Mechanical design is to conceive, analyze and calculate the working principle, structure, movement mode, force and energy transmission mode of the machine, the material and shape and size of each part, and the lubrication method according to the requirements of use, and convert it into a specific description Work process based on manufacturing.
Mechanical design is an important part of mechanical engineering, the first step in mechanical production, and the most important factor in determining mechanical performance. The goal of mechanical design is to design the best machinery under various limited conditions (such as materials, processing capabilities, theoretical knowledge and calculation methods, etc.), that is, to make an optimized design.
Optimal design requires comprehensive consideration of many requirements, generally: best performance, lowest manufacturing cost, smallest size and weight, most reliability in use, lowest consumption and least environmental pollution. These requirements are often contradictory, and their relative importance varies with the type and purpose of the machine. The designer’s task is to weigh the weight and weight according to the specific situation, make overall plans, and make the designed machinery have the best comprehensive technical and economic effects.
In the past, design optimization mainly relied on the designer’s knowledge, experience, and vision. With the development of basic theories of mechanical engineering, value engineering, system analysis and other new disciplines, the accumulation of technical and economic data for manufacturing and use, and the popularization and application of computers, optimization gradually abandons subjective judgments and relies on scientific calculations.
The design of various industrial machinery, especially the overall and systematic mechanical design, must depend on the relevant industrial technology and it is difficult to form an independent discipline. Therefore, professional mechanical design sub-disciplines such as agricultural machinery design, mining machinery design, pump design, compressor design, steam turbine design, internal combustion engine design, machine tool design, etc. have emerged.
Mechanical design classification
Mechanical design can be divided into three types: new design, inherited design and modified design.
- New design
Apply mature science and technology or new technologies that have been proved to be feasible through experiments, and design new types of machinery that have never been seen before.
- Inheritance design
According to the use experience and technological development, the existing machinery is designed and updated to improve its performance, reduce its manufacturing cost or reduce its operating cost.
- Variant design
In order to adapt to new needs, some modifications or additions and deletions to existing machinery have developed variant products that are different from the standard type.
Main process of mechanical design
- Develop design tasks according to user orders, market needs, and new scientific research results.
- Preliminary design. Including determining the working principle and basic structural form of the machine, conducting motion design, structural design, and drawing a preliminary general drawing and preliminary review.
- Technical design. Including modification of the design (based on the preliminary review comments), drawing all parts and new general drawings, and the second review.
- Work drawing design. Including the final modification (according to the second review opinion), drawing all working drawings (such as parts drawing, component assembly drawing, general assembly drawing, etc.), and formulating all technical documents (such as parts list, wearing parts list, instructions for use, etc.).
- Finalized design. Machinery used for batch or mass production. For some simple design tasks (such as the new design of simple machinery, inherited design or variant design of general machinery, etc.), the preliminary design procedure can be omitted.