In this project, the objective is to create a speed reduction system, which is utilized to decrease

rotational speed while enhancing output torque. Speed reducers find applications across various

industries, including transportation, construction, mechanical processing, and others. They

typically consist of multiple shafts and gears. The primary purpose of a speed reducer is to regulate

both speed and output torque. Fig. $1$ illustrates a typical speed reducer, comprising an electric

motor, shafts, gears, pulleys, bearings, a belt, and a chain. The dimensions are detailed in Figure

$1,$ and the gear diameters are provided in Table $1.$ The pressure angle between the gears is $20$

degrees $($Fig$.2).$ The force analysis of the pulleys is depicted in Fig. $3,$ leading to the derivation of

two pulley formulas $($F$1$ F$2=823\mathrm{.}63$ and F$1/$F$2=1\mathrm{.}7287,$ with $\backslash$delta $=11\mathrm{.}536$ degrees$).$ Additionally,

the force analysis of the chain is presented in Fig $4($where one side of the chain experiences zero

force$).$ The electric motor has a power rating of $15$ kW and operates at an angular speed of $1450$

rpm$.$ Furthermore, the power transfer between Gear C and Gear D accounts for $70\%$ of the total

power.

You are asked to complete the following design tasks:

a$)$ Choose a motor for speed reducer from catalogue.

b$)$ Draw the free body diagram $($FBD$)$ of each shaft.

c$)$ Calculate forces exerted on each bearing.

d$)$ Draw shear force and momentum graph for each shaft.

e$)$ Calculate rating life for each bearing $($the bearings work for $10$ years and $8$ hours per day$).$

Calculate load capacity of each bearing for ball bearing and roller bearing.

f$)$ Choose material CK$60$ for shafts and based on momentums obtained from previous parts,

compute the diameters of each step of the shaft $($Factor of safety $($n$)$ is $2.$ D$/$r$=1\mathrm{.}1,$ r$/$d$=0\mathrm{.}05$

$,$ r$=0\mathrm{.}1).$

g$)$ Choose bearings from SKF bearing catalogue.

h$)$ Draw a technical drawing for each shaft.

i$)$ Draw the whole equipment in CAD Software as $3$D$.$