Gearboxes

Gearbox Casing

Functions Buyer's Guide

Classification of

Gearboxes

Gearing

Arrangement

Types of

Gearboxes

Gear box is an essential equipment in a gear assembly. Gear Box is also known as Gear head, Gear reducer

and Speed reducer. The fundamental principle of a gearbox is to transmit the cause of mechanical rotation

between two shafts. In this order, there is a structural support present in between the two shafts. Generally,

gearboxes are kept inside the casings. This helps the gearboxes in their structural support, provides protection

and ensures in doing safe functioning. Normally, the gearboxes are designed in reducing the speed, but

sometimes, a gearbox may be designed for speed enhancing duties. The shafts inside the gearboxes are

placed for the purpose of accepting and delivering the machinery rotation. This machinery rotation (torque) is

achieved in the form of splines that should be suitable to connect or join to another unit. The capacity of

thrusting outward of the shafts will have been limited from the casing. The mechanical rotation which is

generated by the engine is consumed through the gearbox. This in turn, is being converted into a force at the

road surface. To accelerate the vehicle, the force which is being applied can be calculated as follows:

Applied force = Torque at the wheel * radius of the road wheel (including the tyre)

Types of Gearboxes

There are five types of gear boxes. These five types of gear boxes are as follows:

• Spur Gear Box

Spur gearbox is an effective and durable mechanical equipment, which is used for the purpose of

transmitting power and uniform and constant rotatory motion from one parallel shaft to the other shaft.

Spur gearbox is also considered as a capable industrial tool that provides a continuous speed drive.

This speed drive can be increased or decreased according to the requirement.

• Helical Gear Boxes

Helical gearboxes are quite alike the spur gearboxes in working. These gearboxes possess teeth that

are fitted in a spiral format around the gear. The modern helical gearboxes are usually designed on a

modular concept of construction and are available in different ratios. These gearboxes are fabricated to

work absolutely without any noise, thus used in transmission operations.

• Hardened & Ground Gear Box

Hardened and ground gearboxes are considered one of the best types of gearboxes in the gears and

gearbox manufacturing industry. They are widely used in many industrial applications in wind mills,

cement industry, agro industry, fertilizer plants, aviation industry, and so. They are fabricated from

industry standard raw materials like nickel, titanium, and stainless steel.

• Crane Duty Gear Box

These gearboxes are often used in heavy-duty applications. They are one of the advanced types of

gearboxes, which give maximum thermal efficiency. These gearboxes facilitate the proper meshing of

the gear teeth, which results in enhanced performance of the gear. The high efficiency is also ensured

by its precision gearing and accurate bearings. It is often used in mining, automobiles, and construction

industry.

• Twin Lobe Blowers

Twin lobe blowers belong to the class of the blowers having positive displacement. Higher efficiency at

moderate compression ratios is the special feature of these industrial blowers. These blowers are often

used in applications demanding relatively continuous flow rate at different discharge pressures. The

contemporary twin lobe blowers are available in the capacity range 10m3/hr 10,000m3/hr.

• Gear Box Housings

Gearbox housing is a housing or a kind of cover to accommodate or fit the gear and gearing equipment

like flanges, shafts, bearings, etc. There are basically two types of such housings available at present in

the market, i.e., cast gearbox housings and fabricated gearbox housings. Cast housings are made from

a process called metal-casting while fabricated housings are designed in hi-tech machining centers.

• Automatic Gearboxes

For most of the Automatic Gearboxes, there is a selected set of possible gear ranges. The set selection

often have a parking pawl features. This feature closes the output shaft of the transmission. Since

1950's, most of the cars which have sold in USA, equipped with Automatic gearboxes. But, in rest of the

world, this trend has not been followed.

• Semiautomatic Gearboxes

The semiautomatic Gearboxes are also known as clutch less manual transmissions or automated

manual transmissions, e-gears, or paddle shift gearboxes. In semiautomatic gear boxes, there are

sensors, processors and actuators. These things help in shifting the gears on the command of the

drivers.

• Manual Gearboxes

The history of manual gearboxes is very old. The traditional clutches are used in such kind of gearboxes.

Each time, these gears are selected by electrically controlled motors. After the selection, these gears

detach the clutches and the gears are shifted. Once the clutch gets free, it can be used again.

• Marine Gearboxes

The drive is directly connected to the propeller in a traditional Marine gearbox. Marine gearboxes fulfill a

multiple number of marine related purposes. To meet each and every purpose, these marine gears do

also have a large number of different configurations and installation processes.

• Shaft Mounted Gearboxes

Shaft mounted gearboxes are very closely and firmly design in size. These gears are directly mounted

onto the driven shafts. This mounting process helps these gears in avoiding the use of coupling and

base. In Shaft Mounted gears, there is no problem in the adjustment. The boxes of the gears are

suitable for both forward and reverse motion.

• Gear Motors

Gears motors are such type of motors which have a large reduction system. The gearbox is pertained

into the motor. This type of integral arrangement is done in order to increase the mechanical rotational

speed of the motor. But simultaneously, this arrangement reduces the output speed.

Functions of the Gearbox Casing

• It provides structural support for the shaft bearings. This in turn helps in gear loading.

• It transfers the reaction of mechanical rotation (torque) to the other supporting structure of

the gearbox or drive elements.

• It prevents the lubricant from spreading and also prevents the unwanted particals from

coming inside.

• It provides the safety provision and reduce the noise intensity.

• It also reduces the amount of heat that generates due to the internal friction.

• It increases the external and visual qualities of the gearbox.

To obtain the support-rigidity, safety and reliability in operations, the casings must be located, fitted and

fastened properly to their foundations. Proper provision of ventilation should be ensured in these casings for

removing out the heat which generates during the operations.

Buyers Guide (Selection Process of Gearboxes)

Before setting out the buying decision of a gearbox, the most important thing is to ensure about the

requirements of the gearbox. The best selection of a gearbox gives the best outputs in fulfilling the

requirements of the buyers. This kind of successful selection can be achieved by matching the requirements of

the power transmission system with a particular range of gearboxes offered by the manufacturers. So, it is

advisable for the buyers to have some knowledge regarding the system and available hardwares in the market.

A buyers may do the following things before buying a gearbox:

• Collect informations about the system.

• Review those factors that influence the buying decision.

• Prepare the limit of acceptance and ability of these factors.

• Collect informations from different manufacturers for acquiring knowledge regarding

gearboxes. The entire selection process of a gearbox can be enlisted through the

following flow chart:

Classification of Gearboxes

Today, it is possible to obtain such kind of gearboxes which consist the characteristics of two or more than two

kinds of different gearboxes. These kinds of gearboxes are called compound gearboxes. The speed ratio in

such kinds of gearboxes is high because the respective speed ratios of each individual gear box within it are

compounded. The classification of gearboxes is done on the basic of shaft orientation or speed ratio.

Gearing Arrangement for Gearbox

In the gearing arrangement for a gearbox, the various components are: cycloidal, worm, bevel, planetary, spur

and helical.

1. Bevel gear is actually a gear wheel that is meshed with another bevel gear in such a way so that the

shafts can form an angle, which is less than 180».

2. Helical gears join shafts that are parallel. The involute teeth of the helical gears are cut at an angle to

the axis of the rotation. If there are two mating helical gears in the gearing arrangement of the gearbox,

then they must have equal helix angle but opposite hands.

3. In case of spur gears, they connect parallel shafts. They have curled teeth which are parallel to the shaft

and may have either external or internal teeth.

4. The planetary gears may present in total number of two and they are present either on or inside a large

gear. The intense gear ratio is possible due to these gears. When the intention is to turn the input in the

same direction of the output, then these gears are used. Planetary gears can be designed along with a

set of planetary cones or with a gear set.

5. Cycloidal gears are used in pair form and they are arranged in such a way so that the angle formed by

them should be equal to180». The reason behind the formation of 180» is to provide balance to the load

and these gears are driven by many crank shafts. Multiple shafts are present for sharing the load and to

enhance the twisting state firmness.

6. The worm gears are wrapped around a central axle and these have slant plane. This kind of gear

consists one or more than one teeth and these teeth are present in the screwed thread form.

Spur Gearbox

Spur gearbox is an effective and efficient mechanical device or

equipment, which is used for the purpose of transmitting power and

uniform and constant rotary motion from one parallel shaft to the other

shaft. Spur gearbox is also an effective industrial tool that provides a

continuous speed drive, which can be increased or decreased

according to the application area and type of operation to be carried on.

The process of increasing or decreasing the speed of the drive is quite

easy, you have to just increase or decrease the number of teeth in the

driving gear to put the corresponding effect on the whole drive. Some of

the significant parts of these gearboxes include couplings, precision

spur gears, precision shoulder screws, among others. The spur

gearboxes basically come in three different types or varieties, i.e.,

single, double, and multiple stage spur gearbox.

Manufacturing Materials

Spur gearboxes are manufactured by making use of various metals that are perfectly according to the

industrial standards. This is the reason the spur gearboxes are so durable in nature, and so efficient in

operation. Some of these manufacturing materials are as listed below:

• Steel

• Bronze

• Cast Iron

• Tungsten

• Aluminum

• Stainless Steel

• Non-metallic Phenolic

Noted Features

However, the contemporary and advanced spur gearboxes possess a large number of attributes or features, it

is not feasible to mention each and every one of them here. So, for the sake of convenience and providing

quick overview of the product, we are giving here some noted features of spur gearboxes:

• Suitable for a large number of applications

• Advanced and sophisticated design

• Requires low maintenance

• Robust construction

• Corrosion resistant

• Technically ahead

Spur Gearbox Applications

Spur gearboxes have found their application in a large number of industries. They are used in different

industries for different purposes, and also in the same industry for different uses. You can say that it is a kind

of multitasking equipment. Some of the prominent application areas of spur gearbox are as under:

• Conveyors

• Automobiles

• Roller Feeds

• Machine Tools

• Mining Machines

• Indexing Equipment

• Multi-spindle Drivers

• Construction Equipment

Helical Gearbox

Helical gearboxes are quite similar to the spur gearboxes in

functionality. These gearboxes possess teeth that are fitted in a spiral

format around the gear. The contemporary helical gearboxes are

generally designed on a modular concept of construction and are

available in different ratios. These gearboxes are designed to work

absolutely without any noise. Owing to their high durability and noise

free operation, these gearboxes are mostly used in transmission. They

can comfortably bear high shock loads. Although the helical gearboxes

demand sufficiently large initial expense, but they prove to be a onetime

investment. Their efficient performance and low maintenance costs

compensate for the high initial expense.

Advantages of Helical Gearboxes

Following are some of the advantages of the industrial helical gearboxes:

• Can work for long period before requiring service

• Leads to better productivity

• Low servicing costs

• Ease of servicing

• Easy installation

Beneficial Features

The modern helical gearboxes are full of various beneficial features. Some of these prominent features are as

listed below:

• Advanced design

• Noise free operation

• Possesses cooling coil

• Stainless steel housing

• Input/Output shaft extension

• Equipped with reinforced bearings

• Available in foot and flange mounted constructions

Construction Materials

A lot of high quality materials are used for the fabrication or construction of the helical gearboxes. A few out of

them are as follows:

• Stainless Steel

• Carbon Steel

• Aluminum

• Cast-iron

• Titanium

• Iron

Applications

Helical gearboxes found their application in many industries, some of them are given below:

• Steel

• Mining

• Rubber

• Textile

• Medical

• Defense

• Automotive

Hardened and Ground Gearbox

Hardened and Ground gearboxes are widely used in industrial applications

Materials for Fabrication

Hardened and ground gearboxes are considered one of the best types

of gearboxes in the gears and gearbox manufacturing industry. Some of

the materials used in the fabrication of hardened and ground gearboxes

are as listed under:

• Nickel

• Bronze

• Titanium

• Cast Iron

• Aluminum

• Stainless Steel

Special Features

Some of the special features of hardened and ground gearboxes are as given below:

• Ideal for heavy applications

• Ease of maintenance

• Solid construction

• Advanced design

• Have a long life

• Economical

Application Areas

The modern and sophisticated hardened and ground gearboxes are used in a multitude of industrial

applications. Following are some common application areas of these gearboxes:

• Wind Mills

• Cement Mills

• Agro Industry

• Mining Industry

• Fertilizer Plants

• Aviation Industry

• Water Treatment Plants

Twin Lobe Blowers

Twin lobe blowers belong to the positive displacement or root

blowers class. The specialty of these blowers lies in their higher

efficiency at moderate compression ratios ranging from 1.1 to 2.

These blowers are often used in applications demanding relatively

continuous flow rate at different discharge pressures. The modern

twin lobe blowers are available in the capacity range 10m3/hr –

10,000m3/hr. The maximum pressure that they can bear in single

stage construction is 1Kg/cm2 (g). The advanced twin lobe blowers

are designed in such a manner that they do not produce much noise

and vibration while operation. Also, these blowers work properly both

at high and low speeds. The quality of these twin lobe blowers of not

choking even at higher pressure make them ideal for industrial use.

Manufacturing Materials in Twin Lobe Blowers

Twin lobe blowers are basically used for industrial purposes, thus require very sturdy construction and high

quality raw materials. Following industrial grade raw materials are used for the manufacturing of twin lobe

blowers:

• Titanium

• Tungsten

• Alloy Steel

• Nickel Silver

• Carbon Steel

• Beryllium Copper

Features of Twin Lobe Blowers

Following are some of the important features associated with twin lobe blowers:

• Ideal for industrial applications

• Economical maintenance

• Smooth functioning

• Efficient operation

• High durability

• Long lasting

Applications

As we have earlier also said, twin lobe blowers are primarily used for industrial purposes. This equipment has

found its application in the following industries:

• Textile

• Cement

• Agriculture

• Automotive

• Aquaculture

• Water Treatment

Gearbox Housings as Cast and Fabricated

Working and

Utility Structure Applications

The gearbox housing is a member of the gearbox but it is a non-rotating member. It lies at the center of the

gearbox and joins all other elements of the gearbox like flanges, bearings and spiral bevel gears. The base to

adjust the gears with a certain tooth bearing and backlash are the angle of the housing and the offshoot of the

holes. This ensures the best possible running of the gears and standard attribute of transmission.

Gearbox Housings As Cast

Gearbox housings as cast, which are also known as cast gearbox housings are the gear housings that are

made by a process called metal-casting. In other words, we can say that the cast gearbox housings are made

by using molds. This type of gearbox housings are very sturdy and durable in nature. These housings are

available in various types of seals like lip seal, double lip seal, taconite seal, etc.

Gearbox Housings As Fabricated

The fabricated gearbox housings are manufactured by using various industrial standard materials like cast iron,

modular cast iron, steel, and so. Irrespective of the cast gearbox housings, these gearbox housings are

fabricated in hi-tech machining centers. These housings are ideal for heavy industrial gears.

Working and Utility of Gearbox Housing

An oil outlet opening is present in the Gearbox Housing. A gearbox Housing

also consists a method which assists it to work upon the fluid level of the

gearbox. The gearbox housing contains such a device which can work from

two different positions. In the first working position, the height of the fluid level

with in the gearbox housing is predetermined during its filling and operation.

This predetermination is done by an upper opening of the device. In the

second working position, primarily the provision is made to drain-out the

gearbox oil. For this purpose, an oil drain opening of the device is released.

This draining opening is adjust properly beneath the upper opening. This

adjustment allows to drain-out a major portion of oil disposed in the gearbox.

The device which is used to open the drain opening is used from outside of the gear box housing.

Structure of Gearbox Housing

The material that is used most commonly to manufacture gearbox housing is nylon. Through the gear housing

surfaces and thermal condition of the surrounding air, most of the heat is dispelled by the process of radiation.

Dispelling of heat through heat radiation depends on some other factors also, and these factors are:

surrounding structure within the gearbox and the various components which are present. In a gearing housing,

there is a bearing pocket. An extra bearing is installed at the center of the bearing pocket. This ensures the

permanent seal and proper alignment of the bearing.

Applications of Gearbox Housing

Gearing housing has a lot of different applications. Some of these applications are:

• In aerospace transmission.

• In motor sport transmission.

• In other different kinds of transmission.

• In transmission of heat in robots, electric motors, solar gas turbine

motors.

• It forms a complete wet oil slum in the engines. This helps the engine

to drive out the residues from inside.

Automatic Gearboxes

Development Characteristics Parts and

Operations

Significant improvement has been noticed in the Automatic Gearboxes in recent few years. This improvement

has been occurred in the field of their increasing fuel efficiency. But, if we compare the efficiency level of the

automatic and manual gearboxes, we will find that still, the manual gearboxes are more efficient.

Development reasons of Automatic gearboxes

There are two things which are responsible for the development of Automatic gearboxes. These two things are

as follows:

• The arrival of electronics in the 1990's.

• The want of high-speed gear. This want/expectation results into the invention of power gears and

automatic gearshifts.

Characteristics of the Automatic gearboxes

Handling of automatic Gearboxes is easy and the driving experience of these gearboxes is also pretty. The

only two manual things which have to be done manually in such gearbox are: pressing the accelerator to start

the gearbox and pressing the brake to stop these gearbox. The up-down of the gears in automatic gearboxes

is done through hydraulic fluid pressure. Therefore, a regular check-up of hydraulic fluid should be done. The

presence of Automatic gearbox in the automobile, helps in changing the gear ratios automatically when the

vehicle moves. This enables the drivers not to change the gears manually. The automatic transmission in such

kind of gears decreases the fuel efficiency as well as power efficiency.

Hydraulically Operated Form of Automatic Gearboxes

The most dominated form of automatic gear is hydraulically operated form. In this form, a fluid coupling or a

torque converter and a set of planetary gear is used. This provides a scope of torque (mechanical rotation)

multiplication.

Parts and Operations of Hydraulic Automatic Gearboxes

A hydraulic automatic gearbox consists of the following parts:

Fluid Coupling or Torque Converter

This is a hydraulic device which connects the gearbox and the engine. It is used by replacing the mechanical

clutch. It helps the engine to run continuously without stalling. A torque converter also allows different amount

of torque multiplication and that is also at low engine speeds. This thing helps in enhancing the break way

acceleration.

Planetary Gearset

In a Planetary Gearset, by a hydraulic servos, the clutches and bands of the gearset are turned on. This

turning on process is controlled by the valve body. This process results into two or more gear ratios.

Valve Body

It is the hydraulic control center. The fluid which is operated by the fluid coupling/torque converter, comes

through a main pump in pressurized form and reaches to the valve body. The pressurized fluid that comes

from the main pump is regulated and then used to operate the network of the spring-loaded valves, servo

pistons and check balls. The valves use two kinds of pressure, one is from the pump and another from a

centrifugal governor on the output side. The other things which the valves use are the hydraulic signals from

the range selector valves and from the modulator.

The pressure and hydraulic signals help the valves in controlling the selected ratio on the gearset. The

selection of ratio on the gearset is required to control because with the changing speed of the engines in cars

and difference between the pressure changes in different engines. This two things induce to open and close

different sets of valves.

The controlling process of the hydraulic pressure by the valves, induces different clutches and actuators in

controlling the operation of the planetary gearset. Thus, the optimum gear ratio can be determined by the

controlled operation conditions of the planetary gearset. A new Engine Management System has been

introduced in controlling indirectly the valves in many modern automatic gearboxes.

Hydraulic and Lubricating oil

Hydraulic and Lubricating oil is also called Automatic Gearbox Fluid (AFT). Refined petroleum is primarily used

for manufacturing AFT. Later on, it is processed for several times to bring all other properties. As a component

of Automatic gearbox, AFT requires routine check-up.

AFT is considered as a very important constituent of the gearbox due to the following functions:

o Provides lubrication for the gearbox.

o Protects the gearbox from corrosion.

o Conveys mechanical power as it is a hydraulic medium.

Marine Gear Box

Applications How to Fit Marine

Gearbox Precaution

Structural

Overview Performance Advantages

Features

The drive is directly connected to the propeller in a traditional Marine gearbox. Marine gearboxes fulfill a

multiple number of marine related purposes. To meet each and every purpose, these marine gears have a

large number of different configurations and installation processes also. As different marine gears have

different viscosity grade, therefore, at the time their selection, viscosity grade of these gears should be

checked properly. The viscosity grade of the gears largely influences the speed, heat resistant capacity and

gear geometry.

Applications of Marine Gear Boxes

The marine gears are commonly used in different marine vehicles like work boats, fishing boats, yachts etc.

Main propulsion, centrifuges, deck machinery like winches, cranes, pumps, elevators, turning gears and rudder

carriers are the main widely used applications of the marine gears.

How to Fit Marine Gearbox

Generally, with two or more then two engines, Marine Gearboxes are attached. This kind of attachment is

found in the commercial vessels, like roll-on, roll-off ships, ferries etc. After preparing the full blue-print of the

fitting arrangements of this kind of gearboxes, the manufacturers should proceed for their actual production.

The fitting process of the gears in the boxes may arise some intricacies. These intricacies are due to the

existing problems in the boxes, immediate base of the boxes and the ship itself.

Precaution with Marine Gearboxes

The casing of the marine gearbox must be built very firmly. To prevent the marine gear from water, the gears

should be kept in mesh. The casings of the gearboxes should provide extra strength with double engine

designs and ribs.

Structural Overview: Marine Gearboxes

In a simple these Gearbox, the total number of gears which are present is 16. Apart from these gears, there is

an input shaft and an output shaft. The industrial purpose marine gearbox, there are four gears, three shafts,

an intermediate and one shift each for input and output.

What is a High Performance Marine Gear

The physical appearance, working capacity, performance standard and other features of high performance

marine gears are significantly noticeable. The size of these gears comes in the range between 300 mm to 5

meters. The power requirements of these gears are also comparatively low, but their performance is high. For

example, the marine gears inside the fast craft vessels are able to work minimum @ 25 knots (29 mph) which

is a high standard performance. These type of gears are used in luxury yachts, ships, petrol boats etc. The

power and weight ratio of the high performance gear is generally more than 1.5 kw/kg. The usual pitch rate

velocity of these gears is at least 120 meters per second. The reliability of such type of gears is also very high.

Generally, in common type of marine gears, there is a high probability of teeth failure and if this happens then

the vessel will be stopped in the water. This thing is not happened in high performance marine gears. Today,

the requirement of these kind of gears is prevailed for manufacturing of large size gearboxes for large size

ships and other water vessels. These gears provide complicated design of the gearboxes.

Advantages of High Performance Marine Gearboxes

The external forces which comes from the surrounding structure or quivered forces from the propeller, must be

resisted by the high performance Marine Gearboxes. These external forces are in such a way so that these

can be absorbed by the high performance marine gearboxes within the prescribed limit. This prescribed limit is

significantly high in case of Marine Gearboxes. Generally, it is considered that general marine gearboxes can

absorb a assignable of 20% of the full scope of the external forces but for high performance marine gearboxes,

this limit is up to 30%. The extra sucking up capacity gives extra tolerance limit to the high performance

gearboxes against any damage. If these gears don't contain this extra tolerance limit, then the entire bearing

assembly would become overloaded, disrupts the oil film and lastly, devastates the bearing.

Features of Marine Gearbox

• Marine gearboxes normally take less space.

• These gearboxes have high mechanical rotational force (torque) capacity.

• The speed of such gearboxes depends upon their reduction and size. Normally, the speed

varies between 900 to 1,800 rpm.

• The reduction marine gear boxes can be obtained without reversing their functions.

• Both coaxial and offset configurations of the input and output shafts in such gearboxes are

possible. The offset configuration can again be either vertically, horizontally or diagonally.

• The composite design of such gearboxes brings versatility in their production capability and

in spare stocking.

Gear Motor

Advantages Composition Buyer's Guide

Standard for Gear

Motor Applications Selection

Types

Gears motors are such type of motors which have a large reduction system. The gearbox is pertained into the

motor. This type of integral arrangement is done in order to increase the mechanical rotational speed of the

motor. But simultaneously, this arrangement reduces the output speed.

The important feature of a Gear Motor is that the driven shaft and the driving shaft may be coupled directly in it.

In order to reduce the speed of such motors, some other devices like pulley, belts, chains etc. are required.

The separate use of speed reducers has been prohibited for the purpose of reducing the speed of a Gear

motor. The term Gear motor is used to describe such a motor which has an integrated gearbox (gear reduction

unit) within the motor. The benefit of the integrated gearbox is to enhance the mechanical rotational energy of

the motor. The other important thing is that this integrated system also reduces the output speed of the motor.

Advantages of Gear Motor

The most prominent advantage which comes from the gears of the Gear motor is that the direct coupling is

possible for driving shaft to the driven shaft. Another advantage of the Motor gear is that it omits the

requirement of coupling the motor to a distinct outer speed reducer. Therefore, these Motor gears are useful in

hot melt glue pump, conveyor drives, labellings box case electors etc.

Composition of AC Gear Motor

A series of three windings along with a simple rotating section and an composite gearbox are present in the

stator section of a Gear motor. The configuration of a DC motor is done in different ways. The DC motor has a

rotor and a permanent magnetic field stator along with a composite gearbox within it. These DC motors may be

used in different applications of torque and in a variable speed.

Buyer's Guide

To evaluate the performance specifications of a gear motor, a buyer should search informations regarding the:

• Shaft Speed

• Continuity of the torque

• Continuity of the current

• Continuity of the output current

Continuity of the torque means the output capability of the torque under fixed operating conditions. Continuity

of the current implies the highest level of current which can be supplied to the motor winding without

overheating. Continuity of motor output implies the mechanical power supplied by the output of motor.

Standard used for Gear Motor

The service factors and the load differentiations of a Gear motor should be ensured by AGMA

recommendations. For continuous operation of a Gear motor, the lowest service factor should be 1.0 when the

gear motor works with a minimum mechanical strength service factor of 1.3.

Applications of Gear Motor

There is a wide array of applications of the Gear motors. The different things for which gear motor is used are

as follows:

• Used for packaging and labellings purpose.

• Used in case electors, box tapers, heat shrink tunnels, hot melt glue pumps, conveyor drives

and tape dispensers.

• Used for food processing industries.

• Used in weight checking machines, ice making machines, cake baking machines, meat

slicing, golf carts, meat slicing and in breading appliances.

• Used for different transportation devices.

• Used in wheel chairs, stair lifts, golf carts and in pipe line crawlers.

• Used in different machinery tools like drill heads, rotary table drives and for hardness test

also.

Selection of the size of Gear Motor

To take any final decision regarding the selection of the appropriate size of a Motor gear, various factors

should have to consider. These various factors are: 1) the space available for the Motor gear, 2) the current

voltage supply, 3) the required operating speed as well as torque requirements, 4) the duration of operation of

the Motor gear. Apart from these stated factors, other thing which must be understand is the

manufacturing/production planning by the user.

Type of Gear Motor

An Integral Gear motor is the combination/collection of a motor and a specific gear drive. It may also be the

collection of gears like a gear box. Although, the motor of an Integral Gear motor is not fully integrated. This is

because the end bracket or the mounting flange of the motor portion is also a part of the gear assembly. The

mounting flange cannot be used independently out from the complete gear assembly. One shortcoming is

prevailed with Integral Gear Motor, because neither the motor portion nor the entire gear system is able of

being used in large number of general purpose applications. Normally, Integral Gear motors are used for some

specific purposes. These kind of Gear motors also have specific performance features and physical

dimensions. They also possess special physical dimensions, casing, flange and shafting structural

arrangement.

Railway Industry

The Buchli-drive Max. Speed

60km/h. Engine

DC Traction

Motor

Quill Motor Drive Monomotor Bogie

In railways, there is a wide range of gears and gear

equipments used in different railway applications. Here, some

of the gear related applications (railway

machineries/equipments) have been mentioned. For

accomplishing variety of applications related to railways, some

specialized gears and gear boxes are brought into use. These all applications are of specific nature, like

machines used by railways for different safety measures, railway signaling.

The Buchli-drive

In Buchli drive, there is one individual motor in each floating axle. For accommodating each of these two

individual motor, there are sprung locomotive sprung. The weight of each of the motor doesn't have any

connection with the driving wheels. These two motors are lay opened to the movement of the rails. Now a days,

the use of the drive has been reduced drastically, but once up on a time, this drive was used very much.

Construction

The gear-wheels of the gear is placed inside the locomotive box with full safety. Two geared levers and two

dome poles are liable for connection the gear wheel to the spring less driving wheel. The direction of moving of

the driving wheel towards the gear wheel is in vertical form and the internal mechanism is responsible for it.

Spherical implementation is brought in the taps of the driving wheel and in the ends of the tooth-swing. This

spherical implementation assist in keeping the dome poles in leaning position to the wheel-plain.

Standard design In between the wheel disks of the driving wheels, the engine framework lies along with the wheel set bearing. The auxiliary framework in which the gear wheel is housed, present outside the driving wheels and there is a surrounded protective casing present all around of the gear wheel. This protective casing protects the gear wheel. In locomotive motor, each of the gear wheel is propelled by an individual motor and this motor is placed above the gear wheel in the alternative box.

The appearance of the locomotives is not identical on both sides of the central line of the Buchli-drive. From one side, the wheel stars of the drive wheels are covered by the wheel cover box of the gear wheels, and from the other side, these are quite visible. Design with Outside Frame Outside the wheel disks of the driving wheels, the engine framework with the driving wheel housing is present. In the locomotive cabinet, the driving wheel is surrounded by a quill camped. On this locomotive cabinet the gear wheels are mounted. Design of Group Drive In between the floating axle, the motor is placed. The gear wheels of the neighboring axes can be driven by either by a common pinion or by a pinion on both engine wave ends.

Max. Speed 60km/h. Engine

This type of engines consist six-incline cylinders with mechanical changeable speed governor. The transmission process is automated hydraulic one and

twin turbine converters are present, which assist in the transmission process. In these engines, single driven axles are present. These axles contain axle-mounted bevel gear drives with single stage reductions.

The DC Traction Motor

The traditional DC electric motors which are used to drive the trains and locomotives, are of simple type of machines. These DC Tractor motors consist a Case Containing, the fixed electric part i.e. a Stator, and a dynamic electric part, i.e. Rotor. The rotor is always called as an Armature. When the rotor starts to turn, it also turns the pinion. The turning pinion drives a gearwheel. When the gearwheel is driven by the pinion, eventually the axle also start to move along with the wheels of the train, because the gearwheel is meshed onto the axle.

Quill Motor Drive

In railway, where the hollow shaft is required to place round the driving axle, the quill drive is used. In such arrangement, rather than driving the axle, the motor drives the quill. With one end, to one of the two wheels, the quill is attached. Rubber bushed assist in linking the quill with one of the two wheels. At the other end, the quill is attached to a gearwheel by the similar fashion. The most important advantage of this drive is that the weight of the motor drive is carried in the bogie frame. For this thing, quill motor drive is also called as frame mounted motor. Generally, the entire weight of motors is carried-on by the axles directly. The following figure is depicting the configuration of a traction motor with quill drive.

Monomotor Bogie

In this application of railways, there is only one motor and both the axles are driven by this single motor. This monomotor bogie has much popularity in France rather than India. Initially, this bogie was used for the rubber tyres train. In the middle part of the bogie, the monomotor is mounted longitudinally. This monomotor has several gearboxes, and with the help of these gearboxes, it drives all the axles. The functioning process is like the road-vehicle motor. Due to the operation of the rubber tyre round curves, the differential gears have to compensate. The monomotor bogie requires a special type of bogie frame, so that the motor can be accommodated into it.

Gear Manufacturing Process

Manufacturing Process

Steps

Wire Cut Electro Discharge

Machine

Gear manufacturing is today a multi billion dollar industry. As the demands of this industry is growing

manufacturers are now increasingly seeking machining tools and technology that can meet with the tough

challenges. As in this increasingly globalized world order manufacturers need suppliers that has global

resources for delivering state-of-the-art machines, tools etc. Gears are now produced in near-net shape, with a

cut in production as well as labour costs and elimination or reduction of wastes. These are also impacting the

gear manufacturers to have greater freedom in the choice of materials.

Automotive Parts Suppliers

(Image of an assembly line in a Gear manufacturing unit)

Steps in the Manufacturing Process of Gears

The gear manufacturing process is a complex step right from selecting the right material to finally doing the

finishing process for getting an optimum quality gear. Gear blanks in the beginning are first roughed out and

completely stress relieved this is done to minimise the distortion that have taken place after carburising. The

blanks subsequently then undergoes the finishing process. Then the gear cutting process takes place giving

allowance on the tooth flank for grinding. Then subsequently grinding and other steps takes place. Following

are the steps in the gear manufacturing processes:

Inject

Molded

Gears

Gear

Blank

Gear

Cutting Broaching of Gears

Gear

Grinding

Gear

Hobbing

Heat

Treatment

of Gears

Lapping

of Gears

Gear

Machine

Gear

Shaving

Powder

Metal

Gears

Gear

Deburring

Gear

Milling

Gear

Honing

Wire Cut EDM(Electro Discharge Machine)

Wire-Cut EDM

The wire-cut produces gear shapes by cutting the metal gears with a continuously moving wire. Which

operates with rapid, repetitive discharges. This process is used to cut gears that are very thick and intricate. In

the following image the gears are machined into two pieces by using wire EDM.

Electro Discharge Machine

Gear Drives

A Gear Drive System is an integrated form of different gears which are arranged in series form. Gear Drive is a

system, in which all the require gears are brought under a single system. This Gear Drive system transmits

force and motion between two shafts. A motor is required to turn all these gears to do work. There are two

gears which are arranged at two opposite ends of the gear box. Gear at the first end which supplies power, is

called as Input Gear and gear at the other end of the gear drive system is called as Output Gear. The output

gear does the actual work of the gear drive system.

Automotive Components Suppliers

Following are the major Gear Drives:

· Automatic

Transmissions

· Bevel Gear Drives

· Combination Drives

· Crown Gear Drive

· Cycloidal Drives

· Gear-Shift

Transmissions

· Harmonic Drives

· Helical Gear Drives

· Miter Gear Drives

· Spiral Bevel Gear

Drives

· Spur Gear Drives

· Traction Drives

· Variable Speed

Drives

· Worm Drives

Selection: Gear Drive System

The reliability of a Gear Drive system depends upon its quality of components, accurate assembly of these

components and solid design. The proper combination of all these things makes it an accurate and precision

system. A complete and efficient selection process is required for proper gear drive application, and various

operating parameters influence the selection process. These operating parameters include load demand, duty

cycle, external loads, input power, system accessories, facility needs and environment. A Service factor is

another factor on the basic of which the selection of the drive is determined. This service factor accounts for

the varying of torque by the driven machines and the driving gear.

Application of Gear Drive in Cars

In a car, first, the motor turns the shaft which is attached to the gears. So, the gears also start to turn one after

another. Gradually, this turning process passes from one gear to another. When, the last gear a starts to turn

which is attached to the car's axle, the axle starts to move. As a result, the wheels of the car start to move.

This is how a gear system moves a car.

Calculation of Inertia of Gear Drive

If any change takes place in the rotational speed of the gears in the Gear Drive, the load inertia will return back

to the motor through the gears. The inertia of a gear drive system can be calculated with the help of the

following equation.

Motor Speed Motor Torque

Reflected

Load Inertia

Inertia realized

at Motor

Where:

Sm = Motor Speed, rpm

Sl = Load Speed, rpm

Nl = Number teeth on load gear

Nm = Number teeth on motor gear

N = Gear Ratio

Tm = Torque of Motor, lb-in

Tl = Torque of Load, lb-in

e = Efficiency

Jl = Load Inertia, lb-in.-sec2

Jm = Drive Motor Inertia, lb-in.-sec2

Jr = Reflected Load inertia

Jt = Total Inertia, lb-in.-sec2

Traction Drives

Function

Principles Types Limitations

Configuration Applications

Among all other speed changing mechanisms, the most simplest type of mechanism is the Traction Drive.

These drives are the most frequent choice for many drive systems due to their simplicity and having the ability

to adjust the speed smoothly and in excellent way. For more than 100 of years, these drives have been used in

industrial services. In the recent period, these drives are considered as rivals of the best gears and the best

gear belts, because these contain best quality traction fluids and super quality bearing steels which are highly

fatigue resistant. Two conical shape, rotating rollers are used in a common type of Traction drive. These rollers

are used in transferring torque between themselves through the adhesive metallic sheet of a thin film of special

lubricants. In another basic type of Traction Drive, pivotal traction rollers are used. These rollers in this type of

Traction Drive, come in between an output disc and an output disc.

Functional Principles of Traction Drives

This Drive is a kind of fixed-ratio mechanical adjustable speed drive. There are two types of mechanical

adjustable speed drive. Along with variable pitch drive, this is the second type of it. Through metal rollers

running, These Drive transmits power against the mating metal rollers. The ratio between the input and output

speed is controlled to keep to remain constant by moving the rollers and thus changing the diameters of the

contact path. Also, different shape of rollers and mechanical designs have also been used for the same

purpose. The shapes of the rollers may be either cylindrical, conical, rings, discs, toroids or spherical. With the

help of rotational radius of the driven roller on the driven member, the speed ratio is being determined by these

drives. To maximize the efficiency of these drives as well as their life, the roller's normal load to the torque

should be adjusted. For this adjustment, a torque responsive roller loading mechanism is applied in these

Drives. The performance of these Drive in adjusting the mechanical speed with high effectiveness, depends

upon following thing: the friction that is generated between specially shaped output & input plates and the

speed adjustment mechanism.

Types of Traction Drives

• Lubricated Traction Drives – Synthetic fluids are used in these Drives. These fluids reduce

the friction (contact pressure) between the power capacities and the rolling members. The

fluids stat to behave like plastic, when the viscosity of these fluids increases tremendously

under constant high pressure. In transmitting power, these plastic like fluids help the

drives without appreciable metal to metal contact.

• Dry Traction Drives – These drives have removed the use of fluids for lubrication purpose.

Without using any fluids, these drives permit about cent percent efficiency in power

transmission. In place of any fluid lubricants, spiral loaded system is used, which provides

the slippery between the various driven and driving members inside the Dry Traction Drive.

Limitations of Basic Traction Drives

The limitation of these two basic types of Drives is their low potential to resist the high throughput power and

the torque impetuses which are common in the automotive drive-trains. Another shortcoming of these basic

Traction Drives is their low durability. This low durability arises from the high surface weary stresses generate

in the elements of the Traction Drive. Although, the fluid/lubricant technology is improving day by day, but still it

is the major source of concern for these drives. The third type of problem which is found in these Drive is: the

rotating components in these drives are bulky. This reduces the speed of rotation of these components along

with the desired acceleration rate. This in effect, increase the emissions of the vehicles.

Configurations of Traction Drives

There is a great possibility that the configurations of these drives may differ from each another. But, most of

the design differentiations lie in their respective power transferring speed to the outer members. Some

examples are:

• Perbury, Torotrak, Tractionmatic • Full toroid, half toroid, nutating • Traction Tec, Excelermatic, Jaguar • Kraus, Arter, Forster

Applications of Traction drives

In the power transmission industry, it was believed that these Drives would not make any noticeable impact.

The reason was that, most of the experts did not believe that two smooth rollers of a Traction Drive could

transmit force through a fluid. But, today, with the changing advance technology, people start to believe that

traction drives can do this thing. Therefore, in the engineering industry, these drives have made an intense

popularity. These drives are used in various applications in the engineering industry, especially when it is the

requirements of high efficiency and sound operations. These drives are also widely used in engineering

industry, when it is concerned to speed control, bringing compactness and consistency in performances. The

inherent accuracy of these drives is proved by the micrometer speed-setting dials which are fitted on these

drives. Such speed setting dials also provide extra torque even at low speed.

In the planetary vehicles, these drives have proved themselves as the best alternatives of the gear drives.

Contact geometry can be formed in the low wear to the solid lubricants through these drive rollers which are

present in these drives. In contrast, in other traditional drives, to bring smooth torque at low speed, additional

components are required in these.

Traction Drives

Traction drives are fixed-ratio mechanical drives. They transmit power through the traction forces on metal

rollers that are arranged on loaded in a planetary configuration. These rollers can be cones, cylinders, discs,

rings, spheres, or toroids. The speed ratio is determined by the radius of rotation of the driver roller on the

driven member.

A torque responsive roller loading mechanism adjusts roller normal load to applied torque, to maximize drive

efficiency and life. Traction drive depends upon friction between a speed adjusting mechanism and specially

shaped input and output plates to achieve adjustable speed with relatively high efficiency.

Types

Traction drives are of two types:

• Dry Traction Drive - These drives eliminate the need for lubricant and allow nearly 100% efficiency in

power transmission. Slippage between driving and driven members is presented by a spring-loaded

system.

• Lubricated Traction Drives - These drives use synthetic fluids. Traction fluids reduce the contact

pressure between the rolling members to increase life and power capacities. Under high pressure,

viscosity of the fluid increases dramatically so the fluid behaves more like a plastic material. This

plastic-like material enables the drive to transmit power without appreciable metal to metal contact.

Application

Traction drive has not made a major impact on the power transmission industry. This is because of the lack of

confidence in the fact that two smooth rollers can transmit force through a fluid. With the advanced technology,

there are significant changes brought in the traction drives. These drives today, are the ideal for engineering

applications where high efficiency and quiet operation are required.

Traction drive has their applications where compactness, ruggedness, and speed control accuracy are primary

concerns. The micrometer speed-setting dial on most traction drives attests to their inherent accuracy in

maintaining a specific output speed. They provide extra torque at reduced speeds. Traction drives provide an

attractive alternative for gear drives in planetary vehicles. These drives are composed of rollers that form a

contact geometry resulting in low wear to the solid lubricant.