JPH10245870A - Bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make positioning made correctly for thrust plates in positions each between a boas member and its opposite members and to simply insert a connecting pin into a space at the inner circumferential surfaces thereof. SOLUTION: An oil retaining bush 17 is inserted into a bush fitting hole 12A of an arm boss 12, and a connecting pin 15 is inserted into a space at the inner circumferential surface of the oil retaining bush 17. Then, the connecting pin 15 is inserted into insertion holes 13A of brackets 13, and the arm boss 12 is turnably connected with each of the brackets 13. Dust seals 19 are provided at both ends of the oil retaining bush 17, and tips in the axial direction thereof are made to project from the sliding surfaces 12B of the arm boss 12 into spaces 14 between the sliding surfaces and the bracket 13. Then, thrust plates 18 are provided at the spaces 14, being fitted to the outer circumferential side at the tips of the dust seals 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device suitably used as a pin connecting device in a construction machine such as a hydraulic shovel.

[0002]

2. Description of the Related Art Generally, a bearing device is used for a construction machine such as a hydraulic shovel or the like. The bearing device has a bush fitting hole extending in an axial direction, and a bush is fitted into the bush fitting hole. A boss member, a mating member provided at both ends in the axial direction of the boss member, a connecting pin slidably inserted into the bush and rotatably connecting the boss member to the mating member, and a connecting pin. An annular thrust plate which is inserted into the outer peripheral side and is disposed in a gap between the boss member and the counterpart member, and is provided in a bush fitting hole of the boss member located between the bush and the counterpart member; In addition, there has been known a device comprising a sealing means for sealing between the boss member and the connecting pin (for example, Japanese Patent Application Laid-Open No. 8-105444).

Here, an example in which this type of conventional bearing device is used for a pin connecting portion between an arm and a bucket will be described. This bearing device is provided as a boss member on the distal end side of an arm. Boss part, a pair of left and right bracket parts projecting from the bucket as mating members, a bush fitted in the bush fitting hole of the boss part, and an axially intermediate part on the inner peripheral side of the bush. A connection pin is slidably inserted, and has a connection pin rotatably connecting the boss portion and each bracket portion by fixing both ends in the axial direction to each bracket portion.

[0004] The bush is constituted by an oil-impregnated bush in which a relatively high-viscosity lubricating oil is previously impregnated in order to lubricate the sliding surface with the connecting pin. Further, a gap is formed between both ends of the boss portion and each bracket portion,
In these gaps, an annular thrust plate is arranged on the outer peripheral side of the connecting pin. Each thrust plate prevents direct noise from being generated due to sliding of the thrust plate even when an external force or the like in the thrust direction acts between the boss portion and each bracket portion.

When the bucket rotates on the tip end side of the arm, each bracket rotates together with the connecting pin with respect to the boss, and at this time, the connecting pin and the bush slide with each other. Also, when the connecting pin and the bush slide, the friction heat impregnates the lubricating oil impregnated on the inner peripheral side of the bush onto the sliding surface with the connecting pin, so that these sliding surfaces are lubricated. Has become.

[0006]

By the way, in the above-mentioned prior art, the connection pin and the bush can be maintained in a lubricated state by using an oil-containing bush, and abnormal noise such as sliding noise is generated between the connection pin and the bush. Since it is configured to suppress the occurrence, when the boss portion and each bracket portion are configured to allow direct contact, the contact sound between them is better than the contact between the connection pin and the bush. The noise level becomes more noticeable than the sound.

Therefore, in the prior art, a thrust plate is disposed between the boss portion and each bracket portion to prevent the generation of abnormal noise. However, in this case, when assembling the bearing device, it is necessary to dispose two thrust plates on the outer peripheral side of the connecting pin between both ends of the boss portion and each bracket portion. It is necessary to insert a connecting pin into the inner peripheral side of the thrust plate in a state where the portion and each thrust plate are aligned with each other in the radial direction.

For this reason, in the prior art, when the connecting pin is inserted, not only the boss portion and each bracket portion are aligned with each other, but also each thrust plate positioned with respect to the boss portion is manually engaged with the boss portion. Therefore, there is a problem that the operation of inserting the connecting pin requires a great deal of time and makes it difficult to assemble the bearing device.

On the other hand, if the inner diameter of the thrust plate is formed sufficiently larger than the outer diameter of the connecting pin, the connecting pin can be easily inserted into the inner peripheral side of the thrust plate. However, in this case, the thrust plate is likely to be displaced in the radial direction around the connection pin after assembling the bearing device,
There is a possibility that the thrust plate may protrude in the radial direction toward the outer peripheral side of the boss portion, and the inner diameter of the thrust plate must be limited to a size slightly larger than the outer diameter of the connecting pin.

For this reason, when the connecting pin is inserted, if the thrust plate is slightly displaced in the radial direction,
There is a possibility that the outer peripheral surface of the connecting pin may be damaged by contacting the inner peripheral side of the thrust plate, thereby causing a seal member such as a dust seal sliding on the outer peripheral surface of the connecting pin to be damaged or worn at an early stage. Therefore, there is a problem that the reliability of the bearing device is reduced.

The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention can easily align a thrust plate between a boss member and a counterpart member before inserting a connecting pin. The insertion work of the connecting pin can be performed smoothly while maintaining the state, and the outer peripheral surface of the connecting pin can be reliably prevented from being damaged by the thrust plate or the like,
It is an object of the present invention to provide a bearing device capable of greatly improving workability and reliability during assembly.

[0012]

According to the present invention, there is provided a boss member having a bush fitting hole extending in an axial direction, a bush fitted in the bush fitting hole, and a boss member. A mating member provided on both ends in the axial direction of the boss member, and a connecting pin slidably inserted into the bush and rotatably connecting the boss member to the mating member,
An annular thrust plate that is inserted into the outer peripheral side of the connection pin and is disposed in a gap between the boss member and the counterpart member,
The present invention is applied to a bearing device that is provided between a bush and a mating member in a bush fitting hole of the boss member and that includes sealing means for sealing between the boss member and a connecting pin.

A feature of the structure adopted by the first aspect of the present invention is that at least a part of the sealing means on an outer peripheral side is fitted to an end of a bush fitting hole of the boss member, and a tip in an axial direction is provided. A seal mounting portion projecting from the end surface of the boss member toward the inside of the gap, and extending radially inward from the seal mounting portion toward the connection pin, and an inner diameter end side elastically contacts the outer peripheral surface of the connection pin. The thrust plate has an inner diameter greater than an outer diameter of the seal mounting portion.

According to the above configuration, the inner end of the lip extending radially inward from the seal mounting portion fitted to the boss member is elastically slidably in contact with the outer peripheral surface of the connecting pin, thereby connecting to the boss member. Seals between pins. Also,
Since the inner diameter of the thrust plate is formed to be larger than the outer diameter of the seal mounting part, when assembling the bearing device,
The thrust plate can be locked on the outer peripheral side of the axial end of the seal mounting portion protruding from the end surface of the boss member. In this state, the inner peripheral side of the thrust plate is located on the inner peripheral side of the boss member (bush). The thrust plate can be assembled to the boss member in advance while being able to be combined. Then, in a state where the boss member and the counterpart member are aligned with each other, the connection pin is inserted in the inner peripheral side of the boss member in the axial direction, so that the thrust plate is positioned on the outer peripheral side of the connection pin and the boss member is positioned. And the thrust plate can be held in a state of being separated from the outer peripheral surface of the connecting pin.

[0015] In the second aspect of the present invention, the sealing means is constituted by a dust seal for restricting entry of foreign matter from the outside between the boss member and the connecting pin.

[0016] Thus, the intrusion of foreign matter such as dust and moisture from the outside between the boss member and the connecting pin can be restricted by the dust seal, and the intruded foreign matter can be prevented from being mixed into the lubricating oil and the like. Further, when assembling the bearing device, the thrust plate can be mounted on the boss member in a state where the thrust plate is positioned in the radial direction by using the seal mounting portion of the dust seal.

According to the third aspect of the present invention, the axially distal end side of the seal mounting portion has at least one-third of the plate thickness of the thrust plate and a projection smaller than the plate thickness within the gap. It is configured to protrude.

Accordingly, the tip end side in the axial direction of the seal mounting portion projects from the end face of the boss member toward the counterpart member with a projection dimension smaller than the thickness of the thrust plate. In the disposed state, the distal end side in the axial direction of the seal mounting portion is held in a state of being separated from the counterpart member. Further, by setting the protruding dimension to be at least 1/3 of the thickness of the thrust plate, the thrust plate can be stably locked to the outer peripheral side of the distal end of the seal mounting portion when the bearing device is assembled. . Then, during operation of the bearing device, even when the gap between the boss member and the counterpart member temporarily expands due to, for example, an external force in the thrust direction, the thrust plate is larger in diameter than the outer peripheral side of the distal end portion of the seal mounting portion. It can be prevented from being displaced inward in the direction and coming into contact with the connecting pin.

Further, in the invention according to claim 4, the tip end side in the axial direction of the seal mounting portion is projected into the gap with a projection dimension larger than the thickness of the thrust plate, and the outer periphery of the tip end is provided with a thrust plate. A configuration is provided in which an engagement projection is provided that engages with the inner peripheral side.

Thus, the thrust plate can be stably locked on the outer peripheral side of the axial end of the seal mounting portion. In addition, since the engaging projection is provided on the outer periphery of the distal end side of the seal mounting portion, it is possible to restrict the axial movement of the thrust plate with respect to the seal mounting portion during the assembling operation, and the thrust plate falls off from the distal end portion. Can be prevented.

[0021]

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

FIGS. 1 to 3 show a first embodiment of the present invention. In this embodiment, a case where a bearing device is applied to a pin connecting portion of a hydraulic shovel will be described as an example. .

In the figure, 1 is a lower traveling body of a hydraulic shovel, 2
Denotes an upper revolving unit that is rotatably mounted on the lower traveling unit 1, the upper revolving unit 2 includes a revolving frame 3,
An operator cab 4, a machine room, and the like are provided on the revolving frame 3.

Reference numeral 5 denotes a working device provided at the front of the upper swing body 2 so as to be able to move up and down. The working device 5 includes a boom 6 pin-connected to the swing frame 3 of the upper swing body 2, and the boom The arm 7 is pin-connected to the distal end of the arm 6, and the bucket 8 is pin-connected to the distal end of the arm 7. Then, the boom 6, the arm 7, and the bucket 8 are rotated by the boom cylinder 9, the arm cylinder 10, and the bucket cylinder 11, respectively.

Here, each of these pin joints is equipped with a bearing device according to the present embodiment. For example, the arm 7 and the bucket 8 are rotatably connected via a bearing device shown in FIG. I have.

Reference numeral 12 denotes an arm boss as a boss member provided on the distal end side of the arm 7. The arm boss 12 is formed in a substantially cylindrical shape, and a bush fitting for fitting an oil-impregnated bush 17 described later on its inner peripheral side. A mating hole 12A is formed in the axial direction. The arm boss 12 has a substantially circular sliding surface 1 whose axial end faces on both sides with respect to a thrust plate 18 described later.
2B, each of which has an annular tapered portion 12C on the outer peripheral side of each sliding surface 12B.

Reference numerals 13 and 13 denote a pair of left and right brackets projecting from the outside of the bucket 8 as mating members of the arm boss 12, and each of the brackets 13 has a pin insertion fitting into which a connection pin 15 described later is inserted. Holes 13A, 13A are drilled, and each bracket 13 is disposed on both axial ends of the arm boss 12 so as to sandwich the arm boss 12.

Each of the brackets 13 is provided with an arm boss 1.
An inner end surface facing the second thrust plate 13 is a substantially circular sliding surface 13B with respect to the thrust plate 18, and a thrust plate 1 is provided between each sliding surface 13B and each sliding surface 12B of the arm boss 12.
Annular gaps 14, 14 in which 8 are disposed are formed around the connection pin 15. Further, each bracket 13 has an annular tapered portion 13C formed on the outer peripheral side of each sliding surface 12B, and each of the tapered portions 13C is substantially V-shaped between itself and the tapered portion 12C of the arm boss 12. An annular groove is formed.

Reference numeral 15 designates an arm boss 12 for each bracket 13
The connection pin 15 is rotatably connected to the connection pin 15. The connection pin 15 is slidably inserted into the oil-containing bush 17 at an intermediate portion in the axial direction, and both ends in the axial direction are inserted into the pin insertion holes 13 </ b> A of the brackets 13. It is fitted. In this state, the retaining pin 16 is inserted into one end of the connecting pin 15, whereby the connecting pin 15 is fixed to the bracket 13 in a retaining and derotating state.

17 is a bush fitting hole 1 of the arm boss 12
2A shows an oil-impregnated bush as a bush fitted in 2A. The oil-impregnated bush 17 is formed as a cylindrical body having a porous structure, for example, by a sintered alloy of iron and copper or the like. A lubricating oil composed of gear oil of about 240 to 1500 cSt is impregnated in advance. The inner surface of the oil-containing bush 17 is a sliding surface 17A with the connecting pin 15.

The lubricating oil in the oil-containing bush 17 is
When the oil-impregnated bush 17 slides on the connecting pin 15, the viscosity decreases due to the frictional heat, and the oil-containing bush 17 gradually exudes from the sliding face 17A side to the connecting pin 15, and the sliding face 1
7A and the like are continuously lubricated.

Numerals 18 and 18 denote annular thrust plates disposed in the respective gaps 14 between the arm boss 12 and the respective brackets 13. Each of the thrust plates 18 is, for example, abrasion-resistant or self-assembled as shown in FIG. It is made of a lubricating material such as metal or resin, and is formed as an annular thin plate having a thickness t of about 1 to 3 mm.

The inner diameter D1 of each thrust plate 18
Is a dimension (D1) slightly larger than the outer diameter D2 of the cylindrical portion 20A (projecting end portion 20C) of the dust seal 19 described later.
> D2). And each thrust plate 18
At least a part of the inner peripheral side is loosely fitted to the outer peripheral side of the protruding end portion 20C of the dust seal 19, and in this state, both sides are the sliding surfaces 12B, 13B of the arm boss 12 and each bracket 13.
Is in sliding contact with

Thus, even when an external force or the like in the thrust direction acts between the arm boss 12 and each bracket 13, the respective thrust plates 18 slide on the sliding surfaces 12 B, 13 B of the respective thrust plates 18.
To prevent early sliding and abnormal noise due to direct sliding.

Reference numerals 19, 19 denote dust seals as sealing means according to the present embodiment. Each of the dust seals 19 is composed of a seal mounting portion 20, a lip portion 21, and a core metal 22, which will be described later, as shown in FIG. It is located between both ends of the oil-impregnated bush 17 and each bracket 13 to seal between the arm boss 12 and the connecting pin 15.

Reference numeral 20 denotes a seal mounting portion mounted on the inner peripheral side of the arm boss 12, and the seal mounting portion 20 is formed in an approximately L-shaped cross section from an elastic material such as rubber or resin. The seal mounting portion 20 has a portion closer to one side elastically fitted into the bush fitting hole 12A of the arm boss 12, and has an outer diameter D larger than the outer diameter of the connecting pin 15.
2, and a radially inwardly projecting one end from one end of the cylindrical portion 20A.
7 and an annular end face portion 20B which comes into contact with the end face.

The axial end of the cylindrical portion 20A projects from the sliding surface 12B of the arm boss 12 into the gap 14 by a dimension L.
The thrust plate 18 has an annular protruding end portion 20C, whose protruding dimension L has a relationship shown below with respect to the plate thickness t of each thrust plate 18.

[0038]

(Equation 1)

The projecting end 2 of each dust seal 19
OC protrudes into each gap 14 with a protrusion dimension L smaller than the plate thickness dimension t of the thrust plate 18, thereby maintaining a state separated from the sliding surface 13 </ b> B of each bracket 13.

Further, by setting the projecting dimension L of the projecting end portion 20C to be at least one-third of the thickness t of the thrust plate 18, each thrust plate 18 is stably fitted on the outer peripheral side of the projecting end portion 20C. And are kept apart from the outer peripheral surface of the connecting pin 15.

Reference numeral 21 denotes an annular lip portion integrally formed on the inner peripheral side of the seal mounting portion 20, and the lip portion 21 is a cylindrical portion 2
It extends obliquely inward in the radial direction from between 0A and the end face portion 20B, and its inner diameter end is in elastic sliding contact with the outer peripheral surface of the connecting pin 15. Thereby, the dust seal 19 is
Foreign matter such as dust and moisture is prevented from entering the sliding surface between the oil-containing bush 17 and the connecting pin 15 from outside.

Reference numeral 22 denotes a metal core for reinforcing the seal mounting portion 20. The metal core 22 is formed of a material harder than the seal mounting portion 20, such as a metal or a resin, and has a substantially L-shaped cross section. It is embedded in the cylindrical portion 20A and the end surface portion 20B of the portion 20. The other end of the metal core 22 has a protruding end 2.
It extends to the inside of 0C and regulates that the protruding end portion 20C is elastically deformed so as to bend in the radial direction.

Reference numerals 23, 23 denote O-rings for sealing between the arm boss 12 and the respective brackets 13. Each of the O-rings 23 comprises tapered portions 12C, 13C of the arm boss 12 and the respective brackets 13 as shown in FIG. The arm boss 12 and each bracket 13 are attached to the arm boss 12 and each bracket 13 by restricting the foreign matter from entering the space between the arm boss 12 and each bracket 13. This prevents the surfaces 12B, 13B and the respective thrust plates 18 from being damaged.

The bearing device according to the present embodiment has the above-described configuration, and its operation will now be described.

First, when the bucket 8 shown in FIG. 1 rotates with respect to the arm 7, each of the brackets 13 shown in FIG.
Pivots with respect to the arm boss 12 together with the connecting pin 15,
At this time, the oil-containing bush 17 and the connecting pin 15 slide with each other.

The frictional heat generated by the sliding lowers the viscosity of the lubricating oil in the oil-containing bush 17 on the sliding surface 17A side, and the lubricating oil gradually increases between the oil-containing bush 17 and the connecting pin 15. Come out. As a result, the sliding surface 17A between the connecting pin 15 and the oil-impregnated bush 17 is kept in a lubricated state for a long time by the lubricating oil that seeps out of the oil-impregnated bush 17.

On the other hand, when assembling the bearing device, the bush fitting hole 12 of the arm boss 12 in which the oil impregnated bush 17 is fitted.
Insert each dust seal 19 from both ends toward A.
Each dust seal 19 is pushed down to a position where the end face portion 20B comes into contact with the end face of the oil-containing bush 17.

As a result, each dust seal 19 has its protruding end 20C protruding from each sliding surface 12B of the arm boss 12, so that each thrust plate 18 is fitted on the outer peripheral side of each protruding end 20C. Let it. As a result, each thrust plate 18 is assembled to the arm boss 12 in a state where the inner peripheral side is radially aligned with the inner peripheral side of the arm boss 12 (oil-containing bush 17).

Next, the O-rings 23 are temporarily fixed by being inserted and fitted on the outer peripheral sides of both ends of the arm boss 12, and in this state, the arm bosses 12 are disposed between the brackets 13, and the arm bosses 12 (oil-containing bushes 17 ) And the pin insertion hole 13A of each bracket 13 are aligned. Then, while maintaining this state, the connecting pin 15 is axially inserted into the arm boss 12 (oil-containing bush 17) and the inner peripheral side of each thrust plate 18 from the inside of the pin insertion hole 13A of the one bracket 13, and further connected. The tip side of the pin 15 is inserted into the pin insertion hole 13A of the other bracket 13.

Finally, a retaining pin 16 is inserted into one of the brackets 13 to fix the connecting pin 15 between the brackets 13 in a retaining and detent state, and the positions of the temporarily fixed O-rings 23 are shifted. And mounted between the arm boss 12 and the tapered portions 12C, 13C of each bracket 13.

Thus, in the present embodiment, the dust seal 19 is formed from the seal attaching portion 20 and the lip portion 21, and the projecting end 20 C of the seal attaching portion 20 is formed on the arm boss 1.
2 and each bracket 13, and the inner diameter D 1 of the thrust plate 18 is slightly larger than the outer diameter D 2 of the cylindrical portion 20 A (projecting end 20 C) of the seal mounting portion 20. When the bearing device is assembled, each thrust plate 18 can be fitted to the outer peripheral side of the protruding end portion 20C protruding from the sliding surface 12B of the arm boss 12, and in this state, each thrust plate 18 can be fitted. The inner peripheral side of the oil-impregnated bush 17 can be accurately aligned with the inner peripheral side of the oil-impregnated bush 17, and each thrust plate 18 can be pre-assembled on both ends of the arm boss 12.

With this arrangement, after the inner peripheral side of the arm boss 12 (oil-containing bush 17) and the pin insertion hole 13A of each bracket 13 are aligned with each other, only the connection pin 15 is inserted through them, and The thrust plate 18 can be disposed in the gap 14 by being located on the outer peripheral side of the connection pin 15,
The operation of inserting the connecting pin 15 can be performed in substantially the same manner as when there is no thrust plate 18.

Therefore, according to the present embodiment, it is not necessary to support each thrust plate 18 at both ends of the arm boss 12 by manual work or the like, so that the connecting pin 15 can be easily inserted. The assembling work of the bearing device having the thrust plate 18 can be greatly simplified, and when the connecting pin 15 is inserted, the outer peripheral surface of the connecting pin 15 is reliably prevented from contacting the displaced thrust plate 18 and being damaged. As a result, the reliability of the bearing device can be improved.

The projecting end portions 20 of each dust seal 19
C is projected into each gap 14 with a projection dimension L smaller than the plate thickness dimension t of the thrust plate 18. Therefore, when each thrust plate 18 is disposed in the gap 14, each dust seal 19 projects. The end portion 20C can be maintained in a state of being separated from the sliding surface 13B of each bracket 13, and it is possible to reliably prevent the protruding end portion 20C from being worn due to the contact therebetween.

Further, the seal mounting portion 20 of the dust seal 19 is configured such that the projecting dimension L of the projecting end portion 20C is
The thrust plate 18 can be stably fitted to the outer peripheral side of the protruding end portion 20C at the time of assembling the bearing device, so that the assembling work can be performed efficiently. Can be.

Further, during operation of the bearing device, the inner peripheral side of each thrust plate 18 can be always kept away from the outer peripheral surface of the connecting pin, and the outer peripheral surface of the connecting pin 15 is displaced in the radial direction. 18 can be reliably prevented from being damaged by contact with the inner peripheral side of the 18. And even when the gap 14 is temporarily expanded due to, for example, an external force in the thrust direction,
The displacement of each thrust plate 18 radially inward from the protruding end portion 20C can be reliably restricted.

Further, a reinforcing core metal 22 is embedded in the seal mounting portion 20 of each dust seal 19, and the core metal 22 extends to the inside of the protruding end portion 20C.
The seal mounting portion 20 can be reinforced by the
It is possible to reliably restrict elastic deformation such that 0C bends in the radial direction, and to stably hold each thrust plate 18 fitted to the outer peripheral side of the protruding end portion 20C.

Further, since each dust seal 19 is mounted between the arm boss 12 and the connecting pin 15,
Intrusion of foreign matter such as dust and moisture from outside can be restricted between them, and the connecting pin 1
The sliding surface 17A between the oil-containing bush 17 and the oil-impregnated bush 17 can be reliably prevented from being damaged, and the seal mounting portion 20 of each dust seal 19 can be protruded into the gap 14 as the protruding end portion 20C. Each thrust plate 19 during assembly
Can be easily assembled.

On the other hand, the arm boss 12 is
The lubricating oil in the oil-containing bush 17 is slid on the sliding surface 1 with the connecting pin 15 through
7A can be supplied stably, and the sliding surfaces 17A and the like can be continuously lubricated for a long period of time, and they can be reliably prevented from being worn out early and generating a loud friction noise. can do.

Next, FIG. 4 shows a second embodiment according to the present invention. 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 made. It shall be omitted. However, a feature of the present embodiment is that the thrust plate 31 has a configuration in which the resin layers 33 are provided on both sides of the metal plate 32.

Here, the thrust plate 31 is provided with the arm boss 12 and the bracket 13 in substantially the same manner as in the first embodiment.
And a part on the inner peripheral side is fitted to the outer peripheral side of the protruding end 20 </ b> C of the dust seal 19. However, in the present embodiment, the resin layers 33, 3 made of a resin material or the like having abrasion resistance or self-lubricating property are provided on both sides of the annular metal plate 32 serving as the main body of the thrust plate 31.
3 are formed integrally, and the thickness of the thrust plate 31 is, for example, about 3 to 4 mm. Then, each resin layer 33 of the thrust plate 31 is formed by the arm boss 12 and the bracket 13.
Are in sliding contact with the sliding surfaces 12B and 13B.

Thus, in the present embodiment having the above-described structure, substantially the same operation and effect as those of the first embodiment can be obtained. In the present embodiment, in particular, in the present embodiment, both sides of the thrust plate 31 are provided. To the arm boss 1 via each resin layer 32.
2 and the sliding surfaces 12B, 13B of each bracket 13 can be smoothly slid, and these can be reliably prevented from being worn or damaged early.

Next, FIG. 5 shows a third embodiment according to the present invention. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be given. It shall be omitted. However, the feature of the present embodiment is that the axially distal end of the seal mounting portion is made larger than the thickness of the thrust plate and the outer periphery of the thrust plate is engaged with the inner peripheral side of the thrust plate. That is, a collision portion is provided.

Reference numeral 41 denotes a dust seal as a sealing means according to the present embodiment. The dust seal 41 includes a seal mounting portion 42, a lip portion 43, and a cored bar 44 described later.
It is composed of

Reference numeral 42 denotes a seal mounting portion according to the present embodiment mounted on the inner peripheral side of the arm boss 12. The seal mounting portion 42 is substantially the same as the seal mounting portion 20 according to the first embodiment. For example, a cylindrical portion 42A formed of an elastic material such as rubber or resin into a substantially L-shaped cross section, and a portion closer to one side is elastically fitted in the bush fitting hole 12A of the arm boss 12; And an annular end surface portion 42 </ b> B whose one side surface is in contact with the end surface of the oil-containing bush 17.

However, the seal mounting portion 42 according to the present embodiment has a protrusion dimension L1 of the protrusion end portion 42C of the cylindrical portion 42A protruding into the gap 14 from the sliding surface 12B of the arm boss 12.
Are formed to be larger than the plate thickness dimension t of the thrust plate 18, and an engaging flange 42 </ b> D that protrudes radially outward and becomes an engaging protrusion is formed on the outer periphery of the distal end side of the protruding end 42 </ b> C. This is different from the seal attaching portion 20 according to the first embodiment in that the sealing portion 20 is provided.

Here, the outer peripheral side of the engaging flange 42D projecting outward in the radial direction is engaged with the inner peripheral side of the thrust plate 18, whereby the outer peripheral side of the protruding end 42C is loosely fitted. The movement of the thrust plate 18 in the axial direction is restricted to prevent the thrust plate 18 from falling off from the protruding end 42C. Further, the engagement flange portion 42D is formed with an extremely thin thickness dimension.

Reference numeral 43 denotes an annular lip integrally formed on the inner peripheral side of the seal mounting portion 42, and reference numeral 44 denotes a seal mounting portion 4
The lip 43 and the core 44 are configured similarly to the lip 21 and the core 22 according to the first embodiment.

Thus, in the present embodiment configured as described above, substantially the same operation and effect as those of the first embodiment can be obtained. In particular, in the present embodiment, the seal mounting portion 42 The engaging flange 4 is provided on the outer periphery of the distal end side
2D is provided, and the engagement flange portion 42D restricts the axial movement of the thrust plate 18 loosely fitted on the outer peripheral side of the protruding end portion 42C. Accordingly, it is possible to prevent the thrust plate 18 from dropping off from the protruding end portion 42C at the time of assembling the bearing device, and it is possible to perform the assembling work more efficiently.

Further, since the engagement flange 42D is formed to have an extremely thin thickness, after the thrust plate 18 is supported at the time of assembling, the engagement flange 42D is pinched between the thrust plate 18 and the bracket 13 and is worn. ,Disappear. However, the projecting end 42
C is the engagement flange 42D after assembling the thrust plate 18 and the like.
Can be held in the positioned state even if the light beam disappears.

In each of the above embodiments, the inner diameter D 1 of the thrust plates 18, 31 is changed to the dust seals 19, 41.
The protrusions 20C, 42C are formed to have dimensions slightly larger than the outer diameter D2 of the protrusions 20C, 42C, and the thrust plates 18, 31 are loosely fitted to the outer peripheral sides of the protrusion ends 20C, 42C. However, the inner diameter D1 and the like of the thrust plates 18 and 31 may be formed to be larger than the outer diameter D2 of the protruding ends 20C and 42C.

In each of the above embodiments, the thrust plates 18 (31) are provided in the respective gaps 14 in order to prevent the arm bosses 12 and the respective brackets 13 from sliding directly. Not limited to this, each gap 14
A thrust plate (shim plate) is provided in at least one of the gaps 14 to adjust the width dimension of the dust seals, and the shim plate is fitted to the outer peripheral side of the protruding end portions 20C, 42C of the dust seals 19, 41. Is also good.

Further, in each of the above-described embodiments, the reinforcing cores 22 and 44 are embedded in the seal mounting portions 20 and 42 of the dust seals 19 and 41. However, the present invention is not limited to this. The cores 22 and 44 may be omitted by forming the seal mounting portions 20 and 42 of the dust seals 19 and 41 from a material harder than the lip portions 21 and 43.

In the above embodiments, the oil-impregnated bush 17 and the connecting pin 15 are slid. However, the present invention is not limited to this, and the normal bush and the connecting pin 15 are slid. A configuration may be adopted in which lubricating oil is externally supplied to these sliding surfaces.

Further, in each of the above embodiments, the pin connection portion of the hydraulic shovel has been described as an example. However, the present invention is not limited to this, and for example, construction machines such as hydraulic cranes, agricultural and industrial use. The bearing device may be applied to a pin coupling portion provided in a working machine or the like.

[0076]

As described above in detail, according to the first aspect of the present invention, the sealing means is formed of the seal mounting portion and the lip portion, and the tip end side of the seal mounting portion in the axial direction is the boss member and the mating member. And the inner diameter of the thrust plate is formed to be larger than the outer diameter of the seal mounting part.
The thrust plate can be locked on the outer peripheral side of the tip of the seal mounting portion protruding from the end surface of the boss member, and in this state, the inner peripheral side of the thrust plate is accurately aligned with the inner peripheral side of the boss member (bush). At the same time, the thrust plate can be assembled to the boss member in advance. This allows the thrust plate to be located in the gap by being positioned on the outer peripheral side of the connecting pin by merely inserting the connecting pin into the boss member (bush) and the mating member that are aligned with each other. Can be performed almost in the same manner as when there is no thrust plate.
Therefore, the assembling work of the bearing device having the thrust plate can be greatly simplified, and the outer peripheral surface of the bearing device can be reliably prevented from contacting and being damaged by the misaligned thrust plate when the connecting pin is inserted. Reliability can be improved.

According to the second aspect of the present invention, since the sealing means is constituted by a dust seal, it is possible to restrict foreign substances such as dust and moisture from entering between the boss member and the connecting pin from the outside, and the lubrication is achieved. The sliding surface between the connecting pin and the bush can be reliably prevented from being damaged by foreign matter mixed in the oil, and the distal end side of the dust seal (seal mounting portion) in the axial direction is located in the gap between the boss member and the mating member. , The thrust plate can be easily assembled at the time of assembling the bearing device.

According to the third aspect of the present invention, the axially distal end side of the seal mounting portion has a protrusion dimension that is not less than ３ of the plate thickness of the thrust plate and smaller than the plate thickness. Is formed so as to protrude into the gap between the boss member and the counterpart member, so that the tip end side of the seal mounting portion can be held in a state of being separated from the counterpart member, and the tip end of the seal mounting portion is brought into contact with them. Premature wear of the part side can be reliably prevented. Also, when assembling the bearing device,
The thrust plate can be stably locked on the outer peripheral side of the distal end portion of the seal mounting portion, and the assembling work can be performed efficiently. Furthermore, during operation of the bearing device, the inner peripheral side of the thrust plate can be kept constantly separated from the outer peripheral surface of the connecting pin, so that damage to the connecting pin due to contact with the thrust plate can be reliably prevented. Can be.

Further, according to the fourth aspect of the present invention, the distal end portion in the axial direction of the seal mounting portion is projected into the gap with a projection dimension larger than the thickness of the thrust plate, and the outer periphery of the distal end side has a thrust. With the configuration in which the engagement projections are provided to engage with the inner peripheral side of the plate, the thrust plate can be stably locked on the outer peripheral side of the distal end portion of the seal mounting portion, and the assembling work can be performed efficiently. it can. Moreover, by providing an engagement projection on the outer periphery of the tip of the seal mounting portion, it is possible to restrict the axial movement of the thrust plate during the assembling work, so that it is possible to prevent the thrust plate from falling off from the tip and to assemble. Work can be performed more efficiently.

[Brief description of the drawings]

FIG. 1 is an external view showing a working device of a hydraulic shovel to which a bearing device according to a first embodiment is applied.

FIG. 2 is a longitudinal sectional view showing the bearing device according to the first embodiment.

FIG. 3 is an enlarged longitudinal sectional view showing a thrust plate, a dust seal, and the like in FIG. 2;

FIG. 4 is a longitudinal sectional view similar to FIG. 3, showing a thrust plate of a bearing device according to a second embodiment together with a dust seal and the like.

FIG. 5 is a longitudinal sectional view similar to FIG. 3, showing a dust seal according to a third embodiment together with a thrust plate and the like.

[Explanation of symbols]

 Reference Signs List 12 arm boss (boss member) 12A bush fitting hole 13 bracket (counterpart member) 14 gap 15 connection pin 17 oil-impregnated bush (bush) 18, 31 thrust plate 19, 41 dust seal (seal means) 20, 42 seal mounting part 20C, 42C Projecting ends 21, 43 Lips 42D Engagement flanges (engagement projections) D1 Inner diameter dimension D2 Outer diameter dimension L, L1 Projection dimension t Plate thickness dimension

Claims (4)

[Claims] A boss member having an axially extending bush fitting hole formed therein, and a bush fitted in the bush fitting hole; a mating member provided at both axial ends of the boss member; A connection pin slidably inserted into the bush and rotatably connecting the boss member to the counterpart member; and a connection pin inserted into the outer peripheral side of the connection pin and disposed in a gap between the boss member and the counterpart member. An annular thrust plate, and sealing means provided between the bush and the counterpart member in a bush fitting hole of the boss member to seal between the boss member and the connecting pin. The sealing means includes a sealing member having at least a part of an outer peripheral side fitted into an end of a bush fitting hole of the boss member, and a distal end side in an axial direction projecting from an end surface of the boss member into the gap. And a lip portion extending radially inward from the seal mounting portion toward the connecting pin, and having an inner end side elastically slidingly contacting the outer peripheral surface of the connecting pin, wherein the thrust plate is formed of the seal mounting portion. A bearing device having a configuration having an inner diameter dimension equal to or greater than an outer diameter dimension. 2. The bearing device according to claim 1, wherein said sealing means is constituted by a dust seal that restricts foreign matter from entering between said boss member and said connecting pin. 3. An axial end portion side of the seal mounting portion,
3. The bearing device according to claim 1, wherein the thrust plate is configured to project into the gap with a protrusion dimension that is equal to or more than の of a plate thickness dimension and smaller than the plate thickness dimension. 4. 4. An axial front end side of the seal mounting portion,
2. A structure in which the thrust plate is projected into the gap with a projection dimension larger than a thickness of the thrust plate, and an engagement projection is provided on an outer periphery of a tip side thereof to engage with an inner periphery of the thrust plate. 3. The bearing device according to 2.