Sunday, March 14, 2010

Gears


Gears

CNC Hobbing and Shaping.

Spur and helical gear cutting
to 36 inch pitch diameter.

Pitches from 2 to 120 diametral pitch
and metric module from 8m to .4m.

Crown hobbing and shaving.

Tooth rounding, pointing, and chamfering.

Rack Gear

Rack Gears
Click  here to Zoom


We offer super grade rack gears, which are used for converting rotational motion into linear motion. These rack gears feature a flat bar onto which the teeth of a pinion gear are engaged. We make use super grade material for imparting these rack gears lasting features. Committed towards total customer satisfaction, we offer these rack gears at affordable rates.

Features :

The main characteristics of these rack gears are mentioned below:
  • Quiet and smooth operation.
  • Less backlash
  • High steering feel
  • Axis at infinity
Applications :

Our rack gears are catering to the demands of varied industries, such as :
  • Steering mechanism of cars
  • Construction equipment
  • Conveyors
  • Material handling
  • Machine tools
  • Roller feeds

Precision Gears


We manufacture and supply a wide range of high quality precision gears, which are used in applications under conditions of light loading. Conforming to the international quality standards, these precision gears are available in several sizes and dimensions to meet the demands of our clients. Features : Our precision gears are appreciated amidst our clients for their following features:
  • Trouble free superior performance
  • Long service life
  • Excellent surface finish
  • Customization capability
  • Precise dimension
  • Noiseless
Applications : Our range of precision gears find usage in different industries, which include:
  • Metal casting
  • Metal processing
  • Heavy machinery Industry
  • Construction

Gears and Racks&Assemblies

Gears and Racks

  • Spur Gears
  • Miters
  • Bevels
  • Worms & Worm Wheels
  • Helical & Spur Gear Racks

Assemblies

  • Differentials
  • Speed Reducers
  • Gear Boxes
  • Anti-Backlash Gears
Differential
Differentials
Worms and  Worm Gears
Worms & Worm Gears
Speed Reducers
Speed Reducers
Custom  Assembly
Custom Assembly
Application Specific Gears
Application Specific Gears
Bevel Gears
Bevel Gears

spur gears

Introduction

Gears are machine elements used to transmit rotary motion between two shafts, normally with a constant ratio. The pinion is the smallest gear and the larger gear is called the gear wheel.. A rack is a rectangular prism with gear teeth machined along one side- it is in effect a gear wheel with an infinite pitch circle diameter. In practice the action of gears in transmitting motion is a cam action each pair of mating teeth acting as cams. Gear design has evolved to such a level that throughout the motion of each contacting pair of teeth the velocity ratio of the gears is maintained fixed and the velocity ratio is still fixed as each subsequent pair of teeth come into contact. When the teeth action is such that the driving tooth moving at constant angular velocity produces a proportional constant velocity of the driven tooth the action is termed a conjugate action. The teeth shape universally selected for the gear teeth is the involute profile.

Consider one end of a piece of string is fastened to the OD of one cylinder and the other end of the string is fastened to the OD of another cylinder parallel to the first and both cylinders are rotated in the opposite directions to tension the string(see figure below). The point on the string midway between the cylinder P is marked. As the left hand cylinder rotates CCW the point moves towards this cylinder as it wraps on . The point moves away from the right hand cylinder as the string unwraps. The point traces the involute form of the gear teeth.

The lines normal to the point of contact of the gears always intersects the centre line joining the gear centres at one point called the pitch point. For each gear the circle passing through the pitch point is called the pitch circle. The gear ratio is proportional to the diameters of the two pitch circles. For metric gears (as adopted by most of the worlds nations) the gear proportions are based on the module.

m = (Pitch Circle Diameter(mm)) / (Number of teeth on gear).

In the USA the module is not used and instead the Diametric Pitch d pis used

d p = (Number of Teeth) / Diametrical Pitch (inches)



Profile of a standard 1mm module gear teeth for a gear with Infinite radius (Rack ).
Other module teeth profiles are directly proportion . e.g. 2mm module teeth are 2 x this profile


Many gears trains are very low power applications with an object of transmitting motion with minium torque e.g. watch and clock mechanisms, instruments, toys, music boxes etc. These applications do not require detailed strength calculations........

AMD Athlon Processor Overview

The AMD Athlon processor is the first Windows-compatible 64-bit PC processor. The AMD Athlon processor runs on AMD64 technology, a revolutionary technology that allows the processor to run 32-bit applications at full speed while enabling a new generation of powerful 64-bit software applications. Advanced 64-bit operating systems designed for the AMD64 platform from Microsoft, Red Hat, SuSE, and TurboLinux have already been announced.

With the introduction of the AMD Athlon processor, AMD provides customers a solution that can address their current and future computing needs. As the first desktop PC processor to run on the AMD64 platform, the AMD Athlon processor helps ensure superior performance on today’s software with readiness for the coming wave of 64-bit computing. With AMD64 technology, customers can embrace the new capabilities of 64-bit computing on their own terms and achieve compatibility with existing software and operating systems.

Enhanced Virus Protection with Windows XP Service Pack 2
With a unique combination of hardware and software technologies that offer you an added layer of protection, certain types of viruses don't stand a chance. The AMD Athlon processor features Enhanced Virus Protection, when support by the OS, and can help protect against viruses, worms, and other malicious attacks. When combined with protective software, Enhanced Virus Protection is part of an overall security solution that helps keep your information safer.

Industry-leading performance for today’s software
It 's not just about email, Web browsing and word processing anymore. The AMD Athlon processor gives you full-throttle performance to go wherever your digital world takes you. Whether you're watching videos, ripping and playing music, or playing games, AMD64 performance helps you to fully enjoy any multimedia experience with a “you are there” reality. The revolutionary architecture of the AMD Athlon processor enables industry-leading performance to help maximize productivity and deliver a true-to-life digital entertainment experience. HyperTransport technology can increase overall system performance by removing I/O bottlenecks, increasing system bandwidth, and reducing system latency. A fully integrated DDR memory controller helps speed access to memory by offering the processor a direct connection to the main memory. As a result, end users can enjoy quicker application loading and extraordinary application performance.

With 3DNow! Professional technology and support for SSE3, the AMD Athlon processor has more ways to accelerate multimedia applications, enabling stellar performance when working with audio, video and photography software. For a superior experience with high-speed Internet, the AMD Athlon processor combines high-speed memory access and I/O connectivity to help ensure that end users can fully take advantage of a broadband connection to streaming video and audio, and a riveting online gaming experience.

Ready for the 64-bit future
The AMD Athlon processor is designed for people who want to stay at the forefront of technology and for those who depend on their PCs to keep them connected, informed, and entertained. Systems based on AMD Athlon processors are able to deliver leading-edge performance for demanding productivity and entertainment software today and in the future.

With AMD64 technology, the AMD Athlon processor is fully compatible with existing software, while enabling a seamless transition to 64-bit applications. Both 32- and 64-bit applications can run virtually simultaneously and transparently on the same platform. AMD64 technology enables new, cinematic computing experiences and capabilities, in addition to increased performance. AMD64 technology allows end users to take advantage of new innovations such as real-time encryption, more life-like games, accurate speech interfaces, cinema-quality graphic effects, and easy-to-use video and audio editing.

Protect investments with a technically superior PC processor
The AMD Athlon processor is the world’s most technically advanced PC processor and the first Windows-compatible 64-bit PC processor. Advanced technologies in the AMD Athlon processor include:

* AMD64 technology which doubles the number of processor registers and dramatically increases the system memory addressability
* Enhanced multimedia instructions support including 3DNow! Professional technology and SSE2/3
* With up to a 2000 MHz system bus using HyperTransport technology with up to 14.4 GB/sec total processor-to-system bandwidth
* An integrated memory controller with peak memory bandwidth of up to 6.4 GB/sec, supporting PC3200, PC2700, PC2100, or PC1600 DDR SDRAM
* Native execution of 32-bit software, allowing today’s PC software to provide leading-edge performance while enabling a seamless migration to 64-bit software.


The combination of these innovations and features provides customers with performance they need along with tremendous flexibility. Customers can experience outstanding performance running today’s applications and prepare for the next generation of software without having to upgrade or change hardware. For business customers, this extends system life cycles, simplifies technology transition and reduces total cost of ownership.

Purchase with confidence
The AMD Athlon processor is the only industry standard x86 processor with the ability to move beyond the limits of 32-bit computing. The AMD Athlon processor is compatible with Microsoft Windows XP and tens of thousands of PC applications that people around the world use every day. The award-winning AMD Athlon processor won over 100 industry accolades and was the first 1GHz PC processor. Now, the AMD Athlon processor reaches a new milestone by building a path to 64-bit computing for millions of PC users.

AMD Athlon Processor Overview

The AMD Athlon processor is the first Windows-compatible 64-bit PC processor. The AMD Athlon processor runs on AMD64 technology, a revolutionary technology that allows the processor to run 32-bit applications at full speed while enabling a new generation of powerful 64-bit software applications. Advanced 64-bit operating systems designed for the AMD64 platform from Microsoft, Red Hat, SuSE, and TurboLinux have already been announced.

With the introduction of the AMD Athlon processor, AMD provides customers a solution that can address their current and future computing needs. As the first desktop PC processor to run on the AMD64 platform, the AMD Athlon processor helps ensure superior performance on today’s software with readiness for the coming wave of 64-bit computing. With AMD64 technology, customers can embrace the new capabilities of 64-bit computing on their own terms and achieve compatibility with existing software and operating systems.

Enhanced Virus Protection with Windows XP Service Pack 2
With a unique combination of hardware and software technologies that offer you an added layer of protection, certain types of viruses don't stand a chance. The AMD Athlon processor features Enhanced Virus Protection, when support by the OS, and can help protect against viruses, worms, and other malicious attacks. When combined with protective software, Enhanced Virus Protection is part of an overall security solution that helps keep your information safer.

Industry-leading performance for today’s software
It 's not just about email, Web browsing and word processing anymore. The AMD Athlon processor gives you full-throttle performance to go wherever your digital world takes you. Whether you're watching videos, ripping and playing music, or playing games, AMD64 performance helps you to fully enjoy any multimedia experience with a “you are there” reality. The revolutionary architecture of the AMD Athlon processor enables industry-leading performance to help maximize productivity and deliver a true-to-life digital entertainment experience. HyperTransport technology can increase overall system performance by removing I/O bottlenecks, increasing system bandwidth, and reducing system latency. A fully integrated DDR memory controller helps speed access to memory by offering the processor a direct connection to the main memory. As a result, end users can enjoy quicker application loading and extraordinary application performance.

With 3DNow! Professional technology and support for SSE3, the AMD Athlon processor has more ways to accelerate multimedia applications, enabling stellar performance when working with audio, video and photography software. For a superior experience with high-speed Internet, the AMD Athlon processor combines high-speed memory access and I/O connectivity to help ensure that end users can fully take advantage of a broadband connection to streaming video and audio, and a riveting online gaming experience.

Ready for the 64-bit future
The AMD Athlon processor is designed for people who want to stay at the forefront of technology and for those who depend on their PCs to keep them connected, informed, and entertained. Systems based on AMD Athlon processors are able to deliver leading-edge performance for demanding productivity and entertainment software today and in the future.

With AMD64 technology, the AMD Athlon processor is fully compatible with existing software, while enabling a seamless transition to 64-bit applications. Both 32- and 64-bit applications can run virtually simultaneously and transparently on the same platform. AMD64 technology enables new, cinematic computing experiences and capabilities, in addition to increased performance. AMD64 technology allows end users to take advantage of new innovations such as real-time encryption, more life-like games, accurate speech interfaces, cinema-quality graphic effects, and easy-to-use video and audio editing.

Protect investments with a technically superior PC processor
The AMD Athlon processor is the world’s most technically advanced PC processor and the first Windows-compatible 64-bit PC processor. Advanced technologies in the AMD Athlon processor include:

* AMD64 technology which doubles the number of processor registers and dramatically increases the system memory addressability
* Enhanced multimedia instructions support including 3DNow! Professional technology and SSE2/3
* With up to a 2000 MHz system bus using HyperTransport technology with up to 14.4 GB/sec total processor-to-system bandwidth
* An integrated memory controller with peak memory bandwidth of up to 6.4 GB/sec, supporting PC3200, PC2700, PC2100, or PC1600 DDR SDRAM
* Native execution of 32-bit software, allowing today’s PC software to provide leading-edge performance while enabling a seamless migration to 64-bit software.


The combination of these innovations and features provides customers with performance they need along with tremendous flexibility. Customers can experience outstanding performance running today’s applications and prepare for the next generation of software without having to upgrade or change hardware. For business customers, this extends system life cycles, simplifies technology transition and reduces total cost of ownership.

Purchase with confidence
The AMD Athlon processor is the only industry standard x86 processor with the ability to move beyond the limits of 32-bit computing. The AMD Athlon processor is compatible with Microsoft Windows XP and tens of thousands of PC applications that people around the world use every day. The award-winning AMD Athlon processor won over 100 industry accolades and was the first 1GHz PC processor. Now, the AMD Athlon processor reaches a new milestone by building a path to 64-bit computing for millions of PC users.

How To Pick The Best Web Hosting Company

There are a lot of Web Hosting Company. First you should choose Good and Reputable company, then you should Filter that to the Best. Here is the criteria to pick the best Web Hosting Company.

Back End/Network Operations Centers
This is where your accounts are actually housed. Sometimes a hosting provider will lease a part of a larger network and sometimes a hosting provider will develop their own. It is important to find out what kinds and how many fiber optic connections the NOC has. Make sure there is plenty of redundancy built in. Make sure the NOC is managed 24/7, even on holidays. Make sure there are fire suppression systems in place. Last but not least, ask about security. Make sure there are plenty of security measure in place.

Customer Service
Are they friendly? Do they answer their telephones? Are you put on hold and if so, for how long? If you have to leave a message, do they respond quickly? Does the rep on the other end know what they are talking about? Look at their network page and see if they have reports of down time or issue statements about problems.

Technical Support
How long does it take to get questions answered and tasks performed. Send a test support message and gauge the response times. See if they offer 800 toll free support.

Ticketing Systems
Do they have a ticketing system that tracks performance times. This is key. If a hosting company has this, they are serious about improving internally.

Domain Names
Do they offer domain name sales? This can help to consolidate your vendor costs. See about getting a discount on domains if you are buying in bulk on a monthly basis.

Branding You
Does the hosting provider offer branded support? As you grow, you will need to expand and see if the hosting provider will set you up with your own technician in your company name. Do they offer branded control panels and name servers? You need these tools to grow. Find out how easy it is to set these features up for your own account.

Scalable Discounts
If you are growing at a rapid rate, ask for better pricing and discounts. It is ok to ask. It’s even better when you get it and will
reduce your overhead.

Financial Overview
Is that particular company in the red of black? Do they have a good cash flow? How fast is the host growing and can they handle the growth? What are they doing to grow and maintain the customer service level you expect. Are they near a buy out or planning

An Introduction to Domain Names

Simply put, a domain name is a “front” – they are word sequences users enter in their browser’s location bar to visit your site, but are not a Web site’s true address.
Domain names are attached to DNS (Domain Naming System) servers, which are used to translate numeric addresses (known as IP, or Internet Protocol, addresses) into words. Each site you visit on the net has a numeric IP address behind its name, which represents the site’s true address on the Internet.
Domain names are typically categorized by their extension, which is their identifying code. The three most popular types of Top Level Domains (TLDs), which are domains that are not
associated with a country, are:
.COM: Short for .commercial. Domain names with the .com extension are by far the most popular, and can be purchased by any individual or business. .
.NET: Short for .network, this domain extension was originally designed to be used by technical Web sites. However, domains using this extension can be registered by anyone.
.ORG: Short for .organization. Originally designated for non-profit firms and any other organizations that did not fit under the .com or .net extension, any individual or business may now register a .org domain name.
Country Level Domains
Domain names can also be assigned using country extensions. Each country has its own domain extension; Canada, for example, is .ca, while Japan has been assigned .jp. Most countries have specific rules surrounding exactly who can register domains using their extension and for what purpose; it’s therefore important to look before you leap.
Alternative Domain Names
The Internet Corporation for Assigned Names and Numbers (ICANN), the organization responsible for the administration of TLDs worldwide, recently approved several new extensions that are not specific to any country. These are:
* .areo
* .biz
* .coop
* .info
* .museum
* .name
* .pro
Each has been designed for a specific use, and is accompanied by certain restrictions. You can find more information about these TLDs here: http://www.icann.org/tlds/
Other Domain Extensions
In searching for your domain name, you may encounter Web sites offering extensions like .xxx, .free and .mp3. These are not true extensions endorsed by ICANN; rather, they rely on software solutions to guarantee their accessibility to users. Because ICANN has not approved any of these extensions, however, users that do not have the correct software cannot access sites using these names; therefore, they should be used for supplemental purposes only.
Although .com, .net and .org are typically the most visible and talked-about extensions, they are not the only ones available for use. From a functional perspective, country-level domains work just as well as any TLDs, and alternative extensions work just as well. Therefore, don’t necessarily settle for a mediocre TLD when you can get a better one using a different extension.

Friday, February 19, 2010

Aluminum Gears

We are manufacturers and exporters of Aluminium gears. Since its beginning, Ashoka group is involved with the manufacturing a wide range of aluminium gears for industrial and commercial markets , which are used in a wide variety of applications. Aluminium is widely used for light duty instrument gears.

Aluminium is lightweight, non-corrosive and easy to machine. The metal is malleable and has non-magnetic characteristics, it can be molded to any shape. Aluminium gears can be of various shapes. It offers spark proof starting of the engine and offers high strength. It offer smoother running, longer life and silent operation. It is protected with a coating of anodize. They are designed to resist wear for long lasting durability and maximum performance.

Aluminum Gears

The quality of our aluminum gears is regularly checked at every stage from manufacturing to final dispatch. Our long industry experience enable us to manufacture and supply these gears according to customer's drawings and specifications.

Wood Gears

Ashoka group specializes in manufacturing and exporting a range of wooden gears. They are widely used in textile mills and other industrial operations. They are also used in clocks, flour mills and coal mines. Wooden gears are manufactured by making a blank out of wood, drilling the shaft hole and filling a key way in the wood. Then using a gear train at slow speed, long pieces of brass shim stock trimmed to the width of the gear is fed in between a pair of moving gears.

Wood  Gears

This forms the brass with the proper gear tooth shape. The brass with the tooth pattern is wrapped around the wooden blank, overlapped one tooth and soldered together. The wood with brass wrapped around it is then laid down on wax paper and the space between the brass teeth and the wood is filled with epoxy or fiberglass resin to harden the gear. It is then dried and trimmed up of excess epoxy. Gears made of wood are not so durable but they run smoothly and are easier to repair. We use mahogany or hard wood or other superior quality wood for the wooden gears to lend good hardness for resisting wear. Available in a variety of different models, our wooden gears have robust construction.

Brass Gears

Brass gears are one of the most widely demanded gears produced by Ashoka Technologies. We are one of the acclaimed companies engaged in manufacturing these gears.

An advantage of brass gear is that constant meshing work hardens their teeth. Brass gears are also used in locomotives, clocks and in all thermal industries. They are often used in clocks where they work well without any lubricant.

Brass  Gears

The metal has low cost, non-corrosive property and is easy to machine. We use the best quality brass to make our gears. All the properties of brass like good strength, hardness, good electrical conductivity, good corrosion resistance are inherent in our gears. We manufacture durable and highly efficient Brass gears. Our brass gears can be customized as per the specifications and requirements of our customers who are spread all across the globe.

Ground Gears

We specialize in the field of manufacturing and exporting of highest quality ground gears as per Customer specifications upto 45 degree angle

Our manufacturing capacity is :-
Module:- 0.5 to 4 Module
Diameter:- 10mm to 200 mm,
HELIX ANKLE:- 0 degree to 45 degree RH/LH

Features:
  • Smooth finishes
  • High transmission accuracy
  • Higher load capacity
  • Maximum efficiency


Profile:- Standard & Non
Lead & profile graph can be provided
Ground Gears

Pinion Gears

We offer a widely appreciated range of pinion gears and helical pinion gears that are highly reliable and durable. Manufactured using superior quality material, our automotive pinion gear boxes are hugely demanded amongst wide clientele.

Features
  • Use of cutting edge technology.
  • Duly hardened and tempered.
  • Available in various sizes for improving vehicle and steering response.
  • Our automotive pinion gears use tooth modifications system in gearing to improve service life of pinions.
Pinion Gears

Spider Gears Provide Open Differential With Greater Performance


Spider gears are an integral part of you differential. They are part of the gear set that allows your rear wheels to turn at different speeds, which is necessary for many instances. When your vehicle goes into a turn, the out wheel turns at a faster rate than the inner wheel; this is accomplished through a series of gears including spider gears.

Spider gears offer you the ability to turn your vehicle without feeling the rear end bump as you go around a turn. If it weren't for spider gears and side gears within the differential, both rear wheels would turn at the same speed. If you're only going straight, this is not a bad thing, but the moment you go into a turn, the outside wheel will try to speed up. If spider gears and side gears where not in place, that outer wheel would not be able to turn faster than the inner wheel and would actually drag as you went through the turn, producing a bumping, lurching motion.

Spider gears are provided in the differential from the manufacturer and are one of the many shapes that gears can come in. Unlike spur gears, spider gears meet the shaft or other gear at a right angle, allowing them to be seated on shafts that do not touch and allowing the differential to be smaller and yet provide the necessary performance for most applications. Aftermarket, or performance differentials, have differently sized spider gears as well as differential housing to provide better traction for harder usage.

Spider gears are employed in limited slip differentials as well as standard differentials. Within a limited slip differential, spider gears work in conjunction with clutch packs to reduce the speed of a wheel that is spinning much faster than the other. The purpose of the clutch packs is an attempt to keep both rear wheels at relatively the same speed. Their efforts aren't noticeable when you're simply taking a curve, but if one wheel where to be placed on ice or in slick mud, the opposite wheel would be able to grip the road.

A standard differential allows all the torque to go to the wheel with the least amount of resistance; while this isn't a bad thing for street driving, if you intend to take your vehicle off road, or consistently drive in areas where little traction and slick spots are common, a limited slip differential, or fully locking differential is a better choice. The spider gears within these differentials are much larger and made much thicker than they are within standard differentials. With a standard differential, the wheel that has the least amount of traction will get the largest amount of spin, leaving your vehicle sitting still. A limited slip differential is designed to stop that, allowing much more torque to go to the wheel with traction.

Spider gears are one of the modern innovations that allow limited slip differentials to operate. Interestingly, they also play a vital role in locking differentials and standard differentials, as well.

Worm Gear Drives: Quiet, Efficient Performance


Worm gear drives offer many benefits. They take up little space, offer quiet operation and have been used in many different applications. Worm gear drives provide extreme benefits where size is a problem Traditional spur gears would take up considerably more room than what can be accomplished with a simple worm gearbox. They also take advantage of all the major forms of gearing to suit almost any application.

Worm gear drives offer great operation for many different uses. You'll find them in use in use in the mining industry, in ship's rudders and all types of presses. Worm drives offer a great way to amplify a limited amount of torque, though heat can cause them to become less efficient. Worm gears are also used in a limited amount of automotive differentials, though it has fallen out of favor with many manufacturers. Hummer is one of the manufacturers that still utilizes worm gears in their differential, specifically their military vehicles, though some civilian applications have worm gears, as well.

Worm gears were replaced in open differential due to problems with reduction ratios, though many all wheel drive vehicles continue to use worm gear drives in their applications. Large trucks used for hauling very heavy loads often utilize worm gear drives in their differentials, though they require very large differential housings to accommodate the amount of differential fluid needed to dissipate the heat created by the worm gear drive itself.

A worm gear drive consists of two main parts: the worm gear itself, which looks much like a spur gear and the worm, which is a gear shaped like a screw. The benefits that a worm gear drive offers are due to the fact that each revolution of the worm turns the worm gear a whole tooth; this allows them to greatly amplify torque in their relative settings.

Possibly the single best example of a worm gear is the adjustable screw clamp, called a jubilee clamp. These are found almost everywhere and most people are familiar with their appearance. Other forms of the worm gear drive exist, but this is the single most recognizable form that they take. The best applications for a worm gear drive are those in manufacturing industries where greater torque, in a smaller package is required. Since the worm gear drive is able to be set up at right angles to the input shaft, the length of the equipment is significantly reduced. Many industries find that the non-reversible motion is a great benefit, as well. Since the worm can only drive the gear, it means that they can only be used as speed reducers, rather than speed enhancers. The gear cannot drive the worm in a worm gear drive.

Due to these factors, they are an ideal way of decreasing speed, yet increasing power in smaller equipment. While there are many different applications for worm gear drives around the world today, small electric motors are possibly the area that they benefit the most, though musical instruments have been the longest running beneficiary of these devices.

Gear Cutting Is All About Hobbing, Shaping and Grinding

There are several methods that are used in gear cutting. The first one is gear hobbing, where the hobber die and the gear blank are rotated at the same time and speed, when the profile of the hob is transferred on to the gear blank. A milling machine or a jig grinder is used to cut spur and other straight gears. This mechanism makes use of gear cutters that are numbered, along with indexing head or rotary table. The tooth count of the gear forms the basis in determining the number of gear cutters used, and any of the straight gears can be produced this way.

When machining a helical gear, or twist drill, on a machine that is operated manually, a true indexing fixture needs to be used. The indexing fixture would be required to be taken off from the drive worm, and fixed with a gear-train to the machine table, which can then be operated as a carriage on the lathe. With this kind of a system set up, while the machine table moves on the x-axis, the fixture would be moving at a fixed accurate incremental ratio with respect to the table. The machine table would move in a highly controlled manner via the index plate, producing a precision linear movement, such as, a vernier scale.

The gear-cutting tool comprises of a cutter body member, which has a circular shape, a front and a back surface, and an axis on which it rotates. An outer section of this cutter body has several individual projections, arranged equally spaced from each other around the cutter body. The spaces between the projections are so arranged that they can receive the slots for the cutting blades.

There are several machines which are used in gear cutting, and these are briefly mentioned below:

Hobbing Machine

This is a special kind of milling machine, which is used for cutting gears. It is the major machine with is essentially used for spur gears of involute form. This process uses the method of rotating the gear blank and the cutter at the same time, maintaining a fixed ratio between the cutter and the gear blank.

Gear Shaper
For cutting the internal and external gear teeth, a gear shaper machine tool is used. The name "shaper "comes from the action of the machine itself, where the concerned part is engaged on the forward stroke of the cutter, and pulls away from the part on the return stroke. The cutting tool of the shaper has the same pitch that of the gear to be cut.

Gear Grinder
This tool is used to automatically grind a helical gear. A drive source in this machine tool drives a rotating grinding wheel. A second rotating driving source is used to rotate a helical gear, meshed with the teeth on the grinding wheel. The third driving source in the machine tool displaces the helical gear and the second drive source simultaneously. Two pulse generators are used, which are connected to the first and the third drive sources. The pulse output from one is subtracted from the output of the other, and this differential is applied as the drive pulses for the second rotational drive.

Gear Reduction Is the Major Application of Gear Coupling


Gears are seldom used as a single entity. Almost all machines have gears working in pairs. Gear coupling has the following advantages:

Gear Reduction

Gear reduction is the major application of Gear coupling. The motor, which supplies the power to the system usually, has high power but lacks the essential torque required for work. In order to increase its torque the motor is connected directly to a small gear that is coupled with a larger gear. This results in an increase in torque at the expense of speed. Gear reduction is used in cars to convert the power of the motor into higher torque for motion of the wheels along the surface of the road.

Change in Direction of Movement
Most often the direction of application of torque is different than the direction of movement of the supply. The change in direction can be brought about by using gear coupling consisting of a system of two or more bevel gears. An example is the gear differential used in vehicles.

Change in Axis of Motion
When the rotary motion is to be changed to a different axis, gear coupling is used. Two or more gears are coupled in the same plane to change the axis of rotation. Either spur or helical gears can be used for this purpose. Helical gears are preferred as they work more silently in comparison to spur gears. An example is a windmill where the blades and motor are on different axis of rotation.

Change of Rotary to Linear Motion
Industrial machines like conveyor belts require conversion of the rotary motion of the motor to vertical motion for the movement of material. This is brought about by using gear coupling of a rack and pinion gear. The motor is connected to a small pinion gear which moves the rack gear for linear motion. This type of gear coupling is also using in crushers and water pumps.

Fixed Gear Bicycle


The first question that comes to your mind is what a fixed gear is. This term usually applied to bicycles, which have only one gear. This means that there is only one chain-ring fitted to the cranks, and at the back it has only one sprocket. These two are kept tensioned by a single loop of chain. There is no free-wheel mechanism, and this means that you cannot stop pedaling while the bike is in motion. The forward motion of the bike makes the pedals rotate independently.

Fixed gear provides only one gear ratio. This type of gear is mainly found in bicycles, which is also called a fixed-wheel bicycle, where the free-wheel is not present and runs on only one gear ratio. Fixed gear bicycles cannot coast owing the reason that there is no fixed-wheel mechanism, with the result that the pedals run in the same direction as that of the rear wheel. The rider of the bicycle can only restrict the pedal movement in order to stop the bike without having to apply the brake.

Generally, fixed gear bicycles have one gear ratio. Some are fitted with sprockets on each side of the hub, which provide the use of two gear ratios. There could be fixed gear on each side of the hub, or a fixed gear on one side with a free-wheel gear on the other. In case of a 42 teeth chain-ring there could be 19 teeth on the sprocket on one side, with the other having 17. This makes the gear in the later about 11% to 12% higher than the former.

There are distinct advantages of a fixed gear bicycle. In this type of a bike, either side of the drive drain has one cog each, there are no bearings or pawls in the free-wheel, and there is no deraillurs chain to apply the tension. This brings down the weight of the bike to quite an extent, which provides ease of riding and requiring less force to move forward. The drive system of the bike is direct, owing to the absence of the deraillurs, which would mean that, it provides you with increased pedaling efficiency. Your legs feel the traction between the rear tyre and the road. This makes the bike much ore safe to ride in snow and ice. This is the other great advantage in a fixed gear bike.

In normal bikes, the force on the pedals creates a linear motion to the bike. The pedal in this kind of a bike is connected to the chain-ring, which is the front sprocket. It is connected by cams, which translates the force on the pedals to a torque, and this rotates the chain. Where-as, in a fixed gear bicycle the pedals are directly connected to the rear wheel, and the force that is applied to the pedals makes the rear wheel to rotate. Under the circumstances, a fixed gear bicycle can be ridden backwards too. In this situation, the rider can apply the brake or slow down the bike only by restricting pedal movement.

The Most Commonly Seen Examples of Gears -- Bicycle Gears


Bicycles are machines that mostly attract the interest of the kids. It is a machine which lets you travel faster to destinations using the minimum of energy, compared to the energy that you would spend by walking or running to reach the place that you would want to go to. The mechanics that drive the bicycle are all open and exposed, and none of the machineries used are covered with sheet metal. Many of the kids, having curiosity in mechanical tendencies, cannot help but take their bike apart and put it back again.

You might have seen bicycles ridden in the movies or in a circus, where the front and the rear wheels of the bicycle have a funny "penny-farthing" shape. The bicycle used usually had a huge front wheel and a tiny wheel at the back. This type of bicycle appeared in the year 1870, but by the end of the century the bicycle was replaced by what we see normally these days. Just as we find in a kid's tri-cycle, the front wheel of the penny-farthing bicycle is directly connected. This would mean that as you pedal once, the wheel goes through one revolution. If the front wheel of the tri-cycle is taken as 16 inches, the circumference of the wheel comes to 50 inches. Therefore, with each revolution of the pedal, the front wheel travels through 50 inches. Pedaling at the rate of 60 rpm, the tri-cycle would be moving 50 inches per second, which comes to about 2.8 mph. If the pedaling goes up to 120 rpm, which is very unlikely, the tri-cycle would be moving at 5 mph.

The concept of gears in bicycles came from the fact that, it provides the rider with the facility to move faster without pedaling rapidly. If you take an example of a normal bike, the wheels are 26 inches in diameter. With the front chain wheel having 22 teeth and the rear having 30, a bike would have the lowest gear ratio. This would give a gear ratio of 0.73:1, meaning that with each pedal revolution, the front wheel would turn 0.73 times. This would make the bike move forward 60 inches with each pedal stroke. This comes to about 3.4 mph with 60 rpm of pedal revolution.

In the same way, the highest gear ratio in a bike is achieved with the front wheel chain having 44 teeth, and the rear wheel having 11 teeth, which provides a gear ratio of 4:1. Therefore, with 26 inches diameter of the front wheel, the bicycle moves forward by 326 inches with each pedal revolution. If the pedaling is done at 60 rpm, the bike would move forward at a speed of 18.5 mph. If the pedal speed can be doubled to the maximum of 120 rpm, the maximum speed of 37 mph could be attained. The speed range from 3.4 mph to 37 mph is an attractive feature, and that is the reason why bicycles have gears.

The gears at the front of the bicycle are known as chain wheels. This, what is called freewheel, is attached to the rear wheel. Depending upon what kind of a bicycle you have, the freewheel has 5 to 9 gears on it. There is only one direction that the freewheel can spin, and it is locked in the other. This way you can either pedal or you cannot.

There are two derailleurs at the front and back of a bicycle. These are used for changing the gears. The two small cogs at the rear derailleur spin freely. The tension of the chain is maintained by the arm and the lower cog of the derailleur. A spring holds back the cog and the arm. By shifting the gear, you are simply putting the chain on a different ring. Changing the left shifter, the ring at the pedal changes. There are three rings, where the smallest one is 1, the middle one is 2, and the third one is 3. By shifting down, you are changing to the smaller ring. To change the rings on the rear wheel, you use the right shifter, where the biggest ring is 1, and the largest is 6. There are markers in both the right and the left shift, and you can sift any of the shifters looking at the numbers.

Inside a Bevel Gearbox


Gears are used for changing the direction of rotary motion or to increase the torque. Industrial machines typically use a bevel gearbox for these purposes. Let us see the inner construction of a simple bevel gearbox and understand its mechanism.

A Peep Inside a Bevel Gearbox

On opening the housing of a bevel gearbox one comes to know that the construction is really simple. It consists of an input gear coupled with another gear called the output gear at right angles to each other. The gears can be either of spur or helical type. Helical gears are preferred as they are less noisy due to gradual engagement and have a longer life.

In case a reduction in speed is required, the diameter of the output gear is kept larger than that of the pinion. If only change in direction is required the diameters of both the gears are equal.

Materials commonly used are plastic or metal and depend on the load. Three gears are used in case the axis of rotation the same as that of input. The point of contact is well lubricated with gear oil.

Mechanism of a Bevel Gearbox

The electric motor or engine causes the input gear to spin which in turn rotates the output gear. Thus the rotary motion is passed on from the input arm to the output arm.

In case the diameter the output gear is larger than that of the input gear, the torque of the system increases at the expense of speed. Such a system is known as a reducer. The gears are at right angles to each other and hence the direction of the rotary motion is changed.

Applications of a Bevel Gearbox
The property of change of axis and speed of the bevel gearbox is used in a variety of industrial and automotive machines. It is used in turbines, pumps, grinders, etc. In vehicles the gearbox is used in the limited slip differential. One can clearly understand the working of the bevel gearbox by opening a simple hand drill.

Construction and Working of a Bevel Gear Reducer


One of the major applications of gears is gear reduction. The high power and low torque of the supply can be converted into high torque by coupling of a smaller input gear with a larger gear. There are different types of gear reducers depending on the types of gears coupled viz. worm gear reducer, spur gear reducer, bevel gear reducer etc.

Construction of a Bevel Gear Reducer
A bevel gear reducer consists of a small gear acting as a pinion coupled with another gear of a larger diameter at right angles to each other. The gears can be either of spur or helical type. Helical gears are preferred as they are less noisy due to gradual engagement. The material can be either plastic or metal depending on the application. Three gears can be used in case we need to keep the axis of rotation the same as that of input. The whole arrangement is sealed in a metal or plastic casing known as housing. The point of contact is lubricated with gear oil.

Working of a Bevel Gear Reducer
The diameter of the output being larger than that of the input gear, the torque of the system is increased at the expense of speed. Since the speed is decreased, this system is known as a reducer. The gears are at right angles to each other and hence the direction of the rotary motion is changed.

Advantages of a Bevel Gear Reducer
The efficiency of a bevel gear reducer is higher than that of a typical worm gear reducer. The bevel gears have high load capacity.

Applications of a Bevel Gear Reducer

Due to change in direction of the rotary motion the bevel gear reducer finds a variety of applications in industry and automotives. In industries it is used in turbines, pumps, cranks, etc. In automotives it is used in ordinary as well as limited slip differentials.
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