Chain Drive MCQ Quiz - Objective Question with Answer for Chain Drive - Download Free PDF

Explanation:

Chain Conveyors vs. Belt Conveyors

• In industrial conveyor systems, choosing between chain conveyors and belt conveyors depends on various factors including the type of materials being transported, the layout of the facility, and specific operational requirements.
• One of the primary advantages of using chain conveyors over belt conveyors is their greater suitability for vertical and inclined conveying.
• This feature makes chain conveyors an ideal choice for certain industrial applications where materials need to be transported at steep angles or even vertically.

Working Principle of Chain Conveyors:

• Chain conveyors consist of a series of chains driven by sprockets, which move along a track.
• The chains can have attachments or fixtures that hold or drag the materials being conveyed.
• The design and construction of chain conveyors allow them to handle heavy loads and navigate complex paths, including vertical and inclined sections.
• This flexibility is due to the robust nature of the chains and the strong grip they provide on the materials being transported.

Advantages of Chain Conveyors:

• Vertical and Inclined Conveying: Chain conveyors can easily transport materials up steep inclines and even vertically. This capability is essential for industries where space constraints necessitate vertical movement of materials, such as in multilevel manufacturing facilities or warehouses.
• Durability and Strength: Chain conveyors are built to handle heavy and abrasive materials. The chains are made from durable materials that can withstand harsh conditions, making them suitable for industries like mining, automotive, and heavy manufacturing.
• Flexibility in Layout: Chain conveyors can be customized to fit complex layouts. They can navigate tight corners, changes in elevation, and long distances, providing a versatile solution for material handling needs.
• Reduced Slippage: The design of chain conveyors ensures a strong grip on the materials being transported, reducing the risk of slippage and ensuring consistent and reliable movement.

Disadvantages of Chain Conveyors:

• Higher Maintenance Requirements: While chain conveyors are robust, they require regular maintenance to ensure the chains and sprockets remain in good working condition. This maintenance can be more intensive compared to belt conveyors.
• Higher Initial Cost: The construction and materials used in chain conveyors can result in a higher initial cost compared to belt conveyors. However, the long-term durability and efficiency can offset this initial investment.

Applications: Chain conveyors are commonly used in industries where heavy materials need to be transported over long distances or at steep angles. Examples include the automotive industry for moving car parts, mining for transporting ores, and manufacturing for moving heavy components.

Explanation:

Motor speed (N1) = 840 rpm, Compressor speed (N₂) = 210 rpm, velocity ratio = 4, Number of teeth on the smaller sprocket (T₁) = 23

∵ For a chain drive, the velocity ratio (V_R) is inversly proportional to the ratio of teeth on the sprockets:

\(\frac{N_1}{N_2}~=~\frac{T_2}{T_1}\)

⇒ T₂ = 4 × 23 = 92

Explanation:

The power is transmitted from one shaft to the other by means of belts, ropes, chains, and gears.

• The belts and ropes are flexible members which are used where the distance between the two shafts is large.
• The chains also have flexibility but they are preferred for intermediate distances.
• The gears are used when the shafts are very close to each other.
• A chain drive is also called a positive drive because there is no slip.
• If the distance is slightly larger, a chain drive can be used for making it a positive drive.
• Belts and ropes transmit power due to the friction between the belt or rope and the pulley.
• There is a possibility of slip and creep in belts and rope drive and that is why this drive is not a positive drive.

Hence, due to no-slip condition, the chain drive has a maximum efficiency of power transmission.

Explanation:

Chain drive:

• A chain drive is a way of transmitting mechanical power from one place to another.
• It is often used to convey power to the wheels of a vehicle, particularly bicycles and motorcycles.
• It is also used in a wide variety of machines besides vehicles.
• Chains provide a constant velocity ratio and high transmission efficiency.
• Most often, the power is conveyed by a roller chain, known as the drive chain or transmission chain, passing over a sprocket gear, with the teeth of the gear meshing with the holes in the links of the chain.
• The gear is turned, and this pulls the chain putting mechanical force into the system.
• The gear is rotated, and this pulls the chain, exerting mechanical force in the mechanism.
• The chain is made up of several rigid links that are held together by pin joints to provide the necessary flexibility to wrap the driving and driven wheels.

Types of Chain Drives:

• Roller Chain
• Silent Chain
• Leaf Chain
• Flat Top Chain
• Engineering Steel Chain

Explanation:

Chain drives:

• Chain drives are the positive types of the drive-in in which chain and sprocket mechanisms are used to transmit the power by engaging the teeth of the sprocket with gaps in the chain.
• As there will be no slip or loss while transmission so they are positive drives.
•  As the distance of transmission is more in the case of bicycle motorcycles and coal, chain drives are used for the transmission of power.

The relation between the pitch of the chain (P) and the pitch circle diameter of the sprocket (D) is given by the following equation,

P = D sin (180°/T), Where T is the no. of teeth on the sprocket.

Additional Information Comparison among belt drive, gear drive, and chain drive:

• The belts and ropes are flexible members which are used where the distance between the two shafts is large
• The chains also have flexibility but they are preferred for intermediate distances
• The gears are used when the shafts are very close to each other
• This type of drive is also called a positive drive because there is no slip
• If the distance is slightly larger, a chain drive can be used for making it a positive drive
• Belts and ropes transmit power due to the friction between the belt or rope and the pulley
• There is a possibility of slip and creep and that is why this drive is not a positive drive
• The gear drive and chain drive are positive drives

Explanation:

Belt Drive

• The belt drive is the most common method of power transmission.
• The belts are made from leather, cotton, rubber, and synthetic materials.

There are four types of belts:

1. Flat belt
2. V - belt and multiple V - belt
3. Ribbed belt
4. Toothed or timing belt

V - Belt drive

• V - belt drives are generally used when the distance between the shafts is short for flat belt drives.
• Owing to the wedge action between the belt and the sides of the groove in the pulley, the V belt is less likely to slip, hence more power can be transmitted.

Advantages of V -belt drive

• It is compact, so installation is possible in limited space
• It is used when the center distance between the drive and the driven pulleys is short.
• Less vibration and noise
• Cushions the motor and bearings against load fluctuation
• Easy replacement and maintenance

Concept:

There are two advantages of using an idler pulley:

• Initial tension in the belt can be increased from time to time by adjusting the position of adjustable weight or by increasing the adjustable weight value. Due to increase in initial tension, power transmitting capacity of belt drive gets increased.
• Angle of contact on the smaller pulley increases which further increases the ration between friction tension on both the sides because `T1T2" tabindex="0">T1T2T1T2 = eθ" tabindex="0">eθeθ. Hence, in effect power transmitting capacity of belt drive gets further increased.

Explanation:

Chain drives:

• Chain drives are the positive types of the drive-in in which chain and sprocket mechanisms are used to transmit the power by engaging the teeth of the sprocket with gaps in the chain.
• As there will be no slip or loss while transmission so they are positive drives.
•  As the distance of transmission is more in the case of bicycle motorcycles and coal, chain drives are used for the transmission of power.

The relation between the pitch of the chain (P) and the pitch circle diameter of the sprocket (D) is given by the following equation,

P = D sin (180°/T), Where T is the no. of teeth on the sprocket.

Additional Information Comparison among belt drive, gear drive, and chain drive:

• The belts and ropes are flexible members which are used where the distance between the two shafts is large
• The chains also have flexibility but they are preferred for intermediate distances
• The gears are used when the shafts are very close to each other
• This type of drive is also called a positive drive because there is no slip
• If the distance is slightly larger, a chain drive can be used for making it a positive drive
• Belts and ropes transmit power due to the friction between the belt or rope and the pulley
• There is a possibility of slip and creep and that is why this drive is not a positive drive
• The gear drive and chain drive are positive drives

Explanation:

The power is transmitted from one shaft to the other by means of belts, ropes, chains, and gears.

• The belts and ropes are flexible members which are used where the distance between the two shafts is large.
• The chains also have flexibility but they are preferred for intermediate distances.
• The gears are used when the shafts are very close to each other.
• A chain drive is also called a positive drive because there is no slip.
• If the distance is slightly larger, a chain drive can be used for making it a positive drive.
• Belts and ropes transmit power due to the friction between the belt or rope and the pulley.
• There is a possibility of slip and creep in belts and rope drive and that is why this drive is not a positive drive.

Hence, the gear drive and chain drive are positive drives.

Concept:

The main uses are depicted in the figure.

• Running ropes are bent over sheaves and drums. They are therefore stressed mainly by bending and secondly by tension.

• Stationary ropes have to carry tensile forces and are therefore mainly loaded by static and fluctuating tensile stresses.

• Track ropes have to act as rails for the rollers of cabins or other loads in aerial ropeways and cable cranes

Wire ropes are extensively used in hoisting, haulage, and material handling equipment.

From the above usage, the wire ropes experiencing low speeds and high tensile stresses.

Explanation:

The power is transmitted from one shaft to the other by means of belts, ropes, chains, and gears.

• The belts and ropes are flexible members which are used where the distance between the two shafts is large.
• The chains also have flexibility but they are preferred for intermediate distances.
• The gears are used when the shafts are very close to each other.
• A chain drive is also called a positive drive because there is no slip.
• If the distance is slightly larger, a chain drive can be used for making it a positive drive.
• Belts and ropes transmit power due to the friction between the belt or rope and the pulley.
• There is a possibility of slip and creep in belts and rope drive and that is why this drive is not a positive drive.

Hence, due to no-slip condition, the chain drive has a maximum efficiency of power transmission.

Explanation:

Velocity Ratio:

Velocity ratio is the ratio of the speed of the driven pulley to that of the driving pulley.

\(Velocity\;Ratio\;(VR)=\frac{N_2}{N_1}=\frac{D_1\;+\;t}{D_2\;+\;t}\)

where D and t represent diameter and thickness respectively.

In the case of belt drive where the slip (S) is present the velocity ratio is given by:

\(Velocity\;Ratio\;(VR)=\frac{N_2}{N_1}=\frac{D_1\;+\;t}{D_2\;+\;t}\left ( \frac{100\;-\;S}{100} \right )\)

In gear and chain drive velocity ratio is given by:

\(Velocity\;Ratio\;(VR)=\frac{N_2}{N_1}=\frac{D_1}{D_2}\)

∵ slip is absent and thickness is very less as compared to the diameter so it can be ignored, ∴ it is constant.

Additional Information

Following is the relation between Belt, Chain and Gear drive.

Concept:

• The ropes are made from cotton, hemp, manila, synthetic jute, steel wire, etc.
• Rope drives are used for long-distance and for large amounts of power transmission.
• The rope drives are mainly employed in the mining and textile industries.
• Rope drives can be employed when there is a misalignment between the pulleys within limits and in fluctuating temperature and humidity conditions.
• One big advantage of rope drives is that a number of separate drives may be taken from the one driving pulley.
• The groove angle varies from 40° to 60° but is generally 45°.

Concept:

The power is transmitted from one shaft to the other by means of belts, ropes, chains, and gears.

Chain drives 

• Chain drives are the positive types of the drive-in in which chain and sprocket mechanism are used to transmit the power by engaging the teeth of the sprocket with gaps in the chain.
• As there will be no slip or loss while transmission so they are positive drives.
•  As the distance of transmission is more in the case of bicycle motorcycle and coal, chain drives are used for transmission of power.

• The belts and ropes are flexible members which are used where the distance between the two shafts is large
• The chains also have flexibility but they are preferred for intermediate distances
• The gears are used when the shafts are very close to each other
• This type of drive is also called a positive drive because there is no slip
• If the distance is slightly larger, chain drive can be used for making it a positive drive
• Belts and ropes transmit power due to the friction between the belt or rope and the pulley
• There is a possibility of slip and creep and that is why this drive is not a positive drive
• The gear drive and chain drive are positive drives

Explanation:

The power rating of the roller chain is obtained on the basis of four failure criteria.

1. Wear
2. Fatigue
3. Impact
4. Galling

Wear:

• The wear of the chain is caused by the articulation of pins in the bushings which results in elongation of the chain or chain length is increased. 
• This makes the chain ride out on the sprocket teeth, resulting in a faulty engagement. 
• When the elongation 1s excessive, 1t becomes necessary to replace the chain. 
• The permissible elongation of the chain is 1.5 to 2.5%. 

Fatigue:

• As the chain passes around the sprocket wheel, it is subjected to a tensile force, which varies from maximum on the tight side to a minimum on the loose side.
• The chain link is subjected to one complete cycle of fluctuating stresses during every revolution of the sprocket wheel which results in fatigue failure.  

Impact:

• The engagement of the rollers with the teeth of the sprocket results in impact which leads to breakage of roller or bushing.
• By increasing the number of teeth on the sprocket or reducing chain tension and speed we can reduce the magnitude of the impact force. 

Galling:

• Galling is a stick-slip phenomenon between the pin and the bushing
• When the chain tension is high, welds are formed at the high spots of the contacting area.
• Such microscopic weld immediately broke down due to relative motion of contacting surface and eventually leads to excessive wear even in presence of the lubricant.