Floating seal device

Abstract

To provide a floating seal device capable of maintaining a closed state of a gap between a sliding component and a housing.SOLUTION: A floating seal device (1) includes annular elastic rings (7, 8) respectively attached to an inner peripheral surface (20) of a fixed-side housing (2) and an inner peripheral surface (30) of a rotation-side housing (3) that faces the fixed-side housing (2) and rotates relative to the fixed-side housing (2), and sliding components (5, 6) that are attached to the respective housings (2, 3) via the respective elastic rings (7, 8) and slide relative to each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a floating seal device, for example, a floating seal device for sealing a shaft. [Background technology]

[0002] Conventionally, floating seal devices have been known that seal the space between a fixed structure and a rotating structure when connecting a rotating structure such as a travel motor, roller, idler, axle, etc. to allow the rotating structure to rotate relative to the fixed structure. Such floating seal devices seal the sealed fluid by sliding a pair of seal rings relative to each other, and generally use an elastic ring as a secondary seal, providing a floating function that allows the shaft to tilt.

[0003] For example, the floating seal device shown in Patent Document 1 has a floating ring attached via an elastic ring to the inner diameter side of a fixed housing fixed to the aircraft body, and another floating ring attached via an elastic ring to the inner diameter side of a rotating housing. An annular lip is fixed to each floating ring.

[0004] The annular lip has a base portion fixed to the outer peripheral surface of the floating ring, and a lip portion that rises radially outward from the base portion and abuts against the axial end face of the housing in the axial direction. Because the annular lip seals the gap between the floating ring and the housing, pressure from soil and sand that may enter between the housings does not act on the elastic ring, and the sliding surfaces of the floating rings are maintained in abutment. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Microfilm of Utility Model Application No. 60-116438 (Unexamined Utility Model Application No. 62-25375) (pages 7-8, Figure 1) Summary of the Invention [Problem to be solved by the invention]

[0006] In the floating seal device of Patent Document 1, when the two housings tilt relative to each other or move axially, the floating ring and the housing are allowed to move relative to each other in the axial direction due to the elastic force of the elastic ring, so that the sliding surfaces of the floating rings are maintained in contact with each other. However, because the annular lip is structured so that the lip portion abuts against the axial end surface of the housing in the axial direction, when the floating ring and the housing move relative to each other in the axial direction, the lip portion may move away from the axial end surface of the housing, opening up the gap between the floating ring and the housing and making it impossible to prevent the intrusion of soil and sand, etc.

[0007] The present invention has been made in view of these problems, and has as its object to provide a floating seal device that can maintain a closed state of the gap between the sliding part and the housing. [Means for solving the problem]

[0008] In order to solve the above problems, the floating seal device of the present invention is elastic rings attached to the inner circumferential surface of the fixed housing and the inner circumferential surface of the rotating housing which faces the fixed housing and rotates relative to the fixed housing; a sliding part attached to each of the housings via each of the elastic rings and sliding relative to each other, A cover body is fixed to at least one of the housings, extending radially inward toward one or the other of the sliding components. With this, the inner diameter end of the cover body fixed to one of the housings abuts against the outer periphery of one of the sliding parts, so that the cover body can maintain a state in which it closes the gap between one of the sliding parts and one of the housings regardless of the axial movement of one of the sliding parts.

[0009] The cover body may be annular. This allows the gap between one of the sliding components and one of the housings to be closed in the circumferential direction.

[0010] The cover body may be fixed to an axial end surface of the one housing that is located on the other housing side and on the outer diameter side of the sliding component. This makes it possible to stabilize the attachment state of the cover body and to prevent excessive deformation of the cover body.

[0011] A recess may be provided in an axial end surface of the one housing that is located on the other housing side and on the outer diameter side of the sliding component, and the base end of the cover body may be fixed to the recess. This allows the cover body to be easily attached to one of the housings.

[0012] The cover body may have an elastic material having elasticity such that an inner diameter end portion thereof can abut against an outer peripheral surface of one of the sliding components, and a base material fixed to the elastic material and having greater rigidity than the elastic material. With this, the elastic material can follow the axial movement of one of the sliding parts, and the base material can stabilize the attached state of the cover body, thereby suppressing excessive deformation of the cover.

[0013] The elastic material may be made of rubber. According to this, the elastic material is made of rubber with a high coefficient of friction, and therefore has high followability.

[0014] An inner diameter end of the cover body may be inclined toward a space formed between the one housing, the cover body, and the sliding component. This prevents the inner diameter end of the cover body from sliding against the other housing.

[0015] The inner diameter end of the cover body may be curved or bent to form a convex shape toward the inside of a space formed between the one housing, the cover body, and the sliding component. This prevents the inner diameter end of the cover body from sliding against the other housing.

[0016] The cover body may be fixed to both of the housings. This allows the gap between one sliding component and one housing and the gap between the other sliding component and the other housing to be closed.

[0017] The outer peripheral surface of the sliding element may be flat. This ensures that the gap between the sliding part and the housing is closed reliably. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view showing a floating seal device according to a first embodiment of the present invention. [Figure 2] 2 is a schematic view showing a state in which the seal ring has moved to the left from the state shown in FIG. 1. FIG. [Figure 3] FIG. 4 is a cross-sectional view showing a floating seal device according to a second embodiment of the present invention. [Figure 4] 10 is a schematic view showing a state in which the inner diameter end portion of the cover body is pressed against the outer peripheral surface of the seal ring in Example 2. FIG. [Figure 5] FIG. 10 is a cross-sectional view showing a floating seal device according to a third embodiment of the present invention. [Figure 6] 10 is a schematic view showing a state in which the inner diameter end portion of the cover body is pressed against the outer peripheral surface of the seal ring in Example 3. FIG. [Figure 7] FIG. 10 is a cross-sectional view showing a floating seal device according to a fourth embodiment of the present invention. [Figure 8] FIG. 10 is a cross-sectional view showing a floating seal device according to a fifth embodiment of the present invention. [Figure 9] 10 is a schematic view showing a first modified example of a manner in which the cover body is attached to the housing. FIG. [Figure 10] 10 is a schematic view showing a second modified example of the manner in which the cover body is attached to the housing. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A floating seal device according to an embodiment of the present invention will be described below with reference to the accompanying drawings. [Example]

[0020] A floating seal device according to a first embodiment will be described with reference to Figures 1 and 2. In the following description, the left and right sides of the plane of Figure 1 will be referred to as the left and right sides of the floating seal device, and the top and bottom of the plane of Figure 1 will be referred to as the top and bottom sides of the floating seal device.

[0021] The floating seal device 1 of this embodiment 1 has a track roller 3 serving as a rotating side housing rotatably connected to a rotating shaft 9 (see Figure 1) extending from a side frame supporting an endless track, and is used to prevent foreign matter such as soil and mud from entering the rotating shaft 9 side through the gap between the fixed side housing 2 and the track roller 3.

[0022] As shown in Figure 1, the floating seal device 1 is mainly composed of a fixed side housing 2 as one housing, a track roller 3 as the other housing, a fixed side seal ring 5 as one sliding part, a rotating side seal ring 6 as the other sliding part, a fixed side O-ring 7 as a fixed side elastic ring, a rotating side O-ring 8 as a rotating side elastic ring, and cover bodies 10, 10'.

[0023] The fixed side housing 2 is fixed to the side frame. The track rollers 3 are connected to the rotating shaft 9 with the rotating shaft 9 inserted therethrough. The fixed side seal ring 5 is disposed on the inner diameter side of the fixed side housing 2. The rotating side seal ring 6 is disposed on the inner diameter side of the track roller 3. The fixed side O-ring 7 is interposed between the fixed side housing 2 and the fixed side seal ring 5. The rotating side O-ring 8 is interposed between the track roller 3 and the rotating side seal ring 6.

[0024] The track roller 3 is arranged in a state spaced apart from the fixed housing 2 in the axial direction, and is rotatable relative to the fixed housing 2.

[0025] The seal rings 5, 6 and the O-rings 7, 8 separate the outer space S1, which includes the gap between the fixed housing 2 and the track roller 3, from the inner space S2 on the rotating shaft 9 side, and seal the boundary between them. The fixed housing 2, the track roller 3, the seal rings 5, 6, and the O-rings 7, 8 will be described in detail below.

[0026] First, we will explain the fixed housing 2. Referring to Fig. 1, the fixed housing 2 is formed in a stepped cylindrical shape into which the rotary shaft 9 can be loosely inserted. The fixed housing 2 has an inner peripheral portion 2A formed on the inner diameter side facing the track rollers 3, which is recessed in the axial direction and opens toward the track rollers 3. The inner peripheral portion 2A is formed with a seal surface 20 whose diameter decreases toward the inner diameter as it moves away from the opposing track roller 3 in the axial direction.

[0027] In addition, an annular recess 21a recessed to the left is formed on the end face 21 of the fixed housing 2, which is located radially outward of the seal ring 5 and the O-ring 7 and is formed on the track roller 3 side (see Figure 2).

[0028] Next, we will explain the track roller 3. The track roller 3 is formed in a stepped cylindrical shape that can be fitted onto the rotary shaft 9. On the inner diameter side of the track roller 3, facing the fixed housing 2, there is formed an inner peripheral portion 3A that is open to the fixed housing 2 and recessed in the axial direction. A seal surface 30 is formed on the inner peripheral portion 3A, the diameter of which decreases toward the inner diameter as it moves away from the opposing fixed housing 2 in the axial direction.

[0029] In addition, an annular recess 31a recessed to the right is formed in the end face 31 of the track roller 3, which is located radially outer than the seal ring 6 and O-ring 8 and formed on the fixed housing 2 side. This recess 31a extends substantially horizontally from the end face 31 to the right and then extends radially inward substantially perpendicularly, forming a substantially L-shaped cross section.

[0030] Next, the fixed seal ring 5 will be described. The fixed seal ring 5 is made of cast iron and is formed in a stepped cylindrical shape into which the rotating shaft 9 can be loosely inserted. The fixed seal ring 5 has an annular sliding surface 50 at the end opposite the rotating seal ring 6. The outer peripheral surface 5b of the portion constituting the sliding surface 50 is a flat surface that is flat in the circumferential direction (see FIG. 2).

[0031] The stationary seal ring 5 has an annular inclined groove 5a recessed toward the inner diameter side at the axial center of the outer diameter side. The bottom surface of this inclined groove 5a forms a tapered surface 51 whose diameter decreases as it moves away from the sliding surface 50.

[0032] In manufacturing the stationary seal ring 5, Cr-Mo cast iron and Ni-Cr cast iron are preferred materials, but other materials such as copper alloy, carbon steel, SiC, cemented carbide, and ceramics may also be used.

[0033] Next, the rotating-side seal ring 6 will be described. The rotating-side seal ring 6 is made of cast iron and is formed in a stepped cylindrical shape into which the rotating shaft 9 can be loosely inserted. The rotating-side seal ring 6 has an annular sliding surface 60 at the end opposite the fixed-side seal ring 5. The outer peripheral surface 6b of the portion that constitutes the sliding surface 60 is a flat surface that is flat in the circumferential direction (see FIG. 2).

[0034] The rotary seal ring 6 has an annular inclined groove 6a recessed toward the inner diameter side at the axial center of the outer diameter side. The bottom surface of the inclined groove 6a forms a tapered surface 61 whose diameter decreases as it moves away from the sliding surface 60.

[0035] In manufacturing the rotary seal ring 6, Cr-Mo cast iron and Ni-Cr cast iron are preferred materials, but other materials such as copper alloy, carbon steel, SiC, cemented carbide, and ceramics may also be used.

[0036] Next, we will explain the fixed side O-ring 7 and the rotating side O-ring 8. The fixed side O-ring 7 and the rotating side O-ring 8 are made of rubber and are formed into annular shapes that can be fitted onto the inclined grooves 5a, 6a of the fixed side seal ring 5 and the rotating side seal ring 6.

[0037] The fixed side O-ring 7 and the rotating side O-ring 8 are sandwiched in a compressed state between the fixed side housing 2 and the fixed side seal ring 5, and between the track roller 3 and the rotating side seal ring 6. The elastic restoring forces of the fixed side O-ring 7 and the rotating side O-ring 8 act in a direction that brings the fixed side seal ring 5 and the rotating side seal ring 6 closer to each other.

[0038] As a result, a predetermined sliding surface pressure is applied between the sliding surfaces 50, 60 in the axial direction, and the sliding surfaces 50, 60 function as a primary seal.

[0039] In addition, the fixed side O-ring 7, which is in close contact between the fixed side housing 2 and the fixed side seal ring 5, and the rotating side O-ring 8, which is in close contact between the track roller 3 and the rotating side seal ring 6, function as secondary seals.

[0040] In this way, it is possible to reliably prevent the intrusion of foreign matter such as earth and mud from the exterior space S1 into the interior space S2, which contains the lubricating oil as a fluid. Note that the fluid may be something other than lubricating oil.

[0041] The fixed side O-ring 7 and the rotating side O-ring 8 are preferably made of materials such as hydrogenated nitrile rubber (H-NBR), perfluoroelastomer, nitrile rubber (NBR) with a hardness of DuroA 60 to 70, urethane rubber (U), fluororubber (FKM), butyl rubber (IIR), elastic resin, etc.

[0042] The fixed-side seal ring 5 and the rotating-side seal ring 6 attached as described above are able to move relative to the fixed-side housing 2 and the track roller 3 in the axial and radial directions while maintaining contact between the sliding surfaces 50, 60 due to the elastic restoring forces of the fixed-side O-ring 7 and the rotating-side O-ring 8. In other words, relative movement between the fixed-side housing 2 and the track roller 3 is permitted.

[0043] Next, the cover bodies 10, 10' will be described mainly with reference to Figure 2. Since the cover bodies 10, 10' have almost the same shape, only the cover body 10 on the fixed housing 2 side will be described, and the description of the cover body 10' on the track roller 3 side will be omitted.

[0044] The cover body 10 is mainly composed of a rubber body 15 as an elastic material and an annular base material 13 as a base material. The rubber body 15 is made of a rubber material and is configured in an annular shape. The rubber body 15 is mainly composed of a base portion 11 as a base end portion and a plate-shaped portion 12.

[0045] The base 11 has an axial portion extending in the axial direction and a radial portion extending inward from the left end of the axial portion, and is generally L-shaped in cross section. A bulge 11a is formed on the outer peripheral surface of the axial portion.

[0046] The plate-shaped portion 12 extends radially inward from the right end of the axial portion of the base portion 11. An inner diameter portion 12a serving as an inner diameter end portion of the plate-shaped portion 12 extends radially inward from its outer diameter portion 12b at an angle toward the left, i.e., toward the fixed-side housing 2.

[0047] An annular base material 13 having a generally J-shaped cross section and an annular shape is embedded in the base portion 11 and the outer diameter portion 12b of the plate-like portion 12 of the rubber body 15. This annular base material 13 is made of a material that is more rigid than the rubber body 15, and is made of metal in this embodiment. The annular base material 13 is not embedded in the inner diameter end of the outer diameter portion 12b or the inner diameter portion 12a, so that the annular base material 13 is elastically deformable in the axial direction.

[0048] The cover body 10 is fixed to the fixed housing 2 by fitting into a recess 21a provided in the end surface 21 of the fixed housing 2. At this time, the base 11 and the annular base material 13 are press-fitted and fixed into the recess 21a, and the base 11 is pressed against the inner and outer circumferential surfaces that form the recess 21a by the bulging portion 11a.

[0049] Additionally, the outer diameter portion 12b of the plate-shaped portion 12 extends along the end surface 21 of the fixed-side housing 2 toward the inner diameter side.

[0050] The inner diameter portion 12a of the plate-shaped portion 12 is pressed radially against the outer peripheral surface 5b of the stationary seal ring 5. In other words, the cover body 10 closes the gap between the stationary housing 2 and the stationary seal ring 5.

[0051] In this way, the gap between the fixed side housing 2 and the fixed side seal ring 5 is blocked by the cover body 10, thereby preventing foreign matter such as soil and mud from entering the fixed side O-ring 7 side from the outside space S1 through the gap between the fixed side housing 2 and the fixed side seal ring 5.

[0052] This makes it possible to prevent foreign matter from interfering with the urging force of the fixed O-ring 7 toward the fixed seal ring 5, and to prevent the fixed O-ring 7 from being twisted or distorted.

[0053] Next, a state in which the fixed-side housing 2 and the track roller 3 move relative to each other in the axial direction will be described with reference to Figure 2. Here, a state in which the track roller 3 moves in a direction away from the fixed-side housing 2 in the axial direction will be described.

[0054] 2, the fixed-side seal ring 5 and the rotating-side seal ring 6 are strongly biased by the fixed-side O-ring 7 and the rotating-side O-ring 8, so even if the track roller 3 moves slightly axially away from the fixed-side housing 2, i.e., to the right, the positions of the fixed-side seal ring 5 and the rotating-side seal ring 6 remain almost unchanged. That is, the track roller 3 and the rotating-side seal ring 6 move relative to each other in the axial direction while maintaining contact between the sliding surfaces 50, 60. Note that if the track roller 3 moves significantly, the elastic force of the fixed-side O-ring 7 and the rotating-side O-ring 8 allows the fixed-side seal ring 5 and the rotating-side seal ring 6 to follow the movement of the track roller 3 while maintaining contact between the sliding surfaces 50, 60.

[0055] At this time, the inner diameter portion 12a' of the cover body 10' attached to the track roller 3 remains in contact with the outer peripheral surface 6b of the rotating-side seal ring 6 due to the frictional force between the inner diameter portion 12a' and the outer peripheral surface 6b of the rotating-side seal ring 6, and therefore elastically deforms so that the inner diameter end of the outer diameter portion 12b' tilts to the right in the axial direction. In other words, the inner diameter portion 12a' of the cover body 10' deforms in response to the relative axial movement between the track roller 3 and the rotating-side seal ring 6. Note that if the frictional force between the inner diameter portion 12a' of the cover body 10' and the outer peripheral surface 6b of the rotating-side seal ring 6 is low, the plate-shaped portion 12' does not elastically deform, and the inner diameter portion 12a' of the cover body 10' slides to the right along the outer peripheral surface 6b of the rotating-side seal ring 6, thereby following the relative axial movement between the track roller 3 and the rotating-side seal ring 6.

[0056] In this way, even if relative axial movement occurs between the track roller 3 and the rotating side seal ring 6, the cover bodies 10, 10' can maintain a closed state of the gap between the fixed side housing 2 and the fixed side seal ring 5, and the gap between the track roller 3 and the rotating side seal ring 6, thereby effectively preventing foreign matter such as soil and mud from entering from the outside space S1.

[0057] Furthermore, since the plate-shaped portions 12, 12' of the cover bodies 10, 10' are annular, the gap between the fixed side housing 2 and the fixed side seal ring 5 and the gap between the track roller 3 and the rotating side seal ring 6 can be blocked around the entire circumference, making it even more difficult for foreign matter to enter the fixed side O-ring 7 side and the rotating side O-ring 8 side.

[0058] Furthermore, the cover bodies 10, 10' are fixed to the end face 21 of the fixed housing 2 and the end face 31 of the track roller 3, respectively. Specifically, because the plate-like portions 12, 12' extend along the end faces 21, 31, the mounting state of the cover bodies 10, 10' can be stabilized and the plate-like portions 12, 12' can be prevented from being excessively deformed and turned up. Moreover, because the annular base materials 13, 13' also extend along the end faces 21, 31, the plate-like portions 12, 12' can be further prevented from being excessively deformed and turned up, and elastic deformation during tracking is stabilized.

[0059] Furthermore, the bases 11, 11' of the cover bodies 10, 10' are press-fitted and fixed into the recesses 21a of the end face 21 and the recesses 31a of the end face 31. This allows the cover bodies 10, 10' to be easily attached to the fixed housing 2 and the track roller 3.

[0060] Furthermore, since the base portions 11, 11' and the annular base materials 13, 13' are press-fitted and fixed in the recesses 21a, 31a, they are prevented from coming off even when pressure from earth and sand acts on the cover bodies 10, 10'.

[0061] Furthermore, since the annular base materials 13, 13' are embedded in the rubber bodies 15, 15', the mounting state of the cover bodies 10, 10' can be stabilized, and the plate-like portions 12, 12' can be prevented from being excessively deformed and turned up.

[0062] Furthermore, the inner diameter portions 12a, 12a' of the plate-shaped portions 12, 12' extend at an angle that increases in the axial direction as they extend in the inner diameter direction. Specifically, the inner diameter portion 12a on the cover body 10 side extends toward the space S3 surrounded by the fixed-side housing 2, the fixed-side O-ring 7, and the fixed-side seal ring 5, while the inner diameter portion 12a' on the cover body 10' side extends toward the space S4 surrounded by the track roller 3, the rotating-side O-ring 8, and the rotating-side seal ring 6. This prevents the inner diameter portions 12a, 12a' of the cover bodies 10, 10' from sliding against each other, thereby preventing wear on the cover bodies 10, 10'.

[0063] Furthermore, since the cover bodies 10, 10' are not in contact with each other not only at the inner diameter portions 12a, 12a' but also at the base portions 11, 11' and the plate-like portions 12, 12', wear of the cover bodies 10, 10' can be prevented.

[0064] Furthermore, the outer peripheral surface 5b of the stationary seal ring 5 and the outer peripheral surface 6b of the rotating seal ring 6, which come into contact with the inner diameter portions 12a, 12a' of the cover bodies 10, 10', are flat surfaces, so that the gap between the stationary housing 2 and the stationary seal ring 5 and the gap between the track roller 3 and the rotating seal ring 6 can be reliably closed. Furthermore, wear of the inner diameter portions 12a, 12a' of the cover bodies 10, 10' can be reduced even when they slide axially relative to the outer peripheral surface 5b of the stationary seal ring 5 and the outer peripheral surface 6b of the rotating seal ring 6.

[0065] In addition, since the rubber bodies 15, 15' of the cover bodies 10, 10' are made of rubber with a high friction coefficient, the friction between the inner diameter portions 12a, 12a' and the outer peripheral surface 5b of the fixed side seal ring 5 and the outer peripheral surface 6b of the rotating side seal ring 6 increases, making it easier for them to elastically deform and follow the movements of the fixed side seal ring 5 and the rotating side seal ring 6.

[0066] Furthermore, although not shown, when the track roller 3 moves in the axial direction toward the fixed housing 2, the frictional force between the track roller 3 and the outer peripheral surface 6b of the rotating seal ring 6 keeps the track roller 3 in contact with the outer peripheral surface 6b, and the inner diameter end of the outer diameter portion 12b' elastically deforms so as to tilt toward the inside of the track roller 3. This makes it possible to maintain a closed state of the gap between the fixed housing 2 and the fixed seal ring 5, and the gap between the track roller 3 and the rotating seal ring 6.

[0067] In this embodiment, the inner diameter end of the cover body extends at an angle toward the inside of the housing on the side where it is attached, but this is not limiting and the inner diameter end of the cover body may be angled toward the inside of the opposing housing. Also, the inner diameter end of the cover body does not have to be angled. [Example]

[0068] Next, a floating seal device according to a second embodiment will be described with reference to Figures 3 and 4. Note that a description of the same configuration as in the first embodiment will be omitted. Note that in Figure 4, only the cover body 210 side is taken as an example, and a description of the cover body 210' side will be omitted.

[0069] 3, the cover body 210 of the second embodiment has an inner diameter portion 212a that is curved to convex to the left, and the cover body 210' has an inner diameter portion 212a' that is curved to convex to the right.

[0070] As shown in Figure 4, the inner diameter portion 212a of the cover body 210 functions to be pressed against the outer peripheral surface 5b of the fixed side seal ring 5 by the pressure of foreign matter C entering from the outer space S1 outside the machine, thereby improving the sealing performance and making it even more difficult for foreign matter C to enter the fixed side O-ring 7 side.

[0071] Furthermore, since the inner diameter portions 212a, 212a' are convex in the direction away from each other, the inner diameter portions 212a, 212a' of the cover bodies 210, 210' can be prevented from sliding against each other, and wear of the cover bodies 10, 10' can be prevented.

[0072] In this second embodiment, the inner diameter portions 212a, 212a' are curved so as to convex toward the fixed housing 2 and the track roller 3, respectively, but may also be bent, for example, in a shape that is approximately L-shaped in cross section so as to convex toward the inside of the housing to which it is attached. [Example]

[0073] Next, a floating seal device according to a third embodiment will be described with reference to Fig. 5 and Fig. 6. Note that a description of the same configuration as in the first embodiment will be omitted. Note that Fig. 6 only shows the cover body 310 side as an example, and a description of the cover body 310' side will be omitted.

[0074] 5, in the cover bodies 310, 310' of the present embodiment 3, the inner diameter portions 312a, 312a' bulge in the axial direction from the plate-shaped portions 312, 312'. In other words, the inner diameter portions 312a, 312a' are thicker than the plate-shaped portions 312, 312'.

[0075] As shown in Figure 6, the inner diameter portion 312a of the cover body 310 functions to be pressed against the outer peripheral surface 5b of the fixed side seal ring 5 by the pressure of foreign matter C entering from the outer space S1 outside the machine, thereby improving the sealing performance and making it even more difficult for foreign matter to enter the fixed side O-ring 7 side.

[0076] In addition, the contact area between the inner diameter portion 312a of the cover body 310 and the outer peripheral surface 5b of the fixed side seal ring 5 also increases, increasing the friction between the inner diameter portion 312a and the outer peripheral surface 5b of the fixed side seal ring 5, making it easier to follow the movement of the fixed side seal ring 5.

[0077] In this third embodiment, the inner diameter portions 312a, 312a' have a substantially circular cross section, but may have a rectangular or elliptical cross section, or may be freely changed. Furthermore, the inner diameter portions do not necessarily bulge outward from the plate-like portion on both axial sides, but may bulge outward on one axial side. Preferably, they may bulge outward toward the inside of the housing on the side where they are attached. [Example]

[0078] Next, a floating seal device according to a fourth embodiment will be described with reference to Fig. 7. Note that the description of the same configuration as in the first embodiment will be omitted.

[0079] As shown in FIG. 7, in the floating seal device 400 of the fourth embodiment, the recessed portion 421a of the fixed side housing 420 and the recessed portion 431a of the track roller 430 are annular grooves having a rectangular cross section.

[0080] The rubber body 415 of the cover body 410 is composed of a base portion 411 having a rectangular cross section and a plate-like portion 412 that extends radially inward at a constant thickness from the right surface of the inner diameter end of the base portion 411. The rubber body 415' of the cover body 410' is composed of a base portion 411' having a rectangular cross section and a plate-like portion 412' that extends radially inward at a constant thickness from the left surface of the inner diameter end of the base portion 411'. The rubber bodies 415 and 415' are symmetrical in shape.

[0081] A base 411 of the rubber body 415 is press-fitted into a recess 421a of the fixed housing 420. A base 411' of the rubber body 415' is press-fitted into a recess 431a of the track roller 430. The bases 411, 411' are fixed to the fixed housing 420 and the track roller 430 by bolts 14, 14' extending in the axial direction.

[0082] The cover bodies 410, 410' may be fixed to the fixed housing 420 and the track roller 430 simply by press-fitting into the recesses 421a, 431a of the base portions 411, 411' without using the bolts 14, 14'.

[0083] Annular base materials 413, 413' having a crank-shaped cross section are embedded in the cover bodies 410, 410' over the outer diameter portions of the base portions 411, 411' and the plate-like portions 412, 412'.

[0084] The inner diameter ends 412a, 412a' of the plate-shaped portions 412, 412' are pressed against the outer peripheral surface 5b of the stationary seal ring 5 and the outer peripheral surface 6b of the rotating seal ring 6. In other words, the gap between the stationary housing 420 and the stationary seal ring 5 and the gap between the track roller 430 and the rotating seal ring 6 are closed. [Example]

[0085] Next, a floating seal device according to a fifth embodiment will be described with reference to Fig. 8. Note that the description of the same configuration as in the fourth embodiment will be omitted.

[0086] As shown in Figure 8, the floating seal device 500 of this embodiment 5 has an annular rubber member 515 provided on the outer peripheral surface 550b of the fixed side seal ring 550, and an annular rubber member 515' provided on the outer peripheral surface 560b of the rotating side seal ring 560.

[0087] Specifically, an annular groove 551 that opens in the outer diameter direction is provided on an outer peripheral surface 550b of the stationary seal ring 550, and an annular groove 561 that opens in the outer diameter direction is provided on an outer peripheral surface 560b of the rotating seal ring 560. Rubber members 515, 515' are press-fitted and fixed into the annular grooves 551, 561.

[0088] Inner diameter ends 512a, 512a' of cover bodies 510, 510' are pressed against rubber members 515, 515'. As a result, inner diameter ends 512a, 512a' of rubber cover bodies 510, 510' come into contact with rubber members 515, 515', improving sealing performance and increasing frictional force, improving the ability of cover bodies 510, 510' to conform to stationary seal ring 550 and rotating seal ring 560.

[0089] Although the fifth embodiment exemplifies the rubber members 515, 515' being press-fitted into the annular grooves 551, 561, they may be fixed to the sliding components with adhesive, a garter spring, or the like. Furthermore, the fifth embodiment exemplifies the rubber members 515, 515' being separate members from the cover bodies 510, 510', but they may be integrated with each other. This reliably prevents foreign matter such as soil and mud from entering the housing.

[0090] Furthermore, although the inner diameter end of the cover body is relatively slidable in Examples 1 to 4, the inner diameter end of the cover body may also be fixed to the outer circumferential surface of the sliding component in the same manner as in Examples 1 to 4. This can reliably prevent foreign matter such as earth, sand, and mud from entering the housing.

[0091] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

[0092] For example, in Examples 1 to 5, the cover body is illustrated as being annular, but slits may be provided at multiple locations in the circumferential direction. The cover body may also be divided in the circumferential direction, and may be arranged with gaps between them in the circumferential direction, or may be arranged circumferentially overlapping in the axial direction. For example, when the cover body is arranged with a gap in the circumferential direction, it is preferable to provide a gap below the housing and the sliding component. If there is a gap below, foreign matter that passes over the cover body and enters the elastic ring side can be discharged by gravity.

[0093] Furthermore, in the first to fifth embodiments, a cover body is attached to each of a pair of housings, but it is sufficient that a cover body is attached to at least one of the housings.

[0094] Furthermore, in the first to fifth embodiments, the cover body is attached to the axial end surface of the housing, but the cover body may be attached to, for example, the outer peripheral surface or the inner peripheral surface of the housing.

[0095] The cover body can be attached to the housing by any method, such as fitting, welding, or bolts.

[0096] Furthermore, in the above-described Examples 1 to 5, the base material is embedded in the rubber body of the cover body, but the base material may be omitted.

[0097] Furthermore, in the above-described first to fifth embodiments, the cover body is made of an elastic material, but it may be made of a rigid material that does not deform, that is, a base material.

[0098] Although the embodiment in which the substrate is embedded in the rubber body of the cover has been exemplified, the substrate may be fixed to the outside of the rubber body. The substrate is not limited to being annular, but may be arc-shaped or the like, and multiple substrates may be provided.

[0099] In addition, in the above-described Examples 1 to 5, the outer peripheral surface of the sliding component is illustrated as a flat surface, but the outer peripheral surface may be provided with irregularities. In this case, it is preferable that the irregularities are absorbed by the elasticity of the cover body to close the gap.

[0100] Furthermore, in the first to fifth embodiments, the cover body is exemplified as a rubber body made of rubber, but it may be made of a material other than rubber as long as it has elasticity.

[0101] 9, the cover body 610 may be fixed to a recess 621a provided in an end surface 621 of the housing 620 with a substantially L-shaped cross section by a so-called clutch.

[0102] 10, the cover body 710 is fixed to the fixed housing 2. The cover body 710 is crank-shaped, and an inner diameter portion 712a of the cover body 710 abuts against the outer peripheral surface 6b of the rotating seal ring 6. This prevents foreign matter such as soil and sand from entering the fixed housing 2 and between the sliding surfaces 50, 60. Furthermore, the cover bodies do not slide against each other and wear out. Of course, there is no problem with a structure in which a cover body fixed to the track rotor, which is the rotating housing, abuts against the outer peripheral surface of the fixed seal ring. [Explanation of symbols]

[0103] 1 Floating seal device 2 Fixed side housing (one of the housings) 3 Track roller (other housing) 5 Fixed side seal ring (one of the sliding parts) 5b Outer surface (flat surface) 6 Rotating side seal ring (the other sliding part) 6b Outer surface (flat surface) 7 Fixed side O-ring (one of the elastic rings) 8 Rotating side O-ring (other elastic ring) 9 Rotation Axis 10,10' Cover body 11,11' base (proximal end) 12,12' Plate-shaped part 12a,12a' Inner diameter part (inner diameter end) 13,13' Circular base material (base material) 15,15' rubber body 21 End face (axial end face) 21a Recess 31 End face (axial end face) 31a Recess 50 sliding surface 60 sliding surface S1 Outer space S2 Inner space

Claims

1. elastic rings attached to the inner circumferential surface of the fixed housing and the inner circumferential surface of the rotating housing which faces the fixed housing and rotates relative to the fixed housing; a sliding part attached to each of the housings via each of the elastic rings and sliding relative to each other, A floating seal device in which a cover body is fixed to at least one of the housings, the cover body extending radially inward toward one or the other of the sliding components.

2. 2. The floating seal device according to claim 1, wherein the cover body is annular.

3. 2. The floating seal device according to claim 1, wherein the cover body is fixed to an axial end surface of the one housing that is located on the other housing side and on the outer diameter side of the sliding component.

4. A floating seal device as described in claim 3, wherein a recess is provided on an axial end surface of one of the housings located on the other housing side and on the outer diameter side of the sliding component, and the base end of the cover body is fixed to the recess.

5. The floating seal device according to claim 1, wherein the cover body has an elastic material having elasticity such that an inner diameter end thereof can abut against the outer peripheral surface of one of the sliding components, and a base material fixed to the elastic material and having greater rigidity than the elastic material.

6. 6. The floating seal device according to claim 5, wherein the elastic material is made of rubber.

7. 2. The floating seal device according to claim 1, wherein an inner diameter end portion of the cover body is inclined toward a space formed between the one housing, the elastic ring attached to the one housing, and the sliding component.

8. 2. A floating seal device as described in claim 1, wherein the inner diameter end of the cover body is curved or bent in a convex shape toward the space formed between the one housing, the elastic ring attached to the one housing, and the sliding part.

9. The floating seal device according to claim 1 , wherein the cover body is fixed to both of the housings.

10. 2. The floating seal device according to claim 1, wherein the outer peripheral surface of the sliding element is a flat surface.

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