Renkaiden epätasapainon, ilmanpaineen ja ... - TransEco

3AALTO UNIVERSITY SCHOOL OF SCIENCE AND TECHNOLOGYAuthor: Timo NaskaliTitle of the The Influence of Tyre Unbalance, Pressure and Ununi­Thesis: formity on the Energy Consumption of Heavy VehicleDate: 25 May 2010Faculty:Department:Professorship:Supervisor:Instructors:Faculty of Engineering and ArchitectureDepartment of Engineering Desing and ProductionKon­16 Automotive EngineeringProfessor Matti JuhalaOsku Kaijalainen, M.Sc. (Tech.)Abstract of Master’s ThesisNumber of pages:132The aim of this Master’s thesis was to investigate the effects of tyre unbalance, pressure andununiformity on heavy vehicle energy consumption. Also investigate what other effects these featureshave to the vehicle as an environmental viewpoint. Issues are also being considered from theperspective of costs and profitability. The first part of the thesis deal with heavy vehicle tires, theproperties and manufacture, and matters which effects on key issues.Work is largely based on the literature survey on these subjects. No formal studies on the directeffects of imbalance on energy consuption are found. Some studies have found of effects thatimbalance caused, for example, the dynamic wheel load variation effects. Studies on the effects ofununiformity, mainly dealt with matters affecting the ride comfort. A wide range of tire balancingsolutions are on the market, so advertising materials will be readily received. However, there couldnot be found significant research results for the claims of advertisements.Based on the results gathered, it would appear that the tire unbalance has no impact on energyconsumption. The vehicle component wear is likely quite small. Result is largely that the heavyvehicle wheel loads are so large that unbalance does not cause significant variation. The stress of theroad will increase. Most impact is the travel comfort and the steering wheel vibration. Comparativecalculations have been made in support of the results and the unbalance does not have any detectableeffect. In Nokian Tyres was made the measurement of tyre unbalance and radial run out effects. Theresults are in line with previous estimates. The measurements show no effect of imbalances in energyconsumption.The tire pressure has a direct effect on rolling resistance and thus energy consumption.Approximately 10 % of the pressure deficit in heavy vehicle tires increase fuel consumption by 0,5 –0,75 % and 20 % deficit 1 –1,75 %. On average approximately 20 % of the heavy vehicle tirespressure is incorrect.The effects of ununiformity are largely similar to an unbalance. Most of the normal magnitudes ofununiformity have no impact on energy consumption. Tyre radial run out cause some increase inenergy consumption. Tyre ununiformity especially radial run out decrease the ride comfort. In longtermuse tyre ununiformity and unbalance caused faster and irregular tread wear, which increases tyrecosts.Keywords: tyre, tire, wheel, heavy vehicle, truck, unbalance, pressure, ununiformity, energyconsumption, fuel consumption, rolling resistance, radial run out