Track roller for chassis systems with inverted seal and roller edge for the same
By adopting an inverted sealing structure on the track rollers, the problem of metal-faced seals being easily damaged at high speeds is solved, thereby improving sealing performance, simplifying the design, and extending the service life of the track rollers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CATERPILLAR INC
- Filing Date
- 2022-03-18
- Publication Date
- 2026-07-31
AI Technical Summary
The metal-face seals of existing track rollers are easily damaged under high-speed relative motion, leading to performance degradation or failure, and the existing sealing strategies complicate the engineering design of track rollers.
An inverted sealing structure is adopted, which includes first and second sealing assemblies on the roller edge and roller shaft of the track roller. Each sealing assembly consists of an outer sealing carrier, an inner sealing carrier and a face seal. A fluid seal is formed by radial compression, which simplifies the sealing design.
It improves the sealing performance and service life of track rollers, simplifies design complexity, and reduces the failure rate.
Smart Images
Figure CN117043046B_ABST
Abstract
Description
Technical Field
[0001] This disclosure generally relates to a track roller for a chassis system, and more particularly to a track roller having an inverted seal in a face seal assembly. Background Technology
[0002] Tracked machines are used worldwide in a variety of off-highway environments, including applications such as mining, construction, forestry, road building, landfill sites, and many others. A typical tracked machine includes ground-engaging tracks positioned on each side of the machine frame. The ground-engaging tracks extend around a plurality of rotatable track contact elements, which include one or more idler pulleys, drive sprockets, and track rollers. The ground-engaging tracks can advance in a first direction to move the tracked machine forward, in the opposite direction to move the tracked machine backward, and at different speeds to change the tracked machine's direction of travel or orientation.
[0003] Tracked machines tend to be quite heavy, both due to the necessity of certain applications and because their large and complex components are typically constructed to be robust and heavy-duty. The operating conditions they endure can also be quite harsh, involving pushing heavy loads, traversing steep terrain, and interacting with rough and abrasive substrate materials. Track rollers typically bear the majority of the tracked machine's weight and rotate continuously as the machine moves. For this reason, track rollers are usually constructed to withstand a range of loads, which can be substantial, repetitive, and variable depending on how the tracked machine is used. Engineers have developed various lubrication strategies for track rollers in an attempt to optimize field performance and service life.
[0004] In a common track roller design, a metal face seal is used to provide a rotating but fluid-sealed interface between the track roller and the support roller axle. Face seals and related components have been used for many years with great success. However, in some applications, existing sealing strategies may be subjected to relatively high speeds of rotating face seal components relative to each other, ultimately leading to performance degradation or failure. Efforts to adapt to various sealing strategies can also complicate the engineering and design of other components of the track roller. A known track roller assembly configuration is described in U.S. Patent No. 6,364,438 to Hasselbusch et al. In Hasselbusch et al.'s patent, the roller assembly has a roller edge and a roller axle. A retainer is press-fitted into an access opening in the roller edge. An axial thrust bearing is positioned between the outwardly extending flange of the roller axle and the retainer. While Hasselbusch et al.'s patent undoubtedly covers a wide range of applications, there is always room for improvement and the development of alternative strategies. Summary of the Invention
[0005] In one aspect, a track roller for a ground-engaging track system includes a roller edge defining a roller axis and including a first axial end having a first sealing hole formed therein and a second axial end having a second sealing hole formed therein. The track roller also includes a roller shaft extending through the first and second sealing holes. The track roller further includes a first sealing assembly having: a first outer sealing carrier within the first sealing hole and fixed to rotate about the roller shaft with the roller edge; a first inner sealing carrier fixed to the roller shaft; and a first face seal. The track roller also includes a second sealing assembly having: a second outer sealing carrier within the second sealing hole and fixed to rotate about the roller shaft with the roller edge; a second inner sealing carrier fixed to the roller shaft; and a second face seal. The first and second face seals each include an outer sealing ring and an outer sealing element supported in a respective outer sealing carrier, and an inner sealing ring and an inner sealing element supported in a respective inner sealing carrier. Each external sealing element is radially inward from the corresponding external sealing ring and is compressed radially to form a fluid seal with the corresponding external sealing carrier.
[0006] On the other hand, a track roller for a ground-engaging track system includes a roller edge having an outer tread and an inner surface, the inner surface forming a first sealing hole, a second sealing hole, and a shaft hole, the shaft hole defining a roller axis and extending between the first and second sealing holes. The track roller also includes a roller shaft and a sealing assembly comprising: an outer sealing carrier within the first sealing hole and fixed to rotate about the roller shaft with the roller edge; and a face seal. The face seal includes an outer sealing ring and an outer sealing element supported within the outer sealing carrier, and an inner sealing ring and an inner sealing element. The outer sealing element is radially inward from the outer sealing ring and is compressed radially between the outer sealing ring and the outer sealing carrier.
[0007] In another aspect, the edge of a track roller for a chassis system includes a roller housing defining a roller axis extending between an axial end of a first roller housing and an axial end of a second roller housing, and having an outer tread extending circumferentially about the roller axis and axially between an end flange of the first roller housing and an end flange of the second roller housing. The roller housing also includes a first sealing hole formed in the axial end of the first roller housing, a second sealing hole formed in the axial end of the second roller housing, and a shaft hole extending axially between the first and second sealing holes and circumferentially about the roller housing axis. The roller housing also includes a centrally located oil cavity communicating with the shaft hole, a first internal support surface exposed in the shaft hole and extending axially from the oil cavity to the first sealing hole, and a second internal support surface exposed in the shaft hole and extending axially from the oil cavity to the second sealing hole. The roller housing also includes a first oil passage and a second oil passage, each oil passage formed radially outward from the shaft hole and extending axially between the oil cavity and the first and second sealing holes, respectively. Attached Figure Description
[0008] Figure 1 This is a side view of a machine according to one embodiment;
[0009] Figure 2 This is a partial cross-sectional front view of a track roller according to one embodiment;
[0010] Figure 3 Is it like this? Figure 2 A cross-sectional view of the track rollers in the diagram;
[0011] Figure 4 This is a cross-sectional schematic view of a track roller according to another embodiment;
[0012] Figure 5 This is a cross-sectional view of a portion of a track roller according to yet another embodiment; and
[0013] Figure 6 It is suitable for use Figure 5 A schematic view of the floating washer of the track roller. Detailed Implementation
[0014] refer to Figure 1The image illustrates a tracked machine 10 according to one embodiment. The machine 10 is shown in the context of a tracked tractor; however, in other embodiments, the machine 10 may be a tracked loader, excavator, bucket-type mining machine, half-track machine, or other machine. The machine 10 includes a frame 12 and typically has a hydraulically actuated implement system (not shown) coupled to the frame 12. The machine 10 also includes a chassis system or ground-engaging track system 14. System 14 includes a track roller frame 16, a drive sprocket 18, a front idler sprocket 20, a rear idler sprocket 22, a plurality of track rollers 30, and a ground-engaging track 24. The track 24 includes a plurality of track links 26 arranged end-to-end and typically coupled together as two parallel chains, and attached to a plurality of track plates 28. The track 24 will typically be a single track positioned on one side of the machine 10, with substantially identical tracks positioned on opposite sides of the machine 10. System 14 is shown in a so-called “high drive” configuration, but may alternatively be in an oval track configuration or another configuration. As will become more apparent from the following description, the track rollers 30 may be uniquely configured to have a simplified and efficient construction and a seal between rotating components.
[0015] Now also referencing Figure 2 and 3One of the track rollers 30 is shown in more detail below. Each track roller 30 (sometimes referred to in the singular below) includes a roller edge 32 having a roller housing 34 defining a roller axis 36. The roller edge 32 and the roller housing 34 are referred to interchangeably herein. It should be understood that a roller “edge” may include the roller housing and additional attachment components, such as press-fit or otherwise interference-fit components, while a roller “housing” refers only to a single-piece housing. The roller edge 34 includes a first roller housing axial end 38 in which a first sealing hole 40 is formed and a second roller housing axial end 42 in which a second sealing hole 44 is formed. The roller housing 34 includes an outer tread 50 that extends circumferentially around the roller axis 36 and extends axially between the first roller housing end flange 52 and the second roller housing end flange 54. It can be understood that a shaft hole 57 defining the roller axis 36 extends axially between the first sealing hole 40 and the second sealing hole 44. The roller shaft 46 extends through the first sealing hole 40 and the second sealing hole 44 and through the shaft hole 57. In one embodiment, the roller housing 34 is formed of two housing members attached, for example, by friction welding at a weld joint 56. Each of the first sealing hole 40, the second sealing hole 44, and the shaft hole 57 can be understood as being defined by an inner surface 55 of the roller housing 34. The roller housing 34 also forms a centrally located oil cavity 102 communicating with the shaft hole 57, a first internal support surface 59 exposed to the shaft hole 57 and extending axially from the oil cavity 102 to the first sealing hole 40, and a second internal support surface 61 exposed to the shaft hole 57 and extending axially from the oil cavity 102 to the second sealing hole 44. The roller shaft 46 may include a flat portion 48 at one end and generally includes another flat portion (unnumbered) at its opposite end, whereby the roller shaft 46 can be mounted to the track roller frame 16, for example, by means of a clamping collar. Bolt holes (not shown) may extend through the roller shaft 46 and open in the flat portion. The roller shaft 46 is a straight shaft, including a cylindrical outer surface 49 that is uninterrupted in profile between the first sealing hole 40 and the second sealing hole 44. The track roller 30 also includes a first sealing assembly 58 and a second sealing assembly 66, each having an outer cylindrical surface 49 that is also uninterrupted in profile between the first sealing assembly 58 and the second sealing assembly 66. Each of the first sealing assembly 58 and the second sealing assembly 66 can be understood as a metal-faced sealing assembly.
[0016] The first sealing assembly 58 includes a first external sealing carrier 60, which is located within the first sealing hole 40 and fixed to rotate around the roller shaft 46 with the roller edge 32. The first sealing assembly 58 also includes a first internal sealing carrier 62 fixed to the roller shaft 46 and a first face seal 64 (metal face seal). The second sealing assembly 66 includes a second external sealing carrier 68 located within the second sealing hole 44 and fixed to rotate around the roller shaft 46 with the roller edge 32, a second internal sealing carrier 70 fixed to the roller shaft 46, and a second face seal 72 (metal face seal). In an embodiment, the first internal sealing carrier 62 and the second internal sealing carrier 70 are interference-fitted on the roller shaft 46. The roller shaft 46 may include a first knurled surface 90 and a second knurled surface 92, each knurled surface extending circumferentially around the roller axis 36, and the first internal sealing carrier 62 and the second internal sealing carrier 70 may be interference-fitted on the roller shaft 46 on the first knurled surface 90 and the second knurled surface 92, respectively. The first external sealing carrier 60 and the second external sealing carrier 68 can respectively interfere with the roller edge 32 within the first sealing hole 40 and the second sealing hole 44. Since a relatively short axial interference fit length is available, knurled surfaces 90 and 92 can be used to enhance the strength of the interference fit. In an alternative embodiment, a retaining ring (not shown) on the roller shaft 46 can be used in conjunction with or alternative to the interference fit to secure the first internal sealing carrier 62 and the second internal sealing carrier 70 to the roller shaft 46. This type of retaining ring is typically positioned axially outward from the first internal sealing carrier 62 and the second internal sealing carrier 70, such that the first internal sealing carrier 62 and the second internal sealing carrier 70 are each clamped between the retaining ring located in a groove on the roller shaft 56 and the roller housing 34.
[0017] The first sealing element 64 and the second sealing element 72 may each include a metal-faced sealing element, forming a sealing interface between metal components rotatable relative to each other. The first sealing element 64 and the second sealing element 72 each include external sealing rings 74 and 76 supported in respective external sealing carriers 60 and 68, and external sealing elements 78 and 80. Each of the first sealing element 64 and the second sealing element 72 further includes internal sealing rings 82 and 84 supported in respective internal sealing carriers 62 and 70, and internal sealing elements 86 and 88. Each external sealing element 78 and 80 extends radially inward from the respective external sealing rings 74 and 76 and is compressed radially to form a fluid seal with the respective external sealing carriers 60 and 68. As can be seen in the figures, external sealing elements 78 and 80 are positioned within the gaps in the respective external sealing carriers 60 and 68, and are axially and radially compressed by the interference fit of the external sealing carriers 60 and 68 and by their interaction with the inclined surfaces of the external sealing carriers 60 and 68 and / or the inclined surfaces of the external sealing rings 74 and 76. As used herein, the terms “axially inward” and “axially outward” refer to directions along the roller axis 36 toward and away from the center point of the line segment of the roller axis 36 within the roller axis 46, respectively. The terms “radially outward” and “radially inward” refer to directions away from and toward the roller axis 36, respectively. Thus, for example, the first external sealing carrier 60 is axially outward from the first internal sealing carrier 62. Each of the respective sealing rings 74, 76, 82, and 84 may include a metal sealing ring that is annular in shape and has sealing surfaces (not numbered) that are adjacent but typically separated by a thin layer of lubricating oil. Each of the corresponding sealing elements 78, 80, 86 and 88 may include a non-metallic sealing element having a circular, elliptical, polygonal or other cross-section (and is commonly referred to in the art as a torus).
[0018] The track roller 30 also includes a first bearing 94 that is internally or axially inwardly fitted onto the roller shaft 46 within the first internal sealing carrier 62, and a second bearing 96 that is internally or axially inwardly fitted onto the roller shaft 46 within the second internal sealing carrier 70. In the illustrated embodiment, the first bearing 94 includes a journal sleeve 98 and a projecting thrust flange 100, which is attached to and integral with the journal sleeve and positioned within the first sealing bore 40. The journal sleeve 98 rotatably journals and supports the roller housing 34. The thrust flange 100 is sandwiched between the roller edge 32 and the first internal sealing carrier 62 and responds to thrust loads between the roller edge 32 / roller housing 34 and the first internal sealing carrier 62. The second bearing 96 may be similarly configured to have a journal sleeve and a projecting thrust flange.
[0019] As described above, the roller edge 32 / roller housing 34 has an oil cavity 102 centrally located therein. The oil cavity 102 extends circumferentially around the roller shaft 46. The roller edge 32 also forms a first oil passage 104 extending from the oil cavity 102 to the first sealing hole 40 and a second oil passage 106 extending from the oil cavity 102 to the second sealing hole 44. In the illustrated embodiment, the first oil passage 104 and the second oil passage 106 have the form of oil passages or cross holes. The first oil passage 104 and the second oil passage 106 are radially outwardly spaced from the first inner support surface 59 and the second inner support surface 61, respectively. Therefore, the oil passages 104 and 106 are understood to be radially outwardly spaced from the first bearing 94 and the second bearing 96, respectively. Each oil passage 104 may be one of a set of oil passages circumferentially spaced from each other around the roller shaft 36. Similarly, each oil passage 106 may be one of a set of oil passages circumferentially spaced from the roller shaft 36. Figure 3 The diagram also shows an oil filling opening 108 formed in the second axial end 42. The oil filling opening 108 can provide a supply of oil into the region of the second sealing assembly 66, which can then pass through the oil passage 106 and into the oil chamber 102. Oil from the oil chamber 102 can then flow through the oil passage 104 to the first sealing assembly 58. Figure 3 The diagram also shows another oil-filling opening or cavity 110 formed in the roller shaft 46. The oil-filling opening 110 allows oil to be supplied through the roller shaft 46 to the oil cavity 102. In some embodiments, only the oil-filling opening 108 may be used; in other embodiments, only the oil-filling opening 110 may be used; and in still other embodiments, both may be used. When the track roller 30 is in use, this oil-filling opening is typically blocked.
[0020] Now for reference Figure 4 The image shows a track roller 130 according to another embodiment. In the track roller 130, a roller shaft 146 extends through a roller edge 132. For purposes similar to those described in conjunction with the foregoing embodiments, a first sealing assembly 158 and a second sealing assembly 166 are provided. Each of the sealing assemblies 158 and 166 includes an external sealing carrier (unnumbered) that interferes with the roller edge 132, an internal sealing carrier (unnumbered) fixed to the roller shaft 146, and a bearing (unnumbered) that interferes with the roller shaft 146. Although in Figure 3 In the embodiments, each internal sealing element 86 and 88 extends radially inward from the corresponding internal sealing rings 82 and 84, but... Figure 4In the embodiments, the first internal sealing element 186 and the second internal element 188 extend radially outward from the first internal sealing ring 182 and the second internal sealing ring 184, respectively. Each of the first sealing assembly 158 and the second sealing assembly 166 is understood to form face seals 164 and 172, respectively, but the separate assemblies of the sealing rings and sealing elements are inverted relative to each other. (See attached...) Figure 3 Described and Figure 4 As will also be understood in the context of other embodiments envisioned herein, the interference fit of the bearing on the roller shaft eliminates possible oil supply paths as used in some other track rollers. In the absence of an external sealing element and sealing ring with the described configuration, achieving an oil flow path to the face seal can be problematic.
[0021] refer to Figure 5 The image shows a track roller 230 according to yet another embodiment. The track roller 230 includes a sealing assembly 266, a roller edge 232, and the sealing assembly 266 is located within a sealing bore 240, configured substantially similarly to the sealing assembly in any of the foregoing embodiments, positioned around a roller shaft 246, and at least partially within the roller edge 232. The roller edge 232 has an oil cavity 202 centrally located therein, and an oil passage 304 positioned as a recessed groove extending radially outward from a journal sleeve 298 of a bearing 294, which interferes with the roller shaft 246. The recess 304 may be one of a plurality of recesses circumferentially spaced around the roller axis and provides an oil supply path from the oil cavity 202 to the sealing assembly 266. While the recess 304 extends axially, the radially extending recesses formed in the roller edge 232 (one of which is located in…) Figure 5 As can be seen in the diagram and marked 305, it can extend from the groove 304. The floating thrust washer 300 can be within the sealing hole 240 formed in the edge 232. See also Figure 6 The floating thrust washer 300 includes a plurality of internal grooves 301, which together with the roller shaft 246 form a plurality of oil passages.
[0022] Industrial applicability
[0023] Generally refer to the accompanying drawings, but specifically return to... Figure 2 and 3In this embodiment, during operation, the roller shaft 46 can be kept stationary by being mounted to the track roller frame 16. As the track 24 advances around the front idler 20, rear idler 22, and drive sprocket 18, the roller housing 32 can rotate in contact with the track 24. The outer sealing carriers 60 and 68 will rotate with the roller edge 32 while the inner sealing carriers 62 and 70 will remain stationary, wherein rotation between the contacting components occurs at the face seals 64 and 72. Oil can reside in the oil chamber 102 and can be axially distributed outward through the oil passage 104 to maintain oil supply to the face seals 64 and 72.
[0024] This specification is for illustrative purposes only and should not be construed as limiting the scope of this disclosure in any way. Therefore, those skilled in the art will understand that various modifications can be made to the embodiments currently disclosed without departing from the full and reasonable scope and spirit of this disclosure. Other aspects, features, and advantages will become apparent from the accompanying drawings and appended claims. As used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more”. The term “one” or similar language is used when intended to refer to only one item. Furthermore, as used herein, the terms “has,” “have,” “having,” etc., are intended to be open-ended terms. Additionally, the phrase “based on” is intended to mean “at least partially based on” unless otherwise expressly stated.
Claims
1. A track roller (30, 130, 230) for a ground-engaging track system (14), said track roller comprising: Roller edge (32, 132, 232), the roller edge defining the roller axis, and including a first axial end (38) in which a first sealing hole (40, 240) is formed and a second axial end (42) in which a second sealing hole (44) is formed. Roller shafts (46, 146, 246) extend through the first sealing hole (40, 240) and the second sealing hole (44). A first sealing assembly (58, 158) includes: a first external sealing carrier (60) residing within the first sealing holes (40, 240) and fixed to rotate with the roller edges (32, 132, 232) about the roller shaft (46, 146, 246); a first internal sealing carrier (62) fixed to the roller shaft (46, 146, 246); and a first face seal (64, 164). The second sealing assembly (66, 166, 266) includes: a second external sealing carrier (68) which is located within the second sealing hole (44) and is fixed to rotate with the roller edges (32, 132, 232) about the roller shaft (46, 146, 246); a second internal sealing carrier (70) which is fixed to the roller shaft (46, 146, 246); and a second face seal (72, 172). The first surface seal (64, 164) and the second surface seal (72, 172) each include an outer sealing ring (74, 76) and an outer sealing element (78, 80) supported in a respective outer sealing carrier (60, 68), and an inner sealing ring (82, 84, 182, 184) and an inner sealing element (86, 88, 186, 188) supported in a respective inner sealing carrier (62, 70); and Each external sealing element (78, 80) is radially compressed from the corresponding external sealing ring (74, 76) to form a fluid seal with the corresponding external sealing carrier (60, 68).
2. The track rollers (30, 130, 230) according to claim 1, wherein: The first external sealing carrier (60) and the second external sealing carrier (68) respectively interfere with the roller edges (32, 132, 232) within the first sealing hole (40, 240) and the second sealing hole (44); and The roller shafts (46, 146, 246) include an outer cylindrical surface (49) that is uninterrupted in profile between the first sealing assembly (58, 158) and the second sealing assembly (66, 166, 266).
3. The track roller (30, 230) according to claim 1 or 2, wherein each internal sealing element (86, 88, 188) is radially inward from the corresponding internal sealing ring (82, 84) and compressed radially to form a seal with the corresponding internal sealing carrier (62, 70).
4. The track roller (130) according to claim 1 or 2, wherein each internal sealing element (186, 188) is radially outward from the corresponding internal sealing ring (182, 184) and compressed radially to form a fluid seal with the corresponding internal sealing carrier (62, 70).
5. The track roller (30, 230) according to claim 1 or 2, wherein: The roller edges (32, 232) form oil cavities (102, 202) extending circumferentially around the roller shaft (46, 246), a first oil passage (104, 304) extending from the oil cavities (102, 202) to the first sealing hole (40, 240), and a second oil passage (106) extending from the oil cavities (102, 202) to the second sealing hole (44).
6. The track roller (30, 130, 230) according to claim 1 or 2, wherein: The first internal sealing carrier (62) and the second internal sealing carrier (70) are interference-fitted on the roller shafts (46, 146, 246); and The roller shafts (46, 146, 246) include a first knurled surface (90) and a second knurled surface (92), and the first internal sealing carrier (62) and the second internal sealing carrier (70) respectively interfere with each other on the first knurled surface (90) and the second knurled surface (92) on the roller shafts (46, 146, 246).
7. The track rollers (30, 130, 230) according to claim 1 or 2 further include a first bearing (94, 294) interfering with the roller shafts (46, 146, 246) on the inner side of the first internal sealing carrier (62), and a second bearing (96) interfering with the roller shafts (46, 146, 246) on the inner side of the second internal sealing carrier (70); and The first bearing (94, 294) includes a journal sleeve (98, 298) and a protruding thrust flange (100) which is located within the first sealing hole (40, 240) and is sandwiched between the roller edge (32, 132, 232) and the first internal sealing carrier (62).
8. The track roller according to claim 7, wherein: The first bearing (294) includes a journal sleeve (298) and a floating thrust washer (300) located within the first sealing hole (240) and sandwiched between the first internal sealing carrier and the roller edge (232); and The floating thrust washer (300) includes a plurality of internal oil grooves (301), which together with the roller shaft (246) form a plurality of oil passages.