Chain drive and their different types will be discussed in this article. They are an important component of several types of machinery, and they may be used for purposes other than power transmission; however, more on that later. Let’s get this ready to have fun.
Motors and turbines in industrial facilities utilize energy to generate rotating mechanical motion. There must be a mechanism to convey this motion to other components and machines to harness it for productive work. One method of power transfer is the use of sprockets and chain drives.
An unending set of chain links mesh with toothed sprockets to form a chain drive. Chain drives are mostly used for three aspects: timing, material transportation, and power transmission.
Chain Drive – What is it?
A mechanical power transmission system that moves mechanical power from one place to another is a chain drive. In many vehicles, including bicycles and motorcycles, the wheels are powered by a chain drive. It may also be demonstrated in several machines. They are one of the five most prevalent mechanical power transmission methods, along with shaft couplings, gear drives, belt drives, and lead screws. Because each option offers a distinct mix of benefits and drawbacks, engineers must take precautions before making a final decision.
Chain Drive Mechanism
A roller chain, which is also known as a chain drive or transmission chain, typically transmits power by passing over a chain drive sprocket gear and having the gear teeth mesh with the chain links’ holes. When the gear is rotated, the chain pulling exerts a mechanical force on the machine.
To give the flexibility needed to wrap driving and chain driven wheels, the chains are built up of multiple stiff links that are held together by pin joints.
These wheels have specific profile teeth that fit into the chain link’s appropriate recess. Sprocket wheels, often known as bus sprockets, are toothed wheels. Therefore, sprockets and chains are forced to travel together without slipping to maintain the proper velocity ratio.
Chains are used to transfer power and speed from one shaft to the next shaft of a machine when there is a little center distance between the shafts, as in bicycles, motorcycles, agricultural equipment, conveyors, rolling mills, and road rollers.
Long center lengths of up to 8 metros can also be covered by the network. Chains can handle speeds of up to 25 m/s and power of up to 110 kW. High-power transmission is achievable in some instances.
Blockchain chains, which are made of solid or laminated blocks joined by side plates and pins, are also used in conveyor belts and other systems. The sprocket wheels’ teeth come into contact with the blocks. Buckets, hooks, and other devices are linked to the blocks depending on the substance being transported.
Engineering applications for chain drives include the following:
- using a forklift on a hydraulic lift truck;
- rigging and moving bulky items;
- Changing the gear ratios between the driver and the sprocket being chain driven can increase or decrease a driver’s output speed.
- Overhead hoists
- Conveyor belt management
General Description of Chain Drives
Chain drives are oval loops that can run around curves by supplying additional gear (it must be more than two). Idler wheels are used when the gear does not deliver power to the system or does not transmit power. The gear ratio may be changed simply by changing the diameter of the output and input gears about each other.
A duplex chain, which consists of two chains linked side by side, is used to convey additional torque and power. Chain drives use teeth to convey motion between the rollers and the chain as opposed to belt drives, which results in less frictional loss. Chain drives are often made of metal, which makes them hefty and has high inertia.
Parts of roller chain:
For sufficient ultimate strength, pins in chains must have a depth of hardness. The most common type of steel used is a low carbon, alloy, case-hardened steel that has been tempered for core strength. The full diameter of the pins is completely centerless ground.
Bushings are typically made of low-carbon steel that has been case-hardened and tempered to withstand wear and roller contact.
Rollers are built of case-hardened alloy steels and are vulnerable to wear and sprocket impact. The rollers are made of high-carbon steel and are heat-treated.
Tensile loads are applied repeatedly on link plates or sidebars. As a result, heat-treated steels are commonly utilized. The standard chain has formed solid rollers and is composed of high-quality alloy heat-treated steel.
Design of Chain Drive
Chain drives can handle a wide range of weights and speeds and are used in many different applications. The length of the chain varies, and the dimensions of the chain are proportional to one another. The most crucial chain variables are width, pin diameter, pitch, and link plate thickness.
The distance between the link plates and the center of the holes is known as pitch. The pitch determines the shape of the sprocket teeth. The size of the sprocket teeth must match the chain link pitch. The other three measures are directly proportional to the chain’s pitch.
The width is determined by the distance between the inner link plates. The width is approximately 5/8th of the link pitch.
3. Pin Diameter
It’s the diameter of the pin that connects the connection plates’ outer and interior surfaces. It has a link pitch of 5/16th and a roller diameter of 1/2 inch.
4. Link Plate Thickness
The outer and inner link plates are of the same thickness which is generally 1/8th of the link pitch. Any pitch chain’s heavy series link plates have roughly the same thickness as the plates on the chain’s following larger pitch standard series chain.
The chain passes around the sprocket as a series of chordal links. This pattern resembles a non-slip belt being wound around a rotating polygon.
- For smooth operation of chain drives a higher number of teeth 19 or 21 gives better life expectancy to the chain with less noise during operation.
- It is preferable to use an odd number of teeth for the driving chain drive sprocket in combination with an even number of chain links for uniform wear and tear on the teeth and rollers. (In this case, a particular tooth of the sprocket wheel does not come in contact with a particular link of the chain for every rotation.)
Backsliding of chains
The wear of the chain results in the elongation of the chain. To put it another way, the pitch length is extended. This leads to improper chain sprocket engagement because the chain rides out on the sprocket teeth.
Galling is a stick-slip phenomenon between the pin and bushing. When the load is heavy and the speed is high, the high spots (joints) of the contacting surfaces are welded together.
Parameters For Chain Drive
Chain pitch: This is the space between a link’s hinge center and the hinge center of a neighboring link. It’s often indicated with a ‘p’.
Pitch circle diameter of chain sprocket: When the chain is enclosed in a ball, this is the diameter of the circle on which the hinge centers of the chain rest. Pitch circles are circles drawn across the hinge centers of a chain, and the diameter of these circles is referred to as the pitch circle diameter.
Types Of Chain Drive
The three categories of chain drives are listed below.:
- Hoisting and hauling chain drive
- Conveyor chain drive
- A power-transmitting chain drive
Hoisting And Hauling Chain
A hoist is a device for raising or lowering a load using a drum or a lifting wheel around which a rope or chain is wound. It can be operated manually, electrically, or pneumatically and can use chain, fiber, or wire ropes as a lifting medium.
The best-known form is an elevator, the carriage of which is raised and lowered by a lifting mechanism. Most hoists are attached to their loads with a lifting hook.
These chains are used for hoisting and hail and operate at a maximum velocity of 0.25 m/s. The two sorts of chains are hoisting chains and ruling chains.
Chain with oval links:
This type of chain link is oval-shaped. Each link joint is welded. The sprockets used for this type of chain have receptors to obtain the link. In-chain hoists and anchors for maritime activities are the sole applications for these types of chains at low speeds.
Oval link chains are also known as coil chains. They are commonly used as hoisting chains for low to medium loads and are generally meant to be used in low-speed lifting applications. The chain link is oval-shaped and each one is welded after interlocking.
Sometimes, square link types of chains may be used but they are generally avoided due to poor stress distribution and kinking issues.
Chains with square links:
The links of this type of chain are square-shaped. Hoists, cranes, and dredges all employ these chains. The manufacturing cost of this type of chain is less than a chain with oval links, but in these chains, overloading is easily kinking.
Chains with Stud link:
For high-load applications, these chains are a superior substitute. Each chain link is fitted with a stud across its inner width. The studs prevent kinking and increase strength and durability. Stud link chains find use in ship anchors and other heavy-duty lifting machines.
A conveyor chain is a chain that has been specially developed for chain conveyor systems. It is made up of many simple bearings that are connected by connecting plates. Each bearing consists of a pin and a bushing on which the chain roller rotates.
These chains are used to continuously lift and convey materials at speeds up to 2 m/s. The conveyor chains come in two varieties.:
· Detachable or hook joint type chain: When the distance between power transmissions is short, this kind of conveyor chain is employed.
· Closed joint type chain: Most of this chain is formed as a single casting out of a barrel and a link, and after that, the chain is heat-treated to give it exceptional strength.
Cast iron is typically used to make conveyor chains. These chains cannot run smoothly. The conveyor chain operates at a slow speed of about 0.8 to 3 m/s.
Power Transmitting Chain
When there is a little gap between the centers of the shafts, power transmission chains are utilized to transmit mechanical power. These chains have provisions for efficient lubrication. The following three types of power transmission chains are available.
1. Block or bush chain
2. Bush roller chain
3. Silent Chain
1) Block Or Bush Chain
This type of chain was used in the initial stage of development in power transmission. It causes noise when rubbing between the teeth and the link when the sprocket is near or exiting the teeth. These types of chains are used to some extent at small speeds as conveyor chains.
2) Bush Roller Chain
A pin link plate on the outside, a roller link plate on the inside, pins, bushes, and rollers make up a bush roller chain. The bushing, which is fixed in the roller’s hole between the two sides of the chain, is pierced by a pin.
The rollers are free to rotate on the bush which protects the sprocket wheel teeth against wear. Alloy steel is used to make rollers, pins, and bushes.
A bush roller chain is extremely strong and simple to manufacture. It serves well in severe conditions. There is a slight noise with this chain due to the impact of the rollers on the teeth of the sprocket wheel. This chain can be used where there is slight lubrication.
The extended chain sprocket is larger than the pitch of the wheel teeth when one of these chains significantly elongates as a result of the wear and stretching of components. The rollers fit unevenly in the cavities of the wheel. The result is that the total weight falls on one tooth or a few teeth. Stretching of parts increases the wear of roller surfaces and sprocket wheel teeth.
Roller chains are standardized and manufactured on a pitch basis. These chains come in simplex, duplex, or triple strands, as well as single-row or multi-row roller chains.
3) Silent Chain
A silent chain is also known as an inverted tooth chain. It is intended to reduce the negative effects of stretching and provide quiet strolling. When the chain is stretched and the pitch of the chain increases, the links ride on the teeth of the sprocket wheel in a slightly increased radius.
Small pitch fluctuations are automatically corrected by this. There is no relative sliding between the teeth of the inverted tooth chain and the sprocket wheel. When properly lubricated, this chain gives durable service and runs very smoothly and quietly.
Types of Chains in Use
There are many types of chains used in chain drives, each with its advantages and disadvantages. The five most common types in use are as follows:
- Roller chain (bush roller chain)
- Silent chain or inverted tooth chain
- Leaf chain
- Flat-top chain
- Engineering steel chain
Roller chain (Bush roller chain)
The roller chain is perhaps the one that most people think of when discussing chains. Many types of home, industrial, and agricultural machinery, such as conveyors, wire and tube drawing machines, printing presses, vehicles, motorcycles, and bicycles, employ roller or bush roller chains for power transmission. Typically, steel alloys or plain carbon steel is used to make them.
A roller chain is made up of an inner plate (roller link plate), outer plate (pin link plate), bushes, pins, and rollers. The rollers are placed equidistantly between chain links. These rollers engage with the sprocket teeth and transfer power through the chain. An important advantage of roller chains is that they rotate as needed when they come into contact with the sprocket teeth, thus reducing power losses.
In transmission chains, the height of the roller chain link plates (on each side of the roller) is greater than the rollers. This prevents the side plates from making contact with the sprocket during operation. In addition to that, they also act as guides and prevent the roller chain from slipping off.
For roller chains in conveyors, the roller diameter is relatively larger than the height of the sidebars. This prevents contact between the sidebars and the conveyor track and improves chain drive efficiency by eliminating translational friction. Larger rollers also reduce rotational friction.
For greater power requirements, designers can opt for multi-strand roller chains. Having multiple strands permits the use of low speeds and small chain pitches for the same load requirements.
Silent chain (inverted tooth chain)
The silent chain, which is also known as the inverted tooth chain, is made up of several link plates with teeth that are attached to joint components in such a way as to enable unrestricted bending between each pitch.
Silent chains, as seen in the picture, are constructed from stacked rows of flat link plates with gear-type shapes that are intended to contact sprocket teeth similarly to how a rack engages a gear. At each chain junction, one or more pins also permit the chain to bend and hold the links together.
Silent chains from different manufacturers usually cannot be connected. In a wide range of industrial drives where a small, high-speed, smooth, low-noise drive is required, standard quiet chains are employed.
High-performance silent chains are used on very high-speed drives where remarkable smoothness and silence are required. They come in a variety of diameters, pitches, and widths. These chains are commonly used in industrial equipment where ultimate smoothness is required.
Most chain drives are infamous for their high operational noise. In noise-sensitive environments such as enclosed spaces, mines, and residential areas, a quieter chain is more suitable. This keeps the disturbance to the surrounding environment under control and promotes worker well-being.
Let’s talk about silent chains, also referred to as inverted tooth chains. A silent chain can transmit large amounts of power at high speeds while maintaining a quiet operation. The chain consists of flat plates stacked in rows and connected through one or more pins. Each link has the contour of sprocket gear teeth on the underside where it engages with the sprocket teeth.
A silent chain’s weight-carrying capability, tensile strength, and chain width all rise with the number of flat plates in each link.
These are the most basic types of chains in use today. They just have connecting plates and pins. The link plates function alternately as articulated links and pin links. Because leaf chains are intended to run across sheaves for support, they do not mesh with sprocket teeth.
Leaf chains find use in lifting and counterbalancing applications. Some common examples of applications using leaf chains are lifts, lift trucks, forklifts, straddle carriers and lift masts. In all of these low-speed machines, the lift’s chain endures high static loads and a small amount of working load. Leaf chains can handle shock and inertia better than other chain designs.
All lift chains must be capable of handling high tensile stresses without elongating or breaking. They must have sufficient ductility to endure fatigue. As always, lubrication and service environment must be given their due thought already in the design process.
Leaf chains are designed for chain drive lifting rather than power transmission. Tensions are very high, but speeds are slow. Normally the chains work intermittently. Tensile loads, joint wear, and link plate and sheave wear are the key factors taken into account while designing leaf chains.
Since leaf chains are designed to travel across sheaves, they don’t mesh with sprockets, hence there is no provision for them to engage a sprocket. Leaf chains frequently have to raise extremely heavy loads, therefore they require great yield strength and are not permanently stretched when they do so. On lift trucks, leaf chains are probably used the most frequently.
Chains with a flat top are exclusively used for transporting. As the material may be conveyed directly on its links, they can replace conveyor belts and belt drives. An individual link is usually made out of a steel plate with barrel-shaped hollow protrusions on its bottom side. The links are connected to preceding and succeeding links by passing a pin through these protrusions underneath the links. The nature of these joints allows movement only in one direction.
There are special types of flat-top chains that can flex sideways. The pin construction permits sideways movement in both directions to enable the conveyor chain to go around curves.
Low-speed conveyor systems that transfer materials along assembly lines employ flat-top chains.
The Flat-top chain consists of.
· A series of steel top plates with hinge-like barrels curled on each side.
· Pins are inserted through the barrels to make a joint. These act as both beams and bearings.
· Pins are retained by press fits or heading in the barrels of one top plate and are free to articulate in the barrels of the next link.
· The connecting pin is usually either knurled or enlarged on one end to retain the pin in one barrel of the top plate.
· Thus a continuous length of the flat-top chain is formed.
· The flat-top chain is intended only for conveying.
Engineering steel chain
Since the 1880s, engineering steel chains have been in use. The most demanding applications and harshest conditions may be handled by this chain. They were created using hot-rolled steel that was occasionally heat-treated for further sturdiness.
Engineering steel chains are just as relevant today. However, their strength, wear rate, loading capacity, and pitch have increased to match present-day industrial needs.
These chains consist of links and pin joints. The clearance between this chain’s components is larger than other chains as it has to handle dust, dirt, and abrasives under normal operating conditions.
Now many industrial steel chains are employed in drives, even though many are utilized as conveyor chains for material handling. They can be seen in applications such as conveyors, forklifts, bucket elevators, and oil drilling machines.
How to select the right chain drive for your application
With the amount of variety in the form and function of various chain designs, selecting the right chain drive for an application can become a bit overwhelming. The right way to go about this selection is to eliminate unsuitable options by evaluating the chain’s application and features. This will help to narrow down viable options before the final selection. The most important factors in chain drive selection are as follows:
- Chain speed
- Shaft layout
- Distance between the shafts
- Service environment
When selecting the right chain drive for your application, the most important question to focus on is how much power needs to be transferred. The chain must be able to handle the power produced by the prime mover.
The safety of the crew and the chain drive system depends upon the correctness of the calculations at this stage. It is recommended to work with an adequate factor of safety.
Not all chain drives can handle high-speed applications. Some chain drives are specifically designed for low speeds. The specifications can be obtained by carrying out calculations and ensuring that the speed is within the recommended range. This evaluation will considerably narrow down the number of designs that can be used for the application.
Usually, chain drives cannot be used with shafts that are not parallel. Gear drives may have to be considered as an option by the designers if the shafts are not perfectly aligned.
Distance between the shafts
The center distance between shafts should be between 30 and 50 times the chain pitch. The designer must also ensure that a minimum arc of contact of 120 degrees is obtained on the smaller sprocket. If the sprocket has less than five teeth, at least five of them must always be in contact with the chain.
The service environment will dictate the expected resistance of the chain drive to moisture, dirt, abrasives, corrosion, and high temperature. Other factors including vibration, noise levels, and fatigue strength will also be impacted. For instance, in areas where noise is a concern, the designers can opt for the use of an inverted tooth chain.
Most chain drives require lubrication for a satisfactory wear life. Chain type, size, loads, and operating speed will dictate the need and extent of lubrication. Depending on the application, designers may prefer manual, drip-feed, oil bath, or forced feed lubrication.
Some chains are self-lubricated and do not require any external lubrication throughout their service life. These chains utilize bushings comprised of oil-infused sintered polymers or metals, which offer continuous lubrication while in use.
Need for Lubrication
There are six reasons why chain drives need to be lubricated.
- To protect the pin-bushing joint from wearing out
- To absorb impact forces.
- To dissipate any heat generated.
- To flush away foreign materials
- To lubricate chain-sprocket contact surfaces
- To retard rust or corrosion
Types of lubrication
- Manual Lubrication
- Drip lubrication
- Splash Lubrication
- Spay Lubrication
Advantages Of Chain Drive
Compared to drives and gears, chain drives have several benefits.:
· They are practical for traveling both far and close distances.
· Several shafts and be driven from a single chain
· They are compact and have small overall dimensions
· Even in fire hazards, it does not face any bad problems.
· Temperature and environmental conditions do not affect their working
· Initial tension is not required in the chain drive.
· They have very high efficiency (up to 96%)
· No slip and creep during the power transmission, ensuring the perfect velocity ratio.
· Installing the chain drive is simple.
· Chain drives need less maintenance.
· They are resistant to harsh environments.
· They can operate in wet conditions
Disadvantages Of Chain Drive
· Chain Drive can not be used where slip is the system requirement
· Compared to belt drives, it needs perfect alignment.
· Chain drives are more productive than belt drives.
· Chain drives need to be lubricated often.
· load capacity less compared with gear drives
· Conventional chain drive suffers vibrations due to the chordal effect.
· They are not suitable for non-parallel shafts
· They can not be used where precise motion is required
· The chain drive needs accurate and careful mounting.
· They need tweaks, much like a tensioning device, for slack.
Application Of Chain Drive
Chain drives are used in many types of industrial applications, such as:
· Chain drive, a Device widely used for the transmission of power where shafts are separated at distances greater than that for which gears are practical.
· Moving and rigging big objects
· Operation of a hydraulic lift truck fork
· Increasing or decreasing a driver’s output speed by altering gear ratios between the driver and the sprocket being chain driven
· Overhead hoists
· Operating conveyor belts
· Chain drive is used in several industries for several purposes Transportation Industry, Agriculture Machinery, Material Handling Equipment, and Building construction.
Uses of Chain Drive
1. Chain drive components on Bicycle
The chain drive, which has two wheels of identical diameters, was one of the key safety elements that were first introduced in 1885. It is still a very fundamental component of bicycle design.
Although the majority of bicycle chains are constructed of ordinary carbon or alloy steel, some are nickel-plated either to prevent rust or just for aesthetic purposes.
The primary element that distinguished the safety bicycle, which was first launched in 1885 and had two wheels of identical size, from the “high wheeler” style of bicycle was the chain drive. The widespread use of chain driven safety is still a fundamental aspect of bicycle construction today.
The reason a bicycle chain is so efficient is that it shifts the center of the pressure away from the axle, which puts less strain on the bearings and lessens friction in the inner wheel. It was discovered that the higher chain tension was more effective.
Many automobiles used chain drives in the beginning, but eventually, roller chain rear axles took their place. It results in simple designs. Chains are long-lasting but their replacement is harder.
A fundamental necessity for motorcycle design is the utilization of a chain drive, driveshaft, or belt drive. Almost all motorcycle designs have one of these components.
A chain-drive system transmits power from a differential to the rear axle in a vehicle.
Back in the earlier days, automobile chain drives are a very popular power transmission system. It gained prominence as an alternative to the Système Panhard with its rigid Hotchkiss, Driveshaft, and universal joints.
Compared to driveshafts and universal joints, chain drives are easier to design.
Less unsprung weight at the rear wheels makes it possible for the suspension to respond to bumps more quickly. This would result in a more comfortable ride for the vehicle.
What Is Chain Drive?
A chain drive is a means of distributing mechanical power from one place to another. It is frequently employed to supply power to a vehicle’s wheels, especially those of bicycles and motorbikes. In addition to vehicles, it is employed in a broad range of other machinery.
What Are the Types of Chain Drives?
Following are the three types of chain drive
1. Hoisting and hauling chain drive
2. Conveyor chain drive
3. A power-transmitting chain drive
What Is the Application of Chain Drive?
There are several industrial uses for chain drives, including:
· Transporting and rigging heavy items.
· Utilising a hydraulic lift truck’s fork.
· Overhead hoists.
· Operating conveyor belts.
· Changing the gear ratios between a driver and the sprocket being chain driven to increase or decrease a driver’s output speed.
What Is a Chain Drive Used For?
When shafts are separated by longer intervals than those for which gears are practicable, a device called a chain drive is frequently employed to transmit power.
What Are Examples of Chain Drives?
Many different power transmission applications, including bicycles, motorcycles, rolling mills, agricultural equipment, machine tools, conveyors, coal cutters, etc., use chain drives. A chain and two-wheel sprockets, make up a chain drive.
Is Chain Drive Better Than Belt Drive?
It is evident that the two drives function the same way, but a chain drive is more durable than a belt drive. Unlike belt drives, chain drives can lift and move more massive doors, which is why many prefer them. Chain drives are best for steel carriages and not suitable for less heavy door models.
What Is the Advantage of Using a Chain Drive?
Chain drives have the advantage of having higher transmission efficiency than friction drives. Even under inclement weather and heat circumstances, they can function. It can function in a moist environment. It may be used for power transmission across short and long distances.
What Are the Advantages of Chain Drives?
Highly efficient, chain drives give the advantage of more power compared to belts. It can be used for both small and large center distances. Chain drives need less service. They offer up to 98 percent transmission efficiency.
What Is Chain and Chain Drive?
A chain drive is a way of transmitting mechanical power from one place to another. The drive chain or transmission chain, which is most frequently used to transmit power, passes over a sprocket gear, and the teeth of the gear mesh with the holes in the chain link to transmit power.
What Are the Types of Chains?
Depending upon the length of the chain, these are divided into the following types,
· Metric chains.
· Steel band or Band chain.
· Gunter’s chain or surveyor’s chain.
· Engineer’s chain.
· Revenue chain.
Why Would You Use a Belt Drive Over A Chain Drive?
Unlike chain drive, which requires very frequent cleaning, tightening, and maintenance, belt drives are relatively maintenance-free. Belt drive systems also run much smoother, with much fewer jerks as compared to chain drives, and produce incomparably less noise too.
What Are the 4 Differences Between a Belt Drive and A Chain Drive?
Belts and chain drive
Slips may occur in Belt Drive, but there is no slip in Chain Drive. Belt drive has less life span as compared to Chain drive. Lubrication is required in Chain Drive, whereas Belt Drive does not require lubrication. Belt Drives require large space, whereas Chain Drives require moderate spaces.
Which Is Better Cam belt or Chain?
Most automakers recommend replacing the timing belt every 60,000 to 105,000 miles. Timing chains are heavier and more complex than timing belts, but they also last much longer. Unless there’s a problem, timing chains don’t have a replacement interval.
What Are the Limitations of Chain Drive?
Disadvantages of chain drives
· They cannot be used where slip is the system requirement.
· They require precise alignment compared to belt drives.
· They require frequent lubrication.
· They have less load capacity compared with gear drives.
· Their operation is noisy and can cause vibrations.
What Is the Input Movement in A Chain Drive?
In a Chain Drive, the input and output shafts are always parallel. The input and output gears move in the same direction since their teeth do not mesh. Both gears are circling therefore the input and output gears’ type of movement is Rotary and the direction of travel and flow of power is reversible.
What Is Chain Drive-In Motorcycle?
The chain drive system is made up of two sprockets, one on the chain drive gearbox and one on the rear wheel, that are connected by a chain. When the engine is sparked, power is transferred along the chain or shaft to the rear wheel, and the bike moves forward.
The sprocket center lines should be in the same horizontal plane or at an angle of up to 60 degrees for the chain drive to function optimally. Avoid vertical drives whenever possible. Ideally, the chain pitch should be between 30 and 50 times the center distance between sprockets.
30xPitch(P) * Distance between shaft centers (C) * 50xP
Chain drives have a center-to-center adjustment in their design.
Sprockets should have at least 17 teeth wherever practical. This is due to the chain’s formation of a polygon, rather than a circle, around the sprocket. A cyclic drive speed fluctuation known as cordal speed variation will happen if low tooth counts are employed. Lower tooth numbers may be employed at low drive speeds (say, less than 3 m/sec) provided the equipment’s design specification does not depend on this speed variation. Cordal speed fluctuation will result in increased sprocket wear at higher speeds. When operating at speeds more than 3 m/sec, sprockets with 17 to 25 teeth should be heat treated to provide a robust, wear-resistant surface with a Rockwell ‘C’ hardness of 35 to 45.
Chain Drive Calculation or Design procedure of chain drive
The design process adheres to BS 228: 1970.
Following this technique and consulting the DESIGN DATA MANUAL, the chain drive design is completed.
1. Given the input and output RPMs, compute the drive ratio (velocity ratio).
2. Choose the sprocket tooth numbers. Standard sprockets are utilized to save money.
3. Determine the Service (selectable) factor. The service factor considers the conditions in which the chain drive will operate. The driving machinery’s shock stresses and the driven load necessitate a more robust construction. Compute the type (class) of the chain driven equipment using the chart in the DESIGN DATA MANUAL, then choose the relevant column for the driving machinery and determine the selection factor for the number of teeth on the smaller sprocket.
4. Calculate the Design (selection) power.
5. Select chain size from the power rating chart. The design power rating for simplex, duplex, and triplex chains is shown in the three columns on the left-hand side of the chart. Wherever possible simplex chains are used. The design power on the vertical axis is referenced with the speed of the smaller sprocket on the horizontal axis to obtain chain size and lubrication requirements.
6. Check the maximum sprocket bores against the required shaft diameters if known. List or tabulate details of stock numbers for chains, sprockets, and bushes.
7. Determine a suitable center distance if not given. As mentioned a center distance of 30 to 50 times the chain pitch is recommended.
Length of chain
8. Determine the length of the chain in several pitches.
Round off the answer to an even number of pitches.
As the chain must be made up of an even number of pitches, the actual center distance must be redetermined so that it corresponds to the chain length calculated above.
9. Calculate the actual center distance CA.
10. Determine the sprocket pitch diameters and other dimensions as required.
PCD sprocket = number of teeth in sprocket * PCD factor
Chain drives are a great invention in the mechanical world as they can be used for various purposes. In this article, we’ve explained the definition, applications, diagram, components, types, and workings of a chain drive. We’ve also seen the advantages and disadvantages of the system.
I hope you enjoyed the reading, if so, kindly comment on your favorite section of this article. And please don’t forget to share this post with other technical students. Thanks!
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