tomaspin
Mechanical
- Dec 11, 2002
- 52
I am currently looking at a drive belt noise problem on a 4 cylinder diesel engine, and on some installations there is a problem with belt squeal on the fan pulley, especially when shutting the engine down.
The dive belt is a flat ribbed type, and the belt is tensioned on what would normally be the 'slack' side of the drive. The wrap angle on the belt is between 65-78 degrees
As the engine slows down, the inertia in the fan starts to 'drive' the belt, which causes the belt to lose tension and the fan pulley starts to slip and squeal.
The belt squeal corresponds to the last 5/6 compression strokes before the engine stops.
The problem usually starts to occur after about 500 hours use, as the drive belt becomes conditioned. New belts have been used without success.
Our client wants us to look at using a torsionally soft crank pulley to limit the belt shock loads, however I am inclined to recommend that a second belt tensioner is used to maintain tension and improve the wrap angle on fan pulley, as this adresses the root cause of the problem.
Is this type of belt squeal common, and are there any other solutions to it?
Thanks
Tom
The dive belt is a flat ribbed type, and the belt is tensioned on what would normally be the 'slack' side of the drive. The wrap angle on the belt is between 65-78 degrees
As the engine slows down, the inertia in the fan starts to 'drive' the belt, which causes the belt to lose tension and the fan pulley starts to slip and squeal.
The belt squeal corresponds to the last 5/6 compression strokes before the engine stops.
The problem usually starts to occur after about 500 hours use, as the drive belt becomes conditioned. New belts have been used without success.
Our client wants us to look at using a torsionally soft crank pulley to limit the belt shock loads, however I am inclined to recommend that a second belt tensioner is used to maintain tension and improve the wrap angle on fan pulley, as this adresses the root cause of the problem.
Is this type of belt squeal common, and are there any other solutions to it?
Thanks
Tom