A countershaft has a helical gear $($B$),$ a bevel gear $($D$),$ and two supporting $(1)$

Forces act at $375-mm$ dia.

$(2)$

bearings and $C$ as shown in Figure. Loads acting on the bevel gear are

known.

Forces on the helical gears can be determined. Shaft dimensions are

known. All shoulder fillets have a radius of $5$ mm $.$ Only bearing A takes

thrust. The shaft is made of hardened steel. All$-$important surfaces are

finished by grinding.

$($a$)$ Draw load, shear force, and bending moment diagrams for the shaft in

the $xy$ and xz planes. Also draw diagrams showing the intensity of the axial

force and torque along the length of the shaft.

$($b$)$ At points B$,$ C$,$ and E of the shaft, calculate the equivalent stresses in

preparation for proper diameter determination.

$($c$)$ For a reliability of $99\%,$ determine the diameter of the shaft at all points

including $B,C,$ and $E.$ The safety factor is considered as per designer

comment but it shall be greater than $1.$

$($d$)$ Design the relevant key for keyway at B and D$.$

$($Note: Each group shall choose a different material and other designing

parameters like safety factor comparing to others$)$