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

Figure 7

Comparative results of the damping 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 damping,

(b) Cross damping,

(c) Cross damping,

(d) Direct damping,