Cutting element apparatuses, drill bits including same, methods of cutting, and methods of rotating a cutting element

1. A subterranean drilling system, comprising:

a drill string;

a rotary drill bit coupled to the drill string, the rotary drill bit comprising:

a bit body; and

a cutting element coupled to the bit body, the cutting element being structured to rotate in response to torque applied to the cutting element;

a cam assembly coupled to the drill string, the cam assembly comprising a cam surface;

a cam follower assembly in contact with the cam surface of the cam assembly; and

a torque-applying structure coupled to the cam follower assembly, the torque-applying structure configured to apply torque to the cutting element in response to relative rotation between the cam assembly and the cam follower assembly.

2. The drilling system of claim 1 , wherein the cutting element comprises at least one engaging feature and the torque-applying structure comprises a push rod having a first end disposed within a recess defined in the cam follower assembly and a second end structured to engage the at least one engaging feature of the cutting element.

3. The drilling system of claim 2 , wherein the first end of the push rod comprises a superabrasive material.

4. The drilling system of claim 2 , wherein the push rod is biased toward the cam follower assembly.

5. The drilling system of claim 2 , wherein the push rod comprises a flexible portion and a substantially rigid portion.

6. The drilling system of claim 1 , wherein the cam follower assembly comprises at least one cam follower element.

7. The drilling system of claim 6 , wherein the cam follower element comprises a substrate and a superabrasive table bonded to the substrate.

8. The drilling system of claim 1 , wherein at least a portion of the cam follower assembly is pivotably attached to the bit body.

9. The drilling system of claim 8 , wherein at least a portion of the cam follower assembly is rotatably attached to at least a portion of the torque-applying structure.

10. The drilling system of claim 9 , wherein at least a portion of the cam follower assembly pivots in response to relative rotation between the cam assembly and the cam follower assembly; and

wherein at least a portion of the torque-applying structure rotates in response to relative rotation between the cam assembly and the cam follower assembly.

11. The drilling system of claim 1 , wherein the cutting element is limited from rotating in a selected direction.

12. The drilling system of claim 1 , wherein the torque-applying structure is configured to cause the cutting element to rotate in periodic increments.

13. The drilling system of claim 1 , wherein the torque-applying structure is configured to cause the cutting element to rotate continuously.

14. The drilling system of claim 1 , wherein the cutting element rotates within an angle of rotation of less than 360 degrees.

15. The drilling system of claim 1 , further comprising a pressure-compensating assembly, the pressure-compensating assembly structured to at least partially compensate for differences between a pressure within at least a portion of the drill bit and another pressure external to at least a portion of the drill bit.

16. The drilling system of claim 15 , wherein the pressure-compensating assembly comprises a lubricating fluid within a sealed chamber, the sealed chamber being defined by at least one seal member and a dynamic member that is structured to move in response to changes in pressure external to the sealed chamber.

17. The drilling system of claim 1 , wherein the cam assembly comprises a plurality of cam inserts each affixed to a cam body, the plurality of cam inserts at least partially defining at least a portion of the cam surface; and

wherein at least one cam insert of the plurality of cam inserts at least partially surrounds an adjacent cam insert.

18. The drilling system of claim 17 , wherein the plurality of cam inserts are substantially identical.

19. The drilling system of claim 1 , wherein the cam assembly comprises a cam body having a substantially planar bottom surface; and

wherein the cam surface of the cam assembly is angled with respect to the substantially planar bottom surface of the cam body.

20. The drilling system of claim 1 , wherein the cam assembly comprises a substantially annular-shaped cam body;

wherein the cam surface comprises an internal surface of the cam body;

wherein the rotary drill bit is rotatable relative to an axis of rotation; and

wherein a radial distance between the axis of rotation and the internal surface of the cam body varies at different points on the internal surface of the cam body.

21. A subterranean drilling system, comprising:

a drill string;

a rotary drill bit coupled to the drill string, the rotary drill bit comprising:

a bit body;

a first cutting element coupled to the bit body, the first cutting element being structured to rotate in response to torque applied to the cutting element; and

a second cutting element coupled to the bit body; the second cutting element being structured to remain in a fixed position relative to the bit body;

a cam assembly coupled to the drill string, the cam assembly comprising a cam surface;

a cam follower assembly in contact with the cam surface of the cam assembly; and

a torque-applying structure coupled to the cam follower assembly, the torque-applying structure being configured to apply torque to the first cutting element in response to relative rotation between the cam assembly and the cam follower assembly.