Modelling and design of a novel air-spring for a suspension seat

[摘要] Suspension seats are commonly used for earth moving machinery to isolatevehicle operators from vibrations transmitted to the vehicle body. To provide therequired stiffness and damping for these seats, air-springs are typically used inconjunction with dampers. However, to eliminate the need for additional dampers,air-springs can be used in conjunction with auxiliary air volumes to provide bothspring stiffness and damping. The damping is introduced through the flowrestriction connecting the two air volumes.In this study, simplified models of an air-spring were derived followed by a modelincluding the addition of an auxiliary volume. Subsequent to simulations, testswere performed on an experimental apparatus to validate the models.The air-spring models were shown to predict the behaviour of the experimentalapparatus. The air-spring and auxiliary volume model followed the trendpredicted by literature but showed approximately 27 % lower transmissibilityamplitude and 21 % lower system natural frequency than obtained by tests whenusing large flow restriction diameters. This inaccuracy was assumed to beintroduced by the simplified mass transfer equations defining the flow restrictionbetween air-spring and auxiliary volume. The models however showed correlationwhen the auxiliary volume size was decreased by two thirds of the volumeactually used for the experiment.This design of a prototype air-spring and auxiliary volume is presented for asuspension seat used in articulated or rigid frame dump trucks. The goal of thisstudy was to design a suspension seat for this application and to obtain a SEATvalue below 1,1. The design was optimised by varying auxiliary volume size, flowdiameter and load. A SEAT value of less than 0,9 was achieved.

[发布机构] Stellenbosch University