Floating sealing device

Abstract

Provided is a floating seal device capable of supplying lubricating oil between sliding surfaces. A recess (64) is formed in the inner peripheral surface (62) of the rotation-side seal ring (6), the recess (64) extending in the direction opposite to the rotation direction of the rotation-side seal ring (6) toward the sliding surface (60)-side end (62A).

Description

Technical Field

[0001] The invention relates to a floating sealing device for shaft sealing. Background Art

[0002] Conventionally, there is a known floating seal device that performs shaft sealing between a fixed-side structure and a rotating-side structure when a rotating-side structure such as a travel motor, a roller, an idler wheel, or an axle is relatively rotatably connected to a fixed-side structure. Such a floating seal device seals a sealed fluid by making a pair of seal rings slide relative to each other, and generally has a floating function that allows a pair of seal rings to tilt relative to each other by using an elastic ring as a secondary seal.

[0003] If an example of a floating seal device is shown, as shown in Patent Document 1, it has a housing with a fixed side structure, a rotating body with a rotating side structure, a fixed ring arranged on the inner diameter side of the housing, a rotating ring arranged on the inner diameter side of the rotating body, an O-ring clamped in a sealed state between the housing and the fixed ring, and an O-ring clamped in a sealed state between the rotating body and the rotating ring. The inner circumferential surface of the housing and the inner circumferential surface of the rotating body are inclined in a manner of decreasing in diameter in a direction away from each other. In addition, the outer circumferential surface of the fixed ring is approximately parallel to the inner circumferential surface of the housing and is inclined relative to the axis, and the outer circumferential surface of the rotating ring is approximately parallel to the inner circumferential surface of the rotating body and is inclined relative to the axis.

[0004] The two O-rings are elastically deformed respectively, and their respective elastic restoring forces act in the direction of bringing the sliding surface of the fixed ring and the sliding surface of the rotating ring closer. As a result, the sliding surface of the fixed ring and the sliding surface of the rotating ring function as primary seals, and the O-rings function as secondary seals. As a result, foreign matter such as sand and mud can be prevented from entering the machine from outside. In addition, lubricating oil is stored in the machine of the floating seal device, which improves the sliding properties of the sliding surface of the fixed ring and the sliding surface of the rotating ring.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Publication No. 60-18869 (page 1, figure 1) Summary of the invention

[0008] Problems to be solved by the invention

[0009] However, construction machinery and the like equipped with a floating seal device such as that of Patent Document 1 often operate on inclined ground or non-land. When the floating seal device is inclined, the lubricating oil is biased toward the inclined side, and the lubricating oil cannot be fully supplied to the portion exposed above the oil level of the lubricating oil, which may reduce the lubricity. Furthermore, even when the rotating ring rotates at a high speed, the lubricating oil may not be fully supplied to the portion exposed above the oil level of the lubricating oil.

[0010] The present invention has been made in view of such problems, and an object of the present invention is to provide a floating seal device capable of supplying lubricating oil between sliding surfaces.

[0011] Means for solving problems

[0012] In order to solve the above-mentioned problem, the floating seal device of the present invention comprises: a fixed side housing; a rotating side housing, which is rotatable relative to the fixed side housing; a fixed side sealing ring, which is arranged on the inner circumference side of the fixed side housing; a rotating side sealing ring, which is arranged on the inner circumference side of the rotating side housing and slides opposite to the fixed side sealing ring; a fixed side elastic sealing component, which is interposed between the fixed side housing and the fixed side sealing ring; and a rotating side elastic sealing component, which is interposed between the rotating side housing and the rotating side sealing ring, and contains fluid on the inner circumference sides of the fixed side sealing ring and the rotating side sealing ring, wherein a recessed portion is formed on the inner circumferential surface of the rotating side sealing ring, extending toward the sliding surface side end in a direction opposite to the rotation direction of the rotating side sealing ring.

[0013] Thus, as the rotating-side seal ring rotates, the fluid contained in the floating seal device is guided toward between the sliding surfaces by the recessed portion, so that the fluid can be supplied to between the sliding surfaces.

[0014] The recessed portion may be a spiral groove.

[0015] Thus, the fluid can be smoothly supplied between the sliding surfaces using the spiral groove.

[0016] The width of the spiral groove may be narrower than the width of a land portion adjacent to the spiral groove.

[0017] This makes it easy to retain the fluid in the spiral groove, so the fluid can be reliably supplied between the sliding surfaces.

[0018] The recessed portion may be open at an end portion on a sliding surface side of the inner peripheral surface of the rotating-side seal ring.

[0019] This makes it easier to guide the fluid to the sliding surface.

[0020] The recessed portion may be formed over the entire inner peripheral surface of the rotating-side seal ring.

[0021] Thus, the recessed portion extends over a long range in the axial direction, and therefore a larger amount of fluid can be supplied between the sliding surfaces.

[0022] A bottom surface of an end portion of the rotating-side seal ring on a sliding surface side in the recessed portion may be inclined toward an outer diameter side.

[0023] Thus, the fluid can be smoothly supplied to the sliding surface on the outer diameter side.

[0024] The sliding surface of the rotating side seal ring may be arranged on the outer diameter side of the inner peripheral surface of the rotating side seal ring, a tapered surface may be formed between the sliding surface and the inner peripheral surface, and the recess may be provided over the inner peripheral surface and the tapered surface.

[0025] Thus, since the fluid is guided from the inner peripheral surface to the outer diameter side along the tapered surface, the fluid can be more reliably supplied between the sliding surfaces by utilizing the centrifugal force.

[0026] Alternatively, a plurality of recesses may be provided.

[0027] Thus, since the recessed portions are dispersedly arranged in the circumferential direction of the inner peripheral surface of the rotating-side seal ring, the fluid can be evenly supplied over the entire circumferential direction of the sliding surface.

[0028] The rotating-side seal ring may include a reverse recessed portion extending in a direction opposite to the recessed portion extending in one circumferential direction.

[0029] Thus, regardless of the rotation direction of the rotating-side seal ring, the fluid can be supplied between the sliding surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a cross-sectional view showing a floating seal device according to Embodiment 1 of the present invention.

[0031] Figure 2 This is a diagram showing the sliding surface of the rotating side seal ring as viewed from the axial direction.

[0032] Figure 3 It is a cross-sectional view of the rotating side sealing ring.

[0033] Figure 4 This is a schematic diagram of a developed cross section cut along the spiral groove.

[0034] Figure 5 This is a schematic cross-sectional view showing the behavior of lubricating oil when the rotating-side seal ring rotates.

[0035] Figure 6 This is a diagram showing the behavior of lubricating oil when the rotating-side seal ring rotates, as viewed from the axial direction.

[0036] Figure 7 (a) is a cross-sectional view of a rotating side seal ring of Example 2 of the present invention, Figure 7 (b) is a schematic diagram of a developed cross section cut along the spiral groove of Example 2.

[0037] Figure 8 It is a cross-sectional view of a rotating side seal ring according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0038] Hereinafter, a mode for implementing the floating seal device of the present invention will be described based on embodiments.

[0039] Example 1

[0040] Reference Figures 1 to 6 The floating seal device of Example 1 will be described. In addition, for the convenience of description, in the drawings, grooves and the like formed on the sliding surface may be indicated by dots.

[0041] In the floating seal device 1 of the present embodiment 1, the roller 3 as the rotating side housing is relatively rotatable with the rotating shaft 9 (refer to Figure 1 ) connection to prevent foreign matter such as sand and mud from invading the rotating shaft 9 side from the gap between the fixed side housing 2 and the supporting wheel 3.

[0042] like Figure 1 As shown, the floating seal device 1 is mainly composed of a fixed side housing 2, a supporting wheel 3, a fixed side sealing ring 5, a rotating side sealing ring 6, a fixed side O-ring 7 as a fixed side elastic sealing component, and a rotating side O-ring 8 as a rotating side elastic sealing component.

[0043] The fixed side housing 2 is fixed to the side frame. The roller 3 is connected to the rotating shaft 9 in a state where the rotating shaft 9 is inserted therethrough. The fixed side seal ring 5 is arranged on the inner diameter side of the fixed side housing 2. The rotating side seal ring 6 is arranged on the inner diameter side of the 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 roller 3 and the rotating side seal ring 6.

[0044] The track rollers 3 are disposed in a state separated from the fixed-side housing 2 in the axial direction and are relatively rotatable with respect to the fixed-side housing 2 .

[0045] Furthermore, the machine outer side space S1 including the gap between the fixed side housing 2 and the supporting roller 3 and the machine inner side space S2 on the rotating shaft 9 side are divided by the sealing rings 5, 6 and the O-rings 7, 8, and the boundary between them is sealed. The fixed side housing 2, the supporting roller 3, the sealing rings 5, 6 and the O-rings 7, 8 are described in detail below.

[0046] First, the fixed side housing 2 will be described. Figure 1 The fixed side housing 2 is formed into a stepped cylindrical shape into which the rotating shaft 9 can be inserted with play. The fixed side housing 2 has an inner peripheral portion 2A which is open toward the roller 3 and recessed in the axial direction on the inner diameter side of the roller 3.

[0047] The inner peripheral portion 2A is provided with a sealing surface 20 whose diameter decreases toward the inner diameter side as it moves away from the roller 3 side arranged opposite in the axial direction. In addition, an annular wall 21 extending in the radial direction and continuous in the circumferential direction is formed on the side of the inner peripheral portion 2A opposite to the opening on the roller 3 side. When the fixed side O-ring 7 moves in the direction away from the rotating side seal ring 6 in the axial direction, the wall 21 abuts against the fixed side O-ring 7 to restrict its axial movement.

[0048] Next, the supporting wheel 3 will be described. Figure 1 The roller 3 is formed into a stepped cylindrical shape that can be externally fitted on the rotating shaft 9. The roller 3 has an inner peripheral portion 3A that is open toward the fixed side housing 2 and recessed in the axial direction formed on the inner diameter side of the fixed side housing 2.

[0049] The inner peripheral portion 3A is provided with a sealing surface 30 whose diameter decreases toward the inner diameter side as it moves away from the opposite fixed side housing 2 side in the axial direction. In addition, an annular wall 31 extending in the radial direction and continuous in the circumferential direction is formed on the side of the inner peripheral portion 3A opposite to the opening on the fixed side housing 2 side. When the rotating side O-ring 8 moves in the direction away from the fixed side seal ring 5 in the axial direction, the wall 31 abuts against the rotating side O-ring 8 to restrict its axial movement.

[0050] Next, the stationary side seal ring 5 will be described. The stationary side seal ring 5 is made of cast iron, and is formed in a stepped cylindrical shape into which the rotating shaft 9 can be inserted with play.

[0051] The stationary-side seal ring 5 has an annular sliding surface 50 at an end portion facing the rotating-side seal ring 6 .

[0052] The inner peripheral surface 52 of the stationary side seal ring 5 extends substantially parallel to the rotating shaft 9. The inner peripheral surface 52 is arranged on the inner diameter side of the sliding surface 50 and at a position farther from the rotating side seal ring 6 than the sliding surface 50 in the axial direction.

[0053] Furthermore, a tapered surface 53 connected to the sliding surface 50 and the inner peripheral surface 52 is formed between them. That is, the tapered surface 53 extends from the inner peripheral surface 52 toward the rotating side seal ring 6 side while being inclined toward the outer diameter side.

[0054] The stationary seal ring 5 has an annular inclined groove recessed toward the inner diameter side at the axial center portion on the outer diameter side. The bottom surface of the inclined groove is a tapered surface 51 that decreases in diameter as it moves away from the sliding surface 50 .

[0055] When manufacturing the stationary side seal ring 5, Cr-Mo cast iron and Ni-Cr cast iron are preferred materials. In addition, copper alloy, carbon steel, SiC, superhard alloy, ceramics, etc. can also be used.

[0056] 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 inserted with play.

[0057] like Figure 1 and Figure 2 As shown, the rotating-side seal ring 6 has an annular sliding surface 60 at the end portion opposite to the stationary-side seal ring 5 .

[0058] The inner peripheral surface 62 of the rotating side seal ring 6 extends substantially parallel to the rotating shaft 9. The inner peripheral surface 62 is arranged on the inner diameter side of the sliding surface 60 and is farther from the stationary side seal ring 5 than the sliding surface 60 in the axial direction.

[0059] Furthermore, a tapered surface 63 is formed between the sliding surface 60 and the inner peripheral surface 62 as a sliding surface side end surface connected thereto. That is, the tapered surface 63 extends obliquely toward the outer diameter side from the inner peripheral surface 62 toward the stationary side seal ring 5. The spiral groove 64 provided on the inner peripheral surface 62 of the rotating side seal ring 6 will be described in detail later.

[0060] The rotating side seal ring 6 has an annular inclined groove recessed toward the inner diameter side at the axial center portion on the outer diameter side. The bottom surface of the inclined groove is a tapered surface 61 that decreases in diameter as it moves away from the sliding surface 60 .

[0061] When manufacturing the rotating side seal ring 6, Cr-Mo cast iron and Ni-Cr cast iron are preferred materials. In addition, copper alloy, carbon steel, SiC, superhard alloy, ceramics, etc. can also be used.

[0062] Next, the fixed side O-ring 7 and the rotating side O-ring 8 are described. Figure 1 The fixed side O-ring 7 and the rotating side O-ring 8 are made of rubber material and are formed into an annular shape that can be externally fitted into the inclined grooves of the fixed side seal ring 5 and the rotating side seal ring 6 .

[0063] These fixed side O-ring 7 and 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 roller 3 and the rotating side seal ring 6. The elastic restoring force of the fixed side O-ring 7 and the rotating side O-ring 8 acts in a direction in which the fixed side seal ring 5 and the rotating side seal ring 6 approach each other.

[0064] As a result, a predetermined sliding surface pressure is applied between the sliding surfaces 50 and 60 in the axial direction, and the sliding surfaces 50 and 60 function as a primary seal.

[0065] Furthermore, the stationary-side O-ring 7 in close contact between the stationary-side housing 2 and the stationary-side seal ring 5 and the rotating-side O-ring 8 in close contact between the track roller 3 and the rotating-side seal ring 6 function as secondary seals.

[0066] In this way, foreign matter such as sand and mud can be reliably prevented from entering the machine inner space S2 containing the lubricating oil as the fluid from the machine outer space S1. The fluid may be a fluid other than the lubricating oil.

[0067] In addition, regarding the fixed side O-ring 7 and the rotating side O-ring 8, for example, hydrogenated nitrile rubber (H-NBR), perfluoroelastomer, nitrile rubber (NBR) with a hardness of DuroA60 to 70, polyurethane rubber (U), fluororubber (FKM), butyl rubber (IIR) and other resins with elasticity are preferred materials.

[0068] Next, use Figure 2 to Figure 4 The spiral groove 64 of the rotating-side seal ring 6 will be described.

[0069] like Figure 2 to Figure 4 As shown, a plurality of (twelve in this embodiment) spiral grooves 64 as recessed portions having different phases in the circumferential direction are evenly arranged on the inner circumferential surface 62 of the rotating side seal ring 6 .

[0070] The spiral groove 64 is a groove with a substantially rectangular cross section that opens in the inner diameter direction and is recessed in the inner peripheral surface 62 by laser processing or the like. Figure 3 As shown, the land portion 62 a of the inner peripheral surface 62 other than the spiral groove 64 is formed as a convex strip having a substantially rectangular cross section.

[0071] The spiral groove 64 spirally extends toward the sliding surface 60 , more specifically, toward the sliding surface side end portion 62A of the inner peripheral surface 62 in a direction opposite to the normal rotation direction of the rotating-side seal ring 6 .

[0072] Specifically, from Figure 3 When viewed along the axial direction on the right side, that is, on the side opposite to the sliding surface 60, the rotating side seal ring 6 rotates clockwise (refer to Figure 1 , Figure 3 On the other hand, Figure 3 When viewed from the right side of the axial direction, the spiral groove 64 winds counterclockwise while moving toward Figure 3 The left side, that is, the axial sliding surface 60 side, extends in a spiral shape.

[0073] The spiral groove 64 is formed on the inner peripheral surface 62 of the rotating side seal ring 6 so as to wind one or more times in the circumferential direction.

[0074] In this embodiment, the spiral groove 64 extends at an angle of approximately 45 degrees relative to the axial direction of the rotating shaft 9. As a result of the experiment, the spiral groove 64 is preferably inclined at 30 to 60 degrees relative to the axial direction of the rotating shaft 9, and is particularly preferably inclined at approximately 45 degrees relative to the axial direction of the rotating shaft 9.

[0075] The end portion 64A of each spiral groove 64 on the sliding surface 60 side extends from the inner diameter edge of the tapered surface 63 toward the fixed side seal ring 5 side (i.e. Figure 3 Furthermore, the end portion 64B of each spiral groove 64 on the side opposite to the sliding surface 60 is opened from the inner diameter edge of the end surface 66 on the side opposite to the sliding surface 60 to the opposite side of the fixed side seal ring 5.

[0076] In other words, the spiral groove 64 is formed over the entire inner peripheral surface 62 of the rotating-side seal ring 6 .

[0077] Furthermore, the width dimension L1 of the spiral groove 64 is slightly smaller than the width dimension L2 of the land portion 62a (L1<L2). By making the width dimension L2 of the land portion 62a greater than the width dimension L1 of the spiral groove 64, the amount of lubricating oil that passes over the land portion 62a and moves toward the downstream side becomes less, and the lubricating oil is reliably guided toward the sliding surface 60 side. In addition, the width dimension L1 of the spiral groove 64 is preferably 1mm to 2mm. This is because if the width is smaller than this, it is difficult for the lubricating oil to enter the spiral groove 64, and conversely, if the width is larger than this, the lubricating oil is likely to overflow from the spiral groove 64. Furthermore, the deeper the spiral groove 64 and the more spiral grooves 64 there are, the more the volume increases and the greater the centrifugal force, which is preferred.

[0078] And, especially if Figure 4 As shown, the depth dimension L3 of the spiral groove 64 is substantially constant over the entire range of the extending direction of the spiral groove 64. Thus, the lubricating oil is smoothly guided to the sliding surface 60. Figure 4 The figure shows a state where a cross section cut along the spiral groove is developed.

[0079] In such a floating seal device 1, a portion of the upper side of the sliding surface 50 of the fixed side seal ring 5 and the sliding surface 60 of the rotating side seal ring 6 is exposed to a position higher than the oil level of the lubricating oil in the machine inner space S2 (see Figure 6 ).

[0080] like Figure 5 and Figure 6 As shown in FIG. 1 , when the rotating side seal ring 6 rotates, the lubricating oil in the machine inner space S2 is subjected to centrifugal force and is guided from each spiral groove 64 to the sliding surface 60 side. Specifically, the lubricating oil is lifted by each spiral groove 64 and supplied from the end 64A of each spiral groove 64 toward the portion between the sliding surfaces 50 and 60 that is exposed to a position above the oil level of the lubricating oil (see FIG. 1 ). Figure 5 and Figure 6 The lubricating oil discharged from the end 64A of each spiral groove 64 to the tapered surface 63 flows toward the extending direction of the spiral groove 64, that is, the direction opposite to the positive rotation direction of the rotating side seal ring 6, toward the outer diameter side and reaches between the sliding surfaces 50 and 60 (see in particular Figure 6 ).

[0081] In this way, as the rotating side seal ring 6 rotates, the lubricating oil in the machine inner space S2 is sequentially guided toward between the sliding surfaces 50 and 60 by the spiral groove 64, thereby preventing the sliding surfaces 50 and 60 from being poorly lubricated at the portion exposed above the oil level of the lubricating oil. In other words, seizure between the sliding surfaces 50 and 60 can be suppressed.

[0082] Furthermore, since the end portion 64A of the spiral groove 64 is open toward the tapered surface 63 of the rotating-side seal ring 6 , the lubricating oil can be easily guided toward between the sliding surfaces 50 , 60 .

[0083] Furthermore, the spiral groove 64 is formed over the entire inner peripheral surface 62 of the rotating side seal ring 6. In other words, the spiral groove 64 extends over a long range in the axial direction, so that more lubricating oil can be supplied between the sliding surfaces 50, 60.

[0084] Furthermore, a plurality of spiral grooves 64 are evenly arranged on the inner peripheral surface 62 of the rotating side seal ring 6. Thus, lubricating oil can be evenly supplied to the entire range in the circumferential direction between the sliding surfaces 50 and 60.

[0085] Furthermore, since the width L2 of the land portion 62a is larger than the width L1 of the spiral groove 64 , it is possible to suppress the lubricating oil from moving from the spiral groove 64 to the adjacent spiral groove 64 over the land portion 62a , so that the lubricating oil can be reliably supplied to between the sliding surfaces 50 , 60 .

[0086] Furthermore, since the spiral groove 64 has a rectangular shape in cross-sectional view, the lubricating oil is suppressed from moving to the adjacent spiral groove 64 by the side wall surface constituting the spiral groove 64 , and the lubricating oil is easily retained in the spiral groove 64 .

[0087] Furthermore, since the spiral groove 64 is recessed in the inner peripheral surface 62 of the rotating side seal ring 6 by laser processing or the like, the rotating side seal ring 6 and the spiral groove 64 can be easily configured by a single component.

[0088] Example 2

[0089] Next, refer to Figure 7 The floating seal device of the second embodiment is described. In addition, the repeated structural description of the same structure as the above-mentioned first embodiment is omitted. In addition, Figure 7 (b) is a diagram showing an unfolded cross section cut along the spiral groove.

[0090] like Figure 7 (a) and Figure 7 As shown in (b), the end 264A of the spiral groove 264 of the rotating side seal ring 26 of the second embodiment extends in the outer diameter direction and is open. In other words, the spiral groove 264 is provided over the inner peripheral surface 262 and the tapered surface 263 of the rotating side seal ring 26.

[0091] Specifically, if Figure 7 As shown in (b), the spiral groove 264 has a first bottom surface 264a and a second bottom surface 264b. The first bottom surface 264a extends substantially parallel to the inner peripheral surface 262 of the rotating side seal ring 26. The second bottom surface 264b is provided at a position closer to the end 264A side of the spiral groove 264 than the first bottom surface 264a, and is inclined in a manner of expanding the diameter toward the sliding surface 260.

[0092] Thus, the end portion 264A extends from the inner peripheral surface 262 of the rotating side seal ring 26 in the outer diameter direction along the tapered surface 263 and opens, and the lubricating oil is guided to the outer diameter side, so that the lubricating oil can be more reliably supplied to the sliding surface 260 by centrifugal force.

[0093] Furthermore, since the second bottom surface 264 b on the end 264A side of the spiral groove 264 is inclined so as to increase in diameter toward the sliding surface 260 , the lubricating oil can be smoothly supplied to the sliding surface 260 on the outer diameter side by centrifugal force.

[0094] Example 3

[0095] Next, refer to Figure 8 A floating seal device according to Embodiment 3 will be described. In addition, duplicate descriptions of the same structures as those of Embodiment 1 will be omitted.

[0096] like Figure 8 As shown, a plurality of spiral grooves 364 and a plurality of reverse spiral grooves 365 are provided on the inner circumferential surface 362 of the rotating side seal ring 36 of the second embodiment. The reverse spiral groove 365 is a groove extending in a spiral shape in a direction opposite to the spiral groove 364.

[0097] Specifically, from Figure 8 When the right side of the reverse spiral groove 365 is viewed in the axial direction, the reverse spiral groove 365 spirally extends toward the axial sliding surface 360 ​​while winding clockwise. The reverse spiral groove 365 intersects and communicates with the spiral groove 364 at multiple locations.

[0098] In addition, the number of the reverse helical grooves 365 is less than the number of the helical grooves 364. For example, the number of the reverse helical grooves 365 is 1 / 3 of the number of the helical grooves 364.

[0099] Thus, when the rotating side seal ring 36 rotates forward, lubricating oil is supplied to the sliding surface 360 ​​from the spiral groove 364, and when the rotating side seal ring 36 rotates reversely, lubricating oil is supplied to the sliding surface 360 ​​from the reverse spiral groove 365. That is, lubricating oil can be supplied to the sliding surface 360 ​​regardless of the rotation direction of the rotating side seal ring 36.

[0100] Furthermore, since the number of the reverse spiral grooves 365 is smaller than that of the spiral grooves 364 , the reverse spiral grooves 365 are less likely to affect the lubricating oil supplied from the spiral grooves 364 when the rotating-side seal ring 36 is rotating in the normal direction.

[0101] As mentioned above, although the embodiment of the present invention is described with reference to the drawings, the specific structure is not limited to these embodiments, and the change and addition within the range which does not deviate from the summary of the present invention are also included in the present invention.

[0102] For example, in the above-mentioned Embodiments 1 to 3, the concave portion is exemplified as a spiral groove formed by winding more than one turn in the circumferential direction, but the invention is not limited thereto, and the winding of the concave portion may be less than one turn.

[0103] Furthermore, in the first to third embodiments, the sliding surface side end of the recess is open, but the sliding surface side end of the recess may be closed near the sliding surface side end surface of the rotating side seal ring.

[0104] Furthermore, in the above-mentioned first to third embodiments, the end of the recessed portion on the side opposite to the sliding surface is open to the side opposite to the fixed side ring, but the end on the opposite side may be closed.

[0105] Furthermore, in the above-mentioned first to third embodiments, the recessed portion is inclined at approximately 45 degrees with respect to the axial direction, but the invention is not limited thereto, and the angle of the recessed portion with respect to the axial direction can be freely changed.

[0106] Furthermore, in the above-mentioned embodiments 1 to 3, the groove width of the concave portion, the pitch of the winding, and the depth are shown as being constant in the extending direction, but they may be different in the extending direction. Furthermore, the groove width of the concave portion, the pitch of the winding, the depth, etc. may be freely changed.

[0107] Furthermore, in the above-mentioned embodiments 1 to 3, a method of evenly disposing a plurality of recesses on the inner circumferential surface of the rotating side seal ring is illustrated, but the arrangement is not limited to even distribution, and the separation distances between the spiral grooves can be freely changed. Furthermore, there only needs to be at least one recess, and the number can be freely changed.

[0108] Furthermore, in the above-mentioned first to third embodiments, the concave portion is provided on the inner circumferential surface of the rotating side seal ring by laser processing or the like, but for example, the concave portion may be formed on the inner circumferential surface of the rotating side seal ring by embedding a ring member having a concave portion formed therein into the inner circumferential surface of the rotating side seal ring. Furthermore, a plurality of convex portions protruding toward the inner diameter side may be provided on the inner circumferential surface of the rotating side seal ring to form a concave portion between adjacent convex portions, or a ring member having a plurality of convex portions provided to form a concave portion between adjacent convex portions may be embedded in the inner circumferential surface of the rotating side seal ring to form a concave portion on the inner circumferential surface of the rotating side seal ring.

[0109] Furthermore, in the above-mentioned first to third embodiments, the cross-section of the recessed portion is exemplified as being rectangular, but the present invention is not limited thereto, and the cross-section may be a curved surface.

[0110] Furthermore, for example, in the aforementioned embodiments 1 to 3, the floating seal device is described as being used for the side frame and the supporting wheels constituting the circular track, but is not limited thereto and may also be used for travel motors, idler wheels, axles, etc. without limitation.

[0111] Furthermore, in the above-mentioned embodiments 1 to 3, the fixed side housing is described as being a fixed side housing 2 installed on the fixed side structure, but the present invention is not limited thereto, and the fixed side housing may be a part of the fixed side structure or the fixed side structure itself, without limitation. Similarly, the rotating side housing is described as a roller as the rotating side structure itself, but the present invention is not limited thereto, and the rotating side housing may be installed on the rotating side structure or constitute a part of the rotating side structure, without limitation.

[0112] Furthermore, in the aforementioned embodiments 1 to 3, the fixed shaft and the rotating side housing rotate relative to the fixed side housing, but it is also possible that the rotating side housing is rotatably fixed to the fixed shaft that passes through the fixed side sealing ring and the rotating side sealing ring, and the fixed shaft and the rotating side housing rotate relative to each other.

[0113] Furthermore, the stationary side seal ring and the rotating side seal ring may be made of the same member. In this case, the recessed portions are also symmetrically arranged on the inner peripheral surface of the stationary side seal ring with the sliding surface as the boundary.

[0114] Description of symbols

[0115] 1: floating seal device; 2: fixed side casing; 3: supporting wheel (rotating side casing); 5: fixed side sealing ring; 6: rotating side sealing ring; 7: fixed side O-ring (fixed side elastic sealing component); 8: rotating side O-ring (rotating side elastic sealing component); 9: rotating shaft; 36: rotating side sealing ring; 60: sliding surface; 62: inner peripheral surface; 62A: sliding surface side end; 62a: land portion; 63: conical surface (sliding surface side end surface); 64: spiral groove (recessed portion); 64A: end (exit side end); 365: reverse spiral groove; S1: space outside the machine; S2: space inside the machine.

Claims

1. A floating seal device, comprising: Fixed side housing; A rotating side housing, which is relatively rotatable relative to the fixed side housing; A fixed-side sealing ring, which is arranged on the inner circumference of the fixed-side housing; a rotating side sealing ring disposed on the inner circumference of the rotating side housing and slidingly opposed to the stationary side sealing ring; a fixed-side elastic sealing member interposed between the fixed-side housing and the fixed-side sealing ring; and a rotating side elastic sealing member, which is interposed between the rotating side housing and the rotating side sealing ring, A fluid is contained in the inner circumference of the fixed-side seal ring and the rotating-side seal ring. in, A recessed portion is formed on the inner peripheral surface of the rotating side seal ring and extends toward the sliding surface side end portion in a direction opposite to the rotation direction of the rotating side seal ring.

2. The floating seal device according to claim 1, wherein: The recessed portion is a spiral groove.

3. The floating seal device according to claim 2, wherein: The width of the spiral groove is narrower than the width of the land portion adjacent to the spiral groove.

4. The floating seal device according to claim 1, wherein: The recessed portion opens at an end portion on the sliding surface side of the inner peripheral surface of the rotating-side seal ring.

5. The floating seal device according to claim 4, wherein: The recessed portion is formed over the entire inner peripheral surface of the rotating-side seal ring.

6. The floating seal device according to claim 4, wherein: A bottom surface of an end portion of the rotary-side seal ring on the sliding surface side in the recessed portion is inclined toward the outer diameter side.

7. The floating seal device according to any one of claims 1 to 6, wherein: The sliding surface of the rotating side seal ring is arranged at a position closer to the outer diameter side than the inner peripheral surface of the rotating side seal ring, and a tapered surface is formed between the sliding surface and the inner peripheral surface. The recessed portion is provided over the inner peripheral surface and the tapered surface.

8. The floating seal device according to claim 1, wherein: A plurality of recesses are provided.

9. The floating seal device according to claim 1, wherein: The rotating-side seal ring has a reverse recessed portion extending in a direction opposite to the recessed portion extending in one circumferential direction.

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