Fan vibration and its effect on fasteners

[imagineersinc]

I am looking for some good videos online regarding simulation analysis of a fan. A bit about the fan DC Fan Ball Bearing 220MM 48V 103W 6500RPM (PABST 2218F/2TDH) . There would be 10 mounted to a fan panel. Each fan itself would be mounted to its own smaller square plate using 4 x M4 nylock nuts and bolts. The smaller square plate would then be mounted using thumbscrews to a larger panel. My question or concern it that if these fans are running 24-7 for say 5 years on this setup that the thumb screws may eventually start to vibrate and back out. Maybe its an invalid concern but would like to try and simulate this if not figure it out even by hand using solidworks. Suggestions? Comments?

 

[Andrew ONeill]

You're unlikely to be able to model this in any meaningful way. Unless the specific brand of thumbscrew supplier has completed testing to determine the allowable 5 year vibration level on a faster setup close to your proposal (which is highly unlikely).

In practice, I'd suggest applying a liberal amount of liquid thread locker to the thumb screws and call it a day.

 

[drawoh]

imagineersinc,

If you plan on leaving this thing in place for five years, why do you need thumbscrews?

Is all the vibration coming from the fans?

Check out Bolt Science and their website. Look for books by John H. Bickford.

People have done all sorts of testing to see how bolts and screws come loose. In summary, forget lock washers, they don't work. Work out the highest possible bolt tension, and use torque wrenches to make sure you achieve this. Forget the thumbscrews.

 

[imagineersinc]

Thumb screws are so that in case a fan fails it can be removed easily without tools . I know it may not be ideal abs maybe prove to be the least best choice but that was the direction I wanted . I could use nuts with nord lock washers or even just some washers and nylon nuts just not as nice from a user experience . If that makes sense so I’m trying to get the best of both worlds

 

[drawoh]

If a fan fails, your customer will need the correct new fan. You need a fan kit, which can include a screwdriver or hex key.

Does your fan have a plastic or metal body? If you are clamping through both flanges of a plastic body, you cannot use maximum screw tension. Maximum screw tension, good. Nordlock washers, good. A set should be included with the fan kit, along with the correct fastener and hex key.