Posted: November 24th, 2015

Guided Gear Design for an Escalator

As part of your design, you will need to undertake the following tasks:
1-Estimate the loads imposed on the escalator;
2-Calculate the torque required from the gearbox;
3-Calculate the gear forces;
4-Determine the face width of the gears;
5-Assess whether the preliminary estimates for the gear size are satisfactory;
6-Suggest any modifications to the gear design if necessary;
7-List all assumptions.
8-Provide concluding marks for the selected design
You can use and ISO and BS Specification documents (provided) and a data table (provided) as a guide to help you design of the gears (e.g. face width, module, number of teeth). The design must meet the following constraints to be considered as optimised

Constraints must satisfy :

1-Diameter of pinion gear (d1) > 2 x Axial pitch (Pa)
2-Face width of the pinion gear (b) < Diameter of pinion gear (d1)
3-Actual contact stress (σH) < Allowable contact stress (σHP) (pinion gear)
4- Actual root bending stress (σF) < Permissible tooth root bending stress (σFP) (pinion gear)
5-Actual contact stress (σH) < Allowable contact stress (σHP)? (driven wheel)
6-Actual root bending stress (σF) < Permissible tooth root bending stress (σFP) (driven wheel)

You will be required to submit a report which describes the design challenges, as well as the approach that you have taken in designing each of the items. Any assumptions that you make should be mentioned in your report. The main body of the report should not exceed 3 pages in length. It would be appropriate to include a summary of your calculations (table 2) in your report, but detailed calculations should be attached as an appendix, rather than being included in the main body of the report.