Time Reduction and Upgrading of Balancing Machine for Impeller

INTERNATIONAL JOURNAL FOR TRENDS IN ENGINEERING & TECHNOLOGY VOLUME 5 ISSUE 2 – MAY 2015 - ISSN: 2349 - 9303

Time Reduction and Upgrading of Balancing Machine for Impeller M.I.Mohamed Asif1

Z.Mohamed Jameer2

1

2

K.Ramakrishnan College of Engineering, Trichy, Mechanical Department, asifmechengg8@gmail.com

K.Ramakrishnan College of Engineering, Trichy, Mechanical Department , jameermohamed.93@gmail.com

Abstract—The aim of our project was to upgrade a balancing machine. By making suitable external arrangements in the existing balancing machine, the operation time of the machine is curtailed, which in turn increases the productivity of the machine as well as dwindle human effort. It took minimum of a few hours to align the base of the motor bed in the balancing machine. L-angle plate, with a guide, key and disc brake are the extraneous arrangements in balancing machine.

Keywords—Alignment, balancing machine, impeller, l-angle plate.

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INTRODUCTION

BALANCING MACHINE

Balancing is the process of attempting to rotate the rotor with equal mass without any uncompensated centrifugal forces, which is placed on the bearings. This is usually done by adding or removing compensating masses to the rotor in prescribed locations.

A balancing machine is a measuring tool used for balance the rotating machine parts such as impeller rotor for electric motors, fans, turbines, disc brakes, disc drives, propellers, crankshafts, wheel rims, and pumps.

The machine usually consists of two rigid pedestals, with suspension and bearings on top supporting a mounting platform. The unit under test is bolted to the platform and is rotated either with a belt-, air-, or enddrive. As the rotor is rotated, the vibration in the suspension is detected with sensors and that information is used to determine the amount of unbalance in the rotor. Along with phase information, the machine can determine how much and where to add weights to balance the rotor.

The parts of the balancing machine are motor, gearbox, universal joint, bearing supports, and abro balancing software. In this balancing machine, the impeller is to be balanced.

The rotor tends to vibrate if an uneven mass is distributed. The vibration is produced by the interaction of an unbalanced mass component with the radial acceleration, due to rotation, which together generates a centrifugal force and so the rotor rotates along the line of action of the force.

Excessive vibration in rotating machinery can cause unacceptable level of noise and further substantially diminish the life of the shaft bearings.

The entire procedure takes approximately sixteen hours per impeller.

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INTERNATIONAL JOURNAL FOR TRENDS IN ENGINEERING & TECHNOLOGY VOLUME 5 ISSUE 2 – MAY 2015 - ISSN: 2349 - 9303 Physical Properties Table i Physical Properties Density

Content 7.85 g/cm3

Chemical Composition Table ii Element Carbon, C Copper, Cu Iron, Fe Manganese, Mn Phosphorous, P Silicon, Si Sulfur, S

Fig.1 Balancing machine The impellers are used in the mining operation.

L-ANGLE PLATE L-angle plate is a work holding device, which is used as a fixture.

Content 0.25 - 0.290 % 0.20 % 98.0 % 1.03 % 0.040 % 0.280 % 0.050 %

Mechanical Properties

The l-angle plate is made of high-quality material that has been stabilized to prevent further movement or distortion. Slotted holes are machined into the surface to enable the secure attachment of four langle plates to the base of the motor setup with bolting joints, so that motor setup can be correctly aligned in the keyway, which save the machine calibration time.

Table iii Mechanical Properties Tensile Strength, Ultimate Tensile Strength, Yield Elongation at Break (in 200 mm) Elongation at Break (in 50 mm) Modulus of Elasticity Bulk Modulus (typically for steel) Poissons Ratio Shear Modulus

Four l-angle plates are used at the four corners of the machine. A single l-angle plate has eight drilled holes.

Composition 400 - 550 MPa 250 MPa 20.0 % 23.0 % 200 GPa 140 GPa 0.260 79.3 GPa

GUIDE KEY Guide key is a machine element that moves

Fig.2 L-Angle plate

along the keyway path. The guide, key prevents relative side movement of the balancing machine’s motor base

The plate has made on A36 steel has the following characteristics.

setup. To function the guide, key the machine element

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INTERNATIONAL JOURNAL FOR TRENDS IN ENGINEERING & TECHNOLOGY VOLUME 5 ISSUE 2 – MAY 2015 - ISSN: 2349 - 9303 must have a keyway, which is a slot in which the guide,

forming a thin layer of harder metal inthe surface. The

key is fitted to.

case hardening process involves infusing additional carbon into the case. It is usually done after the part has been formed into its final shape.

L-angle plate with guide key

Fig.3 Guide key

Chemical composition of EN 19 steel alloy Table iv Fig.4 L-angle plate with guide key Element

Content

Carbon

0.35-0.45%

Mangenese

0.50-0.80%

Chromium

0.90-1.50%

Molybdenum

0.20-0.40%

Silicon

0.10-0.35%

Sulphur

0.050%max

Phosphrous

0.035%max

2D view of L-angle plate with guide key

The guide, key is made of EN19 alloy steel; it is case hardened, and a thin layer of harder metal forms on its surface, but the core of the guide, key remains softer. The outer surface of the guide, key makes contact with the keyway, so that guide, key has to subsist case hardened. As a result of case hardening, the guide, key will not get fractured (because of the soft core that can absorb the stresses without cracking) and provides adequate wear resistance over the surface.

Fig.5 2D view of L-angle plate with guide key

Case hardening or surface hardening is the process of hardening the surface of a metal object, thus

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INTERNATIONAL JOURNAL FOR TRENDS IN ENGINEERING & TECHNOLOGY VOLUME 5 ISSUE 2 – MAY 2015 - ISSN: 2349 - 9303 Problem description

Balancing Machine

Before making these extraneous arrangements, the balancing machine’s motor base setup is maneuvered forward or backward by clasping it upward with the help of crane hoists. After placing it in the correct position, the alignment of motor base setup has changed because it has no fixtures to locate in the correct position, so that the motor base setup has to be aligned manually by using a dial gauge. This calibration is done with reference to bearing setup support.

Fig.8 Balancing machine

DISC BRAKE The disc brake arrangement setup has to be fitted betwixt the motor and gearbox by replacing the tyre coupling in the existing balancing machine.

Fig.6 Before implementation Implementation of l-angle plate Initially, the setup has to be in correct aligned position. Now, the L-angle plate with guide, key is bolted to the four corners of the motor base setup, so that the base setup is placed in the correct position.

There is no need of alignment afterwards.

Fig. 8 Disc brake

Working While balance the impeller in the balancing machine, it took more time for it to become idle. The impeller is running at a speed of 100 RPM during the balancing process. Due to the disc brake arrangement, the impeller rotation can be stopped in a reduced time using a mechanical actuating lever.

CONCLUSION By making these external arrangements, the operation time of the balancing machine is reduced so that more number of impeller can be balanced. The productivity of the impeller increases without affecting its accuracy, along with it took minimum hours per impeller balance compared to already existing time.

Fig.7 After implementation

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INTERNATIONAL JOURNAL FOR TRENDS IN ENGINEERING & TECHNOLOGY VOLUME 5 ISSUE 2 – MAY 2015 - ISSN: 2349 - 9303 ACKNOWLEDGMENT The authors thank Prof. Saravanavel M.E. and Mr.Anilappukuttan M.E. for their contribution.

REFERENCES [1] Steel Construction Manual, 8th Edition, second revised edition, American Institute of Steel Construction, 1986, ch. 1 pages 1–5.

[2] "MatWeb A36 steel bar". MatWeb. Retrieved 21 January 2012.

[3] Degarmo, E. Paul; Black, J T.; Kohser, Ronald A. (2007), Materials and Processes in Manufacturing (10th ed.), Wiley, ISBN 978-0470-05512-0.

[4] Groover, M. P., 2007, p. 105-106, Fundamentals of Modern Manufacturing: Materials, Processes and Systems, 3rd ed, John Wiley & Sons, Inc., Hoboken, NJ, ISBN 978-0-471-74485-6.

[5] Smith, William F.; Hashemi, Javad (2001), Foundations of Material Science and Engineering (4th ed.), McGraw-Hill, p.394, ISBN 0-07-295358-6.

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