Innovation in Ceiling Fan Design

A mechanical engineer learns everything you need to know in school.

I agree, Bill, if you are referring to his second question. A qualified, university-trained, degreed engineer (ABET-accredited program) should be able to calculate the stress at any point in his moving object (FET might help and make the calculating task a little easier). Too often we see "designers" (CAD drafters) or "engineering technologist" (even with non-engineer BS degrees) who are good at their initial work, "moved up" into "Engineer" positions. This is a perfect example of the "Peter Principle". Often, this is not a problem, as their work seldom requires "outside the box" thinking or complex mathematical calculations or problem solving, or even application of basic engineering and physics principles.

If Mr. "preetam hosmani" does not have a BS degree from an ABET-accredited program, then my answer would be to consult a "real" engineer! If he does have the degree, then shame on him for even asking! I would like to see him (truthfully) respond with what his qualifications are.

As to the first question, it obviously is not a simple task, or fan manufacturers would have done it long ago. It cannot simply be a question of mechanics only. There are surely cost and other issues which enter into the question. There ARE very large bearings which could provide stability in a single unit, but they would hardly be practical for a ceiling fan design from a cost, weight, or esthetic standpoint.

The key reason that two (or more) bearings are used for motors and motorized equipment is that it is much less expensive and practical to provide stability using two small bearings spaced apart on a shaft than one large one. Additionally, ceiling fans must support axial (thrust) loads for weight, as well as radial (vibrational) loads. However, the keys to reducing the size and cost of a one-bearing design would be to locate your centers of mass (the motor components and the fan blades) as close together axially as possible, hopefully even co-axial and concentric. If these masses were balanced extremely well, there would be little if any vibration and only a slender hollow shaft to resist torque, support the weight, and to carry power and control lines, would be required to reach the ceiling.

Alternatively, and here is where thinking outside the box helps, an open framework could be designed, which would provide more stability for the single bearing with multiple ceiling anchoring points, and the motor components and fan blade components designed to counterbalance each other on opposited sides of the framework-mounted bearing, like two children of nearly the same weight sitting motionless astride a "teeter-totter". Again, basic engineering mechanics can be applied to acheive such a design. Would such an "oddball" design be accepted in the marketplace? Difficult to tell. Send me my royalties if it succeeds!

"A mechanical engineer learns everything you need to know in school. " Your kidding right? The engineering world is way bigger than any university. I got twenty five years experience and still learn somethink new everyday. You freash out of school?

preetam hosmani, try http://www.engineersedge.com/wwwboard/wwwboard.htm l they don't care about degrees, only solutions.