The present disclosure relates generally to a replaceable apparatus, specifically a protective wear sleeve, for mounting reducing elements used by excavation machines such as surface excavation machines.
Relatively hard materials are often processed for mining and construction. The variety of materials include rock, concrete, asphalt, coal, and a variety of other types of mineral-based materials. A number of different methods for reducing the size of these hard materials have been developed. One method has been the use of reducing machines having rotary reducing components that move rigid and specialized reducing elements through paths of travel. The reducing components can include rotating drums that move the reducing elements through circular paths of travel. Such drums are typically attached to corresponding machines with a mechanism that allows the position and orientation of the drum to be controlled, to bring the reducing elements into contact with the material being reduced. Alternative reducing components can include boom-mounted chains that carry reducing elements. The chains are typically driven/rotated about their corresponding booms. The reducing elements are mounted to and move along the paths of travel defined by the chains. In use, the booms are moved (e. g., through a pivoting motion) to positions where the reducing elements are brought into contact with the material being reduced.
The reducing elements of reducing machines have been developed to withstand the impact loads and abrasion associated with material reduction activities. Reducing elements can be constructed in a variety of shapes and sizes and have been labeled with various terms including cutters, chisels, picks, teeth, etc. Typical reducing elements include leading impact points or edges and bases. The reducing element holders, or tool holders, are constructed to fit into mounting structures that are integrated with drums or chains used to carry the reducing elements during material reducing applications. The harsh environment associated with material reducing applications virtually guarantees that the reducing elements will wear down over time.
Often, the tips or edges of the reducing elements have a harder construction (e.g., a solid carbide construction) than the tool holders of the reducing elements. When using new reducing elements to reduce material, the leading points or edges are exposed to the majority of the impacts and abrasion action. However, once the leading tips or edges become worn, the tool holders and other components are exposed to more impacts and abrasive action. A variety of potential problems can arise when this occurs, including that the tool holders are less efficient at breaking the material, causing inefficient operation. Once reducing elements are worn there is also a risk of causing damage to the mounting structures of the drums or chains.
A protective wear sleeve can be used as an intermediate wear part between the reducing element and the base. However, the most common use for these sleeves has been to reduce wear on the holder from the spinning reducing element, which tends to, over time, bore out the area that the tooth is mated next to, as described in U.S. Pat. No. 8,783,785, U.S. Pat. No. 8,657,385, and U.S. Pat. No. 5,088,797. However, due to the harsh environment the protective wear sleeve is subjected to, the wear sleeve often also wears at a rapid rate on the exterior, thereby forcing replacement.
In accordance with the following disclosure, the above and other issues are addressed by the following.
The downtime associated with replacing wear components on a cutting drum can be extensive for the machine that the drum is mounted to. Such downtime makes the machine less efficient, which leads to a higher operating cost. At the same time, if too much time is allowed to pass before replacement of wear components, other, more costly, components can be damaged, for example tool holders or the drum itself. The replacement of worn tool holders can be costly and difficult such that the tool holders are often significantly worn before they are replaced. As a result of these issues, there can be significant benefits to replacing the other wear components before wear has progressed past an unacceptable point. A protective wear sleeve provides an option as an intermediate wear part, protecting the more expensive components from rapid wear. Therefore, there is an ongoing need for a protective wear sleeve that has an extended life. An extended lifetime translates into less downtime and a lower replacement frequency. In particular, there is a need for a protective wear sleeve having wear protection on the outer exposed portion of the sleeve that is not protected by the reducing element.
According to an example aspect, the disclosure is directed to a protective wear sleeve for a tooth holder of a cutting tool assembly wherein the tooth holder contains a central bore. The protective wear sleeve includes an elongate body made from a base material, the elongate body including a tooth bore that defines a tooth axis, an axial forward end and an axial rearward end, a mount portion at the rearward end configured for an interference press-fit with the central bore of the tooth holder. The elongate body further including a tooth support collar at the forward end, the tooth support collar including a tooth support surface projecting from the tooth bore out to a tooth collar diameter. The tooth support surface facing generally in a forward direction. The tooth support collar further including a shoulder with an outer diameter equal to, or greater than, the tooth collar diameter and a shoulder thickness along the elongate axis of the body, wherein the shoulder includes a hardfacing portion.
According to another aspect, the disclosure is directed to a protective wear sleeve for a cutting tool assembly that includes a solid body having a first portion and a second portion, the body having a central bore where the central bore defines a central axis. The first portion of the solid body is a shaft portion having a forward end and a rearward end, and the second portion of the solid body is a radial collar integral with the forward end of the shaft portion. The radial collar has a ring support surface that faces at least partially in an outward radial direction. The forward end of the shaft portion and the radial collar together define a tooth support surface that faces in a forward direction, the tooth support surface having an outer diameter. At least one wear ring is disposed on the ring support surface, the at least one wear ring extending around the radial collar. The at least one wear ring has a hardness greater than that of the radial collar and has an outer diameter greater than that of the outer diameter of the tooth support surface.
According to another aspect, the disclosure is directed to an apparatus including a holding block having a protective wear sleeve opening, a cutting tooth having a support flange and a shank, and a protective wear sleeve. The protective wear sleeve includes a solid body having a first portion and a second portion, the body having a central bore for receiving the shank of the cutting tooth, the central bore defining a central axis. The first portion is a shaft portion having a forward end and a rearward end, and the second portion is a radial collar integral with the forward end of the shaft portion. The radial collar has a ring support surface that faces at least partially in an outward radial direction. The forward end of the shaft portion and the radial collar together define a tooth support surface that faces in a forward direction, the tooth support being configured to encase a back side of the support flange of the cutting tooth. The protective wear sleeve further includes at least one wear ring disposed on the ring support surface, the at least one wear ring extending around the radial collar, the at least one wear ring having a hardness greater than that of the radial collar and having an outer diameter greater than that of an outer diameter of the tooth support flange. Wherein the protective wear sleeve is press fit into the protective wear sleeve opening of the holding block, and the cutting tooth being secured in the central bore of the protective wear sleeve and being rotatable around the central axis of protective wear sleeve.
A variety of additional aspects will be set forth in the description that follows. These aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad concepts upon which the embodiments disclosed herein are based.
The present application discloses a protective wear sleeve. Because wear sleeves can be subjected to wear when a cutting action is being carried out, it is advantageous to increase the lifetime of the wear sleeve. The sleeve disclosed herein is configured to resist wear on exterior portions of the sleeve, specifically the radial collar.
The protective wear sleeve 10 can also include the wear ring 22. The wear ring 22 can be disposed around the radial collar 16. As depicted, the wear ring 22 can be disposed 360 degrees around the radial collar 16. The wear ring 22 can be of a variety of materials. In some embodiments, the wear ring 22 can be a weld of hardfacing material. In some embodiments, the wear ring 22 can be a weld of hardfacing material that is disposed 360 degrees around the radial collar 16. In such an embodiment, the protective wear sleeve 10 can be configured to be inserted at any angular rotation about the central axis 13 and still provide hardfacing protection relative to the direction of rotational travel of the tooth 46 held by the protective wear sleeve 10. A hardfacing material can be a material that results from a process where a harder material is applied to a less hard material, the less hard material often called a base. Such a material can then be welded to the base material. In other embodiments, the wear ring 22 may comprise a material with a hardness greater than that of the radial collar 16. In other embodiments yet, the wear ring 22 may be comprised of a material with a hardness between about 40 HRC and about 70 HRC.
In some embodiments the interior surface of central bore 12 can be have a first hardness, the tooth support surface 20 can have a second hardness, the radial collar 16 can have a third hardness, and the wear ring 22 can have a fourth hardness. In some embodiments, the interior surface of the central bore 12 and the tooth support surface 20 may have equal hardnesses. In other embodiments, the interior surface and the central bore 12 may be induction hardened. Induction hardening takes places when a metal part is heated by induction and then quenched. The process changes the material properties of the metal part, thereby increasing its hardness and brittleness. In still other embodiments, the wear ring 22 can have a hardness greater than that of the radial collar 16, and less than that of the tooth support surface 20 and interior surface of the central bore 12. In still other embodiments, the wear ring 22 can have a hardness greater than that of the radial collar 16, the tooth support surface 20 and interior surface of the central bore 12. In the same embodiment, the radial collar 16 may have a hardness less than that of the tooth support surface 20 and the interior surface of the central bore 12. In some embodiments, the radial collar 16 can have a hardness between about 20 HRC and about 30 HRC. In other embodiments, the tooth support surface 20 and the inner surface of the central bore 12 can have a hardness between about 50 HRC and about 60 HRC. In other embodiments still, the radial collar 16 and the shaft portion 14 can be of 4140 steel.
In some embodiments the shaft 14 can have a length between about 3 inches and about 4 inches. In some embodiments, the central bore 12 may have an outer diameter between about 1.70 inches and about 1.75 inches. In other embodiments, the tooth support surface 120 can have an outer diameter between about 3 inches and about 4.75 inches. In other embodiments still, the wear ring 22 can have an outer diameter between about 3 inches and about 4.75 inches. In other embodiments, the shaft portion 14 can have an outer diameter between about 2.250 inches and about 2.260 inches.
In some embodiments the interior surface of central bore 112 can be have a first hardness, the tooth support surface 120 can have a second hardness, the radial collar 116 can have a third hardness and the wear rings 122a, 122b can have a fourth hardness. In some embodiments, the wear rings 122a, 122b can have different hardnesses. In other embodiments still, the forward wear ring 122a can have a greater hardness than any trailing wear ring 122b. In other embodiments, the forward wear ring 122a can have a hardness less than any trailing wear ring 122b. In some embodiments, the interior surface of the central bore 112 and the tooth support surface 120 may have equal hardnesses. In other embodiments, the interior surface of the central bore 112 and the tooth support surface 120 may be induction hardened. In still other embodiments the wear rings 122a, 122b can have hardnesses greater than that of the radial collar 116, the tooth surface 120 and interior surface of the central bore 112. In still other embodiments, the wear rings 122a, 122b can have hardnesses greater than that of the radial collar 116, and less than that of the tooth support surface 120 and interior surface of the central bore 112. In the same embodiment, the radial collar 116 may have a hardness less than that of the tooth support surface 120 and the interior surface of the central bore 112. In some embodiments, the radial collar 116 can have a hardness between about 20 HRC and about 30 HRC. In other embodiments, the tooth support surface 120 and the inner surface of the central bore 112 can have a hardness between about 50 HRC and about 60 HRC. In other embodiments still, the radial collar 116 and the shaft portion 114 can be of 4140 steel.
In some embodiments the shaft 114 can have a length between about 3 inches and about 4 inches. In some embodiments, the central bore 112 may have an outer diameter between about 1.70 inches and about 1.75 inches. In other embodiments, the tooth support surface 120 can have a diameter between about 3 inches and about 4.5 inches. In other embodiments still, the wear ring 122 can have an outer diameter of about between about 3 inches and about 4.5 inches. In other embodiments, the shaft portion 114 can have an outer diameter between about 2.250 inches and about 2.260 inches.
The above specification, examples and data provide a complete description of the manufacture and use of the composition of the inventive aspects. Since many embodiments of the disclosure can be made without departing from the spirit and scope of the inventive aspects, the inventive aspects reside in the claims hereinafter appended.
This application is being filed on 13 Oct. 2015, as a PCT International patent application, and claims priority to U.S. Provisional Patent Application No. 62/065,400, filed Oct. 17, 2014, the disclosure of which is hereby incorporated by reference herein in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2015/055336 | 10/13/2015 | WO | 00 |
Number | Date | Country | |
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62065400 | Oct 2014 | US |