Single-point low-profile locking ring for mechanical seals

Abstract

The mechanical seal uses a locking ring assembly with an associated locking mechanism. The locking mechanism can include a nut element, such as a barrel nut, that allows adjustment of the clamping load and position of the associated bolt element when clamping the mechanical seal components. This adjustment flexibility eliminates or reduces unnecessary bending stress on the bolt element, allowing greater torque to be transferred directly to the locking ring. The barrel nut allows more material to remain in the locking ring, adding overall strength compared to conventional locking elements. Additionally, the locking ring includes multiple notched bending regions that allow the locking ring to flex as the body is tightened around the shaft.

Description

Technical Field

[0001] Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 035,512, filed Jun. 5, 2020, entitled "One-Point Operation Thin Lock Ring for Mechanical Seals", the contents of which are incorporated herein by reference.

[0002] Background Art The present invention relates to an improved and more efficient apparatus and method for transmitting torque from a tightening bolt to a lock ring in a mechanical seal.

Background Art

[0003] Conventional mechanical seals, such as segmented mechanical seals and cartridge-type seals, are used in a wide variety of environments and settings, for example, in mechanical equipment, to provide airtight and fluid-tight seals. Typically, these mechanical seals are mounted within a fixed mechanical housing or fixed device and are provided around a rotating shaft or rod that protrudes from the housing. The mechanical seal is usually bolted to the outside of the housing at the shaft exit point, thus preventing pressurized process fluid from escaping from the housing. Typical mechanical seals include face-type mechanical seals, which include a pair of sealing rings arranged concentrically around a shaft and spaced apart from each other axially. Each sealing ring has multiple sealing surfaces that are biased by a conventional biasing mechanism to make sealing contact with each other. Typically, one sealing ring remains stationary (i.e., a stationary sealing ring), while the other ring is fixed to the shaft and rotates integrally with it (i.e., a rotating sealing ring). This mechanical seal prevents pressurized process fluid from leaking into the external environment by biasing the sealing surfaces of the seal rings into a sealed contact with each other. Typically, the rotating seal ring is mounted within a holder or sleeve assembly arranged concentrically around the apparatus shaft. Similarly, the gland assembly may be solid or may have a pair of gland halves fastened together with screws. The fixed seal ring is typically mounted within the gland assembly.

[0004] Conventional split mechanical seals can use a pair of gland halves and a pair of holder halves that are fixed together. The gland halves are typically fixed together by a pair of locking screws located at each end or side of the gland halves, as is well known. When the other sealing components are assembled and tightened, these locking screws are tightened to fix the seal halves together. One drawback of conventional tightening mechanisms is that users may unintentionally overtighten the locking screws, putting unwanted pressure on the associated locking ring. This unwanted pressure can then damage the locking ring.

[0005] Furthermore, conventional cartridge-type seals use a sleeve component that houses both fixed and rotating seal parts. The sleeve assembly is mounted within the gland component and is rotatably attached to the shaft by a lock ring. One drawback of conventional lock ring assemblies is the use of integrated set screws, which can unintentionally overtighten and damage the shaft. Also, if the set screws of other tightening mechanisms fail, the entire lock ring assembly needs to be replaced. [Overview of the Initiative]

[0006] The present invention relates to a mechanical seal that uses a lock ring assembly to which a locking mechanism is associated. The locking mechanism may include a nut element, such as a barrel nut, which allows for adjustment of the tightening load and position by an associated bolt element when clamping the components of the mechanical seal. This flexibility of adjustment eliminates or reduces unwanted bending stress in the bolt element, so that a greater torque can be transferred directly to the lock ring. With this barrel nut, more material can remain in the lock ring, thus adding overall strength compared to conventional lock elements. Furthermore, the lock ring includes multiple notched bending regions that allow for bending of the lock ring when the body is tightened around the shaft.

[0007] The present invention relates to a mechanical seal, which includes a gland element, a sleeve component having an extension sleeve portion and disposed within the gland, and a lock ring assembly. The lock ring assembly includes a body having a generally ring shape and a top surface, an opposite bottom surface, and a circumferential surface, wherein the top surface has a plurality of openings sized and configured to accommodate a centering element, and the circumferential surface has a plurality of side openings sized and configured to accommodate a set screw. The body further includes a first notch having a curved profile region that forms part of a first flange portion, and a second notch that forms part of a second flange portion. Bolt openings are formed in the first and second flange portions. The body further includes a plurality of notches spaced apart in the circumferential direction to form a bent region. The seal further includes a bolt element sized and configured to accommodate the bolt openings, and a nut element such as a barrel nut having a cylindrical shape complementary in shape to the curved profile region of the first flange portion.

[0008] Furthermore, the sleeve portion may include one or more holes for accommodating the set screw when it is attached to the upper opening formed in the lock ring.

[0009] Furthermore, the present invention relates to a lock ring assembly for a mechanical seal, the lock ring assembly having a generally ring shape and including a body having a top surface, an opposite bottom surface, and a circumferential surface. The top surface has a plurality of openings sized and configured to accommodate centering elements, and the circumferential surface has a plurality of side openings sized and configured to accommodate set screws. The body further includes a first notch formed in the body and having a curved profile region that forms part of a first flange portion, a second notch formed in the body and forming part of a second flange portion, the first and second flange portions having bolt openings, and a plurality of notches formed in the body, which are spaced circumferentially around the body and form a bending region.

[0010] The lock ring may further include a bolt element sized and configured to accommodate the bolt opening, and a nut element such as a barrel nut having a cylindrical shape complementary in shape to the curved profile region of the first flange portion. The lock ring may further include one or more centering elements for mounting to one or more of the plurality of openings. Furthermore, the sleeve portion may include one or more holes, and one or more set screws for mounting to one or more of the plurality of side openings may be configured to engage with the holes in the sleeve portion. [Brief explanation of the drawing]

[0011] The above and other features and advantages of the present invention should be more fully understood by referring to the following detailed description and accompanying drawings, where similar reference symbols in the drawings indicate similar components across these multiple different drawings. These drawings illustrate the principles of the present invention and, although the scale is not constant, indicate relative dimensions. [Figure 1] Figure 1 is a perspective view of a mechanical seal using a lock assembly according to the teachings of the present invention. [Figure 2]Figure 2 is a perspective view of a mechanical seal using the lock assembly taught in the present invention with the centering clip removed. [Figure 3] Figure 3 is a rear perspective view of the lock ring of the lock assembly of the present invention. [Figure 4] Figure 4 is a front perspective view of the lock ring of the lock assembly of the present invention with the nut and bolt removed. [Figure 5] Figure 5 is a perspective view of the bolt element of the lock ring assembly according to the present invention. [Figure 6] Figure 6 is a perspective view of the nut element of the lock ring assembly according to the present invention. [Figure 7] Figure 7 is a partial cross-sectional view of a lock ring assembly and a mechanical seal showing the positioning of a set screw according to the teachings of the present invention. [Figure 8] Figure 8 is a partial cross-sectional view of a lock ring assembly and a mechanical seal showing the positioning of the centering pin according to the teachings of the present invention. [Best Mode for Carrying Out the Invention]

[0012] The present invention relates to a mechanical seal that uses a lock ring assembly to which a locking mechanism is associated. The locking mechanism may include a barrel nut that allows adjustment of the tightening position by an associated bolt when clamping the components of the mechanical seal. The lock ring is configured to accommodate the barrel nut, and the structural integrity of the lock ring is improved because less material can be removed from the body of the lock ring compared to conventional devices. Furthermore, the locking mechanism and lock ring provide flexibility of adjustment to a selected degree by eliminating or reducing unwanted bending stress in the bolt, so that greater torque can be directly transferred to the lock ring.

[0013] The term "shaft" as used herein is intended to refer to any suitable device on which a seal can be attached in a mechanical system, and includes shafts, rods, and other known devices.

[0014] The terms "axial" and "in the axial direction" refer to a direction roughly parallel to the axis of any shaft. The terms "radial" and "radially" refer to a direction roughly perpendicular to the axis of any shaft. The terms "fluid" and "multiple fluids" refer to liquids, gases, and combinations thereof.

[0015] The term "axially inward" as used herein refers to the portion of the fixing device and seal assembly that is located adjacent to the mechanical system that uses the seal assembly. Conversely, the term "axially outward" as used herein refers to the portion of the fixing device and seal assembly that is distal to the mechanical system.

[0016] The term "radially inward" as used herein refers to the portion of a seal assembly proximal to any shaft. Conversely, the term "radially outward" as used herein refers to the portion of a seal assembly distal to its shaft.

[0017] The terms “fixing device,” “fixing mechanical housing,” and / or “stationary surface” as used herein are intended to include any suitable fixing structure that accommodates a shaft or rod to which a seal with a gland is fixed. It will also be readily apparent to a person skilled in the art that a gland assembly may form part of a mechanical seal or part of a fixing device.

[0018] The terms “mechanical seal” and “sealed assembly” as used herein are intended to include any suitable structure that can be mounted around a shaft and to a fixing device for providing a fluid-tight seal. Examples of suitable mechanical seals are intended to include integral seals, cartridge seals, split seals, and other known types of seals and sealed assemblies and components.

[0019] Figures 1 and 2 are perspective views of the mechanical seal of the present invention. The illustrated mechanical seal 10 is preferably circumferentially mounted concentrically around a shaft 12 extending along the pump shaft and is fixed to the outer wall of a fixed device such as a pump or other mechanical device (not shown). The shaft 12 can be provided at least partially inside the fixed device or adjacent to the fixed device. The mechanical seal assembly 10 can be configured to form a fluid-tight seal, thus preventing the process medium (e.g., fluid) from flowing out of the fixed device. This fluid-tight seal is achieved by a sealing member including a rotating seal ring and a stationary seal ring, as known in the art of the present invention. The seal ring can be a split seal ring with a pair of seal ring segments. The seal rings can be arranged in effective sealing contact with each other to form a seal therebetween. The seal rings can be urged into sealing contact with each other by a known biasing mechanism such as a biasing ring or a biasing spring. The seal rings provide a fluid-tight seal operable under a wide range of operating conditions.

[0020] The mechanical seal 10 can also include a gland component 14 and a holder or sleeve component 16 housed within the gland component 14. The sleeve component 16 can have any selected shape or configuration and, in the illustrated embodiment, is formed as a sleeve disposed around the shaft and rotatably coupled to the shaft. The sleeve component 16 is disposed within an internal space formed by the gland component 14. The sleeve component 16 can be fixed to the shaft 12 using a lock ring assembly 20. A series of removable alignment clips 18 can be used as an aid for axially and radially aligning the lock ring assembly 20 with respect to the shaft 12. The alignment clips 18 are removed prior to the operation of the mechanical seal 10.

[0021] The ground component 14 can have a body 32 with a series of circumferentially spaced channels or grooves 34, which are configured to accommodate fastening elements such as bolts for attaching the ground component 14 to a fixing device. One or more fluid passages 36 are formed in the body 32, whereby an external supply fluid such as a barrier or flushing fluid can be introduced or transmitted to the internal region of the ground and thus to the sealing component. The fluid passages 36 can be sealed with a suitable plug 38 if desired. The sleeve component 16 can include an extension sleeve portion 40 at the outer end and a flange portion (not shown) at the inner end that defines a space for accommodating and holding a rotary seal ring. Any selected number of grooves (not shown) can be formed in the sleeve component 16, which are well known in the art of the present invention and are for accommodating one or more sealing elements for forming a fluid seal between the shaft and the ground component 14.

[0022] Figures 3-6 show details of the lock ring assembly 20 of the present invention. The illustrated lock ring assembly 20 is a lock ring 22 sized and configured to be mounted around a shaft and includes a lock ring 22 that applies a radial pressure to the sleeve component 16 to lockingly couple (e.g., lock) the sleeve component 16 to the shaft 12. As shown in FIGS. 3 and 4, the illustrated lock ring 22 includes a body 50 having generally a circular or annular shape. The body 50 includes an upper surface 52 and an opposite bottom surface 54. A plurality of openings 56 are formed in the upper surface 52 and terminate at the bottom surface 54 for accommodating centering elements 58. As shown, for example, in FIG. 8, the centering elements 58 are attached to the openings 56 and project from the bottom surface 54 of the lock ring 22. The centering elements 58 contact the ridges 46 of the ground element 16 and assist in centering the lock ring 22 between the ridges 46 and the shaft 12.

[0023] The body 50 of the lock ring 22 also includes a circumferential or peripheral surface 60. The circumferential surface 60 has a series of side openings 62 spaced circumferentially along the surface 60. As shown in Figures 1 and 7, the side openings 62 are threaded to accommodate set screws 64. The set screws 64 are housed in holes or openings 42 formed in the sleeve portion 40 of the sleeve component 16. In addition to the lock ring 22, the set screws 64 help to secure the sleeve component 16 to the shaft 12.

[0024] A pair of opposing notches 66 and 68 are further formed on the circumferential surface 60. The notches 66 and 68 form a pair of opposing flanges 70A and 70B, each having an opening 72 for receiving a bolt element 24. The flanges 70A and 70B can be joined or fastened together using the bolt element 24 and nut element 26 of the lock ring assembly 20. The notch area 66 is configured to have a curved or cylindrical profile area 74 (e.g., in cross-sectional view) having a selected radius corresponding to the radius of the nut element 26. The notch 68 has a relatively flat notch portion 76 configured to accommodate the bolt element 24. The notch area 68 is configured to form a wall portion 78 on the upper surface 52 of the body 50. The formation of the wall portion 78 leaves additional material on the body of the lock ring 22, thus improving its structural integrity. The circumferential surface 60 also has a pair of spatially spaced notches 80 in the circumferential direction, which function as bending regions when the flanges 70A and 70B are fixed together. Although two notches 80 are shown, those skilled in the art will readily recognize that any suitable number of notches can be employed. The notches extend partially into or across the width of the lock ring 22. The flanges 70A and 70B are separated by space or gap 82. Thus, the lock ring 22 is configured as an annular body having a central opening 84 for accommodating the shaft 12 and sleeve component 16.

[0025] Figures 4 and 5 illustrate a bolt element 24 and a nut element 26, respectively. The illustrated bolt element 24 has a head portion 90 and a threaded stem portion 92. The bolt element 24 is sized and configured to pass through openings 72 formed in flanges 70A and 70B. The head portion 90 of the bolt element 24 is configured to fit into a notch 68 adjacent to a wall portion 78. The illustrated nut element 26 has a cylindrical body 102 with a threaded central opening 104 formed through its interior. The body 102 is sized and configured to fit within the notch 66, particularly within the cylindrical profile region 74. Thus, the cylindrical shape of the nut is complementary in shape to the curved profile region 74. In this way, the nut element 26 is configured as a barrel nut. When installed, the threaded stem portion 92 of the bolt element 24 engages with the threaded opening 104. The bolt can be tightened by an amount selected by the installer. When the bolt elements are tightened, the flanges 70A and 70B are driven to move toward each other along an arc-shaped path. The notches 80 that form the bending region allow the flanges to follow the arc-shaped tightening path. Those skilled in the art will readily recognize that the bolt elements 24 and nut elements 26 can have any selected shape and size.

[0026] Accordingly, the present invention relates to a lock ring assembly 20 for use with a mechanical seal, such as a cartridge-type seal 10. The lock ring assembly 20 includes a lock ring 22, a bolt element 24, and a barrel nut-shaped nut element 26. The bolt element 24 and the nut element 26 are used to secure and fasten the lock ring 22. The bolt element 24 can be fastened via rotation or torque action, as the stem portion 92 of the bolt is housed within the barrel nut 26. The barrel nut may include a threaded central opening 104. The shape and configuration of the lock ring 22 help to reduce stresses such as bending stress on the bolt element 24, as fastening is at a single point compared to conventional lock rings that employ multiple set screws. Furthermore, the illustrated lock ring 22 applies a more uniform clamping force around the shaft 12. As a result, the energy applied to the bolt element 24 via torque helps to stretch the bolt element rather than bend it. Furthermore, instead of replacing the entire lock ring assembly 20 as with conventional lock rings, the bolt element 24 and barrel nut 26 can be replaced.

[0027] The lock ring 22 also has a shallow, relatively small notch area 66 that accommodates the barrel nut 26, so that it is not necessary to remove an excessive amount of material from the body of the lock ring 22. Removing only a small amount of material from there helps maintain the structural integrity of the lock ring 22. The body 50 of the lock ring 22 also includes one or more, preferably multiple, spaced-apart notches 80. The notches 80 form a bending area that helps reduce the energy required to apply a clamping force to the lock ring 22 during the tightening procedure. Thus, the tightening energy can become and be optimized as a clamping force. Furthermore, the use of these bolts and nuts provides a single tightening point compared to conventional lock rings that use multiple set screws.

[0028] The lock ring 22 and its associated locking mechanism may employ multiple alignment clips 18 that can be used to assist in centering the shaft 12 within the mechanical seal. The alignment clips 18 help center the lock ring both radially and axially. Furthermore, the lock ring 22 can be radially centered relative to the shaft 12 using the alignment element 58. The alignment clips 18 also enable safer shipping and handling during transport without extra conventional shipping packaging. The alignment clips 18 are removable before equipment operation.

[0029] Accordingly, it should be evident that the present invention effectively achieves the objectives described above, which are included in the objectives made clear from the foregoing description. Since certain modifications to the above configuration can be made without departing from the scope of the present invention, all matters included in this description or shown in the accompanying drawings are intended to be interpreted as illustrative and not as limiting.

[0030] Furthermore, the following claims should be understood to encompass all the general and specific features of the present invention described herein, as well as all statements relating to the scope of the invention.

[0031] Having described the present invention, the following are the aspects that we claim are novel and wish to secure through a patent certificate.

Claims

1. It is a mechanical seal, Grand elements, A sleeve component having an extension sleeve portion and positioned within the ground element, A lock ring assembly, A lock ring comprising a body having a generally ring shape and comprising an upper surface, an opposite bottom surface, and a circumferential surface, wherein the upper surface has a plurality of openings sized and configured to accommodate a centering element, and the circumferential surface has a plurality of side openings sized and configured to accommodate a set screw, and the body includes a first notch having a curved profile region forming part of a first flange portion, and a second notch forming part of a second flange portion, and bolt openings are formed in the first and second flange portions, A plurality of notches formed in the body of the lock ring, the plurality of notches spaced apart in the circumferential direction around the body to form a bending region, A bolt element sized and configured to accommodate the bolt opening, A mechanical seal comprising a lock ring assembly, the lock ring assembly comprising a nut element having an extended cylindrical shape that extends along the longitudinal axis and whose shape is complementary to the curved profile region of the first flange portion, and a nut element having an opening formed through it that extends perpendicular to the longitudinal axis.

2. The mechanical seal according to claim 1, wherein the nut element is a barrel nut.

3. The mechanical seal according to claim 1, further comprising one or more centering elements for attachment to one or more of the aforementioned openings.

4. The mechanical seal according to claim 1, wherein the extension sleeve portion includes one or more holes and further includes one or more set screws for attachment to one or more of the plurality of side openings, the set screws being configured to engage with the holes of the extension sleeve portion.

5. A lock ring assembly for a mechanical seal, A body having a generally ring shape and comprising an upper surface, an opposite bottom surface, and a circumferential surface, wherein the upper surface has a plurality of openings sized and configured to accommodate centering elements, and the circumferential surface has a plurality of side openings sized and configured to accommodate set screws, A first notch is formed in the main body and has a curved profile region that forms part of the first flange portion, A second notch is formed in the main body and forms part of the second flange portion, and bolt openings are formed in the first and second flange portions, A plurality of notches formed in the main body, wherein the plurality of notches are spaced apart in the circumferential direction around the main body to form a bending region, A bolt element sized and configured to accommodate the bolt opening, A lock ring assembly comprising a nut element having an extended cylindrical shape that extends along the longitudinal axis and whose shape is complementary to the curved profile region of the first flange portion, and a nut element having an opening formed through the interior that extends perpendicular to the longitudinal axis.

6. The lock ring assembly according to claim 5, wherein the nut element is a barrel nut.

7. The lock ring assembly according to claim 5, further comprising one or more centering elements for attachment to one or more of the aforementioned openings.

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