Unbalance in Multicylinder Engines – In-line, V-twin and Radial Engines; Balancing Techniques

Module 4 : Unbalance in Multicylinder Engines – In-line, V-twin and Radial Engines; Balancing Techniques.

Lecture 1 : Unbalance in Multicylinder Engines – In-line, V-twin and Radial Engines; Balancing Techniques.

STATE OF BALANCE OF AN IN-LINE ENGINE

An in-line engine is one wherein all the cylinders are arranged in a single line, one behind the other as schematically indicated in Fig. 4.3. Many of the passenger cars found on Indian roads such as Maruti 800, Zen, Santro, Honda City, Honda CR-V, Toyoto Corolla all have four cylinder in-line engines. Thus this is a commonly employed engine and it is of interest to us to understand the analysis of its state of balance.

For the sake of simplicity of analysis, we assume that all the cylinders are identical viz., r, , and are same. Further we assume that the rotating masses have been balanced out for all cylinders and we are left with only the forces due to the reciprocating masses.

Let be the angular position of crank 1 with respect to the centre line of cylinder 1. Let the remaining cranks be at some fixed angles etc. from the first crank. Thus,

(4.4)

Figure 4.3 Typical Inline engine