Clutch discs, also known as clutch plates, are automotive devices that are integral to the shifting of gears in both automobiles and pieces of heavy machinery. A part of electric, hydraulic, pneumatic and mechanical clutches alike, clutch discs are rounded plates that connect and disconnect the engine of a vehicle and the transmission input shaft of a vehicle to and from one another. When enacted, the engine and the transmission input shaft disconnect temporarily, allowing the gears to shift. Clutch discs and clutch systems are not only useful to the automotive industry, but to, among others, the agriculture, construction, transit, defense and shipping industries as well.
Quick links to Clutch Discs Information
How Shifting a Gear Works
Behind the shift of a gear is a complicated mechanism. To work, the clutch pedal must first be compressed. When the clutch pedal is compressed, it in turn compresses several springs that are connected to a pressure plate as well. From here, this compression tugs at the plate and pulls it, along with the connected clutch disc, away from the flywheel. The flywheel is held securely in place, bolted to the crankshaft of the engine. Once this disconnection takes place, the clutch disc stops rotating, causing its central hub to disconnect from the inner shaft. At this point, the driver of the vehicle may shift gears. Once he or she has shifted gears, the clutch pedal is released and the clutch disc returns to its original position, connected to the flywheel.
Materials Used in Clutch Discs
Much like brake pads, the actions of clutch discs create quite a bit of friction. Too much friction can be very bad for the clutch system, as it can wear away at the coating of the disc, causing the disc to slip against the flywheel and disrupt the transmission. To counteract this, manufacturers frequently fabricate clutch discs from stainless steel. Stainless steel is a steel alloy known in particular for its corrosion resistance, rust resistance and superior durability. To further fortify clutch discs, manufacturers often finish the plates with coatings of friction materials.
- Friction Materials
- Friction materials, also known as brake materials or clutch materials, are pads or linings made of rough or textured materials to slow or decrease friction-causing movement. Once upon a time, the most popular type of friction materials were asbestos fibers. However, today they are seldom used, due to the health risks they pose. Today, friction materials like mineral fibers, chopped glass, cellulose, copper fibers, aramid fibers, steel fibers, ceramics and other carbon composites and semi-metallic and non-metallic materials have replaced asbestos fibers for this application. Friction materials are mixed to create composites for various different clutch systems. Ceramic mix brake pads, for example, are frequently used with the clutch systems of heavy duty application vehicles, like performance cars and trucks. They are chosen for applications like these because they offer extreme strength and durability, superior heat resistance and an increased coefficient of friction. Note that while manufacturers and suppliers may offer general descriptions of common composites to the public, they will often shield the exact details of their friction material ingredients in order to edge out competition.
- Cooling Lubricant Fluid
- Another way that manufacturers can counteract too much friction is by immersing the clutch in a cooling lubricant fluid. In addition to keeping the clutch cool, this fluid facilitates smoother performances, keeps surfaces clean and lengthens the life of clutch systems. Note that clutch discs that use friction materials are called dry clutches, while clutch discs that use lubricant are called wet clutches. Dry clutches and wet clutches both have their merits, but wet clutches do have a tendency to lose some energy and they can be quite slippery. However, to compensate for this slipperiness and improve friction, manufacturers can stack multiple clutch discs in one system.
Things to Consider When Purchasing Clutch Discs
Those in the market for clutch discs must consider a few different factors as they relate to their application. These include: maximum pressure allowances, power, torque rating, rotational speed and type of clutch system (dry or wet) desired. After making their purchase, clutch disc owners must be aware of a few indicators and exacerbators of poor disc health. For example, if the grip of the clutch begins to slip, the clutch disc must be replaced. In addition, raising the engine speed very high while still engaging the clutch will cause early wear on the disc. Clutch disc maintenance is different with every car, as different car models sometimes put it in different places in the engine. A common home of the clutch disc, however, is in between the engine and the gearbox. For more tips about clutch disc maintenance and to find the best match for you, get in contact with an automotive engineer or clutch disk manufacturer today.