Abstract:
The invention relates to a mounting element for attaching an assembly, in particular a pump  10,  to a mount  12.  The mounting element  1  comprises a bracket  11  and a damping element  13.  The damping element  13  comprises a first recess  131  for receiving the assembly. The damping element further comprises a contact surface  130  for contacting the bracket  11.  The bracket secures the damping element  13  in the mount  12.  Adjacent to the first recess  131,  the damping element  13  comprises a second recess  132  which supports a radially symmetric deformation of the cross section of the first recess  131  when the bracket  11  is secured to the mount  12.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to a holder for attaching an assembly, in particular for attaching a pump on a mount. The holder has a bracket and a damping element that partially comprise the assembly. The damping element has a recess that is provided for accommodating the assembly. Furthermore, the damping element has a contact surface for making contact with the bracket. The bracket is provided in order to attach the damping element on the mount. 
         [0002]    An assembly is attached on a mount, preferably on an engine mount of a motor vehicle. In this case, the assembly is exposed to extreme conditions such as, for example, vibration loadings and temperatures that can result in damage to the assembly. A holder that is constructed from a bracket and a damping element is arranged for the purpose of attaching the assembly on the mount. The bracket is preferably made from sheet metal, and the damping element from rubber. Over its service life, the holder must fulfill the specifications and/or the conditions of use with regard to the oscillatory behavior and strength behavior. Furthermore, the natural frequency/resonant frequency of the individual components of a module differs depending on the different material dampings, stiffnesses and types of joint. In order in essence to be able to implement the required service life of the components, the natural frequency must as far as possible be avoided, or its amplitude must be damped. 
       SUMMARY OF THE INVENTION 
       [0003]    It is an object of the invention to implement a holder for an assembly with improved oscillatory behavior and strength behavior. 
         [0004]    A holder for attaching an assembly, in particular a pump, on a mount is provided in accordance with the invention. In this case, the holder has a bracket and a damping element, the damping element comprising a first recess that is provided for accommodating the assembly. Adjacent to the first recess the damping element has a second recess that supports a radially symmetrical deformation of the cross section of the first recess when the bracket is attached on the mount. 
         [0005]    One advantage of the inventive holder consists in that the attachment of the assembly is improved. In particular, the vibration loadings are reduced because of the damping element. Owing to the second recess, the stiffness of the damping element is at least approximately constant over the periphery of the assembly, and this leads to a better clamping joint for the assembly. 
         [0006]    In one embodiment of the invention, the second recess is designed as a slot, the diameter of the slots decreasing in the direction of a bracket end as a function of the position of the slots. A better hold can be ensured between the damping element and the assembly with the aid of the second recess. Furthermore, it is possible to ensure a better clamping joint for the assembly on the basis of an approximately constant stiffness of the damping element. 
         [0007]    In a further embodiment of the invention, the damping element comprises a third recess as a cutout, the cross sectional area of the cutouts increasing as a function of the position of the first recess from the middle of the bracket up to the bracket end. It is thereby possible to achieve an increase in the surface area of the damping element, and thus a better heat dissipation. Furthermore, a smaller oscillation amplitude is achieved by the low mass of the damping element. 
         [0008]    In accordance with a further embodiment of the invention, a fourth recess is provided as a hole in the damping element, at least two holes having a different diameter. Because of the holes in the damping element, it is possible to achieve a smaller oscillation amplitude of the damping element. Furthermore, the damping element provided with holes ensures a better heat dissipation, and an increase in the surface area of the damping element. 
         [0009]    Furthermore, in accordance with a further embodiment of the invention, in a plane of the bracket the damping element is designed in the region of the contact surface as an edge widening in a wedge shape. A constant pressure between the damping element and the assembly can be ensured by compressing the edge of the damping element. The damping element can thereby be adapted to the contours of the assembly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The invention is explained in more detail below with the aid of exemplary embodiments and with reference to the attached drawings, in which: 
           [0011]      FIG. 1  shows a holder for fitting a pump in an unmounted state of a bracket; 
           [0012]      FIG. 2  shows the holder, shown in  FIG. 1 , for fitting a pump in a mounted state of the bracket; 
           [0013]      FIG. 3  shows a sectional view of the damping element; 
           [0014]      FIG. 4  shows a schematic of the bracket; 
           [0015]      FIG. 5A  and  FIG. 5B  show plan views of the bracket with a bushing or a lug; and 
           [0016]      FIG. 6  shows a schematic of a bracket end and a contact surface. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]      FIG. 1  shows a schematic of a holder  1  with a bracket  11  and a damping element  13  in an unmounted state. The damping element  13  comprises a contact surface  130  for making contact with the bracket  11 . The bracket  11  has two bracket ends  111 ,  112  that, as is shown in  FIG. 2 , are provided for attaching the damping element  13  on the mount  12 . The contact surface  130  of the damping element  13  is arranged in this case between the bracket end  111 ,  112  and the mount  12 , and is of rectangular design. Furthermore, the damping element  13  comprises a first recess  131  that is arranged to accommodate the pump  10 . The first recess  131  is arranged centrally in the damping element  13  so that the pump  10  is simultaneously damped. With the aid of the holder  1  it is possible to achieve an improved oscillatory behavior and strength behavior in conjunction with a sinusoidal and/or broadband noise excitation of 200 m/s 2  and a temperature of 120° C. 
         [0018]    The damping element  13  preferably has a second recess  132  that is designed as a slot, the second recess  132  opening into the first recess  131 . At least two slots are arranged in the inner region  14  of the damping element  13  with radial symmetry in relation to a midpoint of the first recess  131 . The slots are provided between the bracket ends  111 ,  112 , the diameter of the slots decreasing in the direction of a bracket end  111 ,  112  as a function of the position of the slots. Furthermore, the slot is of rectangular design, the narrower side of the slot opening into the first recess  131 . The slot that is arranged between the bracket ends  111 ,  112  in the middle of the first recess  131  has the widest diameter. Starting therefrom, five slots are respectively arranged in the direction of a bracket end  111 ,  112 . Alternatively, more or less slots can be arranged in the damping element  13 . Because of the radially arranged slots, a better hold can be enabled between the damping element  13  and the pump  10 . Furthermore, owing to the different diameters of the slots it is possible to achieve a stiffness of the damping element  13  in an at least approximately constant fashion over the entire periphery, and this leads to a improved clamping joint for the pump  10 . 
         [0019]    The damping element  13  comprises a third recess  133  that is designed as a cutout in an outer wall region  15  of the damping element  13 . In this case, the outer wall region  15  of the damping element  13  is the region that faces the bracket  11 . The third recess  133  is arranged in a plane of the bracket  11 , at least two cutouts being arranged in the outer wall region  15  of the damping element  13 . The cutouts are of semicircular design. The cross sectional area of the cutouts increases as a function of the position of the first recess  131  from the middle of the bracket  11  up to the bracket end  111 ,  112 . Starting from the cutout in the middle of the bracket  11 , two cutouts are respectively arranged on the sides of the outer wall region  15  up to the bracket end  111 ,  112 . However, it is possible to provide more or fewer cutouts in the damping element  13 . 
         [0020]    In a plane of the bracket  11  a fourth recess  134  is provided in the damping element  13  as a hole in the region of the contact surface  130  in an unmounted state. However, at least two holes with a different diameter are arranged in the damping element  13 . The hole that is arranged in the vicinity of the mount  12  is designed to be smaller than the hole that is arranged in the vicinity of the outer wall region  15 . In the mounted state, the holes in the damping element  13  have an elliptical shape. It is possible by means of the third recess  133  and the fourth recess  134  to achieve in the damping element  13  an increase in the surface area of the damping element  13  so as to enable a better heat dissipation in the damping element  13 . Furthermore, a small oscillation amplitude can be achieved owing to the low mass of the damping element  13 . 
         [0021]    In a plane of the bracket  11  the damping element  13  is designed in the region of the contact surface  130  to be wider in an unmounted state of the bracket  11  than the spacing of the bracket ends  111 ,  112  with a mounted bracket  11 . Consequently, in the region of the contact surfaces  130  the damping element  13  is compressed by the bracket ends  111 ,  112  in the mounted state of the bracket  11 . In a plane of the bracket  11  the damping element  13  is preferably designed in the region of the contact surface  130  as an edge  16  widening in a wedge shape in the direction of the bracket ends  111 ,  112  in the direction of the contact surface  130 . The angle a of the edge  16  is, however, dependent on size so that, given a larger pump  10 , the angle a of the edge  16  is also designed to be larger. The spacing a that is provided between the bracket  11  and the outer wall region  15  of the damping element  13  is of smaller design than the spacing b that is provided between the bracket ends  111 ,  112  and the contact surface  130 . This gives rise to a difference in size that can be used to implement an axial clamping. As shown in  FIG. 2 , a uniform pressure can be implemented along the periphery of the damping element  13  with the aid of the axial and radial clamping of the damping element  13  with the bracket  11 . If the damping element  13  is clamped only axially with the bracket  11 , a partial pressure results between the damping element  13  and the pump  10  so that the damping element  13  is deformed in an oval fashion. The pump  10  can thereby become detached from the holder  1  because of the vibration loading. 
         [0022]    The damping element  13  is preferably constructed from an elastomer. Alternatively, however, it is also possible to use another material that is suitable for damping a pump  10 . Furthermore, the outer wall region  15  of the damping element  13  is designed as a channel  17  as is shown in  FIG. 3 . The bracket  11  is thereby fixed by the damping element  13  so as to enable a better hold of the bracket  11 , and the damping element  13  is prevented from slipping out during operation. 
         [0023]    Large axial forces caused by the threaded joint can be produced during the attaching of the damping element  13  between the bracket  11  and the mount  12 . In consort with the angular geometry of the bracket  11 , this distortion of the damping element  13  can lead to damage to the damping element  13 . As is shown in  FIGS. 4 and 5A , a lug  20  is embossed in a gap  17  in the bracket end  111 ,  112  in order to avoid this. As shown in  FIG. 5B , instead of the lug  20  it is also possible to provide a bushing  19  in the gap  17  in the bracket ends  111 ,  112 . The bushing  19  and the lug  20 , which are inwardly deformed ensure that the necessary clamping torque of the threaded joint of the bracket  11  and the mount  12  does not result in damage to the damping element  13 . As is shown in  FIG. 6 , the bracket  11  is thereby completely decoupled from the mount  12  so that the distorted length can be limited and it is thereby possible to prevent damage owing to excessively high stressing of the damping element  13 . The bracket  11  is preferably made from metal. However, it is also possible to use another material for the bracket  11 . 
         [0024]    The invention is illustrated using the example of a pump  10 . However, the invention can also be used for other assemblies that are attached on a mount  12 . What is decisive here is the fact that adjacent to the first recess  131  the damping element  13  has the second recess  132 , which supports a radially symmetrical deformation of the cross section of the first recess  131  during attachment of the bracket  11  to the mount  12 . The desired service life of the pump  10  can thereby be implemented with the aid of the damping element  13 . Furthermore, the damping element  13  can be adapted to the contours of the pump  10  owing to the second, third and fourth recesses  132 ,  133 ,  134 .