What Is Spare Parts?

Spare Parts are the basic elements of machine composition. The machine generally includes one or several prime mover parts (such as electric motors, internal combustion engines, steam engines) used to receive external energy; the executive part (such as the tools in the machine tool) that realizes the production function of the machine, and transmits the motion and power of the prime mover to the executive parts. Part of the transmission part (such as the gear and screw transmission mechanism in the machine tool), and the detection and control system (such as the numerical control system in the machine tool) that ensures the coordinated work of each part of the machine (that is, the machine consists of a prime mover part, a transmission part, and an executive part. , the measurement and control part is composed). The machine is further decomposed, and various parts can be obtained.

The Strength Requirements Of Spare Parts

Strength refers to the ability of parts to not break or produce plastic deformation exceeding the allowable limit during operation, which is the most basic requirement for the normal operation of the machine and safe production.

The principle measures to improve the strength of parts are:

• Increase the size of the dangerous section of the part, and design the section shape reasonably to increase the moment of inertia of the section;
• Use high-strength materials, heat treatment to increase strength and reduce internal stress, and control processing technology to reduce or eliminate microscopic defects;
• Strive to reduce the load on the parts;
• Properly involve the structure of the parts to reduce the degree of stress concentration, etc.

The Stiffness Requirements Of Spare Parts

Stiffness refers to the ability of a part to not produce more than a specified elastic deformation during operation. This requirement is only for those parts that will reduce the performance of the machine due to excessive elastic deformation.

The principle measures to improve the overall stiffness of parts are:

• Appropriately increase the section size of the part
• Reasonable design of the section shape of the parts
• Reasonable addition of reinforcing ribs
• Adopt multi-pointing structure, etc.;

The principle measures to improve the contact stiffness of parts are:

• Improve the machining accuracy of the contact surface or properly run and
• Properly increase the contact area
• to reduce unit pressure, etc.

The Life Requirements Of Spare Parts

The life requirement is that the part is required to maintain normal operation during the expected operation period without being scrapped. This requirement is mainly for those parts that are subject to wear or corrosion when working under variable stress and working.

Since the main factors affecting the fatigue limit of parts are stress concentration, size, surface quality and environmental conditions, the main measures to improve the life of parts are:

• Properly involve the structure of the parts to reduce the degree of stress concentration;
• Use machining or surface strengthening treatment to improve the quality of the working surface of the parts;
• Reasonably choose the friction pair matching materials, lubricants and lubrication methods to improve the wear resistance of the parts;
• Choose corrosion resistance
• Use heat treatment to improve the mechanical properties of parts materials, or use rolling, shot peening and other processes to generate favorable residual stress on the surface of parts, etc.

The Technological Requirements Of Spare Parts

The manufacturability requirement of the parts is that under the given process conditions and production level, the parts can be manufactured with less cost and labor, and it is easy to assemble. The structure of the parts should be reasonably designed from the aspects of production batch, material, blank production, processing method, assembly process, and usage requirements.

The Economic Requirements Of Spare Parts

The economic requirement of parts is to manufacture parts that meet the technical requirements with lower cost and less man-hours.

You can take measures to reduce material consumption, use blanks with little or no margin, replace expensive materials with cheap materials, only use high-quality and valuable materials in key parts of the parts, and try to use standard parts to improve the economy of parts.

Other Requirements Of Spare Parts

With the difference in the allowable space, quality restrictions, importance, working conditions, etc. of the parts, various requirements such as volume, quality, reliability, vibration stability, noise, etc. will also be proposed. The designer should treat them differently according to the specific situation. .