Theory of Machine Lab


The apparatus consists of a base upon which bearing holders and drive motor can be mounted. Different bearings can be fitted in bearing block to have different end conditions as, both end fixed, one end free, one end fixed etc. A variable speed motor is provided to drive the motor along with speed control unit. The unit is useful to demonstrate the phenomenon of whirling of shaft with single rotor. As this test is destructive, after the test shaft cannot be again, hence this unit only demonstrates the principle.

  • Test shaft - 3.17mm, 4.75mm dia. 1 mt. long approx.
  • Bearings to provide following end conditions -
  • Both end fixed.
  • One end fixed one end free.
  • Drive motor - 1/6 HP, 6000 RPM.
  • Speed controller unit.

input and output shaft through the epicyclic gear train. The input (driving) shaft carries an arm and pin on which the compound gear wheel is free to remove and it meshes with the fixed wheel and the wheel is keyed to the output (driven) shaft.


Any combination of gear wheels by means of which motion is transmitted from one shaft to another shaft is called a gear train. In case of epicyclical gear trains, the axes of the shafts on which the gears are mounted may move relative to a fixed axis. This experimental apparatus consists of sun and planetary gear box with a sun gear and two planet gears rope and spring balance arrangement to measure output torque and holding torque.

  • Internal Type Epicyclic Gear Train. A Compact Gear Train.(industrial)
  • Motor: Variable speed D. C Motor, 1 HP
  • Rope brake arrangement to measure output torque and holding torque.
  • Control Panel Comprising of-
  • RPM Indicator.
  • Speed Controller


The machine is a motorized unit a camshaft is driven by a D.C. Motor. The shaft runs in a ball bearing. At the end of the cam shaft a cam can be easily mounted. The follower easily can be attached to this push rod and the varies type of the follower can be changed to suit the cam under test. A graduated circular protractor is fitted coaxial with the shaft and a dial gauge can be fitted to note the follower displacement for the angle of cam rotation. A spring is used to provide controlling force to the system. Weights on the follower rod can be adjusted as per the requirements. An arrangement is provided to vary the speed of camshaft. The machine is particularly very useful for testing the cam performance for jump phenomenon during operation. The machine clearly shows the effect of change of inertia forces on jump action of cam follower during the operation.

  • Cams- Tangent and circular type.
  • Follower- flat or mushroom, Roller and Knife-edge.
  • Compression spring.
  • Weights - 200gm & 100gm
  • Motor – variable speed D.C. Motor, ½ H.P.
  • Speed Control Unit
  • Dial Gauge
  • Cams & Followers are suitable hardened to reduce wear


The apparatus consists of a steel shaft mounted in ball bearings in a stiff rectangular mainframe. A set of four blocks of different weights is provided and may be detached from the shaft. A disc carrying a circular protractor scale is fitted to one side of the rectangular frame. A scale is provided with the apparatus to adjust the longitudinal distance of the blocks on the shaft. The circular protractor scale is provided to determine the exact angular position of each adjustable block. The shaft is driven by electric motor mounted under the main frame, through a belt. For static balancing of weights the main frame is suspended to support frame by chains then rotate the shaft manually after fixing the blocks at their proper angles. It should be completely balanced. In this position, the motor driving belt should be removed. For dynamic balancing of the rotating mass system, the main frame is suspended from the support frame by two short links such that the main frame and the supporting frame are in the same plane. Rotate the statically balanced weights with the help of motor. If they rotate smoothly and without vibrations, they are dynamically balanced.

  • Drive Motor, Universal Motor
  • Balancing Weights - 4 Nos. with different size eccentric mass for varying unbalance.
  • Cord & Container with steel balls for relative weight measurement.


The Motorized Gyroscope consists of a disc rotor mounted on a horizontal shaft rotating in the ball bearings of one frame. The rotor shaft is coupled to a motor mounted on a trunion frame having bearings in a yoke frame which is free to rotate about three perpendicular axes. Angular scale and pointer fitted to frame helps to measure precession rate.

  • Demonstration of relationship between applied torque and precession rate along with direction of rotation.
  • Gyroscopic couple easily varied by weights.
  • Precisely balanced rotor.
  • Useful to verify the relationship #T = lw.wp
  • Disc rotor - 30 cm. dia, 10mm thick. approx.
  • Drive - FHP, AC/DC single phase motor
  • Dimmerstat - 2 Amps.
  • Weight set.

6. Journal Bearing Apparatus

The apparatus consists of a plain steel shaft encased in a bearing and directly driven by a small electric motor. The bearing is freely supported on the shaft and sealed at motor end. The motor speed is precisely controlled by control unit and can be run in both directions. The bearing contains twelve equi-spaced pressure tappings around circumference and four along the axis. All are connected by light flexible plastic tubes to the manometer so that the pressure head of all sixteen points can be observed at a time. The bearing can be loaded by attaching weights to the arm supported beneath it.