In this article, you’ll learn what is single plate clutch? Its diagram, parts, working, advantages, and applications all are explained with pictures.
This friction clutch employs a single clutch plate (also known as a friction plate). A friction lining is present on both sides of the friction plate.
The friction lining on the friction plate serves as a holding mechanism for the flywheel and pressure plate as well as a source of friction when the pressure plate exerts a force on it, rotating the three components together as a single unit.
As a result, the flywheel and gearbox are connected to transfer power.
Let’s start with the brief definition of single plate clutch.
What is Single Plate Clutch?
As the name suggests, the single plate clutch is a clutch that is made of only one clutch plate. Typically, a single-plate clutch works on the friction principle and is primarily used in many motor vehicles.
There are two main parts of the single plate clutch. One is attached to the driving shaft, and the other to the driven shaft. These shafts are parallel and concentric; one shaft is fixed to its housing, while the other is splined for axial movement.
When using this clutch, care must be taken to ensure that the friction surfaces engage smoothly and gradually, as this will cause the driven shaft to accelerate to the appropriate speed.
The advantage of using a single clutch is that it is easier to change gears than a cone clutch, as there is less pedal movement. There is no possibility of binding or joining cones in single plate clutches, so they are more reliable than cone clutches.
Let’s discuss the parts of a single plate clutch below.
Parts of Single Plate Clutch
The single plate clutch is made of several components, which are listed below:
- Pressure plate
- Friction lining
- Clutch plate
- Pilot bearing
- Clutch cover
- Release lever
- Clutch shaft
- Fulcrum pin
- Clutch pedal
It is the heaviest of all the parts included within the clutch. In this regard, it is attached to the crankshaft. The other side of the flywheel makes contact with the grasp plate. The primary function of the flywheel is to maintain the rotating mass (inertia) to help the engine’s rotation.
This provides a more consistent delivery of torque while running. This is the part that decides the amount of time to be taken by the whole system concerning engagement and disengagement.
#2 Pressure Plate
The pressure plate of the clutch is attached to the flywheel and spring. It is usually attached to a solid metal plate and takes the help of weight to maintain contact. Its function is to help move the clutch plate towards the flywheel. It is the part that controls the frictional force of the clutch.
#3 Friction Lining
The friction lining is the source from which the friction force is generated. It is usually attached to the grasp plate on both sides. During rotation, the friction lining makes contact with the flywheel and thus creates a frictional force.
With the help of this frictional force, torque is generated. Friction lining is made of a metal that has a high coefficient of friction in nature and never slips, and the surface produces friction.
#4 Clutch Plate
This is the most essential part of the clutch. The clutch plate is made of a thin plate of metals and has a friction lining on both sides. These are primarily intended to transmit power when an engagement occurs.
In addition, the clutch plate entirely depends on the working principle of the friction lining. The clutch plate rotates, and the friction lining produces friction with the flywheel and torque. Sometimes, this component is also called a clutch disc.
The springs are simply attached to the pressure plate via bolts. This usually helps the clutch plate to make contact with the flywheel to generate friction and torque.
The springs keep the flywheel moving forward or backward from the frictional surface of the clutch plate to maintain the amount of force generated by friction. Thus, the high coefficient of friction is also maintained, and a fair amount of torque is generated.
#6 Pilot Bearing
The pilot bearing is usually clamped to the end of the crankshaft to support the end of the transmission input shaft. This prevents the transmission shaft and clutch plate from tilting up and down when the clutch is released. In addition, it also helps the input shaft center of the disc on the flywheel.
#7 Clutch Cover
The clutch cover is attached to the flywheel via a screw connection to the housing. It ensures engine torque transmission to the gear shaft through the clutch disc by depressing the clutch disc on the flywheel.
#8 Release Lever
The release lever is also an important part that helps transfer force from the clutch lever to the pressure plate. This lever is pivoted on the pins of the clutch cover, locating their outer end, and positioned on the pressure plate. An important factor controlling the performance of the clutch assembly is the precise adjustment of the release mechanism.
#9 Clutch Shaft
The clutch shaft is also an essential component of the gearbox. As it is a splined shaft, it slides over the clutch plate hub. An end of the clutch shaft connects to the crankshaft or flywheel, while the other end forms a part of the gearbox.
#10 Fulcrum Pin
In this clutch, the release lever is rotated on the fulcrum pin. With the help of this pin, the release lever transmits the movement of the clutch pedal to the pressure plate when the driver presses the clutch pedal to disengage the clutch.
The release bearings are located at the back of the pressure plate, around the input shaft. To ensure that the pressure plate doesn’t wear out too quickly, it helps to reduce the friction between the release fork and the clutch pressure plate lever.
It is important to properly lubricate the bearing. Release bearings come in mechanical and hydraulic varieties.
#12 Clutch Pedal
It is the clutch’s control parameter, which the driver uses to operate the clutch. When shifting gears, the driver must depress the pedal. It is a group of mechanical linkages that help with the clutch’s engagement and disengagement.
Working of Single Plate Clutch
In a single plate clutch, the flywheel is mounted on the driver shaft. The clutch plate with a splined hub is mounted at one end of the splined driven shaft. It is free to slide axially on the driven shaft as well as rotate along the driven shaft.
There is friction lining on both sides of this clutch plate. Two friction linings of special abrasive material are riveted to the flywheel and pressure plate. A pressure plate is made to rotate internally to move freely on the driven shaft. There is also freedom for the pressure plate to slide axially.
Several springs are attached around the clutch to apply force to the pressure plate, which presses the clutch plate firmly against the flywheel when the clutch is engaged. The clutch is engaged, and the power can be transferred from the driver shaft to the driven shaft.
The pressure plate moves to the left if the driver depresses the pedal. Thus the pressure on the clutch plate does not work. Here the power from the drive shaft is not transmitted to the driven shaft.
When the foot is removed from the clutch pedal, it releases pressure on the pressure plate. The spring causes the pressure plate to exert pressure on the clutch plate, thus resuming power transmission.
To fully understand how a single plate clutch operates, watch the video below:
Purposes of Single Plate Clutch
- They are installed to engage and disengage the driver and driven shaft.
- Their purpose is to connect or disconnect the engine to the rest of the transmission system without stopping the engine.
- This disconnects the engine from the rest of the transmission system to put the vehicle in first gear to start the car comfortably.
- The clutch disconnects the engine from the transmission system to change gear ratios while driving.
- This helps to drive without jerks when starting the vehicle from a resting position or changing gear ratios.
- In addition, it also facilitates gear shifting smoothly without noise and damage.
- The primary function of the single plate clutch is to allow the engine to load slowly without jerking.
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Single Plate Clutch Formula
The formula provided below is used to calculate the single plate clutch’s torque.
Under uniform pressure, the single-plate clutch’s maximum torque gearbox is:-
W = Plates under axial thrust
R1 = Outer radius of friction surface.
R2 = Inner surface of the friction surface
μ = Coefficient of friction
According to the uniform wear theory, the single plate clutch’s maximum torque is:
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- A single plate clutch is considered very good because of its quick response to the operation, i.e., smooth engagement and disengagement of the clutch.
- During operation, the clutch can generate heat due to frictional force, which helps in the power transmission process.
- Since the clutch generates very little heat, no cooling medium is required to cool the system.
- As the torque is reduced, so the power loss is less. Due to low power loss, it is safe for the engines to operate smoothly.
- During the engagement of the clutch, there is no slip. Due to it, the working becomes very smooth.
- As the clutch dries out, moisture damages the clutch and also requires high maintenance.
- Single plate clutch can transmit low torque.
- The clutch springs need to be more rigid, requiring greater force to disengage.
- The space required to adjust the clutch is greater than that of the multi-plate clutch.
- This type of clutch has high wear and tear rate.
- Single plate clutches can be found on most vehicles across the globe in the automotive industry.
- This clutch has a large radial shape. It is commonly used in large vehicles instead of smaller ones, such as buses, cars, and trucks.
- The high coefficient of friction makes single plate clutches the standard choice in most vehicles.
- The torque generation is also much higher with this type of clutch in comparison with a wet clutch, so the clutch can be used mainly in large vehicles.
Wrapping It Up
I hope I have covered everything about “Single Plate Clutch.” If I missed something, or if you have any doubts, let me know in the comments. If you liked this article, please share it with your friends.
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Frequently Asked Questions
It has a single clutch plate that is fixed to the clutch shaft’s splines. A flywheel is attached to the engine’s crankshaft. Through the clutch springs and bolts, a pressure plate is connected to the flywheel.
Due to its attachment to the flywheel, the pressure plate rotates when the engine is running and the flywheel is spinning. They are separated by the friction disc. The clutch is released once the driver has depressed the clutch pedal.
The reliability of a single plate clutch is higher because it won’t bind like a cone clutch does. Slippage is very minimal. Very little power is lost. Heat production is very low.
The clutch lever is used to engage the clutch in motorcycles. When the lever is not being pressed, the clutch plate can be engaged. The clutch plates are disengaged by pulling the lever back towards the rider.
A multi-plate clutch is necessary for high torque output, such as in pickup trucks. It is impossible for a single-plate clutch to generate that much frictional force between the clutch plates and the flywheel.
There are a few common indications that the clutch needs to be replaced, including the clutch pedal feeling loose or spongey, the clutch pedal being difficult to engage, the gearbox making a grinding, whirling or chirping noise in neutral and grinding when shifting gears.