| 1)
| Basic
static load rating
|
|
A
bearing may sustain a local deformation permanently when exposed to an excessively
high static load or impact load. If the permanent deformation is beyond
a specific extent, smooth rotation is imposed. The static load under which
contact surface pressure working between the rolling element and raceway
may generate the following sizes of contact stress is called the basic static
load rating and is used as a reference to determine a high load.
|
|
| Self-aligning ball
bearings |
|
4600MPa
|
| Other ball bearings |
|
4200MPa
|
| Roller bearings |
|
4000MPa
|
|
|
|
| 2) |
Static
equivalent load |
|
The static equivalent load
is a virtually calculated load, under which contact stress of the same degree
as generated under actual loading conditions would occur between the rolling
elements and raceway in the section exposed to the maximum load.
It is calculated by means of the equivalent
static load calculation equation, using the load factors listed in the
tables.
|
|
|
| 3) |
Safety
coefficient |
|
A safety
coefficient is designated, based on empirical data, so as to ensure safety
in relation to basic static load rating.
| where:
|
fs |
: |
safety
coefficient |
|
|
C0 |
: |
basic static
load rating |
N |
|
P0 |
: |
static
equivalent load |
N |
Reference safety
coefficient, obtained based on the past operation records, are shown
in Table 3-2.
Consult Koyo for further advice regarding safety factors appropriate
to individual machines.
|
