Track roller for a tracked vehicle

Abstract

Crawler track roller (10) for a crawler track vehicle, comprising: a cylindrical roller shell (11); a shaft (12) inserted into the roller shell (11); a first holder (14a) which is pressed onto an outer circumference of the shaft (12) and is opposite a first end surface (S4) of the roller shell (11); a second holder (14b) which is pressed onto the outer circumference of the shaft (12) and is opposite a second end surface (S5) of the roller shell (11); a first retaining ring (15a) attached to the outer circumference of the shaft (12) and fixing the first holder (14a); a second retaining ring (15b) which is attached to the outer circumference of the shaft (12) and fixes the second holder (14b), wherein the roller shell (11) comprises a roller shell body (11a), a first bushing (11b) and a second bushing (11c), the roller shell body (11a) has an insertion hole (S3); the first bushing (11b) comprises a first cylindrical portion (111) and a first flange (112) extending outward from the first cylindrical portion (111) in a radial direction, and the first bushing (11b) is press-fitted into the insertion hole (S3) of the roller shell body (11a) and abuts the first holder (14a) at the first flange (112); and the second bushing (11c) comprises a second cylindrical portion (113) and a second flange (114) extending outward from the second cylindrical portion (113) in the radial direction, and wherein the second bushing (11c) is pressed into the insertion hole (S3) of the roller shell body (11a) and abuts against the second flange (114) on the second holder (14b), a first mounting piece (13a) attached to the first end (12b) of the shaft (12) and remote from the first holder (14a); and a second mounting piece (13b) attached to the second end (12c) of the shaft (12) and remote from the second holder (14b).

Description

TECHNICAL FIELD

[0001] The present invention relates to a crawler track roller for a crawler vehicle. STATE OF THE ART

[0002] Traditionally, tracked vehicles such as bulldozers and hydraulic excavators were used for working on uneven terrain. A tracked vehicle has a track unit consisting of tracks, sprockets, idler pulleys, carrier rollers, track rollers, and the like. The track is wound around the sprocket, idler pulley, carrier roller, and track roller.

[0003] JP H08-230 729 A discloses a track roller comprising a shaft, a roller shell, a pair of bushings, and a pair of retaining rings. The bushings and retaining rings rotate around the shaft together with the roller shell. The bushings are press-fitted to the inside of the roller shell. The retaining rings are mounted on grooves provided on the inner peripheral surface of the roller shell. Each bushing is arranged between a retaining ring and the center flange of the shaft so that they do not move in the axial direction of the shaft. The load exerted on the roller shell is supported by the retaining rings and the center flange of the shaft via the bushings.US 4,640,559 A discloses a crawler track roller having a cylindrical roller shell with a roller shell body, a shaft inserted into an insertion hole of the roller shell body, a first retainer press-fitted onto the shaft and facing an end face of the roller shell, a second retainer press-fitted onto the shaft and facing an end face of the roller shell, a first retainer ring attached to the outer periphery of the shaft and fixing the first retainer, and a second retainer ring attached to the outer periphery of the shaft and fixing the second retainer. Further, a first mounting piece and a second mounting piece are provided. The first mounting piece is attached to the first end of the shaft and is remote from the first holder. The second mounting piece is attached to the second end of the shaft and is remote from the second holder.Furthermore, CN 2 01 980 314 U discloses a chain roller with a cylindrical roller shell, a shaft inserted into the roller shell, a first holder attached to the outer circumference of the shaft and opposite an end face of the roller shell, a second holder attached to the outer circumference of the shaft and opposite an end face of the roller shell, a first retaining ring fixing the first holder, and a second retaining ring fixing the second holder. Furthermore, the roller shell comprises a roller shell body, and first and second bushings are press-fitted into an insertion hole of the roller shell body. The first and second bushings each have a cylindrical flange and a radial flange. TECHNICAL PROBLEM

[0004] However, in the crawler track roller in JP H8-230729 A, since the shaft has a central flange, there is a problem that the roller shell is composed of numerous parts, which makes assembly more complicated. The present invention has been conceived in view of the above situation, and an object thereof is to provide a crawler track roller with a simple structure. SOLUTION TO THE PROBLEM

[0005] The crawler track roller according to the present invention comprises a cylindrical roller shell, a shaft, a first retainer, a second retainer, a first retainer ring, and a second retainer ring. The shaft is inserted into the roller shell. The first retainer is press-fitted onto an outer periphery of the shaft and faces a first end surface of the roller shell. The second retainer is press-fitted onto the outer periphery of the shaft and faces a second end surface of the roller shell. The first retainer ring is attached to the outer periphery of the shaft and fixes the first retainer. The second retainer ring is attached to the outer periphery of the shaft and fixes the second retainer. The roller shell has a roller shell body, a first bushing, and a second bushing. The roller shell body has an insertion hole.The first bushing includes a first cylindrical portion and a first flange extending radially outward from the first cylindrical portion. The first bushing is press-fitted into the insertion hole of the roller shell body and abuts the first holder at the first flange. The second bushing includes a second cylindrical portion and a second flange extending radially outward from the second cylindrical portion. The second bushing is press-fitted into the insertion hole of the roller shell body and abuts the second holder at the second flange. Further, a first mounting piece and a second mounting piece are provided. The first mounting piece is attached to the first end of the shaft and is remote from the first holder. The second mounting piece is attached to the second end of the shaft and is remote from the second holder.

[0006] In a preferred embodiment, the shaft has a first annular groove at one end for mounting the first retaining ring and a second annular groove at the other end for securing the second retaining ring.

[0007] In a preferred embodiment, the first holder and the second holder each have an inner peripheral surface in contact with the outer peripheral surface of the shaft and an outer peripheral surface provided substantially perpendicular to the inner peripheral surface.

[0008] In a preferred embodiment, the first holder and the second holder are each formed in a circular ring shape.

[0009] In a preferred embodiment, the track roller further comprises a first seal assembly and a second seal assembly. The first seal assembly is sealingly enclosed between the roller shell and the first retainer. The second seal assembly is sealingly enclosed between the roller shell and the second retainer. BENEFICIAL EFFECTS

[0010] The present invention provides a crawler track roller having a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view of a bulldozer according to one embodiment. Fig. 2 is an oblique view of the crawler roller in this embodiment. Fig. 3 is an exploded oblique view of a crawler roller in this embodiment. Fig. 4 is a cross section along the line AA in Fig. 2. DESCRIPTION OF EMBODIMENTS Structure of the bulldozer 1

[0011] The structure of a bulldozer 1 belonging to this embodiment will be described with reference to the drawings. Fig. 1 is a side view of the bulldozer 1.

[0012] The bulldozer 1 comprises a vehicle body 2, a blade assembly 3, and a crawler-type traveling unit 4. The vehicle body 2 is supported by the crawler-type traveling unit 4. The blade assembly 3 is arranged in front of the vehicle body 2.

[0013] The crawler-type traveling unit 4 includes a crawler frame 5, a sprocket 6, a return pulley 7, a crawler belt 8, support rollers 9, and crawler rollers 10. The crawler frame 5 constitutes the frame of the crawler-type traveling unit 4. The sprocket 6 is mounted on the rear end portion of the vehicle body 2. The return pulley 7 is mounted on the front end portion of the crawler frame 5. The crawler belt 8 is wound around the sprocket 6 and the return pulley 7.

[0014] The support rollers 9 are attached to the upper surface of the crawler frame 5. The support rollers 9 support the crawler 8 from below, preventing the crawler 8 from sagging under its own weight. The crawler rollers 10 are attached to the lower surface of the crawler frame 5. The crawler rollers 10 distribute the body weight and transfer it to the crawler 8. Construction of crawler track rollers 10

[0015] The structure of the crawler rollers 10 in this embodiment will be described with reference to the drawings. Fig. 2 is an oblique view of a crawler track roller 10. Fig. 3 is an exploded oblique view of the crawler roller 10.

[0016] The crawler track roller 10 includes a roller shell 11, a shaft 12, first and second mounting pieces 13a and 13b, first and second holders 14a and 14b, first and second retaining rings 15a and 15b, and first and second seal assemblies 16a and 16b.

[0017] In the following explanation, a direction parallel to the central axis AX of the shaft 12 will be referred to as “axial direction”, and a direction perpendicular to the central axis AX of the shaft 12 will be referred to as “radial direction”. (1) Roller casing 11

[0018] The roller shell 11 is formed in an overall cylindrical shape. The roller shell 11 rotates together with the crawler belt 8 around the central axis AX of the shaft 12. The roller shell 11 has a roller shell body 11a, a first bushing 11b, and a second bushing 11c.

[0019] The roller shell body 11a is formed in a cylindrical shape. The roller shell body 11a has a first flange 31, a second flange 32, and an annular concave portion 33. The first flange 31 is formed at one end of the roller shell body 11a. The second flange 32 is formed at the other end of the roller shell body 11a. The annular concave portion 33 is formed at the central portion of the roller shell body 11a.

[0020] The roller shell body 11a has a first guide surface S1, a second guide surface S2, and an insertion hole S3. The first guide surface S1 is formed between the first flange 31 and the annular concave portion 33. The second guide surface S2 is formed between the second flange 32 and the annular concave portion 33. The first guide surface S1 and the second guide surface S2 guide the connecting links of the crawler belts 8 between the first flange 31 and the second flange 32. The insertion hole S3 is formed along the axis of the roller shell body 11a. The shaft 12 is inserted into the insertion hole S3.

[0021] The roller shell body 11a has a first end surface S4 and a second end surface S5. The first end surface S4 is opposite the first holder 14a. The second end surface S5 is opposite the second holder 14b.

[0022] The first bushing 11b is inserted into the insertion hole S3 from one end of the roller shell body 11a. The first bushing 11b is press-fitted into the insertion hole S3. The first bushing 11b rotates together with the roller shell body 11a.

[0023] The first bushing 11b includes a first cylindrical portion 111 and a first flange 112. The first cylindrical portion 111 is formed in a hollow cylindrical shape. The first flange 112 is continuous with the end at the exterior of the first cylindrical portion 111 in the axial direction. The first flange 112 is a thrust ring formed in an annular shape and extending radially outward from the outer periphery of the first cylindrical portion 111. The first cylindrical portion 111 and the first flange 112 are each made of a metal material (such as lead bronze casting (LBC)). The first cylindrical portion 111 and the first flange 112 are integrally formed from the same metal material. The first cylindrical portion 111 and the first flange 112 may be separately formed from different metal materials.

[0024] The second bushing 11c is inserted into the insertion hole S3 from the other end of the roller shell body 11a. The second bushing 11c is press-fitted into the insertion hole S3. The second bushing 11c rotates together with the roller shell body 11a.

[0025] The second bushing 11c has a second cylindrical portion 113 and a second flange 114. The second cylindrical portion 113 is formed in a hollow cylindrical shape. The second flange 114 is continuous with the end at the exterior of the second cylindrical portion 113 in the axial direction. The second flange 114 is a pressure flange formed in an annular shape extending radially outward from the second cylindrical portion 113. The second cylindrical portion 113 and the second flange 114 are each made of a metal material (e.g., lead bronze casting (LBC)). The second cylindrical portion 113 and the second flange 114 are integrally formed of the same metal material. The second cylindrical portion 113 and the second flange 114 may be separately formed of different metal materials. (2) Wave 12

[0026] The shaft 12 is rod-shaped. The shaft 12 is inserted into the insertion hole S3 of the roller shell 11. The shaft 12 is the rotational axis of the roller shell 11. The shaft 12 has a cylindrical portion 12a, a first end 12b, and a second end 12c.

[0027] The cylindrical portion 12a is formed in a cylindrical shape. The cylindrical portion 12a has a surface T0. The cylindrical portion 12a has a uniform outer diameter overall. The surface T0 is the cylindrical surface of the cylindrical portion 12a. The cylindrical portion 12a is arranged within the roller shell 11.

[0028] One end of the cylindrical portion 12a is disposed within the first bushing 11b of the roller shell 11. One end of the cylindrical portion 12a is inserted into the hollow part of the first bushing 11b. A first annular groove T1 for attaching the first retaining ring 15a is formed at one end of the cylindrical portion 12a. The other end of the cylindrical portion 12a is disposed within the second bushing 11c of the roller shell 11. The other end of the cylindrical portion 12a is inserted into the hollow part of the first bushing 11b. A second annular groove T2 for fastening the second retaining ring 15b is formed at the other end of the cylindrical portion 12a.

[0029] The first end portion 12b is continuous with one end of the cylindrical portion 12a. The first end 12b protrudes outward in the axial direction from one end of the roller shell 11. The first end 12b has a mounting surface T3. The mounting surface T3 faces the lower surface of the crawler frame 5 when the crawler roller 10 is mounted on the crawler frame 5.

[0030] The second end 12c is continuous with the other end of the cylindrical portion 12a. The second end 12c protrudes outward in the axial direction from the other end of the roller shell 11. The second end 12c has a mounting surface T4. The mounting surface T4 faces the lower surface of the crawler frame 5 when the crawler roller 10 is mounted to the crawler frame 5.

[0031] An oil line T5 is formed within the shaft 12. The inlet of the oil line T5 is provided in the end face of the first end 12b. The inlet of the oil line T5 is closed by a plug 36. (3) First and second mounting pieces 13a and 13b

[0032] The first mounting piece 13a is a member for fixing the first end 12b of the shaft 12 to the crawler frame 5. The first mounting piece 13a is formed in an Ω shape. The first mounting piece 13a has an insertion recess U1 and a pair of mounting holes U2.

[0033] The insertion recess U1 is connected to the first end 12b of the shaft 12. A fastener (such as a bolt) is passed through each mounting hole U2. The first mounting piece 13a is fixed to the lower surface of the crawler frame 5 with fasteners inserted into the mounting holes U2.

[0034] The second mounting piece 13b is a member for fixing the second end 12c of the shaft 12 to the crawler frame 5. The second mounting piece 13b is formed in an Ω shape. The second mounting piece 13b has an insertion recess U3 and a pair of mounting holes U4.

[0035] The insertion recess U3 is connected to the second end 12c of the shaft 12. The second mounting piece 13b is positioned relative to the shaft 12 by a pin 35. A fastener (such as a bolt) is inserted into each mounting hole U4. The second mounting piece 13b is fixed to the lower surface of the crawler frame 5 by fasteners inserted into the mounting holes U4. (4) First and second holders 14a and 14b

[0036] The first retainer 14a is a sealing element in the first seal assembly 16a. The first retainer 14a can absorb a load in the axial direction from the roller shell 11. The first retainer 14a is formed in an annular shape. The first retainer 14a is press-fitted onto the outer circumference of the shaft 12. The first retainer 14a has an insertion hole V1, an inner circumferential surface V2, an outer surface V3, and a boss B.

[0037] One end of the cylindrical portion 12a of the shaft 12 is press-fitted into the insertion hole V1. The inner peripheral surface V2 is the inner surface of the insertion hole V1. The inner peripheral surface V2 is in contact with the surface T0 of the cylindrical portion 12a of the shaft 12. The outer surface V3 is the main surface (plate) of the first holder 14a. The outer surface V3 is substantially perpendicular to the inner peripheral surface V2. The outer surface V3 faces the first mounting piece 13a. The outer surface V3 is spaced apart from the first mounting piece 13a. The boss B is a cylindrical part that includes the inner peripheral surface V2. The shaft 12 is press-fitted onto the boss B.

[0038] The second retainer 14b is a sealing element in the second seal assembly 16b. The second retainer 14b can absorb a load in the axial direction from the roller shell 11. The second retainer 14b is formed in an annular shape. The second retainer 14b is press-fitted onto the outer circumference of the shaft 12. The second retainer 14b has an insertion opening V4, an inner circumferential surface V5, an outer surface V6, and a projection B.

[0039] The other end of the cylindrical portion 12a of the shaft 12 is press-fitted into the insertion hole V4. The inner peripheral surface V5 is the inner surface of the insertion hole V4. The inner peripheral surface V5 is in contact with the surface T0 of the cylindrical portion 12a of the shaft 12. The outer surface V6 is the main surface (plate) of the second holder 14b. The outer surface V6 is substantially perpendicular to the inner peripheral surface V5. The outer surface V6 faces the second mounting piece 13b. The outer surface V6 is spaced apart from the second mounting piece 13b.

[0040] As in Fig. 3, a first annular concave part P1 and a second annular concave part P2 are formed in the inner surface of the second holder 14b. The first annular concave part P1 is formed outside the boss portion B in the radial direction. The first annular concave part P1 is formed inside the second annular concave part P2 in the radial direction. A part of the first seal assembly 16a is received in the first annular concave part P1. The second annular concave part P2 is formed outside the first annular concave part P1 in the radial direction. The boss B is a cylindrical part between the inner peripheral surface V5 and the first annular concave part P1. The shaft 12 is press-fitted onto the boss B.

[0041] Although not in Fig. 3, the first annular concave part P1 and the second annular concave part P2 are formed in the inner surface of the first holder 14a, as in the second holder 14b. (5) First and second retaining rings 15a and 15b

[0042] The first retaining ring 15a is a member for fixing the first holder 14a to the shaft 12. The first retaining ring 15a is a snap ring for preventing the first holder 14a from being axially disengaged from the shaft 12 by stopping the movement of the first holder 14a in the axial direction of the shaft 12.

[0043] The first retaining ring 15a is C-shaped. The first retaining ring 15a is attached to the first annular groove T1 formed in the cylindrical portion 12a of the shaft 12.

[0044] The second retaining ring 15b is a member for fixing the second holder 14b to the shaft 12. The second retaining ring 15b is a snap ring for preventing the first holder 14a from being released from the shaft 12 in the axial direction by stopping the movement of the second holder 14b in the axial direction of the shaft 12.

[0045] The second retaining ring 15b is formed in a C-shape. The second retaining ring 15b is fixed to the second annular groove T2 formed in the cylindrical portion 12a of the shaft 12. (6) First and second seal assemblies 16a and 16b

[0046] The first seal assembly 16a is sealed between the roller shell 11 and the first holder 14a. The first seal assembly 16a is arranged outside the shoulder B of the first holder 14a in the radial direction. The first seal assembly 16a is composed of a first inner seal 17, a first inner O-ring 18, a first outer seal 19, and a first outer O-ring 20.

[0047] The first inner seal 17 is formed in an annular shape with an L-shaped cross section. The first inner seal 17 is made of a metal material (such as cast iron). The first inner O-ring 18 is formed in an annular shape. The first inner O-ring 18 is attached to the outside of the first inner seal 17 in the radial direction. The first inner O-ring 18 is made of an elastic member (e.g., rubber). The first inner seal 17 and the first inner O-ring 18 are arranged in the first annular concave part P1 of the first holder 14a.

[0048] The first outer seal 19 is formed in an annular shape with an L-shaped cross section. The first outer seal 19 is made of a metal material (such as cast iron). The first outer O-ring 20 is formed in an annular shape. The first outer O-ring 20 is fitted on the outside of the first outer seal 19. The first outer O-ring 20 is made of an elastic member (such as rubber). A first outer seal 19 and the first outer O-ring 20 are arranged in a first annular concave part S6 formed in the first end surface S4 of the roller shell body 11a.

[0049] The second seal assembly 16b is sealingly enclosed between the roller shell 11 and the second holder 14b. The second seal assembly 16b is arranged outside the projection B of the second holder 14b in the radial direction. The second seal assembly 16b is formed from a second inner seal 21, a second inner O-ring 22, a second outer seal 23, and a second outer O-ring 24.

[0050] The second inner seal 21 is formed in an annular shape with an L-shaped cross section. The second inner seal 21 is made of a metal material (such as cast iron). The second inner O-ring 22 is formed in an annular shape. The second inner O-ring 22 is attached to the outside of the second inner seal 21 in the radial direction. The second inner O-ring 22 is made of an elastic member (such as rubber). The second inner seal 21 and the second inner O-ring 22 are arranged in the first annular concave part P1 of the second holder 14b.

[0051] The second outer seal 23 is formed in an annular shape with an L-shaped cross section. The second outer seal 23 is made of a metal material (such as cast iron). The second outer O-ring 24 is formed in an annular shape. The second outer O-ring 24 is attached to the outside of the second outer seal 23 in the radial direction. The second outer O-ring 24 is made of an elastic member (for example, rubber). The second outer seal 23 and the second outer O-ring 24 are arranged in a second annular concave part S8 formed in the second end surface S5 of the roller shell body 11a. Internal structure of the crawler roller 10

[0052] The internal structure of the crawler roller 10 in this embodiment will be described with reference to the drawings. Fig. 4 is a cross section along the line AA in Fig. 2.

[0053] The roller shell 11, the first inner seal 17, the first inner O-ring 18, the second inner seal 21 and the second inner O-ring 22 are “rotation-side elements” that rotate with respect to the shaft 12.

[0054] The shaft 12, the first and second mounting pieces 13a and 13b, the first and second holders 14a and 14b, the first and second retaining rings 15a and 15b, the first outer seal 19, the first outer O-ring 20, the second outer seal 23 and the second outer O-ring 24 are “fixed members” that are fixed with respect to the crawler frame.

[0055] The first bushing 11b and the second bushing 11c of the roller shell 11 can slide with respect to the shaft 12. The first flange 112 of the first bushing abuts the shoulder B of the first holder 14a, which is positioned outward in the axial direction. The second flange 114 of the second bushing 11c abuts the shoulder B of the second holder 14b, which is positioned outward in the axial direction.

[0056] The first retainer 14a and the second retainer 14b are press-fitted onto the shaft 12. The first retainer 14a abuts the first retaining ring 15a, which is positioned outward in the axial direction. The second retainer 14b abuts the second retaining ring 15b, which is positioned outward in the axial direction.

[0057] The roller shell 11 is thus sandwiched between the first retainer 14a and the second retainer 14b, and the first retainer 14a and the second retainer 14b are fixed by the first retainer ring 15a and the second retainer ring 15b. Accordingly, the thrust load transmitted from the crawler belt 8 to the roller shell 11 is stopped by the pressing force of the first retainer 14a and the second retainer 14b with respect to the shaft 12 and by the holding force of the first retainer ring 15a and the second retainer ring 15b with respect to the first retainer 14a and the second retainer 14b.

[0058] As in Fig. 4, the first annular concave part S6 and a first annular convex part S7 are formed on the first end surface S4 of the roller shell body 11a.

[0059] The first annular concave portion S6 of the roller shell body 11a is formed on the outer side of the first bushing 11b in the radial direction. The first annular concave portion S6 of the roller shell body 11a is continuous with the first annular concave portion P1 of the first holder 14a in the axial direction. Thus, a space for accommodating the first seal assembly 16a is formed. The first inner seal 17 and the first inner O-ring 18 are housed in the first annular concave portion S6 of the roller shell body 11a. The first outer seal 19 and the first outer O-ring 20 are received in the first annular concave portion P1 of the first holder 14a.

[0060] The first annular convex portion S7 of the roller shell body 11a is formed on the outer side of the first annular concave portion S6 in the radial direction. The first annular convex portion S7 of the roller shell body 11a is fitted into the second annular concave portion P2 of the first retainer 14a. Therefore, since a labyrinth structure is formed between the roller shell 11 and the first retainer 14a, sand and dust from the outside are less likely to penetrate into the gap between the first retainer 14a and the roller shell 11.

[0061] As in Fig. 4, the second annular concave part S8 and a second annular convex part S9 are formed on the second end surface S5 of the roller shell body 11a.

[0062] The second annular concave portion S8 of the roller shell body 11a is formed on the outer side of the second bushing 11c in the radial direction. The second annular concave portion S8 of the roller shell body 11a is continuous with the first annular concave portion P1 of the second holder 14b in the axial direction. Thus, a space for accommodating the second seal assembly 16b is formed. The second inner seal 21 and the second inner O-ring 22 are housed in the second annular concave portion S8 of the roller shell body 11a. The second outer seal 23 and the second outer O-ring 24 are housed in the first annular concave portion P1 of the second holder 14b.

[0063] The second annular convex portion S9 of the roller shell body 11a is formed on the outer side of the second annular concave portion S8 in the radial direction. The second annular convex portion S9 of the roller shell body 11a is fitted into the second annular concave portion P2 of the second retainer 14b. Consequently, since a labyrinth structure is formed between the roller shell 11 and the second retainer 14b, sand or dust from the outside is less likely to enter the gap between the roller shell 11 and the second retainer 14b.

[0064] As in Fig. 4, a first oil passage S10, a second oil passage S11, and an oil reservoir S12 are formed inside the roller shell body 11a. The first oil passage S10 and the second oil passage S11 are cylindrical spaces in the roller shell body 11a. The first oil passage S10 is continuous with the first annular concave part S6 and the oil reservoir S12. The second oil passage S11 is continuous with the second annular concave part S8 and the oil reservoir S12. The lubricating oil injected from the oil passage T5 of the shaft 12 is supplied to the first annular concave part S6 through oil passages (not shown) formed inside and on the surface of the shaft 12 and through a notch P3 formed in the boss B of the first holder 14a. The lubricating oil supplied to the first annular concave part S6 is supplied to the first oil passage S10, the oil reservoir S12, the second oil passage S11, and the second annular concave part S8 in this order. Method for assembling a crawler roller 10

[0065] Next, the method of assembling the crawler roller 10 will be described with reference to Fig. 2 to 4.

[0066] First, the first cylindrical portion 111 of the first bushing 11b is press-fitted into the insertion hole S3 of the roller shell body 11a, and the second cylindrical portion 113 of the first bushing 11b is press-fitted into the insertion hole S3 of the roller shell body 11a. When the first and second cylindrical portions 111 and 113 are press-fitted, the first and second flanges 112 and 114 come into contact with the roller shell body 11a.

[0067] Next, the shaft 12 is inserted into the first cylindrical portion 111 of the first bushing 11b and the second cylindrical portion 113 of the first bushing 11b.

[0068] Then, the first inner seal 17 and the first inner O-ring 18 are accommodated in the first annular concave part S6 of the roller shell body 11a, and the second inner seal 21 and the second inner O-ring 22 are accommodated in the second annular concave part S8 of the roller shell body 11a.

[0069] Next, the first outer seal 19 and the first outer O-ring 20 are housed in the first annular concave part P1 of the first holder 14a, and the second outer seal 23 and the second outer O-ring 24 are housed in the first annular concave part P1 of the second holder 14b.

[0070] Next, the first retaining ring 15a is attached to the first annular groove T1 of the shaft 12 in a state where the first holder 14a is in contact with the roller shell 11, and the second retaining ring 15b is attached to the second annular groove T2 of the shaft 12 in a state where the second holder 14b is in contact with the roller shell 11.

[0071] The first and second mounting pieces 13a and 13b are then used to attach the assembly to the crawler frame 5. Features (1) The crawler roller includes the roller shell 11, the first retainer 14a, the second retainer 14b, the first retainer ring 15a, and the second retainer ring 15b. The first retainer 14a is press-fitted onto the outer periphery of the shaft 12 and abuts against the first end surface S4 of the roller shell 11. The second retainer 14b is press-fitted onto the outer periphery of the shaft 12 and abuts against the second end surface S5 of the roller shell 11. The first retainer ring 15a is attached to the outer periphery of the shaft 12 on the outside of the first retainer 14a and fixes the first retainer 14a. The second retainer ring 15b is attached to the outer periphery of the shaft 12 and fixes the second retainer 14b.

[0072] Therefore, the thrust load transmitted from the crawler belt 8 to the roller shell 11 can be stopped by the press-fitting force of the first retainer 14a and the second retainer 14b with respect to the shaft 12 and by the holding force of the first retainer ring 15a and the second retainer ring 15b with respect to the first retainer 14a and the second retainer 14b. Therefore, it is not necessary to provide a central flange on the shaft 12, the external shape of the shaft 12 can be simplified, and the number of parts can be reduced, facilitating assembly.

[0073] (2) The roller shell 11 includes the roller shell body 11a, the first bushing 11b, and the second bushing 11c. The roller shell body 11a has the insertion hole S3. The first bushing 11b includes the first cylindrical portion 111 and the first flange 112. The first bushing 11b is press-fitted into the insertion hole S3 and abuts against the first holder 14a. The second bushing 11c includes the second cylindrical portion 113 and the second flange 114. The second bushing 11c is press-fitted into the insertion hole S3 and abuts against the second holder 14b at the second flange 114.

[0074] The thrust load transmitted from the crawler belt 8 to the roller shell 11 is transmitted from the roller shell body 11a via the first bushing 11b or the second bushing 11c to the first bracket 14a or the second bracket 14b. Consequently, the external shape of the shaft 12 can be simplified, the number of parts included in the roller shell can be reduced, and this facilitates assembly.

[0075] (3) The first mounting piece 13a attached to the first end 12b of the shaft 12 is removed from the first holder 14a, and the second mounting piece 13b attached to the second end 12c of the shaft 12 is removed from the second holder 14b.

[0076] Therefore, the roller shell 11, which is a consumable part, can be replaced as needed, and the first mounting piece 13a and the second mounting piece 13b can be reused.

[0077] (4) The first holder 14a and the second holder 14b are each formed in an annular shape.

[0078] Therefore, the first retainer 14a and the second retainer 14b can be manufactured by forging, so that the surface roughness on the surface of the first retainer 14a that abuts the first bushing 11b and the surface of the second retainer 14b that abuts the second bushing 11c can be reduced. Therefore, the sliding resistance between the first retainer 14a and the first bushing 11b and between the second retainer 14b and the second bushing 11c can be reduced. Other embodiments

[0079] An embodiment of the present invention has been described above, but the present invention is not limited to or by the above embodiment, and various modifications are possible without departing from the scope of the claims.

[0080] In the above embodiment, the structure of the bulldozer 1 was described as an example of a crawler vehicle, but the crawler roller belonging to the present invention can also be applied to a hydraulic excavator or the like.

Claims

[1] Crawler track roller (10) for a crawler track vehicle, comprising: a cylindrical roller shell (11); a shaft (12) inserted into the roller shell (11); a first holder (14a) which is pressed onto an outer circumference of the shaft (12) and is opposite a first end surface (S4) of the roller shell (11); a second holder (14b) which is pressed onto the outer circumference of the shaft (12) and is opposite a second end surface (S5) of the roller shell (11); a first retaining ring (15a) attached to the outer circumference of the shaft (12) and fixing the first holder (14a); a second retaining ring (15b) which is attached to the outer circumference of the shaft (12) and fixes the second holder (14b), wherein the roller shell (11) comprises a roller shell body (11a), a first bushing (11b) and a second bushing (11c), the roller shell body (11a) has an insertion hole (S3); the first bushing (11b) comprises a first cylindrical portion (111) and a first flange (112) extending outward from the first cylindrical portion (111) in a radial direction, and the first bushing (11b) is press-fitted into the insertion hole (S3) of the roller shell body (11a) and abuts the first holder (14a) at the first flange (112); and the second bushing (11c) comprises a second cylindrical portion (113) and a second flange (114) extending outward from the second cylindrical portion (113) in the radial direction, and wherein the second bushing (11c) is pressed into the insertion hole (S3) of the roller shell body (11a) and abuts against the second flange (114) on the second holder (14b), a first mounting piece (13a) attached to the first end (12b) of the shaft (12) and remote from the first holder (14a); and a second mounting piece (13b) attached to the second end (12c) of the shaft (12) and remote from the second holder (14b). [2] A crawler track roller for a crawler vehicle according to claim 1, wherein the shaft (12) has a first annular groove (T1) at one end for mounting the first retaining ring (15a) and a second annular groove (T2) at the other end for fixing the second retaining ring (15b). [3] A crawler track roller for a crawler vehicle according to any one of claims 1 to 2, wherein the first holder (14a) and the second holder (14b) each comprise: an inner peripheral surface (V2, V5) in contact with an outer peripheral surface of the shaft (12); and an outer peripheral surface (V3, V6) which is provided substantially perpendicular to the inner peripheral surface (V2, V5). [4] A crawler track roller for a crawler vehicle according to any one of claims 1 to 3, wherein the first holder (14a) and the second holder (14b) are each formed in a circular ring shape. [5] A crawler track roller for a crawler track vehicle according to any one of claims 1 to 4, further comprising: a first sealing arrangement (16a) sealingly enclosed between the roller shell (11) and the first holder (14a); and a second sealing arrangement (16b) which is sealingly enclosed between the roller shell (11) and the second holder (14b).

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