Helical Gears

 The teeth on helical gears are cut at an angle to the face of the gear. When two teeth on a helical gear system engage, the contact starts at one end of the tooth and gradually spreads as the gears rotate, until the two teeth are in full engagement.

This gradual engagement makes helical gears operate much more smoothly and quietly than spur gears. For this reason, helical gears are used in almost all car transmissions.

Because of the angle of the teeth on helical gears, they create a thrust load on the gear when they mesh. Devices that use helical gears have bearings that can support this thrust load.

One interesting thing about helical gears is that if the angles of the gear teeth are correct, they can be mounted on perpendicular shafts, adjusting the rotation angle by 90 degrees.

Other Topics

IC engine, Air Standard Cycles, Method of Ignition, Gear Types, External vs Internal Gears, External Gear Pump, mechanical Engineering, Gears, Gears Purpose, spur gears,Helical gears,herringbone gear,Worm gears,Mechanical Pdf,English books,Photoshop tutorials,Physics files,Thamizh,Manufacturing,Gears pdf,Computer science,Harry potter,Best 100 english books,Rack and pinion,Face Gears,Involute Splines,Straight sided Spline, Quiz on friction

Spur Gears

Spur gears are by far the most common type of gear and with the exceptions of the "cog" the type of gear that has been around the longest. Spur gears have teeth that run perpendicular to the face of the gear.

Other Topics

IC engine, Air Standard Cycles, Method of Ignition, Gear Types, External vs Internal Gears, External Gear Pump, mechanical Engineering, Gears, Gears Purpose, spur gears,Helical gears,herringbone gear,Worm gears,Mechanical Pdf,English books,Photoshop tutorials,Physics files,Thamizh,Manufacturing,Gears pdf,Computer science,Harry potter,Best 100 english books,Rack and pinion,Face Gears,Involute Splines,Straight sided Spline, Quiz on friction

Gears The Purpose

Gears are generally used for one of four different reasons:

-

To reverse the direction of rotation

-

To increase or decrease the speed of rotation

-

To increase or decrease the speed of rotation

-

To move rotational motion to a different axis

-

To keep the rotation of two axis synchronized 

Other Topics

IC engine, Air Standard Cycles, Method of Ignition, Gear Types, External vs Internal Gears, External Gear Pump, mechanical Engineering, Gears, Gears Purpose, spur gears,Helical gears,herringbone gear,Worm gears,Mechanical Pdf,English books,Photoshop tutorials,Physics files,Thamizh,Manufacturing,Gears pdf,Computer science,Harry potter,Best 100 english books,Rack and pinion,Face Gears,Involute Splines,Straight sided Spline, Quiz on friction

Gears

Gears are wheels with teeth. Gears mesh together and make things turn. Gears are used to transfer motion or power from used to transfer  motion or power from one moving part to another.

Other Topics

IC engine, Air Standard Cycles, Method of Ignition, Gear Types, External vs Internal Gears, External Gear Pump, mechanical Engineering, Gears, Gears Purpose, spur gears,Helical gears,herringbone gear,Worm gears,Mechanical Pdf,English books,Photoshop tutorials,Physics files,Thamizh,Manufacturing,Gears pdf,Computer science,Harry potter,Best 100 english books,Rack and pinion,Face Gears,Involute Splines,Straight sided Spline, Quiz on friction

Mechanical Engineering

Mechanical engineering is a discipline of engineering that applies the principles of engineering, physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems.

Other Topics

IC engine, Air Standard Cycles, Method of Ignition, Gear Types, External vs Internal Gears, External Gear Pump, mechanical Engineering, Gears, Gears Purpose, spur gears,Helical gears,herringbone gear,Worm gears,Mechanical Pdf,English books,Photoshop tutorials,Physics files,Thamizh,Manufacturing,Gears pdf,Computer science,Harry potter,Best 100 english books,Rack and pinion,Face Gears,Involute Splines,Straight sided Spline, Quiz on friction

External Gear Pump

External gear pumps are similar in pumping action to internal gear pumps in that two gears come into and out of mesh to produce flow.  However, the external gear pump uses two identical gears rotating against each other -- one gear is driven by a motor and it in turn drives the other gear.  Each gear is supported by a shaft with bearings on both sides of the gear.
1.  As the gears come out of mesh, they create expanding volume on the inlet side of the pump. Liquid flows into the cavity and is trapped by the gear teeth as they rotate.
2.  Liquid travels around the interior of the casing in the pockets between the teeth and the casing -- it does not pass between the gears. 
3.  Finally, the meshing of the gears forces liquid through the outlet port under pressure.
Because the gears are supported on both sides, external gear pumps are quiet-running and are routinely used for high-pressure applications such as hydraulic applications. With no overhung bearing

Other Topics

IC engine, Air Standard Cycles, Method of Ignition, Gear Types, External vs Internal Gears, External Gear Pump, mechanical Engineering, Gears, Gears Purpose, spur gears,Helical gears,herringbone gear,Worm gears,Mechanical Pdf,English books,Photoshop tutorials,Physics files,Thamizh,Manufacturing,Gears pdf,Computer science,Harry potter,Best 100 english books,Rack and pinion,Face Gears,Involute Splines,Straight sided Spline, Quiz on friction

External vs internal gears

An external gear is one with the teeth formed on the outer surface of a cylinder or cone. Conversely, an internal gear is one with the teeth formed on the inner surface of a cylinder or cone. For bevel gears, an internal gear is one with the pitch angle exceeding 90 degrees. Internal gears do not cause output shaft direction reversal.

Other Topics

IC engine, Air Standard Cycles, Method of Ignition, Gear Types, External vs Internal Gears, External Gear Pump, mechanical Engineering, Gears, Gears Purpose, spur gears,Helical gears,herringbone gear,Worm gears,Mechanical Pdf,English books,Photoshop tutorials,Physics files,Thamizh,Manufacturing,Gears pdf,Computer science,Harry potter,Best 100 english books,Rack and pinion,Face Gears,Involute Splines,Straight sided Spline, Quiz on friction

Gear types

External vs internal gears
Spur
Helical
1 Skew gears
Double helical
Bevel
Spiral bevels
Hypoid
Crown
Worm
Non-circular
Rack and pinion
Epicyclic
Sun and planet
Harmonic drive
Cage gear
Magnetic gear

Other Topics

IC engine, Air Standard Cycles, Method of Ignition, Gear Types, External vs Internal Gears, External Gear Pump, mechanical Engineering, Gears, Gears Purpose, spur gears,Helical gears,herringbone gear,Worm gears,Mechanical Pdf,English books,Photoshop tutorials,Physics files,Thamizh,Manufacturing,Gears pdf,Computer science,Harry potter,Best 100 english books,Rack and pinion,Face Gears,Involute Splines,Straight sided Spline, Quiz on friction

Method of ignition

SI engines, mixture is uniform (conventional engines), mixture is non-uniform (stratified-charge engines) ignition is by the application of external energy (to spark plug)

CI engines, ignition by compression in conventional engine (Diesel engine), pilot injection of fuel in gas engines (eg, natural gas and diesel fuel – dual fuel engines)

Other Topics

IC engine, Air Standard Cycles, Method of Ignition, Gear Types, External vs Internal Gears, External Gear Pump, mechanical Engineering, Gears, Gears Purpose, spur gears,Helical gears,herringbone gear,Worm gears,Mechanical Pdf,English books,Photoshop tutorials,Physics files,Thamizh,Manufacturing,Gears pdf,Computer science,Harry potter,Best 100 english books,Rack and pinion,Face Gears,Involute Splines,Straight sided Spline, Quiz on friction

AIR STANDARD CYCLES

AIR STANDARD CYCLES
Because the products of combustion are not too different from air (in terms of thermodynamic properties) we can analyse the engine cycle as a series of reversible non-flow processes using air as the working fluid throughout the cycle.This is known as an air-standard cycle.

Other Topics

IC engine, Air Standard Cycles, Method of Ignition, Gear Types, External vs Internal Gears, External Gear Pump, mechanical Engineering, Gears, Gears Purpose, spur gears,Helical gears,herringbone gear,Worm gears,Mechanical Pdf,English books,Photoshop tutorials,Physics files,Thamizh,Manufacturing,Gears pdf,Computer science,Harry potter,Best 100 english books,Rack and pinion,Face Gears,Involute Splines,Straight sided Spline, Quiz on friction

IC engine

An Internal Combustion engine is one in which the heat transfer to the working fluid occurs within the engine itself, usually by the combustion of fuel with the oxygen of air

Other Topics

IC engine, Air Standard Cycles, Method of Ignition, Gear Types, External vs Internal Gears, External Gear Pump, mechanical Engineering, Gears, Gears Purpose, spur gears,Helical gears,herringbone gear,Worm gears,Mechanical Pdf,English books,Photoshop tutorials,Physics files,Thamizh,Manufacturing,Gears pdf,Computer science,Harry potter,Best 100 english books,Rack and pinion,Face Gears,Involute Splines,Straight sided Spline, Quiz on friction

Uppercase letters in XHTML tags

Uppercase letters in XHTML tags

In XHTML, unlike HTML, element and attribute names must be all lowercase. For example, onMouseOver is an invalid attribute in XHTML, which requires use of onmouseover instead. Either is fine in HTML.

Ampersands (&'s) in URLs

Ampersands (&'s) in URLs

Another common error occurs when including a URL which contains an ampersand ("&"):

<!-- This is invalid! --> <a href="foo.cgi?chapter=1&section=2&copy=3&lang=en">...</a>

This example generates an error for "unknown entity section" because the "&" is assumed to begin an entity reference. Browsers often recover safely from this kind of error, but real problems do occur in some cases. In this example, many browsers correctly convert &copy=3 to ©=3, which may cause the link to fail. Since ⟨ is the HTMLentity for the left-pointing angle bracket, some browsers also convert &lang=en to 〈=en. And one old browser even finds the entity §, converting &section=2 to §ion=2.

To avoid problems with both validators and browsers, always use & in place of &when writing URLs in HTML:

<a href="foo.cgi?chapter=1&amp;section=2&amp;copy=3&amp;lang=en">...</a>

Note that replacing & with &amp; is only done when writing the URLin HTML, where "&" is a special character (along with "<" and ">"). When writing the same URLin a plain text email message or in the location bar of your browser, you would use "&" and not "&amp;". With HTML, the browser translates "&amp;" to "&" so the Web server would only see "&" and not "&amp;" in the query string of the request.

Writing HTML in a SCRIPT Element

Writing HTML in a SCRIPT Element

A common error (and the most common source of erroneous bug reports for the WDG HTML Validator) occurs when writing HTML tags within a SCRIPT element:

<script type="text/javascript">
<!--
  // This is an error!
  document.write("</P>");
// -->
</script>

As mentioned in the HTML 4 Recommendation's note about specifying non-HTML data in element content, end tags are recognized within SCRIPT elements, but other kinds of markup--such as start tags and comments--are not. This is an unintuitive quirk of SGMLfor elements defined to have CDATA content.
Authors should avoid using strings such as "</P>" in their embedded scripts. In JavaScript, authors may use a backslash to prevent the string from being parsed as markup:

<script type="text/javascript">
<!--
  document.write("<\/P>");
// -->
</script>

Note that in XHTML, authors must also take care when using start tags within a script element. For details, see the Script and Style elements section of the XHTML 1.0 Recommendation as well as the HTML compatibility guideline for embedded scripts.