JP2012071647A - Rotary apparatus for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability and a service life by protecting floating seal composed of an O-ring and a seal ring from the outside.SOLUTION: An oil absorbing material 24 is applied to the external side surface of a stationary O-ring 21 facing a clearance 17 between the collar 12B of a shaft supporting member 12 and the large-diameter collar 19A of a stationary seal ring 19. An oil absorbing material 24 of a similar type is applied to the external side surface of a rotating O-ring 22 facing a clearance 17 between a seal accommodation hole 15C of a roller 15 and the large-diameter collar 20A of a rotating seal ring 20. When charged with an oil liquid from the outside of the clearance 17 in this state, the oil absorbing material 24 absorbs the oil liquid to form a foreign matter invasion preventing film 23. The foreign matter invasion preventing film 23 covers, from the outside, a portion facing the clearance 17 of the stationary seal ring 19, the rotating seal ring 20, the stationary O-ring 21 and the rotating O-ring 22.

Description

  The present invention relates to a rotation device for a construction machine that is preferably used as a crawler track guide roller, a traveling device, an idler wheel device or the like in a construction machine such as a hydraulic excavator or a hydraulic crane.

  Generally, a lower traveling body of a tracked vehicle such as a hydraulic excavator includes a track frame having left and right side frames, a traveling device provided on one end side of each side frame, and an idler wheel device provided on the other end side. And a crawler belt wound around the drive wheel (sprocket) of the traveling device and the idler wheel (idler) of the idler wheel device, and guiding the crawler belt toward the drive wheel and idler wheel, and a lower crawler belt guide roller It is roughly structured. The traveling device, idler wheel device, crawler belt guide roller, and the like described above constitute a rotating device for the construction machine.

  Here, the crawler belt guide roller as the rotation device of the construction machine is rotatably supported by, for example, a shaft support member (fixed body) fixed to the side frame and the shaft support member via a roller support shaft or the like. And a floating seal that seals a gap formed between the shaft support member and the roller.

  The floating seal is sandwiched between a pair of seal rings having seal surfaces in sliding contact with each other, between the outer peripheral surface of one seal ring and the shaft support member, and between the outer peripheral surface of the other seal ring and the roller. The pair of O-rings is configured to seal a gap between the two liquid-tightly when the roller rotates with respect to the shaft support member. Accordingly, for example, the lubricating oil is sealed in the roller, and the sliding portion between the shaft and the roller is lubricated by the lubricating oil, so that the roller can be smoothly rotated over a long period of time (for example, Patent Documents). 1).

  A traveling device as another rotating device used for a construction machine includes a hydraulic motor, a speed reducer that decelerates the rotation of the hydraulic motor and transmits it to a drive wheel, a motor housing (fixed body) that houses the hydraulic motor, and a speed reducer. And a floating seal that seals a gap between a reduction gear housing (rotating body) that houses the machine.

  When the speed reducer housing rotates with respect to the motor housing, the gap between the two is liquid-tightly sealed with a floating seal, thereby sealing the lubricating oil in the speed reducer housing and forming the speed reducing mechanism. Gears and the like can be properly lubricated with lubricating oil (see, for example, Patent Document 2).

  Here, the crawler belt guide roller of Patent Document 1 described above is configured to close a gap formed between the shaft support member and the roller by filling with grease or the like. As a result, foreign matter such as earth and sand and muddy water can be prevented from entering the gap between the shaft support member and the roller from the outside toward the floating seal, and the floating seal can be prevented from being damaged by this foreign matter. . In addition, the traveling device of Patent Document 2 is configured to prevent foreign matter from entering the gap between the motor housing and the reduction gear housing by filling the gap between the motor housing and the reduction gear housing with grease or the like. It has become.

  On the other hand, as another conventional technique, a fixed body such as a shaft support member, one annular space surrounded by one seal ring and one O ring, a rotating body such as a roller, the other seal ring and the other O ring A floating seal is known in which a hollow annular soft elastic body made of a urethane tube or the like is provided in the other annular space surrounded (see, for example, Patent Document 3).

Japanese Utility Model Publication No. 6-51082 Japanese Patent No. 2939924 JP-A-5-33870

  However, in the prior art disclosed in Patent Document 1 described above, gel-like grease is filled in the gap formed between the shaft support member and the roller, and thus, for example, when a hydraulic excavator travels in a muddy ground. There is a problem that foreign matter such as earth and sand pushes the grease and enters the gap between the shaft support member and the roller, and the foreign matter damages the floating seal. Also, in the prior art disclosed in Patent Document 2, the grease filled in the gap between the motor housing and the reduction gear housing is displaced by foreign matter entering from the outside during traveling of the hydraulic excavator, so that the foreign matter floats. There is a problem that the seal is damaged. Furthermore, in the prior arts of Patent Documents 1 and 2, foreign matter such as earth and sand is prevented from entering by the O-ring and the lip seal, so that the floating seal may be damaged if the O-ring and the lip seal are broken.

  Moreover, the prior art according to Patent Document 3 described above has a problem that the above-described soft elastic body filling operation is difficult and workability is poor. Furthermore, a hollow soft elastic body made of urethane tube or the like may be damaged by foreign matter that has entered the gap from the outside, and there is a problem that it is difficult to ensure durability and life for a long time use. . In particular, when external muddy water or the like flows into the gap and freezes, this influence is not only applied to the soft elastic body but also to the O-ring and the seal ring, and there is a problem that durability and life are reduced.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to protect a floating seal composed of an O-ring and a seal ring from the outside, thereby improving durability and life, and sealing performance. It is an object of the present invention to provide a rotating device for a construction machine that can ensure a long period of time.

  In order to solve the above-described problems, the present invention provides a fixed body that is fixed to a vehicle body side of a construction machine and a gap that is rotatably provided to the fixed body and opens to the outside. And a floating seal that seals the gap between the fixed body and the rotating body, and the floating seal includes an inner peripheral side of the fixed body and an inner peripheral side of the rotating body. And a pair of seal rings having seal surfaces that are slidably in contact with each other, and are sandwiched between the outer peripheral surface of each seal ring and the inner peripheral surface of the fixed body and the rotary body, The present invention is applied to a rotating device of a construction machine that is configured by a pair of O-rings that seal and apply an axial pressing force to each seal ring.

  A feature of the configuration adopted by the invention of claim 1 is that each O-ring is provided with an oil-absorbing material at a position facing the gap between the inner peripheral surface of the fixed body and the rotating body and each seal ring. In addition, the oil-absorbing material is configured to form a foreign matter intrusion prevention film that absorbs oil liquid injected from the outside into the gap between the fixed body and the rotating body and prevents foreign matter from entering. There is.

  According to a second aspect of the present invention, the oil-absorbing material is configured such that polymer powder made of polynorbornene or the polymer sheet is applied or adhered to the surface of the O-ring.

  Furthermore, according to the invention of claim 3, the oil liquid absorbed by the oil-absorbing material is configured to use synthetic oil, mineral oil or biodegradable oil.

  According to the first aspect of the present invention, when an oil liquid is injected from the outside into the gap formed between the fixed body and the rotating body in a state where the rotating device (for example, the crawler belt guide roller) of the construction machine is assembled, The oil absorbing material applied to or attached to the pair of O-rings absorbs the oil liquid and expands in volume, whereby a foreign matter intrusion prevention film can be formed between the gap and each O-ring. The foreign matter intrusion prevention film can prevent foreign matters such as muddy water and earth and sand from entering the periphery of the O-ring and the like and accumulating.

  Therefore, it is possible to prevent the seal surface of each seal ring constituting the floating seal from being damaged by the intrusion of earth and sand or the rust caused by the intrusion of muddy water or seawater. It can suppress that the elasticity of a ring falls by freezing of muddy water etc. Thereby, the sealing surface of each seal ring can be appropriately slidably contacted by the elasticity of each O-ring, and a liquid-tight seal can be achieved between the relatively rotating fixed body and the rotating body. As a result, for example, by lubricating between the fixed body and the rotating body using a lubricating oil sealed by a floating seal, the rotating body can be smoothly rotated with respect to the fixed body, durability as a floating seal, Lifespan can be improved.

  According to the invention of claim 2, the oil-absorbing material can be formed by using polymer powder made of polynorbornene or the polymer sheet. The powder can be attached to the surface of the O-ring using a coating means in a paste-like state. Moreover, when using the said polymer sheet | seat, this sheet | seat can be made to adhere by adhere | attaching on the surface of an O-ring.

  According to the third aspect of the present invention, the foreign matter intrusion prevention film can be formed by absorbing the oil liquid composed of synthetic oil, mineral oil or biodegradable oil into the oil-absorbing material and expanding the volume thereof. In particular, when biodegradable oil is used, adverse effects on the external environment and the like can be suppressed.

It is a front view which shows the hydraulic shovel provided with the lower crawler belt guide roller by the 1st Embodiment of this invention. It is sectional drawing which expanded the bearing, roller, and floating seal of the lower crawler belt guide roller from the arrow II-II direction in FIG. FIG. 3 is an enlarged cross-sectional view of a main part illustrating a floating seal, a foreign matter intrusion prevention film, and the like in FIG. 2. It is sectional drawing in the same position as FIG. 3 which shows the state which apply | coats an oil-absorbing material to a stationary O ring and a rotation O ring from the outside, respectively, and inject | pours an oil liquid. It is sectional drawing which expands and shows the driving device by the side of the drive wheel by the 2nd Embodiment of this invention.

  Hereinafter, a construction machine rotating 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 it is applied to a crawler belt guide roller of a hydraulic excavator.

  1 to 4 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a hydraulic excavator as a construction machine. The hydraulic excavator 1 includes a self-propelled crawler-type lower traveling body 2 and an upper revolving body 3 that is rotatably mounted on the lower traveling body 2. The working device 4 is provided so as to be movable up and down on the front side of the upper swing body 3, and excavation work or the like is performed using the working device 4.

  Reference numeral 5 denotes a track frame constituting the lower traveling body 2, and the track frame 5 has left and right side frames 6 extending in the front and rear directions (only the right side is shown). A driving wheel 7 is provided on one end side of the side frame 6, and an idler wheel 8 is provided on the other end side of the side frame 6.

  Here, as shown in FIG. 2, the side frame 6 is formed as a hollow frame that has a reverse U-shaped cross section and extends in the front and rear directions of the vehicle. Thick left and right lower plates 6A, 6A extending in the front and rear directions are provided on the lower end side of the side frame 6, and a lower crawler belt guide roller 11 described later is spaced between the lower plates 6A. A plurality are provided with a gap.

  9 is a crawler belt wound between the drive wheel 7 and the idler wheel 8, and the crawler belt 9 is driven by a traveling device (for example, a traveling hydraulic motor or the like) on the drive wheel 7 side. The lower track 2 is caused to travel around the drive wheel 7 and the idler wheel 8 while being guided by the upper crawler belt guide roller 10 and the lower crawler belt guide rollers 11 described later.

  Reference numerals 10 and 10 denote two upper crawler belt guide rollers rotatably provided on the upper surface side of the side frame 6. Each upper crawler belt guide roller 10 drives the crawler belt 9 by supporting the crawler belt 9 from below. The guide is directed toward the wheel 7 and the idler wheel 8.

  .. Are a plurality of lower crawler belt guide rollers as rotating devices provided on the lower plate 6A of the side frame 6. Each lower crawler belt guide roller 11 turns the crawler belt 9 into a drive wheel 7 and an idler wheel 8. It will guide you towards. As shown in FIGS. 2 to 3, each lower crawler belt guide roller 11 is constituted by a shaft support member 12, a roller 15, a floating seal 18 and the like which will be described later.

  Reference numerals 12 and 12 denote left and right shaft support members as fixed bodies provided fixed to the lower plates 6A of the side frame 6, respectively. These left and right shaft support members 12 are called collars, for example, and support a roller support shaft 13 described later in a state where it is horizontally extended in the left and right directions. Each shaft support member 12 is formed in a stepped cylindrical shape having shaft insertion holes 12A extending in the left and right directions, and is fixed to the lower plate 6A of the side frame 6 using bolts (not shown) or the like. .

  Further, on the outer peripheral side of each shaft support member 12, a cylindrical flange 12 </ b> B having a substantially L-shaped cross section is provided to accommodate a floating seal 18 described later. The flange portion 12B of the shaft support member 12 serves as an axial end surface 12C formed of an annular surface facing the annular step surface 15E of the roller 15 described later and a gap 17 in the axial direction, and a radially inner side surface of the flange portion 12B. And a seal mounting surface 12D. The seal mounting surface 12D is inclined obliquely inward in the radial direction with respect to the axial end surface 12C, and is formed as a concave surface on which a fixed-side O-ring 21 described later is mounted in an elastically deformed state.

  Reference numeral 13 denotes a roller support shaft supported by the left and right shaft support members 12, and the roller support shaft 13 rotatably supports a roller 15 described later. Here, both end portions of the roller support shaft 13 in the axial direction (left and right directions) are inserted into the shaft insertion holes 12A of the respective shaft support members 12 and are retained in the axial direction by the retaining pins 14. At the same time, the shaft support member 12 is prevented from rotating.

  A roller 15 is located between the left and right shaft support members 12 and is rotatably supported by the roller support shaft 13. Here, the roller 15 is formed of a stepped cylindrical body having a shaft insertion hole 15A formed at the center, and large-diameter flange portions 15B and 15B projecting radially outward are integrally formed on both end sides in the axial direction. Has been. Further, the both ends of the roller 15 have an inner diameter larger than that of the shaft insertion hole 15A, a seal accommodating hole 15C for accommodating a later-described floating seal 18, and an inner diameter larger than that of the seal accommodating hole 15C. A bearing housing hole 15D for housing the flange portion 12B of the shaft support member 12 is formed concentrically with the shaft insertion hole 15A.

  Further, an annular step surface 15E is formed between the seal housing hole 15C and the bearing housing hole 15D of the roller 15 as shown in FIG. 3, and the annular step surface 15E is axially connected to the axial end surface 12C of the shaft support member 12. Are facing each other. The roller 15 is also provided with a seal mounting surface 15F on the peripheral wall side of the seal accommodation hole 15C, and the seal mounting surface 15F is inclined obliquely inward in the radial direction with respect to the annular step surface 15E. The ring 22 is formed as a concave surface to be mounted in an elastically deformed state. Furthermore, an oil sump chamber 15G for storing the lubricating oil L is formed in the axial direction intermediate portion of the shaft insertion hole 15A (see FIG. 2).

  Cylindrical slide bearings 16 and 16 are fitted and fixed to the shaft insertion hole 15A of the roller 15 from both ends in the axial direction, and the roller 15 is attached to the roller support shaft 13 via each slide bearing 16. It is rotatably supported. The roller 15 guides the crawler belt 9 toward the drive wheel 7 and the idler wheel 8 while restricting the crawler belt 9 from being displaced in the left and right directions by the left and right flange portions 15B. At this time, the sliding surface between the roller support shaft 13 and the slide bearing 16 is constantly lubricated by the lubricating oil L supplied from the oil reservoir chamber 15G of the roller 15, and this lubricating oil L is roller-rolled by the floating seal 18 described later. 15 is sealed.

  Reference numerals 17 and 17 denote left and right circumferential clearances formed between the shaft support member 12 and the roller 15 that rotate relative to each other. The clearances 17 are shown in FIGS. 2 and 3. As described above, an annular shape is formed over the entire circumference between the flange portion 12 </ b> B of the shaft support member 12 and the bearing receiving hole 15 </ b> D of the roller 15, and opens to the outside of the roller 15. The roller 15 and the shaft support member 12 constitute a fixed body and a rotating body that rotate relative to each other with a gap 17 formed therebetween.

  Reference numerals 18 and 18 denote left and right floating seals provided between the left and right shaft support members 12 and the rollers 15. The floating seal 18 seals a gap 17 formed between the rotating roller 15 and the shaft support member 12. The floating seal 18 seals the lubricating oil L stored in the oil sump chamber 15 </ b> G in the roller 15, and suppresses entry of foreign matter such as muddy water and earth and sand into the roller 15. Here, as shown in FIGS. 3 and 4, the floating seal 18 includes a fixed side seal ring 19, a rotation side seal ring 20, a fixed side O ring 21, a rotation side O ring 22, and the like, which will be described later. .

  Reference numeral 19 denotes a fixed side seal ring located on the shaft support member 12 side. The fixed side seal ring 19 is paired with a rotation side seal ring 20 to be described later, and in a state facing the rotation side seal ring 20, It is arranged on the inner peripheral side of the flange portion 12 </ b> B provided on the shaft support member 12. Here, the fixed-side seal ring 19 is formed in a cylindrical shape using, for example, a metal material having excellent wear resistance and corrosion resistance, and has a large-diameter flange portion 19A facing the rotary-side seal ring 20, and the large-diameter flange portion. And an annular sealing surface 19B formed on the outer end surface of 19A. Further, the outer peripheral surface 19C of the fixed-side seal ring 19 facing the seal mounting surface 12D of the flange 12B becomes a tapered surface that gradually increases in diameter toward the large-diameter flange 19A, and the outer peripheral surface 19C and the flange 12B Between the seal mounting surface 12D, a fixed-side O-ring 21 described later is mounted in an elastically deformed state.

  Reference numeral 20 denotes a rotation-side seal ring located on the roller 15 side. The rotation-side seal ring 20 is made of the same components as the stationary-side seal ring 19 and is arranged on the inner peripheral side of the seal accommodation hole 15C provided in the roller 15. ing. Here, a large-diameter flange 20A is provided in a portion of the rotation-side seal ring 20 that faces the fixed-side seal ring 19, and a seal surface 19B of the fixed-side seal ring 19 is provided on an end surface of the large-diameter flange 20A. An annular sealing surface 20B is formed in fluid-tight sliding contact therewith. Further, the outer peripheral surface 20C of the rotation-side seal ring 20 that faces the inner peripheral surface (seal mounting surface 15F) of the seal accommodation hole 15C of the roller 15 becomes a tapered surface that gradually expands toward the large-diameter flange 20A. Between the outer peripheral surface 20C and the seal mounting surface 15F, a rotation side O-ring 22 described later is mounted in an elastically deformed state.

  Reference numeral 21 denotes a fixed-side O-ring that constitutes a part of the floating seal 18, and the fixed-side O-ring 21 is formed as an annular elastic ring using an oil-resistant rubber material such as butadiene rubber. . The fixed-side O-ring 21 is sandwiched between the seal mounting surface 12D of the flange 12B provided on the shaft support member 12 and the outer peripheral surface 19C of the fixed-side seal ring 19 in an elastically deformed state. The fixed-side O-ring 21 seals between the flange 12B of the shaft support member 12 and the fixed-side seal ring 19, and constantly presses the fixed-side seal ring 19 toward the rotation-side seal ring 20 in the axial direction. It is.

  Reference numeral 22 denotes a rotation-side O-ring that constitutes a part of the floating seal 18. The rotation-side O-ring 22 is formed in the same manner as the fixed-side O-ring 21 described above, and the seal mounting surface 15F of the roller 15 and the rotation-side seal ring. The outer peripheral surface 20 </ b> C is sandwiched in an elastically deformed state. The rotation-side O-ring 22 seals between the seal accommodation hole 15 </ b> C of the roller 15 and the rotation-side seal ring 20, and constantly presses the rotation-side seal ring 20 toward the fixed-side seal ring 19 in the axial direction. Is.

  As a result, the seal surface 19B of the fixed side seal ring 19 and the seal surface 20B of the rotation side seal ring 20 collide with each other by the axial pressing force applied from the fixed side O ring 21 and the rotation side O ring 22. Thus, the gap 15 between the shaft support member 12 and the roller 15 is liquid-tightly sealed while allowing the roller 15 to rotate relative to the shaft support member 12. L is sealed.

  23 and 23 are foreign substance intrusion prevention films employed in the present embodiment, and one of the foreign substance intrusion prevention films 23 is formed on the flange 12B of the shaft support member 12 as shown in FIG. The fixed-side O-ring 21 is covered from the gap 17 side (outer side) between the fixed-side seal ring 19 and the large-diameter flange portion 19A, and bulges in the radial direction to a position reaching the axial end surface 12C of the shaft support member 12. . The other foreign matter intrusion prevention film 23 covers the rotation-side O-ring 22 from the gap 17 side (outer side) between the seal accommodation hole 15C of the roller 15 and the large-diameter flange portion 20A of the rotation-side seal ring 20, and the roller It bulges in the radial direction to a position reaching 15 annular step surfaces 15E.

  These foreign matter intrusion prevention films 23 are arranged so as to abut against each other in the axial direction within a gap 17 between the shaft support member 12 and the roller 15 as shown in FIG. The foreign matter intrusion prevention film 23 allows the roller 15, the rotation-side seal ring 20, and the rotation-side O-ring 22 to rotate relative to the shaft support member 12, the fixed-side seal ring 19, and the fixed-side O-ring 21. The space is sealed.

  That is, as shown in FIG. 3, the two foreign matter intrusion prevention films 23 are provided on the fixed side seal ring 19, the rotary side seal ring 20, the fixed side O ring 21, and the rotary side O ring 22 that face the gap 17 from the outside. It is the composition which covers. As a result, the foreign matter intrusion prevention film 23 prevents foreign matters such as muddy water and earth and sand from entering the floating seal 18 from the outside through the gap 17 between the shaft support member 12 and the roller 15, thereby preventing the floating seal 18 from entering the foreign matter. It protects from.

  Reference numeral 24 denotes an oil-absorbing material as a material for the foreign matter intrusion prevention film 23. The oil-absorbing material 24 is formed, for example, by preparing a powder made of an oil-absorbing polymer typified by polynorbornene as a paste. . Here, the oil-absorbing material 24 made of a paste-like material is fixed on the fixed side facing the gap 17 between the flange 12B of the shaft support member 12 and the large-diameter flange 19A of the fixed-side seal ring 19 as shown in FIG. It is applied to the outer surface of the O-ring 21 with a predetermined thickness. Similarly, the oil absorbing material 24 made of a paste-like material also faces the gap 17 between the seal accommodation hole 15C of the roller 15 and the large-diameter flange portion 20A of the rotation side seal ring 20 for the rotation side O-ring 22. Applied to the outer surface.

  In this state, the oil liquid 25 is injected into the gap 17 between the shaft support member 12 and the roller 15 in the direction of arrow A shown in FIG. 4 using means such as a dropper or a nozzle. At this time, the oil-absorbing material 24 applied to the outer surfaces of the fixed-side O-ring 21 and the rotating-side O-ring 22 absorbs the oil liquid 25 and expands in volume, so that two foreign objects enter as shown in FIG. The prevention film 23 is formed between the gap 17 and the O-rings 21 and 22. The foreign matter intrusion prevention film 23 prevents foreign matters such as muddy water and earth and sand from entering the surroundings of the O-rings 21 and 22 to be deposited or fixed.

  In this case, the foreign matter intrusion prevention film 23 has higher flexibility than the O-rings 21 and 22 by using an oil-absorbing material 24 made of an oil-absorbing polymer such as polynorbornene as a material. For this reason, the O-rings 21 and 22 are not elastically deformed or receive an extra load by the foreign matter intrusion prevention film 23, and the performance as the floating seal 18 is not adversely affected.

  As the oil liquid 25 to be absorbed by the oil-absorbing material 24, an oil liquid of the same type as the lubricating oil L stored in the oil reservoir chamber 15G of the roller 15, such as synthetic oil or mineral oil, may be used. Moreover, if the biodegradable oil decomposed | disassembled by microorganisms is used as the said oil liquid 25, the influence which it has on the surrounding environment can be suppressed.

  The lower crawler belt guide roller 11 of the hydraulic excavator 1 according to the present embodiment has the above-described configuration. Next, the operation thereof will be described.

  When the operator of the hydraulic excavator 1 performs a traveling operation, the crawler belt 9 is driven to rotate between the idler wheel 8 and the drive wheel 7 of the lower traveling body 2. Each of the lower crawler belt guide rollers 11 provided in the lower traveling body 2 moves the crawler belt 9 up and down between the drive wheel 7 and the idler wheel 8 as the respective rollers 15 rotate with respect to the shaft support member 12. Guidance to suppress.

  At this time, the rotation-side seal ring 20 of the floating seal 18 rotates integrally with the roller 15, and the rotation-side seal ring 20 rotates by bringing the seal surface 20 B into sliding contact with the seal surface 19 B of the fixed-side seal ring 19. The space between the roller 15 and the shaft support member 12 is sealed in a liquid-tight manner. Thereby, the floating seal 18 can hold the lubricating oil L in the roller 15, and the lubricating oil L can properly lubricate the sliding surface between the roller support shaft 13 and the slide bearing 16, etc. Smooth rotation of the roller 15 can be compensated.

  By the way, in the lower crawler belt guide roller 11, a circumferential clearance 17 that is opened to the outside is formed between the shaft support member 12 and the roller 15 that rotate relative to each other. If foreign matter such as muddy water or earth and sand adheres to the sealing surfaces 19B and 20B, the fixed O-ring 21 and the rotating O-ring 22 of the floating seal 18 through the gap 17, the floating seal 18 may be damaged by the foreign matter. There is.

  Therefore, according to the present embodiment, when the lower crawler belt guide roller 11 including the floating seal 18 is assembled, the oil-absorbing material 24 made of a paste-like material as shown in FIG. It is applied to the outer surface of the fixed-side O-ring 21 that faces the gap 17 between the fixed-side seal ring 19 and the large-diameter flange portion 19 </ b> A. It is applied to the outer surface facing the gap 17 between the seal accommodation hole 15 </ b> C and the large-diameter flange 20 </ b> A of the rotation-side seal ring 20.

  Next, in this state, into the gap 17 between the shaft support member 12 and the roller 15, oil liquid 25 is injected in the direction indicated by the arrow A shown in FIG. The oil liquid 25 at this time is absorbed by each oil-absorbing material 24 applied to the outer surfaces of the stationary O-ring 21 and the rotating O-ring 22. As a result, each oil-absorbing material 24 absorbs the oil and expands in volume, and as shown in FIG. 3, two foreign matter intrusion prevention films 23 are formed between the gap 17 and the O-rings 21 and 22. Yes.

  That is, as shown in FIG. 3, the two foreign matter intrusion prevention films 23 are provided on the fixed side seal ring 19, the rotary side seal ring 20, the fixed side O ring 21, and the rotary side O ring 22 that face the gap 17 from the outside. It is configured to cover. Further, these foreign matter intrusion prevention films 23 are arranged so as to collide with each other in the gap 17 between the shaft support member 12 and the roller 15. The rotation-side seal ring 20 and the rotation-side O-ring 22 seal between the shaft support member 12, the fixed-side seal ring 19 and the fixed-side O-ring 21 while allowing them to rotate relative to each other.

  As a result, the foreign matter intrusion prevention film 23 can prevent foreign matter from entering the floating seal 18 from the outside through the gap 17 between the shaft support member 12 and the roller 15, and protect the floating seal 18 from foreign matter. it can. For this reason, for example, when the excavator 1 travels in a muddy ground, foreign matter such as muddy water, earth and sand, and the like are transferred from the gap 17 between the shaft support member 12 and the roller 15 to the fixed O ring 21 and the rotating O ring 22. Intrusion toward the surface can be prevented by the foreign matter intrusion prevention film 23.

  As a result, for example, the seal surfaces 19B and 20B of the seal rings 19 and 20 can be prevented from being damaged due to intrusion of foreign matter such as earth and sand, or rust from being generated due to intrusion of muddy water. Further, it is possible to prevent muddy water or the like from adhering to the fixed side O-ring 21 and the rotation side O-ring 22 and to suppress the elasticity of each of the O-rings 21 and 22 from being lowered due to freezing of muddy water or the like.

  Accordingly, the sealing surface 19B of the fixed side seal ring 19 and the sealing surface 20B of the rotary side seal ring 20 are properly brought into sliding contact with each other, and the roller 15 rotating by the floating seal 18 and the shaft support member 12 are sealed in a liquid-tight manner. can do. Thus, the lubricating oil L is prevented from leaking to the outside, and the sliding surface between the roller support shaft 13 and the slide bearing 16 can be properly lubricated by the lubricating oil L. Can be rotated smoothly and the reliability of the lower crawler belt guide roller 11 can be improved.

  In this case, the foreign matter intrusion prevention film 23 has higher flexibility than the O-rings 21 and 22 of the floating seal 18 by using an oil-absorbing material 24 made of an oil-absorbing polymer such as polynorbornene as a material. For this reason, the O-rings 21 and 22 are not elastically deformed or receive an extra load by the foreign matter intrusion prevention film 23, and it is possible to prevent the performance as the floating seal 18 from being adversely affected. The foreign matter intrusion prevention film 23 can prevent foreign matters such as muddy water and earth and sand from entering the surroundings of the O-rings 21 and 22 to be deposited or fixed.

  Moreover, according to the present embodiment, as shown in FIG. 3, each foreign matter intrusion prevention film 23 has a diameter within the gap 17 between the axial end surface 12 </ b> C of the shaft support member 12 and the annular step surface 15 </ b> E of the roller 15. It is formed so as to bulge outward in the direction. For this reason, even when a foreign substance (for example, muddy water) that has entered the gap 17 between the shaft support member 12 and the roller 15 freezes in a cold region or the like, this influence causes each seal ring 19 constituting the floating seal 18. , 20 can be prevented by the foreign matter intrusion prevention film 23 from reaching the seal surfaces 19B, 20B.

  As a result, the sealing surface 19B of the fixed side seal ring 19 and the sealing surface 20B of the rotation side seal ring 20 are properly slidably contacted with each other, and the space between the rotating roller 15 and the shaft support member 12 is liquid-tight by the floating seal 18. Sealing can be performed, and the performance as the floating seal 18 can be ensured over a long period of time, and the durability and life can be improved.

  Next, FIG. 5 shows a second embodiment of the present invention, and a feature of the second embodiment is that a foreign matter intrusion prevention film is applied to a traveling device of a hydraulic excavator. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, reference numeral 31 denotes a traveling device as a rotating device used in the excavator 1, and the traveling device 31 is used in place of the traveling device for the drive wheel 7 described in the first embodiment. The traveling device 31 includes a hydraulic motor 33 attached to the traveling device bracket 32, a speed reducer 34 that decelerates the rotation of the hydraulic motor 33, and drive wheels (sprockets) that transmit the rotation decelerated by the speed reducer 34 to the crawler belt 9. ) 35, the floating seal 18, and a foreign matter intrusion prevention film 38 to be described later.

  Here, the hydraulic motor 33 is accommodated in a cylindrical motor housing 33 </ b> A fixed to the travel device bracket 32. On the other hand, the speed reducer 34 includes a speed reducer housing 34A formed in a covered cylindrical shape and a three-stage planetary gear speed reduction mechanism 34B provided in the speed reducer housing 34A. The driving wheel 35 is fixed to the front.

  In this case, the reduction gear housing 34A is rotatably attached to the motor housing 33A via bearings 36, 36, and the reduction gear housing 34A and the motor housing 33A are relatively rotated with a gap 37 formed therebetween. A fixed body and a rotating body are configured.

  The floating seal 18 described in the first embodiment is provided between the reduction gear housing 34A and the motor housing 33A, and the clearance between the reduction gear housing 34A and the motor housing 33A is provided by the floating seal 18. By sealing 37, the lubricating oil for lubricating the planetary gear reduction mechanism 34B and the like is sealed in the reduction gear housing 34A.

  Reference numeral 38 denotes a foreign matter intrusion prevention film provided in a gap 37 between the reduction gear housing 34A and the motor housing 33A. The foreign matter intrusion prevention film 38 is the same as the foreign matter intrusion prevention film 23 described in the first embodiment. It is configured in the same manner and prevents foreign matter such as muddy water and earth and sand from entering the gap 37 between the reduction gear housing 34A and the motor housing 33A from the outside toward the floating seal 18.

  Thus, even in the traveling device 31 according to the second embodiment configured as described above, the foreign matter intrusion prevention film 38 is provided in the gap 37 between the reduction gear housing 34A and the motor housing 33A that rotate relative to each other. Thus, foreign matter can be prevented from entering the gap 37 from the outside toward the floating seal 18. Thereby, the sealing performance of the floating seal 18 can be kept good, and the traveling device 31 can be operated smoothly over a long period of time.

  In the first embodiment, an example is given in which an oil-absorbing material is formed from a polymer powder made of polynorbornene as a paste and applied to the O-rings 21 and 22 from the outside. explained. However, the present invention is not limited to this. For example, when the polymer sheet is used, the sheet can be adhered to the surface of the O-ring. This is the same for the second embodiment.

  In the first embodiment, the case where the rotating device of the construction machine is applied to the lower crawler belt guide roller 11 has been described as an example. However, the present invention is not limited to this, and may be applied to the upper crawler belt guide roller 10, for example. Further, as in the idler device of a hydraulic excavator, it can also be applied to prevent foreign matter from entering the floating seal from the clearance between the shaft support member and the idler wheel that rotate relative to each other. is there.

  Moreover, in the said 2nd Embodiment, the traveling apparatus 31 of the hydraulic shovel was mentioned as an example as a rotation apparatus of a construction machine, and was demonstrated. However, the present invention is not limited to this, and can be applied to, for example, a tracked vehicle such as a hydraulic crane and a wheeled vehicle such as a wheel loader. In short, the present invention can be applied to various rotating devices using a floating seal. It is.

11 Lower crawler belt guide roller (rotating device)
12 Shaft support member (fixed body)
13 Roller support shaft 15 Roller (rotating body)
17, 37 Clearance 18 Floating seal 19 Fixed side seal ring 19B, 20B Seal surface 20 Rotating side seal ring 21 Fixed side O ring 22 Rotating side O ring 23, 38 Foreign matter intrusion prevention film 24 Oil absorbing material 25 Oil liquid 31 Traveling device Rotating device)
33 Hydraulic motor 33A Motor housing (fixed body)
34 Reducer 34A Reducer housing (rotary body)

Claims (3)

A fixed body provided fixed to the vehicle body side of the construction machine, a rotating body provided rotatably with respect to the fixed body, and having a gap opened between the fixed body and the fixed body, and the fixed body And a floating seal that seals the gap between the rotating body and the rotating body,
The floating seal includes a pair of seal rings disposed opposite to the inner peripheral side of the fixed body and the inner peripheral side of the rotating body and having seal surfaces that are in sliding contact with each other; the outer peripheral surface of each seal ring; Construction composed of a pair of O-rings that are sandwiched between the inner peripheral surface of the fixed body and the rotating body, seal between them, and apply an axial pressing force to each of the seal rings. In the rotation device of the machine,
In each O-ring, an oil-absorbing material is added at a position facing the gap between the inner peripheral surface of the fixed body and the rotating body and each seal ring,
The oil-absorbing material is configured to form a foreign matter intrusion prevention film that absorbs oil liquid injected from the outside into the gap between the fixed body and the rotating body and prevents foreign matter from entering. Rotating equipment for construction machinery.   2. The rotating device for a construction machine according to claim 1, wherein the oil-absorbing material is formed by applying or adhering a polymer powder made of polynorbornene or a sheet made of the polymer to a surface of the O-ring.   The rotation device for a construction machine according to claim 1 or 2, wherein the oil liquid absorbed by the oil-absorbing material is configured to use synthetic oil, mineral oil, or biodegradable oil.

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