Rotary shaft seal for mixing apparatus

Abstract

A rotary shaft seal for mounting on a vessel wall includes a plurality of adapter plates, an internal seal assembly, and a casing. The internal seal assembly includes first and second sealing caps and a mounting ring. The mounting ring is disposed between the first and second sealing caps and defines axial spring holes from a first side to a second side of the mounting ring. The central casing is disposed between first and second adapter plates of the plurality of adapter plates and defines a central cavity that receives the internal seal assembly. Each axial spring hole defined in the mounting ring is configured to receive a respective coil spring such that a plurality of coil springs extends a predetermined axial distance from the first side and from the second side of the mounting ring and applies an axial force to the first and second sealing caps.

Description

TITLE OF THE INVENTION

[0001] Rotary Shaft Seal for Mixing ApparatusCROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. provisional patent application numbers 63 / 725,762, filed on November 27, 2024, and 63 / 659,010, filed on June 12, 2024, the disclosures of which are herein incorporated by reference in their entireties.BACKGROUND OF THE INVENTION

[0003] The present invention relates to a seal for a mixing apparatus and more particularly to a seal for sealing a gap surrounding a rotating shaft where the shaft penetrates a wall of a mixing apparatus or other vessel.

[0004] Advanced mixing equipment is required for the manufacturing process in a wide variety of industries, such as food processing, cement production, and pharmaceutical production. In order to avoid loss of material during processing, seals are placed between the rotating and stationary portions of such equipment. The use of seals reduces material loss and contamination while contributing to environmental safety for plant employees.SUMMARY

[0005] The present disclosure provides a description of rotary shaft seals a mixing apparatus and methods of assembling such rotary shaft seals.

[0006] A rotary shaft seal for mounting on a vessel wall, includes: a plurality7of adapter plates; an internal seal assembly including a first sealing cap, a second sealing cap, and a mounting ring, said mounting ring being disposed between the first sealing cap and the second sealing cap and defining a plurality of axial spring holes therethrough from a first side of the mounting ring to a second side of the mounting ring; and a central casing disposed between a first adapter plate and a second adapter plate of the plurality of adapter plates and defining a central cavity configured to receive the internal seal assembly, wherein each axial spring hole of the plurality of axial spring holes defined in the mounting ring is configured to receive a respective coil spring such that a plurality of coil springs (1) extends a predetermined axial distance from the first side of the mounting ring and from the second side of the mounting ring and (2) applies an axial force to the first sealing cap and the second sealing cap.

[0007] A method for assembling a rotary shaft seal onto a vessel wall, wherein the rotary shaft seal includes a first adapter plate, a second adapter plate, an internal seal assembly, anda central casing, the method includes: sliding, over a shaft, the first adapter plate, via a first bore hole defined therethrough, such that mounting apertures defined in the first adapter plate align with mounting holes in the vessel wall; sliding, over the shaft, a first sealing cap of the internal seal assembly, via a second bore hole defined therethrough, until a sealing surface of the first sealing cap contacts an inner facing surface of the first adapter plate; sliding, over the shaft, a mounting ring of the internal seal assembly, via a third bore hole defined therethrough, wherein the mounting ring defines a plurality of axial spring holes therethrough from a first side of the mounting ring to a second side of the mounting ring; inserting a spring coil into each axial spring hole of the plurality of axial spring holes such that a plurality of coil springs extends a predetermined axial distance from the first side of the mounting ring and from the second side of the mounting ring and contacts an inwardly facing surface of the first sealing cap; sliding, over the shaft, a second sealing cap of the internal seal assembly, via a fourth bore hole defined therethrough, until an inner facing surface of the second sealing cap is positioned against the coil springs extending from the second side of the mounting ring; sliding, over the shaft, the central casing, via a fifth bore hole defined therethrough, such that (1) a central cavity of the central casing receives the internal seal assembly, and (2) a first end face of the central casing engages with the inner facing surface of the first adapter plate; and sliding, over the shaft, the second adapter plate, via a sixth bore hole defined therethrough, until an inner facing surface of the second adapter plate engages with a second end face of the central casing.

[0008] A rotary shaft seal for mounting on a vessel wall, including: an end plate; a plurality7of wear plates; an internal seal assembly including a first rotor cup, a second rotor cup, a clamp, and a seal boot configured to be positioned about an outer surface of the clamp, wherein (1) the clamp and the seal boot are disposed between the first rotor cup and the second rotor cup, and (2) wherein the internal seal assembly is disposed between at least two wear plates of the plurality' of wear plates; and an outer housing including a first end face and a second end face, wherein the second end face is configured to engage with an inner facing surface of the end plate and defines an internal cavity configured to house the plurality of wear plates and the internal seal assembly.

[0009] A method for assembling a rotary shaft seal onto a vessel wall, wherein the rotary shaft seal includes an end plate, a plurality' of wear plates, an internal seal assembly, and an outer housing, the method includes: sliding, over a shaft, an end plate, via a first bore hole defined therethrough, such that mounting holes defined in the end plate align with mounting holes in the vessel wall; sliding, over the shaft, at least a first wear plate of the plurality ofwear plates, via a second bore hole defined therethrough, such that the at least the first wear plate is in facing engagement with an inner facing surface of the end plate; sliding, over the shaft, the internal seal assembly, via a third bore hole defined therethrough, until a first face of a first rotor cup of the internal seal assembly contacts the at least the first wear plate, wherein the first rotor cup further includes a second face that defines a first plurality of axial spring holes; sliding, over the shaft, at least a second wear plate of the plurality of wear plates, via a fourth bore hole defined therethrough, until the at least the second wear plate is in facing engagement with the second rotor cup of the internal seal assembly; and sliding, over the shaft, the outer housing, via a fifth bore hole defined therethrough, until (i) the outer housing is positioned over the internal seal assembly and (ii) a plurality of mounting apertures defined in the outer housing align with the mounting holes of the end plate.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0010] The following detailed description of the invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, shown in the drawings is an embodiment which is presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.

[0011] In the drawings:

[0012] Fig. 1 is a left side and front perspective view of a preferred embodiment of a rotary shaft seal according to the present invention;

[0013] Fig. 2 is an exploded perspective view of the rotary shaft seal of Fig. 1;

[0014] Fig. 3 is a side sectional partial perspective view of the outer housing of rotary shaft seal of Fig. 1 taken along line 3-3 of Fig. 1;

[0015] Fig. 4 is a right side and front perspective view of the internal seal assembly of the rotary shaft seal of Fig. 1;

[0016] Fig. 5 is a cross-sectional view of the internal seal assembly of Fig. 4 taken along line 5-5 of Fig. 4;

[0017] Fig. 6 is a left side and front perspective view of a center mounting ring of the internal seal assembly of Fig. 4;

[0018] Fig. 7 is a right side and perspective view of the outer seal rings of the internal seal assembly of Fig. 4;

[0019] Fig. 8 is a side sectional perspective view of the rotary shaft seal of Fig. 1 taken along line 3-3 of Fig. 1;

[0020] Fig. 9 is a left side and front perspective view of a second preferred embodiment of a rotary shaft seal according to the present invention;

[0021] Fig. 10 is an exploded perspective view of the rotary shaft seal of Fig. 9;

[0022] Fig. 11 is an exploded view of an internal seal assembly of the rotary shaft seal ofFig. 9;

[0023] Fig. 12A is an exploded view of a central clamp of the internal seal assembly of the rotary shaft seal of Fig. 11;

[0024] Fig. 12B is a partial exploded view of the central clamp and seal boot of the internal seal assembly of the rotary shaft seal of Fig. 11;

[0025] Fig. 13 is a partial exploded view of the internal seal assembly of the rotary shaft seal of Fig. 9;

[0026] Fig. 14 is a left side and front perspective view of the internal seal assembly of the rotary shaft seal of Fig. 9;

[0027] Fig. 15 is a partial exploded view of the rotary shaft seal of Fig. 9;

[0028] Fig. 16 is a side sectional perspective view of the rotary shaft seal of Fig. 9 along line 6-6 of Fig. 9;

[0029] FIG. 17 is a front sectional perspective view of the rotary shaft seal of Fig. 9 along line 6-6 of Fig. 9 and a magnified view of the internal seal assembly of the rotary' shaft seal; and

[0030] FIG. 18 is a front sectional perspective view of the rotary shaft seal of Fig. 9 along line 6-6 in which O-rings are incorporated on an inner diameter of first and second rotor cups.DETAILED DESCRIPTION OF THE INVENTION

[0031] Reference will now be made in detail to an embodiment of the invention, examples of which are illustrated in the accompanying drawings. The terminology7used in the description of the invention herein is for the purpose of describing the particular embodiment only and is not intended to be limiting.

[0032] As used in the description of the invention, the singular forms ’'a". “an” and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The words “and / or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. The words “comprises” and / or “comprising,” when used herein, specify the presence or the stated features, integers, steps, operations, elements, components, and / or groups, but do not preclude the presence oraddition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0033] It should also be understood that the terms “about,” “approximately,” “generally,” “substantially” and like terms, used herein when referring to a dimension or characteristic of a component of the invention, indicate that the described dimension / characteristic is not a strict boundary or parameter and does not exclude variations therefrom that are functionally similar. At a minimum, such references that include a numerical parameter would include variations that, using mathematical and industrial principles accepted in the art (e.g., rounding, measurement or other systematic errors, manufacturing tolerances, etc.), would not vary the least significant digit.

[0034] The words “right,” left,” “lower,” “upper,” “front” and “rear” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the seal, and designated parts thereof. The terminology includes the words noted above, derivatives thereof and words of similar import.

[0035] Although the words first, second, etc., are used herein to describe various elements, these elements should not be limited by these words. These words are only used to distinguish one element from another. For example, a first end could be termed a second end without departing from the scope of the present invention.

[0036] Referring to the drawings in detail, wherein like numerals indicate like elements throughout, in Figs. 1-8, a first preferred embodiment of a rotary shaft seal, generally designated 10, is shown. Referring to Fig. 1, the rotary shaft seal 10 is shown in a mounted position with respect to a vessel wall 12, which typically is a strong metal wall of a tank, mixer, or other container. The vessel wall 12 is omitted in Figs. 2-7. A shaft 14. which is depicted as a solid cylinder, but may alternatively have a central bore, is rotatable and rotates when in use. The shaft 14 passes through the vessel wall 12. The rotary shaft seal 10 seals the shaft 14 and vessel wall 12 when the shaft 14 is in use and rotating.

[0037] The rotary shaft seal 10 comprises both non-rotating and rotating portions.Referring to Figs. 1-3, the rotary shaft seal 10 includes a non-rotating outer housing 16 which includes a first adapter plate 18. The first adapter plate 18 is non-rotatably fixed to the vessel wall 12. The first adapter plate 18 includes a central bore 20 (aligned with the shaft 14). The central bore 20 is sized to accommodate the shaft 14 and preferably is sized to fit closely about the shaft 14, while providing some clearance to accommodate runout (deviation from true circular, axial rotation of the shaft as defined above). An appropriate range of clearancemay in some embodiments range from about 0.25 inch (6.4 mm) to 0.38 inch (9.5 mm). The first adapter plate 18 may be non-rotatably and axially fixed to the vessel wall 12 by a plurality of screws (not shown) passing through mounting apertures 22 (Fig. 2) in the first adapter plate 18 and engaging the vessel wall 12, in manner well understood by those of ordinary7skill in the art. The first adapter plate 18 is formed of a sturdy material sufficiently strong and having other properties, such as corrosion resistance, required for the application, as known in the art. Stainless steel is a suitable material for this component.

[0038] Adjacent the first adapter plate 18 is a central casing 24 having an outside diameter or surface which generally corresponds to the outside diameter or surface of the first adapter plate 18. The central casing 24 has a bore extending therethrough defining an internal generally cylindrical surface 26 for receiving an internal seal assembly 28, further described below. The central casing 24 has a first end face 30 and second end face 31 positioned opposite the first end face 30. The first adapter plate 18 includes an inner facing surface 32 which is in facing engagement with the first end face 30. The inner facing surface 32 includes an annular channel 34 for receiving an O-ring 36. The O-ring 36 forms a seal between the first end face 30 and the inner facing surface 32. The O-ring 36, and all O-rings mentioned hereinafter, is constructed of a high-performance fluoroelastomer, preferably manufactured by VITON, that is particularly suitable for high temperature, high RPM and high-pressure environments as defined below. While it is preferred that a high-performance fluoroelastomer be used, other materials could be used as understood by those of ordinary skill in the art. The central casing 24 includes a series of mounting holes 38 which are aligned with the mounting apertures 22 when the central casing 24 is mounted to the first adapter plate 18.

[0039] A second adapter plate 40 is positioned opposite the first adapter plate 18 and is generally identical to the first adapter plate 18. That is, the second adapter plate 40 includes a central bore 42, mounting apertures 44 and inner facing surface 46. The second adapter plate 40 further includes an annular channel 48 and an O-ring 50 identical to the first adapter plate 18. The second end face 31 is in sealed facing relation with the inner facing surface 46 of the second adapter plate 40 due to the presence of the O-ring 50. Bolts (not shown) pass through the aligned mounting apertures 22 of the first adapter plate 18, mounting holes 38 of the central casing 24 and the mounting apertures 44 of the second adapter plate 40 to secure the first adapter plate 18, central casing 24, and second adapter plate 40 as one assembly against the vessel wall 12. The central casing 24 and second adapter plate 40 are made of the same material as the first adapter plate 18.

[0040] Referring now to Figs. 2-8, there is shown the internal seal assembly 28, which includes a central mounting ring 52 and first and second sealing caps 54, 56, respectively, positioned on opposite sides of the central mounting ring 52. The central mounting ring 52 includes a central bore 58 for receiving the shaft 14 in a non-rotatable manner. That is, the central bore 58 of the mounting ring 52 is sized to slidably receive the shaft 14 for initial mounting purposes. The mounting ring 52 includes a series of radial holes 60 receiving set screws (not shown) to secure the mounting ring 52 to the shaft 14 in a rotatably fixed manner, such that the mounting ring 52 rotates with the shaft 14. The mounting ring 52 is preferably constructed of the same material as the first adapter plate 18.

[0041] Referring to Figs. 2 and 6, the central mounting ring 52 includes a pair of guiding pins 62 passing through a pair of oppositely disposed axial pin holes 64 extending through the mounting ring 52. The guiding pins 62 are positioned within the axial pin holes 64 via a slip or slidable fit so they have a slip fit on the central mounting ring 52 and can axially move in and out with respect to the central mounting ring 52. The guiding pins 62 extend a predetermined axial distance from either side of the central mounting ring 52 for guiding interaction with the first and second sealing caps 54, 56, as described in more detail hereinafter. The central mounting ring 52 further includes four coil springs 66 loosely positioned in four axial spring holes 68 equidistantly spaced around the mounting ring 52. The coil springs 66 extend a predetermined axial distance on both sides of the central mounting ring 52 for applying an axial force to the first and second sealing caps 54, 56, as described in more detail hereinafter.

[0042] Referring now to Figs. 4-5 and 7-8, as mentioned above, the first and second sealing caps 54, 56 are also formed as a ring and are similarly shaped to the central mounting ring 52. Each of the first and second sealing caps 54, 56 have a central bore 72 for fixedly receiving the shaft 14 in a non-rotatable fashion. The central bores 72 of the first and second sealing caps 54, 56 includes an annular channel 74 extending endlessly around the central bores 72. An O-ring 76 is positioned in each of the annular channels 74 of the first and second sealing caps 54, 56 for sealingly fixed engagement with the shaft 14. The inside diameter of the first and second sealing caps 54. 56 and the diameter of the O-rings 76 is selected to form a tight seal between the between the first and second sealing caps 54, 56 and the shaft 14 so that material cannot pass between the internal seal assembly 28 and the shaft 14. While O-rings are described and show- herein, other cross-sectional shapes could be used such square, elliptical or oval. Each of the first and second sealing caps 54. 56 have a generally flat sealing surface 54a, 56a in facing engagement with the generally flat innerfacing surfaces 32, 46 of the first and second adapter plates 18, 40, respectively, to form a seal therebetween. Each of the first and second sealing caps 54. 56 have inwardly facing surfaces 54b, 56b facing the central mounting ring 52.

[0043] Each of the first and second sealing caps 54, 56 have a pair of corresponding axial pin holes 70 extending through the respective inwardly facing surfaces 54b, 56b partially into the first and second sealing caps 54, 56 a predetermined depth for slidably receiving a portion of the respective guide pin 62 extending from the central mounting ring 52. The predetermined depth of the axial pin holes 70 in the first and second sealing caps 54, 56 is less than the width of the first and second sealing caps 54, 56.

[0044] Each of the first and second sealing caps 54, 56 have four axial spring holes 78 correspondingly positioned to the axial spring holes 67 in the central mounting ring 52 for receiving a portion of one of the coil springs 66. Each of the four axial spring holes 78 extends through the respective inwardly facing surfaces 54b, 56b partially into the first and second sealing caps 54, 56 a predetermined depth for slidably receiving a portion of a respective coil spring 66 extending from the central mounting ring 52. The predetermined depth of the axial spring holes 78 in the first and second sealing caps 54, 56 is less than the width of the first and second sealing caps 54, 56. While two guide pins 62 and four coil springs 66 are disclosed, the present invention is not so limited. A different number of guide pins and coil springs could be used, such as for guide pins and six coil springs.

[0045] The first and second sealing caps 54, 56 are preferably constructed of a high strength material that will slowly wear when rotated against a metallic material, such as stainless steel. Preferably, the first and second sealing caps 54, 56 are constructed of polytetrafluoroethylene (PTFE) which is a fluoropolymer and is commonly known by its trade name, TEFLON®. Unique properties of PTFE include nonreactivity, hydrophobicity, a low' coefficient of friction, and good insulating properties. Any other material which exhibits similar performance characteristics, such as PEEK, mineral filled PTFE , Rulon, or Carbon based materials, would also be suitable.

[0046] The internal seal assembly 28 is positioned within the outer housing 16 between the first and second adapter plates 18, 40 with the central mounting ring 52 positioned equidistantly between the first and second adapter plates 18, 40. The distance between the inner facing surfaces 32, 46 of the first and second adapter plates 18, 40 is slightly larger than the combined width of the mounting ring 52 and the first and second sealing caps 54, 56. When the internal seal assembly 28 is positioned within the outer housing 16, the first and second sealing caps 54, 56 can slide along the guide pins 62 outwardly toward the innerfacing surfaces 32, 46 of the first and second adapter plates 18, 40 under the forces applied by the coil springs 66. The coil springs 66 provide a constant outer force on the first and second sealing caps 54, 56 so that as the first and second sealing caps 54, 56 rotate against the inner facing surfaces 32, 46 of the first and second adapter plates 18, 40 a seal is formed therebetween. Over time as the first and second sealing caps 54, 56 rotate against the inner facing surfaces 32, 46 of the first and second adapter plates 18, 40 they begin to wear down. In order to automatically compensate for the wear, the coil spnngs 66 continually maintain good sealing contact between the first and second sealing caps 54, 56 and the first and second adapter plates 18, 40 even as the first and second sealing caps 54, 56 begin to wear. Thus, the rotary shaft seal 10 is self-adjusting, reducing the need for maintenance to maintain sealing performance.

[0047] To assemble the rotary shaft seal 10 onto the vessel wall 12 and shaft 14, the first adapter plate 18 is slid over the shaft 14 with the mounting apertures 22 aligned with the mounting holes (not shown) in the vessel wall 12 and the O-ring 36 facing away from the vessel wall 12. The first sealing cap 54 is then slid over the shaft 14 until the sealing surface 54a contacts the inner facing surface 32 of the first adapter plate 18. The mounting ring 52 is then slid over the shaft 14 until the guide pins 62 enter the axial pin holes 70 and the mounting ring 52 is close to but not touching the first sealing cap 54. The mounting ring 52 is then axially and rotatably secured to the shaft 14 using the set screws (not shown) placed through the radial holes 60. Then the coil springs 66 are positioned through the axial spring holes 68 in the mounting ring 52 and the axial spring holes 78 in the first sealing cap 54. The second sealing cap 56 is then slid over the shaft 14 until the coil springs 66 and guide pins 62 are positioned within the corresponding holes in the second sealing cap 56 and the guide pins 62 bottom out in the second sealing cap 56. Next the central casing 24 and second adapter plate 40 are positioned over and against the internal seal assembly 28 with the mounting holes and apertures 38, 44 of the central casing 24 and the second adapter plate 40 aligned with the mounting apertures 22 in the first adapter plate 18 to allow bolts to pass therethrough into engagement with mounting holes (not shown) in the vessel wall 12. After the bolts are tightened down the rotary shaft seal 10 is fully assembled.

[0048] Once the rotary shaft seal 10 is assembled on the shaft 14 and vessel wall 12, the contents within the vessel are sealingly maintained in the vessel as the shaft 14 rotates because of the O-rings 76 inside the first and second sealing caps 54, 56 maintaining the seal between the first and second sealing caps 54, 56 and the shaft 14 and the sealing surfaces 54a, 56a sliding against the inner facing surfaces 32, 46 of the first and second adapter plates 18,40. The rotary shaft seal 10 is particularly suitable for high temperature, up to 400°F, high pressure, up to 600°F, high pressure, up to 100 PSI and high RPMs, up to 3600RPM, without having the seal fail. The first and second sealing caps 54, 56 serve different purposes. The present rotary shaft seal is an air purged seal. That is the first cap seal 54 prevents the mixed product from leaking into the rotary shaft seal 10. The second sealing cap 56 prevents air inside the rotary shaft seal 10 from leaking out, thus maintaining a positive differential pressure inside the rotary shaft seal 10. Higher temperatures can be achieved by using a high temperature O-ring 76 or a high temperature packing ring (not shown). Similarly, the first and second sealing caps 54,56 could formed of carbon components instead of PTFE. The materials of the O-ring 76 and first and second sealing caps 54, 56 could be mixed and matched of different high temperature materials to gain the high temperature, high pressure and high RPMs as desired.

[0049] Figs. 9-16 depict a second preferred embodiment of a rotary' shaft seal 110 in which a clamp 180 replaces the mounting ring 52 and set screws (not shown), of the first preferred embodiment.

[0050] The rotary shaft seal 110 is configured to be mounted to a vessel wall (for example, vessel wall 12 depicted in Fig. 1). Similar to the rotary shaft seal 10 described above with respect to Figs. 1-9 of the first preferred embodiment, the rotary' shaft seal 110 is configured to receive a shaft (e.g., shaft 14 of Fig. 1) through a central bore (discussed in more detail herein) and is configured to seal the shaft and vessel wall when the shaft is in use and rotating.

[0051] Like the rotary shaft seal 10 of the first preferred embodiment, the rotary shaft seal 110 includes both non-rotating and rotating portions. As depicted in Figs. 9. 10, 15 and 16, the rotary shaft seal 110 includes an end plate 118 and a non-rotating outer housing 116 (herein referred to as “outer housing’’). The end plate 118 includes an outer facing surface 132 and an inner facing surface 133. The outer facing surface 132 is configured to be positioned against the vessel wall (not shown) such that the end plate 118 is non-rotatably fixed thereto. The inner facing surface 133 is in facing engagement with a second end face 131 of the outer housing 116. The end plate 118 defines a plurality of mounting holes 138 extending from the outer facing surface 132 to the inner facing surface 133 and is configured to be non-rotatably and axially fixed to the vessel wall by a plurality7of screws or bolts (not shown). Each screw or bolt passes through a respective mounting hole 138 in the end plate 118 and engages the vessel wall 12, in a manner that would be understood by those or ordinary skill in the art. The inner facing surface 133 of the end plate 118 defines an internalcavity' 126 configured to secure wear plates 111, 113 (discussed below) and includes an annular channel 134 configured to receive an O-ring 136. The O-ring 136 is configured to form a seal between the inner facing surface 133 of the end plate 118 and the second end face 131 of the outer housing 116 so that material cannot pass therebetween.

[0052] The end plate 118 further defines a plurality of axial screw holes 139 configured to receive respective screws 148 (e.g., socket head cap screws) for securing wear plates 111, 113 to the end plate 118 and defines a central bore 121 aligned with the shaft (not shown). The central bore 121 is sized to accommodate the shaft and is, preferably, sized to fit closely about the shaft while providing some clearance to accommodate runout.

[0053] The end plate 118, similar to the first adapter plate 18 described with respect to the first preferred embodiment, is formed of a sturdy material sufficiently strong and having other properties, such as corrosion resistance, required for the application, as know n in the art. Stainless steel is a suitable material for this component.

[0054] The outer housing 116, as shown in Fig. 9, is positioned adjacent to the end plate 118 and has an outside diameter or surface that substantially corresponds to an outside diameter or surface of the end plate 118. As illustrated in Figs. 9. 10. 15 and 16. the outer housing 116 includes a first end face 130, a second end face 131 positioned opposite the first end face 130, and an inner facing surface 135. The first end face 130 of the outer housing 116 defines a central bore 120 configured to receive the shaft (not depicted) and defines mounting apertures 144 that extend from the first end face 130 to the second end face 131. The mounting apertures 144 of the outer housing 1 16 are aligned w ith the mounting holes 138 of the end plate 118 when the outer housing is mounted to the end plate 118. The mounting apertures 144 of the outer housing 116 are configured to receive a respective screw' of bolt (not shown). Each screw or bolt passes through the aligned aperture 144 of the outer housing 116 and the mounting holes 138 of the end plate 118 to secure an assembled rotary shaft seal 110 against the vessel w all. The second end face 131 of the outer housing 116 is in facing engagement w ith the outer facing surface 133 of the end plate 118 and defines an internal cavity 124 within the outer housing 116 configured to house wear plates 115, 117 (secured to the inner facing surface 135. discussed hereinafter) and an internal seal assembly 128 (discussed below).

[0055] The outer housing 116 further defines a plurality of axial screw holes 145 between the first end face 130 of the outer housing 116 and the inner facing surface 135 of the outer housing 116 configured to receive respective screws 146 (e.g., socket head cap screws) forsecuring wear plates 111, 113 to the outer housing 116 within the internal cavity 124 (discussed in more detail hereinafter).

[0056] The rotary shaft seal 110 further includes the internal seal assembly 128 and wear plates 111, 113, 115, 117. As illustrated in Figs. 10-15, the internal seal assembly 128 includes a clamp 180, a seal boot 152, a first rotor cup 154 and a second rotor cup 156.

[0057] The clamp 180 defines a central bore 190 therethrough configured to receive the shaft in a non-rotatable manner and includes a diameter D that is slightly smaller than that of the shaft such that clamp 180 is stretched about an outer surface of the shaft. The clamp 180 includes a first (upper) flange 182 that extends from an outer surface of the clamp 180 in a first (upward) radial outward direction, opposite the central bore 190. The first (upper) flange 182 defines a hole 184 therethrough configured to receive screw 185 A (see, e.g.. Fig. 12B). The clamp 180 includes a second (lower) flange 186 that extends from the outer surface of the clamp 180 in a second (downward) radial outward direct on from the clamp 180, opposite the central bore 190. In other words, both the first flange 182 and the second flange 186 extend from the outer surface of the clamp 180, but from opposite sides, i.e., spaced 180 degrees apart. The second (lower) flange 186 defines a hole therethrough (not shown) configured to receive screw 189A.

[0058] The clamp 180 is comprised of two portions: a first half portion 180A and a second half portion 180B (see. e g., Fig. 12A) which, when secured together, as depicted in Fig. 12B. form a ring and define the central bore 190. The first half portion 180A of the clamp 180 includes a first half portion 182A of the first (upper) flange 182 and a first half portion 186A of the second (low er) flange 186. The first half portions 182A, 186A of the first (upper) and second (lower) flanges 182, 186 define holes 184A, 188A, respectively, therethrough. The second half portion 180B of the clamp 180 includes a second half portion 182B of the second (upper) flange 182 and a second half portion 186B of the second (lower) flange 186. The second half portions 182B, 186B of the second (upper) and second (lower) flanges 182B, 186B define holes 184B, 188B, respectively, therethrough.

[0059] The first and second half portions 180A,180B of the clamp 180 are configured to be mounted about the outer circumference of the shaft and secured together via screws 185 A, 185B. Specifically, holes 184 A, 184B defined by the first and second (upper) flanges 182A, 182B are configured to receive screw 185 A, and holes 188 A, 188B defined by the first and second (lower) flanges 186A, 186B are configured to receive screw 189A. Nuts 185B, 189B are attached to respective screws 185 A, 189A. The central bore 190 of the clamp 180 then slidably receives the shaft for initial mounting purposes. Once in a desired position, theclamp 180 is secured. Because the diameter D of the clamp 180 is slightly smaller than that of the shaft, as the nuts 185B, 189B are screwed onto their respective screws 185 A, 189A, the first and second half portions 180A, 180B of the clamp 180 are stretched about the outer circumference of the shaft such that the clamp 180 is secured to the shaft in a rotatably fixed manner such that the clamp 180 rotates with the shaft. The clamp 180 is formed of a metal material (e.g., stainless steel) sufficiently strong and having properties, such as corrosion resistance, required for the application, as known in the art.

[0060] As depicted in Figs. 10, 11, 12B and 13, the seal boot 152 of the internal seal assembly 128 is formed as a ring and is configured to be positioned about an outer surface of the clamp 180. The seal boot 152 defines a central bore 153 configured to fixedly receive the clamp 180. The seal boot 152 further defines a first (upper) radial aperture 160 configured to receive the first (upper) flange 182 of the clamp 180 and a second (lower) radial aperture 161 configured to receive the second (lower) flange 186 of the clamp 180. The seal boot 152 is configured to be stretched about the outer surface of the clamp 180 and, thus, be sealed thereto.

[0061] While the seal boot 152 is depicted and descnbed above as being configured to be stretched about the outer surface of the clamp 180, in some embodiments, the first and second half portions 180A, 180B of the clamp 180 may be configured to be mounted about an outer circumference of the clamp 180 (and shaft) and secured together via the screws 185 A, 185B such that the seal boot is secured within central bore 190 of the clamp 180.

[0062] The first rotor cup 154 and the second rotor cup 156 of the internal seal assembly 128 are also formed as a ring and define a central bore 157 therethrough configured to receive the internal seal assembly 128 and the shaft.

[0063] The first rotor cup 154 of the internal seal assembly 128 includes a first face 154A and a second face 154B and defines an internal cavity 155 configured to receive a portion of the assembled clamp 180 and seal boot 152. The first rotor cup 154 is comprised of two portions: a first (upper) portion 159A and a second (lower) portion 159B. The first (upper) portion 159A of the first rotor cup 154 includes two screw holes 162 on either side that align with screw holes of the second (lower) portion 159B of the first rotor cup 154, as depicted in Figs. 11 and 13. The first (upper) portion 159A and the second (lower) portion 159B are configured to be secured to each via a screw 170, as illustrated in Fig. 14, and nut (not shown).

[0064] The first face 154A of the first rotor cup 154 has a generally flat surface that is in facing engagement with a wear plate 113. The second face 154B of the first rotor cup 154inwardly faces the clamp 180 and seal boot 152 but may not directly engage therewith. Specifically, as depicted in Fig. 17, a first gap 150a is provided between the second face 154B of the first rotor cup 154 and the seal boot 152. The first gap 150a provides a space for the seal boot 152 to expand without resulting in axial forces on the first rotor cup 154. The second face 154B of the first rotor cup 154 defines four axial spring holes 168 equidistantly spaced around the second face 154B of the first rotor cup 154 that extend a predetermined depth for slidably receiving a portion of a respective coil spring 166. The predetermined depth of the axial spring holes 168 in the first rotor cup 154 is less than the width of the first rotor cup 154. The second face 154B of the first rotor cup 154 further defines a first (upper) groove 158A configured to receive the first (upper) flange 182 of the clamp 180 and a second (lower) groove 158B configured to receive the second (lower) flange 186 of the clamp 180.

[0065] The second rotor cup 156 of the internal seal assembly 128 is similar in form to the first rotor cup 154 as it includes a first face 156A and a second face 156B and defines an internal cavity 151 configured to receive a portion of the assembled clamp 180 and seal boot 152. The second rotor cup 156 is also comprised of two portions: a first (upper) portion 163 A and a second (lower) portion 164B. The first (upper) portion 163 A of the second rotor cup 156 includes two screw holes 162 on either side that align with screw holes of the second (lower) portion 164B of the second rotor cup 156, as depicted in Figs. 11 and 13. The first (upper) portion 163 A and the second (lower) portion 163B are configured to be secured to each via a screw (like screw 170) and nut 171, as illustrated in Fig. 14.

[0066] The first face 156A of the second rotor cup 156 has a generally flat surface that is in facing engagement with a wear plate 115. The second face 156B of the second rotor cup 156 inwardly faces the clamp 180 and seal boot 152 but may not directly engage therewith. Specifically, as depicted in Fig. 17, a second gap 150b is provided between the second face 156B of the second rotor cup 156 and the seal boot 152. The second gap 150b provides a space for the seal boot 152 to expand without resulting in axial forces on the second rotor cup 156. The second face 156B of the first rotor cup 154 defines four axial spring holes (not shown) equidistantly spaced around the second face 156B of the second rotor cup 156 that extend a predetermined depth for slidably receiving a portion of a respective coil spring 166. The predetermined depth of the axial spring holes in the second rotor cup 156 is less than the width of the second rotor cup 156. The four axial spring holes defined in the second rotor cup 156 are correspondingly positioned and / or aligned to the axial spring holes 168 of the first rotor cup 154. The second face 156B of the second rotor cup 156 further defines a first (upper) groove 164 A configured to receive the first (upper) flange 182 of the clamp 180 and asecond (lower) groove 164B configured to receive the second (lower) flange 186 of the clamp 180.

[0067] In some embodiments, the first and second rotor cups 154, 156 may define respective annular channels, 147a, 147b within inner diameters thereof configured to accommodate respective o-rings 149a, 149b, as depicted in FIG. 18.

[0068] Preferably, the first and second rotor cups 154, 156 may be constructed of PTFE, PEEK, mineral filled PTFE, Rulon, or Carbon based materials.

[0069] A plurality of wear plates (e.g., stator wear plates) are positioned on each side of the internal seal assembly 128 for wear compensation. Specifically, as depicted in Figs. 2, 15 and 16, wear plates 111, 113, 115, 117 are formed as a ring and define a central bore 123 therethrough configured to receive the shaft. Each wear plate defines a plurality of a plurality of axial screw holes 119, each configured to receive a respective screw (e.g., socket head cap screw).

[0070] Wear plates 111 and 113 are positioned on a first side of the internal seal assembly 128 and are configured to be secured to the end plate 118. Specifically, a first side 113A of wear plate 113 is in facing engagement with the first face 154A of the first rotor cup 154, and a second side 113B of wear plate 113 is in facing engagement with a first side 11 1 A of wear plate 111. A second side 111 B of wear plate 111 is in facing engagement with the inner facing surface 133 within the internal cavity 126 of end plate 118. The screw holes 119 defined in the wear plate 113 are aligned with the screw holes 119 defined in wear plate 111. Together, the aligned screw holes 119 in wear plates 1 1 1 and 1 13 are configured to receive respective screws 148. The wear plates 111 and 113 may then be mounted to the end plate 118 by aligning the holes 119 of wear plates 111, 113 with corresponding holes 139 defined in the end plate 118, inserting the screws 148 therethrough, and securing the screws 148 to the end plate via respective nuts (not shown).

[0071] Wear plates 115 and 117 are positioned on a second side of the internal seal assembly 128 and are configured to be secured to the inner facing surface 135 within the internal cavity 124 of the outer housing 116. Specifically, a first side 115A of wear plate 115 is in facing engagement with the first face 156A of the second rotor cup 156. and a second side 115B of wear plate 115 is in facing engagement with a first side 117A of wear plate 117. A second side 117B of wear plate 117 is in facing engagement with the inner facing surface 135 within the internal cavity 124 of the outer housing 116. The screw holes 119 defined in wear plate 115 are aligned with the screw holes 119 defined in wear plate 117. Together, the aligned screw holes 119 in wear plates 115 and 117 are configured to receive respectivescrews 146. The wear plates 115 and 117 may then be positioned within the internal cavity 124 of the outer housing 116 such that the holes 119 of wear plates 115 and 117 are aligned with corresponding holes 145 defined in the outer housing 116. The wear plates 115 and 117 may then be mounted to the outer housing 116 by inserting the screw s 146 therethrough, and securing the screws 146 to the outer housing 116 via respective nuts (not shown).

[0072] Once wear plates 115 and 117 are secured to the inner facing surface 135 of the outer housing 116. the internal seal assembly 128 is positioned within the internal cavity 127 of the outer housing 116 between wear plates 115, 117 and wear plate 11 1, 113 fixed to the end plate 118. When the internal seal assembly 128 is positioned within the outer housing 116, the first and second rotor cups 154, 156 push outwardly toward the inner facing surfaces 135 of the outer housing and the end plate 118 under the forces applied by the coil springs 166. The coil springs 166 provide a constant outer force on the first and second rotor cups 154, 156 so that as the first and second rotor cups 154, 156 rotate (along with the clamp 180 and seal boot 152) against the respectively adjacent wear plates, a seal is formed therebetween. Specifically, the first rotor cup 154 of the internal seal assembly 128 rotates against the first side of w ear plate 113, which is in facing engagement with the first face 154A of the first rotor cup 154. Similarly, the second rotor cup 156 of the internal seal assembly 128 rotates against the first side of w ear plate 115 that is in facing engagement w ith the first face 156A of the second rotor cup 156.

[0073] Over time, as the first and second rotor cups 154, 156 rotate against w ear plates 1 13 and 115, they begin to wear down. In order to automatically compensate for the wear, the coil springs 166 continually maintain good sealing contact betw een the first and second rotor cups 154, 156 and the wear plates 113 and 115, even as the first and second rotor cups 154, 156 begin to wear. Thus, the rotary shaft seal 10 is self-adjusting, reducing the need for maintenance to maintain sealing performance.

[0074] Moreover, the wear plates 113 and 115 will also wear over time due to the first and second rotor cups 154, 156 rotating thereagainst. A user may switch the wear plates positions to compensate for the wear. For example, a user may switch the positions of wear plates 111 and 113 such that the first rotor cup 154 of the internal seal assembly 128 rotates against wear plate 111. Similarly, the user may switch the positions of wear plates 1 15 and 117 such that the second rotor cup 156 of the internal seal assembly 128 rotates against w ear plate 117.

[0075] To assemble the rotary shaft seal 110 onto the vessel wall (not shown) and shaft (not shown), the O-ring 136 is positioned within annular channel 134 in the inner facingsurface 133 of the end plate 118. Wear plates 111, 113 are then secured to the first end plate 118, via screws 148, as previously described. The end plate 118 (with O-ring and secured wear plates 1 11 and 113) is slid over the shaft with the mounting holes 138 aligned with mounting holes (not shown) in the vessel wall and the O-ring 136 and wear plates 111, 113 facing away from the vessel wall. The first rotor cup 154 is then slid over the shaft until the first face 154A of the first rotor cup 154 contacts the first side first side of wear plate 113, which is secured to the end plate 118. The clamp 180 then slides over the shaft until the clamp 180 is close to but not touching the first rotor cup 154. The clamp 180 is then secured to the shaft. As previously described, because the diameter D of the clamp 180 is slightly smaller than that of the shaft, as nuts 185B, 189B are screwed onto their respective screws 185 A, 189A. the first and second half portions 180A, 180B of the clamp 180 are stretched about the outer circumference of the shaft such that the clamp 180 is secured to the shaft in a rotatably fixed manner and rotates with the shaft. The seal boot 152 then slides over the shaft and is stretched about the outer surface of the clamp 180 such that the first (upper) flange 182 of the clamp 180 is positioned within the first (upper) radial aperture 160 of the seal boot 152, and the second (lower) flange 186 of the clamp 180 is positioned within the second (lower) radial aperture 161 of the seal boot 152. Then the coil springs 166 are positioned within the axial spring holes 168 in the first rotor cup 154. The second rotor cup 156 is then slid over the shaft until the coil springs 166 are positioned within the corresponding spring holes in the second rotor cup 156. Next wear plates 115, 117 are secured to inner facing surface 135 within the internal cavity 124 of the outer housing 116, via screws 146, as previously described, and the outer housing 116 then slides over the shaft and is positioned over and against the internal seal assembly 128 with the mounting apertures 144 of the outer housing 116 aligned with the mounting holes 138 of the end plate 118 to allow bolts to pass therethrough into engagement with mounting holes (not shown) in the vessel wall. After the bolts are tightened down, the rotary shaft seal 110 is fully assembled.

[0076] Once the rotary shaft seal 110 is assembled on the shaft and vessel wall, as the shaft rotates, so does the internal seal assembly 128 (including the clamp 180, seal boot 152 and first and second rotor cups 154, 156). As the internal seal assembly 128 rotates (with the shaft), it slides against the adjacent wear plates (as discussed above).

[0077] The rotary shaft seal 110 of the second preferred embodiments may work with or without air pressure. The size of the spring coils 166 may be adjusted depending on whether air is used.

[0078] As is the rotary shaft seal 10 of the first preferred embodiment, the rotary shaft seal 110 of the second preferred embodiment is suitable for high temperature, up to 400°F. high pressure, up to 600°F, high pressure, up to 100 PSI and high RPMs, up to 3600RPM, without having the seal fail. Higher temperatures can be achieved by using a high temperature O-ring 136 or a high temperature packing ring (not shown). Similarly, the first and second rotor cups 154. 156 may be formed of carbon components instead of PTFE. The materials of the O-nng 136 and first and second rotor cups 154. 156 could be mixed and matched of different high temperature materials to gain the high temperature, high pressure and high RPMs as desired.

[0079] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. For instance, while the rotary shaft seal 10 of the first preferred embodiment is formed of the central casing 24 and the first and second adapter plates 18, 40 (i.e., three pieces), one of the first or second adapter plates 18, 40 could be integrally formed with central casing 24 for a two-piece construction, without departing from the spirit and scope of the invention. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention.

Claims

WHAT IS CLAIMED IS:

1. A rotary’ shaft seal for mounting on a vessel wall, comprising: a plurality of adapter plates; an internal seal assembly including a first sealing cap, a second sealing cap, and a mounting ring, said mounting ring being disposed between the first sealing cap and the second sealing cap and defining a plurality’ of axial spring holes therethrough from a first side of the mounting ring to a second side of the mounting ring; and a central casing disposed between a first adapter plate and a second adapter plate of the plurality’ of adapter plates and defining a central cavity’ configured to receive the internal seal assembly, wherein each axial spring hole of the plurality of axial spring holes defined in the mounting ring is configured to receive a respective coil spring such that a plurality of coil springs (1) extends a predetermined axial distance from the first side of the mounting ring and from the second side of the mounting ring and (2) applies an axial force to the first sealing cap and the second sealing cap.

2. The rotary shaft seal according to claim 1, wherein the central casing has an outer diameter that substantially corresponds to an outer diameter of the first adapter plate and an outer diameter of the second adapter plate, and wherein the rotary shaft seal defines a central bore therethrough configured to receive a shaft.

3. The rotary' shaft seal according to claim 1, wherein an inner facing surface of the first adapter plate defines a first annular channel configured to receive a first O-ring for forming a seal between the central casing and the inner facing surface of the first adapter plate.

4. The rotary’ shaft seal according to claim 3, wherein an inner facing surface of the second adapter plate defines a second annular channel configured to receive a second O-ring for forming a seal between the central casing and the inner facing surface of the second adapter plate.

5. The rotary' shaft seal according to claim 1, wherein the central mounting ring defines a plurality of axial pin holes extending therethrough, each axial pin hole configured to receive a respective guiding pin.

6. The rotary' shaft seal according to claim 1, wherein the first sealing cap has a first inwardly facing surface that faces the central mounting ring and defines a plurality of first axial pin holes extending a predetermined depth into the first sealing cap, and the second sealing cap has a second inwardly facing surface that faces the central mounting ring and defines a plurality' of second axial pin holes extending the predetermined depth into the second sealing cap.

7. The rotary shaft seal according to claim 6, yvherein the plurality of first axial pin holes and the plurality of second axial pin holes are configured to slidably receive a portion of respective guide pins extending from the central mounting ring.

8. The rotary shaft seal according to claim 1, wherein the first sealing cap defines a first plurality' of axial spring holes in an inwardly facing surface of the first sealing cap. and the second sealing cap defines a second plurality’ of axial spring holes in an inwardly facing surface of the second sealing cap, wherein the first plurality' of axial spring holes and the second plurality of axial spring holes are correspondingly aligned with the plurality of axial spring holes defined in the central mounting ring.

9. The rotary shaft seal according to claim 8, wherein each axial hole of the first plurality' of axial holes extends a predetermined depth in the inwardly facing surface of the first sealing cap, each axial hole of the second plurality of axial holes extends the predetermined depth in the inyvardly facing surface of the second sealing cap, and each axial hole of the first plurality' of axial holes and the second plurality- of axial holes is configured to receive a portion of a respective coil spring extending from the central mounting ring.

10. The rotar\' shaft seal according to claim 1, wherein the first sealing cap and the second sealing cap are configured to rotate against an inner facing surface of the first adapter plate and an inner facing surface of the second adapter plate, respectively, and as the first sealing cap and the second sealing cap rotate, the plurality of coil springs provide a constant outer force on the first sealing cap and the second sealing cap such that a seal is maintained between the first sealing cap and the inner facing surface of the first adapter plate and between the second sealing cap and the inner facing surface of the second adapter plate.

11. The rotary shaft seal according to claim 1, wherein the first adapter plate defines a plurality of mounting apertures and is configured to be mounted to the vessel wall by a plurality of screws, each screw passing through a respective mounting aperture and engaging with the vessel wall.

12. A method for assembling a rotary' shaft seal onto a vessel wall, wherein the rotary shaft seal includes a first adapter plate, a second adapter plate, an internal seal assembly, and a central casing, the method comprising: sliding, over a shaft, the first adapter plate, via a first bore hole defined therethrough, such that mounting apertures defined in the first adapter plate align with mounting holes in the vessel wall; sliding, over the shaft, a first sealing cap of the internal seal assembly, via a second bore hole defined therethrough, until a sealing surface of the first sealing cap contacts an inner facing surface of the first adapter plate; sliding, over the shaft, a mounting ring of the internal seal assembly, via a third bore hole defined therethrough, wherein the mounting ring defines a plurality of axial spring holes therethrough from a first side of the mounting ring to a second side of the mounting ring; inserting a spring coil into each axial spring hole of the plurality’ of axial spring holes such that a plurality of coil springs extends a predetermined axial distance from the first side of the mounting ring and from the second side of the mounting ring and contacts an inwardly facing surface of the first sealing cap; sliding, over the shaft, a second sealing cap of the internal seal assembly, via a fourth bore hole defined therethrough, until an inner facing surface of the second sealing cap is positioned against the coil springs extending from the second side of the mounting ring;sliding, over the shaft, the central casing, via a fifth bore hole defined therethrough, such that (1) a central cavity of the central casing receives the internal seal assembly, and (2) a first end face of the central casing engages with the inner facing surface of the first adapter plate; and sliding, over the shaft, the second adapter plate, via a sixth bore hole defined therethrough, until an inner facing surface of the second adapter plate engages with a second end face of the central casing.

13. The method for assembling the rotary shaft seal onto the vessel wall according to claim 12, wherein the inner facing surface of the first adapter plate defines a first annular channel configured to receive a first O-ring for forming a seal between the first end face of the central casing and the inner facing surface of the first adapter plate.

14. The method for assembling the rotary shaft seal onto the vessel wall according to claim 12, wherein the first sealing cap defines a first plurality of axial spring holes in the inwardly facing surface of the first sealing cap, and wherein the sliding of the mounting ring over the shaft includes aligning each axial spring hole of the plurality of axial spring holes defined in the mounting ring with a corresponding axial spring hole of the first plurality of axial spring holes defined in the first sealing cap.

15. The method for assembling the rotary shaft seal onto the vessel wall according to claim 14, wherein each axial spring hole of the first plurality of axial spring holes defined in the first sealing cap extends a predetermined depth in the inwardly facing surface of the first sealing cap, and wherein inserting the spring coil into each axial spring hole of the plurality of axial spring holes of the mounting ring includes inserting a portion of each spring coil that extends from the first side of the central mounting ring into the corresponding axial spring hole of the first plurality of axial spring holes defined in the first sealing cap.

16. The method for assembling the rotary shaft seal onto the vessel wall according to claim 15, wherein the second sealing cap defines a second plurality of axial spring holes in the inwardly facing surface of the first sealing cap, and wherein sliding the second sealing cap over the shaft includes aligning each axial spring hole of the plurality of axial spring holes defined in the mounting ring with a corresponding axial spring hole of the second plurality of axial spring holes defined in the second sealing cap such that each spring coil that extends from the second side of the central mounting ring is received in the corresponding axial spring hole of the second plurality of axial spring holes.

17. The method for assembling the rotary shaft seal onto the vessel wall according to claim 16, wherein each axial spring hole of the second plurality of axial spring holes defined in the second sealing cap extends the predetermined depth in the inwardly facing surface of the second sealing cap.

18. The method for assembling the rotary shaft seal onto the vessel wall according to claim 13, wherein the inner facing surface of the second adapter plate defines a second annular channel configured to receive a second O-ring for forming a seal between the second end face of the central casing and the inner facing surface of the second adapter plate.

19. The method for assembling the rotary shaft seal onto the vessel wall according to claim 12, wherein the central casing includes a plurality of mounting holes, and wherein sliding the central casing over the shaft includes aligning each mounting hole of plurality of mounting holes of the central casing with a corresponding mounting aperture of the first adapter plate.

20. The method for assembling the rotary shaft seal onto the vessel wall according to claim 19, wherein the second adapter plate includes a plurality’ of mounting apertures, and wherein sliding the second adapter plate over the shaft includes aligning each mounting aperture of the plurality of mounting apertures of the second adapter plate with a corresponding mounting hole of the plurality of mounting holes of the central casing.

21. The method for assembling the rotary shaft seal onto the vessel wall according to claim 20, further comprising: inserting a bolt through aligned holes and apertures of the rotary shaft seal such that the bolt passes through a mounting aperture of the second adapter plate, a corresponding mounting hole of the central casing, a corresponding mounting aperture of the first adapter plate and into a corresponding hole in the vessel wall.

22. A rotary' shaft seal for mounting on a vessel wall, comprising: an end plate; a plurality of wear plates; an internal seal assembly including a first rotor cup, a second rotor cup, a clamp, and a seal boot configured to be positioned about an outer surface of the clamp, wherein (1) the clamp and the seal boot are disposed between the first rotor cup and the second rotor cup, and (2) wherein the internal seal assembly is disposed between at least two wear plates of the plurality of wear plates; and an outer housing including a first end face and a second end face, wherein the second end face is configured to engage wi th an inner facing surface of the end plate and defines an internal cavity configured to house the plurality of wear plates and the internal seal assembly.

23. The rotary shaft seal according to claim 22, wherein the first rotor cup includes a first face and a second face, said second face of the first rotor cup inwardly faces the clamp and the seal boot and defines a first plurality of axial spring holes, each axial spring hole of the first plurality of axial spring holes extending a predetermined depth and configured to receive a first portion of a respective coil spring of a plurality of coil springs, and wherein the second rotor cup includes a first face and a second face, said second face of the second rotor cup inwardly faces the clamp and the seal boot and defines a second plurality of axial spring holes, each axial spring hole of the second plurality of axial spring holes extending the predetermined depth and configured to receive a second portion of the respective coil spring.

24. The rotary shaft seal according to claim 22,wherein the first rotor cup includes a first face and a second face, said second face defining an internal cavity configured to receive a first portion of the clamp and seal boot, and wherein the second rotor cup includes a first face and a second face, said second face defining an internal cavity configured to receive a second portion of the clamp and seal boot.

25. The rotary shaft seal according to claim 22, wherein the clamp defines a central bore therethrough configured to receive a shaft in a non-rotatable manner.

26. The rotary shaft seal according to claim 22, wherein the clamp includes (1) a first flange that extends from an outer surface of the clamp in an first radial outward direction, and (2) a second flange that extends from the outer surface of the clamp in a second radial outward direction, said second radial outward direction being opposite the first radial outward direction.

27. The rotary shaft seal according to claim 26, wherein the first flange defines a first hole configured to receive a first screw and the second flange defines a second hole configured to receive a second screw.

28. The rotary shaft seal according to claim 22, wherein the seal boot of the internal seal assembly defines a first radial aperture configured to receive the first flange of the clamp, and a second radial aperture for receiving the second flange of the clamp.

29. The rotary’ shaft seal according to claim 22, wherein the first rotor cup includes a first portion and a second portion, wherein the first portion is configured to be secured to the second portion via at least one screw.

30. The rotary shaft seal according to claim 22, wherein the second rotor cup includes a first portion and a second portion, wherein the first portion is configured to be secured to the second portion via at least one screw.

31. The rotary shaft seal according to claim 22, wherein the outer housing has an outer diameter that substantially corresponds to an outer diameter of the end plate, and wherein the rotary shaft seal defines a central bore therethrough configured to receive a shaft.

32. The rotary shaft seal according to claim 22, wherein at least a first wear plate of the plurality of wear plates is positioned on a first side of the internal seal assembly and is configured to be secured to the end plate, and wherein at least a second wear plate of the plurality of wear plates is positioned on a second side of the internal seal assembly and is configured to be secured to an inner facing surface within the internal cavity of the outer housing.

33. The rotary shaft seal according to claim 22, wherein the first rotor cup of the internal seal assembly is configured to rotate against a first side of a first wear plate of the plurality of wear plates, and the second rotor cup of the internal seal assembly is configured to rotate against a first side of a second wear plate of the plurality of wear plates.

34. The rotary’ shaft seal according to claim 23, wherein, under forces applied by the plurality of coil springs, the first rotor cup is configured to push outwardly toward an inner facing surface of the outer housing, and the second rotor cup is configured to push outw ardly tow ard an inner facing surface of the end plate.

35. The rotary shaft seal according to claim 23, wherein the plurality of coil springs provide a constant outer force on the first rotor cup and the second rotor cup so that as the first and rotor cup and second rotor cup rotate, against respectively adjacent wear plates, a seal is formed therebetween.

36. A method for assembling a rotary' shaft seal onto a vessel wall, wherein the rotary' shaft seal includes an end plate, a plurality of wear plates, an internal seal assembly, and an outer housing, the method comprising: sliding, over a shaft, an end plate, via a first bore hole defined therethrough, such that mounting holes defined in the end plate align with mounting holes in the vessel wall; sliding, over the shaft, at least a first wear plate of the plurality of wear plates, via a second bore hole defined therethrough, such that the at least the first wear plate is in facing engagement with an inner facing surface of the end plate; sliding, over the shaft, the internal seal assembly, via a third bore hole defined therethrough, until a first face of a first rotor cup of the internal seal assembly contacts the atleast the first wear plate, wherein the first rotor cup further includes a second face that defines a first plurality of axial spring holes; sliding, over the shaft, at least a second wear plate of the plurality of wear plates, via a fourth bore hole defined therethrough, until the at least the second wear plate is in facing engagement with the second rotor cup of the internal seal assembly; and sliding, over the shaft, the outer housing, via a fifth bore hole defined therethrough, until (i) the outer housing is positioned over the internal seal assembly and (ii) a plurality of mounting apertures defined in the outer housing align with the mounting holes of the end plate.

37. The method for assembling the rotary shaft seal onto the vessel wall according to claim 36, wherein each axial spring hole of the first plurality of axial spring holes extends a predetermined depth within the second face of the first rotor cup, and wherein sliding the internal seal assembly over the shaft includes inserting, into each axial spring hole of the first plurality of axial spring holes, a first portion of a respective coil spring.

38. The method for assembling the rotary shaft seal onto the vessel wall according to claim 36, wherein sliding the internal seal assembly over the shaft includes sliding, over the shaft, a clamp and securing the clamp to the shaft.

39. The method for assembling the rotary shaft seal onto the vessel wall according to claim 38, wherein the clamp includes a first flange that defines a hole therethrough configured to receive a first screw and a second flange defines a second hole therethrough configured to receive a second screw.

40. The method for assembling the rotary shaft seal onto the vessel wall according to claim 39, wherein sliding the internal seal assembly over the shaft further includes sliding, over the shaft, a seal boot such that the seal boot is positioned about an outer surface of the clamp.

41. The method for assembling the rotary shaft seal onto the vessel wall according to claim 40, wherein the seal boot defines a first radial aperture configured to receive the first flange of the clamp and a second radial aperture configured to receive the second flange of the clamp.

42. The method for assembling the rotary shaft seal onto the vessel wall according to claim 37, wherein sliding the internal seal assembly over the shaft includes sliding, over the shaft, the second rotor cup, said second rotor cup including a first face and a second face, said second face of the second rotor cup (i) inwardly faces the clamp and the seal boot and (ii) defines a second plurality of axial spring holes.

43. The method for assembling the rotary shaft seal onto the vessel wall according to claim 42, further comprising: positioning each axial spring hole, of the second plurality of axial spring holes of the second rotor cup, over a second portion of the respective coil spring.

44. The method for assembling the rotary shaft seal onto the vessel wall according to claim 36, further comprising: inserting bolts through aligned holes and apertures of the rotary shaft seal such that a respective bolt passes through a mounting aperture of the outer housing, a corresponding mounting hole of the end plate, and a corresponding hole in the vessel wall.

45. The method for assembling the rotary shaft seal onto the vessel wall according to claim 36, wherein the inner facing surface of the end plate defines a first annular channel configured to receive a first O-ring for forming a seal between the at least the first wear plate and the inner facing surface of the end plate.

Images