Ceramic&Exsev bearing series More and more bearings are being used in extreme special environments, such as in a vacuum, or in a clean, corrosive, or heated place. In some cases bearings are required to be insulated or antimagnetic. Applications of bearings in such environments are increasing in the field of state-of-the-art technology, e.g. vacuum equipment, aerospace equipment and semi-conductor production facilities. Bearings made of conventional materials and lubricants can hardly meet these new needs. JTEKT has succeeded in developing a series of bearings for use in extreme special environments, having started from the study of the very basics of materials and testing of their performance under various severe conditions. Exsev bearings for use in a vacuum environment Bore diameter 4 – 40 mm Exsev bearings for use in a clean environment Bore diameter 4 – 40 mm Ceramic bearings JTEKT has standardized the following bearings as the "Koyo bearing series". ¡Exsev bearings for use in a clean environment Designed for use in a vacuum. The friction surface of the bearing interior is coated with solid lubricant (or soft metal). Bearings pre-lubricated with special grease are also available. ¡Exsev bearings for use in a vacuum environment Produce insignificant contamination, provided with rolling elements and a cage made of self-lubricating materials. Optimal for use in environments which need to be clean. ¡Ceramic bearings Ceramic rings and rolling elements (silicon nitride Si3N4) ensure excellent performance in various extreme special environments. ¡For details, refer to JTEKT separate catalog "Ceramic bearings and bearings for extreme special environments" (CAT. NO. B2004E). C1 C2 Bore diameter 4 – 120 mm Linear ball bearings for vacuum Ball complement bore diameter 3 – 40 mm

The chart below summarizes the EXSEV bearing series and the conditions in which each operates successfully. Materials and lubricants which are resistant to certain special conditions are listed in Tables 1 and 2. Major Koyo EXSEV bearing series made of these materials and lubricants are listed in Table 3. Table 2 EXSEV bearing lubricants Lubricant Operating temperature range ; Vacuum resis- Steam pressure tance(room at high temperature) temperature Pa Pa Vacuum grease − 30 to + 200 Atmospheric pressure(105) to 10−5 Polytetrafluoroethylene resin − 100 to + 200 (PTFE) Atmospheric pressure to 10−5...

Table 3 Koyo EXSEV bearing series models and types Characteristics(selective points) Exsev bearings for use in a vacuum environment Vacuum resistance 1) Operating temperature range, ; Cleanness Repeated alternation between atmospheric pressure and medium vacuum environments − 30 to + 200 (class 1005) Repeated alternation between atmospheric pressure and high vacuum environments Exsev bearings for use in a clean environment From high vacuum to ultra-high vacuum − 100 to + 300 − 100 to + 350 − 200 to + 350 − − Repeated alternation between atmospheric pressure and medium vacuum environments − )...

Service life depends on use conditions. At present, it is not possible to predict their service life under varied use conditions. However, based on a variety of experiments and tests, JTEKT has established an experimental formulae to predict the lives of bearings. The formulae is described in the following subsections for reference only. 0.1 Special polymeric fluoride Equivalent load / load rating ■ Life of EXSEV Bearings EXSEV bearings, lubricated with a solid lubricant, are usually used under relatively light load conditions, such as 10% of their static load ratings or less. These bearings...

bearing series for use in a vacuum environment d 20 ∼ 40 mm B (Refer.) r Open type Full complement type Designed to accommodate only radial load. Therefore, most suitable for highspeed rotation. r uD Boundary dimensions (mm) r 1) ud Bearing No. Atmospheric pressure to 10 −5 Pa With vacuum MoS2 coating grease filled (cage) (Refer.) Basic 10−3 to 10−10 Pa Ag ion-plating (balls) d D B 20 20 42 47 12 14 0.6 1 SV 6004 ZZST SV 6204 ZZST SE 6004 ZZSTMSA7 SE 6204 ZZSTMSA7 SE 6004 ZZSTMG3 SE 6204 ZZSTMG3 25 25 47 52 12 15 0.6 1 SV 6005 ZZST SV 6205 ZZST SE 6005 ZZSTMSA7 SE 6205 ZZSTMSA7 30 30 55 62 13...

EXSEV bearing series-

bearing series for use in a clean environment d (25) ∼ 40 mm B r r ud uD Bearing No. Boundary dimensions (mm) r −30°C to 200°C Clean Class10 −100°C to 200°C Clean Class10 200°C to 260°C Clean Class10 d D B 25 52 15 1 SE 6205 ZZSTPRZ SE 6205 ZZSTPR SE 6205 ZZSTPRB 30 30 55 62 13 16 1 1 SE 6006 ZZSTPRZ SE 6206 ZZSTPRZ SE 6006 ZZSTPR SE 6206 ZZSTPR SE 6006 ZZSTPRB SE 6206 ZZSTPRB 35 35 62 72 14 17 1 1.1 SE 6007 ZZSTPRZ SE 6207 ZZSTPRZ SE 6007 ZZSTPR SE 6207 ZZSTPR SE 6007 ZZSTPRB SE 6207 ZZSTPRB 40 40 68 80 15 18 1 1.1 SE 6008 ZZSTPRZ SE 6208 ZZSTPRZ SE 6008 ZZSTPR SE 6208 ZZSTPR SE 6008 ZZSTPRB...

Hybrid ceramic bearings (for high speed applications) Refer. d (75) ∼ 120 mm B B r r1 r r r r 70,72 series r uD HAR 0,9 series Boundary dimensions (mm) r D B is mainly * This type of bearingrotating parts used in high speed such as machine tool spindles. Since rolling elements are made of ceramics, this type of bearing is shown here, even though not designed as EXSEV bearing series. (Bearing rings are made of high carbon chromium bearing steel) r1 ud uD ud uD d B r1 r ud NU 10 series Bearing No. r1 min. min. 75 115 20 1.1 0.6 80 80 110 125 16 22 1 1.1 0.6 0.6 85 85 120 130 18 22 1.1 1.1 90 90...

K-series super thin section ball bearings Koyo K-series super thin section ball bearings were developed to meet current engineering needs for thinner, lighter bearings. They are used extensively in automation and labor saving equipment, such as industrial robots. These bearings are sorted into nine dimension series according to cross-sectional area. Those of the same dimension series have an equivalent cross-sectional area irrespective of the bore diameter. They are available in three types that differ in structure. ■ Deep groove type Carries radial load, axial load in both directions, and combined...