Clutch is a mechanism, which allows controlling a torsion torque passed from engine to wheels. With producing of first cars with combustion engine, the need in mechanism, which would pass driving torque from motor to wheels, appeared. Engineers found out that vehicle needs idle running and different speed movement. But transmission ratio is necessary for this. Clutch is element a vehicle component part, which is called a transmission.
• Purpose of clutch pressure plate
• Construction and operation principle
• Types of pressure plates
• Exploitation issues
One of the main units of clutch is pressure plate with several components installed in one frame. Task of clutch plate is coupling and uncoupling of fly wheel with rim and, therefore, clutch engagement and disengagement. Clutch plate is an essential part of engine clutch construction. If it fails, the whole mechanism might breakdown as well. So, let’s find out, what is clutch pressure plate for?
Purpose of clutch pressure plate
Depending on constructional features, there are several types of car clutch:
- Electromagnetic clutch.
- Friction clutch.
- Hydraulic clutch.
Clutch is very important unit of a car. It is necessary for disconnecting engine and transmission during braking or gear shifting, and also for connecting those two car components back for a vehicle to start off. Besides, clutch also serves as safety appliance. It protects transmission from heavy loads and different impact blows. Due to its functional capabilities, clutch is quite simple vehicle component.
Its main purpose is transferring of torsion torque from drive portion and fly wheel, which is kind of retransmitter, to driven disk and then to gearbox input shaft. Due to elastic press plates – clutch plate tabs, driven disk is coupled in place of clutch plate and fly wheel pressure disk. When driver presses clutch pedal, driven disk branches out from pressure disk. In this moment the torsion torque can’t be transferred.
The most important component of whole clutch unit is pressure plate. The quality of whole system operation depends on it. Clutch pressure plate is responsible for disk and fly wheel interworking, and, therefore, for clutch engagement and disengagement. Clutch plate is an indispensible part. If there is any malfunction, the whole mechanism might fail.
Construction and operation principle
Pressure plate is a single construction unit. It consists of: pressure disk, diaphragm spring and inclosure. Clutch pressure plate interworks with other components of engine. Pressure plate inclosure is pinned to fly wheel on one side. On another side, pull-back spring fixed on pressure plate interworks with throw-out bearing. Pressure disk serves as connector of fly wheel and driven disk. When the clutch is disengaged, pressure disk presses on driving disk, which interworks with fly wheel.
The clutch is engaged at the moment, when pressure disc stops pressing and driving disk rotates separately from fly wheel. Pressure disk makes contact with pressure plate inclosure due to leaf springs, which are called tangential.
Next element of clutch pressure plate is diaphragm spring. It provides necessary effort for connection of disk and flying wheel, and for torsion torque transferring take place. The spring leans against inclosure corner and resembles petals. From inner side of inclosure, the spring is fixed with bolts and backup rings. Throw-out bearing provides pressure on clutch pressure plate tabs edges. As a result, the spring inside pressure plate stops interworking with pressure disk.
Types of pressure plates
Functional peculiarities of clutch pressure plates may be different. There are pressure plates of pressing or drawing action. Plate with pressing operation principle is more common. Peculiarity of this construction is that while clutch is operational, the tabs shift towards fly wheel. Plates of drawing action operate otherwise – their tabs shift from fly wheel. The component of such construction is smaller in diameter and is used only for space saving under cowl.
Also, there are special pressure plates, which are meant for replacement of standard ones. Their main difference is in special diaphragm, due to which the downforce is 1.5 times increased. This effect is reached because of using of more firm materials and much more complicated geometry of spring. Such clutch pressure plates are mostly installed on customized vehicles for power increasing.
Main malfunctions that may occur are usually connected with tabs deformation. In some time the tabs lose their elasticity. As a result, full clutch disengagement is not performed. That leads to hard gear shifting. If the pressure plate is worn out, then in some period of time throw-out bearing and clutch disk fail.