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Combined needle roller bearing is a bearing unit composed of centripetal needle roller bearing and thrust bearing or angular contact ball bearing. It has compact structure, small volume and high rotation accuracy. It can bear high radial load and certain axial load at the same time. Moreover, the product has various structural forms, wide adaptability and easy installation.
The combined needle roller bearing is used at the place where the mating shaft is designed as the bearing raceway, which has certain requirements for the hardness of the bearing; Or equipped with our company’s special IR standard inner ring for sleeve insertion, there is no requirement for shaft hardness, and its structure will be more compact. It is widely used in machine tools, metallurgical machinery, textile machinery, printing machinery and other mechanical equipment, and can make the mechanical system design more compact and dexterous.
This kind of bearing is composed of centripetal needle roller and thrust full ball, or thrust ball, thrust cylindrical roller, or angular contact ball, which can bear unidirectional or bidirectional axial load. It can also be designed according to the special structural requirements of users.
Dimensional tolerance and geometric accuracy shall be in accordance with JB / t8877. The difference between the needle roller diameters is 2 μ m. The accuracy grade is G2 (national standard gb309). The diameter of the inscribed circle of the bearing without inner ring shall meet the tolerance class F6 before assembly. The radial clearance of bearing shall comply with group 0 specified values in GB / t4604. The special accuracy grade shall be in accordance with GB / T307 1. For details of special requirements for bearing clearance, inscribed circle and accuracy grade, please contact our company.
The needle roller is made of GCr15 bearing steel and hardened hrc60-65.
The inner and outer rings are made of GCr15 bearing steel and hardened hrc61-65. The cage is made of high-quality low carbon steel or reinforced nylon.
The axial load of nkia and nkib series bearings shall not exceed 25% of the radial load. The support used for alternating axial load must be installed opposite. Thrust bearing components must be preloaded up to 1% of the basic axial static load rating. When using plastic cages (suffix TN), continuous operation shall not exceed the operating temperature + 120 ° C. The thrust bearing components shall move freely in the bearing pedestal. For the general configuration design of bearings, see the relevant recommendations in the application technology of rolling bearings.
Rolling bearings — combined needle roller and thrust cylindrical roller bearings — Boundary dimensions (gb-11)
JB / t3122-1991 rolling bearings — combined needle roller bearings and thrust ball bearings — Boundary dimensions (JB-1)
JB / t3123-1991 rolling bearings — combined needle roller bearings and angular contact ball bearings — Boundary dimensions (JB-1)
JB / t6644-1993 rolling bearings – needle roller and bi-directional thrust cylindrical roller combined bearings – Dimensions and tolerances (jb-3)
JB / t8877-2001 rolling bearings – technical conditions for needle roller combined bearings (jb-12)