Page 38 - Y-bearing-units

Selection of Y-bearing unit size

Equivalent static bearing load Requisite static load rating
An equivalent static bearing load is defined as The requisite basic static load rating C 0 can be
the hypothetical load which, if applied, would determined from
cause the same maximum rolling element load
in the bearing as the actual loads. The equiva- C 0 = s 0 P 0
lent static bearing load for Y-bearings and
Y-bearing units is obtained from the general where
equation C 0 = basic static load rating, kN
P 0 = equivalent static bearing load, kN
s 0 = static safety factor
P 0 = 0,6 F r + 0,5 F a
where Experience based guideline values of the static
P 0 = equivalent static bearing load, kN safety factor s 0 for Y-bearings and Y-bearing
F r = actual radial bearing load, kN units are provided in table 4.
F a = actual axial bearing load, kN

If P 0 < F r , calculate with P 0 = F r .
NOTE: When calculating P 0 , the maximum load
that can occur should be used and its radial and
axial components inserted in the equation
above. If a static load acts in different directions
on a bearing, the magnitude of these
components will change. In these cases, the
components of the load giving the largest value
of the equivalent static bearing load P 0 should
be used.

Table 4
Guideline values for static safety factor s 0
Type of operation Required static
safety factor s 0
Normal loads and smooth, vibration-free operation,
where noise levels are not specified, and speeds are
very low ≥ 0,5
Normal loads and smooth, vibration-free operation,
where noise levels are normal ≥ 1
Normal loads and high degree of running accuracy,
where low noise levels are specified ≥ 2
Pronounced shock loads, very slow or non-rotating bearings ≥ 2

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