Momo
,
Saturday, 14th of August 2010 10:14:39 AM
l am designing an engine and l think the skf 1215 ball bearing is adequate.
Momo
Reading the data sheet of it at skf.com, l do not understand some
Registered User
things:
a)What are the dynamic and static load ratings? the sheet
Joined: Thursday, 10th of June 2010, 04:00:20
says 39kN and 15.6 kN. The rotor l am designing weights about half a ton,
Posts: 687
so it is lower than 15.6kN, but l do not know if l am making the correct
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interpretation.
b)The maximum temperature the engine could reach is
200degC. l could not find the temp rating of the bearing. Can it stand
200degC?
c) l am planning to use a bearing housing FNL 515 for this.
Does this housing include a shaft seal?
Thanks for your help.
BABESKIES!!!<3
,
Sunday, 15th of August 2010 05:06:57 AM
Please read the definition of static & dynamic load rating.
BABESKIES!!!<3
Registered User
SKF 1215 is a Self-aligning ball bearings, cylindrical bore, unsealed
Joined: Wednesday, 2nd of June 2010, 12:59:02
bearing.
Posts: 971
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SKF 1215 K is a Self-aligning ball bearings, Tapered bore, unsealed
bearing.For that you have to use adapter sleeve.For that you have to use
FNL 515A or FNL 515 B which contain shaft seal that you have to mention
seperately.
http://skf.com/skf/productcatalogue/Forwarder?action=PPP&lang=en&imperial=false&windowName=null&perfid=524091&prodid=5240910505
http://skf.com/skf/productcatalogue/Forwarder?action=PPP&lang=en&imperial=false&windowName=null&perfid=114003&prodid=1140031215
for housing:
http://skf.com/skf/productcatalogue/Forwarder?newlink=&action=search&lang=en&prodid=5240940515
**FOR FNL housing you have to use 1215K Bearing.
**Static Equivalent Radial Load (Por) :
The Static Equivalent Radial Load is a static radial load that would cause
the same total permanent deformation on the most heavily stressed
ball/raceway contact as the actual load.
**For static & dynamic load rating please visit following link:
http://efunda.com/DesignStandards/bearings/bearings_rotary_ld_life.cfm
[Bearings - Basic dynamic load rating is the load at which 90% of a group
of bearings can survive 1 million inner-race revolutions. However, some
bearing manufacturers use 90 million inner-race revolutions as the rating
basis. In either case, the bearing is basic load rating is the figure of
merit used to evaluate bearing life in applications where fatigue --
rather than inadequate lubrication, excessive temperature, overloading, or
overspeeding -- is the primary failure mechanism. Relationships for
predicting bearing fatigue life under both constant & sinusoidally varying
radial loads are given elsewhere in this chapter.
Relations for calculating basic dynamic load rating for conventional
bearings are given in Sections 9 & 11 of the AFBMA Standards. The
calculated ratings tend to be low because of recent advances in bearing
technology.
Bearings - Basic static-load rating is the maximum radial or thrust load a
bearing can endure without excessive permanent deformation. Maximum
deformation of rolling element or race that does not significantly degrade
bearing performance is 0.0001 times the diameter of rolling element
bearings. Equations for basic static load for standard bearings are given
in Sections 9 & 11 of the AFBMA Standards. ]
Minimum load
In order to provide satisfactory operation, self-aligning ball bearings,
like all ball & roller bearings, must always be subjected to a given
minimum load, particularly if they are to operate at high speeds or are
subjected to high accelerations or rapid changes in the direction of load.
Under such conditions the inertia forces of the balls & cage, & the
friction in the lubricant, can have a detrimental influence on the rolling
conditions in the bearing arrangement & may cause damaging sliding
movements to occur between the balls & raceways.
The requisite minimum load to be applied to self-aligning ball bearings
can be estimated using
Pm = 0,01 C0
where
Pm = equivalent minimum load, kN
C0 = basic static load rating, kN