WO2021195680A1

WO2021195680A1 - Hydraulic shock absorber, and method for the assembly of a shock absorber

Info

Publication number: WO2021195680A1
Application number: PCT/AT2021/060102
Authority: WO
Inventors: Klaus Grausgruber
Original assignee: Stiwa Automation Gmbh
Priority date: 2020-04-02
Filing date: 2021-03-26
Publication date: 2021-10-07
Also published as: AT523688A1

Abstract

The invention relates to a hydraulic shock absorber (1) comprising a cylindrical housing (2) with a housing outer shell surface (4) and a housing inner shell surface (5), a bottom closure (7) which is arranged on a first end side (6) of the housing (2), a piston (11) and a piston rod (3) which is coupled to the piston (11), a closure cover (9) which is arranged on the second end side (8), which lies opposite the first end side (6), and has a through hole (10) for the piston rod (3) which can be moved in the axial direction of the housing (2). The housing inner shell surface (5), the bottom closure (7) and the closure cover (9) delimit a housing interior (12), wherein the piston (11) divides the housing interior (12) into a first interior chamber (13) and a second interior chamber (14), and wherein a flow connection (15) is configured between the first interior chamber (13) and the second interior chamber (14). The invention relates, furthermore, to a method for the assembly of a hydraulic shock absorber (1).

Description

HYDRAULIC SHOCK ABSORBER AND PROCEDURE FOR ASSEMBLING A SHOCK ABSORBER

The invention relates to a hydraulic shock absorber and a method for assembling a hydraulic shock absorber.

From DE 202014004193 U1 and DE 20302121 U1 hydraulic shock absorbers are known which have a housing in which a piston is movably guided by means of a piston rod,

The object of the present invention was to overcome the disadvantages of the prior art and to create an improved hydraulic shock absorber and to provide a method for assembling a hydraulic shock absorber which allows a high degree of automation.

This object is achieved by a device and a method according to the claims.

The invention relates to a hydraulic shock absorber comprising a cylindrical housing with an outer casing surface and an inner casing surface, a bottom closure which is arranged on a first end face of the housing, a piston and a piston rod coupled to the piston, a closure cover which is arranged on the second end face opposite to the first end face and has a through-hole for the piston rod which is movable in the axial direction of the housing. The inner casing surface of the base closure and the closure cover delimit an interior space, the piston dividing the interior space into a first interior chamber and a second interior chamber and a flow connection being formed between the first interior chamber and the second interior chamber. The first interior chamber and the second interior chamber form a fluid receiving space for a fluid medium, for example a hydraulic fluid.

The bottom closure in the sense of this document can be an independent component which is arranged on the first end face of the housing. In particular, it can be provided that the bottom closure and the housing are connected to one another in one piece. This can be achieved, for example, by a weld seam. In an alternative embodiment variant, it is also conceivable that the bottom closure is designed in one piece with the housing. In particular, it can be provided that the housing interior is produced from a solid material blank by mechanical processing, for example by turning. In this case, the machining process can be carried out in such a way that the inner casing surface directly adjoins the bottom closure. Furthermore, it is also conceivable that the housing, together with the bottom closure, is cast in one piece.

The present shock absorber is particularly suitable for industrial use, with maximum energy absorption and gentle damping being achieved by the structure according to the invention. Furthermore, thanks to the modular design, the shock absorber is scalable in terms of size and is therefore suitable for a wide variety of applications where braking and damping of moving masses is required,

The hydrostatic piston guide also ensures that when the shock absorber is actuated, there is only little wear and that wear is largely prevented. The shock absorber according to the invention thus has a comparatively long service life.

Furthermore, it can be expedient if a helical groove is formed in a helical region of the inner casing surface of the housing, via which the flow connection between the first interior chamber and the second interior chamber is established.

The helical groove enables high power consumption to be achieved through maximum utilization in every piston position. Furthermore, a defined damping characteristic can be achieved by providing the helical groove within the inner casing surface, with the helical groove serving as a throttle element. At the same time, a helical groove can easily be produced in the inside surface of the housing.

Because a fluid medium can flow between the piston and the piston guide surface, which is formed by the helical groove, during the entire stroke of the shock absorber, the relatively moving parts can be separated by a sliding film, which can further minimize wear. In addition, due to the continuous flow of the fluid medium through the helical groove, only low stress on the fluid medium is achieved.

Furthermore, it can be provided that the helical groove has a constant groove pitch, whereby a uniform flow of the fluid medium can be achieved, regardless of the piston position along the helical groove. Furthermore, a helical groove with a constant groove pitch can be produced simply and inexpensively.

In addition, it can be provided that a groove base of the helical groove has a constant shape over the entire length of the helical groove. In particular, a thread chisel can be used here, which, viewed over the length of the helical groove, moves deeper and deeper into the housing to change the cross-section during the manufacturing movement.

Inner jacket surface is immersed. In particular, it can be provided that the bottom of the groove, viewed in cross section, is formed at its deepest point by a straight line which runs parallel to the shock absorber axis. Furthermore, groove side walls can be formed which, viewed in cross section, can be arranged at an angle between 85% and 95% to the straight line of the groove base. Furthermore, the straight line of the groove edge can be connected to the groove side walls by means of a transition radius.

In addition, it can be provided that a groove base of the helical groove has a constant radius over the entire length of the helical groove, whereby an even flow of the fluid medium can be achieved regardless of the piston position along the helical groove. Furthermore, a helical groove with a constant radius can be produced simply and inexpensively. In particular, a thread chisel can be used here which, in order to change the cross section over the length of the helical groove, dips deeper and deeper into the inner casing surface during the manufacturing movement.

Alternatively, it can be provided that the helical groove has different contour shapes over its length. This can be achieved, for example, by changing the turning tools for different longitudinal areas of the helical groove. This measure can also change the cross section over the length of the helical groove.

An embodiment is also advantageous according to which it can be provided that the helical groove has a groove depth minimum and a groove depth maximum, the groove depth from Groove depth minimum to groove depth maximum increases continuously, whereby a progressive damping effect of the hydraulic shock absorber can be achieved. Furthermore, the continuous tapering of the helical groove enables a low-vibration and precise braking of a moving mass to be achieved. According to a further development, it is possible for the groove depth maximum to be arranged closer to the second end face than the groove depth minimum.

When the piston retracts, the throttle cross-section acting on the trailing edge steadily decreases, which means that the braking effect on a moving mass can be continuously increased and thus smooth, slower damping can be achieved. It can also be useful if the axial extent of the helical region of the helical groove is between 10% and 50%, in particular between 20% and 40%, preferably between 25% and 35% of a housing length, with a distance of the groove depth minimum to the first Front side is between 10% and 50%, in particular between 20% and 40%, preferably between 25% and 35% of the housing length. The housing length is measured between the first and second end faces of the housing.

A piston guide surface can be formed along the axial extension of the helical region of the helical groove, along which a type of continuous lubricating film for the piston can form. A low-wear extension and retraction of the piston in the course of a damping movement can thus be achieved. In addition, it can be provided that the piston has a receiving bore for the piston rod, an outer surface of the piston rod in the region of the receiving bore and / or the inner surface of the receiving bore having at least one flow channel, the flow channel opening into a fluid passage , wherein a check valve is arranged in the area of the fluid passage. The check valve comprises a valve housing with a valve inlet and a valve outlet, a valve spring and a ball which can be adjusted by means of the valve spring.

In a basic position, the check valve is open and the first interior chamber is filled with the fluid medium. When an external force is applied, the piston rod pushes in with the piston, the check valve closes and the fluid medium flows via the helical groove into the second interior chamber, whereby a damping force or supporting force acts on the retracting piston via the stroke, which counteracts the axial movement.

When resetting or extending the shock absorber, the piston rod with the piston is pushed back into the basic position by means of the ejection spring, the check valve opening for a quick return flow of the fluid medium from the second interior chamber into the first interior chamber, the fluid medium passing through the flow channel the fluid passage can flow.

Furthermore, it can be provided that the ejection spring and the helical groove have an incline in opposite directions. In particular, it can be provided, for example, that the ejection spring has a right-hand slope and the helical groove has a left-hand slope. Alternatively, it can be provided that the ejection spring has a left-hand slope and the helical groove has a right-hand slope.

In an alternative embodiment, the check valve and piston can also be made in one piece.

Furthermore, it can be provided that a volume compensation is arranged in the housing interior in order to compensate for the volume of the retracting or compressing piston or of the displaced fluid medium in the course of damping.

According to a particular embodiment, it is possible that the volume compensation has a receiving sleeve with a guide bore and a guide surface and that at least a first volume compensation seal and at least one axially displaceable second volume compensation seal with an inner sealing lip and an outer sealing lip The inner sealing lip of the second volume compensation seal interacts with the guide surface of the receiving sleeve and the outer sealing lip of the second volume compensation seal interacts with the inner casing surface and a volume compensation chamber is formed between the first volume compensation seal and the second volume compensation seal . The second volume compensation seal can be actuated with a means for applying a potential energy, such as a pretensioning spring or gas pressure. The first volume compensation seal is arranged at a first longitudinal end of the receiving sleeve and interacts with the inner casing surface. The diameter of the guide bore is made slightly larger than the outer diameter of the piston rod in order to guide the piston rod safely.

The inner sealing lip and the outer sealing lip can be used to ensure that the fluid medium does not flow into the volume compensation chamber. The second volume compensation seal is only displaced when the piston is retracted or compressed with the piston rod in order to compensate for the volume of the piston or the displaced fluid medium.

According to an advantageous development, it can be provided that a fluid connection is formed between the volume compensation chamber and the second interior chamber. While the second volume compensation seal is displaced in the axial direction in order to compensate for the volume of the retracting piston or the displaced fluid medium, the volume of the volume compensation chamber is reduced. As a result, sufficient volume can be created in the second interior chamber for the fluid medium displaced in the course of the damping. In particular, it can be advantageous if a guide and sealing package for the piston rod is arranged in the interior of the housing on the closure cover, which package comprises at least one wiper, at least one first piston rod guide, at least one second piston rod guide, at least one main seal and the volume compensation.

This can ensure that the piston rod is guided securely, the fluid receiving space is reliably sealed off from the outside and no foreign particles penetrate into the interior of the housing from the outside. The piston rod can advantageously be designed to be non-magnetic, which ensures that no dirt particles adhere magnetically to the piston rod. The wiper can be made from a textile element such as felt, for example, in order to wipe dirt particles off the piston rod before they penetrate the interior of the housing.

The guide and sealing package according to the invention can also ensure that the piston rod is guided in a straight line, so that wear of a shock absorber can still be prevented.

Furthermore, it can be provided that the second piston rod guide has at least one passage opening for a fluid medium which can flow via the passage opening from the first interior chamber into the second interior chamber and vice versa.

In addition, it can be provided that the piston rod is non-magnetic, which can prevent metallic dirt particles from adhering to the piston rod and being introduced into the interior of the housing when the piston rod is retracted.

Furthermore, it can be provided that the piston has an axial piston bore, the axial piston bore opening into a fluid passage, a check valve being arranged in the region of the fluid passage. This has the advantage that the piston can be designed to allow the fluid to flow back.

Furthermore, it can be provided that the piston is designed to be rotationally symmetrical in its basic shape.

Furthermore, it can be provided that several piston axial bores are arranged distributed in the circumferential direction over the piston, which are introduced into the piston starting from an end face and that a first flow groove is formed which is arranged on an inner jacket surface of the piston, with those piston axial bores, which, starting from the same of the end faces of the piston, are introduced into the latter, open into the first flow groove. This has the advantage that it is easy to make the piston permeable to a fluid. In addition, the presence of several piston axial bores can increase the flow volume. Furthermore, the first flow groove can easily be made in the piston by means of a lathe chisel.

Furthermore, it can be provided that the piston axial bores are arranged at a radial distance from a shock absorber axis. In particular, it can be provided that three piston axial bores are arranged in the piston at an angular distance of 120 °.

Furthermore, it can be provided that a diameter of the first flow groove is selected so large that the first flow groove and the individual piston axial bores overlap.

Furthermore, it can be provided that the piston has a receiving bore for the piston rod, with those piston axial bores which open into the first flow groove being arranged around the receiving bore in the piston.

Fenier can provide that a second flow groove is formed, with those piston axial bores which are introduced into the piston starting from the first end face of the piston open into the first flow groove and those piston axial bores which start out from the second end face of the Pistons are introduced into this, open into the second flow groove. This has the advantage that sufficient space can be created in the piston for both the piston rod and the check valve.

Furthermore, it can be provided that the piston has a spring receptacle for the valve spring of the check valve, with those piston axial bores which open into the second flow groove being arranged around the spring receptacle in the piston.

Furthermore, it can be provided that a spring holder is formed which is inserted into the spring receptacle of the piston. The spring holder can have a receiving bore for guiding the valve spring. This has the advantage that the valve spring can be safely received in the spring holder.

In addition, it can be provided that an oil passage bore is formed in the spring holder adjacent to the receiving bore. This has the advantage that the oil located in the receiving bore can escape from the receiving bore through the oil passage bore. This can improve the response time of the check valve.

Furthermore, it can be provided that the spring holder is formed from a ferromagnetic material, in particular from a steel material. This measure can achieve that when assembling the hydraulic shock absorber, the spring holder with the inserted spring can be held overhead without the spring falling out of the spring holder.

Furthermore, it can be provided that a step is formed in the housing inner jacket surface, the housing inner jacket surface having a first housing inside diameter in the area of the first end face of the housing, which extends up to the step and the housing inner jacket surface then has a second inside diameter of the housing on the step, the first inside diameter of the housing being smaller than the second inside diameter of the housing. This has the advantage that the individual components of the hydraulic shock absorber can easily be installed in the housing of the hydraulic shock absorber.

Furthermore, it can be provided that a ventilation hole is arranged in the housing, in particular in the area of the first inner diameter of the housing. This has the advantage that the individual components of the hydraulic shock absorber can easily be installed in the housing of the hydraulic shock absorber, with as little air as possible being trapped in the interior of the hydraulic shock absorber. In addition, this measure allows air to escape from the volume compensation chamber via the vent hole into the environment when the second volume compensation seal moves relative to the housing.

Furthermore, it is conceivable that a filter material, such as a porous material, in particular a sintered material, is arranged in the ventilation hole. With such a design, dirt can be prevented from entering the interior of the housing via the ventilation hole.

Furthermore, it can be provided that a ventilation channel is arranged in the closure cover and / or in the stripper and / or in the first piston rod guide.

The invention also relates to a method for assembling a hydraulic shock absorber, comprising the method steps

- Provision of a cylindrical housing with an outer casing surface and an inner casing surface;

- Insertion of a piston with a piston rod; - Closing the housing with a cover on a second end face of the housing;

- Filling a housing interior with a fluid medium;

- Closing the housing with a bottom closure on a first end face of the housing.

According to the invention, a method for the reliable, highly automated assembly of a hydraulic shock absorber is provided, the assembly method being suitable for shock absorbers of the most varied of sizes.

Furthermore, in the course of assembly, before the interior of the housing is filled with the fluid medium, a guide and sealing package for the piston rod can be inserted into the housing.

According to a further development, it is possible that a helical groove is made on the inner casing surface of the housing by means of a lathe chisel, the lathe chisel being advanced radially to the inner casing surface during the movement in the axial direction of the housing at the same time.

With a turning tool, a helical groove can be easily and reliably made in the inner casing surface of the housing, with the method, similar to thread turning, being able to be carried out in a highly automated manner.

Furthermore, it can be expedient if the lathe chisel is continuously advanced over the length of the helical groove, as a result of which a continuously decreasing or increasing groove depth can be produced over the helical area. It is also conceivable here for the groove depth to reach a groove-run maximum in the middle of the helical region.

In addition, it can be provided that during the filling of the housing interior with the fluid medium, a housing interior pressure between 0 mbar and 950 mbar, in particular between 10-12 mbar and 300 mbar, preferably between 10 mbar and 100 mbar, is applied.

By applying a vacuum in the interior of the housing, bubble-free filling with the fluid medium can be ensured, thereby increasing the quality of a Shock absorber or an improvement in the damping effect of the shock absorber can be achieved. During the evacuation process of the housing interior, the housing can also be rotated in order to ensure complete evacuation or to improve the evacuation process,

Advantageously, the fluid medium is also evacuated before the interior of the housing is filled in order to ensure or further improve a bubble-free, complete filling of the interior of the housing.

Furthermore, it can be provided that while the interior of the housing is being filled with the fluid medium, the piston is moved and / or rotated in the axial direction.

With this method step it can also be achieved that all the spaces in the interior of the housing are filled with the fluid medium in order to improve the complete, bubble-free filling of a shock absorber.

According to a particular embodiment, it is possible that while the interior of the housing is being filled with the fluid medium, the housing is made to vibrate, which can further improve the fact that the fluid medium reaches all the spaces in the interior of the housing in order to completely or . to fill bubble-free. The vibration can be a shaking movement or an application of ultrasound.

According to an advantageous development, it can be provided that while the interior of the housing is being filled with the fluid medium, the filling level is measured in order to stop the filling process when a maximum filling quantity is reached. This can prevent or prevent the fluid medium from escaping from the interior of the housing when it is closed.

In particular, it can be advantageous if the fluid medium is tempered before the filling process and / or during the filling process in order to increase the viscosity of the fluid medium. This can also ensure that all the spaces in the interior of the housing are exposed to the fluid medium during the filling process.

Furthermore, it can be provided that the temperature of the housing is controlled in order to further improve the viscosity of the fluid medium during filling. In addition, it can be provided that the housing is closed with the bottom closure when a maximum fill level is reached, as a result of which the housing interior can be designed to be pressure-tight and liquid-tight.

An embodiment is also advantageous, according to which it can be provided that a second volume compensation seal of a volume compensation with an inner sealing lip along a guide surface of a receiving sleeve of the volume compensation in Axial direction is shifted.

The volume compensation develops a kind of membrane effect and acts as compensation for manufacturing or filling tolerances, which further ensures that the fluid receiving space or housing interior is filled with the fluid medium completely and without bubbles.

For a better understanding of the invention, it is explained in more detail with reference to the following figures.

They each show in a greatly simplified, schematic representation:

1 shows an embodiment of a hydraulic shock absorber,

Fig. 2 is a sectional view of an embodiment of a hydraulic shock absorber;

3 shows a sectional view of a further exemplary embodiment of a hydraulic

Shock absorber;

4 shows a detailed view of an embodiment of a helical groove;

5 shows a detailed view of an embodiment of a volume compensation;

FIGS. 6 a and b each show a sectional view of different exemplary embodiments of piston rod guides;

7 shows a sectional view of an exemplary embodiment of a piston rod with a flow channel; 8 shows a schematic representation of an embodiment for producing a helical groove;

9 shows a schematic representation of an embodiment of the infeed of a turning chisel for producing a helical groove;

10 shows a further exemplary embodiment of a shock absorber;

11 shows a further exemplary embodiment of a shock absorber;

FIG. 12 shows a perspective sectional illustration of the exemplary embodiment of the shock absorber according to FIG. 11;

13 shows a first detailed view of the exemplary embodiment of the shock absorber according to FIG. 11; 14 shows a second detailed view of the exemplary embodiment of the shock absorber according to FIG.

11;

FIG. 15 shows an illustration of the housing of the exemplary embodiment of the shock absorber according to FIG. 11.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference symbols or the same component designations, it being possible for the disclosures contained in the entire description to be transferred accordingly to the same parts with the same reference symbols or the same component designations . The position details chosen in the description, such as above, below, to the side, etc., also relate to the figure immediately described and shown and these position details must be transferred to the new position in the event of a change in position.

1 shows an exemplary embodiment of a hydraulic shock absorber 1 with a cylindrical housing 2 in which an amagnetic piston rod 3 is mounted so as to be axially displaceable.

From the sectional view of an exemplary embodiment of the hydraulic shock absorber 1 shown in FIG. 2, it can be seen that the cylindrical housing 2 has an outer casing surface 4 and an inner casing surface 5. On a first end face 6 of the housing 2, the housing 2 is closed in a pressure-tight manner with a bottom closure 7. At a to the second end face 8 opposite the first end face 6, the housing 2 is also closed with a closure cover 9 which has a through hole 10 for the piston rod 3 which is movable in the axial direction of the housing 2. The piston rod 3 is coupled to a piston 11. The housing inner jacket surface 5, the bottom closure 7 and the closure cover 9 delimit a housing interior 12, which the piston 11 divides into a first interior chamber 13 and a second interior chamber 14. A flow connection 15 is formed between the first interior chamber 13 and the second interior chamber 14, as a result of which the first interior chamber 13 and the second interior chamber 14 form a fluid receiving space 16.

When the hydraulic shock absorber 1 is ready for use, the fluid receiving space 16 is filled with a fluid medium 17, in particular with a hydraulic fluid. When the hydraulic shock absorber 1 is extended and retracted, the piston 11 slides in the axial direction of the housing 2 the fluid medium 17 via the flow connection 15 from the first interior chamber 13 into the second interior chamber 14, with friction being generated. The kinetic energy of the fluid medium 17 is converted into heat, the movement of the piston 11 is damped, with a damping effect being achieved by means of the hydraulic shock absorber 1. In the embodiment of the hydraulic shock absorber 1 shown in FIG. 2, a helical groove 19 is formed in a helical region 18 of the inner casing surface 5 in order to form the flow connection 15 between the first interior chamber 13 and the second interior chamber 14.

In the exemplary embodiment, the helical groove 19 has a constant groove pitch 20, with a groove base 21 of the helical groove 19 also having a constant radius 22 over the entire length of the helical groove 19. The helical groove 19 also has a groove depth minimum 23 and a groove depth maximum 24, the groove depth 25 increasing continuously from the groove depth minimum 23 to the groove depth maximum 24 and the groove depth maximum 24 being closer to the second end face 8 than the groove depth -Minimum 23. The axial extent of the helical region 18 of the helical groove 19 is between 25% and 35% of a housing length 26, a distance 27 of the groove depth minimum 23 from the first end face 6 likewise being between 25% and 35% of the housing length 26. The housing length 26 is measured between the first end face 6 and the second end face 8 of the housing 2.

A piston guide surface 28 is formed along the helical region 18, along which the piston 11 is guided in the axial direction during the compression and extension of the hydraulic shock absorber 1. The design of the helical groove 19 according to FIG. 2 results in a progressive damping of the hydraulic shock absorber 1.

In FIG. 2 it can be seen that a guide and sealing package 29 for the piston rod 3 is then arranged on the closure cover 9. The guide and sealing package 29 comprises a wiper 30 in order to prevent contamination of the housing interior 12, in particular the fluid medium 17 received in the fluid receiving space 16. In order to seal the wiper 30 and hold it in position, a sealing ring 31 with a clamping function is provided in the circumferential direction opposite the inner casing surface 5 of the housing.

Because the piston rod 3 is non-magnetic, it is also prevented that metallic dirt particles adhere to the piston rod 3 and get further into the housing interior 12.

The guide and sealing package 29 further comprises a first piston rod guide 32, a second piston rod guide 33, at least one main seal 34 and a volume compensation 35. The main seal is sealed by means of additional sealing rings 31 or clamped in the corresponding position in the housing 2. The second piston rod guide 33 has a plurality of passage openings 36 for the fluid medium 17 so that the fluid medium 17 can additionally flow in the axial direction in the direction of volume compensation 35 when the hydraulic shock absorber 1 is retracted or compressed.

When the hydraulic shock absorber is rebounded or extended, the fluid medium 17 flows via the flow connection 15 from the second interior chamber 14 into the first interior chamber 13, the ejection movement of the piston 11 being supported by an ejection spring 37. According to a further exemplary embodiment not shown in detail, the ejection spring 37 can be arranged between the piston 11 and the bottom closure 7.

In addition, in order to accelerate the rebound or extension, the fluid medium 17 flows via a flow channel 38 in the piston 11 and a check valve 39 into the first interior chamber 13. According to the embodiment shown in FIG. 2, the piston 11 has a receiving bore 40 for the piston rod 3, the flow channel 38 being formed on an outer jacket surface 41 of the piston rod 3 in the region of the receiving bore 40. The flow channel 38 opens into a fluid passage 42, the check valve 39 being arranged in the area of the fluid passage 42.

In an embodiment not shown in detail, the flow channel 38 can also be formed on the inner jacket surface 43 of the receiving bore 40 of the piston 11.

The check valve 39 comprises a valve housing 44 with a valve inlet 45 and a valve outlet 46, a valve spring 47 and a ball 48 adjustable by means of the valve spring 47 the first end face 6, the fluid passage 42 being released and the fluid medium 17 flowing into the first interior chamber 13.

According to an exemplary embodiment, when the hydraulic shock absorber 1 shown in FIG. 2 is installed, the ejection spring 37 is inserted into the housing. The piston 11 with the piston rod 3 and the check valve 39 arranged on it is then inserted into the housing 2. This is a preassembled assembly comprising piston 11, piston rod 3 and check valve 39.

Following this, the guide and sealing package 29 is introduced into the housing 2. This can again be a preassembled assembly, or the second piston rod guide 33, volume compensation 35, main seal 34, first piston rod guide 32 and wiper 30 are introduced or pressed into the housing one after the other. The housing 2 is then closed with a cover 9 on the second end face 8 of the housing 2 and the housing interior 12 is filled with the fluid medium 17, with a housing interior pressure between 10 mbar and 10 mbar during the filling of the housing interior 12 with the fluid medium 17 100 mbar is applied, during which, according to one exemplary embodiment, the piston 11 is moved and / or rotated in the axial direction so that the fluid medium 17 reaches all the spaces and a largely air-free filling of the hydraulic shock absorber 1 is ensured. In addition or as an alternative to this, the housing 2 can be made to vibrate, for example by means of ultrasound or a shaking movement. In order to eliminate manufacturing or filling quantity tolerances during the filling process, a second volume compensation seal 49 of the volume compensation 35 with an internal sealing lip 50 is displaced in the axial direction along a guide surface 51 of a receiving sleeve 52 of the volume compensation 35. The volume compensation 35 acts here as a type of membrane. After completion of the filling process, the housing 2 is closed with the bottom closure 7 on the first end face 6 of the housing 2.

The valve spring 47 or the ejection spring 37 can, in an exemplary embodiment not shown in detail, be any means for applying a potential energy.

FIG. 3 shows a further and possibly independent embodiment of a hydraulic shock absorber 1, the same reference numerals or component designations being used for the same parts as in the preceding FIGS. 1 and 2. In order to avoid unnecessary repetition, reference is made to the detailed description in the preceding FIGS. 1 and 2.

In the exemplary embodiment of the hydraulic shock absorber 1 shown in FIG. 3, the check valve 39 and piston 11 are made in one piece, that is to say from one component. Fluid passage 42 and valve inlet 45 or also valve outlet 46 here form a common channel for a fluid medium 17 which is formed within the integral component. In the embodiment shown in FIG. 3, a closure ball 53 is provided as the bottom closure 7, a housing interior 12 being sealed by pressing or pressing in the closure ball 53.

FIG. 4 shows a further and possibly independent embodiment of a hydraulic shock absorber 1, the same reference symbols or component designations being used for the same parts as in the preceding FIGS. 1 to 3. In order to avoid unnecessary repetition, reference is made to the detailed description in the preceding FIGS. 1 to 3.

4 shows a detailed view of an embodiment of a helical groove 19 which is provided in a housing inner jacket surface 5 of a housing 2 of the hydraulic shock absorber 1.

In the exemplary embodiment, the helical groove 19 has a constant groove pitch 20. The helical groove 19 also has a groove depth minimum 23 and a groove depth maximum 24, the groove depth 25 continuously increasing from the groove depth minimum 23 to the groove depth maximum 24 and the groove depth maximum 24 being arranged closer to the second end face 8 than the groove depth minimum 23, the axial extent of the helical region 18 of the helical groove 19 is between 25% and 35% of a housing length 26, with a distance 27 of the groove depth minimum 23 to the first end face 6 likewise between 25% and 35% of the housing length 26 is. FIG. 5 shows an embodiment of a volume compensation 35, the same reference numerals or component designations being used again for the same parts as in the preceding FIGS. 1 to 4. In order to avoid unnecessary repetition, reference is made to the detailed description in the preceding FIGS. 1 to 4. 5 shows a detailed view of an embodiment of the volume compensation 35, which is arranged in the housing interior 12 of a hydraulic shock absorber 1. The volume compensation 35 has a receiving sleeve 52 with a guide bore 54 and a guide surface 51, with a first volume compensation seal 55 and at least one axially displaceable second volume compensation seal 49 with an interior Sealing lip 50 and an outer sealing lip 56 are formed. The second volume compensation seal 49 is arranged such that it can be displaced in the axial direction by means of a prestressing spring 57.

As an alternative to this, in an embodiment not shown in detail, the second volume compensation seal 49 can also be actuated by means of gas pressure.

The diameter of the guide bore 54 of the volume compensation 35 according to FIG. 5 is here slightly larger than the outer diameter of the piston rod 3, as a result of which the piston rod 3 is guided within the guide bore 54 of the volume compensation 35.

The inner sealing lip 50 of the second volume compensation seal 49 interacts with the guide surface 51 of the receiving sleeve 52 and the outer sealing lip 56 of the second volume compensation seal 49 is designed in such a way that it interacts with the inner casing surface 5 of the housing. A volume equalization chamber 58 is formed between the first volume equalization seal 55 and the second volume equalization seal 49, a fluid connection 59 being formed between the volume equalization chamber 58 and a second interior chamber 14 of the hydraulic shock absorber 1.

During retraction or compression, a fluid medium 17 flows via a flow connection 15 from a first interior chamber 13 into the second interior chamber 14 and the second volume compensation seal 49 is displaced in the axial direction in the direction of a second end face 8 of the hydraulic shock absorber 1 by sufficient To create volume for the fluid medium 17 displaced into the second interior chamber 14. The volume equalization chamber 58 is reduced in size, the sealing by means of the inner sealing lip 50 and outer sealing lip 56 of the second volume equalization seal 49 ensuring that the fluid medium 17 does not penetrate into the volume equalization chamber 58. In FIGS. 6a and 6b, different embodiments of a second piston rod guide 33 are shown, the same reference numerals or component names being used for the same parts as in the preceding FIGS. 1 to 5. In order to avoid unnecessary repetitions, reference is made to the detailed description in the preceding FIGS. 1 to 5. 6a and 6b each show a sectional view of different embodiments of the second piston rod guide 33. The second piston rod guide 33 in each case has at least one passage opening 36 for a fluid medium 17, a piston rod 3 being received within the second piston rod guide 33 such that it can be displaced in the axial direction.

6a shows an essentially circular second piston rod guide 33, a passage opening 36 being formed on each of two opposite sides.

6b shows an essentially circular second piston rod guide 33, with four passage openings 36 arranged in the circumferential direction being provided which have a polygonal shape.

A sectional view of an embodiment of a piston rod 3 is shown in FIG. 7, the same reference numerals or component designations being used again for the same parts as in the preceding FIGS. 1 to 6. In order to avoid unnecessary repetition, reference is made to the detailed description in the preceding FIGS. 1 to 6.

The piston rod 3 shown in FIG. 7 has several flow channels 38. A piston 11 has a receiving bore 40 for receiving the piston rod 3, the flow channels 38 being formed on an outer jacket surface 41 of the piston rod 3 in the region of the receiving bore 40. For this purpose, the piston rod 3 has an essentially triangular cross section in the region of the receiving bore 40 in order to form the flow channels 38 on the outer jacket surface 41.

FIG. 8 shows an embodiment of the manufacture of a helical groove 19, the same reference numerals or component designations being used again for the same parts as in the preceding FIGS. 1 to 7. In order to avoid unnecessary repetitions, reference is made to the detailed description in the preceding FIGS. 1 to 7.

8 shows a schematic representation of the production of a helical groove 19 with a lathe tool 60. The helical groove 19 is made on an inner casing surface 5 of a housing 2 of a hydraulic shock absorber 1 by the lathe bit 60 during the movement in the axial direction of the housing 2 is delivered at the same time radially to the housing inner jacket surface 5.

FIG. 9 shows an embodiment of the infeed of a lathe tool 60 for producing a helical groove 19, the same reference numerals or component designations being used again for the same parts as in the preceding FIGS. 1 to 8. In order to avoid unnecessary repetition, reference is made to the detailed description in the preceding FIGS. 1 to 8.

According to FIG. 9, the turning tool 60 is continuously advanced over the length of the helical groove 19 in the y-direction. As an alternative to this, in an embodiment not shown in detail, the turning tool 60 can be advanced over a partial area of the length of the helical groove 19.

The exemplary embodiments show possible design variants, whereby it should be noted at this point that the invention is not restricted to the specific design variants shown, but rather diverse combinations of the individual design variants are possible with one another and this possibility of variation is possible due to the

Teaching for technical action through objective invention lies within the ability of the person skilled in the art working in this technical field.

A further embodiment of the shock absorber 1 is shown in FIG. 10, the same reference numerals or component designations being used again for the same parts as in the preceding FIGS. 1 to 9. In order to avoid unnecessary repetition, reference is made to the detailed description in the preceding FIGS. 1 to 9.

As can be seen from FIG. 10, it can be provided that the check valve 39 is designed in the form of a poppet valve 39 which has a holding area 61 by means of which it is received in the valve housing 44. The poppet valve 39 can be designed to be rotationally symmetrical. In particular, it can be provided that a groove for receiving the holding area 61 of the poppet valve 39 is formed in the valve housing 44. Furthermore, it can be provided that the poppet valve 39 has a sealing wing 62, which serves to seal off the fluid passage 42. Furthermore, throughflow openings 63 can be formed in the poppet valve 39, which serve for the passage of the fluid medium 17. The throughflow openings 63 can be designed to be distributed over the circumference.

When the fluid medium 17 - from left to right in FIG. 10 - is pressed through the fluid passage 42, the sealing wing 62 is opened by the fluid pressure and the fluid medium 17 can flow through it. When the fluid medium 17 - from right to left in FIG. 10 - is pressed through the flow openings 63 in the direction of the fluid passage 42, the sealing wing 62 is closed by the fluid pressure and the fluid medium 17 can be prevented from flowing through.

As can also be seen from FIG. 10, it can be provided that, instead of using a bottom lock 7 designed as an individual part, the bottom lock 7 is an integral part of the housing 2.

As can also be seen from FIG. 10, it can be provided that a step 64 is formed on the housing inner jacket surface 4. As a result of the gradation 64, a front diameter 65 and a rear diameter 66 can be formed on the inner casing surface 4 of the housing. The front diameter 65 can be smaller than the rear diameter 66.

It can thus be provided that the second volume compensation seal 49 is arranged in the area of the front diameter 65. The aforementioned gradation 64 makes it possible to achieve that the second volume compensation seal 49 can easily be pushed into the housing 2 in the area of the rear diameter 66 and the second volume compensation seal 49 does not yet have a sealing effect here. A sealing effect of the second volume compensation seal 49 is only achieved in the area of the front diameter 65, which means that the second volume compensation seal 49 can be pushed into the housing 2 as freely as possible. This measure can ensure that the gas volume in the volume compensation 35 can be kept as small as possible and the volume compensation 35 can thus be filled with the fluid medium 17 as well as possible. In addition, this design has the advantage that the area of the rear diameter 66 only needs to have a lower surface accuracy than the area of the front diameter 65 and thus the shock absorber 1 can be manufactured inexpensively. In FIGS. 11 to 15, a further embodiment of the shock absorber 1 is shown in different views, the same reference numerals or component names being used for the same parts as in the preceding FIGS. 1 to 10. In order to avoid unnecessary repetitions, reference is made to the detailed description in the preceding FIGS. 1 to 10.

As can be seen from a synopsis of FIGS. 11-13, in the present exemplary embodiment it can be provided that the shock absorber 1 has the following structure. The housing 2 can be formed in one piece with the bottom closure 7. In particular, it is conceivable, for example, that the housing 2 together with the bottom closure 7 is manufactured by mechanical processing. From the second end face 8, which is open, the piston 11 together with the piston rod 3 pressed into it and the check valve 39 received in the piston 11 can be inserted in the housing 2.

The piston, the structure of which is shown in detail in FIG. 13, can have a first end face 69 and a second end face 70. As can be seen from FIG. 11, provision can be made for the ejection spring 37 to be arranged between the second end face 70 of the piston 11 and the bottom closure 7. In particular, it can be provided that the ejector spring 37 is designed as a kink-proof spring.

As can also be seen from FIG. 11, a stop ring 67 can be positioned in the housing 2, which serves as a discharge limit for the piston 11 or the piston rod 3. In particular, it can be provided that the first end face 69 of the piston 11 rests on the stop ring 67 in the fully ejected state. The stop ring 67 can be received in a stationary manner in the housing 2. Subsequent to the stop ring 67, the second volume compensation seal 49 can be accommodated in the housing 2 in a displaceable manner. The first piston rod guide 32 can be arranged at a distance from the second volume compensation seal 49, whereby the volume compensation chamber 58 can be formed between the first piston rod guide 32 and the second volume compensation seal 49. Furthermore, the prestressing spring 57 can be arranged between the first piston rod guide 32 and the second volume compensation seal 49. The first piston rod guide 32 can be received in a stationary manner in the housing 2. By shifting the second volume compensation seal 49 relative to the housing 2 or relative to the first piston rod guide 32, the volume of the second interior chamber 14 can be compensated. The stripper 30 can be arranged next to the first piston rod guide 32. Subsequent to the stripper 30, the closure cover 9 can be arranged. The closure cover 9 can be connected to the housing 2 by means of a welded connection, in particular a laser welded connection.

As can also be seen from FIG. 11, it can be provided that the piston 11, in its basic shape, is rotationally symmetrical with respect to the shock absorber axis 68.

As can be seen from a synopsis of FIGS. 12 and 13, provision can be made for a receiving bore 73 to be formed on the second end face 70 of the piston 11, which is used to receive a spring holder 72. The spring holder 72 can have a spring receptacle 71 in which the valve spring 47 can be inserted. In particular, it can be provided that the spring holder 72 is pushed or pressed into the receiving bore 73 in the axial direction.

Furthermore, a receiving bore 40 can be formed in the piston 11, which is introduced into the piston 11 starting from the first end face 69 and serves to receive the piston rod 3.

As can also be seen from FIG. 13, it can be provided that an oil passage bore 74 is arranged in the spring holder 72, which adjoins the spring receiving bore 73.

Furthermore, in the present exemplary embodiment, piston axial bores 75 are made in the piston 11 both on the first end face 69 and on the second end face 70. Furthermore, a first flow groove 76 can be formed which fluidly connects those piston axial bore 75 which are introduced into the piston 11 from the first end face 69. Analogous to this, a second flow groove 77 can be formed which is flow-coupled to those piston axial bores 75 which are introduced into the piston 11 from the second end face 70.

If the piston 11 is reset after an actuation, the fluid can flow from the first end face 69 through the piston axial bores 75 to the first flow groove 76 and flow from there through the fluid passage 42 into the second flow groove 77, the fluid then flowing through the piston connected to the second flow groove 77 benaxialbohmngen 75 reaches the second end face 70 of the piston 11. Here, the ball 48 is lifted from its ball seat 78 against the spring force of the valve spring 47 and thus separated into an open position.

11 shows a detail of the shock absorber 1 in the area of the second end face 8 of the housing 2

As can be seen from FIG. 14, it can be provided that the housing inner jacket surface 5 has an area with a first housing inner diameter 80 and an area with a second housing inner diameter 81. The area with the first housing inner diameter 80 and the area with the second housing inner diameter 81 can be connected to one another by a step 79.

The closure cover 9, the wiper 30 and the first piston rod guide 32 can be arranged in the region of the first housing inner diameter 80.

Furthermore, it can be provided that a ventilation hole 82 is formed in the housing 2, which penetrates the housing 2 radially. As an alternative or in addition, it can be provided that a ventilation channel 83 is formed in the closure cover 9, in the stripper 30 and / or in the first piston rod guide 32. In particular, it can be provided that the ventilation channel 83 is formed by a recess on the circumference of the closure cover 9 of the wiper 30 of the first piston rod guide 32.

15 shows the housing 2 without internal components in a longitudinal section. As can be seen from FIG. 15, it can be provided that an area with a third housing inner diameter 84 adjoins the area of the second housing inner diameter 81; the area with the fourth housing inner diameter 84 can serve to accommodate the stop ring 67. Furthermore, it can be provided that the helical groove 19 is arranged in an area with a fourth inside diameter 85 of the housing. The fourth internal housing diameter 85 can be smaller than the third internal housing diameter 84, which can be smaller than the second internal housing diameter 81, which can be smaller than the first internal housing diameter 80. The scope of protection is determined by the claims. However, the description and the drawings are to be used to interpret the claims; individual features or combinations of features from the various exemplary embodiments shown and described can represent independent inventive solutions. The task on which the independent inventive solutions are based can be found in the description.

All information on value ranges in the present description are to be understood in such a way that they include any and all sub-areas, e.g. the information 1 to 10 is to be understood as meaning that all sub-areas, starting from the lower limit 1 and the upper limit 10 with are included, ie all subranges begin with a lower limit of 1 or greater and end at an upper limit of 10 or less, for example 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

For the sake of clarity, it should finally be pointed out that, for a better understanding of the structure, some elements have been shown not to scale and / or enlarged and / or reduced.

List of references 1 Shock absorber 31 Sealing ring 2 Housing 32 First piston rod guide 3 Piston rod 33 Second piston rod guide 4 Housing outer jacket surface 34 Main seal 5 Housing inner jacket surface 35 Volume compensation 6 First end face 36 Passage opening 7 Bottom closure 37 Ejection spring 8 Second end face 38 Flow channel 9 Closure cover 39 Check valve 10 Through hole 40 Receiving bore 11 piston 41 outer jacket surface 12 housing interior 42 fluid passage 13 first interior chamber 43 inner jacket surface 14 second interior chamber 44 valve housing 15 flow connection 45 valve inlet 16 fluid receiving space 46 valve outlet 17 fluid medium 47 valve spring 18 spiral area 48 ball 19 spiral groove 49 second volume compensation 20 groove incline 21 groove base 50 internal Sealing lip 22 radius 51 guide surface 23 groove depth minimum 52 receiving sleeve 24 groove depth maximum 53 locking ball 25 groove depth 54 guide bore 26 housing length 55 first volume issue Light seal 27 Distance 56 outer sealing lip 28 Piston guide surface 57 Pre-tensioning spring 29 Guide and sealing package 58 Volume compensation chamber 30 Wiper 59 Fluid connection 60 turning tools

61 Holding area 62 Sealing wing 63 Flow opening 64 Gradation

65 front diameter 66 rear diameter 67 stop ring 68 shock absorber axis 69 first end face 70 second end face 71 spring retainer 72 spring holder

73 Spring receiving bore 74 Oil passage bore 75 Piston axial bore 76 First flow groove 77 Second flow groove 78 Ball seat 79 Gradation

80 first inside diameter of the housing

81 second inside diameter of the housing

82 Vent hole

83 ventilation duct

84 third inside diameter of the housing

85 fourth inside diameter of the housing

Claims

Patent claims

1. Hydraulic shock absorber (1) comprising a cylindrical housing (2) with an outer casing surface (4) and an inner casing surface (5); a bottom closure (7) which is arranged on a first end face (6) of the housing (2); a piston (11) and a piston rod (3) coupled to the piston (11); a closure cover (9) which is arranged on the second end face (8) opposite to the first end face (6) and has a through hole (10) for the piston rod (3) which is movable in the axial direction of the housing (2); wherein the inner casing surface (5) of the bottom closure (7) and the closure cover (9) delimit a housing interior (12); wherein the piston (11) divides the housing interior (12) into a first interior chamber (13) and a second interior chamber (14); and wherein a flow connection (15) is formed between the first interior chamber (13) and the second interior chamber (14).

2. Hydraulic shock absorber (I) according to claim 1, characterized in that a helical groove (19) is formed in a helical region (18) of the inner casing surface (5).

3. Hydraulic shock absorber (1) according to claim 2, characterized in that the helical groove (19) has a constant groove pitch (20).

4. Hydraulic shock absorber (1) according to one of claims 2 or 3, characterized in that a groove base (21) of the spiral groove (19) has a constant shape over the entire length of the spiral groove (19).

5. Hydraulic shock absorber (1) according to one of claims 2 to 4, characterized in that the helical groove (19) has a groove depth minimum (23) and a groove depth maximum (24), the groove depth (25 ) increases continuously from the groove depth minimum (23) to the groove depth maximum (24).

6. Hydraulic shock absorber (1) according to claim 5, characterized in that the groove depth maximum (24) is arranged closer to the second end face (8) than the groove depth minimum (23).

7. Hydraulic shock absorber (1) according to one of claims 2 to 6, characterized in that the axial extension of the helical region (18) of the helical groove (19) is between 10% and 50%, in particular between 20% and 40% %, preferably between 25% and 35% of a housing length (26), with a distance (27) of the groove depth minimum (23) to the first end face (6) between 10% and 50%, in particular between 20% and 40%, is preferably between 25% and 35% of the housing length (26).

8. Hydraulic shock absorber (1) according to one of the preceding claims, characterized in that the piston (11) has a receiving bore (40) for the piston rod (3), with an outer jacket surface (41) of the piston rod (3) in the area the receiving bore (40) and / or the inner circumferential surface (43) of the receiving bore (40) has at least one flow channel (38), the flow channel (38) opening into a fluid passage (42), wherein in the area of the fluid passage ( 42) a check valve (39) is arranged.

9. Hydraulic shock absorber (1) according to one of the preceding claims, characterized in that a volume compensation (35) is arranged in the housing interior (12).

10. Hydraulic shock absorber (1) according to claim 9, characterized in that the volume compensation (35) has a receiving sleeve (52) with a guide bore (54) and a guide surface (51) and that at least one first volume compensation seal (55) and at least one axially displaceable second volume compensation seal (49) with an internal sealing lip (50) and an external sealing lip (56) are formed, the internal sealing lip (50) of the second volume compensation seal (49) with the guide surface (51) ) the receiving sleeve (52) interacts and wherein the outer sealing lip (56) of the second volume compensation seal (49) with the housing Inner jacket surface (5) interacts and a volume compensation chamber (58) is formed between the first volume compensation seal (55) and the second volume compensation seal (49).

11. Hydraulic shock absorber (1) according to claim 10, characterized in that a fluid connection (59) is formed between the volume compensation chamber (58) and the second interior chamber (14).

12. Hydraulic shock absorber (1) according to one of the preceding claims, characterized in that a guide and sealing package (29) for the piston rod (3) is arranged in the housing interior (12) on the closure cover (9), wel- Ches comprises at least one scraper (30), at least one first piston rod guide (32), at least one second piston rod guide (33), at least one main seal (34) and the volume compensation (35).

13. Hydraulic shock absorber (1) according to claim 12, characterized in that the second piston rod guide (33) has at least one passage opening (36) for a fluid medium (17).

14. Hydraulic shock absorber (1) according to one of the preceding claims, characterized in that the piston rod (3) is non-magnetic.

15. Hydraulic shock absorber (1) according to one of the preceding claims, characterized in that the piston (11) has a piston axial bore (75), the piston axial bore (75) opening into a fluid passage (42), wherein in the region of the fluid id passage (42) a check valve (39) is arranged.

16. Hydraulic shock absorber (1) according to claim 15, characterized in that a plurality of piston axial bores (75) are arranged distributed in the circumferential direction over the piston (11), which starting from an end face (69, 70) in the piston (11) are introduced and that a first flow groove (76) is formed, which on an inner circumferential surface (43) of the piston (11), with those piston axial bores (75) which, starting from the same of the end faces (69, 70) of the piston (11), open into the first flow groove (76).

17. Hydraulic shock absorber (1) according to claim 16, characterized in that a second flow groove (77) is formed, with those piston axial bores (75) which are introduced into the piston (11) starting from the first end face (69) open into the first flow groove (76) and those piston axial bores (75) which are introduced into the piston (11) from the second end face (70) of the piston (11) open into the second flow groove (77).

18. Hydraulic shock absorber (1) according to one of the preceding claims, characterized in that a step (79) is formed in the inner casing surface (5) of the housing, the inner casing surface (5) in the area of the first end face (6 ) of the housing (2) has a first housing inner diameter (80) which extends up to the step (79) and the housing inner jacket surface (5) having a second housing inner diameter (81) adjoining the step (79) , wherein the first housing inner diameter (80) is smaller than the second housing inner diameter (81).

19. A method for the assembly of a hydraulic shock absorber (1), in particular a hydraulic shock absorber (1) according to one of the preceding claims, comprising the steps of: - providing a cylindrical housing (2) with a housing outer jacket surface (4) and a housing Inner circumferential surface (5);

- Insertion of a piston (11) with a piston rod (3) connected to it into the housing

(2);

- Closing the housing (2) with a closure cover (9) on a second end face (8) of the housing (2);

- Filling a housing interior (12) with a fluid medium (17);

- Closing the housing (2) with a bottom closure (7) on a first end face (6) of the housing (2).

20. A method for the assembly of a hydraulic shock absorber (1), in particular a hydraulic shock absorber (1) according to one of the preceding claims, comprising the method steps:

- Provision of a cylindrical housing (2) with an outer casing surface (4) and an inner casing surface (5), as well as a bottom closure (7) on a first end face (6) of the housing (2),

(2),

- Filling a housing interior (12) with a fluid medium (17);

- Closing the housing (2) with a closure cover (9) on a second end face (8) of the housing (2).

21. The method according to claim 19 or 20, characterized in that a helical groove (19) is introduced by means of a turning tool (60) on the inner casing surface (5), the turning tool (60) during the movement in the axial direction of the housing (2 ) is delivered at the same time radially to the inner casing surface (5).

22. The method according to claim 21, characterized in that the turning tool (60) is fed continuously over the length of the helical groove (19).

23. The method according to any one of claims 19 to 22, characterized in that during the filling of the housing interior (12) with the fluid medium (17) a housing interior pressure between 0 mbar and 950 mbar, in particular between 10 ^-12 mbar and 300 mbar , is preferably applied between 10 mbar and 100 mbar.

24. The method according to any one of claims 19 to 23, characterized in that while the housing interior (12) is being filled with the fluid medium (17), the piston (11) is moved and / or rotated in the axial direction.

25. The method according to any one of claims 19 to 24, characterized in that the housing (2) is caused to vibrate while the housing interior (12) is being filled with the fluid medium (17).

26. The method according to any one of claims 19 to 25, characterized in that the fill level is measured while the housing interior (12) is being filled with the fluid medium (17).

27. The method according to any one of claims 19 to 26, characterized in that the fluid medium (17) is tempered before the filling process and / or during the filling process.

28. The method according to any one of claims 19 to 27, characterized in that the housing (2) is tempered.

29. The method according to any one of claims 19 to 28, characterized in that the housing (2) is closed with the bottom closure (7) when a maximum fill level is reached.

30. The method according to any one of claims 19 to 29, characterized in that during the closing of the housing (2) with the bottom closure (7) and / or during the filling of the housing interior (12) with the fluid medium (17) a second volume - the volume compensation seal (49) of a volume compensation (35) with an internal sealing lip (50) is displaced in the axial direction along a guide surface (51) of a receiving sleeve (52) of the volume compensation (35).