1. [ Introduction ]……………………………………………………………………3 AW 2. [ Specification of chosen device ]…………………………………………….3 AW 3. [ Planning ]……………………………………………………………………..3 JB 4. [ Analysis of the system ]……………………………………………………4 AW
4.1. [ Wheel mechanism ]…………………………………………………………4 AW
4.1.1. [ DC motor analysis ]…………………………………………………………4 AW 5.1.2. [ Co-ordination of the wheels ]…………………………………………….8 AW 5.1.3. [ Belt drive ]……………………………………………………………..…...11 AW 5.1. [ Epicyclic gearing ]…………………………………………………………12 SS
4.2.1. [ Planetary Gears ]…………………………………………………………..12 SS 5.2.4. [ Calculating the Turns ratio ]………………………………………….....13 SS 5.2.5. [ Calculating the turns ratio for compound planetary gearing ]…….14 SS 5.2.6. [ Calculating the pulley RPM ]………………………………………..…...15 SS 5.2.7. [ Table of results ]…………………………………………………………..16 SS 5.2.8. [ Calculating the motor RPM ]…………………………………………..…17 SS 5.2.9. [ Calculating the torque input ]…………………………………….……..17 SS 5.2.10. [ Torque splits in the planet system ]………………………………..…..18 SS 5.2.11. [ Advantages of compound planetary gears ]……………………….…18 SS 5.2. Torque lifting mechanism………………………………………….…...20 JB 4.3.1. [ Co-efficient of Friction ]……………………………………….…………..21 JB 4.3.2. The Brush Mechanism…………………………………………..……….22 JB 4.3.3. [ The Lifting Mechanism ]………………………………….……………….24 JB 4. [ Conclusion in relation to a wheel motor analysis ]…………………...….26 AW 5. [ Evaluation ]………………………………………………………………………26 AW 6. [ References ]………………………………………………………………….....27 AW 7. [ Appendix ]………………………………………………………………………..27 AW
1. Introduction This report has been compiled as a part of the module Reverse Engineering for BEng Mechanical and Electrical Engineering at Inverness College. The aim of the module is to gain knowledge, skills and understanding of electro-mechanical system. The main objective is to carry out a hands-on investigation and analysis of chosen item within a group of 3 or 4 students.
2. Specification of chosen device
3. Planning
* 01/02/13 Choose which piece of equipment to reverse engineer * 08/02/13 Dis-assembled the robovac taking measurements and pictures * 15/02/13 Finished Dis-assembly of robovac , Then what elements of the Device were chosen to analyse further * 22/02/13 Assembled the robovac, started research into elements of the device that had been chosen to analyse further which were wheel mechanism including wheel co-ordination, epicyclic gearing and the Torque lifting mechanism * 01/03/13 Compile Presentation and start typing up of report * 08/03/13 Present presentation to class of peers, finish compiling report and assess colleagues through reviews * 15/03/13 Hand in report and completed colleague reviews
4. Analysis of the system
5.1. Wheel mechanism
M-288 has two wheels providing the locomotion. Wheels are spring-loaded so they are always pressing down getting a positive traction, even if the robot goes over the cables or moving from hard floor onto a carpet.
When the cover of the wheel was removed, the belt transmission appeared. There were two pulleys connected through square-section belt. The smaller pulley is attached to a motor while a bigger one attaches onto the wheel itself. This together with the planetary gearing transmits the motion from the motor to the wheel with the high torque and low speed.
4.1.1. DC motor analysis
The DC motor that runs the wheel was analysed. The product code or any sort of writing was not visible on the motor after dis-assembly. The shaft diameter was measured to be 2mm. The diameter of the motor itself is 24 mm. The motor has a
