Miniature Bearings
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MINIATURE AND EXTRA-SMALL BALL BEARINGS CATALOG Thank you for your valuable support of > KOYO products.Recent industrial applications demand more sophisticationin a variety of machines and equipment. Rotation parts for information processing, audio, andvisual equipment that include such features as high toler- ance and low torque are highly desired by users. To meet such demands, we at > KOYO exploit state-of-the-art research facilities and leading-edge production methods to improve the performance and life of toleranceminiature and extra-small ball bearings. The information contained in...

Miniature and extra-small ball bearings includethose with outer ring flanges, thin section types, and narrow-width types, as well as standard ones. The above are also categorized as open,shielded, and sealed types. 1.1 Types and Features > This type of bearing can carry a radial load and axial load inboth directions simultaneously. Featuring low frictional torque, it is suitable for applicationswhere high rotation speed or low noise and vibration are required. This type of deep groove ball bearing has a flange on one endof the outside surface. Since mounting is carried out using the side of...

The RD seal has a labyrinth structure in the shape of aletter Z formed by the seal lip and inner ring seal groove. The torque requirement of this type of bearing is as low asthat of the non-contact type since the lip is extremely light contact with the seal groove of the inner ring, yet this newlydeveloped item offers excellent grease sealability and dustprevention. In this type of bearing, a press-worked shield is utilized. These bearings are classified as Z and ZX types accordingto the manner in which the shield is fixed to the outer ring. A ZL type, in which the inner ring is provided...

the bearing, such as bearing type, boundary dimensions,dimension accuracy, running accuracy, and internal clearance. It consists of a basic number and a supplementary code. The designation of a bearing indicates the specifications of 68, 69, 60, 62, 631 > Bearing type codeBearing series codeBore diameter numberSpecific item codeShield/seal code Bearing ring form code Tolerance code Material codeClearance codeCage code No code ɿɿɿɿ standard typewide typeouter ring with flangeouter ring with resin flange No code ɿɿ bearing steelstainless steel WF FN ST M1M2M30 ɿɿɿ ʙ 5 Ж m3 M4M5M6 8 ɿɿɿ ʙ 13 Ж...

In addition to JIS designation, KOYO uses supplementarycodes, for ease of understanding of bearing specifications. The designation structure is shown in Tables 1.2 to 1.4. In general, boundary dimensions of bearings conform toJIS B 1512 (Boundary Dimensions for Rolling Bearings). Designation of such standard bearings is specified by JISB 1513 (Designation of Rolling Bearings). > Bearing type code Bore diameter numberFlange code Outside diameter number MLWML ɿɿ standard widthwide type FFN ɿɿɹ outer ring with flangeouter ring with resin flange ʷ 10) 8040 ɿɿ nominal bearing bore diameter 8...

In general, a ribbon type or crown type cage made of steelis used in miniature and extra-small ball bearings. The ribbon type cage is used in relatively large bearings,while the crown type is used in smaller ones. Molded polyamide resin cages are becoming increasinglypopular, as they are advantageous in terms of running torque,grease life, and noise. The T-molded cage is designed to perform similarly to thatof the single-shielded type bearing. Table 1.5 shows types, codes, and names of cages used inminiature and extra-small ball bearings. When a bearing rotates under a load, the raceway...

Table 3.3 (1) Tolerances for Metric Series Deep Groove Ball Bearings --Inner Rings--(1) Inner ring (bore diameter) ʔʔ ʔ > Unit Ж m Nominal borediameter Single plane meanbore diameterdeviation lowermax.upper Single borediameter deviation Single radial plane borediameter variation Mean borediametervariation V d > p Class d > Diameter series ʢ mm ʣ ᷎ d > mp ᷎ d > s 7,8,92,3,40,1 V d > mp over up to loweruppermax.max.max. (2) Inner ring (running accuracy and width) > Class 0Class 6Class 5Class 4 Class 2 0.6 > 1 ʣ 2.510 2.5 0.6 > ɹ 00 0 0 0 > ʔ 8 ʔʔ ʔ 109 5 4 ʔ 876565 3 2 1.5 > 1 ʣ 2.510 2.5 0.6...

Table 3.4 Tolerances for Flanges of Flanged Deep Groove Ball Bearings(1) Tolerance for flange outside diameter > Unit Ж m Nominal flangeoutside diameter C 1 ɹɹ Single flange outside diameter deviationField 1Field 2 D ʢ > 1 mm ʣ ᷎ D > 1s overup toupperlowerupperlower 1018 1018 30 > ʴ 220 > ʔ 36 00 0 > ʔ 36 > ʴ 270 > ʔ 43 > ʔ 43 > П D П D ʴ 330 > ʔ 52 > ʔ 1 ɹɹ 52 > 1. Field 2 is applicable when the outside surface of the flange is used for positioning2. For the tolerance of deep groove ball bearings with resin flanges (FN bearings), see the bearing dimen- sion tableRemarks: ɿɹɿɹ ɿɹ nominal...

Miniature and Extra - small Ball Bearings Table 3.5 (1) Tolerances for Inch Series Deep Groove Ball Bearings --Inner Rings-- (1) Inner ring (bore diameter) d ʽ 10 mm > Unit Ж m Single plane mean borediameter deviationSingle bore diameterdeviation Single radial plane bore diameter variationMean bore diametervariation Class Class ᷎ d > mp ᷎ d > s V d > p V d > mp lowermax.upper loweruppermax. ABMA 5PABMA 7PABMA 9P ʔ 5.1 > ʔ 5.1 2.52.5 1.32.52.51.3 > ʔ 5.1 > ʔ 5.1 > ʔ 2.5000000 > ʔ 2.5 d ʽ 10 mm > Unit Ж m Radial runout ofassembledbearing inner ring Face runoutwith boreFace runoutwith...

The rotation speed of a bearing is restricted chiefly by tem-perature increases caused by frictional heat generated in thebearing. When the speed limit is reached, it becomes impos-sible to continue operation due to seizure and the like. The limit on rotation speed of a bearing represents the maxi-mum value at which the bearing can continue operation with-out generating seizure-causing heat. Accordingly, the rotation speed limit differs with each bear-ing type, dimensions, and accuracy, as well as with lubrica- tion methods, quality and quantity of lubricant, cage material,loading...