Mech 3002 explanation

MECH 3002 Project
This project aims to provide the students with hands-on experience in design and selecting appropriate
machine elements. The students will be required to design a reduction gearbox for an electric motor
shown in Figure 1. The motor model can be downloaded from cuLearn. The reduction gearbox needs to
be modelled in Fusion 360 and accompanied by engineering drawings that include the appropriate
tolerances.
Electric motor specification
• Power: 1.5kW at 1800 RPM
• Maximal dynamic radial load at shaft: 2kN
• Maximum static radial load at the shaft: 1kN
• Maximum axial shaft load: 0.8kN
Reduction gearbox requirements
• The output shaft rotation need to be reduced to 600 RPM
• Maximal dynamic radial load at output shaft: 2kN
• Maximum static radial load at the output shaft: 1kN
• Maximum axial output shaft load: 0.8kN
• The output shaft centre needs to be on a horizontal line that goes through the motor shaft centre,
but the distance from the motor shaft can be adjusted to fit your design. The output shaft needs to
be parallel to the motor shaft
• The output shaft diameter needs to be 12mm
• The gearbox housing cannot interfere with the base plate
• The gearbox housing needs to be attached directly to the electric motor
1
Figure 1. Dimensions in mm. Other dimensions can be
determined from the model. Base plate
Horizontal line on which
the centre of output shaft
needs to be
• During the assembly, the gearbox will be filled with lubricant, and therefore leakage needs to be
prevented during the operation
• Only 250 gearboxes will be produced
• The mass of the reduction gearbox should be reduced as much as possible
• The electric motor and gearbox will drive a water pump 5 days per week, 10 hours per day, 45
weeks per year for at least 7 years before being replaced.
Design procedure:
Each student as to design a reduction gearbox for the electric motor based on specification given above.
A 3D model of the motor is available on cuLearn. The gearbox needs to be designed in Fusion 360 no
alternatives are allowed. Proper engineering drawings need to be generated, which included appropriate
tolerances. The tolerances and fits should be selected according to ISO 2768-1 and ISO 286.
Most of the required machine elements can be downloaded directly into Fusion 360 from McMasterCarr.
All the required machine elements need to be included in the Bill Of Material (BOM) in an
assembly engineering drawing. There might be some additional machining and heat treatment required
on parts imported from McMaster-Carr. These changes need to be documented in engineering drawings.
March 15. 2021 will be the design freeze where you have to submit your Fusion 360 gearbox assembly.
After the design freeze, only small changes to the gearbox design will be allowed.
Design report:
The most important aspects of the project is your design and the proper selection and specification of the
required machine elements. Therefore only a short report will be required which should not exceed 2
pages. Pictures and the engineering drawings go into the appendix. In addition, the following will need
to be included:
• Title, your name and student number and a short summary (120 words max.)
• Briefly explain your gearbox design, which should include:
I. material selection
II. stress analysis if required (in the appendix)
III. how you prevent lubrication leak
IV. how it is attached to the electric motor
V. how the gearbox will be manufactured
• Briefly justify your choices of gears. Include all necessary calculations in the appendix. Briefly
describe any machining that may be required if you use stock gears.
• Briefly justify your choices of other machine elements, such as bearings and bolts, required for
your design. Include all necessary calculations in the appendix
Submit the project report as a PDF to cuLearn. Please share your Fusion 360 assembly with the TAs.
The engineering drawings with the proper tolerances need to be attached to your project report.
NOTE: Include all applicable calculations we cover in the course for the machine elements to justify
your selections. FEA will only be considered if you show with an analytical calculation that your
model assumptions and results are correct.