Axial compensator unit, valve assembly

Abstract

Axial compensator unit (1) for a valve assembly (20), comprising: - an axially elastically deformable bellows section (2) which has a first axial bellows end (3) and a second axial bellows end (4) and extends tubularly from its first axial bellows end (3) to its second axial bellows end (4) along an axial direction (A) of the axial compensator unit (1), - a fastening section (5) for fastening the axial compensator unit (1) to a valve housing (22) of the valve assembly (20), wherein the fastening section (5) integrally transitions into the first axial bellows end (3), - a coupling section (6) for coupling an actuating element (23) of the valve assembly (20) with a valve element (21) of the valve assembly (20), wherein the coupling section (6) integrally transitions into the second axial bellows end (4); - wherein the bellows section (2) is formed with a first plastic material (K1), - wherein the fastening section (5) is formed with a second plastic material (K2), and - wherein the fastening section (5) has a circumferential annular groove (7) for partially receiving a sealing ring (24) in such a way that a portion of the sealing ring (24) protruding from the annular groove (7) can be applied to the valve housing (22) along the axial direction (A).

Description

[0001] The invention relates to an axial compensator unit for a valve assembly and to such a valve assembly. Furthermore, the present disclosure, with two aspects, relates to a method for manufacturing such an axial compensator unit.

[0002] Particularly in applications within the pharmaceutical, food, and / or chemical industries—for example, in the production or processing of paints or explosives—valve devices are frequently used that consist of a valve body and a valve element adjustable relative to the valve body. Some such valve devices have an open state for fluid flow and a closed state to prevent fluid flow. Also common are valve devices that do not have a completely closed state, but rather where the valve element is adjustable relative to the valve body between a position for maximum flow and another position for minimum flow, in order to regulate the flow of fluid through the valve device depending on its position.

[0003] The valve housing is often provided with a passage through which a drive coupling is formed between the valve element located inside the valve housing and an actuator for adjusting the valve element. To seal this passage fluid-tight against the external environment, an axially elastically deformable axial compensator unit is often used, projecting into or located inside the valve housing. Such an axial compensator unit typically has a first axial end connected to the valve element and a second axial end that is fluid-tightly connected to the valve housing, particularly in the region of an opening edge of the passage.

[0004] Sometimes, such a metal axial compensator unit is made of metal, with an elastically deformable sealing ring element, which can be clamped between the second axial end and the valve body, to seal the passage through the valve body. In other cases, a plastic axial compensator unit made of a single, homogeneous plastic material is used, but in this case, typically without a separate sealing ring element. This is because the plastics used for such a unit are usually not sufficiently dimensionally stable to reliably withstand the forces required to deform such a sealing ring element over a large number of valve adjustment cycles.This omission of a separate elastic sealing ring element in conventional plastic axial compensator units necessitates, in turn, the high-precision manufacturing of both the valve housing and the plastic axial compensator unit to tight tolerances in order to ensure a reliable seal between the second axial end and the valve housing. This is complex and costly.

[0005] It is an object of the present invention to provide an axial compensator unit for a valve assembly, as well as such a valve assembly, each exhibiting improved properties. In particular, a particularly durable axial compensator unit is to be provided that functions reliably even with coarser manufacturing tolerances.

[0006] This problem is solved by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent claims. The wording of all claims is made explicit by reference to the content of this description.

[0007] An axial compensator unit according to the invention is designed for use in a valve device which has a valve element that is axially adjustable under partial elastic deformation of the axial compensator unit.

[0008] The axial compensator unit for the valve assembly has a bellows section that is designed to be axially elastically deformable. The bellows section has a first axial end and a second axial end. The bellows section extends tubularly from its first axial end to its second axial end along an axial direction of the axial compensator unit. This axial direction can correspond to the adjustment direction, also known as the stroke direction, of the valve element relative to a valve housing of the valve assembly.

[0009] The axial compensator unit has a mounting section designed for attaching the axial compensator unit to the valve housing of the valve assembly. The mounting section and the first axial bellows end are integrally joined, in particular integrally or by a material bond. Preferably, the mounting section is annular. The mounting section may have an outer circumference that is preferably designed to be at least partially received in a passage in the valve housing that is matched to the mounting section.

[0010] The axial compensator unit has a coupling section designed to connect an actuator of the valve assembly to the valve element. Specifically, the coupling section connects an axial end of the actuator of the valve assembly to the valve element. The actuator can, for example, be driven bidirectionally along the axial direction by means of an actuator of the valve assembly to adjust the valve element relative to the valve housing in order to vary the flow of fluid through the valve assembly. The coupling section merges integrally, in particular integrally or with a material bond, into the second bellows end.

[0011] The bellows section of the axial compensator unit is made of, preferably, a first plastic material. The mounting section is made of, preferably, a second, and in particular a different, plastic material.

[0012] Preferably, the first plastic material of the bellows section and the second plastic material of the fastening section are different plastic materials, for example with different compositions and / or properties.

[0013] The second plastic material may expediently include a reinforcing device. In particular, the second plastic material differs from the first plastic material at least or even exclusively with regard to the reinforcing device. Such a reinforcing device may, in particular, include reinforcing fibers, fillers, and / or at least one plastic compound component.

[0014] The mounting section of the axial compensator unit has an annular groove, which is, in particular, circumferentially shaped. The annular groove can extend around a central axis of the mounting section, the central axis being longitudinally extended along the axial direction. The annular groove can be arranged coaxially with the central axis. The circumferential annular groove of the mounting section is designed to partially receive a sealing ring such that a portion of the sealing ring protruding from the annular groove (in a mounted state of the axial compensator unit on the valve housing) can be pressed against the valve housing. In other words, the annular groove can have a groove depth that is smaller than the thickness of a profile of the sealing ring, such that the portion of the sealing ring partially received in the annular groove protrudes beyond the annular groove.

[0015] Preferably, the sealing ring is designed to be elastically deformable. The sealing ring can be made of or consist of an elastomeric material, such as rubber. For example, the sealing ring can be an O-ring.

[0016] When installed, the sealing ring between the valve housing and the axial compensator unit can be compressed in such a way that it is deformed, thus providing the desired sealing effect. This deformation allows the sealing ring to at least partially compensate for any manufacturing tolerances in the mounting section and / or the valve housing.

[0017] Advantageously, the invention allows, on the one hand, the good elastic properties of the first plastic material of the bellows section to be utilized, so that the axial compensator unit can withstand a particularly large number of adjustment cycles for adjusting the valve element relative to the valve housing, especially without breakage. The corresponding fatigue strength of the bellows section promotes the longevity of the axial compensator unit. On the other hand, the design of the mounting section with a second plastic material makes it possible to realize the mounting section with greater dimensional stability relative to the bellows section, i.e., greater stiffness, which is sufficient to absorb the sealing-promoting deformation forces acting on the sealing ring, especially without the mounting section yielding or failing.Because the axial compensator unit is constructed from various plastic materials, allowing the use of a sealing ring, the elastic flexibility of the sealing ring enables leak-free compensation of larger tolerances between the mounting section and the valve housing. Furthermore, the separate sealing ring can be easily replaced if necessary – for example, to renew the seal during maintenance.

[0018] In some embodiments, the first plastic material, particularly under continuous stress, may not behave fully elastically, resulting in plastic deformation. In particular, the second plastic material differs from the first in this property (creep behavior, especially characterized by the creep modulus) such that, under the same load, the resulting plastic deformation of the second plastic material is lower than that of the first. This can increase the reliability of the combination of sealing ring and mounting section.

[0019] In some embodiments, the sealing ring is not a component, particularly not a fixed one, of the axial compensator unit. However, other embodiments are also conceivable in which the sealing ring is fixed in the annular groove, in particular glued in place.

[0020] The axial compensator unit can expediently support the sealing ring, which is partially received in the annular groove, for example by friction fit and / or form fit.

[0021] Advantageously, the axial compensator unit and the sealing ring, which is partially inserted into the annular groove, can together form an axial compensator-sealing ring assembly for the valve assembly. For example, to assemble the valve assembly, the sealing ring can first be partially inserted into the annular groove to assemble the axial compensator-sealing ring assembly, whereby the assembled axial compensator-sealing ring assembly is then attached to the valve body in such a way that the sealing ring is compressed between the mounting section of the axial compensator unit and the valve body.

[0022] In one embodiment, the bellows section surrounds an inner bellows chamber of the axial compensator unit. The coupling section integrally carries the valve element, and alternatively or additionally, the coupling section axially closes the inner bellows chamber at the second bellows end.

[0023] The actuating element can be coupled to the coupling section, projecting through the bellows interior, or can be coupled to it. A coupling contour of the coupling section for attaching the actuating element can therefore face the bellows interior. Preferably, the coupling contour borders directly on the bellows interior.

[0024] In a further embodiment, the fastening section has a flange section that projects radially outwards from the bellows section. Preferably, the flange section is annular in shape. The annular groove is arranged on one side of the flange section, with this side of the flange section pointing axially towards the coupling section.

[0025] In a further embodiment, the mounting section has a contact surface that preferably has a conical circumferential profile. The contact surface of the mounting section is designed for axial contact with a complementary mating surface of the valve housing. Viewed in an axial section of the axial compensator unit, the annular groove has a radially outer groove flank that extends radially inwards from a circumferential radially inner edge region of the contact surface, preferably obliquely to the axial direction. The contact surface itself extends obliquely to a radially inner groove flank of the annular groove, preferably parallel to the axial direction.

[0026] Preferably, viewed in axial section, both the radially inner and the radially outer groove flanks transition tangentially into a rounded groove base section of the annular groove. The groove base section can be complementary to a cross-sectional outline of the sealing ring to be accommodated. The cross-sectional outline of the sealing ring to be accommodated can be essentially circular in the unloaded and / or deformation-free state of the sealing ring, but other cross-sectional outline shapes are also conceivable.

[0027] In a further embodiment, viewed in axial section, the radially inner edge region of the contact surface and a radially outer end of a material transition, which integrally connects the mounting section with the bellows section, are arranged at the same height along the axial direction. The material transition can be a mixing zone in which the different plastic materials of the mounting section and the bellows section merge into one another, particularly in a flowing manner.

[0028] In some embodiments, the material transition can be formed by a weld. In other embodiments, the material transition can be created by zoned raw material distribution during the primary forming process of a blank for the axial compensator unit.

[0029] In a further embodiment, both the coupling section and the bellows section comprise the same first plastic material; preferably, the valve element also comprises the first plastic material of the coupling section. The first plastic material of the bellows section is preferably polytetrafluoroethylene (PTFE).

[0030] In a further embodiment, the second plastic material of the fastening section is a plastic compound material. This plastic compound material is a mixture of at least two compound components. One of the compound components of the plastic compound material can correspond to the first plastic material of the bellows section, while at least one other compound component of the plastic compound material differs from the first plastic material of the bellows section.

[0031] Preferably, as already indicated above, the second plastic material is more dimensionally stable and / or stronger than the first plastic material of the bellows section.

[0032] Preferably, at least one compound component of the plastic compound material is a polytetrafluoroethylene (PTFE) and at least one other compound component of the plastic compound material is a polyetheretherketone (PEEK).

[0033] In a further embodiment, the bellows section is corrugated. Alternatively or additionally, an outer contour of the bellows section—viewed in axial section—has a meandering shape. Preferably, a concave meander loop of the meandering path closest to the mounting section can have a greater axial extent than another concave meander loop of the meandering path closest to the valve element. Such uneven axial extents of the concave meander loops can advantageously influence the deformation behavior of the bellows section.

[0034] A valve assembly according to the invention comprises a valve housing and a valve element that is axially adjustable relative to the valve housing. The valve assembly also has an actuating element designed for axially adjusting the valve element between a first valve element position and a second valve element position. Preferably, the valve assembly has an actuator designed for driving the actuating element to axially adjust the valve element. The actuating element can, for example, be rod-shaped. The actuating element can optionally be understood as a connecting rod for coupling the actuating element to the coupling section. The valve assembly includes an axial compensator unit according to the invention as described above.In the annular groove of the axial compensator unit, a sealing ring, particularly of the valve assembly, is partially recessed such that a portion of the sealing ring protrudes from the annular groove along the axial direction, allowing it to be deformed by contact with the valve housing, particularly in a sealing manner. The actuating element and the valve element are coupled to each other via the coupling section of the axial compensator unit in such a way that the bellows section of the axial compensator unit undergoes axial elastic deformation when the valve element is axially adjusted relative to the valve housing. The advantages of the axial compensator unit mentioned above also apply to the valve assembly with such an axial compensator unit.

[0035] In some embodiments, the valve assembly has an open state for fluid flow and a closed state to prevent such fluid flow through the valve assembly. The states can be changed by adjusting the valve element relative to the valve housing, in particular continuously.

[0036] In other embodiments, the valve device does not have a completely closed state, but the valve element is adjustable relative to the valve housing between a position for a maximum flow cross-section and another position for a minimum flow cross-section in order to regulate the flow of fluid guided through the valve device depending on the position, in particular steplessly.

[0037] The disclosure further relates, with one aspect each, to two methods for manufacturing an axial compensator unit according to the invention. These two methods are hereinafter referred to as the "first" method and the "second" method.

[0038] The first method disclosed serves to manufacture an axial compensator unit according to the invention as described above. The axial compensator unit can be manufactured by carrying out the first method. The first method comprises a step in which a granulate mixture is provided for the first plastic material of the bellows section. In a further, and in particular subsequent, step, another granulate mixture is provided for the second plastic material of the mounting section. In a further, and in particular subsequent, step of the first method, a single green body with a zoned distribution of the two granulate mixtures for both the bellows section and the mounting section is produced. In a further, and in particular subsequent, step of the first method, a blank is produced as a sintered body resulting from sintering the single green body.In a further, particularly subsequent and / or final, step of the first process, the resulting blank is machined to give the axial compensator unit its final shape. Preferably, the blank is produced with a substantially circular cylindrical shape, from which the final shape of the axial compensator unit is subtractively obtained by external and internal turning.

[0039] The second method according to the disclosure serves to manufacture an axial compensator unit according to the invention as described above. The axial compensator unit can be manufactured by carrying out the second method. The second method comprises a step in which a granulate mixture is provided for the first plastic material of the bellows section. In a further, and in particular subsequent, step, another granulate mixture is provided for the second plastic material of the mounting section. In a further, and in particular subsequent, step of the second method, separate green bodies are produced, each containing one of the two granulate mixtures for the bellows section and for the mounting section.In a further, and in particular subsequent, step of the second process, a blank is produced by sintering the separate green bodies and subsequently welding the resulting separate sintered bodies together. In a further, and in particular subsequent and / or final, step of the second process, the resulting blank is machined to give the axial compensator unit its final shape. Preferably, the blank is produced with a substantially circular cylindrical shape, from which the final shape of the axial compensator unit is subtractively obtained by external and internal turning.

[0040] Further advantages and features of the invention will become apparent from the claims and from the following description of a preferred embodiment, which is illustrated with reference to the drawings. In this context, identical reference numerals refer to identical, similar, or functionally equivalent components.

[0041] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of this disclosure. Fig. Figure 1 shows in schematic axial section an embodiment of a valve device which includes an embodiment of an axial compensator unit, and Fig. Figure 2 shows an enlarged detail of an axial section of the axial compensator unit. Fig. 1.

[0042] A valve assembly 20 is designed to regulate the flow of fluid through it. The valve assembly 20 has a valve housing 22, which defines a fluid channel through which the fluid can flow. The valve assembly 20 also has a valve element 21, which is axially adjustable relative to the valve housing 22. The valve element 21 is adjustable within the fluid channel of the valve housing 22 such that, depending on its position relative to the valve housing 22, different flow cross-sections of the valve assembly 20 result.

[0043] For axial adjustment of the valve element 21 between a first valve element position and a second valve element position, an adjusting element 23 of the valve assembly 20 is provided. The flowable cross-section of the valve assembly 20 differs in the first valve element position from that in the second valve element position.

[0044] The valve assembly 20 has an axial compensator unit 1. The axial compensator unit 1 undergoes a region-specific elastic deformation when the valve element 21 is axially adjusted.

[0045] The axial compensator unit 1 provided for the valve assembly 20 has a bellows section 2 that is axially elastically deformable. The bellows section 2 extends along an axial direction A of the axial compensator unit 1 in a tubular shape. A first axial bellows end 3 of the bellows section 2 is opposite a second axial bellows end 4 of the bellows section 2 along the axial direction A.

[0046] The axial compensator unit 1 has a mounting section 5, which serves to attach the axial compensator unit 1 to the valve housing 22. The mounting section 5 merges integrally into the first axial bellows end 3. In particular, the mounting section 5 and the bellows section 2 can be formed in one piece.

[0047] The axial compensator unit 1 has a coupling section 6, which serves for the mechanical coupling of the actuating element 23 of the valve assembly 20 with the valve element 21. The coupling section 6 merges integrally into the second axial bellows end. The coupling section 6 and the bellows section 2 can be formed as a single piece. In this respect, the bellows section, the mounting section, and the coupling section can be comprised of a single monolithic body of the axial compensator unit 1.

[0048] The coupling section 6 connects the actuating element 23 and the valve element 21 in such a way that the bellows section 2 of the axial compensator unit 1 is axially elastically deformed when the valve element 21 is axially adjusted.

[0049] Bellows section 2 is formed with, in this case, a first plastic material K1. In contrast, fastening section 5 is formed with, in this case, a second plastic material K2 (different from the first plastic material K1). Both bellows section 2 and fastening section 5 are therefore based on plastic materials, which, however, differ in their type, composition, and / or properties.

[0050] The second plastic material K2 is stiffer than the first plastic material K1 of bellows section 2. Alternatively or additionally, the second plastic material K2 can have a higher strength than the first plastic material K1 of bellows section 2.

[0051] The mounting section 5 has a circumferential annular groove 7. The circumferential annular groove 7 serves to partially receive a sealing ring 24 of the valve assembly 20 such that a ring-shaped portion of the sealing ring 24 protrudes from the annular groove 7. This portion of the sealing ring 24, projecting beyond the annular groove 7, is fluid-tight against the valve housing 22 along the axial direction A when the valve assembly 20 is assembled. Preferably, the sealing ring 24 is pressed against the valve housing 22 in such a way that it is deformed between the mounting section 5 and the valve housing 22 to provide a sealing effect. The sealing ring 24 can thus be partially received in the annular groove such that an annular portion of it protrudes from the groove 7 along the axial direction A, allowing it to be compressed by the contact of the valve housing 22.

[0052] In this case, the bellows section 2 surrounds an inner bellows chamber 8 of the axial compensator unit 1. The inner bellows chamber 8 is axially fluid-tightly sealed at the second bellows end 4 by means of the coupling section 6. The inner bellows chamber 8 is open at the first axial bellows end 3.

[0053] The coupling section 6 can integrally support the valve element 21, in particular in one piece or by a material bond. In the present case, the actuating element 23 projects through the bellows interior 8 and is coupled to the coupling section 6 on a side of the coupling section 6 that directly borders the bellows interior 8. As in the present case, the valve element 21 can be integrally formed on the coupling section 6 axially opposite the actuating element 23.

[0054] The mounting section 5, for example, has a circumferential flange section 9 that projects radially outwards from the bellows section 2. An outer circumference of the flange section 9 can be received in a complementary bore of the valve housing 22, with the actuating element 23 projecting at least partially through this bore.

[0055] The annular groove 7 is located on the side of the flange section 9 that points along the axial direction A towards the coupling section 6. For example, the annular groove runs radially around the outside of the bellows section 2.

[0056] The mounting section 5, for example, has a contact surface 11, which in this case is conical. The contact surface 11 is axially oriented against a complementary counter surface 26 of the valve housing 22. The contact between the contact surface 11 and the counter surface 26 particularly limits the deformation of the sealing ring 24.

[0057] Based on the axial section of the Fig. Figure 1 shows, for example, that the annular groove 7 has a radially outer groove flank 13, which extends radially inwards from a circumferential radially inner edge region 12 of the contact surface 11, in this case obliquely to the axial direction A. Furthermore, the axial section shows that the contact surface 11 extends obliquely to a radially inner groove flank 14 of the annular groove 7, which, for example, runs parallel to the axial direction A.

[0058] The annular groove 7 has a rounded groove base section 18, which, for example, is complementary to a round cross-sectional outline of the sealing ring 24 to be received. In the axial section, the radially inner groove flank 14 and the radially outer groove flank 13 can each transition tangentially into the rounded groove base section 18, as is the case here.

[0059] In the axial section, it is also evident that the radially inner edge region 12 of the contact surface 11 is arranged along the axial direction A, for example, at the same axial height as a radially outer end 15 of a material transition 16, wherein this material transition 16 integrally connects the fastening section 5 with the bellows section 2. The material transition 16 is illustrated here with a solid line; it is understood that this representation is intended only for better comprehension. The material transition 16 need not be a sharply defined line in the axial section; it can also correspond to a mixing zone in which the first plastic material K1 and the second plastic material K2 are mixed.

[0060] The coupling section 6 and the bellows section 2 comprise the same first plastic material K1. The valve element 21 is also made of this first plastic material K1. Preferably, the coupling section 6, the valve element 21, and the bellows section 2 are made of a homogeneous material that comprises or is the first plastic material K1. The plastic material K1 of the bellows section 2 can be polytetrafluoroethylene (PTFE), or, as in the present case, a different material.

[0061] The second plastic material K2 of fastening section 5 is, for example, a plastic compound material KC. The plastic compound material KC comprises a mixture of at least two compound components C1 and C2. In this case, the plastic compound material KC consists of a first compound component C1 made of polytetrafluoroethylene (PTFE) and a second compound component C2 made of polyetheretherketone (PEEK).

[0062] Relative to the first plastic material K1 of bellows section 2, an additional compound component can be added to the second plastic material K2, for example, as in the present case, in the form of PEEK. The additional compound component can have a mechanically reinforcing effect.

[0063] Bellows section 2, for example, is corrugated. As in the present case, an outer contour 17 of bellows section 2 (viewed in the axial section) can have a meandering shape. For example, a concave meander loop 19A of the meandering path closest to the fastening section 5 can have a greater axial extent along the axial direction A than another concave meander loop 19B of the meandering path closest to the valve element 21. In contrast, convex meander loops of the meandering path can have a uniform axial extent and / or a uniform radius of curvature.

[0064] The axial compensator unit 1 can be manufactured, for example, by first providing a granulate mixture for the first plastic material K1 of the bellows section 2. Then, a different granulate mixture can be provided for the second plastic material K2 of the mounting section 5. Based on the provided granulate mixtures, either a common green body can be produced for both the bellows section 2 and the mounting section 5, or two separate green bodies can be produced for the bellows section 2 and the mounting section 5. This is followed by the production of a blank, either by sintering the common green body or by sintering the separate green bodies and welding the resulting separate sintered bodies together. The blank thus obtained is then machined to give the axial compensator unit 1 its final shape, such as, in particular, the Fig. 1 to take away, to lend.

[0065] At the in Fig. In the embodiment of the valve device 20 shown in Figure 1, for example, there is no completely closed state, but the valve element 21 is adjustable relative to the valve housing 22 between a position for a maximum flow cross-section and another position for a minimum flow cross-section in order to regulate the flow of fluid guided through the valve device 20 depending on the position.

[0066] Other embodiments of the valve device 20 have, in addition to an open state for fluid to flow through and a closed state for preventing such fluid flow through the valve device 20.

Claims

[1] Axial compensator unit (1) for a valve assembly (20), comprising: - an axially elastically deformable bellows section (2) which has a first axial bellows end (3) and a second axial bellows end (4) and extends tubularly from its first axial bellows end (3) to its second axial bellows end (4) along an axial direction (A) of the axial compensator unit (1), - a fastening section (5) for fastening the axial compensator unit (1) to a valve housing (22) of the valve assembly (20), wherein the fastening section (5) integrally transitions into the first axial bellows end (3), - a coupling section (6) for coupling an actuating element (23) of the valve assembly (20) with a valve element (21) of the valve assembly (20), wherein the coupling section (6) integrally transitions into the second axial bellows end (4); - wherein the bellows section (2) is formed with a first plastic material (K1), - wherein the fastening section (5) is formed with a second plastic material (K2), and - wherein the fastening section (5) has a circumferential annular groove (7) for partially receiving a sealing ring (24) in such a way that a portion of the sealing ring (24) protruding from the annular groove (7) can be applied to the valve housing (22) along the axial direction (A). [2] Axial compensator unit (1) according to claim 1, - wherein the bellows section (2) surrounds a bellows interior (8) of the axial compensator unit (1), - wherein the coupling section (6) integrally supports the valve element (21) and / or axially closes the bellows interior (8) at the second axial bellows end (4), - wherein preferably the actuating element (23) is coupled or can be coupled to the coupling section (6) projecting through the bellows interior (8). [3] Axial compensator unit (1) according to claim 1 or 2, - wherein the fastening section (5) has a flange section (9) projecting radially outwards from the bellows section (2), - wherein the annular groove (7) is arranged on a side of the flange section (9) pointing along the axial direction (A) towards the coupling section (6). [4] Axial compensator unit (1) according to one of claims 1 to 3, - wherein the fastening section (5) has a contact surface (11) which is designed for axial contact with a complementary counter surface (26) of the valve housing (22), - considered in an axial section: - the annular groove (7) has a radially outer groove flank (13) extending radially inwards from a circumferential radially inner edge region (12) of the contact surface (11), and - wherein the contact surface (11) runs obliquely to a radially inner groove flank (14) of the annular groove (7); - in particular, when viewed in the axial section, the radially inner groove flank (14) and the radially outer groove flank (13) each transition tangentially into a rounded groove base section (18) of the annular groove (7). [5] Axial compensator unit (1) according to claim 4, - wherein - viewed in the axial section - the radially inner edge region (12) of the contact surface (11) is arranged along the axial direction (A) at the same axial height as a radially outer end (15) of a material transition (16) which integrally connects the fastening section (5) with the bellows section (2). [6] Axial compensator unit (1) according to any one of the preceding claims, - wherein the coupling section (6) and the bellows section (2) have the same first plastic material (K1); and / or - wherein the first plastic material (K1) comprises polytetrafluoroethylene (PTFE). [7] Axial compensator unit (1) according to any one of the preceding claims, - wherein the second plastic material (K2) of the fastening section (5) is a plastic compound material (KC) comprising a mixture of at least two compound components (C1, C2), of which in particular at least one compound component (C1) is a polytetrafluoroethylene (PTFE) and at least one other compound component (C2) is a polyetheretherketone (PEEK); and / or - wherein the second plastic material (K2) is more dimensionally stable and / or stronger than the first plastic material (K1) of the bellows section (2). [8] Axial compensator unit (1) according to any one of the preceding claims, - wherein the bellows section (2) is corrugated tubular in shape; and / or - wherein an outer contour (17) of the bellows section (2) - viewed in an axial section - has a meandering course, wherein in particular a concave meander loop (19A) of the meandering course nearest to the fastening section (5) has a greater axial extent along the axial direction (A) than another concave meander loop (19B) of the meandering course nearest to the valve element (21). [9] Valve assembly (20) comprising: - a valve housing (22) and a valve element (21) axially adjustable relative to the valve housing (22), - an actuating element (23) for axially adjusting the valve element (21) between a first valve element position and a second valve element position, - an axial compensator unit (1) according to one of the preceding claims, - wherein a sealing ring (24) is partially received in the annular groove (7) of the axial compensator unit (1) such that the area of ​​the sealing ring (24) protrudes from the annular groove (7) along the axial direction (A) in order to be deformed by contact with the valve housing (22), - wherein the coupling section (6) of the axial compensator unit (1) couples the actuating element (23) and the valve element (21) together in such a way that the bellows section (2) of the axial compensator unit (1) is axially elastically deformable when the valve element (21) is axially adjusted.

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