JP5148371B2 - Bearing device - Google Patents

Description

  The present invention relates to a bearing device suitable for use in, for example, a pin coupling portion of a working device equipped in a construction machine such as a hydraulic excavator.

  Generally, a hydraulic excavator as a construction machine is provided with a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and an upside-down movable structure on the front side of the upper revolving body. It is roughly constituted by the working device. The working device of the hydraulic excavator is roughly constituted by a boom, an arm and a bucket, and a bearing device is used between the upper swing body and the boom, between the boom and the arm, and between the arm and the bucket. It is connected so that it can rotate.

  Here, for example, the bearing device provided between the boom and the arm is inserted into the boss member provided on the base end side of the arm and having an inner peripheral side as a bush fitting hole, and the bush fitting hole of the boss member. And a pair of brackets, which are provided on the front end side of the boom and are arranged to face the boss member of the arm in the axial direction, and are fitted into the bushes of the boss member and the brackets. It is generally constituted by a connecting pin that is rotatably connected.

  In this case, since the inner peripheral surface of the bush and the outer peripheral surface of the connecting pin are always in sliding contact, an oil groove is usually formed on the inner peripheral surface of the bush, and lubricating oil such as grease is supplied to the oil groove. Thus, the sliding contact surface between the inner peripheral surface of the bush and the connecting pin is lubricated (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 7-35556

  Here, in the above-described conventional bearing device, a grease passage is formed in the central portion of the connecting pin, and the grease supplied to the grease passage is filled in a grease reservoir chamber formed inside the boss member. It has a configuration. The grease filled in the grease reservoir is supplied to the sliding contact surface between the inner peripheral surface of the bush and the connecting pin through an oil groove formed on the inner peripheral surface of the bush.

  However, in the above-described conventional bearing device, it is difficult to sufficiently supply the grease filled in the grease reservoir chamber of the boss member to the oil groove formed on the inner peripheral surface of the bush. There is a problem that the lubricity of the sliding contact surface with the connecting pin is lowered.

  The present invention has been made in view of the above-described problems of the prior art, and can supply a sufficient amount of lubricating oil to the sliding contact surface between the inner peripheral surface of the bush and the connecting pin, thereby improving the lubricity between the two. It is an object of the present invention to provide a bearing device that can perform the above.

In order to solve the above-described problems, the present invention provides a left and right boss cylinder comprising an intermediate cylinder extending in the left and right directions, and cylinders provided at both left and right ends of the intermediate cylinder, respectively. is constituted by the left, and a boss member greasing hole is provided to the inner peripheral side of the right boss cylinder extends radially located inside the end surface becomes bush fitting hole, the left of the boss member a bush which is fitted respectively to the right of the bush fitting bore, and a connecting pin for connecting the thrust bearing disposed on both sides are fitted into these bushings across the boss member and the bush relatively rotatably It is applied to the bearing device provided.

The feature of the configuration in which the invention of claim 1 is adopted, the bush, the left, and an inner bush which is arranged at a site corresponding to Kyuaburaana respectively formed on the right of the boss cylinder, these than the axial dimension of the inner bushing is arranged between the inner bushing and the thrust bearing is constituted by an outer bush set to long, the inner bushing, the total located in the inner peripheral side thereof An inner circumferential annular groove comprising a circumferential groove is provided, and an oil hole for guiding the lubricating oil from the greasing hole to the inner circumferential annular groove is provided. On the inner circumferential side of the outer bush, a spiral shape along the connecting pin is provided. And a spiral groove into which lubricating oil flows from the inner annular groove of the inner bush.

According to the invention of claim 2, the inner bush is provided with an outer peripheral annular groove including an entire peripheral groove at a position corresponding to the greasing hole on the outer peripheral side of the inner bush, and the oil hole includes the outer annular groove and the there between the inner circumferential annular groove lubricating oil from communicating with the lubrication hole from said outer peripheral annular groove that has a configuration which leads to the inner peripheral annular groove.

The invention of claim 3 resides in that the outer bush is formed using a sintered metal material.

According to a fourth aspect of the present invention, the spiral groove of the outer bush is constituted by a plurality of concave grooves that are continuous from one end side to the other end side in the axial direction of the outer bush and both end portions are open to the end surfaces. It is in.

  According to the first aspect of the present invention, when lubricating oil is supplied to the greasing hole provided in the boss member, the lubricating oil is guided to the inner peripheral annular groove through the oil hole provided in the inner bush, It is supplied to the sliding contact surface between the peripheral surface and the outer peripheral surface of the connecting pin. The lubricating oil overflowing from the inner peripheral annular groove of the inner bush flows into the spiral groove provided on the inner peripheral side of the outer bush, and the sliding contact between the inner peripheral surface of the outer bush and the connecting pin along the spiral groove. Supplied to the surface over a wide range. As a result, a sufficient amount of lubricating oil can be supplied to the sliding contact surfaces of the inner bushing and outer bushing and the connecting pins, and the lubricity of the sliding surfaces of the inner peripheral surfaces of the bushes to the connecting pins can be improved. Can be increased.

  In this case, the spiral groove of the outer bush extends spirally along the connecting pin, so that a large groove length can be secured, and a large amount of lubricating oil can be introduced into the spiral groove. For this reason, for example, even if an unbalanced load or a partly large load is applied to the outer bush due to bending of the connecting pin, the outer bush is caused by a large amount of lubricating oil introduced into the spiral groove of the outer bush. It is possible to reliably lubricate the sliding contact surface between the inner peripheral surface and the connecting pin.

  Furthermore, an inner peripheral annular groove is provided on the inner peripheral side of the inner bush, and a spiral groove is provided on the inner peripheral side of the outer bush, thereby forming the inner peripheral annular groove in the inner bush and the spiral groove in the outer bush. The forming operation can be performed individually. Thereby, for example, complicated grooving such as providing both an annular groove and a spiral groove on the inner peripheral side of one bush can be eliminated, and damage to the cutting tool used for this grooving can be suppressed. As a result, the workability of the work of providing the inner peripheral annular groove on the inner peripheral side of the inner bush and the work of providing the spiral groove on the inner peripheral side of the outer bush can be improved, and the manufacturing cost of the entire bearing device can be reduced. it can.

Moreover , since the axial dimension of the outer bush is set to be longer than the axial dimension of the inner bush, it is possible to make it difficult for the outer bush to come out of the bush fitting hole of the boss member. For this reason, for example, even if an unbalanced load is applied to the outer bush due to the bending of the connecting pin, it is possible to reliably suppress the outer bush from being pulled out from the bush fitting hole of the boss member. As a result, the connecting pin can be stably supported by the inner bush and the outer bush.

According to the invention of claim 2 , by providing the outer peripheral annular groove at a position corresponding to the greasing hole located on the outer peripheral side of the inner bush, the lubricating oil injected into the greasing hole of the boss member is supplied to the inner bush. The outer peripheral annular groove can be reliably guided to the inner peripheral annular groove through the oil hole.

According to the invention of claim 3 , when the outer bush is formed with the metal powder made of the sintered metal material, the spiral groove can be integrally formed on the inner peripheral surface of the outer bush. Thereby, compared with the case where a spiral groove is formed, for example using a cutting tool etc., workability | operativity when forming a spiral groove in an outer side bush can be improved.

According to the invention of claim 4 , the spiral groove of the outer bush is constituted by a plurality of concave grooves that are continuous from one end side to the other end side of the outer bush and both end portions open to the end face. Lubricating oil overflowing from the inner annular groove can surely flow into the respective recessed grooves opened in the end face of the outer bush, and can be supplied over almost the entire length of the outer bush. Accordingly, a sufficient amount of lubricating oil can be supplied to the sliding contact surface between the inner peripheral surface of the outer bush and the connecting pin, and the lubricity between the two can be improved.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a bearing device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where the bearing device is applied to a hydraulic excavator.

  In the figure, reference numeral 1 denotes a hydraulic excavator. The hydraulic excavator 1 includes a self-propelled crawler-type lower traveling body 2, an upper revolving body 3 that is turnably mounted on the lower traveling body 2, and the upper swivel. The working device 4 is provided roughly on the front side of the body 3 so as to be able to move up and down.

  The working device 4 includes a boom 5 that is pivotally connected to the front side of the upper swing body 3, an arm 6 that is pivotally connected to the tip of the boom 5, and the arm 6. The bucket 7 is pivotally connected to the front end side thereof, and the boom cylinder 8, the arm cylinder 9, and the bucket cylinder 10 are roughly configured.

  Here, the pin coupling portion between the upper swing body 3 and the boom 5, the pin coupling portion between the boom 5 and the arm 6, and the pin coupling portion between the arm 6 and the bucket 7 are respectively provided with bearing devices. For example, the boom 5 and the arm 6 are rotatably connected via a bearing device 11 described later.

  Reference numeral 11 denotes a bearing device provided at a pin coupling portion between the boom 5 and the arm 6, and the bearing device 11 supports the arm 6 so as to be rotatable with respect to the boom 5. As shown in FIG. 2, the bearing device 11 includes an arm boss 12, an inner bush 17, an outer bush 21, each bracket 23, a connecting pin 27, and the like, which will be described later.

  Reference numeral 12 denotes an arm boss as a boss member provided on the base end side of the arm 6, and the arm boss 12 is integrally fixed to the base end side of the arm 6 using means such as welding. Here, the arm boss 12 is formed of a thin cylindrical body extending from the left and right sides of the intermediate cylinder 13 and a thick cylindrical body fixed to the left and right ends of the intermediate cylinder 13 by welding. And left and right boss cylinders 14, 14. The inner peripheral side of the left and right boss cylinders 14 is a bush fitting hole 14A, and an inner bush 17 and an outer bush 21 described later are fitted into the bush fitting hole 14A. Yes.

  15 and 15 are greasing holes formed in the left and right boss cylinders 14, and the greasing holes 15 are located on the inner side (on the intermediate cylinder 13 side) of the end face 14 </ b> B in the axial direction of the boss cylinder 14. Then, it is drilled in the radial direction and opens to the bush fitting hole 14A. A grease nipple 16 is screwed into each greasing hole 15, and a grease gun or the like (not shown) is connected to the grease nipple 16, so that an outer peripheral annular groove of an inner bush 17 described later through the greasing hole 15. In this configuration, lubricating oil such as grease can be supplied to the inner circumferential groove 18 and the inner circumferential groove 18.

  Reference numerals 17 and 17 denote cylindrical inner bushes respectively inserted into the bush fitting holes 14A of the left and right boss cylinders 14, and each of the inner bushes 17 corresponds to the greasing hole 15 of the boss cylinder 14. It is arranged at a position and is fitted in the bush fitting hole 14A in a press-fitted state. Here, as shown in FIGS. 2 to 4, the inner peripheral side of the inner bush 17 becomes a pin insertion hole 17 </ b> A into which a later-described connecting pin 27 is slidably inserted. The connecting pin 27 is slidably supported together with the outer bush 21. Further, an outer peripheral annular groove 18 described later is formed on the outer peripheral surface 17B of the inner bush 17, and an inner peripheral annular groove 19 described later is formed on the inner peripheral surface 17C of the inner bush 17.

  Reference numeral 18 denotes an outer peripheral annular groove formed on the outer peripheral surface 17B of the inner bush 17. The outer peripheral annular groove 18 cuts out the central portion in the axial direction of the outer peripheral surface 17B of the inner bush 17 in a concave shape over the entire circumference. Thus, it is formed as a circumferential groove having a groove width larger than the diameter of the greasing hole 15. The outer peripheral annular groove 18 is arranged at a position corresponding to the greasing hole 15 of the boss cylinder 14, and the lubricating oil injected into the greasing hole 15 is introduced into the outer peripheral annular groove 18. Yes.

  Reference numeral 19 denotes an inner peripheral annular groove formed on the inner peripheral surface 17C of the inner bushing 17, and this inner peripheral annular groove 19 is recessed in the central portion in the axial direction of the inner peripheral surface 17C of the inner bushing 17 over the entire circumference. By being notched in a shape, it is formed as an entire circumferential groove having a groove width substantially equal to the outer circumferential annular groove 18. The inner peripheral annular groove 19 communicates with the outer peripheral annular groove 18 through each oil hole 20 described later.

  Reference numerals 20 and 20 denote a plurality of (for example, two) oil holes provided penetrating in the radial direction of the inner bush 17, and each oil hole 20 includes an outer annular groove 18 and an inner annular groove provided in the inner bush 17. 19 to communicate with. As a result, the lubricating oil injected into the greasing hole 15 of the boss cylinder 14 is guided from the outer peripheral annular groove 18 to the inner peripheral annular groove 19 through the oil hole 20, and the inner peripheral surface 17C of the inner bush 17 and the later-described It is configured to be supplied to the slidable contact surface with the connecting pin 27.

  21 and 21 are a pair of left and right cylindrical outer bushes that are inserted into the bushing fitting holes 14A of the left and right boss cylinders 14 adjacent to the inner bushing 17. It arrange | positions between the bush 17 and the bracket 23 mentioned later, and is fitted in the bush fitting hole 14A in the press-fit state.

Here, the outer bush 21 is configured as a porous sintered oil-impregnated bearing formed using a sintered metal material, and includes, for example, a lubricating oil such as mineral oil or synthetic oil, or MoS ₂ (two Solid lubricants such as molybdenum sulfide), WS ₂ (tungsten disulfide), and graphite are impregnated. The inner peripheral side of the outer bush 21 is a pin insertion hole 21A into which a later-described connecting pin 27 is slidably fitted. The outer bush 21 can slide the connecting pin 27 together with the adjacent inner bush 17. To support. Further, a spiral groove 22 described later is formed on the inner peripheral surface 21 </ b> B of the outer bush 21.

  Reference numeral 22 denotes a spiral groove formed on the inner peripheral surface 21B of the outer bush 21. The spiral groove 22 is constituted by a plurality of concave grooves 22A extending spirally along a connecting pin 27 described later. Lubricating oil overflowing from the inner peripheral annular groove 19 flows. Here, as shown in FIGS. 3 and 5, the concave grooves 22 </ b> A constituting the spiral groove 22 are arranged at equal intervals in the circumferential direction of the outer bush 21, and the other from one end side in the axial direction of the outer bush 21. It is continuous toward the end side. Further, both end portions of each concave groove 22 </ b> A are open ends 22 </ b> B and 22 </ b> B that open to the end surface 21 </ b> C in the axial direction of the outer bush 21.

  Then, the lubricating oil overflowing from the inner peripheral annular groove 19 of the inner bush 17 flows into each concave groove 22A constituting the spiral groove 22 through the opening end 22B, and this lubricating oil flows along each concave groove 22A. By being supplied over almost the entire length of the outer bush 21, the sliding contact surface between the inner peripheral surface 21 </ b> B of the outer bush 21 and the connecting pin 27 can be lubricated with a sufficient amount of lubricating oil. ing.

  On the other hand, as shown in FIG. 3, assuming that the axial dimension of the outer bush 21 is A and the axial dimension of the inner bush 17 is B, these axial dimensions A and B are set in the relationship of the following formula 1. Yes.

  Thus, by setting the axial dimension A of the outer bush 21 to be longer than the axial dimension B of the inner bush 17, the bush fitting hole 14A of the boss cylinder 14 constituting the arm boss 12 is It is possible to make it difficult for the outer bush 21 to come off in the axial direction. Thereby, for example, even if the connecting pin 27 is bent and an unbalanced load is applied to the outer bush 21, the outer bush 21 is prevented from being pulled out from the bush fitting hole 14 </ b> A, and is connected by the inner bush 17 and the outer bush 21. The pin 27 can be stably supported.

  Further, since the outer bush 21 provided with the spiral groove 22 is formed using a sintered metal material, when the outer bush 21 is formed with metal powder made of a sintered metal material, A spiral groove 22 composed of a plurality of concave grooves 22A can be integrally formed on the inner peripheral surface 21B. Thereby, compared with the case where a spiral groove is formed, for example using a cutting tool etc., it becomes the structure which can improve workability | operativity when forming the spiral groove 22 in the internal peripheral surface 21B of the outer side bush 21. FIG. .

  23 and 23 are a pair of left and right brackets as counterpart members provided at the tip of the boom 5. Each bracket 23 is formed in a flat plate shape using a thick steel plate or the like, and the connecting pin 27 is inserted. A pin insertion hole 23A to be fitted is provided. Each bracket 23 is disposed so as to face the arm boss 12 in the axial direction with the arm boss 12 sandwiched from the left and right directions, and the arm boss 12 is connected by the connecting pin 27 inserted into the pin insertion hole 23A. It is supported so as to be relatively rotatable. Here, a locking plate 24 for locking the connecting pin 27 is fixed to one bracket 23 by means of welding or the like, and the connecting pin 27 is removed from the locking plate 24 in the axial direction. The retaining plate 25 to be secured is detachably attached using a bolt 26.

  Reference numeral 27 denotes a connecting pin for connecting the arm boss 12 and the left and right brackets 23 in a relatively rotatable manner. The connecting pin 27 is an inner bush fitted to the boss cylinder 14 of the arm boss 12 as shown in FIG. 17 and the outer bush 21, and the left and right brackets 23 are slidably inserted into the pin insertion holes 23A. Here, on one end side in the axial direction of the connecting pin 27, a flange portion 27A having a substantially trapezoidal shape with a tip end side tapered is integrally provided.

  Then, by inserting the connecting pin 27 into the inner bush 17 and the outer bush 21 of the arm boss 12 and the pin insertion holes 23A of the left and right brackets 23, the arm boss 12 and the left and right brackets 23 are connected to each other. 27 is connected so as to be relatively rotatable. In this state, the flange portion 27A of the connecting pin 27 is engaged with the retaining plate 24 of the bracket 23, and is sandwiched between the retaining plate 25 attached to the retaining plate 24 with the bolt 26 and the bracket 23. As a result, the connecting pin 27 can be prevented from rotating with respect to each bracket 23 and can be prevented from being removed in the axial direction.

  The bearing device 11 according to the present embodiment has the above-described configuration. During excavation work using the hydraulic excavator 1, the arm cylinder 9 shown in FIG. The arm 6 attached to the distal end side can rotate upward and downward with respect to the boom 5.

  Here, when performing a greasing operation on the bearing device 11 during maintenance or inspection of the hydraulic excavator 1, a grease gun is applied to the grease nipple 16 attached to the greasing hole 15 of the arm boss 12 (boss cylinder 14). Etc. (not shown) are connected and lubricating oil such as grease is injected into the greasing hole 15 by the grease gun.

  Thereby, the lubricating oil injected into the greasing hole 15 is led out from the outer peripheral annular groove 18 of the inner bush 17 to the inner peripheral annular groove 19 through each oil hole 20 and connected to the inner peripheral surface 17C of the inner bush 17. The entire surface of the sliding contact surface with the pin 27 is supplied.

  In this case, the inner circumferential surface 21B of the outer bush 21 adjacent to the inner bush 17 is provided with a spiral groove 22 composed of a plurality of concave grooves 22A, and both end portions of each concave groove 22A serve as shafts of the outer bush 21. It becomes the opening end 22B opened to the end surface 21C of a direction.

  As a result, the lubricating oil overflowing from the inner circumferential annular groove 19 of the inner bush 17 flows into the respective concave grooves 22A through the opening ends 22B, and almost the entire area of the outer bush 21 in the length direction along the respective concave grooves 22A. To be supplied. In this way, the lubricating oil that has flowed into the respective concave grooves 22A constituting the spiral groove 22 allows the sliding contact surface between the inner peripheral surface 21B of the outer bush 21 and the connecting pin 27 to be properly formed with a sufficient amount of lubricating oil. Can be lubricated.

  Thus, according to the present embodiment, the inner bush 17 and the outer bush 21 are fitted into the bush fitting hole 14A of the boss cylinder 14 constituting the arm boss 12, and the inner annular bush 17 has the outer annular groove 18 and The inner circumferential groove 19 and the oil hole 20 are provided, and the outer bush 21 is provided with a spiral groove 22 including a plurality of concave grooves 22A.

  As a result, the lubricating oil injected into the greasing hole 15 is led out from the outer peripheral annular groove 18 of the inner bush 17 to the inner peripheral annular groove 19 through each oil hole 20 and connected to the inner peripheral surface 17C of the inner bush 17. It can be supplied over a wide range to the sliding contact surface with the pin 27. On the other hand, lubricating oil overflowing from the inner circumferential annular groove 19 of the inner bush 17 is caused to flow into the respective concave grooves 22A constituting the spiral groove 22 of the outer bush 21, and the length of the outer bush 21 along these concave grooves 22A. It can be supplied to almost the entire area in the vertical direction.

  Thus, a sufficient amount of lubricating oil is applied to the sliding contact surface between the inner peripheral surface 17C of the inner bush 17 and the connecting pin 27 and the sliding contact surface between the inner peripheral surface 21B of the outer bushing 21 and the connecting pin 27. Since it can supply, the lubricity of the sliding surface of the inner peripheral surface 17C of the inner side bush 17, the inner peripheral surface 21B of the outer side bush 21, and the connection pin 27 can be improved. As a result, the arm boss 12 and the bracket 23 can always be relatively rotated relative to each other, and the reliability of the bearing device 11 can be improved.

  In this case, the spiral groove 22 of the outer bush 21 is constituted by a plurality of concave grooves 22A extending spirally along the connecting pin 27. Therefore, by ensuring a large groove length of each concave groove 22A, A large amount of lubricating oil can flow into the groove 22. For this reason, for example, even if the connecting pin 27 bends due to a load acting on the arm boss 12 and an offset load or a partially large load acts on the outer bush 21, it is introduced into the spiral groove 22 of the outer bush 21. With the large amount of lubricating oil, the sliding contact surface between the inner peripheral surface 21B of the outer bush 21 and the connecting pin 27 can be reliably lubricated.

  In addition, since the axial dimension A of the outer bush 21 is set to be longer than the axial dimension B of the inner bush 17, the outer bush 21 is in the bush fitting hole 14 </ b> A of the boss cylinder 14 constituting the arm boss 12. Can be prevented from coming off in the axial direction. Thereby, for example, even if the connecting pin 27 is bent due to a load acting on the arm boss 12 and an unbalanced load acts on the outer bush 21, the outer bush 21 is removed from the bush fitting hole 14 </ b> A of the arm boss 12 (boss cylinder 14). Extraction can be reliably suppressed. As a result, the connecting pin 27 can be stably supported by the inner bush 17 and the outer bush 21, and the reliability of the bearing device 11 can be improved.

  In addition, since the inner peripheral annular groove 19 is provided on the inner peripheral side of the inner bush 17 and the spiral groove 22 is provided on the inner peripheral side of the outer bush 21, the inner peripheral annular groove 19 is formed on the inner bush 17. The work and the work of forming the spiral groove 22 in the outer bush 21 can be performed separately. This eliminates the need for complicated grooving such as providing both an inner circumferential groove and a spiral groove on the inner peripheral surface of one bush, and can prevent damage to the cutting tool used for this grooving. . As a result, the workability of the operation of forming the inner peripheral annular groove 19 on the inner peripheral side of the inner bush 17 and the operation of forming the spiral groove 22 on the outer bush 21 can be improved, and the manufacturing cost of the entire bearing device 11 is reduced. can do.

  Further, since the outer bush 21 is formed using a sintered metal material, when the outer bush 21 is formed with metal powder made of a sintered metal material, the spiral groove 22 is formed on the inner peripheral surface 21B of the outer bush 21. Can be integrally molded. Thereby, compared with the case where a spiral groove is formed, for example using a cutting tool etc., workability | operativity when forming the spiral groove 22 in the outer side bush 21 can be improved further.

  In the above-described embodiment, the case where the outer peripheral annular groove 18 of the inner bush 17 is formed over the entire outer periphery 17B of the inner bush 17 is illustrated. However, the present invention is not limited to this. For example, a plurality of arc grooves may be intermittently formed on the outer peripheral surface 17B of the inner bush 17.

  Moreover, in embodiment mentioned above, the case where the two oil holes 20 which connect between the outer side annular groove 18 provided in the inner side bush 17 and the inner side annular groove 19 are provided is illustrated. However, the present invention is not limited to this, and for example, one or three or more oil holes may be provided.

  Furthermore, in embodiment mentioned above, the bearing apparatus 11 used for the pin coupling | bond part between the boom 5 and the arm 6 of the hydraulic shovel 1 is illustrated. However, the present invention is not limited to this, and the bearing device according to the present invention includes two members such as a pin coupling portion between the upper swing body 3 and the boom 5 and a pin coupling portion between the arm 6 and the bucket 7. The present invention can be widely applied to a portion where the gaps are rotatably connected.

1 is a front view showing a hydraulic excavator to which a bearing device according to an embodiment of the present invention is applied. It is sectional drawing which looked at the bearing apparatus from the arrow II-II direction in FIG. It is sectional drawing of the principal part expansion which shows the inner side bush, outer side bush, etc. in FIG. 2 in the state which removed the connection pin. It is a partially broken perspective view which shows an inner side bush by itself. It is a partially broken perspective view which shows an outer side bush alone.

Explanation of symbols

11 Bearing device 12 Arm boss (boss member)
14 Boss cylinder 14A Bushing fitting hole 14B, 21C End face 15 Greasing hole 17 Inner bush 17A, 21A Pin insertion hole 17B Outer peripheral surface 17C, 21B Inner peripheral surface 18 Outer peripheral annular groove 19 Inner peripheral annular groove 20 Oil hole 21 Outer Bush 22 Spiral groove 22A Concave groove 23 Bracket (mating member)
27 Connecting pin

Claims (4)

The left and right boss cylinders are composed of an intermediate cylinder extending in the left and right directions and left and right boss cylinders composed of cylinders respectively provided at both left and right ends of the intermediate cylinder. A boss member provided with a greasing hole which is located on the inner side of the end face and extends in the radial direction, the inner peripheral side of which is a bush fitting hole,
Bushes respectively inserted into the left and right bush fitting holes of the boss member;
In the bearing device comprising a coupling pin which relatively rotatably connects the mating member is inserted into these bushings are arranged on both sides of the boss member and the bush,
The bush, the left, and an inner bush which is arranged at a site corresponding to Kyuaburaana respectively formed on the right of the boss cylinder, the inner being arranged between the thrust bearing and those of the inner bushing Consists of an outer bush set longer than the axial dimension of the bush,
The inner bush is provided with an inner peripheral annular groove formed on the inner peripheral side and formed with an entire peripheral groove, and with an oil hole that guides lubricating oil from the greasing hole to the inner peripheral annular groove,
A bearing having a configuration in which a spiral groove is formed on the inner peripheral side of the outer bush, which is formed by a spiral concave groove along the connecting pin and into which lubricating oil flows from the inner peripheral annular groove of the inner bush. apparatus. The inner bush is provided with an outer peripheral annular groove including an entire peripheral groove at a position corresponding to the greasing hole located on the outer peripheral side thereof ,
Before Kiyuana the claim 1 comprising a structure that leads to the inner peripheral annular groove lubricant from and communicating between said inner annular groove and the outer circumferential annular groove the lubrication hole from said outer peripheral annular groove Bearing device. Said outer bush, a bearing apparatus according to claim 1 or 2 comprising forming by using a sintered metal material. Helical groove of the outer bush is formed by constituted by a plurality of grooves which continuously both ends toward the other end from one end side in the axial direction are open to the end face each of the outer bushing according to claim 1, 3. The bearing device according to 3 .

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