Leg tube assembly and method for manufacturing a leg tube assembly

Abstract

A leg tube assembly (200) for a working machine (100) comprises a first tube (202) connected to a frame (108) of the working machine (100), and a second tube (208) connected to the first tube (202) and displaceable relative to the first tube (202) between an extended position and a retracted position. The first tube (202) defines a first inner surface (204). The second tube (208) comprises a tube body (212) defining a second inner surface (214), a second outer surface (216), a first end (218), and a second end (220). The tube body (212) defines at least one recess (222, 322) on the second outer surface (216). The second tube (208) comprises at least one support element (224, 324) which is arranged within the at least one recess (222, 322) of the tube body (212) between the first tube (202) and the tube body (212) of the second tube (208).The at least one support element (224, 324) is designed to engage with the first inner surface (204) of the first tube (202) and comprises either a bearing (224) or a wear pad (324).

Description

Technical field The present disclosure relates to a working machine, a leg tube assembly for the working machine and a method for manufacturing the leg tube assembly for the working machine. State of the art Working machines, such as a reclaimer or a cold milling machine, can be used for various applications, including full-depth recovery or soil stabilization. These machines typically feature a cutting rotor. They also include vertically adjustable leg tubes used to raise and lower the machine relative to the ground surface. The leg tubes rest on bearings to hold them in place during the raising and lowering process. Specifically, each leg tube incorporates two bearings positioned at its lower end within a support frame structure to secure the leg bores.However, since the upper end of each leg tube is not supported, the leg tube can tilt within the support frame structure, which can lead to increased wear of the leg tubes and an inaccurate tracking / ground contact position, which is undesirable. US Patent No. 11,772,445 describes a construction machine, in particular a road milling machine, consisting of a machine frame, a chassis with front and rear devices with at least one pair of front devices and / or one pair of rear devices, wherein at least one pair of the front or rear devices is connected to the machine frame via lifting columns, each having a hydraulically adjustable piston-cylinder unit, a drive device for separately driving the hydraulically adjustable piston-cylinder unit of the lifting columns, and a control device designed to control the stroke adjustment of the lifting columns by means of the hydraulically adjustable piston-cylinder units, as well as a method for controlling the stroke position of a piston-cylinder unit of a lifting column of a construction machine, in particular a construction machine according to the invention. Summary of Disclosure In one aspect of the present disclosure, a leg tube assembly for a working machine is provided. The leg tube assembly comprises a first tube connected to a frame of the working machine. The first tube defines a first inner surface. The leg tube assembly also comprises a second tube connected to the first tube and displaceable relative to the first tube between an extended position and a retracted position. The second tube is accommodated within the first tube. The second tube comprises a tube body defining a second inner surface, a second outer surface opposite the second inner surface, a first end that is located within the first tube in both the extended and retracted positions of the second tube, and a second end that extends out of the first tube when the second tube is in the extended position.The pipe body defines at least one recess on its second outer surface. This recess extends axially from the first end of the pipe body to the second end and extends at least partially along a circumferential direction. The second pipe also includes at least one support element located within the recess of the pipe body. This support element is positioned between the first pipe and the pipe body of the second pipe. The support element is designed to engage with the first inner surface of the first pipe. The support element comprises either a bearing or a wear pad. In another aspect of the present disclosure, a working machine is provided. The working machine comprises a frame. The working machine also comprises several leg tube assemblies connected to the frame. Each of the several leg tube assemblies is adjustable to raise or lower the working machine relative to the ground surface. Each of the several leg tube assemblies comprises a first tube connected to the frame of the working machine. The first tube defines a first inner surface. Each of the several leg tube assemblies also comprises a second tube connected to the first tube and which can be displaced relative to the first tube between an extended position and a retracted position. The second tube is accommodated within the first tube.The second tube comprises a tube body defining a second inner surface, a second outer surface opposite the second inner surface, a first end that is located inside the first tube in both the extended and retracted positions, and a second end that extends out of the first tube when the second tube is in the extended position. The tube body defines at least one recess on its second outer surface. This at least one recess extends axially from the first end of the tube body to the second end of the tube body and extends at least partially along a circumferential direction. The second tube also comprises at least one support element arranged within the at least one recess of the tube body. This at least one support element is located between the first tube and the tube body of the second tube.The at least one support element is designed to engage with the first inner surface of the first tube. The at least one support element comprises either a bearing or a wear pad. In another aspect of the present disclosure, a method for manufacturing a leg tube assembly for a machine tool is provided. The method comprises forming a first tube of the leg tube assembly. The first tube defines a first inner surface. The method also comprises forming a tube body of a second tube of the leg tube assembly. The tube body defines a second inner surface, a second outer surface opposite the second inner surface, a first end, and a second end opposite the first end. The method further comprises defining at least one recess on the second outer surface of the tube body. The at least one recess extends axially from the first end of the tube body to the second end of the tube body and extends at least partially along a circumferential direction.The method comprises arranging at least one support element of the second tube within the at least one recess of the tube body. The at least one support element comprises either a bearing or a wear pad. The method further comprises connecting the second tube to the first tube by receiving the first tube within the second tube. The at least one support element is arranged between the first tube and the tube body of the second tube. The method comprises engaging the at least one support element with the first inner surface of the first tube by coupling the second tube to the first tube. Further features and aspects of this revelation will become apparent from the following description and the accompanying drawings. Brief description of the drawings Fig. 1 is a schematic side view of a working machine according to an example of the present disclosure; Fig. 2 is a perspective view of a part of the working machine from Fig. 1, showing a pair of leg tube assemblies; Fig. 3A is a schematic representation of a leg tube assembly from Fig. 2 according to an example of the present disclosure; Fig. 3B is a schematic representation of a second tube of the leg tube assembly from Fig. 3A; Fig. 4 is an exploded view of a support element and a tube body of the second tube from Fig. 3B; Fig. 5 is a schematic representation of a second tube of the leg tube assembly from Fig. 2 according to another example of the present disclosure; Fig. 6 is a schematic representation of a support element connected to the second tube from Fig. 5; Fig. 7A is a schematic representation of a washer for the second tube from Figs. 5 and 6; Fig.Figure 7B is a sectional view of the washer and support element connected to the second tube from Figures 6 and 7A; Figure 7C is a schematic representation illustrating an inner surface of a tube body of the second tube from Figures 5 and 6; and Figure 8 is a flowchart for a method of manufacturing the leg tube assembly for the working machine according to an example of the present disclosure. Detailed description Where possible, the same reference numerals are used in the drawings to refer to identical or similar parts. Fig. 1 is a schematic side view of a working machine 100 according to an example of the present disclosure. Here, the working machine 100 has an embodiment as a reloading machine. In other examples, the working machine 100 can comprise any other machine used for milling, road preparation, soil stabilization, surface pulverization, and other related applications, such as a cold milling machine, a rotary mixer, and the like. The working machine 100 operates on a ground surface 102. The working machine 100 defines a front end 104 and a rear end 106. The working machine 100 comprises a frame 108. An energy source (not shown) is positioned near the front end 104 in a compartment (not shown). The compartment is covered by a hood 110, which can be opened to provide access to the energy source. The energy source can be a motor, a battery system, a fuel cell, or a combination thereof. A pair of front wheels 112 is arranged near the front end 104 of the work machine 100. Two rear wheels 114 are also arranged near the rear end 106 of the work machine 100. Alternatively, the work machine 100 can have crawler tracks (not shown) instead of the wheels 112, 114. The work machine 100 has an operator's cab 116. If the work machine 100 is configured in a manual or semi-autonomous configuration, an operator can sit in the operator's cab 116 to operate the work machine 100. Furthermore, the machine 100 includes a mixing chamber 118, which is defined between the front and rear wheels 112, 114. The mixing chamber 118 is an enclosed space defined beneath the frame 108 and extending laterally over the machine 100. A rotor (not shown) is also arranged within the mixing chamber 118. The rotor is rotatably coupled to the machine 100 to perform one or more machine operations, such as cutting, mixing, and / or pulverizing material. The rotor is driven by the power source. The rotor comprises a shell element and a number of cutting units arranged on the shell element. Referring to Figures 1 and 2, the frame 108 comprises a number of support structures 120. The working machine 100 also comprises a number of leg tube assemblies 200 connected to the frame 108. In some embodiments, the working machine 100 comprises four leg tube assemblies 200. The four leg tube assemblies 200 are similar to each other in their construction and dimensions. Each of the leg tube assemblies 200 is adjustable to raise or lower the working machine 100 relative to the ground surface 102. The leg tube assemblies 200 can also be referred to as lifting columns. In some embodiments, the wheels 112, 114 can be connected to the frame 108 via the leg tube assemblies 200. Each support structure 120 of the frame 108 accommodates and supports a corresponding leg tube assembly 200 from among the leg tube assemblies 200.Each leg tube assembly 200 may include an actuator (not shown), for example a hydraulic actuator, to facilitate raising and lowering the frame 108 relative to the wheels 112, 114. As shown in Fig. 3A, the leg tube assembly 200 comprises a first tube 202, which is connected to the frame 108 (see Fig. 1) of the working machine 100. The first tube 202 defines a first inner surface 204. The first tube 202 also defines a first outer surface 206. In addition, in some embodiments, two bearings 208 are arranged on the first outer surface 206 near a lower end of the first tube 202. The leg tube assembly 200 also includes a second tube 210, which is connected to the first tube 202 and is displaceable relative to the first tube 202 between an extended position and a retracted position. The second tube 210 is accommodated within the first tube 202. The second tube 210 slides based on actuation of the actuator. The second tube 210 comprises a tube body 212. The tube body 212 defines a second inner surface 214, a second outer surface 216 opposite the second inner surface 214, a first end 218 which is located within the first tube 202 in both the extended and retracted positions of the second tube 210, and a second end 220 which extends out of the first tube 202 when the second tube 210 is in the extended position. The second tube 210 is shown in the extended position in Fig. 3B. As shown in Fig. 3B, the tube body 212 defines one or more recesses 222 on its second outer surface 216. The one or more recesses 222 extend axially from the first end 218 of the tube body 212 to the second end 220 of the tube body 212 and extend at least partially along a circumferential direction D1. In the example shown in Fig. 3B, the one or more recesses 222 comprise an annular recess 222 that extends circumferentially along the second outer surface 216 of the tube body 212. The one or more recesses 222 may hereafter be referred to interchangeably as "the annular recess 222". As shown in Fig. 4, the second tube 210 also comprises one or more support elements 224, which are arranged within the one or more recesses 222 of the tube body 212. The one or more support elements 224 are arranged between the first tube 202 and the tube body 212 of the second tube 210. The one or more support elements 224 engage in the first inner surface 204 of the first tube 202. The one or more support elements 224 comprise a bearing 224 or a wear pad. In the example shown in Fig. 4, the one or more support elements 224 comprise the single, annular bearing 224, which is received in the annular recess 222 of the tube body 212. The one or more support elements 224 may hereinafter be referred to interchangeably as "the annular bearing 224" or "the bearing 224". During operation, the ring bearing 224 moves together with the second tube 210.The ring bearing 224 is made of metal or a composite material. For example, the ring bearing 224 can be made of bronze. Figures 5 to 7C illustrate a further embodiment of the present disclosure. With reference to Figure 5, the leg tube assembly 200 comprises a second tube 310. The second tube 310 is essentially similar to the second tube 210 described with reference to Figures 3 and 4, with common components being designated by the same numbers. The tube body 212 of the second tube 310 defines one or more recesses 322 on the second outer surface 216. In the example shown in Figure 5, the one or more recesses 322 comprise a number of recesses 322 spaced apart from one another circumferentially along the second outer surface 216 of the tube body 212. In particular, the number of recesses 322 comprises four recesses 322. Furthermore, the tube body 212 defines a number of pairs of first through holes 326. In particular, the tube body 212 defines four pairs of first through holes 326.Each first through-hole 326 extends from the second inner surface 214. Each pair of first through-holes 326 is connected to a corresponding recess 322. Referring to Fig. 6, the second tube 310 comprises one or more support elements 324 arranged within the one or more recesses 322 of the tube body 212. In the example shown in Fig. 5, the one or more support elements 324 comprise a number of wear pads 324. The one or more support elements 324 may hereafter be referred to interchangeably as "the wear pad 324". Each recess 322 of the number of recesses 322 accommodates a corresponding wear pad 324 of the number of wear pads 324. In particular, the number of wear pads 324 comprises four wear pads 324. Each wear pad 324 is rectangular. However, each wear pad 324 may also have a different shape. Furthermore, each wear pad 324 defines a pair of second through-holes 328. Referring to Figures 7A and 7B, the second tube 310 further comprises a number of washers 330. Each washer 330 is arranged between a corresponding wear pad 324 and the tube body 212. The number of washers 330 comprises four washers 330. The washer 330 has a U-shaped slot 331. The washer 330 has a rectangular shape. Alternatively, the washer 330 may have another shape. The dimensions and shape of the wear pad 324 correspond to the dimensions and shape of the washer 330. The wear pads 324 and the washers 330 may be made of a wear-resistant material. In some examples, the wear pads 324 and the washers 330 are made of a polymer, a metal, or a composite material.In one example, the number of wear pads can be 324 and the number of washers can be 330, both made of bronze. Referring to Figures 7B and 7C, the second tube 310 further comprises a number of pairs of fasteners 332. Each wear pad 324 is connected to the tube body 212 and a corresponding washer 330 by a corresponding pair of fasteners 332 from the number of pairs of fasteners 332. Each second through-hole 328 (see Figure 6) is aligned with a corresponding first through-hole 326 (see Figure 5) in the tube body 212 to receive a corresponding fastener 332. The number of fasteners 332 comprises four pairs of fasteners 332. Each fastener 332 may comprise a bolt, a screw, a pin, and the like.In some embodiments, every second through-hole 328 in the wear pad 324 can have a threaded hole, and each fastener 332 can have a number of external threads to engage with and connect to the corresponding second through-hole 328 of the wear pad 324. Each fastener 332 is connected to the tube body 212 and a corresponding wear pad 324, such that a head 334 of the fastener 332 engages in the second inner surface 214 of the tube body 212. It should be noted that individual features shown or described for one embodiment may be combined with individual features shown or described for another embodiment. The implementation described above does not in any way limit the scope of this disclosure. Therefore, it should be noted that although some features are shown or described to illustrate the use of this disclosure in connection with functional segments, these features may be omitted from the scope of this disclosure as defined in the appended claims. Industrial applicability The present disclosure relates to the leg tube assemblies 200 for the working machine 100. Each leg tube assembly 200 comprises the support element 224, 324, i.e., the annular bearing 224 or the number of wear pads 324. During operation, the support element 224, 324 moves with the second tube 210. Furthermore, the annular bearing 224 can support an upper end, i.e., the first end 218 of the second tube 310, when the second tube 310 is fully retracted and the working machine 100 is in its lowest position relative to the ground surface 102. Additionally, the annular bearing 224 can provide support when lateral loads act on the frame 108. Furthermore, the number of wear pads 324 can support the upper end of the second tube 310 and reduce wear on the bearings 208. The second tube 310 also includes washers 330, which allow the upper end of the second tube 310 to be tightened without having to replace the wear pads 324. Additionally, the ring bearing 224 and the number of wear pads 324 help to hold the second tube 310 in its desired position, thereby holding the leg tube assembly 200 more securely, which can increase the stability of the machine and lead to a better cut. Moreover, the support element 224 allows controlled movement of the second tube 310 relative to the first tube 202, which in turn can prevent wear and enable precise positioning of the leg tube assembly 200. Fig. 8 is a flowchart for a process 800 for manufacturing the leg tube assembly 200 for the working machine 100. Referring to Figs. 1, 2, 3, 4, 5, 6, 7 to 8, in step 802 the first tube 202 of the leg tube assembly 200 is formed. The first tube 202 defines the first inner surface 204. In step 804, the tube body 212 of the second tube 210, 310 of the leg tube assembly 200 is formed. The tube body 212 defines the second inner surface 214, the second outer surface 216 opposite the second inner surface 214, the first end 218, and the second end 220 opposite the first end 218. In step 806, one or more recesses 222, 322 are defined on the second outer surface 216 of the tube body 212. The one or more recesses 222, 322 extend axially from the first end 218 of the tube body 212 to the second end 220 of the tube body 212 and extend at least partially along the circumferential direction D1. In step 808, the one or more support elements 224, 324 of the second tube 210, 310 are arranged in the one or more recesses 222, 322 of the tube body 212. The one or more support elements 224, 324 comprise either the bearing 224 or the wear pad 324. In step 810, the second pipe 210, 310 is connected to the first pipe 202 as soon as the first pipe 202 has been inserted into the second pipe 210, 310. The one or more support elements 224, 324 are arranged between the first pipe 202 and the pipe body 212 of the second pipe 210, 310. In step 812, one or more support elements 224, 324 are engaged with the first inner surface 204 of the first tube 202, based on the coupling of the second tube 210, 310 with the first tube 202. In some examples, the one or more recesses 222 comprise the annular recess 222, which extends circumferentially along the second outer surface 216 of the tube body 212. The one or more support elements 224 comprise the single annular bearing 224, which is received in the annular recess 222 of the tube body 212. Step 808 further comprises the step in which the annular bearing 224 is received in the annular recess 222 of the tube body 212. In some examples, the one or more recesses 322 comprise the number of recesses 322 spaced apart circumferentially along the second outer surface 216 of the tube body 212. The one or more support elements 324 comprise the number of wear pads 324. Step 808 further comprises the step in which each recess 322 from the number of recesses 322 receives the corresponding wear pad 324 from the number of wear pads 24. In some examples, the second tube 310 further comprises the number of washers 330. The second tube 310 further comprises the number of pairs of fasteners 332. Step 808 further comprises the step in which each washer 330 is arranged in the corresponding recess 322, such that each washer 330 is positioned between the corresponding wear pad 324 and the tube body 212. Step 808 further comprises the step in which each wear pad 324 is connected to the tube body 212 and the corresponding washer via the corresponding pair of fasteners 332. It should be noted that one or more steps 802, 804, 806, 808, 810, 812 of method 800 can be carried out in a different order than that shown in Fig. 8. Furthermore, several steps 802, 804, 806, 808, 810, 812 can be carried out together. Although aspects of the present disclosure have been specifically shown and described with reference to the embodiments mentioned above, it will be clear to the person skilled in the art that various additional embodiments can be considered by modifying the disclosed rinsing system, battery system, and methods without departing from the spirit and scope of the disclosure. Such embodiments should be understood as falling within the scope of the present disclosure as determined on the basis of the claims and their equivalents. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature US 11,772,445

[0003]

Claims

Leg tube assembly (200) for a construction machine (100), wherein the leg tube assembly (200) comprises: a first tube (202) connected to a frame (108) of the construction machine (100), wherein the first tube (202) defines a first internal surface (204); and a second tube (208) connected to the first tube (202) and displaceable relative to the first tube (202) between an extended position and a retracted position, wherein the second tube (208) is accommodated within the first tube (202), the second tube (208) comprising: a tube body (212) having a second inner surface (214), a second outer surface (216) opposite the second inner surface (214), a first end (218) arranged within the first tube (202) in both the extended and retracted positions of the second tube (208), and a second end (220) extending out of the first tube (202),when the second tube (208) is in the extended position, wherein the tube body (212) defines at least one recess (222, 322) on its second outer surface (216), and wherein the at least one recess (222, 322) extends axially from the first end (218) of the tube body (212) to the second end (220) of the tube body (212) and extends at least partially along a circumferential direction (D1); and at least one support element (224, 324) arranged within the at least one recess (222, 322) of the tube body (212), wherein the at least one support element (224, 324) is arranged between the first tube (202) and the tube body (212) of the second tube (208), wherein the at least one support element (224, 324) is designed to engage with the first inner surface (204) of the first tube (202), and wherein the at least one support element (224, 324) comprises either a bearing (224) or a wear pad (324). Leg tube assembly (200) according to claim 1, wherein the at least one recess (222) comprises an annular recess (222) which extends circumferentially along the second outer surface (216) of the tube body (212). Leg tube assembly (200) according to claim 2, wherein the at least one support element (224) comprises a single annular bearing (224) which is received in the annular recess (222) of the tube body (212). Leg tube assembly (200) according to claim 3, wherein the annular bearing (224) is made of a metal or a composite material. Leg tube assembly (200) according to claim 1, wherein the at least one recess (322) comprises a plurality of recesses (222, 322) spaced apart from each other in the circumferential direction along the second outer surface (216) of the tube body (212). Leg tube assembly (200) according to claim 5, wherein the at least one support element (324) comprises a plurality of wear pads (324) and wherein each recess (322) from the plurality of recesses (322) accommodates a corresponding wear pad (324) from the plurality of wear pads (324). Leg tube assembly (200) according to claim 6, wherein the multiple recesses (322) comprise four recesses (222, 322) and wherein the multiple wear pads (324) comprise four wear pads (324). Leg tube assembly (200) according to claim 6, wherein the second tube (208) further comprises: a plurality of washers (330), wherein each washer (330) from the plurality of washers (330) is arranged between a corresponding wear pad (324) and the tube body (212); and a plurality of fastening element pairs (332), wherein each wear pad (324) is connected to the tube body (212) and a corresponding washer (330) via a corresponding fastening element pair (332) from the plurality of fastening element pairs (332). Leg tube assembly (200) according to claim 8, wherein the multiple wear pads (324) and the multiple washers (330) consist of a polymer, a metal or a composite material.

Images