PLATE-CLUTCH 2S9018 - Caterpillar

All Industrial And Marine Engines So EquippedPower take off clutches on Caterpillar engines have two functions. First, they must smoothly bring a load up to operating speed from a stop. Second, they must be strong enough to continually transmit engine torque to the load being driven. Since friction is the primary means by which a clutch does its job, the operator must be constantly aware of the possibility for clutch overheating and damage.
Clutch slippage, and the resulting heat buildup is at its greatest when the torque of the engine is first transmitted to a stationary load. In light duty applications, when the load is easy to start, the clutch may slip for only a second. In heavy duty applications, the slippage can continue for several seconds. But problems can arise if clutch slippage continues for an excessive amount of time. The number of clutch engagements in a given period of time also determines the total heat input to the clutch.
If for some reason, the amount of load is so great that it cannot be started, such as when a rock crusher is jammed by a large rock, all of the engine horsepower will be converted to heat as the clutch slips. Repeatedly engaging and slipping a clutch in an attempt to start a stalled load will generate more heat than the clutch was designed to withstand. Severe overheating of the clutch and damage to clutch parts is possible.
If the machine is operating and there are any signs of overheating, such as smoke, radiated heat, or discolored parts, the operator should stop the engine at once and allow the engine to cool before inspecting the clutch for possible damage.
The overheating of the clutch can cause thermal cracks to develop in the clutch parts. The thermal cracks can eventually lead to a burst failure, which can result in breakage of the clutch housing with pieces being expelled with considerable force. This failure results in extensive damage to the drive train. Any clutch which has been overheated in this manner should be disassembled and checked for cracked parts. If there is any question as to the reuseability of the parts, replace them.
If the clutch is damaged to the point of a burst failure, expelled pieces can cause personal injury to anyone in the immediate area. Proper safeguards must be followed to prevent accidents.