Page 1 :
EXPERIMENT NO. 4, Practical Name: Worm and Worm Wheel, , INTRODUCTION, , Worm and worm wheel consists of a square threaded screw (known as worm) and a toothed, wheel (known as worm wheel) geared with each other. A wheel is attached to the worm, over, which passes a rope a load is securely mounted on the worm wheel., , FORMULA USED, , Let L = Radius of the, , wheel r = Radius of the, , load drum W = Load, , lifted, , P = Effort applied to lift the load, , T = Number of teeth on the worm wheel, , If the worm is single threaded (i.e., for one revolution of the wheel, the worm pushes the worm, wheel through one tooth) then for one revolution of the wheel the distance moved by the effort =, 2nL, , The load drum will move through = 1/ T, , revolution Distance, through which the load will, , move = 2nr/T, , V.R = (Distance moved by P) / (Distance moved by W) = (2nL / (2 M)ar, LT /r In general, if the worm is n threaded then, V.R = LT / nr 7, M.A=W/P Worm t, n=M.A/V.R |, , , , , , , , , , , , , , , , , , , , , , , , Figure - Worm and worm, , Scanned with CamScanner

Page 2 :
PROCEDURE:, , ap, , PND, , Firstly stabilize the Single Start Worm and Worm Wheel machine and wrap the cord, around the load drum and the effort wheel., , Put some weight on the load drum. And add the some effort to the effort wheel via, hanger., , Hit the machine with some material, thus you will see some kind of movement in the, load drum as well as in effort wheel., , Write down the reading in the observation table, , After this apply the above procedure, four to five times with gradually increasing the, Load as well as Effort to the load drum and effort pulley respectively., , Write down the all reading in the given observation table., , Measure the radius of the load drum and the radius of the effort wheel., , Calculate the MA, VR and n of machine., , SAMPLE DATA SHEET:, , Diameter of wheel, D in cm, , V.R., , Diameter of axle, d in cm, , Weight of load pan/hanger =agm, , = Weight of effort pan/hanger =, , , , , , b gm= —, . Load Effort M.A = W/P % n= x 100, © Wit in Total Wt in Total, weight weight, Pan, wi W=atwi Pan, P=b+w2, w2, (gm) (gm) (gm) (gm), , , , , , , , , , , , , , , , , , , , , , Scanned with CamScanner

Page 3 :
RESULT:, , Mean efficiency of apparatus ......, , , , PRECAUTIONS:, 1. Lubricate the screw before starting the experiment., , 2. Trapping should be done after adding the weight in the effort hanger., 3. Overlapping of string should not be there., , Scanned with CamScanner