What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
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.
Stud bolts generally need to be surface treated. There are many types of bolt surface treatments. Generally, electroplating, blackening, oxidation, phosphating, and electroless zinc flake coating are commonly used. However, electroplated fasteners account for a large proportion of the actual use of fasteners. Especially in automobiles, tractors, home appliances, instrumentation, aerospace, communications and other industries and fields are more widely used. However, for threaded fasteners, not only a certain anti-corrosion capability is required in use, but also the interchangeability of threads must be ensured, which can also be called screwability here. In order to meet the dual-use performance of anti-corrosion and interchangeability required by threaded fasteners in use, it is very necessary to formulate special plating standards. [1] The GB/T5267.1-2002 [Threaded Fastener Electroplating Coating] standard is one of the national standards Fastener Surface Treatment series of standards, which include: GB/T5267.1-2002 [Fastener Electroplating Layer]; GB/T5267.2-2002 [Fastener electroless zinc flake coating] two standards. This standard is equivalent to the international standard ISO4042; 1999 [Threaded fastener electroplating layer]. This standard replaces the GB/T5267-1985 [Threaded Fastener Electroplating Coating] standard.
As a special kind of rivet parts, the rivets for shrinking brake pads are used in the accessories of the automobile industry. The original brake pad rivets do not have a chamfered structure, so the materials cannot be normally fed during assembly, or there are burrs, which lead to unqualified batches. When improving this structure, many manufacturers in the same industry often solve the problem by machining chamfering, but for brake pad rivets with thin thickness, it is impossible to achieve the problem of beating and bad material after chamfering processing.
In view of the above problems, Guangdong Yueluo Hardware Industry Co., Ltd. aims to provide a new type of open blind rivet suitable for riveting of aluminum, steel and stainless steel sheets with foamed materials.
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