Electric Drive Unit, Hybrid Drive Device, And Vehicle

Abstract

An electric drive unit for a hybrid drive, in particular for a vehicle, has an increased power output and degree of efficiency, while thermal loading as well as required installation space and manufacturing costs are minimized. The electric drive unit has an asynchronous machine with a rotor with a rotor cage, in particular a rotor cage which is formed with copper conductors. The asynchronous machine is formed with a stator having a shaft winding. The shaft winding is formed with a device for star-delta changeover. The rotor is formed with a rotor internal cooling device. A step-up gear mechanism is arranged in a power train between the rotor and the output element. There is also described a hybrid drive device with an electric drive unit, and a vehicle that has an electric drive unit and/or a hybrid drive device.

Claims

1-9. (canceled)

10. An electric drive unit, comprising: an output element for outputting mechanical energy that is generated in the electric drive unit; an asynchronous machine having a rotor formed with a squirrel cage and having a stator fitted with a wave winding; said wave winding being configured with a device for performing a star-delta switching function; said rotor having a rotor interior cooling device; and a transmission gearing arranged in a force flow between said rotor and said output element.

11. The electric drive unit according to claim 10, wherein said squirrel cage is configured with copper conductors.

12. The electric drive unit according to claim 10, configured for a vehicle having an electric drive system or a hybrid drive system.

13. The electric drive unit according to claim 10, wherein said transmission gearing comprises a planetary gear.

14. The electric drive unit according to claim 13, wherein said planetary gear is configured for a dual-shaft operation with an epicyclic transmission.

15. The electric drive unit according to claim 14, wherein said planetary gear has a transmission ratio between 1:1.5 and 1:2.

16. The electric drive unit according to claim 10, which comprises a cooling medium and/or lubricant chamber for said rotor, and wherein said transmission gearing is disposed in or in close vicinity to said cooling medium and/or lubricant chamber.

17. The electric drive unit according to claim 10, wherein said rotor comprises: a rotor carrier having a supporting region that extends substantially in an axial and circumferential direction of said rotor; an arrangement of magnetic regions disposed on said supporting region and configured with a laminated stack and said squirrel cage; and at least one cooling medium duct between said arrangement of magnetic regions and said rotor carrier and encompassed by said rotor interior cooling device.

18. The electric drive unit according to claim 17, wherein said at least one cooling medium duct of said rotor interior cooling device is configured to conduct a flow of a cooling medium and/or a lubricant for cooling and/or lubricating at least said rotor.

19. The electric drive unit according to claim 10, wherein said device for implementing the star-delta switching function comprises: an open multiphase system of said asynchronous machine formed with a predetermined number of phases and open windings; said asynchronous machine having a given number of first connectors and a given number second connectors, wherein the given number is equal to the predetermined number of phases of said asynchronous machine; a circuit arrangement for supplying said asynchronous machine with a multiphase voltage, said circuit arrangement having the predetermined number of phases from an energy source that is configured to deliver a first direct current voltage; said circuit arrangement having a first inverter stage for supplying said first connectors of said asynchronous machine from said energy source and a second inverter stage for supplying said second connectors of said asynchronous machine from said energy source by way of at least one switching element so as to selectively obtain a second direct current voltage from the first direct current voltage of said energy source and to deliver the second direct current voltage to said second inverter stage; and wherein said first inverter stage and said second inverter stage are configured to selectively connect said first and second connectors of said asynchronous machine to form a star connection or a delta connection so as to supply power to said asynchronous machine.

20. A hybrid drive device, comprising: at least one electric drive unit according to claim 10; at least one internal combustion engine; and at least one clutch device for selectively connecting and disconnecting a force flow between said internal combustion engine and said output element of said at least one electric drive unit.

21. A vehicle, comprising an electric drive unit according to claim 10.

22. The vehicle according to claim 21, which further comprises an internal combustion engine and a clutch device for selectively connecting and disconnecting a force flow between said internal combustion engine and said output element of said electric drive unit.

Description

SHORT DESCRIPTION OF THE DRAWINGS

[0028] In the drawing, corresponding elements in all figures are provided with identical reference numerals and a repeated description of these elements is omitted. In the drawing:

[0029] FIG. 1 illustrates a simplified schematic view of a drive train of a motor vehicle having a hybrid drive device that is fitted with an electric drive unit, as is used in the prior art,

[0030] FIG. 2 illustrates a simplified schematic view of an exemplary embodiment of a drive train of a motor vehicle having a hybrid drive device that is fitted with an electric drive unit in accordance with the invention,

[0031] FIG. 3 illustrates a simplified schematic view of one half of a longitudinal section through an electric drive unit in accordance with the invention and used in a drive train of a motor vehicle having a hybrid drive device,

[0032] FIG. 4 illustrates a simplified schematic view of a winding schema for an example of a wave winding, and

[0033] FIG. 5 illustrates a simplified schematic circuit diagram of an example of a device for performing the star-delta switching function, as said device is used in an exemplary embodiment of the electric drive unit in accordance with the invention.

[0034] The configurations that are illustrated in the drawing are further described hereinunder and in particular of said configurations the exemplary embodiments of the invention are described.

PREFERRED EMBODIMENT OF THE INVENTION

[0035] FIG. 1 illustrates a simplified schematic view of a drive train of a motor vehicle having a hybrid drive device 301 and said drive train is referred to with the reference numeral 300. The drive train 300 comprises the hybrid drive device 301 that is fitted with an electric drive unit 302, as is used in the prior art. Furthermore, the hybrid drive device 301 comprises an internal combustion engine 303 and a first clutch device 304 that is used to selectively connect and/or disconnect a force flow between the internal combustion engine 303 and an output element 305 of the electric drive unit 302. The electric drive unit 302 is configured with a stator 306 and a rotor 307. The rotor 307 is in particular configured with an arrangement of magnetic regions that is however not illustrated in detail in FIG. 1, said arrangement of magnetic regions having at least one permanent magnet and being connected in a non-positive locking manner to the output element 305. In particular, the output element 305 is formed with a rotor shaft of the rotor 307. The force flow can be guided from the output element 305 to a double clutch transmission 311 by way of a double clutch 308 that comprises a second clutch device 309 and a third clutch device 310, and in fact in particular said force flow can be guided by way of the second clutch device 309 to a first input shaft 312 of the double clutch transmission 311 and by way of the third clutch device 310 to a second input shaft 313 of the double clutch transmission 311. The force flow can be further guided from an output shaft 314 of the double clutch transmission 311 by way of a differential transmission 315 to drive wheels 316 of the motor vehicle.

[0036] FIG. 2 illustrates, based on the configuration according to FIG. 1, in a simplified schematic manner an exemplary embodiment of a drive train 103 of a motor vehicle 102 having a hybrid drive device 101 that is fitted with an exemplary embodiment of an electric drive unit 100 in accordance with the invention. The electric drive unit 100 is configured with an asynchronous machine 104 that is indicated in a symbolic longitudinal illustration, said asynchronous machine having a rotor 105 that comprises a squirrel cage that is in particular configured with copper conductors. Moreover, this asynchronous machine 104 comprises a stator 106 that is configured with a wave winding 107 having in particular open windings, in other words open winding ends. The asynchronous machine 104 consequently represents an open multiphase system that comprises a predetermined number of phases, said multiphase system having open windings. The two winding ends of each of the windings or winding strings for each phase of the asynchronous machine 104 can be supplied independently of one another by way of a multi-conductor cable 109 by means of a circuit arrangement 108 for supplying the asynchronous machine 104 from an energy source (not illustrated) that is essentially configured so as to deliver a first direct current, and the number of wires of said multi-conductor cable corresponds to the total number of winding ends of the wave winding 107. It is also possible using the circuit arrangement 108 during operation to implement a star-delta switching function of the wave winding 107 of the asynchronous machine 104.

[0037] The rotor 105 of the asynchronous machine 104 is configured with a rotor interior cooling device 109 that is indicated in FIG. 2 symbolically by means of a cooling medium duct that is tube-shaped and is encompassed in the rotor interior cooling device 109. It is possible for a cooling medium to be guided through the cooling medium duct, arrow 110 symbolizes this cooling medium flow. Thermal energy that occurs during operation of the asynchronous machine 104 is dissipated by the rotor cooling device 109 from the interior of the rotor 105.

[0038] The electric drive unit 100 of the hybrid drive device 101 comprises an output element 112 that can be coupled by way of the first clutch device 304 to the internal combustion engine 303 so as to selectively connect and/or disconnect a force flow between the internal combustion engine 303 and the output element 112. The force flow can be guided from the output element 112 back to the double clutch transmission 311 by way of the double clutch 308 having the second clutch device 309 and the third clutch device 310, and in fact as in the case of the configuration according to FIG. 1 in particular selectively by way of the second clutch device 309 to the first input shaft 312 of the double clutch transmission 311 and by way of the third clutch device 310 to the second input shaft 313 of the double clutch transmission 311. In contrast to the configuration according to FIG. 1 in the case of the arrangement according to FIG. 2 however a transmission gearing 113 is arranged in a force flow between the rotor 105 and the output element 112, said transmission gearing being indicated symbolically in FIG. 2. The transmission gearing 113 is advantageously configured and arranged coaxially with respect to the rotor 105 and the output element 112. It is preferred that the transmission gearing 113 is configured as a planetary gear for a dual-shaft operation having an epicyclic transmission, wherein the planetary gear comprises a transmission ratio of in particular 1:1.5 to 1:2 by which transmission ratio the rotational speed of the rotor 105 is higher than the rotational speed of the output element 112 and thereby both the internal combustion engine as well as the first and the second input shaft 312, 313.

[0039] FIG. 3 illustrates a simplified schematic view of a half of a longitudinal section, said half being created along an axis of rotation 114, through the exemplary embodiment of the electric drive unit 100 in accordance with the invention according to FIG. 2, used in the drive train 103 of the motor vehicle 102 having the hybrid drive device 101. An example for more precise details of a spatial arrangement of the individual construction elements or assemblies of the electric drive unit 100 are indicated in a simplified schematic manner. An input hub 115 that can rotate about the axis of rotation is on the one hand connected in a non-positive locking manner to the internal combustion engine 303 that is not illustrated in FIG. 3 for simplicity, in particular the crankshaft of said internal combustion engine, and on the other hand is connected in a non-positive locking manner to an inner multiplate set of the first clutch device 304 that is configured with a multiplate clutch. The output element 112 is configured with a hollow shaft-type bearing region 116 and is mounted in bearings 117 in a drive housing 118 so as to be able to rotate about the axis of rotation 114. Moreover, the output element 112 is configured with a clutch supporting region 119 in which said output element is connected in a non-positive locking manner to each outer multiplate set of each of the first 304, the second 309 and the third 310 clutch device. An inner multiplate set of the second clutch device 309 is connected in a non-positive locking manner to the first input shaft 312, and an inner multiplate set of the third clutch device 310 is connected in a non-positive locking manner to the second input shaft 313 that comprises the first input shaft 312 in a hollow shaft manner, wherein both the first input shaft 312 as well as also the second input shaft 313 are arranged so as to be able to rotate about the axis of rotation 114.

[0040] The rotor 105 of the asynchronous machine 104 comprises a rotor carrier 120 having a supporting region 121 that extends essentially in the axial and circumferential direction of the rotor 105, and said rotor comprises an arrangement of magnetic regions 122 that is arranged on the supporting region 121 and is configured with a laminated stack and the squirrel cage. The rotor 105 furthermore comprises at least one cooling medium duct 123 that is at least in part provided and/or configured between the arrangement of magnetic regions 122 and the rotor carrier 120, said cooling medium duct being encompassed by the rotor cooling device 110. In particular, the at least one cooling medium duct 123 is arranged along a delimiting surface, along which the arrangement of magnetic regions 122 sits on the supporting region 121 at least in part in a non-positive locking and positive locking manner. It is preferred that the arrangement of magnetic regions 122 is configured as a hollow-cylindrical shape and is mounted by means of for example interference fit on the delimiting surface that forms a cylindrical surface of the supporting region 121, said surface being coaxial with respect to the axis of rotation 114. The at least one cooling medium duct 123 is then formed by means of recesses that are formed in an axial and/or tangential and/or helical manner along the delimiting surface in the supporting region 121 and/or the arrangement of magnetic regions 122. FIG. 3 illustrates in a symbolic manner a cooling medium duct 123 that is aligned axially along the delimiting surface. Moreover, the rotor carrier 120 comprises a bearing region 124 that is configured as coaxial with respect to the axis of rotation 114 and said rotor carrier is mounted in said bearing region by way of a bearing 125 in the drive housing 118 so as to be able to rotate about the axis of rotation 114.

[0041] The transmission gearing 113 is arranged in the force flow between the rotor carrier 120 and the output element 112 of the electric drive unit 100. In addition thereto, a sun wheel 126 that is provided with outer teething is connected coaxially with respect to the axis of rotation 114 in a non-positive locking manner to the drive housing 118 and is fixed to said drive housing. A ring gear 127 of the transmission gearing 113 is connected in a non-positive locking manner to the bearing region 124 of the rotor carrier 120 and consequently can rotate together with the rotor carrier 120 about an axis of rotation 114. The ring gear 127 consequently rotates with the rotor 105. At least one planet gear 128 of the transmission gearing 113 is in engagement with both the sun wheel 126 as well as with the ring gear 127. The at least one planet gear 128 is mounted on the output element 112 in such a manner that said planet gear can rotate about a respective planet gear axis 129 in such a manner that said planet gear can rotate with the output element 112 about the axis of rotation 114. It is possible by means of this arrangement to achieve a transmission ratio between the rotational speeds of the rotor 105 and output element 112 in which case the rotor rotates more rapidly than the output element. It is preferred that the sun wheel 126 and ring gear 127 are dimensioned in such a manner that a transmission ratio of 1:1.5 to 1:1.2 is produced.

[0042] The transmission gearing 113 is arranged in accordance with FIG. 3 in the interior of the rotor carrier 120 in a cooling medium and/or lubricant chamber that is provided at that location, in particular an oil chamber 130, of the hybrid drive device 101. The cooling medium and/or lubricant chamber, in particular oil chamber 130, is configured so as to receive an intended supply of cooling medium and/or lubricant, in particular an oil. Cooling medium and/or lubricant ducts are arranged starting from the cooling medium and/or lubricant chamber, in particular oil chamber 130 and the cooling medium and/or lubricant, in particular oil, is conveyed in said ducts from the cooling medium and/or lubricant chamber, in particular oil chamber 130, into a single or multi-circuit cooling medium and/or lubricant circulation, in particular an oil circulation. This cooling medium and/or lubricant circulation, in particular oil circulation, is symbolically indicated in FIG. 3 by means of arrows; the cooling medium flow 111 in the at least one cooling medium duct 123 of the rotor interior cooling device 110 is also associated with said cooling medium and/or lubricant circulation. In detail, the arrows 131 describe a cooling medium and/or lubricant circulation, in particular oil circulation, for cooling and/or lubricating the double clutch 308 having the second clutch device 309 and the third clutch device 310, the arrows 132 describe a cooling medium and/or a lubricant circulation, in particular oil circulation, for cooling and/or lubricating the first clutch device 304, the arrows 133 describe a cooling medium and/or lubricant circulation, in particular oil circulation, for cooling and/or lubricating the bearing 117, the arrows 134 describe a cooling medium and/or lubricant circulation, in particular oil circulation, for cooling and/or lubricating the bearing 125 and also for cooling an air gap 138 between the rotor 105 and stator 106 of the asynchronous machine 104, the arrows 135 describe a cooling medium and/or lubricant circulation, in particular oil circulation, for cooling winding heads of the wave winding 107 of the stator 106 and the arrows 136 describe a cooling medium and/or lubricant circulation, in particular oil circulation, for cooling the stator 106 by way of cooling medium grooves and/or lubricant grooves 139 on the stator outer periphery. In particular, at least one part current of the cooling medium and/or lubricant circulation, in particular oil circulation 132, is guided through the first clutch device 304 as a cooling medium flow 111 into the at least one cooling medium duct 123 of the rotor interior cooling device 110. The transmission gearing 113 is cooled and/or lubricated directly from the cooling medium and/or lubricant chamber, in particular oil chamber, 130. The arrow 137 symbolizes a cooling medium return flow and/or lubricant return flow, in particular oil return flow, to the cooling medium and/or lubricant chamber, in particular oil chamber, 130. It is preferred in particular that the first input shaft 312 for the cooling medium and/or lubricant circulation, in particular oil circulating system, 132 and 133 is configured with a hole in the manner of a hollow shaft.

[0043] It is also possible using the above-mentioned cooling medium and/or lubricant circulations in the case of a high power density in the described hybrid drive device to keep the thermal load on the individual elements and/or assemblies low. By way of example, a so-called ATF—“automatic transmission fluid”—that can withstand temperatures up to a maximum 150° C. is used as a cooling medium or lubricant. The result of this is that when operating a hybrid drive device that is configured in accordance with the invention a cooling medium temperature and/or lubricant temperature of approximately 90° C. can be maintained, in other words not exceeded, depending on operating conditions for in particular the rotor 105 and the clutch devices 304, 309, 310. A particularly effective cooling procedure is achieved, in particular of the rotor 105 that without the described measures for cooling would have developed much higher temperatures. A reliable and stable and safe operation is thereby ensured by means of the invention.

[0044] FIG. 5 illustrates a simplified schematic circuit diagram of an example for the circuit arrangement 108 for supplying the asynchronous machine 104 having a device for performing the star-delta switching function as said device is used in the above-described exemplary embodiment of the electric drive unit 100 in accordance with the invention. In addition thereto, FIG. 4 illustrates a simplified schematic illustration of a section of a winding arrangement that is configured in a known manner for an example of a wave winding to clarify a possible construction of the wave winding 107. A winding arrangement of this type is for example known from the monograph of Müller/Ponick: “Berechnung Elektrischer Maschinen” [Commutation of electric machines]. The conductors of the wave winding are always guided in the circumferential direction of the rotor from a stator groove to a next stator groove without returning as in the case of a loop winding, as a result of which in particular particularly space-saving winding heads can be achieved. In the case of the wave winding according to FIG. 4, the stator grooves are numbered through 1, 2, 3, . . . and for example a conductor is placed one after the other in a first, seventh, thirteenth etc. stator groove.

[0045] The circuit arrangement 108 is configured so as to supply power to the asynchronous machine 104 and is configured as a device for performing the star-delta switching function of the asynchronous machine 104. The asynchronous machine 104 forms an open multiphase system that comprises a predetermined number of phases, in particular a three-phase system. In accordance with the present invention, the wave winding 107 of the stator 106 that is connected to the device for performing the star-delta switching function is configured with open windings whose connectors form the first U, V, W and second X, Y, Z connectors of the asynchronous machine 104. In FIGS. 2 and 3, the first U, V, W and second X, Y, Z connectors of the asynchronous machine 104 are combined to form the multi-conductor cable 109. An energy source (not illustrated) that is essentially configured so as to deliver a first direct current voltage is preferably formed by means of a traction battery of a vehicle, a fuel cell or the like and can be connected using connectors P and N. The circuit arrangement 108 generates from the first direct current voltage a multiphase voltage that comprises the predetermined number of phases and supplies with said multiphase voltage the asynchronous machine 104 at its first U, V, W and second X, Y, Z connectors. For this purpose, the circuit arrangement 108 comprises a first inverter stage of semiconductor switches Q11, Q12, Q13, Q14, Q15, Q16, in this case transistors having non-return diodes, for supplying from the energy source the number of the first connectors U, V, W of the asynchronous machine 104, said number of phases corresponding to the predetermined number of phases, in this case the number of phases is 3. Moreover, a second inverter stage of semiconductor switches Q21, Q22, Q23, Q24, Q25, Q26, likewise in this case transistors having non-return diodes, is provided to supply the number of second connectors X, Y, Z of the asynchronous machine 104 with a second direct current, said number of second connectors X, Y, Z corresponding to the predetermined number of phases. This second direct current can be obtained from a second, independent energy source. However, it is preferred that in the exemplary embodiment according to FIG. 5 two switching elements V1, V2 are provided so as to selectively obtain the second direct current voltage from the first direct current voltage of the energy source at the connectors P, N and to deliver said second direct current voltage that is obtained from the first direct current voltage of the energy source to the second inverter stage Q21, Q22, Q23, Q24, Q25, Q26. The first inverter stage Q11, Q12, Q13, Q14, Q15, Q16 and the second inverter stage Q21, Q22, Q23, Q24, Q25, Q26 are configured so as to selectively connect the first U, V, W and the second X, Y, Z connectors of the asynchronous machine 104 to form a star connection or a delta connection for the purpose of supplying the asynchronous machine 104.

[0046] The invention renders possible the construction of a compact and high-performance hybrid drive device 101 that owing to its compact construction can be used in a particularly flexible manner. In particular, a longitudinal or transverse installation position is possible in a vehicle 102, in other words with a position of the axis of rotation 114 in a longitudinal or a transverse direction of the vehicle 102 without the associated installation space limitations for the hybrid drive device 101 causing noticeable limitations in the performance capability of the hybrid drive device 101.

LIST OF REFERENCE NUMERALS

[0047] 100 Electric drive unit [0048] 101 Hybrid drive device [0049] 102 Motor vehicle [0050] 103 Drive train [0051] 104 Asynchronous machine [0052] 105 Rotor of 104 [0053] 106 Stator of 104 [0054] 107 Wave winding of 104 [0055] 108 Circuit arrangement for supplying power to 104 [0056] 109 Multi-conductor cable for supplying power to 107 from 108 [0057] 110 Rotor interior cooling device [0058] 111 Arrows, symbolizing cooling medium flow in 110 [0059] 112 Output element of 100 [0060] 113 Transmission gearing [0061] 114 Axis of rotation [0062] 115 Input hub [0063] 116 Bearing region of 112 [0064] 117 Bearing [0065] 118 Drive housing [0066] 119 Clutch supporting region of 112 [0067] 120 Rotor carrier of 105 [0068] 121 Supporting region of 120 [0069] 122 Arrangement of magnetic regions of 105 [0070] 123 Cooling medium duct [0071] 124 Bearing region of 120 [0072] 125 Bearing [0073] 126 Sun wheel of 113 [0074] 127 Ring gear of 113 [0075] 128 Planet gear of 113 [0076] 129 Planet gear axis of 113 [0077] 130 Cooling medium and/or lubricant chamber, in particular oil chamber [0078] 131 Arrows: cooling medium and/or lubricant circulation, in particular oil circulation, for 308 [0079] 132 Arrows: cooling medium and/or lubricant circulation, in particular oil circulation, for 304 [0080] 133 Arrows: medium and/or lubricant circulation, in particular oil circulation, for 117 [0081] 134 Arrows: cooling medium and/or lubricant circulation, in particular oil circulation, for 125, 138 [0082] 135 Arrows: cooling medium and/or lubricant circulation, in particular oil circulation, for winding heads of 107 [0083] 136 Arrows: cooling medium and/or lubricant circulation, in particular oil circulation, for 139 of 106 [0084] 137 Arrow: cooling medium return flow and/or lubricant return flow, in particular oil return flow, to 130 [0085] 138 Air gap [0086] 139 Cooling medium grooves and/or lubricant grooves of 106 [0087] 300 Drive train [0088] 301 Hybrid drive device [0089] 302 Electric drive unit (prior art) [0090] 303 Internal combustion engine [0091] 304 First clutch device [0092] 305 Output element of 302 [0093] 306 Stator of 302 [0094] 307 Rotor of 302 [0095] 308 Double clutch [0096] 309 Second clutch device of 308 [0097] 310 Third clutch device of 308 [0098] 311 Double clutch transmission [0099] 312 First input shaft [0100] 313 Second input shaft [0101] 314 Output shaft [0102] 315 Differential transmission [0103] 316 Drive wheels [0104] N Connector of 108 [0105] P Connector of 108 [0106] Q11 Semiconductor switch of the first inverter stage [0107] Q12 Semiconductor switch of the first inverter stage [0108] Q13 Semiconductor switch of the first inverter stage [0109] Q14 Semiconductor switch of the first inverter stage [0110] Q15 Semiconductor switch of the first inverter stage [0111] Q16 Semiconductor switch of the first inverter stage [0112] Q21 Semiconductor switch of the second inverter stage [0113] Q22 Semiconductor switch of the second inverter stage [0114] Q23 Semiconductor switch of the second inverter stage [0115] Q24 Semiconductor switch of the second inverter stage [0116] Q25 Semiconductor switch of the second inverter stage [0117] Q26 Semiconductor switch of the second inverter stage [0118] V1 Switching element [0119] V2 Switching element [0120] U First connector of 104 [0121] V First connector of 104 [0122] W First connector of 104 [0123] X Second connector of 104 [0124] Y Second connector of 104 [0125] Z Second connector of 104