Pressure-resistant piston media separator, especially for a linear drive of a ship's rudder machine

Abstract

The present invention relates to a pressure-resistant piston media separator 10, wherein the pressure-resistant piston media separator 10 comprises a first piston cylinder 20 with a first piston 30, wherein the pressure compensation vessel 10 comprises a first region 40 and a second region 50, wherein the first region 40 is separated from the second region 50 by the first piston 30, wherein the first region 40 is in contact with the environment, wherein the second region 50 is connected to a hydraulic system, wherein the pressure-resistant piston media separator 10 comprises a piston rod 80, wherein the piston rod 80 is connected to the first piston 30, wherein the pressure-resistant piston media separator 10 comprises a second piston cylinder 90 and a second piston 100, wherein the second piston 100 is connected to the piston rod 80, wherein the pressure-resistant piston media separator 10 comprises a third region, wherein the third region is a sealed gas volume.wherein the third area is variable in size by the second piston 100, wherein the second piston 100 has a fourth area 110 on one side of the second piston 100 with the piston rod 80 and a fifth area 320 on the side of the second piston 100 opposite the fourth area 110, wherein the first piston 30 has a first seal 170 against the first area 40 and a second seal 180 against the second area 50, wherein the first piston 30 has a test cavity 190 located between the first seal 170 and the second seal 180, wherein the first piston 30 and the piston rod 80 have a passage 200, wherein the passage 200 connects the test cavity 190 to a side of the second piston 100 facing away from the fourth area 110, characterized in that the passage 200 is connected to a hose 210 arranged in the fifth area 320 is.,

Description

The invention relates to a pressure-resistant piston media separator. For example, in a linear drive for a ship's rudder machine, mechanical movement occurs against the external pressure. To avoid work against the external pressure, the hydraulic fluid in a pressure-resistant piston media separator is brought to approximately the external pressure by pressurizing the hydraulic fluid in the pressure-resistant piston media separator with the external pressure from the surrounding medium. A corresponding linear drive for a ship's rudder machine is known from DE 10 2016 204 248 A1. There, the term pressure equalization tank is used as an alternative term for the pressure-resistant piston media separator. The piston of the pressure-resistant piston media separator is moved in one direction by incoming hydraulic fluid and in the other by the surrounding medium.Since this piston must also have a very good seal, it exhibits a corresponding frictional resistance. This can lead to situations where, at low external pressure, i.e., very shallow diving depths (including when surfaced), the pressure exerted by the surrounding medium, the water, on the piston is insufficient to move it. This can result in a vacuum on the hydraulic fluid side, causing outgassing and consequently bubble formation. This leads to two problems. First, the bubbles dissolve very slowly when re-dissolved in the hydraulic fluid. Second, the bubbles cause unpredictable behavior. In particular, locking the rudder position, which is achieved by shutting off the hydraulics, becomes difficult. If gas bubbles are present in this area, the rudder position can change unintentionally. From DE 10 2021 211 387 A1 a pressure-resistant piston media separator is known, in particular for a linear drive of a ship's rudder machine. One challenge in the state of the art has proven to be the ability to detect a leak to the test cavity through the procedure. The object of the invention is therefore to improve the detection of such leaks, so that even small leaks can be detected particularly early. This problem is solved by the pressure-resistant piston media separator with the features specified in claim 1. Advantageous further developments are described in the dependent claims, the following description, and the drawing. The pressure-resistant piston media separator according to the invention comprises a first piston cylinder with a first piston. The pressure equalization vessel has a first section and a second section within the first piston cylinder, which are separated by the first piston. The first section is in contact with the environment, in particular with water, if the pressure-resistant piston media separator is used for a ship's steering system, especially a submarine. Thus, the ambient pressure always prevails in the first section. The second section is connected to a hydraulic system, for example, a steering system. This ensures that the hydraulic fluid is also subject to ambient pressure, so that the steering mechanism does not have to work against the ambient pressure. However, it is essential to reliably prevent contact between the first and second areas, as this could allow hydraulic fluid to enter the water or vice versa. In the first case, in addition to the environmental hazard, there is a risk of detection, for example, of a submarine; in the second case, there is a risk of damage to the hydraulic system, such as corrosion. Therefore, the first piston has a primary seal against the first area and a secondary seal against the second area. To detect leaks, the first piston has a test cavity located between the primary and secondary seals. If the primary seal leaks, water enters the test cavity; if the secondary seal leaks, hydraulic fluid enters the test cavity. According to the invention, the feedthrough is connected to a hose. For the purposes of this invention, "hose" refers to any flexible connecting element suitable for conveying a fluid. The hose can be made of, for example, plastic, fabric-reinforced plastic, or metal. This allows for two advantageous variations. First, the hose can be easily routed outwards. The flexibility of the hose compensates for the movement of the second piston. This alone facilitates easier visual detection, as the escaping fluid no longer needs to be detected internally. Alternatively, the hose can also be connected to a sensor. This offers a further advantage.This also means that the volume of the test cavity, feedthrough and hose is closed, so that before a liquid reaches the end of the hose, a leak can already be detected by a pressure increase, thus enabling even earlier detection. In a further embodiment of the invention, the pressure-resistant piston media separator has a second piston. However, since the retraction of the first piston does not always occur reliably and independently, an addition by means of a second piston cylinder with a second piston is known from DE 10 2021 211 387 A1. The pressure-resistant piston media separator has a piston rod. The piston rod is connected to the first piston. Furthermore, the pressure-resistant piston media separator has a second piston cylinder and a second piston. The second piston is connected to the piston rod, thus directly coupling the first and second pistons. The pressure-resistant piston media separator has a third section, wherein the third section is a closed gas volume. The size of the third section can be changed by the second piston.This means that the pressure changes due to the enclosed volume when the position of the first piston, and thus of the second piston, changes, resulting in a restoring force. The second piston has a fourth section on one side of the piston with the piston rod, and a fifth section on the opposite side of the second piston. The third section can be formed solely by the fourth section. Alternatively, the third section can consist of the fourth section and an extension section, with the extension section being located outside the second piston cylinder. In this case, the fourth section and the extension section are preferably connected to each other via a gas-carrying connection through the second piston cylinder.To detect this, the first piston and piston rod have a through-hole connecting the test cavity to a fifth chamber located on the side of the second piston opposite the fourth chamber. This allows water or hydraulic fluid to be seen, as shown in DE 10 2021 211 387 A1, thus enabling the detection of a leak. The through-hole is connected to a hose located in the fifth chamber. This allows for two advantageous configurations. First, the hose can be easily routed out of the fifth chamber. The hose's flexibility compensates for the movement of the second piston. This alone facilitates easier visual detection, as the escaping fluid no longer needs to be detected inside the fifth chamber. Alternatively, the hose can also be connected to a sensor.This has a further advantage. The volume of the test cavity, feedthrough and hose is also enclosed, so that before a liquid reaches the end of the hose, a leak can be detected via a pressure increase, thus enabling even earlier detection. In another embodiment of the invention, the hose is connected to a sensor. This can be, for example, a pressure sensor, since, as already explained, a pressure increase occurs due to the closed volume. However, the volume can also be designed to be open to the outside, and then, for example, the escape of liquid can be detected using a conductivity sensor or a heat capacity sensor. In a further embodiment of the invention, a partition wall is arranged between the first piston cylinder and the second piston cylinder. The partition wall has a passage for the piston rod. To ensure and test the tightness of this passage, the partition wall has a first sealing element adjacent to the piston rod, separating it from the second area, and a second sealing element separating it from the fourth area. A second test cavity is arranged between the first and second sealing elements. The partition wall has a penetration through which the second test cavity is connected to the environment. This prevents gas from the third area from entering the hydraulic system or hydraulic fluid from entering the third area. Since the partition wall also leads directly to the outside, any leaks can be detected immediately. In a further embodiment of the invention, the fifth compartment is closed with a sealing element. The fifth compartment has a vent for connection to the environment. This allows the fifth compartment to be easily kept clean, thus preventing the second piston from becoming blocked. At the same time, the vent ensures that a closed gas volume does not form in the fifth compartment, so that the functionality of the sealing element is not impaired. In another embodiment of the invention, the ventilation element is arranged in the closure element. In a further embodiment of the invention, the closure element has a passage element for the hose or a sensor, wherein the hose is connected to the sensor. The passage element can either be a bore through which the hose passes, or it can be a hose feedthrough which has a connection element for the hose on the side of the fifth area, preferably on both sides. Further embodiments known from DE 10 2021 211 387 A1 are also fully applicable to the pressure-resistant piston media separator according to the invention and are hereby incorporated. The pressure-resistant piston media separator according to the invention is explained in more detail below with reference to an embodiment shown in the drawing. Fig. 1 exemplary pressure-resistant piston media separator Figure 1 shows a schematic, not to scale, cross-sectional view of an exemplary pressure-resistant piston media separator 10. The part of the pressure-resistant piston media separator 10 shown on the left consists of a first cylindrical piston 20 in which a first piston 30 is movably arranged. On one side, here on the left, is a first section 40, which is at ambient pressure via a connection to the environment 60, for example, a seawater connection. On the other side is the second section 50, in which a hydraulic fluid is located, which can be supplied to and removed from the hydraulic system 70 via a connection. The piston rod 80 also runs within the second section 50. The second piston cylinder 90 with the second piston 100 is essential for achieving the restoring effect. The second piston 100 is also connected to the piston rod 80 and thus performs the same movement as the first piston 30. To make the gas-tight third section as compact as possible, it consists, in the example shown, of a fourth section 110 inside the second piston cylinder 90 and an expansion section 120 surrounding the second piston cylinder. The gas pressure inside the third section can be precisely adjusted, particularly with nitrogen, via a filling valve 140. The fourth section 110 and the expansion section 120 are connected to each other via a gas-carrying connection 130. To facilitate the initial filling of the first section 40 with water, the piston rod 80 has a vent opening 150, which, on the side of the second piston 100 and thus easily accessible from the outside, has a feedthrough closure 160 to prevent water from the environment from entering the interior during normal operation. Therefore, the feedthrough closure 160 must be able to withstand the maximum immersion pressure. Furthermore, the first piston 30 has a first seal 170 against the water side of the first section 40 and a second seal 180 against the hydraulic side of the second section 50. To detect a leak in either of these seals 170 or 180, a test cavity 190 is arranged between the seals 170 and 180, which is connected to the feedthrough 200. In the event of a leak in the first seal 170, seawater can thus enter the area outside the second piston 100 and be easily detected. Likewise, in the event of a leak in the second seal 180, hydraulic fluid can enter the area outside the second piston 100 and be easily detected. According to the invention, in the fifth area 320, hose 210 is connected to the feedthrough 200. This allows hose 210 to be easily routed out of the fifth area 320. Due to the flexibility of hose 210, it can follow the movement of the second piston 100. To protect the fifth compartment 320 from contamination, for example, it is closed by a sealing element 220. To prevent pressure from building up inside the fifth compartment 320, the sealing element 220 has a vent 230, ensuring that the fifth compartment 320 maintains the same pressure as the interior of the boat. The sealing element 220 also has a passage element 240, onto which a hose 210 is attached on one side and an outer hose 250 on the other. The outer hose then leads to a sensor 260, for example, a pressure sensor. The partition 310 between the second area 50 and the fourth area 110 has a passage for the piston rod 80. To seal this passage, a first separating seal 270 is arranged on the side facing the second area 50 and a second separating seal 280 on the side facing the fourth area 110. Between the first separating seal 270 and the second separating seal 280 is a second test cavity 290, which is connected to the environment via the partition passage 300 in order to detect a leakage in either of the separating seals 270 or 280. Reference sign 10 Pressure-resistant piston media separator 20 First piston cylinder 30 First piston 40 First section 50 Second section 60 Connection to the environment 70 Connection to the hydraulic system 80 Piston rod 90 Second piston cylinder 100 Second piston 110 Fourth section 120 Expansion section 130 Gas-carrying connection 140 Filling valve 150 Venting port 160 Feedthrough plug 170 First seal 180 Second seal 190 Test cavity 200 Feedthrough 210 Hose 220 Closure element 230 Venting element 240 Passage element 250 Outer hose 260 Sensor 270 First separating seal 280 Second separating seal 290 Second test cavity 300 Partition feedthrough 310 Partition 320 Fifth section

Claims

Pressure-resistant piston media separator (10), wherein the pressure-resistant piston media separator (10) comprises a first piston cylinder (20) with a first piston (30), wherein the piston media separator (10) comprises a first region (40) and a second region (50), wherein the first region (40) is separated from the second region (50) by the first piston (30), wherein the first region (40) is in contact with the environment, and wherein the second region (50) is connected to a hydraulic system, wherein the pressure-resistant piston media separator (10) comprises a piston rod (80), wherein the piston rod (80) is connected to the first piston (30), wherein the first piston (30) has a first seal (170) against the first region (40) and a second seal (180) against the second region (50), and wherein the first piston (30) has a test cavity located between the first seal (170) and the second seal (180). (190) exhibitswherein the first piston (30) and the piston rod (80) have a through-hole (200), characterized in that the through-hole (200) is connected to a hose (210). Pressure-resistant piston media separator (10) according to claim 1, characterized in that the pressure-resistant piston media separator (10) has a second piston cylinder (90) and a second piston (100), wherein the second piston (100) is connected to the piston rod (80), wherein the pressure-resistant piston media separator (10) has a third region, wherein the third region is a closed gas volume, wherein the third region is variable in size by the second piston (100), wherein the second piston (100) has a fourth region (110) on one side of the second piston (100) with the piston rod (80) and a fifth region (320) on the side of the second piston (100) opposite the fourth region (110), wherein the passage (200) connects the test cavity (190) to a side of the second piston (100) facing away from the fourth region (110), wherein the passage (200) is connected to a fifth area (320) is connected to the hose (210). Pressure-resistant piston media separator (10) according to one of the preceding claims, characterized in that the hose (210) is connected to a sensor (260). Pressure-resistant piston media separator (10) according to one of the preceding claims, characterized in that a partition (310) is arranged between the first piston cylinder (20) and the second piston cylinder (90), wherein the partition (310) has a passage for the piston rod (80), wherein the partition (310) has a first separating seal (270) adjacent to the piston rod (80) to the second area (50) and a second separating seal (280) to the fourth area (110), wherein a second test cavity (290) is arranged between the first separating seal (270) and the second separating seal (280), wherein the partition (310) has a partition passage (300), wherein the partition passage (300) connects the second test cavity (290) to the environment. Pressure-resistant piston media separator (10) according to one of the preceding claims, characterized in that the fifth area (320) is closed with a closing element (220), wherein the fifth area (320) has a ventilation element (230) for connection with the environment. Pressure-resistant piston media separator (10) according to claim 5, characterized in that the venting element (230) is arranged in the closure element (220). Pressure-resistant piston media separator (10) according to one of claims 5 to 6, characterized in that the closure element (220) has a passage element (240) for the hose (210) or a sensor (260), wherein the hose (210) is connected to the sensor (260).

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