Understanding the Clutch for Choosing a Clutch Release Bearing

When choosing the right clutch release bearing, you obviously need to know which model you're buying the replacement for. However, are you aware of what a clutch actually is doing when you buy a clutch release bearing? Here is some insight for those of you who aren't sure exactly how the whole thing works.

Introducing the Clutch

A clutch is a gadget that links and detaches the drive from the transmission. Lawn mowers or tractors usually contain either a belt tensioning or friction clutch (likewise called stress plate clutch). Bigger yard tractors may utilize a disc clutch in combination with a shaft drive. If the tractor contains a hydrostatic transmission, it will not have a different clutch.

Common belt tensioning clutches use a spring idler pulley to manage the belts. When the pedal is depressed, the idler pulley withdraws from the transmission belt to disengage the transmission. When the pedal is released, the pulley springs back into place, and pushes on the transmission belt to create the engagement with the transmission.

Friction disc clutches are normally situated directly between the engine and the transmission. With this clutch, one disc is driven by the engine, and the other disc is connected to the shaft output. The disc is driven by the engine called a drive disc, and this disc is connected to shaft driven output disc. Friction materials or lugs placed on the surface drive disc allows the drive disc to interlock with the driven disc. As long as 2 discs are not touching, the drive disc can rotate easily without influencing the driven disc. If the discs are compressed, the rotating drive disc will involve the driven disc, and the 2 discs will rotate with each other. A spring loaded system is linked to the hold pedal utilized to pull discs with each other or apart. When a hold pedal on a mower is launched, discs compress and clutch becomes engaged. When the clutch pedal is depressed, the discs move away from each other and the clutch disengages.

The two Main Types

There are two significant kinds disc or plate clutches: the dry clutch and also the wet clutch. A dry clutch is similar to a vehicle clutch, normally seen just on larger tractors. Six main components that a clutch is composed of are engine flywheel, clutch disc, pressure plate and cover, clutch release bearing, and also the clutch release linkage, or fork.

In a dry clutch, the clutch discs placement is between the engine's flywheel and the pressure plate (there may be more than one clutch plate present). A pressure or stress plate is fastened to the engine flywheel. The clutch side of the flywheel is machined to supply a friction or rubbing surface area for the clutch disc. Clutch discs are covered with friction product on both sides.

The clutch release bearing slides onto the transmission input shaft and moves by the linkage of the clutch. This linkage is connected to the pedal. Springs on the clutch keeps pressure on the plate as well as the driven disc. When the driver depresses the clutch pedal, the links loosen the spring tension and causes the driven disc to disengage from the engine, so the power transfer stops. When the driver lets off the clutch pedal, the springs in turn push the pressure plate against the driven disc, and power is reconnected from engine to transmission.

A wet clutch includes discs splined to the drum as well as the pressure plates, which are splined to a center hub. The drum connects to the input shaft, and the center hub is connected to the output. Friction product is applied to both sides of each disc. The plates and discs both run in oil. When hydraulic pressure is applied, the disc and the plates are pressed together. They rotate with each other, the hub and drum rotate with each other, and power is moved from input shaft to output shaft. In some devices, plates and disc are pushed together mechanically.

It is important to consider the standard distinctions between a dry clutch and a wet clutch. Dry will not run if polluted with oil, discs will slide as well and not allow the transmission to engage. A wet clutch requires oil to run properly.

So, there it is. Now you know what's going on all around that replacement clutch release bearing you need. More than you ever realized, quite possibly.