Piston compressor throttle arrangement

Abstract

A sliding surface (9) of a body of an axially movable piston compressor (20) is to be sealed. The seal disc holder (3) has an L-shaped radial cross section with a first leg (4) extending in the axial direction (A) and a second leg (5) extending transversely to the axial direction (A). The axial height (H4) of the first leg (4) is selected such that a plurality of seal discs (2) stacked on the bearing surface (6) have axial play in use. A first annular gap (RS1) formed between the interface surface (8) and the seal disc (2) is fluidly connected to the high pressure side (1a) by a gas passage opening (7). A second annular gap (RS2) is formed between the sliding surface (9) of the body to be sealed and the seal disc (2). Wear-related expansion of the second annular gap (RS2) is limited by the radial width of the first annular gap (RS1).

Description

Technical Field

[0001] The present invention relates to a throttle arrangement (arrangement, array, configuration) for a piston compressor. The present invention further relates to a piston compressor having such a throttle arrangement and to the use of such a throttle arrangement in a piston compressor.

Background Art

[0002] Compressors, particularly piston compressors, are commonly used for compressing liquids or gases. In order to prevent or at least minimize an undesired or disorderly outflow of the compressed medium, the compression chamber must be sealed as well as possible from its surroundings. The area where the piston rod passes through the cylinder is usually sealed (sealed, sealed) with a so-called piston rod packing. This piston rod packing is configured with a plurality of seal elements arranged behind each other in the axial direction of the piston rod.

[0003] The throttle ring is a piston rod seal element that is arranged at the end facing the compression chamber of the piston rod packing to reduce the dynamic pressure peak. The dynamic pressure component, that is, the difference between the compression pressure and the suction pressure that changes from zero to the maximum value during one rotation of the crankshaft, must be kept away from those actual seal elements in order to protect the actual seal elements from destruction.

[0004] Throttle rings known from the prior art are usually designed as seal elements without friction from the beginning, or are designed to have low running-in wear as seal elements without friction (frictionless). Such throttle rings are known, for example, from Patent Document 1.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] However, a typical frictionless throttle ring has the disadvantage of contributing little to sealing the dynamic pressure component. Therefore, the actual sealing element located downstream will wear out rapidly. Furthermore, if there is contact between the throttle ring and its mating part during operation, the minimum clearance between the throttle ring and its mating part increases in relation to wear. As a result, the sealing function of the throttle ring is further reduced and eventually lost.

[0007] The present invention builds upon the aforementioned prior art and aims to at least reduce such and further drawbacks of the prior art. In particular, it aims to define the type of throttle configuration described at the beginning that has improved sealing performance compared to known throttle ring designs and enables a longer service life. [Means for solving the problem]

[0008] This objective is addressed, particularly for sealing the dynamic pressure component, by a throttle arrangement having the features of the independent claim, a piston compressor having such a throttle arrangement, and the use of such a throttle arrangement in a piston compressor. Advantageous design and further development are the subject of the dependent claims.

[0009] This objective is addressed, in particular, by a throttle arrangement for sealing the sliding surfaces of the body of an axially movable piston compressor. The throttle arrangement has a high-pressure side on the compression chamber side and a low-pressure side on the crank drive side during use. The throttle arrangement according to the present invention comprises a plurality of annular seal discs and a seal disc holder. The seal disc holder has an L-shaped radial cross-section formed by a first leg extending axially and a second leg extending laterally with respect to the axial direction. The second leg is annular. The second leg has a bearing surface facing the high-pressure side. On this bearing surface, the seal discs are arranged axially on top of each other. The first leg is cylindrical. The first leg extends from the bearing surface toward the high-pressure side along the outer or inner circumference of the second leg. The axial height of the first leg is selected such that the seal discs stacked on the bearing surface have a constant axial clearance during use. As a result, the seal discs are not clamped together in the axial direction and are therefore movable laterally relative to the axial direction. The first leg has a plurality of gas passage openings and an interface facing the direction of the seal discs. When the seal discs are aligned coaxially with the first leg and the body to be sealed, a first annular gap is formed between the interface and the seal discs in each case. This first annular gap is fluidly connected to the high-pressure side via the gas passage openings. A second annular gap is formed in each case between the sliding surface of the body to be sealed and the seal discs. The increase in the size of the second annular gap due to wear is essentially limited by the radial width (radial dimension) of the first annular gap.

[0010] The throttled seal disc holder according to the present invention is a seal disc magazine in which seal discs lie side by side with their seating surfaces facing each other in a kind of series connection, forming a seal disc pack. Typically, the radial width of the second annular gap in the non-operating state of the throttled arrangement is smaller than the radial width of the first annular gap. Therefore, during the run-in process, some wear caused by contact between the seal discs and the sealed object during operation is tolerated on the surfaces of the seal discs facing the sliding surfaces before the seal discs are protected from further wear by the interface. In other words, the seal disc holder ensures that the individual seal discs cannot move relative to each other in the run-in state by a distance greater than the radial distance defined by the first annular gap. Therefore, it prevents, or at least significantly suppresses, further expansion of the second annular gap. The throttled arrangement according to the present invention is particularly suitable for sealing the piston rod or piston of a dry-operating piston compressor. Furthermore, the throttle configuration according to the present invention can also be used when compressing very light gases such as hydrogen, where a sealing element that maintains a consistently good sealing effect over a long period of time is required.

[0011] The sealing effect is due to the different positions of the seal discs relative to each other. Therefore, in contrast to throttle rings known from prior art, wear on individual discs can be limited without directly leading to deterioration of the sealing effect. However, excessive wear on individual seal discs can lead to the formation of more arrangements that have linear flow paths that do not exhibit sufficient flow resistance. Therefore, limiting radial wear is absolutely necessary.

[0012] Therefore, in a preferred embodiment of the throttle arrangement according to the present invention, the radial width of the first annular gap, and thus the substantially maximum allowable radial clearance between the seal discs in the seal disc holder, is 1 mm or less in each case.

[0013] The number, position, and shape of the gas passage openings in the seal disc holder can be varied according to individual requirements. In a preferred embodiment of the throttle arrangement according to the present invention, the gas passage opening extends across the entire axial height of the first leg of the seal disc holder. This ensures that the high-pressure gas pressure is effective along the entire axial height of the seal disc pack, i.e., between each seal disc within the seal disc holder.

[0014] Alternatively or additionally, in the throttle arrangement according to the present invention, the gas passage openings are evenly arranged in the circumferential direction of the first leg of the seal disc holder. This ensures that the high-pressure gas pressure is effective along the entire circumferential direction of the seal discs, thus preventing uneven loading between the seal discs.

[0015] In a more preferred embodiment of the throttle arrangement according to the present invention, the ratio of the sum of the areas of the gas passage openings to the boundary area, i.e., the area comprising the gas passage openings, is 1:2 to 1:4. Preferably, the ratio of the sum of the areas of the gas passage openings to the boundary area is between 1:2.8 and 1:3. The specified range represents a particularly preferred compromise between the mechanical stability of the seal ring holder, particularly the limitation of the radial clearance between the seal discs in the seal disc holder, and the effectiveness of the gas pressure from the high-pressure side on the seal discs. Optimal limitation of the radial clearance between the seal discs reduces contact between the seal discs and the moving piston rod during use, thereby minimizing friction-related wear between the seal discs.

[0016] In a more preferred embodiment of the throttle arrangement according to the present invention, the first leg of the seal disc holder has eight gas passage openings. Preferably, the eight gas passage openings extend across the entire axial height of the first leg and are evenly distributed in the circumferential direction of the first leg. The resulting symmetry means that the pressure acts particularly uniformly on the throttle arrangement, thereby increasing the service life of the throttle arrangement.

[0017] Depending on the design of the piston compressor in which the throttle configuration is used, the throttle configuration according to the present invention can be dry-running or oil-lubricated. In the case of a dry-running throttle configuration, at least the seal discs must have dry-running characteristics. If the seal disc holder also contacts the sliding surface of the body to be sealed during operation, it is preferable that at least the second leg of the seal disc holder has dry-running properties.

[0018] In a more preferred embodiment of the throttle arrangement according to the present invention, the seal disc holder is integrally formed, i.e., comprises a single component. Preferably, the seal disc holder is made of a material that has good emergency running properties in dry running operation of the throttle arrangement. Such a seal disc holder has particularly high stability and enables an extremely long service life of the throttle arrangement according to the present invention.

[0019] Preferably, the seal disc holder is made of a pure or filled high-temperature polymer, a pure or filled fiber composite material, or a metal such as bronze in the case of very high pressure differences.

[0020] Suitable high-temperature polymers include pure or filled polyether ether ketone (PEEK), pure or filled polyimide (PI), pure or filled polyphenylene sulfide (PPS), or pure or filled epoxy.

[0021] Suitable fiber composite materials are, for example, carbon fiber reinforced plastics (CFRP). Carbon fiber reinforced plastic CFRP is a composite material in which carbon fibers are embedded in a plastic matrix, such as polyether ether ketone PEEK or epoxy. The matrix material is used not only to bond the fibers together but also to fill the gaps. Other thermosetting plastics and thermoplastic plastics are also suitable as matrix materials.

[0022] Physical, mechanical, and / or tribological properties are improved by adding inorganic fillers such as carbon, graphite, glass fibers, MoS2, and / or glass fibers to the plastics used. Thus, particularly dry running (dry lanning) characteristics can be imparted.

[0023] Suitable metals include materials such as aluminum, lead, or bronze materials like tin bronze, and brass. Within the framework of the radial clearance between individual seal disks, these seal disks may be misaligned with respect to the coaxial alignment of all seal disks with respect to the interface surface within the receiving space. This displacement occurs differently for each pair of seal disks. The width of the gap with the piston rod changes due to the dynamic pressure component acting between the seal disks. A kind of dynamic labyrinth seal is formed by all combinations of seal disks. The flow resistance increases due to this dynamic labyrinth seal. Particularly with respect to the dynamic pressure component, the sealing effect of the throttle arrangement is improved.

[0024] Flow resistance results from the random orientation of the shield disks relative to each other, which is different from the coaxial direction. Therefore, the number of shield disks in the throttle arrangement according to the present invention should be at least three. Preferably, the number of shield disks in the throttle arrangement according to the present invention is exactly five. This number of shield disks ensures particularly efficient flow conversion (diversion, bypass). At the same time, the axial height of the throttle arrangement can be kept compact.

[0025] According to the series connection of the shield disks in the throttle arrangement according to the present invention, the individual shield disks do not necessarily have to have the best possible sealing effect. This is because, as described above, the sealing effect of the throttle arrangement is based on the combination of a plurality of shield disks and the increase in flow resistance due to the continuous rear arrangement of the shield disks in the throttle arrangement.

[0026] However, it is advantageous if the shield disks in the throttle arrangement according to the present invention are formed as a single piece (one piece) and are endless. Thereby, the shield disks can be manufactured in a particularly robust manner with respect to a load having a dynamic pressure difference.

[0027] In a preferred embodiment of the throttle arrangement according to the present invention, the shield disks have an axial height between 1 mm and 5 mm. Preferably, the axial height of the shield disks is between 2.4 mm and 2.6 mm. Thereby, the throttle arrangement can be made particularly compact in the axial direction.

[0028] Within the throttle configuration, pressure decreases from the high-pressure side to the low-pressure side, that is, from the seal disc positioned at the top of the seal disc holder towards the seal disc supported on the bottom surface of the pressure-receiving chamber. The pressure within the seal gap, i.e., the pressure within the second annular gap, decreases towards the low-pressure side. On the other hand, the pressure acting on the outer surfaces of the seal discs, i.e., the pressure within the first annular gap, remains constant. Therefore, the same pressure is applied to the outer and inner surfaces of the seal disc positioned at the top of the throttle configuration. Conversely, the greatest pressure difference exists between the outer and inner surfaces of the seal disc positioned at the bottom of the throttle configuration. Due to the elastoplastic deformation of the seal disc in the radial direction caused by the pressure difference, the seal gap becomes smaller. Furthermore, the lowest seal disc may have a higher wear probability compared to the other seal discs.

[0029] To account for these different loads acting on the seal discs, in a preferred embodiment of the throttle arrangement according to the present invention, the seal discs are made of different materials. The modulus of elasticity (or Young's modulus) is a material parameter in materials engineering. In the case of linear elastic behavior, the modulus of elasticity (or Young's modulus) describes the proportional relationship between stress and strain during deformation of a solid. The modulus of elasticity increases as the resistance of the material to elastic deformation increases. The modulus of elasticity is usually determined by a tensile test of a plastic material sample. In this case, a sample with a known initial cross-section is clamped to a tensile testing machine and then a tensile force F is applied. The tensile force is increased over a certain period of time. As the tensile force increases, it is plotted against the resulting change in length ΔL. The test method for tensile testing is specified, for example, in EN_ISO_527-1 / -2.

[0030] The seal discs located at the bottom of the throttle device according to the present invention experience the largest pressure difference. Therefore, the elastic modulus of the materials used between the seal discs preferably increases towards the lower pressure side. This measure can further improve the flow resistance and service life of the throttle device. For example, according to the present invention, one or more seal discs located at the top are made of a relatively soft material, such as filled PTFE. Then, one or more seal discs made of a high-temperature polymer, such as PEEK, PPS, or PI, are placed in the intermediate region. Finally, one or more seal discs made of a material having high strength, such as bronze or ceramic, may be placed in the bottom region. Of course, it is also conceivable according to the present invention to use a mixture of different polymers in a single seal disc, and / or to use fillers, for example, to improve dry running properties.

[0031] A harder disc, characterized by a higher modulus of elasticity, ensures that in this combination, sufficient elastoplastic deformation is still not achieved. To this end, it is preferable according to the present invention that at least one, preferably all, of the multiple seal discs in the seal disc holder have different axial heights than the other seal discs.

[0032] In a preferred embodiment of the throttle arrangement according to the present invention, the axial height between the seal discs increases in the direction of the low pressure. The increase in the axial dimension between the seal discs results in an increase in the outer peripheral area of ​​each seal disc. Therefore, the effect of the gas pressure is increased, and an improved sealing effect is achieved.

[0033] This objective is further addressed by piston compressors having at least one throttle arrangement as described herein, particularly dry-running piston compressors.

[0034] This objective is further addressed by the use of the throttle arrangement described herein for sealing the piston rod or piston, particularly with respect to dynamic pressure differences. Various embodiments of the present invention will be described below with reference to the drawings. Here, identical or corresponding elements are generally given the same reference numerals. [Brief explanation of the drawing]

[0035] [Figure 1a] A top view of a first embodiment of the throttle arrangement according to the present invention. [Figure 1b] A longitudinal cross-sectional view passing through the throttle assembly along line BB in Figure 1a. [Figure 2a] Figure 1a is a top view of the seal disc holder. [Figure 2b] A longitudinal cross-sectional view passing through the seal disc holder along line BB in Figure 2a. [Figure 3a] Figure 1a shows a top view of the seal disc. [Figure 3b] A longitudinal cross-sectional view passing through the seal disc along line CC in Figure 3a. [Figure 4] A longitudinal cross-sectional view through a piston compressor, showing half of the throttle arrangement according to the present invention from Figure 1a, which has a piston rod. [Figure 5] A longitudinal cross-sectional view of a piston compressor having the throttle arrangement according to the present invention, passing through the piston rod packing. [Figure 6a] A top view of a second embodiment of the throttle arrangement according to the present invention. [Figure 6b] A longitudinal cross-sectional view passing through the throttle assembly along line CC in Figure 6a. [Figure 7] A longitudinal cross-sectional view through a piston compressor, showing half of the throttle arrangement according to the present invention shown in Figure 6a, which has a cylinder tread (cylinder groove). [Figure 8] A side view of a piston having multiple throttle arrangements according to the present invention. [Modes for carrying out the invention]

[0036] Figure 1a shows a top view of a first embodiment of a throttle arrangement 1 according to the present invention, comprising a seal disc holder 3 and a plurality of seal discs 2. Thus, according to the shown top view, only the uppermost seal disc in the axial direction A is visible in this representation. The seal disc holder 3 has an L-shaped radial cross section in the radial direction R, as can be seen below in Figure 1b. The seal disc holder 3 comprises a first leg portion 4 extending (running) in the axial direction A and a second leg portion 5 extending laterally with respect to the axial direction A. The second leg portion 5 has an annular design. The second leg portion 5 has a bearing surface 6 on which the plurality of seal discs 2 are arranged overlapping each other in the axial direction A. The first leg portion 4 is cylindrical, and the second leg portion 5 is annular. The first leg portion 4 is cylindrical and extends circumferentially U along the outer circumference of the second leg portion 5 and from the bearing surface 6 toward the seal discs 2. The first leg portion 4 also has an interface surface 8 on the side facing the seal discs 2. This interface 8 is interrupted in the circumferential direction U by eight uniformly distributed gas passage openings 7.

[0037] Figure 1b shows a longitudinal section passing through the throttle arrangement 1 shown in Figure 1a, along the line of intersection BB in Figure 1a. A total of five seal discs 2a to 2e are visible, overlapping each other in the axial direction A. The seal discs 2a to 2e can be inserted into the seal disc holder 3 from the high-pressure side 1a. The lowest seal disc 2e arranged in the seal disc holder 3 rests on the bearing surface 6 of the seal disc holder 3 with its flank facing the low-pressure side 1b. In this embodiment, the second leg portion 5 faces radially inward relative to the first leg portion 4. As a result, the cylindrical first leg portion 4 extends along the outer circumference of the second leg portion 5, i.e., from the bearing surface 6, over a range slightly higher than the total axial height of the stacked seal discs 2a to 2e in the direction of the high-pressure side 1a. In this embodiment, the first leg portion 4 and the interface surface 8 have an axial height H4 of 13 mm. The axial height of each seal disc 2a to 2e is 2.5 mm. The difference between the axial height H4 of the first leg portion 4 and the sum of the axial heights of the stacked seal discs 2a to 2e results in an axial clearance of 0.5 mm for the seal disc 2 in the seal disc holder 3 in the illustrated embodiment. Therefore, as will be explained in detail below, it is guaranteed that the seal disc 2 is able to move radially during use.

[0038] Figure 2a is a top view of the seal disc holder 3 of throttle arrangement 1 shown in Figure 1a. The seal disc holder 3 comprises a circular second leg 5 having a bearing surface 6. This bearing surface 6 has a holder central through-opening 13 extending axially A to receive a piston rod (not shown). The holder central through-opening 13 is defined by the inner circumferential surface 14 of the second leg 5. The seal disc holder 3 further comprises a first leg 4 extending outward along the outer circumference of the second leg 5. The first leg 4 has an interface surface 8 facing inward in the radial direction R. This interface surface 8 defines a receiving space for a seal disc (not shown). The first leg 4 is interrupted by eight gas passage openings 7 uniformly distributed in the circumferential direction U. The interface surface 8 is subdivided into eight interface surface segments (8) by the eight gas passage openings 7. The central angle between the centers of two adjacent interface segments (8) is 45° in each case.

[0039] Figure 2b shows a longitudinal section passing through the seal disc holder 3 shown in Figure 2a, along the line of intersection BB in Figure 2a. In the illustrated embodiment, the inner diameter D of the holder's central through-opening 13 of the second leg portion 5 is defined by the inner circumferential surface 14. 13 The height is 50 mm. The clear diameter of the receiving space D8 defined by the interface segments (segmentations) (8) is 69 mm. The first leg 4 has an axial height H4 of 13 mm and is interrupted circumferentially by eight gas passage openings 7. Each gas passage opening 7 extends across the entire axial height H4 of the first leg 4 and has an arc length B7 of approximately 19 mm. The arc length B8 of each interface segment (8) thus obtained is approximately 10 mm. The specified arc length is measured along the side of the interface 8 facing the high-pressure side 1a.

[0040] Figure 3a is a top view of the seal disc 2 from the throttle arrangement 1 shown in Figure 1a. The seal disc 2 is formed as a single piece. The seal disc 2 is endless in the circumferential direction U. The seal disc 2 has a central seal through-opening 12 in the axial direction A for receiving a piston rod (not shown). However, as will be detailed below regarding a second embodiment of the throttle arrangement according to the present invention, the central seal through-opening 12 of the annular seal disc 2 may alternatively serve to receive the cylindrical first leg portion 4 of the seal disc holder 3. The seal disc 2 has an outer circumferential surface 10 facing outward in the radial direction R and an inner circumferential surface 11 facing radially inward. The inner circumferential surface 11 defines the central seal through-opening 12 of the seal disc 2 in a direction laterally with respect to the axial direction A.

[0041] Figure 3b shows a longitudinal section passing through the seal disc 2 shown in Figure 3a, along the line of intersection CC in Figure 3a. The axial height H2 of the seal disc 2 is 2.5 mm, and the outer diameter D2 relative to the outer circumferential surface 10 of the seal disc 2 is 68 mm. The clear diameter D of the central through-opening (central passage opening) 12 of the seal, surrounded by the inner circumferential surface 11, is... 12 It is 50mm.

[0042] Figure 4 shows a longitudinal section through the throttle arrangement 1 according to the present invention, as shown in Figure 1a. In this representation, only half of the throttle arrangement 1 and half of the piston rod 21 are visible. The individual seal discs 2a-2e, the cylindrical first leg portion 4, and the body to be sealed, i.e., the piston rod 21 in this embodiment, are coaxially aligned with each other in the illustrated depiction. As a result, first annular gaps RS1a-RS1e are formed in each case between the interface surface 8 and the outer circumferential surfaces 10a-10e of the seal discs 2a-2e. These first annular gaps RS1a-RS1e are fluidly connected to the high-pressure side 1a via a gas passage opening (not shown). In addition, second annular gaps RS2a-RS2e are formed between the sliding surface 9 of the piston rod 21 and the inner circumferential surfaces 11a-11e of the seal discs 2a-2e, respectively. The radial width of the second annular gap RS2a to RS2e is 0.1 mm, which is approximately 1 / 5 of the radial width of the first annular gap RS1a to RS1e in the illustrated embodiment. In a new state, that is, for a certain period before the seal discs 2a to 2e retract, the seal discs 2a to 2e are designed such that their inner circumferential surfaces 11a to 11e protrude radially beyond the inner circumferential surface 14 of the central through-opening of the second leg portion 5, as shown in Figure 4. In the embodiment shown in Figure 4, the inner diameter of the seal discs 2a to 2e is only a fraction of a millimeter or a tenth of a millimeter larger than the diameter of the piston rod 21. During operation, the seal discs 2a to 2e and the moving piston rod 21 come into contact with each other, causing the inner circumferential surfaces 11a to 11e to abut against the sliding surface 9 during the break-in period. As a result, material is removed from each of the abutting inner circumferential surfaces 11a to 11e of the seal discs 2a to 2e. The inner diameters of the seal discs 2a to 2e, and therefore the second annular gap RS2, grow continuously to a diameter substantially corresponding to the first annular gap RS1 before further wear of the seal discs 2a to 2e is prevented by the limitation of radial clearance by the interface surface 8.Therefore, in the use of the throttle arrangement 1 according to the present invention, slight wear on the inner circumferential surfaces 11a to 11e of the seal discs 2a to 2e is permitted before the seal discs 2a to 2e are prevented from further wear by the first annular gap RS1a to RS1e.

[0043] Figure 5 shows a longitudinal section through the piston rod packing 22 of a dry-operation piston compressor 20 having a throttle configuration 1 according to the present invention. The piston compressor 20 has a piston rod 21 mounted to be longitudinally movable in the axial direction A. When the throttle configuration 1 is installed or used, the cylinder is located on the high-pressure side 1a, and the piston rod drive unit (crank drive side) is located on the low-pressure side 1b. The piston rod packing 22 comprises a plurality of chamber rings 26, each having a seal ring 23 positioned inside a chamber ring 26. These chamber rings 26 are arranged back to back. In the embodiment shown in Figure 5, each seal ring 23 is positioned between a cover ring 24 and a support ring 25. Between two adjacent chamber rings 26, there is a so-called sandwich ring, in each case, in the direction of the piston rod 21, comprising a cover ring 24, a seal ring 23, and a support ring 25. However, the presence of the support ring and cover ring is not absolutely necessary, as indicated by the seal element located at the bottom of the piston rod packing 22. The throttle arrangement 1 is located at the high-pressure side inlet of the piston rod packing 22. In the illustrated embodiment, the throttle arrangement 1 comprises three seal discs 2a to 2c arranged in a seal disc holder 3, overlapping each other in the axial direction A. The axial height A of the throttle arrangement 1 is therefore somewhat smaller than the width (dimension) of the groove formed by the two adjacent chamberings 26 that house the throttle arrangement 1. Thus, the throttle arrangement 1 is inserted between these chamberings 26 with axial play A. The seal discs 2a to 2c are not clamped between the bearing surface 6 and the chamberings 26 adjacent to the high-pressure side throttle arrangement, due to the fact that the first leg 4 of the seal disc holder 3 extends slightly above the uppermost seal disc 2a located within the seal disc holder 3. Thus, the seal discs 2a to 2c have axial clearance A when in use, allowing for radial movement of the seal discs 2a to 2c during use.

[0044] Figure 6a shows a top view of a second embodiment of the throttle arrangement 1 according to the present invention, comprising a seal disc holder 3 and a plurality of seal discs 2. Thereafter, according to the shown top view, only the uppermost seal disc 2 in the axial direction A is visible in this representation. The seal disc holder 3 has an L-shaped radial cross section in the radial direction R, as can be seen below in Figure 6b. The seal disc holder 3 comprises a first leg portion 4 extending (running) in the axial direction A and a second leg portion 5 extending laterally with respect to the axial direction A. The second leg portion 5 has an annular design. The second leg portion 5 has a bearing surface 6 on which the seal discs 2 are arranged overlapping each other in the axial direction A. The first leg portion 4 is cylindrical, and the second leg portion 5 is annular. The first leg portion 4 is cylindrical, and it extends circumferentially U along the inner circumference of the second leg portion 5, from the bearing surface 6 towards the seal discs 2. Furthermore, the first leg portion 4 has an interface surface 8 on the side facing the seal disc (seal ring disc) 2 that is shaped like a cylinder jacket in the circumferential direction U. This interface surface 8 is interrupted by eight uniformly distributed gas passage openings 7 in the circumferential direction U.

[0045] Figure 6b shows a longitudinal section along the line of intersection DD in Figure 6a, passing through the throttle arrangement 1 shown in Figure 6a. A total of five seal discs 2a to 2e are visible. These seal discs 2a to 2e are stacked on top of each other in the axial direction A. The seal discs 2a to 2e can be inserted into the seal disc holder 3 from the high-pressure side 1a. As a result, the seal disc 2e positioned at the bottom of the seal disc holder 3 rests on the bearing surface 6 of the second leg portion 5 such that the flank of the seal disc 2e faces toward the low-pressure side 1b. In the illustrated embodiment, the second leg portion 5 is oriented radially outward relative to the first leg portion 4. Consequently, the cylindrical first leg portion 4 extends along the inner circumference of the second leg portion 5, i.e., from the bearing surface 6 toward the high-pressure side 1a, over a range slightly greater than the total axial height of the stacked seal discs 2a to 2e. The axial height H4 of the first leg portion 4 is 13 mm, and the axial heights (not shown) of the seal discs 2a to 2e are each 2.5 mm. The difference between the axial height H4 of the first leg portion 4 and the sum of the axial heights of the stacked seal discs 2a to 2e results in an axial clearance of 0.5 mm between the seal discs 2a to 2e in the seal disc holder 3 in the illustrated embodiment. Therefore, the seal discs 2a to 2e can be reliably moved radially during use.

[0046] Figure 7 shows a longitudinal section through a piston compressor, which comprises a cylinder 27, a piston 28, and at least one throttle configuration 1 positioned on the piston 28, as described above in Figures 6a and 6b. The piston 28 is configured as a built-up piston. Thus, the piston 28 comprises a plurality of piston bodies 29 arranged continuously in the axial direction A. Each piston body 29 has a chamber disc 29a that forms an internal space 29b. The throttle configuration 1 is positioned in the internal space 29b. In Figure 7, the compression chamber (1a) of the piston compressor 20 is located at the top, and the crankcase, i.e., the low-pressure side (low-pressure section) 1b, is located at the bottom. The throttle configuration 1 comprises a seal disc holder 3 and four annular seal discs 2a to 2d. Each of these seal discs 2a to 2d forms a first annular gap RS1 between its radially inward circumferential surfaces 11a to 11d and the interface surface 8 of the seal disc holder 3. The seal disc holder 3 is positioned with a lateral gap relative to the axial direction A with respect to the chamber disc 29a, thus forming an internal gap 29c. In the illustrated embodiment, the axial height H4 of the first leg portion 4 is slightly smaller than the axial height of the internal space 29b. As a result, the internal gap 29c is fluidly connected to the high-pressure side space (1a), which is located further above and therefore not visible in the illustrated figure. Consequently, the first annular gap RS1 is also fluidly connected to the high-pressure side space (1a) via the gas passage opening 7 of the first leg portion 4 (not visible in the illustrated figure 7). During operation of the piston compressor 20, the seal discs 2a to 2d come into contact with the sliding surface 9 of the cylinder 27, resulting in material being removed from the outer circumferential surfaces 10a to 10d of the seal discs 2a to 2d. Therefore, the outer diameter of the seal discs 2a to 2d, and thus the second annular gap RS2 between the outer circumferential surfaces 10a to 10d and the sliding surface 9, continuously increases. As soon as the second annular gap RS2 grows to a diameter substantially corresponding to the first annular gap RS1, further wear of the seal discs 2a-2d is prevented by the limitation of radial clearance by the interface surface 8.Therefore, in the embodiment of throttle arrangement 1 according to the present invention shown in Figure 7, slight wear is first allowed on the outer circumferential surfaces 10a to 10d of the seal discs 2a to 2d before the seal discs 2a to 2d are prevented from further wear by the first annular gap RS1a to RS1d.

[0047] Figure 8 is a side view of an example of a piston 28 having four throttle arrangements 1 according to the present invention, starting from the high-pressure side 1a and arranged at intervals from each other in the axial direction A in the first region A1 of the piston 28. In the axial direction A, the piston 28 is then configured with five additional sealing elements 30 in the second region A2. Furthermore, a guide ring 31 is located on the low-pressure side 1b. [Explanation of Symbols]

[0048] 1...Throttle placement. 1a... High-voltage side. 1b... Low-pressure side.

[0049] 2... Seal disc. 3…Seal disc holder. 4...First leg.

[0050] 5...Second leg. 6...Bearing surface. 7…Gas passage opening.

[0051] 8...Interface. 9…The sliding surface of the sealed object (sealed object, object to be sealed). 10... The outer surface of the seal disc.

[0052] 11... The inner surface of the seal disc. 12... The central through-hole of the seal disc. 13...The central through-hole of bearing surface 6.

[0053] 14...Inner circumferential surface of the central through hole 13. 20... Piston compressor. 21... Piston rod.

[0054] 22... Piston rod packing. 23... Seal ring. 24... Covering.

[0055] 25...Support ring. 26... Chambering. 27...Cylinder.

[0056] 28... Piston. 29... Piston body. 29a... Chamber disc.

[0057] 29b...Inside. 29c...Internal gap. 30... Sticker element.

[0058] 31... Guide ring. A... Axis direction. B7… Arc length of the gas passage opening.

[0059] B8... Arc length of the boundary segment. D2... Outer diameter of the seal disc. D 12 ...Inner diameter of the seal disc.

[0060] D8... Inner diameter of the receiving chamber. D 13 ...Inner diameter of the central through-hole 13. H2…Axial height of the seal disc.

[0061] H4…Axial height of the first leg. R... Radial direction. RS1…First annular gap.

[0062] RS2…Second annular gap. U...Circumferential direction.

Claims

1. A throttle arrangement (1) for sealing a sliding surface (9) of a body that is movable in the axial direction (A), The throttle arrangement (1) includes a high-pressure side (1a) on the compression chamber side and a low-pressure side (1b) on the crank drive side when in use. The throttle arrangement (1) comprises a plurality of annular seal discs (2) and a seal disc holder (3), The seal disc holder (3) has an L-shaped radial cross-section having a first leg portion (4) extending in the axial direction (A) and a second leg portion (5) extending laterally with respect to the axial direction (A). The first leg portion (4) and the second leg portion (5) both form the L-shaped radial cross-section, The second leg portion (5) has an annular design, and the second leg portion (5) has a bearing surface (6) facing the direction of the high pressure side (1a), and the seal discs (2) are arranged on the bearing surface (6) overlapping each other in the axial direction (A). The first leg portion (4) is cylindrical and extends along the outer or inner circumference of the second leg portion (5) from the bearing surface (6) in the direction of the high-pressure side (1a). The axial height (H) of the first leg portion (4) ４ The seal discs (2) stacked on the bearing surface (6) are selected to have axial play (A) when in use. The first leg portion (4) has a plurality of gas passage openings (7), The first leg portion (4) has an interface surface (8) facing the direction of the seal disc (2), When the seal disc (2) is coaxially aligned with the first leg portion (4) and the body to be sealed, a first annular gap (RS1) is formed between the interface surface (8) and the seal discs (2), and the first annular gap (RS1) is fluidly connected to the high-pressure side (1a) by a plurality of gas passage openings (7). The second annular gap (RS2) is formed between the sliding surface (9) of the body being sealed and the seal discs (2), and the expansion of the second annular gap (RS2) related to wear is limited by the radial width of the first annular gap (RS1). Throttle configuration (1).

2. The radial width of the first annular gap (RS1) shall not exceed 1 mm. The throttle arrangement (1) according to claim 1.

3. The gas passage openings (7) are located at the axial height (H) of the first leg portion (4). ４ It extends throughout the entirety of The throttle arrangement (1) according to claim 1 or 2.

4. The gas passage openings (7) are uniformly distributed in the circumferential direction (U) of the first leg portion (4). The throttle arrangement (1) according to any one of claims 1 to 3.

5. The ratio of the sum of the areas of the gas passage openings (7) to the area of ​​the interface (8) that includes the areas of the gas passage openings (7) is between 1:2 and 1:

4. The throttle arrangement (1) according to any one of claims 1 to 4.

6. The first leg portion (4) is provided with eight gas passage openings (7), The throttle arrangement (1) according to any one of claims 1 to 5.

7. The seal disc holders (3) are formed integrally with each other. The throttle arrangement (1) according to any one of claims 1 to 6.

8. The number of the aforementioned seal disks (2) is at least three. The throttle arrangement (1) according to any one of claims 1 to 7.

9. Each of the seal discs (2) is a one-piece and formed in an endless manner. The throttle arrangement (1) according to any one of claims 1 to 8.

10. The axial height (H) between the seal discs (2) ２ ) is between 1 mm and 5 mm. The throttle arrangement (1) according to any one of claims 1 to 9.

11. The seal discs (2) are made of different materials from each other. The throttle arrangement (1) according to any one of claims 1 to 10.

12. At least one of the seal disks (2) has a different axial height (H) than the other seal disks (2). ２ ) has The throttle arrangement (1) according to any one of claims 1 to 11.

13. The axial height (H) between the seal discs (2) ２ ) increases in the direction of the low-pressure side (1b), The throttle arrangement (1) according to claim 12.

14. Having at least one throttle arrangement (1) according to any one of claims 1 to 13, Piston compressor (20).

15. In the piston compressor (20) according to claim 14, for sealing the piston rod (21) or the piston (28), Use of the throttle arrangement (1) according to any one of claims 1 to 13.

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