Abstract:
The invention relates to a new type of hydraulic module for actuating at least one hydraulic control element with a hydraulic pump in a housing, with an electric motor fastened to a first housing side for driving the pump, with a tank located on a second housing side opposite the first side for a hydraulic fluid, e.g. hydraulic oil, with flow channels produced in the housing produced preferably by bore holes for the hydraulic fluid to supply this fluid from the tank to a pump chamber, for transmitting the hydraulic fluid conveyed by the pump to a pressure connection located on the housing, for connection of the at least one actuating element and for returning the hydraulic fluid from the pressure connection into the tank.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    An object of the invention is to present a hydraulic module that can be used, for example, in motor vehicles, but also in other areas, as a drive or actuator for functional elements, in particular, wherever there is a requirement for high power in a small design.  
           [0002]    An object of the invention is also to present a hydraulic module with a very small design, and which, together with the at least one actuated control element, or actuator, forms a hydraulic system that is fully enclosed from the outside and requires only electric lines for power supply and/or actuation.  
         SUMMARY OF THE INVENTION  
         [0003]    “Hydraulic module”, in accordance with the invention, refers to a hydraulic unit with a very compact design. “Pressure regulating shut-off valve”, in accordance with the invention, is a valve that can be electrically actuated between a non-blocking and a blocking position and simultaneously functions as a pressure regulating valve in the blocking position, whereby the value of the pressure regulated with this valve can be regulated, or controlled, by the degree of activation, i.e., for example, by the current flowing through an electric or magnetic operating element. This makes it possible not only to adapt the maximum pressure at the pressure connection or output, which allows universal application of the hydraulic module, but also enables regulation of the pressure during the actuating movement of the control element actuated with the hydraulic module according to a specified program or profile.  
           [0004]    The hydraulic module according to the invention features a design that is fully enclosed or encapsulated from the outside, so that this module will operate trouble-free even in rough environments.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]    The invention is described in more detail below based on the drawings of sample embodiments, as follows:  
         [0006]    [0006]FIG. 1 is a simplified depiction of a partial view of a hydraulic module according to the invention;  
         [0007]    [0007]FIG. 2 is a simplified functional depiction of the module of FIG. 1; and  
         [0008]    [0008]FIG. 3 is a depiction similar to FIG. 1 of an alternate embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0009]    The hydraulic module generally designated  1  in FIG. 1 is intended especially, but not exclusively, for use in road vehicles, in particular for the actuation of hydraulic control elements or actuators. In FIG. 1, such an actuating element  2  is depicted by way of example in the form of a hydraulic cylinder with a pressure or pull-back spring  3  for resetting the cylinder or the piston  4  and the piston rod  5  to a starting position. The actuating element  2  in the depicted embodiment is connected via a hydraulic line  6  with a single pressure connection  7  of the hydraulic module  1 . Generally, it is also possible that the actuating element  2  is directly flanged onto the hydraulic unit  1 , thus forming one structural unit with the hydraulic module. The hydraulic module  1  consists essentially of a block  8  made of a suitable material, for example of metal, e.g. steel, forming the housing for a hydraulic pump  9 , which has a single movable piston  10 .  
         [0010]    The piston  10 , which is formed by a bolt or tappet  10 . 1 , can move axially in a section  11 . 1  of a hole  11  in the block  8 , against the effect or force of a pull-back spring  12 , which encloses the tappet  10 . 1  forming the piston  10  and pretensions the piston in the depiction selected for FIG. 1 in a bottom stroke position. The section  11 . 1  forms the cylinder space of the piston pump  9 .  
         [0011]    Above the piston  10  or the piston surfaces, the bore hole  11  continues in a section  11 . 2  with an enlarged diameter in comparison with the section  11 . 1  and in a section  11 . 3  connecting to the section  11 . 2 , which (section  11 . 3 ) has an enlarged diameter in comparison with the section  11 . 2 , forming the connection  7  and for this purpose is provided with suitable internal threads for screwing in a nipple of the hydraulic line  6 .  
         [0012]    Below the section  11 . 3  the borehole forms a section  11 . 4  with an enlarged diameter, which leads into an interior space  13  of the block  8 . In this interior space  13 , a shaft  16  is mounted on bearings at both ends by means of bearings  14  and  15  and has a cam  17  between its two ends or between the bearings  14  and  15 .  
         [0013]    As depicted, the interior space  13  that is closed toward the outside has two sections, namely section  13 . 1  with an enlarged diameter, in which also the cam  17  is accommodated and the section  13 . 2 , in which the bearing  14  for the left end of the shaft  16  is located in FIG. 1 and which is open at this end of the shaft  16  and leads into the interior  18  of a tank  19  for a hydraulic fluid, e.g. hydraulic oil.  
         [0014]    The other end of the shaft  16  is mounted on bearings by means of the bearing  15  in a circular disk-shaped cover, which tightly seals the interior  13  on this side by means of a sealing ring  21  and is accommodated in a recess  22  of the block  8  such that the side of the cover  20  facing away from the interior  13  is in alignment with the flat side surface  8 . 2  of the housing  8 . The right end of the shaft  16  in FIG. 1 extends with a seal through the cover  20  using a seal  23 . This end is connected via a coupler  24  with the shaft  25  of an electric motor  26  for driving the shaft  16 . The coupler  24  is located in a housing element  27 , which is flanged onto the side surface  8 . 1  of the block  8  and on which also the electric motor  26  is fastened by means of flanging.  
         [0015]    The tank  19  and its interior  18  are formed by a cup-shaped housing  28 , which in the depicted embodiment has a hollow cylinder-shaped circumference and a closed bottom. The housing  28  is fastened tightly with its open side using a sealing ring  29  to a ring-shaped projection or flange  30 , for example by means of pressing. The projection  30  is located on the side surface  8 . 2  opposite the side surface  8 . 1  and concentrically encloses in this embodiment the common axis of the shaft  16  and of the electric motor  26 , so that the electric motor  26  with the coupler  24  and the tank  19  are located on opposite parallel side surfaces  8 . 1  and  8 . 2  of the block  8 .  
         [0016]    As FIG. 1 further shows, the axis of the bore hole  11 , which is open on the top side  8 . 3  of the block  8  at section  11 . 3  or on the connection  7  there, is radial to the longitudinal axis L.  
         [0017]    The tappet end  10 . 2  with the enlarged diameter works together with the cam  17 . The pressure spring  12  is also supported on one end against this end  10 . 2 . The other end of the pressure spring  12 , i.e. the top end in the depiction in FIG. 1, fits against the shoulder formed by the transition between the sections  11 . 1  and  11 . 4 .  
         [0018]    In block  8 , several flow channels  31 - 34  are formed by bore holes, namely the flow channel  31 , which in the depicted embodiment is parallel to the bore hole  11  and is closed at the upper end in FIG. 1 in the area of the top side  8 . 2  by means of a seal  35  and leads with its lower end in FIG. 1 via a channel  32  into the interior  18  of the tank.  
         [0019]    Two parallel flow channels  33  and  34  lead into the flow channel  31 , of which the flow channel  33  leads with its other end into the section  11 . 1  of the bore hole  11 , i.e. into the cylinder space of the piston pump  9 , and the channel  34  leads with its other end into the section  11 . 2  of the bore hole  11 . At the transition between the channel  31  and the channel  33  there is a controllable valve  36 , which consists of a valve seat  37  and a tappet  38  that works together with the latter. The tappet  38  can be moved, by means of an electric actuating element  39 , which in the depicted embodiment is an electromagnet located on the side surface  8 . 2 , to a position blocking the valve  36 , whereby the blocking effect of the valve  36  or the force with which the valve tappet  38  presses against the valve seat  37  can be adjusted by controlling or regulating the flow through the magnet coil of the actuating element  39 . The valve  36  is furthermore designed so that it opens when the actuating device  39  is not activated.  
         [0020]    In the channel  34  there is a check or non-return valve  40 , which opens for the flow of the hydraulic fluid from the channel  31  into the section  11 . 1  or into the cylinder space of the piston pump  9  and closes for the flow in the opposite direction. A further a check or non-return valve  41  is located at the transition between the section  11 . 1  and the section  11 . 2 , i.e. between the openings of the channels  33  and  34  into the bore hole  11 . This non-return valve  41  opens for the flow of the hydraulic fluid from the cylinder space of the piston pump  9  into the section  11 . 2 .  
         [0021]    In order to ensure the correct operation of the hydraulic module  1  in any installation and any orientation, there is a compensating and pressure element  42  in the tank interior  18  to keep the hydraulic fluid in the tank interior  18 , and when the hydraulic module  1  is not activated also in the entire system including the connected actuating element  2 , at a specified primary pressure, so that especially also the piston pump  9  with only one piston functions reliably in any state and orientation of the hydraulic module  1  and so that no air or gas bubbles can form in the system. The interior  13  is also completely filled with the hydraulic fluid when the hydraulic module  1  is in working order. The compensating and pressure element  42  consists in the depicted embodiment of a gastight covering  43 , which is made of a flexible and/or elastic material and seals off an interior space  44 . The interior space  44  is filled with a gas, for example with air or nitrogen, and is under pressure at least when the hydraulic module  1  is operable.  
         [0022]    The functioning principle of the hydraulic module  1  can be described as follows, taking into account the block-wiring diagram in FIG. 2:  
         [0023]    In order to actuate the control element  2 , i.e. to move this actuator from its starting position, the electric motor  26  and, simultaneously or afterwards, the actuating device  39  are activated. The piston pump  9  supplies the hydraulic fluid under pressure via the channel formed by the sections  11 . 2  and  11 . 3  to the actuating element  2  when the valve is closed, thus actuating the actuator  2 . The pressure of the compensating and pressure element  42  causes the hydraulic fluid to flow from the tank interior  18  via the channels  32 ,  31 ,  34  and the non-return valve  40  to the cylinder (section  11 . 1 ) of the piston pump  9 .  
         [0024]    By adjusting the flow through the coil of the actuating device  39 , the force with which the tappet  38  presses against the valve seat  37  and therefore the pressure at which the valve  36  opens can be adjusted, for the return of the hydraulic fluid from the section  11 . 2  to the tank interior  18 . The valve  36  therefore functions as a controllable pressure-regulating valve.  
         [0025]    In order to return the actuator  2  to its starting position, first the motor  36  for example is switched off and then the actuating element  39  of the valve  36  is deactivated, so that the valve  36  opens and the hydraulic fluid can flow back from the actuator  2  via the opened valve  36  and the corresponding flow channels  33 ,  31  and  32  into the tank interior  18 , in the depicted embodiment under the force of the pull-back or pressure spring  3 .  
         [0026]    The fact that the interior  13  is connected with the tank interior  18  via the gap of the bearing  14  results in lubrication of the bearings  14  and  15 . At the same time, hydraulic fluid flowing from the interior  13  can flow back into the tank interior  18  via leaks from the piston  10  to the interior  13 .  
         [0027]    As depicted, the hydraulic module  1  has a very compact design with small dimensions, whereby the housing  26 . 1  of the motor  26 , the housing of the coupler  27  and also the housing  28  of the tank  19  all have a regular cylindrical shape with the same outer diameter and are arranged on the same axis. The block  8  is for example rectangular, such that its flat bottom side  8 . 4  is tangentially on one plane with the peripheral surface of the housings  26 . 1 ,  27  and  28  and in the direction perpendicular to the plane of projection has a width that is approximately the same as the outer diameter of these housings. Only part of the height of the block  8  extends beyond the top side of the housings  26 . 1 ,  27  and  28  in FIG. 1.  
         [0028]    Before operating the hydraulic module  1  and the actuator  2  controlled with this module, the system must be filled with the hydraulic fluid, for example via the removable seal  35 . Before filling the system, the pressure in the interior  44  is for example the same as the atmospheric pressure.  
         [0029]    The overall system is then filled at a specified primary pressure, de-aerating all spaces and flow channels, so that after the system is filled the pressure and compensating element  42  produces the necessary primary pressure for operation in the tank interior  18  and in the spaces or channels connected with this interior, whereby this primary pressure is, of course, much lower than the hydraulic pressure produced by the piston pump  9  when the valve  36  is closed.  
         [0030]    The use of the housings  26 . 1 ,  27  and  28  and also of a cup-shaped housing  39 . 1  for the actuating element  39  gives the hydraulic module  1   a  fully encapsulated design.  
         [0031]    [0031]FIG. 3 shows as a further possible embodiment a hydraulic module  1   a , which differs from the hydraulic module  1  essentially only in the fact that instead of the tank  19  on the block  8 , there is a tank  19   a , which is connected via a hydraulic line  45  with a space  46  located in the block  8 . This space  46  is closed toward the outside by a coupler plate or cap  47 , which in the same manner as the tank housing  28  is attached to a flange of the block  8  and sealed by means of the seal  29 , such that it overlaps the flange. Both the hydraulic line  45  and the channel  32  lead into the space  46 . Furthermore, the section  13 . 2  of the interior  13  also leads into the space  46 .  
         [0032]    The tank  19   a  is formed by a closed tank body  48  with a compensating and pressure element  49 , which limits on one side the tank interior  50  with variable volume that is connected with the hydraulic line  45 . In the depicted embodiment, the tank body  48  is a cylinder body, in which the compensating element  49  designed as a piston can move axially, when enlarging the volume of the tank interior  50  against the effect of a spring force, which for example is provided by a mechanical spring  51  and/or by the fact that the space  52  formed on the other side of the compensating element  49  in the tank body  48  is pressurized with a pressurized gas, for example with pressurized nitrogen.  
         [0033]    The invention was described above based on a sample embodiment. It goes without saying that further modifications and variations are possible. For example, it is also possible that the tank  19   a  has a ring-shaped design, e.g. enclosing the electric motor  26 , whereby the piston serving as a compensating element  49  then also has a ring-shaped design.  
       Reference list  
       [0034]    [0034] 1  hydraulic module  
         [0035]    [0035] 2  control element or actuator  
         [0036]    [0036] 3  pressure or pull-back spring  
         [0037]    [0037] 4  piston of actuator  
         [0038]    [0038] 5  piston rod of actuator  
         [0039]    [0039] 6  hydraulic line  
         [0040]    [0040] 7  connection  
         [0041]    [0041] 8  block  
         [0042]    [0042] 8 . 1 ,  8 . 2  side surface of block  8   
         [0043]    [0043] 8 . 3  top of block  
         [0044]    [0044] 8 . 4  bottom of block  
         [0045]    [0045] 9  piston pump  
         [0046]    [0046] 10  piston  
         [0047]    [0047] 10 . 1  bolt or tappet  
         [0048]    [0048] 10 . 2  bolt section or tappet section  
         [0049]    [0049] 11  bore hole  
         [0050]    [0050] 11 . 1 - 11 . 4  bore hole section  
         [0051]    [0051] 12  spring  
         [0052]    [0052] 13  interior  
         [0053]    [0053] 13 . 1 ,  13 . 2  section of interior  
         [0054]    [0054] 14 ,  15  bearing for shaft  16   
         [0055]    [0055] 16  shaft  
         [0056]    [0056] 17  cam  
         [0057]    [0057] 18  interior of tank  
         [0058]    [0058] 19  tank  
         [0059]    [0059] 20  cover  
         [0060]    [0060] 21  seal  
         [0061]    [0061] 22  recess for cover  20   
         [0062]    [0062] 23  seal  
         [0063]    [0063] 24  coupler  
         [0064]    [0064] 25  motor shaft  
         [0065]    [0065] 26  electric motor  
         [0066]    [0066] 26 . 1  motor housing  
         [0067]    [0067] 27  housing for coupler  24   
         [0068]    [0068] 28  tank housing  
         [0069]    [0069] 29  seal  
         [0070]    [0070] 30  ring-shaped section or flange  
         [0071]    [0071] 31 - 34  flow channel  
         [0072]    [0072] 35  seal  
         [0073]    [0073] 36  controllable or variable valve  
         [0074]    [0074] 37  valve seat  
         [0075]    [0075] 38  tappet  
         [0076]    [0076] 39  control element  
         [0077]    [0077] 39 . 1  housing  
         [0078]    [0078] 40 ,  41  non-return valve  
         [0079]    [0079] 42  compensating and pressure element  
         [0080]    [0080] 43  covering  
         [0081]    [0081] 44  interior of covering  43   
         [0082]    [0082] 45  hydraulic line  
         [0083]    [0083] 46  space  
         [0084]    [0084] 47  end element or end cap  
         [0085]    [0085] 48  body of tank  
         [0086]    [0086] 49  compensating element in body of tank  
         [0087]    [0087] 50  interior of tank  
         [0088]    [0088] 51  spring element  
         [0089]    [0089] 52  space for holding pressure medium