RBC Thin Section Ball Bearings

RBC thin section ball bearings are engineered to solve a variety of design problems that cannot be solved with conventional ball bearings.

operating conditions

Lubrication

Lubricants serve a number of very important purposes in ball bearings, including:

  • protecting bearing surfaces from corrosion
  • reducing rolling and sliding friction
  • preventing metal-to-metal contact between balls and raceway
  • providing a barrier against external contaminants (grease)
  • removing heat (oil)

Lack of lubrication or inadequate lubrication is the most common cause of bearing failure.

Standard RBC Thin Section Ball Bearings are lubricated with either oil or grease. The unsealed bearings, the K series, are thoroughly coated in MIL-PRF-3150 or MIL­PRF-6085 oil and drained of excess. Sealed bearings are lubricated with MIL-PRF-23827 grease. The external surfaces of sealed bearings are lightly coated with the same grease for corrosion resistance. Additional lubricants are also available. 

Temperature
 
Standard RBC Thin Section Ball Bearings can operate at temperatures from -65°F to 250°F Temperatures up to 350°F can be reached if the bearings are temperature stabilized. By the use of special materials RBC can provide bearings for operation to 900°F. Contact us for recommendations on bearings operating above 250°F.

Limiting Speed

The limiting speed of a bearing is dependent upon a number of different factors including bearing size, bearing type, ball separator design, lubrication and loading. The limiting speeds for the bearings shown are determined using the following:

N = 1000 * k    with N = Speed (RPM)
 
E = D+B (Bearing Pitch Diameter)
                           
2 
k - constant, see table below 

The k values shown give the maximum speeds at which a typical thin section ball bearing can operate. It is recommended that operating speeds of large diameter bearings in a given series be reduced up to 40% of the calculated rating to avoid high bearing temperatures.

Speed ratings can also be impacted by load conditions, lubrication, alignment and ambient temperature. All of these factors must be considered when designing thin section ball bearings into your application.

 Bearing Type Load Condition k Value
Grease Oil
C or A Radial or Thurst 16 20 
X Thrust 10 12
X Radial, Combined Radial & Thrust or Moment 3 4