Track roller unit for a crawler chassis, crawler chassis and working machine

Abstract

Track roller unit of a crawler chassis (1), wherein the track roller unit comprises: a shaft (21) with an outer circumferential surface (21aa) which is provided with a recessed section (21ea, 21eb) in which a cooling medium is housed; a roller (22a, 22b) which is rotatable relative to the outer circumferential surface (21aa) of the shaft (21); a first sliding bearing (23aa, 23ba) that supports the roller (22a, 22b) so that it is rotatable relative to the outer circumferential surface (21aa) of the shaft (21) and absorbs a force in the radial direction of the shaft (21); and a floating seal (26a, 26b) with a rotation-side element (26aR, 26bR) supported by the roller (22a, 22b) and a fastening-side element (26aF, 26bF) sliding together with the rotation-side element (26aR, 26bR), wherein in the radial direction of the shaft (21) the recessed section (21ea, 21eb) faces: a sliding section between the rotation-side element (26aR, 26bR) and the fastening-side element (26aF, 26bF) in the floating seal (26a, 26b); and the first sliding bearing (23aa, 23ba), characterized by the fact that the recessed section (21ea, 21eb) in a cross-section perpendicular to an axis (C) of the shaft (21) has linearly extending side walls, the distance between which increases continuously towards the outside in the radial direction of the shaft (21), and the shaft (21) comprises a flow path (21c) extending in the axial direction of the shaft (21) and a branch flow path (21da, 21db) extending from the flow path (21c) in the radial direction of the shaft (21) outwards to the recessed section (21ea, 21eb), and the branch flow path (21da, 21db) is provided at a position facing the first sliding bearing (23aa, 23ba) in the radial direction of the shaft (21), with the recessed section (21ea, 21eb) being arranged between them.

Description

Technical field

[0001] The present invention relates to a track roller unit of a crawler chassis, the crawler chassis and a working machine. State of the art

[0002] A floating seal, installed in a roller of a working machine, allows a sealing ring located on the rotating side to slide relative to a sealing ring located on the mounting side, thereby sealing one end of a path through which lubricating oil is supplied.

[0003] Recently, it has become necessary to improve the working efficiency of construction machinery such as bulldozers by increasing their travel speeds. Increasing the rotational speed of the rollers increases the amount of heat generated around the floating seal.

[0004] To deal with such a situation, for example JP 2004-082819 A discloses a technique for suppressing the generation of frictional heat in a roller assembly by designing a bearing with a mechanism for regulating a sliding motion relative to a shaft.

[0005] DE 600 10 340 T2 is considered the closest prior art and discloses a track roller unit of a crawler undercarriage according to the features in the preamble of independent claims 1 and 5. In detail, this known track roller unit also comprises a shaft whose outer circumference is provided with a recessed section, wherein this recessed section faces both a sliding bearing, which rotatably supports a roller, and a floating seal in the radial direction of the shaft.

[0006] From US patent 2005 / 0040705A1, a shaft for a roller wheel is known that rotatably supports a roller mounted externally between two end sections and that accepts a load in a diametrical direction from the roller. The central part of the shaft is provided with a pair of recesses at symmetrical locations with respect to the axis of the shaft. The cross-sectional shape of the shaft is therefore approximately L-shaped along the recesses.

[0007] The standard DIN ISO 12128 1998-07-00 concerns “Plain bearings - Lubrication holes, lubrication grooves and lubrication pockets - Dimensions, shapes, designation and their application for bearing bushings”.

[0008] This standard discloses, for example, various forms of lubrication grooves attached to the inner circumference of a bearing bushing by means of cross-sectional representations.

[0009] From Schmid E., Weber R.: Gleitlager. Berlin [etc.]: Springer, 1953, ISBN 9-783-64286-8740, it is known that lubrication grooves in bearings can occasionally be milled longitudinally into journals. However, it is criticized here that such grooves are impractical, as they lead to a constant change in the eccentricity of the shaft (shaft oscillation). Summary of the invention: Technical problem

[0010] The mechanism for regulating a sliding motion disclosed in the above-mentioned JP 2004-082819 A has a complicated structure.

[0011] The present invention aims to provide a track roller unit of a crawler chassis, the crawler chassis and a working machine that are able to suppress heat generation by improving cooling performance in a simple structure.

[0012] This task is solved by a track roller unit according to claim 1, a track roller unit according to claim 5, a crawler chassis according to claim 6 and a working machine according to claim 7.

[0013] A track roller assembly of a crawler undercarriage according to the present invention comprises a shaft, a roller, a first plain bearing, and a floating seal. The shaft has an outer circumferential surface provided with a recessed section in which a cooling medium is housed. The roller is rotatable relative to the outer circumferential surface of the shaft. The first plain bearing supports the roller so that it is rotatable relative to the outer circumferential surface of the shaft and absorbs a force in a radial direction along the shaft. The floating seal comprises a rotating element, which is supported by the roller, and a mounting element, which slides together with the rotating element. In the radial direction of the shaft, the recessed section faces: a sliding section between the rotating element and the mounting element in the floating seal; and the first plain bearing.The recessed section has linear sidewalls in cross-section perpendicular to an axis of the shaft, the distance between which increases continuously outwards in the radial direction of the shaft. The shaft comprises a flow path extending in the axial direction of the shaft and a branch flow path extending from the flow path outwards in the radial direction of the shaft to the recessed section. The branch flow path is located at a position facing the first sliding bearing in the radial direction of the shaft, with the recessed section situated between them. Advantageous effects of the invention

[0014] The present invention enables the realization of a track roller unit of a crawler chassis, the crawler chassis and a working machine that are able to suppress heat generation through improved cooling performance with a simple structure. Brief description of the drawings Fig. Figure 1 is a schematic side view showing a configuration of a bulldozer as an example of a working machine according to a first embodiment of the present invention. Fig. Figure 2 is a perspective partial view showing a configuration of a roller used in the machine in Fig. 1 is included. Fig. 3 is a first cross-sectional view showing the configuration of the Fig. The 2nd roller shown is shown. Fig. 4 is a second cross-sectional view showing the configuration of the Fig. The 2nd roller shown is shown. Fig. 5 is a cross-sectional view of a wave along a line VV in Fig. 4. Fig. 6 is a cross-sectional view, which illustrates a construction method of the in Fig. The 2nd wheel shown is depicted. Fig. Figure 7 is a first cross-sectional view showing a configuration of a roller included in a working machine according to a second embodiment of the present invention. Fig. Figure 8 is a second cross-sectional view showing the configuration of the roller included in the working machine according to the second embodiment of the present invention. Fig. 9 is a cross-sectional view, representing a first step in a construction process of the in Fig. The 7 shown roller is shown. Fig. 10 is a cross-sectional view, representing a second step in the construction process of the in Fig. The roller shown in section 7 is shown. Fig. Figure 11 is a first cross-sectional view showing a configuration of a roller included in a working machine according to a third embodiment of the present invention. Fig. Figure 12 is a second cross-sectional view showing the configuration of the roller included in the working machine according to the third embodiment of the present invention. Fig. 13 is a perspective partial view showing a configuration of a machine in the working machine in Fig. 1 included deflection pulley is shown. Description of the embodiments

[0015] Embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the description and the accompanying drawings, identical or corresponding components are designated by the same reference numerals, and their descriptions are not repeated. For the sake of clarity, some configurations may be omitted or simplified in the accompanying drawings. At least some of the embodiments and modifications can optionally be combined. (First embodiment)<Konstruktion der Arbeitsmaschine>

[0016] First, a configuration of a bulldozer is presented as an example of a working machine according to the first embodiment of the present invention with reference to Fig. 1 described. It should be noted that the present invention is not limited to a bulldozer, but is applicable to any working machine with a crawler undercarriage, such as a hydraulic excavator.

[0017] Fig. Figure 1 is a schematic side view showing a configuration of a bulldozer as an example of a working machine according to the first embodiment of the present invention. As shown in Fig. Figure 1 shows that a bulldozer as a working machine 100 according to the present embodiment essentially comprises a crawler chassis 1, a vehicle body 2 and a working tool 3. The vehicle body 2 and the working tool 3 form a working machine body.

[0018] The vehicle body 2 comprises a driver's cab 4 and an engine compartment 5. The cab 4 is located in an upper rear area of ​​the vehicle body 2, and the engine compartment 5 is located in front of the cab 4.

[0019] The working device 3 comprises a blade 6, a frame 7, an angle cylinder 8, and a lifting cylinder 9. The blade 6 is positioned in front of the vehicle body 2. The blade 6 is supported on the right and left sides by the frame 7. One end of the frame 7 is attached to the rear of the blade 6 by a rotatable support section. The other end of the frame 7 is rotatably mounted to the side of the vehicle body 2.

[0020] The shield 6 is driven by the angle cylinder 8 and the lifting cylinder 9. One end of the angle cylinder 8 is rotatably mounted on the rear of the shield 6. The other end of the angle cylinder 8 is rotatably mounted on the side of the vehicle body 2.

[0021] Due to the extension and retraction of the angle cylinder 8 by hydraulic pressure, the shield 6 pivots about a support section on the frame 7. This causes an upper end 6a of the shield 6 to move in the forward / reverse direction (in the right / left direction). Fig. 1) in order to perform an angle control of the shield 6 in the forward / reverse direction.

[0022] One end of the lifting cylinder 9 is rotatably mounted on an upper surface of the frame 7. An intermediate section of the lifting cylinder 9 is rotatably mounted on a side surface of the vehicle body 2. The lifting cylinder 9 expands and contracts under hydraulic pressure to move the shield 6 around the other end of the frame 7 in an upward / downward direction.

[0023] The crawler undercarriage 1 comprises a pair of right and left crawler track units 1A.

[0024] The pair of right and left track units 1A are spaced apart in the width direction of a bulldozer 100. The pair of right and left track units 1A is arranged so that the vehicle body 2 lies between them.

[0025] The pair of right and left track unit 1A essentially comprises a track 10, a running roller 20, a support roller 20a, a drive wheel (pinion) 41, a deflection roller (guide wheel) 42 and a track frame 43.

[0026] The drive wheel 41 and the track frame 43 are each attached to a side section of the vehicle body 2. The idler wheel 42, a plurality of track rollers 20, and a plurality of support rollers 20a are each attached to the track frame 43.

[0027] The drive wheel 41 is rotatably arranged behind the crawler frame 43. The idler wheel 42 is rotatably arranged, for example, on a front end section of the crawler frame 43. The multiple track rollers 20 are rotatably arranged on the underside of the crawler frame 43. The multiple support rollers 20a are rotatably arranged on the top of the crawler frame 43.

[0028] The track 10 is ring-shaped (endless) and looped over the drive wheel 41 and the idler wheel 42. Furthermore, the track 10 is rotatably mounted by the multiple running rollers 20 and the multiple support rollers 20a, which are arranged between the drive wheel 41 and the idler wheel 42.

[0029] The crawler belt 10 engages with the drive wheel 41 and is configured to rotate when the drive wheel 41 is driven. When the crawler belt 10 rotates, each idler wheel 42, the multiple track rollers 20, and the multiple support rollers 20a come into contact with the crawler belt 10 and can thus be driven to rotate.

[0030] The working machine body, formed from vehicle body 2 and working device 3, is carried in a movable manner by the crawler drive unit 1. <Konfiguration der Laufrolle 20>

[0031] The following describes a configuration of the roller 20 used in the working machine 100 according to the present embodiment, with reference to the Fig. 2, Fig. 3, Fig. 4 to Fig. 5 described.

[0032] Fig. Figure 2 is a perspective partial view showing a configuration of the roller used in the machine in Fig. 1 is included. Fig. 3 and Fig. Figure 4 represents a first cross-sectional view and a second cross-sectional view, respectively, each showing the following: Fig. The 2 shown configurations of the roller are shown. Fig. 5 is a cross-sectional view of a wave along a line VV in Fig. 4.

[0033] The cross-sections in the Fig. 3 and Fig. Four lines run along an axis C of shaft 21 and are cut at angles that differ from each other by 90 degrees. Furthermore, the cross-section runs in Fig. 5 along the direction orthogonal to axis line C.

[0034] As in Fig. As shown in Figure 2, the roller 20 in the present embodiment comprises a shaft 21, rollers 22a and 22b, sliding bearing elements 23a and 23b, floating seals 26a and 26b and supports 27a and 27b.

[0035] The shaft 21 is surrounded externally by two rollers 22a and 22b. A sliding bearing element 23a is arranged between the shaft 21 and the roller 22a. A bracket 27a is attached to one end face of the shaft 21. A rotating side element 26aR of the floating seal 26a is supported by the roller 22a. A mounting-side element 26aF of the floating seal 26a is supported by the shaft 21, with the bracket 27a positioned between them.

[0036] The sliding bearing element 23b is arranged between the shaft 21 and the roller 22b. The bracket 27b is attached to the other end face of the shaft 21. A rotating side element 26bR of the floating seal 26b is supported by the roller 22b. A mounting-side element 26bF of the floating seal 26b is supported by the shaft 21, with the bracket 27b positioned between them.

[0037] As in Fig. As shown in Figure 3, the shaft 21 comprises a shaft body 21a and an intermediate flange 21b. The shaft body 21a has an axis line C (an imaginary line) that passes through the center of the axis of the shaft body 21a.

[0038] The intermediate flange 21b projects radially outwards from the shaft body 21a with respect to an outer circumferential surface 21aa of the shaft body 21a. The intermediate flange 21b has an annular shape and projects circumferentially from the outer circumferential surface 21aa of the shaft body 21a along its entire circumference. The intermediate flange 21b is formed integrally with the shaft body 21a. The intermediate flange 21b is located near the center of the shaft body 21a in the axial direction of the shaft body 21a (in the direction in which the axis line C runs).

[0039] The intermediate flange 21b has end faces 21ba and 21bb facing each other in the axial direction of the shaft body 21a. Each of these two end faces 21ba and 21bb of the intermediate flange 21b is, for example, orthogonal to the outer circumferential surface 21aa of the shaft body 21a. The two end faces 21ba and 21bb of the intermediate flange 21b are, for example, parallel to each other.

[0040] Each of the rollers 22a and 22b has a cylindrical shape. Each of the rollers 22a and 22b has a through-hole that extends from one end face to the other. The shaft 21 is inserted into the through-hole of each of the rollers 22a and 22b. Each of the rollers 22a and 22b surrounds the shaft 21 from the outside.

[0041] One end of roll 22a and one end of roll 22b abut each other, so that they are in contact with each other. One end of roll 22a and one end of roll 22b are fastened together by a weld 22c. The weld 22c is provided along the entire circumference in the circumferential direction.

[0042] The area where rollers 22a and 22b meet is located on the radial outside of shaft 21 with respect to intermediate flange 21b. Weld 22c is also located on the radial outside of shaft 21 with respect to intermediate flange 21b.

[0043] The roller 22a has an end surface 22ab at the position of a recess that extends from one end of the roller 22a towards the other end of the roller 22a. The roller 22b has an end surface 22bb at the position of a recess that extends from one end of the roller 22b towards the other end of the roller 22b.

[0044] The sliding bearing element 23a has a cylindrical flange shape. The sliding bearing element 23a is pressed onto an inner circumferential surface 22aa of the roller 22a. Thus, the sliding bearing element 23a is rotatable together with the roller 22a. The sliding bearing element 23a is located between the inner circumferential surface 22aa of the roller 22a and the outer circumferential surface 21aa of the shaft 21. The sliding bearing element 23a is also located between the end surface 21ba of the intermediate flange 21b and the end surface 22ab of the roller 22a.

[0045] The sliding bearing element 23a has a through hole that extends from one end to the other. The shaft 21 is inserted into the through hole of the sliding bearing element 23a. The sliding bearing element 23a surrounds the shaft 21 from the outside.

[0046] The sliding bearing element 23a comprises a radial sliding bearing 23aa (a first sliding bearing) and an axial sliding bearing 23ab (a second sliding bearing). The radial sliding bearing 23aa absorbs the force in the radial direction of the shaft 21. The radial sliding bearing 23aa has a cylindrical shape. The axial sliding bearing 23ab has an annular shape that projects radially outwards from one end of the radial sliding bearing 23aa. The axial sliding bearing 23ab absorbs the force in the axial direction of the shaft 21. The axial sliding bearing 23ab is, for example, orthogonal to the radial sliding bearing 23aa. The axial sliding bearing 23ab forms a flange area opposite the radial sliding bearing 23aa. The radial sliding bearing 23aa and the axial sliding bearing 23ab are formed in one piece.

[0047] The radial plain bearing 23aa is arranged between the inner circumferential surface 22aa of the roller 22a and the outer circumferential surface 21aa of the shaft 21. The radial plain bearing 23aa supports the roller 22a in such a way that it is rotatable relative to the outer circumferential surface 21aa of the shaft 21. The radial plain bearing 23aa accepts a load in the radial direction.

[0048] The axial sliding bearing 23ab is arranged between the end face 21ba of the intermediate flange 21b and the end face 22ab of the roller 22a. The axial sliding bearing 23ab supports the roller 22a so that it is rotatable relative to the end face 21ba of the intermediate flange 21b. The axial sliding bearing 23ab accepts a load in the axial direction.

[0049] The sliding bearing element 23b has a cylindrical flange shape. The sliding bearing element 23b is pressed onto the inner circumferential surface 22ba of the roller 22b. Thus, the sliding bearing element 23b is rotatable together with the roller 22a. The sliding bearing element 23b is located between the inner circumferential surface 22ba of the roller 22b and the outer circumferential surface 21aa of the shaft 21. The sliding bearing element 23b is also located between the end face 21bb of the intermediate flange 21b and the end face 22bb of the roller 22b.

[0050] The sliding bearing element 23b has a through hole that extends from one end to the other. The shaft 21 is inserted into the through hole of the sliding bearing element 23b. The sliding bearing element 23b surrounds the shaft 21 from the outside.

[0051] The sliding bearing element 23b comprises a radial sliding bearing 23ba (a first sliding bearing) and an axial sliding bearing 23bb (a second sliding bearing). The radial sliding bearing 23ba absorbs the force in the radial direction of the shaft 21. The radial sliding bearing 23ba has a cylindrical shape. The axial sliding bearing 23bb has an annular shape that projects radially outwards from one end of the radial sliding bearing 23ba. The axial sliding bearing 23bb absorbs the force in the axial direction of the shaft 21. The axial sliding bearing 23bb is, for example, orthogonal to the radial sliding bearing 23ba. The axial sliding bearing 23bb forms a flange area opposite the radial sliding bearing 23ba. The radial sliding bearing 23ba and the axial sliding bearing 23bb are formed in one piece.

[0052] The radial plain bearing 23ba is arranged between the inner circumferential surface 22ba of the roller 22b and the outer circumferential surface 21aa of the shaft 21. The radial plain bearing 23ba supports the roller 22b so that it is rotatable relative to the outer circumferential surface 21aa of the shaft 21. The radial plain bearing 23ba accepts a load in the radial direction.

[0053] The axial sliding bearing 23bb is arranged between the end face 21bb of the intermediate flange 21b and the end face 22bb of the roller 22b. The axial sliding bearing 23bb supports the roller 22b in such a way that it is rotatable relative to the end face 21bb of the intermediate flange 21b. The axial sliding bearing 23bb accepts a load in the axial direction.

[0054] Each of the brackets 27a and 27b is attached to the outer circumferential surface 21aa of the shaft body 21a. Two rollers 22a and 22b are clamped between the brackets 27a and 27b.

[0055] The floating seal 26a comprises a rotating side element 26aR and a mounting-side element 26aF. The rotating-side element 26aR is supported by the roller 22a. Therefore, the rotating-side element 26aR rotates together with the roller 22a. The rotating-side element 26aR is rotatable relative to the mounting-side element 26aF.

[0056] The rotating element 26aR comprises an elastic ring 26aa and a metal sealing ring 26ab. The metal sealing ring 26ab is supported by the inner circumferential surface 22aa of the roller 22a, with the elastic ring 26aa positioned between them.

[0057] The fastening element 26aF comprises an elastic ring 26ac and a metal sealing ring 26ad. The metal sealing ring 26ad is supported by the bracket 27a, with the elastic ring 26ac positioned between them.

[0058] Each of the elastic rings 26aa and 26ac is, for example, an O-ring and is made of resin or a similar material. Each of the metal sealing rings 26ab and 26ad is made of a metallic material.

[0059] The elastic force of each of the elastic rings 26aa and 26ac causes the metal sealing rings 26ab and 26ad to come into contact with each other, thus maintaining a seal. When the rotating element 26aR rotates relative to the fixing element 26aF, the metal sealing rings 26ab and 26ad slide relative to each other while remaining in a sealed position. This prevents the lubricating oil from leaking out.

[0060] The floating seal 26b comprises a rotating side element 26bR and a mounting-side element 26bF. The rotating-side element 26bR is supported by the roller 22b. Therefore, the rotating-side element 26bR rotates together with the roller 22b. The rotating-side element 26bR is rotatable relative to the mounting-side element 26bF.

[0061] The rotating element 26bR comprises an elastic ring 26ba and a metal sealing ring 26bb. The metal sealing ring 26bb is supported by the inner circumferential surface 22ba of the roller 22b, with the elastic ring 26ba arranged between them.

[0062] The fastening element 26bF comprises an elastic ring 26bc and a metal sealing ring 26bd. The metal sealing ring 26bd is supported by the bracket 27b, with the elastic ring 26bc positioned between them.

[0063] Each of the elastic rings 26ba and 26bc is, for example, an O-ring and is made of resin or a similar material. Each of the metal sealing rings 26bb and 26bd is made of a metallic material.

[0064] The elastic force of each of the elastic rings 26ba and 26bc causes the metal sealing rings 26bb and 26bd to come into contact with each other, thus maintaining a seal. As the rotating element 26bR rotates relative to the fixing element 26bF, the metal sealing rings 26bb and 26bd slide relative to each other while remaining in a sealed position. This prevents leakage of the lubricating oil.

[0065] As in Fig. As shown in Figure 4, the shaft body 21a comprises a flow path 21c, branch flow paths 21da and 21db, and recessed sections 21ea and 21eb. The flow path 21c, the branch flow paths 21da and 21db, and the recessed sections 21ea and 21eb are each filled with lubricating oil.

[0066] The lubricating oil also serves as a cooling medium. The cooling medium can be something other than oil and can, for example, be grease. The cooling medium can be any medium as long as it can cool floating seals 26a and 26b, radial plain bearings 23aa and 23ba, and axial plain bearings 23ab and 23bb.

[0067] Each of the recessed sections 21ea and 21eb serves as a compartment in which a cooling medium is housed. Each of the recessed sections 21ea and 21eb is arranged on the outer circumferential surface of the shaft 21, in particular on the outer circumferential surface 21aa of the shaft body 21a. Each of the recessed sections 21ea and 21eb is recessed from the outer circumferential surface 21aa of the shaft body 21a in the radial direction towards the inner circumference.

[0068] In the radial direction of shaft 21, the recessed section 21ea faces: the sliding section between the rotating element 26aR and the fastening element 26aF in the floating seal 26a; and the radial sliding bearing 23aa. In the radial direction of shaft 21, the recessed area 21ea faces the sliding area between the rotating element 26aR and the fastening element 26aF in the floating seal 26a and the radial sliding bearing 23aa. The recessed section 21ea faces the axial sliding bearing 23ab in the radial direction of shaft 21.

[0069] In the radial direction of the shaft 21, the recessed section 21ea faces the rotating element 26aR and the mounting element 26aF of the floating seal 26a. In the radial direction of the shaft 21, the recessed section 21ea also faces an area located between the radial sliding bearing 23aa and the floating seal 26a.

[0070] The recess 21ea extends axially from a position radially facing the radial sliding bearing 23aa to a position radially facing the mounting-side element 26aF of the floating seal 26a. The recessed section 21ea preferably extends axially from a position radially opposite the axial sliding bearing 23ab to a position radially opposite the mounting-side element 26aF of the floating seal 26a.

[0071] In the radial direction of shaft 21, the recessed section 21eb faces: the sliding section between the rotating element 26bR and the fastening element 26bF in the floating seal 26b; and the radial sliding bearing 23ba. In the radial direction of shaft 21, the recessed section 21eb faces: the sliding section between the rotating element 26bR and the fastening element 26bF in the floating seal 26b and the radial sliding bearing 23ba. The recessed section 21eb faces the axial sliding bearing 23bb in the radial direction of shaft 21.

[0072] In the radial direction of the shaft 21, the recessed section 21eb faces the rotating element 26bR and the mounting element 26bF of the floating seal 26b. In the radial direction of the shaft 21, the recessed section 21eb also faces an area located between the radial sliding bearing 23ba and the floating seal 26b.

[0073] The recess 21eb extends axially from a position radially facing the radial sliding bearing 23ba to a position radially facing the mounting-side element 26bF of the floating seal 26b. The recessed section 21eb preferably extends axially from a position radially opposite the axial sliding bearing 23bb to a position radially opposite the mounting-side element 26bF of the floating seal 26b.

[0074] The recessed sections 21ea are arranged symmetrically with respect to the axis line C. The recessed sections 21eb are arranged symmetrically with respect to the axis line C. The recessed sections 21ea and recessed sections 21eb are arranged symmetrically with respect to a center line D that runs axially through the center of the intermediate flange 21b.

[0075] The flow path 21c extends linearly through the shaft body 21a along the axis of the shaft 21. One end of the flow path 21c is located closer to one end of the shaft 21 than the intermediate flange 21b and is also located in a region radially opposite the recessed section 21ea. The other end of the flow path 21c reaches the other end of the shaft 21 radially.

[0076] Each of the branch flow paths 21da and 21db extends, for example, linearly from flow path 21c radially outward from the shaft 21. Branch flow path 21da connects flow path 21c and the recessed section 21ea. Branch flow path 21db connects flow path 21c and the recessed section 21eb. Branch flow path 21da is located closer to one end of the shaft 21 than the intermediate flange 21b. Branch flow path 21db is located closer to the other end of the shaft 21 than the intermediate flange 21b.

[0077] As in Fig. As shown in Figure 5, several recessed sections 21ea are provided on the outer circumferential surface 21aa of the shaft body 21a. The plurality of recessed sections 21ea may consist of, for example, two separate recessed sections 21ea. However, the plurality of recessed sections 21ea may also consist of three or more recessed sections 21ea that are separate from one another.

[0078] The plurality of recessed sections 21ea can be provided point-symmetrically with respect to a point through which the axis line C passes orthogonally to the axis line C in a cross-section. The plurality of recessed sections 21ea can be provided line-symmetrically with respect to a straight line E that passes through the axis line C. <Konstruktion der Laufrolle 20>

[0079] The following describes the construction of the roller 20 in the present embodiment with reference to Fig. 6 described.

[0080] Fig. 6 is a cross-sectional view showing a method for constructing the in Fig. The roller shown in section 2 is shown. As in Fig. As shown in Figure 6, the sliding bearing element 23a is first attached to the inner circumferential surface 22aa of the roller 22a by an interference fit. This brings the radial sliding bearing 23aa of the sliding bearing element 23a into contact with the inner circumferential surface 22aa of the roller 22a. In addition, the axial sliding bearing 23ab of the sliding bearing element 23a comes into contact with the end face 22ab of the roller 22a.

[0081] Furthermore, the sliding bearing element 23b is press-fitted to the inner circumferential surface 22ba of the roller 22b. This brings the radial sliding bearing 23ba of the sliding bearing element 23b into contact with the inner circumferential surface 22ba of the roller 22b. Additionally, the axial sliding bearing 23bb of the sliding bearing element 23b comes into contact with the end face 22bb of the roller 22b.

[0082] Then the shaft 21 is inserted in the direction of the inner circumference of roller 22a and in the direction of the inner circumference of roller 22b. In particular, the shaft 21 is inserted in the direction of the inner circumference of each of the sliding bearing elements 23a and 23b.

[0083] As in Fig. As shown in Figure 3, one end of roller 22a and one end of roller 22b are welded together. Thus, rollers 22a and 22b are connected to each other by the weld seam 22c. In this state, the radial sliding bearing 23aa of the sliding bearing element 23a is located between the outer circumferential surface 21aa of the shaft body 21a and the inner circumferential surface 22aa of roller 22a. Furthermore, the axial sliding bearing 23ab of the sliding bearing element 23a is located between the end surface 21ba of the intermediate flange 21b and the end surface 22ab of roller 22a.

[0084] Furthermore, the radial sliding bearing 23ba of the sliding bearing element 23b is arranged between the outer circumferential surface 21aa of the shaft body 21a and the inner circumferential surface 22ba of the roller 22b. Additionally, the axial sliding bearing 23bb of the sliding bearing element 23b is located between the end surface 21bb of the intermediate flange 21b and the end surface 22bb of the roller 22b.

[0085] As in Fig. As shown in Figure 4, in this state the recessed section 21ea faces radially towards the shaft 21: the sliding section between the rotating element 26aR and the fastening element 26aF in the floating seal 26a; and the radial sliding bearing 23aa. The recessed section 21ea faces radially towards the shaft 21 and the axial sliding bearing 23ab.

[0086] In the radial direction of shaft 21, the recessed section 21eb faces the sliding section between the rotating element 26bR and the fastening element 26bF in the floating seal 26b and the radial sliding bearing 23ba. The recessed section 21eb faces the axial sliding bearing 23bb in the radial direction of shaft 21.

[0087] Then the rotating element 26aR of the floating seal 26a is attached to the inner circumferential surface of the roller 22a. The rotating element 26bR of the floating seal 26b is attached to the inner circumferential surface of the roller 22b.

[0088] Then the bracket 27a, to which the mounting-side element 26aF of the floating seal 26a is attached, is attached to the shaft 21. The bracket 27b, to which the mounting-side element 26bF of the floating seal 26b is attached, is attached to the shaft 21.

[0089] This is how the roller 20 is constructed in the present embodiment. <Funktionen und Effekte>

[0090] The functions and effects of the present embodiment are then described.

[0091] According to the roller 20 of the present embodiment, as in Fig. As shown in Figure 4, the recessed section 21ea, which houses the cooling medium, faces radially along the shaft 21 towards the sliding section between the rotating element 26aR and the mounting element 26aF in the floating seal 26a and the radial sliding bearing 23aa. Thus, the cooling medium in the recessed section 21ea can cool both the radial sliding bearing 23aa and the floating seal 26a. This allows for improved cooling performance and reduced heat generation in a simple structure with a recessed section 21ea.

[0092] In the radial direction of the shaft 21, the recessed section 21eb, which houses the cooling medium, faces the sliding section between the rotating element 26bR and the mounting element 26bF in the floating seal 26b and the radial sliding bearing 23ba. Thus, the cooling medium in the recessed section 21eb can cool both the radial sliding bearing 23ba and the floating seal 26b. This allows for improved cooling performance and reduced heat generation in a simple structure with a recessed section 21eb.

[0093] Furthermore, in the present embodiment of the roller 20, the recessed section 21ea faces the axial sliding bearing 23ab in the radial direction of the shaft 21, as shown in Fig. Figure 4 shows that the cooling medium in the recessed section 21ea can also cool the axial sliding bearing 23ab. This allows for further improvement of the cooling performance and further suppression of heat generation in a simple structure with the recessed section 21ea.

[0094] Furthermore, in the roller 20 of the present embodiment, the recessed section 21eb faces the axial sliding bearing 23bb in the radial direction of the shaft 21, as shown in Fig. Figure 4 shows that the cooling medium in the recessed section 21eb can also cool the axial sliding bearing 23bb. This allows for further improvement of the cooling performance and further suppression of heat generation in a simple structure with the recessed section 21eb.

[0095] According to the roller 20 in the present embodiment, the recessed sections 21ea are provided in a line-symmetrical manner with respect to the axis line C of the shaft 21, as shown in Fig. 4 shown. This facilitates the uniform supply of the cooling medium in the circumferential direction of the respective radial plain bearing 23aa and the floating seal 26a.

[0096] The recesses 21eb are arranged symmetrically to the axis C of the shaft 21. This facilitates the uniform supply of the cooling medium in the circumferential direction of the radial plain bearing 23ba and the mechanical seal 26b. (Second embodiment)<Konfiguration der Laufrolle 20>

[0097] The following describes the configuration of the roller 20 according to the second embodiment of the present invention with reference to the Fig. 7 and Fig. 8 described.

[0098] Fig. 7 and Fig. Figure 8 represents a first cross-sectional view and a second cross-sectional view, respectively, each showing a configuration of a roller included in a machine according to the second embodiment of the present invention. As shown in Fig. As shown in Figure 7, the roller 20 in the present embodiment differs in its configuration from the roller 20 in the one shown in Fig. 2, Fig. 3, Fig. 4 to Fig. 5 first embodiment shown in that a bushing 24 and a fastening element 25 are additionally provided.

[0099] The bushing 24 has a cylindrical flange shape with a cylindrical section and a flanged section. The flanged section of the bushing 24 projects radially outwards from the cylindrical section of the bushing 24. The bushing 24 is arranged between the outer circumferential surface of the shaft 21 (outer circumferential surface 21aa of the shaft body 21a) and the inner circumferential surface 22aa of the roller 22a. In particular, the cylindrical section of the bushing 24 is arranged between the outer circumferential surface of the sliding bearing element 23a and the inner circumferential surface 22aa of the roller 22a.

[0100] The bushing 24 is pressed onto the inner circumferential surface 22aa of the roller 22a. The cylindrical section of the bushing 24 is in contact with the inner circumferential surface of the roller 22a. The flanged section of the bushing 24 rests against the end face of the roller 22a. The bushing 24 is fastened to the roller 22a by a plurality of fasteners 25. Each of the plurality of fasteners 25 is, for example, a bolt. Each of the bolts 25 is screwed through the flanged section of the bushing 24 into an internally threaded section of the roller 22a. Thus, the bushing 24 is configured to rotate together with the roller 22a.

[0101] The sliding bearing element 23a is pressed onto an inner circumferential surface 24a of the bushing 24. Thus, the sliding bearing element 23a is configured to rotate together with the roller 22a and the bushing 24. The radial sliding bearing 23aa of the sliding bearing element 23a is in contact with the inner circumferential surface 24a of the bushing 24. The radial sliding bearing 23aa is located between the outer circumferential surface 21aa of the shaft body 21a and the inner circumferential surface 24a of the bushing 24.

[0102] Furthermore, the axial sliding bearing 23ab of the sliding bearing element 23a is in contact with the end face 24b of the bushing 24. The axial sliding bearing 23ab is located between the end face 24b of the bushing 24 and the end face 21ba of the intermediate flange 21b.

[0103] The rotating element 26aR of the floating seal 26a is supported by the roller 22a with the bushing 24 arranged between them. Thus, the rotating element 26aR rotates together with the bushing 24 and the roller 22a. The rotating element 26aR is configured to be rotatable relative to the mounting-side element 26aF. The metal sealing ring 26ab of the rotating element 26aR is supported by the inner circumferential surface 24a of the bushing 24, with an elastic ring 26aa arranged between them.

[0104] As in Fig. As shown in Figure 8, the recessed section 21ea faces radially towards the rotating element 26aR and the mounting element 26aF of the floating seal 26a in the direction of the shaft 21. Furthermore, the recessed section 21ea also faces radially towards an area located between the radial sliding bearing 23aa and the floating seal 26a.

[0105] The recessed section 21ea extends axially from a position radially facing the axial sliding bearing 23ab to a position radially facing the fastening-side element 26aF of the floating seal 26a. The axial dimension of the recessed section 21ea can be smaller or larger than the axial dimension of the bushing 24.

[0106] Since the configuration of the present embodiment is essentially the same as that of the first embodiment, with the exception of the above, the same elements are designated by the same reference numerals, and their description is not repeated. <Konstruktion der Laufrolle 20>

[0107] The following describes the construction of the roller 20 in the present embodiment with reference to the Fig. 9 and Fig. 10 described.

[0108] The Fig. 9 and Fig. 10 are each a cross-sectional view, which shows a method for constructing the in Fig. The 7-point roller shown illustrates the sequence of steps. As in Fig. As shown in Figure 9, one end of roller 22a and one end of roller 22b are first welded together. Rollers 22a and 22b are thus joined by a weld seam 22c. Then, the sliding bearing element 23b is attached to the inner circumference of roller 22b by an interference fit. Finally, the shaft 21 is inserted into rollers 22a and 22b.

[0109] As in Fig. As shown in Figure 10, the sliding bearing element 23a is pressed onto the inner circumferential surface 24a of the bushing 24. The bushing 24, into which the sliding bearing element 23a is pressed, is pressed onto the inner circumferential surface 22aa of the roller 22a. Thus, the bushing 24 is positioned between the outer circumferential surface 21aa of the shaft 21 and the inner circumferential surface 22aa of the roller 22a. The bushing 24 is then fastened to the roller 22a with a fastening element 25, e.g., a bolt.

[0110] In this state, the radial sliding bearing 23aa of the sliding bearing element 23a and the bushing 24 are located between the outer circumferential surface 21aa of the shaft body 21a and the inner circumferential surface 22aa of the roller 22a. Furthermore, the axial sliding bearing 23ab of the sliding bearing element 23a is located between the end surface 21ba of the intermediate flange 21b and the end surface 24b of the bushing 24.

[0111] Furthermore, the radial sliding bearing 23ba of the sliding bearing element 23b is located between the outer circumferential surface 21aa of the shaft body 21a and the inner circumferential surface 22ba of the roller 22b. Additionally, the axial sliding bearing 23bb of the sliding bearing element 23b is located between the end surface 21bb of the intermediate flange 21b and the end surface 22bb of the roller 22b.

[0112] As in Fig. As shown in Figure 8, in this state, the recessed section 21ea faces the sliding section between the rotating element 26aR and the fastening element 26aF in the floating seal 26a and the radial sliding bearing 23aa in the radial direction of the shaft 21. The recessed section 21ea faces the axial sliding bearing 23ab in the radial direction of the shaft 21.

[0113] In the radial direction of the shaft 21, the recessed section 21eb faces the sliding section between the rotating element 26bR and the fastening element 26bF of the floating seal 26b and the radial sliding bearing 23ba. The recessed section 21eb faces the axial sliding bearing 23bb in the radial direction of the shaft 21.

[0114] As in Fig. As shown in Figure 7, the rotating element 26aR of the floating seal 26a is attached to the inner circumferential surface of the roller 22a. Furthermore, the rotating element 26bR of the floating seal 26b is attached to the inner circumferential surface of the roller 22b.

[0115] Then the bracket 27a, to which the mounting-side element 26aF of the floating seal 26a is attached, is attached to the shaft 21. The bracket 27b, to which the mounting-side element 26bF of the floating seal 26b is attached, is attached to the shaft 21.

[0116] This is how the roller 20 is constructed in the present embodiment. <Funktionsweise und Effekte>

[0117] According to the present embodiment, as in Fig. As shown in Figure 8, a recessed section 21ea, containing the cooling medium, faces the sliding section between the rotating element 26aR and the mounting element 26aF in the floating seal 26a and the radial sliding bearing 23aa in the radial direction of the shaft 21. Similarly, a recessed section 21eb, containing the cooling medium, faces the sliding area between the rotating element 26bR and the mounting element 26bF in the floating seal 26b and the radial sliding bearing 23ba in the radial direction of the shaft 21. Therefore, with a simple structure, the cooling performance can be improved and heat generation suppressed, as in the first embodiment.

[0118] According to the present embodiment, the bushing 24 is arranged between the outer circumferential surface 21aa of the shaft 21 and the inner circumferential surface 22aa of the roller 22a. The rotating element 26aR of the floating seal 26a is supported by the roller 22a, with the bushing 24 positioned between them. Because the bushing 24 is provided in this way, the roller 20 has a simpler design than in the first embodiment, which is described below.

[0119] In the case where no socket is provided, as in Fig. As shown in Figure 6, the rollers 22a and 22b are arranged so that they surround the shaft 21 from the outside, and then the rollers 22a and 22b are welded together. In this case, the heat during welding can lead to thermal stresses in the rollers 22a and 22b. Such thermal stress can prevent the rollers 22a and 22b from rotating relative to the shaft 21.

[0120] On the other hand, if the bushing 24 is provided, the bushing 24 is pressed into the roller 22a, as in Fig. Figure 10 shows how this prevents the wave 21 from falling out of the rollers 22a and 22b. Thus, as shown in Fig. 9 and Fig. Figure 10 shows that the shaft 21 is inserted into the rollers 22a and 22b after the rollers 22a and 22b have been welded together. Accordingly, it can be checked whether or not thermal stresses occur in the rollers 22a and 22b after they have been welded together and before they are attached to the shaft 21. Such a check allows rollers 22a and 22b exhibiting large thermal stresses to be eliminated before assembly. This simplifies assembly and also allows the rollers 22a and 22b to rotate relative to the shaft 21. (Third embodiment)<Konfiguration der Laufrolle 20>

[0121] The following describes the configuration of a roller 20 according to the third embodiment of the present invention with reference to the Fig. 11 and Fig. 12 described.

[0122] Fig. 11 and Fig. Figures 12 each show a first cross-sectional view and a second cross-sectional view, each of which shows a configuration of a roller included in a working machine according to the third embodiment of the present invention. As shown in Fig. As shown in Figure 11, the roller 20 according to the present embodiment differs in its configuration from the roller 20 according to the one shown in Figure 11. Fig. 7 and Fig. 8 second embodiment shown in that a snap ring is used as a fastening element 25b.

[0123] A snap ring 25b is used as a fastening element 25b instead of the fastening element 25 in the second embodiment. Therefore, in the present embodiment, the fastening element 25, such as a bolt in the second embodiment, is not used.

[0124] The snap ring 25b is, for example, a spring ring with an annular shape that is partially notched. The snap ring 25b is fitted into an annular groove provided in the inner circumferential surface 22aa of the roller 22a. When the snap ring 25b is attached to the roller 22a, its inner diameter is smaller than the outer diameter of the bushing 24. The outer diameter of the snap ring 25b is larger than the outer diameter of the bushing 24. Thus, the snap ring 25b prevents the bushing 24 from falling out of the roller 22a in the axial direction and secures the bushing 24 to the roller 22a.

[0125] As in Fig. As shown in Figure 12, the recessed section 21ea faces both the rotation-side element 26aR and the mounting-side element 26aF of the floating seal 26a in the radial direction of the shaft 21. Furthermore, the recessed section 21ea also faces an area located between the radial sliding bearing 23aa and the floating seal 26a in the radial direction of the shaft 21.

[0126] The recessed section 21ea extends axially from a position radially facing the axial sliding bearing 23ab to a position radially facing the fastening-side element 26aF of the floating seal 26a. The axial dimension of the recessed section 21ea is larger than the axial dimension of the bushing 24.

[0127] Since the configuration of the present embodiment is essentially the same as that of the second embodiment, with the exception of the above, the same elements are designated by the same reference numerals, and their description is not repeated.

[0128] In the construction of the roller 20 in the present embodiment, the bushing 24 is fastened to the roller 22a by a snap ring 25b instead of a fastening element, such as a bolt. Since the way in which the roller 20 is formed in the present embodiment is essentially the same as in the second embodiment, the description is not repeated.

[0129] According to the present embodiment, the same effects can be achieved as in the first and second embodiments. (Modifications)

[0130] The configuration of the present invention is applicable not only to the roller 20, but also to the guide wheel 42, the support roller 20a, and the like. A configuration obtained by applying the configuration of the present invention to the guide wheel 42 is described below with reference to Fig. 13 described.

[0131] Fig. Figure 13 is a perspective partial view showing a configuration of the machine 100 in the work machine. Fig. 1 guide wheel included shows. As in Fig. As shown in Figure 13, the guide wheel 42 according to the present embodiment comprises a shaft 21, a roller 42a, sliding bearing elements 23a and 23b, a bushing 24, a fastening element 25, floating seals 26a and 26b and supports 27a and 27b.

[0132] The guide wheel 42 according to the present embodiment differs in configuration from the roller 20 according to the second embodiment mainly in the configuration of the roller 42a. The roller 42a has a through-hole into which the shaft 21 is inserted. The through-hole is configured such that a large-diameter section and a small-diameter section are connected in the axial direction.

[0133] In the small diameter section, the radial sliding bearing 23ba of the sliding bearing element 23b is arranged between the inner circumferential surface of the roller 42a and the outer circumferential surface of the shaft body 21a.

[0134] In the large-diameter section, the radial plain bearing 23ba of the plain bearing element 23b and the bushing 24 are arranged between the inner circumferential surface of the roller 42a and the outer circumferential surface of the shaft body 21a. The axial plain bearing 23bb of the plain bearing element 23b is arranged between the end face of the roller 42a and the end face of the intermediate flange 21b, which form a height difference between the small-diameter and large-diameter sections. The axial plain bearing 23ab of the plain bearing element 23a is arranged between the end face of the intermediate flange 21b and the end face of the bushing 24.

[0135] In the radial direction of shaft 21, the recessed section 21ea faces the sliding section between the rotating element 26aR and the fastening element 26aF in the floating seal 26a and the radial sliding bearing 23aa. The recessed section 21ea faces the axial sliding bearing 23ab in the radial direction of shaft 21.

[0136] In the radial direction of shaft 21, the recessed section 21eb faces the sliding section between the rotating element 26bR and the fastening element 26bF of the floating seal 26b and the radial sliding bearing 23ba. The recessed section 21eb faces the axial sliding bearing 23bb in the radial direction of shaft 21.

[0137] Since the configuration of the guide wheel 42 is essentially the same as the configuration of the roller 20 according to the second embodiment, with the exception of the above, the same elements are designated by the same reference numerals, and their description is not repeated.

[0138] Even in the case where the configuration of the present invention is applied to other rollers such as the guide wheel 42 and the upper roller 20a, as described above, the same effect as in the second embodiment can be achieved.

[0139] While the configuration obtained by applying the design of the second embodiment to the guide wheel 42 has been described previously, the design of the first or third embodiment can be applied to the guide wheel 42. Furthermore, any design of the first to third embodiments can be applied to the support roller 20a. Reference symbol list

[0140] 1 Crawler undercarriage, 1A Crawler track, 2 Vehicle body, 3 Working implement, 4 Cab, 5 Engine compartment, 6 Shield, 6a Upper end, 7 Frame, 8 Angle cylinder, 9 Lifting cylinder, 10 Crawler track, 20 Running roller, 20a Support roller, 21 Shaft, 21a Shaft body, 21aa Outer circumferential surface, 21b Intermediate flange, 21ba, 21bb, 22ab, 22bb, 24b End face, 21c Flow path 21da, 21db Branch flow path, 21ea, 21eb Recess, 22a, 22b, 42a Roller, 22aa, 22ba, 24a Inner circumferential surface, 22c Weld seam, 23a, 23b Sliding bearing element, 23aa, 23ba Radial sliding bearing, 23ab, 23bb axial sliding bearing, 24 bushing, 25, 25b fastening element, 25b snap ring, 26a, 26b floating seal, 26aF, 26bF mounting-side element, 26aR, 26bR rotating side element, 26aa elastic ring, 26ab, 26ad metal sealing ring, 27a, 27b bracket, 41 drive wheel, 42 idler wheel, 43 crawler frame, 100 bulldozer.

Claims

[1] Track roller assembly of a crawler chassis (1) wherein the track roller assembly comprises: a shaft (21) with an outer circumferential surface (21aa) which is provided with a recessed section (21ea, 21eb) in which a cooling medium is housed; a roller (22a, 22b) which is rotatable relative to the outer circumferential surface (21aa) of the shaft (21); a first sliding bearing (23aa, 23ba) that supports the roller (22a, 22b) so that it is rotatable relative to the outer circumferential surface (21aa) of the shaft (21) and absorbs a force in the radial direction of the shaft (21); and a floating seal (26a, 26b) with a rotation-side element (26aR, 26bR) supported by the roller (22a, 22b) and a fastening-side element (26aF, 26bF) sliding together with the rotation-side element (26aR, 26bR), wherein in the radial direction of the shaft (21) the recessed section (21ea, 21eb) faces: a sliding section between the rotation-side element (26aR, 26bR) and the fastening-side element (26aF, 26bF) in the floating seal (26a, 26b); and the first sliding bearing (23aa, 23ba), characterized by , that the recessed section (21ea, 21eb) in a cross-section perpendicular to an axis (C) of the shaft (21) has linearly extending side walls, the distance between which increases continuously towards the outside in the radial direction of the shaft (21), and the shaft (21) comprises a flow path (21c) extending in the axial direction of the shaft (21) and a branch flow path (21da, 21db) extending from the flow path (21c) in the radial direction of the shaft (21) outwards to the recessed section (21ea, 21eb), and the branch flow path (21da, 21db) is provided at a position facing the first sliding bearing (23aa, 23ba) in the radial direction of the shaft (21), with the recessed section (21ea, 21eb) being arranged between them. [2] Track roller unit of the crawler chassis (1) according to claim 1, wherein the shaft (21) contains an intermediate flange (21b) which projects outwards in a radial direction, the roller assembly further comprises a second sliding bearing (23ab, 23bb) which rotatably supports the roller (22a, 22b) relative to the intermediate flange (21b) and absorbs a force in an axial direction of the shaft (21), and the recessed section (21ea, 21eb) faces the second sliding bearing (23ab, 23bb) in the radial direction of the shaft (21). [3] Roller unit of the crawler chassis (1) according to claim 1 or 2, wherein a plurality of the recessed sections (21ea, 21eb) are arranged symmetrically to the axis line (C) of the shaft (21). [4] Roller unit of the crawler chassis (1) according to one of claims 1 to 3, further comprising a bushing (24) which is arranged between the outer circumferential surface (21aa) of the shaft (21) and an inner circumferential surface (22aa, 22ba) of the roller (22a, 22b), wherein the rotating element (26aR, 26bR) is supported by the roller (22a, 22b) with the bushing (24) located between them. [5] Track roller assembly of a crawler chassis (1), wherein the track roller assembly comprises: a shaft (21) with an outer circumferential surface (21aa) which is provided with a recessed section (21ea, 21eb) in which a cooling medium is housed; a roller (22a, 22b) which is rotatable relative to the outer circumferential surface (21aa) of the shaft (21); a first sliding bearing (23aa, 23ba) that supports the roller (22a, 22b) so that it is rotatable relative to the outer circumferential surface (21aa) of the shaft (21) and absorbs a force in the radial direction of the shaft (21); and a floating seal (26a, 26b) with a rotating element (26aR, 26bR) which is supported by the roller (22a, 22b) and a fastening element (26aF, 26bF) which slides together with the rotating element (26aR, 26bR), wherein in the radial direction of the shaft (21) the recessed section (21ea, 21eb) faces: the rotating element (26aR, 26bR) and the fastening element (26aF, 26bF) in the floating seal (26a, 26b); and the first sliding bearing (23aa, 23ba), characterized by , that the recessed section (21ea, 21eb) in a cross-section perpendicular to an axis (C) of the shaft (21) has linearly extending side walls, the distance between which increases continuously towards the outside in the radial direction of the shaft (21), and the shaft (21) comprises a flow path (21c) extending in the axial direction of the shaft (21) and a branch flow path (21da, 21db) extending from the flow path (21c) in the radial direction of the shaft (21) outwards to the recessed section (21ea, 21eb), and the branch flow path (21da, 21db) is provided at a position facing the first sliding bearing (23aa, 23ba) in the radial direction of the shaft (21), with the recessed section (21ea, 21eb) being arranged between them. [6] Crawler undercarriage (1), comprising: the roller unit according to any one of claims 1 to 5; and a track unit (1A) which has a ring shape and is rotatably mounted on the roller unit. [7] Working machine (100), comprising: the crawler chassis (1) according to claim 6; and a working machine body (2, 3) which is supported by the crawler chassis (1).

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