Abstract:
A pump with an integral, electronically commutated, direct-current motor ( 2 ) with permanent magnetic inner rotor disposed in a wet chamber, which forms with a turbine pump wheel ( 22 ) a compact, structural pump-rotor unit ( 3 ), a claw-pole stator ( 9 ) positioned in a dry chamber ( 4 ), the claw-pole stator ( 9 ) having four claw-pole plates ( 6, 6′ ) made of a soft magnetic material, a ring-shaped winding ( 12 ) and a claw-pole stator ( 9 ) including a soft magnetic back-iron ring ( 13 ) mounted on the claw-pole plates( 6, 6′ ) and disposed around the winding ( 12 ) and a separating can ( 10 ), which separates the dry chamber from the wet chamber ( 5 ), characterized in that the claw-pole plates ( 6, 6′ ) and additional claw-pole plates ( 66, 66′ ) are stamped and bent together, in which a plate strip for the additional claw-pole plates ( 66, 66′ ) contains a central borehole from a previous work step.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    (1) Field of the Invention 
         [0002]    The invention concerns a pump with an integral electronically commutated, direct-current motor with an inner, permanent-magnetic rotor disposed in a wet chamber, which forms a compact structural pump-rotor unit with a turbine pump wheel, a claw-pole plate made of a soft magnetic material disposed in a dry chamber or dry space, a ring-shaped winding, and a soft magnetic, return or back-iron ring mounted on the claw-pole plate and disposed around the winding, including a claw-pole stator and a can like partition wall that acts as a containment shell to separate the dry chamber from the wet chamber or wet space. 
         [0003]    (2) Description of Related Art Including Information Under 37 CFR 1.974 and 1.98 
         [0004]    Such a pump is known from German patent DE 10 2006 021 246 A1, which is provided with a claw-pole stator consisting of two claw-pole plates with paraxial claws gripping one another, forming opposing poles. Because the claw-pole plates are each made of a single, soft magnetic plate, the stator turns out to be in saturation, primarily in the area of the axial stator ends with higher voltage applied at the winding, whereby the performance of the pump is limited. Claw-pole stators are distinguished by simple fabrication, low weight, and sturdiness. Hence, in many cases, it excludes the use of armature stators, with a plurality of single-pole windings and a plated stator set, in particular in use as a supplementary water pump in a vehicle. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    The task of the present invention is hence to produce a pump with which higher efficiency and performance are attainable than with conventional claw-pole stators and whose advantages can thereby be essentially maintained, in particular low weight, simple design, and therewith economical fabrication and sturdiness. 
         [0006]    This task is achieved according to the invention by increasing the cross-section of the soft magnetic poles of the four claw-pole plates, whereby the claw-pole plates can carry a greater magnetic flux. The basic design is changed only insubstantially compared with the successful execution. Furthermore, it is possible to operate the pump with a single stator coil. Due to the different lengths of the claw poles, weight can be saved without changing the basic design. Due to the use of long claw poles, a greater pole surface is usable. The higher performance achieved justifies the higher manufacturing costs required for this. The shorter claw poles can be manufactured by conventional and economically very favorable methods, namely by stamping out of a sheet-metal plate and by the distortion of the sheet-metal plate. Due to the identical radius in the transition region, a smaller free space remains between the two claw-pole plates, whereby it is ensured that the two claw-pole plates can fit very close to one another. 
         [0007]    Because the length of the claw poles in the paraxial direction are disposed at a radial distance farther away from the pump rotor unit and are less than the radius of the same inscribed circle, the additional weight of the shorter claw poles can, at the same time, be limited for greater weight efficiency. 
         [0008]    It has been shown that the shorter claw poles fulfill the assumptions cited with a claw-pole surface between 40% and 75% and/or lengths of 30% to 60% of the longer claw poles. 
         [0009]    It can be advantageous to choose the plate thickness of the shorter claw poles to be less than the plate thickness of the longer claw poles, if the required performance is thereby attainable. Thus more weight is saved, and manufacture is possible even more economically. 
         [0010]    In order to keep eddy-current losses in the stator as small as possible, it is proposed to provide the surfaces of the claw-pole plates adjacent to one another with an insulating layer. The usual varnish layers are suitable here, such as are also suitable for sets of plates. With plates that lie on top of one another in the magnetic circuit, vibrations can occur which cause unacceptable noise. In order to avoid or at least clearly limit this effect, it is proposed that the claw poles of a claw-pole plate be conically deformed to a slight extent in the pre-assembled state, insofar as a shift back to a parallel axis is possible within the elastic region and the deformed claw poles are moved back in the assembled state at least partially in the direction of the parallel axis and in this position are connected to adjacent like-pole (homopolar) claw-poles by a mechanical load. The mechanical load prevents the claw poles from swinging free and thus being able to cause noise. Additionally, the fastening is reinforced by nippling, gluing, or spot-welding. It is also possible to manufacture the mechanical load by joining the claw-pole plates to one another. 
         [0011]    Because the claw-pole plate with the longer claw poles is assumed, as a rule, to have the higher magnetic flux, it is important to close the magnetic circuit above these plates with the magnetic return or back-iron ring to be as loss-free possible. Hence, in order to keep tolerance-conditioned air gaps as small as possible, the claw-pole ring with the shorter claw poles exhibits an insignificantly smaller outside diameter than the claw-pole ring with the longer claw poles. For this, a diameter difference of less than 0.1 mm is used. Consequently, it is ensured that the back-iron ring preferably fits the ring with the larger diameter and the greater magnetic flux. 
         [0012]    In order to improve the sturdiness of the stator unit and to minimize body noise-transmission, it is proposed that a plastic shaped body be connected to at least one ring of a claw-pole plate on one side facing away from the winding, that it exhibit reception means for a conductor plate and a cut clamp connector, in which the plastic shaped body is manufactured by injection molding, and that the four claw-pole plates be at least partially enclosed and fastened, whereby the stator forms a compact ring body, which fits the split tube only above rib-like and/or burl-like areas. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    An embodiment example of the invention is explained in detail hereinafter using the drawings. These show: 
           [0014]      FIG. 1 , one of two different claw-pole plates consisting of a partial stator core, 
           [0015]      FIG. 2 , one of two partial stators from the  FIG. 1  combined stator core, 
           [0016]      FIG. 3 , another illustration of two partial stators from another perspective, 
           [0017]      FIG. 4 , another illustration of the claw-pole plates according to claim  1 , 
           [0018]      FIG. 5 , an illustration of  FIG. 4  from another perspective, 
           [0019]      FIG. 6 , a sectional view of a pump, 
           [0020]      FIG. 7 , a detail view of the claw-poly plates, 
           [0021]      FIG. 8 , a body-noise-minimizing stator shot, 
           [0022]      FIG. 9 , an exploded view of parts of the pump, and 
           [0023]      FIG. 10 , a further exploded view of the pump. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]      FIGS. 1 ,  4 , and  5  show one partial stator core  26  made up of two different claw-pole plates  6 ,  66 . The differences in the claw-pole plates  6 ,  66  consist essentially of different radii for the inscribed circle of the claw poles  77 . Both claw-pole plates  6 ,  66  exhibit a ring  8 ,  88 , from which by means of a bend radius R 1 , R 2  ( FIG. 7 ) the claw poles deviate about 90° and run parallel to a pump axis  11 . The claw poles  7 ,  77  are trapezoidal in their basic form in the present example. The claw poles  7 ,  77  each exhibit like poles (homopolar). Both of the rings  8 ,  88  and the claw poles  7 ,  77  are large areas adjacent to one another. The claw poles  7 ,  77  are aligned parallel to a central pump axis  11 . 
         [0025]      FIGS. 2 and 3  show one combined stator core made up of two partial stators  26 ,  26 ′, in which the trapezoidally constructed claw poles  7 ,  7 ′,  77 ,  77 ′ fit inside one another respectively under air-gap loading and consequently forms a north and a south pole alternating over the circuit. Both of the partial stator cores differs due to recesses  27 , which serve as breaches for the winding connections and as distortion insurance. 
         [0026]      FIG. 6  shows a sectional view through the pump and the integral, electronically commutated direct-current motor, with the stator plates  6 ,  66 , consisting of the claw poles  7 ,  77  and the rings  8 ,  88 , in which these are embedded in a plastic shaped body  14 , which is manufactured by injection molding of the claw-pole plates. The plastic shaped body is a stand-alone component, which serves as a coil body for a winding  12 . The plastic shaped body  14 , together with the winding and a back-iron ring  13 , which is firmly connected, by means of shaping the partial areas of the back-iron ring  13 , to the rings  8 ,  88  of the claw-pole plates  6 ,  66 , forms a claw-pole stator  9 . The claw-pole stator  9  draws a conductor plate  16  through a mechanical reception means  15 , which, on the one hand, is electrically connected to the ends of the winding  12  and on the other hand through a conductor plate  31  to a plug  30  (FIGS.  9 , 10 ). The claw-pole stator  9  is disposed around a separating can  10  or containment shell that forms a can-like partition wall and is force-fit connected to the separating can. A motor housing  20 , together with the separating can  10 , forms a dry chamber  4  into which the claw-pole stator  9  is received and is impermeable to liquids. Within the separating can  10  is a permanent magnetic pump-rotor unit  3 , which consists of a motor section and a pump section. The motor section is disposed radially inside the claw poles  7 ,  77  and exhibits a permanent magnet ring, which is patterned from a plastic-bound magnet material together with a turbine pump wheel  22  and a bearing shaft. The pump-rotor unit  3  is mounted on an axle  29 , which on the one hand is fastened to a floor  28  of the separating can  10  and on the other hand is fastened in the pump housing. The pump-rotor unit  3  is located in a wet chamber  5 , which is bounded by the pump housing  23  and the separating can  10 . The pump housing encloses an axisymmetric pump intake  24  and a pressure connection  25  ( FIG. 8 ), which runs radially to the pump axis  11 . The permanent magnet of the pump-rotor unit can also be made of sintered ferrite material, plastic-bound ferrite material, plastic-bound rare-earth material, or pressed rare-earth material. The ring magnet can be composed of segments, also additionally injected with plastic, or surrounded by a metal ring. Also, the pump-rotor unit can be further provided with a soft magnetic back-iron ring. 
         [0027]      FIG. 7  shows the claw-pole plates  6 ,  66  in the transition region between the rings  8 ,  88  and the claw poles  7 ,  77 , which are characterized by radii R 1 , R 2 . The radii R 1  and R 2  are equally large or at least of the same order of magnitude. 
         [0028]      FIG. 8  shows how the claw-pole stator  9  is fitted on the separating can  10  and in the motor housing  20 . The separating can  10  is one piece with three paraxial ribs  19 , onto which the claw-pole stator  9  is pressed. The motor housing  20  is one piece with five paraxial ribs  21 , across which the motor housing is drawn up tight to the claw-pole stator  9 . The ribs serve to transmit, to a limited extent only, noise produced by the pump-rotor unit, to the motor housing. 
         [0029]      FIG. 9  shows an exploded view with the pump housing  23 , the separating can  10 , the claw-pole stator  9 , with the winding  12 , the conductor plate  16  which is fastened through the reception means to the claw-pole stator, recesses  17  for the cut clamp connector  18  and cut clamp connector  18  electrically connected to the conductor plate  16  (illustration without back-iron ring) and the motor housing  20  with a plug  30 . 
         [0030]      FIG. 10  shows a further exploded view of the housing parts of the pump, with the pump housing  23 , with the pump intake  24  and the pressure connection  25 , the separating can  10  with the floor  28  and the motor housing  20 . 
         [0031]    To recap, the present invention relates to a pump  1  with integral, electronically commutated, direct-current motor  2  with a permanent magnetic inside rotor disposed in a wet chamber, which forms with a turbine pump wheel  22  a compact structural pump-rotor unit  3 , disposed in a dry chamber  4 , claw-pole plates  6 ,  6 ′ made of a soft magnetic material, a ring-shaped winding  12  and a soft magnetic back-iron ring  13  mounted on one of the claw-pole plates  6 ,  6 ′ and disposed around the winding  12  including a claw-pole stator  9  and a separating can  10 , which separates the dry chamber from the wet chamber  5 . 
         [0032]    The claw-pole stator  9  has four claw-pole plates  6 ,  66 , which includes respectively several connecting claw poles  7 ,  77  extending parallel to the pump axis  11  and rings  8 ,  88  disposed at right angles to the pump axis. Two like-pole (homopolar) claw-pole plates  6 ,  66  and two opposite-pole claw-pole plates  6 ′,  66 ′ interact with the same winding. The like-pole as well as the opposite-pole claw-pole plates each consist of two differently constructed claw-pole plates  6 ,  66 ,  6 ′,  66 ′ which are fitted inside one another, so that the claw poles  7 ,  77 ,  7 ′,  77 ′ of two like-pole (homopolar) claw-pole plates are a great and different radial distance from the pump-rotor unit but are disposed in the same angular sector, in which the radial difference corresponds to the plate thickness of the claw poles that are closer to the pump-rotor unit. 
         [0033]    The length of the claw poles  7 ,  7 ′ in a paraxial direction, which are disposed radially closer to the pump-rotor unit, is greater than the radius of an inscribed circle that is bounded by the same claw poles  7 ,  7 ′. The bend radii R 1 , R 2  of the claw-pole plates fitted inside one another  6 ,  66  or  6 ′,  66 ′ in the transition region between the rings  8 ,  88  or.  8 ′,  88 ′ and the claw poles  7 ,  77  or  7 ′,  77 ′ are at least approximately equally large, so that between the claw-pole plates  6 ,  66  or  6 ′,  66 ′ there is a gap in the transition region. 
         [0034]    It is to be understood that the present invention is not limited to the illustrated embodiments described herein. Various types and styles of user interfaces may be used in accordance with the present invention without limitation. Modifications and variations of the above-described embodiments of the present invention are possible, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims and their equivalents, the invention may be practiced otherwise than as specifically described. 
       REFERENCE LIST 
       [0035]      1  Pump 
         [0036]      2  Direct-current motor 
         [0037]      3  Pump-rotor unit 
         [0038]      4  Dry chamber or dry space 
         [0039]      5  Wet chamber or wet space 
         [0040]      6 ,  66 ,  6 ′,  66 ′ Claw-pole plates 
         [0041]      7 ,  77 ,  7 ′,  77 ′ Claw poles 
         [0042]      8 ,  88 ,  8 ′,  88 ′ Ring 
         [0043]      9  Claw-pole stator 
         [0044]      10  Separating Can (Containment Shell) 
         [0045]      11  Pump axis 
         [0046]      12  Annular Winding 
         [0047]      13  Back-iron ring 
         [0048]      14  Plastic shaped body 
         [0049]      15  Reception means for the conductor plate 
         [0050]      16  Conductor plate 
         [0051]      17  Reception means for cut clamp connector 
         [0052]      18  Cut clamp connector 
         [0053]      19  Rib-like area 
         [0054]      20  Motor housing 
         [0055]      21  Ribs 
         [0056]      22  Turbine pump impeller 
         [0057]      23  Pump housing 
         [0058]      24  Pump intake 
         [0059]      25  Pressure connections 
         [0060]      26 ,  26 ′ Partial stator core 
         [0061]      27  Recess 
         [0062]      28  Floor of separating can 
         [0063]      29  Axis 
         [0064]      30  Plug 
         [0065]      31  Conductor plate