What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
At present, the connecting shafts of commonly used food processing knives on the market generally use square bayonet, which is not easy to install parts, and it is time-consuming and laborious when replacing parts; Increased processing costs. There is also a link structure with a circular bayonet on the market, but it is easy to loosen and not firm after the entire food processor is used for a period of time, which affects the use of the machine. Therefore, a connection structure that is easy to operate and simple to process is urgently needed.
In the prior art, there are two ways to feed the screws of the locking screw machine, the air blowing type and the air suction type. The air suction type is suitable for relatively small screws. If the screw size is larger than M2, smaller than M5, and the length-diameter ratio is larger than 1.7, the air-blown screw machine can be selected.
The main purpose is to make industrial products form a fixed one. In use, it often occurs that the teeth cannot be closely attached, and the screw heads are broken if they are locked too hard, or the teeth are not locked tightly and fail to meet the conditions of use, all of which are accuracy problems. . Screws are mass products, not hand-made works of art. In mass production, they are supplied to consumers in order to achieve high precision, stable quality and popular prices. The accuracy of screws is usually 6g (class 2, the American standard IFI is 2A teeth), and the rough screws used in construction projects are 8g (class 3, IFI is 1A teeth). Common types of screws Screw A: Machine Screw: Machine screw B: Tapping Screw: Self-tapping screw (for metal and plastic) B-1: Sheet Metal Tapping Screw. (Iron die self-tapping screw) B- 2: Plastic Tapping Screw. (for plastic, self-tapping screw) C: Wooden Screw : Woodworking screw D: Drywall Screw : Cement wall screw E: Self Drilling Screws (stainless steel drilling screw, composite material drilling screw) F : Expansion screw, four-piece expansion screw, also known as: four-piece gecko. The grades of expansion bolts are divided into: 45, 50, 60, 70, 80. Materials of expansion screws: mainly austenitic A1, A2, A4, 1 stainless steel plate, metal steel plate, galvanized steel plate, engineering installation. 2. Indoor and outdoor installation of metal curtain wall and metal light compartment. 3 Generally, angle steel, channel steel, iron plate and other metal materials are combined for installation. 4. Assembly engineering of car boxes, container boxes, shipbuilding, refrigeration, screw machine equipment, etc. Features: 1. Drilling and tapping, locking is completed at one time, and the bonding force is strong. 2. Save construction time and improve work efficiency. E-1:STAINLESS STEEL SELF DRILLING SCREWS E-2:Bi-Metal Self Drilling Screws Common materials of composite drilling screws a.Low Carbon Steel: carbon steel carbon steel is divided into low carbon steel, medium carbon steel, high Carbon steel and alloy steel. b. SS-304: Stainless Steel 304 and 316 belong to stainless steel c. SS-302: Stainless Steel 302: better structural toughness d. Aluminum 5052: Aluminum alloy 5052 d. Brass: Brass e. Bronze: Bronze f . UNS C11000 Copper: Antimony Copper
At present, for roller or needle roller bearings without cages, ribs, and low-speed operation, the structure mainly includes inner and outer rings and rollers or needle rollers in the raceway between the inner and outer rings, and additional The retaining rings on both sides of the roller or needle roller, among which the retaining rings added on both sides of the roller or needle roller are annular steel sheets punched from metal sheet, and their function in the bearing is only Correctly guide the rollers or needle rollers to run normally in the raceway between the inner and outer rings to prevent the rollers or needle rollers from deviating and slipping out of the raceway. The defect of the retaining ring of this structure is that first, because the rigid retaining ring and the inner ring are completely separated, there is a gap between the retaining ring and the installation shaft during installation. When the bearing is working, The retaining ring is driven by the outer ring and the rollers or needle rollers to rotate around the installation shaft. Due to the inconsistency of the structure, the retaining ring is easy to fall off during the rotation process, the safety of use is poor, and the rollers or needle rollers will appear toward the raceway. The situation of one side offset, which causes the bearing load center to offset, affects the reliability of the bearing operation, and ultimately affects the service life of the bearing; There is a gap between the raceways of the needle, so the tidbits, dust, etc. generated during the working process will continue to enter the raceway between the inner and outer rings. It is stuck; in addition, due to the gap between the steel retaining ring and the raceway, the grease stored in the raceway will be continuously lost, which will cause the bearing to heat up due to frequent lack of grease, or even burn out, which also affects the to the service life of the bearing.
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