Mechanical seal device for liquids

Abstract

The application discloses a mechanical seal device for liquid, which is used for sealing a rotating shaft penetrating through a device shell and comprises a rotating ring seat, a rotating seal ring, a static seal ring and a static ring seat, and an end surface of the rotating seal ring is abutted to an end surface of the static seal ring by means of a spring to form a seal interface perpendicular to an axial direction, the seal interface comprises an abutment point in contact with a liquid medium in an axial section; and a circular ring-shaped surrounding rim is arranged around the rotating seal ring and the static seal ring for stirring the liquid medium, at least a part of the surrounding rim is shaped with an inclined surface inclined towards the abutment point, the inclined surface comprises a starting point close to the abutment point and an ending point away from the abutment point in the axial section, the starting point is separated from the abutment point by a distance and the ending point does not exceed the abutment point in the axial direction. The mechanical seal device for liquid provided by the application can effectively keep impurities in the liquid medium away from the seal interface and has good processing economy.

Description

TECHNICAL FIELD

[0001] The present application relates to mechanical seal technology, and more particularly, to a mechanical seal device for liquid with a surrounding design. BACKGROUND

[0002] Generally, a rotating device includes a rotating shaft and a device shell, and a mechanical seal device for liquid seals the rotating shaft passing through the device shell, so that the liquid in the device shell is isolated from the air outside the device shell. The mechanical seal device for liquid includes a dynamic seal ring and a static seal ring installed around the rotating shaft, wherein the end face of the dynamic seal ring is abutted to the end face of the static seal ring by means of a spring to form a sealing interface perpendicular to the axial direction.

[0003] In the production process of the industries such as metallurgy, electricity, petrochemical, coal mine, and papermaking, it is necessary to use a rotating device (for example, a pump) with a mechanical seal device for liquid to transport a slurry liquid containing impurities such as hard particles or fibers. However, the impurities in the slurry liquid are prone to accumulate between the gap between the dynamic seal ring and the rear pump cover of the mechanical seal device, to scale between the static seal ring and the O-ring of the static seal ring, and to collide and enter the sealing interface, thereby causing the dynamic seal ring and / or the static seal ring to lose the axial compensation ability due to jamming. Moreover, in the case that the hard particles in the slurry liquid enter the sealing interface, the end face of the dynamic seal ring and the end face of the static seal ring are also likely to be worn.

[0004] In the existing design, the solution to the above problems is to set the dynamic seal ring and the static seal ring to be flush on the side of the sealing interface in contact with the liquid, so as to avoid the impurities in the liquid from accumulating at the sealing interface and colliding and entering the sealing interface; on the side of the sealing interface in contact with the air, there is no need to be flush due to the absence of the problem of impurities, and one of the dynamic seal ring and the static seal ring is truncated for the purpose of reducing friction. This is a reasonable design in accordance with fluid mechanics and thermodynamics. Although it is also proposed in the existing design to set the dynamic seal ring and the static seal ring to be one higher than the other on the side of the sealing interface in contact with the liquid, the influence of the impurities in the liquid on the sealing interface is often ignored.

[0005] In summary, there are the following difficulties in the application of the mechanical seal device for liquid to the rotating device such as the slurry liquid pump: the dynamic seal ring and the static seal ring in the slurry liquid are severely worn, and are extremely prone to damage to cause leakage of the pump; the service life of the mechanical seal device for liquid is too short, so that it needs to be replaced frequently under the condition that the pump stops running, causing economic losses; a large amount of flushing water is required to flush the mechanical seal device for liquid, causing resource waste and cost increase.

[0006] Furthermore, in Chinese patent CN 209856382U, it is proposed that one of the dynamic sealing ring or the static sealing ring on the side in contact with the liquid at the sealing interface is provided with a surrounding rim, the surrounding rim includes an inclined surface inclined towards the other of the dynamic sealing ring or the static sealing ring, under the condition that the surrounding rim causes the liquid in flow to form turbulent flow, the impurities in the liquid also leave the sealing interface along the inclined surface due to the centrifugal force. Although this design improves the service life of the sealing device, the machining process of the dynamic sealing ring and / or the static sealing ring becomes complex, and the flexibility is poor. SUMMARY

[0007] In order to solve the deficiencies in the existing mechanical sealing device for liquid, the present application provides a mechanical sealing device for liquid which can effectively keep impurities in the liquid medium away from the sealing interface and has good processing economy, thereby reducing the possibility of impurities accumulating at the sealing interface and colliding and entering the sealing interface.

[0008] According to one aspect of the present application, a mechanical sealing device for liquid is provided for sealing a rotating shaft passing through a device housing to prevent liquid medium in the device housing from leaking, the mechanical sealing device for liquid comprising: a dynamic ring seat, a dynamic sealing ring, a static sealing ring, and a static ring seat installed around the rotating shaft, wherein the dynamic ring seat is fastened to the rotating shaft and supports the dynamic sealing ring, the static ring seat is fastened to the device housing and supports the static sealing ring, and the end surface of the dynamic sealing ring is abutted to the end surface of the static sealing ring by means of a spring to form a sealing interface perpendicular to the axial direction, the sealing interface includes an abutment point in contact with the liquid medium in the axial cross section; and a circular ring-shaped surrounding rim surrounding the dynamic sealing ring and the static sealing ring for agitating the liquid medium, at least a part of the surrounding rim is shaped with an inclined surface inclined towards the abutment point, the inclined surface includes a starting point close to the abutment point and an ending point away from the abutment point in the axial cross section, the starting point is separated from the abutment point by a distance and the ending point does not exceed the abutment point in the axial direction.

[0009] Optionally, the surrounding rim is integrally formed with one of the static sealing ring and the dynamic sealing ring, so that the cross section of one of the static sealing ring and the dynamic sealing ring is higher than the cross section of the other of the static sealing ring and the dynamic sealing ring, and a part of one of the static sealing ring and the dynamic sealing ring is abutted to the other of the static sealing ring and the dynamic sealing ring.

[0010] Optionally, the surrounding rim is integrally formed with the dynamic ring seat, and wherein the surrounding rim protrudes from the dynamic ring seat to seat on the outer peripheral surface of the dynamic sealing ring; or wherein the surrounding rim protrudes from the dynamic ring seat and is separated from the dynamic sealing ring by a distance.

[0011] Optionally, the surrounding rim is integrally formed with the static ring seat, and the side of the surrounding rim away from the abutment point is configured to abut against the inner wall surface of the device housing.

[0012] Optionally, the liquid mechanical seal device further comprises a cylindrical or annular additional component, the peripheral ridge is integrally formed with the additional component, the additional component is detachably mounted on the side of the dynamic ring seat opposite to the side supporting the dynamic seal ring, and the generatrix of the outer peripheral surface of the dynamic ring seat is parallel or at an angle to the axial direction.

[0013] Optionally, the dynamic seal ring is connected to the outer peripheral surface or the inner peripheral surface of the dynamic ring seat by means of an O-ring, and the static seal ring is connected to the outer peripheral surface or the inner peripheral surface of the static ring seat by means of another O-ring.

[0014] Optionally, the inclined surface comprises at least one of a straight surface, an arc surface, and a corrugated surface.

[0015] Optionally, the axial section of the peripheral ridge is configured to comprise at least one of a conical shape, a polygonal shape, and an arc shape.

[0016] Optionally, the peripheral ridge is arranged only on the outside of the sealing interface, or the peripheral ridge is arranged only on the inside of the sealing interface.

[0017] Optionally, the dynamic seal ring and the static seal ring are respectively of a monolithic structure or a split structure.

[0018] Optionally, the liquid mechanical seal device further comprises: a gland connected to the static ring seat; and a shaft sleeve sleeved on the rotating shaft, the shaft sleeve is integrally extended with the dynamic ring seat or connected to the dynamic ring seat as a separate component, so as to assemble the dynamic ring seat, the dynamic seal ring, the static seal ring, the static ring seat, and the spring together to form a packaged mechanical seal.

[0019] The liquid mechanical seal device has the following advantages:

[0020] (1) The peripheral ridge is designed to stir the liquid medium in the flow and form a turbulent flow, so that the liquid medium changes in temperature, flow rate, and pressure, and impurities mixed in the liquid medium, especially hard particles, cannot be deposited along with the chaotic movement of the liquid medium, thereby avoiding the accumulation of impurities at the sealing interface and the collision and entry of the impurities into the sealing interface;

[0021] (2) The peripheral ridge is designed to act as a barrier and a pump, which not only effectively blocks the impurities in the liquid medium from entering the sealing interface, i.e., the mechanical seal operation area, but also facilitates the heat dissipation of the static seal ring and the dynamic seal ring as the sealing rings, so as to reduce the thermal deformation;

[0022] (3) The dynamic seal ring and / or the static seal ring can be connected to the dynamic ring seat and / or the static ring seat by means of an O-ring on the inner peripheral surface and / or the outer peripheral surface, respectively, to further expand the heat dissipation area; and

[0023] (4) The sealing effect of the liquid mechanical seal device is significantly improved, and the service life is prolonged.

[0024] Other features of the present application, its nature and advantages will become more apparent from the detailed description of exemplary embodiments of the application which follows, in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0026] Figure 1 is an axial sectional view of a mechanical seal device for liquid mounted on a rotating equipment according to an embodiment of the present application;

[0027] Figure 2 is Figure 1 is a detailed axial sectional view of a static seal ring and a dynamic seal ring of the mechanical seal device for liquid in

[0028] Figure 3 is an axial sectional view of a mechanical seal device for liquid mounted on a rotating equipment according to another embodiment of the present application;

[0029] Figure 4 is Figure 3 is a detailed axial sectional view of a static seal ring and a dynamic seal ring of the mechanical seal device for liquid in

[0030] Figure 5 is an axial sectional view of a mechanical seal device for liquid mounted on a rotating equipment according to another embodiment of the present application;

[0031] Figure 6 is an axial sectional view of a mechanical seal device for liquid mounted on a rotating equipment according to another embodiment of the present application;

[0032] Figure 7 is an axial sectional view of a mechanical seal device for liquid mounted on a rotating equipment according to another embodiment of the present application;

[0033] Figure 8 is an axial sectional view of a mechanical seal device for liquid mounted on a rotating equipment according to another embodiment of the present application; and

[0034] Figure 9 is an axial sectional view of a mechanical seal device for liquid mounted on a rotating equipment according to another embodiment of the present application. DETAILED DESCRIPTION

[0035] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of the components and steps set forth in the embodiments, the numerical expressions, and the numerical values are not limiting to the scope of the present application unless otherwise specifically stated.

[0036] Techniques and equipment known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered part of the specification where appropriate.

[0037] In all of the examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Thus, other examples of the exemplary embodiments can have different values.

[0038] It should be noted that like numerals and letters refer to like items throughout the drawings, and once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

[0039] In the following, the mechanical seal device for a liquid provided by the present application is also referred to as a seal device. The exemplary seal devices are suitable for use in a rotating device, such as a pump. The rotating device comprises a device housing 101 and a rotating shaft 100 which passes through the device housing 101 to be at least partially built into the device housing 101. In view of this, "axially" means in the direction of the axis L of the rotating shaft 100, "cross-sectionally" means in a vertical plane which contains the axis L of the rotating shaft 100, "end face" means in a plane which is perpendicular to the axis L of the rotating shaft 100, "front" means in the direction of further insertion into the device housing 101 in the axial direction, i.e. towards the left in the figures, "rear" means in the direction of exit from the device housing 101 in the axial direction, i.e. towards the right in the figures, "inward" means in the direction of approach to the axis L of the rotating shaft 100 in the radial direction, and "outward" means in the direction of departure from the axis L of the rotating shaft 100 in the radial direction.

[0040] In general, Figures 1 to 9 The exemplary seal devices shown each comprise a plurality of components which are assembled together and cooperate with one another to seal the rotating shaft 100 with respect to the device housing 101, thereby preventing the liquid medium in the device housing 101 from leaking. These exemplary seal devices can be of the cartridge type or of the split type.

[0041] The plurality of components can comprise a dynamic ring which is fixed to the rotating shaft 100 and rotates together with the rotating shaft 100, and a static ring which is fixed with respect to the device housing 101 and does not rotate together with the rotating shaft 100.

[0042] The dynamic ring comprises a dynamic ring seat 1 and a dynamic seal ring 2 which is supported by the dynamic ring seat 1 and is circumferentially positioned with respect to the dynamic ring seat 1 by means of a plurality of positioning pins 3 in order to prevent relative rotation.

[0043] The static ring comprises a static ring seat 5 and a static sealing ring 4 supported by the static ring seat 5, the static ring seat 5 is provided with a plurality of springs 6 for pushing the static sealing ring 4 forward, and the static sealing ring 4 is circumferentially positioned relative to the static ring seat 5 by a plurality of positioning pins 8 to prevent relative rotation. The springs 6 push the static sealing ring 4 forward on the dynamic sealing ring 2, so that a certain axial pressure is maintained between the dynamic sealing ring 2 and the static sealing ring 4, and the dynamic sealing ring 2 is allowed to rotate relative to the static sealing ring 4. In the present application, the springs 6 are preferably cylindrical small springs, or the springs 6 can also be replaced by bellows.

[0044] The static ring seat 5 can be fastened to the rear wall surface of the equipment shell 101 by a plurality of bolts 7 to cover the hole of the equipment shell 101 through which the rotating shaft 100 passes. Therefore, it can also be said that in the present application, the static ring seat 5 also serves as a gland which is well known in the prior art. Additionally or alternatively, the sealing device can comprise a gland connected to the static ring seat 5, and the gland is fastened to the rear wall surface of the equipment shell 101 by a plurality of bolts 7 to cover the hole of the equipment shell 101 through which the rotating shaft 100 passes.

[0045] One or both of the dynamic sealing ring 2 and the static sealing ring 4 can have a monolithic or split structure, that is, comprising a pair of semicircular annular halves which are combined together around the rotating shaft 100 relative to each other to form a complete sealing ring. At the joint interface between the two halves, that is, the split surface, a structure that matches each other, such as a convex-concave matching structure, can be provided to facilitate the connection state between the two halves. From the axial direction, the split line between the two halves is perpendicular to the axial direction.

[0046] If both the dynamic sealing ring 2 and the static sealing ring 4 are split, the split surfaces of the two need to be staggered in the circumferential direction.

[0047] The present application takes into account the problem of easy replacement of the dynamic sealing ring 2 and the static sealing ring 4, and preferably both adopt a split structure. However, only one of the dynamic sealing ring 2 and the static sealing ring 4 (especially the one that is easy to wear) adopts a split structure, which is also within the scope of the present application.

[0048] The material of the dynamic sealing ring 2 and the static sealing ring 4 can be any one of plastic, ceramic (for example, silicon carbide), graphite, and metal alloy (for example, tungsten carbide). The material of the dynamic ring seat 1 and the static ring seat 5 can be metal alloy, such as 316 stainless steel and 304 stainless steel, etc.

[0049] In the following, a plurality of embodiments related to the design of the annular enclosure provided by the present application will be introduced, it should be noted that according to the specific application scenario, the plurality of embodiments can be combined or used alone.

[0050] In reference to Figure 1 and details can be found inFigure 2 In the embodiment of FIG. 1, the shroud 102 is integrally formed with the static seal ring 4 and disposed immediately adjacent to the seal interface 9. Specifically, the static ring seat 5 can be provided with an annular groove 14 into which the rear end portion of the static seal ring 4 is received to be pushed forward by the spring 6 so that the end face formed by the front end portion of the static seal ring 4 is brought into abutment with the end face of the dynamic seal ring 2 to constitute the seal interface 9 perpendicular to the axial direction, the seal interface 9 including, in cross section, the abutment point Cl with which the liquid medium comes into contact. In addition, the rear end portion of the static seal ring 4 is connected to the static ring seat 5 by means of the O-ring 11 on the inner peripheral surface.

[0051] The shroud 102 extends radially away from the seal interface 9 as it approaches the seal interface 9 in the axial direction from the front end portion of the static seal ring 4 to surround the dynamic seal ring 2 and the static seal ring 4. The cross section of the shroud 102 integrally formed with the static seal ring 4 is higher than the cross section of the dynamic seal ring 2 and the cross section of the dynamic ring seat 1, and a portion of one of the static seal ring 4 and the dynamic seal ring 2 is brought into abutment with the other of the static seal ring 4 and the dynamic seal ring 2.

[0052] In Figure 1 and Figure 2 , the cross section of the shroud 102 is shown as being tapered, but it is understood that the cross section of the shroud 102 can be configured to include, but not limited to, at least one of a taper, a polygon (e.g., a triangle, a rectangle, and a pentagon, etc.), and an arc, as long as the shroud 102 protrudes more into the liquid medium than the dynamic seal ring 2 and the dynamic ring seat 1 to act to stir the liquid medium in flow in the vicinity of the seal interface 9 to form turbulence so that the liquid medium changes in temperature, flow rate, and pressure, where impurities, particularly hard particles, in the liquid medium will also be unable to settle with the turbulent movement of the liquid medium.

[0053] At least a portion of the shroud 102 is shaped with an inclined surface 102A inclined toward the abutment point Cl, and impurities present in the stirred liquid medium are discharged along the inclined surface 102A due to centrifugal force to move away from the seal interface 9. The centrifugal force is generated due to the rotation of the rotating shaft 100.

[0054] For example, in Figure 2 , the inclined surface 102A includes, in cross section, a starting point Al proximal to the abutment point Cl and a terminal point Bl distal to the abutment point Cl, the starting point Al being spaced apart from the abutment point Cl and the terminal point Bl not exceeding the abutment point Cl in the axial direction. The terminal point Bl is the highest point of the cross section protruding into the liquid medium. A line connecting the starting point Al and the terminal point Bl is inclined toward the abutment point Cl. The line connecting the starting point Al and the abutment point Cl is configured as a broken line.

[0055] The inclined surface 102A can be configured to include, but is not limited to, at least one of a straight surface, an arc surface, and a wrinkled surface.

[0056] Alternatively, multiple protrusions are densely distributed on the inclined surface 102A to increase the friction between impurities that come into contact with the inclined surface 102A and the inclined surface 102A, making it easier for impurities to adhere to the inclined surface 102A by means of friction, so as to be quickly discharged along the inclined surface 102A.

[0057] Since both the end faces of the dynamic sealing ring 2 and the static sealing ring 4 need to meet high roughness requirements to achieve a "mirror-like" finish, thereby reducing the frictional force when the dynamic sealing ring 2 rotates relative to the static sealing ring 4, it is often necessary to further grind the end faces of the dynamic sealing ring 2 and the static sealing ring 4 separately during the machining process. Figure 1 Since the rim 102, which is integrally formed with the static sealing ring 4, does not extend axially beyond the sealing interface 9, the tool used for grinding the end face of the static sealing ring 4 will be completely unaffected by the rim 102 integrally formed with the static sealing ring 4.

[0058] To describe it in even more detail, Figure 1 It can also be observed that the rotating ring seat 1 includes a front section with a first outer diameter and a rear section with a second outer diameter, the first outer diameter being larger than the second outer diameter. The exemplary sealing device also includes a bushing 32 with a third outer diameter, the second outer diameter being larger than the third outer diameter. The bushing 32 extends rearward integrally with the rotating ring seat 1 or is connected to the rotating ring seat 1 as a separate component to assemble the rotating ring seat 1, the rotating sealing ring 2, the stationary sealing ring 4, the stationary ring seat 5, and the spring 6 together to form a packaged mechanical seal.

[0059] The inner circumferential surface of the front section of the moving ring seat 1 is connected to the rotating shaft 100 by means of an O-ring 12.

[0060] Due to the difference in outer diameter between the front and rear sections of the moving ring seat 1, and the difference in outer diameter between the rear section and the bushing 32, the moving ring seat 1 forms a stepped surface for seating the moving sealing ring 2. The moving sealing ring 2 is correspondingly shaped to complement this surface; that is, the moving sealing ring 2 includes a front section with a first inner diameter and a rear section with a second inner diameter, the first inner diameter being larger than the second inner diameter. The inner circumferential surface of the front section of the moving sealing ring 2 is connected to the bushing 32 by means of another O-ring 13. The presence of O-rings 12 and 13 facilitates heat dissipation of the moving sealing ring 2.

[0061] In a cartridge mechanical seal, the rotating ring is pre-assembled relative to the stationary ring, and the bushing 32 extends through the stationary ring seat 5 to reach the outside of the equipment housing 101, forming an axial clearance relative to the inner circumferential surface of the stationary ring seat 5 so as not to hinder the rotating ring from rotating with the rotating shaft 100.

[0062] Then, the locking ring 15 is mounted around the sleeve 32, the locking ring 15 positions the dynamic ring relative to the static ring in axial and radial directions by means of a plurality of positioning blocks 16 (usually three), and the positioning blocks 16 are fastened to the rear end face of the static ring seat 5 by means of bolts 17 which pass through each positioning block 16 in the axial direction. Then, the rotating shaft 100 is inserted into the assembled dynamic ring and static ring, and one or more fastening screws (not shown) are screwed into the locking ring 15 in the radial direction and pass through the sleeve 32, thereby fastening the assembled dynamic ring and static ring to the rotating shaft 100. Then, the positioning blocks 16 can be removed from the rear end face of the static ring seat 5.

[0063] Optionally, a part of the dynamic sealing ring 2 close to the sealing interface 9 forms a bevel chamfer 103 which is inclined away from the sealing interface 9, that is, the bevel chamfer 103 is inclined upward and forward, and the degree of inclination is substantially equal to the degree of inclination of the line between the starting point A1 and the ending point B1, so as to form a uniform inclined space which is easy for impurities to leave the sealing interface 9. In this way, the end face of the dynamic sealing ring 2 and the end face of the static sealing ring 4 are also set to be substantially flush. In order to reduce the friction when the dynamic sealing ring 2 rotates relative to the static sealing ring 4, the end face of the static sealing ring 4 is truncated on the side which contacts the air, so as to reduce the area of the sealing interface 9.

[0064] The static ring seat 5 can also be provided with a flushing hole 19, and due to the spacing between the outer peripheral surface of the static sealing ring 4 and the outer peripheral surface of the annular groove 14, one end of the flushing hole 19 can be in fluid communication with the inside of the equipment shell via the spacing. If necessary, impurity-free flushing water can be poured through the other end of the flushing hole 19 to flush the sealing device. If the rotating equipment is working, the pressure of the flushing water will be greater than the pressure of the liquid medium in the shell.

[0065] In the embodiments described above with reference to Figure 3 and details can be found in Figure 4 , the difference between the embodiments described above with reference to Figure 1 and Figure 2 is that the surrounding edge 202 is integrally formed with the dynamic sealing ring 2. The surrounding edge 202 extends away from the sealing interface 9 in the radial direction as it approaches the sealing interface 9 in the axial direction, so that the cross section of the surrounding edge 202 integrally formed with the dynamic sealing ring 2 is higher than the cross section of the static sealing ring 4, and so that a part of one of the static sealing ring 4 and the dynamic sealing ring 2 is fitted to the other of the static sealing ring 4 and the dynamic sealing ring 2.

[0066] In the embodiments described above with reference to Figure 4In this design, the starting point A2 of the inclined surface 202A is separated from the contact point C2 by a certain distance, and the ending point B2 does not extend beyond the contact point C2 axially. The ending point B2 is the highest point of the cross-section protruding into the liquid medium. The line connecting the starting point A2 and the ending point B2 is inclined towards the contact point C2. The line connecting the starting point A2 and the contact point C2 is configured as an arc. Therefore, during the machining process, the tool used to grind the end face of the dynamic sealing ring 2 will be completely unaffected by the rim 202 integrally formed on the dynamic sealing ring 2.

[0067] When the surrounding edge 202 and the dynamic sealing ring 2 are integrally formed, a portion of the static sealing ring 4 near the sealing interface 9 forms a chamfered face 203 that is inclined away from the sealing interface 9. That is, the chamfered face 203 is inclined upward and backward, and the degree of inclination is approximately equal to the degree of inclination of the inclined surface 202A, so as to form a uniform inclined space that facilitates the removal of impurities from the sealing interface 9.

[0068] In addition to being integrally formed with the dynamic sealing ring 2 or the static sealing ring 4, the surrounding edge can also be integrally formed separately or in combination with the static ring seat 5. Specifically, in Figure 1 In this design, the perimeter 302 begins from the front end face of the stationary ring seat 5 and extends radially away from the sealing interface 9 as it approaches the sealing interface 9 axially. On the side approaching the sealing interface 9, at least a portion of the perimeter 302 is formed with an inclined surface 302A that is inclined relative to the sealing interface 9. Simultaneously, the perimeter 302 abuts against the inner wall surface of the equipment housing 101 perpendicular to the rear wall surface on the side away from the sealing interface 9. The perimeter 302 of the stationary ring seat 5, in addition to helping to agitate impurities in the flowing liquid medium, also helps to ensure the stationary ring seat 5 is correctly positioned relative to the equipment housing 101 during installation. Of course, the perimeter 302 of the stationary ring seat 5 will not extend axially beyond the sealing interface 9.

[0069] See Figure 5 In this embodiment, the surrounding edge 402 is integrally formed with the moving ring seat 1 and is disposed adjacent to the sealing interface 9. Figures 1 to 4 The difference in the implementation method lies in the change of the cross-sectional shape of the moving ring seat 1 and the moving sealing ring 2. The first outer diameter of the front section and the second outer diameter of the rear section of the moving ring seat 1, which are integrally formed with the surrounding edge 402, increase from front to back to form a conical shape, and an annular groove 21 for receiving the front section of the moving sealing ring 2 is provided in the rear section of the moving ring seat 1. Correspondingly, the rear section of the moving sealing ring 2 is larger in outer diameter than the front section of the moving sealing ring 2 to complement the moving ring seat. The outer peripheral surface of the front section of the moving sealing ring 2 is connected to the moving ring seat 1 by means of an O-ring 13'.

[0070] The peripheral edge 402 extends from the outer peripheral surface of the ring seat 1 in a radial direction away from the sealing interface 9 as it approaches the sealing interface 9 in the axial direction, wherein at least a portion of the peripheral edge 402 is seated on the rear section of the dynamic sealing ring 2 in the axial direction to form an inclined surface 402A inclined toward the sealing interface 9. The starting point A3 of the inclined surface 402A is spaced apart from the contact point C3 by a distance and the ending point B3 does not exceed the contact point C3 in the axial direction. The ending point B3 is the highest point of the cross section protruding into the liquid medium. The side of the peripheral edge 402 away from the sealing interface 9 forms a rearwardly upwardly inclined surface along the entire outer peripheral surface of the ring seat 1. The peripheral edge 402 of the ring seat 1 does not extend beyond the sealing interface 9 in the axial direction, so that the structure of the sealing device remains compact, especially in the axial direction.

[0071] In the embodiments shown in Figure 6 , the difference from the embodiments shown in Figure 5 is that a cylindrical or annular additional component 22 is detachably mounted on the side of the ring seat 1 opposite to the side supporting the dynamic sealing ring 2, for example, a plurality of fastening screws 23 are screwed into the additional component 22 in the axial direction and pass through the front section of the ring seat 1, thereby fastening the additional component 22 to the front section of the ring seat 1. Alternatively, the front section of the ring seat 1 is provided with an additional step, so that the additional component 22 can be seated on the front section of the ring seat 1. The additional component 22 is specifically used to provide the peripheral edge 502 and is easy to replace, and can be added to the ring seat 1 without greatly modifying the structure of the original ring seat 1. In Figure 6 , the peripheral edge 502 is spaced apart from the dynamic sealing ring 2 by a distance, and obviously the starting point A4 of the inclined surface 502A is spaced apart from the contact point C4 by a distance and the ending point B4 does not exceed the contact point C4 in the axial direction. The ending point B4 is the highest point of the cross section protruding into the liquid medium. In this case, the generatrix of the outer peripheral surface of the ring seat 1 is parallel or at an angle to the axial direction.

[0072] In the two embodiments shown in Figure 7 and Figure 8 , the peripheral edges 602, 702 are still integrally formed with the ring seat 1, the difference is that the ring seat 1 is no longer fixed to the rotating shaft 100 by the locking ring 15, but a plurality of fastening screws are directly screwed into the front section of the ring seat 1 in the radial direction, thereby fastening the ring seat 1 to the rotating shaft 100, in other words, the exemplary sealing device is a split type. However, this does not affect the design of the peripheral edge. As shown in Figure 7 , the peripheral edge 602 can protrude from the ring seat 1 to be seated on the outer peripheral surface of the dynamic sealing ring 2, and the starting point A5 and the ending point B5 of the inclined surface 502A are spaced apart by a distance and the ending point B5 does not exceed the contact point C5 in the axial direction. As shown in Figure 8As shown, the peripheral rim 702 can also extend from the dynamic ring seat 1 and be spaced apart from the dynamic sealing ring 2 by a distance. Obviously, the starting point A6 of the inclined surface 702A is spaced apart from the abutting point C6 by a distance and the ending point B6 does not exceed the abutting point C6 in the axial direction. Therefore, the application scenario of the peripheral rim is very flexible.

[0073] The peripheral rim formed integrally with the dynamic sealing ring 2 and / or the dynamic ring seat 1 also plays a barrier role to at least partially block impurities flowing along with the liquid medium in the flow to the sealing interface 9.

[0074] In the embodiment shown in Figures 1 to 4 , the inner peripheral surface of the rear end portion of the static sealing ring 4 is connected to the static ring seat 5 by means of the O-ring 11, and the O-ring 20 is arranged between the front end face of the static ring seat 5 and the rear wall face of the equipment housing 101. By comparison, in the embodiment shown in Figures 5 to 8 , the outer peripheral surface of the rear end portion of the static sealing ring 4 is connected to the static ring seat 5 by means of the O-ring 11', and the sealing gasket 20' is arranged between the static ring seat 5 and the rear wall face of the equipment housing 101. These are only illustrative examples of various configurations of the sealing device, and do not affect the role of the peripheral rim.

[0075] In the embodiment shown in Figures 1 to 8 , the liquid medium in the equipment housing 101 is sealed by the outer peripheral surfaces of the static sealing ring 4, the dynamic sealing ring 2, and the dynamic ring seat 1, that is to say, the dynamic ring is located in the equipment housing 101. In the embodiment shown in Figure 9 , the dynamic ring changes from being located in the equipment housing 101 to being located outside the equipment housing 101, and thus the liquid medium in the equipment housing 101 is sealed by the inner peripheral surfaces of the dynamic sealing ring 2, the static sealing ring 4, and the static ring seat 5. In this case, the peripheral rim 802 is formed integrally with one of the dynamic sealing ring 2 and the static sealing ring 4.

[0076] In the embodiment shown in Figures 1 to 8 , the peripheral rims 102, 202, 302, 402, 502, 602, 702 are only arranged outside the sealing interface 9, that is to say, further away from the rotating shaft 100 in the radial direction. In the embodiment shown in Figure 9 , the peripheral rim 802 is only arranged inside the sealing interface 9, that is to say, closer to the rotating shaft 100 in the radial direction. At least a portion of the peripheral rim 802 is formed with an inclined surface 802A inclined toward the abutting point C7, the inclined surface 802A includes a starting point A7 close to the abutting point C7 and an ending point B7 away from the abutting point C7 in the cross section, the starting point A7 is spaced apart from the abutting point C7 by a distance and the ending point B7 does not exceed the abutting point C7 in the axial direction. The ending point B7 is the highest point of the cross section protruding into the liquid medium.

[0077] While certain embodiments of the application have been described herein in detail, those skilled in the art will appreciate that modifications can be made without departing from the scope and spirit of the application. The scope of the application is defined by the appended claims.

Claims

1. A mechanical seal device for a liquid, for sealing a rotating shaft (100) passing through a device housing (101) to prevent leakage of a liquid medium inside the device housing (101), the mechanical seal device for the liquid comprising: a dynamic ring seat (1), a dynamic seal ring (2), a static seal ring (4), and a static ring seat (5) mounted around the rotating shaft (100), wherein the dynamic ring seat (1) is fastened to the rotating shaft (100) and supports the dynamic seal ring (2), the static ring seat (5) is fastened to the device housing (101) and supports the static seal ring (4), and an end surface of the dynamic seal ring (2) is brought into abutment with an end surface of the static seal ring (4) by means of a spring (6) to form a seal interface (9) perpendicular to an axial direction, the seal interface (9) including, in an axial cross section, abutment points (Cl, C2, C3, C4, C5, C6, C7) in contact with the liquid medium; and a circular ring-shaped rim (102, 202, 302, 402, 502, 602, 702, 802) surrounding the dynamic seal ring (2) and the static seal ring (4) for agitating the liquid medium, at least a portion of the rim being shaped with an inclined surface (102A, 202A, 302A, 402A, 502A, 602A, 702A, 802A) inclined toward the abutment points, the inclined surface including, in the axial cross section, a starting point (Al, A2, A3, A4, A5, A6, A7) proximate to the abutment points and an ending point (Bl, B2, B3, B4, B5, B6, B7) distal from the abutment points, the starting point being separated from the abutment points by a distance and the ending point not exceeding the abutment points in the axial direction.

2. The mechanical sealing device for a liquid according to claim 1, wherein The rim (102, 202) is integrally formed with one of the static seal ring (4) and the dynamic seal ring (2) such that a cross section of the one of the static seal ring (4) and the dynamic seal ring (2) is higher than a cross section of the other of the static seal ring (4) and the dynamic seal ring (2), and such that a portion of the one of the static seal ring (4) and the dynamic seal ring (2) abuts the other of the static seal ring (4) and the dynamic seal ring (2).

3. The mechanical sealing device for a liquid according to claim 1, wherein The rim (402, 602, 702) is integrally formed with the dynamic ring seat (1), and wherein the rim (402, 602) extends from the dynamic ring seat (1) to seat on an outer peripheral surface of the dynamic seal ring (2); or wherein the rim (702) extends from the dynamic ring seat (1) and is separated from the dynamic seal ring (2) by a distance.

4. The mechanical sealing device for a liquid according to claim 1 or 2, wherein The rim (302) is integrally formed with the static ring seat (5), and a side of the rim (302) facing away from the abutment points is configured to abut against an inner wall surface of the device housing (101).

5. The mechanical sealing device for a liquid according to claim 1 or 3, wherein A cylindrical or circular ring-shaped additional member (22) is further included, the rim (502) is integrally formed with the additional member (22), the additional member (22) is detachably mounted to a side of the dynamic ring seat (1) axially opposite to a side supporting the dynamic seal ring (2), and a generatrix of an outer peripheral surface of the dynamic ring seat (1) is parallel or forms an angle with the axial direction.

6. The mechanical sealing device for a liquid according to any one of claims 1 to 5, wherein The dynamic sealing ring (2) is connected to the outer circumferential surface or the inner circumferential surface of the dynamic ring seat (1) by means of an O-ring (13, 13'), and the static sealing ring (4) is connected to the outer circumferential surface or the inner circumferential surface of the static ring seat (5) by means of another O-ring (11, 11').

7. The mechanical sealing device for a liquid according to any one of claims 1 to 6, wherein The inclined surface comprises at least one of a straight surface, an arc surface, and a corrugated surface.

8. The mechanical sealing device for a liquid according to any one of claims 1 to 7, wherein The axial section of the peripheral rim is configured to comprise at least one of a conical shape, a polygonal shape, and an arc shape.

9. The mechanical sealing device for a liquid according to any one of claims 1 to 8, wherein The peripheral rim (102, 202, 302, 402, 502, 602, 702) is arranged only on the outside of the sealing interface (9), or the peripheral rim (802) is arranged only on the inside of the sealing interface (9).

10. The mechanical sealing device for a liquid according to any one of claims 1 to 9, wherein The dynamic sealing ring (2) and the static sealing ring (4) are respectively of a monolithic or split structure.

11. The mechanical sealing device for a liquid according to any one of claims 1 to 10, wherein Further comprising: a gland connected to the static ring seat (5); and a shaft sleeve (32) sleeved on the rotating shaft (100), the shaft sleeve (32) extending integrally with the dynamic ring seat (1) or being connected to the dynamic ring seat (1) as a separate component, so as to assemble the dynamic ring seat (1), the dynamic sealing ring (2), the static sealing ring (4), the static ring seat (5), and the spring (6) together to form an assembled mechanical seal.

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