Fluid damper with a compensation space in a piston rod

Abstract

The invention relates to a fluid damper (100) comprising: a working space (110) filled with a damping fluid; a piston rod (120) which is movable relative to the working space (110) along a stroke axis (H) and is guided out of the working space (110) along the stroke axis (H) at least at a first end (111) of the working space (110); a compensation space (121) located at least partially in the piston rod (120), the compensation space (121) being designed to receive a volume of the damping fluid displaced by the piston rod (120) during an insertion movement of the piston rod (120) into the working space (110); and a piston unit (130) fastened to the piston rod (120), wherein the piston unit (130) separates the working space (110) into a first subspace (112) between the piston unit (130) and the first end (111) of the working space (110) and a second subspace (114) between the piston unit (130) and a second end (113) of the working space (110). The piston unit (130) comprises a piston main body (131), the piston main body (131) having a number of compensation channels (132) for connecting the compensation space (121) to the second subspace (114) such that the damping fluid is conducted, and a number of working channels (133) for connecting the first subspace (112) to the second subspace (114) such that the damping fluid is conducted, wherein the number of compensation channels (132) overlaps the number of working channels (133) along the stroke axis (H).

Description

Description Title of the invention: Fluid damper with a compensation chamber in a piston rod. Technical field

[0001] The invention relates to a fluid damper comprising a working chamber filled with a damping fluid; a piston rod displaceable relative to the working chamber along a stroke axis and extending out of the working chamber at least at a first end along the stroke axis; a compensation chamber arranged at least partially in the piston rod, wherein the compensation chamber is designed to receive a volume of damping fluid displaced by the piston rod during an insertion movement of the piston rod into the working chamber; and a piston assembly attached to the piston rod, wherein the piston assembly divides the working chamber into a first sub-chamber between the piston assembly and the first end of the working chamber and a second sub-chamber between the piston assembly and a second end of the working chamber. State of the art

[0002] Fluid dampers of this type are known, for example, from publication WO 2023 / 143758 A1. This damper comprises a hollow piston rod as a compensating chamber, with the piston assembly mounted on an adapter screwed onto the piston rod. Since the compensating chamber is located within the piston rod, a bottom valve connecting the compensating chamber to the working chamber must also be integrated into the piston assembly, increasing its complexity and requiring additional installation space. Because the radial nozzle pistons used in the damper according to WO 2023 / 143758 A1 must have a fluid bypass across their outer circumference for proper function, a guide band cannot be located there, necessitating a separate guide assembly. Directional damping in both progressive and The degressive range requires two independently operating piston sections: one in the tension direction and one in the compression direction. The adapter needed to attach the piston assembly with all the aforementioned functions to the piston rod is expensive to manufacture and has a considerable length. In some applications, this length renders the damper unusable without relocating pivot points, resulting in further costs. For example, when damping solar panels that track the sun's position, an excessively long damper may necessitate a higher mounting position for the solar panels. The adapter's significant manufacturing effort is due to its considerable length combined with the large diameter difference. This results in substantial machining costs, especially since this component must be made of high-strength material to withstand the operating loads. Technical task

[0003] The object of the invention is to further develop a generic fluid damper in such a way that the fluid damper can be manufactured more cost-effectively and compactly without loss of functionality. Technical solution

[0004] The present invention provides a fluid damper according to claim 1, which solves the technical problem. Advantageous embodiments are the subject of the dependent claims.

[0005] The fluid damper comprises at least one working chamber filled with a damping fluid, for example, hydraulic oil. The working chamber is, for example, cylindrical in shape, arranged coaxially to a stroke axis of the fluid damper, and / or enclosed by a pressure tube.

[0006] The fluid damper comprises at least one piston rod that is displaceable relative to the working space along a stroke axis and extends out of the working space at least at a first end along the stroke axis. The piston rod is, for example, hollow cylindrical shape, arranged coaxially to the lifting axis and / or made of steel.

[0007] The fluid damper comprises at least one compensating chamber arranged at least partially, and in particular completely, within the piston rod. The compensating chamber is designed to accommodate a volume of damping fluid displaced by the piston rod during its insertion into the working chamber. The compensating chamber is filled, for example, with a compressible compensating medium, such as a gas, particularly nitrogen. The compensating chamber can, for example, include a separating piston, particularly one with a spring load, so that the volume of the compensating chamber is variable. The compensating chamber can be open to the environment surrounding the fluid damper, with the opening of the compensating chamber to the environment preferably sealed with a gas-permeable membrane to prevent the ingress of contaminants.

[0008] The fluid damper comprises at least one piston assembly attached to the piston rod, wherein the piston assembly divides the working space into a first subspace between the piston assembly and the first end of the working space and a second subspace between the piston assembly and a second end of the working space.

[0009] The piston assembly comprises a piston body, preferably a single piece, wherein the piston body includes a number of compensating channels for the damping fluid-conducting connection of the compensating chamber to the second sub-chamber and a number of working channels for the damping fluid-conducting connection of the first sub-chamber to the second sub-chamber. The piston body is, for example, made of a plastic, a metal, and / or by sintering.

[0010] The piston body can be made of two parts or multiple parts. This allows, for example, compensation channels and / or working channels that do not run coaxially to the lifting axis to be realized using a sintering process.

[0011] The number of compensating channels overlaps the number of working channels along the stroke axis. Therefore, the compensating channels are not located in front of or behind the working channels with respect to the stroke axis, as in WO 2023 / 143758 A1, but rather alongside the working channels. The working channels and / or the compensating channels are preferably arranged entirely within the piston body.

[0012] The piston assembly is preferably designed such that the damping fluid can only pass through the working channels from the first sub-space to the second sub-space and back, and / or that the damping fluid can only pass through the compensation channels from the second sub-space to the compensation space and back. Beneficial effects

[0013] When the piston rod is inserted into the working chamber along the stroke axis in a compression direction, the damping fluid flows through the working channels from the second sub-chamber in front of the piston assembly into the first sub-chamber behind the piston assembly, and the volume of damping fluid displaced by the piston rod flows through the equalization channels from the second sub-chamber into the equalization chamber. When the piston rod is extended out of the working chamber along the stroke axis in a tension direction opposite to the compression direction, the damping fluid flows back through the working channels from the first sub-chamber into the second sub-chamber and through the equalization channels back from the equalization chamber into the second sub-chamber.

[0014] During the extension and retraction of the piston rod, the compensating and working channels define flow resistances that act on the flowing damping fluid. These flow resistances, in turn, define damping forces of the fluid damper that counteract the extension and retraction. By appropriately designing the compensating and working channels, the damping forces of the fluid damper can therefore be adjusted.

[0015] By arranging the compensating and working channels in a common, and preferably one-piece, piston body, the fluid damper can be manufactured particularly cost-effectively and compactly. The integration and overlapping arrangement of the compensating and working channels along the stroke axis within the piston body results in a shorter piston assembly length along the stroke axis, for example, by one-third, thereby reducing the dead length of the fluid damper. Furthermore, due to the reduced length of the piston assembly, achieved, for example, by a guide element on the piston assembly, a lower bending moment transverse to the stroke axis acts on the piston assembly and on the connection between the piston assembly and the piston rod. This allows for greater mechanical stability of the piston assembly and the connection to be ensured with less effort than in conventional fluid dampers.

[0016] In the fluid damper known from WO 2023 / 143758 A1, the working piston is annular in shape and attached via its inner diameter to a tubular adapter located at the end of the piston rod. This adapter has a smaller diameter radially to the stroke axis than the piston rod. With this type of attachment, the hydraulic load on the working piston exerts a high bending moment on the piston and the attachment area, making reliable attachment and a mechanically stable piston achievable only with considerable effort. The inventive integration of the compensating channels and working channels into a common piston body eliminates the need to attach a separate working piston to the piston rod via an adapter. This, in turn, eliminates the need for the complex adapter and its associated adverse effects on the stability of the working piston and its attachment. Description of the execution types

[0017] The number of compensating channels and / or the number of working channels preferably each comprise a plurality of compensating channels. and / or working channels, preferably two, four, or six compensating channels and / or working channels. An even number of compensating channels and / or working channels has the advantage that half of the compensating channels and / or working channels can be configured to direct the damping fluid into the working chamber when the piston rod is inserted, and the other half of the compensating channels and / or working channels to direct the damping fluid out of the working chamber when the piston rod is extended. By using differently configured compensating channels and / or working channels for insertion and extension, the fluid damper can exert different damping forces against the insertion and extension phases.The equalization channels for the inflow of the damping fluid into the equalization chamber can, for example, have a smaller cross-sectional area and thus a higher flow resistance than the equalization channels for the outflow of the damping fluid from the equalization chamber.

[0018] The greater the number of compensating and / or working channels, the more homogeneously the piston assembly is subjected to the damping fluid load during movement, thus extending the piston assembly's service life. However, the complexity of manufacturing the piston body increases with the number of compensating and / or working channels. Therefore, for practical applications, four or six compensating and / or working channels have proven optimal.

[0019] The number of compensating channels and / or the number of working channels preferably runs along the stroke axis through the piston body. This allows for particularly simple manufacturing of the compensating channels and / or working channels, for example, as bores through the piston body. Furthermore, due to the working channels passing through the piston body, it is not necessary for the damping fluid to flow around an outer circumferential surface of the piston body that rotates around the stroke axis in order to be drawn from the to flow from the first sub-chamber into the second sub-chamber and back. This allows, for example, a fixing sleeve for attaching the piston body to the piston rod and / or a guide band for guiding the piston body in a pressure tube of the fluid damper to be arranged on the outer circumferential surface in a space-saving manner.

[0020] The compensating channels are preferably arranged on an inner circular ring around the stroke axis; and the working channels are preferably arranged on an outer circular ring around the stroke axis, the inner circular ring lying radially inside the outer circular ring to the stroke axis. This arrangement is particularly space-saving and allows the ends of the working channels or the compensating channels to be easily covered with a common, annular cover element in order to regulate the flow of the damping fluid through the working channels or the compensating channels.

[0021] The piston body preferably comprises a number, in particular a plurality, of radial openings connecting the number of working channels to the first sub-chamber, directing the damping fluid radially to the stroke axis. When the damping fluid flows from the second sub-chamber into the first sub-chamber, the radial openings advantageously direct it into a region of the first sub-chamber surrounding the piston rod radially to the stroke axis.

[0022] The piston body preferably comprises at least one circulating channel rotating around the stroke axis, wherein the at least one circulating channel connects the damping fluid to the number of working channels at one end facing the first sub-chamber and / or the second sub-chamber. The at least one circulating channel advantageously distributes the damping fluid to the number of working channels, thus ensuring a homogeneous load on the piston body. Additionally or alternatively, at least one corresponding circulating channel can also be provided for the number of compensating channels. The circulating channels advantageously allow a mounting of the piston base body on the piston rod that is arbitrarily rotated around the stroke axis, thus eliminating the need for a rotation lock and a mounting of the piston base body on the piston rod aligned at a specific angle of rotation.

[0023] The piston assembly preferably comprises a number, in particular a plurality, of cover elements, wherein the number of cover elements covers at least a part of the number of compensation channels and / or the number of working channels at each end of the number of compensation channels and / or the number of working channels facing the compensation space, the first subspace and / or the second subspace.

[0024] At least some of the cover elements are, for example, ring-shaped. Preferably, at least some of the cover elements are designed such that each cover element covers one end of several, in particular all, compensation channels or working channels, so that the piston assembly comprises a particularly small number of components.

[0025] At least some of the cover elements are, for example, slidably positioned along the stroke axis on the ends of the compensating or working channels. This means that when the piston assembly moves in one direction along the stroke axis, the damping fluid presses the cover element against its ends, thus closing the compensating or working channels. When the piston assembly moves in the opposite direction, the damping fluid lifts the cover element from its ends, allowing the damping fluid to flow through the compensating or working channels with minimal resistance. In this simple way, a direction-dependent damping force is generated by the fluid damper.

[0026] The ends of the working channels and / or the compensating channels preferably each have a raised edge relative to the piston body. Advantageously, cover elements with low adhesion tendency can rest on this raised edge, independent of the form and positional tolerances of the piston body. The raised edge Advantageously, the piston body can be easily post-processed after its manufacture to adjust the flow resistance of the damping fluid through the working channels and / or compensation channels. Furthermore, the raised edge prevents a loss of damping force due to foreign particles becoming trapped under the cover elements.

[0027] The piston assembly preferably comprises a number, in particular a plurality, of spring elements, wherein the number of spring elements preloads at least a part of the number of cover elements onto the associated ends of the number of compensation channels and / or the number of working channels.

[0028] The spring elements allow adjustment of the flow resistance acting on the damping fluid flowing through the compensating channels and / or working channels, and thus the damping force of the fluid damper. For example, the spring elements can be used to define that the compensating channels and / or working channels are only released by their respective cover elements when the pressure exerted on the cover elements by the damping fluid exceeds a predefined switching pressure. This provides overpressure protection, preventing damage to the fluid damper and / or any structure connected to it. Preferably, such overpressure protection is implemented by a cover element on the end of the compensating channels facing the compensating chamber, to prevent excessive pressure in the working chamber if the piston rod is inserted too quickly.

[0029] The spring elements are, for example, integrated into the cover elements, whereby the cover elements can be designed in particular as spring discs or spring ring discs, and / or components separate from the cover elements, for example coil springs, elastomer rings and / or wave spring rings.

[0030] The piston assembly preferably comprises a number, in particular a plurality, of transfer ports, wherein the number of transfer ports allows the damping fluid to flow around at least a portion of the number of cover elements that cover the corresponding ends of the number of compensation channels and / or the number of working channels. The cross-sectional area of ​​at least one of the transfer ports is preferably significantly smaller than the cross-sectional area of ​​the corresponding compensation channel or working channel.

[0031] The overflow openings allow the damping fluid to flow through a compensating or working channel even when it is covered by the corresponding cover element. This allows the piston assembly to be moved by the damping fluid, and thus the piston rod to be extended and retracted, even when the compensating and / or working channels are covered, for example, because the corresponding cover elements are designed as overpressure protection and only release the compensating and / or working channels in the event of an overload.

[0032] The piston assembly preferably comprises at least one fixing sleeve attached to the piston rod, wherein the fixing sleeve presses the piston body along the stroke axis onto an end of the piston rod located in the working chamber. The fixing sleeve is, for example, hollow cylindrical and / or arranged coaxially to the stroke axis. The fixing sleeve is, for example, screwed onto the piston rod, screwed into the piston rod, and / or clamped to the piston rod and / or positively connected, in particular by at least one groove and / or lug. The fixing sleeve allows for easy attachment of the piston body as well as the cover elements and spring elements to the piston rod. Furthermore, the fixing sleeve can press the cover elements onto the piston body so that the cover elements seal against the corresponding ends of the working channels and / or compensating channels.

[0033] In the fluid damper known from WO 2023 / 143758 A1, the working piston is annular and disc-shaped, and is attached via its inner diameter to a tubular adapter located at the end of the piston rod. This adapter has a smaller diameter radially to the stroke axis than the piston rod. With this type of attachment, the hydraulic load on the working piston causes a high bending moment on the piston and the attachment area, making reliable attachment and a mechanically stable piston achievable only with considerable effort. In contrast, according to the present invention, the piston assembly can be held by the fixing sleeve at its outer diameter and supported on the piston rod at the same time.This results in a significantly lower bending moment acting on the fastening areas and on the piston assembly compared to the prior art, so that a reliable fastening and a mechanically sufficiently stable piston assembly can be achieved with significantly less effort.

[0034] The fixing sleeve can, for example, be cold-formed and / or upsetting from a drawn tube as a hollow body with a small wall thickness in relation to its diameter measured perpendicular to the stroke axis, and / or turned from a sleeve with minimal machining effort.

[0035] The fixing sleeve preferably comprises a number, in particular a plurality, of radial sleeve openings for connecting the number of working channels to the first sub-chamber, directing the damping fluid radially to the stroke axis. The radial sleeve openings are, for example, arranged adjacent to the radial base body openings of the piston body. When the damping fluid flows from the second sub-chamber into the first sub-chamber, the radial sleeve openings advantageously direct it into a region of the first sub-chamber that surrounds the piston rod radially to the stroke axis.

[0036] The fixing sleeve preferably comprises at least one sealing element that seals the fixing sleeve to a shell wall of the working chamber, for example, a sealing ring, in particular an embossed one, especially an O-ring, an elastomer ring and / or a PTFE ring.

[0037] The sealing element ensures that the damping fluid passes exclusively through the working channels from the first sub-chamber to the second sub-chamber and back.

[0038] The piston body can include at least one sealing element, for example a sealing ring, in particular an O-ring, that seals the piston body to the fixing sleeve. The sealing element can prevent uncontrolled flow of the damping fluid between the piston body and the fixing sleeve. The fixing sleeve is preferably pressed so precisely onto the piston body that a separate sealing element is not necessary.

[0039] The fixing sleeve preferably comprises at least one guide element, for example a guide band, which guides the fixing sleeve along a wall of the working chamber. The arrangement of the guide element on the fixing sleeve results in a particularly compact design of the piston assembly. Furthermore, arranging the guide element close to the piston rod reduces bending moments acting on the piston assembly and on the connection between the piston assembly and the piston rod during operation of the fluid damper.

[0040] The fixing sleeve preferably comprises at least one cylindrical sleeve, wherein the cylindrical sleeve is attached to the piston rod and surrounds the piston body radially to the stroke axis; and at least one cover plate, for example two cover plates, wherein the cover plate is attached to the cylindrical sleeve and surrounds the piston body on a side facing the second partial chamber and / or on a side facing the compensation chamber and preferably preloads and / or fixes the piston body against the piston rod and / or the cover elements against the piston body. The at least one cover plate is, for example, screwed into the cylindrical sleeve and / or screwed onto the cylindrical sleeve and / or clamped between the piston body and the piston rod.

[0041] The spring elements can, for example, be supported by at least one cover plate.

[0042] The at least one cover plate preferably comprises a number, in particular a plurality, of recesses for connecting the damping fluid, which guides it along the stroke axis, at least a portion of the compensating channels and / or the working channels to the second partial space and / or to the compensating space. At least one section of the piston body containing the compensating channels can, for example, pass through at least one of the recesses. Brief description of the drawings

[0043] Further advantages, objectives and features of the invention are explained with reference to the following description and accompanying drawings, in which exemplary objects according to the invention are shown.

[0044] Figure 1 shows a schematic view of the piston rod and piston assembly of a fluid damper according to the invention.

[0045] Figure 2 shows a schematic longitudinal section through the piston rod and piston assembly from Figure 1.

[0046] Figure 3 shows another schematic longitudinal section through the piston rod and piston assembly from Figure 1.

[0047] Figure 4 shows a schematic cross-section through the piston assembly from Figure 1.

[0048] Figure 5 shows a schematic perspective view of the piston body of the piston assembly from Figure 1.

[0049] Figure 6 shows a schematic top view of the piston body from Figure 5.

[0050] Figure 7 shows a schematic longitudinal section through the piston body from Figure 5. Fig. 1

[0051] Figure 1 shows a schematic view of the piston rod 120 and the piston assembly 130 of a fluid damper according to the invention,

[0052] The piston rod 120, for example, is hollow cylindrical in shape and arranged coaxially to the stroke axis H of the fluid damper.

[0053] The piston assembly 130, for example, is attached to one end of the piston rod 120 and divides the working space of the fluid damper into a first sub-space 112 and a second sub-space 114.

[0054] The piston assembly 130 comprises, for example, a fixing sleeve 139 attached to the piston rod 120, which includes a cylinder sleeve 143 radially enclosing the piston body (not visible) of the piston assembly 130 with respect to the stroke axis H. The cylinder sleeve 143 is, for example, hollow cylindrical and arranged coaxially with respect to the stroke axis H.

[0055] The fixing sleeve 139 comprises, for example, a number of radial sleeve openings 142 for connecting the number of working channels (not visible) in the piston body with the first partial chamber 112, which conducts the damping fluid radially to the stroke axis H. Two of the sleeve openings 142 are visible in Figure 1.

[0056] The fixing sleeve 139 comprises, for example, a sealing element 140, in particular a sealing ring, which seals the fixing sleeve 139 to a shell wall (not shown) of the working space.

[0057] The fixing sleeve 139 comprises, for example, at least one recess, in particular a groove circumferential around the stroke axis H, for receiving a guide element (not shown), in particular a guide band, which guides the fixing sleeve 139 on the outer wall of the working space.

[0058] The piston assembly 130 comprises, for example, a cover element 135, in particular a spring-loaded ring washer, which covers a number of compensating channels (not visible) in the piston body at its end facing the second partial chamber 114. The cover element 135 is, for example, fastened to the piston body by a fastening means 146, in particular by a nut, and is preferably pre-tensioned against the end of the compensating channels. Fig. 2

[0059] Figure 2 shows a schematic longitudinal section through the piston rod 120 and the piston assembly 130 from Figure 1 along the stroke axis H and the section plane BB marked in Figure 1.

[0060] In addition to the features already described for Figure 1, the following features are visible in Figure 2:

[0061] The piston rod 120, for example, is hollow and contains a compensation chamber 121 to accommodate a volume of damping fluid displaced by the piston rod 120 during an insertion movement into the working chamber of the fluid damper.

[0062] The piston assembly 130 comprises a one-piece piston body 131, wherein the piston body 131 includes a number of, for example, four compensating channels 132 for the damping fluid-conducting connection of the compensating chamber 121 with the second sub-chamber 114 and a number of, for example, four, working channels 133 for the damping fluid-conducting connection of the first sub-chamber 112 with the second sub-chamber 114. Two of the compensating channels 132 and two of the working channels 133 are visible in Figure 2.

[0063] The compensating channels 132 and the working channels 133, for example, run along the stroke axis H through the piston body 131.

[0064] The compensating channels 132 are, for example, arranged on an inner circular ring around the stroke axis H; and the working channels 133 are, for example, arranged on an outer circular ring around the stroke axis H, wherein the inner circular ring lies radially to the stroke axis H inside the outer circular ring.

[0065] The piston assembly 130 comprises, for example, a number of, in particular four, cover elements 135, wherein the cover elements 135 each connect the compensating channels 132 and the working channels 133 to the compensating chamber 121, the first sub-chamber 112 and the second sub-chamber 114 cover the end of the equalization channels 132 and the working channels 133 facing the other end.

[0066] The piston package 130 comprises, for example, a number of, in particular four, spring elements 136, wherein the spring elements 136 preload the cover elements 135 onto the associated ends of the compensation channels 132 and the working channels 133.

[0067] The two ends of the compensating channels 132 are, for example, covered by two cover elements 135, in particular in the form of spring ring washers, which are attached to the piston body 131 by means of fastening means 146, in particular with a screw and a nut or with a rivet, and in particular preloaded onto the ends of the compensating channels 132.

[0068] The two ends of the working channels 133 are, for example, covered by two cover elements 135, in particular in the form of ring discs, which are pre-tensioned onto the ends of the working channels 133 by two separate spring elements 136, in particular in the form of coil springs.

[0069] The fixing sleeve 139 comprises, for example, at least one cover plate 144, in particular two cover plates 1444, wherein the two cover plates 14 are attached to the cylinder sleeve 143 and enclose the piston base body 131 on a side facing the second partial space 114 and on a side facing the compensation space 121.

[0070] The cover plate 144 adjacent to the compensation chamber 121 is, for example, clamped between the piston body 131 and the piston rod 120. The cover plate 144 adjacent to the second sub-chamber 114 is, for example, attached to the cylinder sleeve 143 by means of a connecting element 148, in particular by means of a thread, a flange, a lug and / or a bead.

[0071] The cylinder sleeve 143 is, for example, attached to the piston rod 120 by means of a connecting element 148, in particular by means of a thread. A stop element 149, in particular a snap ring, can, for example, be attached to the piston rod 120 to ensure precise To simplify the positioning of the cylinder sleeve 143 relative to the piston rod 120.

[0072] The piston assembly 130 includes, for example, a number of, say, eight, transfer openings 138, wherein the transfer openings 138 allow the damping fluid to flow around the cover elements 135, which cover the associated ends of the compensation channels 132 and the working channels 133.

[0073] The two compensating channels 132 visible in Figure 2 each have an overflow opening 138 at their end facing the compensating chamber 121, and the two working channels 133 visible in Figure 2 each have an overflow opening 138 at their end facing the first sub-chamber 112. This allows the damping fluid to enter the compensating channels 132 and working channels 133 at these ends, despite the covering elements 135, and flow into the second sub-chamber 114, lifting the covering elements 135 from the ends facing the second sub-chamber 114. Thus, the compensating channels 132 and working channels 133 visible in Figure 2 are traversed by the damping fluid when the piston rod 120 is pushed out of the working chamber.

[0074] Sealing elements 140 can be arranged between the piston base body 131 and the cylinder sleeve 143, between the piston base body 131 and the cover plate 144 facing the compensation chamber 121 and / or between this cover plate 144 and the cylinder sleeve 143. Fig. 3

[0075] Figure 3 shows a further schematic longitudinal section through the piston rod 120 and the piston assembly 130 from Figure 1 along the stroke axis H and the section plane CC marked in Figure 2.

[0076] In addition to the features already described for Figure 1 or Figure 2, the following features are visible in Figure 3:

[0077] The piston body 131 comprises, for example, a number of, in particular four, radial body openings 134 for connecting the number of working channels 133 with the first partial space 112, in particular through the radial sleeve openings 142 of the cylinder sleeve 143, which directs the damping fluid radially to the stroke axis H.

[0078] The piston body 131 comprises, for example, at least one recirculating channel 137 rotating around the stroke axis H, in particular two recirculating channels 137, wherein one of the two recirculating channels 137 connects the working channels 133 to each other at an end facing the first subspace 112 and at an end of the working channels 133 facing the second subspace 114.

[0079] The cover plate 144 adjacent to the second sub-chamber 114 includes, for example, a number of recesses 145 for connecting the compensating channels 132 and the working channels 133 with the second sub-chamber 114, which conducts the damping fluid along the stroke axis H. A section of the piston body 131 containing the compensating channels 132, for example, passes through one of the recesses 145.

[0080] The cover plate 144 adjacent to the compensation chamber 121 includes, for example, a recess 145 through which the section of the piston body 131 containing the compensation channels 132 is passed.

[0081] The two compensating channels 132 and working channels 133 visible in Figure 3 each have, for example, an overflow opening 138 at their end facing the second sub-chamber 114. This allows the damping fluid to enter the compensating channels 132 and working channels 133 at these ends, despite the covering elements 135, and flow into the first sub-chamber 112 or into the compensating chamber 121, whereby the damping fluid lifts the covering elements 135 from the ends facing the second sub-chamber 114 or the compensating chamber 121. The compensating channels 132 and working channels 133 visible in Figure 3 are thus traversed by the damping fluid when the piston rod 120 is pushed into the working chamber. Fig. 4

[0082] Figure 4 shows a schematic cross-section through the piston assembly 130 from Figure 1 transverse to the stroke axis H and along the section plane DD marked in Figure 2.

[0083] Figure 4 also shows the pressure tube 115 of the fluid damper. F° y* ig.5

[0084] Figure 5 shows a schematic perspective view of the piston base body 131 of the piston assembly 130 from Figure 1.

[0085] Figure 5 shows the one-sided ends of the four equalization channels 132, two of which, for example, each have an overflow opening 138. One of the bypass channels 137 and the radial base body openings 134 are also visible. Fig. 6

[0086] Figure 6 shows a schematic top view of the piston body 131 from Figure 5 along the stroke axis H. A top view in the opposite direction along the stroke axis H corresponds to the top view shown in Figure 6 with a 90° rotation about the stroke axis H.

[0087] In addition to the features described in Figure 5, Figure 6 shows the one-sided ends of the four working channels 133, two of which, for example, each have an overflow opening 138. The ends of the working channels 133 each have, for example, a raised edge 150 relative to the bottom of the bypass channel 137. Fig. 7

[0088] Figure 7 shows a schematic longitudinal section through the piston body 131 from Figure 5 along the stroke axis H and the section plane AA marked in Figure 6.

[0089] The compensating channels 132 and working channels 133 visible in Figure 7 each have, for example, an overflow opening 138 at their left end, so that the damping fluid can pass through these compensating channels 132 and working channels 133, even with cover elements resting on the left ends of the compensation channels 132 and working channels 133, the damping fluid can flow from left to right through the piston body 131. However, if cover elements rest on the right ends of the compensation channels 132 and working channels 133, the damping fluid cannot flow from right to left through these compensation channels 132 and working channels 133 through the piston body 131.

[0090] In the compensating channels 132 and working channels 133 not visible in Figure 7, the configurations of the right and left sides are, for example, reversed compared to the visible compensating channels 132 and working channels 133, so that the damping fluid can flow through the piston body 131 from right to left through the non-visible compensating channels 132 and working channels 133.

Claims

Claims 1. Fluid damper including a. a working space filled with a damping fluid; b. a piston rod (120) which is movable relative to the working space along a lifting axis (H) and extends out of the working space along the lifting axis (H) at least at a first end of the working space; c. a compensation chamber (121) arranged at least partially in the piston rod (120), wherein the compensation chamber (121) is designed to receive a volume of damping fluid displaced by the piston rod (120) during an insertion movement of the piston rod (120) into the working chamber; and d. a piston assembly (130) attached to the piston rod (120), wherein the piston assembly (130) divides the working space into a first partial space (112) between the piston assembly (130) and the first end of the working space and a second partial space (114) between the piston assembly (130) and a second end of the working space, characterized in that e. the piston assembly (130) comprises a piston body (131), wherein the piston body (131) comprises a number of compensating channels (132) for the damping fluid-conducting connection of the compensating chamber (121) with the second sub-chamber (114) and a number of working channels (133) for the damping fluid-conducting connection of the first sub-chamber (112) with the second sub-chamber (114), wherein the number of compensating channels (132) overlaps the number of working channels (133) along the stroke axis (H).

2. Fluid damper according to claim 1, wherein the piston body (131) is a single piece.

3. Fluid damper according to claim 1 or 2, wherein the number of compensating channels (132) and / or the number of working channels (133) each constitute a plurality of compensating channels (132) and / or working channels (133), preferably two, four or six compensating channels (132) and / or working channels (133).

4. Fluid damper according to one of claims 1 to 3, wherein the number of compensating channels (132) and / or the number of working channels (133) each run along the stroke axis (H) through the piston body (131).

5. Fluid damper according to claim 4, a. wherein the number of compensating channels (132) is arranged on an inner circular ring around the stroke axis (H); and b. wherein the number of working channels (133) is arranged on an outer circular ring around the stroke axis (H), wherein the inner circular ring lies radially to the stroke axis (H) inside the outer circular ring.

6. Fluid damper according to one of claims 1 to 5, wherein the piston body (131) comprises a number of radial body openings (134) for the connection of the number of working channels (133) with the first subspace (112) which directs the damping fluid radially to the stroke axis (H).

7. Fluid damper according to one of claims 3 to 6, wherein the piston body (131) comprises at least one circulating channel (137) rotating around the stroke axis (H), wherein the at least one circulating channel (137) conductively connects the number of working channels (133) at one end of the number of working channels (133) facing the first subspace (112) and / or the second subspace (114).

8. Fluid damper according to one of claims 1 to 7, wherein the piston assembly (130) comprises a number of cover elements (135), wherein the number of cover elements (135) represents at least a portion of the number of compensation channels (132) and / or the number of working channels (133), each at one of the compensation chambers (121), the covers the first subspace (112) and / or the end facing the second subspace (114) of the number of compensating channels (132) and / or the number of working channels (133).

9. Fluid damper according to claim 8, wherein the piston assembly (130) comprises a number of spring elements (136), wherein the number of spring elements (136) preloads at least a part of the number of cover elements (135) onto the associated ends of the number of compensating channels (132) and / or the number of working channels (133).

10. Fluid damper according to claim 8 or 9, wherein the piston assembly (130) comprises a number of transfer ports (138), wherein the number of transfer ports (138) allows the damping fluid to flow around at least a part of the number of cover elements (135) that cover the associated ends of the number of compensation channels (132) and / or the number of working channels (133).

11. Fluid damper according to one of claims 1 to 10, wherein the piston assembly (130) comprises a fixing sleeve (139) attached to the piston rod (120), wherein the fixing sleeve (139) presses the piston body (131) along the stroke axis (H) onto an end of the piston rod (120) arranged in the working space.

12. Fluid damper according to claim 11, comprising the fixing sleeve (139) a. a number of radial sleeve openings (142) for connecting the number of working channels (133) with the first partial chamber (112), which conducts the damping fluid radially to the stroke axis (H); b. a sealing element (140) sealing the fixing sleeve (139) to a shell wall of the working chamber; and / or c. a guide element that guides the fixing sleeve (139) along a shell wall of the work space.

13. Fluid damper according to claim 11 or 12, comprising the fixing sleeve (139) a. a cylinder sleeve (143), wherein the cylinder sleeve (143) is attached to the piston rod (120) and surrounds the piston body (131) radially to the stroke axis (H); and b. at least one cover plate (144), wherein the at least one cover plate (144) is attached to the cylinder sleeve (143) and surrounds the piston body (131) on a side facing the second partial space (114) and / or on a side facing the compensation space (121) and preferably preloads and / or fixes the piston body (131) against the piston rod (120).

14. Fluid damper according to claim 13, wherein the at least one cover plate (144) comprises a number of recesses (145) for the connection of at least a part of the number of compensating channels (132) and / or the number of working channels (133) with the second subspace (114) and / or with the compensating space (121), which conducts the damping fluid along the stroke axis (H).

Images