For 1040 hot rolled steel The ultimate tensile strength is :

However the Tensile yield Strength is:

In this case, this steel would not be suitable for the pins

For Type 301 cold rolled stainless steel:

And the Tensile yield Strength is:

Therefore it appears that stainless steel can be used for the pins to withstand the shear

stresses involved.

Shear stress Part 3

In this analysis we will determine if the shaft pin that is

secured into the shaft will shear at the maximum

torque limit. The shaft pin is located a distance from

the center of the shaft which is:

The maximum torque is obtained from the previous analysis:

The resulting force at the distance specified is calculated using the equation:

The minimum cross sectional area of the shaft pin is determined from the diameter:

Therefore the maximum shear stress acting on the pin is:

If we compare this value to the above material strength values for steel

and stainless steel it is evident that either of the materials could be used.

However, considering that this is also a very small component and

the amount of error in our approach and calculation is unknown,

it may be a wise decision to use stainless steel to compensate

for any possible error

Seizure Recovery System for Fuel System Distributor

Concept #4

More Shear Stress Analysis

This analysis will take into account the forces acting on the pin that holds the shaft disk to the shaft pin. the intent is to determine whether the forces encountered during a seizure will shear the small pin. Again we assume the maximum torque to be:

We can picture that on the onset of the seizure the small pin

will remain stationary with the disk and the shaft pin will

try to keep rotating. (Hopefully this will not be the case, but to

determine the maximum shear force, we will assume this).

Therefore, given the distance from the center of the fuel drive

shaft to the point of contact between the disk pin and the shaft

pin, the maximum force acting on the pin can be determined:

The Force located at this point on the

shaft can be calculated using the equation:

This force is acting at an angle to the pin. If we take the

component of this force that is acting normal to the pin, the

maximum shear force can be calculated.

Therefore the shear stress on the pin is:

The diameter of these pins must be given to determine the cross sectional area and the resulting shear stresses in the pins.

The shear force on the pins will depend on the angle of the disk and the Force from the maximum allowable torque of the shaft. An angle of 45 degrees is a good approximation

Depending on the material chosen for the pins, this design may or may not hold up to the required torque levels.