Gearbox projectThe creative journey

Design Criteria & ConstraintsMaterial

1 A4 sheet of acrylic 3mm thickness

Glue

string/cord

Minimum performanceLift at least 8kg

Lift up to at least 0.5m

Powered by a DC electric motor

Mounted on a plate that will be secured by studs and nuts providedNo washers can be used

IdeasPlanetary gear systems

Grinder gears

Extreme reduction gear sets

Cycloidal gear system Extreme gear reduction11 million to one

http://3dprint.com/wp-content/uploads/2015/07/Untitled20.png

Why use spur gear in this project?Simpler design, allows for more effort to be put into refinement.

Compact and simple to construct

Spur gear have a high power transmission efficiency

Less chance and easier to spot for fault

ModelWe used meccano gears with a similar sized motor to see how it performs

Reduction was about 125 to 1

Lifts 4 kg, then the string broke

Flawed design

Gearbox initial design concept Utilize spur gear

Housing for the gear hold together by box joint

Two shaft for gear

Hole for mounting

Relevance and effectivenessImplements conventional knowledge, allowing for more effective use of work time.

From previous knowledge it does the job.

Fits within given parameters for project.

Works.

Safe; will work in conjunction with housing for safety.

Materials and design will provide enough operating hours for the task required.

ProblemisationLess materials used, simpler design (less room for mistake or error).

The solution shows how existing solutions could be improved.

Predictable behaviour..

Preliminary calculationsTime for ascent: sqrt[(2hm)/dF]=t, from s=ut+1/2at^2

Where h=height for weight to ascend, m=mass of weight, dF=[T(out/r(finalShaft)]-mg.

Power Output: P=VI=ωΤ

Where P (watts)=output power, V (v)=input voltage, I=input amperage, ω=motor shaft speed, Τ=motor shaft torque

ω1/ω2=d1/d2

Where ω=angular velocity, d=pitch diameter

Ta/Tb=Na/Nb

Where T=torque, N=number of teeth

Aiming for ~1:4400 ratio for motor to lift 8kg with maximum efficiency (+10% output torque)

Fin.

Oliver Morton

Stefan Radulovic

Son Trinh