LOW PROFILE SINGLE-POINT DRIVE LOCKING RING FOR A MECHANICAL SEAL.

Abstract

A mechanical seal (10) employing a locking ring assembly (20, 22) with an associated locking mechanism. The locking mechanism may include a nut element (26), such as a barrel nut, which allows an associated bolt element (24) to adjust the clamping load and position while clamping the mechanical seal components. This adjustability eliminates or reduces unwanted bending stresses in the bolt element, thereby allowing more torque to be transferred directly to the locking ring. The barrel nut allows more material to remain in the locking ring, thus providing additional overall strength compared to a traditional locking element.The locking ring also includes a plurality of flexing regions in the form of notches (80) that allow the locking ring to flex when the main body (32, 50) is tightened around the shaft (12).

Description

[1] This application claims priority to United States of America provisional patent application serial number 63 / 035,512, filed on June 5, 2020, and entitled SINGLE POINT ACTUATION LOW-PROFILE LOCK RING FOR A MECHANICAL SEAL, the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [2] The present invention relates to an improved and more efficient device and method for transferring torque from a tightening bolt to a locking ring in a mechanical seal. [3] Conventional mechanical seals, such as split mechanical seals and cartridge seals, are used in a wide variety of environments, such as mechanical equipment, to provide a pressure-tight and fluid-tight seal. Mechanical seals are usually positioned around a rotating rod or shaft that is mounted in and protrudes from a stationary mechanical housing or piece of stationary equipment. The mechanical seal is usually bolted to the outside of the housing at the shaft outlet, thereby preventing the loss of pressurized process fluid from the housing. ινΐΛ / a / zuzz / uio¿oo Typical mechanical seals include face-type mechanical seals, which consist of a pair of sealing rings arranged concentrically around a shaft and axially separated from each other. Each sealing ring has sealing faces that are pushed into sealing contact by conventional pushing mechanisms. Usually, one sealing ring remains stationary (i.e., the stationary seal ring) while the other ring is secured to the shaft and rotates with it (i.e., the rotating seal ring). The mechanical seal prevents leakage of pressurized process fluid to the external environment by pushing the sealing faces of the seal rings into sealing contact. The rotating seal ring is usually mounted on a bracket or sleeve assembly arranged concentrically around the equipment shaft.Similarly, the cable gland assembly can be solid or consist of a pair of gland halves that are also secured together by a screw. The stationary sealing ring is typically mounted inside the cable gland assembly. [4] Conventional split mechanical seals may employ a pair of gland halves and a pair of support halves secured together. The gland halves are typically secured together, as is known, by a pair of locking screws located at each end or side of the gland halves. The locking screws are then tightened once the other seal components are assembled and tightened, thereby securing the seal halves. A drawback of conventional tightening mechanisms is that the user may inadvertently overtighten the locking screws, thereby applying unwanted pressure to an associated locking ring. This unwanted pressure can then damage the locking ring. [5] Additionally, conventional cartridge-type seals employ a sleeve assembly that mounts the stationary and rotating seal components together. The sleeve assembly is mounted inside the gland component and is rotatably connected to a shaft by the locking ring. A drawback of conventional locking ring assemblies is that they use integrated set screws, which can be inadvertently overtightened and may damage the shaft. Furthermore, if a set screw or other tightening mechanism fails, the entire locking ring assembly needs to be replaced. BRIEF DESCRIPTION OF THE INVENTION [6] The present invention relates to a mechanical seal employing a locking ring assembly associated with a locking mechanism. The locking mechanism may include a nut element, such as a barrel nut, which allows an associated bolt element to adjust the tightening load and position while clamping the mechanical seal components. This adjustability eliminates or reduces unwanted bending stresses in the bolt element, thereby allowing more torque to be transferred directly to the locking ring. The barrel nut allows more material to remain in the locking ring, thereby providing additional overall strength compared to a traditional locking element.The locking ring also includes a plurality of flexing regions in the form of notches that allow the locking ring to flex when the main body is tightened around the shaft. [7] The present invention relates to a mechanical seal comprising a gland element, a sleeve component having an elongated sleeve portion disposed within the gland, and a locking ring assembly. The locking ring assembly includes a locking ring having a main body generally annular in shape and having a top surface, an opposing bottom surface, and a circumferential surface, wherein the top surface has a plurality of openings formed therein that are dimensioned and configured to receive a centering element, and the circumferential surface has a plurality of side openings formed therein that are dimensioned and configured to receive a fixing screw.The main body also includes a first trim section having a curved profile region that forms part of a first flange portion and a second trim section that forms part of a second flange portion. The first and second flange portions have bolt openings formed therein. The main body also includes a plurality of notches that are circumferentially spaced to form flex regions. The seal further includes a bolt element that is sized and configured to seat in the bolt openings and a nut element, such as a barrel nut, having a cylindrical shape that is complementary in form to the curved profile region of the first flange portion. [8] Additionally, the sleeve portion may also include one or more holes to receive the fixing screw when mounted in the upper openings formed in the locking ring.[9] The present invention also relates to a locking ring assembly for a mechanical seal comprising a main body generally annular in shape and having a top surface, an opposing bottom surface, and a circumferential surface. The top surface has a plurality of openings formed therein that are dimensioned and configured to receive a centering element, and the circumferential surface has a plurality of side openings formed therein that are dimensioned and configured to receive a fixing screw.The main body also includes a first trim section formed in the main body and having a curved profile region that forms part of a first flange portion, a second trim section formed in the main body and forming part of a second flange portion where the first and second flange portions have a bolt opening formed therein, and a plurality of notches formed in the main body and circumferentially spaced around the main body to form bending regions.

[10] The locking ring may further include a bolt element that is sized and configured to seat in the bolt openings, and a nut element, such as a barrel nut, having a cylindrical shape that is complementary in shape to the curved profile region of the first flange portion. The locking ring assembly may also include one or more centering elements for mounting in one or more of the plurality of openings. Additionally, the sleeve portion may include one or more holes, and one or more set screws for mounting in one or more of the plurality of side openings may be configured to engage the hole in the sleeve portion. BRIEF DESCRIPTION OF THE DRAWINGS

[11] These and other features and advantages of the present invention will be more fully understood by reference to the following detailed description together with the accompanying drawings in which similar reference numbers refer to similar elements across different views. The drawings illustrate the main features of the invention and, although not to scale, show relative dimensions.

[12] FIGURE 1 is a perspective view of a mechanical seal employing a locking assembly according to the teachings of the present invention.

[13] FIGURE 2 is a perspective view of a mechanical seal employing a locking assembly according to the teachings of the present invention with the centering clamps removed.

[14] FIGURE 3 is a rear perspective view of the locking ring of the locking assembly of the present invention.

[15] FIGURE 4 is a front perspective view of the locking ring of the locking assembly of the present invention with the nut and bolt removed.

[16] FIGURE 5 is a perspective view of the bolt element of the locking ring assembly of the present invention. ινΐΛ / a / zuzz / uio¿oo

[17] FIGURE 6 is a perspective view of the nut element of the locking ring assembly of the present invention.

[18] FIGURE 7 is a partial cross-sectional view of the locking ring assembly and mechanical seal showing the positioning of a fixing screw according to the teachings of the present invention.

[19] FIGURE 8 is a partial cross-sectional view of the locking ring assembly and mechanical seal showing the positioning of the centering pin according to the teachings of the present invention. DETAILED DESCRIPTION

[20] The present invention relates to a mechanical seal employing a locking ring assembly with an associated locking mechanism. The locking mechanism may include a barrel nut that allows an associated bolt to adjust to a tightening position while clamping the mechanical seal components. The locking ring can be configured to seat the barrel nut, requiring less material to be removed from the locking ring body compared to conventional devices, thereby improving the structural integrity of the locking ring. Additionally, the locking mechanism and locking ring provide a selectable degree of adjustability by eliminating or reducing unwanted bending stresses on the bolt, thereby allowing more torque to be transferred directly to the locking ring.

[21] As used herein, the term shaft is intended to refer to any suitable device in a mechanical system to which a seal can be mounted, and includes shafts, rods, and other known devices.

[22] As used herein, the terms axial and axially refer to a direction generally parallel to the axis of a shaft. The terms radial and radially as used herein refer to a direction generally perpendicular to the axis of a shaft. The terms fluid and fluids refer to liquids, gases, and combinations thereof.

[23] As used herein, the term axially interior refers to that portion of stationary equipment and a seal assembly that is disposed close to the mechanical system that employs the seal assembly. Conversely, the term axially exterior, as used herein, refers to the portion of stationary equipment and a seal assembly that is distant from the mechanical system.

[24] As used herein, the term radially inside refers to the portion of the seal assembly near a shaft. Conversely, the term radially outside, as used herein, refers to the portion of the seal assembly far from the shaft.

[25] As used herein, the terms stationary equipment, stationary mechanical housing, and / or static surface are intended to include any suitable stationary structure housing a shaft or rod to which a seal having a gland is secured. Those skilled in the art will readily recognize that the gland assembly may form part of the mechanical seal or part of the stationary equipment.

[26] As used herein, the terms mechanical seal and sealing assembly are intended to include any suitable structure that can be mounted around a shaft and stationary equipment to provide a fluid-tight seal. Examples of suitable mechanical seals include solid seals, cartridge seals, split seals, and other known sealing assembly and sealing configurations and types.

[27] FIGURES 1 and 2 are perspective views of the mechanical seal of the present invention. The illustrated mechanical seal 10 is preferably concentrically arranged around a shaft 12 that extends along a pump shaft and is secured to an external wall of stationary equipment, such as a pump or other mechanical device (not shown). The shaft 12 may be mounted, at least partially, within or adjacent to the stationary equipment. The mechanical seal assembly 10 may be constructed to provide a fluid-tight seal, thereby preventing a process medium (e.g., a fluid) from escaping the stationary equipment. The fluid-tight seal is achieved by means of sealing members, including a rotating seal ring and a stationary seal ring, as known in the art. The seal rings may be split seal rings having a pair of seal ring segments.Sealing rings can be arranged in operative sealing contact with each other to form a seal. The sealing rings can be pushed into this sealing contact by known pushing mechanisms, such as push rings and push springs. Sealing rings provide a fluid-tight seal operable under a wide range of operating conditions.

[28] The mechanical seal 10 may also include a gland component 14 and a sleeve component or support 16 that seats within the gland component 14. The sleeve component 16 may have any selected shape or configuration, and in the illustrated embodiment, it is formed as a sleeve that is disposed around and rotatably coupled to the shaft. The sleeve component 16 is disposed within the interior space formed by the gland component 14. A locking ring assembly 20 may be used to secure the sleeve component 16 to the shaft 12. A series of removable centering clamps 18 may be employed to assist in centering the locking ring assembly 20 both axially and radially with respect to the shaft 12. The centering clamps 18 are removed prior to operation of the mechanical seal 10.

[29] The gland component 14 may have a main body 32 having a series of circumferentially spaced channels or grooves 34 configured to receive fasteners, such as bolts, for mounting the gland component 14 to stationary equipment. The main body 32 may also have one or more fluid passages 36 formed therein to introduce or permit communication to an internal region of the gland and, therefore, the sealing components with an externally supplied fluid, such as a barrier or flushing fluid. The fluid passages 36 may be sealed, if desired, with a suitable plug 38. The sleeve component 16 may have an elongated sleeve portion 40 at an outboard end and a flanged portion (not shown) at an onboard end defining a space for receiving and retaining the rotating seal ring.The sleeve component 16 may have any selected number of grooves (not shown) formed therein to seat one or more sealing elements to form a fluid seal between the shaft and the gland component 14, as known in the art.

[30] Figures 3 to 6 show details of the locking ring assembly 20 of the present invention. The illustrated locking ring assembly 20 includes a locking ring 22 that is dimensioned and configured to seat around the shaft and to apply radial pressure to the sleeve component 16 to lock (e.g., lock) the sleeve component 16 to the shaft 12. As shown in Figures 3 and 4, the illustrated locking ring 22 has a main body 50 that is generally circular or annular in shape. The main body 50 includes an upper surface 52 and an opposing lower surface 54. The upper surface 52 has a plurality of openings 56 formed therein that terminate at the lower surface 54 for seating centering elements 58.As shown, for example, in FIGURE 8, the centering element 58 is mounted in the opening 56 and projects from the lower surface 54 of the locking ring 22. The centering element 58 makes contact with a raised portion 46 of the gland element 16 in order to help center the locking ring 22 between the raised portion 46 and the shaft 12.

[31] The main body 50 of the locking ring 22 also has a circumferential or peripheral surface 60. The circumferential surface 60 has a series of lateral openings 62 formed therein that are circumferentially spaced along the surface 60. The lateral openings 62 may be threaded in order to receive a set screw 64, as shown in FIGURES 1 and 7. The set screw 64 seats within a hole or opening 42 formed in the sleeve portion 40 of the sleeve component 16. The set screw 64, in addition to the locking ring assembly 20, helps to secure the sleeve component 16 to the shaft 12.

[32] The circumferential surface 60 further has formed therein a pair of opposing cutouts 66 and 68. Cutouts 66, 68 form a pair of opposing flanges 70A, 70B, each of which has an opening 72 formed therein to receive the bolt element 24. Flanges 70A, 70B can be mated or secured to each other using the bolt element 24 and the nut element 26 of the locking ring assembly 20. Cutout region 66 is configured to have a curved or cylindrical profile region 74 (e.g., when viewed in cross-section) having a selected radius that corresponds to the radius of the nut element 26. Cutout 68 has a relatively flat cutout section 76 configured to seat the bolt element 24. The trim region 68 is configured to form a wall portion 78 on the upper surface 52 of the main body 50.The formation of the wall portion 78 allows additional material to remain in the main body of the locking ring 22, thereby improving its structural integrity. The circumferential surface 60 also has a pair of circumferentially spaced notches 80 formed on it, which function as flexural regions when the flanges 70A, 70B are secured together. Although two notches 80 are illustrated, a person skilled in the art will readily recognize that any suitable number of notches may be employed. The notches extend partially across the width of the locking ring 22. The flanges 70A, 70B are separated by a gap 82. In this way, the locking ring 22 is configured as a circular crown having a central opening 84 to seat around the shaft 12 and the sleeve component 16.

[33] Figures 4 and 5 illustrate bolt element 24 and nut element 26, respectively. The illustrated bolt element 24 has a head portion 90 and a threaded shank portion 92. The bolt element 24 is sized and configured to pass through the openings 72 formed in the flanges 70A, 70B. The head portion 90 of the bolt element 24 is configured to seat in the cutout 68 adjacent to the wall portion 78. The illustrated nut element 26 has a main cylindrical body 102 having a threaded center opening 104 formed through it. The main body 102 is sized and configured to seat in the cutout 66 and specifically in the cylindrical profile region 74. As such, the cylindrical shape of the nut is complementary in form to the curved profile region 74. In this way, nut element 26 is configured as a barrel nut.When mounted there, the threaded shank portion 92 of bolt element 24 engages with the threaded opening 104. The bolt can be tightened by an amount selected by the installer. As the bolt element is tightened, the flanges 70A and 70B are driven closer together along an arced path. The notches 80 that form the flexing regions allow the flanges to follow the arced tightening path. A person skilled in the art will readily recognize that the bolt element 24 and the nut element 26 can be of any selected shape and size.

[34] Accordingly, the present invention relates to a locking ring assembly 20 for use with a mechanical seal, such as, for example, a cartridge-type seal 10. The locking ring assembly 20 includes a locking ring 22, a bolt element 24, and a nut element 26 in the form of a barrel nut. The bolt element 24 and the nut element 26 are used to secure and tighten the locking ring 22. The bolt element 24 can be tightened by a turning or torque action while the shank portion 92 of the bolt seats within the barrel nut 26. The barrel nut may include a threaded center opening 104.The shape and configuration of the locking ring 22 help reduce stress, such as bending stress, on the bolt element 24, as there is only one tightening point in the field, compared to conventional locking rings that use multiple set screws. Additionally, the illustrated locking ring 22 also applies a more uniform clamping force around the shaft 12. As a result, the torque applied to the bolt element 24 stretches rather than bends the bolt element. Furthermore, the bolt element 24 and barrel nut 26 can be replaced instead of the entire locking ring assembly 20, as with conventional locking rings.

[35] The locking ring 22 also has a relatively small, shallow recess 66 that seats the barrel nut 26, and therefore it is not necessary to remove excess material from the main body of the locking ring 22. Removing only a small amount of material from it helps preserve the structural integrity of the locking ring 22. The main body 50 of the locking ring 22 also includes one or more, and preferably a plurality, of separate notches 80. The notches 80 form flexure regions that help reduce the energy required to apply a clamping force to the locking ring 22 during the tightening procedure. The tightening energy can thus be directed toward the clamping force and can be optimized.Additionally, the use of the bolt and nut provides a single tightening point compared to prior art locking rings that employ multiple fixing screws.

[36] The locking ring 22 and associated locking mechanism may employ a plurality of centering clamps 18, which can be used to help center the shaft 12 within the mechanical seal. The centering clamps 18 help center the locking ring both radially and axially. Additionally, centering elements 58 can be used to radially center the locking ring 22 relative to the shaft 12. The centering clamps 18 also allow for safer handling and shipping during transport without extraordinary shipping packaging. The centering clamps 18 are removable before equipment operation.

[37] In this way, it will be seen that the invention efficiently achieves the aforementioned objectives, some of which are evident from the preceding description. Because certain changes can be made to the above constructions without departing from the scope of the invention, it is intended that all the material contained in the preceding description or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.

[38] It should also be understood that the following claims are to cover all the generic and specific features of the invention described herein, and all statements of the scope of the invention which, as a matter of language, could be said to fall within them.

Claims

1. A mechanical seal, comprising a gland element, a sleeve component having an elongated sleeve portion, the sleeve component disposed within the gland, and a locking ring assembly including a locking ring having a main body generally annular in shape and having a top surface, an opposing bottom surface, and a circumferential surface, wherein the top surface has formed therein a plurality of openings sized and configured to receive a centering element and wherein the circumferential surface has formed a plurality of side openings sized and configured to receive a set screw, wherein the main body includes a first cutout section having a curved profile region forming part of a first flange portion,and a second trim section that forms part of a second flange portion, wherein the first and second flange portions have a bolt opening formed therein, a plurality of notches formed in the main body of the locking ring and circumferentially spaced around the main body to form bending regions, a bolt element that is sized and configured to seat in the bolt openings, and a nut element having a cylindrical shape that is complementary in shape to the curved profile region of the first flange portion.

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

3. The mechanical seal of claim 1, further comprising one or more centering elements for mounting in one or more of the plurality of openings.

4. The mechanical seal of claim 1, wherein the sleeve portion includes one or more holes, further comprising one or more fixing screws for mounting in one or more of the plurality of side openings, and wherein the fixing screw is configured to engage with the hole in the sleeve portion.

5. A locking ring assembly for a mechanical seal, comprising a main body generally annular in shape having a top surface, an opposing bottom surface, and a circumferential surface, wherein the top surface has a plurality of openings sized and configured to receive a centering element and the circumferential surface has a plurality of side openings sized and configured to receive a set screw, a first cutout section formed in the main body having a curved profile region forming part of a first flange portion, a second cutout section formed in the main body forming part of a second flange portion, wherein the first and second flange portions have a bolt opening formed therein,a plurality of notches formed in the main body and circumferentially spaced around the main body to form bending regions, a bolt element that is sized and configured to seat in the bolt openings, and a nut element having a cylindrical shape that is complementary in shape to the curved profile region of the first flange portion.

6. The locking ring of claim 5, wherein the nut element is a barrel nut.

7. The locking ring of claim 5, further comprising one or more centering elements for mounting in one or more of the plurality of openings.

8. The locking ring of claim 5, wherein the sleeve portion includes one or more holes, further comprising one or more fixing screws for mounting in one or more of the plurality of side openings, and wherein the fixing screw is configured to engage with the hole in the sleeve portion.

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