Speed Limit and Maximum Acceleration

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4.1 Speed Limit

The limiting speed of rolling element bearings is primarily a function of size and internal design. The speed limits given in this catalog should not be exceeded on a continuous basis to prevent premature failure due to excessive temperature. Contact RBC for solutions to high speed applications.

4.2 Maximum Acceleration (Deceleration)

A sufficiently large tangential friction force Ft , acting between outside diameter and track is needed to change the rotational speed of cam follower and yoke roller outer rings.

where u = coefficient of friction (outer ring to track)

(10)

The force Ft produces a moment Mt, which must accelerate the masses of outer ring and rollers around the bearing axis, plus the rollers in the load zone around their own axes.

The movement Mt can be calculated using:

(11)

Accelerating the mass of the outer ring normally requires the largest part of moment Mt. Assuming a coefficient of friction of m = 0.10 and a typical cam follower design, the following equation may be used for an estimate of the permissible angular acceleration a:

(12)

Excessive acceleration causes sliding of the outer ring on the track. The effects range from minor uniform wear on cam follower and track to flat spots on the cam follower with subsequent failure.