SPINDLE, SHAFT SUPPORTING DEVICE AND METHOD OF SUPPORTING A ROTATABLE SHAFT

1 . A spindle, comprising:

a shaft;

at least one non-contact bearing in operable communication with the shaft;

a housing in operable communication with the at least one non-contact bearing such that the shaft is rotatable relative to the housing; and

at least one non-contact thrust bearing in operable communication with the shaft configured to transfer oscillations to the shaft in directions parallel to an axis of the shaft.

2 . The spindle of claim 1 , further comprising a bearing support in operable communication with the at least one non-contact thrust bearing.

3 . The spindle of claim 2 , further comprising an oscillator configured to oscillate the bearing support in a direction parallel to the axis of the shaft.

4 . The spindle of claim 2 , wherein oscillation of the bearing support is transferred to the shaft through the at least one non-contact thrust bearing.

5 . The spindle of claim 2 , further comprising a bushing fixed to the shaft and in operable communication with the bearing support via the at least one non-contact thrust bearing.

6 . The spindle of claim 2 , further comprising a membrane configured to prevent rotation of the bearing support relative to the housing.

7 . The spindle of claim 6 , wherein a natural frequency of the membrane is selected to be near a frequency of the oscillations to be transferred.

8 . The spindle of claim 2 , further comprising a non-contact hydrostatic bearing in operable communication between the housing and the bearing support.

9 . The spindle of claim 1 , wherein the at least one non-contact thrust bearing is two non-contact thrust bearings and each of the two non-contact thrust bearings is configured to urge the shaft in one of two opposing directions.

10 . The spindle of claim 1 , wherein the at least one non-contact bearing is two non-contact bearings spaced longitudinally from one another.

11 . The spindle of claim 1 , wherein the at least one non-contact bearing is a journal bearing.

12 . The spindle of claim 1 , wherein fluid is provided to at least one of the non-contact bearings.

13 . The spindle of claim 12 , wherein the fluid is pressurized.

14 . The spindle of claim 1 , further comprising an electrical motor configured to rotate the shaft.

15 . A shaft supporting device, comprising:

a housing;

a shaft in operable communication with the housing;

at least one non-contact bearing in operable communication with the housing and the shaft configured to provide radial support to the shaft;

a bearing support in operable communication with the housing and the shaft via at least one non-contact bearing; and

at least one non-contact thrust bearing in operable communication with the bearing support and the shaft configured to transfer oscillatory motion from the bearing support to the shaft.

16 . A method of supporting a rotatable shaft, comprising:

rotationally supporting a shaft with at least one non-contact bearing;

axially positioning the shaft with at least one non-contact thrust bearing; and

transferring axial oscillations to the shaft through the at least one non-contact thrust bearing.