Page 191 of catalogue Super Precision Bearings of Schaeffler Technologies GmbH & Co. KG

Engineering
Deflection and rigidity

Deflection and rigidity
Bearing set rigidity is dependant upon bearing arrangement and preloading. Rigidity of the entire machine tool system is, besides from bearing rigidity, substantially determined by shaft and housing rigidity as well.

Bearing Arrangement

Suffix

ca N/μm

KaE α = 15° and α =25° N

DB TBT QBC

ca1) 1,64 · ca 2 · ca 2,24 · ca 2,64 · ca

3 · FV 6 · FV 6 · FV 9 · FV 9 · FV

Axial rigidity c a Axial rigidity is defined as a quotient from axial load and axial displacement. c a = F a /δ a c a = axial rigidity [N/μm] F a = axial load [N] δ a = axial deflection [μm]
KaE = Unloading force

QBT PBC

FV = Preloading force

1)

Bearing Tables

15: Axial rigidity ca of a bearing set at a centrically acting axial load

Unloading force K aE If a bearing set is loaded by a centrically acting axial load, then the bearings are loaded as a result of deflection and their contact angle is set against the load direction while the opposing fitted bearing is simultaneously relieved. Unloading force K aE is defined as the force that unloads bearings by relieving the bearing set of the centrically acting axial load.

190