Automobile

Understanding Multi plate clutch

To transfer power between the engine shaft and the transmission shaft, a multi-plate clutch uses many clutch plates to make contact with the engine flywheel. When large torque output is required, a multi-plate clutch is employed in automobiles and machines.

Today you’ll learn the definition, applications, construction, parts, types, working principle, advantages, and disadvantages of a multi-plate clutch.

multi plate clutch

Read more: Understanding automobile clutch

What is a multi-plate clutch?

The multi-plate clutch uses multiple clutch plates to make contact with the engine flywheel to transfer power between the engine shaft and the transmission shaft. A multi-plate clutch is used in automobiles and machinery where high torque output is required.

A multi-plate clutch transfers more power from the engine to the transmission shaft of an automobile vehicle while simultaneously compensating for torque loss due to slippage. This clutch is used in heavy machinery, commercial vehicles, special purpose military vehicles, racing cars, and motorcycles. Due to the restricted space in their gearboxes, scooters and motorcycles use multi-plate clutches. Multiple clutches are made up of more than three discs or plates in order to increase torque output.

Applications

Multi-plate clutches, as previously said, are utilized in heavy vehicles such as racing automobiles and motorbikes to transmit tremendous torque. Due to the assembly of friction surface contact, these clutches are smooth and easy to use when compared to single plate clutches. It can be employed in situations where space is at a premium. Below are some common applications of multi-plate clutch:

  • It is utilized in Scooters and motorcycles where the overall area required to accommodate the clutch is limited.
  • In Two-Wheelers with limited space, a multi-plate wet clutch is used.
  • It’s also employed in racing automobiles where maximum torque transmission is required.
  • It’s found in vehicles like Heavy Transport and Special Purpose Vehicles.
  • It’s utilized in big vehicles to transmit strong torques when a single plate clutch of the same size isn’t enough.
  • A multi-plate dry clutch is used in heavy-duty transport vehicles, such as tractor-trailers, where power and torque requirements are greater.

Read more: Understanding Single Plate Clutch

Construction

The architecture of a multi-plate clutch is similar to that of a single plate clutch, with the exception of the number of clutch plates. The total number of clutch plates is divided into two sets, with one clutch plate from each set being alternated.

One pair of plates is placed into grooves on the flywheel, while the other is slid onto the pressure plate hub’s splines. A strong coil spring reliably presses these plates, which are then joined in a drum. By manipulating the clutch pedal, a multi-Plate clutch functions similarly to a single-plate clutch.

The friction surfaces will rise as the number of clutch plates increases. The clutch’s capacity to transmit more torque for the same size improves as the friction surface grows. The torque transmitted by a small multi-plate clutch is similar to that transmitted by a single plate clutch with twice the diameter.

Parts

The following are the major parts of a multi-plate cone:

components of multi plate clutch

Pressure plate:

A plate that was joined to the splined sleeves and then to the pedal fulcrum. The sleeves attached to the pedal fulcrum travel outward when the clutch pedal is squeezed, driving the pressure plate linked to this splined sleeve.

Clutch Plate:

It’s a metallic plate with frictional lines on the outside. It transmits power between the engine shaft and the transmission shaft by frictional contact with the flywheel.

Thrust Springs:

These are springs that are employed behind the pressure plate. The pressure plate uses the stiffness of these springs to maintain frictional contact with clutch plates, which promotes clutch engagement.

Clutch Pedal:

The driver of the vehicle uses a clutch pedal to control the clutch’s engagement and disengagement.

Splined Shaft & Inner Splined Sleeves:

The full clutch assembly is mounted on an outside splined gearbox input shaft. The clutch plates, pressure plate, inner splined sleeve, and clutch casing are all part of this system, and it rotates with it.

Flywheel:

It’s a component of the engine. It can also be thought of as a component of the clutch system, which is defined as the transmission of power from the engine output shaft to the transmission shaft via frictional contact between a clutch and the engine’s flywheel.

Diaphragm Spring:

The thrust springs used in spring-type clutches are replaced with a single diaphragm-type spring in the diaphragm-type clutch system.

Read more: Understanding Diaphragm clutch

Diagram of multi-plate clutch:

Diagram of multi plate clutch 1

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Types of Multi-Plate Clutch

The following are the various types of a multi-plate clutch.

Spring multi-plate clutch:

A cover is fitted to the flywheel in this type of Multi-Plate Clutch. On the cover, there are multiple clutch plates. With the help of clutch springs or thrust springs, the outer plates of the clutch apply thrust on the inner plates, forming a drive and engaging the plates. To disengage the clutch, the mechanism pulls back the endplate, compressing the springs and releasing the other plates. This clutch is found in older automobiles and motorcycles.

Diaphragm multi-plate clutch:

The spring-type multi-plate clutch is also known as the diaphragm-type clutch. The name diaphragm clutch comes from the fact that it is made up of a particular crown-shaped finger-type spring. There are no thrust springs or clutches included. The diaphragm bears against the outer ring during a clutch engagement, while the response load is carried by the inner ring during clutch disengagement. This clutch is used in modern motorcycles and automobiles.

Hydraulic multi-plate or automatic transmission clutch:

This clutch is used in automatic transmission automobiles. The multi-plate clutch is connected to a hydraulic mechanism carrying highly compressed fluid that operates with the accelerated pedal. The hydraulic device, which is operated by the accelerator pedal, receives the engagement and disengagement of the clutch plates.

Wet and Dry Plate Clutch:

In general, wet clutches contain numerous clutch plates and a supply of oil to lubricate and cool the components (in vehicles). This clutch is housed within the engine’s housing. Because the wet clutches are amplified, they can handle significantly larger torque inputs. Wet clutches are often smaller than dry clutches.

When compared to dry clutches, wet clutches produce less noise. The presence of oil between the plates aids in noise control. The wet clutch has a lot less wear and tear. The lubricating fluid in a wet clutch keeps surfaces clean, resulting in smoother performance and longer life. Because the surface area rises due to the presence of numerous plates, wet clutches have a higher coefficient of friction.

A Dry Clutch is a clutch that does not require any liquid (oil) to engage and instead relies on friction. The plate of this clutch is located outside the engine housing. Because the friction plate gets heated due to friction, the dry clutch is usually bigger to maximize the surface area of the friction plate for efficient air cooling. The degree of noise in the dry clutch is higher, and it continues to rise as the clutch wears down.

A single frictional surface transmits power between two plates in a dry clutch. As a result, they do not have a significantly lower coefficient of friction. Because there is no oil in a dry clutch, the torque transmission of these clutches is better. Dry clutches are single-plate clutches that do not have an oil supply.

Read more: Different Types of clutch and their working principle

Working Principle

The working of a multi-plate clutch is less complex and can be easily understood. When the clutch is in the engaged position, that is, when the clutch pedal is not depressed. The thrust springs do not move, therefore the rigidity produced by these springs keeps the pressure above the pressure, despite the plate’s inner surface having friction lines.

The frictional contact between the friction lines of the pressure plate and the friction lines of numerous clutch plates is maintained as a result of the pressure provided to the pressure surface, resulting in frictional force being applied to the flywheel. The frictional contact between the various clutch plates and the wheel is supported by this frictional force, resulting in clutch engagement.

When the clutch pedal is depressed, the fulcrum at its inner end spins, causing the inner splined sleeve through which the pressure plate is connected to travel outward, applying pressure to the thrust springs. The thrust springs move as a result of this force, releasing tension on the pressure plate and removing the frictional force between the pressure plate, clutch plate, and flywheel.

As a result of the frictional force being removed, frictional contact between the pressure plate, clutch plate, and flywheel breaks resulting in clutch disengagement.

Read more: Types of differential and their functions

Watch the video below to learn more about the working of a multi-plate clutch:

Advantages and disadvantages of a multi-plate clutch

Advantages:

The followings are the advantages of a multi-plate clutch in its various applications.

  • It’s possible to get more torque transmission capacity.
  • The clutch assembly’s size is reduced as the diameter is reduced due to the increased friction surface.
  • It is quite dependable.
  • It’s built to withstand the weight of huge cars.
  • Better acceleration will be increased.
  • Reducing the clutch’s weight is a good idea.
  • Reduce the amount of pedal effort required to operate the clutch.

Read more: Understanding the working of automobile brainbox

Disadvantages:

Despite the advantages of a multi-plate clutch, some limitations still occur. Below are the disadvantages of multi-plate clutches in their various applications.

  • They rapidly heat up.
  • Multi-plate clutches are large and cumbersome.
  • The cost of multi-plate clutches is prohibitive.

Conclusion

Multi-plate clutches use multiple clutch plates to make contact with the engine flywheel to transfer power between the engine shaft and the transmission shaft. A multi-plate clutch is used in automobiles and machinery where high torque output is required. That is all for this article, where the definition, applications, construction, parts, types, working principle, advantages, and disadvantages of a multi-plate clutch are been discussed.

I hope you learn a lot from the reading, if so, kindly share with other students. Thanks for reading, see you around!