rope brake dynamometer

for counting frictional resistance of rotating shaft dynamometers are used. by finding frictional resistance we can calculate break power.

1. Name: kemkar jaimin ajitkumar E n. No.: 160123119014 class and batch: 5 th D2 subject: theory of machine (2151902) Subject Guide: Prof. Vipal panchal ANALYSIS OF ROPE BRAKE DYNAMOMETER

2. CONTENTS INTRO. TO DYNAMOMETERS ROPE BRAKE DYNAMOMETER DERIVATION EXAMPLE REFERENCES

3. DYNAMOMETER What is dynamometer? Dynamometer is a device which is used to measure the frictional resistance. By knowing frictional resistance we can determine the torque transmitted and hence the power of the engine or rotating shaft. Thus dynamometer can be used either to measure force, torque or power. Types of dynamometer: Absorption type dynamometer Prony brake dynamometer Rope break dynamometer Transmission type dynamometer Belt transmission dynamometer Epicyclic dynamometer Torsion dynamometer

4. ROPE BREAK DYNAMOMETER Absorption dynamometer the work done by the engine is absorbed by the frictional resistance of the brake which is converted into heat during the process of measurement. Rope break dynamometer It consists of one, two or more ropes wrapped over the rim of a pulley keyed to the shaft of the engine. The upper end of the ropes is attached to a spring balance (S) while the lower end carries a dead weight (W). In order to prevent the slipping of the rope over the pulley, 3 to 4 ‘U’ shaped wooden blocks are placed at the interval around the circumference of pulley. If high power is produced, then heat is generated due to friction between rope and pulley or drum. To prevent this, pulley is provided with internal flanges on the rim, forming channel for flow of water to cool the pulley or drum.

5. ACTUAL APPLICATIONS

6. EQUATION OF BREAK POWER Let, W = dead weight of suspended weight S = spring balance reading D = diameter of pulley or drum N = speed of the engine d = diameter of the rope (W-s) = net break load Frictional torque due to rope = [ ]  

7. But the torque transmitted by engine at constant speed equal to frictional torque due to ropes. If diameter of rope (d) is neglected,  

8. EXAMPLE The following data is given from lab. experiment: Diameter of drum (D) = 1 m Diameter of rope (d) = 10 mm = 0.01 m Weight on the brake (W) = 50 kg = = 490.5 N Speed of engine (N) = 200 rpm Spring balance reading (s) = 120 N Brake power of the engine for rope brake dynamometer is given by,  

9. REFERENCES Book: Tech-Max (by Dr. F. B. Sayyad) Images: indiamart : https:// 4.imimg.com/data4/DB/VL/MY-2200754/engines-500x500.jpg me-mechanicalengineering.com: https:// cdn.me-mechanicalengineering.com/wp-content/uploads/2015/12/transmission-dynamometer.png

10. THANK YOU