Standard parts refer to the commonly used parts (parts) such as threaded parts, keys, pins, rolling bearings, etc. In a broad sense, it includes standardized fasteners, connectors, transmission parts, seals, hydraulic components, pneumatic components, bearings, springs and other mechanical parts. In a narrow sense, only standardized fasteners are included. The standard part commonly known in China is the abbreviation of the standard fastener, which is a narrow concept, but the existence of a broad concept cannot be ruled out. In addition, there are industry standard parts, such as automobile standard parts, mold standard parts, etc., which also belong to generalized standard parts.
Generalized Basic Introduction
Generalized standard parts are mechanical parts (parts) and components with clear standards. DIN) and other standards are also widely used in the world.
Mechanical parts and components with a high degree of standardization and strong industry versatility are also known as general-purpose parts.
Generalized standard parts include fasteners, connectors, transmission parts, seals, hydraulic components, pneumatic components, bearings, springs, etc., all of which have corresponding national standards and are highly versatile across industries.
Industry standard parts, this concept belongs to the convention in the industry, and there is no clear regulation. Common industry standard parts include mold standard parts, automobile standard parts, etc. When a product is widely used in the industry, it is a common part; the standard of common parts is usually formulated by leading companies in the industry and widely accepted by the industry, so that the enterprise standard becomes the de facto industry standard, which can also be called an industry standard part .
Mold standard parts, including injection mold base, push rod push tube, hot runner mold, etc.
There are many types of automotive standard parts, such as spark plugs, door locks, shock absorbers, automotive fasteners, etc. For details, please refer to the “Automotive Standard Parts Manual”.
The more mature an industry is, the higher the degree of standardization and generalization, the more standard parts, and the lower the industry cost. However, it is necessary to avoid excessive standardization, which will lead to monotonous product categories in the industry and low-end competition.
(also: connectors) including threaded connectors (also known as fasteners) and hub connectors, pin connectors, riveting parts, glued parts, welding parts, etc.
Transmission parts, belt transmission parts, chain transmission parts
Gear transmission parts: including involute cylindrical gears, bevel gears and worms, etc.
Friction wheel, reducer, continuously variable transmission, shaft extension
Couplings, Clutches and Hydraulic Couplings
Pneumatic transmission parts, hydraulic transmission parts
Flywheel (similar to transmission parts, actually energy storage parts), bearings, sliding bearings, rolling bearings
Springs, cylindrical springs, disc springs, rubber springs, leaf springs, ring springs, etc.
It is difficult to say that these parts are mechanical standard parts, but they have a high degree of standardization and are highly relevant to the machinery industry; including: lubricating oil, grease and lubricating devices, lifting and handling parts and operating parts (pulley ropes, etc.), motors and travel switches ,and many more.
In addition, there are commonly used materials, such as cast iron, cast steel, steel and steel, copper and alloys, aluminum and alloys, engineering plastics, rubber products, composite materials and other non-metallic materials and products, with a high degree of standardization and generalization and strong correlation .
Narrow Sense Standard Parts
Standard parts in a narrow sense are standardized fasteners, which are actually a kind of connecting parts (connecting parts), but because of the wide variety of applications, they are counted as one type in actual use, or even referred to as standard parts, which usually include the following 12 types of parts :
1. Bolt: A type of fastener consisting of a head and a screw (a cylinder with an external thread), which needs to be matched with a nut to fasten and connect two parts with through holes. This form of connection is called a bolted connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection.
2. Stud: A type of fastener that has no head and only has external threads on both ends. When connecting, one end of it must be screwed into the part with the internal threaded hole, the other end must pass through the part with the through hole, and then screw the nut, even if the two parts are tightly connected as a whole. This form of connection is called a stud connection, which is also a detachable connection. It is mainly used for occasions where one of the connected parts is thick, requires a compact structure, or is not suitable for bolt connection due to frequent disassembly.
3. Screw: It is also a type of fastener composed of head and screw. It can be divided into three categories according to the purpose: machine screw, set screw and special purpose screw. Machine screws are mainly used for a fastened connection between a part with a fixed threaded hole and a part with a through hole, without the need for nut matching (this connection form is called screw connection, which is also a detachable connection; it can also be Cooperate with the nut, it is used for the fast connection between two parts with through holes.) The set screw is mainly used to fix the relative position between the two parts. Special purpose screws, such as eyebolts, are used for hoisting parts.
4. Nuts: with internal threaded holes, generally in the shape of flat hexagonal cylinders, and also in flat square cylinders or flat cylinders, with bolts, studs or machine screws, used to fasten and connect two parts, so that the become a whole.
Special Categories of Nuts:
High-strength self-locking nuts are a category of self-locking nuts with high strength and reliability. It is mainly based on the introduction of European technology, which is used for road construction machinery, mining machinery, vibration machinery and equipment, etc. There are very few domestic manufacturers of such products.
Nylon self-locking nut is a new type of high anti-vibration and anti-loosening fastening parts, which can be used in various mechanical and electrical products with a temperature of -50 to 100 °C. Aerospace, aviation, tanks, mining machinery, automobile transportation machinery, agricultural machinery, textile machinery, electrical products and various types of machinery have a sharp increase in the demand for nylon self-locking nuts, because its anti-vibration and anti-loosening performance is much higher than other Various anti-loose devices, and the vibration life is several times or even dozens of times higher. At present, more than 80% of the accidents of mechanical equipment are caused by loose fasteners, especially in mining machinery, and the use of nylon self-locking nuts can prevent major accidents caused by loose fasteners.
5. Self-tapping screw: Similar to machine screw, but the thread on the screw is a special thread for self-tapping screw. It is used to fasten and connect two thin metal components to make them a whole. Small holes need to be made in advance on the components. Due to the high hardness of this kind of screw, it can be directly screwed into the hole of the component, so that the Form the corresponding internal thread. This form of connection is also a detachable connection.
6. Wood screw: It is also similar to machine screw, but the thread on the screw is a special thread for wood screw, which can be directly screwed into the wooden component (or part), used to connect a metal (or non-metal) with a through hole. The parts are fastened together with a wooden element. This connection is also a detachable connection.
7. Washers: A type of fastener with an oblate ring shape. It is placed between the supporting surface of the bolt, screw or nut and the surface of the connecting parts, which increases the contact surface area of the connected parts, reduces the pressure per unit area and protects the surface of the connected parts from damage; another type of elastic washer, It can also play a role in preventing the nut from loosening.
8. Retaining ring: It is installed in the shaft groove or hole groove of the machine and equipment, and plays the role of preventing the parts on the shaft or the hole from moving left and right.
9. Pins: mainly used for parts positioning, and some are also used for parts connection, fixing parts, transmitting power or locking other fasteners.
10. Rivet: A type of fastener consisting of a head and a nail rod, used to fasten and connect two parts (or components) with through holes to make them a whole. This form of connection is called rivet connection, or riveting for short. It belongs to the non-detachable connection. Because to separate the two parts that are joined together, the rivets on the parts must be broken.
11. Assemblies and connection pairs: Assemblies refer to a type of fasteners supplied in combination, such as a combination supply of certain machine screws (or bolts, self-supplied screws) and flat washers (or spring washers, lock washers); connection Auxiliary refers to a type of fasteners supplied by a combination of special bolts, nuts and washers, such as high-strength hexagon head bolts for steel structures.
12. Welding nail: a heterogeneous fastener composed of a nail rod and a nail head (or no nail head), which is fixed and connected to a part (or component) by welding so as to be connected with other parts.