Abstract:
A hydraulic aggregate, particularly for supplying conveyor and lifting devices with pressurized fluid, has a tank ( 1 ) on the end side relative to a main axis of the device and functional components mounted on it. The functional components are a hydraulic pump ( 5 ) and a coupling body ( 3 ) having a valve device and a line arrangement for drawing in and returning hydraulic fluid to and from the tank ( 1 ). Configured as a reversing aggregate, the inlet end ( 19 ) of the suction line ( 15 ) of the line arrangement is disposed at a location within the tank ( 1 ) where the bottom of the fluid present in the tank ( 1 ) is located when the aggregate is operated with the main axis vertical and when the aggregate is operated with the main axis tilted relative to the vertical, preferably perpendicular to the vertical.

Description:
FIELD OF THE INVENTION 
     The invention relates to a hydraulic aggregate, particularly for supplying conveyor and hoisting gear with pressurized fluid, having a tank on the end side relative to a major axis of the device and functional components mounted thereon. The functional components comprise at least one hydraulic pump and one connecting body with a valve device and a line arrangement for intake and return of hydraulic fluid to and from the tank. 
     BACKGROUND OF THE INVENTION 
     Hydraulic aggregates of this type are known; see, for example, DE 10 2004 032 256 B3. Such aggregates are used as compact units in various types of conveyor and hoisting gear for actuation of lifting cylinders. The pertinent hydraulic pump is conventionally driven by an electric motor, especially for nonstationary applications, for example, in the actuation of loading platforms. Direct current motors are used which can be operated in a power class of about 0.8 kW to 3.0 kW from the pertinent on-board network. 
     As a result of the diverse fields of application and the resulting different installation situations, such hydraulic aggregates are conventionally implemented in various design concepts. Fundamental differences exist, especially between versions for installation with a vertical major axis and versions for horizontal installation. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide a hydraulic aggregate with a construction permitting use in different installation situations without a change of the design concept being necessary. 
     This object is basically achieved according to the invention by a hydraulic aggregate where the entry end of the intake line via which the hydraulic pump takes hydraulic fluid from the tank is situated at that location within the tank at which the bottom of the fluid in the tank is located, regardless of whether the aggregate is installed with the major axis vertical or whether the installation position is horizontal. In this way, a reversible unit in the manner of a modular system is devised with which different situations of use and installation can be covered. 
     Preferably, the tank has an end wall part on the end side relative to the major axis and at least one other boundary wall part which directly follows it. The arrangement can be made such that the entry end of the intake line is in the transition region from the end wall part and boundary wall part. This arrangement ensures that both for a vertical installation position in which the end wall part forms the tank bottom, and for a horizontal installation position in which the boundary wall part which follows the end wall part forms the tank bottom, the entry end of the intake line is located on the bottom where the fluid is present. 
     Especially advantageously at least a large part of the tank has a shape inscribed in a rectangular solid or cuboid, preferably with a more or less square outline of the end-side end wall part. The entry end of the intake line is located closely adjacent to one corner of the end wall part, that is, in the region of the rectangular solid or cuboid in which two wall parts border one another at a right angle. Depending on whether the installation position is vertical or horizontal, one of the wall parts forms the tank bottom. 
     Especially advantageously, the arrangement is made such that the fill inlet of the tank is on the cover wall of the rectangular solid or cuboid. The cover wall is opposite the end-side end wall part, in the region of that corner diagonally opposite the corner assigned to the entry end of the intake line. Not only is a reversing possible between the vertical and horizontal installation positions, but for the horizontal installation position the two side walls of the rectangular solid or cuboid bordering the corner assigned to the entry end of the intake line form the tank bottom. In other words, for the horizontal installation position, another reversing possibility exists, specifically one possible rotation also around the major axis of the device which is horizontal in this case. 
     Especially preferred, for mounting the connecting body on the tank, its cover wall has a round socket projecting from its surface with a flange edge for contact of the connecting flange of the connecting body. A tension clip with a hollow section extends positively over the tank-side flange edge and the connecting flange of the connecting body. In this way, especially simple and reliable linking of the metallic connecting body to a tank made of a UV-resistant material, for example, of PE material, is possible without screw fittings being necessary with the disadvantages as ordinarily occur in screw connections between metal bodies and thin-walled plastic bodies. 
     Advantageously, a hood, preferably likewise of UV-resistant plastic, in the form of a rectangular solid or cuboid, is open on one side in which the mounted part located on the tank can be housed. The hood open side can be mounted on the tank. The linking can likewise take place positively when a groove-like indentation is formed in the boundary wall parts of the tank forming the side walls of the rectangular solid or cuboid and extends continuously in a plane perpendicular to the major axis in the vicinity of the cover wall over the periphery of the rectangular solid or cuboid. This indentation in interaction with an end rib projecting to the inside on the end edge surrounding the open side of the rectangular solid or cuboid can form the positive connection by engagement of the end rib of the hood with the indentation of the tank. 
     To form an essentially smooth box shape of the aggregate, the side walls of the hood mounted on the tank can form planar extensions of the side walls of the rectangular solid or cuboid of the tank. A protected (for example, against rock impact and against UV radiation) unit is then devised which is closed, except for the accesses to electrical and hydraulic connections. 
     Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring to the drawings which form a part of this disclosure: 
         FIG. 1  is a slightly schematically simplified front elevational view of a hydraulic aggregate according to an exemplary embodiment of the invention, shown in the vertical installation position; 
         FIG. 2  is a schematically simplified perspective view of the hydraulic aggregate of  FIG. 1  in the vertical installation position, with the hood partially open and the tank shown partially cut away; 
         FIG. 3  is a schematically simplified side elevational view of the hydraulic aggregate of  FIG. 1  in the horizontal installation position, with one side wall each of the hood and tank being omitted for viewing into the interior; 
         FIG. 4  is a schematically simplified, enlarged partial perspective view of only the linking region between the tank and the connecting body, partially cut open, and 
         FIG. 5  is a front elevational view of a partial extract of only the region designated as V in  FIG. 1 , shown greatly enlarged relative to  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 to 3  illustrate overall representations of the exemplary embodiment of the aggregate according to the invention.  FIG. 1  showing the exemplary embodiment in the closed state, an essentially closed box shape being formed.  FIGS. 2 and 3  illustrates the aggregate partially open, from which inner components can be removed. Proceeding from an end-side tank  1 , components being functional elements are mounted directly on the tank, specifically a connecting body  3  and a hydraulic pump  5 . The pump  5  is an electrically driven motor-pump unit with a DC motor  7 . A hood  9  shown lifted in  FIG. 2  and having largely the form of a rectangular solid or cuboid open on one side, when it is mounted on the tank as shown in  FIGS. 1 and 3 , forms a jacket for the components mounted on the tank  1 . The jacket has on only one side a wall opening  11  forming a passage for hydraulic and electrical lines to the connecting body  3  and for fasteners acting on the connecting body  3 . The connecting body  3  is a metallic valve block with a valve arrangement or device  3   a  for controlling hydraulic ports  13  and has a line arrangement  3   b  for removal and return of hydraulic fluid into and out of the tank  1 . In the figures, only one intake line  15  of the line arrangement is visible. On the end of the intake line  15  is a suction filter  17  whose filter inlet forms the entry end  19  of the intake line  15 . 
     According to the shape of the hood  9 , the tank  1  largely also has the form of a rectangular solid or cuboid with an end-side planar end wall  21 . Aside from the rounding on its corners  23 , end wall  21  has a rectangular outline which is more or less square. As further boundary wall parts of the tank  1 , planar side walls  25  and  27  ( FIG. 2 ) follow and extend to the upper cover wall  29  of the tank  1 . As can be taken from  FIGS. 2 and 3 , the entry end  19  of the intake line  15  is closely adjacent to a corner  23 , i.e., in a junction region in which the end wall  21  and the side walls  25  and  27  abut one another. Moreover, in this corner region, there is a fluid drain  31  in the side wall  27 . There is a fill inlet  33  visible only in  FIG. 3  on the cover wall  29  of the tank  1  at a location diagonally opposite the entry end  19  of the intake line  15 , relative to the rectangular solid or cuboidal shape of the tank  1 ; i.e., in  FIG. 3  it is offset into the plane of the drawing to the back relative to the entry end  19  which lies in the plane of the drawing. 
     In this positioning of the entry end  19  of the intake line  15  and the fill inlet  33 , it is ensured that the entry end  19  is located underneath the fluid level present in the tank ( 1 ), and the fill inlet  33  is above the fluid level, even if the tank  1  and the hydraulic aggregate as a whole assume different installation positions.  FIGS. 1 and 2  show the aggregate in a position corresponding to a vertical installation position in which the end wall  21  forms the tank bottom on which the bottom of the fluid is present. In the horizontal installation position shown in  FIG. 3  and in which one side wall  27  forms the tank bottom, the entry end  19  of the intake line  15  is likewise located underneath the fluid level, with the fill inlet  33  being located above the fluid level, as in the vertical installation position. In contrast to  FIG. 3 , for a horizontal installation position the orientation could also be such that the side wall  25  which is visible in  FIG. 2  and which is omitted in  FIG. 3  forms the tank bottom. Compared to the situation shown in  FIG. 3 , another reversing possibility of rotation around the major axis  1   a  of the device exists for a horizontal installation position. 
     Details of the mounting of the connecting body  3 , which is a metallic valve block, are shown in  FIG. 4 . As shown, on the upper cover wall  29  of the tank  1 , a round pipe socket  35  is molded on. Pipe socket  35  has a comparatively large diameter, in the illustrated example, is more than half the width of the tank  1  and is located offset out of the central region of the cover wall  29 , as can be seen from  FIG. 3 . The intake line  15  and a return line (not shown) extend through the socket  35  to the connecting body  3 . Connecting body  3  has a ring body  37  engaging the socket  35  with a seal  39  and forms a radially projecting connecting flange  41  adjoining a flange edge  43  of the socket  35 . A tension clip  45  has a hollow profile matched to the connecting flange  41 . The tension clip  45  extends positively over the connecting flange  41  and flange edge  43 . A toggle clamp (not shown) is provided on the tension clip  45 . 
     As already mentioned, the hood  9  has the form of a rectangular solid or cuboid, is matched to the outside shape of the tank  1 , is open on one side and, aside from an opening  11 , is closed so that in the assembled state the hydraulic aggregate, as shown in  FIG. 1 , has an essentially closed box shape. To mount the hood  9  on the tank  1 , in the vicinity of its cover wall  29 , is provided with an indentation  47  in the shape of a groove with rounded side walls and extending continuously over the entire peripheral region of the tank  1 . This indentation  47  forms a seat for positive accommodation of an end rib  49  projecting to the inside and made on the end edge surrounding the open side of the rectangular solid or cuboid of the hood. This end rib  49  can be snapped into the indentation  47  with slight elastic deformation of the end edge of the hood. For additional security, a metallic tension band  51 , see  FIG. 5 , can be provided to lock the end rib in the indentation  47 . 
     The termination part located on the opening  11  with the hood  9  closed is a sheet metal plate  53  in the form of a rounded rectangle whose edge is encompassed on three sides by a U-profile seal  55  extending on one side wall  25  along the facing end of the connecting body  3  along the major axis. When the hood  9  is in place, the profile seal  55  forms the seal relative to the edge of the opening  11  of the hood  9 . The side of the sheet metal plate  53  bordering the tank  1  on the fourth side assigned to the tank  1  forms an end edge  57  deformed out of the plane of the plate. The end edge  57  can be positively held in the indentation  47  where it can be secured by cementing or welding. With the hood  9  in place, the end rib  49  of the hood  9  additionally extends over the end edge  57  of the plate  53 , optionally with additional locking by an overreaching tension band  51 , as shown in  FIG. 5 . 
     As viewed in  FIG. 2 , in an embodiment which is not further detailed, the wall of the hood  9 , which wall is the rear wall here, can be arranged as a guide part in an extension of the side wall  25  of the tank  1 . For example, the rear wall of the hood can be secured on the projecting plate  53 . In this respect, the remaining three side parts of the hood  9  are then slipped from the top onto the tank  1  and are connected, as described, via longitudinal guides located on the end on the end sides of the rear wall. In doing so, as viewed in  FIG. 2 , the back end wall of the hood  9  can also be an integral component of the projecting plate arrangement  53 , which in turn can be secured on the tank  1  and/or on the connecting body  3 . 
     As can be seen from  FIGS. 1 and 2 , the sheet metal plate  53  has a passage  59  and openings  61 . The passage  59  forms an access to the hydraulic ports  13  on the connecting body  3  and to threaded bores  63  in the connecting body  3  designed for fastening screws to secure the aggregate on the pertinent bracket. 
     As a modular system, the invention allows not only the coverage of different installation situations due to the available reversing possibility, but can also be easily adapted to different power classes. Thus, for example, the volume of the tank  1  can be easily matched to the requirements of the hydraulic system by the tank height being increased, with only the intake line  15  needing to be provided with a correspondingly greater length. All other components and their linking to the tank  1 , in which optionally only the distance between the end wall  21  and the top wall  29  has changed, remain unchanged. 
     While one embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.