JPH09279627A - Bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily align a pin insertion hole of a bracket with a pin insertion hole of a boss when the bracket is coupled to the boss through a connection pin. SOLUTION: Each thrust plate 21 is formed from sintered oil containing alloy into an annular shape, and the plate 21 is detachably mounted to the outer end surface of each boss 12 in such is manner that a guide hole 22 is coaxially positioned with respect to a pin insertion hole 19A of a bush 19 provided in an arm boss 11. Each holding bolt 29 is screwed into a threaded hole 16D of each bracket 16 to movably hold each movable plate 25 with respect to the bracket 16 through the bolt 29. Further, the guide hole 22 of the plate 21 and a fitting protrusion 25B of the plate 25 each have a tapered portion. Thus, the protrusion 25B can be advanced into the guide hole 22 through the bolt 29 so as to be firmly fitted therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device which is preferably used for a pin connecting portion of a working device mounted on a construction machine such as a hydraulic excavator.

[0002]

2. Description of the Related Art Generally, a boss having a pin insertion hole, a pair of brackets formed at both ends of the boss and having pin insertion holes corresponding to the boss, and a pin insertion hole between each bracket and the boss. A bearing device including a connecting pin that is inserted into the bracket and rotatably connects a boss between the brackets is disclosed in, for example, Japanese Utility Model Publication No. 3-48118 and Japanese Utility Model Publication No. 2-1127.
It is known from Japanese Patent Publication No. 43, etc.

In this type of conventional bearing device, a bush or the like is fitted into a pin insertion hole of a boss provided at the distal end of an arm or the like, and a connecting pin is slidably inserted into the bush. At the same time, both ends of the connection pin are integrally attached to a bracket provided on one side of the bucket or the like, so that the bucket is rotatably connected to the arm via the connection pin.

[0004] The bucket disposed on the distal end side of the arm is rotated about the connecting pin with respect to the arm by operating a bucket cylinder via a link mechanism or the like to perform excavation work or the like. Has become.

[0005]

By the way, in the above-described bearing device according to the prior art, when the bucket is to be mounted on the arm via the connecting pin when replacing the bucket, the connecting pin is connected to the boss and each bracket. In order to insert the pin insertion holes, the respective pin insertion holes must be aligned with each other in advance.

However, in the prior art, it is the actual situation that the centering of each of the pin insertion holes as described above must rely on the operator's visual confirmation work or the like. As a result, it takes a lot of time to align the pin insertion holes,
There is a problem that work efficiency at the time of bucket replacement and the like is greatly reduced, and that a worker is greatly fatigued and burdened.

At the time of the above-mentioned centering operation, for example, with one worker placing the bucket on the ground or the like, the other worker rotates the arm while viewing the pin insertion hole on the bracket side. Thus, the center of each pin insertion hole is aligned so that the arm is positioned with respect to the bucket. As a result, when assembling the bucket to the arm, it is necessary for the operator to continue positioning the arm and the bucket so as to keep the respective pin insertion holes aligned until the connection pins are completely inserted into the respective pin insertion holes. In addition, there is a problem that the labor of the worker becomes enormous, and the number of persons required for such work increases.

The present invention has been made in view of the above-mentioned problems in the prior art, and when each bracket is assembled to a boss via a connecting pin, the pin insertion holes of the bracket and the boss are easily aligned with each other. It is an object of the present invention to provide a bearing device which can be adjusted, for example, can greatly reduce the time required for replacement work of a bucket or the like, and can surely improve the overall work efficiency.

[0009]

In order to solve the above-mentioned problems, the present invention is provided with a boss having a pin insertion hole, and a pin insertion hole which is arranged at both ends of the boss and corresponds to the boss. The present invention is applied to a bearing device including a pair of brackets and a connecting pin that is fitted into pin insertion holes of each bracket and a boss and that rotatably connects the boss between the brackets.

The feature of the structure adopted by the invention of claim 1 is that a pair of guide members are formed on both ends of the boss on the inner peripheral side thereof with guide holes concentric with the pin insertion hole. A movable member having a fitting convex portion fitted in the guide hole of each guide member, and having a pin hole through which the connecting pin is inserted on the inner peripheral side, The positioning means is provided to hold the movable member in the axial direction of the connecting pin so that the fitting convex portion of the movable member enters and retracts into the guide hole of the guide member.

According to this structure, when the pin insertion holes of the boss and the brackets are aligned with each other, first, the fitting convex portions of the movable member are retracted from the guide holes of the guide member. Is moved to the bracket side (outward in the axial direction of the connecting pin) via the positioning means.
Next, the brackets are arranged so as to face the boss so that both ends of the boss are sandwiched between the brackets, and the fitting convex portions of the movable members face the opposite ends of the boss. Finally, the movable member is moved to the inner side in the axial direction of the connecting pin via the positioning means so that the fitting convex portion enters the guide hole of the guide member, and the fitting convex portion is guided to the guide member. Securely fit (insert) in the hole.

As a result, the boss can be positioned between the brackets by supporting the bosses between the fitting projections of the movable members, and the pin insertion hole of the boss that is concentric with the guide hole of the guide member. The axis line can be aligned with the pin insertion hole of the bracket (pin hole of the movable member) through the fitting protrusion and the guide hole, and these pin insertion holes can be automatically aligned. . Then, the connecting pin can be easily inserted into each of the pin insertion holes while the boss is positioned between the brackets by the fitting convex portion and the guide hole.

In the invention according to claim 2, a taper portion is formed in at least one of the guide hole of the guide member and the fitting convex portion of the movable member, and the fitting portion is formed through the taper portion. By fitting the fitting convex portion into the guide hole, the pin insertion holes of the bracket and the boss are aligned with each other.

With this configuration, when the fitting convex portion of the movable member is inserted into the guide hole of the guide member for fitting, even if the axis line between the fitting convex portion and the guide hole is deviated, the fitting convex portion is moved into the guide hole. And the fitting convex part can be guided through the tapered part,
The axes of both can be easily matched.

Further, in the invention according to claim 3, the guide member is formed of a material having a self-lubricating property at least on the contact surface side in contact with the movable member.
As a result, when the boss is rotated with respect to each bracket, the sliding resistance acting between the fitting projection of the movable member and the guide hole of the guide member is reliably reduced by the self-lubricating material. be able to.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Here, FIGS. 1 to 7 show an example in which the bearing device according to the embodiment of the present invention is applied to a working device of a hydraulic excavator.

In FIG. 1, reference numeral 1 denotes a hydraulic shovel to which a bearing device according to the present invention is applied. A working device 3 for performing excavation work or the like is disposed on an upper revolving body 2 of the hydraulic shovel 1 so as to be able to move up and down. Have been. The working device 3 includes a boom 4 that is pin-connected to the upper swing body 2, an arm 5 that is pin-connected to the tip side of the boom 4, and a bucket 6 that is pin-connected to the tip side of the arm 5. The boom 4, the arm 5, and the bucket 6 perform a rotating operation by a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a link 10, and the like, which are connected to each other via a pin connecting portion.

Here, each of these pin joints is provided with a bearing device according to the present embodiment.
The bucket 6 and the bucket 6 are relatively rotatably connected via a bearing device shown in FIGS.

2 and 3, reference numeral 11 denotes an arm 5
Arm boss as a boss provided on the tip side of
The arm boss 11 is formed integrally from a boss portion 12 described later and a boss pipe 14 that connects the boss portions 12 to each other in a substantially cylindrical shape.

Reference numerals 12 and 12 denote a pair of boss portions provided on both the left and right sides of the boss pipe 14, and each of the boss portions 12 has a bushing fitting which is a stepped hole in the axial direction as shown in FIGS. Dowel holes 13, 13 are formed. Further, the outer end surface of the boss portion 12 is spaced apart in the circumferential direction of each bush fitting hole 13 and has four screw holes 12A for each countersunk screw 24, which will be described later.
12A, ... (Only two are shown) are formed. The boss 12 has a bush fitting hole 13 into which a connecting pin 31 described later is fitted.

Reference numeral 14 is a boss pipe for connecting the boss portions 12 to each other. The boss pipe 14 has a connecting pin 3 on the inner peripheral side thereof.
An annular lubricating oil storage chamber 15 is formed between the first lubricating oil storage chamber 15 and the first lubricating oil storage chamber 1. Further, the boss pipe 14 is formed with a screw hole 14A in which a later-described grease nipple 33 is screwed in the radial direction.

Reference numerals 16 and 16 denote a pair of brackets protruding from the bucket 6 to the outside. Each bracket 16 has a bracket body 16A extending in the radial direction of the boss portion 12, as shown in FIGS. The bracket main body 16A is composed of reinforcing plates 16B and 16C fixed to the inner and outer surfaces thereof by means such as welding. The bracket main body 16A and the reinforcing plates 16B and 16C of each bracket 16 have a large-diameter pin insertion hole 17 penetrating in the thickness direction, and the bracket main body 16A separated from the pin insertion hole 17 in the circumferential direction. Small-diameter screw holes 16D (only one is shown) that penetrate the reinforcing plates 16B and 16C in the thickness direction are formed.

Of the brackets 16, the bracket 16 located on the right side in FIG. 2 has a screw extending through the bracket body 16A and the reinforcing plate 16C on the outer peripheral side of the pin insertion hole 17 in the thickness direction. A hole 16E is formed, and a fixing bolt 32 described later is screwed into the screw hole 16E.
Then, each bracket 16 is rotatably connected to both ends of the arm boss 11 by the connecting pin 31 inserted into each pin insertion hole 17. It should be noted that the reinforcing plate 16B of each bracket 16 is provided with each tapered surface portion 18 on the outer peripheral side thereof.

Reference numerals 19 and 19 denote a pair of bushes fitted in the bush fitting holes 13 of each boss 12, and each of the bushes 19 is, for example, a carbon steel pipe for machine structure (STKM material).
And the like, and the inner peripheral side thereof is the connecting pin 31.
Is a pin insertion hole 19A into which is inserted slidably.
Reference numerals 20 and 20 denote seal rings 20 mounted on the opening end sides of the bush fitting holes 13. The seal rings 20 prevent dust and the like from entering between the sliding surfaces of the bush 19 and the connecting pin 31. And prevents the lubricating oil such as grease from leaking from the lubricating oil storage chamber 15.

Reference numerals 21 and 21 denote thrust plates serving as guide members detachably provided on the end faces of both ends of each boss 12, and the thrust plate 21 is shown in FIGS.
As shown in FIG. 2, the guide hole 22 is formed in an annular shape from a hard resin material having a self-lubricating property or a metal material such as a sintered oil-impregnated alloy. And the guide hole 2
2 is formed as a taper hole having a taper portion, and is gradually reduced in diameter in the axial direction toward the outer end surface of the boss portion 12. Further, the thrust plate 21 has a total of four bolt insertion holes 21A, 21A, ... (Only two are shown) spaced apart from each other in the circumferential direction of the guide hole 22 at positions corresponding to the screw holes 12A of each boss portion 12. Has been formed.

Further, on the outer peripheral side of the thrust plate 21, there is formed a taper surface portion 23 whose diameter gradually increases toward the outer end surface side of the boss portion 12, and the taper surface portion 23 forms a taper surface portion 27 of a movable plate 25 which will be described later. V-shaped grooves are formed between them. The thrust plate 21 is integrally attached to the outer end surface of the boss portion 12 via each countersunk screw 24 so as to position the guide hole 22 concentrically with the pin insertion hole 19A of the bush 19. As a result, the thrust plate 21 receives the thrust load acting between the arm boss 11 and each bracket 16 between itself and the movable plate 25.

Reference numerals 25 and 25 denote movable plates as a pair of movable members provided on each bracket 16 so as to be movable with respect to each thrust plate 21, and the movable plates 25 are shown in FIGS. 2 to 7. As described above, the movable plate portion 25A having a large diameter is formed into a stepped disc shape from a metal material having high rigidity, and the axial direction inner end surface (hereinafter referred to as inner end surface) of the movable plate portion 25A from the axial direction. It is composed of a tapered fitting convex portion 25B formed so as to project.
In addition, each bracket 1 is provided on the inner peripheral side of each movable plate 25.
A pin hole 25C corresponding to the pin insertion hole 17 of No. 6 is formed, and a connecting pin 31 is inserted into the pin hole 25C.

Here, the fitting convex portion 2 of each movable plate 25
5B is formed as a taper portion that gradually reduces in diameter from the end surface of the movable plate portion 25A toward the tip end side with an inclination angle corresponding to the guide hole 22 of the thrust plate 21. The axially outer end surface of the movable plate portion 25A (hereinafter referred to as the outer end surface) is spaced apart in the circumferential direction of the pin hole 25C,
Each bottomed bolt fitting hole 26 (only one is shown) is formed at a position corresponding to the screw hole 14A of each bracket 16.

Further, on the outer peripheral side of the movable plate portion 25A, a taper surface portion 27 is formed at an axially inner position and a taper surface portion 28 is formed at an axially outer position. Each V-shaped groove is formed between the tapered surface portion 23 of each thrust plate 21 and the tapered surface portion 18 of the bracket 16. In addition, the movable plate 2
As shown in FIG. 7, the total plate thickness T including the movable plate 25A and the fitting projection 25 is calculated from the distance L between the thrust plate 21 provided on the arm boss 11 and the bracket 16 as shown in FIG. Is also formed to be slightly smaller.

The movable plates 25 are movably held by the brackets 16 via holding bolts 29, etc., which will be described later, and are integrated with the brackets 16 to form the arm boss 1.
It is adapted to be rotated relative to 1.

29, 29, ... Respective spring washers 3
Retaining bolts (only two are shown) as positioning means screwed into the screw holes 16D of the brackets 16 through 0, and each retaining bolt 29 has a reinforcing plate on the tip side as shown in FIGS. 3 and 7. It projects from 16B toward the movable plate 25 side and is inserted in the bolt fitting hole 26 in a loosely fitted state with a slight gap.

Then, each holding bolt 29 has a pin insertion hole 17 in each bracket 16 and a pin hole 2 in the movable plate 25.
5C and 5C with their axes aligned with each other, each movable plate 25 is movably held from the reinforcing plate 16B side of each bracket 16 to each thrust plate 21 side, and with respect to the guide hole 22 of this thrust plate 21. Movable plate 25
The fitting convex portion 25B is made to enter or retract.

Here, as shown in FIG. 6, each bracket 16
When the arm bosses 11 are arranged opposite to each other, the holding bolts 29 screwed into the screw holes 16D of the bracket 16 are rotated in a direction of loosening the heads 29A of the holding bolts 29.
Is projected from the reinforcing plate 16C of the bracket 16 by a certain size. Then, in this case, the movable plate 25 is brought into contact with the reinforcing plate 16B of the bracket 16, and the movable plate 25 is fixed to the bracket 16 while maintaining a minute gap between each movable plate 25 and each thrust plate 21. Are supported via the holding bolts 29.

Next, the arm boss 1 is provided between the brackets 16.
5, the holding bolts 29 are screwed into the screw holes 16D almost completely, and the movable plate 25 is attached to the bottom side of the bolt fitting hole 26 at the tip side of each holding bolt 29. The fitting convex portion 25B of the movable plate 25 is strongly fitted into the guide hole 22 of the thrust plate 21 by being pushed through. After inserting the connecting pin 31 into each bracket 16 and the arm boss 11, the holding bolt 29 is slightly loosened as shown in FIG. 3 to reduce the protrusion size on the tip end side with respect to each reinforcing plate 16B, and each movable plate. The outer end surface of the plate portion 25A and each reinforcing plate 1
6B and the size of the gap between the thrust plate 21 and the movable plate portion 25A are appropriately adjusted.

Reference numeral 31 denotes a connecting pin that rotatably connects each bracket 16 of the bucket 6 to the arm boss 11 of the arm 5. The connecting pin 31 has its both ends inserted into the pin insertion holes 17 of each bracket 16. Both sides of the intermediate portion are slidably fitted in the pin insertion holes 19A of each bush 19. The connecting pin 31 has a large-diameter head 31A provided on one axial side thereof fixed to one bracket 16 via each fixing bolt 32.
It is held in a state in which it does not come out and is locked against rotation.

Reference numeral 33 denotes a grease nipple screwed into the screw hole 14A of the boss pipe 14, and the grease nipple 33 is for supplying lubricating oil into the lubricating oil storage chamber 15 from the outside. The lubricating oil supplied into the lubricating oil storage chamber 15 keeps the sliding surface between the connecting pin 31 and each bush 19 in a constantly lubricated state, and a part of this lubricating oil flows between the sliding surfaces. Is exuded to the outside through each seal ring 20, and is also supplied between each thrust plate 21 and the movable plate 25.

Reference numerals 34 and 34 denote O-rings disposed in the V-shaped groove between the tapered surface portion 23 of each thrust plate 21 and the tapered surface portion 27 of each movable plate 25. Reference numerals 35 and 35 denote tapered surface portions of the bracket 16. 18 and movable plates 25
2 shows another O-ring arranged in the V-shaped groove between the taper surface portion 28 and the taper surface portion 28. And each of these O-rings 3
Numerals 4 and 35 prevent dust and the like from entering from the outside into the gaps between the thrust plates 21 and the movable plates 25, and between the movable plates 25 and the reinforcing plates 16B of the brackets 16. At the same time, the lubricating oil or the like supplied into the lubricating oil storage chamber 15 is prevented from leaking to the outside, and the arm boss 11 and each bracket 16 via the connecting pin 31 are prevented.
It is intended to compensate for smooth rotation with the.

The bearing device according to the present embodiment has the above-described structure, and the bucket 6 pin-connected to the tip side of the arm 5 via the bearing device is attached to each bush 19 attached to the arm boss 11. As the connecting pin 31 rotates, the distal end side of the arm 5 rotates.

In the bearing device according to the present embodiment as described above, when the bucket 6 is assembled to the arm 5 via the connecting pin 31 when the bucket 6 is replaced, the connecting pin 31 is attached to each bracket. 16 and arm boss 11
Since they are inserted into the pin insertion holes 17 and 19A, it is necessary to align the pin insertion holes 17 and 19A with each other in advance.

Therefore, the arm boss 11 and each bracket 1
A method of aligning the pin insertion holes 17 and 19A with the pin 6 will be described.

First, as shown in FIG. 6, each holding bolt 29
By rotating the heads 29A so that the heads 29A project from the reinforcing plates 16C of the brackets 16 by a certain size, the movable plates 25 are brought into contact with the surfaces of the auxiliary plates 16B, respectively. The movable plate 25 is supported by each bracket 16 via each holding bolt 29.

Next, as shown in FIGS. 6 and 7, the brackets 16 are arranged so as to face each other so as to sandwich both ends of the arm boss 11. Here, the plate thickness dimension T of the movable plate 25
Is set to be slightly smaller than the separation dimension L between the reinforcing plate 16B and the thrust plate 21, so that a minute gap can be secured between each thrust plate 21 and each movable plate 25. Thereby, the arm bosses 11 can be smoothly arranged between the brackets 16.

Finally, as shown in FIG. 5, each holding bolt 29 is almost completely screwed into the screw hole 16D of each bracket 16, and the movable plate 25 is bolt-fitted at the tip side of each holding bolt 29. By pushing through the bottom side of the hole 26, the fitting convex portions 25B are inserted into the guide holes 22.

Here, even when the axes of the fitting projections 25B and the guide holes 22 are deviated when the fitting projections 25B enter, the fitting projections 25B and the guide holes 22 are tapered. Since it is formed as a part, each fitting convex portion 25
B can be easily guided into each guide hole 22, and thus each fitting convex portion 25B can be securely and strongly fitted into each guide hole 22.

As a result, the arm boss 11 can be positioned between the brackets 16 by supporting the arm boss 11 between the fitting convex portions 25B, and the guide hole 2 can be provided.
Arm boss 11 (bush 19) that is concentric with 2
Pin insertion hole 19A of each bracket 16 pin insertion hole 1
7, the axis (axis AA) can be surely matched with each other through the fitting convex portion 25B and the guide hole 22, and the pin insertion holes 17 and 19A can be easily aligned.

Then, the arm boss 11 is attached to the fitting convex portion 2
5B and the guide hole 22, the connecting pin 31 is positioned between the brackets 16 and the connecting pin 31 is inserted into each of the pin insertion holes 1
It can be easily inserted into 7, 19A.

Therefore, in this embodiment, the time required for the centering of the pin insertion holes 17 and 19A when the bucket 6 is replaced can be greatly shortened, and the fatigue and burden on the operator can be greatly reduced. It is possible to surely improve the work efficiency and the like.

Further, as described in the prior art, the connecting pin 3
Eliminating the need for the operator to position the bucket 6 and the arm 5 so as to keep the pin insertion holes 17 and 19A aligned until the insertion of the pin 1 into the pin insertion holes 17 and 19A is completed. This also makes it possible to significantly reduce the labor and the like of the workers and surely reduce the number of workers and the like required for such work.

Further, since the thrust plate 21 is formed from a sintered oil-impregnated alloy having self-lubricating property, the thrust load from each bracket 16 is rotated through each movable plate 25 when each bucket 6 is rotated. By allowing the thrust plates 21 and 21 to receive, the sliding resistance and the like acting between each thrust plate 21 and each movable plate 25 can be effectively reduced, and thus the thrust resistance between each thrust plate 21 and each movable plate 25 can be reduced. It is possible to reliably prevent abnormal wear phenomena such as wearing wear from occurring, and each thrust plate 21
The life of each movable plate 25 and the like can be greatly extended.

Furthermore, each O-ring 34 arranged in the V-shaped groove of each tapered surface portion 23 and each tapered surface portion 27 can be slid with respect to the tapered surface portion 23, and each O-ring 34 can be slid. The life etc. can be reliably extended.

On the other hand, the thrust plate 21 and the movable plate 25 are connected to the countersunk screws 24 and the holding bolts 29, respectively.
Since the arm boss 11 and each bracket 16 are detachably provided via the above-mentioned components, the thrust plate 21 and the movable plate 25 can be easily replaced even when the thrust plate 21 and the movable plate 25 have a life. Therefore, the work efficiency at the time of replacement work can be improved.

Further, when adjusting the clearance between the thrust plate 21 and the movable plate 25, the screwing position of each holding bolt 29 is changed, or the holding bolt 29 is replaced with a different length or the like. By providing the holding bolts, it is possible to easily finely adjust the gap between the thrust plate 21 and the movable plate 25, and it is possible to reliably improve the work efficiency during such maintenance work.

Further, even when an attachment such as another bucket is attached to the arm 5, the thrust plate 2
By detaching 1 from the arm boss 11 via each countersunk screw 24, the attachment can be easily attached to the arm boss 11, whereby it is not necessary to newly manufacture the attachment according to the shape of the arm boss 11, etc. It is possible to reduce the manufacturing cost of such an attachment.

Although the thrust plate 21 is made of a material having a self-lubricating property in the above embodiment, the movable plate 25 may be made of a material having such a self-lubricating property. A solid lubricant or the like may be embedded in at least one of the surfaces of the thrust plates 21 and the movable plates 25.

Further, in the above-described embodiment, the case where the bearing device is applied to the pin connecting portion between the arm 5 and the bucket 6 of the hydraulic excavator 1 has been described as an example, but the present invention is not limited to this, and for example, a link is provided. The present invention can be widely applied to other pin coupling portions such as a pin coupling portion between 10 and the bucket 6 and a pin coupling portion between the arm 5 and the arm cylinder 8.

[0057]

As described in detail above, according to the invention of claim 1, a pair of guide members having guide holes formed concentrically with the pin insertion holes of the boss on the inner peripheral side are provided on both end sides of the boss. And a movable member in which each bracket has a fitting protrusion that fits into a guide hole of each guide member, and a pin hole through which the connecting pin is inserted is formed on the inner peripheral side, and the movable member. Since a positioning means for holding the movable member movably in the axial direction of the connecting pin so that the fitting convex portion of the guide member moves into and out of the guide hole of the guide member, the pin between the boss and each bracket is provided. When aligning the insertion holes with each other,
By fitting the fitting convex portion of the movable member into the pin hole of the guide member, the respective pin insertion holes can be automatically aligned, and the fitting convex portion and the guide hole allow the boss to be attached to the bracket. The connecting pin can be easily inserted into each of the pin insertion holes in a state of being positioned therebetween.

Therefore, the time required for centering the pin insertion holes can be greatly shortened, and the fatigue, burden, etc. on the worker during such work can be greatly reduced, and work efficiency and the like can be surely improved. You can Further, as described in the related art, it is necessary for the worker to continue to position the boss and the bracket so as to keep the pin insertion holes aligned with each other until the connection pin is completely inserted into the pin insertion holes. It can be eliminated, and the labor and the like of the worker can be greatly reduced by this, and the number of workers and the like required for such work can be surely reduced. Further, by moving the movable member through the positioning means during maintenance work of the bearing device, it is possible to easily finely adjust the gap between the guide member and the movable member. It is possible to greatly improve efficiency and the like.

According to the second aspect of the invention, when the connecting pins of the bracket and the boss are aligned with each other, the fitting convex portion of the movable member is easily inserted into the guide hole of the guide member via the taper portion. They can be fitted together, the time required for such centering can be greatly reduced, and the overall work efficiency and the like can be further improved.

On the other hand, according to the third aspect of the present invention, it is possible to surely prevent abnormal wear phenomenon such as adhesion wear between the movable member and the guide member when the bracket is rotated. The life etc. of the member can be greatly extended.

[Brief description of drawings]

FIG. 1 is an external view showing a working device or the like of a hydraulic excavator to which a bearing device according to an embodiment of the present invention is applied.

FIG. 2 is an enlarged vertical cross-sectional view of the bearing device as seen from the direction of arrows II-II in FIG.

FIG. 3 is an enlarged view of a main part in FIG. 2;

FIG. 4 is a front view showing a thrust plate and the like as viewed in the direction of arrows IV-IV in FIG.

FIG. 5 is an enlarged vertical cross-sectional view of an essential part at a position substantially similar to that of FIG. 2, showing a state where the arm boss and each bracket are aligned.

FIG. 6 is a vertical cross-sectional view similar to FIG. 5, showing a state in which arm bosses are arranged between the brackets and before centering.

FIG. 7 is an enlarged view of a main part in FIG. 6;

[Explanation of symbols]

 11 Arm Boss (Boss) 16 Bracket 19 Bush 17, 19A Pin Insertion Hole 21 Thrust Plate (Guide Member) 22 Guide Hole (Tapered Part) 25 Movable Plate (Movable Member) 25B Fitting Convex Part (Tapered Part) 25C Pin Hole 29 Holding Bolt (positioning means)

Claims (3)

[Claims] 1. A boss having a pin insertion hole, a pair of brackets formed on both ends of the boss and having pin insertion holes corresponding to the boss, and a pair of brackets inserted into the bracket and the boss. A bearing device comprising a connecting pin that is fitted between the brackets and rotatably connects a boss, and guide holes that are concentric with the pin insertion hole are formed on the inner peripheral side at both ends of the boss. A pair of guide members is provided, and each of the brackets is provided with a fitting protrusion that fits into the guide hole of each guide member, and a pin hole through which the connecting pin is inserted is formed on the inner peripheral side. A member and positioning means for holding the movable member movably in the axial direction of the connecting pin so that the fitting convex portion of the movable member enters and retracts into the guide hole of the guide member. A bearing device characterized by the above. 2. A tapered portion is formed on at least one of the guide hole of the guide member and the fitting convex portion of the movable member, and the fitting convex portion is fitted into the guide hole through the tapered portion. The bearing device according to claim 1, wherein the pin insertion holes of the bracket and the boss are aligned with each other. 3. The bearing device according to claim 1, wherein at least the contact surface side of the guide member that contacts the movable member is made of a material having self-lubricating properties.