APPLICATION OF THE METHODS OF SELECTION OF GEAR BOX RATIOS TO PASSENGER CARS

Document Type : Original Article

Authors

1 Col Dr., Chief of Dept. of Motor Vehicles, Military Technical College, Cairo, Egypt.

2 COL DR., Lecturer at the Dept. of Motor Vehicles, Military Technical College, Cairo, Egypt.

Abstract

Selection of ratios in mechanical transmission of motor vehicles can be done according to various mathematical prog-ressions such as : arithmatic, harmonic and geometric with constant and increasing roots. In a paper presented by the same authors, a comparison of the methods of selecting the gear ratios has been made. This was done by calculating the wasted power due to their stepped tractive effort - speed characteristics relative to the ideal one with continuous power transmission. it has been concluded that the gemetric progression would give the least wasted power. This conclusion was based on calcula-tions considering the data of only one Jeep car. The objective of this paper is to prove the validity of the above mentioned conclusion. In this regard, same method of comparison was applied to 14 small and medium class dif-ferent passenger cars having engines of swept volume between 0,9 and 1.6 litre.