Press fit question. 1

[spottedcow]

Im not a student (any more), but I have a question that involves a question from the supplementary textbook Link. The question on page four, says "the hub has a nominal thickness of 1/2 inch". Is this length, thickness of the wall on one side, or both sides (diameter-id)? Thanks...

 

[desertfox]

Hi spottedcow
Its the wall thickness on one side the hub.

desertfox

 

[spottedcow]

Thanks. Now, if I had a non uniform gear (thin rim as they call it in industry or offset rim) that I wanted an interference fit on a shaft (pinion), what is the protocol on wall thickness?

 

[MikeHalloran]

The protocol is: look it up in Machinery's Handbook.


Mike Halloran
Pembroke Pines, FL, USA

 

[desertfox]

Hi

If you mean gears like shown on this link:-

http://kmoddl.library.cornell.edu/model.php?m=420

then your interference fit needs to cater for the largest load the gear experiences during operation, I am assuming that your trying to ensure your gear doesn't spin on the shaft independently of being driven.

Can you put all your questions into one post rather than ask a new question each time, also give us much information as possible to your problem including any sketches or drawings/pictures

desertfox

 

[rb1957]

sorry, but "protocol" ? ... design requirements is much more intuitive, and leads you to ask (yourself) the right questions ...

what are the design requirements ? oh, that'll define a torque that joint needs to transmit. ah, so the question is what level of interference do i need to transmit X ft.lbs of torque ? har, hum ... i wonder if a google that if i'll get anywhere ? oh shucks, i'll just post something on eng-tips ... those smart guys'll figure it out for me ... (yes, we are mind readers)

Quando Omni Flunkus Moritati

 

[tbuelna]

spottedcow-

Since this website is about offering "engineering tips", here's a free and easy way to get a partial answer to your question: Get this free download that can be used with the free version of Google SketchUp to calculate section properties. Your cross section should include the hub wall thickness, web thickness, fillets, and rim thickness to the tooth root diameter. The gear teeth can be ignored since they do not contribute to radial stiffness.

On the other hand, if you'd prefer to become better educated by learning the fundamentals involved then I would recommend starting with Roark's 6th edition, sec. 12.4 Multielement Shells of Revolution.

Best of luck to you.