electrical engineering : MOTOR REWINDING

BEARING AND LUBRICATION PART 3

<h3 class="post-title entry-title"><a href="http://hayatei.blogspot.com/2010/12/bearing-and-lubrication.html">BEARING AND LUBRICATION PART 1</a> </h3><h3 class="post-title entry-title"> </h3><h3 class="post-title entry-title"><a href="http://hayatei.blogspot.com/2010/12/bearing-and-lubrication-part-2.html">BEARING AND LUBRICATION PART 2</a></h3><h3 class="post-title entry-title"> </h3><h3 class="post-title entry-title" style="background-color: yellow; color: red; font-weight: normal; text-align: center;"><span style="font-size: large;"> <span style="font-family: Arial;">Removal Of Bearing</span></span></h3><h3 class="post-title entry-title" style="font-weight: normal; text-align: justify;"><span style="font-size: small;"> In case that the bearing is so damaged as to hinder motor operation, the bearing is to be removed in the following manner.</span></h3><span style="font-size: small;">Remove the bearing housings such as the bearing end cover, the bracket, the bearing housing, etc.<br />
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Remove the grease runner or ring nuts by loosening the set screws, if provided, or by removing the washer stopper if the ring is tightened by means of the screws or binding nuts.<br />
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Draw out the bearing as shown in Fig. 1-5.</span><br />
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<span style="font-size: small;"></span><br />
<span style="font-size: small;"></span><br />
<div style="text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/bearing-and-lubrication-part-3.html"><img alt="http://img103.herosh.com/2010/12/21/923283009.png" src="http://img103.herosh.com/2010/12/21/923283009.png" /></a> </div><div style="text-align: center;"></div><div style="background-color: magenta; color: yellow; text-align: center;"><span style="font-size: medium;">Fig. 1-5 Removal Of Bearing</span></div><h3 class="post-title entry-title" style="font-weight: normal; text-align: justify;"><span style="font-size: small;"></span></h3><h3 class="post-title entry-title" style="font-weight: normal; text-align: justify;"><span style="font-size: small;"></span></h3><h3 class="post-title entry-title" style="font-weight: normal; text-align: justify;"><span style="font-size: small;"><br />
 </span></h3><div style="background-color: yellow; color: red; text-align: center;"><span style="font-size: large;">Caution</span></div><br />
<div style="text-align: justify;">In carrying-out disassembly, place the disassembled parts in order on a clean work table, and protect them against dust and dirt. Prepare various jigs necessary for removal depending on the type of machine.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;"></div><div style="text-align: justify;"><br />
</div><div style="background-color: red; color: yellow; text-align: center;"><span style="font-size: large;">Fitting Of Bearing</span></div><br />
The bearing is to be fitted in the following manner<br />
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<div style="background-color: yellow; color: red; text-align: center;"><span style="font-size: large;">Caution</span></div><br />
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<div style="background-color: yellow; color: red; text-align: justify;">The anti-friction bearing is of higher precision than other mechanical parts, and so a due care is to be given to its handling to prevent them from becoming dusty, stained, scratched and marred.</div><div style="text-align: justify;"><br />
</div><div style="text-align: justify;">Before fitting the bearing in position, its neck and threaded parts are to be made perfect, and cleaned completely by means of cleaning oil. the ring nut is to be temporarily fitted to the shaft beforehand to see if it is perfectly matched to it.</div><br />
<div style="text-align: justify;">The end cover, grease runner, ring nut and locking washer are to be cleaned beforehand.</div><br />
<div style="text-align: justify;">The bearing is to be heated in oil for expansion of its inner diameter.</div><br />
<br />
<div style="background-color: yellow; color: red; text-align: justify;">Caution: The heating temperature should not exceed 120ºC. The temperature higher than this will reduce the load tolerance of the bearing steel, thus resulting in the shorting of its durability.</div><br />
The heated bearing is to be set in place after the inside and cover has been fitted.<br />
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<div style="text-align: justify;">The inner ring of the bearing is to be tightened fully against the shoulder part of the shaft after the ring nut has been tightened. After the bearing has cooled down to room temperature, the ring nut is to be tightened again and locked with a washer.</div><br />
<div style="text-align: justify;">Fill the space between the bearing races and the balls with grease. Inject grease into the inside end cover space, the grease amounting to 1/2 to 1/3 of the capacity.</div><br />
<div style="text-align: justify;">The housings such as the bracket, bearing housing, etc. are to be fitted in position.</div><div style="text-align: justify;"><br />
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<h3 class="post-title entry-title"> </h3><h3 class="post-title entry-title"> </h3><h3 class="post-title entry-title"> </h3><h3 class="post-title entry-title"> </h3><h3 class="post-title entry-title"> </h3>

BEARING AND LUBRICATION PART 3

BEARING AND LUBRICATION PART 1 BEARING AND LUBRICATION PART 2 Removal Of Bearing In case that the bearing is so damaged as to hinder...

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THE MOTOR STRUCTURE

All motors have a similar basic construction. Each has two main parts:<br />
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            1.         The stator.<br />
            2.         The rotor.<br />
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The stator is normally mounted on the frame.  This frame is usually cylindrical in shape.  The field poles with field windings on them are part of the stator.  The identification plate is also mounted on the stator. The frame has end bells or plates attached to it. These hold the bearings.  When the rotor shaft journals are mounted in the bearings, the bells support the rotor.<br />
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The rotor is mounted on a shaft, which has two journal bearings, one at each end.  The bearings are accurately machined to provide the proper amount of endplay for the rotor.  There is a clearance of .001 to .002 between the motor shaft and the bearing<br />
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The windings are insulated copper wire.  This insulation is usually a polyester material.  It is resistant to moisture and has considerable dielectric and mechanical strength.<br />
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Both alternating current (AC) and direct current (DC) may be used to operate electric motors.  Following motor types are most commonly used: -<br />
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AC - Single phase<br />
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            Split phase induction.<br />
            Capacitor-start induction.<br />
            Capacitor-start, capacitor run.<br />
            Shaded pole.<br />
            Universal.<br />
            Repulsion.<br />
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AC - Three phase<br />
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            Squirrel cage induction<br />
            Wound rotor induction<br />
            Synchronous<br />
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DC -    Series<br />
            Shunt<br />
            Compound<br />
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Today, the capacitor motor is being used on most household applications.  It is the most popular single-phase machine.

THE MOTOR STRUCTURE

All motors have a similar basic construction. Each has two main parts: 1. The stator. 2. The roto...

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Mechanical Motion From Electrical Energy

<div dir="ltr" style="text-align: left;" trbidi="on"><div class="MsoNormal" style="color: red; margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify; text-indent: -36pt;"><span style="font-size: large;"><span style="font-family: Arial; letter-spacing: -0.1pt;">        </span><u><span style="font-family: Arial; letter-spacing: -0.1pt;">Mechanical Motion From Electrical Energy</span><span style="font-family: Arial; letter-spacing: -0.1pt;"></span></u></span></div><div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">If a current carrying wire is placed in another magnetic field, magnetic forces are produced to either attract or repel wire depending on direction of two fields.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial;">The lines of force can be compared to elastic bands, which stretch outward when a force is exerted upon them and contract when the force is removed.</span></div><div class="MsoNormal" style="margin-left: 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="color: red; margin-left: 36pt; text-align: justify;"><span style="font-size: large;"><u><span style="font-family: Arial;">Characteristics of magnetic lines of force:</span></u></span></div><div class="MsoNormal" style="margin-left: 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">a.         Magnetic lines of force pass through all materials, there is no insulator against them.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">b.         Each magnetic line forms a closed loop. Its direction is externally from the North Pole to the South Pole.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify; text-indent: 36pt;"><span style="font-family: Arial;">c.         Magnetic lines of force do not cross each other</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify; text-indent: 36pt;"><span style="font-family: Arial;">d.         Magnetic lines of force tend to shorten themselves</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="color: red; margin: 0cm 28.45pt 0.0001pt 36pt; text-align: left;"><u><span style="font-size: large;"><span style="font-family: Arial;"></span></span><span style="font-size: large;">Laws of attraction and repulsion</span></u></div><div class="MsoNormal" style="margin-left: 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">a.         Two unlike poles North and South will attract each other if brought together</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">b.         Two like poles, North and North, or South and south will repel each other if brought together. Note that lines of force traveling in the same direction cause repulsion.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">c.         The force between two magnets decreases rapidly with the distance of separation.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">d.         The rule, which relates the direction of magnetic field and conventional current flow, shown in figure 1.1, is known as the Right Hand Rule.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><span style="font-family: Arial;"> </span><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://www12.0zz0.com/2010/12/15/08/553479626.png" src="http://www12.0zz0.com/2010/12/15/08/553479626.png" /></a></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><b><span style="font-family: Arial;">Fig.1-1.Application of the right hand rule</span></b></div><div></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><span style="font-family: Arial;">The magnetic fields around conductors interact to produce forces of attraction or repulsion as shown on <b>Fig.1-2.</b></span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://img105.herosh.com/2010/12/15/612512520.png" src="http://img105.herosh.com/2010/12/15/612512520.png" /></a><span style="font-family: Arial;"><b> </b></span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><span style="font-family: Arial;"><b><br />
</b></span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><b><span style="font-family: Arial;">Fig.1-2.Forces of interaction between current carrying conductors</span></b></div><div style="text-align: center;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><br />
</div><div style="text-align: center;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><br />
</div><div style="text-align: center;"></div><div class="MsoBodyTextIndent" style="margin-right: 28.45pt; text-align: center;">The lines of force flowing in opposite direction produce force of attraction, while lines of force flowing in the same direction produce repulsion.</div><div style="text-align: center;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><br />
</div><div style="text-align: center;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><b><span style="font-family: Arial;">The principle of motor operation is shown in</span></b><span style="font-family: Arial;"> <b>Fig.1-3.</b></span></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><br />
</div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://img103.herosh.com/2010/12/15/572203354.png" src="http://img103.herosh.com/2010/12/15/572203354.png" /></a><span style="font-family: Arial;"><b> </b></span></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><span style="font-family: Arial;"><b> </b></span></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"></div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><b><span style="font-family: Arial;">Diagram 1.3a current is flowing in the coil thus no flux is produced and no torque is present no motion.</span></b></div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><br />
</div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"></div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"></div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://img102.herosh.com/2010/12/15/126379707.png" src="http://img102.herosh.com/2010/12/15/126379707.png" /></a><b><span style="font-family: Arial;"> </span></b></div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><b><span style="font-family: Arial;"><br />
</span></b></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><span style="font-family: Arial;"><b> </b></span></div><div style="text-align: center;"></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"></div><div align="center" class="Document2" style="direction: ltr; margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial;">Diagram 1.3b Current is passing through the coil, the flux produced causes repulsion force (same direction of lines of force). The coil rotates.</span></b></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://img105.herosh.com/2010/12/15/923467887.png" src="http://img105.herosh.com/2010/12/15/923467887.png" /></a><span style="font-family: Arial;"> </span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><span style="font-family: Arial;"> </span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><b><span style="font-family: Arial;">Diagram 1.3c No torque since the coil is not being pushed from or propelled out of the field. No cutting of lines of force.</span></b></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://img105.herosh.com/2010/12/15/706426291.png" src="http://img105.herosh.com/2010/12/15/706426291.png" /></a><b><span style="font-family: Arial;"> </span></b></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><b><span style="font-family: Arial;"><br />
</span></b></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"></div><h2 style="text-align: center;"><span style="font-size: small;">Fig.1-3d.The motor principle</span><span style="font-size: small;"><span style="font-family: Arial;"> </span></span><span style="font-size: small;"><span style="font-family: Univers;"> </span></span></h2><h2 style="text-align: center;"><span style="font-size: small;"><span style="font-family: Univers;">Diagram 1.3d the coil is rotated by 180 </span><span style="font-family: Symbol;">°</span><span style="font-family: Univers;"> from original position, for the motor to </span></span></h2><h2 style="text-align: center;"></h2><div class="MsoBodyText" style="text-align: center;">continue to rotate in the same direction; the supply voltage must be reversed.</div><div></div><div class="Document2" style="direction: ltr; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial;">An AC supply or a commentator can do this.</span></b></div><h2 style="text-align: center;"><span style="font-size: small;"><span style="font-family: Univers;"> </span></span></h2><div></div><div style="text-align: center;"><br />
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<div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><span style="font-family: Arial;"> </span></div></div>

Mechanical Motion From Electrical Energy

Mechanical Motion From Electrical Energy If a current carrying wire is placed in another magnetic field, magnetic forces are produc...

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INTRODUCTION TO MOTORS

<div dir="ltr" style="text-align: left;" trbidi="on"><br />
<div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify; text-indent: -36pt;"><b><span style="font-family: Arial; letter-spacing: -0.15pt;">1.0</span></b><b><span style="font-family: Arial; font-size: 12pt; letter-spacing: -0.15pt;">       </span></b><b><u><span style="font-family: Arial; letter-spacing: -0.15pt;">INTRODUCTION</span></u></b><u><span style="font-family: Arial; font-size: 12pt; letter-spacing: -0.15pt;"></span></u></div><div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">A motor is a device, which converts electrical energy into mechanical energy. The modern power station requires a wide range of electric motors ranging from small fractional power to motors as large as 15 MW. There are about 2,000 motors in a typical power station.</span></div><div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify; text-indent: -36pt;"><b><span style="font-family: Arial; letter-spacing: -0.1pt;">2.0       <u>PRINCIPLES OF ELECTRIC MOTORS OPERATION</u></span></b></div><div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">One of the most frequently used effects of electric current is its ability to produce force called magnetism. This force is responsible for the operation of motors, generators, measuring instruments, and communication equipment, transformers and control devices.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">Iron, nickel, and some oxides and alloys are called magnetic materials because they can be magnetized. A rough classification divides magnets into two groups; permanent and temporary magnets.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">A permanent magnet will keep its strength after the magnetizing force is removed. Many alloys make excellent permanent magnets as well as high carbon steels. </span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">Temporary magnets become strongly magnetized when placed inside current carrying coil. These electromagnets have a much wider use and a greater variety of applications than permanent magnets. The material used most frequently for electromagnets is the soft alloy silicon iron. This alloy is used in transformers, motors, and generators, relays, and other electromagnetic equipment. </span></div></div>

INTRODUCTION TO MOTORS

1.0 INTRODUCTION A motor is a device, which converts electrical energy into mechanical energy. The modern power station requires a ...

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