RU2711773C1 - Soft landing cylinder - Google Patents

Abstract

FIELD: machine building.SUBSTANCE: invention relates to the machine building. Cylinder of soft fit comprises housing with multiple outlets made in lower part of cylinder and multiple outlets. In housing there is a piston chamber made so that it can be filled with water by means of recharging unit arranged in cover. Piston is located in piston chamber with possibility of longitudinal movement. Upper part of the rod is connected to the piston, and the lower one – contains the angular deviation leveling unit. When the rod collides and the piston moves from the lower position to the upper position, water is discharged through the plurality of outlet openings thus providing impact damping.EFFECT: acceleration of cylinder recharging process with simultaneous provision of leveling of angular deflection of rod.8 cl, 6 dwg

Description

FIELD OF THE INVENTION

The present invention relates to a soft landing cylinder, which absorbs shock load during installation of equipment of the subsea production system on a base located on sea soil using hydraulic resistance of water.

BACKGROUND

Shock absorbers used when installing underwater structures on a base located on the seabed that dampen the shock load or reduce the value of shock acceleration are disclosed, for example, in document US 2014/0318909 A1 (published on 10/30/2014), as well as in US 8256587 B2 (published on September 4, 2012).

The shock absorber disclosed in publication US 2014/0318909 A1, contains a cylinder and a piston mounted with the possibility of linear movement in the cylinder and having a rod whose diameter is slightly larger than half the diameter of the piston.

The piston has an upper solid part and a lower annular part covering the piston rod. In the upper part of the piston there are many longitudinal through holes. On top of these holes are covered with a membrane, which is formed by an annular disk made with the possibility of longitudinal movement within the limited boundaries of the guide having a sealing ring. The specified disk has two O-rings to provide sealing of the piston during its movement upward.

In its upper part, the cylinder of the known shock absorber is closed by a lid attached to the cylinder by means of a weld.

In its lower part, the cylinder of the known shock absorber has an end element that abuts the cylinder around the piston rod and forms a guide for the piston rod. In the lower part, the end element is provided with an annular plate containing a locking rod that interacts with a semicircular groove in the lower part of the piston rod. By rotating the locking rod, the piston rod is held during transportation and released during installation operations.

In the lower part of the cylinder of the known device, a plurality of inlets are made, which are in communication with the possibility of transferring a fluid with longitudinal through holes of the piston. A compartment formed inside the cylinder between the piston in the lower position and the upper cover is provided with a plurality of outlet openings. The diameter of these holes decreases upward so that when the piston moves, the cross section of the flow passing through the holes will decrease predominantly exponentially with respect to the asymptotic value determined by the highest outlet and the ventilation hole passing through the cylinder cover.

In the shock absorber known from the publication US 8256587 B2, the cylinder in its upper part is provided with a protrusion, while the cylinder cover is attached to the protrusion by means of a bolted connection. The protrusion and the cover also contain through holes for engaging the bolts for temporary connection of the shock absorber with the structure, which must be placed on the base located on the seabed.

The shock absorbers known from these publications allow damping a significant shock load arising from the movement of the installation devices and the movement of the structure to be installed on the base located on the seabed.

Nevertheless, often during operations of lowering the structure to the seabed by means of a hook suspension of the crane in the last phase of the descent, the structure is subject to vertical displacements, which causes several significant vertical displacements before the structure stands on the base located on the seabed.

Thus, there is a need to ensure that the position of the shock absorber rod is maintained during such movements, that is, to carry out the sufficiently fast process of recharging the shock absorber in order to ensure effective shock damping under these conditions.

In addition, the design features of the known shock absorbers do not allow to sufficiently level the angular deviations of the piston rod that occur when it is moved during damping.

The present invention aims to overcome at least one drawback inherent in the technical solutions of the prior art.

SUMMARY OF THE INVENTION

The technical problem to be solved during the creation of the present invention was the creation of a soft-fit cylinder, the design of which allows to accelerate the recharging of the cylinder under conditions when the installed structure is subject to vertical displacements, while ensuring the leveling of angular deviations of the rod that occur during its movement during damping.

The technical result achieved by the implementation of the invention is to accelerate the recharging of the soft landing cylinder. In addition, the design of the soft-fit cylinder according to the invention provides the ability to level the angular deviation of the rod by up to 5 degrees. It is known that the shock absorbers that currently exist make it possible to level the angular deviation of the rod by 1.5–2.5 degrees.

The claimed technical result, which consists in accelerating the reloading process of the soft landing cylinder, is achieved by the cylinder reloading unit located in the cylinder cover.

The specified cylinder reloading unit contains a plate attached to the cylinder cover from its inner side by means of a guide screw and arranged to linearly move along the specified guide screw, as well as inlet openings located in the cylinder cover, the cross section of which increases in the direction from the inside of the cylinder cover to her outside.

The specified increase in the cross section of the inlets in the direction from the inner side of the cylinder cover to its outer side provides a decrease in resistance when filling the cylinder with water and an increase in the coefficient of flow of water passing through these openings.

In addition, the claimed technical result, which consists in providing leveling of the angular deviation of the rod, is ensured by the leveling unit of the angular deviation located in the lower part of the rod.

The specified node contains a ball element made with the possibility of placing inside the cavity formed in the lower part of the rod, and a clamping nut made with the possibility of providing a rotary connection of the lower part of the rod and the ball element.

In more detail, this problem and the claimed technical result are respectively solved and achieved due to the fact that the soft landing cylinder contains:

cover;

housing;

a piston chamber formed in the housing and configured to be filled with water through a cylinder reloading unit located in the cover and a plurality of outlet openings made in the lower part of the housing;

a piston located in the piston chamber with the possibility of longitudinal movement along the axis of the piston chamber from a lower position to an upper position;

a rod having an upper part connected to the piston and a lower part configured to lead outward from the housing, the lower part of the rod further comprising an angular deflection leveling unit;

at the same time, when the rod collides and the piston moves from a lower position to an upper position, the piston chamber is formed in such a way as to ensure the release of water through a plurality of outlet openings formed therein, thereby providing shock damping.

The indicated problem and the claimed technical result are respectively solved and achieved also due to the fact that the soft-fit cylinder body is additionally provided in its lower part with a guide sleeve adjacent to the body around the rod and forming a guide for moving the piston, as well as a guide ring to ensure rod sealing when moving it.

Additionally, this problem and the claimed technical result is accordingly solved and achieved due to the fact that the rod in its upper part is connected to the piston by means of a screw connection, and the piston is additionally equipped with a seal placed in the piston chamber to provide sealing of the piston during its longitudinal movement along the piston axis cameras from the lower position to the upper position.

In addition, this problem and the claimed technical result is accordingly solved and achieved due to the fact that the outlet openings made in the lower part of the housing have a cross section that decreases in the direction from the inner side of the housing to its outer side.

BRIEF DESCRIPTION OF THE DRAWINGS

The above advantages of the invention will become more apparent from the following description of a preferred embodiment, given with reference to the accompanying drawings, in which:

- in FIG. 1 shows a soft seat cylinder with the piston in the lower position in accordance with a preferred embodiment of the invention,

- in FIG. 2 shows a reloading unit for a soft-seated cylinder in an open position in accordance with a preferred embodiment of the invention,

- in FIG. 3 shows a reloading unit for a soft-fit cylinder in a closed position in accordance with a preferred embodiment of the invention,

- in FIG. 4 shows an angular deflection leveling assembly in accordance with a preferred embodiment of the invention,

- in FIG. 5 shows a soft-fit cylinder during charging of a cylinder in accordance with a preferred embodiment of the invention,

- in FIG. 6 depicts a soft seat cylinder during shock damping in accordance with a preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Next, with reference to the accompanying drawings, a soft-fit cylinder is described in accordance with a preferred embodiment of the invention.

In FIG. 1 is a schematic illustration of a soft-fit cylinder comprising a housing (1) and a piston (2) configured to linearly move within a piston chamber formed inside the housing (1).

In the lower part of the housing (1) there are many outlet openings (3).

In this case, the outlet openings (3) have a cross section that decreases in the direction from the inner side of the housing (1) to its outer side.

The soft seat cylinder also contains a rod (4), in its upper part connected to the piston (2).

In a preferred embodiment, as shown in FIG. 1, said connection of the rod (4) and piston (2) is provided with a screw (5) and a washer (6).

In the cover (7) of the soft-seated cylinder, the reloading unit of the soft-seated cylinder is shown in FIG. 2 and 3.

The reloading unit for the soft-fit cylinder contains a plate (8) attached to the inside of the cylinder cover (7) by means of a guide screw (9). In addition, the said cylinder reloading unit comprises inlet openings (10) made on the cylinder cover (7).

In a preferred embodiment of the invention, the plate (8) is further provided with a seal (11), which provides a seal to the plate (8) as it moves along the guide screw (9).

Said inlet openings (10) are conical, due to which a decrease in resistance is achieved when the cylinder is filled with water and an increase in the coefficient of flow rate of water passing through these openings.

The specified plate (8) is made with the possibility of linear movement along the guide screw (9) between the open position in which water enters through the inlet holes (10) (shown in Fig. 2) and the closed position (shown in Fig. 3) )

The rod (4) in its lower part contains a node for leveling the angular deviation (illustrated in Fig. 4), which includes a ball element (12) located inside a cavity made in the lower part of the rod (4), as well as a clamping nut (13) by means of which a rotary connection of the ball element (12) and the rod (4) is provided.

As shown in FIG. 4, the indicated rotary connection of the ball element (12) and the rod (4) provides the leveling of the angular deviation of the rod (4) arising from its collisions during damping.

In addition, the housing (1) in its lower part is equipped with a guide sleeve (13) adjacent to the housing (1) around the stem (4) and forming a guide for moving the piston (2), as well as a guide ring (14) to ensure stem sealing (4) when moving it.

Additionally, the piston (2) is provided with a seal (15) located in the piston chamber to provide a seal to the piston (2) during its longitudinal movement along the axis of the piston chamber from a lower position to an upper position.

During descent, the piston (2) with the stem (4) are in the position shown in FIG. 1. In this case, water fills the piston chamber of the housing (1) mainly through the inlet openings (10) and the outlet openings (3), flowing around the plate (8) in the open position shown in FIG. 2.

When moving the piston (2) from the lower position shown in FIG. 5, upon impact of the stem (4), the plate (8) will move to the closed position, thus providing water displacement through the outlet openings of the piston chamber made in the housing (1).

In the case when during the descent operation in its final phase the entire structure undergoes additional vertical displacements before final installation on the base located on the seabed, the cylinder reloading unit according to the present invention located in the cylinder cover (7) provides fast and efficient refilling a piston chamber made in the housing (1) in order to maintain the position of the rod, and as a result, effective shock damping.

It should be understood that the preferred embodiment of the invention described above by way of example does not limit the scope of the present invention. After reviewing the present description, those skilled in the art can propose many changes and additions to the described embodiments, all of which will fall within the scope of patent protection of the invention defined by the following claims.

Claims (8)

1. A soft seat cylinder comprising a cover; housing; a piston chamber formed in the housing and configured to be filled with water through a cylinder reloading unit located in the cover and a plurality of outlet openings made in the lower part of the housing; a piston located in the piston chamber with the possibility of longitudinal movement along the axis of the piston chamber from a lower position to an upper position; a rod having an upper part connected to the piston and a lower part configured to lead outward from the housing, the lower part of the rod further comprising an angular deflection leveling unit; at the same time, when the rod collides and the piston moves from the lower position to the upper position, the piston chamber is formed in such a way as to ensure the discharge of water through the plurality of outlet openings provided therein, thereby providing shock absorption damping. 2. The cylinder according to claim 1, characterized in that the cylinder reloading unit comprises a plate attached to the cover on its inner side by means of a guide screw and arranged to linearly move along the specified guide screw, as well as inlet openings located in the cover, the cross section of which increases in the direction from the inside of the cylinder cover to its outside. 3. The cylinder according to claim 2, characterized in that the cylinder reloading unit further comprises a seal to provide sealing of the plate as it moves along the guide screw. 4. The cylinder according to claim 1, characterized in that the leveling unit of the angular deviation contains a ball element made with the possibility of placing inside the cavity formed in the lower part of the rod, and a clamping nut made with the possibility of providing a rotary connection of the lower part of the rod and the ball element. 5. The cylinder according to claim 1, characterized in that the housing in its lower part is provided with a guide sleeve adjacent to the housing around the stem and forming a guide for moving the piston, as well as a guide ring to ensure sealing of the rod when moving it. 6. The cylinder according to claim 1, characterized in that the rod in its upper part is connected to the piston by means of a screw connection. 7. The cylinder according to claim 1, characterized in that the piston is further provided with a seal located in the piston chamber to provide a seal to the piston during its longitudinal movement along the axis of the piston chamber from a lower position to an upper position. 8. The cylinder according to claim 1, characterized in that the outlet openings made in the lower part of the housing have a cross section that decreases in the direction from the inner side of the housing to its outer side.

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