CUTTER HEAD FOR LONGWALL SHEARER

Abstract

A cutter head for a longwall shearer includes a drum, a vane, and a plurality of cutting bits. The drum includes a first end and a second end and defines an axis of rotation extending therebetween. The vane is connected to the drum and extends in a helical manner along at least a portion of the axis. The vane defines an edge surface extending along an outer perimeter of the vane. The cutting bits are secured to the vane edge surface. Each cutting bit includes a block and a bit coupled to the block. The block is secured to the edge surface and extends beyond the outer perimeter of the vane.

Description

BACKGROUND

The present invention relates to the field of mining machines. Specifically, the present invention relates to a cutter head for a longwall shearer.

A conventional shearer drum includes radial cutting bits positioned within bit holders. The drum includes a spiral vane having a loading fence extending along the outer perimeter of the vane. The fence urges cut material into the space between the vane surfaces, and the vane carries cut material from the mine face to a face conveyor behind the shearer drum. The vane includes notches formed along the loading fence, and bit holders are coupled to the vane in the notches. The bit holders have a rectangular hole aligned along a radius extending from the longitudinal axis of the drum. An outer edge of the loading fence has a constant radius relative to the longitudinal axis of the drum, and the loading fence is a constant distance below the radius of the bit tips to prevent the loading fence from rubbing against solid, uncut material to prevent damage and ignition of flammable gas. In one embodiment, the minimum distance between the loading fence and the bit tips is about 100 mm. U.S. Pat. No. 4,657,308 shows an example of a forward attack bit and a bit holder, which also requires a notched vane in the drum.

SUMMARY

In one aspect, the invention provides a longwall shearer for removing material from a mine face. The longwall shearer includes a movable chassis, a first arm, a second arm, a first cutter head, and a second cutter head. The first arm includes a first end pivotably coupled to the chassis and a second end. The second arm includes a first end pivotably coupled to the chassis and a second end. The first cutter head includes a first drum, a first vane, and a plurality of first cutting bits coupled to the first vane. The first drum is coupled to the second end of the first arm and defines a first axis of rotation. The first vane extends in a helical manner along at least a portion of the first axis and defines a first edge surface. The first cutting bits are secured to the first edge surface of the first vane and extend beyond the first edge surface. The second cutter head includes a second drum, a second vane, and a plurality of second cutting bits coupled to the second vane. The second drum is coupled to the second end of the second arm and defines a second axis of rotation. The second vane extends in a helical manner along at least a portion of the second axis and defines a second edge surface. The second cutting bits are secured to the second edge surface of the second vane and extend beyond the second edge surface.

In another aspect, the invention provides a cutter head for a longwall shearer. The cutting head includes a drum, a vane, and a plurality of cutting bits. The drum includes a first end and a second end and defines an axis of rotation extending therebetween. The vane is connected to the drum and extends in a helical manner along at least a portion of the axis. The vane defines an edge surface extending along an outer perimeter of the vane. The cutting bits are secured to the vane edge surface. Each cutting bit includes a block and a bit coupled to the block. The block is secured to the edge surface and extends beyond the outer perimeter of the vane.

In yet another aspect, the invention provides cutter head for a longwall shearer, the cutter head including a drum, a vane connected to the drum, a plurality of cutting bits, and a loading fence. The drum includes a first end and a second end and defines an axis of rotation extending therebetween. The vane is connected to the drum and extends in a helical manner along at least a portion of the axis. The vane defines an edge surface extending along an outer perimeter of the vane. The plurality of cutting bits is secured to the vane edge surface. Each cutting bit includes a block and a bit removably coupled to the block. The block is secured to the edge surface and extends beyond the outer perimeter of the vane. The block includes a slot, and the bit includes a tip and a shank received within the block slot. The shank defines a shank axis extending at an angle with respect to a line extending radially from the drum axis. The loading fence is secured to the edge surface and protrudes from the edge surface. The loading fence extends between two adjacent cutting bit blocks in a direction generally parallel to the vane. The loading fence and sides of the cutting bit blocks form a continuous loading surface.

Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a mining machine.

FIG. 2 is a side view of a cutter head.

FIG. 3 is a perspective view of a cutting bit assembly.

FIG. 4 is a reverse perspective view of the cutting bit assembly of FIG. 3.

FIG. 5 is a top view of the cutting bit assembly of FIG. 3.

FIG. 6 is a side view of the cutting bit assembly of FIG. 3.

FIG. 7 is an exploded perspective view of a holder block and bit.

FIG. 8 is a perspective view of the cutter head of FIG. 2 with several cutting bit assemblies removed.

FIG. 9 is a perspective view of a cutter head including a cutting bit assembly according to another embodiment.

FIG. 10 is a perspective view of the cutting bit assembly of FIG. 9.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Use of “including” and “comprising” and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Use of “consisting of” and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.

FIG. 1 illustrates a longwall shearer 10 including a chassis or base 14 and a pair of cutting assemblies 18. The base 14 is configured to tram along a face (not shown) of material to be mined in a first direction 26 and a second direction 28 opposite the first direction 26. As the base 14 moves in the first direction 26, a first cutting assembly 18a is in a leading position and a second cutting assembly 18b is in a trailing position. In the illustrated embodiment, the first cutting assembly 18a is elevated to cut material, such as coal, from an upper portion of the mine face, while the second cutting assembly 18b is in a lower position to cut material from a lower portion of the mine face.

Each cutting assembly 18 includes a ranging arm 30 and a cutter head 34. In the illustrated embodiment, the cutting assembly 18 also includes a guide assembly 38; in other embodiments, the cutting assembly 18 may not include the guide assembly 38. The ranging arm 30 is pivotably coupled to the base 14 on one end and rotatably supports the cutter head 34 on another end.

As shown in FIG. 2, each cutter head 34 includes a drum 54, vanes 58, and a plurality of cutting bit assemblies or cutting bit systems 62 coupled to the vanes 58. In the illustrated embodiment, the drum 54 has a generally cylindrical shape. The drum 54 has a first end 70 and a second end 74, and a drum axis 78 is defined therebetween. The first end 70 is pivotably coupled to the ranging arm 30, and the second end 74 engages the mine face. The drum 54 rotates about the drum axis 78 in a first direction 82.

The vanes 58 are connected to the drum 54 and extend in a spiral or helical manner along the periphery or outer surface of the drum 54, along at least a portion of the drum axis 78 between the first end 70 and the second end 74. In the illustrated embodiment, the cutter head 34 includes multiple vanes 58; in other embodiments, the cutter head 34 may include one vane 58, or it may include fewer or more vanes 58 than the illustrated embodiment. The vane 58 defines an edge surface 84 proximate an outer perimeter of the vane 58 and a loading surface 86 extending between the outer surface of the drum 54 and the edge surface 84. The edge surface 84 includes a first or leading edge proximate the first end 70 of the drum 54 and a second or trailing edge proximate the second end 74 of the drum 54. The loading surface 86 is shaped or contoured to match the helical shape of the vane 58. As the drum 34 rotates, the vane 58 urges the cut material from the second end 74 toward the first end 70, where the cut material is deposited onto a face conveyor (not shown) below the chassis 10 (FIG. 1).

As shown in FIGS. 3 and 4, each cutting bit system 62 includes a holder block 90, and bit 94, and a fence or loading plate 98. The holder 90 includes side surfaces 102 proximate the edges of the edge surface 84, and a slot 110 extending through the holder block 90 (FIG. 4). The holder block 90 is secured (for example, by welding) to the edge surface 84 of the vane 58 and extends outwardly from the edge surface 84 in a direction that is generally perpendicular to the drum axis 78 (FIG. 2). The loading plate 98 is positioned between adjacent bit holder blocks 90 to urge cut material into the space between the loading surfaces 86 of the vanes 58 and facilitate movement of the cut material away from the mine face. The holder blocks 90 and plates 98 are coupled to one another and to the vane 58 (e.g., by welding). The holder blocks 90 and plates 98 effectively form an integral loading surface that is continuous with the loading surface 86 of the vane 58 to engage and scroll the cut material toward the first end 70 of the drum 54.

Each holder block 90 includes at least one angled side surface 102 that approximately matches the contour of the adjacent loading surface 86. The side surface 102 is substantially flush with the loading surface 86, permitting the holder block 90 and the bit 94 to be aligned with the leading edge of the edge surface 84, or the edge proximate the first end 70 of the drum 54. In the illustrated embodiment, the top surface of each holder block 90 is continuous with a respective loading fence 98 immediately behind the block 90. Additionally, as best shown in FIGS. 5 and 6, the side surface 102 of the holder block 90 is angled from top to bottom so that a top portion is aligned with the leading edge of the vane 58 and extends along the contour of the loading surface 86. In addition, the bit 94 is positioned so that a cutting tip 106 extends beyond the leading edge and is positioned over the space between the loading surfaces 86 of the vane 58. Since the side of the bit holder block 90 and the bit 94 are positioned flush or nearly flush with the loading surface 86 of the vane 58, material that is cut by the bit 94 is more likely to fall directly into the space between the loading surfaces 86 of the vane 58 and scroll toward the first end 70. This configuration increases the drum's loading efficiency, or the ability to carry cut material from the mine face to the face conveyor.

In the illustrated embodiment, grooves are formed in the ends of the blocks 90 to facilitate positioning and attaching the loading plates 98 to the holder blocks 90 by welding. As shown in FIGS. 3 and 4, the height of the loading plate 98 varies along the length of the plate 98 in order to facilitate loading of the cut material along the vane 58 and onto the face conveyor. The plate 98 is higher at its leading end where it closely follows a bit 94 and holder block 90, and the height is lower at the trailing end to prevent rubbing coal or rock. Thus, the higher leading end of the plate 98 moves through the rock more easily to engage more of the cut material and carry the material toward the space between the loading surfaces 86 of the vane 58.

As shown in FIG. 7, the bit 94 includes a first portion 122 having the tip 106 for engaging the mine face, a second portion or shank 126, and a retention hole 130. In the illustrated embodiment the holder block 90 also includes an opening 114 and a spray nozzle 118 received within the opening 114 to spray fluid onto the cut material and/or the bit 94. In the illustrated embodiment, the bit 94 also includes a shoulder 134 abutting the holder block 90. Also, in the illustrated embodiment, the shoulder 134 includes an opening 138 that is aligned with the opening 114 for the spray nozzle 118. The spray nozzle 118 is secured within the opening 114 by a threaded connection, and the holder 90 has internal water passages (not shown) to supply water or other fluid to the spray nozzle 118 from passages (not shown) in the drum vane 58.

The shank 126 extends away from the first portion 122 of the bit 94 and is received within the slot 110. In the illustrated embodiment, the retention hole 130 is positioned proximate an end of the shank 126 that protrudes from the slot 110 of the holder block 90. The bit 94 is secured to the holder block 90 by passing a pin 140 or other member through the retention hole 130 to prevent the shank 126 from sliding out of the slot 110. As best shown in FIG. 4, the holder blocks 90 stand proud of the edge surface 84 (i.e., extend above the edge surface 84), and the rear of the slot 110 is accessible behind the loading plate 98 to facilitate assembly and removal of the bit 94.

Although FIGS. 3-6 show two holder blocks 90 and one loading plate 98 coupled to the vane edge surface 84, it is understood that additional cutting bit systems 62 are positioned along the length of the vane 58 proximate a leading edge. In addition, the grooves between the blocks 90 and the plate 98 may be filled in (e.g., by welding) in order to form a smooth surface between the plates 98 and the side surfaces 102 of the blocks 90. In addition, each cutting assembly 18a, 18b includes cutting bit systems 62 that are oriented based on the rotation of the cutter drum 34. For example, one of the cutter heads 34 includes cutting bit systems 62 with a “left” or counter-clockwise orientation and the other cutter head 34 includes cutting bit systems 62 with a “right” or clockwise orientation.

Referring to FIG. 8, the shank 126 defines a shank axis 142 that is oriented at an angle to a line intersecting the drum axis 78, rather than being aligned along a radial line extending from the axis 78. In the illustrated embodiment, the shank axis 142 is aligned with a line that is substantially tangent to the edge surface 84 of the vane 58. In one embodiment, the shank axis 78 may be aligned with a line that is substantially tangent to the outer surface of the drum 54. The tip 106 is angled toward the direction of rotation of the drum 54; the shank 126 extends away from the direction of rotation of the drum 54, and is oriented at an angle that is more tangential relative to the drum 54 than conventional forward attack bits.

Positioning the cutting bit assembly 62 on the edge surface 84 of the vane 58 permits the holder blocks 90 and bits 94 to become continuous with the loading surface 86 rather than being positioned in notches of the loading surface 86. The tip of each bit 94 is substantially aligned with the loading surface 86. The cutting bit system 62 simplifies the amount of disassembly required to remove broken bits 94 or accumulated dirt. In addition, the same bits 94 can be used for either cutting assembly 18a, 18b, since the direction of rotation of each cutter head 34 does not require separate bit geometry. The cutting bit system 62 is less expensive to produce and provides superior loading performance compared to conventional conical-bit or radial-bit drums. Furthermore, the cutting bit system 62 reduces the complexity of manufacturing and maintenance of the cutting assembly 18a by reducing the need to form notches on the vane 58 to support the holder 90.

FIGS. 9 and 10 illustrate a cutting bit system 462 according to another embodiment. Each holder block 490 and loading plate 498 is positioned on the edge surface 84 of the vane 58. Each bit 494 includes a shank 526 (FIG. 10) defining a shank axis 542 and is positioned within a slot 510 of the holder block 490. The shank axis 542 is aligned radially with respect to the drum axis 78. Each shank axis 542 is aligned to intersect the drum axis 78. Also, the same bits 494 can be used for the cutter head 34 of either cutting assembly 18a, 18b since the direction of rotation of each cutter head 34 does not require separate bit geometry.

Thus, the invention provides, among other things, a cutter head for a longwall shearer. Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described.

Claims

1. A longwall shearer for removing material from a mine face, the longwall shearer comprising: a movable chassis;a first arm including a first end pivotably coupled to the chassis and a second end;a second arm including a first end pivotably coupled to the chassis and a second end;a first cutter head including a first drum, a first vane, and a plurality of first cutting bits coupled to the first vane, the first drum coupled to the second end of the first arm and defining a first axis of rotation, the first vane extending in a helical manner along at least a portion of the first axis and defining a first edge surface, the first cutting bits secured to the first edge surface of the first vane and extending beyond the first edge surface;a second cutter head including a second drum, a second vane, and a plurality of second cutting bits coupled to the second vane, the second drum coupled to the second end of the second arm and defining a second axis of rotation, the second vane extending in a helical manner along at least a portion of the second axis and defining a second edge surface, the second cutting bits secured to the second edge surface of the second vane and extending beyond the second edge surface.

2. The longwall shearer of claim 1, wherein the first cutting bits are spaced apart along the first edge surface, and wherein the first cutter head includes a loading fence secured to the first edge surface and extending between two adjacent cutting bits in a direction generally parallel to the vane.

3. The longwall shearer of claim 1, wherein each first cutting bit includes a block secured to the first edge surface and a bit removably coupled to the block.

4. The longwall shearer of claim 3, wherein the bit includes a shank and a tip, wherein the block includes a slot for receiving the shank.

5. The longwall shearer of claim 4, wherein the shank defines a shank axis, the shank axis extending at an angle with respect to a line extending radially from the first axis.

6. The longwall shearer of claim 5, wherein the shank axis is substantially aligned along a line that is tangent to the first edge surface.

7. The longwall shearer of claim 1, wherein the first vane defines a contoured loading surface extending between the first drum and the first edge surface, wherein each first cutting bit has a tip that is aligned with the loading surface.

8. A cutter head for a longwall shearer, the cutter head comprising: a drum including a first end and a second end and defining an axis of rotation extending therebetween;a vane connected to the drum and extending in a helical manner along at least a portion of the axis, the vane defining an edge surface extending along an outer perimeter of the vane; anda plurality of cutting bits secured to the vane edge surface, each cutting bit including a block and a bit coupled to the block, the block secured to the edge surface and extending beyond the outer perimeter of the vane.

9. The cutter head of claim 8, wherein the plurality of cutting bits are spaced apart at intervals along the edge surface.

10. The cutter head of claim 9, further comprising a loading fence secured to the edge surface and protruding from the edge surface, the loading fence extending between two adjacent cutting bit blocks in a direction generally parallel to the vane, the loading fence and the cutting bit blocks forming a continuous loading surface.

11. The cutter head of claim 10, wherein the vane defines a loading surface extending between the drum and the edge surface, wherein the loading fence is aligned with the loading surface.

12. The cutter head of claim 8, wherein the bit is removably coupled to the block.

13. The cutter head of claim 12, wherein each cutting bit further includes a pin, the bit including a hole for receiving the pin to removably couple the bit to the block.

14. The cutter head of claim 8, wherein the bit includes a shank and a tip, wherein the block includes a slot for receiving the shank.

15. The cutter head of claim 14, wherein the shank defines a shank axis, the shank axis extending at an angle with respect to a line extending radially from the drum axis.

16. The cutter head of claim 15, wherein the shank axis is substantially aligned along a line that is tangent to the edge surface.

17. The cutter head of claim 8, wherein the vane defines a loading surface extending between the drum and the edge surface, wherein the block includes a side surface that is generally continuous with the loading surface, and the bit having a tip that is aligned with the loading surface.

18. A cutter head for a longwall shearer, the cutter head comprising: a drum including a first end and a second end and defining an axis of rotation extending therebetween;a vane connected to the drum and extending in a helical manner along at least a portion of the axis, the vane defining an edge surface extending along an outer perimeter of the vane;a plurality of cutting bits secured to the vane edge surface, each cutting bit including a block and a bit removably coupled to the block, the block secured to the edge surface and extending beyond the outer perimeter of the vane, the block including a slot, the bit including a tip and a shank received within the block slot, the shank defining a shank axis extending at an angle with respect to a line extending radially from the drum axis; anda loading fence secured to the edge surface and protruding from the edge surface, the loading fence extending between two adjacent cutting bit blocks in a direction generally parallel to the vane, the loading fence and sides of the cutting bit blocks forming a continuous loading surface.

19. The cutter head of claim 18, wherein the shank axis is substantially aligned along a line that is tangent to the edge surface.

20. The cutter head of claim 18, wherein the vane defines a loading surface extending between the drum and the edge surface, wherein the loading fence is aligned with the loading surface.

21. The cutter head of claim 18, wherein the vane defines a loading surface extending between the drum and the edge surface, wherein the block includes a side surface that is generally continuous with the loading surface, and the bit having a tip that is aligned with the loading surface.