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Gearing Motors

12/31/2006 2:27 AM

hey everybody... i just wanna ask about something almost known but I need information...

lets say that we have this plot:

where:
1)motor.
2) column shaft.

what i need to know whats the parameters which let me determine the lengths:
1) h the vertical length from the postion where the belt from the the motor links the shaft to the top.

2)d the horizantal length from motor to shaft.

with my best wishes

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Guru
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#1

Re: Gearing Motors

01/01/2007 4:36 AM

You have furnished nowhere near enough information for even the most general of cases, and therefore I can't begin to offer a formula to determine your two unknowns when you furnish no "knowns". A general formula may not be possible in any case.

Where are the bearings?

What HP/rpm and/or torque are we dealing with to use in determining the force on the column shaft from the belt?

What is the diameter of the column shaft?

Typically, we work from the other direction: we know what we have to drive off the column shaft, the rpms, and where we can locate bearings. We know if we are working with a fixed column shaft diameter or one that we select. We then calculate required pulley diameters (I'm assuming a pulley on the column shaft), based on required rpm and motor rpm, what size/type motor we need in terms of HP and starting torque, what kind of belt(s) we need to transmit this power, what bearings we need for the shaft based on their locations, mounting considerations, rpms, and both the side loads and thrust loads they will encounter. Minimum distance between the motor and the column shaft will then be able to be easily determined. The order of these things can vary, but somethings must be determined before some other things can. Other considerations are cost, design life, available space, etc.

What you are asking looks like something you conjured up to help you answer test questions, not any real world application.

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Power-User

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#2

Re: Gearing Motors

01/01/2007 9:09 AM

Your questions are out of line.

1) Height; your vertical length is what you design the shaft length to be......there is no formula for this equation.

If you use the base alignment of the drive motor pully, the perpendicular parallel plane of the pully on the drive shaft to the mounting base of the drive motor.

This gives your actual base start point/ reference point in your alignment. Now this is an actual reference point as the height of the belt being perpendicular to the start reference surface point. You now have a given plane parallel to the base reference surface.

Your first question makes no sence, due to the fact you have not given the start reference point of the shaft, nor the overal length of the shaft. Thus this question is irrellevent as per "the position where the belt from the motor links the shaft to the top". It does not matter on the vertical lenght. You design your overall lenght to what you need of the secondary drive shaft. Your pully is located on your shaft at the proper alignment of pully to pully, both being parallel of each other.

There for the length of your shaft can be any length you desire for your application. There is no none formula for this question because it is a non-functioning formula.

The only length/ height/ distance, required to know is the actual size of your primary drive pully to the turns ratio of your secondary pully. This is the important issue. Turns ratio for your governed RPM required to maximize your energy of the motor to the total out-put of required energy of the load, being a fan assembly, an extended drive axle for a conveyor belt, a transitional drive belt to transfer your shaft power source to drive an unknown factor of another equation.

Next is the requirements of this energy in action; is it to drive a vertical axial fan in a cooling shaft? Is this shaft being supported by "X" number of bearings. Your weight of the fan blade assembly verses bearing load factor, weight of shaft and overall load?

Remember, your base reference start point is the location of your primary drive pully. Then the secondary pully is parallel to the primary. This is the actual start reference point of the whole deal. Then you design everything from this new parallel reference point.

Your second question; " the horizontal length from the motor shaft"?, is determined by the diameter of you primary and secondary pullies, plus the direct distance from center line to center line of the parallel plane, motor : vertical shaft location, ( this distance is your design).

The parallel plane is the exact distance, and the diameter of the pullies is the outer rotational distance for the actual length size of your drive belts.

So to formulate this length, because this is the actual truth of your question..............what is the size or required length for my drive belt?

Because the length/(distance of shaft to motor axle) is set by you in your design.

You will take the distance of your parallel plane, center-line : center-line; the diameter of each pully on their perspective shaft, and calculate the total circumfrance of this new area you just created in your design.

Good luck..........

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#3

Re: Gearing Motors

01/01/2007 9:57 AM

Ask a futzy question,

Get fuzzy answers.

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Guru
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#4
In reply to #3

Re: Gearing Motors

01/01/2007 4:58 PM

A fuzzy question here?

How silly!

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Active Contributor

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#6
In reply to #3

Re: Gearing Motors

01/03/2007 4:00 AM

hey all..

First i wanna thank u for all information that u gave t me...

but i wanna say sth to Strilling and Greg:
well if u see that my question is fuzzy and silly, then y did ureply to it, u can just keep ur opinion for urself and go away, because now am sure that u dont know the answer... and no honey its not a test question..

anyway..

for lormaximo:

wht i want to design, is a system makes sth like pancackes (but in they called it Qataif in asia),

so what i need the system i drew b4, i designed the plate and the shaft and i w know the load over the bearings, and all information is with me... but wht i dont know is the location of the belt (this is just wht i need, the parameters which tell the location of the motor on the shaft),

the shaft length = 1m with 20 N load
the plate wil have 170 N load

best wishes..

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Guru
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#7
In reply to #6

Re: Gearing Motors

01/03/2007 11:44 AM

I have nothing further to add medo433q:

Your original question, coupled with your response to Stirling Stan and myself, plus the still sadly incomplete information you furnished, speak eloquently of your capabilities.

Good Luck my friend, (because you will certainly need it).

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Guru
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#5

Re: Gearing Motors

01/02/2007 8:46 PM

Fundamental Geometry needed ,medo433g:

  1. Centre to center distance between motor and shaft.
  2. Motor pulley OD
  3. Belt cross section drawing
  4. Do you plan to bring in the belt from above the open-ended fat shaft andengage onto the (tiny) motor's pulley
  5. Is the motor base rigidly fixed or on a hinged fulcrum(to lock later)

I think this PROBLEM ought to go to a Nursery School Class

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Greg G (3); LordMaximo (1); medo433q (1); MUKULMAHANT (1); Stirling Stan (1)

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