What Is Multi-Plate Clutch?
The clutch is a device used to attach and dismantle an engine with a gearbox. A clutch in which two or more clutch plates are used is called a multi-plate clutch. The multi-plate clutch has multiple plates so that we can transfer as much torque as possible.
Adding plates to the Cuttack to create a multi-plate clutch will increase the torque capacity of the clutch without increasing the spring strength or clutch diameter. As the number of clutches plate increases, the number of friction surfaces will also increase, and hence the torque transmitting capacity of the clutch also increases.
The small-size multi-plate clutch delivers nearly double torque compared to a single plate clutch of diameter. As we know, the clutch is the most important integral part of a power train as it is used to shift the drive from the engine shaft to the transmission shaft to the required torque or speed output, but what is the need for a multi-plate clutch. Then let’s discuss-
Where high torque output is required, like a pickup truck, a single plate clutch fails to provide the much frictional force (between the flywheel and clutch plates) that is required to provide such high torque, Therefore in a heavy vehicle such as a pickup truck multi-plate clutch is used.
Two-wheeler vehicles such as bikes and scooters have packaging problems due to their small size, so a multi-plate clutch with smaller clutch plates meets the required torque output requirement instead of a larger single-plate clutch. Are, are used. They are transmitting power between the engine shaft and transmission shaft.
When the clutch is engaged (to transmit power between the flywheel and the transmission shaft), multiple plates of a multi-plate clutch provide greater friction force between the flywheel and the pressure plate than a single clutch for which the slip The probability is almost negligible in a multi-plate clutch.
When we go to the terrains having different ups & downs or different road challenges, multi-plate clutches are required to maintain the smooth and steady engagement between the engine and the transmission shaft, which in turn continuously provides the required amount of torque and speed to the vehicle.
The effort required by the driver on the clutch pedal to engage or close the clutch is less in a multi-plate clutch than in a single plate clutch.
Types of Multi-Plate Clutch:
#1. Spring Type Multi-Plate Clutch
In a spring-type multi-plate clutch, a cover is bolted to the flywheel of the engine. Inside this cover, the clutch plates, pressure plates, thrust bearing, etc., are present. Unlike the diaphragm clutches, thrust springs are used to move the clutch plate, which pushes the clutch plates and creates contact between them, and hence the clutch comes in the engaged position.
#2. Diaphragm type multi-plate clutch
In the diaphragm type multi-plate clutch, a diaphragm spring is used instead of a thrust spring to push the pressure plate & bring the clutch in engaged condition. The diaphragm spring used in these clutches is a crown-shaped finger-type spring. This diaphragm spring applies the pressure plates, which further pushes the clutch plates for the engagement of the clutch.
#3. Hydraulic operated or Automatic Clutch
Hydraulic Operated Clutch is used in modern vehicles with an automatic transmission system. In this type of clutch, hydraulic devices are used instead of springs for the engagement & disengagement of the clutch.
This hydraulic device contains highly compressed liquid, & it is operated by an acceleration pedal as it is used in automatic transmission.
Why a Multi-Plate Clutch Is Needed:
The torque transmitting capacity of the clutch depends on the factors given below:
- Co-efficient of friction actings between the frictional surface.
- The radius of the friction surface.
- Clamping force between the force holdings the frictional surface together.
- The number of the frictional surface.
- There is a limit to which the coefficient of friction can be increased, and due to high friction, the clutches may become fierce while engaging.
- The radio cannot be increased much as the clutches have to be fixed inside a motor vehicle. So the size & radius of the clutches can not be increased very much.
- The clamping forces cannot be increased much because a higher clamping force may require excessive driver efforts.
- It can be easily increased by increasing the number of clutch plates, & the torques transmitting capacity of clutches can be increased easily without any loss. Because of this, reason multi-plate clutch was needed and invented.
Parts of Multi-Plate Clutch:
#1. Input Shaft
This input shaft is connected with the engine crankshaft. It takes power from the engine. The other end of the input shafts is connected to the flywheel.
Since the flywheel attaches to the input shaft, the flywheel also rotates when the input shaft rotates. The flywheel’s teeth are bitten on its surface that stabilizes on the pinion’s teeth that rotate with power from the battery and help in self-starting.
#3. Clutch Plates
The clutch plate is a circular disk and has a friction lining on either side of the clutch plate. Friction linings are presents on both sides of the clutch plates to increase the coefficient of friction between both sides of the clutch plate and between the clutch plate and separator plates. The abrasive lining is made of carbon fiber, sandwich bronze, or graphite. These clutch plates also have springs that are used to soak the clamp plate during rotation.
#4. Separator plates
A separator plate is used to separate the two clutch plates from each other. These separator plates are also called steel disks because they are made of steel. They are kept within the basket. These separators are placed between two clutches plates. Generally, these clutch plate is made of steel, but in some cases, it is made of cast iron. It also has a circular disk-like shape.
#5. Clutch Pack
All clutch and set of separator plates are also called clutch packs.
#6. Pressure plate
These plates are called pressure plates because it maintains pressure on the clutch plates and the divider plates. This pressure plate is attached to the splendid sleeves, and these sleeves are attached to the paddle fulcrum. When the pedal is pressed, the sleeve is attached to the pedal, which has an outward movement which in turn shakes the pressure plate. These pressure plates apply pressure to the clutch plate and separator plates so that the clutch plate and separator plates are connected to each other as well as the flywheel. Since clutch plates and separator plates are connected due to pressure plates, the separator plates also rotate when the clutch plates rotate.
#7. Diaphragm Spring
The diaphragm spring is convex shaped and topped. The clamping force on the facing friction is provided by the diaphragm spring.
#8. Cover Plate
This cover plate is bolted with a flywheel and is used to cover the entire system of the multi-plate clutch.
Working Principle of Multi-Plate Clutch:
Discuss the working principle of multi-plate clutch; it can be said at first that it has two types of work processes. One is an attractive process, and the other is a disruptive process. Regarding this, two types are discussed here below:
When the clutch pedals are pressed, the pressure bearing on the pressure plate diaphragm spring moves the center of the acting diaphragm spring in the forward direction, but the corners of the diaphragm spring that are connected to the pressure plates move in the backward direction, and Therefore pressure plates also move in backward direction because the corners of the diaphragms spring are fired with a pressure plate.
As the pressure plate moves backward, pressure plates release pressure from the clutches plates as well as the separator plate. As the pressures are released from the clutch & separator plates, the clutch plate also displaces from the flywheel & allows the flywheel to rotate freely without turning on the clutch shaft. Therefore, the clutch comes into a disengaged position.
As soon as the clutch is in a disengaged position, the engine is displaced with the gearbox, & there is no power transmission between the two.
When the clutch pedals are released, the pressure plates again pressurize the clutch plates and the separator plates, and the clutch plates and the group of separator plates will again be joined with the flywheel, and the power of the input shaft will be transmitted to the output shaft. Therefore, the power transmission between the engine and the gearbox will resume.
Construction of Multi-Plate Clutch:
The construction of a multi-plate clutch is similar to a single plate clutch except for the number of clutch plates. The total number of clutch plates is divided into two sets, with one from each set arranged alternately.
One set of plates slides into the grooves on the flywheel and the other on the split on a pressure plate hub. These plates are reliably pressed by a strong coil spring and assembled into a drum. The multi-plate clutch work in the same way as the single-plate clutch operating the clutch pedal.
As the number of clutch plates will increase, the friction surfaces will also increase. Increasing the friction surface increases the ability of the clutch to transmit more torque for the same size. The small-sized multi-plate clutch transmits approximately the same torque as a single-plate clutch of twice the diameter.
Advantages of Multi-Plate Clutch:
Multi-plate clutches have several advantages. Some of the benefits are given below:
- Since multi-plate clutches are made of more clutch plates, the torque transmission capacity is much higher.
- This type of clutches is small in size. Due to its compacts size, the multi-plate clutch is suitable for any type of vehicle worldwide. Since motorcycles and scooters have limited space, the multi-plate clutch can be easily fitted due to its compact size.
- Compared to a single-plate clutch, the diameter of a multi-plate clutch is smaller than that of a single-plate. Because of this feature, multi-plate clutches can be used in many sports such as racing and others.
- The multi-plate clutch has several friction surfaces. Since the transmission of torque depends on the number of friction surfaces, in the case of a multi-plate clutch, the torque exceeds the single-plate clutch.
- Due to the advantage of a high torque rate, in the case of heavy vehicles, which are mainly used for commercial purposes, a multi-plate clutch can be used easily.
- Compared to a single-plate clutch, the multi-plate clutch helps the engine perform with better acceleration.
- A force is required to press the clutch pedal to turn the clutch. To operate a multi-plate clutch, less pedal effort is required.
Disadvantages of Multi-Plate Clutch:
It also has some disadvantages. Some of the disadvantages are given below:
- The weight of a multi-plate clutch is heavy, so it is not suitable for all-time use.
- The cost of a multi-plate clutch, as well as its maintenance, is very expensive. So, with a low budget, this is not good for users of multi-plate clutches.
- Since the number of friction surfaces is greater than that of a single-plate clutch, more heat can also be generated. Due to excess heat, the engine heats up quickly. In this case, a cooling medium is required for a multi-plate clutch. So, for the cooling medium, users have to spend extra money. Due to this drawback, the cost of maintenance becomes higher.
Applications of Multi-Plate Clutch:
- Multi-Plate clutch is used where the required space where the clutch needs to be installed is very less like in motorcycles and scooters.
- It is also used in racings care where high accelerations are required & torque transmission criteria are maximum.
- They are used in heavy transport vehicles and special purpose vehicles.