NA4915 Double Row Needle Roller Bearing with Inner Ring 1PCS Needle Bearing Size 75mm*105mm*30mm

Needle bearings are roller bearings with cylindrical rollers that are both thin and long relative to their diameter. This type of roller is called a needle roller. Despite having a small cross-section, the bearing still has a high load bearing capacity. Needle roller bearings are equipped with thin and long rollers (roller diameter D ≤ 5mm, L/D ≥ 2.5, L is the roller length), so the radial structure is compact. When its inner diameter size and load capacity are the same as other types of bearings, the outer diameter is the smallest, making it particularly suitable for support structures with limited radial installation dimensions. According to different usage scenarios, bearings without inner rings or needle rollers and cage components can be selected. At this time, the journal surface and outer shell hole surface that match the bearing are directly used as the inner and outer rolling surfaces of the bearing. To ensure the same load capacity and operating performance as bearings with ring rings, the hardness, processing accuracy, and surface quality of the shaft or outer shell hole raceway surface should be similar to those of the bearing ring raceway. This type of bearing can only withstand radial loads Stamped outer ring needle roller bearings are needle roller bearings with thin stamped outer rings. Its main feature is a low cross-sectional height and high load-bearing capacity. Mainly used for bearing configurations that are compact in structure, cheap in price, and cannot be used as raceway components for needle roller cages. The bearings and bearing housings must be installed in an interference fit manner. If axial positioning functions such as shoulder and stop ring can be omitted, then the bore inside the bearing box can be made extremely simple and economical. The stamped outer ring needle roller bearings installed at the shaft end have double-sided open type and single-sided closed type. The base end face of the closed stamped outer ring can withstand relatively small axial guiding forces. Stamped outer ring needle roller bearings generally do not come with an inner ring. In situations where the shaft neck cannot be hardened or ground, the inner ring listed in the table can be used. The quenched steel plate outer ring of the stamped outer ring needle roller bearing cannot be separated from the needle roller holder assembly. The free space for storing lubricants can extend the interval for replenishing lubrication. Bearings generally adopt a single row design. Except for the wider specification bearings 1522162220302538 and 3038 series, which are equipped with two needle roller cage components. The outer ring of the bearing has lubricating oil holes. According to user needs, all single row stamped outer ring needle roller bearings with a shaft diameter greater than or equal to 7mm can be equipped with an outer ring with lubricating oil holes (code suffix AS1). Oil sealed stamped outer ring needle roller bearings can be provided with open or closed end oil sealed stamped outer ring needle roller bearings (3 to 5) in situations where oil seals cannot be installed due to space limitations. This type of bearing is equipped with a friction type oil seal made of polyurethane or synthetic rubber, which is filled with lithium based grease with good anti rust properties and suitable for operating temperatures ranging from -20 to+100 ℃. The inner ring of the oil sealed bearing is 1mm wider than the outer ring, which ensures that the oil seal works well and prevents the shaft from being contaminated even when there is a slight displacement of the bearing relative to the bearing box. The inner ring of the bearing also has lubrication holes, which can be supplemented with lubrication from the outer or inner ring according to the requirements of the bearing configuration A solid ring needle roller bearing is composed of one or two rings and a needle roller assembly with a cage. According to different application scenarios, bearings can be divided into those with inner rings or those without inner rings. Therefore, solid ring needle roller bearings can meet the requirements of light weight, small space occupation, and high power transmission. Solid ring needle roller bearings have a smaller volume and higher load-bearing capacity. Structural type: outer ring with double gear edge (or double lock ring) and retaining frame for needle roller bearings NA and NAV. NKI type can be installed with inner and outer rings (with lock ring, complete set of needle rollers and retaining frame) respectively, with high authorized speed and divided into single row and double row. If the shaft cannot be used as a raceway, that is, if it is impossible or uneconomical to harden the shaft by grinding, then this type of needle roller bearing with an inner ring can be used

• Features: NA and NKI type bearings without inner rings are RNA and NK type needle roller bearings. This type of bearing has no inner ring and is suitable for support structures with limited radial installation dimensions. The journal that matches the bearing is directly used as the rolling surface. As the shaft of the raceway surface, it must be quenched and ground, and only when it is machined to the appropriate size and shape accuracy, can the entire needle roller bearing have a high service life and operating accuracy. Meanwhile, due to the absence of an inner ring, the diameter of the shaft can also be appropriately increased, thereby also increasing rigidity
• Bearing material:gcr15 or 52100
• Needle roller bearings have a high load-bearing capacity and are suitable for supporting structures with limited installation dimensions. The journal surface is hardened as a rolling surface, and the bearing is inserted into the seat hole by pressing fit without the need for axial positioning. Before installation, the bearing should be injected with an appropriate amount of lubricating grease. Normally, BK type bearings do not need to be lubricated again after assembly. They are used for supporting shafts without protruding ends, and the end face is closed to provide a sealing effect and can withstand small axial movements
• Bearing type: Needle roller bearing Model: NA4915 Inner diameter (mm): 75 Outer diameter (mm): 105 Width (mm): 30 Lubricating speed (r/min): 5400 Cor(kN)：164 Cr(kN)：88.0 Oil lubrication speed (r/min):- Weight (KG): 0.773
• Service commitment: Our company's business and technical support department is available 24 hours a day to provide you with protection