Torque required to rotate this wheel?

In summary, the individual is an electronics engineer who is weak in mechanical parts and is seeking help with rotating a 30kg wheel with a diameter of 60cm using a single phase AC motor at 30-60 rpm. They are unsure of the torque required and the motor rating. The conversation discusses the importance of torque in maintaining speed and suggests measuring the torque needed. The individual also mentions using a microcontroller and relay to alternate the rotation of the wheel. The expert advises measuring the torque needed and suggests using a gear reduction for a smaller motor. They recommend using a 0.25hp motor and measuring the torque to determine the required motor rating.
  • #1
ravinaval
3
0
Dear experts,
I am an electrOnics engg and weak in mech parts .
please refer to the attached images of this hand machine,
The wheel at the top weighs 30 kg and is rotated through hand because of which the horizontal plate attached at the bottom moves down and cuts objects using die placed.

I want to rotate this wheel using single phase Ac motor at around 30-60 rpm but I have no idea of torque required and the rating of motor to buy.
Can anybody please help.
Wheel weight -30 KG
Wheel diameter - 60 cm

Thanks in advance, Please help
 

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  • #2
The net torque required to turn a wheel at a constant rate is zero. Torque is a kind of force - do you remember Newton's Laws?

Losses in the mechanism tend to depend on speed, this is why you need a non-zero applied torque to maintain a constant speed. You want to use a motor to apply some torque. What is important here is how fast you want to get up to that speed - you'll want a throttle on the motor to keep it there.

Bottom line - the information is not enough to do a calculation - we need to know about the lubricant and the contact points and so on as well. You'll have to measure the required torque or the losses.
 
  • #3
Thank Simon for replying.
 
  • #4
Hi Simon,

I m planning to rotate the above wheel clockwise for 360 degrees and then anticlockwise for next 360 degree and repeating this pattern alternately, so definitely there will be some torque required.
This alternate rotation I will be doing eith the help microcontroller and relay.

If you can just give a rough idea about what rating motor should I buy, whether it is 1HP or 2HP.
Or whether 2 HP mottor will be sufficient to rotate the wheel ?
 
  • #5
I think it would be easiest to just measure the torque needed as the press is applied by hand. The highest torque will be right towards the end of the stroke, and will be determined by how much output force you need to apply, and the ratio and efficiency of the screw.

If you can use a digital torque wrench to drive the wheel to see how much torque is being used, you will have a number to work with.

If you put a gear reduction on it, a much smaller motor can be used, of course, and you will probably be best off just replacing that heavy wheel with a lighter large diameter gear, pulley or sprocket, and using that as your reduction gear/belt/chain drive.
 
  • #6
ravinaval said:
Hi Simon,

I m planning to rotate the above wheel clockwise for 360 degrees and then anticlockwise for next 360 degree and repeating this pattern alternately, so definitely there will be some torque required.
Of course there will be - you are not paying attention: torque causes acceleration.

This alternate rotation I will be doing eith the help microcontroller and relay.

If you can just give a rough idea about what rating motor should I buy, whether it is 1HP or 2HP.
Or whether 2 HP mottor will be sufficient to rotate the wheel ?
Probably a 0.25hp motor will turn the wheel - slowly.
Please pay attention - to know about the torque required, we need to know about how still the wheel is and how quickly you want it to change it's speed.

You are best to just measure it.
 

Related to Torque required to rotate this wheel?

1. What is torque?

Torque is a measure of the force required to rotate an object around an axis or pivot point.

2. How is torque calculated?

Torque is calculated by multiplying the force applied to an object by the distance from the axis of rotation to the point where the force is applied.

3. What factors affect the torque required to rotate a wheel?

The factors that affect the torque required to rotate a wheel include the size and weight of the wheel, the friction between the wheel and its axis of rotation, and the force applied to the wheel.

4. How is torque related to rotational inertia?

Rotational inertia, also known as moment of inertia, is a measure of an object's resistance to changes in its rotational motion. The greater the rotational inertia of an object, the greater the torque required to rotate it.

5. How can torque be increased or decreased?

Torque can be increased by applying a greater force or by increasing the distance from the axis of rotation to the point of application. It can be decreased by applying less force or decreasing the distance from the axis of rotation to the point of application.

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