The objective of this experiment is to make a comparison between the efficiency of different different bearing materials by determining determining the resistance resistance of friction to rotation. The bearing materials materials which are being used in this experiment experiment are t ufnol, ufnol, cast iron and ball bearing. bearing. The fundamental device comprises of single flywheel on a horizontal shaft which both closures will be connected with the center section of testing bearings. A weight load is hang up on the shaft of flywheel by using string The amount of weight load which required for each bearing material to initiate rotation of flywheel at constant speed is entirely different. esides that, grease grease lubrica lubricant nt is also used to test the resista resistance nce of frictio friction n to rotatio rotation n of the bearing bearing materials. ased on the data obtained, contrast between materials of bearing used are shown clearly clearly.. Theref Therefore ore,, the tenden tendency cy for rotatio rotation n of the flywhee flywheell depend dependss on the frictio frictional nal resistance of bearing materials. INTRODUCTION
The The word word !bea !bearin ring! g! inco incorp rpor orate atess the the mean meanin ing g of !to !to bear bear,! ,! in the the sense sense of !to support,! and !to carry a burden.! This refers to the fact that bearings support and carry the burden of revolving axles. The application of bearings are beneficial to our daily life these days especially for various industries that rely on machinery "lain bearings are composed of just the bearing surface with no rolling elements and have a high load#carrying capacity while rolling rolling element bearings are built to handle both radial and thrust loads which are relatively small. The jewel bearings are plain bearings with a metal spindle that turns in a jewel#lined pivot hole which usually used in mechanical watches or clocks whereas fluid bearings are used in high load, high speed or high precision applications. $n the other hand, the magnetic bearings carry the loads by relying on the magnetic fields while the flexure bearings are similar as hinge, in which motion is supported by a load element that bend.
%n this experiment, different type of bearing materials is being used to test whether how much load is needed to make flywheel flywheel to rotate with constant constant speed under different condition condition is determined. determined. &urthermore, &urthermore, grease oil is also being introduced to investigate investigate the efficiency efficiency of bearing in minimizing the friction caused by the rotational motion of of shaft.
Discussion
ased on the results obtained, it is shown that the most weight load needed initiate the rotation of flywheel is tufnol without grease application whereas the least weight load required is ball bearing. 'hen pulling force is applied onto the flywheel, the horizontal shaft start to rotate due to the kinetic energy generated by the pulling force and gravitational force of weight load.
The configuration of the ball bearing separates the rotating shaft from the fixed bearing frame with free rolling elements while different type of material surfaces are adopted by the other types of bearing to reduce the sliding friction rotation of horizontal shaft. Thus, the ball bearings encounters a much smaller friction comparing to the other bearings. &urthermore, a small layer of lubricant has been added on to the surface of ball bearing to eliminate power loss and starting strain. esides, the use of ball bearings also help to save cost as no adjustment, repair or attention is necessary other than periodical lubrication. As a summary, the advantages of ball bearing enable it to become more popular than other types of bearing as well as increment of its usage in various industrial fields.
The quantity of weight load needed for flywheel to rotate with constant speed is affected by some factors. $ne of the utmost factors is the application of grease. (rease is a solid to semi#fluid product of dispersion of a thickening agent in liquid lubricant. The lubricating grease is formed by three main components which are oil, thickener and additives. The function of grease is to remain in contact with and lubricate moving surfaces without leaking out under the force of gravity, centrifugal action or being squeezed out under pressure. %ts major practical requirement is that it retains its properties under shear forces at all temperatures it experiences during use. Therefore, it has been used widely on a lot of machineries as it is less costly and has high consistency.
)rror Analysis
y comparing the data in two tables above, it can be seen that the coefficient of rotational friction of the theoretical data is higher than the experimental data. This is because some errors have occurred when running the experiments. $ne of the error is that the force applied to pull the flywheel is not constant as the amount of force required for each bearing material to start the rotation is different. esides that, the status of the apparatus is not closely inspected before the experiment is carried out. &urthermore, the deviation of the experimental data from the theoretical data can also be caused by the imbalance amount of greased applied onto the bearings due to careless when applying it. *oreover, error in obtaining the result exists when wrong measurements are made by the observer. +ast but not least, excessive friction and energy loss can be the causes with the coating of the bearing and flywheel.
Conclusion y observing the tabulated data, the coefficient of rotational friction for the surface of testing bearing is smaller when the weight quantity needed to make the flywheel to rotate with constant speed is lower. esides that, the amount of weight load required will be minimized by the presence of grease application because of the formation of lubrication layer that can help to decrease the coefficient of rotational friction. To prevent and minimize the experimental errors , status of the experimental apparatus need to be inspected carefully in order to ensure its functionality so that the accurate experimental results can be obtained. +astly, it is important to repeat the experiment procedures for several times to determine the average value as this can help to reduce the deviation of experimental data from its respective theoretical value.
