Seal gasket

Abstract

A seal gasket (20) for a vacuum pump, the seal gasket (20) comprising a first surface (30, 40), a second surface (32, 42) opposite the first surface (30, 40), opposing side walls (34, 36; 44, 46) disposed between the first surface (30, 40) and the second surface (32, 42), and one or more protrusions (48a, 48b, 48c, 48d) extending from the first surface.

Description

[Technical Field]

[0001] The present invention relates to a seal gasket for a vacuum pump and to a vacuum pump. [Background technology]

[0002] Rotary machines, such as compressors or pumps, require careful design and manufacture so that moving parts cooperate precisely with one another. Providing effective seals to seal the machines tends to be problematic, especially when fluid flow is driven by a pressure differential between the machine and the surrounding environment. It would be desirable to provide an improved seal. Summary of the Invention [Means for solving the problem]

[0003] In one aspect, a seal gasket for a vacuum pump is provided, the seal gasket comprising a first surface, a second surface opposite the first surface, an opposing sidewall disposed between the first surface and the second surface, and one or more protrusions extending from the first surface.

[0004] The seal gasket can include a plurality of protrusions extending from the first surface, and the protrusions can be spaced apart from one another at discrete locations across the first surface.

[0005] The one or more protrusions may extend substantially perpendicularly from the first surface.

[0006] Each of the protrusions can have a cross section that is a rounded polygon, for example a rounded square or a rounded rectangle.

[0007] Each protrusion may have a proximal end where the protrusion is connected to the first surface and a distal end opposite the proximal end. The length of the protrusion between the proximal and distal ends may be between 1 mm and 6 mm. The proximal end may be spaced apart from one or both of the opposing side walls in a direction from one side wall to the other. The proximal end may be spaced apart from the first side wall by a distance of 0.4 mm or less in a direction from one side wall to the other. The proximal end may be spaced apart from the second side wall by a distance of 0.4 mm or less in a direction from one side wall to the other.

[0008] The sealing gasket may be a one-piece gasket. The sealing gasket may be a molded gasket. The sealing gasket may be deformable. The gasket may be elastomeric.

[0009] The seal gasket can include a first seal member defining a closed shape, a second seal member defining a closed shape, a first longitudinal seal member coupled between the first seal member and the second seal member, and a second longitudinal seal member coupled between the first seal member and the second seal member. The first seal member and / or the second seal member can define a respective closed shape selected from the group of closed shapes consisting of an annular, a circular, an oval, an ellipse, a stadium, a rounded polygon, a rounded square, a rounded rectangle, and a squawk. Each of the first seal member and / or the second seal member can include a respective plurality of protrusions extending outward from an outer surface.

[0010] In a further aspect, there is provided a vacuum pump comprising a shell stator defining at least one pumping chamber, end pieces attachable to either end of the shell stator, and a sealing gasket as claimed in any of the claims.

[0011] The shell stator and / or end piece may define one or more seal grooves in which a seal gasket is positioned. The one or more seal grooves may include one or more voids extending from a sidewall of the seal groove. One or more protrusions may be received in each void. The voids may be slots.

[0012] For each protrusion and each void in which it is housed, the length of the void from the open end of the void to the closed end of the void may be greater than the length of the portion of the protrusion that is within the void, thereby allowing expansion of the protrusion within the void in a direction along the length of the protrusion.

[0013] For each protrusion and each cavity in which it is housed, the width of the cavity in a direction perpendicular to the direction from the open end of the cavity toward the closed end of the cavity can be less than or equal to the width of the portion of the protrusion that is within the cavity, thereby allowing for a tight fit of the protrusion within the cavity.

[0014] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram (not to scale) showing the housing of a vacuum pump. [Figure 2] FIG. 1 is a schematic diagram of a sealing gasket (not to scale). [Figure 3] 1 is a further schematic view of a sealing gasket (not to scale); FIG. [Figure 4] 1 is a schematic diagram (not to scale) showing a cross section of a sealing gasket. [Figure 5] 1 is a process flow chart illustrating certain steps of a method for assembling a seal gasket into a housing. [Figure 6] 1 is a schematic diagram (not to scale) showing a sealing gasket installed in a housing. [Figure 7]1 is a schematic diagram (not to scale) showing a portion of a sealing gasket within a housing. [Figure 8] FIG. 1 is a schematic diagram (not to scale) showing a portion of a housing. [Figure 9] 1 is a schematic diagram (not to scale) showing a further sealing gasket incorporated into the housing. [Figure 10] 1 is a schematic diagram (not to scale) showing an alternative sealing gasket. [Figure 11] 1 is a schematic diagram (not to scale) showing an alternative sealing gasket. [Figure 12] 10 is a schematic diagram (not to scale) showing a top view of a further sealing gasket; FIG. [Figure 13] 1 is a schematic diagram (not to scale) showing a perspective view of a further sealing gasket; [Figure 14] 10 is a schematic diagram (not to scale) showing a portion of a further sealing gasket disposed in a sealing groove formed in a shell stator of the housing. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] FIG. 1 is a schematic diagram (not to scale) illustrating a housing 10 of a vacuum pump according to one embodiment. The housing 10 comprises a pair of shell stators 12, 14 and a pair of end plates 16, 18. The shell stators 12, 14 define recesses that receive components of the vacuum pump. The shell stators 12, 14 fit together to hold the components within the recesses. The end plates 16, 18 are then brought to hold the shell stators 12, 14. This allows for convenient assembly of the vacuum pump.

[0017] In other words, the vacuum pump housing 10 may be formed from multiple components, including shells 12, 14 and end plates 16, 18, which must be sealed together when assembled. In the configuration shown in Figure 1, the stator is formed by assembling two housing parts or shells 12, 14 held between a pair of end plates 16, 18.

[0018] As will be described in more detail below, in this embodiment, one or more (e.g., two) longitudinal seals are disposed along the mating surfaces of the shell stators 12, 14 to properly seal the shell stators 12, 14. Additionally, a pair of annular seals are disposed between the end plates 16, 18 and the shell stators 12, 14 to ensure a proper seal between the shell stators 12, 14 and their respective end plates 16, 18.

[0019] FIG. 2 is a schematic diagram (not to scale) of a sealing gasket 20 for sealing the housing 10, according to one embodiment.

[0020] The seal gasket 20 includes a first seal member 22, a second seal member 24, a first longitudinal seal member 26, and a second longitudinal seal member 28.

[0021] In this embodiment, the first and second seal members 22, 24 are generally annular seal members. However, in other embodiments, the first and second seal members 22, 24 can have or define a different shape, preferably a closed shape such as an oval, an ellipse, a stadium, a rounded square, a squircle, a rounded rectangle, or a rounded polygon.

[0022] The first seal member 22 includes a first annular surface 30, a second annular surface 32 opposite the first annular surface 30, a first radially inner surface 34, and a first radially outer surface 36 opposite the first radially inner surface 34. The first radially inner surface 34 and the first radially outer surface 36 are disposed between the first annular surface 30 and the second annular surface 32.

[0023] The second seal member 24 includes a third annular surface 40, a fourth annular surface 42 opposite the third annular surface 40, a second radially inner surface 44, and a second radially outer surface 46 opposite the second radially inner surface 44. The second radially inner surface 44 and the second radially outer surface 46 are disposed between the third annular surface 40 and the fourth annular surface 42.

[0024] The first longitudinal seal member 26 is bonded or attached between the first radially outer surface 36 (of the first annular seal member 22) and the second radially outer surface 46 (of the second annular seal member 24).

[0025] The second longitudinal seal member 28 is coupled or attached between the first radially outer surface 36 (of the first annular seal member 22) and the second radially outer surface 46 (of the second annular seal member 24).

[0026] The second longitudinal seal member 28 is disposed opposite the first longitudinal seal member 26. That is, the second longitudinal seal member 28 is coupled to the first and second annular seal members 22, 24 on the opposite side of the first and second annular seal members 22, 24 from the side on which the first longitudinal seal member 26 is coupled to the first and second annular seal members 22, 24.

[0027] The first annular seal member 22 is a ring-shaped seal member and has a square or rectangular cross section.

[0028] The second annular seal member 24 is a ring-shaped seal member and has a square or rectangular cross section.

[0029] The first longitudinal seal member 26 may be an O-ring cord. The first longitudinal seal member 26 has a square or rectangular cross section.

[0030] The second longitudinal seal member 28 may be an O-ring cord. The second longitudinal seal member 28 has a square or rectangular cross section.

[0031] In this embodiment, the sealing gasket 20 is a continuous, one-piece sealing gasket.

[0032] In this embodiment, the seal gasket 20 includes a plurality of protrusions 48a, 48b, 48c, and 48d. More specifically, the seal gasket 20 includes a first plurality of protrusions 48a extending vertically from the first annular surface 30. The seal gasket 20 also includes a second plurality of protrusions 48b extending vertically from the third annular surface 40. The seal gasket 20 also includes a third plurality of protrusions 48c extending vertically from the upper surface (in the orientation of FIG. 1 ) of the first longitudinal seal member 26. The seal gasket 20 also includes a fourth plurality of protrusions 48d extending vertically from the upper surface (in the orientation of FIG. 1 ) of the second longitudinal seal member 28.

[0033] Preferably, the plurality of protrusions 48a, 48b, 48c, 48d are of substantially the same shape and size.

[0034] The sealing gasket 20 is made of a deformable or flexible material, such as an elastomeric material (e.g., a fluoroelastomer (FKM / FPM) or a perfluoroelastomer (FFKM)) or silicone, such that the sealing gasket 20 is deformable or flexible. Thus, the sealing gasket 20 can be deformed into a desired shape or configuration suitable for use as a seal for the housing 10.

[0035] FIG. 3 is a schematic diagram (not to scale) showing the sealing gasket 20 modified into a configuration suitable for sealing the housing 10.

[0036] In this configuration, the first and second seal members 22, 24 are rounded squares, i.e., defined squares, with curved or rounded corners. This configuration has major surfaces (first and second radially inner and outer surfaces 34, 36 of the first seal member 22 and second and second radially inner and outer surfaces 44, 46 of the second annular seal member 24) that abut major surfaces of the end plates 16, 18 and adjacent surfaces of the shell stators 12, 14 in use. In this example, the first and second seal members 22, 24 have substantially planar axial outer surfaces provided by the first and second radially inner and outer surfaces 34, 44, respectively. The first and second seal members 22, 24 have substantially planar axial inner surfaces provided by the first and second radially outer surfaces 36, 46, respectively. The longitudinal seal members 26, 28 are coupled between the opposing axially inner surfaces of the annular seal members 22, 24 (i.e., between the first radially outer surface 36 and the second radially outer surface 46). The annular seal members 22, 24 have a substantially constant thickness.

[0037] In this configuration, the first annular surface 30 of the first seal member 22 is moved or rotated to define a radially outer wall of the first seal member 22. Accordingly, each protrusion 48a of the first plurality of protrusions 48a extends radially outward from the first annular surface 30.

[0038] Similarly, in this configuration, the third surface 40 of the second seal member 24 is moved or rotated to define a radially outer wall of the second seal member 24. Thus, each protrusion 48b of the second plurality of protrusions 48b extends radially outward from the third surface 30.

[0039] In this configuration, the first longitudinal seal member 26 is moved or rotated so that each protrusion 48c of the third plurality of protrusions 48c extends outward from the seal gasket 20 in a direction substantially perpendicular to the direction along the length of the seal gasket 20.

[0040] Similarly, in this configuration, the second longitudinal seal member 28 has been moved or rotated so that each protrusion 48d of the fourth plurality of protrusions 48d extends outward from the seal gasket 20 in a direction substantially perpendicular to the direction along the length of the seal gasket 20 and in the opposite direction to the direction in which the protrusions 48c extend.

[0041] FIG. 4 is a schematic diagram (not to scale) showing a cross section through the sealing gasket 20 at the location of the protrusion 48.

[0042] 4 shows a cross section through first seal member 22 along the length of first protrusion 48a. Those skilled in the art will appreciate that second, third and fourth pluralities of protrusions 48b-d may be similarly formed.

[0043] In this embodiment, the protrusion 48 a extends substantially perpendicularly from the first annular surface 30 away from the first seal member 20 .

[0044] Preferably, protrusion 48a has a cross section in the shape of a rounded polygon. In this embodiment, the cross section of protrusion 48a taken in a plane perpendicular to the page in Figure 4 and indicated by dotted line 50 has the shape of a rounded square or a rounded rectangle.

[0045] The protrusion 48 a includes a proximal end 52 where the protrusion 48 a connects to the first annular surface 30 , and a distal end 54 opposite the proximal end 52 .

[0046] The length l1 of the protrusion 48a between the proximal end 52 and the distal end 54 may depend on the application. For example, the length l1 may be between about 1 mm and 6 mm, or between about 2 mm and 5 mm, or between about 3 mm and 5 mm, with a preferred value for l1 being about 4 mm, for example.

[0047] In this embodiment, the proximal end 52 is spaced a first distance d1 from the first radially inner surface 34 (in a direction along the first annular surface 30). The first distance d1 may depend on the application. For example, the first distance d1 may be about 0.4 mm or less, or about 0.3 mm or less, or about 0.2 mm or less, or about 0.1 mm or less; for example, a preferred value for d1 may be about 0.1 mm.

[0048] In this embodiment, the proximal end 52 is spaced from the first radially outer surface 36 (in a direction along the first annular surface 30) by a second distance d2. Preferably, the second distance d2 is approximately equal to the first distance d1. The second distance d2 may depend on the application. For example, the second distance d2 may be about 0.4 mm or less, or about 0.3 mm or less, or about 0.2 mm or less, or about 0.1 mm or less. For example, a preferred value for d2 may be about 0.1 mm.

[0049] In this embodiment, the protrusion 48a is tapered along its length, i.e., the width w1 of the protrusion 48a decreases (e.g., linearly) from the proximal end 52 to the distal end 54.

[0050] FIG. 5 is a process flow diagram illustrating certain steps (s50-s58) of a method 500 for fitting, installing, or assembling a sealing gasket 20 to a housing 10.

[0051] FIG. 6 is a schematic diagram (not to scale) showing the assembly of sealing gasket 20 into housing 10 that is useful in understanding the process of FIG.

[0052] In step s50, a shell stator 14 is provided into which vacuum pump components (not shown) are assembled.

[0053] In step s52, the sealing gasket 20 is positioned relative to the shell stator 14 such that the first and second longitudinal sealing members 26, 28 are positioned within sealing grooves extending along the mating surface of the shell stator 14. This can be as shown in FIG.

[0054] In step s54, the shell stator 12 is brought into intimate contact with the longitudinal seal members 26,28.

[0055] Referring to FIG. 6, the shell stator 12 can be moved onto the longitudinal seal members 26, 28 toward the mating surface of the shell stator 14 as indicated by the arrow and reference numeral 60 in FIG.

[0056] In step s56, the shell stators 12, 14 are clamped together, which compresses the longitudinal seal members 26, 28.

[0057] Thus, after step s56, the annular seal members 22,24 tend to extend or protrude axially from the axial ends of the assembled shell stators 12,14.

[0058] In step s58, the end plates 16, 18 are brought together to compress the annular seals 22, 24 axially (ie, longitudinally).

[0059] The annular seal members 22,24 are positioned in annular seal grooves positioned in the shell stators 12,14 and / or end plates 16,18.

[0060] 6, end plate 18 is shown moved onto first annular seal member 22 at a first end of assembled shell stators 12, 14. End plate 16 can be moved onto second annular seal member 24 at a second end (opposite the first end) of assembled shell stators 12, 14, as indicated by arrow and reference numeral 62 in FIG.

[0061] Thus, a method for fitting, mounting, or assembling the sealing gasket 20 to the housing 10 is provided.

[0062] In this embodiment, the seal gasket 20 is positioned in a seal groove formed in one or both of the shell stators 12, 14 and / or end plates 16, 18. The seal groove includes a plurality of voids or slots into which each of the protrusions 48a-d is received.

[0063] 7 is a schematic diagram (not to scale) illustrating one example of a seal groove 70 into which the first seal member 22 of the seal gasket 20 fits. Other portions of the seal gasket 20 may be positioned in other seal grooves in a similar or identical manner.

[0064] The seal groove 70 is a closed-shaped seal groove and may have, for example, an annular, loop-shaped, ring-shaped, oval, elliptical, rounded square or rounded rectangular shape (i.e., a square or rectangle with rounded corners), squircle, or rounded polygonal shape.

[0065] The seal grooves 70 may be formed in the end faces of the shell stators 12, 14 or the end plates 16, 18.

[0066] The seal groove 70 includes a void or slot 72 that extends outward from a sidewall of the seal groove, specifically an outer wall 73 of the seal groove 70. At least a portion of the protrusion 48a of the first seal member 22 is positioned within the slot 72.

[0067] In this embodiment, the length l2 of the slot 72 from the opening or open end 74 of the slot 72 to the closed end 76 of the slot 72 is greater than the length l3 of the portion of the protrusion 48a located within the slot 72. Accordingly, a gap 78 exists between the distal end 54 of the protrusion 48a and the closed end 76 of the slot 72. This advantageously tends to allow expansion of the protrusion 48a within the slot 72 in a direction along the length of the protrusion, for example, due to heating and / or compression of the sealing gasket 20.

[0068] In this embodiment, the width w2 of the slot 72 (width w2 is in a direction perpendicular to the length l2 of the slot 72) is equal to or less than the width of the portion of the protrusion 48a that is within the slot 72. This advantageously tends to provide an interference fit of the protrusion 48a within the slot 72. Thus, during assembly (e.g., during step s52 of method 500 of FIG. 5 ), the sealing gasket 20 tends to be held in place by the protrusions 48a-d being held or gripped within the slot 72. Twisting or movement of the sealing gasket 20 out of the seal groove tends to be reduced or eliminated. This tends to reduce the likelihood of the sealing gasket 20 becoming dislodged from its position in the assembled system, thus reducing the likelihood of gas leakage.

[0069] Preferably, the first seal member 22 is thinner than the seal groove 70. Also, preferably, the width w1 of the protrusion 48a near its proximal end is sufficiently greater than the opening 74 of the slot 72 so that that portion of the protrusion 48a cannot fit into the slot 72. This tends to advantageously allow the first seal member 22, distal from the protrusion 48a, to be within the seal groove 70 but spaced apart from the outer wall 73 of the seal groove 70, i.e., there is a gap 80a between the first seal member 22 and the outer wall 73. Furthermore, in this embodiment, when the first seal member 22 is fitted into the seal groove 70 and the protrusion 48a is received in the slot 72 (as shown in FIG. 7 ), the first seal member 22 is spaced apart from the inner wall 82 of the seal groove 70, i.e., there is a gap 80b between the first seal member 22 and the inner wall 82 (the inner wall 82 faces the outer wall 73). This advantageously tends to allow expansion of the first seal member 22 within the seal groove 70 due to, for example, heating and / or compression of the seal gasket 20. This also advantageously tends to facilitate installation of the seal gasket into the housing 10.

[0070] FIG. 8 is a schematic diagram (not to scale) showing the seal groove 70 and slot 72 without the seal gasket 20 disposed therein.

[0071] In this embodiment, there is a step 84 between the bottom surface 86 of the seal groove 70 and the opening 74 of the slot 72. Preferably, the magnitude of the step 84 along the outer wall 73 from the bottom surface 86 of the seal groove 70 to the opening 74 is substantially the same as the first distance d1 and / or the second distance d2.

[0072] The sealing gasket tends to be easy to mount to the housing or vacuum pump.

[0073] Advantageously, the seal gaskets described herein tend to be relatively easy to manufacture compared to conventional seal assemblies. For example, seal gaskets tend to be relatively easy to manufacture by molding. For example, the seal gasket can be molded as a single piece, a substantially planar or flat article (such as shown in FIG. 2 and described in more detail above), in a mold, and then deformed or manipulated into a desired shape or configuration (e.g., as shown in FIG. 3 and described in more detail above). Molding can be performed using a mold having a first portion including a recess in the desired shape of the seal gasket, and a substantially planar second portion can be positioned over the recess in the first portion, thereby defining a mold cavity in which the seal gasket can be formed. Advantageously, seal gaskets formed in this manner tend to be free of parting lines (where two different surfaces of a mold meet). Therefore, the likelihood of separation of the seal gasket tends to be significantly reduced. Additionally, any mold flash present on the molded seal gasket tends to be limited to non-critical areas of the seal gasket, such as areas extending outward from the top surface of the seal gasket when oriented as in Figure 2. This tends to improve the robustness and stability of the seal gasket.

[0074] The sealing gasket can be designed to be slightly shorter than the longitudinal groove (i.e., gasket groove) in the shell stator to reduce tension during assembly, which tends to self-align regardless of the depth of the annular groove.

[0075] Advantageously, the seal gasket may be molded with its sides in one plane (i.e., the configuration of FIG. 2). This tends to result in a continuous sealing surface with no parting lines from the mold sidewall, which ensures a highly reliable sealing surface. This one-piece seal shape can be reconfigured to fit the seal housing using only bending; the seal does not require twisting of any sections.

[0076] It should be understood that the cord and gasket may have various shapes or thicknesses to suit the configuration of the housing.

[0077] In the above embodiments, the seal gasket is a continuous, one-piece seal gasket. However, in other embodiments, the seal gasket comprises multiple separate parts that are joined together. The multiple parts can be joined together by any joining means or method, such as using an adhesive, using fusing, or using an interference fit.

[0078] In the above embodiments, the seal gasket has a substantially constant cross-section across the part. However, in other embodiments, the seal gasket has a non-constant cross-section.

[0079] In the above embodiments, the sealing gasket has a square or rectangular cross section. However, in other embodiments, some or all of the sealing gasket has an alternative cross section other than square or rectangular, such as circular, triangular, oval, etc.

[0080] In the above embodiments, the sealing gasket may be made of an elastomer. In some embodiments, the sealing gasket may be made of another deformable material, such as a metal.

[0081] It will be appreciated that although the major surfaces of the sealing gaskets in the above embodiments are substantially planar, they may be of any suitable shape suitable for engaging the major surfaces of the end plates and the adjacent surfaces of the shell stators.

[0082] 2 shows 16 protrusions on the seal gasket, one skilled in the art would understand that any suitable number of protrusions and corresponding slots in the seal groove could be implemented. The greater the number of protrusions and slots, the less likely the seal gasket will exit the seal groove.

[0083] In the above embodiment, the protrusion has a shape as described in more detail with reference to Figure 4. Specifically, the protrusion has a rounded square or rounded rectangular cross-section, tapers inwardly along its length from the proximal end to the distal end, and extends in one direction from the body of the seal gasket. However, in other embodiments, the protrusion has a different suitable shape or configuration.

[0084] 9 is a schematic diagram (not to scale) illustrating a further embodiment of a sealing gasket 90. In this embodiment, the protrusion 92 is a substantially L-shaped or hook-shaped protrusion that fits or plugs into a correspondingly shaped cavity 94 in the housing 10.

[0085] In the above embodiment, the sealing gasket may be manufactured as a substantially planar or flat article by molding as a single piece, as shown in Figure 2. However, in other embodiments, the sealing gasket may be manufactured in various ways by molding as a substantially planar or flat article by molding as a single piece, as shown, for example, in Figure 10 (see single piece, substantially planar or flat gasket 130) or Figure 11 (see single piece, substantially planar or flat gasket 140).

[0086] In some embodiments, the sealing gasket includes an annular sealing member that seals against the end plate in use. However, these sealing members can have shapes other than strictly annular. The sealing member defines a closed shape, and can define a closed shape other than annular, such as a loop, a ring, an oval, an ellipse, an oval, a rounded square or a rounded rectangle (i.e., a square or rectangle with rounded corners), a squircle, or a rounded polygon.

[0087] Next, an embodiment will be described in which the sealing member that seals the endplate in use defines a rounded square, i.e., substantially a squircle.

[0088] 12 and 13 are schematic illustrations (not to scale) of a further sealing gasket 150 for sealing the housing 10, according to one embodiment.

[0089] The seal gasket 150 includes a first seal member 151 , a second seal member 152 , a first longitudinal seal member 153 , and a second longitudinal seal member 154 .

[0090] The first seal member 151 defines a closed shape. Specifically, in this embodiment, the first seal member 151 defines a rounded square, i.e., a square with rounded corners, or substantially a squircle.

[0091] First seal member 151 includes a first rounded square surface 161, a second rounded square surface 162 opposite first rounded square surface 161, a first inner surface 163, and a first outer surface 164 opposite first inner surface 163. First inner surface 163 and first outer surface 164 are disposed between first rounded square surface 161 and second rounded square surface 162.

[0092] The first seal member 151 includes a first curved section 165 a, a second curved section 165 b, a third curved section 165 c, a fourth curved section 165 d, a first substantially straight section 166 a disposed between the first curved section 165 a and the second curved section 165 b, a second substantially straight section 166 b disposed between the second curved section 165 b and the third curved section 165 c, a third substantially straight section 166 c disposed between the third curved section 165 c and the fourth curved section 165 d, and a fourth substantially straight section 166 d disposed between the fourth curved section 165 d and the first curved section 165 a. The first longitudinal seal member 153 is coupled to the first curved section 165 a. The second longitudinal seal member 154 is coupled to the third curved section 165c.

[0093] The first seal member 151 includes a first plurality of protrusions 178a. The first plurality of protrusions 178a extend perpendicularly from the first rounded square surface 161. In this embodiment, there are eight protrusions 178a in the first plurality of protrusions 178a. However, in other embodiments, there may be a different number of protrusions 178a in the first plurality of protrusions 178a.

[0094] In this embodiment, a first plurality of protrusions 178a are positioned at each boundary between the straight and curved sections of the first seal member 151. Protrusion 178a is positioned at the boundary between first curved section 165a and first substantially straight section 166a. Protrusion 178a is positioned at the boundary between first substantially straight section 166a and second curved section 165b. Protrusion 178a is positioned at the boundary between second curved section 165b and second substantially straight section 166b. Protrusion 178a is positioned at the boundary between second substantially straight section 166b and third curved section 165c. Protrusion 178a is positioned at the boundary between third curved section 165c and third substantially straight section 166c. Additionally, protrusion 178a is positioned at the boundary between third substantially straight section 166c and fourth curved section 165d, and protrusion 178a is positioned at the boundary between fourth substantially straight section 166d and first curved section 165a.

[0095] The second seal member 152 defines a closed shape. Specifically, in this embodiment, the second seal member 152 defines a rounded square, i.e., a square with rounded corners, or substantially a squircle.

[0096] Second seal member 152 includes a third rounded square surface 171, a fourth rounded square surface 172 opposite third rounded square surface 171, a second inner surface 173, and a second outer surface 174 opposite second inner surface 173. Second inner surface 173 and second outer surface 174 are disposed between third rounded square surface 171 and fourth rounded square surface 172.

[0097] The second seal member 152 includes a fifth curved section 175 a, a sixth curved section 175 b, a seventh curved section 175 c, an eighth curved section 175 d, a fifth substantially straight section 176 a disposed between the fifth curved section 175 a and the sixth curved section 175 b, a sixth substantially straight section 176 b disposed between the sixth curved section 175 b and the seventh curved section 175 c, a seventh substantially straight section 176 c disposed between the seventh curved section 175 c and the eighth curved section 175 d, and an eighth substantially straight section 176 d disposed between the eighth curved section 175 d and the fifth curved section 175 a. The first longitudinal seal member 153 is coupled to the fifth curved section 175 a. The second longitudinal seal member 154 is coupled to the seventh curved section 175c.

[0098] The second seal member 152 includes a second plurality of protrusions 178b. The second plurality of protrusions 178b extend perpendicularly from the third rounded square surface 171. In this embodiment, there are eight protrusions 178b in the second plurality of protrusions 178b. However, in other embodiments, there may be a different number of protrusions 178b in the second plurality of protrusions 178b.

[0099] In this embodiment, the second plurality of protrusions 178b are positioned at each boundary between the straight and curved sections of the second seal member 152. Protrusion 178b is positioned at the boundary between fifth curved section 175a and fifth substantially straight section 176a. Protrusion 178b is also positioned at the boundary between fifth substantially straight section 176a and sixth curved section 175b. Protrusion 178b is also positioned at the boundary between sixth curved section 175b and sixth substantially straight section 176b. Protrusion 178b is also positioned at the boundary between sixth substantially straight section 166b and seventh curved section 175c. Protrusion 178b is also positioned at the boundary between seventh curved section 175c and seventh substantially straight section 176c. Additionally, protrusion 178b is positioned at the boundary between seventh substantially straight section 176c and eighth curved section 175d. Also, protrusion 178b is positioned at the boundary between eighth curved section 175d and eighth substantially straight section 176d. Also, protrusion 178b is positioned at the boundary between eighth substantially straight section 176d and fifth curved section 175a.

[0100] The first longitudinal seal member 153 is coupled or attached between the first outer surface 164 (of the first seal member 151) and the second outer surface 174 (of the second seal member 152).

[0101] The first longitudinal seal member 153 includes a third plurality of protrusions 178c extending perpendicularly therefrom. In this embodiment, there are two protrusions 178c in the third plurality of protrusions 178c. However, in other embodiments, there may be a different number of protrusions 178c in the third plurality of protrusions 178c.

[0102] The second longitudinal seal member 154 is coupled or attached between the first outer surface 164 (of the first seal member 151) and the second outer surface 174 (of the second seal member 152).

[0103] The second longitudinal seal member 154 is disposed opposite the first longitudinal seal member 153. That is, the second longitudinal seal member 154 is coupled to the first and second seal members 151, 152 on the opposite side of the first and second seal members 151, 152 from the side to which the first longitudinal seal member 153 is coupled to the first and second seal members 151, 152.

[0104] The second longitudinal seal member 154 includes a fourth plurality of protrusions 178d extending perpendicularly therefrom. In this embodiment, there are two protrusions 178d in the fourth plurality of protrusions 178d. However, in other embodiments, there may be a different number of protrusions 178d in the fourth plurality of protrusions 178d.

[0105] Preferably, the plurality of protrusions 178a-d are substantially the same shape and size.

[0106] The first seal member 151 has a square or rectangular cross section, and the second seal member 152 has a square or rectangular cross section.

[0107] The first longitudinal seal member 153 may be an O-ring cord. The first longitudinal seal member 153 may have a square or rectangular cross section.

[0108] The second longitudinal seal member 154 may be an O-ring cord. The second longitudinal seal member 154 may have a square or rectangular cross section.

[0109] In this embodiment, the sealing gasket 150 is a continuous, one-piece sealing gasket.

[0110] The sealing gasket 150 is made of a deformable or flexible material, such as an elastomeric material (e.g., a fluoroelastomer (FKM / FPM) or a perfluoroelastomer (FFKM)) or silicone, such that the sealing gasket 150 is deformable or flexible. Thus, the sealing gasket 150 can be deformed into a desired shape or configuration suitable for use as a seal for the housing 10.

[0111] The sealing gasket 150 can be mounted within the housing 10, for example, as described in detail above with reference to FIG. 5. In this manner, the first and second longitudinal sealing members 153, 154 can be disposed in sealing engagement with the shell stators 12, 14, which can be clamped together to compress the longitudinal sealing members 153, 154. Additionally, the rounded square sealing members 151, 152 can be positioned within closed-shaped seal grooves positioned in the shell stators 12, 14 and / or end plates 16, 18. The seal grooves can have any suitable closed shape, such as annular, circular, oval, elliptical, stadium-shaped, rounded square, squircle, rounded rectangle, rounded polygon, etc.

[0112] 14 is a schematic diagram (not to scale) showing a first seal member 151 fitted into a closed seal groove 177 located in the shell stators 12, 14. In this embodiment, the seal groove 177 defines a rounded square or a rounded rectangle. In this embodiment, the second seal member 152 may be fitted into a substantially identical closed seal groove 177 at the opposite end of the shell stators 12, 14.

[0113] In this embodiment, curved sections 165a-d of first seal member 151 are positioned in respective substantially straight portions of seal groove 177. Also, substantially straight sections 166a-d of first seal member 151 are positioned in respective curved portions of seal groove 177.

[0114] In detail, the first curved section 165a is disposed in a first substantially linear portion 180a of the seal groove 177, the second curved section 165b is disposed in a second substantially linear portion 180b of the seal groove 177, the third curved section 165c is disposed in a third substantially linear portion 180c of the seal groove 177, the fourth curved section 165d is disposed in a fourth substantially linear portion 180d of the seal groove 177, the first substantially linear section 166a is disposed in a first curved portion 182a of the seal groove 177, the second substantially linear section 166b is disposed in a second curved portion 182b of the seal groove 177, the third substantially linear section 166c is disposed in a third curved portion 182c of the seal groove 177, and the fourth substantially linear section 166d is disposed in a fourth curved portion 182d of the seal groove 177.

[0115] As described above, a substantially rounded square seal element is disposed within the rounded square seal groove, with the curved sections of the rounded square seal element positioned within the substantially straight portion of the seal groove and the substantially straight section of the seal element positioned within the curved portion of seal groove 177. This advantageously tends to reduce stress on the rounded square seal element. Specifically, compound bending and / or twisting of the seal element during installation within the seal groove tends to be reduced compared to seal elements of other shapes. This tends to improve seal life. Furthermore, retention of the seal element within the seal groove retainer tends to be improved. For example, reduced twisting and / or compound bending of the seal element tends to reduce the likelihood of the seal element twisting out of the seal groove.

[0116] The protrusions 178a-d are an interference fit in their respective slots, which advantageously improves retention of the seal member within the seal groove and tends to reduce the likelihood of leakage.

[0117] Although exemplary embodiments of the present invention are disclosed in detail herein with reference to the accompanying drawings, it should be understood that the present invention is not limited to the precise embodiments, and that various changes and modifications may be made therein by those skilled in the art without departing from the scope of the present invention as defined by the appended claims and their equivalents. [Explanation of symbols]

[0118] 10. Housing 12, 14 Shell stator 16, 18 End plates 20 Sealing gasket 22 first annular seal member 24 second annular seal member 26 first longitudinal seal member 28 second longitudinal seal member 30 First Annular Surface 32 Second Annular Surface 34 first radially inner surface 36 first radially outer surface 40 Third Annular Surface 42 Fourth Circular Surface 44 second radially inner surface 46 second radially outer surface 48a-d Protrusion 50 planes 52 proximal end 54 distal end s50-s58 method steps 60, 62 direction 70 Seal groove 72 slots 73 Exterior Wall 74 Open End 76 Closed end 78 Gap 80a gap 80b gap 82 Inner wall 84 steps 86 bottom 90 Seal gasket 92 Protrusion 94 void 130, 140 Seal gasket 150 Seal Gasket 151 first seal member 152 second seal member 153 first longitudinal seal member 154 second longitudinal seal member 161 First Rounded Square Surface 162 Second Rounded Square Surface 163 first inner surface 164 first outer surface 165a-d Curved part 166a-d Straight section 171 Third Rounded Square Surface 172 Fourth Rounded Square Surface 173 Second inner surface 174 Second outer surface 175a-d Curved part 176a-d Straight section 178a-d Projections 180a-d Curved part 182a-d Straight section

Claims

1. A seal gasket for a vacuum pump, The first surface and The second surface opposite to the first surface, A side wall on the opposite side, positioned between the first surface and the second surface, A first sealing member that defines a closed shape, A second sealing member that defines a closed shape, A first longitudinal sealing member is coupled between the first sealing member and the second sealing member, A second longitudinal sealing member is coupled between the first sealing member and the second sealing member, Equipped with, The aforementioned seal gasket is a molded, deformable, one-piece gasket. The first sealing member, the second sealing member, the first longitudinal sealing member, and the second longitudinal sealing member have a square or rectangular cross-section. The first sealing member and the second sealing member are coupled between their opposing axial inner surfaces. One or more protrusions extend radially outward from the first surface that defines the radial outer wall of the first sealing member. Seal gasket.

2. The seal gasket according to claim 1, comprising a plurality of projections extending from the first surface at separate positions and spaced apart from each other across the first surface.

3. The seal gasket according to claim 1, wherein one or more of the protrusions extend perpendicularly from the first surface.

4. The seal gasket according to claim 1, wherein each of the protruding portions has a cross-section, and the shape of the cross-section is a rounded polygon, for example, a rounded square or a rounded rectangle.

5. Each of the one or more of the aforementioned protrusions is The protruding portion has a proximal end that is connected to the first surface, The distal end opposite to the proximal end, Equipped with, The seal gasket according to claim 1, wherein the length of the protrusion between the proximal end and the distal end is between 1 mm and 6 mm.

6. Each of the one or more of the aforementioned protrusions is The protruding portion has a proximal end that is connected to the first surface, The distal end opposite to the proximal end, Equipped with, The seal gasket according to claim 1, wherein the proximal end is spaced apart from one or both of the opposite side walls in the direction from one side wall to the other side wall.

7. The proximal end is spaced at a distance of 0.4 mm or less from the first side wall in the direction from one side wall to the other side wall, and / or The seal gasket according to claim 6, wherein the proximal end is spaced at a distance of 0.4 mm or less from the second side wall in the direction from one side wall to the other side wall.

8. The seal gasket according to claim 1, wherein the seal gasket is an elastomer.

9. The seal gasket according to claim 1, wherein the first seal member and the second seal member define a closed shape selected from the group of closed shapes consisting of annular, circular, oval, elliptical, stadium-shaped, rounded polygon, rounded square, rounded rectangle, and square.

10. The seal gasket according to claim 1, wherein each of the first seal member and the second seal member is provided with a plurality of the protrusions that extend outward from the radial outer wall of the first seal member and the second seal member, respectively.

11. A shell stator defining at least one pump chamber, An end piece that can be attached to any end of the aforementioned shell stator, The seal gasket according to claim 1, A vacuum pump equipped with, The shell stator and / or the end piece define one or more seal grooves in which the seal gasket is positioned. The one or more seal grooves are provided with one or more gaps extending from the side walls of the seal grooves. The one or more protrusions are housed in the respective gaps, and the vacuum pump is provided.

12. The vacuum pump according to claim 11, wherein the gap is a slot.

13. The vacuum pump according to claim 11, wherein, with respect to the protrusion and the void in which the protrusion is housed, the length of the void from the open end to the closed end is greater than the length of the portion of the protrusion within the void, thereby allowing the protrusion within the void to expand in a direction along the length of the protrusion.

14. The vacuum pump according to claim 11, wherein, with respect to the protrusion and the void in which the protrusion is housed, the width of the void in a direction perpendicular to the direction from the open end of the void to the closed end of the void is less than or equal to the width of the portion of the protrusion located within the void, thereby enabling the protrusion to be tightly fitted within the void.

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