SD-1.28 Crank Mechanism

The apparatus is intended to represent a simple engine mechanism and may be used by the students for simple experiments to investigate:
1 – The relationship between the piston displacement and the crank angle for a given connecting rod/crank radius ratio.
2 – The relationship between the turning moment on the crank shaft and the crank angle for a given force on the piston.

The crank effort may be determined by attaching suitable masses to the beam balance arm.

The piston is fitted with brass rollers running on guide bars and needle roller bearings are fitted in the connecting rod so that friction is reduced to a minimum.

A protractor is attached to the crank which may be rotated on the beam balance arm and clamped in any predetermined angular position.

A linear scale is attached to the piston guide so that the piston displacement can be measured.