JPH09184518A - Bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a burden on a workman at the time of greasing operation, prevent a noise such as 'a squeak' generated when a bucket is rotated, and retain a comfortable working environment. SOLUTION: A powder material in which a total of 27weight% of nickel and chrominium is added to a cemented carbide material such as tungsten carbide, is thermally sprayed on both end surfaces 13B, 14C of an arm boss 13 and a bracket 14. Hereby, spray deposits 19, 20 as hard abrasion resistance layers having rigidity are formed on both end surfaces 13B, 14B, and also the surfaces of the spray deposits 19, 20 are formed as uneven surfaces having surface roughness of less than about 30μm. When a bucket is rotated, intervals between the spray deposits 19, 20 are retained under lubrication for a long period by a lubricant such as grease, and abrasive wear, adhesive wear and so on generated between the spray deposits 19, 20 are prevented, and also the grease is prevented from being leaked from the interval between the spray deposits 19, 20 to the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device preferably used for a pin connecting portion of a working device equipped in a construction machine, for example.

[0002]

2. Description of the Related Art Generally, there is known a bearing device in which a boss portion of one side member and a bracket portion of a counterpart member are rotatably connected via a connecting pin.

When the bearing device according to the prior art of this kind is used for a pin connecting portion of a working device equipped in a hydraulic excavator or the like, for example, a bush fitting hole is provided on the inner peripheral side at the tip side of an arm as one side member. And a bush having an insertion hole on the inner peripheral side is fitted into the bush fitting hole of the boss portion, and the connecting pin is slidably inserted into the insertion hole of the bush. Both ends of the connecting pin are integrally attached to a bracket provided on one side of the bucket as a counterpart member, so that the bucket is rotatably connected to the arm via the connecting 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.

Here, the boss portion and the bracket portion are respectively provided with contact surfaces for bringing them into contact with each other, and the thrust load acting on the boss portion side or the bracket portion side is received by the contact surfaces. By doing so, the thrust direction of the bracket part with respect to the boss part (axial direction of the connecting pin)
It is designed to prevent backlash.

Further, inside the connecting pin, a grease supply passage or the like is formed so that one end side is opened to the outside and the other end side is opened to the sliding surface between the bush and the connecting pin. Then, a lubricant such as grease is regularly lubricated from outside to the sliding surface via the grease supply passage or the like, and a part of the grease lubricated between the sliding surfaces is a boss portion. It is also supplied to the contact surface between the bracket and the bracket.

During excavation work, the grease is kept in a lubricated state between the sliding surface between the bush and the connecting pin and the contact surface between the boss portion and the bracket portion, and sliding between the sliding surface and the contact surface is performed. By reducing the resistance, the bucket can be smoothly rotated relative to the arm.

[0008]

By the way, in the above-mentioned bearing device according to the prior art, since the thrust load acting on the boss portion or the bracket portion is received by the contact surface between the boss portion and the bracket portion, An extremely large surface pressure acts on the surfaces, and the sliding resistance between the contact surfaces becomes very large. Therefore, by supplying a part of the grease supplied to the sliding surface between the bush and the connecting pin also to the contact surface between the boss portion and the bracket portion, it is possible to maintain the lubrication state between the contact surfaces. ing.

However, in order to keep the contact surface between the boss portion and the bracket portion in a lubricated state at all times, it is necessary to shorten the interval of greasing time to the contact surface and frequently perform greasing. There is a problem in that such maintenance work such as greasing work becomes troublesome for a person and a heavy burden is imposed on the person.

On the other hand, in the bearing device mounted between the bucket and the arm, since the bucket is configured to handle a large amount of earth and sand, earth and sand are formed from the outside between the contact surfaces of the boss portion and the bracket portion. They often invade the small gaps created. Then, when the bucket is relatively rotated with respect to the arm in a state in which soil or the like has entered the gap between the contact surfaces as described above, the soil or sand forms scratches or the like on the contact surface. As a result, there is a problem that severe wear such as so-called "abrasive wear" occurs between the sliding surfaces, and the progress of wear and damage on the contact surface is accelerated.

Further, when the contact surfaces are worn or damaged as described above, the gap in the thrust direction formed between the contact surfaces becomes large. As a result, rattling occurs between the contact surfaces, and an abnormal noise such as a "rattling" sound is easily generated due to such rattling when the bucket rotates, which deteriorates the work environment at the work site. There is a problem of doing. Further, the grease supplied to the contact surface leaks to the outside through this gap,
There is a problem that the appearance around the bucket becomes poor.

Further, when a lubricant such as grease that is greased between the sliding surfaces causes an oil film breakage when the bucket rotates, adhesive wear or the like easily occurs between the sliding surfaces. In addition, "squeal" caused by such wear and damage
It is easy to generate abnormal noises such as, which also causes a problem that the work environment such as the work site is deteriorated.

Therefore, in order to solve the problems of the prior art, as a bearing device, for example, Japanese Patent Laid-Open No. 6-
The one described in Japanese Patent No. 159346 (hereinafter referred to as other conventional technology) is known.

In this bearing device, a tubular member (collar) is fitted on the inner peripheral side of the connecting pin insertion hole provided in the bracket portion to fill the gap between the connecting pin and the bracket portion, and An annular groove for supplying grease to the radially inner portion is formed on the axially outer end surface. Further, a thrust ring is fitted inside the annular groove at a radially inner position, and an axial outer end surface of the thrust ring is brought into contact with an axial inner end surface of the tubular member.
Further, a seal member is arranged inside the annular groove at a radially outer position to prevent the grease supplied into the annular groove from leaking to the outside. As a result, the contact surface between the thrust ring and the cylindrical member is always kept in a lubricated state, frequent grease supply to the contact surface is unnecessary, and the boss portion and the bracket portion are directly slid. In dynamic contact,
The boss portion and the bracket portion are prevented from being worn or damaged.

However, in such another conventional technique, the thrust load from the boss side or the bracket side is
Since the seal member is configured to receive the thrust ring together with the thrust ring, the seal member is apt to be damaged or damaged by such thrust load, resulting in a problem that the life of the seal member is shortened.

Further, when the seal member is worn or damaged in this way, earth and sand enter the contact surface between the thrust ring and the tubular member to easily cause abrasive wear and the annular groove. The grease that has been lubricated to the outside easily leaks to the outside.

As a result, also in the other conventional techniques, as in the above-mentioned conventional technique, it is necessary to frequently perform the greasing work of grease or the like, which causes a problem that such a maintenance work is burdensome for the operator. is there. Further, when the bucket rotates, there is a problem that an abnormal noise such as a “squeaking noise” or a “backlash noise” is generated and the working environment is deteriorated, and grease leaking from the abutting surface causes a problem around the bucket. There is a problem that the external appearance becomes poor.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention can increase the interval of the greasing time to the contact surface between the boss portion and the bracket portion, etc., and the greasing work performed by the operator. It is possible to significantly reduce the burden of such as, and when the bracket part is rotated relative to the boss part, it is possible to reliably prevent the abrasive wear, adhesion wear, etc. that occur between the boss part and the bracket part. An object of the present invention is to provide a bearing device capable of reliably preventing "squealing noise", "rattle noise" and the like due to such wear and damage and maintaining a comfortable working environment.

[0019]

In order to solve the above-mentioned problems, the invention according to claim 1 employs a structure in which a boss portion of one member and a bracket portion of a mating member are connected via a connecting pin. In a rotatably connected bearing device, a hard wear-resistant layer having rigidity is provided on at least one of the contact surfaces of the boss portion and the bracket portion, and the wear-resistant layer is superposed. It is formed by either one of a hard alloy material and a ceramic material.

With this structure, at least one of the contact surfaces of the boss portion and the bracket portion can be reliably protected by the hard wear-resistant layer having rigidity. It is possible to reliably prevent the contact surface provided with the wear resistant layer from being worn or damaged when the boss portion is rotated relative to the bracket portion. Then, as the material of the wear resistant layer, either one of the cemented carbide material and the ceramic material can be selected.

Further, in the invention according to claim 2, a surface treatment layer having corrosion resistance is previously formed on at least one of contact surfaces of the boss portion and the bracket portion, and then the surface treatment layer is formed. There is a structure in which the wear resistant layer is provided on the upper side.

With this structure, even when the wear resistant layer has a porous structure and pores are formed inside so as to penetrate in the thickness direction thereof, the contact surface side is mediated by the pores. The surface treatment layer can surely prevent the surface treatment layer from being directly exposed to the outside air and corroding.

Further, in the invention described in claim 3, in the bearing device in which the boss portion of the one side member and the bracket portion of the mating member are rotatably connected via a connecting pin, the boss portion and the bracket At least one contact surface side of the contact surface with the part is fitted with a ring-shaped member through which the connecting pin is inserted on the inner peripheral side, and the ring-shaped member is formed of at least the surface side with a cemented carbide. The wear-resistant layer is made of one of alloy material and ceramic material.

With this structure, after the wear resistant layer is formed on at least the surface side of the ring-shaped member in advance,
By inserting the connecting pin into the inner peripheral side of the ring-shaped member, the ring-shaped member can be fitted and easily attached to at least one of the contact surfaces of the boss portion and the bracket portion. .

Furthermore, in the invention described in claim 4,
The ring-shaped member has a structure in which a surface treatment layer having corrosion resistance is formed on the surface side in advance, and then the wear-resistant layer is provided on the surface treatment layer.

As a result, when the wear-resistant layer is formed on the surface side of the ring-shaped member, even if pores penetrating in the thickness direction are formed in the wear-resistant layer, the surface of the ring-shaped member is The surface treatment layer can reliably prevent the surface treatment layer from being directly exposed to the outside air through the pores and corroded.

On the other hand, in the fifth aspect of the invention, the surface treatment layer is formed by electroless nickel plating.

As a result, the surface-treated layer having corrosion resistance can be easily formed by electroless nickel plating. Further, if the abrasion resistant layer and the surface treatment layer are appropriately subjected to heat treatment or the like, the adhesion between the contact surface (the surface of the ring-shaped member) between the boss portion and the bracket portion and the nickel plating layer, and the nickle The adhesion between the plating layer and the wear resistant layer can be improved, and the hardness of the wear resistant layer can be further increased.

Furthermore, in the invention described in claim 6,
The wear resistant layer is composed of a thermal spray coating formed by thermal spraying one of the cemented carbide material and the ceramic material.

As a result, on the contact surface between the boss portion and the bracket portion or on the surface of the ring-shaped member, a thermal spray coating as a wear resistant layer is easily formed from either one of the cemented carbide material and the ceramic material. be able to. Also,
By forming the wear-resistant layer by the thermal spray coating, the surface of the thermal spray coating can be easily formed as an uneven surface having a surface roughness of about several tens of μm.

Further, in the invention described in claim 7, the thermal spray coating is formed by performing a thermal spray treatment on a powder material containing 10 to 30 wt% of nickel and chromium in total in a cemented carbide material. It is in. As a result, the sprayed coating can be reliably formed as a wear-resistant layer having excellent sliding characteristics and high hardness.

Further, in the invention described in claim 8, the surface of the wear resistant layer is provided with an uneven surface having a surface roughness of about 30 μm or less.

As a result, when a lubricant such as grease is applied to the contact surface between the boss portion and the bracket portion, the grease can be captured in the concave side surface of the wear resistant layer, and the surface of the wear resistant layer can be captured. Can be reliably maintained in a lubricated state, and grease can be prevented from leaking to the outside from between the contact surfaces.

On the other hand, in the invention according to claim 9, in the bearing device in which the boss portion of the one side member and the bracket portion of the mating member are rotatably connected via a connecting pin, the boss portion and the bracket A wear resistant layer is formed on both contact surfaces with the part, and the wear resistant layer has a total of nickel and chromium of 10 to 10
It is formed by subjecting a powder material containing 30% by weight and the remainder being a cemented carbide material to thermal spraying treatment.

According to a tenth aspect of the invention, in the bearing device in which the boss portion of the one side member and the bracket portion of the mating member are rotatably connected via a connecting pin, the boss portion and the bracket are provided. On both contact surfaces with the portion, provided with a ring-shaped member through which the connecting pin is inserted on the inner peripheral side, respectively, the wear-resistant layer is formed on at least the surface side of each ring-shaped member, The wear-resistant layer is formed by subjecting a powder material containing nickel and chromium in a total amount of 10 to 30% by weight and the remainder being a cemented carbide material to thermal spraying treatment.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bearing device according to an embodiment of the present invention will be described below in detail with reference to the accompanying drawings, taking as an example a case where the bearing device is applied to a pin connecting portion of a hydraulic shovel.

1 to 3 show a first embodiment of the present invention.

In the figure, 1 is a lower traveling body of a hydraulic excavator, 2 is an upper revolving body which is a work machine body mounted on the lower traveling body 1 so as to be rotatable, and the upper revolving body 2 is a revolving frame 3 A driver's cab 4, a machine room (not shown), etc. are provided on the revolving frame 3.

Reference numeral 5 denotes a working device provided on the front part of the upper revolving structure 2 so as to be able to move up and down. The working device 5 includes a boom 6 pin-connected to the revolving frame 3 of the upper revolving structure 2 and the boom. The arm 7 is generally composed of an arm 7 that is pin-connected to the tip side of 6 and a bucket 8 that is pin-connected to the tip side of the arm 7. Then, the boom 6 and the arm 7 are rotated by a boom cylinder 9 and an arm cylinder 10 which are connected to each other via a pin coupling portion, respectively, and the bucket 8 and the arm 8 are rotated.
Is rotated by the bucket cylinder 11 via links 12, 12.

Here, each of these pin coupling portions is equipped with a bearing device, for example, the arm 7 which is one side member.
The bucket 8 serving as a mating member is rotatably coupled to each other via the bearing device shown in FIGS. 2 and 3.

Reference numeral 13 denotes an arm boss provided on the tip side of the arm 7 as a boss portion. The arm boss 13 is formed of a metal material such as cast iron into a substantially cylindrical shape, and its inner peripheral side is formed on both sides in the axial direction. Position the bush fitting holes 13A, 13
A is provided. Here, both end sides of the arm boss 13 in the axial direction are end surfaces 13B and 13B as contact surfaces for the end surface 14C of each bracket 14, which will be described later. An annular taper surface portion 13C is formed on the outer peripheral side of each end surface 13B as shown in FIG. Each end surface 13B has a sprayed coating 19 described below formed on the surface thereof, and receives a thrust load from the bucket 8 together with each sprayed coating 19.

Reference numerals 14 and 14 denote a pair of brackets, which are projectingly provided on the outside of the bucket 8 and are arranged so as to sandwich the arm boss 13 of the arm 7, and each of the brackets 14 is a flat plate made of a metal material such as a steel plate. It is formed into a shape. The bracket 14 is provided with pin insertion holes 14A and 14A which are concentric with the bush fitting holes 13A. Further, on the outer surface of the one bracket 14, the end surface of the cylinder portion 14B is fixed to the outer edge portion of the pin insertion hole 14A by means such as welding, and the cylinder portion 14B has a bolt insertion hole in the radial direction (see FIG. (Not shown) is formed.

Here, the pin insertion hole 1 of each bracket 14
The outer peripheral side of 4A is formed thick, and its inner surface in the axial direction serves as end surfaces 14C, 14C as contact surfaces for the end surfaces 13B of the arm boss 13. Further, annular taper surface portions 14D are formed on the outer peripheral side of the end surfaces 14C, and the taper surface portions 14D are formed between the taper surface portions 13C and the taper surface portions 14C as shown in FIG.
A V-shaped groove is formed as shown in FIG. And each of the end faces 1
4C has each spray coating 20 described below formed on its surface,
The thrust load from the arm 7 is received together with each of the thermal spray coatings 20.

Reference numerals 15 and 15 denote a pair of bushes. Each bush 15 is formed of sintered metal or the like into a substantially cylindrical shape, and its outer peripheral side is press-fitted into each bush fitting hole 13A of the arm boss 13. It is fitted in.

16 is an arm boss 1 between each bracket 14.
3 shows a columnar connecting pin rotatably connected to each other. The connecting pin 16 is slidably inserted into the inner peripheral side of the bush 15, and the pin insertion holes 14 of the brackets 14 are provided at both axial ends.
It is inserted in A. A bolt insertion hole (not shown) is formed in the radial direction on one end side of the connecting pin 16 in the axial direction, and the bolt insertion hole and the bracket 14 (the tubular portion 14) are formed.
By inserting a fixing bolt or the like (not shown) into the bolt insertion hole of B), the connecting pin 16 is retained with respect to the bracket 14 so as not to rotate.

Here, on the outer peripheral surface of the connecting pin 16, the shallow groove grooves 16A, 16 are formed in a portion which becomes a sliding surface with the bush 15.
A, ... Are formed at regular intervals in the circumferential direction. In addition, each of the left and right end surfaces of the connecting pin 16 has a concave portion 16B,
16C is formed, and the base end sides of the grease injection passages 16D and 16E are opened in the concave portions 16B and 16C, respectively. On the other hand, the tip ends of the grease injection passages 16D and 16E extend radially outward from both sides of the intermediate portion of the connecting pin 16 in the radial direction and open in the concave grooves 16A.

Then, each grease injection path 16D, 16E
A lubricant such as grease is injected from the grease nipples 17, 17 screwed to the screw, and this grease is supplied to the sliding surface between the connecting pin 16 and each bush 15 and is slid by the concave groove 16A. Form a uniform oil film over the entire space,
The space between the sliding surfaces is efficiently maintained in a lubricated state.

Reference numerals 18 and 18 denote oil seals as seal members. The oil seals 18 are located outside the bushes 15 in the axial direction and are fitted in the bush fitting holes 13A of the arm boss 13. Here, each oil seal 1
Reference numeral 8 prevents foreign matter such as earth and sand from entering the sliding surface between the bush 15 and the connecting pin 16 from the outside, and a part of the lubricant such as grease lubricated between the sliding surfaces. Is supplied between the end faces 13B and 14C (sprayed coatings 19 and 20).

Reference numerals 19 and 19 denote end faces 13 of the arm boss 13.
A sprayed coating as a wear-resistant layer formed by subjecting B to a spraying treatment, 20 and 20 are end faces 1 of each bracket 14.
4A and 4B respectively show a sprayed coating as a wear-resistant layer formed by performing a spraying treatment on the entire inner surface in the axial direction including 4C.

Here, each of the thermal spray coatings 19 and 20 is made of a hard cemented carbide material having rigidity and heat resistance, as shown in FIG. In this case, as the cemented carbide material, for example, a powder material obtained by adding nickel and chromium to a material such as tungsten carbide in a total amount of 10 to 30% by weight, for example, 27% by weight is used. It is formed by thermal spraying using a method such as a method.

Each of the thermal spray coatings 19 and 20 contains nickel and chromium in a total amount of 10 to 30% by weight, and the rest 70
It may be formed by subjecting a powder material made of a cemented carbide material such as ˜90 wt% tungsten carbide to a thermal spraying process using a means such as a plasma spraying method or a high energy gas spraying method.

The thermal spray coatings 19 and 20 are slidably and substantially slidably in contact with each other, and when the bucket 8 is rotated relative to the bracket 14, the bucket 8 side or the bracket 14 side. By directly receiving the thrust load from the thermal sprayed coatings 19 and 20, it is possible to reliably prevent the end faces 13B and 14C from sliding directly on each other and causing wear and damage. In addition, each spray coating 1
When earth and sand or the like enters into a slight gap formed between 9 and 20, the earth and sand can be surely ground between the thermal spray coatings 19 and 20.

The surface of each of the thermal spray coatings 19 and 20 formed by the thermal spraying process is formed as an uneven surface (not shown) having a surface roughness of about 30 μm or less. Thereby, when the thermal spray coatings 19 and 20 are brought into sliding contact with each other, a plurality of recess spaces (not shown) can be formed on the side surfaces of the recesses of the thermal spray coatings 19 and 20. Then, this recessed space captures the grease replenished between the thermal spray coatings 19 and 20 from the sliding surface between the bush 15 and the connecting pin 16 and confine it inside, so that the space between the thermal spray coatings 19 and 20 can be maintained for a long time. The grease is kept in a lubricated state for a long time, and the grease is prevented from leaking from the sprayed coatings 19, 20 to the outside.

The thickness t of each of the thermal spray coatings 19 and 20 is t.
May be set arbitrarily, but in consideration of the fact that the specific gravity of the powder material is heavy and the price is expensive, the dimension t is set to 5
It is set to about 0 to 200 μm and each thermal spray coating 1
9,20 years of durability for 10 years (total operating time of about 8000
It is preferable to be able to compensate for about (time). Also,
Each of the thermal spray coatings 19 and 20 is formed of a hard (harder than silica sand) ceramic material having rigidity and heat resistance, for example, a ceramic material containing silicon carbide, titanium carbide, alumina, chromium oxide or the like as a main component. You may.

Reference numerals 21 and 21 denote O-rings as seal members, and each O-ring 21 is elastically deformed in a V-shaped groove between the tapered surface portion 13C of the arm boss 13 and each tapered surface portion 14D of the bracket 14. It is installed with a teenager. The O-rings 21 prevent foreign matter from entering the gap between the spray coatings 19 and 20 from the outside between the arm boss 13 and the brackets 14 and replenish between the spray coatings 19 and 20. This is to prevent the grease that has been taken out from leaking to the outside.

The bearing device according to the present embodiment has the above-described structure, and the bucket 8 pin-connected to the tip end side of the arm 7 through the bearing device is attached to each bush 15 attached to the arm boss 13. By rotating the connecting pin 16, the distal end side of the arm 7 is rotated.

When the bucket 8 is rotated, the thrust load acting on the arm 7 side and the bucket 8 side is applied to the end faces 13B, 14 of the arm boss 13 and the bracket 14.
By accepting at C, rattling of the bucket 8 with respect to the arm 7 in the thrust direction is prevented. Therefore, extremely large surface pressures due to the thrust load act on the end surface 13B and the end surface 14C, respectively.

However, in this embodiment, the thermal spray coatings 19 and 20 made of hard cemented carbide material having rigidity and heat resistance are formed on the end surfaces 13B and 14C of the arm boss 13 and the bracket 14, respectively. Together with the respective thermal spray coatings 19,
By sliding 20 on each other, the thrust load from the arm 7 side and the bucket 8 side is applied to the thermal spray coatings 19 and 2 respectively.
0 will be accepted directly.

As a result, when the bucket 8 is rotated, the grease replenished between the thermal spray coatings 19 and 20 is captured in a plurality of recessed spaces formed between the surfaces (uneven surfaces) of the thermal spray coatings 19 and 20. Can be confined. Since the sprayed coatings 19 and 20 can be kept in a lubricated state for a long period of time, the wear and damage generated between the sprayed coatings 19 and 20 can be significantly reduced, and the grease can be applied between the end surfaces 13B and 14C. It can be effectively prevented from leaking from the outside.

Even when the grease replenished between the thermal spray coatings 19 and 20 has run out of oil film, there is no sticking wear or seizure due to sliding frictional heat generated between the thermal spray coatings 19 and 20. It can be surely prevented.

Further, during the excavation work, when earth and sand enter from the outside between the O-ring 21 and the tapered surface portions 13C and 14D between the thermal spray coatings 19 and 20, the earth and sand and the like are cemented with cemented carbide. It can be ground between the thermal spray coatings 19 and 20 made of material, and it is possible to reliably prevent the thermal spray coatings 19 and 20 (each end surface 13B and 14C) from being abraded by such earth and sand. be able to.

Further, earth and sand crushed between the thermal spray coatings 19 and 20 can be held between the thermal spray coatings 19 and 20, and foreign matter such as earth and sand slides between the connecting pin 16 and the bushes 15. It can be surely prevented from entering the space.

Therefore, in this embodiment, the thermal spray coatings 1 are formed on the end surfaces 13B and 14C of the arm boss 13 and the bracket 14, respectively.
Since 9 and 20 are formed, the space between the thermal spray coatings 19 and 20 can be kept in a lubricated state by grease or the like for a long period of time, and the grease replenished between the thermal spray coatings 19 and 20 runs out of oil film. However, it is possible to reliably prevent the end faces 13B and 14C from being worn or damaged.

As a result, the smooth rotation of the bucket 8 can be compensated for a long period of time, and the life of the bearing device can be greatly extended. For example, each spray coating 1
When the thickness t of 9, 20 is set to 50 to 200 μm, the service life of each thermal spray coating 19, 20 can be compensated for about 10 years (total operation time: about 8000 hours).

Further, it is possible to greatly extend the interval of grease replenishment time, and it is possible to surely reduce maintenance work such as greasing work which is a burden on the operator. Further, it is possible to reliably prevent adhesion wear and the like that occurs between the sprayed coatings 19 and 20, and it is possible to effectively generate an abnormal noise such as a “squeaking noise” due to such wear when the bucket 8 rotates. Can be prevented.

Further, when the earth and sand enter the slight gap between the end faces 13B and 14C, the sprayed coatings 19 and 2 are formed.
It is possible to reliably prevent severe wear such as abrasive wear from occurring at 0. As a result, rattling of the bucket 8 with respect to the arm 7 in the axial direction can be eliminated, and abnormal noise such as "rattle" caused by such rattling can be prevented. As a result, it is possible to effectively reduce the noise source generated from the hydraulic excavator including the above-mentioned "squeaking noise" and the like, and it is possible to maintain a comfortable working environment.

Furthermore, it is possible to prevent the grease replenished between the thermal spray coatings 19 and 20 from leaking to the outside through the gap between the thermal spray coatings 19 and 20, and to improve the appearance of the bearing device. Can be good.

On the other hand, each of the thermal spray coatings 19 and 20 is formed by subjecting each end face 13B, 14C to a thermal spray treatment of a powder material containing a total of 27% by weight of nickel and chromium in a cemented carbide material such as tungsten carbide. It can be easily formed, and the reliability of each thermal spray coating 19, 20 as a hard and wear-resistant layer having rigidity can be surely enhanced.

Further, by forming each of the thermal spray coatings 19 and 20 by thermal spraying treatment, the surface of each of the thermal spray coatings 19 and 20 can be easily formed as an uneven surface having a surface roughness of about 30 μm or less. As a result, after the thermal spraying treatment, it is possible to eliminate the work of forming the uneven surface by subjecting the surfaces of the thermal spray coatings 19 and 20 to surface treatment, and to improve the workability when forming the thermal spray coatings 19 and 20. It can be effectively improved.

Further, each of the thermal spray coatings 19 and 20 can be formed of a ceramic material instead of the cemented carbide material, and the material selection for forming each of the thermal spray coatings 19 and 20 can be facilitated.

Next, FIG. 4 shows a second embodiment of the present invention. The feature of this embodiment is that after a surface treatment layer having corrosion resistance is previously formed on the contact surface between the boss portion and the bracket portion,
Each wear-resistant layer is provided on the surface-treated layer. 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 figure, 31 and 31 are surface treatment layers provided on the end faces 13B of the arm boss 13, and 32 and 32 are surface treatment layers provided on the end face 14C side of the brackets 14, respectively. Then, the surface treatment layers 31, 3
Spray coatings 33 and 34 described later are formed on the surface 2.

Here, the surface treatment layers 31 and 32 are the end faces 1
Electroless nickel plating treatment is performed on 3B and 14C to form a nickel layer having corrosion resistance, and the thickness dimension thereof is set to about 5 to 20 μm.

When a plurality of pores or the like are formed in the thermal spray coatings 33 and 34 as described later, the surface treatment layers 31 and 32 have the end surfaces 13B and 14C directly exposed to the outside air through the pores and the like. It reliably prevents exposure to and corrosion.

33, 33 are end faces 13 of the arm boss 13.
Thermal spray coating as wear resistant layer provided on B side, 34, 3
Reference numeral 4 denotes a thermal spray coating provided on the end surface 14C side of each bracket 14. And each of the thermal spray coatings 3
3 and 34 are formed on the surface treatment layers 31 and 32 in the same manner as the thermal spray coatings 19 and 20 described in the first embodiment. Here, the thermal spray coatings 33, 34 may be formed with a plurality of pores (not shown) penetrating in the thickness direction depending on the processing conditions at the time of formation.

The surface treatment layers 31 and 32 and the thermal spray coatings 33 and 34 are appropriately subjected to heat treatment or the like at about 500 ° C. to 700 ° C. to form the end faces 13B and 14C and the surface treatment layers 31 and 32. And between the surface treatment layers 3
Although the adhesion between the thermal sprayed coatings 33 and 34 can be further improved, and the hardness of the thermal sprayed coatings 33 and 34 can be further improved. , 34 may be arbitrarily selected in consideration of the sliding characteristics required as the wear resistant layer, the processing cost required for the heat treatment, and the like.

Thus, in this embodiment having such a structure, it is possible to obtain substantially the same operational effects as those of the first embodiment, but particularly in this embodiment, the respective end faces 13B, 14 are formed.
Each surface treatment layer 31, 32 having corrosion resistance is formed on C, and each thermal spray coating 3 is formed on each surface treatment layer 31, 32.
Since 3, 34 are formed, it is possible to reliably prevent the end surfaces 13B, 14C from being exposed to the outside air and corroding, and thereby the durability of the arm boss 13 and each bracket 14 can be significantly improved. The life of the bearing device can be extended more reliably, and the reliability of the device can be further improved.

Further, the surface treatment layers 31, 32 and the thermal spray coatings 33, 34 are appropriately subjected to heat treatment or the like at about 500 ° C. to 700 ° C. to enhance the sliding characteristics etc. of the end faces 13B, 14B. , The reliability can be greatly improved.

Next, FIGS. 5 to 7 show a third embodiment of the present invention. The feature of this embodiment is that a surface treatment layer having corrosion resistance is previously formed on the contact surface between the boss portion and the bracket portion. After that, each abrasion-resistant layer is provided on the surface-treated layer. 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 figure, 41 is each end surface 13 of the arm boss 13.
Reference numeral 42 denotes an annular groove provided in B, and 42 denotes an annular groove provided in the end surface 14C of each bracket 14 (only one is shown in each case). Here, as shown in FIGS. 5 and 6, each of the annular grooves 41 has the end face 13B formed in the bush fitting hole 1
It is formed as a circular groove concentric with the bush fitting hole 13A by notching radially outward from the position of the outer edge portion of 3A.

Further, each annular groove 42 is formed as an annular concave groove in each end face 14C at a position corresponding to each annular groove 41,
The groove depth and groove width correspond to each annular groove 41.
Then, ring-shaped members 43 and 44, which will be described later, are provided in the annular grooves 41 and 42, respectively.

Reference numeral 43 denotes a ring-shaped member provided in each annular groove 41, and 44 denotes a ring-shaped member provided in each annular groove 42 (only one is shown in each case). Here, the ring-shaped members 43, 44 are formed as annular discs as shown in FIG. 7, and bolt insertion holes 43A, 43A, ..., Bolt insertion holes 44A, 44A are provided at upper, lower, left and right positions thereof. ，
Are formed respectively. In addition, the ring-shaped member 4
Each of the thermal spray coatings 46, 47 described later is previously formed on the surface of
Are formed.

Then, the ring-shaped members 43 and 44 are inserted into the respective bolt insertion holes 43A and 44A with the bolts 45 (only four are shown) and the screw holes 48 and 49 to be described later.
It is fitted in each annular groove 41, 42 by being screwed into. Further, the plate thickness dimension of the ring-shaped members 43 and 44 is formed to be equal to or greater than the groove depth of each annular groove 41 (each annular groove 42).
The surfaces of 3, 44 are located substantially on the same plane as the end surfaces 13B, 14C.

Reference numeral 46 denotes a sprayed coating as a wear resistant layer formed on the surface of each ring-shaped member 43, and 47 denotes a sprayed coating as a wear resistant layer formed on the surface of each ring-shaped member 44 (both are 1 Only the individual pieces are shown).

Although the thermal spray coatings 46 and 47 are formed on the surfaces of the ring-shaped members 43 and 44 in substantially the same manner as the thermal spray coatings 19 and 20 described in the first embodiment, Each of the thermal spray coatings 46, 47 is formed at the upper, lower, left, and right positions through the bolt insertion holes 43A, 44A. Then, when the bucket 8 is rotated, the thermal spray coatings 46, 47 are slid on each other, so that the end surfaces 13
It surely prevents B and 14C from sliding directly.

Incidentally, 48 and 49 are the bolt insertion holes 4 described above.
3A and 44A show screw holes formed on the groove bottom side of each annular groove 41 and each annular groove 42 at positions corresponding to 3A and 44A.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same operational effects as those of the first embodiment, but in particular, in this embodiment, each of the arms 7 and the bucket 8 is formed. When it is difficult to directly perform thermal spraying on the end faces 13B and 14C, the thermal spray coatings 46 and 47 are formed on the surfaces of the ring-shaped members 43 and 44 in advance, and then the ring-shaped members 46 and 47 are attached to the bolts. Through 45 etc.
By fitting each annular groove 41 and each annular groove 42,
The thermal spray coatings 46, 47 can be easily formed on the end faces 13B, 14C.

Next, FIGS. 8 and 9 show a fourth embodiment of the present invention, which is characterized in that one of the contact surfaces of the boss portion and the bracket portion is provided. A shim plate for adjusting the clearance, which is a ring-shaped member, is arranged, and a surface treatment layer having corrosion resistance is formed in advance on the surface of the shim plate and the contact surface of the other side. There is a wear layer. In this embodiment, the same components as those in the second embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numerals 50, 50, ... Show three screw holes formed by penetrating the bracket 14 in the plate thickness direction. The screw holes 50 are spaced apart from each other by about 120 degrees as shown in FIG. Are arranged in the circumferential direction of the pin insertion hole 14A. Further, each bolt 51 is screwed into each screw hole 50, and each bolt 51 has a tip portion 51A protruding from the end surface 14C of the bracket 14 toward a shim plate 52 described later by a certain dimension.

Reference numeral 52 denotes a shim plate for adjusting the clearance, which is a ring-shaped member. As shown in FIG. 9, the shim plate 52 is composed of a pair of shim halves 52A and 52A formed in a substantially half ring shape. The shim halves 52A are arranged at positions symmetrical to the left and right with respect to the dividing line OO.

Here, engaging grooves 53, 53, 54, 54 are formed as notch grooves in the respective shim half-split bodies 52A at positions corresponding to the tips 51A of the respective bolts 51. The engaging grooves 53 are slanted at an angle .theta.1 of about 60.degree. With respect to the dividing line OO at the lower part of the substantially semicircular inner end of the ends of the shim halves 52A. It opens upward. Further, each of the engaging grooves 54 is opened at an upper end portion along the dividing line OO in the end portion of each of the shim halves 52A in a direction perpendicular to the dividing line OO.

Then, the engaging groove 53 of each of the shim halves 52A is formed.
Are engaged with bolts 51 located on both the left and right sides of the dividing line OO so as to be hooked from the outside in the radial direction, and each engaging groove 54 is engaged with the opposing engaging groove 54. Abutting against each other, a substantially circular alignment groove is formed so that the bolt 51 located on the dividing line OO can be engaged from both the left and right sides.

Reference numeral 55 denotes a surface treatment layer provided on the surface of the shim plate 52, and 56 denotes a thermal spray coating formed on the surface treatment layer 55. The surface treatment layer 55 and the thermal spray coating 56 are formed on the second surface. The surface treatment layers 31 and 32 and the thermal spray coatings 33 and 34 described in the examples are formed. Then, by appropriately changing the plate thickness dimension of the shim plate 52, a gap between the spray coating 56 formed on the shim plate 52 and the spray coating 33 formed on the end surface 13B of the arm boss 13 is eliminated, and each bracket is removed. Axial rattling of the arm boss 14 with respect to the arm boss 13 is reliably prevented.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same effects as the second embodiment. However, particularly in this embodiment, the end surface 13B of the arm boss 13 and the end surface of the bracket 14 can be obtained. The shim plate 52 for gap adjustment is arranged between the shim plate 52 and the 14C, and the sprayed coating 56 is formed on the surface of the shim plate 52 via the surface treatment layer 55. By replacing them, it is possible to reliably prevent the rattling of each bracket 14 in the axial direction with respect to the arm boss 13, and it is possible to significantly improve the durability of the shim plate 52 and further improve the reliability of the device. Can be made.

Next, FIG. 10 shows a fifth embodiment of the present invention. In this embodiment, the same components as those in the fourth embodiment are designated by the same reference numerals and the description thereof will be omitted. And
However, the feature of this embodiment is that four bolts 61 are provided on the bracket 14 in place of the three bolts 51 described in the fifth embodiment, and the shim plate 62 is provided between the bolts 61 and the arm boss. Is disposed between the end surface (not shown) of the bracket 14 and the end surface 14C of the bracket 14, and the sprayed coating 65 is formed on the surface of the shim plate 62 via a surface treatment layer (not shown).

Here, the bolts 61 are arranged in the circumferential direction with respect to the pin insertion hole 14A of the bracket 14 so as to be spaced apart upward, downward, left, and right, and the tip end 61A of the bolt 61 is attached to the bracket 1.
The end surface 14C of No. 4 projects outward by the thickness of the shim plate 62.

Further, the shim plate 62 is composed of a pair of half ring-shaped shim halves 62A and 62A, which is similar to each of the shim halves 52A described in the fifth embodiment. . However, substantially U-shaped engaging grooves 63, 63 are formed in the middle part of the inner end of the semi-circular shaped member 62A, which has a substantially semi-circular shape, along the dividing line OO. In addition, it differs from the shim plate 52 in that substantially U-shaped engaging grooves 64, 64 are formed in the upper and lower end surfaces.

The engaging groove 63 opens obliquely downward at an angle .theta.2 of about 60.degree. With respect to the dividing line OO, and engages with the tips 61A of the bolts 61 located on the left and right sides. At the same time, the engagement grooves 64, 64 open in the direction perpendicular to the dividing line OO, and are engaged with the tip portions 61A of the bolts 61 located above and below.

Thus, in this embodiment having the above-mentioned structure, it is possible to obtain the same effects as those of the fifth embodiment.

Next, FIG. 11 shows a sixth embodiment of the present invention. In this embodiment, the same components as those in the fourth embodiment are designated by the same reference numerals, and the description thereof will be omitted. And
However, the feature of this embodiment is that four bolts 71 are provided on the bracket 14 in place of the three bolts 51 described in the fifth embodiment, and the shim plate 72 is provided between the arm bosses 71 through the respective bolts 71. Is disposed between the end surface (not shown) and the end surface 14C of the bracket 14, and the spray coating 75 is formed on the surface of the shim plate 72 via a surface treatment layer (not shown).

Here, the bolts 71 are arranged on the left and right sides of the parting line OO so as to be spaced apart from each other on the upper and lower sides, and the tip end portion 7
1A projects outward from the end surface 14C of the bracket 14 by the thickness of the shim plate 72.

Further, the shim plate 72 is composed of shim halves 72A, 72A formed in a substantially C shape, and the arc of each of the shim halves 72A has an angle range of, for example, about 120 to 170 degrees. It extends all over. And each of the shim halves 7
The upper end of the arc-shaped inner end of the 2A end is approximately U
The U-shaped engaging grooves 73, 73 are formed, and the substantially U-shaped engaging grooves 74, 74 are formed on the end surface located on the opposite side to the upper end surface along the dividing line OO.

The engaging groove 73 opens obliquely downward, and the tip portions 7 of the left and right bolts 71 located on the upper side.
1A, the engaging groove 74 is opened obliquely downward at an angle θ3 of about 45 degrees with respect to the dividing line OO, and the tip portions 71A of the left and right bolts 71 located on the lower side.
Is engaged.

Thus, in this embodiment having the above-mentioned structure, it is possible to obtain the same effects as those of the fifth embodiment.

Next, FIG. 12 shows a seventh embodiment of the present invention. In this embodiment, the same components as those in the fifth embodiment are designated by the same reference numerals and the description thereof will be omitted. And
However, the feature of this embodiment is that the shim halves 62A forming the shim plate 62 are replaced with the engaging grooves 63 and 64 described in the fifth embodiment, and the outer shape is an arc shape. Larger engagement grooves 81 and 82 are formed, and the engagement grooves 81 and 8 are formed.
2 is opened in a direction substantially perpendicular to the dividing line OO.

Thus, in this embodiment having the above-mentioned structure, it is possible to obtain the same effects as those of the fifth embodiment.

In the third embodiment described above, only the thermal spray coatings 46, 47 are formed on the surfaces of the ring-shaped members 43, 44, but the present invention is not limited to this.
The surface treatment layers described in the second embodiment may be previously formed on the surfaces of the ring-shaped members 43 and 44, and then the thermal spray coatings 46 and 47 may be formed on the surface treatment layers.

In the first to third embodiments, the thermal spray coatings 19, 20 (33, 34, 46, 47) are formed on the end faces 13B, 14C of the arm boss 13 and the brackets 14, respectively. However, the present invention is not limited to this, and for example, the thermal spray coating is formed only on one of the end surfaces 13B and 14C (contact surface), and the thermal spray coating is directly formed on the other end surface (contact surface). Alternatively, the contact may be made indirectly via a shim plate or the like, which can surely prevent the end surface (contact surface) on the side where the sprayed coating is formed from being worn or damaged.

On the other hand, of the end faces 13B, 14C, a wear resistant layer such as a thermal spray coating made of cemented carbide is formed on one end face side, and a ceramic material (for example, silicon carbide, titanium carbide, alumina) is formed on the other end face side. And a wear resistant layer such as a thermal spray coating made of a ceramic material containing chromium oxide as a main component).

Further, in each of the above-described embodiments, each of the thermal spray coatings 19, 20 (33, 34, 46, 4) is rotated when the bucket 8 is rotated.
7, 56, 65, 75) are directly slid on each other, but the respective sprayed coatings 19, 20 (33, 34,
46, 47, 56, 65, 75), a thrust plate (a shim plate or the like) for receiving the thrust load from the arm 7 or the bucket 8 may be arranged.

Furthermore, in the above-described embodiment, the bearing device is described as being provided in the pin coupling portion between the arm 7 and the bucket 8, but the present invention is not limited to this, and for example, the work shown in FIG. In the device 5, the bearing device may be applied to the pin connecting portion between the swing frame 3 and the boom 6 and the pin connecting portion between the boom 6 and the arm 7. Further, the bearing device is not limited to the hydraulic excavator, and the hydraulic device is not limited to the hydraulic excavator. It may be applied to other construction machines such as cranes.

[0112]

As described in detail above, according to the present invention, as described in claim 1, at least one of the contact surfaces of the boss portion and the bracket portion has a hard resistance having rigidity. Since a wear layer is provided and the wear resistant layer is made of either one of a cemented carbide material and a ceramic material, it is supplied between the wear resistant layers when the boss portion is rotated relative to the bracket portion. Even if a lubricant such as grease causes an oil film to run out, or if earth and sand enter the slight gaps between the contact surfaces, severe wear such as abrasive wear or adhesive wear between the wear-resistant layers Can be effectively prevented.

Therefore, it is possible to surely prevent the contact surfaces of the boss portion and the bracket portion from directly sliding on each other when the boss portion is rotated, and the contact surfaces are worn or damaged. The life of the bearing device can be reliably extended, and the reliability and the like of the device can be significantly improved. Also,
The interval of grease replenishment time can be greatly extended,
It is possible to reliably reduce maintenance work such as greasing work, which is a burden on the operator. Furthermore, it is possible to effectively prevent abnormal noise such as “squeaking” or “rattle” from occurring between the contact surfaces when the brackets are rotated, and when the bearing device is used in a construction machine or the like. Can maintain a comfortable working environment. Furthermore, either one of the cemented carbide material and the ceramic material can be selected as the wear resistant layer, and the material for forming the wear resistant layer can be easily selected.

Further, according to the invention described in claim 2, even when the wear resistant layer has a porous structure and pores or the like are formed so as to penetrate therethrough in the thickness direction, the contact surface is corroded. The surface treatment layer can surely prevent the boss portion and the bracket portion from being damaged, and the life of the bearing device can be extended more reliably. The reliability of can be further improved.

Further, in the invention according to claim 3, even when it is difficult to directly form the wear resistant layer on the contact surface on the boss side or the contact surface on the bracket side, the wear resistant layer is formed on at least the ring-shaped member. A wear-resistant layer can be easily formed on the contact surface by fitting the ring-shaped member onto the contact surface after pre-forming on the surface side. It is possible to reliably improve efficiency and the like.

Furthermore, in the invention described in claim 4,
Even when pores or the like are formed to penetrate through the wear-resistant layer in the thickness direction thereof, the surface treatment layer can reliably prevent the surface of the ring-shaped member from corroding. It is possible to greatly improve durability and the like.

On the other hand, in the invention described in claim 5, the surface treatment layer having corrosion resistance can be easily formed by electroless nickel plating, and the surface treatment layer allows the contact surface (ring shape) between the boss portion and the bracket portion to be formed. Corrosion of the surface of the member can be reliably prevented, and the durability and the like of the boss portion and the bracket portion (ring-shaped member) can be further improved.

In the invention according to claim 6, the contact surface between the boss portion and the bracket portion (the surface of the ring-shaped member) is
It is possible to easily form a thermal spray coating as a wear resistant layer, and to form an uneven surface having a surface roughness of about several tens of μm by performing surface processing etc. on the surface of each thermal spray coating after the thermal spray treatment. It is possible to eliminate unnecessary work and surely improve workability when forming each sprayed coating.

Further, according to the invention of claim 7, the sprayed coating can be reliably formed as a wear resistant layer having excellent wear resistance and high hardness, and the reliability of the sprayed coating as the wear resistant layer can be further improved. Can be improved. Further, by appropriately subjecting the wear resistant layer and the surface-treated layer to heat treatment,
The reliability of the thermal spray coating as the wear resistant layer can be greatly improved.

Furthermore, in the invention described in claim 8,
The sprayed coating can be reliably kept in a lubricated state by a lubricant such as grease for a long period of time, and smooth rotation of the bracket portion with respect to the boss portion can be reliably compensated.
Further, when a lubricant such as grease is supplied to the wear resistant layer, it is possible to further extend the greasing interval at the time of greasing grease and the like, and it is possible to greatly reduce the greasing work performed by the operator. .

Further, it is possible to surely prevent the lubricant such as grease from leaking to the outside from the contact surface between the boss portion and the bracket portion, and the leakage of such grease or the like causes the appearance of the bearing device concerned. It is possible to reliably prevent the appearance of the item from being deteriorated.

On the other hand, in the invention described in claim 9, it is possible to reliably prevent the contact surfaces of both the boss portion and the bracket portion from being worn or damaged, and to further improve the life of the bearing device. It can be postponed.

According to the tenth aspect of the invention, the ring-shaped members can be slid against each other, and the contact surfaces of both the boss portion and the bracket portion are surely prevented from being worn or damaged. Therefore, it is possible to obtain an effect substantially similar to that of claim 9.

[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 of the present invention is applied.

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

FIG. 3 is a cross-sectional view of essential parts showing an enlarged view of a boss portion, a bracket portion, a thermal spray coating and the like in FIG.

FIG. 4 is an enlarged view showing a boss portion, a bracket portion, a thermal spray coating and the like of a bearing device according to a second embodiment of the present invention.
It is a sectional view similar to FIG.

FIG. 5 is an enlarged vertical sectional view showing a main part of a bearing device according to a third embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view of essential parts showing a boss portion, a bracket portion, a ring-shaped member, a thermal spray coating and the like in FIG.

FIG. 7 is a front view showing the ring-shaped member in FIG.

FIG. 8 is an enlarged view showing a boss portion, a bracket portion, a thermal spray coating and the like of a bearing device according to a fourth embodiment of the present invention.
It is a sectional view similar to FIG.

9 is a cross-sectional view showing the overall shape of the shim plate as viewed in the direction of the arrow IX-IX in FIG.

FIG. 10 is a sectional view similar to FIG. 9 showing an overall shape of a shim plate according to a fifth embodiment of the present invention.

FIG. 11 is a sectional view similar to FIG. 9 showing an overall shape of a shim plate according to a sixth embodiment of the present invention.

FIG. 12 is a sectional view similar to FIG. 9 showing an overall shape of a shim plate according to a seventh embodiment of the present invention.

[Explanation of symbols]

5 Working device 7 Arm (one side member) 8 Bucket (counterpart member) 13 Arm boss (boss part) 13B End surface (contact surface) 14 Bracket (bracket part) 14C End surface (contact surface) 16 Connecting pin 19, 20, 33, 34 , 46, 47, 56, 65, 7
5 Thermal Sprayed Coating (Abrasion Resistant Layer) 31, 32, 55 Surface Treatment Layer 43, 44 Ring Member 52, 62, 72 Shim Plate (Ring Member) 52A, 62A, 72A Shim Half Split Body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Manabu Ogasawara 650, Kazunachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Tsuchiura Plant

Claims (10)

[Claims] 1. A bearing device in which a boss portion of a one-side member and a bracket portion of a counterpart member are rotatably connected via a connecting pin, and at least one of contact surfaces of the boss portion and the bracket portion is A bearing device characterized in that a hard wear-resistant layer having rigidity is provided on one of the contact surfaces, and the wear-resistant layer is made of one of a cemented carbide material and a ceramic material. 2. A surface treatment layer having corrosion resistance is previously formed on at least one contact surface of the contact surfaces of the boss portion and the bracket portion, and then the wear resistant layer is provided on the surface treatment layer. The bearing device according to claim 1, which is configured. 3. A bearing device in which a boss portion of one side member and a bracket portion of a mating member are rotatably connected via a connecting pin, and at least one of contact surfaces of the boss portion and the bracket portion. A ring-shaped member through which the connecting pin is inserted is fitted on the contact surface side of the ring-shaped member, and at least the surface side of the ring-shaped member is made of either a cemented carbide material or a ceramic material. A bearing device comprising a wear resistant layer made of one material. 4. The bearing according to claim 3, wherein a surface treatment layer having corrosion resistance is previously formed on the surface side of the ring-shaped member, and then the wear resistant layer is provided on the surface treatment layer. apparatus. 5. The bearing device according to claim 2, wherein the surface treatment layer is formed by electroless nickel plating treatment. 6. The wear resistant layer is formed of a thermal spray coating formed by thermal spraying one of the cemented carbide material and the ceramic material. The bearing device according to 4 or 5. 7. The bearing device according to claim 6, wherein the thermal spray coating is formed by subjecting a cemented carbide material to a powder material containing nickel and chromium in an amount of 10 to 30 wt% in total. . 8. The uneven surface having a surface roughness of about 30 μm or less is provided on the surface of the wear resistant layer.
The bearing device according to 2, 3, 4, 5, 6 or 7. 9. A bearing device in which a boss portion of a one-side member and a bracket portion of a mating member are rotatably connected via a connecting pin, wherein contact surfaces of both the boss portion and the bracket portion are provided. A bearing formed by forming a wear-resistant layer, the wear-resistant layer containing 10 to 30% by weight of nickel and chromium in total, and the rest being formed by spraying a powder material made of a cemented carbide material. apparatus. 10. A bearing device in which a boss portion of a one-side member and a bracket portion of a mating member are rotatably connected via a connecting pin, wherein contact surfaces of both the boss portion and the bracket portion are provided. , Ring-shaped members into which the connecting pins are inserted are provided on the inner peripheral side, and wear-resistant layers are formed on at least the surface side of the ring-shaped members, and the wear-resistant layers are nickel and chromium. Of 10 to 30% by weight in total, and the rest is formed by thermal spraying a powder material made of a cemented carbide material.