Road-removal system employing polycrystalline diamond compacts
View Patent ↗Embodiments disclosed herein are directed to a system for removing road material. In an embodiment, the system may include a milling drum and at least one pick mounted on the milling drum. The pick may include polycrystalline diamond at least partially forming one or more working surfaces of the pick.
1. A system for removing a road material, the system comprising:
a milling drum rotatable about a rotation axis; and
a plurality of picks mounted on the milling drum, each of the plurality of picks including:
a pick body;
a polycrystalline diamond compact (“PDC”) directly attached to the pick body, the PDC having a curved bottom edge, a top cutting edge generally opposite the curved bottom edge including a portion that is substantially linear, and a substantially planar working surface extending between the curved bottom edge and the top cutting edge; and
a shield having a different composition from and attached to the pick body, the shield positioned near the PDC.
2. The system of claim 1 , wherein the substantially planar working surfaces has a back rake angle and the back rake angles include one or more of a negative back rake angle or a positive back rake angle.
3. The system of claim 2 , wherein each of the pick bodies includes an angled portion having an approximately matching angle with the back rake angle of the substantially planar working surface.
4. The system of claim 2 , wherein the back rake angle is about 6 degrees to about 14 degrees.
5. The system of claim 2 , wherein the back rake angle is about 8 degrees to about 12 degree.
6. The system of claim 2 , wherein the back rake angle is about 10 degrees.
7. The system of claim 2 , wherein the back rake angle is about 30 degrees positive back rake angle to about 30 degrees negative back rake angle.
8. The system of claim 1 , wherein at least a portion of the top cutting edge is rounded.
9. The system of claim 1 , wherein each of the PDCs includes a chamfer extending between the substantially planar working surface to one or more side surfaces, and the chamfer at least partially forms the top cutting edge.
10. The system of claim 9 , wherein at least a portion of the top cutting edge is un-chamfered.
11. The system of claim 2 , wherein the working surface has one or more portions having one or more side rake angles.
12. The system of claim 1 , wherein a bottom side of the PDC is nonlinear, a top side of the shield is nonlinear, and the bottom side of the PDC abuts the top side of the shield, and the bottom side of the PDC and the top side of the shield have complementary shapes.
13. The system of claim 1 , wherein at least a portion of the pick body includes cemented carbide.
14. The system of claim 1 , wherein the pick body has a first width, the PDC has a second width that is greater than the first width, and a portion of the PDC is unsupported by the pick body.
15. A method of removing road material, the method comprising:
advancing a plurality of picks toward road material, each of the plurality of picks including:
a pick body;
a polycrystalline diamond compact (“PDC”) directly attached to the pick body, the PDC forms a substantially planar working surface; and
a shield having a different composition from and attached to the pick body, the shield positioned near the PDC; and
advancing the cutting edges and the substantially planar working surfaces of the picks into the road material, thereby failing at least some of the road material while having the substantially planar working surfaces oriented at one or more of a positive rake angle or negative rake angle.
16. The method of claim 15 , further comprising producing a reconditioned surface having a non-perpendicular orientation relative to the working surfaces.
17. The method of claim 15 , wherein the cutting edge of each of the plurality of picks is formed between the substantially planar working surface and one or more side surfaces.
18. A system for removing a road material, the system comprising:
a milling drum rotatable about a rotation axis; and
a plurality of picks mounted on the milling drum, each of the plurality of picks including:
a pick body;
a polycrystalline diamond compact (“PDC”) directly attached to the pick body, the PDC including a substrate bonded to a polycrystalline diamond table having a substantially planar working surface and forming at least a portion of a cutting edge of each of the plurality of picks, each of the substantially planar working surfaces having a negative or positive back rake angle of about 6 degrees to about 14 degrees; and
a shield distinct having a different composition and attached to the pick body, the shield positioned near the PDC.
19. A system for removing a road material, the system comprising:
a milling drum rotatable about a rotation axis; and
a plurality of picks mounted on the milling drum, at least some of the plurality of picks including:
a pick body; and
a polycrystalline diamond compact (“PDC”) attached to the pick body, the PDC having a curved bottom edge, a top cutting edge generally opposite the curved bottom edge including a portion that is substantially linear, and a substantially planar working surface extending between the curved bottom edge and the top cutting edge.
20. The system of claim 19 , wherein the curved bottom edge is convexly curved and the top cutting edge is substantially parallel with an upper surface of the pick body.
21. The system of claim 19 , wherein the curved bottom edge generally defines part of a circle.
22. The system of claim 19 , wherein at least a portion of the top cutting edge is rounded.
23. The system of claim 19 , wherein the pick body defines a pocket that receives the PDC, the curved bottom edge of the PDC having a complementary geometry to a geometry of the pocket.
24. The system of claim 23 , wherein the pick body includes an angled face that at least partially defines the pocket that receives the PDC, the angled face being substantially parallel to the working surface of the PDC.
25. The system of claim 19 , wherein the PDC includes a substrate bonded to a polycrystalline diamond table, the polycrystalline diamond table includes the curved bottom edge and the top cutting edge.
26. The system of claim 19 , wherein the substantially planar working surface exhibits a substantially semicircular geometry.
27. The system of claim 19 , wherein the substantially planar working surface exhibits a truncated circular geometry.
28. The system of claim 19 , wherein the substantially planar working surface has a negative back rake angle.
29. The system of claim 28 , wherein the negative back rake angle is between 0 degrees and about 30 degrees.
30. The system of claim 28 , wherein the negative back rake angle is about 8 degrees to about 12 degree.
31. The system of claim 28 , wherein the negative back rake angle is about 10 degrees.
32. The system of claim 19 , wherein:
the substantially planar working surface has a negative back rake angle
the substantially planar working surface exhibits a truncated circular geometry;
the pick body includes a substantially planar upper surface that is substantially parallel with the top cutting edge of the PDC; and
the pick body defines a pocket that receives the PDC, the curved bottom edge of the PDC having a complementary geometry to a geometry of the pocket.