A machine is the combination of interrelated bodies, links or elements, which are characterized by being resistant and in general rigid. These links are so chosen and arranged that in operation they can collectively either transfer other forms of energy into mechanical energy or receive mechanical energy power, from external power from external source, transmit and modify it, thus doing work in performing some task.
MACHINE DESIGN: It is the creation of new and better machines and improving the existing ones. A new or better machine is one which is more economical in the overall cost of production and operation. In designing a machine part or a machine as a whole, all types of forces stresses involved should be given due consideration so that it with stand under these forces without rupture or undue distortion.
DESIGN CONSIDERATIONS: The following are some general characteristics, which influence the design of elements or the entire machine system.
- Thermal Consideration
- Surface Finish
GENERAL PROCEDURE IN DESIGN
In designing a machine, there is no specific rule: it can be done in so many ways. However, generally a procedure to solve the problem can be adopted and follows.
- Firstly make a complete statement of the problem, clearly indicating the purpose of the machine to be designed.
- Select the possible groups of mechanisms, which will give the desired motion.
- Find the forces acting on each member of the machine and the energy transmitted by each member.
- Select the best material.
- Find the size of each member of the machine, considering the forces acting and the stresses within permissible limits.
- Modify the size of the member to agree with the past experience and judgment to facilitate manufacture.
- Draw the detailed drawing of each component and the assembly of the machine with complete specification for the material and manufacturing process suggested.