JPH1086863A - Roller device of rail installing type vehicle and manufacture of rolling wheel body for roller device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve strength of a rolling wheel body, and stably actuate it over a long period of time by constituting the rolling wheel body of a single stepped cylindrical body whose lengthwise directional intermediate part is diametrically expanded by becoming a swelling part by plastic deformation. SOLUTION: Though dead weight of a hydraulic shovel always acts on a rolling wheel body 16, this rolling wheel body 16 is formed as a single stepped cylindrical body. That is, the rolling wheel body 16 is composed of a pair of cylindrical parts 16A and 16A positioned in lengthwise directional both end parts and a swelling part 16B which is positioned between the respective cylindrical parts 16A and whose diameter is expanded outward in the radial direction. Therefore, in the rolling wheel body 16, a joining part whose strength is partially reduced can be eliminated, and damage of the rolling wheel body 16 can be prevented, and a lower side roller device 10 can be stably actuated over a long period of time. Strength of the whole rolling wheel body 16 can also be secured by this swelling part 16B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller device rotatably provided on a track frame of a tracked vehicle for guiding a crawler belt for traveling, and a method of manufacturing a rolling element for the roller device.

[0002]

2. Description of the Related Art In general, a tracked vehicle such as a hydraulic shovel or a hydraulic crane includes a lower traveling body and an upper revolving superstructure provided on the lower traveling body. Here, the lower traveling body is composed of a track frame, sprockets and idlers provided separately on front and rear sides of the track frame, and a traveling crawler belt mounted between the sprocket and the idler. I have. The track frame is provided with a plurality of roller devices located between the sprocket and the idler, and each of the roller devices guides the running crawler belt.

As disclosed in Japanese Utility Model Laid-Open No. 1-98784, for example, a roller device used for such a tracked vehicle includes a track frame, a support shaft fixed to the track frame, and a A roller is provided rotatably on the outer peripheral side of the support shaft via a pair of bearings, and guides a crawler belt for traveling. An oil reservoir space filled with lubricating oil is formed at the axially intermediate portion of the rolling element,
The oil sump space is sealed by seal members provided at both axial ends of the rolling element, and a lubricating oil filled in the oil sump space lubricates a sliding surface between the spindle and the bearing. Has become.

[0004] The rolling element according to the prior art is usually composed of a pair of rolling element half-pieces which are symmetrical left and right in the axial direction, and each of the rolling element half-pieces is individually formed by hot forging. , And then joined by welding at an intermediate portion in the axial direction.

[0005]

However, when manufacturing one rolling element, a heating step of heating a material for forming each rolling element half member to a high temperature, and a heating step of heating the heated material to gold. A forging process of forging and pressing using a mold, a machining process of forming a joint for welding by machining each forged half-rolling member, and joining of each half-rolling member It is necessary to go through a welding step of joining the parts by welding.

As described above, in order to manufacture one rolling element, a number of steps such as a heating step, a forging step, a machining step, and a welding step are required, and equipment costs in the heating step and the forging step are required. , There is a problem that the manufacturing cost of the rolling element increases.

[0007] When one rolling element is formed by welding each rolling element half-split member, for example, a tracked vehicle can be operated for a long period of time at a work site where the unevenness of the ground is severe. In such a case, there is a problem that cracks or the like occur in the welded joint portion of the rolling element body, and the roller device cannot be stably operated for a long period of time.

The present invention has been made in view of the above-mentioned problems of the prior art, and can reduce the manufacturing cost of the rolling body and improve the strength of the rolling body, thereby stabilizing the rolling body for a long period of time. It is an object of the present invention to provide a roller device and a method of manufacturing a roller body for a roller device, which can be operated by using the roller device.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a tracked vehicle provided on a track frame of a tracked vehicle, wherein a traveling crawler is guided by a rolling element. In the roller device of (1), the rolling element is formed of a single stepped cylindrical body whose diameter in the middle portion in the length direction becomes a bulging portion due to plastic deformation and whose diameter is enlarged.

As described above, according to the present invention, by forming the rolling element from a single stepped cylindrical body, for example, a plurality of individually formed members are joined by welding or the like to form one rolling element. As compared with the case of forming, a machining step and a welding step for forming a joint can be eliminated. Moreover, in the present invention, compared to a rolling element body composed of a plurality of members joined by welding or the like, a joint part whose strength is partially reduced is hidden,
Uniform strength can be obtained.

In this case, it is preferable that the rolling element is formed to have a substantially uniform thickness over its entire length.

The present invention also provides a track frame of a tracked vehicle, a support shaft fixed to the track frame, and rotatably provided on an outer peripheral side of the support shaft via a pair of bearings, In a roller device for a tracked vehicle including a rolling element that guides a crawler belt for traveling, the rolling element is located on both sides in a length direction and a pair of cylinders in which the bearings are fitted on an inner peripheral side. And a bulging portion located between the cylindrical portions and bulging radially outward and integrally formed with the cylindrical portions.

[0013] According to the above construction, the rolling body rotates the track around the support shaft by rotating the cylindrical part against the track while engaging the bulging portion with the track for running, thereby rotating the track around the track. Guide to the frame. By forming the rolling element integrally with each cylindrical portion and the bulging portion, the manufacturing cost of the rolling element can be reduced, and the strength of the rolling element can be improved.

In this case, it is preferable that the rolling body has a substantially uniform thickness in the cylindrical portion and the bulging portion.

Further, according to the present invention, the bearing comprises a cylindrical spacer fitted on the inner peripheral side of each cylindrical portion of the rolling element, and an outer peripheral side fitted on the inner peripheral side of the spacer and an inner peripheral side supported. A cylindrical bush that slides on the outer peripheral surface of the shaft. Thus, the cylindrical portion of the rolling element can be reinforced by the spacer and the bush.

Further, according to the present invention, the reinforcing cylinders are fitted to the respective cylindrical portions of the rolling element body on the outer peripheral side of the respective cylindrical portions so that the reinforcing cylinders always contact the crawler belt. Because it is in contact, each cylindrical portion of the rolling element can be protected.

Further, according to the present invention, the bulging portion of the rolling element is provided with a reinforcing bending portion which is located at an intermediate portion in the longitudinal direction and extends over the entire circumference, whereby the bulging portion is provided. The strength of the projection can be improved.

On the other hand, in the method of manufacturing a roller body for a roller device according to the present invention, a step of cutting a pipe material as a material of the roller body into a predetermined length, and applying a high pressure to an inner peripheral surface of the pipe material. And pressurizing the pipe material from both ends in the length direction to form a bulging portion at the middle portion in the length direction of the pipe material.

According to the above manufacturing method, the pipe is pressurized from both ends in the axial direction while applying a high pressure to the inner peripheral surface of the pipe, so that the pipe is deformed plastically with the axial middle portion as the bulging portion. The cylindrical portions located on both sides in the length direction of the pipe member and the bulging portions located in the middle portion in the length direction can be integrally formed.

Further, in the method of manufacturing a roller body for a roller device according to the present invention, a step of cutting a pipe material as a material of the roller body into a predetermined length, and an annular concave portion corresponding to the bulging portion A step of clamping the pipe material by a mold having:
By applying a high pressure to the inner peripheral surface of the pipe material and pressing the pipe material from both ends in the longitudinal direction, the intermediate portion in the longitudinal direction of the pipe material is plastically deformed in the concave portion of the mold and expanded. And forming a protrusion.

According to the above manufacturing method, in a state where the pipe material cut to a certain length is clamped by the mold, the pipe material is applied to the inner peripheral surface of the pipe material while applying a high pressure to the pipe material at both ends in the longitudinal direction. By pressing from above, the middle part in the longitudinal direction of the pipe material is plastically deformed in the concave portion of the mold, so that a bulged portion having a certain shape corresponding to the concave portion can be formed.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to FIGS.

FIGS. 1 and 2 show a first embodiment of the present invention. Reference numeral 1 denotes a hydraulic shovel as a tracked vehicle equipped with a roller device according to the present embodiment. The hydraulic shovel 1 includes a lower traveling body 2 and an upper swing which is pivotably mounted on the lower traveling body 2. A work device 4 for performing excavation work or the like on the front part of the upper swing body 3
Is provided so as to be able to move up and down.

Reference numeral 5 denotes a track frame constituting the lower traveling unit 2, and the track frame 5 is a center frame 5A.
And disposed on both the left and right sides of the center frame 5A,
And a pair of side frames 5B (only one is shown) extending rearward. And the side frame 5B
Is provided with a sprocket 6 at one end, and an idler 7 at the other end.

Reference numeral 8 denotes a traveling crawler belt wound between the sprocket 6 and the idler 7. The crawler belt 8 drives the sprocket 6 to rotate, thereby driving the idler 7 and upper roller devices 9, which will be described later, The lower traveling device 2 is driven to rotate around on the lower roller device 10 to travel.

Reference numerals 9 and 9 denote two upper roller devices rotatably provided on the upper surface side of the side frame 5B. Each of the upper roller devices 9 supports the crawler belt 8 from below, and the crawler belt 8 is mounted on the side frame 5B. 5B is prevented from contacting.

Reference numerals 10, 10,... Denote a plurality of lower roller units rotatably arranged on the lower surface side of the side frame 5B. Each of the lower roller units 10 includes a sprocket 6 and an idler 7 together with the side frame 5B. The crawler belt 8 is guided along.

Here, the roller device according to the present embodiment is applied to each of the lower roller devices 10.
The lower roller device 10 will be described with reference to FIG.

In the figure, reference numerals 11 and 11 denote left and right support brackets which are located on the lower surface side of the side frame 5B and constitute a part of the track frame. 16 is rotatably supported. A bolt insertion hole 11 </ b> A into which a mounting bolt 13 described later is inserted is formed at the lower end side of each support bracket 11.

Reference numeral 12 denotes a support shaft fixed between the left and right support brackets 11. The support shaft 12 has a large-diameter portion 12A located at an intermediate portion in the axial direction, and a small-diameter portion 12A located at both ends in the axial direction.
B, 12B, and bearing fitting portions 12C, 12C which are located between the small-diameter portions 12B and the large-diameter portions 12A, and into which ball bearings 15 described later are fitted.
2D and 12D are screwed. And the support shaft 12
The fixing bolts 13, 13 inserted into the bolt insertion holes 11 </ b> A of the support brackets 11 are fixed to the respective support brackets 11 by screwing into the screw holes 12 </ b> D.

Reference numerals 14 and 14 denote support collars positioned between the support brackets 11 and inserted through the small-diameter portion 12B of the support shaft 12. The lower ends of the support collars 14 project toward the support brackets 11, respectively. Each of the support brackets 11 serves as a load receiving portion 14A for supporting a lower end portion thereof. Accordingly, the load of the excavator 1 is transmitted from each support bracket 11 to the support shaft 12 via each support collar 14.

Reference numerals 15 and 15 denote each bearing fitting portion 12 of the support shaft 12.
Each ball bearing 15 is positioned between the end of the large diameter portion 12A of the support shaft 12 and each retaining ring 17 described later.
The outer ring of each ball bearing 15 is a rolling element 16
Are press-fitted to the inner peripheral side of each cylindrical portion 16A.

Reference numeral 16 denotes a rolling element rotatably provided between the left and right support brackets 11 via respective ball bearings 15. The rolling element 16 comprises a pair of cylindrical members located at both ends in the longitudinal direction. It comprises parts 16A, 16A, and a bulging part 16B located between the cylindrical parts 16A and having a radially outwardly expanding diameter. Here, the rolling element 16 is made of a pipe material such as a carbon steel tube for machine structure (STKM material), a manganese steel (SMn material), and a carbon steel for machine structure (S45C, S40C, S35C). The rolling body 16 is formed as a single stepped cylindrical body having a substantially uniform thickness over its entire length by subjecting these pipe members to bulging.

The rolling element 16 is rotatably supported by the support shaft 12 by fitting the outer ring of each ball bearing 15 to the inner peripheral side of each cylindrical portion 16A.
Each ball bearing 15 is held in a retaining state by retaining rings 17, 17 fitted on the inner peripheral side of A.

Here, the outer periphery of each cylindrical portion 16A of the rolling element 16 abuts on the protruding portions 8A, 8A protruding from the inner peripheral surface of the crawler belt 8, and the bulging portion 16B engages with each protruding portion 8A. By doing so, the crawler belt 8 is prevented from separating from the rolling element 16.
An oil reservoir 18 for storing lubricating oil for lubricating the ball bearings 15 and the like is formed between the bulging portion 16B of the rolling element 16 and the support shaft 12, and the oil reservoir 18 is It is closed by a sealing plug 19.

Reference numerals 20 and 20 denote seal members located at both ends of the rolling element 16 and disposed between the left and right support collars 14, respectively. The stationary seal 20A is fitted on the outer peripheral side of the bearing fitting portion 12C, and the rotary seal 20B is press-fitted on the inner peripheral side of the cylindrical portion 16A of the rolling element 16. Then, the sealing member 20
The lubricating oil stored in the oil sump 18 is discharged from both ends of the rolling element 16 to the outside by the respective lips provided on the rotating side seal 20B elastically and constantly slidingly contacting the fixed side seal 20A. This prevents leakage and earth and sand from entering from both ends of the rolling element 16.

Reference numerals 21 and 21 denote retaining rings fitted to the respective small diameter portions 12B of the support shaft 12. Each of the retaining rings 21 positions the support collar 14 inserted through the small diameter portion 12B of the support shaft 12 in the axial direction. Is what you do.

The lower roller device 10 according to the present embodiment has the above-described configuration, and the rolling element 16 of the lower roller device 10 has the bulging portion 16 B attached to the crawler belt 8 when the lower traveling body 2 is traveling. The crawler belt 8 rotates on the support shaft 12 while being engaged between the protrusions 8A, and moves on the protrusions 8A of the crawler belt 8.

In this case, the excavator 1 is attached to the rolling element 16.
The rolling member 16 is formed as a single stepped cylindrical body. Therefore, as compared with a case where a plurality of individually formed members are joined by welding or the like to form one rolling body, for example, a rolling body used in a roller device of the related art, The rolling element 16 can eliminate a joint part where the strength is partially reduced.
Therefore, for example, even when the hydraulic excavator 1 is operated for a long period of time at a work site where the unevenness of the ground is severe, the roller body 16 can be prevented from being damaged, and the lower roller device 10 is stable for a long period of time. Can operate.

Further, by forming the bulging portion 16B at the intermediate portion in the longitudinal direction of the rolling element 16, the strength of the entire rolling element 16 can be secured, and the rolling element 16 is formed to be relatively thin. can do. As a result, each cylindrical portion 1 of the rolling element 16
A ball bearing 15 can be provided between the shaft 6A and the support shaft 12, and the rotational performance of the rolling member 16 is greatly improved as compared with a case where a bush or the like is provided between the rolling member and the support shaft, for example. be able to.

Further, by forming the entire rolling body 16 relatively thin, the weight of the rolling body 16 can be reduced, and the workability of assembling the lower roller device 10 can be improved. .

Further, by forming the entire rolling body 16 relatively thin, the volume of the oil reservoir 18 can be increased, so that a large amount of lubricating oil is stored in the oil reservoir 18. As a result, the lubricity of the ball bearing 15 and the like is improved, and the lower roller device 10 can be operated smoothly for a longer period of time.

Next, a method of manufacturing the rolling body 16 (bulging) according to the present embodiment will be described with reference to FIGS.

First, a pipe material 31 such as a carbon steel tube for machine structure (STKM material), a manganese steel (SMn material), and a carbon steel for machine structure (S45, S40C, S35C), etc., which are the materials of the rolling element, are shown in FIG. Cut to length as shown in 3.

As a mold for molding the rolling element 16, a pair of half molds 32, 32 for clamping the pipe material 31 in the radial direction and preparing the same, are prepared. Here, in each half mold 32, a semicircular small-diameter concave portion 32A having an inner diameter corresponding to the outer diameter of the pipe material 31 is formed in the length direction, and is located at an intermediate portion of the small-diameter concave portion 32A. Rolling body 1
Large-diameter concave portion 3 having a shape corresponding to bulging portion 16B of No. 6
2B is formed.

Next, as shown in FIG. 4, the pipe member 31 is clamped from the radial direction by each half mold 32 in a state where the middle portion in the length direction of the pipe member 31 coincides with the large-diameter concave portion 32B. Further, a pair of pressing dies 33, 33 having an oil passage 33 </ b> A formed in the center portion are connected to the small-diameter concave portions 32 of each half mold 32.
A is inserted from both the left and right sides into A, and is brought into contact with both ends of the pipe material 31.

In this state, high-pressure oil is introduced into the pipe material 31 through the oil passages 33A of the pressing dies 33, and the pressing dies 33 are pressurized in a direction approaching each other (in the direction of arrow A) to form a pipe. The material 31 is compressed in the axial direction. Thereby, as shown in FIG. 5, plastic deformation (plastic flow) occurs such that the middle portion in the length direction of the pipe member 31 expands in the large-diameter concave portion 32 </ b> B of each half mold 32.

As a result, as shown in FIG.
1 and a bulging portion 16B corresponding to the shape of the large-diameter concave portion 32B of each half mold 32, and the rolling element 16 having a substantially uniform thickness over the entire length is obtained. be able to.

Then, both ends of the bulging portion 16B of the rolling element 16 and the outer peripheral surface of the cylindrical portion 16A are subjected to induction hardening to harden the both end surfaces of the bulging portion 16B and the outer peripheral surface of the cylindrical portion 16A. Form a layer.

Thus, in the method of manufacturing the rolling element 16 according to the present embodiment, a single pipe member 31 is cut with a fixed length, and a high pressure is applied to the inner peripheral surface of the pipe member 31. By pressing the pipe member 31 from both ends, the rolling element 16 as a single stepped cylindrical body having the cylindrical portion 16A and the bulging portion 16B can be formed by cold working.

For this reason, in the present embodiment, the joint portion is formed in comparison with a case where a plurality of individually formed members are joined by welding or the like to form one rolling element as in the prior art. This eliminates the need for a machining step and a welding step to perform the heating, and also eliminates the need for a step of heating the material using a heating furnace or the like, as compared with a case where a rolling element is formed by hot forging. As a result, the number of manufacturing steps and manufacturing equipment can be reduced, and the manufacturing cost of the rolling element can be significantly reduced.

Next, FIG. 7 shows a second embodiment of the roller device according to the present invention. The feature of this embodiment is that a bending portion for reinforcement is formed on the bulging portion of the rolling element over the entire circumference. I did it.
In this embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

In the drawing, reference numeral 41 denotes a lower roller device according to the present embodiment. The lower roller device 41 includes a support bracket 11, a support shaft 12, a ball bearing 15, a seal member 20, and a rolling element 42 to be described later. And so on.

Reference numeral 42 denotes a rolling body applied to the present embodiment. The rolling body 42 has a pair of cylindrical portions 42A, 42A located at both ends in the longitudinal direction and a position between the cylindrical portions 42A. And a bulging portion 42B whose diameter is increased outward in the radial direction. Further, an intermediate portion in the axial direction of the bulging portion 42B is formed as a reinforcing bending portion which is depressed in the diameter reducing direction over the entire circumference. Annular recess 4
2C is formed.

Here, the rolling element 42 is formed on a pipe material cut into a fixed length by using a mold having a concave portion corresponding to the cylindrical portion 42A, the bulging portion 42B and the annular concave portion 42C. By performing the bulging process described above, a single stepped cylindrical body having a substantially uniform wall thickness over its entire length is formed.

The present embodiment has the above-described configuration. By forming the rolling element 42 as a single stepped cylindrical body, a plurality of individually formed members as in the prior art are welded or the like. As compared with the case where one rolling element is formed by joining with each other, it is possible to eliminate a joint part whose strength is partially reduced. In this respect, there is no particular difference in the present embodiment from the first embodiment.

However, the rolling element 42 according to the present embodiment has a configuration in which the bulging part 42B can be reinforced by providing the annular dent 42C over the entire circumference of the bulging part 42B. The strength of the entire roller 42 can be increased, and the lower roller device 41 can operate stably for a long period of time.

Next, FIG. 8 shows a third embodiment of the roller device according to the present invention. The feature of this embodiment is that a bearing fitted between the support shaft and the rolling element is provided. A cylindrical spacer fitted on the inner peripheral side of each cylindrical portion, and a cylindrical bush fitted on the outer peripheral side to the inner peripheral side of the spacer and the inner peripheral side slidingly contacting the outer peripheral surface of the support shaft. . In this embodiment, the same components as those in the above embodiments are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, reference numeral 51 denotes a lower roller device according to the present embodiment. The lower roller device 51 includes a support bracket 11, a rolling element 16, a support shaft 52, a spacer 54, and a cylindrical bush 55 described later. , Floating seal 5
It consists of 6 mag.

Reference numeral 52 denotes a support shaft fixed between the left and right support brackets 11 via mounting bolts 13.
A large-diameter portion 52A located at an axially intermediate portion, and bearing fitting portions 52B, 5 located at both axial ends of the large-diameter portion 52A.
2B, and mounting bolts 13
Are screwed into the screw holes 52C.

53, 53 are left and right support brackets 11
And a lower end of each of the support collars 53 protrudes toward each of the support brackets 11, and is inserted into the bearing fitting portion 52 </ b> B of the support shaft 52.
Is a load receiving portion 53A that supports the lower end of the load receiving portion 53A. Further, a seal accommodating recess 53B for accommodating the floating seal 56 is formed on the inner end surface of each support collar 53.

Reference numerals 54, 54 designate cylindrical portions 16A of the rolling element 16
A cylindrical spacer press-fitted on the inner peripheral side is shown, and each spacer 54 constitutes a support for supporting a bush 55 described later. Here, tapered seal receiving recesses 54A whose diameter gradually decreases inward from the outside in the radial direction to the inside in the axial direction are formed on both end surfaces in the axial direction of each spacer 54. An oil passage 54B penetrating in the axial direction is formed in the inner peripheral side of each spacer 54. The oil passage 54B is sealed with the oil reservoir 18 formed in the bulging portion 16B of the rolling element 16. The lubricating oil stored in the oil reservoir 18 is supplied to the sliding surface between the support shaft 52 and each cylindrical bush 55, the sliding surface of the floating seal 56, and the like by communicating with the housing recess 54A.

Reference numerals 55 and 55 denote cylindrical bushes serving as sliding bearings. Each of the cylindrical bushings 55 is formed in a cylindrical shape from, for example, a lead-bronze-based metal material, and its outer end face has a flange-shaped enlarged flange. A portion 55A is formed. Each cylindrical bush 55 has its outer peripheral side press-fitted into the inner peripheral side of the spacer 54, and its inner peripheral side forms a sliding surface on which the spindle 52 slides. Each cylindrical bush 55 is held in a positioned state between the large-diameter portion 52A of the support shaft 52 and the inner end surface of the support collar 53.

Reference numerals 56 and 56 denote a seal accommodating recess 53B of each support collar 53 and a seal accommodating recess 54A of each spacer 54.
The floating seals 56 are provided between a pair of seal rings 56A, 56A slidingly contacting each other and a pair of O-rings 56B, 56B.
B. Then, the lubricating oil stored in the oil reservoir 18 is transferred to the rolling element 1 by a pair of seal rings 56 </ b> A constantly slidingly contacting each floating seal 56.
6 is prevented from leaking to the outside from both ends, and earth and sand are prevented from entering from both ends of the rolling element 16.

This embodiment has the configuration as described above, and the present embodiment can provide the same effects as those of the above embodiments. However, particularly in the present embodiment, the rolling element 1
6 each spacer 54 fitted on the inner peripheral side of each cylindrical portion 16A
And each cylindrical bush 55 fitted on the inner peripheral side of each spacer 54, each cylindrical portion 16A of the rolling element 16 can be reinforced from the inner peripheral side. As a result, the rolling element 16
Can be extended, and the lower roller device 51 can operate stably for a longer period of time.

Next, FIG. 9 shows a fourth embodiment of the roller device according to the present invention. The feature of this embodiment is that a reinforcing cylinder is fitted on the outer peripheral side of each cylindrical portion of the rolling element. It is in.
In this embodiment, the same components as those in the above embodiments are denoted by the same reference numerals, and description thereof will be omitted.

In the drawing, reference numeral 61 denotes a lower roller device according to the present embodiment. The lower roller device 61 includes a support bracket 11, a support shaft 62, a rolling element 64, and a cylindrical bush 6.
5, a floating seal 66, a reinforcing cylinder 67, and the like.

Reference numeral 62 denotes a support shaft fixed between the left and right support brackets 11 via mounting bolts 13.
Is a large-diameter portion 62A located at an axially intermediate portion, and bearing fitting portions 62B, 6 located at both axial ends of the large-diameter portion 62A.
2B, and mounting bolts 13
Are screwed into the screw holes 62C and 52C.

63, 63 are left and right support brackets 1
1, the lower end of each of the support collars 63 protrudes toward the support bracket 11, and the support bracket 1
1 is a load receiving portion 63A that supports the lower end portion. Further, a seal accommodating recess 63B for accommodating the floating seal 66 is formed on the inner end surface of each support collar 63.

Reference numeral 64 denotes a rolling element rotatably provided between the left and right support brackets 11 via a cylindrical bush 65 described later. The rolling element 64 is a pair of rolling elements located at both ends in the longitudinal direction. , And a bulging portion 64B located between the cylindrical portions 64A and having a radially outwardly enlarged diameter. Here, the rolling element 64 is formed by performing a bulging process on a pipe material cut to a predetermined length by using a mold having a concave portion corresponding to the cylindrical portion 64A and the bulging portion 64B. It is formed as a single stepped tubular body having a substantially uniform wall thickness over its entire length. Also,
Both end surfaces in the axial direction of the rolling element body 64 are tapered so as to gradually decrease in diameter obliquely inward from the outside in the radial direction to the inside in order to hold a floating seal 66 described later between the seal accommodating recess 63B of each support collar 63. The surface is 64C.

Reference numerals 65 and 65 denote cylindrical bushes as bearings. Each of the cylindrical bushes 65 is formed in a cylindrical shape from, for example, a material in which a solid lubricant is embedded in high-strength brass or a sintered oil-impregnated alloy. The outer peripheral side of each cylindrical bush 65 is press-fitted into the inner peripheral side of the rolling element 64, and the inner peripheral side is the support shaft 62.
To form a sliding surface. Further, each cylindrical bush 65 is provided with an end portion of the large diameter portion 62A of the support shaft 62 and each retaining ring 1.
7 and is positioned with respect to the support shaft 62.

Numerals 66 and 66 denote floating seals provided between the seal accommodating recess 63B of each support collar 63 and the tapered surface 64C of the wheel body 64. Each of the floating seals 66 is a pair of seal rings slidingly contacting each other. 66
A, 66A and a pair of O-rings 66B, 66B.

Reference numerals 67, 67 designate cylindrical portions 64A of the rolling element 64, respectively.
The reinforcing cylinders 67 are press-fitted to the outer peripheral side, and each of the reinforcing cylinders 67 replaces each of the cylindrical portions 64A by covering each of the cylindrical portions 64A of the rolling element 64 over the entire circumference. It rolls on the protrusion 8A of the crawler belt 8.

This embodiment has the above-described configuration, and the same effects as those of the above embodiments can be obtained in this embodiment. However, particularly in this embodiment, the rolling element 6
Since the reinforcing cylinder 67 is fitted to the outer peripheral side of each cylindrical portion 64A of 4, the rolling body 64 is effectively prevented from directly abutting with the crawler belt 8 to cause cracking or breakage. be able to. As a result, the life of the rolling element 64 can be extended,
The lower roller device 61 can operate stably for a longer period of time.

In each of the above embodiments, the case where the roller device according to the present invention is applied to the lower roller device has been described as an example. However, the present invention is not limited to this. May be.

In each of the above embodiments, a hydraulic shovel is taken as an example of a tracked vehicle. However, the present invention is not limited to this, and can be widely applied to a roller device of a tracked vehicle such as a hydraulic crane. Can be.

[0077]

As described in detail above, claims 1 and 2 have been described.
According to the invention of the present invention, a rolling element used for a roller device of a tracked vehicle to guide a crawler belt for traveling, a single unit in which the middle part in the length direction becomes a swelling part due to plastic deformation and has a large diameter. Since it is formed of a stepped cylindrical body, for example, compared with a case where a plurality of individually formed members are joined by welding or the like to form one rolling element, a machining process for forming a joint portion, The welding step can be omitted, and the manufacturing cost of the rolling element can be reduced.

Further, compared with a rolling element made up of a plurality of members joined by welding or the like, it is possible to eliminate a joint part whose strength is partially reduced, so that the strength of the rolling element can be improved. The strength of the whole rolling element body can be increased by the bulging portion, and the roller device can be operated stably for a long period of time.

According to the third and fourth aspects of the present invention, the rolling elements for guiding the crawler belt for traveling are provided on a pair of cylinders located on both sides in the longitudinal direction and bearings are fitted on the inner peripheral side. And a bulging portion located between the cylindrical portions and bulging radially outward and integrally formed with the cylindrical portions.
In addition to obtaining substantially the same effects as those of the invention, it is possible to form the rolling element from a thin-walled pipe material or the like by increasing the strength of the entire rolling element by a bulging portion formed by cold working. This makes it possible to reduce the overall size and weight. Also, since the thickness of the rolling element can be reduced,
The bearing provided in each cylindrical portion can be constituted by a rolling bearing such as a ball bearing, and the rolling element can be more smoothly rotated with respect to the support shaft.

Further, according to the fifth aspect of the invention, a cylindrical spacer fitted to the inner peripheral side of each cylindrical portion of the rolling element body, and an outer peripheral side fitted to the inner peripheral side of the spacer and an inner peripheral side supported. Since the bearing is constituted by the cylindrical bush slidingly contacting the outer peripheral surface of the shaft, each cylindrical portion of the rolling element can be reinforced from the inner peripheral side. As a result, the life of the rolling element can be extended, and the stable operation of the roller device can be compensated for a longer period.

According to the sixth aspect of the present invention, since the reinforcing cylinder is fitted to each cylindrical portion of the rolling element, the rolling element directly abuts the crawler belt to prevent cracking or breakage. This can be effectively prevented, and the life of the rolling element can be extended.

According to the seventh aspect of the present invention, the strength of the bulging portion can be improved by providing a reinforcing bent portion at the bulging portion of the rolling body, and the entire rolling body can be improved. Strength can be further increased.

Further, according to the invention of claim 8, after the pipe material as the material of the rolling element is cut to a predetermined length, the pipe material is cut while applying a high pressure to the inner peripheral surface of the pipe material. By applying pressure from both ends in the axial direction and plastically deforming the axial middle part of the pipe material, the cylindrical part located on both longitudinal sides of the pipe material and the bulging part located in the longitudinal middle part are cooled. It can be formed integrally by processing.

Therefore, a rolling element for a roller device can be formed from a pipe material by relatively simple equipment, and a plurality of individually formed members as in the prior art are joined by welding or the like to form one rolling element. Since a machining process and a welding process for forming a joint can be eliminated as compared with the case of forming, and a facility such as a heating furnace can be eliminated as compared with hot forging, a rolling element Manufacturing cost can be reduced.

Further, according to the ninth aspect of the present invention, the pipe material is clamped by the mold having the concave portion corresponding to the bulging portion, so that the longitudinal middle portion of the pipe material is recessed by the mold. It can be plastically deformed in the part. Therefore,
A bulged portion having a certain shape corresponding to the concave portion of the mold can be reliably formed.

[Brief description of the drawings]

FIG. 1 is an external view showing a hydraulic shovel to which a roller device according to a first embodiment of the present invention is applied.

FIG. 2 is a longitudinal sectional view of the lower roller device as viewed from the direction of arrows II-II in FIG. 1;

FIG. 3 is a vertical cross-sectional view showing a pipe material, a mold, and the like, which are used as materials for manufacturing the rolling body.

FIG. 4 is a longitudinal sectional view showing a state where a pipe material is clamped by a mold.

FIG. 5 is a longitudinal sectional view showing a state in which a pipe material is plastically deformed.

FIG. 6 is a longitudinal sectional view showing a state where a rolling element is formed.

FIG. 7 is a longitudinal sectional view showing a roller device according to a second embodiment.

FIG. 8 is a longitudinal sectional view showing a roller device according to a third embodiment.

FIG. 9 is a longitudinal sectional view showing a roller device according to a fourth embodiment.

[Explanation of symbols]

5 Track frame 10, 41, 51, 61 Lower roller device (roller device) 11 Support bracket (bracket) 12, 52, 62 Support shaft 15 Ball bearing (bearing) 16, 42, 64 Roller body 16A, 42A, 64A Cylindrical portion 16B, 42B, 64B Swelling portion 31 Pipe material 32 Half mold (die) 32B Large diameter concave portion (concave portion) 42C Annular concave portion (bent portion) 55, 65 Cylindrical bush (bearing) 54 Spacer 67 Reinforcing cylinder

Claims (9)

[Claims] 1. A roller device for a tracked vehicle which is provided on a track frame of a tracked vehicle and guides a crawler belt for traveling by a rolling member, wherein the rolling member has an intermediate portion in a longitudinal direction. A roller device for a track-mounted vehicle, wherein the roller device is formed of a single stepped cylindrical body whose diameter has been increased by forming a bulging portion by plastic deformation. 2. The roller device for a tracked vehicle according to claim 1, wherein the rolling element is formed to have a substantially uniform thickness over the entire length. 3. A track frame for a tracked vehicle, a support shaft fixedly provided to the track frame, and a crawler track for traveling provided rotatably on a peripheral side of the support shaft via a pair of bearings. A roller device for a tracked vehicle comprising a rolling element for guiding the rolling element, the rolling element is located on both sides in the length direction, and each of the bearings is fitted on an inner peripheral side; A roller device for a track-mounted vehicle, comprising a swelling portion which is located between the respective cylindrical portions and swells radially outward and is integrally formed with the respective cylindrical portions. 4. The roller device for a tracked vehicle according to claim 3, wherein the rolling body has the cylindrical portions and the bulging portions formed to have substantially uniform thicknesses. 5. The bearing has a cylindrical spacer fitted on the inner peripheral side of each cylindrical portion of the rolling element, an outer peripheral side fitted on the inner peripheral side of the spacer, and an inner peripheral side disposed on an outer peripheral side of the support shaft. 4. The roller device for a tracked vehicle according to claim 3, comprising a cylindrical bush that slides on a surface. 6. The tracked vehicle according to claim 3, wherein a reinforcing cylinder is fitted to each cylindrical portion of the rolling element body on an outer peripheral side of each cylindrical portion. Roller device. 7. The swelling portion of the rolling element is provided with a reinforcing bending portion located at a middle portion in the longitudinal direction and extending over the entire circumference. 7. The roller device for a tracked vehicle according to 4, 5, or 6. 8. A method for manufacturing a roller body for a roller device provided on a track frame of a tracked vehicle and used for guiding a crawler belt for traveling, wherein a pipe material as a material of the roller body is provided. A step of cutting the pipe material into a certain length, and by applying a high pressure to the inner peripheral surface of the pipe material and pressing the pipe material from both ends in the longitudinal direction, the pipe material swells to a longitudinally intermediate portion of the pipe material. Forming a rolling part for a roller device. 9. A method of manufacturing a roller body for a roller device provided on a track frame of a tracked vehicle and used to guide a crawler belt for traveling, wherein a pipe material as a material of the roller body is provided. A step of cutting to a certain length, a step of clamping the pipe material by a mold having an annular concave portion corresponding to the bulging portion, and a process of applying high pressure to an inner peripheral surface of the pipe material. Forming a swelled portion by pressurizing the material from both ends in the longitudinal direction to plastically deform the middle portion in the longitudinal direction of the pipe material in the concave portion of the mold to form a bulged portion. Manufacturing method.