Reference no: EM132172136
In this assignment, you are to work in a group of FOUR (4) students. Your group is to design a speed reducer that involves shaft, gears, key and keyway, etc. Upon completion of the assignment, each groups shall submit a project report. You are expected to solve the problems with engineering calculation as a team.
PROJECT BRIEF
Our client has several machines that need light duty power to operate properly. However,market available motors usually run at particular range of rotational speed. The machines require a slower speed than the motors when supply the power. To reduce the speed and consistently increase the torque, a speed reducer is introduced.
The following requirement must be satisfied by the speed reducer.
• Power to be delivered: 40 kW.
• Input speed: 2000 rpm.
• Output speed: 600 - 700 rpm.
• Input and output shafts extend 50 mm outside gearbox.
• Output shaft and input shaft in-line.
• Gear and bearing live >40000 hours.
• Infinite shaft life.
Scope of Supply:
Working in a team of FOUR (4), you are required to prepare a design proposal for the system of speed reducer.
Design Portfolio and Marking Scheme:
Working in the team, you are required to submit a design report which contains the following sections.
1. A design specification for the speed reducer, including drive shafts. (Please note that this is a design specification and therefore needs to provide details of what it is you are required to design it should therefore be written in the future tense. Your specification should include all limitations imposed upon the design by the conditions described or implied above as well as any further details you deem relevant. It should not include irrelevant details and must not be written as a product specification, i.e. NOT as a document which provides details of an already existing product).
2. From the speed reducer requirement above, determine the speed, torque, and gear ratiosbeing developed.
3. From the list of available gears in the market and taking account of the torque that each of the gears is required to transmit, select appropriate gears to provide the ratios needed to achieve the running speeds of the speed reducer with safety factors of at least 1.2 wear and bending. Please note that the ratios do not need to be achieved in a single stage only.
All gears used must be clearly listed and specified by part number, module, torque capacity and material type.
4. Taking into account of the details you provided in your design specification and the information provided in this design brief undertake a review of materials to determine a suitable material from which the hollow shafts might be manufactured. You are to discuss in your own words the rationale you have used for your selection and provide clear reasons why you have selected the material you have chosen. You need to choose three candidate materials and make your own final selection from these three and give reasons for your final choice.
This is an individual activity and you are required to submit an individual report for this section of the assignment. You are not to discuss this section of the report with other team members. Each material mustbe specified by either a British Standard or an ISO Standard. All relevant material properties for each of your choices must be given and the units used mustbe SI units. The use of imperial units is not permitted and will incur penalties by marks being deducted.
The Weighted Objectives Method is not to be used at this point in your report. The discussion above is all that is needed.
5. Using the Weighted Objectives Method select an appropriate material, from those previously suggested by the individual members of your group. You need to provide a brief but clear explanation of the objectives chosen and provide a clear rationale for the weightings you have set for each of the Objectives.
6. Using the material, you selected in Question 4, determine appropriate size for each of the hollow shafts by using force analysis. A shaft layout diagram needs to be provided in this section of your report to give an indication of the layout and to demonstrate that the required rotational direction has been achieved. All assumptions made in your calculations must be clearly stated.
7. Using an appropriate material (specified by a British standard), determine the necessary size of all standard keys and keyways for each shaft.
8. Give an overview of the manufacturing methods to be employed in the production of the hollow shafts. This is to include all features of the shafts includung the keyways. (Please note a detailed description of the methods used. All that is required is an outline of the methods that could be used to make these components.
This is an individual activity and you are required to submit an individual report for this section of the assignment. You are not to discuss this section of the report with other team members.All relevant material properties for each of your choices must be given and the units used must be SI units. The use of imperial units is not permitted and will incur penalties by marks being deducted.