1 Lec MDP Introduction

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<ul><li><p>8/8/2019 1 Lec MDP Introduction</p><p> 1/4</p><p>1MEA05 Machine Design Practice</p><p>1 of 4Nirma University of Science &amp; Technology</p><p>Institute of Diploma StudiesDepartment of Mechanical Engineering</p><p>M. J. SoniLecturer in Mech. Engg.</p><p>Lecture: 1 Introduction to Machine Design</p><p>Objectives</p><p>! Defining Machine</p><p>! Classification of Machines</p><p>! Defining Machine Design</p><p>! Types of Design</p><p>! Design Process</p><p>MachineAs per the encyclopedia of Britannica, Machine can be defined as below.</p><p>Machine is an object, having unique purpose, that replace or augment (enhance) the human oranimal effort for the accomplishment of physical task</p><p>Thus machine is a device, which will be useful to human being to achieve some useful purpose inbetter manner. This broad definition will covers the simple devices like pulley, levers, wedge, wheelscrews (five basic simple machines) and the complex mechanical systems like Airplanes, Largeships etc.</p><p>One another way of defining machine is</p><p> Machine is a combination of mechanisms and other components that transform, transmit or usethe energy, force or motion for the specific purpose</p><p>Machines can be classifies as below</p><p>Machines for generating Mechanical EnergyThese are the machines known as prime movers. These machines convert some form of energy into mechanical energy.Steam engines, I.C. Engines, Gas turbines are examples of prime movers.</p><p>Machines for transforming mechanical energy.These machines are known as converting machines. These machines convert mechanical energyinto another form of energy.Electric generator, Hydraulic pumps are the examples of converting machines.</p><p>Machines for utilizing mechanical energyThese machines receives mechanical energy and deliver and utilize it to perform some useful work.Machine tools like lathe, milling machine etc. are the examples of these types of machines.</p><p>Machine DesignThe word design came from a Latin word designaremeans to designate or mark out.</p><p>Design can be defines as</p><p>Intellectual activities, which leads to organize the human ability and other physical resources tocreate things to satisfy the human needs</p></li><li><p>8/8/2019 1 Lec MDP Introduction</p><p> 2/4</p><p>1MEA05 Machine Design Practice</p><p>2 of 4Nirma University of Science &amp; Technology</p><p>Institute of Diploma StudiesDepartment of Mechanical Engineering</p><p>M. J. SoniLecturer in Mech. Engg.</p><p>This is a broad definition, which will cover the different areas like textile design, architectural designinterior design for house etc.</p><p>Engineering design is a subset of design, which can be defined as</p><p> Engineering design is an iterative decision making activity to create plans by which resources are</p><p>converted into engineering system , process or devices to perform some desirable functions</p><p>Machine design is a branch of engineering design, which primarily concerns with the systems bywhich energy is converted into useful mechanical forms.</p><p>In a way machine design is nothing but a process of creating useful device or system which arecalled machined by application of the knowledge of different core areas of mechanical engineeringlike mathematics, kinematics, static, dynamics, strength of material, engineering materials andengineering drawing.</p><p>Types of Design</p><p>Machine design can be broadly classifies in following types</p><p>Adaptive designIn most of the cases the designer will adapt the existing design and then modify it and make a newdesign. These designs are known as adaptive design. In this types of design less speciaknowledge or skills are required. The final output of this type of design process is more or lesssame as the original design with some minor modifications. For example, designing a bicycle withspeedometer fitted on it can be told as an adaptive design.</p><p>Developed designIn this type of design designer start with the exiting design and developed a new design based onthe existing design. But the final outcome of this process is totally different than the original design</p><p>This design process needs more scientific training and special knowledge compare to adaptivedesign. For example, development of a washing machine with whirling mechanism from the originadesign of rotating mechanism can be told developed design.</p><p>New designIn this type of design totally new machine is invented using the basic principles of science. Foexample when conductor is moving in the electric field, electric current will be induced in theconductor is a principle of science and designing an electrical generator based on this principle iscalled new design. This design process requires high level of creativity as well as expertise in therespective areas.</p></li><li><p>8/8/2019 1 Lec MDP Introduction</p><p> 3/4</p><p>1MEA05 Machine Design Practice</p><p>3 of 4Nirma University of Science &amp; Technology</p><p>Institute of Diploma StudiesDepartment of Mechanical Engineering</p><p>M. J. SoniLecturer in Mech. Engg.</p><p>Machine Design ProcessMachine design cycle is shown in the following block diagram</p><p>1. Need Generated</p><p>At this stage need is generated from the resources like market survey.</p><p>2. Preliminary Need Statement</p><p>Need</p><p>PreliminaryNeed Statement</p><p>Need Analysis</p><p>Generation ofIdeas</p><p>Evaluation</p><p>DesignDevelopment</p><p>Evaluation</p><p>Detailed Design</p><p>Prepare Master Assembly Lay</p><p>Subassembly Design</p><p>Component Level Design</p><p>Design for Manufacturing</p><p>Standardization and OptimizaPrototype Building &amp;</p><p>Testing</p><p>Evaluation</p><p>Design Drawing</p><p>Yes</p><p>Yes</p><p>No</p><p>No</p><p>Yes</p><p>No</p></li><li><p>8/8/2019 1 Lec MDP Introduction</p><p> 4/4</p><p>1MEA05 Machine Design Practice</p><p>4 of 4Nirma University of Science &amp; Technology</p><p>Institute of Diploma StudiesDepartment of Mechanical Engineering</p><p>M. J. SoniLecturer in Mech. Engg.</p><p>From the raw need Preliminary need statement is prepared with all the required functionaspecification.</p><p>3. Need Analysis</p><p>Need is analyzed in with respect to feasibility.</p><p>4. Generation of Ideas</p><p>Different ideas are generated with different mechanisms and sketches are prepared. Thisideas are evaluated with respect to design requirement and finalized.</p><p>5. Design Development</p><p>From finalized idea, design is developed and once again evaluated against need andfeasibility.</p><p>6. Detailed Design</p><p>At this stage detailed design is created, which involves selection of materials, deciding theshape and size of components, manufacturing consideration, standardization etc.</p><p>7. Prototype Building</p><p>At this stage prototype is developed based on detailed design and tested for the functionaand other operational parameters.</p><p>8. Design Drawing &amp; Production</p><p>After the evaluation of prototype, final drawings are prepared and released for theproduction.</p><p>References</p><p>1. Design of Machine Elements - C. S. Sharma &amp; Kamlesh Purohit2. Machine Design - P.C. Sharma &amp; D. K. Agrawal3. Machine Design - T. V. Sundararaja Moorthy &amp; N. Sanmugam4. Machine Design - R. L. Norton</p></li></ul>