Crankshaft Mechanical Press

[Lohaar]

Hello guys,
I am a student and looking forward to getting detailed knowledge on complete calculations and formulas related to force, torque, etc. of a 6-inch crankshaft mechanical forging press. I want to know how to calculate the force generated by the crankshaft, along with torque and any other useful details about it. Can anyone please help me with genuine sources like books, PDFs, or any source where all this is mentioned?

Thanks and Regards.

 

[XR250]

A class in statics should be all you need.

I mean statics and dynamics

 

[3DDave]

First, if you mean a flywheel driven oscillating mechanical press -

Theoretically, near the bottom of the stroke, the force is only limited by the strength of the press and the elasticity of the press and the resistance of the material. If the press is considered to be perfectly rigid, unlimited strength, and the material is unyielding, the theoretical force is infinite.

The main feature of the process is to store energy in rotation of the flywheel and transfer that energy into plastic deformation of the material being worked. How much force actually is applied is generally limited by how much the work piece fights back.

As a practical matter, I think operators of such machines figure out rather quickly what works and what doesn't and will just move to a larger machine if required.

 

[BrianPetersen]

Fairly familiar with machines like this. As noted above, the tonnage applied infinitesimally surrounding bottom-dead-centre is infinite if deflections are not considered. The actual tonnage will be determined by what it takes to deform the workpiece during the last part of the approach stroke.

A critical part of the tooling set-up procedure on such equipment is the adjustment of the "shut height" so that the closest approach of the platens is what the tooling is designed for. Large mechanical presses have tonnage monitoring and limiting systems to mitigate damage, but it is still very possible to break stuff in a big hurry if one is not careful.

Large mechanical presses usually have an adjustable counterbalance system, which consists of a couple of big air cylinders connected to a big surge tank, and a means of regulating the pressure in the surge tank. The intent is for the counterbalance system to fairly closely offset the mass of the upper platen and the upper part of the tooling.

The energy that it takes to bang the workpiece into shape, comes from the flywheel, whose speed drops during the closing part of the stroke as the kinetic energy is transferred into changing the shape of the workpiece. The drive motor obviously re-accelerates the flywheel. The intent is that the motor has to supply the average amount of power through the stroke (offsetting the energy that it takes to deform the workpiece), the flywheel handles the peak.

The amount of energy that it takes to perform the working stroke, is workpiece and tooling specific.