Patent Publication Number: US-2010116608-A1

Title: Suspension and damping device for motor vehicles

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to European patent applications EP 08169350.9 filed Nov. 18, 2008 and EP 08171551.8 filed Dec. 12, 2008, and is a Continuation-in-Part (CIP) application of and claims priority to U.S. patent application Ser. No. 11/242,363 filed Oct. 3, 2005, which claims priority to German patent application 20 2004 005 632.2 filed Apr. 8, 2004 and U.S. provisional patent application 60/668,773 filed Apr. 6, 2005. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a suspension and damping device for the load-bearing and spring-loaded wheel support and for the damping of suspension movements in a motor vehicle, comprising at least one spring cylinder having a piston which is guided in a cylinder such that it can move relative thereto and acts against an elastically compressible spring medium in order to generate a load-bearing supporting spring force, wherein for damping a separate circuit of a hydraulic damping medium is provided, the circuit being independent of the spring medium. 
     BACKGROUND OF THE INVENTION 
     WO 03/106202 A1 describes such a suspension device, wherein in some embodiments, a damping device comprises a separate circuit of a hydraulic damping medium, the circuit being independent of the spring cylinder and the spring medium. For this purpose, at least one separate damper cylinder having a damper piston which is guided in a cylinder such that it can move relative thereto and at least one damper valve which is hydraulically connected to the damper cylinder are required. The piston of the spring cylinder is driven by a drive device, which is designed as a gearwheel mechanism and which converts the pivoting movements of a wheel swinging fork supporting arm into the linear relative movements between the cylinder and piston of the spring cylinder. In the process, the damping device having the same drive device and the spring cylinder are to interact, however the media (spring and damping media) are to be completely separated from each other. The reason behind this is that in this way no thermal dependence exists, as a result of which damping-related heating of the damping medium is not critical because the temperature of the spring medium, and therefore also the pressure and the pressure-dependent supporting spring force, remain unaffected thereby. In contrast, heating of the spring medium would also bring about a change in the pressure and consequently in the supporting spring force. The known suspension and damping device, however, has a relatively complex design, which is apparent from the relatively large installation volume and weight. 
     In addition, conventional telescoping spring cylinders, which often are also referred to as “suspension strut”, are known, which are installed directly between the wheel or wheel swinging fork and the vehicle frame. In the case of a hydropneumatic design of such suspension struts, a hydraulic medium is displaced against a compressible medium, and at the same time this hydraulic flow is also conducted over an integrated damper valve. As a result of the damping effect (restriction), the hydraulic medium however is heated quickly and at times considerably. This heating also affects the compressibility, in particular pneumatic, medium in that the pressure thereof, and consequently the supporting spring force, increase. This results in unfavorable, highly fluctuating suspension and damping properties. 
     SUMMARY OF THE INVENTION 
     The underlying object of the invention is to create a suspension and damping device of the generic type described above, which is characterized by a particularly compact and lightweight design and optimal suspension and damping properties. 
     According to the invention, this object may be achieved by various embodiments provided herein and described below. 
     According to at least one embodiment of the invention, the piston inside the cylinder separates two working chambers from each other, wherein the first working chamber is associated with the spring medium and the second working chamber is associated with the damping medium. The spring cylinder according to the embodiment of invention is therefore in principle a kind of suspension strut in the conventional sense, however a hydraulic damping circuit is separated from the spring medium by the piston. The second working chamber is hydraulically connected to a hydraulic container by a damper valve arrangement in that the damping medium has a defined initial pressure, such as 3 to 5 bar. In this way, the flow of the damping medium into the second working chamber is supported (accelerated) during compression of the spring cylinder. 
     In one embodiment of the invention, at least two suspension and damping devices (damper units) are interconnected into one damping system, wherein at least two damper valves are hydraulically connected to the same, common hydraulic container. 
     In one aspect, the invention is based on the realization that in a vehicle comprising several damper units not all damper valves are always subject to equal loads, so that also the heating of the damping medium is not uniformly high. Due to the claimed connection of the damper valves to the common hydraulic container, the damping medium can advantageously be exchanged between the individual damper units such that as a result of temperature equalization overall an advantageous reduction in the temperature of the damping medium is achieved. Consequently, the damping medium is continuously exchanged (mixed) between the individual damper units, which overall causes an effective cooling action. 
     The damping system according to one embodiment of the invention can therefore be employed particularly advantageously in combination with hydropneumatic spring cylinders, wherein each damper unit comprises a telescoping spring cylinder, which includes a piston that is guided in a cylinder such that it can move relative thereto, said piston acting against an elastically compressible spring medium in order to generate a load-bearing supporting spring force. Due to the cooling action, the spring cylinder can be subjected to higher loads, because overall it is heated less. Due to the higher permissible load to which the suspension system can be subjected, the driving performance can be considerably increased, above all also for off-road vehicles. 
     According to a further aspect of the invention, the hydraulic container comprises a cooling element for dissipating heat of the damping medium to the outside to the surrounding area. 
     As a result of this embodiment according to the invention, a high percentage of the heat produced by the restriction is dissipated from the damping medium via the cooling element from the hydraulic container to the outside to the surrounding area. Due to this cooling action of the damping medium, heat transfer to a spring medium is also reduced if the damping device is used in combination with a hydropneumatic spring cylinder. Due to this cooling action according to the invention, the spring cylinder can be subjected to higher loads because it is heated less on an overall basis. Due to the higher permissible load to which the suspension system can be subjected, the driving performance can be further increased, above all also for off-road vehicles. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described below in more detail with reference to several preferred embodiments illustrated in the drawings. The following are shown in schematic, in part axially cut representative illustrations: 
         FIG. 1  Illustrates a first embodiment of a suspension and damping device according to the invention; 
         FIG. 2  is a reduced view of the device according to  FIG. 1  in a compressed state; 
         FIG. 3  is a view analogous to  FIG. 2  in the extended state; 
         FIG. 4  is a second embodiment of the device according to the invention in an illustration analogous to  FIG. 1 ; 
         FIGS. 5 and 6  are illustrations of the embodiment depicted in  FIG. 4  respectively in a compressed state and an extended state; 
         FIG. 7  illustrates illustrations a third embodiment according to the invention; 
         FIGS. 8 and 9  are illustrations of the embodiment depicted in  FIG. 7  respectively in a compressed state and an extended state; 
         FIG. 10  is another embodiment of a suspension and damping device according to the invention; 
         FIG. 11  is one embodiment of the invention illustrated by way of the embodiment according to  FIGS. 4 to 6 ; 
         FIG. 12  is a suspension system for a vehicle comprising, by way of example, three spring cylinders and a damping system according to the invention, all components being shown in the longitudinal sectional view; 
         FIG. 13  is an enlarged partial view from  FIG. 12  of a spring cylinder with the associated damper unit; 
         FIG. 14  is a further embodiment of the suspension device for a vehicle, comprising a telescoping spring cylinder and a damping device according to the invention, all components being shown in the longitudinal sectional view; and 
         FIG. 15  is an illustration as in  FIG. 14  in a further advantageous embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the different figures of the drawings, in general identical or functionally equivalent parts and components are denoted with the same reference numerals. As a result, any description of a part, which references one or more defined drawing figures, analogously also applies to the other drawing figures in which the part bearing the corresponding reference numeral is likewise shown. 
     In the exemplary embodiments according to  FIGS. 1 to 11 , a suspension and damping device  1  according to the invention comprises (at least) one spring cylinder  2 , which is provided for direct arrangement between a vehicle wheel or a wheel swinging fork support arm and a vehicle frame (both not shown). The spring cylinder  2  is composed in a telescoping manner of a cylinder  4  and a piston  6  that is guided therein in a linearly displaceable manner, the piston having a piston rod  8 , which is led through the cylinder  4  in a peripherally sealed manner. 
     The piston  6  acts indirectly (such as is shown in  FIGS. 1 to 6 ) or directly (such as is shown in  FIGS. 7 to 10 ) against an elastically compressible spring medium FM in order to generate a load-bearing supporting spring force F. A separate circuit of a hydraulic damping medium DM is provided for damping suspension movements, the circuit being independent of the spring medium FM. 
     The piston  6  rests against the inside surface of the cylinder  4  by way of at least one annular piston seal. In this way, the piston  6  separates two working chambers from each other inside the cylinder  4 , wherein a first working chamber  10  is associated with the spring medium FM and a second working chamber  12  is associated with the damping medium DM. The piston  6  according to the invention consequently also separates a “spring circuit” from a “damping circuit”. 
     In the preferred embodiment shown, the spring cylinder  2  is configured as a pressure cylinder. This means that it basically acts as a compression spring in order to support the respective load. For this purpose, the first working chamber  10  associated with the spring medium FM is formed as a cylindrical space on the side of the piston  6  opposite of the piston rod  8 . The second working chamber  12  encloses the piston rod  8  in an annular or hollow-cylindrical manner. Since the second working chamber  12  according to the invention is associated with the damping medium DM, in this embodiment the piston rod  8  advantageously acts as a cooling element for cooling the damping medium DM heating during damping or restriction. 
     The second working chamber  12  is connected to a hydraulic container  16  by way of a damper valve arrangement  14 . The damper valve arrangement  14  is preferably integrated in an inlet region of the hydraulic container  16 . The hydraulic container  16  is preferably disposed externally as a separate component, separate from the spring cylinder  2 , and connected by a line  18  to the second working chamber  12  of the spring cylinder  2 . As the damper valve arrangement  14  is integrated in the inlet region of the hydraulic container  16 , damping or restriction related heating of the damping medium DM advantageously takes places in a region that is removed from the spring cylinder  2 , and consequently removed from the spring medium FM. In addition, as a result of the external hydraulic container  16 , advantageously also an additional cooling effect for cooling the damping medium DM is achieved in that heat is dissipated to the surrounding area via a large outer surface (cooling surface). While a portion of the heat may also reach the second working chamber  12  by way of the damping medium DM, the piston rod  8 , as was already indicated above, acts as a cooling element in that it is surrounded by the damping medium DM, thereby transporting the heat thereof to the outside. This is particularly effective because during the suspension movements the piston rod also in part moves to the outside out of the cylinder  4  and can dissipate heat there to the surrounding area. The piston rod  8  acts as or forms a kind of “heat pump”. In addition, heat is also dissipated via the outer surface of the cylinder  4  to the surrounding area. In this way, due to the arrangement according to the invention, overall very large cooling surfaces are used for effective cooling of the damping medium DM such that heat transfer via the piston  6  to the spring medium is advantageously minimal at best. 
     Additionally, in the preferred embodiments, damping takes place only in half the suspension cycle, specifically through a corresponding design of the damper valve arrangement  14  (comprising throttle and check valves) only during extension, while compression movements are nearly undamped, so that heat can only be produced during extension. The compression stroke can be used for cooling. During compression, hydraulic damping can be foregone because the spring medium FM has almost a damping effect due to an ascending spring characteristic curve. 
     The hydraulic container  16  is preferably disposed in a vehicle such that it is disposed approximately parallel next to the spring cylinder  2 , specifically such that the damping medium DM is located in the lower region due to gravity. Air may be provided in a space  19  above the damping medium DM. According to at least one embodiment of the invention, this space  19  above the damping medium DM should be pressurized to a defined initial pressure, such as 3 to 5 bar, in order to support (accelerate) the flow into the second working chamber during compression. 
     In the embodiments according to  FIGS. 1 to 6 , and also according to  FIG. 11 , the first working chamber  10  is connected by a line  20  to a spring accumulator  22  containing the elastically compressible spring medium FM. This spring accumulator  22  is preferably designed as a hydropneumatic piston-type accumulator comprising a dividing piston  26  that is freely movable (floating) in an accumulator cylinder  24 . The dividing piston  26  rests against the inner surface of the accumulator cylinder  24  in a sealing manner by way of at least one sealing ring, thereby hydraulically separating an accumulator chamber  28 , which is connected by the line  20  to the first working chamber  10 , from a spring chamber  30 , which contains the spring medium FM, wherein the first working chamber  10  and the spring chamber  28  are filled completely with a hydraulic medium HM. In this way, the piston  6  of the spring cylinder  2  acts directly against the spring medium FM inside the spring chamber  30  by way of the hydraulic medium HM and the dividing piston  26 . 
     During compression, a defined volume of the hydraulic medium HM is displaced by the piston  6  into the accumulator chamber  28 , thereby displacing the dividing piston  26  against the spring medium FM in the direction of the spring chamber  30 . The resulting volume reduction increases the pressure of the spring medium FM and consequently also the supporting force F. 
     In the embodiment according to  FIGS. 1 to 3 , the dividing piston  26  is disposed as a dividing wall completely inside the accumulator cylinder  24 . As a result, it must have a relatively large axial length in order to prevent it from tilting inside the accumulator cylinder  24  and thereby becoming jammed (referred to as “drawer effect”). 
     In contrast, according to the embodiment shown in  FIGS. 4 to 6  the dividing piston  26  comprises a dividing piston rod  32 , which extends axially through the accumulator chamber  28  and is led through the accumulator cylinder  24  to the outside in a sealed manner. The dividing piston rod  32  achieves additional guidance of the dividing piston  26  to prevent tilting such that the dividing piston  26  can be designed to have a shorter axial length. In this way, the overall length of the spring accumulator  22  can be reduced. In addition, due to the dividing piston rod  32 , the spring accumulator  22  in this design also acts as a pressure converter such that the pressure of the spring medium FM is always smaller than the pressure of the hydraulic medium HM. This is due to the fact that the pressurized opposing surfaces of the dividing piston  26  are different in size. On the side of the spring chamber  30 , the spring medium FM acts on a larger surface, so that a lower pressure of the spring medium FM suffices for a static equilibrium of the dividing piston  26 . In other words, due to the smaller annular surface of the dividing piston  26  that encloses the dividing piston rod  32 , the opposing pressure of the hydraulic medium HM must be larger in order to keep the dividing piston  26  in equilibrium. 
     It is further shown in  FIGS. 4 to 6 , and also in  FIG. 11 , the spring accumulator  22  is preferably disposed parallel next to the spring cylinder  2 , specifically in an orientation in which the piston rod  8  of the spring cylinder  2  and the dividing piston rod  32  of the spring accumulator  22  point in the same direction with respectively equivalent directions of movement. As is apparent from the illustrations in  FIGS. 5 and 6 , the dividing piston rod  32  moves out of the spring accumulator  22  when the spring cylinder  2  also extends, which is to say when the piston rod  8  likewise moves out of the cylinder  4 . In this way, problems regarding collisions with other vehicle components during the vehicle suspension movements are avoided. 
     In the embodiment according to  FIGS. 7 to 9 , the first working chamber  10  of the spring cylinder  2  is filled directly with the elastically compressible spring medium FM such that the piston  6  acts directly against the spring medium FM. As a result, an additional, external spring accumulator  22  can be foregone. This produces a particularly compact and lightweight design of the suspension and damping device  1 . However, since the compressible spring medium FM cannot be compressed arbitrarily, and in particular not to a volume of zero, in this embodiment a minimum residual volume is formed by the hollow space  34  inside the piston  6  and the piston rod  8 . 
     As an alternative to, or in addition to the hollow space  34 , according to  FIG. 10  an external additional container  36  may be connected by a line  38  to the first working chamber  10 . In this design too, the elastic spring medium FM is provided directly in the first working chamber  10 . 
     In particular a gaseous medium, such as nitrogen, can be used as the compressible spring medium FM. As an alternative, any arbitrary other medium, such as a liquid or paste-like (high-viscosity) medium, is suited. A conventional, in particular a low-viscosity hydraulic oil can be used as the damping medium DM and/or hydraulic medium HM. 
     It is also apparent from  FIGS. 1 to 6  that the spring cylinder  2  is preferably equipped with a device for hydraulic end-of-stroke damping. This end-of-stroke damping is denoted in  FIGS. 1 and 4  with reference numeral  40 . This end-of-stroke damping  40  in the compression direction preferably ensures a slowing of the suspension movements toward an end of the compression stroke before a mechanical limit stop is reached. Specifically, it is a path-dependent hydraulic throttling device comprising a tappet  42  which can be disposed in the piston  6  in a telescoping manner and comprises an axial flow channel, into which a plurality of radial transverse openings flow, which are distributed over the length. By lowering the tappet  42  into the piston  6 , the transverse openings are successively closed during the movement to the limit stop position. In this way, the flow resistance is successively increased because, when the tappet  42  has mechanical contact in the region of an outlet opening of the cylinder  4  (see the positions in  FIGS. 2 and 5 ), the hydraulic medium HM can flow out only via the transverse openings and the axial channel of the tappet  42 . In this way, the respective movement is gently slowed, and hard contact with the limit stop is advantageously avoided. 
       FIG. 11  illustrates a hydraulic leveling device  44 , which is designed such that a static vehicle level can be varied by feeding hydraulic medium HM to or draining it from the spring circuit. For this purpose, the leveling device  44  comprises a control valve  46 , a tank  48 , and a pump  50 . The control valve  46  is designed as a 3/3 way valve and is closed in the position shown. In a first control position, the pump  50  can be connected to the suspension circuit in order to feed hydraulic medium, thereby raising the level. In a second control position, the suspension circuit is connected to the tank  48  in order to drain hydraulic medium so as to lower the level. 
     Below, the special embodiment according to  FIGS. 12 and 13  are explained. 
     As is first apparent from  FIG. 12 , a damping system  100  according to one embodiment of the invention is shown, which comprises at least two damper units  102  for damping wheel suspension movements inside a vehicle. In general, in a wheeled vehicle each wheel is equipped with a dedicated damper unit  102  such that a four wheel vehicle comprises four damper units  102 , even if in  FIG. 12  only three damper units  102  are shown by way of example. Each damper unit  102  has a hydraulic damper valve  104  for restricting flows of a hydraulic damping medium DM, which are caused by suspension movements. 
     According to the invention, at least two, preferably all, damper valves  104  present in the damping system are hydraulically connected to a common hydraulic accumulator container  106 . For this purpose, this hydraulic container  106  comprises an accumulator chamber  108  for volume portions of the damping medium DM, which vary during the damping of the suspension movements. The damping medium DM present in the accumulator chamber  108  is preferably pressurized to an initial pressure p. In a preferred embodiment, the hydraulic container  106  for this purpose comprises a pressure chamber  110  adjacent to the accumulator chamber  108 , wherein the pressure chamber comprises a compressed gas DG pressurizing the damping medium DM to the initial pressure p. The initial pressure p of the compressed gas DG may range between 2 and 20 bar, particularly between 3 and 10 bar. This initial pressure p supports the respective return flow of the damping medium DM out of the accumulator chamber  108  back via the respective damper valve  104 . It is further advantageous for the accumulator chamber  108  to be separated from the pressure chamber  110  by a dividing element in a media-tight manner. In the illustrated example according to  FIG. 12 , a dividing piston  112  which is guided in a freely movable (floating) manner is disposed as the dividing element inside the cylindrical hydraulic container  106 . Due to the dividing element, the hydraulic container  106  can advantageously be disposed in any arbitrary spatial orientation, for example as is shown in  FIG. 12  such that the accumulator chamber  108  is disposed “at the top” and the pressure chamber  110  “at the bottom”. 
     At this point, it should be noted that the hydraulic container  106  serves exclusively as a reservoir for the damping medium DM flowing back and forth for damping purposes. This means that the hydraulic container  106  is exclusively associated with the damping circuit and consequently has no spring effect for wheel support in the vehicle. 
     In a further advantageous embodiment, however, the damping system is basically combined with a suspension system. For this purpose, each damper unit  102  is preferably part of a telescoping spring cylinder  114 , which is provided between a vehicle wheel or a wheel suspension and a vehicle frame (not shown) particularly for arrangement as a suspension strut. Each spring cylinder  114  comprises a cylinder  116  and a piston  118  which is guided therein such that it can carry out linear relative movements thereto, the piston acting against an elastically compressible spring medium FM in order to generate a load-bearing supporting spring force F. At each spring cylinder  114 , the piston  118  separates two working chambers  120  and  122  from each other inside the cylinder  116  in a media-tight manner; the first working chamber  120  is associated with the spring medium FM, while the second working chamber  122  is associated with the hydraulic damping medium DM. In this way, two circuits of the spring medium FM for suspension and of the damping medium DM for damping are created, which are independent of each other. In this way, largely thermal independence between the media DM and FM is achieved. On the piston side, the piston  118  is connected to a piston rod  124 , which is led through the cylinder  116  to the outside in a peripherally sealed manner. As a result, one of the two working chambers is designed as an annular chamber enclosing the piston rod  124 . 
     In the illustrated preferred embodiment, the annular chamber enclosing the piston rod  124  forms the second working chamber  112  associated with the damping medium DM, while an opposing cylinder chamber forms the first working chamber  120  associated with the spring medium FM. 
     The first working chamber  120  is filled with the elastically compressible spring medium FM and is connected in particular by a line  126  to an additional spring accumulator  128 , which is likewise filled with spring medium FM. The spring medium FM is pressurized to an accordingly high pressure level in order to generate the supporting spring force F by applying pressure to the piston  118 . 
     As an alternative to this embodiment, it is also possible to fill the first working chamber  120  with a hydraulic medium and connect it hydraulically to the spring accumulator  128 , wherein the spring accumulator  128  can then be designed as a hydropneumatic accumulator, for example comprising a dividing piston between the hydraulic medium and the spring medium. 
     The second working chamber  122  is filled with the hydraulic damping medium DM and connected to the associated damper valve  104 . The damper valve  104  can be disposed on the outside or inside of the associated spring cylinder  114  (not shown). In the illustrated advantageous embodiment, however, each damper valve  104  is designed as a separate component having a dedicated valve housing  130  to be disposed away from the spring cylinder  114 . For this purpose, reference is made in particular to the enlarged illustration in  FIG. 13 . According to this illustration, the valve housing  130  comprises an input connection  132  to be connected to the spring cylinder  114  and an output connection  134  to be connected to the hydraulic cylinder  106 . Inside the valve housing  130 , a throttle valve arrangement  136  is disposed between the input connection  132  and the output connection  134 . The input connection  132  of each damper valve  104  is connected to the associated spring cylinder  114 , specifically to the second working chamber  122  thereof, by way of a hydraulic line  138 . The output connections  134  of all damper valves  104  are connected to the common hydraulic container  106  by way of hydraulic lines  140  (see  FIG. 12 ). 
     At least the respective hydraulic line  140  leading to the common hydraulic container  106  can be detachably connected to the damper valve  104  by way of a hydraulic coupling (plug connection). Each damper valve  104  is thus a hydraulically closed system that is completely filled with damping medium DM. The throttle valve arrangement  136  is disposed in the vicinity of the input connection  132 , so that a receiving chamber  142  for a defined, but relatively low volume of the damping medium DM is produced between the throttle valve arrangement  136  and the output connection  134 . The damping medium DM can be filled into the receiving chamber  142  via a filling connection  144 , and as a result, into the second working chamber  122  of the spring cylinder  114  via the throttle valve arrangement  136  and the hydraulic line  138 . 
     Each throttle valve arrangement  136  comprises two partial valves, specifically a first partial valve having a relatively higher throttling resistance for the flow of the damping medium DM into the hydraulic container  106  and a second partial valve having a relatively lower throttling resistance for the reverse flow out of the hydraulic container  106  back into the spring cylinder  114 . In this way, it is achieved that the compression of the spring cylinder  114  is damped little, while the extension is damped more strongly. 
     In particularly nitrogen is used as the compressed gas DG for the hydraulic container  106  and/or as the spring medium FM for the spring cylinder  114  and/or optionally for the additional spring accumulator  128 . 
     Through the preferably external arrangement of each damper valve  104 , separate from the respective spring cylinder  114 , and in particular through the connection according to the invention of the damper valves  104  to the common hydraulic container  106 , very effective cooling of the damping medium DM heating during throttling is achieved. In this way, heat transmission inside the respective spring cylinder  114  to the spring medium FM is kept extraordinarily low such that the spring system equipped with the damping system according to the embodiment of the invention ensures very consistent suspension and damping properties. 
     The embodiment according to  FIGS. 14 and 15  will now be described. 
     As is first apparent from  FIG. 14 , a damping device  201  according to one embodiment of the invention comprises at least one damper unit  202  for damping wheel suspension movements inside a vehicle. In general, in a wheeled vehicle each wheel is equipped with a dedicated damper unit  202  such that a four wheel vehicle comprises four damper units  202 . The damper unit  202  has a hydraulic damper valve  204  for reducing flows of a hydraulic damping medium DM caused by suspension movements. A hydraulic container  206  is connected downstream of the damper valve  204 , which is to say it is connected hydraulically downstream thereof. 
     This hydraulic container  206  comprises an accumulator chamber  208  for volume portions of the damping medium DM, which vary during the damping of the suspension movements. The damping medium DM present in the accumulator chamber  208  is preferably pressurized to an initial pressure p. In a preferred embodiment, the hydraulic container  206  for this purpose comprises a pressure chamber  210  adjacent to the accumulator chamber  208 , wherein the pressure chamber comprises a compressed gas DG pressurizing the damping medium DM to the initial pressure p. The initial pressure p of the compressed gas DG may range between 2 and 20 bar, particularly between 3 and 10 bar. This initial pressure p supports the respective return flow of the damping medium DM out of the accumulator chamber  208  back via the respective damper valve  204 . 
     According to at least one embodiment of the invention, the hydraulic container  206  from  FIGS. 14 and 15  comprises a cooling element  212  for removing heat of the damping medium DM to the outside to the surrounding area. In a preferred embodiment, the cooling element  212  is formed by an intermediate wall  218 , which is disposed inside an in particular cylindrical housing  214  of the housing container  206  and comprises a plurality of continuous flow openings  216 . This intermediate wall  218 , and also the housing  214 , are each made of a material having good thermal conductivity, in particular metal, and are connected to each other in a heat-conducting manner. In this way, heat produced by restricting (internal molecular friction) the damping medium DM is dissipated from the interior of the hydraulic container  6  via the cooling element  212  or the intermediate wall  218  to the housing  214  and then emitted to the outside to the surrounding area via the outer surface of the housing  214 . 
     In the first embodiment according to  FIG. 14 , the compressed gas DG is directly applied to damping medium DM. The hydraulic container  206  must be oriented in the space such that the accumulator chamber  208  is disposed vertically at the bottom and the pressure chamber  210  at the top. In this design, the intermediate wall  218  can be disposed arbitrarily in the region of the accumulator chamber  208  and/or in the region of the pressure chamber  210  (depending on the fill level of the accumulator chamber  208 ). The damping medium DM and/or the compressed gas DG thus flow through the flow openings  216  of the intermediate wall  218  with respect to the suspension-related flows of the damping medium DM. In the preferred embodiment shown in  FIG. 14 , the intermediate wall  218 , regardless of the fill level of the accumulator chamber  208 , is always disposed inside the pressure chamber  10  such that only the compressed gas DG flows through the flow openings  216 . In the process, the heat is transmitted from the damping medium DM via the compressed gas DG into the intermediate wall  218  and dissipated from there to the outside to the housing  214 . 
     In the embodiment according to  FIG. 15 , the accumulator chamber  208  is separated in a media-tight manner from the pressure chamber  210  by a dividing element. In the illustrated example, a dividing piston  220  which is guided in a freely movable (floating) manner is disposed as the dividing element inside the cylindrical hydraulic container  206 . Due to the dividing element, the hydraulic container  206  can advantageously be disposed in any arbitrary spatial orientation, for example deviating from the illustration shown in  FIG. 15 , such that the accumulator chamber  208  is disposed “at the top” and the pressure chamber  210  “at the bottom”. In the embodiment according to  FIG. 15 , the intermediate wall  218  is likewise preferably disposed inside the pressure chamber  210 , specifically at such a location that for all suspension-related flows of the damping medium DM occurring in practical applications the ability of the dividing piston  220  to move remains ensured. In this embodiment, the heat produced in the damping medium DM is transmitted via the dividing piston  220  into the compressed gas DG and is then removed via the cooling element  212 . As an alternative to this embodiment according to  FIG. 15 , it is in principle also possible to dispose the intermediate wall  218  inside the accumulator chamber  208 . 
     At this point, it should be noted again that the hydraulic container  206  serves exclusively as a reservoir for the damping medium DM flowing back and forth for damping purposes. This means that the hydraulic container  206  is exclusively associated with the damping circuit and consequently has no spring effect for wheel support in the vehicle. 
     In a further advantageous embodiment, however, the damping system  201  is basically combined with a suspension system. For this purpose, each damper unit  202  is preferably part of a telescoping spring cylinder  222 , which is provided between a vehicle wheel or a wheel suspension and a vehicle frame (not shown) particularly for arrangement as a suspension strut. The spring cylinder  222  comprises a cylinder  224  and a piston  226  guided therein such that it can carry out linear relative movements, the piston acting against the pressure of an elastically compressible spring medium FM in order to generate a load-bearing supporting spring force F. The piston  226  separates two working chambers  228  and  230  from each other inside the cylinder  224  in a media-tight manner. The first working chamber  228  is associated with the spring medium FM, while the second working chamber  230  is associated with the hydraulic damping medium DM. In this way, two circuits of the spring medium FM for the suspension and of the damping medium DM for the damping are created, which are independent of each other. In this way, largely thermal independence between the media DM and FM is achieved. On the piston side, the piston  226  is connected to a piston rod  232 , which is led through the cylinder  224  to the outside in a peripherally sealed manner. As a result, one of the two working chambers is designed as an annular chamber enclosing the piston rod  232 . 
     In the illustrated preferred embodiments, the annular chamber enclosing the piston rod  232  forms the second working chamber  230  associated with the damping medium DM, while an opposing cylinder chamber forms the first working chamber  228  associated with the spring medium FM. 
     The first working chamber  228  is filled with the elastically compressible spring medium FM and in particular is connected by a line  234  to an additional spring accumulator  236 , which is likewise filled with spring medium FM. The spring medium FM is pressurized to an accordingly high pressure level in order to generate the supporting spring force F by applying pressure to the piston  226 . 
     As an alternative to this embodiment, it is also possible to fill the first working chamber  228  with a hydraulic medium and connect it hydraulically to the spring accumulator  236 , wherein the spring accumulator  236  should then be designed as a hydropneumatic accumulator, for example comprising a dividing piston between the hydraulic medium and the spring medium. 
     The second working chamber  230  is filled with the hydraulic damping medium DM and is connected to the damper valve  204 . The damper valve  204  can be disposed in principle on the outside or inside of the spring cylinder  222  (not shown). In the illustrated, advantageous embodiments, however, the damper valve  204  is designed as a separate component having a dedicated housing  214  disposed away from the spring cylinder  222  and is connected to the spring cylinder  222  by a hydraulic line  238 . 
     The throttle valve  204  in turn comprises two partial valves, specifically a first partial valve having a relatively higher throttling resistance for the flow of the damping medium DM into the hydraulic container  206  and a second partial valve having a relatively lower throttling resistance for the reverse flow out of the hydraulic container  206  back into the spring cylinder  222 . In this way, it is achieved that the compression of the spring cylinder  222  is damped little, while the extension is damped more strongly. 
     In particularly nitrogen is used as the compressed gas DG for the hydraulic container  206  and/or as the spring medium FM for the spring cylinder  222  and/or optionally for the additional spring accumulator  236 . 
     Through the preferably external arrangement of the damper valve  204 , separate from the spring cylinder  222 , and in particular through the cooling element  212  according to the invention, very effective cooling of the damping medium DM heating during throttling is achieved. In this way, heat transmission inside the respective spring cylinder  222  to the spring medium FM is kept extraordinarily low such that the spring system equipped with the damping system according to the embodiment of the invention ensures very consistent suspension and damping properties. 
     In a further advantageous embodiment of the invention, the hydraulic container  206  comprises a pressure control valve  240 , which is designed in particular such that it opens starting a defined overpressure, which corresponds to the respective maximum value of the initial pressure p. The pressure control valve  240 , for example, opens starting at approximately 20 bar, preferably starting at approximately 10 bar. The pressure control valve  240  advantageously prevents the higher pressure of the spring medium FM from causing impermissible overpressure in the hydraulic container  206  in the event of a leak in the region of the seals of the piston  226 . 
     The hydraulic container  206  can furthermore have a filling valve  242  in a suitable location of the housing  214 . In addition, the spring accumulator  236  is also equipped with a filling valve  244 . 
     A person skilled in the art will appreciate, the above description is meant as an illustration of the implementation of the principles of this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from the spirit of this invention, as defined in the following claims.