ULTRA-DEEP INDUCTION HARDENING FOR CONVEYOR BUSHINGS

Abstract

Disclosed herein is an example track pad (112) having a ground-contacting portion (202) for use in a track-based machine (100) to propel and support the machine (100) across a supporting surface. The track pad (112) may be a track pad (112) that forms a link of a chain forming the track (102) for the track-based machine (100). The track pad (112) includes a cast body (114) formed of a first alloy steel having a first strength and toughness. The track pad (112) includes a roll path (116) that contacts a roller (502) of the track-based machine (100). The roll path (116) is hardened through an induction hardening process to achieve a hardness level at a depth of 32 millimeters or more from the surface of the roll path (116). The roll path (116) is shaped and positioned to contact rollers (110) of the track drive assembly and thereby reduce wear and fatigue on the track pad (112) as a result of contact and force transferred through the roller (502).

Description

1 / 25 “ULTRA-DEEP INDUCTION HARDENING FOR CONVEYOR BELT CUSHIONS” Technical Field

[0001] This disclosure relates to hardening processes for tracks for track-type machines. More specifically, this disclosure relates to tracks with a running track that is induction hardened to a depth more than twice a typical depth using an ultra-deep induction hardening process. Fundamentals

[0002] Tracked machines are widely used in construction, mining, forestry, and other similar sectors. The undercarriage of such tracked machines uses track assemblies, rather than wheels, to provide propulsion that engages with the ground. Such track assemblies may be preferred in environments where creating sufficient traction is problematic, such as those frequently found in the industries identified above. Specifically, instead of rolling over a work surface on wheels, tracked machines use one or more track assemblies that include an endless cycle of coupled track links that define outer surfaces, which support track shoes, and inner surfaces that move over one or more rotating track engagement elements, such as drive sprockets, idler wheels, tensioners, and rollers, for example.

[0003] Typical track assembly designs include a track pin fixed or rotatably connected to a pair of chain links and a bushing rotatably positioned between the links and around the track pin. Such track assemblies can operate in extremely harsh environments where the track joints may be exposed to various abrasive mixtures of water, dirt, sand, rock, or other mineral or chemical elements. For heavy equipment such as cable excavators and Petition 870250080246, dated 09 / 08 / 2025, p. 15 / 164 2 / 25 similar, track cushions are used that incorporate the track rail and track shoe in a single unit body.

[0004] The track assembly may include a plurality of blade shoes connected end-to-end by means of pins to form an endless loop. The endless loop of blade shoes may be wound around corresponding drive wheels, one or more idler wheels, and at least one roller. The drive wheels may engage pins (or engage bushings that enclose pins), drive shoulders, or other features of the blade shoes and thus transmit torque from the motor to the track assemblies. The idler wheels and rollers may guide the track assemblies in a general elliptical path around the drive wheels. A tensioner may be located between the idler wheel and the drive wheel to separate these components and thus maintain a desired tension of the track assembly. The blade shoes may serve to transmit torque from the drive wheels as a linear drive force (traction) on a ground surface.The weight of the machine can be transmitted from the drive wheel, guide wheel, and rollers through the blade shoes as a rolling force on the ground surface.

[0005] For example, U.S. Patent No. 10,669,602 (the “patent '602”) describes a manufacturing process for a component subject to wear. The process involves depositing a coating layer with a thickness greater than 0.5 mm onto a steel body of a component. The steel body is described as having a hardness between about 43 HRC and about 60 HRC using a hard coating process. The hard coating process includes heat treating the component to austenitize it and then cooling it in a liquid bath. After heating, the component can be tempered after removal from the liquid bath. In one example, patent '602 includes a track shoe for a track-type machine. However, due to the additional material (coating) being added to the component, the processing time for a blade shoe (e.g., track pad) is increased, as well as the Petition 870250080246, dated 08 / 09 / 2025, page 16 / 164 3 / 25 complexity and price. The interface between the drive wheel, the guide wheel and the rollers described in patent '602 can experience high contact stresses that lead to scoring failure of typical track pads.

[0006] Examples of modalities of this disclosure are aimed at overcoming the deficiencies described above. Summary

[0007] In an exemplary embodiment of the present disclosure, a general aspect includes a track system for track-based machinery. The track system includes an undercarriage supporting the track-based machinery. The system also includes a sprocket coupled to the undercarriage and driven by a motor and a roller coupled to the undercarriage. The system also includes a set of track pads forming an endless loop around the undercarriage, adjacent track pads coupled via bushings, a track pad of the track pad assembly may include a body formed of an alloy steel with a first surface configured to contact a support surface and a second surface configured to contact the roller, wherein the body is produced by at least induction hardening on the second surface to a hardness of at least 50 HRC to a depth of 32 millimeters from the second surface.

[0008] Implementations may include one or more of the following features. The alloy steel may include a medium carbon steel alloy that may include, by weight percent: carbon in a range of 0.30 percent to 0.40 percent, manganese in a range of 0.80 to 1.30 percent, nickel in a range of 1.00 to 1.70 percent, chromium in a range of 0.80 to 1.30 percent, and molybdenum in a range of 0.20 to 0.80 percent. A transverse thickness of the track pad, from the first surface to the second surface, may be in a range of 250 millimeters to 400 millimeters. The body may be induction hardened to a depth of at least ten percent of the transverse thickness to a hardness in a range of 50 HRC to 60 HRC. The track pad may have a mass in a range of 1000 to 2000 Petition 870250080246, dated 09 / 08 / 2025, p. 17 / 164 4 / 25 kilograms. Induction hardening of the body may include setting a clamping distance between an induction coil and the second surface at a target distance, performing two or more induction preheating passes with the induction coil using a first set of parameters, performing an austenitizing pass using the induction coil using a second set of parameters, cooling the second surface using a polymer cooling material, and tempering the body after cooling. The clamping distance may be in the range of 4 millimeters to 7 millimeters. The first set of parameters may include induction power in the range of 170 kilowatts to 200 kilowatts, induction frequency in the range of 300 hertz to 700 hertz, sweep speed in the range of 60 millimeters per minute to 90 millimeters per minute, and a maximum surface temperature of 1000 degrees Celsius.The second set of parameters may include induction power in the range of 170 kilowatts to 200 kilowatts, induction frequency in the range of 300 hertz to 700 hertz, sweep speed in the range of 55 millimeters per minute to 70 millimeters per minute, and a maximum surface temperature of 1000 degrees Celsius, a minimum temperature at a depth of 32 millimeters from the second surface of 820 degrees Celsius, and a flow rate for the polymer cooling material in the range of 20 cubic meters per hour to 30 cubic meters per hour. The polymer cooling material may include polymer at a concentration of at least 10 percent.

[0009] A general aspect includes a method for forming a track cushion for track-based machinery. The method includes casting a body for the track cushion using an alloy steel. The method also includes causing the body to harden through a heat treatment and cooling process. The method further includes causing an induction heat treatment of a track of the track cushion by at least setting a clamping distance between an induction coil and the track to a target distance, performing two or more induction preheating passes with the induction coil using a first set of Petition 870250080246, dated 08 / 09 / 2025, page 18 / 164 5 / 25 parameters, perform an austenitizing pass using the induction coil using a second set of parameters, cool via the bearing using a polymer cooling material, and temper the body after cooling.

[0010] A general aspect includes a conveyor belt pad. The conveyor belt pad includes a body formed from an alloy steel with a first surface configured to contact a support surface, and a second surface configured to contact a roller, wherein the body is produced by induction hardening on the second surface by at least: setting a clamping distance between an induction coil and the second surface to a target distance; performing two or more induction preheating passes with the induction coil using a first set of parameters; performing an austenitizing pass using the induction coil using a second set of parameters; cooling the second surface using a polymer cooling material; and tempering the body after cooling. Brief Description of the Figures

[0011] Figure 1 is a perspective view of a set of tracks for a track-type machine, implementing a track cushion with ultra-deep hardening in the running track, according to at least one example.

[0012] Figure 2 is a perspective view of the ultra-deep hardened conveyor belt cushion, according to at least one example.

[0013] Figure 3 is a view of a process for hardening a conveyor belt cushion running track, according to at least one example.

[0014] Figure 4 illustrates a cross-sectional view of a conveyor belt cushion with an induction component for induction heat treatment of a conveyor belt cushion surface, according to at least one example.

[0015] Figure 5 is a cross-sectional illustration of the composite conveyor cushion in contact with a roller of the conveyor assembly, according to at least one example. Petition 870250080246, dated 08 / 09 / 2025, page 19 / 164 6 / 25

[0016] Figure 6 is another sectional illustration of the conveyor belt cushion in contact with the roller of the conveyor belt assembly, according to at least one example.

[0017] Figure 7 is a flow diagram representing an example method for hardening the conveyor belt cushion described in this document, according to at least one example. Detailed Description

[0018] Detailed reference will now be made to the embodiments of the disclosure, examples of which are illustrated in the accompanying figures. Wherever possible, the same reference numbers will be used in all drawings to refer to identical or similar parts. Various embodiments of the present disclosure include a track member, such as a track cushion, and a track that may use a plurality of track members according to various embodiments of the present disclosure, etc.

[0019] Figure 1 is a perspective view of a track assembly 100 for a track-type machine, implementing the composite track cushion, according to at least one example. The track assembly 100 may be part of a track-type machine with a motor supported by a frame and configured to drive a tracked undercarriage. The track-type machine may be any machine that performs an operation associated with an industry, such as mining, construction, farming, or any other industry known in the art. For example, the track-type machine may be a material handling machine, such as a front excavator, a cable excavator, a hydraulic excavator, a bulldozer, a wheel loader, or other material handling machine.

[0020] The track assembly 100 includes an undercarriage frame 104 that supports a drive wheel 106, idler wheel 108, and rollers 110. The undercarriage frame 104 may include various components or elements to support different components of the track-type machine. The drive wheel 106 may be driven by a motor of the track-type machine. Petition 870250080246, dated 09 / 08 / 2025, p. 20 / 164 7 / 25 to make the track 102 rotate around the undercarriage frame 104 to propel the track-type machine.

[0021] The track 102 is coupled to the undercarriage frame 104 in a conventional manner. The track-type machine may include several tracks 102 to drive the track-type machine. The track 102 includes a plurality of track pads coupled together 112 forming an endless loop that extends around the drive wheel 106, idler wheel 108 and rollers 110, among other components. The rollers 110 are also mounted on the undercarriage frame 104 to support the track-type machine and the idler track 102.

[0022] The unique design of the 102 track and the overall track and undercarriage system of which it is a component are designed to allow the tracked machine to operate in certain environments, such as soft ground conditions, without getting stuck. Although the use of an excavator or cable excavator in the machine environment is discussed in this document, it should be understood that the machine may comprise a different type of machine. For example, tracked tractors or even half-track machines are contemplated in this document. Furthermore, the machine may employ a conveyor or other type of machine where the tracks are used for purposes other than ground contact elements. Additionally, the machine may be some type of hydraulic excavator, bulldozer, backhoe, etc.

[0023] The track cushions 112 include a cast body 114 formed from an alloy steel, such as a medium carbon steel, which forms the primary structural portion of the track cushion 112. The cast body 114 includes contact surfaces for mounting on a support surface and bushing contact surfaces for joining the track cushions 112 to the track 102. The cast body 114 also includes a running track 116. The running track 116 may contact the rollers of the undercarriage structure 104, as shown and described in relation to Figures 5 and 6. Petition 870250080246, dated 08 / 09 / 2025, page 21 / 164 8 / 25

[0024] In some respects, the 112 conveyor cushions may be sized such that specific forming processes are unavailable. For example, the dimensions of the 112 conveyor cushion may exceed 800 mm to 3600 mm in length by 300 mm to 600 mm in width by 250 mm to 400 mm in thickness, thus making forming via forging press unavailable due to size restrictions of forging presses. In some instances, the 112 conveyor cushion may have a mass in the range of 1000 to 2000 kilograms which may also result in forming and / or hardening processes that may be used for smaller scale conveyor cushions being unavailable for conveyor cushions of the size and dimensions described in this document.Furthermore, effective heat treatment and processing to a specific hardness and / or through annealing can be difficult due to the size of the conveyor belt pads 112, which can retain a large amount of thermal heat during processing and therefore be difficult to cool and achieve the hardness and toughness levels required to withstand the forces experienced by the conveyor belt pads 112 during use.

[0025] In typical conveyor belt pads and conventional induction hardening processes, the hardness cannot extend beyond about 17 millimeters. In the examples described in this document, hardening is enabled to reach an ultra-deep level, to a depth of about 32 millimeters. In conventional conveyor belt pads, hardening to a limited depth, such as only up to 20 millimeters, can result in abnormal or unexpected wear. The depth may be in a range of 20 millimeters to 40 millimeters in some examples. In typical induction hardening systems, especially for conveyor belt pads, the induction frequency is often in a range of about 1000 hertz to 4000 hertz with traditional processes. To achieve the desired hardness depth and thus improve the service life and wear characteristics of the conveyor belt pads, a frequency of about 300 hertz can be used for the induction process.In this way, the processes of... Petition 870250080246, dated 08 / 09 / 2025, page 22 / 164 9 / 25 Existing induction heating can be used, with different parameters and settings, to achieve hardness at the desired depths. Furthermore, the use of induction heating described in this document on conveyor belt pads with the size and mass characteristics described herein can allow for surface heating control and thus reduce grain growth and control grain sizes in the conveyor belt pad material.

[0026] In one example, induction hardening can be performed at a frequency of 300 hertz to achieve the depths indicated in this document. Consequently, for a track pad of a track-based machine, such as an electric wireline excavator (ERS), the techniques and systems in this document can enable hardening to a range of 50 Rockwell hardness C (HRC) to 60 HRC at a depth of 32 mm over the surface of the track 116.

[0027] Consequently, the track cushions 112 can be formed from a material with sufficient hardness to withstand an aggressive environment, such as mining, while also being able to withstand the forces applied across the track cushion assembly to support the weight of the track-type machine. For example, the cast body 114 can be formed from a hardenable steel with high hardness and shock resistance. In some examples, the cast body 114 can be formed from a medium carbon alloy steel.

[0028] In some instances, alloy steel may include a medium carbon steel alloy that includes carbon in a range of 0.30 to 0.40 percent by weight, manganese in a range of 0.80 to 1.30 percent by weight, nickel in a range of 1.00 to 1.70 percent by weight, chromium in a range of 0.80 to 1.30 percent by weight, and molybdenum in a range of 0.20 to 0.80 percent by weight. In some instances, alloy steel may include additional elements and / or components not listed in this document.

[0029] In some respects, at least part of the present disclosure refers to the formation, production and / or manufacture of the conveyor belt cushion 112 and of Petition 870250080246, dated 09 / 08 / 2025, p. 23 / 164 10 / 25 components and systems in which the conveyor cushion is used, such as the 100 conveyor assembly and / or the conveyor-type machine.

[0030] The formation of the 112 conveyor belt cushion may include casting a body for the 112 conveyor belt cushion from an alloy steel. The body may be hardened through a traditional heat treatment and cooling process. The body may be treated to improve the hardness, toughness and / or other characteristics of the conveyor belt cushion.

[0031] In order to harden the track 116 of the track pad 112, induction hardening of the track 116 can be used to improve the wear characteristics of the track pad 112. Induction hardening of the track 116 can include setting a clamping distance between an induction heating system (e.g., a coil). The clamping distance can be set so that a distance between the coil and the surface of the track 116 is in the range of 4 mm to 7 mm. The coil may be able to be moved parallel to a surface of the track 116 while maintaining the clamping distance.

[0032] After the clamping distance is defined, the process for hardening the rolling track 116 further includes performing two or more induction preheating passes through the rolling track 116 with the induction coil at the clamping distance. The preheating passes can be performed using a first set of parameters. For example, the preheating passes can include two to five passes of the induction coil. The preheating passes can be performed with the induction coil supplying 170 kilowatts to 200 kilowatts of power to the rolling track 116. Furthermore, the first parameters can be performed with the coil frequency set within a range of 300 to 700 hertz. The coil can be driven through the rolling track 116 at a sweep speed in a range of 60 millimeters per minute to 90 millimeters per minute.In this way, the rolling track can be preheated before hardening, with preheating being performed. Petition 870250080246, dated 09 / 08 / 2025, p. 24 / 164 11 / 25 heating to a depth of 116 in the rolling track. The surface of the rolling track 116 can be maintained, during induction preheating, at less than 1000 degrees Celsius.

[0033] After the preheating passes, an austenitizing and cooling pass can be performed on the rolling track 116 using the induction coil and a second set of parameters. The second set of parameters may include the induction coil supplying 170 kilowatts to 200 kilowatts of power to the rolling track 116. Furthermore, the first set of parameters can be performed with the coil frequency set within a range of 300 to 700 hertz. The coil can be driven along the rolling track 116 at a sweep speed in a range of 55 millimeters per minute to 70 millimeters per minute. The surface of the rolling track 116 can be maintained, during the austenitizing pass, at less than 1000 degrees Celsius. Additionally, at a depth of at least 32 millimeters, the temperature can be at least 820 degrees Celsius.Cooling after the austenitizing process may include cooling the track 116 using a polymer cooling material. The polymer cooling material may include a polymer cooling with a concentration of at least ten percent polymer within the cooling material. The cooling material may be distributed to the track 116 at a rate of 20 cubic meters per hour to 30 cubic meters per hour. In a particular example, the cooling polymer may be distributed at a rate of 28 cubic meters per hour to the track 116.

[0034] After the austenitizing process, the 112 conveyor belt cushion can be tempered, specifically after cooling. Tempering can occur at a temperature of up to 180 degrees Celsius. Tempering can occur after a 3-hour delay following cooling. Additionally, tempering can occur for up to 240 minutes at the tempering temperature.

[0035] After treating the runway 116, one or more additional surfaces may be treated in a manner similar to that described. Petition 870250080246, dated 08 / 09 / 2025, page 25 / 164 12 / 25 above for the track 116. For example, a ground contact surface can be treated to increase its hardness and provide a hardness depth, as described in this document, which can improve the service life of the track cushion 112.

[0036] Figure 2 is a perspective view of the composite track cushion showing the rolling track 116, according to at least one example. The track cushion 112 of this disclosure may be applicable to any mobile track-type machine. However, the disclosed track cushions 112 may be particularly applicable to larger machines where the forces passing through the track assembly are significant and may affect the longevity of the track cushions 112. This may be particularly important for expensive machines operating full-time where downtime and the price of replacement track cushions are costly for the owner.

[0037] Figure 2 shows a track pad 112 which may include one or more pairs of spaced links 204 and 206 which are generally parallel to each other. Each link 204 and 206 may include at least one pin hole formed at one end thereof for connecting to the links of other track pads 112, thus forming a chain. The track pad 112 may include a ground contact surface 202. The ground contact surface 202 may be disposed on a lower side of the cast body 114. In this example, the ground contact surface 202 and the links 204 and 206 are integrally formed as a single cast and / or forged component. In other embodiments, links 204 and 206 and the ground contact surface 202, as well as other components described in this document, may be formed separately and joined by any suitable process known in the art, such as by welding and / or using threaded fasteners, if desired.The ground contact surface 202 can have any external geometry known in the art. For example, the ground contact surface 202 can generally resemble a plate, include protrusions or claws. Petition 870250080246, dated 09 / 08 / 2025, p. 26 / 164 13 / 25 transverse, have openings and / or include any other features common in the technique.

[0038] The cast body 114 includes a rolling track 116 disposed on the upper side of the insert 118. The rolling track 116 may be disposed between the links 204 and 206. The rolling track 116 may define a surface for guiding a roller of the drive assembly through the track cushion 112. The rolling track 116 may include a wear surface that engages with the roller. The weight of the track-type machine may be transmitted from the roller through the rolling track 116.

[0039] The track 116 may be flat, arched, or have any shape suitable for engaging the roller. For example, the roller may have a curvature, and the track 116 may be shaped with a similar curvature. When the machine is in motion, additional rolling and sliding forces between the track 116 and the roller create frictional wear of the track 116. Abrasive debris, such as gravel, dirt, sand, or other earthy material, may become lodged between the roller and the track 116 and cause additional wear and / or grinding of the track 116.

[0040] The track 116 can be hardened as described in this document. In order to harden the track 116 of the conveyor belt 112, induction hardening of the track 116 can be used to improve the wear characteristics of the conveyor belt 112. Induction hardening of the track 116 can include setting a clamping distance between an induction heating system (e.g., a coil). The clamping distance can be set so that a distance between the coil and the surface of the track 116 is in the range of 4 millimeters to 7 millimeters. The coil may be able to be moved parallel to a surface of the track 116 while maintaining the clamping distance.

[0041] After the fixing distance is defined, the process for hardening the running track 116 also includes carrying out two or more Petition 870250080246, dated 09 / 08 / 2025, p. 27 / 16414 / 25 induction preheating passes through the rolling track 116 with the induction coil at the clamping distance. The preheating passes can be performed using a first set of parameters. For example, the preheating passes can include two to five passes of the induction coil. The preheating passes can be performed with the induction coil supplying 170 kilowatts to 200 kilowatts of power to the rolling track 116. Furthermore, the first parameters can be performed with the coil frequency set within a range of 300 to 700 hertz. The coil can be driven through the rolling track 116 at a sweep speed in a range of 60 millimeters per minute to 90 millimeters per minute. In this way, the rolling track can be preheated before hardening, with the preheating performing the heating to a depth of the rolling track 116.The surface of the track 116 can be maintained, during induction preheating, at less than 1000 degrees Celsius.

[0042] After the preheating passes, an austenitizing and cooling pass can be performed on the rolling track 116 using the induction coil and a second set of parameters. The second set of parameters may include the induction coil supplying 170 kilowatts to 200 kilowatts of power to the rolling track 116. Furthermore, the first second set of parameters can be performed with the coil frequency set within a range of 300 to 700 hertz. The coil can be driven along the rolling track 116 at a sweep speed in a range of 55 millimeters per minute to 70 millimeters per minute. The surface of the rolling track 116 can be maintained, during the austenitizing pass, at less than 1000 degrees Celsius. Additionally, at a depth of at least 32 millimeters, the temperature can be at least 820 degrees Celsius.Cooling after the austenitizing process may include cooling the raceway 116 using a polymer cooling material. The polymer cooling material may include a polymer cooling with a concentration of at least ten percent polymer. Petition 870250080246, dated 08 / 09 / 2025, page 28 / 164 15 / 25 within the cooling material. The cooling material can be distributed to the running track 116 at a rate of 20 cubic meters per hour to 30 cubic meters per hour. In a particular example, the cooling polymer can be distributed at a rate of 28 cubic meters per hour to the running track 116.

[0043] After the austenitizing process, the 112 conveyor belt cushion can be tempered, specifically after cooling. Tempering can occur at a temperature of up to 180 degrees Celsius. Tempering can occur after a 3-hour delay following cooling. Additionally, tempering can occur for up to 240 minutes at the tempering temperature.

[0044] After treating the running track 116, one or more additional surfaces may be treated in a manner similar to that described above for the running track 116. For example, a ground contact surface 202 and / or drive shoulders 120 may be treated to increase its hardness and provide a hardness depth as described in this document which may improve the service life of the track cushion 112.

[0045] In the example of Figure 2, the track cushion 112 includes a pair of drive protrusions 120 disposed on the upper side of the cast body 114 that engage the drive wheels in the track assembly. The drive protrusions 120 may be disposed between links 204 and 206 on either side of the running track 116. In other embodiments, the drive protrusions 120 may be positioned in other locations on the track cushion 112, and fewer or more drive protrusions 120 may be included. The drive protrusions 120 may contact openings, pockets, or teeth of the drive wheels in the track assembly to receive torque from the motor and provide traction force to the track cushion 112 to move the machine. The 120 drive cams may have one or more wear surfaces that come into contact with the drive wheels.When the machine is in motion, these wear surfaces can suffer grinding and wear from the forces transmitted by the drive wheels, which can be... Petition 870250080246, dated 08 / 09 / 2025, page 29 / 164 16 / 25 enlarged when abrasive debris becomes lodged between the drive protrusions 120 and the drive wheels.

[0046] In some instances, the drive shoulders 120 may be partially and / or entirely formed from a material that has high wear and abrasion resistance, including high impact resistance, tensile strength, and yield strength. In some instances, a manganese steel may be used for the drive shoulders 120, such as a steel alloy with 10% or more manganese content. In some instances, the alloy may have between 12-14% manganese steel. In some instances, ASTM A128 steel may be used for the drive shoulders. The manganese steel alloy for the drive shoulders hardens rapidly after being put into use without an increase in brittleness, thus providing greater wear and abrasion resistance against the track assembly sprockets than the cast body 114.In some examples, other alloys and work-hardening materials may be used to form the drive lobes, including stainless steels and other steel alloys with work-hardening properties similar to manganese steel.

[0047] To withstand rolling forces without cracking or breaking, drive shoulders can be formed from a high-strength metal, such as manganese steel. Manganese steel can be cast to produce 120 drive shoulders of any suitable shape and dimensions, but it can be brittle after casting. Thus, 120 drive shoulders can be solution-treated to achieve an austenitic grain structure in the metal, which improves overall hardness. Before casting, chromium can be added to the manganese steel to promote faster work hardening of the austenitic manganese steel. Because austenitic manganese steel is also soft, 120 drive shoulders may undergo plastic deformation during use.Instead of performing expensive and time-consuming heat treatment processes to harden the cast body 114, work hardening of the drive lobes 120 can provide the necessary hardness to withstand the forces experienced during use. Petition 870250080246, dated 08 / 09 / 2025, page 30 / 164 17 / 25 actuation lobes 120 and / or inserts of the actuation lobes 120 can be formed and friction-welded or otherwise joined to the cast body 114.

[0048] Figure 3 is a view of a process 300 for hardening a track 314 of the conveyor cushion 304, according to at least one example. The conveyor belt cushion 304 may be similar and / or identical to the conveyor belt cushion 112, and the running track 314 may be similar and / or identical to the running track 116. In order to harden the running track 314 of the conveyor belt cushion 304, induction hardening of the running track 314 may be used to improve the wear characteristics of the conveyor belt cushion 304. Induction hardening of the running track 314 may include setting a clamping distance between an induction heating system 306 and the running track 314 in step 302. The clamping distance may be set so that a distance between the coil and the surface of the running track 314 is in a range of 4 millimeters to 7 millimeters.The coil may be able to be moved parallel (e.g., along direction 310) to a surface of the raceway 314 while maintaining the clamping distance.

[0049] After the clamping distance is defined in step 302, process 300 for hardening the rolling track 314 further includes performing two or more induction preheating passes in step 308 along the rolling track 314 with the induction coil at the clamping distance. The preheating passes can be performed using a first set of parameters. For example, the preheating passes can include two to five passes of the induction coil. The preheating passes can be performed with the induction coil supplying 170 kilowatts to 200 kilowatts of power to the rolling track 314. Furthermore, the first parameters can be performed with the coil frequency set within a range of 300 to 700 hertz. The coil can be driven along the rolling track 314 at a sweep speed in a range of 60 millimeters per minute to 90 millimeters per minute.In this way, the rolling track can be preheated before hardening, with the pre. Petition 870250080246, dated 09 / 08 / 2025, p. 31 / 164 18 / 25 heating by performing heating at a depth of 314 in the track. The surface of the track 314 can be maintained, during induction preheating, at less than 1000 degrees Celsius.

[0050] After the preheating passes, process 300 may include, in step 312, an austenitizing and cooling pass that may be performed on the rolling track 314 using the induction coil and a second set of parameters. The second set of parameters may include the induction coil supplying 170 kilowatts to 200 kilowatts of power to the rolling track 314. Furthermore, the first set of parameters may be performed with the coil frequency set within a range of 300 to 700 hertz. The coil may be driven along the rolling track 314 at a sweep speed in a range of 55 millimeters per minute to 70 millimeters per minute. The surface of the rolling track 314 may be maintained, during the austenitizing pass, at less than 1000 degrees Celsius. Additionally, at a depth of at least 32 millimeters from the surface of the rolling track 314, the temperature may be at least 820 degrees Celsius.

[0051] After the austenitizing pass, in step 316, process 300 may include cooling with third parameters. Cooling after the austenitizing pass may include cooling the rolling track 314 using a polymer cooling material 318. The polymer cooling material 318 may include a polymer cooling material with a concentration of at least ten percent polymer within the cooling material. The polymer cooling material may be distributed to the rolling track 314 at a rate of 20 cubic meters per hour to 30 cubic meters per hour. In a particular example, the cooling polymer may be distributed at a rate of 28 cubic meters per hour to the rolling track 314.

[0052] After the austenitizing process, the conveyor belt cushion 304 can be tempered in step 320 using a heat source 322, specifically after cooling. Tempering can occur at a temperature of up to 180 Petition 870250080246, dated 08 / 09 / 2025, page 32 / 164 19 / 25 degrees Celsius. Tempering can occur after a 3-hour delay following cooling. Additionally, tempering can occur for up to 240 minutes at the tempering temperature.

[0053] After treating the track 314, one or more additional surfaces may be treated in a manner similar to that described above for the track 314. For example, a ground contact surface may be treated to increase its hardness and provide a hardness depth, as described in this document, which may improve the service life of the track cushion 304.

[0054] Figure 4 illustrates a sectional view 400 of a conveyor belt pad 402 with an induction component 404 for induction heat treating a surface 412 of the conveyor belt pad 402, according to at least one example. During the induction heat treatment described in this document, the induction component 404 is set at a clamping distance 406 within a range of 4 to 7 millimeters from the surface 412 of the conveyor belt pad 402. The induction component 404 is held at the clamping distance 406 as the induction component 404 passes parallel to the surface 412 of the conveyor belt pad 402 (e.g., along direction 408).

[0055] Induction component 404 can be used, according to process 300, to induction harden the surface region 410 of the conveyor belt pad 402. The surface region 410 can extend to a depth of 32 millimeters or more into the body of the conveyor belt pad 402, the depth measured from surface 412.

[0056] Figures 5 and 6 provide sectional illustrations of the track cushion 112 with the ultra-deep hardened running track 116 contacting a roller 110 of the track assembly 100, according to at least one example. The roller 110 includes a roller surface 502 that contacts the running track 116. The roller 110 is coupled to the undercarriage frame 104 which supports the weight of the track-type machine. Consequently, the roller 110, and therefore the roller surface 502, transmits Petition 870250080246, dated 09 / 08 / 2025, p. 33 / 164 20 / 25 force for the track 116 and the track cushion 112 to support the track-type machine.

[0057] The internal structure of the conveyor belt cushion 112 may have variable geometry, including passages, columns, holes, protrusions, and various other shapes and configurations. In some examples, the composite conveyor belt cushion 112 has a solid body. In some examples, as illustrated in Figure 6, the conveyor belt cushion 112 may include varied internal geometry. The conveyor belt cushion 112, and more specifically the cast body 114, are dimensioned and configured to provide structural support to the conveyor belt cushion 112 and thus support the conveyor-type machine.

[0058] Figure 7 is a flow diagram representing an example method for hardening the track cushion described in this document, according to at least one example. The track cushion 112 described in this document may be applicable to any tracked mobile machine. However, the disclosed track cushion may be particularly applicable to larger machines where the forces passing through the track assembly are significant and may affect the longevity of the track cushion. This may be particularly important for expensive machines operating full-time where downtime and the cost of replacement track cushions are expensive for the owner.

[0059] Process 700 can be carried out to produce the track pads described in this document for use in track-type machines. In 702, process 700 involves casting a body using alloy steel. The alloy steel may have sufficient hardness to withstand an aggressive environment, such as mining, while also being able to withstand the forces applied through the track pad assembly to support the weight of the track-type machine. For example, the cast body may be formed from a hardenable steel with high hardness and shock resistance. In some examples, the cast body may be formed from a medium carbon alloy steel. For example, the cast body may include a medium carbon alloy steel that includes carbon in a range of 0.30 to 0.40 percent by weight, manganese in a range of 0.80 to 1.30 percent Petition 870250080246, dated 09 / 08 / 2025, p. 34 / 164 21 / 25 percent by weight, nickel in a range of 1.00 to 1.70 percent by weight, chromium in a range of 0.80 to 1.30 percent by weight, and molybdenum in a range of 0.20 to 0.80 percent by weight. In some instances, the alloy steel may include additional elements and / or components not listed in this document.

[0060] In 704, process 700 includes uniformly hardening the cast body to a first level of hardness. The hardness may be based on the operating environment and / or intended use for the conveyor cushion, but may include directly hardening the cast body.

[0061] In 706, process 700 may include induction heat treatment (e.g., induction hardening) of a cast body bearing track. The induction heat treatment process may include subprocesses 708-714 for induction hardening of the bearing track. In order to harden the bearing track of the conveyor cushion, a clamping distance may be defined between an induction heating system and the bearing track in step 708. The clamping distance may be defined so that a distance between the coil and the bearing track surface 314 is in a range of 4 mm to 7 mm. The coil may be able to be moved parallel to a bearing track surface while maintaining the clamping distance.

[0062] After the clamping distance is defined in step 708, process 700 further includes performing two or more induction preheating passes along the rolling track with the induction coil at the clamping distance in step 710. The preheating passes can be performed using a first set of parameters. For example, the preheating passes can include two to five passes of the induction coil. The preheating passes can be performed with the induction coil supplying 170 kilowatts to 200 kilowatts of power to the rolling track. Furthermore, the first parameters can be performed with the coil frequency set within a range of 300 to 700 hertz. The coil can be driven along the rolling track at a sweep speed in a range of 60 millimeters per minute to 90 millimeters per minute. Petition 870250080246, dated 09 / 08 / 2025, p. 35 / 164 22 / 25 minutes. In this way, the raceway can be preheated before hardening, with preheating heating to a depth within the raceway. The surface of the raceway can be maintained, during induction preheating, at less than 1000 degrees Celsius.

[0063] After the preheating passes, process 700 may include, in step 712, an austenitizing and cooling pass that may be performed on the rolling track using the induction coil and a second set of parameters. The second set of parameters may include the induction coil supplying 170 kilowatts to 200 kilowatts of power to the rolling track. Furthermore, the first set of parameters may be performed with the coil frequency set within a range of 300 to 700 hertz. The coil may be driven along the rolling track at a sweep speed in a range of 55 millimeters per minute to 70 millimeters per minute. The surface of the rolling track may be maintained, during the austenitizing pass, at less than 1000 degrees Celsius. Additionally, at a depth of at least 32 millimeters from the surface of the rolling track, the temperature may be at least 820 degrees Celsius.

[0064] After the austenitizing pass, in step 712, process 700 may include cooling with third parameters. Cooling after the austenitizing pass may include cooling the running track using a polymer cooling material. The polymer cooling material may include a polymer cooling material with a concentration of at least ten percent polymer within the cooling material. The polymer cooling material may be distributed to the running track at a rate of 20 cubic meters per hour to 30 cubic meters per hour. In a particular example, the cooling polymer may be distributed at a rate of 28 cubic meters per hour to the running track.

[0065] After the austenitizing process, the conveyor belt cushion can be tempered in step 714 using a heat source, specifically after cooling. Tempering can occur at a temperature of up to 180 degrees. Petition 870250080246, dated 08 / 09 / 2025, page 36 / 164 23 / 25 Celsius. Tempering can occur after a 3-hour delay following cooling. Additionally, tempering can occur for up to 240 minutes at the tempering temperature.

[0066] After treating the track, one or more additional surfaces may be treated in a manner similar to that described above for the track in step 716. For example, a ground contact surface may be treated to increase its hardness and provide a hardness depth, as described in this document, which may improve the service life of the track pad. Finally, additional machining and / or finishing may be performed on the track pad in 718 to prepare the track pad for assembly with the track-type machine.

[0067] It should be noted that some of the operations in process 700 may be performed out of the order presented, with additional elements and / or without some elements. Some of the operations in process 700 may also occur substantially simultaneously and therefore may conclude in a different order from the order of operations shown above. Industrial applicability

[0068] This disclosure describes systems, structures, and methods for improving the wear tolerance and toughness of components, such as components for track-type machines. These improved components may include track pads used in track assemblies of track-based machines. The track pads, as disclosed in this document, may have a running track and / or wear surface with an ultra-deep hardening performed on it for a track pad contact surface. The contact surface may be a surface that contacts a roller of the track drive assembly for the track-based machine.Although track cushions and procedures for track cushions are discussed in the context of tracked machines and undercarriages of such tracked machines, it should be noted that track cushions and the mechanisms for forming them are applicable to a wide range of mechanical systems, such as... Petition 870250080246, dated 08 / 09 / 2025, page 37 / 164 24 / 25 any mechanical system that can benefit from improved wear resistance of contact surfaces against friction and abrasion in regions of high force transfer.

[0069] As a result of the systems, devices, and methods described in this document, consumable machine parts, such as track pads, can have a longer service life. For example, the track pads described in this document can have a longer service life than traditional track pads that are not formed by the mechanisms described in this document. In some cases, the track pads and / or other components can allow for a 25% to 400% improvement in the service life of consumable track-type machine parts. This reduces downtime in the field, reduces the frequency of overhaul and maintenance, and generally reduces the cost of heavy equipment such as track-type machines. Improved reliability and reduced downtime at the field level also improve the user experience, so that the machine can be dedicated to its intended purpose for longer periods and for a greater overall percentage of its service life.Improved machine uptime and reduced scheduled maintenance can enable more efficient resource deployment (e.g., fewer but more reliable machines at a construction site). Thus, the technologies disclosed in this document improve the efficiency of project resources (e.g., construction resources, mining resources, etc.), provide greater project resource uptime, and improve the financial performance of project resources.

[0070] Although aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by modifying the machines, systems, and methods disclosed without departing from the spirit and scope of what is disclosed. Such embodiments should be understood as being within the scope of Petition 870250080246, dated 08 / 09 / 2025, page 38 / 164 25 / 25 present disclosure, as determined based on the claims and any equivalents thereof.

[0071] The recitation of the value ranges presented in this document is intended only as a shorthand method of individually referring to each separate value within the range, unless otherwise indicated in this document, and each separate value is incorporated into the descriptive report as if it were individually described in this document. All methods described in this document may be performed in any suitable order, unless otherwise indicated in this document. Petition 870250080246, dated 08 / 09 / 2025, page 39 / 164

Claims

1 / 4 CLAIMS 1.Track system (102) for track-based machinery (100) characterized in that it comprises an undercarriage (104) supporting the track-based machinery (100); a toothed wheel (106) coupled to the undercarriage (104) and driven by a motor; a roller (110) coupled to the undercarriage (104); and a set of track cushions (112) forming an endless loop around the undercarriage (104), adjacent track cushions (112) coupled by means of bushings (204), a track cushion (112) of the track cushion assembly (112) comprising: a body (114) formed of an alloy steel with a first surface (202) configured to contact a support surface and a second surface (116) configured to contact the roller (110), wherein the body (114) is produced by at least induction hardening on the second surface (116) to a hardness of at least 50 HRC to a depth of 32 millimeters from the second surface (116).

2. Conveyor belt system (102), according to claim 1, characterized in that the alloy steel comprises a medium carbon steel alloy comprising, by weight percent: carbon in a range of 0.30 percent to 0.40 percent; manganese in a range of 0.80 to 1.30 percent; nickel in a range of 1.00 to 1.70 percent; chromium in a range of 0.80 to 1.30 percent; and molybdenum in a range of 0.20 to 0.80 percent.

3. Conveyor belt system according to claim 1, characterized in that the transverse thickness of the conveyor belt cushion (112), from the first surface to the second surface, is in the range of 250 millimeters to 400 millimeters. Petition 870250080246, dated 08 / 09 / 2025, page 40 / 164 2 / 4 4. Conveyor belt system, according to claim 3, characterized in that the body (114) is induction hardened to a depth of at least ten percent of the transverse thickness to a hardness in a range of 50 HRC to 60 HRC.

5. Conveyor belt system according to claim 1, characterized in that the conveyor belt cushion (112) has a mass in the range of 1000 to 2000 kilograms.

6. Method for forming a conveyor belt cushion (112) for conveyor-based machinery (100), characterized in that it comprises: casting a body (114) for the conveyor belt cushion (112) using an alloy steel; causing the hardening of the body (114) through a heat treatment and cooling process; and causing an induction heat treatment of a running track (116) of the conveyor belt cushion (112) by at least: setting a fixing distance (406) between an induction coil (404) and the running track (116) to a target distance; performing two or more induction preheating passes with the induction coil (404) using a first set of parameters; performing an austenitizing pass using the induction coil (404) using a second set of parameters; cooling the running track (116) using a polymer cooling material; and temper the body (114) after cooling.

7. Method according to claim 6, characterized in that the first set of parameters comprises: induction power in a range of 170 kilowatts to 200 kilowatts; induction frequency in a range of 300 hertz to 700 hertz; sweep speed in a range of 60 millimeters per minute to 90 millimeters per minute; and a maximum surface temperature of 1000 degrees Celsius.

8. Method according to claim 6, characterized in that the second set of parameters comprises: induction power in the range of 170 kilowatts to 200 kilowatts; induction frequency in the range of 300 hertz to 700 hertz; sweep speed in the range of 55 millimeters per minute to 70 millimeters per minute; and a maximum surface temperature of 1000 degrees Celsius; a minimum temperature at a depth of 32 millimeters from the rolling track of 820 degrees Celsius; and a flow rate for the polymer cooling material in the range of 20 cubic meters per hour to 30 cubic meters per hour.

9. Conveyor belt cushion (112) characterized in that it comprises: a body (114) formed of an alloy steel with: a first surface (202) configured to contact a support surface, and a second surface (116) configured to contact a roller (110), wherein the body (114) is produced by induction hardening on the second surface (116) by at least: defining a clamping distance (406) between an induction coil (404) and the second surface (116) to a target distance; performing two or more induction preheating passes with the induction coil (404) using a first set of parameters; performing an austenitizing pass using the induction coil (404) using a second set of parameters; cooling the second surface (116) using a polymer cooling material; and tempering the body (114) after cooling.

10. Conveyor belt cushion (112), according to claim 9, Petition 870250080246, dated 08 / 09 / 2025, p. 42 / 164 4 / 4 characterized in that: the conveyor belt cushion (112) has a mass in a range of 1000 to 2000 kilograms; and the alloy steel comprises a medium carbon steel alloy comprising, by weight percent: carbon in a range of 0.30 percent to 0.40 percent; manganese in a range of 0.80 to 1.30 percent; nickel in a range of 1.00 to 1.70 percent; chromium in a range of 0.80 to 1.30 percent; and molybdenum in a range of 0.20 to 0.80 percent. Petition 870250080246, dated 09 / 08 / 2025, p. 43 / 164

Images