Screw It!
This is a bulk handling forum and your question has got sod all to do with bulk handling.
In the background, your seniors are to blame. Either they haven't told you all the facts, probably because they don't know what the're doing or
else they are covering their posteriors by putting you in the firing line. Present your calculation and let them decide. It is the owners' money they're spending. Out of spite: I'd fully agree with making them splash out, on behalf of the owners, sizing about three steps up if they don't know what they're about.
I hope that is all you'll get out of this bulk-online forum, otherwise we'll be deluged with questions straight out of Machinery's Handbook: even if it is edition 26. ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Re: Measurement Of Torque In Motor
The data sheet of the motor should have a speed torque curve.
Otherwise, it takes a torque sensor between the motor and the load. Not something you can do on a shoestring budget - but looks like you have gone far farther than that. ■
Re: Measurement Of Torque In Motor
Hello,
From the information mentioned by you, possibly it seems you are designing push - pull screw mechanism to create certain thrust (force).
1) Decide resisting force along screw axis (it originates from the object).
2) Refer mechanical engineering text book, chapter mechanical jack. They give formula for required torque to operate (turn) screw when resisting force is known. Choose correct pitch, lead angle, etc. so that screw remains self locking. Also consider applicable friction coefficient in relation to materials and lubrication.
3) Your selected motor (or drive) torque should be larger (right from starting to steady state operation) than the resisting torque. Refer torque - speed graph of motor manufacturers.
The above design procedure is well known and routine. Screw mechanism basic principle is as if one is pulling (sliding) the object on inclined up - down path, synonymous to lead angle.
Ishwar G. Mulani
Author of Book : Engineering Science And Application Design For Belt Conveyors (new print November, 2012)
Author of Book : Belt Feeder Design And Hopper Bin Silo
Advisor / Consultant for Bulk Material Handling System & Issues.
Pune, India.
Tel.: 0091 (0)20 25871916
Email: conveyor.ishwar.mulani@gmail.com
Website: www.conveyor.ishwarmulani.com ■
Re: Measurement Of Torque In Motor
It was very nice to go through this thread. It is very useful and learning one for me. It is my ever first post on this board. Feeling happy to have such a useful discussion board 
■
Torque On A Plate Inside A Circular Pipe
Dear Team
I am currently working on a project and to select a actuator, i need to calculate the torque on the surface of a circular plate inside a circular pipe.
On what basis can I go ahead with such calculation?
There is air-flow in the pipe whose characteristics are known. I just want to know how to calculate the torque required to turn the plate by 90 degrees
Thanks in advance
Vineet ■
General Kinedynamics
Dear Vineet,
you need to elaborate the kinematical and dynamical model of your application.
This is mathematics and applied physics, parameters to be known:
rotational inertia, external resistances to be applied, speed of rotation to be achieved, acceleration & deceleration characteristics.
The torque requirement is the consequence of the sum of the resistance torques (resistance against rotation from bearings, friction, inclination etc.) and the required acceleration torque to get up to required speed.
Some engineering handbook should provide you the basic formulae and modelling strategy.
What i cannot fathom right now is the influence of the airflow, there you might need more specific research to be done.
--> It is always a good idea to illustrate such an issue with a sketch!
Regards
R. ■
Measurement of Torque in Motor
Dear All,
I have selected a series of motors, which are costly enough to buy even once. We need it for a lead screw mechanism, which needs to push a object of weight (or Force ) of 15Kg. The general formula for measurement of the torque i have found in internet is
Torque= r x F.
where is the torque vector
r is the displacement vector (a vector from the point from which torque is measured to the point where force is applied),
F is the force vector.
The (Torque) value of the motor is between the range of 0.48-1.47 Nm (SI unit of Torque) and it suits my application well.
The value of r is 10mm or 0.01m and the force is 15Kg.
I have calculated using this formula, and as stated above it suits my application well. But my seniors want to be confirmly sure, whether these are the only factors required to measure the torque of the motor. And since this motor is very costly , I too want to be sure beyond doubt.
If there are any other factors required, to be taken into account for the calculation of motor torque, kindly mention, along with its formula.
Thanks and Regards,
Vignesh ■