Conceptual Design and Finite Element Analysis of a Five-Minute Mini D.C Powered Air Compressor for Inflating Automobile Tyres

In this study, a Five-minute DC powered tyre inflator has been successfully designed. The machine was designed to satisfy a tyre specification of R205/65R15 95H because it is widely used by both private and commercial vehicle users. The design has two units; the compressor side and the electric motor side. The components of the compressor side include; piston, crank shaft, cylinder, cylinder head, rings, crank case, valves, pressure gauge and four studs. The design analysis of the reciprocating parts, connecting rod and crank shaft was done and structural integrity of the members evaluated using Finite Element modelling tool in Solidworks CAD application. Under the action of 155 N load on top of the piston, the simulation result indicates that a maximum stress of was reached along the fillet neck of the connecting rod, and this value is lower than the yield strength of the material used which is . The strength worthiness with respect to slenderness ratio of the connecting rod was confirmed by the buckling analysis with a shape factor of 0.8. Upon the subjection of the crank shaft to a load of 155 N acting normally to the crank pin, the shaft experienced a negligible resultant displacement of and a maximum stress of with a minimum factor of safety of indicating that the crank shaft design is appropriate. The volumetric efficiency is found to be 80% while the working efficiency is 62.5%. The conceptual design is considered fit for fabrication based on the design analysis and evaluation.