Lab mannaul
Aim :- To study and verify the Torque relationship
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- EPICYCLIC GEAR TRAIN HOLDING TORQUE APPARATUS EXPERIMENT NO. 02 CAM ANALYSIS APPARATUS AIM
- SPECIFICATIONS
- EXPERINMENTAL PROCEDURE
- EXPERIMENT NO. 03 GOVERNOR APPARATUS AIM
- SERVICES REQUIRED FROM CUSTOMER
- CALCULATIONS
| Aim :- To study and verify the Torque relationship.
Ti + Th + To = 0 Where,
To = Output Torque. OBSERVATION TABLE :-
CALCULATIONS :- a) Ti = Input Torque. This can be calculated as below……. V = Motor input voltage & I = Motor input current. Motor Input Power = V × I Motor output power = V × I × Efficiency Ti = × n × Where,
N = Speed of motor & N = efficiency of motor – 80% = 0.8 b) Holding Torque :- Th = T × r × 9.81 Nm Where T is the readings of tension on spring balances. Where, R = Radius of Holding drum = 0.060 m. c) Output Torque :- To = (T1 – T2) × R × 9.81 Nm Where T1 – T2 – Reading of tension on Spring balances. Where, R = Radius of output drum = 0.095 m Take following steps to verify the torque relationship. Put on the spring balances on gear unit and output shaft pulley. Connect the control panel to motor. Start the motor and measure input & output shaft speeds. Note down the readings of T on Gear unit T1 & T2 on pulley unit. Find out Th, Ti & To. We find that Ti + Th = To EPICYCLIC GEAR TRAIN & HOLDING TORQUE APPARATUS EXPERIMENT NO. 02 CAM ANALYSIS APPARATUS AIM:- Experimental analysis of different cam - follower configurations for different dead weight and spring tension configurations Cams are used in machines to move a component in a prescribed path e. g. textile machined tools, I.C. engines, printing machines etc. Cam is a mechanical member for transmitting desired motion to follower‘by direct contact. Various types of cams and followers are used in practice like wedge, radial or cylindrical cams and reciprocating or oscillating followers with flat face, mushroom face or roller. The apparatus provides study of three types of cams and followers with dial gauge, follower displacement diagrams can be plotted and by rotating the cam, ‘jump’ phenomenon can be observed SPECIFICATIONS : - I ) Cams - Eccentric, tangent & circular arc cam one each, Followers - Flat faced, Mushroom , and Roller followers one each. Push rod assembly with spring and dead weights. Variable speed motor to drive the cams. Angular scale and dial gauge - I each. EXPERINMENTAL PROCEDURE : - I ) Fit the required cam over the cam shaft and required followers to the push rod.
Set angular scale at required position. Adjust the weight seat and dial gauge. Rotate the cam by hand and note down the dial – gauge reading at every 300 intervals. . 5) Remove the dial gauge. Switch ‘.ON’ the power supply. Slowly increase The motor speed. 6) At particular speed a particular striking sound is heard. This speed is called ‘Jump Speed’. At this speed, follower does not follow the exact path guided by cam contour. Note down this speed. Use of this cam-follower system beyond this speed is useless, because desired follower motion is not obtained. 7) Repeat the procedure for different dead weight and spring tension Configurations at different cam - follower configurations. OBSERVATIONS: Cam _________ Follower _________
Jump Speed = rpm. Dead weight = N To draw the graph jump speed (RPM) Vs. Dead weight
While starting the motor, ensure that the dial gauge has been removed. Tighten the loaded weights by the check nut. CAM ANALYSIS APPARATUS EXPERIMENT NO. 03 GOVERNOR APPARATUS AIM :- To determine the controlling force at given speed, sensitiveness at given limits of lift and governor effort and power. INTRODUCTION : Governors are used for maintaining the speeds of the engines within prescribed limits from no load to full load. In petrol engines, governors control the throttle valve of carburetor and in diesel engines, they control position of fuel pump rack. Most of the governors are of centrifugal type. These governors use flyweights to create centrifugal force. Depending upon the speed, position of weights change, which is transmitted to sleeve through governor links. Ultimately, the sleeve operates the throttle or fuel pump. The apparatus consists of a spindle mounted in bearings vertically. Three types of governors can be mounted over the spindle, namely porer, proell and hartnell. A sleeve attached to governor links is lifted by outward movement of balls, due to centrifugal force. Lift of the sleeve is measured over a scale.The spindle is rotated by a variable speed motor.
Governor assemblies porter, proell and hartnell, one each to be mounted over the universal Spindle, one at a time. Variable speed D.C. motor to rotate the spindle – ¼ H.P., 1500 R.P.M. Speed controller for the motor. Spring of stiffness – 7007 N/m. Sleeve with scale and pointer. Weights to be added to sleeve (0.50kg) - 3 Nos. The whole unit is mounted over a sturdy frame. SERVICES REQUIRED FROM CUSTOMER :- 230 v, 5 Amp, AC supply with earthing connection. Table top area of about 0.6 × 0.6 m. Tachometer for speed measurement – contact type. EXPERIMENTAL PROCEDURE: ' Mount the required governor assembly over the spindle and tighten the bolt over the top link. Switch ‘ON’ the mains supply and slowly rotate the dimmer knob so that the spindle is rotating and the sleeve is lifted to, say 1cm. Note down the speed and lift of governor. Slightly increase the speed so that sleeve lifts to, say 2 cms. Again note down the speed and lift. Repeat the procedure for different sleeve lifts. Repeat the procedure for different sleeve weights. Fill up the observation table. Note - Weights can be added for Porter and Proell governor while spring or -initial spring or initial spring compression can be changed for Hartnell governor. . OBSERVATIONS: Governor - ______ Weight added over sleeve :- ___ N Spring stiffness - 7007 N/m lnitial spring compression – 3mm.
CALCULATIONS: AIM :- To determine the controlling force at given speed, sensitiveness at given limits of lift and governor effort and power. Porter Governor: - Data i) Length of each link, I = 0. 130m. ii) Initial radius of rotation, r0 = 0.135 m. iii) Mass of sleeve assembly, W = 3.2 Kg. .’. Weight of sleeve assembly + Weight added on sleeve, W = (3.2 + ____ ) N. iv) Total mass of flyballs, w = 0.5 Kg. .’. Total weight of balls, w = 4.9 N. v) Lift (x I ) CALCULATIONS: Radius of rotation at specd N – Lift, x1 = 2.(C0 – C1) C0 = 0.1m C1 = mtr. Now, I2 = C12 + S12. S: = mtr. Radius of rotation = 0.05 + Si 1 mtr, Angular velocity , ꞷ1 = (2. π . N1) / 60 rad/sec. Download 1.49 Mb. Share with your friends:
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