical and experimental results are found to agree well with each other. The theoretical equations provide an effective tool for air spring design.

Theoretical and Experimental Analysis of the Non-Linear Characteristics of an Air Spring with an Orifice

This paper proposes a simple but accurate method for calculating the dynamic properties of an air spring employing an orifice to produce a damping force. Air springs are very common in rail, automobile, and vibration isolation applications. However, because this type of air spring has non-linear flow characteristics, an accurate analysis approach is yet to be proposed up to the present day. The restoring and damping force in an air spring with an orifice damper vary with the amplitude of the body. This amplitude dependency has not been considered in previous studies. Proposed herein is a simple model for calculating the air spring constant and damping coefficient. However, iterative calculation is required due to the non-linearity of the spring. The theoretical and experimental results are found to agree well each other. The theoretical equations provide an effective tool for air spring design.

Development and analysis of an air spring model

The analytical model of an air spring can be effectively used for the design of air spring equipped vehicles to provide better ride and handling characteristics along with various functions for passenger convenience. However, establishing a general model of an air spring poses particular difficulties due to the severe nonlinearities in the stiffness and the hysteresis effects, which are hardly observed in conventional coil springs. The purpose of this study is to develop a general analytic model of an air spring — one which represents the main characteristics of stiffness and hysteresis and which can be connected to a model of pneumatic systems desigined to control air spring height. To this end, the mathematical model was established on the basis of thermodynamics with the assumptions that the thermodynamic parameters do not vary with the position inside the air spring, that the air has the ideal gas property, and that the kinetic and potential energies of the air are negligible. The analysis of the model has revealed that the stiffness is affected by the volume variation, the heat transfer, and the variation of the air mass and the effective area. However, the hysteresis is mainly affected by the heat transfer and the variation of the effective area. In particular, it was revealed that the increase of the volume due to the cross-sectional area increases the stiffness, while the increase of the volume due to the other reason decreases it. In addition, the model was used to develop the sufficient stability condition, and the stability of the model was analyzed. The paper also presents the comparison between the simulation and experimental results to validate the established model and demonstrates the potential of the model to be usefully employed for the development of the air spring and its algorithm for use in a pneumatic system.

Air Suspension for Road Vehicles

This paper presents a résumé of the course of development of the air springs of the double-convoluted and rolling-lobe types. The theory of the air spring design is discussed and typical methods of installation are described. The present-day air springs are limited to a maximum pressure of 100 lb/in2 to cater for the maximum static load. There are no minimum pressure requirements for a double-convolution bellows, but in order to obtain good flexing life and maximum spring response the rolling-lobe type is generally limited to a minimum pressure of 40 lb/in2. The ancillary equipment for an air suspension system is described, this consisting of compressor, storage tank and levelling valves.