Floating seal device

Abstract

The utility model provides a kind of floating sealing device, it is used to install on rotating shaft in pressure system.The floating sealing device includes a pair of floating seal ring, a pair of O-ring and floating seal seat.One floating seal ring is fixed, and another floating seal ring rotates with rotating shaft.Each floating seal ring includes: radial ring portion, the outer diameter side of its sealing end face is provided with first sealing surface, and the inner diameter side is provided with non-sealing surface relative to the distal end of first sealing surface Inclination, and first sealing surface is mutually abutted and forms seal;And conical ring portion, it protrudes to distal end from the back side of radial ring portion.A pair of O-ring is correspondingly assembled on the outer taper surface of the conical ring portion of a pair of floating seal ring.Floating seal seat has seat cavity, for accommodating a pair of floating seal ring and a pair of O-ring.Second sealing surface is arranged between first sealing surface and non-sealing surface, and second sealing surface is inclined to distal end relative to first sealing surface.The floating sealing device of the utility model can maintain stable sealing state even after pressure increases.

Description

Technical Field

[0001] This utility model relates to a sealing device, and more specifically, to a floating sealing device. Background Technology

[0002] Typically, floating seal devices allow for sealing of the end face gap under a certain design pressure. However, as pressure increases, the contact force between the floating seal and the sealing surface also increases, leading to increased wear between the sealing surfaces and potentially causing failure. If the pressure continues to increase, the O-ring on the floating seal ring may be squeezed out, resulting in seal failure. For example, in construction machinery, hydraulic motors are often matched with reducers as end actuators. Floating seal devices are used for dynamic sealing in the reducer. The pressure inside the hydraulic motor cavity is much higher than that in the reducer. If the seal fails, hydraulic oil will leak into the reducer, increasing the pressure on the sealing surface of the floating seal ring. If the reducer continues to operate, this will lead to excessive wear on the sealing surface and even leakage. Because it is difficult to monitor the pressure increase inside the cavity under normal conditions, the floating seal is often already damaged and lubricating oil has leaked out of the cavity by the time it is discovered. Subsequent downtime for repairs consumes manpower and resources and delays normal production.

[0003] Therefore, there is a need in the art for a floating sealing device that can provide a stable and good seal even with pressure changes. Utility Model Content

[0004] The purpose of this invention is to provide a floating sealing device that maintains good sealing behavior even under significant pressure changes. This floating sealing device can withstand pressure variations, passively switching the sealing surface when pressure increases, passively releasing the increased pressure on the floating sealing ring, and dynamically maintaining a stable sealing state. After the pressure recovers, it can return to the initial sealing state.

[0005] To solve the above-mentioned technical problems, according to this utility model, a floating sealing device is provided for installation on a rotating shaft in a pressure system. The floating sealing device includes a pair of floating sealing rings, a pair of O-rings, and a floating sealing seat. One of the floating sealing rings is fixed, while the other rotates with the rotating shaft. Each floating sealing ring includes: a radial ring portion, with a first sealing surface on the outer diameter side of its sealing end face and a non-sealing surface inclined distally relative to the first sealing surface on its inner diameter side, the first sealing surfaces abutting against each other to form a seal; and a conical ring portion protruding distally from the back side of the radial ring portion. A pair of O-rings are correspondingly fitted onto the outer conical surface of the conical ring portion of the pair of floating sealing rings. The floating sealing seat has a cavity for accommodating the pair of floating sealing rings and the pair of O-rings. A second sealing surface is provided between the first sealing surface and the non-sealing surface, the second sealing surface being inclined distally relative to the first sealing surface.

[0006] According to a preferred embodiment of the present invention, the angle of inclination of the second sealing surface relative to the first sealing surface is in the range of 1-2 degrees.

[0007] According to a preferred embodiment of the present invention, the radial widths of the first sealing surface and the second sealing surface are equal.

[0008] According to a preferred embodiment of the present invention, the radial width of the first sealing surface and the second sealing surface ranges from 2 to 3 millimeters.

[0009] According to a preferred embodiment of the present invention, the angle at which the non-sealing surface is inclined relative to the first sealing surface at the distal end is in the range of 3-5 degrees.

[0010] According to a preferred embodiment of the present invention, the angle between the back side of the radial ring portion of the floating seal ring and the outer conical surface of the conical ring portion is 90 degrees.

[0011] According to a preferred embodiment of the present invention, the outer diameter end of the radial ring portion of the floating seal ring extends 1.5 mm axially toward the O-ring side.

[0012] According to a preferred embodiment of the present invention, a groove is provided on the radially inner side of the floating seal ring at a position opposite to the O-ring.

[0013] According to a preferred embodiment of the present invention, the groove is configured such that the minimum thickness of the tapered ring is half the radial width of the distal end of the tapered ring.

[0014] According to a preferred embodiment of the present invention, a plurality of support ribs are disposed in the groove.

[0015] The floating sealing device of this invention, by modifying the structure of the floating seal ring, such as by adding a sealing surface and / or creating grooves, causes the floating seal ring to undergo slight radial deformation towards the rotation center when the pressure increases. This ultimately reduces the axial contact pressure acting on the sealing surface and / or dynamically changes the sealing position to maintain a sealing state. The reduction in axial contact pressure on the sealing surface helps maintain a good sealing state over a long period. The shoulder also prevents the O-ring from being squeezed out due to increased pressure. Attached Figure Description

[0016] To enable those skilled in the art to more fully understand this utility model, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Wherein:

[0017] Figure 1 This is an axial cross-sectional view of a floating sealing device according to an embodiment of the present invention;

[0018] Figure 2 This is a perspective view of an axial cross-section of one side of a floating sealing device according to another embodiment of the present invention;

[0019] Figure 3 for Figure 2 An axial cross-sectional view of one side of the floating sealing device shown;

[0020] Figure 4 The contact condition of the sealing end face of the floating seal ring under normal pressure (left) and increased pressure (right);

[0021] Figure 5 This is a schematic diagram illustrating the state changes of the floating seal ring under increased pressure.

[0022] Figure 6 This is an axial cross-sectional view of a modified embodiment of the floating sealing ring of the floating sealing device according to the present invention;

[0023] Figure 7 This is an axial cross-sectional view of another variant embodiment of the floating sealing ring of the floating sealing device according to the present invention;

[0024] Figure 8 A partial cross-sectional perspective view of an embodiment of the floating seal ring with supporting ribs of this utility model; and

[0025] Figure 9 This is a graph comparing the floating sealing device of this utility model with existing floating sealing devices. Detailed Implementation

[0026] To make the present invention clearer, a specific embodiment of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited to the embodiment described below.

[0027] It should be noted that the directional terms used in this article, such as "up" and "down", "top" and "bottom", "left" and "right", are only for the purpose of explaining the structure of the product with reference to the accompanying drawings. The directions indicated are only the approximate directions shown in the accompanying drawings and do not represent the actual direction of use of the product.

[0028] Floating seal devices are widely used in various mechanical equipment and typically consist of a floating seal ring, an O-ring, and a floating seal seat. Floating seal rings are used in pairs, with one ring rotating with the rotating parts of the equipment while the other remains stationary. The O-ring is fitted between the back of the floating seal ring and the floating seal seat, rotating with the corresponding floating seal ring or remaining stationary, providing auxiliary static sealing and elastic compensation. The floating seal seat has a cavity for mounting the floating seal ring and the O-ring.

[0029] During equipment operation, the rotation of the shaft causes lubricating oil to form an oil film between the sealing surfaces of a pair of floating seal rings, thus achieving a sealing function. The O-rings, under preload within the floating seal seat, generate radial and axial forces, which help ensure a tight fit between the sealing surfaces of the floating seal rings and provide sealing compensation. Simultaneously, the floating seal rings can float within the floating seal seat, automatically adjusting their position through the elastic compensation of the O-rings to compensate for misalignment or deflection between rotating and stationary components, thereby ensuring effective contact between the sealing surfaces of the floating seal rings.

[0030] This invention provides an improved floating seal device, which is particularly suitable for use in pressure systems. For example... Figure 1 As shown, the floating seal device includes a pair of floating seal rings 1, a pair of O-rings 2, and a floating seal seat 3. The O-rings 2 are disposed on the outer conical surface of the floating seal rings 1, between the outer conical surface of the floating seal rings and the inner conical surface of the floating seal seat.

[0031] like Figure 1 As shown, the pair of floating seal rings 1 have identical structures, with their sealing end faces 11 positioned opposite each other. The following mainly refers to... Figures 2 to 3 The specific structure of one of the floating seal rings will be described in detail. The other floating seal ring has the same structure as the one described in this article, so it will not be described in detail here.

[0032] Figure 3This is an axial cross-sectional view of a floating seal ring 1 of the floating sealing device of this utility model. As shown, the floating seal ring 1 has a sealing end face 11 opposite to another floating seal ring and a distal end 12 opposite to the sealing end face 11. On the sealing end face 11, there is a first sealing surface 111 on the outer diameter side of the floating seal ring 1 and a non-sealing surface 110 on the inner diameter side of the floating seal ring. Under normal pressure conditions, the two opposing first sealing surfaces 111 fit together to form a surface seal, with the sealing surfaces perpendicular to the equipment axis. This surface seal, combined with the auxiliary seal of the O-ring, can effectively prevent the medium from leaking to the outside or related components, and prevent external dust and other impurities from entering the interior of the equipment, thereby protecting internal components from contamination and extending their service life. The non-sealing surface 110 is inclined relative to the first sealing surface 111 towards the body side (i.e., the distal end 12) of the floating seal ring, thereby forming a space between the two opposing non-sealing surfaces 110. This space can accommodate lubricating oil, etc. As the equipment rotates, the lubricating oil can enter the sealing surface through centrifugal force and capillary action, thereby forming an oil film to ensure the sealing, lubrication, and cooling of the sealing surface. The non-sealing surface 110 is inclined at a certain angle relative to the first sealing surface 111, preferably, for example, 3-5 degrees.

[0033] According to a preferred embodiment of the present invention, a second sealing surface 112 is added between the first sealing surface 111 and the non-sealing surface 110. This second sealing surface 112 is inclined at the distal end 12 (i.e., the body side of the floating seal ring) relative to the first sealing surface 111. Under normal pressure, the opposing second sealing surface 112 can function as an oil groove, similar to the non-sealing surface 110, to deliver lubricating oil to the first sealing surface 111. Using this technical solution of the present invention, when the system pressure increases, the pressure acting on the floating seal ring and the O-ring increases, causing the O-ring to be squeezed towards the sealing end face and undergo slight deformation. This increases the radial component of the force acting on the floating seal ring, causing the first sealing surface 111 to change into the second sealing surface 112. The sealing effect is thus changed to be formed between the two second sealing surfaces, preventing seal failure due to increased pressure.

[0034] Figure 4 The diagram shows the change from the first sealing surface 111 to the second sealing surface 112. Figure 4 The left figure shows the first sealing surface 111 in contact and the second sealing surface 112 separated, which is the operating condition of the floating seal ring's sealing end face under normal pressure. In this condition, the second sealing surface 112 functions like the non-sealing surface 110, and the space between the two second sealing surfaces 112 serves as an oil passage groove. Figure 4The right figure shows the situation where the first sealing surface 111 is separated and the second sealing surface 112 is in contact. This is the operating condition of the sealing end face of the floating seal ring when the equipment is under increased pressure. Under this condition, the second sealing surface 112 temporarily replaces the first sealing surface 111 to achieve the sealing function. After the high pressure is released, the first sealing surface 111 will continue to provide the seal, and the seal will not fail due to the increase in pressure.

[0035] The inclination angle of the second sealing surface 112 relative to the first sealing surface 111 is not limited. According to a preferred embodiment, the inclination angle of the second sealing surface 112 relative to the first sealing surface 111 is less than 3 degrees, more preferably 1-2 degrees. According to a preferred embodiment, the radial width of the second sealing surface is substantially the same as the radial width of the first sealing surface, but the present invention is not limited thereto, and the radial widths of the first and second sealing surfaces may be different. The radial widths of the first sealing surface 111 and the second sealing surface 112 are not limited. According to a preferred embodiment, for example, the radial widths of both the first sealing surface 111 and the second sealing surface 112 may fall within the range of 2 to 3 millimeters.

[0036] According to one embodiment of the present invention, the outer diameter end of the radial ring portion 13 of the floating seal ring 1 extends radially outward and is inclined toward the O-ring, so as to form a shoulder 15 protruding obliquely backward (inclined toward the O-ring) on ​​the radial ring portion 13. Preferably, the back surface of the radial ring portion 13 is not vertical, but has an angle of 90 degrees with the outer conical surface of the conical ring portion 14. With this technical solution of the present invention, when the system pressure increases, the O-ring is squeezed and moved toward the sealing end face. When the O-ring is squeezed and rests against the back surface of the radial ring portion 13, the shoulder 15 can block the O-ring. Therefore, compared with the structure of the prior art floating seal ring where the back surface of the radial ring portion 13 is parallel to the first sealing surface 111, this shoulder 15 arrangement of the radial ring portion 13 allows the O-ring to be better held in the seat cavity of the floating seal seat even under high pressure, and it will not be squeezed out of the floating seal ring.

[0037] The shoulder 15 extends an axial length P towards the O-ring side. According to a preferred embodiment, this axial length P is 1.5 mm. Preferably, the back surface of the radial ring 13 and the outer conical surface of the conical ring 14 are transitioned by a rounded corner. Preferably, the radial ring 13 extends radially outward (towards the float seal seat) to form a step at its radially outer end that mates with the inner wall of the float seal seat. According to a preferred embodiment, after the float seal ring and the O-ring are assembled in the float seal seat, the step of the radial ring 13 is offset from the minimum diameter of the seat cavity of the float seal seat by a certain width. Preferably, this offset width Q is, for example, greater than 1 mm. The design of the shoulder and step at the radially outer end of the radial ring 13 makes the fit between the O-ring, the float seal ring, and the seat cavity more stable, preventing the O-ring from being squeezed out due to increased pressure.

[0038] According to one embodiment of this utility model, a groove 15 is provided on the inner diameter side of the floating seal ring to weaken or reduce the rigidity of the conical ring portion 14, making it easier to deform. The shape of the structure is not limited. The deepest point of the groove is preferably located at the contact point between the O-ring and the conical ring portion. Figure 1 , Figure 3 , Figure 6 and Figure 7 As shown, the groove can be, for example, an asymmetrical inverted V-shape, a sloping-bottom opening shape, or a symmetrical inverted V-shape. Using this technical solution of the present invention, when the system pressure increases, the conical ring 14 with the groove 15 is more prone to radial deformation due to weakened rigidity, such as... Figure 5 As shown by the dashed line, as the pressure increases, the floating seal ring 1 deforms, and the O-ring 2 is also compressed and moves towards the sealing end face 11, deforming as well. The space inside the floating seal cavity is released, and the compression deformation reduces the axial force on the floating seal ring, effectively preventing wear failure caused by friction on the sealing surface after a sudden increase in pressure. At the same time, the radial force of the O-ring on the floating seal ring increases, causing the first sealing surface to change into a second sealing surface. The sealing effect is formed between the two second sealing surfaces, preventing seal failure due to increased pressure.

[0039] According to a preferred embodiment that weakens the rigidity of the tapered ring, such as Figure 1 As shown, the groove 15 is an asymmetrical inverted V-shape, with the long side of the inverted V-shape parallel to the outer conical surface of the conical ring 14, such that the thickness of the conical ring (i.e., the thickness of the section perpendicular to the outer conical surface of the conical ring in the axial section) T1 is approximately half the radial width T2 of the distal end of the conical ring 14, that is, T1 is approximately 0.5 × T2. According to an optional embodiment, as Figure 6As shown, the groove 15 has a segment 151 parallel to the outer conical surface of the conical ring 14 only on the opposite side of the position where the conical ring 14 contacts the O-ring. The thickness T1 of this parallel segment 151 is approximately 0.5 × T2. According to another optional embodiment, such as Figure 7 As shown, the groove 15 is an inverted V-shaped groove, and the deepest part of the groove has a thickness T1 of approximately 0.5 × T2 in the direction perpendicular to the outer cone surface.

[0040] According to a preferred embodiment of the present invention, multiple support ribs 16 may be provided in the groove 15 along the circumferential direction of the floating seal ring. Figure 8 This embodiment of a floating seal ring with support ribs 16 is shown. The plurality of support ribs 16 are preferably arranged uniformly along the circumferential direction. The plurality of support ribs 16 are used to enhance the stiffness of the floating seal ring, and in conjunction with the groove arrangement, the overall stiffness of the floating seal ring is maintained within a reasonable range.

[0041] According to one embodiment of this invention, the floating seal ring is made of a wear-resistant metal material. O-rings are typically made of rubber with good elastic deformation.

[0042] Figure 9 A comparison graph is shown between the improved floating seal device using this invention and a prior art floating seal device. The horizontal axis represents the sealing gap SG (e.g., Figure 1 As shown in the figure, the vertical axis represents the contact pressure CF, the solid line represents the floating sealing device of this invention, and the dashed line represents the floating sealing device of the prior art. As shown in the figure, under the same sealing gap SG, after the pressure in the seat cavity increases, the axial contact pressure CF on the sealing surfaces of the pair of floating seal rings of this invention is always smaller. This smaller axial contact pressure helps to avoid excessive wear of the floating seal rings, thereby extending the service life of the sealing device.

[0043] The floating seal device of this invention can be used in many scenarios. For example, the floating seal device can be installed on the output shaft of a speed reducer. In scenarios where a speed reducer is used in conjunction with a hydraulic motor, when a motor failure causes hydraulic oil to leak into the speed reducer, it can prevent the floating oil seal on the speed reducer from failing due to high pressure.

[0044] This invention offers the following beneficial technical effects: Under increased pressure, the conical ring portion of the floating seal ring deforms, allowing the second sealing surface to perform its sealing function; the O-ring is compressed towards the sealing end face, and a shoulder with an increased diameter and inclined towards the O-ring prevents the O-ring from being squeezed out; thus, a good sealing effect can be maintained even with increased pressure. With the deformation of the floating seal ring and the deformation and movement of the O-ring, the axial force on the sealing surface generated by the entire floating sealing device decreases, effectively preventing excessive wear of the sealing surface caused by sudden pressure increases, which could lead to seal failure. Therefore, this contributes to achieving good and long-term sealing performance.

[0045] The specific embodiments described above are for illustrative purposes only and are not intended to limit the scope of this utility model. Those skilled in the art can make various modifications and variations without departing from the inventive concept of this utility model, and all equivalent technical solutions fall within the protection scope of this utility model. The protection scope of this utility model is defined by the appended claims.

Claims

1. A floating seal device for mounting on a rotating shaft in a pressure system, the floating seal device comprising: A pair of floating seal rings (1), wherein one of the floating seal rings is fixed and the other floating seal ring rotates with the rotating shaft, each floating seal ring comprising: The radial ring portion (13) has a first sealing surface (111) on its outer diameter side and a non-sealing surface (110) on its inner diameter side that is inclined towards the distal end (12) relative to the first sealing surface (111). The first sealing surfaces (111) are placed against each other to form a seal. A tapered ring portion (14) extends from the back side of the radial ring portion (13) to the distal end (12). A pair of O-rings (2) are correspondingly fitted onto the outer conical surface of the conical ring portion (14) of a pair of floating seal rings (1); and A floating seal seat (3) having a seat cavity for accommodating the pair of floating seal rings (1) and the pair of O-rings (2). The feature is that a second sealing surface (112) is provided between the first sealing surface (111) and the non-sealing surface (110), and the second sealing surface (112) is inclined at the distal end (12) relative to the first sealing surface (111).

2. The floating sealing device according to claim 1, characterized in that, The angle at which the second sealing surface is tilted relative to the first sealing surface ranges from 1 to 2 degrees.

3. The floating sealing device according to claim 1 or 2, characterized in that, The radial widths of the first sealing surface and the second sealing surface are equal.

4. The floating sealing device according to claim 3, characterized in that, The radial width of the first sealing surface and the second sealing surface ranges from 2 to 3 millimeters.

5. The floating sealing device according to claim 1 or 2, characterized in that, The angle at which the non-sealing surface is tilted relative to the first sealing surface at the distal end ranges from 3 to 5 degrees.

6. The floating sealing device according to claim 1 or 2, characterized in that, The angle between the back side of the radial ring portion (13) of the floating seal ring and the outer conical surface of the conical ring portion (14) is 90 degrees.

7. The floating sealing device according to claim 1 or 2, characterized in that, The outer diameter end of the radial ring portion (13) of the floating seal ring extends 1.5 mm axially toward the O-ring side.

8. The floating sealing device according to claim 1, characterized in that, A groove (15) is provided on the radial inner side of the floating seal ring at the position opposite to the O-ring.

9. The floating sealing device according to claim 8, characterized in that, The groove is configured such that the minimum thickness of the tapered ring is half the radial width of the distal end (12) of the tapered ring.

10. The floating sealing device according to claim 8, characterized in that, Multiple support ribs (16) are provided in the groove (15).

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