1. BK50A2200 Design Methodologies and Applications of Machine Element Design Lecture 1 Fundamentals of the systematic design approach D.Sc Harri Eskelinen

2. Common requirements for an effective design method are as follows: The method must be applicable to every type of design activity, no matter in which specialist field. The method must be applicable to every type of design activity, no matter in which specialist field. The method should facilitate the search for optimum solutions. The method should facilitate the search for optimum solutions. The method should be compatible with the concepts, methods and findings of other disciplines. The method should be compatible with the concepts, methods and findings of other disciplines. The method should not rely on finding solutions by chance. The method should not rely on finding solutions by chance. The method should facilitate the application of known solutions to related tasks. The method should facilitate the application of known solutions to related tasks. The method should be compatible with electronic data processing. The method should be compatible with electronic data processing. The method should be easily taught and learned. The method should be easily taught and learned. The method should reduce workload, save time, prevent human errors, and help to maintain active interest. The method should reduce workload, save time, prevent human errors, and help to maintain active interest.

3. MOST COMMON DESIGN APPROACHES Systematic Design Systematic Design Reverse Engineering Reverse Engineering Concurrent Engineering Concurrent Engineering Cross-technological Approach Cross-technological Approach Virtual Engineering ( Virtual Prototyping and Manufacturing) Virtual Engineering ( Virtual Prototyping and Manufacturing) Approaches Based on the Use of Integrated Product Teams Approaches Based on the Use of Integrated Product Teams Collaborative Design Collaborative Design

4. Briefly about Reverse Engineering 1 The process of duplicating an existing component, subassembly, or product, without the aid of drawings, documentation, or computer model is in many cases called as "reverse engineering". 1 The process of duplicating an existing component, subassembly, or product, without the aid of drawings, documentation, or computer model is in many cases called as "reverse engineering". 2 In reverse engineering the component is measured by a coordinate measuring machine or the surface profiles are laser scanned. As the geometry is measured, a dimensioned 3-D wire frame image is generated and displayed on a monitor. After the measuring is complete, the wire frame image is dimensioned. 2 In reverse engineering the component is measured by a coordinate measuring machine or the surface profiles are laser scanned. As the geometry is measured, a dimensioned 3-D wire frame image is generated and displayed on a monitor. After the measuring is complete, the wire frame image is dimensioned. 3 The component is then re-manufactured from a cost-effective foam or plastics, which could be coated with a specific material to test component’s performance. 3 The component is then re-manufactured from a cost-effective foam or plastics, which could be coated with a specific material to test component’s performance. 4 If any changes are needed to the geometry, they are easy to produce to the soft material. When the new prototype is ready, the new geometry can be read either with the CMM-technique or laser scanning again. 4 If any changes are needed to the geometry, they are easy to produce to the soft material. When the new prototype is ready, the new geometry can be read either with the CMM-technique or laser scanning again. 5 The exact geometry can be optimised by filtering the data to the CAD-modeller. Finally the required CNC-code for a real product is compiled with the CAM-module. 5 The exact geometry can be optimised by filtering the data to the CAD-modeller. Finally the required CNC-code for a real product is compiled with the CAM-module.

5. In mechanisms design one way to apply reverse engineering is to start e.g. from the required motion path of the mechanisms needed in the specific function of a machine. In mechanisms design one way to apply reverse engineering is to start e.g. from the required motion path of the mechanisms needed in the specific function of a machine. If we are able to draw at least a raw draft of the motion path, it usually gives the first ideas of adequate mechanism types. So the designing process starts from the "results" of “mechanisms analysis” (= one way to carry out mechanisms synthesis) - this could be called "reverse engineering". If we are able to draw at least a raw draft of the motion path, it usually gives the first ideas of adequate mechanism types. So the designing process starts from the "results" of “mechanisms analysis” (= one way to carry out mechanisms synthesis) - this could be called "reverse engineering". If the motion path and the selected mechanism type are known, it is possible to use computer aided means to 3D- simulate the mechanisms construction and its components and carry out the final dimensioning process. If the motion path and the selected mechanism type are known, it is possible to use computer aided means to 3D- simulate the mechanisms construction and its components and carry out the final dimensioning process.

6. Briefly about Concurrent Engineering Design The simultaneous interest of design and manufacturability makes up the CE Design. The transition from design to manufacturability is also reflected in the interaction of different CE Design intellectual activities (such as marketing). The simultaneous interest of design and manufacturability makes up the CE Design. The transition from design to manufacturability is also reflected in the interaction of different CE Design intellectual activities (such as marketing). Traditional consecutive process stages Simultaneous and parallel process stages Concurrent Engineering (CE), Simultaneous Engineering (SE), Parallel Engineering. Traditional Design Process.

7. Briefly about Cross-Technological Approaches The design engineer meets different areas of science, different human views, various industrial and technical goals and many environmental opinions.  See an example of mechatronics on the right. The design engineer meets different areas of science, different human views, various industrial and technical goals and many environmental opinions.  See an example of mechatronics on the right.

8. Briefly about Virtual Engineering Virtual Engineering includes at least virtual prototyping and manufacturing Virtual Engineering includes at least virtual prototyping and manufacturing Different kinds of simulations and visualisations are used to illustrate the propagation of the design process. Different kinds of simulations and visualisations are used to illustrate the propagation of the design process. By using virtual models it is possible to combine geometrical, physical, functional and manufacturability simulations of the product. By using virtual models it is possible to combine geometrical, physical, functional and manufacturability simulations of the product. In mechanical engineering also the main functions of the machine or the flow of the process could be simulated. In mechanical engineering also the main functions of the machine or the flow of the process could be simulated.

9. Worm gear Springs

11. Approaches Based on the Use of Integrated Product Teams Use of IPT’s is a practical way to carry out the cross-technological approach Use of IPT’s is a practical way to carry out the cross-technological approach The key members of the team for mechanical engineering are e.g. as follows: The key members of the team for mechanical engineering are e.g. as follows: experts on mechanical engineering experts on mechanical engineering designers (e.g. strength calculations and mechanisms design) designers (e.g. strength calculations and mechanisms design) experts on material science experts on material science experts on pneumatics and hydraulics experts on pneumatics and hydraulics experts on optics experts on optics experts on electrical engineering experts on electrical engineering experts on material science experts on material science experts on related industrial areas (medicine, paper and wood industry, steel industry etc.) experts on related industrial areas (medicine, paper and wood industry, steel industry etc.)

12. Briefly about Collaborative Design WBS= Work Breakdown Structure

13. SYSTEMATIC DESIGN Different researchers have emphasised either their own weightings of specific steps and phases of the design process and they have presented their own methodologies for the “systematic approach”. Different researchers have emphasised either their own weightings of specific steps and phases of the design process and they have presented their own methodologies for the “systematic approach”. The most common way to understand "systematic design approach" of technical systems and products is presented in VDI 2221 (1987). The most common way to understand "systematic design approach" of technical systems and products is presented in VDI 2221 (1987).

14. The flow of work during the systematic design process Traditionally the flow of work during the systematic design process is dealt in following main phases: Traditionally the flow of work during the systematic design process is dealt in following main phases: 1 The first phase is the task clarification and finding the general functions to be performed. 1 The first phase is the task clarification and finding the general functions to be performed. 2 The method moves on step by step from one phase to another 2 The method moves on step by step from one phase to another 3 The solution is developed from qualitative to quantitative product properties 3 The solution is developed from qualitative to quantitative product properties 4 The solution can be found also by developing or combining the existing product or component variants 4 The solution can be found also by developing or combining the existing product or component variants 5 The purpose is to find algorithms or rules to describe the design process 5 The purpose is to find algorithms or rules to describe the design process 6 usually the problems for manufacturing or manufacturability analysis are met in the end of the process 6 usually the problems for manufacturing or manufacturability analysis are met in the end of the process

15. A generalized model of the systematic design approach

16. A detailed modelof the systematic design approach by Pahl & Beitz The flow of work during the systematic design process is dealt in four main phases: 1. Planning and clarifying the task: specification of information 2. Conceptual design: specification of principle 3. Embodiment design: specification of layout (construction) 4. Detail design: specification of production

17. A simplified and rough example from packaging technology Requirements to pack a new product are collected and the main task is clarified: Shatter- and waterproof packing One principal solution is found to be the use of a wrapping machine combined with some type of padding elements or protective film A new wrapping film material (new layered plastic/foil) is evaluated to be the best (both its economic and technical properties) if wrapped tightly enough Angular direction of each wrapping cycle should be varied 5 degrees so that adequate sealing properties are achieved. Detailed changes needed to the commercial wrapping machine to enable the use of new film material and angular positioning of the wrapping head are listed

18. The requirement list for the systematic design approach

19. System requirements vs. component requirements General requirements of packaging Requirements of the packaging line Requirements of the conveyor unit Requirements of the rolling bearings The main task is to derive the requirements of each component from the general and system requirements.

20. General requirements of packaging Costs Environment Marketing -Appearance Laws and degrees Packaging materials -Sealing Logistiscs -Mechanical handling - Delivery time -Temperature -Light Product inside -Foodstuff -Fragile items Consumer -Information about the product -Functionality -Amount of waste and refuse Derived general requirements of the packaging equipment: -Label and marking facilities of the equipment -Total process time needed for the packaging process -Possible packaging technologies and processes

21. Contents of the requirements list When preparing a detailed requirements list, either for the system or for its mechanical units or components, it is essential to state whether individual items are When preparing a detailed requirements list, either for the system or for its mechanical units or components, it is essential to state whether individual items are Demands (must me met under all circumstances) Demands (must me met under all circumstances)or Wishes (should be taken into consideration whenever it is possible) Wishes (should be taken into consideration whenever it is possible)

22. Further on demands and wishes can be classified into to groups: Quantitative and qualitative aspects. Further on demands and wishes can be classified into to groups: Quantitative and qualitative aspects. Quantity: All data involving numbers or magnitudes, such as “maximum weight”, “power output”, “throughput”, “volume flow rate” etc. Quantity: All data involving numbers or magnitudes, such as “maximum weight”, “power output”, “throughput”, “volume flow rate” etc. Quality: All data involving permissible variations or special requirements such as “waterproof”, “corrosion proof”, “vibration or shock proof” etc. Quality: All data involving permissible variations or special requirements such as “waterproof”, “corrosion proof”, “vibration or shock proof” etc. Notice, that requirements should, immediately when possible, be quantified. Notice, that requirements should, immediately when possible, be quantified.

23. Main headings of the requirement list Geometry Geometry Size, height, width, length, diameter, space requirement, number, arrangement, connection, extension Size, height, width, length, diameter, space requirement, number, arrangement, connection, extension Kinematics Kinematics Type of motion, direction of motion, velocity, acceleration Type of motion, direction of motion, velocity, acceleration Forces Forces Direction of force, magnitude of force, frequency, weight, load, deformation, stiffness, elasticity, stability, resonance Direction of force, magnitude of force, frequency, weight, load, deformation, stiffness, elasticity, stability, resonance Energy Energy Output, efficiency, loss, friction, ventilation, state, pressure, temperature, heating, cooling, supply, storage, capacity, conversion Output, efficiency, loss, friction, ventilation, state, pressure, temperature, heating, cooling, supply, storage, capacity, conversion

24. Material Material Physical and/or chemical properties of the initial and final product, auxiliary materials, prescribed materials (food regulations etc.) Physical and/or chemical properties of the initial and final product, auxiliary materials, prescribed materials (food regulations etc.) Signals Signals Inputs and outputs, display, control equipment Inputs and outputs, display, control equipment Safety Safety Direct safety principles, protective systems, operational, operator and environmental safety Direct safety principles, protective systems, operational, operator and environmental safety Ergonomics Ergonomics Man-machine relationship, type of operation, clearness of layout, lighting, aesthetics Man-machine relationship, type of operation, clearness of layout, lighting, aesthetics

25. Production Production Factory limitations, maximum possible dimensions, preferred production methods, means of production, achievable quality and tolerances Factory limitations, maximum possible dimensions, preferred production methods, means of production, achievable quality and tolerances Quality control Quality control Possibilities of testing and measuring, application of special regulations and standards Possibilities of testing and measuring, application of special regulations and standards Assembly Assembly Special regulations, installation, sitting, foundations Special regulations, installation, sitting, foundations Transport Transport Limitations due to lifting gear, clearance, means of transport (height and weight), nature and conditions of dispatch Limitations due to lifting gear, clearance, means of transport (height and weight), nature and conditions of dispatch

26. Operation Operation Quietness, wear, special uses, marketing area, destination (e.g. sulphurous atmosphere, tropical conditions) Quietness, wear, special uses, marketing area, destination (e.g. sulphurous atmosphere, tropical conditions) Maintenance Maintenance Servicing intervals (if any), inspection, exchange and repair, painting, cleaning Servicing intervals (if any), inspection, exchange and repair, painting, cleaning Recycling Recycling Reuse, reprocessing, waste disposal, storage Reuse, reprocessing, waste disposal, storage Costs Costs Maximum permissible manufacturing costs, cost of tooling, investment and depreciation Maximum permissible manufacturing costs, cost of tooling, investment and depreciation Schedules Schedules End date of development, project planning and control, delivery date End date of development, project planning and control, delivery date

27. How to derive the requirements of each individual machine element? It is necessary to know the fundamentals and criteria of dimensioning of each machine element included to the construction or the equipment. It is necessary to know the fundamentals and criteria of dimensioning of each machine element included to the construction or the equipment. Requirement list should include enough data for calculating the initial values to make it possible to select the right type and size of the machine element. Requirement list should include enough data for calculating the initial values to make it possible to select the right type and size of the machine element.

28. A simplified case example Requirements of the roller conveyor Requirements of the roller conveyor Size and weight of the packet  width of the conveyor, strength and diameter of each roller element Size and weight of the packet  width of the conveyor, strength and diameter of each roller element Type of motion (backward-and-forward, high speed, continuous use, easy to move the load)  number of roller elements, low friction Type of motion (backward-and-forward, high speed, continuous use, easy to move the load)  number of roller elements, low friction Forces (critical position of the packet)  maximum vertical load and bending moment of each roller element Forces (critical position of the packet)  maximum vertical load and bending moment of each roller element Environment (dusty)  non-adhesive surface properties of roller elements Environment (dusty)  non-adhesive surface properties of roller elements Operation ja maintenance (twenty-four-hours use, long servicing intervals)  high wear-resistance of roller elements Operation ja maintenance (twenty-four-hours use, long servicing intervals)  high wear-resistance of roller elements

29. Requirements of the bearings Requirements of the bearings Diameter of each roller element  Possible bearing sizes (diameter) Diameter of each roller element  Possible bearing sizes (diameter) Type of motion, low friction  Possible bearing types, speed limits Type of motion, low friction  Possible bearing types, speed limits Maximum vertical load and bending moment of each roller element  Allowable axial, radial and bending loading of bearings Maximum vertical load and bending moment of each roller element  Allowable axial, radial and bending loading of bearings Environment (dusty)  Double-sided sealing of bearings Environment (dusty)  Double-sided sealing of bearings High wear-resistance  Carbide or nitride based materials of the roller elements of bearings High wear-resistance  Carbide or nitride based materials of the roller elements of bearings Twenty-four-hours use  Self-lubricant bearings Twenty-four-hours use  Self-lubricant bearings

30. A conveyor belt of the pallet handling system A conveyor belt of the pallet handling system Required belt speed due to process Required belt speed due to process Maximum load Maximum load Required properties of the power transmission unit -Gear ratio -Speed and torque -Power Dimensioning of worm gears

31. Some problems when systematic design approach is applied: Some problems when systematic design approach is applied: In systematic design approach, especially according to VDI 2221, it is typical that the functional design of a product and its modular construction are followed by the documentation for manufacturing and assembly. Because these two stages are presented in design scheduling flowcharts to be consecutive (not parallel), it is possible that the designer does not give enough attention to manufacturing aspects during modularization. In systematic design approach, especially according to VDI 2221, it is typical that the functional design of a product and its modular construction are followed by the documentation for manufacturing and assembly. Because these two stages are presented in design scheduling flowcharts to be consecutive (not parallel), it is possible that the designer does not give enough attention to manufacturing aspects during modularization. Another problem from the designer’s point of view is that there is a lot of subjective information available during different design stages and development of the solution is, however, based on this “facts”. Another problem from the designer’s point of view is that there is a lot of subjective information available during different design stages and development of the solution is, however, based on this “facts”. The third problem might be that “new” products or designs are too easily tried to be developed only by combining already existing modules or other “old” technical solutions The third problem might be that “new” products or designs are too easily tried to be developed only by combining already existing modules or other “old” technical solutions

32. Exercise 1 Exercise 1A. Exercise 1A. Select any machine element or component of a worm gear (e.g. bearings, shafts, gears etc.) illustrated in the figure below and try to derive detailed requirements (and wishes) of this component to make it possible to select the appropriate type, size and material of the component. Select any machine element or component of a worm gear (e.g. bearings, shafts, gears etc.) illustrated in the figure below and try to derive detailed requirements (and wishes) of this component to make it possible to select the appropriate type, size and material of the component. Exercise 1B. Exercise 1B. Make a comparison table about the advantages and opportunities vs. disadvantages and difficulties, which could be met, if the following design methodologies or approaches are applied in machine design: Make a comparison table about the advantages and opportunities vs. disadvantages and difficulties, which could be met, if the following design methodologies or approaches are applied in machine design: Reverse Engineering Reverse Engineering Systematic Design Approach Systematic Design Approach Virtual Engineering Virtual Engineering Concurrent Engineering Concurrent Engineering Cross-technological Approach Cross-technological Approach