Brake testing South Africa

ECE90 Brake Testing (Pty) Ltd is a company that was established with the objective of providing a test and certification service for replacement brake lining assemblies. This being primarily to the requirements of the Economic Commission for Europe ECE Regulation 90 but also other national, international and industry specifications used in the brake friction industry.

Thursday, June 15, 2006

Modern brake dynamometer

by W.S. Scholtz

A modern brake test Dynamometer uses an absorption unit, in this case a brake disk and calliper assembly, to dissipate or convert the power or kinetic energy into heat or thermal energy. The power used to do this is calculated as follows:

Horsepower = Torque x RPM / 5252
Remember that RPM is Revolutions per Minute and the unit for Torque in this instance is measured in foot/pounds. 5252 is a constant and is also derived from Watt’s observation.

The above imperial system for units of measure is used to provide the Horsepower formula as it describes the origins of the measure of power best. The SI system or metric system uses, amongst other units, kilowatts (Kw) in place of horsepower and Newton-meter (Nm) for torque.

With a modern dynamometer, such as is used by ECE-90 Brake Testing (Pty) Ltd, the Dynamometer Test Report uses Newton Meter (Nm) and the Friction-coefficient (Mu) as a unit and ratio of measure respectively.

Basic construction:
dynamometer construction

A Dynamometer consists of the following main elements. (See Fig.1 above)

The drive-train (revolving assembly) consists of the following elements: Motor (1), Interchangeable flywheels (2) and Brake Disk (3). The flywheels and brake disk is matched to the part number to be tested.

The test bed (mounted in bearings aligned with the drive-train but held in position with the load arm. It has therefor the potential to rotate but is retained by the load arm) The test bed consist of the following elements: Calliper & Adapter (4), Power transfer axle (5), Load Bearing Arm (6) and Loadcell.

Please visit Passenger vehicle dynamometer brake testing for more details and services on offer.