Page 1048 - Rollingbearings

21 Hybrid bearings
Greases for sealed bearings Hybrid bearings with SKF hybrid cylindrical roller bearings are
The standard grease, suitable for most com- special steel rings itted with one of the following cages:
mon operating conditions of electric motors
and generators, is indicated by the designa- and coatings • a glass ibre reinforced PA66 cage,
tion sufix WT (table 3, page 245) window-type, roller centred (designation
For additional information about greases, For speciic application requirements, hybrid sufix P)
refer to Selecting a suitable grease, bearings can be customized: • a glass ibre reinforced PEEK cage,
page 116 window-type, roller centred (designation
• bearing rings stabilized for temperatures sufix PH)
Grease life ≤ 300 °C (570 °F) • a machined brass cage, riveted, roller
The estimated grease life is typically at least • bearing rings made of through-hardened centred (designation sufix M)
twice as long as for same-sized bearings stainless steel for enhanced corrosion and • a machined brass cage, window-type,
with steel balls (Grease life for capped bear- wear-resistance and with good high- inner or outer ring centred (depending on
ings, page 246) temperature properties bearing design) (designation sufix ML)
• bearing rings made of through-hardened
stainless steel for cryogenic temperatures For additional information, refer to Cages,
XL hybrid bearings • bearing rings made of high-temperature page 502
tool steel When used at high temperatures, some
• are identiied by the designation sufix • ring coating with zinc chromate or thin lubricants can have a detrimental effect on
VA970 dense chromium for corrosion protection polyamide cages For additional information
• are designed to meet the application • ring coating based on molybdenum for low about the suitability of cages, refer to Cages,
requirements for electric generators in friction, especially in vacuum or gas page 187
larger wind turbines applications
• are available for the most commonly used
generator sizes (product table, For availability and detailed information,
page 1050) contact SKF

Hybrid cylindrical Cages
roller bearings SKF hybrid deep groove ball bearings are

itted with one of the following cages:
• are separable
• are suitable for high speeds • a stamped steel cage, riveted, ball centred
21 • accommodate heavy radial loads (no designation sufix)
• accommodate axial displacement (ig. 4) • a glass ibre reinforced PA66 cage, snap-
• are commonly used in electric motors, type, ball centred (designation sufix TN9)
especially traction motors, and in applica- • a glass ibre reinforced PEEK cage, snap-
tions running under severe operating type, ball centred (designation sufix TNH)
conditions • a machined brass cage, riveted, ball cen-
tred (designation sufix M)

Basic design bearings For additional information, refer to Cages,
page 249
The NU design cylindrical roller bearing, Fig. 3
which has two integral langes on the outer Hybrid cylindrical roller bearing
ring and no langes on the inner ring, is the
standard basic design for hybrid cylindrical
roller bearings (ig. 3)

1046