What is Multi Plate Clutch? its Diagram and How it Works

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.

Well, in this reading, we’ll explore what a multi-plate clutch is, its applications, construction, parts, types, and how it works. We’ll also discuss its advantages and disadvantages.

Let’s begin!

What is Multi-Plate Clutch?

The multi-plate clutch uses multiple clutch plates to contact 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 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.

Related: What Is A Clutch? Its Functions, Parts and How it Works

Applications

Multi-plate clutches, as previously said, are utilized in heavy vehicles such as racing automobiles and motorcycles 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. You can use it in scenarios where space is limited. 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.

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 multiplate clutch functions similarly to a singleplate 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 of a Multi-Plate Clutch

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

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.

Diagram

multi plate clutch

Types of Multi-Plate Clutch

The following are the various types of 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.

Related: What is Single Plate Clutch? its Diagram and How it Works

How Does Multiplate Clutch Work?

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.

Difference Between Single-Plate Clutch and Multi-Plate Clutch

The clutch serves as a key mechanism for transferring power between the engine shaft and transmission shaft.

Common types include single-plate and multi-plate clutches, which are designed to increase torque output and compensate for torque loss due to slippage.

Multi-plate clutches are used in heavy machinery, commercial vehicles, special-purpose military vehicles, racing cars, and motorcycles due to limited space in their gearboxes.

On the other hand, single plate clutches are the most popular type, consisting of only one clutch plate attached to the clutch shaft’s splines.

The engine flywheel revolves with the crankshaft, and when the clutch pedal is depressed, the pressure plate is fastened to the flywheel by clutch springs.

The clutch plate is grasped between the flywheel and the pressure plate, with friction linings on both sides, causing the clutch plate to circle with the flywheel. The clutch shaft rotates in tandem with the clutch plate.

Difference between multi-plate clutch and single-plate clutch in tabular form:

Multi-Plate Clutch

Single Plate Clutch

There are more than two pairs of friction surfaces in contact. A total of two pairs of friction surfaces are in contact.
It is composed of two or more clutch plates. There is only one clutch plate on it.
It ensures a smooth and gradual engagement. It does not ensure a smooth Engagement.
It requires less space. It requires more space.
Application- Two-wheelers, racing cars, and some heavy-duty trucks. Application- Trucks, Jeeps, cars, etc.
For the same size, torque transmission capacity is more. For the same size, torque transmission capacity is less.
Since it has a number of friction plates instead of a single, frictional power loss is more. Frictional power loss is less.
For the same power transmission, smaller in size. For the same power transmission, larger in size.

Advantages and disadvantages of a multi-plate clutch

Advantages:

The following 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.

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.

FAQs

What is a multi-plate clutch?

A multi-plate clutch is a mechanical device used in automotive and industrial applications to transmit power from the engine to the transmission system. It is a highly efficient and reliable type of clutch that utilises multiple friction plates to engage and disengage the power flow.

What is the function of a plate clutch?

As a crucial part of a vehicle’s transmission system, it plays a pivotal role in controlling power transfer from the engine to the wheels. This type of clutch operates on a relatively simple yet effective principle, relying on a single friction plate and essential components to engage and disengage power seamlessly.

What is the purpose of a multiple-disc clutch?

The most popular reason is for an increase in torque-holding capacity. The most important reason is to reduce the clutch assembly’s moment of inertia (MOI).

What is a multi-clutch transmission?

a transmission with several clutches can be called a multi-clutch transmission. For example, the Koenigsegg Jesko has a transmission with one clutch per gear, making for a total of 7 clutches.

What is the difference between a single-plate and multi-plate clutch?

The main difference between a single-plate clutch and a multiplate clutch is the number of friction plates used. A single-plate clutch has one friction plate, while a multi-plate clutch has two or more friction plates.

Which is better, wet multi-plate clutch or slipper clutch?

A slipper clutch is better than a wet clutch because it can withstand high braking force, aggressive downshifts, and rear wheel lockups.

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