Foreword Welcome to value-conscious company. We are proud of the advanced engineering and quality construction of each equipment equipment we manufacture. This manual explains the working of equipment. Please read it thoroughly and have all the occupants follow the instructions carefully. Doing so will help you enjoy many years of safe and trouble free operation. When it comes to service remember that K.C. Engineers knows your equipment best and is interested in your complete satisfaction. We will provide the quality maintenance and any other assistance you may require. All the information and specifications in this manual are correct at the time of printing. However, Because of K.C. Engineers policy of continual product improvement we reserve the right to make changes at any time without notice. Please note that this manual explains all about the equipment including options. Therefore you may find some explanations for options not installed on your equipment. You must follow the instructions and maintenance instructions given in the manual carefully to avoid possible injury or damage. Proper maintenance will help ensure maximum performance, greater reliability, and longer life for the product.
K.C. Engineer E ngineerss
Trusted by over 1 million members
Try Scribd FREE for 30 days to access over 125 million titles without ads or interruptions! Start Free Trial Cancel Anytime.
Trusted by over 1 million members
Try Scribd FREE for 30 days to access over 125 million titles without ads or interruptions! Start Free Trial Cancel Anytime.
Contents 1.
Objective
……………………………………
1
2.
Aim
………………………………….. …………………………………..
1
3.
Introduction
…………………………………… ……………………………………
1
4.
Theory
……………………………………
1
5.
Description Descripti on
……………………………………
2
6.
Utilities Required
……………………………………
3
7.
Experimental Experimenta l Procedure
……………………………………
3
8.
Observation & Calculation
……………………………………
3
9.
Nomenclature
……………………………………
4
10.
Precautions & Maintenance Instructions Instructi ons ……………………………………
4
11.
Troubleshooting Troubleshoot ing
……………………………………. 4
12.
References
……………………………………. 4
Trusted by over 1 million members
Try Scribd FREE for 30 days to access over 125 million titles without ads or interruptions! Start Free Trial Cancel Anytime.
JOURNAL BEARING APPARATUS 1.
OBJECTIVE: To study the pressure profile of lubricating oil at various conditions of load and speed.
2.
AIM: To plot the Cartesian pressure curve.
3.
INTRODUCTION: This apparatus helps to demonstrate and study the effect of important variables such as speed, viscosity and load, on the pressure distribution in a Journal bearing. The portion of a shaft, which revolves in the bearing and is subjected to load at right angle to the axis of shaft, is known as Journal. The whole unit consisting of journal and its supporting part is known as Bearing. The whole arrangement is known as Journal bearing.
4.
THEORY: Journal Bearing Apparatus is designed on the basis of hydrodynamic bearing action used in practice. In a simple journal bearing the bearing surface is bored out to a slightly larger diameter than that of the journal. Thus, when the journal is at rest, it makes contact with the bearing surface along a line, the position of which is determined by the line of action of the external load. If the load is vertical as in fig. 3. The line of contact is parallel to the axis of the journal and directly below that axis. The crescent shaped space between the journal and the bearing will be filled with lubricant. When rotation begins the first tendency is for the line of contact to move up the bearing surface in the opposite direction to that of rotation as shown at Fig 2. When the journal slides over the bearing, the true reaction of the bearing on the journal is inclined to the normal to the two surfaces at the friction angle
θ
and this
Trusted by over 1 million members
Try Scribd FREE for 30 days to access over 125 million titles without ads or interruptions! Start Free Trial Cancel Anytime.
As the speed of rotation of the journal increases, the viscous force which tends to drag the oil between the surfaces also increases, and more and more of the load is taken by the oil film in the convergent space between the journal and bearing. This gradually shifts the line of contact round the bearing in the direction of motion of the journal. Due to this two surfaces are completely separated and the load is transmitted from the journal to the bearing by the oil. The film will only break through if it is possible for the resultant oil pressure to be equal to the load, and to have same line of action. The pressure of the oil in the divergent part of the film may fall below that of the atmosphere, in which case air will leak in from the ends of the bearing. Assuming that the necessary conditions are fulfilled and that the complete film is formed, the point of nearest approach of journal to the bearing will by this time have moved to the position shown Fig 1.
5.
DESCRIPTION: The apparatus consists of a M.S. bearing mounted freely on a steel journal shaft. This
Trusted by over 1 million members
Try Scribd FREE for 30 days to access over 125 million titles without ads or interruptions! Start Free Trial Cancel Anytime.
One oil inlet mounted on journal to supply lubricating oil. One ball valve is also provided to release the trap air. An oil reservoir accompanies the set-up to store the sufficient oil for experiment. This reservoir supplies oil to the bearing.
6.
EQUIRED : UTILITIES R EQUIRED
1. Electricity Supply : Single Phase, 220 VAC, 50 Hz, 5-15 amp socket with earth connection. 2. Lubricating Oil SAE-40: 2 Ltrs. Approximately. 3. Floor Area : 1 m x 1 m
7.
EXPERIMENTAL PROCEDURE: 1.
Fill two-liter lubricating oil (SAE 40) in feed tank.
2.
Release the air from the supply tube and journal with help of ball valve.
3.
Check that some oil leakage is there for cooling.
4.
Set the speed with help of dimmer stat and let the journal run for about 5 minutes to achieve the steady state.
5.
Add the required loads and keep it horizontal position.
6.
Note the RPM of the journal shaft.
7.
Note pressure readings at different peripheral positions (after 100 or 150) rotation of the journal, with help compound pressure gauge.
8.
8.
After each reading, release pressure & take the next reading.
9.
Repeat the experiment for the various speeds and loads.
10.
After the test is over set dimmer to zero position and switch off main supply.
OBSERVATION & CALCULATION: OBSERVATION: W2
=
----------- kg
N
=
----------- RPM
Trusted by over 1 million members
Try Scribd FREE for 30 days to access over 125 million titles without ads or interruptions! Start Free Trial Cancel Anytime.
OBSERVATION TABLE: S.No.
θ
P, kg/cm
2
Plot a graph between θ vs. P
9.
10.
NOMENCLATURE: N
=
Revolutions per minute
P
=
Nominal bearing pressure, kg/cm2
W2
=
Total vertical load on the journal, kg
θ
=
Angle
PRECAUTIONS & MAINTENANCE INSTRUCTIONS: 1.
Never run the apparatus if power supply is less than 180 volts & above than 230 volts.
11.
12.
2.
Increase the speed gradually.
3.
Do not run the journal & bearing with out lubricant oil.
4.
Use clean lubricant oil.
5.
Always keep apparatus free from dust.
TROUBLESHOOTING: 1.
If the main light is not ON check the ma in switch.
2.
If the motor is not working, check the rotary switch & dimmer state.
3.
If the oil is not passing through any hole of bearing, check the hole.
R EFERENCES EFERENCES: 1.
Thomas Bevan, “The Theory of Machines” , 3rd ed., CBS Publishers & Distributors, ND, 1984, Page 210-214.
