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JP-7855611-B2 - Sealing device for rods

JP7855611B2JP 7855611 B2JP7855611 B2JP 7855611B2JP-7855611-B2

Inventors

  • ヘルミッヒ， エグベルト
  • シュトファーズ， クリスティアン

Assignees

  • ハンメルマン ゲゼルシャフト ミット ベシュレンクテル ハフツング

Dates

Publication Date
20260508
Application Date
20220513
Priority Date
20210517

Claims (9)

  1. A sealing device for sealing a rod (2) that is translationally and/or rotationally movable within the high-pressure chamber (31) of a pressure- resistant housing (3) filled with a liquid medium, between a high-pressure chamber (31) and a low-pressure region (8), The seal cylinder (4) is housed within the housing (3) and forms a first annular gap (9) between the outer jacket surface (42) of the seal cylinder (4) and the inner wall (32) of the housing (3) that separates the high-pressure chamber (31). The inner diameter of the inner surface (41) of the seal cylinder (4) is sized such that the rod (2) is enclosed by the seal cylinder (4) while forming a second annular gap (10) that forms a dynamic seal. A pressing ring (5) is located near the low-pressure end face (44) and contacts the outer surface (42) of the jacket of the seal cylinder (4) to statically seal the first annular gap (9), and also deforms a portion of the inner surface (41) of the jacket of the seal cylinder (4) toward the rod (2). In a sealing device comprising a pressing ring (11) fixed to the housing (3) in a low-pressure region (8) and receiving a portion of the rod (2), thereby pressing the pressing ring (5) against the stepped projection of the pressure-resistant housing (3), maintaining the pressure of the seal cylinder (4) against the housing (3) and forming deformation of a portion of the inner surface (41) of the jacket of the seal cylinder (4), A seal ring (7) for statically sealing the first annular gap portion (9) is positioned in contact with the outer surface (42) of the seal cylinder (4) near the high-pressure side end face (45). The seal cylinder (4) has at least one connecting channel (43) extending from the outer surface (42) to the inner surface (41), The sealing device is characterized in that the position of the connection channel (43) is provided in a region away from the pressing ring (5) in order to prevent deformation of the seal cylinder (4), and is adapted to the material of the seal cylinder (4).
  2. The connecting channel (43) is introduced into the area of the jacket of the seal cylinder (4) between the pressing ring (5) and the seal ring (7), The sealing device according to claim 1, wherein the connecting channel (43) is spaced at least 10% of the distance between the pressing ring (5) and the sealing ring (7) from the pressing ring (5) or the sealing ring (7).
  3. The sealing device according to claim 2, wherein the connecting channel (43) is spaced at least 25% of the distance between the pressing ring (5) and the sealing ring (7) from the pressing ring (5) or the sealing ring (7).
  4. A sealing device according to any one of claims 1 to 3, wherein an annular receiving portion (47) is integrally formed on the outer surface (42) of the jacket of the seal cylinder (4) near the high-pressure side end face (45) of the seal cylinder (4), and the seal ring (7) is received within the receiving portion (47).
  5. The sealing device according to claim 4, wherein the receiving portion (47) of the ring is configured as a stepped portion extending from the high-pressure side end face (45) of the seal cylinder (4) into the outer surface (42) of the jacket of the seal cylinder (4).
  6. The sealing device according to any one of claims 1 to 3 , wherein the high-pressure side end face (45) of the seal cylinder (4) is covered by a ring cap (6).
  7. The sealing device according to any one of claims 1 to 3, wherein the sealing cylinder (4) has a collar (46) near the low-pressure side end face (44), and a pressing ring (5) is supported on the back side of the collar (46) which faces away from the low-pressure side end face ( 44 ).
  8. The sealing device according to any one of claims 1 to 3 , wherein the seal cylinder (4) is made of ceramic material.
  9. A device comprising a rod (2) that is translationally and/or rotationally movable within a high-pressure chamber (31) of a pressure-resistant housing (3) filled with a liquid medium, A seal cylinder (4) is provided to separate the high-pressure chamber (31) from the low-pressure region (8), and the seal cylinder (4) is received inside the housing (3), forming a first annular gap (9) between the annular outer surface (42) of the seal cylinder (4) and the inner wall (32) of the housing (3) that separates the high-pressure chamber (31). A portion of the rod (2) is received within the seal cylinder (4) to form a second annular gap (10) that forms a dynamic seal. A pressing ring (5) is positioned against the outer surface (42) of the seal cylinder (4) near the low-pressure end face (44) to statically seal the first annular gap (9) and to deform a portion of the inner surface (41) of the seal cylinder (4) toward the rod (2). In the low-pressure region (8), the pressing ring (11) that receives a portion of the rod (2) is fixed to the housing (3) and maintains a state in which the seal cylinder (4) is pressed into the housing (3), while the pressing ring (5) is pressed against the stepped projection of the pressure-resistant housing (3). In a device in which a portion of the inner surface (41) of the jacket of the seal cylinder (4) deforms toward the rod (2) by pressing the pressing ring (11) against the low-pressure end face of the housing (3) and the seal cylinder (4), A seal ring (7) for statically sealing the first annular gap portion (9) is placed on the outer surface (42) of the seal cylinder (4) near the high-pressure side end face (45). The seal cylinder (4) has at least one connecting channel (43) extending from the outer surface (42) to the inner surface (41), and the first annular gap portion (9) is connected to the second annular gap portion (10) via the connecting channel (43) so that fluid can pass through it. The device is characterized in that the position of the connection channel (43) is provided in a region away from the pressing ring (5) in order to prevent deformation of the seal cylinder (4) and is suited to the material of the seal cylinder (4).

Description

The present invention relates to a sealing device for a rod, comprising the preceding section of claim 1. A general sealing device is known, for example, from European Patent No. 1,353,096. In this publication, a seal ring is used to seal a rod, which moves in a transition region between a high-pressure region and a low-pressure region of a guide chamber of a housing that guides the rod. The seal ring surrounds the rod and is partially deformed by the high pressure in the high-pressure region with the help of a compression ring, so that the deformation of the seal ring reduces the gap between the seal ring and the rod to the extent that the rod leaks only a desired amount of fluid. Such gap sealing devices have been proven effective in practice. The problem is that, especially at very high pressures in the high-pressure range up to 3000 bar (3059 kgf/ cm² ) or 4000 bar (4079 kgf/ cm² ), the operating pressure applied to the outer surface of the seal cylinder becomes very large, and depending on the elastic modulus of the seal cylinder material, the seal cylinder may sometimes deform too much even in front of the pressure ring. Preferred embodiments are described in more detail below with reference to the accompanying drawings. This is a cross-sectional view of the rod and the housing surrounding it, which includes a seal cylinder located inside the housing. Figure 1 is a cross-sectional view of the apparatus, illustrating the typical pressures on the outer surface of the jacket and the inner surface of the seal cylinder during the pressure stroke of the apparatus. This is a representation corresponding to Figure 2 in the suction stroke of the device. In the following drawings, terms such as top, bottom, left, right, front, and rear refer only to exemplary representations and positions of the sealing device, housing, sealing cylinder, rod, annular gap, connecting channel, etc., selected in each drawing. These terms should not be understood restrictively; rather, different operating positions or mirror-symmetric designs may alter these criteria. In the following, a static seal is understood as a fluid seal between two bodies that do not move relative to each other. A dynamic seal is understood as a fluid seal or flow reduction to an acceptable level between two bodies that move relative to each other. Figures 1 to 3 show sealing devices for a rod 2 that extends between the high-pressure chamber 31 and the low-pressure region 8 of the housing 3, respectively. The rod 2 can be translated along its longitudinal axis L in the direction of translational movement T. The rod 2 can also be rotated. Rotational motion of the rod 2 about its longitudinal axis L is also possible. At least one portion of the rod 2 is movably mounted inside the housing 3. For example, in the region of the pressing ring 11, a seal cylinder 4 is provided to separate the high-pressure chamber 31 from the low-pressure region 8. This seal cylinder 4 is housed within the housing 3, forming a first annular gap 9 between the circumferential outer surface 42 of the seal cylinder 4 and the inner wall 32 of the housing 3, which forms the boundary of the high-pressure chamber 31. Furthermore, the thrust ring 11 shown in Figures 1 to 3 first supports the rod 2, and then presses the seal cylinder 4 into the housing 3, ensuring that the thrust ring 11 is securely screwed into the housing. Rod 2 passes through a passage in the seal cylinder 4, which is bounded by the inner surface 41 of the seal cylinder 4's jacket. The diameter of the inner surface 41 of the seal cylinder 4 is slightly larger than the diameter of the outer surface 42 of the rod 2. As a result, the rod 2, together with the seal cylinder 4, forms a dynamic seal also known as a gap seal. Such a gap seal is characterized in that, at the high-pressure end of the gap seal, high pressure is also present in the annular gap 10, but gradually decreases towards the low-pressure end of the annular gap 10. As mentioned at the beginning, and also referred to in European Patent No. 1 353 096, in order to maintain leakage as a result of using such a small throttle gap, a pressing ring 5 is provided near the low-pressure end face 44 on the outer surface 42 of the jacket of the seal cylinder 4, as shown in Figures 1 to 3. As soon as the thrust ring 11 is screwed into the housing 3, a portion of the inner surface 41 of the seal cylinder 4 deforms in the direction of the rod 2, thereby pressing the thrust ring 5 against the stepped shoulder of the housing 3. As a result of the force applied to the longitudinal axis L of the rod 2, the pressure ring 5 deforms. During this deformation, the pressure-resistant housing 3 resists expansion by the seal cylinder 4 itself from two sides and from a third side extending perpendicular to the direction of the force F in the axial direction of the rod 2. The pressure ring 5 generates a force, which is essentially directed radially toward the rod 2, causing the desired de