Patent Publication Number: US-2023155437-A1

Title: Drive equipment for an electric vehicle, and vehicle

Description:
The present invention relates to a drive equipment for an electric vehicle, having: a stator which is configured for generating a magnetic rotating field and has: a stator core which extends along a longitudinal axis and in which a multiplicity of slots disposed in the circumferential direction are configured, and a stator winding which occupies a plurality of winding zones in the slots, wherein each winding zone in a cross-sectional plane that is perpendicular to the longitudinal axis by way of a centric radial division is sub-divided into a first side and into a second side; and a converter equipment for converting magnetic energy of the rotating field into a rotating output movement of the drive equipment, wherein the converter equipment has a rotor which conjointly with the stator forms a rotating electric machine such that the rotor is able to be set in a rotating rotor movement which, as a function of the rotating field, selectively has one of two opposite rotation directions, and has a transmission portion which is configured for transmitting rotating rotor movements to the rotating output movement. 
     In addition, the invention relates to a vehicle. 
     JP 5 935 587 B2 discloses an electric machine and a gearbox which are disposed in a parallel-hybrid vehicle. The electric machine has a stator having a stator core and a stator winding as well as a rotor. 
     In electrically driven vehicles, an ideally smooth delivery of torque, i.e., a delivery of torque with as few ripples as possible, is desirable in order to achieve a positive NVH (noise, vibration, harshness) behaviour. This can be achieved in particular by way of minor torque ripples and minor parasitic forces in an electric machine of the drive equipment. In the case of stator windings of a stator of the electric machine, a required number of windings are to be disposed symmetrically, with a minor winding overhang, and so as to be easy to connect and in a production-friendly manner with a view to au-tomated production with a high level of process reliability, in a stator core of the stator. 
     The invention is based on the object to configure an option for driving a vehicle with minor torque ripples. 
     In a drive equipment of the type mentioned at the outset, this object is achieved according to the invention in that the converter equipment has one of the two rotation directions of the rotating rotor movement as the preferred rotation direction, wherein the second side along the preferred rotation direction succeeds the first side and each winding zone on the first side occupies a smaller cross-sectional area of the slots than on the second side. 
     The drive equipment according to the invention has a stator. The stator is configured for generating a magnetic rotating field. The stator has a stator core. The stator core extends along a longitudinal axis. A multiplicity of slots are configured in the stator core. The slots are disposed in the circumferential direction. The stator furthermore has stator windings. The stator winding occupies a plurality of winding zones in the slots. Each winding zone in a cross-sectional plane by way of a centric radial division is subdivided into a first side and into a second side. The cross-sectional plane is perpendicular to the longitudinal axis. The drive equipment furthermore has a converter equipment for converting magnetic energy of the rotating field into a rotating output movement of the drive equipment. The converter equipment has a rotor. The rotor conjointly with the stator forms a rotating electric machine such that the rotor is able to be set in a rotating rotor movement. The rotating rotor movement, as a function of the rotating field, selectively has one of two opposite rotation directions. The converter equipment furthermore has a transmission portion. The transmission portion is configured for transmitting the rotating rotor movement to the rotating output movement. The converter equipment furthermore has one of the two rotation directions of the rotating rotor movement as the preferred rotation direction. The second side along the preferred rotation direction succeeds the first side. Each winding zone on the first side occupies a smaller cross-sectional area of the slots than on the second side. 
     The invention is based on the concept that in the case of the winding zones being occupied in a non-uniform manner, a more favourable NVH behaviour is achieved in one rotation direction than along the other rotation direction of the rotating rotor movement. The invention exploits this concept in that the occupation of the winding zones is chosen according to the preferred rotation direction of the drive equipment. Achieved as a result is low torque ripple, this enabling particularly smooth running of the electric machine, while at the same time the stator winding is symmetrically disposed in the slots. 
     The stator core is typically configured from a multiplicity of individual sheets which are disposed in a stack and/or mutually isolated. To this extent, the stator core can also be referred to as laminated stator core. The cross-sectional plane is defined in particular by the radial direction and the circumferential direction. The radial division runs in particular on a plane that is defined by the longitudinal axis and the radial direction. The stator core typically has an end side and a further end side that lies opposite the end side. 
     The rotor can be permanently excited or not permanently excited. The rotor can be separately excited. The rotor can be magnetically excited or voltage-excited. The transmission portion is in particular also configured for converting the rotating rotor movement into the rotating output movement. The rotation directions of the rotating rotor movement can also be un-derstood to be orientations of the rotating rotor movement so that the preferred rotation direction corresponds to a preferred orientation. 
     Each winding zone preferably extends across at least two slots, particularly preferably across at least three slots, or at least four slots. Portions of the stator winding that are associated with the same phase of the electric machine are typically disposed in each winding zone. 
     The division can run through the [(x+1)/2] th  slot of a respective winding zone when x is odd, and run so as to be centric between the (x/2) th  and the [(x/2)+1] th  slot of a respective winding zone when x is even, x describing the number of slots occupied by a respective winding zone. 
     The preferred rotation direction can be predefined in various ways. In general, a presence of the preferred rotation direction of the rotating rotor movement can initiate the vehicle to travel forward, and a presence of the other rotation direction of the rotating rotor movement can initiate the vehicle to travel in reverse. 
     It is possible for an efficiency of the transmission portion in the preferred rotation direction to be higher than in the other rotation direction. In other words, the transmission portion can be configured in such a manner that the transmission of the rotating rotor movement to the rotating output movement in the presence of the preferred rotation direction is more efficient than in the presence of the other rotation direction of the rotating rotor movement. For example, mechanical losses of the transmission portion are less in the presence of the preferred rotation direction than in the presence of the other rotation direction. 
     It can also be provided that the transmission portion has a gearbox having an asymmetrical design embodiment that determines the preferred rotation direction. For example, a respective tooth of mutually meshing gear wheels of the gearbox can thus be of an asymmetrical configuration. 
     The drive equipment can furthermore have a control equipment for the transmission portion, which for the preferred rotation direction has a larger number of selectable operating modes than for the other one of the rotation directions. A larger number of operating modes can thus be provided for forward travel than for travel in reverse. 
     It is also possible for the drive equipment to have a ventilation equipment which in the preferred rotation direction has a higher cooling efficiency than in the other one of the rotation directions. For example, the higher cooling efficiency can be derived from the position of an air intake, the latter in the presence of the preferred rotation direction receiving headwind. 
     The stator winding in the drive equipment according to the invention can be configured as a round-wire winding. 
     Alternatively, the stator winding can be configured as a shaped conductor winding, in particular as a hairpin winding. The stator winding in a shaped conductor winding is configured, in particular, by a multiplicity of shaped conductors which configure a current path, or a plurality of current paths, for a current which for generating the rotating field passes through the stator winding. The shaped conductors can be configured from a metal rod and/or have a rectangular or radiused rectangular cross section. Each part, or one part, of the shaped conductor preferably has two straight portions which extend in the axial direction within a respective slot. The straight portions can be connected to one another by a coil end portion on the first end side of the stator core. Each straight portion on the further end side of the stator core can be adjoined by an end portion. The straight portions are preferably configured so as to be integral to the coil end portion and/or to the end portions. The end portions of two respective shaped conductors are preferably mechanically connected to one another in an electrically conductive and materially integral manner, in particular by welding, so as to configure the stator winding. Moreover, one part of the shaped conductors, in particular for connecting the stator winding to a phase connector and/or to one or a plurality of neutral points provided shaped conductor, can have a straight portion, a connector portion on the first end side, and an end portion on the further end side. 
     In the drive equipment according to the invention it is preferable that the stator winding has a number of N strands and a number of 2·P poles, and the number of slots is 2·P·N·q, where q≥2, and each winding zone extends across at least q+1 of the slots, where P, N and q are natural numbers. q can also be referred to as the hole count, or the number of slots for each pole and phase, respectively. Each winding zone is preferably radially subdivided into first to L th  tiers which are designated according to their sequence in the radial direction, wherein the tiers configure first to (L/2) th  double tiers, wherein the double tier comprises the (2i−1) th  and the (2i) th  tier for all 1≤i≤(L/2), where L≥6 and is even, where L and i are natural numbers. The number of the tiers can be 6, 8, 10, 12, 14 or 16. In a design embodiment of the stator winding as a hairpin winding, a straight portion of one of the shaped conductors can be disposed in each tier. 
     A number of the double tiers, being less than the number of the other double tiers, is preferably displaced by at least one slot counter to the preferred rotation direction in relation to the other double tiers counter to the preferred rotation direction. Such a disposal of the double tiers may also be referred to as a non-uniform pitch of the stator winding. It can be achieved as a result that each winding zone of the first side occupies the smaller cross-sectional area than on the second side. In particular, a radially outer double tier, a radially inner double tier or a radially central double tier may be displaced. 
     It can moreover be provided that each winding zone in the circumferential direction is subdivided into first to q th  sub-winding zones which comprise in each case all tiers and are designated according to their sequence in the circumferential direction, wherein the stator winding for a respective strand has a phase winding, wherein the phase winding comprises at least one sub-winding which forms a current path and comprises internal portions that are disposed within the slots, and connection portions that are disposed on end sides of the stator core and in each case connect in an electrically conductive manner two internal portions which are directly successive in terms of the current path. The internal portions can be configured by the straight portions of the shaped conductors. The connection portions on the first end side can be configured by the end coil portions of the shaped conductors. The connection portions on the further end side can be configured by the connected end portions of two different shaped conductors. 
     The stator winding can have a neutral point. The at least one sub-winding of a respective strand can be wired so as to form the neutral point. The stator winding can also have two neutral points and a plurality of sub-windings for each strand. In this instance, one of the sub-windings of a respective strand can be wired so as to form one of the neutral points, and another one of the sub-windings of a respective strand can be wired so as to form the other of the neutral points, 
     According to a first variant of design embodiment, the sub-winding can comprise a plurality of conductor sequences of successive internal portions in terms of the current path, wherein each conductor sequence is disposed in one of the double tiers and forms a full encirclement of the stator core. In this way, a wave winding can be configured as a stator winding. 
     It is also preferable for first to L/2 th  of the conductor sequences to run in each case along a circumferential direction, in particular along the preferred rotation direction, wherein [(L/2)+1] th  to L th  of the conductor sequences run in each case along a further circumferential direction that is counter to the circumferential direction. As a result, the wave winding can be wound in the opposite direction. 
     In a refinement it can be provided that each conductor sequence which directly succeeds another conductor sequence in terms of the current path is disposed in a different sub-winding zone than the other conductor sequence 
     In the first variant of design embodiment it is furthermore preferable for a further sub-winding, which corresponds to the sub-winding, to be provided, wherein a respective internal portion of the further sub-winding that lies in the same tier of the same winding zone as an internal portion of the sub-winding, is disposed in a different sub-winding zone than the sub-winding zone in which the internal portion of the sub-winding lies. To this extent, the sub-winding can also be referred to as the first sub-winding, and the further sub-winding can be referred to as the second sub-winding. 
     A second and a third variant of design embodiment will be described hereunder. 
     In order for a combined lap/wave winding to be formed in the second and the third variant of design embodiment, it can be provided that one of the at least one sub-winding comprises a set of first to P th  conductor sequences of the first type that are successive in the sequence of their designation in terms of the current path and are in each case disposed in first to fourth directly adjacent winding zones for the same strand. Each conductor sequence of the first type preferably comprises first to (L/2) th  pairs of one first of the internal portions and one second of the internal portions, and the pairs are designated according to their sequence along the current path. The first and second internal portions can be disposed in different tiers of the same double tier. It is preferable here for the first pair to be disposed in the first double tier, wherein the second pair is disposed in the (L/2) th  double tier, wherein the third pair is disposed in the second double tier, or the third to (L/2) th  pairs are disposed in the second to [(L/2)-1] th  double tier. The third winding zone, in which the internal portions of the first to (P−1) th  conductor sequences are disposed, can be the first winding zone in which the conductor sequence that succeeds the conductor sequence in terms of the current path is disposed. The fourth winding zone in which the internal portions of the first to (P−1) th  conductor sequences are disposed, can be the second winding zone in which the conductor sequence that succeeds the conductor sequence in terms of the current path is disposed. This sub-winding can also be referred to as the first sub-winding. 
     In the second and the third variant of design embodiment it can alternatively or additionally be provided that one of the at least one sub-winding comprises a set of first to P th  conductor sequences of the second type that are successive in the sequence of their designation in terms of the current path and are in each case disposed in two directly adjacent winding zones for the same strand. It is preferably provided that each conductor sequence of the second type comprises first to (L/2) th  pairs of one first of the internal portions and one second of the internal portions, and the pairs are designated according to their sequence along the current path. The first and the second internal portions here can be disposed in different tiers of the double tier corresponding to the designation of the pair. It is preferably provided that the first to (P−1) th  conductor sequences of the second type by way of one of the connection portions are connected to the conductor sequence of the second type that is successive along the current path, and the succeeding conductor sequence of the second type is disposed in two directly adjacent winding zones for the same strand. This sub-winding can also be referred to as the second sub-winding. 
     The sub-windings preferably run about the stator core in opposite circumferential directions. 
     In the second variant of design embodiment it can be provided that the first internal portion of the pairs of the conductor sequences of the or of a respective sub-winding is disposed in one of the tiers of the double tier, and the second internal portion of the pairs of the conductor sequences of the or of a respective sub-winding is disposed in the other one of the tiers of the double tier. 
     In the third variant of design embodiment, the first internal portion of the pairs of the conductor sequences with an odd-numbered designation of the or of a respective sub-winding can be disposed in one of the tiers of the double tier, the second internal portion of the pairs of the conductor sequences with an odd-numbered designation of the or of a respective sub-winding can be disposed in the other tier of the double tier, the first internal portion of the pairs of the conductor sequences with an even-numbered designation of the or of a respective sub-winding can be disposed in the other tier of the double tier, and the second internal portion of the pairs of the conductor sequences with an even-numbered designation of the or of a respective sub-winding can be disposed in the one tier of the double tier. 
     In a preferred design embodiment it can furthermore be provided that the or a respective sub-winding comprises in total q sets of the conductor sequences which are in each case disposed in the same sub-winding zone, wherein each set that directly succeeds another set of the same sub-winding in terms of the current path, is disposed in a different sub-winding zone than the other set. 
     The object on which the invention is based is furthermore achieved by a vehicle comprising a drive equipment according to the invention, which is configured for driving the vehicle. 
     The preferred rotation direction can also be an installed position of the drive equipment in a vehicle body. The rotating output movement preferably acts on an axle and/or on wheels of the vehicle. 
     A winding zone contains only portions of the stator winding of the same strand, i.e. U. V, or W. 
     A winding zone in the circumferential direction can extend across a specific number of slots. Said winding zone in terms of these slots can be divided in a radially centric manner in the circumferential direction. These parts can be identified as a first and a second sub-winding zone. 
     Further advantages and details of the present invention can be derived from the exemplary embodiments described below and by means of the drawings. The latter are schematic illustrations in which: 
    
    
     
         FIG.  1    shows a schematic diagram of an exemplary embodiment of the vehicle according to the invention, having a first exemplary embodiment of the drive equipment according to the invention; 
         FIG.  2    shows a perspective view of the stator of the drive equipment according to the first exemplary embodiment; 
         FIG.  3    shows a schematic diagram of the stator winding disposed in the stator core, according to the first exemplary embodiment; 
         FIG.  4    shows a schematic diagram of a winding zone in the slots, according to the first exemplary embodiment; 
         FIG.  5    shows a block circuit diagram of the stator winding according to the first exemplary embodiment; 
         FIG.  6    shows a winding diagram of a phase of the stator winding according to the first exemplary embodiment; 
         FIG.  7    shows a block circuit diagram of the stator winding according to a second exemplary embodiment of the drive equipment according to the invention; 
         FIG.  8    shows a winding diagram of a phase of the stator winding according to the second exemplary embodiment; 
         FIG.  9    shows a block circuit diagram of the stator winding according to a third exemplary embodiment of the drive equipment according to the invention; and 
         FIG.  10    shows a winding diagram of a phase of the stator winding according to the third exemplary embodiment. 
         FIG.  1    shows a schematic diagram of an exemplary embodiment of a vehicle  1  having a first exemplary embodiment of a drive equipment  2 . 
     
    
    
     The drive equipment  2  has a stator  3  which is configured for generating a magnetic rotating field. The drive equipment  2  furthermore has a converter equipment  4  for converting magnetic energy of the rotating field into a rotating output movement  5  of the drive equipment  2 . 
     The converter equipment  4  has a rotor  6  which conjointly with the stator  3  forms a rotating electric machine  7  such that the rotor  6  is able to be set in a rotating rotor movement  8 . The converter equipment  4  moreover has a transmission portion  9  which is configured for transmitting and converting the rotating rotor movement  8  to the rotating output movement  5 . 
     The transmission portion  9  has one of the two rotation directions of the rotating rotor movement  8  as the preferred rotation direction  10 . The latter results in particular from an efficiency of the transmission portion  9  in the preferred rotation direction  10  being higher than in the other one of the rotation directions. Accordingly, the transmission portion  9  is configured in such a manner, for example, that the transmission of the rotating rotor movement  8  to the rotating output movement  5  in the presence of the preferred rotation direction  10  is more efficient than in the presence of the other rotation direction of the rotating rotor movement  8 . 
     The preferred rotation direction  10  can also result from the transmission portion  7  having a gearbox  11  having an asymmetrical design embodiment that determines the preferred rotation direction  9  To this end, a respective tooth of mutually meshing gear wheels  12  of the gearbox  11  can be of an asymmetrical configuration, for example. Likewise, the preferred rotation direction  10  can also result from the drive equipment  2  having a control equipment  13  for the transmission portion  9 , which for the preferred rotation direction  10  has a larger number of selectable operating modes than for the other one of the rotation directions. A larger number of operating modes can thus be provided for the forward travel than for the travel in reverse of the vehicle  1 . Furthermore, the preferred rotation direction  10  can also result from the drive equipment  2  having a ventilation equipment  14  which in the preferred rotation direction  10  has a higher cooling efficiency than in the other one of the rotation directions. Moreover, the preferred rotation direction  10  can also be a result of an installed position of the drive equipment  2  in the vehicle  1 . 
     As is furthermore shown in  FIG.  1   , the rotating rotor movement  8  by way of a shaft  15  of the drive equipment  2  acts on the transmission portion  9 . The rotating output movement  5  by way of an axle  16  of the vehicle  1  acts on the wheels  17  of the latter. 
       FIG.  2    shows a perspective view of the stator  3  of the drive equipment  2  according to the first exemplary embodiment. 
     The stator  3  has a stator core  20  which extends along a longitudinal axis  21  and in which a multiplicity of slots  22  disposed in the circumferential direction are configured. The stator core  20  in an exemplary manner here surrounds a receptacle space  23  for the rotor  6  (see  FIG.  1   ) and has a first end side  24  and a second end side  25  that lies opposite said first end side  24 . Moreover, the stator  3  has a stator winding  26 . 
       FIG.  3    shows a schematic diagram of the stator winding  26  disposed in the stator core  20 . 
     The stator winding occupies a plurality of winding zones  27  in the slots  22 . Each winding zone here in a cross-sectional plane, which corresponds to the plane of the drawing in  FIG.  3   , that is perpendicular to the longitudinal axis  21  (see  FIG.  2   ), by a centric radial division  28  is subdivided into a first side  29  and into a second side  30 . In the present exemplary embodiment, each winding zone  27  in an exemplary manner extends across three slots  22  such that the division  28  runs so as to be centric through the second of the three slots  22  of the winding zone  27 . 
     The second side  30  along the preferred rotation direction  10  is successive to the first side  29 . As can be seen, each winding zone  27  on the first side  29  occupies a smaller cross-sectional area of the slots  22  than on the second side  30 . 
     It can furthermore be seen in  FIG.  3    that the stator winding  26  has N=3 strands U, V, W for a respective phase of the electric machine  7  (see  FIG.  1   ). Each winding zone  27  contains only proportions of the stator winding  26  of the same strand U, V, W. A hole count q of the stator winding  26  in the present exemplary embodiment is two. Each winding zone  27  presently extends across a number of slots  22 , said number being q+1. Moreover, each winding zone  27  is sub-divided into first to q th  sub-winding zones  31   a ,  31   b , specifically into a first sub-winding zone  31   a  and into a second sub-winding zone  31   b.    
       FIG.  4    shows a schematic diagram of a winding zone  27  in the slots  22 . 
     Each winding zone  27 , which in  FIG.  3    is identified by a hatched area, is radially sub-divided into first to sixth (L th ) tiers, the latter being designated according to their sequence in the radial direction from radially outside to radially inside. The tiers  32   a - f  form first to third [(L/2) th ] double tiers  33   a - d , wherein the i th  double tier comprises the (2i−1) th  and the (2i) th  tier for all 1≤i≤(L/2). Accordingly, the first double tier  33   a  comprises the first tier  32   a  and the second tier  32   b , the second double tier  33   b  comprises the third tier  32   c  and the fourth tier  32   d , and the third double tier  33   c  comprises the fifth tier  32   e  and the sixth tier  32   f . A double tier  33   a , presently the radially outer-most double tier  33   a , is displaced by a slot  22  counter to the preferred rotation direction  10  in relation to the other double tiers  33   b ,  33   c  counter to the preferred rotation direction. 
       FIG.  5    shows a block circuit diagram of the stator winding  26  according to the first exemplary embodiment. 
     The stator winding  23  for each strand U, V, W has a phase winding  34   u ,  34   v ,  34   w . Each phase winding  34   u ,  34   v ,  34   w  comprises a first sub-winding  35   a  and a second sub-winding  35   b , which in each case configure a current path. Each sub-winding  35   a ,  35   b  comprises a number of conductor sequences  36   a - f  which correspond to the number of layers L and are connected in series. 
     Each phase winding  34   u ,  34   v ,  34   w  is connected to a phase connector  37 . The phase windings  34   u ,  34   v ,  34   w  are furthermore wired so as to form two neutral points  38   a ,  38   b , wherein the first sub-windings  35   a  are wired so as to form the first neutral point  38   a , and the second sub-windings  35   b  are wired so as to form the second neutral point  38   b . The phase connectors  37  and the neutral points  38   a ,  38   b  are also illustrated in  FIG.  2   . 
       FIG.  6    shows a winding diagram of a phase U of the stator winding  26  according to the first exemplary embodiment; 
     The stator winding  26  has 2·P=10 poles, N=3 phases and a hole count q=2. The number of slots  22  is 2·P·N·q=60. A slot numbering from 1 to 60 is indicated in  FIG.  6   . Each sub-winding  35   a ,  35   b  comprises the internal portions  39  that are disposed within the slots  22 , and connection portions  40 ,  41  that are disposed on the end sides  24 ,  25  of the stator core  20  (cf.  FIG.  2   ), and connect in each case in an electrically conductive manner two directly successive internal portions  39  in terms of the current path. The connection portions  40  here are situated on the second end side  25 , and the connection portions  41  are situated on the first end side  24 . The connection portions  40  are illustrated by solid lines, and the connection portions  41  are illustrated by dashed lines, in  FIG.  6   . 
     The stator winding  26  is configured as a wave winding. The conductor sequences  36   a - f  are in each case configured by a plurality of successive internal portions  39  that are connected in series by connection portions  40 ,  41  In the first exemplary embodiment, each conductor sequence  36   a - f  forms a complete encirclement about the stator core  20  in the circumferential direction. The first to third (L/2 th ) conductor sequences  36   a - c  here run in each case along the preferred rotation direction  10 , and the fourth to sixth conductor sequences  36   c - f  run in each case counter to the first to third conductor sequences  36   a - c , thus counter to the preferred rotation direction  10 . Each conductor sequence  36   a - f  is disposed in one of the double tiers  33   a -c. Each conductor sequence  36   b - f  which directly succeeds another conductor sequence  36   a - e  in terms of the current path, is disposed in a different sub-winding zone  31   a ,  31   b  than the other conductor sequence  36   a - e . The conductor sequences  36   a - f  as a result are disposed in an alternating manner in different sub-winding zones  31   a ,  31   b.    
     The second sub-winding  35   b  to this extent corresponds to the first sub-winding  35   a . In the second sub-winding  35   b , a respective internal portion  39  which lies in the same tier  32   a - f  of the same winding zone  27  as an internal portion  39  of the first sub-winding  35   a , is disposed in a different sub-winding zone  31   a ,  31   b  than the sub-winding zone  31   a ,  31   b  in which the internal portion  39  of the first sub-winding  35   a  lies. 
     In both sub-windings  35   a ,  35   b  the internal portions  39 , which are connected directly by a connection portion  40 ,  41  and are associated with the same conductor sequence  36   a - f , are mutually spaced apart by q·N=6 slots. 
     In the first sub-winding  35   a , the internal portion  39  of the first conductor sequence  36   a  and the internal portion  39  of the second conductor sequence  36   b , which is connected directly to the former by a connection portion  41 , are mutually spaced apart by q·N=6 slots. The internal portion  39  of the second conductor sequence  36   b  and the internal portion  39  of the third conductor sequence  36   c , which is connected directly to the former by a connection portion  41 , are mutually spaced apart by q·N+1=7 slots. The internal portion  39  of the third conductor sequence  36   c  and the internal portion  39  of the fourth conductor sequence  36   d , which is connected directly to the former by a connection portion  41 , are mutually spaced apart by q·N−1=5 slots. The internal portion  39  of the fourth conductor sequence  36   d  and the internal portion  39  of the fifth conductor sequence  36   e , which is connected directly to the former by a connection portion  41 , are mutually spaced apart by q·N−1=5 slots. The internal portion  39  of the fifth conductor sequence  36   e  and the internal portion  39  of the sixth conductor sequence  36   f , which is connected directly to the former by a connection portion  41 , are mutually spaced apart by q·N+2=8 slots. 
     In the second sub-winding  35   b , the internal portion  39  of the first conductor sequence  36   a  and the internal portion  39  of the second conductor sequence  36   b , which is connected directly to the former by a connection portion  41 , are mutually spaced apart by q·N+2=8 slots. The internal portion  39  of the second conductor sequence  36   b  and the internal portion  39  of the third conductor sequence  36   c , which is connected directly to the former by a connection portion  41 , are mutually spaced apart by q·N−1=5 slots. The internal portion  39  of the third conductor sequence  36   c  and the internal portion  39  of the fourth conductor sequence  36   d , which is connected directly to the former by a connection portion  41 , are mutually spaced apart by q·N+1=7 slots. The internal portion  39  of the fourth conductor sequence  36   d  and the internal portion  39  of the fifth conductor sequence  36   e , which is connected directly to the former by a connection portion  41 , are mutually spaced apart by q·N+1=7 slots. The internal portion  39  of the fifth conductor sequence  36   e  and the internal portion  39  of the sixth conductor sequence  36   f , which is connected directly to the former by a connection portion  41 , are mutually spaced apart by q·N=6 slots. 
     As can furthermore be derived from  FIG.  6   , the first conductor sequences  36   a  of the sub-windings  35   a ,  35   b  are connected to the phase connector  37 . The sixth conductor sequences  36   f  of the sub-windings  35   a ,  35   b  are connected to the neutral points  38   a ,  38   b , wherein the sixth conductor sequence  36   f  of the first sub-winding  35   a  here is connected to the first neutral point  38   a , and the sixth conductor sequence  36   f  of the second sub-winding  35   b  is connected to the second neutral point  38   b.    
     The phase windings  34   v ,  34   w  of the strands V, W correspond to the previously described phase winding  34   u  of the strand U, and are disposed in relation to the strand U so as to be displaced by q·N=6 slots in the circumferential direction. 
     With reference to  FIG.  2   , the stator winding  26  by way of a multiplicity of shaped conductors  42  is configured as a hairpin winding. The shaped conductors  42  are configured from a metal rod and have a rectangular or radiused rectangular cross section. One part of the shaped conductors  42  has two straight portions  43 ,  44  which extend in the axial direction within a respective slot  22  and configure the internal portions  39 . The straight portions  43 ,  44  on a first end side  24  of the stator core  20  are connected to one another by way of an end coil portion  45 , the latter configuring the connection portion  40   b . The end coil portion  45  is configured so as to be integral to the straight portions  43 ,  44 . On a second end side  25  of the stator core  20 , each straight portion  43 ,  44  is adjoined by an end portion  46 . The end portions  46  of two respective shaped conductors  42  are mechanically connected to one another in electrically conductive and materially integral manner, in particular by welding. Two end portions  46  that are connected to one another configure a connection portion  40   a  on the second end side  25 . The shaped conductors, which are not illustrated in detail and are connected to one of the phase connectors  37 , or one of the neutral points  38   a ,  38   b , respectively, have only one straight portion and one end portion, the latter conjointly with the end portion  46  of a shaped conductor that has two straight portions  43 ,  44  configuring a connection portion  40   a  on the second end side  25 . 
       FIG.  7    shows a block circuit diagram of the stator winding  26  according to a second exemplary embodiment of the drive equipment  2 . With the exception of the variances described hereunder, all embodiments pertaining to the further exemplary embodiment can be applied to the second exemplary embodiment. Identical or functionally equivalent components are provided with identical reference signs. 
     In the second exemplary embodiment, the stator winding  26  is a combined wave/lap winding. The stator winding  26  comprises the first sub-winding  35   a  of a respective phase winding  34   u ,  34   v ,  34   w  a first set  50   a  of first to fourth (P th ) conductor sequences of the first type  51   a - d  that are successive in the sequence of their designation in terms of the current path. Moreover, the first sub-winding  35   a  comprises a second set  50   b  of first to fourth (P th ) conductor sequences of the first type  51   a - d.    
     The second sub-winding  35   b  of a respective phase winding  34   u ,  34   v ,  34   w  comprises a first set  52   a  of first to fourth (P th ) conductor sequences of the second type  53   a - d  that are successive in the sequence of their designation in terms of the current path. Moreover, the second sub-winding  35   b  comprises a second set  52   b  of first to fourth (P th ) conductor sequences of the second type  53   a - d.    
     The number of sets  50   a ,  50   b ,  52   a ,  52   b  of a respective sub-winding  35   a ,  35   b  here corresponds to the hole count q. 
       FIG.  8    shows a winding diagram of a phase U of the stator winding  26  according to the second exemplary embodiment. 
     The stator winding  26  according to the second exemplary embodiment has 2-P=8 poles, and accordingly has 48 slots  22 . 
     Each conductor sequence of the first type  51   a - d  is disposed in first to fourth directly adjacent winding zones  27   a - d  for the same strand U, and comprises first to third [(L/2) th ] pairs  54   a - c  of one first internal portion  39   a  and one second internal portion  39   b . The pairs  54   a - c  are designated according to their sequence along the current path. 
     The first internal portions  39   a  and the second internal portions  39   b  are disposed in different tiers  32   a - f  of the same double tier  33   a - c . The first pair  54   a  is disposed in the first double tier  33   a , the second pair  54   b  is disposed in the third [(L/2) th ] double tier  33   c , and the third pair  54   c  is disposed in the second double tier  33   b . In general terms, the third to (L/2) th  pairs are disposed in the second to [(L/2)-1] th  double tier. 
     The third winding zone  27   c , in which the internal portions  39   a ,  39   b  of the first to third conductor sequences of the first type  51   a - c  [(P−1) th ] are disposed, is the first winding zone  27   a  in which the conductor sequence  51   b - d  which succeeds the conductor sequence of the first type  51   a - c  in terms of the current path is disposed Accordingly, the fourth winding zone  27   d , in which the internal portions  39   a ,  39   b  of the first to third [(P−1) th ] conductor sequences of the first type  51   a - c  are disposed, is the second winding zone  27   b  in which the conductor sequence of the first type  51   b - d , which succeeds the conductor sequence of the first type  51   a - c  in terms of the current path, is disposed. 
     Each conductor sequence of the second type  53   a - d  is disposed in two directly adjacent winding zones  27   e ,  27   f  for the same strand U, and comprises first to third [(L/2) th ] pairs  54   d - f  of one first internal portion  39   c  and one second internal portion  39   d  The pairs  54   d - c  are designated according to their sequence along the current path. 
     The first and second internal portions  39   c ,  39   d  are disposed in different tiers  32   a - f  of the double tier  33   a - c , the latter corresponding to the designation of the pair  54   d - f . The first to third [(P−1) th ] conductor sequences of the second type  53   a - c  by way of one of the connection portions  40   b  are connected to the conductor sequence of the second type  53   b - d  which succeeds along the current path. The succeeding conductor sequence of the second type  53   b - d  is disposed in two directly adjacent winding zones  27  for the same strand U. 
     The first and second sub-windings  35   a ,  35   b  run about the stator core  20  in opposite circumferential directions, wherein the second sub-winding  35   b  runs along the preferred rotation direction  10 . 
     In the second exemplary embodiment, the first internal portion  39   a ,  39   c  of the pairs  54   a - f  is disposed in one of the tiers  32   a - f  of the double tier  33   a - c , and the second internal portion  39   b ,  39   d  of the pairs  54   a - f  is disposed in the other tier  32   a - f  of the double tier. 
       FIG.  9    shows a block circuit diagram of the stator winding  26  according to a third exemplary embodiment of the drive equipment  2 . With the exception of the variances described hereunder, all embodiments pertaining to the second exemplary embodiment can be applied to the third exemplary embodiment. Identical or functionally equivalent components are provided with identical reference signs. 
     In the third exemplary embodiment, the first sub-winding  35   a  additionally has a third set  50   c  of conductor sequences of the first type  51   a - d , and the second sub-winding  35   b  additionally has a third set  52   c  of conductor sequences of the second type  53   a - d , wherein the conductor sequences  51   a - d ,  53   a - d  are not illustrated for the sake of clarity in  FIG.  9   . 
       FIG.  10    shows a winding diagram of a phase U of the stator winding  26  according to the third exemplary embodiment. 
     The stator winding  26  according to the third exemplary embodiment, like the second exemplary embodiment, has 2·P=8 poles, but a hole count q=3. Accordingly, the number of slots  22  is 72. It can be derived from the increase in the hole count q that each of the third sets  50   c ,  52   c  are provided. 
     In the third exemplary embodiment, the first internal portion  39   a ,  39   c  of the pairs  54   a ,  54   c ,  54   d ,  54   f  with an odd-numbered designation of the conductor sequences  51   a - d ,  53   a - d  of a respective sub-winding  35   a ,  35   b  is disposed in one of the tiers  32   a - f  of the double tier  33   a - c , and the second internal portion  39   b ,  39   d  of the pairs  54   a ,  54   c ,  54   d ,  54   f  with an odd-numbered designation of the conductor sequences  51   a - d ,  53   a - d  of a respective sub-winding  35   a ,  35   b  is disposed in the other tier of the double tier  33   a - c . The first internal portion  39   a ,  39   c  of the pairs  54   b ,  54   e  with an even-numbered designation of the conductor sequences  51   a - d ,  53   a - d  of a respective sub-winding  35   a ,  35   b  is disposed in the other tier  39   b ,  39   d  of the double tier  33   a - c , and the second internal portion  39   b ,  39   d  of the pairs  54 ,  54   e  with an even-numbered designation of the conductor sequences  51   a - d ,  53   a - d  of a respective sub-winding  35   a ,  35   b  is disposed in the one tier  32   a - f  of the double tier  33   a - c.    
     In the third exemplary embodiment, the second double tier  33   b  in relation to the first double tier  33   a  and the third double tier  33   c  is moreover displaced counter to the preferred rotation direction  10 . 
     According to further exemplary embodiments, which correspond in each case to one of the previously described exemplary embodiments, the stator winding  26  is not configured as a hairpin winding but as a round-wire winding. 
     According to further exemplary embodiments, which correspond in each case to one of the previously described exemplary embodiments, the number of poles is larger or smaller, the number of conductor sequences being correspondingly increased or reduced. 
     According to further exemplary embodiments, which correspond in each case to one of the previously described exemplary embodiments, the stator winding  26  has only one neutral point for all sub-windings  35   a ,  35   b.