Lab mannaul


Aim :- To study and verify the Torque relationship



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Aim :- To study and verify the Torque relationship.

Ti + Th + To = 0

Where,
Ti = Input Torque. . Th = Holding Torque

To = Output Torque.


OBSERVATION TABLE :-



Input Power

Holding Load

(Kg)



(Kg)


Input Speed

N 1 RPM


Output Speed

N2 RPM

v I

T

TI T2




































































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,


  1. Followers - Flat faced, Mushroom , and Roller followers one each.




  1. Push rod assembly with spring and dead weights.




  1. Variable speed motor to drive the cams.




  1. 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.



  1. Set angular scale at required position.




  1. Adjust the weight seat and dial gauge.




  1. 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 _________



Sr.N0.

Cam Angle

Follower displacement (mm)

1

0




2

20




3

40




4


60




5

800




6

100




7

120




8


140




9

1 60




10

1 80









11

200




12

220




13


240




14

260




15

280




16

300




17

320




18

340




19

360



Jump Speed = rpm. Dead weight = N

To draw the graph jump speed (RPM) Vs. Dead weight


PRECAUTIONS :-
I ) Fix the key and bolt, for cam tightening properly.


  1. While starting the motor, ensure that the dial gauge has been removed.




  1. 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.
SPECIFICATIONS :-


  1. Governor assemblies porter, proell and hartnell, one each to be mounted over the universal

Spindle, one at a time.


  1. Variable speed D.C. motor to rotate the spindle – ¼ H.P., 1500 R.P.M.




  1. Speed controller for the motor.




  1. Spring of stiffness – 7007 N/m.




  1. Sleeve with scale and pointer.




  1. Weights to be added to sleeve (0.50kg) - 3 Nos.

The whole unit is mounted over a sturdy frame.


SERVICES REQUIRED FROM CUSTOMER :-


  1. 230 v, 5 Amp, AC supply with earthing connection.




  1. Table top area of about 0.6 × 0.6 m.




  1. Tachometer for speed measurement – contact type.

EXPERIMENTAL PROCEDURE: '

  1. Mount the required governor assembly over the spindle and tighten the bolt over the top link.

  2. 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.

  3. Note down the speed and lift of governor.

  4. 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.

  5. Repeat the procedure for different sleeve weights.

  6. 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.



Sr. No.

Governor - speed Rpm

Sleeve lift m





1.







2.











CALCULATIONS:

AIM :- To determine the controlling force at given speed, sensitiveness at given limits of lift and governor effort and power.

  1. 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.


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