Bevel Gears

Materials used

Materials used to manufacture these gears are used keeping in mind certain factors including design life, power transmission requirements, noise generation. Some of the important materials used are :

• Metal – Steel, cast iron and stainless steel.
• Plastic – Acetal and polycarbonate.

Important specifications to be considered

• Gear center
• Bore diameter
• Shaft diameter

Use of Bevel Gear

These gears find wide application in a number of fields including :

• Automotive industry
• Textile industry
• Industrial engineering products

---

Helical Gears

Helical gear is a popular type of gear having its teeth cut at an angle, thus allowing for more gradual and smoother meshing between gear wheels. The helical gears are a refinement over spur gears.The teeth on helical gears are specially cut at an angle, so as to face the gear. As two teeth on the gear system engage, it starts a contact on one end of the tooth which gradually spreads with the gear rotation, until the time when both the tooth are fully engaged.The gears are available in different sizes, shapes and designs to meet the customer specifications.

Materials Used

These gears can be manufactured from superior quality materials including stainless steel, steel, cast iron, brass etc. depending on the application.

Use of Helical Gears

These gears are used in areas requiring high speeds, large power transmission, or where noise prevention is important.

• Automobiles
• Textile
• Aerospace
• Conveyors

---

Worm Gears

A worm gear is a type of gear, engaging with a worm to significantly reduce rotational speed, or allowing higher torque to be transmitted. The gear can achieve a higher gear ratio than spur gears of the same size.

Materials Used

Worm gears can be constructed from a number of materials depending on the end application. Some of the popularly use materials are :

• Brass
• Stainless steel
• Cast iron
• Aluminum
• Hardened steel

The gears can operate under difficult conditions and have the ability to achieve large speed reductions. The gears also transmit high loads at high speed ratios.

Types of Worm Gears

• Non-throated
• Single-throated
• Double-throated

Use of Worm Gears

These gears find application in :

• Electric motors
• Automotive components

Ground Gears

Advantages of Ground Gears 

Ground Gears offer various advantages to its users, some of which are:

• High Precision: Achieving high precision is not a difficult task for ground gears since in the grinding process, there is little removal of material in the final pass.
• Superior Surface Finish: Grinding makes the surface of ground gears more shiny than that obtained from any other machining technique.
• Improved Flexibility: Hardened steel alloys can be used to developed into ground gears that gives its added flexibility.
• Minimal Surface Stress: There is minimum residual surface stress in ground gears.
• Load Carrying Capacity: Ground Gears exhibit a higher load carrying capacity.
• Minimal Wear and Tear: Ground gears have minimal wear and tear that results in prolonged life.

Limitations of Ground Gears

Though ground gears offer multiple benefits and advantages, they too have some limitations:

• There is a limit to grinding procedures and that is to ferrous material.
• Hard metals can be grind in an efficient and better way than the soft ones.
• In case of worm or helical gears, grinding may not be the ideal solution. This is due to the reason that it often involves deviations in terms of removal and profile.
• Gear grinding machines are not as popular as hobbing machinery.
• Grinding demands higher costs, as it is a secondary operation.

Applications

These gears find wide application in a number of fields including :

• High Speed Rotation: Ground gears are ideal for uses in applications that need noise and vibration resistance in the case of high-speed gear drives. An example can be that of ground spur gears.
• Positioning: CP Racks and Pinions are recommended for perfect positioning applications. In these cases, ground gears are used in calculating for reducing pitch errors.

Precision Gears

Precision gears are custom-made actuators that can be designed for varying uses and applications. These gears are generally used in applications under conditions of light loading. Precision gears are generally preferred for their precise, smooth, compact, noiseless and reliable performance.Precision gears can be manufactured as per the customer’s drawings or based on a functional description depending on the type of application. The different types of precision gear products include, – spur gears, helical gears, worm gears, anti-backlash gears, cluster gears, clutch gears, face gears, planetary gears, gear assemblies, gear boxes, bevel gears, miter gears, metric gears, internal gears, idler gears, gear rack & pinion, worms, worm shafts, splines, spline shafts, se shafts, and more. These gears can be manufactured as per the exact customer specifications or according to application need.The quality and performance of a precision gear depends on the quality of blank in which it is cut. Thus it is essential to hold tight tolerances without grinding.Precision gears are known for their trouble free superior performance, long service life, and excellent surface finish and customization capability. These gears are used in a variety of industrial applications, such as heavy machinery Industry, metal casting, metal processing, construction, and more. 

---

Rack Gears

A rack is generally used for converting rotational motion into linear motion. It is a flat bar onto which the teeth of a pinion gear are engaged. It is a kind of gear whose axis is at infinity. These gears are designed to accommodate a wide variety of applications.

Materials Used

A variety of materials are used keeping in mind the application. Some popularly used materials are :

• Plastic
• Brass
• Steel
• Cast Iron

These gears ensure quieter and smoother operation. The mechanism provides less backlash and greater steering feel.

Use of Rack Gear

The gear is commonly used in steering mechanism of cars. Other important applications of rack gears include :

• Construction equipment
• Machine tools
• Conveyors
• Material handling
• Roller feeds

---

Sprockets

A sprocket is a gear having metal teeth that meshes with a chain. Also known as a cog wheel, it is a small toothed ring that can fit onto the rear wheel. It is a thin wheel having teeth that engage with a chain.

Materials Used

A variety of materials can be used to manufacture superior quality sprockets used in different industries. Some of the materials used are :

• Stainless steel
• Hardened steel
• Cast iron
• Brass

Use of Sprockets

This simple gear finds application in diverse areas including :

• Food industry
• Bicycles
• Motorcycles
• Cars
• Tanks
• Industrial machines
• Movie projectors and cameras

---

Segment Gears

The segment gear, as the name suggests, is basically a gear wheel. These gear wheels are composed of a large number of pieces that are small parts of a circle. A segment gear is connected to the arms or trappings of the water wheel.The segment gear comes with a part for receiving or communicating the reciprocating motion from or to a cogwheel. These gears also comprise of a sector of a circular ring or gear. There are also cogs on the periphery.Segment Gears are available in various finishes, such as untreated or heat-treated and can be designed as a single component or as an entire system.

Applications

Segment gears, which are basically gear wheels, are used in variety of industrial uses and applications. These gears offer various advantages such as improved flexibility, superior surface finish, high precision and minimum wear and tear. Some of the uses of segment gears include:

• Defense
• Rubber
• Railways

---

Planetary Gear

Planetary gear is an outer gear that revolves around a central sun gear. Planetary gears can produce different gear ratios depending on which gear is used as the input, which one is used as the output.

Materials Used

The gears can be constructed from a variety of materials including :

• Stainless steel
• Hardened steel
• Cast iron
• Aluminum

The gears are suitable for reduction of high RPM electric motors for use in high-torque low RPM applications. These gears are used in precision instruments because of their reliability and accuracy.

Use of Planetary Gears

These gears are the most widely used gears having diverse applications including :

• Sugar industry
• Power industry
• Wind turbines
• Marine industry
• Agriculture industry

---

Internal Gear

An internal gear is a hollow gear with teeth cut on its internal surface. The teeth in such a gear project inwards instead of outwards from the rim.

Materials Used

There is a variety of materials being used to manufacture internal gears depending on the end application. Some of the popularly used materials are :

• Plastic
• Aluminum alloys
• Cast iron
• Stainless steel

The teeth in such gears can either be spur or helical. The internal teeth have a concave shape with a base thicker than that of an external gear. The convex shape and a strong base help in making the teeth stronger and also creating less noise.

Advantages of Internal Gear

• The gears are specially designed to accommodate a wide range of equipment.
• The gears are cost-effective and ideal for a broad range of light-duty applications.
• The non-binding tooth design ensures smooth and quiet operation.

Use of Internal Gears

• Light duty applications
• Rollers
• Indexing

---

External Gear

One of the simplest and most used gear units, external gears are extensively used in gear pumps and other industrial products for smooth functioning. These gears have straight teeth parallel to the axis. The teeth transmit rotary motion between parallel shafts.

Materials Used

The gears can be constructed from a variety of materials including :

• Stainless steel
• Hardened steel
• Cast iron
• Aluminum

The kind of material used in manufacturing these gears depends on the end use they are being put to.

Use of External Gears

These gears are used in diverse fields including :

• Coal industry
• Mining
• Steel plants
• Paper and pulp industry

---

More Resources /articles

Theory of Machine Article , Notes , Question and Answer

Machine Design Notes , article , Interview Que. and Ans.

Mechanical Subjectwise Basic Concept Notes ,Articles

---