Abstract:
An electric motor with an electronics housing ( 6 ) includes a removable cover ( 10 ) as well as an operating unit. The operating unit includes an operating panel ( 20 ) fastened on the cover ( 10 ). The cover ( 10 ) with the operating panel ( 20 ) is connectable to a lower part ( 8 ) of the electronics housing ( 6 ) in at least two alternative alignments. A pump assembly is also provided with such an electric motor.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a United States National Phase Application of International Application PCT/EP2013/053291 filed Feb. 19, 2013 and claims the benefit of priority under 35 U.S.C. §119 of European Patent Application EP 12159620.9 filed Mar. 15, 2012, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to an electric motor with an electronics housing which comprises a removable cover as well as an operating unit, as well as to a pump assembly with such an electric motor. 
       BACKGROUND OF THE INVENTION 
       [0003]    Electric motors as a rule comprise a stator housing and an electronics housing attached on the stator housing. Electronic control elements for the control or for the drive of the electric motor are arranged in the electronics housing. In particular, a frequency converter can be arranged in the electronics housing. Moreover, such electronics housings as a rule comprise an operating unit, at which necessary settings can be carried out for operating the electric motor and moreover display elements can be provided, in order to display certain operating conditions of the electric motor. 
         [0004]    Such operating units as a rule are aligned such that they can be optimally observed and viewed from a certain side of the electric motor. In particular, possible inscriptions and display elements are aligned such that they can be read from a certain side. This is disadvantageous if the electric motor in operation needs to be set up such that it cannot be operated or viewed from this certain side. Then there is the problem that the operating unit can only be observed the other way round. 
       SUMMARY OF THE INVENTION 
       [0005]    It is therefore an object of the invention, to improve an electric motor with an electronics housing, to the extent that the operating unit can be read and operated in a simple manner from different directions. 
         [0006]    According to the invention, an electric motor is provided with an electronics housing which comprises a removable cover as well as an operating unit. The operating unit comprises an operating panel fastened on the cover. The cover, with the operating panel, is connectable to a lower part of the electronics housing in at least two alternative alignments. 
         [0007]    According to a further aspect of the invention, a pump assembly is provided with an electric drive motor. The electric drive motor is the above-mentioned electric motor. 
         [0008]    The electric motor according to the invention, in the known manner, comprises an electronics housing. In particular, control elements and other electronic elements and other electronic components for the control or for the operation of the electric motor can be arranged in this electronics housing. Particularly preferably, a frequency converter can also be arranged in the electronics housing. The electronics housing is preferably fastened on the outer side of a stator housing of the electric motor. Moreover, the electronics housing comprises a removable cover. The cover can, for example, be removed, in order to be able to connect electrical connection leads in the inside of the electronic housing. This, for example, can be a mains connection lead and/or a connection lead for the connection to external sensor elements or control elements. The cover preferably closes the electronics housing at an upper side which is away from the stator housing. Moreover, an operating unit is arranged on the cover, via which operating unit settings of operating conditions of the electric motor can be carried out and which moreover comprises display elements for the display of operating conditions of the electric motor. 
         [0009]    According to the invention, one envisages the operating unit having an operating panel fastened on the cover. The operating panel is thereby that component which can be observed from the outside and on which possibly present operating elements such as push buttons or likewise are arranged. This operating panel is preferably fixedly connected to the cover, so that together with the cover it can be removed from the electronics housing. According to the invention, the cover with the operating panel is now connectable in at least two alternative alignments, to a lower part of the electronics housing. I.e. the operating panel of the operating unit can be aligned differently in a simple manner, by way of the cover being connected to the lower part of the electronics housing in alternative alignments. For example, the cover can be connectable, for example screwed to the lower part at two positions rotated by 90° or 180°. Thus, the operating panel together with the cover can also be rotated by 90° or 180°. Thus, depending on the installation position of the electric motor, the operating panel with the cover can be fastened on the lower part of the electronics housing in that one of the alternative alignments, in which the operating panel can be optimally viewed. The fixed arrangement of the operating panel on the cover thereby has the advantage that no further assembly steps are necessary for aligning the operating panel when setting up and assembling the electric motor, since the cover must be removed in any case for the connection of electrical connection leads and then subsequently can be simply fastened on the lower part of the electronics housing again in the desired alignment. 
         [0010]    Preferably, the interfaces of the cover which come into contact with the lower part are designed mirror-symmetrically to a middle line or symmetry axis of the cover, in order to permit an alignment in two alternative alignments rotated by 180°. This permits the cover to be fastened on the lower part in a manner rotated by 180° about a rotation axis, wherein the rotation axis extends normally to the middle line of the cover and intersects this. The interfaces which come into contact with the lower part are the bearing-contact surfaces or bearing-contact edges of the cover, which come to bear on corresponding bearing-contact surfaces or bearing-contact edges of the lower part. Moreover, these are the fastening elements such as screws and corresponding screw holes or threaded holes. In particular, these screws and threaded holes are arranged symmetrically to one another such that the cover can always be fastened on the lower part with the same fastening elements in all alternative alignments. Thus, no additional fastening elements are necessary for the different alignments. With the rotation of the cover from a first alignment into the second alignment, then for example a screw does not engage into a first threaded hole but into a second, oppositely lying threaded hole, and the screw, which in the first alignment would engage into the second oppositely lying threaded hole, accordingly engages into a first threaded hole. 
         [0011]    According to a further preferred embodiment, the operating unit apart from the operating panel comprises an electronics unit which is arranged in the lower part in a manner separated from the cover and which cooperates with the operating panel. The electronics unit is not connected to the cover and preferably contains display elements as for example a display or LED, and operating elements such as electrical switch elements or buttons. The operating panel is designed such that the display elements, which are arranged on the electronics unit, can be seen through the operating panel. Windows or fibre-optics can be provided in the operating panel for this. Moreover, mechanical operating elements are provided in the operating panel, which act on electrical switch elements in the electronics unit, for example electrical switches or buttons. A transmission of the switch function can be effected mechanically or for example also by way of magnetic coupling. 
         [0012]    Particularly preferably, the operating panel is designed as a purely mechanical component which is free of electrical components. This has the advantage that the operating panel can be separated from the electronics unit without any problem. Thus, no connection whatsoever, in particular no electrical connection between the cover and the lower part and the electronics housing is necessary, so that the cover can easily be completely removed. The electronics unit can remain with the remaining electronic components in the inside of the terminal box or the electronics housing in its lower part. 
         [0013]    Thereby, the electronics unit in the lower part is preferably fastenable in at least two alignments corresponding to the alternative alignments of the cover. This, when e.g. the cover is rotated into a second alternative alignment, permits the electronics unit, which comes to lie below the cover, to also be able to be aligned in the lower part accordingly in a second alternative alignment, so that the electronics unit always retains a predefined alignment relative to the operating panel which is connected to the cover, independently of the envisaged several alternative alignments of the cover, in which the cover is fastened on the lower part. The electronics unit is always accordingly aligned in the lower part before fastening the cover. 
         [0014]    The electronics unit for this can be fixed in the lower part via at least one locking element. This permits the electronics unit to be easily released and to be able to be fixed in the desired alignment or angular position in the lower part, without a special tool being necessary for this. Alternatively or additionally, the electronics unit can be secured in the lower part, for example also by way of screws. 
         [0015]    The operating panel is further preferably provided with at least one transparent window, and the electronics unit with at least one display element which is placed below this window. Such a display element can be a display such as a LED display or LCD display or an illumination element such as an LED. With regard to the display, as the case may be, it can be the case of a touch-sensitive display, wherein then the transparent window of the operating panel is designed such that it does not hinder the touch-sensitive function of a display lying therebelow or such that it supports this function as the case may be. The transparent windows can be completely transparent or partly transparent. Moreover, the windows can also be colored and/or carry inscriptions which, as the case may be, are not visible until the display element has been switched on. This can be achieved by way of a part-transparent design which does not contrast with the surroundings in the switched-off condition of the display element, so that the window is only visible in the illuminated condition. 
         [0016]    Further preferably, the operating panel comprises at least one elastically deformable push region and the electronics unit comprises at least one electrical switch element placed below this push region. By way of pressure onto the push region, this can be deformed such that the push region acts on an electrical switch element lying therebelow, in the electronics unit, for example on a switch or button on the electronics unit. Thus, a purely mechanical connection between the push region of the operating panel and an electrical switch element in the electronics unit is achieved. Thus, no electrical connections to the operating panel for any operating elements, which are to be operable for the outside, are necessary. Thus, the operating panel with the cover can be designed in a manner in which it can be easily separated from the electronics unit. 
         [0017]    The electronics unit for its part is preferably electrically connected via at least one plug connection and/or cable connection to further electronic components arranged in the lower part. These further electronic components can in particular be arranged on a circuit board, to which the electronics unit is connected via the plug connection or cable connection. The plug connection can be designed such that it can engage at several angular positions. Alternatively, one can design several plug connections, wherein the electronics unit then, depending on the selected alignment, can become electrically conductively engaged with one of these several plug connections in the lower part of the terminal box. Alternatively, a cable connection can be formed, which permits a rotatability or alignment ability of the electronics unit at different angular positions or alignments. Thereby, only the cable connection between the electronics units and the further electronic components or a circuit board moves. 
         [0018]    According to a further preferred embodiment, the electronics unit via at least one spring element is held in bearing contact on the operating panel and/or in bearing contact on an inner side of the cover. This is advantageous, in order to be able to ensure the desired interaction of the operating panel with the electronics unit. For this, the electronics unit must preferably be held in a defined position to the operating panel, in particularly be arranged adequately close to the operating panel, so that for example deformable push regions of the operating panel can act on electric switch elements in the electronics unit, and display elements are visible from the outside through windows in the operating panel. The spring elements can thereby compensate occurring tolerances between the electronics unit and the operating panel, which can result for example also from the fastening of the cover. In particular, if a seal is arranged between the cover and the lower part and is deformed on fastening the cover, one cannot ensure that the distance between the cover and the lower part is always the same in an exactly defined manner. Certain distance fluctuations can be then compensated by the at least one spring element, so that the electronics unit is always held with the desired bearing contact on the operating panel and/or on the inner side of the cover. Particularly preferably, several spring elements, in particular three or four spring elements are present, in order to impinge the electronic unit with force in a uniform manner. 
         [0019]    The at least one spring element is further preferably fastened on a covering which is arranged in the inside of the electronics housing and which covers electronic components arranged in the lower part, to the cover. Thereby, the covering is preferably arranged such that electrical connection leads or connection terminals which are required in order to connect connection leads such as for example a mains lead and/or control or data leads which are to be connected to the electronics housing are not covered. Thus, by way of the covering, it is ensured that on removal of the cover, the electrical components in the electronics housing remain protected by the covering and merely the necessary connection elements are freely accessible after removal of the cover. The electronics unit is preferably fastened via the spring elements on this covering, i.e. the at least one spring element is preferably fastened on the covering. 
         [0020]    The electronics unit for its part can in turn be arranged in a separate enclosure or in a separate housing, which protects the electronic components of the electronics unit. Thus, electronic components of the electronics unit are in particular protected if the cover is removed from the lower part of the electronics housing. Thus, the electronic components of the electronics unit cannot be inadvertently damaged, for example when connecting connection leads in the inside of the terminal box. As the case may be, necessary electrical switch elements can be arranged in the known manner in openings or recesses of such a housing of the electronics unit. 
         [0021]    Particularly preferably, the at least one spring element is an elastomer element. Such an elastomer element can be manufactured in a very simple and inexpensive manner. Moreover, the elastomer element can be preferably designed as one piece with a seal arranged on the covering. Such a seal on the one hand can seal the covering with respect to the housing walls of the lower part of the electronics housing, so that the electronic components are arranged below the covering in a sealed-off space. On the other hand, the seal is preferably in bearing contact with the lower part and the cover in a sealing manner, when the cover is put onto the lower part. I.e. the seal extends between the bearing-contact surfaces between the cover and the lower part and serves for sealing off the inner space which is enclosed by the lower part and the cover, to the outside. An elastomer element which serves as a spring element, together with such a seal can be easily formed directly on the covering with injection molding, so that an inexpensive and simple manufacture is possible. 
         [0022]    The operating panel is preferably arranged on an outer side of the cover, and the cover below the operating panel has at least one opening, so that display elements below the cover, i.e. display elements which are situated on the electronics unit, are visible from the outside through the operating panel and the cover. Deformable push regions can thus also act through the opening in the cover onto electrical switch elements on the electronics unit. The operating panel is preferably fastened on the outer side of the cover by way of an adhesive connection. Simultaneously, a tight connection is thus created, so that the opening in the cover is sealed to the outside. 
         [0023]    Thereby, the operating panel further preferably on its surface which is away from the electronics unit has a closed cover film. This on the one hand leads to an optically pleasant appearance of the operating field. On the other hand, the operating panel is easy to clean from the outside, since a smooth surface is thus created. Moreover, no openings or gaps are in the operating panel, into which openings or gaps contamination or for example moisture can penetrate. 
         [0024]    Particularly preferably an electric motor according to the preceding description is applied as an electric drive motor in a pump assembly, for example in a single-stage or multi-stage centrifugal pump assembly. Such a pump assembly with such an electric motor as has been previously described is accordingly likewise the subject matter of the invention. 
         [0025]    The invention is hereinafter described by way of example and by way of the attached figures. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    In the drawings: 
           [0027]      FIG. 1  is a perspective entire view of an electric motor according to the invention; 
           [0028]      FIG. 2  is a view according to  FIG. 1 , with which the cover is fastened on the electronics housing in an alignment which is rotated by 180°; 
           [0029]      FIG. 3  is an exploded view of the electric motor according to  FIGS. 1 and 2 ; 
           [0030]      FIG. 4  is an opened perspective view of the electronics housing; 
           [0031]      FIG. 5  is a view of the electronics housing according to  FIG. 4  with a released electronics unit; 
           [0032]      FIG. 6  is a sectioned view through the opened electronic housing; and 
           [0033]      FIG. 7  is a view of the detail VII in  FIG. 6 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]    Referring to the drawings in particular, the electric motor according to the invention comprises a stator housing, in which the stator and rotor of the electric motor are arranged in the known manner. A rotor shaft  4  extends out of the stator housing  2  to the outside at one axial side. With respect to the rotation axis X of the electric motor, an electronics housing  6  is arranged on the radial side on the stator housing  2  on the outer periphery of this stator housing. The electronics housing  6  consists of a lower part  8  which is connected, in particular screwed, to the stator housing  2 , and of a cover  10  which covers or closes the lower part  8  at its side which is away from the stator housing  2 . For this, the cover  10  with its peripheral edge  12  comes to bear on a peripheral edge or end-edge  14  of the lower part  18 . The cover  10  is fastened on the lower part  8  via four screws which engage into the screw holes  16  of the cover  10  and through these into threaded holes  18  in the lower part  8 . The cover  10  is designed in a mirror-symmetric manner to the Y-axis in the region of its peripheral edge  12  and in the arrangement of the screw holes  16 . This permits the cover  10  to be fastened on the lower part  8  in two arrangements which are rotated by 180° to one another, as is shown in  FIGS. 1 and 2 . In  FIG. 1 , the cover  10  is fastened on the lower part  8  in a first alignment and in  FIG. 2  in a second alignment rotated by 180°. 
         [0035]    The cover  10  on its upper side away from the lower part  8  carries an operating panel  20  of an operating unit. The operating panel  20  is designed as a film element of plastic and is bonded to the cover  10 , so that it is fixedly connected to the cover  10 . As is to be recognized in  FIGS. 1 and 2 , the operating panel  20  together with the cover  10  is aligned differently, depending on the angular position, in which the cover  10  is fastened on the lower part  8 . Thus, it is to be recognized that in  FIG. 1 , the operating elements in the form of push regions  22  are situated on the left in the picture, whilst the same operating elements in the form of the push regions  22  in the alignment according to  FIG. 2  are situated on the right in the view. Apart from the push regions  22 , the operating panel  20  also comprises a window  24  which is designed in a transparent manner. Openings or recesses  26  are formed in the cover  10 , below the window  24  and the push regions  22  of the operating panel  20 . The openings  26  are covered over and tightly closed by way of the operating panel  20 , which is fastened on the outer side of the cover  10 . The operating panel  20  represents a purely mechanical component without electrical elements and with the cover  10  can be completely removed from the lower part  8 . Below the cover  10  and there below the operating panel  20 , an electronics unit  28  is arranged in the inside of the electronics housing and together with the operating panel  20  forms the operating unit. The electronics unit  28  carries a display  30 , LED  32  and electrical switch elements  34  in the form of buttons. The switch elements  34  thereby lie below the push regions  22  of the operating panel  20  so that with a pressure on the push regions  22 , these can be deformed in the direction of the electronics unit  28  and press onto the switch elements  34 . The display  30  lies below the window  24  and the LEDs  32  lie below a transparent further region of the operating panel  20 , so that they can illuminate through the operating panel  20 . 
         [0036]    The electronics unit  28  in its inside comprises a circuit board  36 , on which the display  30 , the switch elements  34  and the LED  23  are arranged and electronic components of the operating unit are attached. The circuit board  36  is arranged below a covering or in a housing  38  and is fastened in this housing  38 . The housing  38  is preferably designed in a completely transparent manner and covers the display  30  and the LEDs  32  and comprises openings, through which the switch elements  34  extend to the outside towards the operating panel  20 . The housing  38  moreover comprises locking elements in the form of locking hooks  40 , with which the electronics unit  28  is fastened in the lower part  8 . 
         [0037]    A circuit board  42  which carries electronic components, in particular electronic components of a frequency converter, is arranged in the lower part  8 . The circuit board  42  is covered by a covering  44  for the protection of this circuit board  42  and the electronic components. The covering  44  in particular serves for protecting the circuit board  42  and the electronic components when the cover  10  is removed. The cover  10  in particular is removed when electric connection leads which are led through cable feed-throughs  46  into the inside of the electronics housing  6 , are to be connected onto corresponding connection elements on the circuit board  42 . The covering  44  comprises openings  48 , through which respective connection leads can be connected on connection elements on the circuit board  42  which are not shown in detail here. 
         [0038]    The electronics unit  28  is fixed with the locking hooks  40  in locking recesses  50  in the covering  44 . Thereby, locking recesses  50  are provided, which are likewise arranged in a mirror-symmetrical manner with respect to the symmetry axis Y. This permits the electronics unit  28  to also be fastened on the covering  44  with two alignments which are rotated by 180°. Thus, the electronics unit  28  can be fixed on the covering  44  in a manner matching the alignment of the cover  10 , so that the display  30  is always situated below the window  24 , and the switch elements  34  below the push regions  26  of the operating panel  20 . The electrical connection between the circuit board  36  and the circuit board  42  is thereby created by way of a cable connection  52 , which permits a rotation of the electronics unit  28  by 180° relative to the covering  44  and the circuit board  42  which is arranged below this. 
         [0039]    Spring elements in the form of elastomer elements  54  are provided, in order to hold the electronics unit  28  in bearing contact on the inner side of the cover  10  and in particular to hold the switch elements  34  in bearing contact with the push regions  22  of the operating panel  20 . The elastomer elements  54  extend in a column-like manner outwards away from the covering  4  and are aligned parallel to one another. Thereby, four elastomer elements  54  are provided, of which in each case two are arranged symmetrically to the symmetry axis Y. The elastomer elements  54  engage into the receiver  56  on the housing  38  of the electronics unit  28 . Thereby, the receivers  58  are open to the covering  44 . Likewise four receivers  56  are provided, of which in each case likewise two are arranged mirror-symmetrically to the symmetry axis Y. This permits the electronics unit  28  with its housing  38  to be put onto the elastomer elements  54  alternatively in two angular positions which are rotated by 180° to one another. 
         [0040]    The locking connection between the locking hooks  4  and the locking recesses  50  is designed with play, so that the elastomer elements  54  are compressed when the locking hooks  40  engage into the locking recesses  50 . Moreover, so much play is provided in the locking connection, that even after engagement of the locking hooks  40  into the locking recesses  50 , the electronics unit  28  can be moved further onto the covering  44  by way of pressure. Firstly, the electronics unit  28  as is shown in  FIG. 4  is fixed on the covering  44  via the locking connection. Subsequently, the cover is stuck onto the lower part  8  in the alignment or angular position corresponding to the selected alignment of the electronics unit  28 . Thereby, the inner side of the cover  10  comes into contact with the upper side of the electronics unit  28  or its housing  38  and presses the electronics unit  28  by way of further compression of the elastomer elements  54  against the spring force of the elastomer elements  54 , further towards the covering  44 . In this manner, a secure bearing contact of the electronics unit  28  on the inner side or outer side of the operating panel  20  or the inner side of the cover  10  in the region of the operating panel  20  is ensured. 
         [0041]    The elastomer elements  54  are integrally formed on the covering  44  and are designed as one piece with a seal  58  on the outer periphery of the covering  44 . The seal  58  comes to bear between the lower part  8  and the cover  10  in the region of their peripheral edges  12  and  14  and seals the gap between the cover  10  and the lower part  8 . The seal  58  thus together with the elastomer elements  54  can be formed on the covering  44  by way of injection molding. 
         [0042]    While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.