Dynamic Coefficients Identification of Water-Lubricated Hybrid Bearings Used in High-Speed Spindles with Different Excitation Methods

Figure 6

Comparative results of the stiffness coefficients by additional unbalance excitation: one water supply pressure (2.5 MPa) and six journal rotating speeds (9,000 r/min to 24,000 r/min).

(a) Direct stiffness,

(b) Cross stiffness,

(c) Cross stiffness,

(d) Direct stiffness,