The basic requirements for designing machinery are:
(1) has good performance, realizes the expected function and meets the use requirements. Simple operation, simple maintenance and convenient maintenance. There is no need to pursue "multi-function", because "multi-function" will increase costs and reduce reliability.
(2) Safety Many major accidents come from mechanical failure. Seal leakage caused the space shuttle Challenger to crash, landing gear failure caused an air crash, and brake failure caused an accident. Frequent car recalls have exposed the safety hazards caused by poor mechanical design. Mechanical design must be people-oriented. All parts related to personal safety or major equipment accidents must be carefully and strictly designed or checked, and experience or "analogy" cannot be used instead.
The calculation instructions shall be properly kept for verification. Exposed moving parts should be equipped with protective nets. There must be a safety interlock device or remote control for the parts that are easy to cause personal injury. The specifications and installation of electrical components and wires must meet safety standards. In addition to the first time, in order to protect the equipment, overload protection devices such as safety pins and safety valves, as well as warning devices such as red lights and alarm bells should be set up.
(3) It is reliable and durable, and there is no fault or little fault within the predetermined service life. The period of overhaul or replacement of wearing parts should not be too short, so as to avoid frequent downtime affecting production. However, it is inappropriate to overemphasize "durability". Modern production is regularly updated and expected to be scrapped, and the "long life" of a single component has no practical significance for the whole machine. The abuse of expensive materials in pursuit of "durability" suddenly increased the cost.
(4) Standard parts and complete sets of components should be selected as much as possible in economic design, which is not only reliable and cheap, but also can greatly save the design workload. It can be said that the number of standard parts used in design is an important symbol to evaluate the design level. We should pay attention to saving precious raw materials and reducing costs. Parts design must attach importance to processing technology and strive to reduce processing costs. Good economy is not only reflected in low manufacturing cost, but also in high efficiency and low efficiency of the machine.
(5) The noise of machines that meet the requirements of environmental protection shall not exceed the standard. Do not use prohibited raw materials, such as asbestos. Ensure that the machine will not leak water, oil, dust and smoke during use. Wastewater and waste gas in production must be treated and discharged up to standard.