The overrunning clutch is also commonly known as the freewheel. It is a component in the transmission of a vehicle which is responsible for deactivating the drive shaft in certain situations. The drive shaft is usually deactivates and stops working with the driven shaft when it reaches a faster rotation speed than the drive shafts' speed. This occurrence is often referred to as an overdrive.
If you want to further understand what an overdrive is then you should look at the functionality of a standard bicycle. Usually if the person riding the bicycle were to stop pedaling randomly it would cause an overdrive. This is due to the fact that the driven shaft will be rotating faster than the drive shaft. If the bicycle is a fixed-gear unit that does not include a freewheel then the back wheel of the bicycle would force the pedals to continue rotating.
Importance of an Overrunning Clutch in Vehicles
If you have a vehicle with a manual transmission then the overrunning clutch will come in extremely handy in some situations. For instance, when you are driving down a hill you are likely going to be releasing your foot from the gas pedal. This will cause the throttle to close and the wheels will try to take over as the power source for the engine. This could also be attempted with a higher RPM.
If this occurred with a 2-stroke engine then the situation could become extremely serious as it could cause the pistons in the engine to seize up. Further damage to the engine could occur as a result of the overdrive that occurred if the vehicle has a 2-stroke engine.
Design of the Overrunning Clutch
The overrunning clutch usually consists of a design that features two discs that are loaded with springs. The discs have saw-toothed sides which will be compressing together naturally. The functional design of the overrunning clutch could be slightly compared to a ratchet. The overrunning clutch will rotate in a single direction until the saw-toothed side of the drive disc locks up with the saw-toothed side of the driven disc.
When the overrunning clutch is running properly both the drive disc and driven disc will be rotating at the same speed. A decrease in speed for the drive disc could cause the driven disc to bypass the saw-toothed side of the drive disc. When this happens the driven disc will continue rotating by itself and a clicking sound may be noticed. Also, there are many other types of designs of overrunning clutches that may be used in automobiles and other vehicles.
Benefits of an Overrunning Clutch
The overrunning clutch is essentially used as an automatic clutch as it allows for changing gears automatically. You also have the ability to change the gear up or down in a manual transmission vehicle. At the same time there is no need to let off on the clutch pedal. The ultimate result of having the overrunning clutch is a greater functionality of the clutching system in your vehicle.
By having an overrunning clutch in any vehicle with a carbureted engine it will also add to the fuel efficiency of . This is not a very noticeable difference in fuel economy but it is worth mentioning. An additional benefit of the overrunning clutch is that it will minimize the amount of wear and tear that takes place on the manual clutch. The only major disadvantages to using the overrunning clutch is that it will cause excessive wear and tear on the brakes and you will not be able to use engine braking any more.
Overrunning clutches should not be used in truck or vehicles that travel in mountains. If you attempt to use an overrunning clutch in such situations then it could cause your braking system to overheat. The overrunning clutch is only useful in passenger vehicles and similar automobiles. It is commonly found in bicycles, snowmobiles, and similar types of vehicles.
The overrunning clutch offers many safety benefits and it should be an essential component in most vehicles. It is important that you know how it works and how you can troubleshoot an overdrive problem. To get a decent understanding on the functionality of the overrunning clutch you should just take a look at how the freewheel works in a bicycle. Ultimately, an overrunning clutch is necessary for your vehicle to run as effectively as possible. Also, the overrunning clutch is an extremely useful safety component that should be used in most vehicles.