JP2009185937A - Bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance workability in grease supplying operation by suppressing intrusion of the earth, sand, etc. into a greasing hole provided in a boss member. <P>SOLUTION: A projection 26 is formed on each O-ring 25 to seal the gap between the end face 14B in axial direction of a boss cylinder 14 and end faces 19B and 20B of a left 19 and a right thrust plate 20, and in the condition that the gaps between the boss cylinder 14 end face 14B and the thrust plate end faces 19B and 20B are sealed with O-rings 25, the greasing hole 15 in the boss cylinder 14 is choked by fitting the projection 26 on the O-ring 25 in the greasing hole 15. The projection 26 on the O-ring 25 hinders certainly the earth, sand, etc. from intruding into the greasing hole 15, which precludes clogging of a grease nipple 16 accommodated in a nipple accommodation hole 15B of the greasing hole 15, and it is possible to enhance the workability in the grease supplying operation. <P>COPYRIGHT: (C)2009,JPO&INPIT

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, a bearing device provided between an arm and a bucket is disposed so as to face a boss member provided on the distal end side of the arm and provided with a bush on the inner peripheral side, and to face the boss member in the axial direction. It is roughly constituted by a pair of brackets as mating members, and bushes of the boss members and connecting pins that are fitted into the brackets and connect the boss members and the brackets so as to be relatively rotatable.

  In this case, the outer peripheral surface of the boss member is usually provided with a greasing hole for supplying lubricating oil to the sliding surface between the bush and the connecting pin, and a grease nipple is attached to the greasing hole. Then, during regular maintenance and inspection work, lubricating oil such as grease is supplied to the sliding surface between the bush and the connecting pin through the grease hole from the grease nipple, so that the boss member and each bracket can be connected over a long period of time. And can be smoothly rotated relative to each other (see, for example, Patent Document 1).

JP 2000-120893 A

  As another prior art, an oil hole extending in the axial direction is provided in the connecting pin, a large-diameter nipple accommodating hole communicating with the oil hole is provided, and a grease nipple is screwed to the bottom of the nipple accommodating hole. The bearing apparatus which became is proposed (refer patent document 2).

Japanese Utility Model Publication No. 7-20341

  The bearing device of Patent Document 2 protects a grease nipple from earth and sand during excavation work by closing the nipple accommodation hole with a plug having a cover surface portion while the grease nipple is accommodated in the nipple accommodation hole. It has a configuration that can.

  However, in the prior art according to Patent Document 2 described above, a slit is provided in the lid surface portion of the plug in order to connect the grease injecting metal fitting to the grease nipple housed in the nipple housing hole during the greasing operation.

  For this reason, at the time of excavation work, for example, in a muddy ground, soft mud enters into the nipple accommodation hole through the slit of the lid surface portion. And the mud which penetrate | invaded in the nipple accommodation hole solidifies, and there exists a problem that workability | operativity at the time of greasing work will fall because a grease nipple is clogged with this solidified mud.

  The present invention has been made in view of the above-described problems of the prior art, and suppresses intrusion of earth or the like into a greasing hole provided in a boss member, thereby improving workability of a greasing operation. The purpose is to provide.

  In order to solve the above-described problems, the present invention provides a boss member having a bush disposed on the inner peripheral side, a counterpart member disposed to face the boss member in the axial direction, the bush of the boss member, and the counterpart. A connecting pin that is inserted into a member and connects the boss member and the counterpart member so as to be relatively rotatable, and a gap between the axial end surface of the boss member and the counterpart member is sealed over the entire circumference. The present invention is applied to a bearing device that includes a ring and a greasing hole that is provided on the boss member and supplies lubricating oil to a sliding surface between the bush and the connecting pin.

  A feature of the configuration adopted by the invention of claim 1 is that the greasing hole is provided on an end face in the axial direction of the boss member, and the O-ring is provided with a protruding portion for closing the greasing hole of the boss member. It is in providing.

  According to a second aspect of the present invention, the counterpart member is provided with a thrust receiving portion facing the boss member in the axial direction, and a protrusion of the O-ring is provided at a portion corresponding to the greasing hole in the thrust receiving portion. Is provided with a notch portion that serves as a guide when the boss member is attached to and removed from the greasing hole of the boss member.

  According to a third aspect of the present invention, the greasing hole of the boss member is formed to have an oil hole that guides lubricating oil from the outside of the boss member to the bush, and communicates with the oil hole and opens to the outside. The oil hole is configured with a nipple accommodating hole that accommodates a nipple for supplying grease, and the protruding portion of the O-ring is configured to close the grease supplying hole by fitting into the nipple accommodating hole. There is.

  According to a fourth aspect of the present invention, a boss member-side taper groove inclined in a taper shape is provided on the outer peripheral side of the axial end surface of the boss member, and on the outer peripheral side of the axial end surface of the counterpart member. A counter member side taper groove facing the boss member side taper groove and inclined in a taper shape over the entire circumference is provided, and the O-ring is provided between the boss member side taper groove and the counter member side taper groove. The greasing hole is arranged to open to the boss member-side tapered groove.

  According to the first aspect of the present invention, the connecting pin is used to connect the boss member and the counterpart member, and the gap between the axial end surface of the boss member and the counterpart member is sealed by the O-ring. The greasing hole of the boss member can be closed by a protrusion provided on the O-ring. Accordingly, it is possible to reliably prevent the sand and the like from entering the greasing hole by the protruding portion of the O-ring, and to smoothly circulate the lubricating oil through the greasing hole, thereby improving the workability of the greasing work. be able to. As a result, the sliding surface between the bush of the boss member and the connecting pin can always be properly lubricated with the lubricating oil, and the boss member and the counterpart member can be smoothly relatively rotated over a long period of time.

  Also, by providing a protrusion using an O-ring that seals the gap between the axial end face of the boss member and the counterpart member, for example, a dedicated plug for closing the greasing hole of the boss member, etc. Compared with the case of using, the number of parts can be reduced, and it can contribute to the reduction of manufacturing cost. Further, by providing the protruding portion on the O-ring, even if the protruding portion is detached from the greasing hole of the boss member for some reason, the protruding portion can be prevented from being lost.

  According to the second aspect of the present invention, when the protruding portion of the O-ring is attached to and removed from the greasing hole in the portion corresponding to the greasing hole in the thrust receiving portion of the counterpart member, a guide for the protruding portion is provided. A notch is provided. Therefore, during the greasing operation on the sliding surface between the bush of the boss member and the connecting pin, the position of the notch portion of the thrust receiving portion and the position of the greasing hole are matched to thereby close the greasing hole of the boss member. The protruding portion of the ring can be easily removed from the greasing hole along the notch of the thrust receiving portion, and the lubricating oil can be supplied to the sliding surface between the bush and the connecting pin through the greasing hole.

  On the other hand, after supplying the lubricating oil, the protruding portion of the O-ring can be easily attached to the greasing hole of the boss member along the notch portion of the thrust receiving portion. As described above, since the attaching and removing operations of the protrusions with respect to the greasing holes can be performed quickly by the guides of the notches, the workability of the greasing operations can be further enhanced.

  According to the invention of claim 3, since the greasing hole is constituted by the oil hole and the nipple accommodating hole, and the protruding portion of the O-ring is fitted to the nipple accommodating hole, the grease supplying hole accommodated in the nipple accommodating hole is provided. The oil nipple can be protected by the protrusion of the O-ring.

  According to the invention of claim 4, since the greasing hole is opened in the boss member side tapered groove, the O ring is arranged between the boss member side tapered groove and the counterpart member side tapered groove. The protrusion can be securely attached to the greasing hole. Thereby, the effect | action which seals the clearance gap between the axial direction end surface of a boss member, and the other party member, and the effect | action which prevents the penetration | invasion of the foreign material into a greasing hole can be performed simultaneously by one O-ring. .

  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 arm 6 and the bucket 7 are rotatably connected via a bearing device 11 described later.

  In this case, the excavator 1 in FIG. 1 shows a state in which the working device 4 is in a greasing posture, the boom 5 extends forward, the arm 6 is folded to the vehicle body side, and the bucket 7 is connected to the boom 5 and the arm. It is held between six. And in the state which hold | maintained these boom 5, the arm 6, the bucket 7, etc. in the greasing posture shown in FIG. 1, the pin coupling part between the upper turning body 3 and the boom 5 and between the boom 5 and the arm 6 are used. The pin coupling portion, the pin coupling portion between the arm 6 and the bucket 7 and the like are periodically lubricated with lubricating oil such as grease.

  Reference numeral 11 denotes a bearing device provided at a pin coupling portion between the arm 6 and the bucket 7, and the bearing device 11 supports the bucket 7 so as to be rotatable with respect to the arm 6. As shown in FIG. 2, the bearing device 11 includes an arm boss 12, a bush 17, a bracket 18, a connecting pin 23, an O-ring 25, and the like which will be described later.

  Reference numeral 12 denotes an arm boss as a boss member provided on the distal end side of the arm 6, and the arm boss 12 is integrally fixed to the distal end of the arm 6 by means of welding or the like. 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.

  And the inner peripheral side of the left and right boss cylinders 14 is a bush fitting hole 14A, and a bush 17 described later is fitted into the bush fitting hole 14A. Further, the axial end surfaces 14B of the left and right boss cylinders 14 face the left and right brackets 18 to be described later, respectively. Further, as shown in FIG. 3 and the like, a boss member side taper groove 14C inclined in a taper shape is formed on the outer peripheral side of the end surface 14B of the boss cylinder 14, and this boss member side taper groove 14C is formed. In the configuration, one end side of a greasing hole 15 to be described later is opened.

  15 and 15 are greasing holes applied to the present embodiment, and each greasing hole 15 is provided on the end face 14B in the axial direction of the left and right boss cylinders 14, unlike the prior art. Yes. Each of these greasing holes 15 supplies lubricating oil to a sliding surface between a bush 17 and a connecting pin 23 described later. Here, as shown in FIGS. 2 to 4, the greasing hole 15 is provided to extend obliquely downward from the boss member side tapered groove 14 </ b> C provided on the end surface 14 </ b> B of the boss member 14 toward the bush fitting hole 14 </ b> A. ing.

  In this case, the greasing hole 15 communicates with the small-diameter oil hole 15A for guiding the lubricating oil from the outside of the boss cylinder 14 to the bush fitting hole 14A, and opens into the boss member-side tapered groove 14C. And a large-diameter nipple accommodating hole 15B. The grease nipple 16 for grease supply is accommodated in the nipple accommodation hole 15B with the tip end screwed into the oil hole 15A, and a grease gun or the like (not shown) is connected to the grease nipple 16. Thus, the lubricating oil such as grease is supplied to the sliding surface between the bush 17 and the connecting pin 23 through the greasing hole 15.

  Reference numerals 17 and 17 denote cylindrical bushes respectively provided in the bush fitting holes 14A of the boss cylinders 14, and these bushes 17 are fitted into the bush fitting holes 14A of the boss cylinders 14 in a press-fitted state. Yes. A connecting pin 23 described later is slidably fitted on the inner peripheral side of each bush 17, and an inner peripheral surface 17 </ b> A of the bush 17 is a sliding surface with the connecting pin 23. Here, as shown in FIGS. 4 and 6, an annular inner peripheral oil groove 17 </ b> B is formed on the inner peripheral surface 17 </ b> A of the bush 17, and an annular outer peripheral oil groove 17 </ b> C is formed on the outer peripheral surface of the bush 17. The inner circumferential oil groove 17B and the outer circumferential oil groove 17C communicate with each other through a communication hole 17D.

  The outer peripheral side oil groove 17C of the bush 17 communicates with a greasing hole 15 provided in the boss cylinder 14, and lubricating oil such as grease supplied through the greasing hole 15 is supplied to the outer peripheral side oil groove of the bush 17. It is configured to be supplied to the sliding surface of the bush 17 and the connecting pin 23 (the inner peripheral surface 17A of the bush 17) through 17C, the communication hole 17D, and the inner peripheral oil groove 17B.

  18 and 18 are a pair of left and right brackets as counterpart members fixedly attached to the bucket 7, and each bracket 18 is formed in a flat plate shape using a thick steel plate or the like, and a connecting pin 23 described later. A pin insertion hole 18A into which is inserted is provided. Each bracket 18 is disposed so as to face the arm boss 12 in the axial direction with the arm boss 12 interposed therebetween, and is attached to the arm boss 12 so as to be relatively rotatable by a connecting pin 23 inserted into the pin insertion hole 18A. It is what

  Reference numeral 19 denotes a left thrust plate as a thrust receiving portion provided on the left bracket 18, and the left thrust plate 19 is fixed to an inner surface of the left bracket 18 on the arm boss 12 side by means of welding or the like. The boss cylinder 14 faces the end face 14B in the axial direction with a slight gap. Here, as shown in FIGS. 4 and 7, the left thrust plate 19 is formed in a thick disk shape as a whole, and a pin insertion hole into which a connecting pin 23 described later is inserted at the center thereof. 19A is provided.

  Further, on the outer peripheral side of the end surface 19B in the axial direction of the left thrust plate 19, the opposing member side taper groove facing the boss member side taper groove 14C provided in the boss cylinder 14 and inclined in a taper shape over the entire circumference. 19C is formed. Further, a notch 27 described later is formed in a part of the end surface 19B of the left thrust plate 19 in which the counterpart member side tapered groove 19C is formed.

  Reference numeral 20 denotes a right thrust plate as a thrust receiving portion provided on the right bracket 18, and the right thrust plate 20 is provided on an inner surface of the right bracket 18 on the arm boss 12 side via a gap adjusting mechanism 21 described later. And face the axial end face 14B of the boss cylinder 14 with a slight gap. Here, as shown in FIGS. 6 and 8, the right thrust plate 20 is formed in a disk shape thinner than the left thrust plate 19, and a pin into which a connection pin 23 described later is inserted is inserted into the center portion thereof. An insertion hole 20A is provided.

  Further, on the outer peripheral side of the axial end surface 20B of the right thrust plate 20, the opposing member side taper groove facing the boss member side taper groove 14C provided in the boss cylinder 14 and inclined in a taper shape over the entire circumference. 20C is formed. A plurality of bolt holes (female screw holes) 20D into which bolts 21E described later are screwed are screwed between the pin insertion hole 20A and the counterpart member side tapered groove 20C. Furthermore, a notch 28 described later is formed in a part of the end surface 20B of the right thrust plate 20 in which the counterpart member side tapered groove 20C is formed.

  Reference numeral 21 denotes a gap adjusting mechanism provided between the bracket 18 and the right thrust plate 20. The gap adjusting mechanism 21 includes the end faces 19 B and 20 B of the left and right thrust plates 19 and 20 and the end face 14 B of the boss cylinder 14. The gap formed between the two is adjusted. Here, as shown in FIG. 6, the gap adjusting mechanism 21 includes an inner spacer 21A, an outer spacer 21B fixed to the right bracket 18 by welding or the like, and a presser plate 21C disposed outside the outer spacer 21B. , A plurality of thin shim plates 21D, 21D,... Disposed between the inner spacer 21A and the right thrust plate 20 and between the outer spacer 21B and the presser plate 21C, the bracket 18 and the spacers 21A, 21B, The holding plate 21 </ b> C and the shim plates 21 </ b> D are inserted into the bolt holes 20 </ b> D of the right thrust plate 20 and are configured by a plurality of bolts 21 </ b> E.

  Then, by adjusting the number of shim plates 21D arranged between the inner spacer 21A and the right thrust plate 20, the gap between the end surface 19B of the left thrust plate 19 and the end surface 14B of the boss cylinder 14 is increased. The gap between the end surface 20 </ b> B of the plate 20 and the end surface 14 </ b> B of the boss cylinder 14 can be appropriately adjusted by the gap adjusting mechanism 21.

  Reference numeral 22 denotes a cylindrical rotation ring that is fixedly attached to the outer surface of the left bracket 18 opposite to the left thrust plate 19. The rotation stop ring 22 connects a connecting pin 23 (described later) to the bracket 18. Is to prevent and prevent rotation. Here, the locking ring 22 is arranged concentrically with the pin insertion hole 18A of the bracket 18, and a stopper insertion hole 22A through which a stopper pin 24 described later is inserted in the rotation ring 22 in the radial direction. Is provided.

  Reference numeral 23 denotes a connecting pin that connects the arm boss 12 and the left and right brackets 18 so as to be relatively rotatable. The connecting pin 23 is a bush fitted to the boss cylinder 14 of the arm boss 12 as shown in FIG. 17, the pin insertion holes 18A of the left and right brackets 18, the pin insertion holes 19A, 20A of the left and right thrust plates 19, 20 and the gap adjusting mechanism 21 are slidably inserted. Here, a large-diameter flange portion 23A is integrally provided at one end side of the connecting pin 23, and a stopper insertion hole 23B through which a stopper pin 24 described later is inserted in the other end side of the connecting pin 23 in the radial direction. Is provided.

  The connecting pin 23 is inserted into each bush 17 of the arm boss 12, pin insertion holes 18 A of the left and right brackets 18, pin insertion holes 19 A and 20 A of the left and right thrust plates 19 and 20, and the gap adjusting mechanism 21. The stopper pin 24 is inserted into the stopper insertion hole 23B of the connecting pin 23 and the stopper insertion hole 22A of the locking ring 22 with the large-diameter flange 23A in contact with the holding plate 21C of the gap adjusting mechanism 21. By doing so, the connecting pin 23 is attached to each bracket 18 so as not to be pulled out.

  Reference numerals 25 and 25 denote a boss member-side tapered groove 14C of the boss cylindrical body 14 and a counterpart member-side tapered groove 19C of the left thrust plate 19, and a boss member-side tapered groove 14C of the boss cylindrical body 14 and a counterpart member of the right thrust plate 20. Left and right O-rings provided between the side taper grooves 20C, and the O-rings 25 are axial end surfaces 14B of the boss cylinder 14 and the axial directions of the left and right thrust plates 19 and 20, respectively. The gap between the end faces 19B and 20B is sealed over the entire circumference. Here, as shown in FIGS. 4, 6, 9 and the like, the O-ring 25 is formed as a ring body having a circular cross section using an elastic material such as rubber. Further, the O-ring 25 is integrally formed with a protrusion 26 described later.

  The O-ring 25 includes a gap between the end surface 14B in the axial direction of the boss cylinder 14 and the end surface 19B of the left thrust plate 19, the end face 14B in the axial direction of the boss cylinder 14 and the end surface 20B of the right thrust plate 20. By closing the gap between the two, foreign matter such as earth and sand is prevented from entering the gap.

  Reference numeral 26 denotes a protrusion provided on the O-ring 25, and the protrusion 26 closes the greasing hole 15 provided in the boss cylinder 14. Here, the protrusion 26 is formed of a substantially truncated cone-shaped protrusion that is integrally formed with the O-ring 25 and protrudes from the surface of the O-ring 25, for example. In this case, as shown in FIG. 4 and the like, the outer diameter of the protruding portion 26 on the protruding end side is set to be the same as or slightly smaller than the diameter of the nipple accommodating hole 15B constituting the greasing hole 15. The outer diameter of the base side (O-ring 25 side) is set to be approximately equal to or slightly larger than the diameter of the nipple accommodating hole 15B.

  4 and 6, the gap between the axial end surface 14B of the boss cylinder 14 and the end surfaces 19B, 20B of the left and right thrust plates 19, 20 is sealed by an O-ring 25. In this state, the protrusion 26 extends along the axial center line AA of the greasing hole 15 provided in the boss cylinder 14 and fits into the nipple accommodating hole 15B of the greasing hole 15 without a gap. As a result, the gap between the axial end surface 14B of the boss cylinder 14 and the end surfaces 19B, 20B of the left and right thrust plates 19, 20 is sealed by the O-ring 25, and at the same time integrated with the O-ring 25. The provided protrusion 26 can block the greasing hole 15 of the boss cylinder 14 and can reliably prevent foreign matters such as earth and sand from entering the greasing hole 15.

  27 is a notch provided in the left thrust plate 19, and the notch 27 is a part of the outer peripheral edge of the left thrust plate 19 in which the counterpart member side tapered groove 19C is formed, as shown in FIGS. The portion is formed by notching diagonally so as to be substantially parallel to the axial center line AA of the greasing hole 15. In this case, the notch 27 is formed in a portion corresponding to the greasing hole 15 of the boss cylinder 14 with the arm boss 12 of the arm 6 and each bracket 18 of the bucket 7 held in the greasing posture shown in FIG. Has been.

  The protrusion 26 of the O-ring 25 is guided by the notch 27 by contacting the surface of the notch 27 when the boss cylinder 14 is attached to and removed from the greasing hole 15 and is lubricated. It moves along the axial center line AA of the hole 15. Thereby, it is the structure which can perform the attachment and removal operation | work of the projection part 26 with respect to the greasing hole 15 rapidly by the guide of the notch part 27. FIG.

  Reference numeral 28 denotes a notch provided in the right thrust plate 20, and the notch 28 is a part of the outer peripheral edge of the right thrust plate 20 in which the counterpart member side tapered groove 20C is formed, as shown in FIGS. The part is formed by notching diagonally so as to be substantially parallel to the axial center line AA of the greasing hole 15. In this case, similarly to the notch 27 of the left thrust plate 19, the notch 28 also has the greasing hole 15 of the boss cylinder 14 with the arm boss 12 and each bracket 18 held in the greasing posture shown in FIG. 2. It is formed in the part corresponding to.

  The protrusion 26 of the O-ring 25 is guided by the notch 28 when attached to and removed from the greasing hole 15 of the boss cylinder 14, and along the axial center line AA of the greasing hole 15. Moving. Thereby, it is the structure which can perform the attachment and removal operation | work of the projection part 26 with respect to the greasing hole 15 rapidly with the guide of the notch part 28. FIG.

  The bearing device 11 according to the present embodiment has the above-described configuration. At the time of excavation work using the hydraulic excavator 1, the bucket cylinder 10 shown in FIG. The bucket 7 is rotated about the connecting pin 23 of the bearing device 11 to excavate earth and sand.

  Here, in a state where the gap between the axial end surface 14B of the boss cylinder 14 and the left and right thrust plates 19 and 20 is sealed by the O-ring 25, the protrusion 26 provided on the O-ring 25 is The boss cylinder 14 is fitted into the nipple housing hole 15B of the greasing hole 15 without any gap. Thereby, the greasing hole 15 of the boss cylinder 14 can be closed by the protruding portion 26 provided integrally with the O-ring 25.

  Therefore, for example, even when excavation work is performed in a muddy area, the protrusion 26 can reliably prevent soft mud from entering the greasing hole 15. As a result, the grease nipple 16 accommodated in the nipple accommodating hole 15B of the greasing hole 15 can be reliably prevented from being clogged with mud or the like, and the grease nipple 16, the greasing hole 15 and the like can be prevented over a long period of time. Can be maintained in an appropriate state.

  Next, when performing a greasing operation on the bearing device 11 and the like in accordance with maintenance and inspection operations on the excavator 1, first, the working device 4 of the excavator 1 is moved to the greasing posture shown in FIG. .

  Thus, when the working device 4 of the excavator 1 is in a greasing posture and the arm boss 12 of the arm 6 and each bracket 18 of the bucket 7 hold the greasing posture as shown in FIG. A notch portion 27 provided in the boss cylinder body 14 is disposed at a portion corresponding to the greasing hole 15 provided in the boss cylinder body 14, and a notch portion 28 provided in the right thrust plate 20 is provided in the boss cylinder body 14. It arrange | positions in the site | part corresponding to the fat hole 15. FIG.

  In this state, the protrusion 26 of the O-ring 25 is pulled with a tool (not shown) such as a screwdriver, for example, so that the protrusion 26 is guided by the notch 27 of the left thrust plate 19 and supplied. The grease hole 15 can be easily removed from the nipple accommodation hole 15B, and the grease nipple 16 can be exposed to the outside of the boss cylinder 14.

  Then, as shown in FIG. 4, a grease gun (not shown) is greased with the protrusion 26 removed from the nipple housing hole 15 </ b> B of the greasing hole 15 being hooked on the outer peripheral surface of the left thrust plate 19, for example. Connected to the nipple 16 and discharges lubricating oil such as grease. Thereby, the lubricating oil such as grease slides between the bush 17 and the connecting pin 23 through the oil hole 15A of the greasing hole 15, the outer oil groove 17C of the bush 17, the communication hole 17D, and the inner oil groove 17B. Since it is supplied to the surface (the inner peripheral surface 17A of the bush 17), the sliding surface can be properly lubricated.

  Thus, after the greasing operation on the sliding surface of the bush 17 and the connecting pin 23 is completed, the protrusion 26 of the O-ring 25 hooked on the outer peripheral surface of the left thrust plate 19 is again inserted into the greasing hole. It is made to fit in 15 nipple accommodation holes 15B.

  In this case, since the notch 27 provided in the left thrust plate 19 is disposed at a portion corresponding to the greasing hole 15 provided in the boss cylinder 14, the protrusion 26 of the O-ring 25 is connected to the notch 27. Can be easily fitted into the nipple housing hole 15B of the greasing hole 15 in the state of being guided by. As a result, the gap between the end surface 14B of the boss cylinder 14 and the left thrust plate 19 is sealed by the O-ring 25, and at the same time, the greasing hole of the boss cylinder 14 is provided by the protrusion 26 provided integrally with the O-ring 25. 15 can be closed and foreign matter such as earth and sand can be reliably prevented from entering the greasing hole 15.

  Thus, according to the present embodiment, the protrusion 26 is provided on the O-ring 25 that seals the gap between the axial end surface 14B of the boss cylinder 14 and the left and right thrust plates 19 and 20, and the boss By fitting the protrusion 26 of the O-ring 25 into the greasing hole 15 of the boss cylinder 14 with the gap between the end surface 14B of the cylinder 14 and the thrust plates 19 and 20 sealed by the O-ring 25. The greasing hole 15 is closed by the protrusion 26.

  This reliably prevents the sand and the like from entering the greasing hole 15 by the projection 26 of the O-ring 25, and the grease nipple 16 accommodated in the nipple accommodating hole 15B of the greasing hole 15 is clogged. Can be prevented. For this reason, since lubricating oil can be smoothly distribute | circulated through the grease nipple 16 and the greasing hole 15, workability | operativity of a greasing operation | work can be improved. As a result, the sliding surface between the bush 17 and the connecting pin 23 provided on the arm boss 12 can always be properly lubricated with the lubricating oil, and the arm boss 12 of the arm 6 and each bracket 18 of the bucket 7 can be maintained over a long period of time. And can be rotated relatively smoothly.

  Further, by providing a protrusion 26 on the O-ring 25 that seals the gap between the end surface 14B of the boss cylinder 14 and the left and right thrust plates 19 and 20, for example, the greasing hole 15 of the boss cylinder 14 is provided. Compared with the case where a dedicated plug or the like for closing is used, the number of parts can be reduced, and the manufacturing cost can be reduced. Further, by providing the protrusion 26 on the O-ring 25, for example, even if the protrusion 26 is detached from the greasing hole 15 due to vibration during excavation work, the protrusion 26 is prevented from being lost. Can do.

  Further, the left and right thrust plates 19 and 20 are supplied to portions corresponding to the greasing holes 15 of the boss cylinder 14 with the arm boss 12 and the left and right brackets 18 held in a greasing posture. Notches 27 and 28 extending substantially parallel to the axial center line AA of the oil hole 15 are provided.

  As a result, the protrusion 26 of the O-ring 25 that closes the greasing hole 15 can be easily removed from the greasing hole 15 along the notches 27 and 28 provided in the left and right thrust plates 19 and 20. The lubricating oil can be supplied to the sliding surface between the bush 17 and the connecting pin 23 through the grease nipple 16 accommodated in the nipple accommodation hole 15B of the grease supply hole 15. On the other hand, after supplying the lubricating oil, the protruding portion 26 of the O-ring 25 can be easily attached to the greasing hole 15 along the cutout portions 27 and 28 of the left and right thrust plates 19 and 20. Thus, when the protrusion 26 of the O-ring 25 is attached to and removed from the greasing hole 15, the protrusion 26 with respect to the greasing hole 15 is guided by the notches 27 and 28. Since the attachment and removal operations can be performed quickly, the workability of the greasing operation can be further enhanced.

  In the above-described embodiment, the case where the protrusion 26 is integrally formed with the O-ring 25 is illustrated. However, the present invention is not limited to this. For example, a protrusion formed of a member different from the O-ring may be formed, and the protrusion may be attached to the O-ring.

  In the above-described embodiment, the case where the gap adjusting mechanism 21 is provided between the right thrust plate 20 and the bracket 18 is illustrated. However, the present invention is not limited to this, and the right thrust plate 20 may be fixed to the bracket 18 by welding or the like, for example, similarly to the left thrust plate 19.

  Furthermore, in embodiment mentioned above, the bearing apparatus 11 used for the pin coupling | bond part between the arm 6 and the bucket 7 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 boom 5 and the arm 6. 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 an enlarged view which shows the arm front-end | tip part in FIG. 1 in the state which removed the bucket. It is an expanded sectional view which expands and shows the left thrust plate, notch part, greasing hole, O-ring, protrusion part, etc. in FIG. It is an expanded sectional view similar to FIG. 4 which shows the state which removed the protrusion part from the greasing hole. It is an expanded sectional view which expands and shows the right thrust plate, notch part, greasing hole, O-ring, protrusion part, etc. in FIG. It is a perspective view which shows a left thrust plate alone. It is a perspective view which shows a right thrust plate alone. It is a perspective view which shows an O-ring alone.

Explanation of symbols

11 Bearing device 12 Arm boss (boss member)
14 Boss cylinder 14B, 19B, 20B End face 14C Boss member side taper groove 15 Greasing hole 15A Oil hole 15B Nipple receiving hole 16 Grease nipple (greasing nipple)
17 Bush 18 Bracket (mating member)
19 Left thrust plate (thrust receiving part)
19C, 20C Opposite member side taper groove 20 Right thrust plate (thrust receiving part)
23 Connecting pin 25 O-ring 26 Projection 27, 28 Notch

Claims (4)

A boss member having a bush disposed on the inner peripheral side, a counterpart member arranged to face the boss member in the axial direction, the bush of the boss member and the counterpart member, and the boss member A connecting pin that connects the counterpart member so as to be relatively rotatable, an O-ring that seals the gap between the axial end surface of the boss member and the counterpart member over the entire circumference, and the bush provided on the boss member And a lubrication hole for supplying lubricating oil to the sliding surface between the connecting pin and the connecting pin,
The bearing device is characterized in that the grease supply hole is provided in an end face in the axial direction of the boss member, and the O-ring is provided with a projection portion that closes the grease supply hole of the boss member.   The counterpart member is provided with a thrust receiving portion that faces the boss member in the axial direction, and a protruding portion of the O-ring is provided at a portion corresponding to the greasing hole in the thrust receiving portion. The bearing device according to claim 1, wherein a notch portion serving as a guide is provided for attachment to and removal from the hole. The greasing hole of the boss member is formed with an oil hole that guides lubricating oil from the outside of the boss member to the bush, and communicates with the oil hole and opens to the outside. It is composed of a nipple housing hole that houses a nipple for fat,
The bearing device according to claim 1, wherein the protruding portion of the O-ring is configured to close the greasing hole by fitting into the nipple accommodating hole.   A boss member-side taper groove inclined in a taper shape is provided on the outer peripheral side of the axial end face of the boss member, and the boss member-side taper groove is provided on the outer peripheral side of the axial end face of the counterpart member. A counter member-side tapered groove that is inclined in a taper shape over the entire circumference, and the O-ring is disposed between the boss member-side taper groove and the counterpart member-side taper groove, and the greasing hole The bearing device according to claim 1, 2, or 3, wherein the bearing device is configured to open to the boss member side tapered groove.

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