Power operated rotary knife

1. An annular rotary knife blade comprising:

a body and a blade section extending from the body, the body and the blade section both centered about a central axis of rotation of the annular rotary knife blade;

the body including a first end and an axially spaced apart second end and an inner wall and a radially spaced apart outer wall, the outer wall of the body including a first surface being arcuate and protruding outwardly with respect to the central axis of rotation, the first surface including an upper region and a lower region, the upper region of the first surface being axially closer to the first end of the body and the lower region of the first surface being axially closer to the second end of the body;

the body further including a driven gear comprising a plurality of gear teeth, the plurality of gear teeth including outer surfaces comprising at least a part of the first surface; and

the outer wall of the body including a first bearing surface and a second bearing surface for rotatably supporting the annular rotary knife blade for rotation about the central axis of rotation, the first bearing surface including an upper bearing face in the upper region of the first surface, the outer surfaces of the plurality of gear teeth comprising at least a part of the upper bearing face; and

the outer wall of the body further including a bearing race protruding inwardly with respect to the central axis of rotation, the bearing race including the second bearing surface.

2. The annular rotary knife blade of claim 1 wherein the first bearing surface includes a lower bearing face in the lower region of the first surface.

3. The annular rotary knife blade of claim 2 wherein the outer surfaces of the plurality of gear teeth comprising at least a part of the upper bearing face in the upper region of the first surface and at least a part of the lower bearing face in the lower region of the first surface.

4. The annular rotary knife blade of claim 1 wherein at least a portion of the bearing race is arcuate in axial extent.

5. The annular rotary knife blade of claim 1 wherein the bearing race is axially closer to the second end of the body than the first surface.

6. The annular rotary knife blade of claim 1 wherein the bearing race is concave radially inwardly with respect to the central axis of rotation.

7. The annular rotary knife blade of claim 1 wherein the bearing race includes an upper region and a lower region, the upper region of the bearing race being axially closer to the first end of the body and the lower region being axially closer to the second end of the body, the second bearing surface including at least one of an upper bearing face in the upper region of the bearing race and a lower bearing face in the lower region of the bearing race.

8. The annular rotary knife blade of claim 1 wherein the plurality of gear teeth of the driven gear extend axially downwardly from the first end of the body and extending radially through the outer wall of the body, the plurality of gear teeth include outer surfaces comprising at least a part of the upper region of the first surface.

9. An annular rotary knife blade comprising:

a body and a blade section extending from the body, the body and the blade section both centered about a central axis of rotation of the annular rotary knife blade;

the body including a first end and an axially spaced apart second end and an inner wall and a radially spaced apart outer wall, the outer wall of the body including a first surface being arcuate and protruding outwardly with respect to the central axis of rotation, the first surface including an upper region and a lower region, the upper region of the first surface being axially closer to the first end of the body and the lower region of the first surface being axially closer to the second end of the body;

the body further including a driven gear comprising a plurality of gear teeth, the plurality of gear teeth including outer surfaces comprising at least a part of the first surface; and

the outer wall of the body including a first bearing surface for rotatably supporting the annular rotary knife blade for rotation about the central axis of rotation, the first bearing surface including an upper bearing face in the upper region of the first surface and a lower bearing face spaced axially from the upper bearing face, the outer surfaces of the plurality of gear teeth comprising at least a part of the upper bearing face.

10. The annular rotary knife blade of claim 9 wherein the lower region of the first surface includes the lower bearing face of the first bearing surface.

11. The annular rotary knife blade of claim 9 wherein the first surface of the outer wall of the body of the annular rotary knife blade is an arcuate surface having a constant radius of curvature.

12. The annular rotary knife blade of claim 9 wherein the upper region of the first surface extends between an upper end portion and an intermediate portion and the lower region of the first surface extends between a lower end portion and the intermediate portion, the intermediate portion includes a radial outermost location of the body of the annular rotary knife blade.

13. The annular rotary knife blade of claim 9 wherein the blade section extends from the second end of the body and the first surface of the outer wall of the body is convex radially outward with respect to the central axis of rotation of the annular rotary knife blade.

14. The annular rotary knife blade of claim 9 wherein the plurality of gear teeth of the driven gear extend axially downwardly from the first end of the body and extending radially through the outer wall of the body, the plurality of gear teeth include outer surfaces comprising at least a part of the upper region of the first surface.

15. The annular rotary knife blade of claim 9 wherein the outer wall of the body further includes a bearing race that is concave radially inward with respect to the central axis of rotation, the bearing race including an upper region and a lower region, the upper region of the bearing race being axially closer to the first end of the body and the lower region being axially closer to the second end of the body, the outer wall of the body further including a second bearing surface for rotatably supporting the annular rotary knife blade for rotation about the central axis of rotation, the second bearing surface including at least one of an upper bearing face in the upper region of the bearing race and a lower bearing face in the lower region of the bearing race.

16. The annular rotary knife blade of claim 15 wherein the upper bearing face and the lower bearing face of the first bearing surface and the upper bearing face and the lower bearing face of the second bearing surface are arcuate in axial extent.

17. An annular rotary knife blade comprising:

a body and a blade section extending from the body, the body and the blade section both centered about a central axis of rotation of the annular rotary knife blade;

the body including a first end and an axially spaced apart second end and an inner wall and a radially spaced apart outer wall, the outer wall of the body including:

a first surface being arcuate and protruding outwardly with respect to the central axis of rotation, the first surface including an upper region and a lower region, the first surface upper region being axially closer to the first end of the body and the first surface lower region being axially closer to the second end of the body; and

a bearing race protruding inwardly with respect to the central axis of rotation, the bearing race including a bearing race upper region and a bearing race lower region, the upper region of the bearing race being axially closer to the first end of the body and the lower region being axially closer to the second end of the body;

the body further including a driven gear comprising a plurality of gear teeth, the plurality of gear teeth including outer surfaces comprising at least a part of the first surface; and

the outer wall of the body including a first bearing surface and an axially spaced apart second bearing surface for rotatably supporting the annular rotary knife blade for rotation about the central axis of rotation, the outer surfaces of the plurality of gear teeth comprising at least a part of the first bearing surface.

18. The annular rotary knife blade of claim 17 wherein the bearing race comprises at least a part of the second bearing surface.

19. The annular rotary knife blade of claim 17 wherein the first bearing surface of the outer wall includes an upper bearing face in the first surface upper region and a lower bearing face in the first surface lower region, the outer surfaces of the plurality of gear teeth comprising at least a part of the upper bearing face of the first bearing surface.

20. The annular rotary knife blade of claim 17 wherein the first bearing surface of the outer wall includes an upper bearing face in the first surface upper region and a lower bearing face in the first surface lower region, plurality of gear teeth comprising at least a part of one of the upper bearing face and the lower bearing face of the first bearing surface.

21. The annular rotary knife blade of claim 17 wherein the second bearing surface of the outer wall includes a lower bearing face in the bearing race lower region.

22. The annular rotary knife blade of claim 17 wherein the second bearing surface of the outer wall includes at least one of an upper bearing face in the upper region of the bearing race and a lower bearing face in the lower region of the bearing race.

23. The annular rotary knife blade of claim 17 wherein the first bearing surface of the outer wall includes a lower bearing face spaced axially from the upper bearing face and the lower region of the first surface includes the lower bearing face of the first bearing surface.