Crop processor and a manufacturing process for a crop processor

1. A crop processor for cracking kernels in a forage harvester, the crop processor comprising: a housing having an inlet and an outlet; and a first comminuting roll and a second comminuting roll, both mounted inside the housing, the first comminuting roll and the second comminuting roll being arranged in parallel to define an opening between the first comminuting roll and the second comminuting roll, wherein the first comminuting roll and the second comminuting roll are configured to rotate, during use, in opposing rotation directions to transport a flow of harvested crop, received from the inlet, through the opening towards the outlet, wherein the first comminuting roll is configured to rotate at a greater speed than the second comminuting roll,

wherein the first comminuting roll and the second comminuting roll each comprise a plurality of teeth arranged on a circumferential surface thereof, each of the plurality of teeth comprising a leading edge which faces in the rotation direction of the comminuting roll on which the plurality of teeth are arranged,

wherein the leading edge of the teeth of the second comminuting roll comprises a hard region having a greater hardness than the leading edge of the teeth of the first comminuting roll, and

wherein the plurality of teeth of the first comminuting roll comprise a substantially flat-top edge; wherein the substantially flat-top edge comprises a hard region having a greater hardness than the leading edge of the teeth of the first comminuting roll.

2. The crop processor according to claim 1 , wherein a trailing edge of the teeth of the first comminuting roll comprises a hard region having a greater hardness than the leading edge of the teeth of the first comminuting roll.

3. The crop processor according to claim 1 , wherein the hard region of the leading edge of the teeth of the second comminuting roll has a greater hardness than a trailing edge of the teeth of the second comminuting roll.

4. The crop processor according to claim 1 , wherein the plurality of teeth of the second comminuting roll comprise a substantially flat-top edge; wherein the substantially flat-top edge comprises a hard region having a greater hardness than the trailing edge of the teeth of the second comminuting roll.

5. The crop processor according to claim 1 , wherein the hard region comprises a wear resistant layer having been deposited by laser-cladding.

6. The crop processor according to claim 1 , wherein the teeth comprise an air hardened surface region.

7. The crop processor according to claim 1 , wherein at least one edge of the teeth comprise a laser hardened surface region.

8. The crop processor according to claim 1 , wherein the plurality of teeth have an asymmetrical profile in an axial section of the comminuting roll on which the plurality of teeth are arranged.

9. A forage harvester comprising a crop processor according to claim 1 .

10. A method of manufacturing a crop processor for cracking kernels in a forage harvester, the method comprising:

manufacturing a first comminuting roll and a second comminuting roll; and

assembling the comminuting rolls into a housing having an inlet and an outlet, the first comminuting roll and the second comminuting roll being arranged in parallel to define an opening between the first comminuting roll and the second comminuting roll,

wherein the first comminuting roll and the second comminuting roll are configured to rotate, during use, in opposing directions to transport a flow of harvested crop, received from the inlet, through the opening towards the outlet,

wherein the first comminuting roll is configured to rotate at a greater speed than the second comminuting roll, and wherein manufacturing the first comminuting roll and the second comminuting roll comprises:

providing a pair of substantially cylindrical shaped rolls;

machining a plurality of teeth in the substantially cylindrical shaped rolls, each of the plurality of teeth comprising a leading edge arranged, during use, to face in a rotation direction of the crop comminuting roll in which the plurality of teeth are machined;

forming a hard region on the leading edge of the teeth of the second comminuting roll, the hard region having a greater hardness than the leading edge of the teeth of the first comminuting roll; and

wherein the plurality of teeth of the first comminuting roll comprise a substantially flat-top edge;

wherein the substantially flat-top edge comprises a hard region having a greater hardness than the leading edge of the teeth of the first comminuting roll.

11. The method according to claim 10 , wherein the method further comprises forming a hard region on a trailing edge of the teeth of the first comminuting roll arranged to face away from the rotation direction of first comminuting roll, the hard region having a greater hardness than the leading edge of the teeth of the first comminuting roll.

12. The method according to claim 10 , wherein forming the hard region comprises forming the hard region on the leading edge of the teeth of the second comminuting roll to have a greater hardness than a trailing edge of the teeth of the second comminuting roll, the trailing edge being arranged to face away from the rotation direction of the second comminuting roll.

13. The method according to claim 10 , wherein forming the hard region comprises laser-cladding a wear resistant layer onto an edge of the teeth of at least one of the first comminuting roll and the second comminuting roll.

14. The method according to claim 13 , wherein manufacturing the first comminuting roll and the second comminuting roll further comprises air hardening at least one edge of the teeth.