Abstract:
A dynamo-electric machine includes a self-supporting housing that has a laminated core section and at least one connecting section in the axial extension of the laminated core section. The laminated core section accommodates and secures, and at least sectionally surrounds all sides of, a laminated core of a stator. The individual sheets of the laminated core have a basic outer shape with an especially octagonal cross-section, a stator bore surrounded by radially arranged grooves which are evenly distributed along the circumference of the stator bore, a yoke back that radially adjoins the grooves and extends equidistantly from the stator bore, and axial cavities in the sheet, in regions between the yoke, back and the basic outer shape of the sheets.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is the U.S. National Stage of International Application No. PCT/EP2011/058406, filed May 24, 2011, which designated the United States and has been published as International Publication No. WO 2012/159660. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a dynamo-electric machine comprising a self-supporting housing that has a laminated core section. 
     A plurality of motor concepts exists for air and water cooling, for attaching the terminal box, for the arrangement of bearings and also for a concrete embodiment of the cooling of a dynamo-electric machine. Air cooling of a dynamo-electric machine is thus known from EP 0 387 743 A1. DE 197 42 255 C1 describes a three-phase machine without a casing having cooling pipes arranged in parallel with the axis in a stator laminated core. Furthermore, liquid-cooled electric machines are also known for instance from U.S. Pat. No. 5,084,642 A and DE 91 12 631 U1, wherein diversion pieces and inlet and outlet connecting pieces are cast into the bearing shields. An electric machine without a casing is also known from AT 170 766, the sheets of which have cooling and foot projections. 
     Electric machines without a casing have a lack of rigidity of the laminated core and are provided with pot bearing shields for mounting the shaft, said pot bearing shields being comparatively complicated to produce and thus comparatively expensive. 
     Dynamo-electric machines with casings result in an enlargement of the active part, since, inter alia, the cooling is not provided to the same degree as in a dynamo-electric machine without a casing. 
     SUMMARY OF THE INVENTION 
     On this basis the object underlying the invention is to avoid the afore-cited disadvantages. Taking into account in particular the new efficiency classes, a dynamo-electric machine, which is comparatively easy to produce, is furthermore to be produced, in particular at the low voltage level. 
     The solution of the set object is achieved by a dynamo-electric machine comprising a self-supporting housing, that has a laminated core section and at least one connecting section in the axial extension of the laminated core section. The laminated core section receives, secures, and at least sectionally surrounds all sides of a laminated core of a stator formed from axially layered sheets. The individual sheets of the laminated core have a basic outer shape with an especially octagonal cross-section having
         a stator bore surrounded by radially arranged grooves which are evenly distributed along the circumference of the stator bore,   a yoke back that radially adjoins the grooves and extends equidistantly from the stator bore,   axial recesses in the sheet, in regions between the yoke back and the basic outer shape of the sheets.       

     This dynamo-electric machine has a self-supporting housing, which has a simple angular laminated core section, including an angular laminated core. Furthermore, the self-supporting housing has at least one connecting section in the axial extension of the laminated core section. In the case of several connecting sections, these are advantageously arranged on both sides at the axial ends of the laminated core. 
     In accordance with the invention, the objects of the self-supporting housing are now clearly defined and summarized. A platform concept thus results, which now enables individual embodiments (for instance liquid cooling with noise attenuation and heat exchanger on the machine etc.) to be realized in a simple manner, without designing a new machine concept and constructively implementing the same. 
     This speeds up the lead times when ordering a machine for instance. 
     A platform concept for dynamo-electric machines is thus ensured in a simple manner. This is above all of particular interest for powerful machines in the low voltage range, in other words below 1000 V nominal voltage, since dynamo-electric machines are provided there for a variety of purposes. 
     The laminated core section of the self-supporting housing is thus used to fix the laminated core of a stator across the defined contact areas between laminated core section of the housing and laminated core. These contact areas are used in particular as torque supports and/or to package the laminated core. Similarly the short-circuit torques are to be accepted there. 
     In a further embodiment, the lateral surfaces of the laminated core section of the housing are open, so that only a frame, if necessary supported by one or more struts, fulfils the afore-cited objects. The laminated core section thus comprises a regular prism with reinforced edges and the contact areas in its most rudimentary basic spatial shape. 
     The connecting section of the housing is arranged directly on the laminated core section in the axial extension. The connecting section and laminated core section are advantageously embodied from one material, and in particular in one piece. 
     The self-supporting housing with its laminated core section and its connecting section is structured in an extremely simple manner and only consist of a few basic elements. These can be produced from steel, cast steel or grey cast iron or also from aluminum. 
     All connection possibilities of additional apparatuses and/or auxiliary devices, e.g. air guidance, air distribution, attachment of a fan, attachment of add-on coolers, bearing shields, terminal boxes etc, now take place exclusively by way of the one or the further connecting sections of the housing. With two connecting sections, the laminated core section is disposed between these two connecting sections. Functions and/or connection possibilities of the connecting section, which are not used, for instance on account of only an external cooling, and not an add-on cooler being provided, can be covered and/or closed by covers, blanking plugs and/or blanking covers on the connecting section. 
     This significantly simplifies the basic structure of the housing, since only one housing is now to be provided at an axis height of a dynamo-electric machine, with which all connection possibilities, cooling options etc. can be realized. 
     For instance, all cooling methods can thus be realized individually or in combination, like for instance self-ventilation or forced ventilation, water cooling or water cooling with forced ventilation, also as a separate add-on cooler. Depending on the installation site and climatic requirements, the dynamo-electric machine can thus be easily adjusted to the conditions with an optimal degree of efficiency. 
     In this way an air flow or a liquid is guided across the axial recesses of the sheet. In the case of liquid cooling, it is particularly advantageous for reasons such as making a good seal if tubes are provided in the recesses for this purpose, which are thermally connected to the laminated core. This is done for instance by means of thermally conductive casting material and/or caulking and/or axial injection and/or hydraulic expansion of the tubes in the recesses of the laminated core. 
     The recesses are arranged as a closed contour within the sheets between the yoke back and the outer edge or as cooling ribs and/or clamp recesses for tubes on the outer surface of the laminate core. 
     On account of the very simply structured housing with its connecting sections, the position of the terminal box can advantageously be almost freely selected, since the attachment of the terminal box is only bound to the connecting section and not to specific receiving surfaces, such as for instance in the case of a ribbed housing. 
     The laminated core of the stator is advantageously provided with an octagonal cross-sectional shape, wherein, when viewed in the peripheral direction, shorter and longer sides are arranged alternately. The peripheral direction is disposed on an imaginary plane, which is arranged at right angles to the virtual machine axis. 
     This cross-sectional shape simplifies inter alia the manufacturing process, particularly if one assumes that these sheets are stamped from wound sheet metal coils. 
     The sheets arranged axially one after the other and forming the laminated core of the stator advantageously comprise surface-enlarging structures, irrespective of the contact areas, on their outer sides. The cooling efficiency is thus increased. 
     The contact areas are advantageously provided on the shorter sides of the sheets and/or the laminated core, so that a predetermined distance can be set between a side wall of the laminated core section of the housing and a longer side of the laminated core. Noise damping mats can be placed into this free space for instance. In accordance with the invention, the minimized contact of the laminated core and the housing thus reduces the noise emissions of the dynamo-electric machine. 
     Furthermore, optimized material usage results from the inventive dynamo-electric machine with its self-supporting housing and its laminated core, since, unlike a round laminated core, the corners of the laminated core can now also be used. Furthermore, high rigidity results on account of the use of the self-supporting housing. 
     If the side walls of the laminated core section are closed, the laminated core is protected from spray water from all directions. 
     The use of this self-supporting housing in a dynamo-electric machine avoids pot bearing shields which are comparatively technically and financially costly. In accordance with the invention, less costly bearing shields are now arranged here in the connecting sections. 
     The laminated core of the stator advantageously has pressure plates applied to it on its front sides, said pressure plates axially pressing the individual axially layered sheets against one another. 
     According to one exemplary embodiment, the pressure plates in the region of the stator bore and/or grooves and also possible cooling recesses correspond to the dimensions of the sheets, but nevertheless have a larger outer diameter than the individual sheets. This is advantageous in that the pressure plates exclusively come to rest on the predetermined contact areas of the interior of the laminated core section of the housing. A free space between the surface of the laminated core and the interior of the laminated core section is thus produced between the sides of the laminated core, which advantageously comprise an octagonal basic shape with shorter and longer laminated core sides. 
     Damping materials can now be used in this free space, advantageously already pre-fabricated damping mats, which can be attuned to predetermined oscillation frequencies and noise frequencies of the motor and/or a converter connected to the motor and thus filter out specifically known frequencies. 
     The internal arrangement of the damping materials now protects these from external influences, such as weathering, aggressive media or mechanical damage and thus retains their function for longer. Furthermore, the damping mats are in a closed free space and can therefore not slip in the direction of the winding or the rotor on account of vibrations of the laminated core and thus reach the rotating masses. 
     The damping mats are advantageously glued, screwed or fastened by holding eyelets to the laminated core or to the interior of the laminated core section or to the interior of the housing cover plates, in other words the side walls. These damping mats result in a noise reduction, such as is of extreme importance particularly during operation of the dynamoelectric machine on the converter. These additional measures enable noise limit values to be retained without changes to the converter controller. Converters can thus continue to be operated with a low clock frequency on inventive dynamo-electric machines. 
     In a further embodiment, the pressure plates correspond to the sheets in terms of their cross-section. Therefore, the shorter sides of the laminated core and those of the pressure plates rest on the interior of the laminated core section of the housing in the contact areas provided therefor. Contact areas thus result between the surface of the laminated core and the interior of the laminated core section, said contact areas extending beyond the entire axial length of the laminated core. Damping materials, in particular damping mats with the afore-described advantageous effects can be inserted into the free spaces between the longer sides of the laminated core and the interiors of the laminated core sections of the housing corresponding thereto in the manner cited above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The invention and further advantageous embodiments of the invention are described in more detail below with the aid of basic exemplary embodiments, in which: 
         FIGS. 1, 2  show basic longitudinal sections of two embodiments, 
         FIG. 3  shows a cross-section through an embodiment according to  FIG. 1 , 
         FIG. 4  shows a cross-section of an embodiment with damping mats, 
         FIGS. 5 to 11  show embodiments of different laminated cores, 
         FIG. 12  shows a housing with a laminated core, 
         FIG. 13  shows a perspective representation, 
         FIGS. 14, 15  show different arrangements of cooling apparatuses on a housing, 
         FIG. 16  shows a basic liquid cooling connection on a housing, 
         FIGS. 17, 18  show add-on coolers and/or add-on converters on a housing, 
         FIG. 19  shows the arrangement of a terminal box on the housing, 
         FIGS. 20, 21  show water cooling with different laminated cores, 
         FIG. 22  shows a protective tube for cooling holes, 
         FIG. 23  shows a protective tube and cooling ribs, 
         FIGS. 24 to 27  show further embodiments of the housing, 
         FIG. 28  shows a perspective representation of a dynamo-electric machine. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 1  shows a basic representation of a longitudinal section of an inventive self-supporting housing  1  of a dynamo-electric machine  23 , having a stator  22 , the laminated core  5  of which is formed by pressure plates  4  on the end faces. 
     With the construction type of a self-supporting housing  1 , the receiving sheets, reinforcements, profiles and paneling are non-detachably connected to one another using different joining technologies (soldering, welding, gluing), so that a single-piece housing  1  is produced. The supporting function is assumed here by the housing structure alone. The rigidity is achieved by the compact housing structure by if necessary hollow housing parts having the largest possible cross-section and thus a higher resisting torque. Beading, indentations etc., such as for instance in  FIG. 21  and  FIG. 25 , increase the rigidity of the housing  1 . 
     The pressure plates  6  package the laminated core  5  and press it axially together, so that extremely narrow gaps are produced between the individual sheets. Despite this, dust and/or moisture can enter this gap through capillary action. The housing  1  has a laminated core section  2  and connecting sections  3  adjoining axially thereto. In this representation, the connecting sections  3  and laminated core section  2  have different heights. The connecting sections  3  can similarly be embodied with the same cross-section, the same height or as also inferred from  FIG. 1 , with a larger cross-section. 
     In this case, the lower sections of the connecting areas  3  simultaneously form feet, on which the dynamo-electric machine  12  is to be operated. The laminated core  5  is, as indicated clearly in this representation, arranged within the laminated core section  2 . The laminated core section  2  of the housing  1  has no further function or connection possibilities. It is used to position and if necessary protect the laminated core  5 . For installation purposes, it is only advantageous if the connecting areas  3  and/or the laminated core section  2  provide means for attaching eyebolts  27 , e.g. threaded inserts. 
       FIG. 2  shows a longitudinal section of a dynamo-electric machine  23 , wherein the differences between this figure and  FIG. 1  consist in the sheets of the laminated core  5 , and also the pressure plates  4  having essentially the same diameter and a similar cross-section. The entire laminated core  5  is likewise arranged here in the laminated core section  2 . 
     In  FIG. 1 , only the pressure plates  4  rest against the interior of the laminated core section  2  of the housing  1  in the provided contact areas  7 . Whereas in  FIG. 2 , both the pressure plates and also the predetermined areas of the laminated core  5  rest against the contact areas  7  of the laminated core section  2 , as can be seen in  FIG. 3 . 
     When viewed cross-sectionally in terms of its basic outer shape,  FIG. 3  shows that the laminated core section  2  of the housing  1  can in particular be embodied to be square, octagonal or also to have further corners, in other words essentially as a polygon. The interior of the laminated core section  2  of the housing  1  forms an octagon, which, in particular at the shorter interior sides, forms contact areas  7  for the laminated core  5  and/or only for the pressure plates  4  of the laminated core  5 . 
     As shown in  FIG. 4 , prefabricated damping mats  8  are inserted into the resulting free spaces  6  between the interior of the laminated core section  2  and the surface of the laminated core  5 , said damping mats  8  advantageously being attuned to certain frequencies in the converters supplying electrical energy to the dynamo-electric machine  23 . The converter  17  can thus continue to be operated with a low clock frequency. The damping mats  8  have a very simple rectangular shape and can be obtained already prefabricated. They are not visible from the outside in the case of closed side walls of the housing  1 . On account of the internal arrangement, the damping mats  8  are protected from external influences, such as weather or mechanical damage or slipping. 
     Furthermore, the damping mats  8  are advantageously fixed to the interior of the laminated core section  2  or laminated core  5  by means of glue, screw connections or additional holding eyelets, so that a slipping within the free space  6  is ruled out. This prevents the damping mats  8  from reaching the area of the winding of the stator  22  or rotating parts of the dynamo-electric machine  23 . The damping mats can also be attached to the interior of separate side walls  38 , such as for instance shown in  FIG. 28 . 
       FIGS. 5 to 11  show basic sheets of the laminated core  5  which is arranged in the laminated core section  2 . The sheets basically have an octagonal basic shape, which, despite surface-enlarging measures such as notching, recesses on the outer periphery or within the sheet, remains unchanged. In this embodiment the octagonal basic shape has shorter sides  25  and longer sides  24 , which alternate in the peripheral direction and thus allow for a positioning and fixing of the laminated core  5  across its shorter sides  25  and the contact areas  7  on the interior of the laminated core section  2  of the housing  1 . The sheets basically have a stator bore  9 , which is surrounded by grooves  10  and teeth  11  of the sheets. The sheets are arranged here at right angles to a virtual axis  26  in each instance. 
     The recesses  24  in the sheets and ultimately also in the laminated core  4 , which run axially, are suited to receiving cooling tubes of a liquid cooling system of the dynamo-electric machine  23  and are used as ventilation channels for self-ventilation or forced ventilation. The cooling ribs  33  arranged on the outer periphery are embodied in particular by the design such that these are also suited as clamp recesses  38  for snap-in cooling tubes  37  of a liquid cooling system. 
     Irrespective of  FIG. 10 , the yoke back of the stator  22  is free of recesses, so that the field line curve of the magnetic field produced in the grooves  10  by a winding system is not negatively affected. An essentially annular area of the sheets is understood here to be a yoke back, said area radially outwardly adjoining the grooves. 
     The yoke back extends, without any recesses, preferably radially at least about a half groove depth. 
     In other words, the annular area of the yoke back has at least one value in its radial extension, which corresponds to half the groove depth of the respective sheet and/or laminated core. 
       FIG. 10  shows additional recesses in the area of the yoke back, which are arranged essentially opposite to the shorter side  25  in each instance. Existing heat sources can thus additionally be cooled. 
       FIG. 12  shows a perspective representation of a laminated core  5  in the housing  1 , wherein the laminated core  5  is formed from sheets according to  FIG. 7 . In this figure the laminated core  5  was axially introduced into the laminated core section  2  through a connecting section  3 . Here the other connecting section  3  or the laminated core section  2  advantageously comprises an end stop, which provides a defined insertion depth of the laminated core  5  into the housing  1 . 
     The connecting sections  3  have openings  12 , which are inter alia suited to attaching cooling channels, terminal boxes etc. Furthermore, the connecting sections  3  furthermore have beads in their corners, which improve the rigidity of the housing  1 . 
       FIG. 13  shows the assembly process on a housing  1  similar to  FIG. 12 , here the laminated core  5  is axially inserted into the housing  1  with a winding, not shown in further detail, and a protective hood  35 , depending on the embodiment of the type of protection according to IEC  34 - 5 . 
       FIG. 14  shows, like the following FIGS., exemplary embodiments of the inventive concept, namely that the ventilation apparatus  14 , terminal box  20  etc. can now only be attached by way of the connecting sections  3 .  FIG. 14  thus indicates a ventilation apparatus which can be connected axially to the connecting section  3 . An external cooling of the dynamo-electric machine is thus possible for instance. The laminated core section  2  remains unaffected thereby. 
     Furthermore, according to  FIG. 15  a cooling apparatus or an external cooler can likewise be arranged above the connecting section  3 . 
       FIG. 16  shows the fundamental option of a connection  15  of a liquid cooling system on the dynamo-electric machine  23 . Cooling tubes  27  are naturally to be arranged herefor in the recesses  34  (see in particular  FIGS. 5 to 11 ) within the laminated core  5  or on the laminated core  5  of the stator  22  and connected in a flow-specific fashion to the front faces of the laminated core  5  within the connecting areas  3 . 
       FIG. 17  shows, in a further embodiment, the housing  1  with its laminated core section  2  and the two connecting sections  3 . The openings  12  of the connecting section  3  open into a heat exchanger  16 , advantageously air-air or air-water heat exchanger, wherein the heated and/or back-cooled cooling air is discharged and/or fed by way of openings  12  in the connecting sections  3  of the dynamo-electric machine  23  which are provided herefor. The laminated core section  2  remains unaffected thereby. 
     In addition to the embodiment according to  FIG. 17 ,  FIG. 18  shows a converter  17 , which is positioned on the heat exchanger  16  or, together with the heat exchanger  16 , forms a structural unit. The converter  17  is cooled here by the heat exchanger  16 . The electrical connecting lines are supplied herefor through the heat exchanger  16  and via the connecting section  3  to the winding system of the stator  22  of the dynamo-electric machine  23 . 
       FIG. 19  shows a terminal box  20  on the connecting section  3 , wherein the terminal box  20  with the alignment of its external electrical connection  21 , which can be set in various directions by means of an, in particular, stoppable rotating mechanism. 
     All connecting elements such as terminal boxes  20 , heat exchangers  16 , converters  17  etc. can only be attached alone or in any combination to the connecting sections  3  and can be contacted with the winding, or cooling facilities of the dynamo-electric machine  23  etc. by way of the openings  12 . 
     In order to realize the designs according to IEC  34 - 7 , the required flanges, feet  18  etc. are now only provided on the connecting sections  3 . 
       FIG. 20  shows a cooling system arranged in a serpentine shape around the laminated core  5 , the cooling tubes  37  of which are arranged on the periphery of the laminated core  5  in the clamp recesses  39 . The further recesses  34  within the laminated core  5  are used above all for air cooling purposes. The laminated core section  2  is embodied to be essentially axially longer in this figure, for representational purposes, than the laminated core  5  in order to be better able to show the contact area  7 . 
       FIG. 21  shows, in a further representation, a cut-out housing  1 , which provides bearing shields  19  on the connecting sections  3 , into which a rotor is mounted. The rotor is in this case embodied as a short circuit rotor, it can for instance also be a permanently-excited rotor of a synchronous machine. 
     Similarly, as also shown in  FIG. 20 , a liquid cooling system is arranged on the periphery of the laminated core  5 . The connection  15  for the liquid cooling system is disposed on the B-side of the dynamo-electric machine  23 , in other words on the side facing the shaft end  13 . For reasons of clarity, the stator  22  is shown without a winding system. 
     Beads  36  reinforce the laminated core section  2 . Feet  18  are disposed in the connecting sections  3 . 
       FIGS. 22 and 23  each show protective hoods  35 , which cover the winding system and/or the cooling tube  27  and thus protect against external influences depending on the requirements of the type of protection according to IEC  43 - 5 . In these figures, ribs or beads reinforce the protective tube  35 . 
       FIG. 25  shows a housing  1 , in which the inventive basic idea has been retained compared with the previously described embodiments, but the side walls  38  remain open in the laminated core section  2 . A comparatively higher rigidity compared with machines without casings is still achieved by this design. 
     The original side walls  38  can preferably be exchanged. Each gap can be sealed by various side walls. The oscillation properties of the housing  1  can be influenced by side walls  38  with other (plastic, glass fiber, steel . . . ) and/or thicker or thinner material. In a further embodiment, side walls  38  have an insert, which protrudes into the free space  6 . These are for instance closed or perforated holding elements for damping material. 
     In order to further increase the rigidity, webs  28  are, if necessary, provided in the remaining openings of the open side walls, as shown in  FIG. 24 . 
     On account of the absence of side walls  38  of the laminated core section  2 , the contact areas  7  can be particularly effectively processed for instance, as shown in  FIG. 26 , with a lathe tool, since the working areas  29  of a lathe tool of a machine tool project beyond the boundary edges  30 . 
       FIG. 27  shows a perspective representation of a housing  1 , with open side walls, which has material accumulations at the axial ends of its laminated core section  2 , which are particularly suited to attaching an eyebolt  27 . An opening  12  in the right connecting section  3  is sealed for instance by a cover. The openings  12  not occupied by functional elements such as coolers, terminal boxes  20  can thus be covered such that the respective type of protection is preserved. 
       FIG. 28  shows a dynamo-electric machine  23  in a possible embodiment of the described platform concept, wherein a shaft end  13  protrudes from the one connecting section  3 , said shaft end  13  being held in a bearing shield  19  in this connecting area  3 . Furthermore, the openings  12  of this connecting area  3  are provided with a ventilation grid  31  and a terminal box  20 . Similarly, eyebolts  27  are provided in the connecting sections  3 . The other connecting section  3  has an axially aligned ventilation hood  32 . The side wall  38  is sealed by screw connections.