Abstract:
A coupling for handling fluid media, preferably for cryogenic media or liquefied natural gas. The coupling has a single core or multicore coupling connector plug and a coupling socket, with associated ball valves. Rotating rings associated with the coupling connector plug and the coupling socket allow for opening and closing of the ball valves to permit transfer of fluids via a conduit that can extend into the coupling socket past the plane of separation.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION  
       [0001]     This application claims the priority of DE 101567405, filed Nov. 19, 2001, the disclosure of which is expressly incorporated by reference herein.  
         [0002]     The invention relates to a coupling, particularly for cryogenic media and liquefied natural gas, having 
        a single-core or multicore coupling plug and a coupling socket. When coupled, a conduit of the coupling plug, which is constructed to be movable with respect to the coupling plug in the axial direction, extends or can extend beyond the plane of separation into the coupling socket.        
 
         [0004]     The invention also comprises 
        a plug-side ball valve,     a socket-side ball valve,     the ball valves being constructed for the leading-through of the conduit, and     devices for opening and closing the ball valves.        
 
         [0009]     The invention also relates to the use of such a coupling.  
         [0010]     In the following, the designations of special cryogenic medium will be preceded corresponding to their state of aggregation by the letters “G” for “gaseous” and “L” for “liquid”; thus, for example, GH 2  or LH 2  for gaseous or liquid hydrogen respectively. Furthermore, the terms “CNG” and “LNG” are used for compressed or liquefied natural gas.  
         [0011]     Hydrogen and natural gas are currently becoming more and more significant as energy carriers because of the rising demand for energy and increased environmental awareness. Thus, trucks, buses, passenger cars and railroad engines are already driven by means of natural-gas or hydrogen-operated engines. Furthermore, first attempts are being made to power airplanes by means of the above-mentioned media.  
         [0012]     The storage of the hydrogen or natural gas “on board” the above-mentioned means of transport makes the most sense in liquid form. For this purpose, the hydrogen and LNG have to be cooled to approximately 25 K. and 112 K. respectively and have to be maintained at this temperature, which can be implemented only by corresponding insulating measures at the storage containers or tanks. However, because of the low density of GH 2  and CNG, storage in the gaseous state in the above-mentioned means of transport, as a rule, is less advantageous because the storage has to take place in large-volume, heavy storage tanks at high pressures.  
         [0013]     German Patent Document DE-A 41 04 711 describes a conventional coupling of the above-mentioned type. The principle of such a coupling is based on a system in which two ball valves—one on the plug side and one of the socket side—are flanged to one another. Subsequently, a vacuum-insulated fill pipe moves through the passage bores of the ball valves from the plug side, through which fill pipe the (cryogenic) medium flows to the socket side of the coupling. After the filling operation, the plug moves back, and the ball valves are closed again. Subsequently, the mutual flanging of the ball valves is separated. A refueling coupling of this type permits an overfilling of (cryogenic) liquids, while, on the outside, a cooling of the visible components cannot be detected.  
         [0014]     When applying the above-described principle, it is necessary to open or close the plug-side ball valve and the socket-side ball valve by a 90°-rotation of the balls. Conventionally, this actuating operation has been carried out by a manual lever which—as normally used for ball valves—opens or closes the ball by a 90°-rotation. By means of a gearwheel drive, which engages when the coupling halves are connected, the socket-side ball valve is simultaneously opened or closed.  
         [0015]     For automatic applications, for example, such as refueling by means of a so-called refueling robot, it becomes possible to actuate the plug-side ball valve by means of a hydraulic or pneumatic drive. The socket-side ball valve is opened in the same manner as during the manual operation by way of a gearwheel, which engages during the linking-up of the coupling flanges.  
         [0016]     However, based on the geometrical situations, the gearwheels in the aforementioned conventional coupling have to engage before the flanges contact one another. An exact mutual engagement of the teeth during the link-up operation requires a very good axial guidance of the plug side relative to the socket side. Because of the extremely limited space conditions, a guidance, such as a cone-type guidance, cannot be used in the required form. A successful link-up operation therefore depends on the skill of the operating personnel or on the sensor system and precise control of the refueling robot.  
         [0017]     Furthermore, during the link-up operation, the torsional axes of the ball valves have to be situated in a plane, so that the teeth of the gearwheel drive also engage in a plane.  
         [0018]     In addition, it has to be ensured that during the link-up, the tooth tip of one side engages in a tooth base of the opposite side. If two tooth tips butt in front of one another, the flanges cannot be connected.  
         [0019]     Also, as a result of their exposed arrangement, the gearwheels are exposed to considerable dirt contamination due to weather influences. Because of the narrow tolerances, which exist in the case of a toothing, any dirt contamination may lead to jamming of the gearwheels and to increased wear.  
         [0020]     It is an object of the present invention to provide a coupling of the above-mentioned type, particularly for cryogenic media and liquefied natural gas, which avoids the above-mentioned disadvantages.  
         [0021]     This and other objects and advantages are achieved according to one or more embodiments of the invention by a coupling valve where: 
        the devices for opening and closing the ball valves are constructed as 1) a rotating ring which is assigned to the coupling plug and can be displaced in the longitudinal direction of the coupling plug, and 2) as a rotating ring which is assigned to the coupling socket and is in an operative connection with the socket-side ball valve; wherein     the rotating rings can be rotated about the longitudinal axis of the coupling plug and the coupling socket;     the rotating rings have devices for the force-locking and/or form-locking mutual connection; and     the rotating ring assigned to the coupling plug is in an operative connection with the plug-side ball valve and/or an arbitrary driving device is assigned to the plug-side ball valve.        
 
         [0026]     According to an embodiment of the invention, the two ball valves are not immediately connected with one another or moved into an operative connection with one another during the connecting of the coupling plug and the coupling socket, but rather when the actual connection operation between the coupling plug and the coupling socket has already been concluded. Thus, the coupling flanges can first be connected with one another in the conventional manner, but without the possibility of an occurrence of previous restrictions by an inexact axial guidance and mutual engagement of the pairs of gearwheels.  
         [0027]     It is not necessary for the rotating ring assigned to the coupling plug to be constructed as a complete ring. On the contrary, it is sufficient for this ring to consist of partial rings or partial ring bodies.  
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0028]     The coupling according to the invention as well as further developments of the latter will be explained in detail in relation to the embodiment illustrated in the figure. The figure shows a perspective partial representation of a possible embodiment of the coupling according to the invention. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0029]     The coupling has a plug-side flange  9  and a socket-side flange  10  which are form-lockingly connected with one another by means of a clamping  8 . The actual coupling operation between the coupling plug and the coupling socket will be concluded when the clamping-together  8  of the two flanges  9  and  10  has taken place.  
         [0030]     According to the invention, the coupling has a plug-side rotating ring  3  as well as a socket-side rotating ring  4 . The two rotating rings  3  and  4  can be rotated about the longitudinal axis of the coupling plug and the coupling socket (illustrated by the two wide arrows). In addition, the plug-side rotating ring  3  can be displaced in the longitudinal direction of the coupling plug (illustrated by the narrow arrow). While the plug-side rotating ring  3  is in an operative connection with the plug-side ball valve  1 , the socket-side rotating ring  4  is in an operative connection with the socket-side ball valve  2 .  
         [0031]     However, the rotating ring  3  assigned to the coupling plug does not have to be in an operative connection with the plug-side ball valve  1 . In an alternative embodiment, the plug-side ball valve  1  can be moved by an arbitrary driving device—such as, for example, another rotating ring which is independent of the rotating ring  3  assigned to the coupling plug, a hydraulic or pneumatic piston drive, or an electric-motor drive. In still another embodiment, the plug side ball valve  1  can be operatively connected to both the rotating ring  3  and an arbitrary driving device.  
         [0032]     In an embodiment, if the coupling plug and the coupling socket or their flanges  9  and  10  are clamped to one another ( 8 ) as illustrated in the figure, the opening of the ball valves  1  and  2  takes place in that the plug-side rotating ring  3  is displaced by means of a defined advancing force in the direction of the socket-side rotating ring  4 . Preferably, the two rotating rings  3  and  4  have notches on their faces so that they can be mutually connected in a form-locking and force-locking manner. In such an embodiment, the notches of the plug-side rotating ring  3  engage with the notches of the socket-side rotating ring  4 .  
         [0033]     Now the plug-side rotating ring  3  is rotated about its longitudinal axis by the customer, the operating personnel and/or automatically. The defined advancing force is preferably maintained in this case. Here, the displacing and/or rotating movement of the plug-side rotating ring  3  can take place by means of a hydraulic, pneumatic or electric drive.  
         [0034]     If the two rotating rings  3  and  4  have already engaged, the socket-side rotating ring  4  is immediately rotated along as a result of the form-locking and force-locking. If no engagement exists yet between the two rotating rings  3  and  4  because, for example, the notch heads are matched up in front of one another, the plug-side rotating ring will at first rotate by a notch head width, without taking along the socket-side rotating ring. However, subsequently, the plug-side notch head will engage in the notch base of the socket-side rotating ring  4 , if the defined advancing force of the plug-side rotating ring  3  was maintained. The angle difference resulting from the above-described slight rotation—compared with the immediate engagement of the two rotating rings  3  and  4 —can be tolerated because of the minimal size of the angle.  
         [0035]     The two rotating rings  3  and  4  are connected with ring gears  5  and  11 , which are situated in an area of the respective connection side not visible on the outside and protected from becoming dirty. The above-mentioned ring gears  5  and  11  drive the drive shafts  7  and  13  of the ball valves  1  and  2  by way of pinion gears  6  and  12 .  
         [0036]     A defined angular rotation of the rotating rings  3  and  4  therefore results in a 90°-rotation of the ball valves  1  and  2  or their balls defined by the transmission ratio of the ring gears and bevel gears.  
         [0037]     In the embodiment of the coupling according to the invention illustrated in the figure, the two ball valves  1  and  2  are opened or closed in a synchronous manner. If the plug-side ball valve  1  is moved by means of a driving device other than the above-described driving device, this plug-side ball valve  1  can be opened or closed also in an asynchronous manner with respect to the socket-side ball valve  2 .  
         [0038]     As soon as the ball valves  1  and  2  are opened, the vacuum-insulated fill pipe  14  moves through the passage bores of the ball valves  1  and  2 , and the filling operation can start. After the termination of the filling operation, the fill pipe  14  is withdrawn and the ball valves  1  and  2  are closed again in the reverse sequence. After the plug-side rotating ring  3  has moved back again, the clamping connection  8  of the coupling flanges  9  and  10  can be opened up and the coupling plug and coupling socket can thus be separated from one another.  
         [0039]     As an alternative to the above-described notches, the rotating rings  3  and  4  or their mutually abutting head sides may have a friction lining or friction linings. A conical construction of the head sides of the rotating rings  3  and  4  is also conceivable. The torque required for rotating the balls of the ball valves  1  and  2  will then be transmitted by friction. The normal force (pressure force) required for this purpose is generated by way of the above-explained defined advancing force of the plug-side rotating ring  3 .  
         [0040]     The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.