Electrical discharge machining device and method

1. An electrical discharge machining (EDM) device, comprising:

a spindle that is rotatable about a longitudinal axis;

a guide structure comprising a plurality of guideways; and

a plurality of electrodes, each of the electrodes coupled to the spindle via a flexible link, and slidably engaged with a respective one of the plurality of guideways;

wherein the plurality of electrodes are effective to machine a workpiece, the workpiece generally encircling the plurality of electrodes, the workpiece having a wall with an inner surface and an outer surface, the inner surface facing and being machined by the electrodes, wherein as the spindle rotates in a first rotational movement to a first position, the plurality of electrodes are brought into contact with a first radial area of the inner surface, and as the spindle rotates in a second rotational movement from the first position to a second position, the plurality of electrodes are brought into contact with a second radial area of the inner surface, the first radial area being different from the second radial area.

2. The EDM device of claim 1 , wherein each of the electrodes is installed on a slider configured to slide along the respective one of the plurality of guideways.

3. The EDM device of claim 1 , wherein each of the guideways extend along a direction angled with respect to a longitudinal axis of the spindle.

4. The EDM device of claim 1 , wherein the guide structure is fixed relative to a supporting element configured to support the workpiece to be machined.

5. The EDM device of claim 1 , wherein the flexible link and each of the guideways are configured to allow the plurality of electrodes, driven by the spindle, to be fed to a workpiece to be machined, respectively along directions angled with respect to a moving direction of the spindle.

6. The EDM device of claim 1 , wherein the flexible link and each of the guideways are configured to allow the plurality of electrodes to be fed to the workpiece to be machined, respectively along directions angled with respect to a longitudinal axis of the spindle, by driving the spindle to move along and/or rotate around the longitudinal axis thereof.

7. The EDM device of claim 6 , wherein the directions are at substantially equal angles with respect to the longitudinal axis of the spindle.

8. The EDM device of claim 1 , further comprising a carriage assembled with the spindle, wherein the carriage has an increased horizontal size compared to the spindle, in a plane substantially perpendicular to a longitudinal axis of the spindle, and the flexible link is configured to couple the plurality of electrodes to the carriage at a position near an outer boundary of the carriage.

9. The EDM device of claim 1 , wherein the workpiece is an annular part with one or more holes extending through the wall of the workpiece from the inner surface to the outer surface.

10. The EDM device of claim 1 , wherein the plurality of electrodes are arranged at different positions and extend outward from the spindle and rotate together as the spindle rotates.

11. The EDM device of claim 1 , wherein the plurality of electrodes are configured to create holes in the workpiece.

12. An electrical discharge machining (EDM) device, comprising:

a carriage configured to be assembled to a rotatable spindle;

a guide structure comprising a plurality of guideways; and

a plurality of electrode holders holding selected ones of a plurality of electrodes, the plurality of electrode holders being coupled to the carriage via a plurality of flexible links, respectively, and slidable along the plurality of guideways, respectively,

wherein the flexible links and the guideways are configured to allow the electrodes to be fed to a workpiece to be machined, respectively along different directions angled with respect to a moving direction of the carriage;

wherein the plurality of electrodes are effective to machine the workpiece, the workpiece generally encircling the plurality of electrodes, the workpiece having a wall with an inner surface and an outer surface, the inner surface facing and being machined by the electrodes, wherein as the spindle rotates in a first rotational movement to a first position, the plurality of electrodes are brought into contact with a first radial area of the inner surface, and as the spindle rotates in a second rotational movement from the first position to a second position, the plurality of electrodes are brought into contact with a second radial area of the inner surface, the first radial area being different from the second radial area.

13. The EDM device of claim 12 , wherein the workpiece is an annular part with one or more holes extending through the wall of the workpiece from the inner surface to the outer surface.

14. The EDM device of claim 12 , wherein the plurality of electrodes are arranged at different positions and extend outward from the spindle and rotate together as the spindle rotates.

15. The EDM device of claim 12 , wherein the plurality of electrodes are configured to create holes in the workpiece.

16. A method for machining a workpiece by an electrical discharge machining device that comprises a rotating spindle defining an axis, the workpiece generally encircling a plurality of electrodes, the workpiece having a wall with an inner surface and an outer surface, the inner surface facing and being machined by the plurality of electrodes, a guide structure comprising a plurality of guideways, and wherein the plurality of electrodes are coupled to the rotating spindle via a plurality of flexible links respectively and slidably engaged with the plurality of guideways respectively, the method comprising:

installing the workpiece to a supporting element;

fixing the guide structure relative to the supporting element; and

feeding the plurality of electrodes to the workpiece to create desired geometry, respectively along directions angled with respect to a moving direction of the rotating spindle;

wherein as the rotating spindle rotates in a first rotational movement to a first position, the plurality of electrodes are brought into contact with a first radial area of the inner surface of the workpiece, and as the rotating spindle rotates in a second rotational movement from the first position to a second position, the plurality of electrodes are brought into contact with a second radial area of the inner surface of the workpiece, the first radial area being different from the second radial area.

17. The method of claim 16 , wherein the workpiece is an annular part with one or more holes extending through the wall of the workpiece from the inner surface to the outer surface.

18. The method of claim 16 , wherein the plurality of electrodes are arranged at different positions and extend outward from the rotating spindle and rotate together as the rotating spindle rotates.

19. The method of claim 16 , wherein the plurality of electrodes are configured to create holes in the workpiece.