What forces act on bolts of a rotating coupling?

Question

I am trying to solve an engineering problem and i need the solution of this.
I want to calculate the shear and tensile stresses acting on bolts of a rotating flexible coupling. The coupling is mounted to an engine crankshaft by these bolts and the opposite flange of the coupling connected to another shaft that drives a compressor. All i know is that shear stress can be obtained from the torsion formular using the engine torque and that some of the components of tensile stress is the bolt preload and bending moment.
I now want to know if there are other force components that contribute to the tensile and shear stresses. One of them that i have thought about is the centrifugal force due to the coupling mass but i am not quite sure about it.

Any assistance will highly be appreciated.

Answer 1

Misalignment, even on a microscopic scale, causes sheer stress on the bolts. Misalignment can occur both as an angular error and a pure displacement error where the axis of rotation has a linear displacement. Applied motor torque and the stress due to tightening the bolts are two obvious sources of bolt stress. In a well designed coupling angular and linear misalignment will not cause high stresses; in fact, that is the entire purpose of the coupling -- to protect the bearings from being overloaded due to misalignment.

Answer 2

Out of the torque transmitted you calculate the shear force each bolt is subjected to. Bolts are tightened and that subject them to tensile stress. You only consider these two prime effects and forget about the rest because they are negligible.

Answer 3

Hi so you need as wealth of knowledge about the bolt size and tensile strength and shear force required the amount of power being transmitted through the coupling.

Answer 4

Do a free body diagram of the coupling at different positions thru it's motion. For one thing, the force due to gravity will vary (although the magnitude is probably so low that this can be neglected). Other potential sources of loads includes vibration, thermal stress, the torque on the bolts, and probably other things.