Abstract
The present disclosure relates to an electromechanical apparatus (100) and to a transmission unit comprising the electro-mechanical apparatus (100) for changing motion parameters and to a vehicle comprising the transmission unit, the electro-mechanical apparatus (100) comprising a first rotating electromechanical ma-chine (110) comprising a first stator (112) and a first rotor (120), a second rotating electromechanical machine (130) having a smaller radial extension than the first rotating electromechanical machine (110) and comprising a second stator (132) and a second rotor (140), wherein the second rotating electromechanical ma-chine (130) is arranged radially within the first rotating electromechanical ma-chine (110) thereby forming an interleaving region (176) of the electromechanical apparatus (100), and wherein the first stator (112) and the second stator (132) are ironless, and wherein the first rotor (120) and the second rotor (140) are per-manent-magnet rotors or rotors comprising a winding for electrical excitation.
Claims
1. An electromechanical apparatus for changing motion parameters, the electromechanical apparatus comprising: a. a first rotating electromechanical machine comprising a first stator and a first rotor, which is arranged to be rotatable with respect to a common axis of rotation, b. a second rotating electromechanical machine having a smaller radial extension than the first rotating electromechanical machine and comprising a second stator and a second rotor, which is arranged to be rotatable with respect to the common axis of rotation, wherein the second rotating electromechanical machine is arranged radially within the first rotating electromechanical machine thereby forming an interleaving region of the electromechanical apparatus, wherein the first stator and the second stator are ironless, thereby having no material of high magnetic permeability inside or extending into a region of its coil, and wherein the first rotor is a permanent-magnet rotor or a rotor comprising a winding for electrical excitation, and wherein the second rotor is a permanent-magnet rotor or a rotor comprising a winding for electrical excitation.
2. The electromechanical apparatus according to claim 1, wherein the first rotating electromechanical machine and the second rotating electromechanical machine are designed as an internal rotor electromechanical machine, and wherein an input shaft, which is configured to be coupled to one of the first rotor or the second rotor, is arranged coaxially with respect to an output shaft, which is configured to be coupled to the other of the first rotor or the second rotor.
3. The electromechanical apparatus according to claim 1, wherein the first rotating electromechanical machine is designed as an internal rotor electromechanical machine and the second rotating electromechanical machine is designed as an external rotor electromechanical machine, and wherein an input shaft, which is configured to be coupled to one of the first rotor or the second rotor, is arranged eccentrically with respect to an output shaft, which is configured to be coupled to the other of the first rotor or the second rotor.
4. The electromechanical apparatus according to claim 2, wherein the input shaft is arranged on one axial end of the electromechanical apparatus, and the output shaft is arranged on the other opposing axial end of the electromechanical apparatus.
5. The electromechanical apparatus according to claim 2, wherein the electromechanical apparatus comprises a gear stage arranged between at least one of: the input shaft and the first rotor, the input shaft and the second rotor, the first rotor and the output shaft and the second rotor and the output shaft.
6. The electromechanical apparatus according to claim 1, wherein a. the first stator and the second stator comprise each a helical lamination stack of a helically wound strip of magnetically permeable material, having multiple turns, wherein the strip comprises two main surfaces and two side surfaces, wherein at least one of the two main surfaces comprises an insulation coating, and/or b. wherein the first rotor and the second rotor comprise each a helical lamination stack of a helically wound strip of magnetically permeable material, having multiple turns, wherein the strip comprises two main surfaces and two side surfaces, wherein at least one of the two main surfaces comprises an insulation coating.
7. The electromechanical apparatus according to claim 1, wherein a. the first stator and the second stator comprise each a continuous hairpin winding having at least two winding layers or comprise each a continuous wave winding having at least two winding layers, and b. wherein the first rotor comprises permanent magnets or a continuous hairpin winding having at least two winding layers or comprises a continuous wave winding having at least two winding layers, and c. wherein the second rotor comprises permanent magnets or a continuous hairpin winding having at least two winding layers or comprises a continuous wave winding having at least two winding layers.
8. The electromechanical apparatus according to claim 1, wherein the first rotating electromechanical machine has a first machine thickness from its maximum radial outer extension at the interleaving region to its minimum radial inner extension at the interleaving region in a range from 30 mm to 15 mm, preferably from 25 mm to 20 mm, more preferably of 22 mm.
9. The electromechanical apparatus according to claim 1, wherein the second rotating electromechanical machine has a second machine thickness from its maximum radial outer extension at the interleaving region to its minimum radial inner extension at the interleaving region in a range from 30 mm to 15 mm, preferably from 25 mm to 20 mm, more preferably of 22 mm.
10. The electromechanical apparatus according to claim 1, wherein the first rotating electromechanical machine has a maximum radial outer diameter at the interleaving region in a range from 100 mm to 1000 mm, preferably from 150 mm to 350 mm, more preferably of 300 mm.
11. The electromechanical apparatus according to claim 1, wherein a ring-shaped axially extending gap at the interleaving region between the first rotating electromechanical machine and the second electromechanical machine has a thickness of less than 10 mm, preferably of less than 5 mm, more preferably of 3 mm.
12. The electromechanical apparatus according to claim 1, wherein the electromechanical apparatus comprises at its first axial end a first bearing and at its second opposing axial end a second bearing, wherein the first bearing and the second bearing are arranged between two parts selected from a group consisting of: the first stator, the second stator, the first rotor and the second rotor.
13. The electromechanical apparatus according to claim 12, wherein a support of the first rotor (comprises: a. a first bearing arranged between the first stator and the first rotor on one axial end of the electromechanical apparatus, and b. a second bearing arranged between the second rotor and the first rotor on the other axial end of the electromechanical apparatus.
14. The electromechanical apparatus according to claim 12, wherein the support of the second rotor comprises: a. a first bearing arranged between the first stator and the second rotor on one axial end of the electromechanical apparatus, and b. a second bearing arranged between the second rotor and the first rotor on the other axial end of the electromechanical apparatus.
15. The electromechanical apparatus according to claim 1, wherein the first stator comprises a first stator shell, a first lamination stack and a first coil, and wherein the second stator comprises a second stator shell, a second lamination stack, and a second coil.
16. The electromechanical apparatus according to claim 1, wherein the material of the first stator and/or the second stator inside or extending into a region of its coil has a magnetic permeability of less than 300, preferably of less than 40.
17. A transmission unit for changing motion parameters, the transmission unit comprising: a. an electromechanical apparatus according to claim 1, b. an electrical component configured to receive electric current, generated during operation of the first or second rotating electromechanical machine, and configured to transmit electric current to the other of the first or second rotating electromechanical machine, to drive an output shaft, and c. a transmission unit battery connected to the electrical component and configured to store electrical power received from the electromechanical apparatus and configured to provide electrical power to the electromechanical apparatus, in particular to the rotating electromechanical machine configured to drive the output shaft.
18. The transmission unit according to claim 17, wherein the electrical component comprises a converter, which is configured to transform the received electric current having first electric properties, in particular a first AC frequency, to the desired electric current having second electric properties, in particular a second AC frequency, for the rotating electromechanical machine, configured to drive the output shaft.
19. The transmission unit according to claim 17, wherein the electrical component comprises a control unit for controlling the properties of the electric current transmitted to the first or second rotating electromechanical machine such that a desired transmission ratio, in particular continuously variable transmission ratio, between the first rotor and the second rotor is realized.
20. A vehicle comprising a transmission unit according to claim 17, wherein the vehicle further comprises: a. an internal combustion engine, which is configured to propel an input shaft of the electromechanical apparatus; b. a drive train, which is mechanically connected to an output shaft of the electromechanical apparatus and which is configured to propel the vehicle; and c. a vehicle battery, which is electrically connected to the electrical component and configured to store electrical power received from the electromechanical apparatus and configured to provide electrical power to the vehicle, in particular to the electromechanical apparatus.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0058] The present disclosure will be explained in more detail, by way of example, with reference to the drawings in which:
[0059] FIG. 1: shows schematically a longitudinal section view of an electromechanical apparatus according to a first embodiment of the present disclosure,
[0060] FIG. 2: shows schematically a cross section view in a radial plane of the electromechanical apparatus according to the first embodiment of the present disclosure,
[0061] FIG. 3: shows schematically a longitudinal section view of an electromechanical apparatus according to a second embodiment of the present disclosure,
[0062] FIG. 4: shows a side view of the electromechanical apparatus according to the second embodiment of the present disclosure,
[0063] FIG. 5: shows schematically in a perspective view a helical lamination stack according to a first exemplary embodiment,
[0064] FIG. 6: shows schematically in a perspective view an electromechanical apparatus according to an embodiment of the present disclosure with cut-away sections to show the interior of the apparatus,
[0065] FIG. 7: shows schematically in perspective view a cylindrical continuous hairpin winding according to a first exemplary embodiment,
[0066] FIG. 8: shows schematically a transmission unit comprising the electromechanical apparatus according to an exemplary embodiment,
[0067] FIG. 9: shows schematically a vehicle comprising the transmission unit according to an exemplary embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0068] FIG. 1 and FIG. 2 show schematically an electromechanical apparatus 100 according to a first exemplary embodiment. FIG. 1 shows a longitudinal section view and FIG. 2 shows a radial cross section view of the electromechanical apparatus 100. The electromechanical apparatus 100 comprises a first rotating electromechanical machine 110 and a second rotating electromechanical machine 130. The first rotating electromechanical machine 110 comprises a first stator 112 and a first rotor 130. The first stator 112 comprises a first stator shell 113, a first lamination stack 114, preferably comprising a first helical wound strip 115, and a first coil 116, preferably comprising a first continuous hairpin winding 117. The first rotor 120 comprises a first rotor shell 121 and first magnets 118. The second rotating electromechanical machine 130 comprises a second stator 132 and a second rotor 140. The second stator 132 comprises a second stator shell 133, a second lamination stack 134, preferably comprising a second helical wound strip 135, and a second coil 136, preferably comprising a second continuous hairpin winding 137. The second rotor 140 comprises a second rotor shell 141 and second magnets 138.
[0069] According to another embodiment (not shown in the figures), the first rotor comprises, instead of the first magnets 118, a winding for electrical excitation, the winding for electrical excitation is preferably a continuous hairpin winding. It is additionally preferred that the second rotor comprises, instead of the second magnets 138, a winding for electrical excitation, the winding for electrical excitation is preferably a continuous hairpin winding. In this embodiment, the first rotor and the second rotor may also comprise each a respective lamination stack comprising a helical wound strip.
[0070] The first rotating electromechanical machine 110 as best shown in the FIGS. 1, 2 and 3, in particular the first rotor 120, is configured to rotate during operation around a common axis of rotation 122. The second rotating electromechanical machine 130, in particular the second rotor 140, is configured to rotate during operation around the common axis of rotation 122. Further, the figures show that the first rotating electromechanical machine 110 and the second rotating electromechanical machine 130 are arranged interleavingly with respect to each other, thereby forming an interleaving region 176. The interleaving region 176 is the axial extension of the electromechanical apparatus 100, in which the first rotating electromechanical machine 110 and the second rotating electromechanical machine 130 overlap. Arranging the two rotating electromechanical machines 110, 130 coaxially and in interleaving manner reduces advantageously the required installation space. The figures further show that the second rotating electromechanical machine 130 is arranged entirely within the first rotating electromechanical machine 110.
[0071] The stators 112, 132 of the respective rotating electromechanical machines 110, 130, are configured to guide the magnetic field within the corresponding rotating electromechanical machine 110, 130. The stator shells 113, 133 are configured to function as the housing of the stators 112, 132 and hold the other parts of the stators 112, 132 in place during operation of the electromechanical apparatus 100. The stator shells 113, 133 may additionally comprise cooling means (not shown in the figures) for cooling the respective electromechanical machines 110, 130. The lamination stacks 114, 134, comprising the helical wound strip 115, 135, which are configured to reduce eddy currents and increase the efficiency of the rotating electromechanical machine 110, 130. The coils 116, 136 are configured to guide electric current trough the corresponding stator 112, 132. In the embodiments as presented in the Figures, the coils 116, 136 preferably comprise the continuous hairpin winding 117, 137.
[0072] The continuous hairpin winding 117, 137, as best shown in the FIGS. 6 and 7, have at least two layers 1171, 1172 comprising wires, which are hairpin-shaped and provide straight wire segments, which run in parallel to the common axis of rotation 122. Next to a first straight segment, on one or both ends of the straight segment, the wire is folded and bent such that a subsequent second straight segment runs anti-parallel at a distance to the first straight segment. The hairpin winding 117, 137 is continuous in that each hairpin wire section, defined by comprising one or two or few straight segments, is continuous, i.e. in one piece, with the next hairpin wire section. In particular, there is no necessity for electrical joins created by welding, soldering, or similar technique between the hairpin wire sections. However, the wires of the continuous hairpin winding 117, 137 may ultimately be joined by some welding or similar technique at their ends, e.g. for star-grounding or delta-connecting different phases of the continuous hairpin winding.
[0073] The continuous hairpin winding 117, 137 has two layers 1171, 1172 of hairpin wire one upon the other when seen in a radial direction. A given wire changes position, for example, from a first layer 1171 to a second layer 1172 or vice versa when seen around the continuous hairpin winding 117, 137 such that the first straight segment is arranged in the first layer 1171 and then is folded and bent such that the second or subsequent or next straight segment is arranged in the second layer 1172. The continuous hairpin winding 117, 137 or the continuous wave winding, according to this embodiment, function as coils 116, 136 for the corresponding rotating electromechanical machines 110, 130, which require relative little radial installation space, which helps to arrange the first and second rotating electromechanical machine 110, 130 coaxially and in an interleaving manner with respect to each other without the need for huge radial dimensions.
[0074] The first rotating electromechanical machine 110 is configured to work as an electric motor or as a generator. This depends on the required application of the electromechanical apparatus 100. The second rotating electromechanical machine 130 is also configured to work as an electric motor or as a generator, which depends on the required application of the electromechanical apparatus 100.
[0075] FIGS. 1 and 2 show a first variant of the electromechanical apparatus 100. In this variation, the first rotating electromechanical machine 110 and the second rotating electromechanical machine 130 are designed as internal rotor electromechanical machines. In other words, the respective rotors 120, 140 are arranged radially within the respective stators 112, 132. According to this embodiment, an input shaft 160 of the electromechanical apparatus 100 is integrally formed with the second rotor shell 141. Different couplings between the input shaft 160 and the second rotor shell 141 are also conceivable. An output shaft 170 of the electromechanical apparatus 100 is, according to this embodiment, integrally formed with the first rotor shell 121. Different couplings between the output shaft 170 and the first rotor shell 121 are also conceivable. The first output shaft 160 and the second output shaft 170 are arranged coaxially with respect to each other and with respect to the common axis of rotation 122.
[0076] FIG. 1 further shows the support concept 150 comprising different bearings of the first embodiment of the electromechanical apparatus 100. As it can be seen, all of the bearings are arranged relatively close to the common axis of rotation 122, which advantageously reduces rolling speeds of the bearings and therefore increases lifespans of the bearings. The bearings comprise first bearings 151, which are arranged on one axial end of the electromechanical apparatus 100, and second bearings 152, which are arranged on the other opposing axial end of the electromechanical apparatus 100. Having the bearings 151, 152 on both axial ends increases the stability and accuracy of rotation, which enables to have relatively high rotational speeds of the rotors 120, 140. According to this embodiment, all parts of the electromechanical apparatus 100 are connected rotatable via bearings concentric to the common axis of rotation 122, which increases stability, reduces vibration and out of balance enabling high torque and power output especially at high rotation speeds.
[0077] FIG. 1 shows as support 150 for the first rotor 120 one first bearing 151 arranged between the first rotor shell 121 and the first stator shell 113. In other words, the support 150 is the bearing concept. The first stator shell 113 is in this embodiment coupled to the second stator shell 133 and the first bearing 151 of the first rotor 120 is arranged at the coupling portion. FIG. 1 further shows one second bearing 152 arranged on the opposite axial end between the first stator shell 113 and the first rotor shell 121, in particular, the output shaft 170, which is according to this embodiment coupled to the first rotor shell 121.
[0078] FIG. 1 further shows as support 150 for the second rotor 140 one first bearing 151 arranged between the second rotor shell 141 and the first stator shell 121, in particular between the coupling portion of the first stator shell 121 and the second stator shell 133. One second bearing 152 is arranged on the opposite axial end of the electromechanical apparatus 100 between the second rotor shell 141 and the first rotor shell 121, in particular, the output shaft 170, which is according to this embodiment coupled to the first rotor shell 121.
[0079] FIG. 1 further shows an additional third bearing 153 arranged between the second stator shell 133 and the first rotor shell 121, in particular, the output shaft 170, for additionally or alternatively supporting the second stator shell 133 with respect to the first rotor shell 121.
[0080] FIG. 2 shows the cross section through the interleaving portion 176 of the variant as shown in FIG. 1. FIG. 2 shows advantageously the thickness of the different rotating electromechanical machines 110, 130. The first rotating electromechanical machine 110 has a first machine thickness 200 extending from the first stator shell 113 to the first rotor shell 121. The second rotating electromechanical machine 130 has a second machine thickness 201 extending from the second stator shell 133 to the second rotor shell 141. An axial extending gap 124 is arranged between the first rotating electromechanical machine 110 and the second rotating electromechanical machine 130. The electromechanical apparatus 100 has an overall thickness 202 extending from the first stator shell 113 to the second rotor shell 141. In other words, the overall thickness is the sum of the first machine thickness 200, the second machine thickness 201 and the axially extending gap 124. The FIGS. 1 and 2 further show a cavity 210 arranged radially within the interleaving portion 176. The cavity is a result of the radially compact electromechanical machines 110, 130. It demonstrates even without further calculations that this electromechanical apparatus 100 is of low weight, as a significant volume is empty and not filled with heavy metals.
[0081] FIGS. 3 and 4 show the second variation of the electromechanical apparatus 100. According to this embodiment, the first rotating electromechanical machine 110 is designed as internal rotor electromechanical machines, and the second rotating electromechanical machine 130 is designed as external rotor electromechanical machine. In other words, second rotor 140 is arranged radially outside of the second stator 132. According to this embodiment, an input shaft 160 of the electromechanical apparatus 100 is integrally formed with the first rotor shell 121. Different couplings between the input shaft 160 and the first rotor shell 121 are also conceivable. An output shaft 170 of the electromechanical apparatus 100 is, according to this embodiment, coupled with the second rotor shell 131 via a mechanical gear stage 180, in particular a spur gear stage. The first output shaft 160 and the second output shaft 170 are not arranged coaxially with respect to each other; instead, they have an axle offset with respect to each other. The gear stage 180 enables to modify the rotational properties between the second rotor 140 and the output shaft 170.
[0082] FIGS. 3 shows, that the second stator 132 of the second electromechanical machine 130 enters the electromechanical apparatus 100 at the center of one axial end. This second stator 132 is located inside of two rotors 120, 140, but is according to this embodiment immotile. The second stator 132 is configured to absorb the torque of the electromechanical apparatus 100 and is configured to provide access to electrical connectors and cooling, for example water-cooling. The output shaft 170 can therefore not exit the electromechanical apparatus 100 coaxially with respect to the common axis of rotation 122 as shown in FIG. 1, because the center is occupied by the second stator 132. This problem is overcome as disclosed by adding an eccentrically arranged gear stage 180. With the gear stage 180, the output shaft 170 is shifted away from the center as best shown in FIG. 4.
[0083] FIG. 3 further shows the support concept 150 comprising different bearings of the second embodiment of the electromechanical apparatus 100. As it can be seen, all of the bearings are arranged relatively close to the axis of rotation 122, 142, which advantageously reduces rolling speeds of the bearings and therefore increases lifespans of the bearings. The bearings comprise first bearings 151, which are arranged on one axial end of the electromechanical apparatus 100 and second bearings 152, which are arranged on the other opposing axial end of the electromechanical apparatus 100. Having the bearings 151, 152 on both axial ends increases the accuracy and stability of rotation, which enables to have relatively high rotational speeds.
[0084] FIG. 3 shows as support 150 for the first rotor 120 one first bearing 151 arranged between the first rotor shell 121 and the first stator shell 113. This first bearing 151 of the first rotor 120 is arranged on the input shaft 160, which is according to this embodiment coupled to the first rotor shell 121. FIG. 3 further shows one second bearing 152 arranged on the opposite axial end of the electromechanical apparatus 100 between the first rotor shell 121 and the second rotor shell 141.
[0085] FIG. 3 further shows as support 150 for the second rotor 140 one first bearing 151 arranged between the second rotor shell 141 and the second stator shell 133. One second bearing 152 is arranged on the opposite axial end of the electromechanical apparatus 100 between the second rotor shell 141 and the second stator shell 133.
[0086] FIG. 3 further shows a third bearing 153 arranged between the second stator shell 133 and the first rotor shell 121, in particular, the input shaft 160, for additionally or alternatively supporting the second stator shell 133 with respect to the first rotor shell 121. Similarly as shown in the embodiment of FIG. 1, the first stator 112, the second stator 132, the first rotor 120 and the second rotor 140 are all on both axial ends coupled by bearings concentric with respect to the common axis of rotation 122, which increases stability, reduces vibration level and coming out of balance, thereby enabling high torque and power output even at high rotation speeds.
[0087] FIG. 4 shows in a side view of the second embodiment the particularly advantageous offset of the output shaft 170 with respect to the common axis of rotation 122.
[0088] FIG. 5 shows a perspective view of the first or second lamination stack 114, 134 as used for example in the first or second rotating electromechanical machine 110, 130. The helical lamination stack 114, 134 is formed out of the helically wound strip 115, 135 of magnetically permeable material, e.g. an iron alloy. The strip 115, 135 preferably has a rectangular cross-section. Thus, the strip 115, 135 has two main surfaces 1151 and two side surfaces 1152. The main surfaces 1151 are arranged parallel to each other and form the surfaces with the largest extension in terms of area. The side surfaces 1152 are also arranged parallel to each other. Further, the side surfaces 1152 are arranged perpendicular to the main surfaces 1151 and connect the two main surfaces 1152 with each other. The main surfaces 1151 and the side surfaces 1152 define the mantle of the strip 115, 135. The thickness of the strip 115, 135 is the short extension between the side surfaces 1152. The width of the strip 115, 135 is the short extension between the main surfaces 1151. The other or long extension of the main surfaces 1151 and the side surfaces 1152 defines a length of the strip 115, 135. The strip 115, 135 is closed or concluded by two end surfaces, which form the tips of the strip 115, 135. FIG. 5 further shows the insulation coating 1153, which is arranged on at least one of the two main surfaces 1151. The insulation coating 1153 is configured to electrically insulate two neighboring main surfaces 1151 of different turns or windings of the helical lamination stack 114, 134. In another embodiment, the insulation coating 1153 is arranged at both main surfaces 1151. In an embodiment, the helical lamination stack 114, 134 forms a segment, which is, for example, arranged with other segments on the stator shells 113, 133.
[0089] In an embodiment, the helical lamination stack 114, 134 is a multiple geared lamination stack (not shown in FIG. 5). The multiple geared lamination stack is formed out of a plurality of helically wound strips 115, 135 having the same inclination angle or pitch angle. The different strips 115, 135 may have different thicknesses, may comprise different materials and/or may have different insulation coatings.
[0090] FIG. 6 shows schematically an electromechanical apparatus 100 according to an embodiment of the present disclosure with cut-away sections to show the interior of the electromechanical apparatus 100. FIG. 6 shows partially an embodiment of the first rotating electromechanical machine 110. FIG. 6 shows the first stator shell 113, the first lamination stack 114 with the first helical wound strip 115, the first coil 116, which comprises the first continuous hairpin winding 117, first magnets 118 arranged on the first rotor shell 121. In addition, the common axis of rotation 122 is shown. The first continuous hairpin winding 117 comprises the first winding layer 1171 and the second winding layer 1172. Within the first rotor shell 121, the second rotating electromechanical machine 130 is arranged (not shown in FIG. 6).
[0091] In this embodiment, the helical lamination stack 114 is connected with the first stator shell 113 via a permanent connection. The connection is, for example, formed via a form-fit, press-fit, force-fit or a chemical connection. The helical lamination stack 114 is, for example, press fitted, screwed, shrinked and/or glued into or on the first stator shell 113.
[0092] The continuous hairpin winding 117 can have two sets of three phase windings U1, V1, W1, U2, V2, W2, wherein a phase winding U1 of the first set and a corresponding phase winding U2 of the second set have the same electrical phase (and e.g. may be joined together, not shown in FIG. 7). The continuous hairpin winding 117 has input leads, comprising wires, for each of the phase windings U1, V1, W1, U2, V2, W2 in the same region of the electromechanical apparatus 100 such that electrical connection of the continuous hairpin winding 114 is efficient and uncomplicated. In particular, all input leads are within a common, preferably small, azimuthal angular region. An end of each phase winding U1, V1, W1, U2, V2, W2 is electrically joined to at least one other phase winding of the phase windings U1, V1, W1, U2, V2, W2, for example to form a star ground 24 or delta connection. The continuous hairpin winding 114 comprises straight segments extending parallel to the axis 122, bend segments, including an offset bend, and a folded segment.
[0093] As can be seen in FIG. 6, the first stator shell 113 forms part of an ironless stator of the rotating electromechanical machine 110. Specifically, the first helical lamination stack 114, the first stator shell 113 and the first hairpin windings 117 is comprised by the first ironless stator 112. The first continuous hairpin winding 117 is covered by the helical lamination stack 114 along its entire axial extension (i.e. its extension parallel to the rotation axis 122). The inner surface of the first helical lamination stack 114 is arranged adjacent to the first continuous hairpin windings 117 and holds the continuous hairpin windings 117 in position. The continuous hairpin windings 117 is entirely arranged within the first stator shell 113 and is thereby protected from mechanical damage, shocks, and contaminations.
[0094] The first stator 112 has advantageous small radial extensions and at the same time a high efficiency and is suitable for large industrial or automotive applications.
[0095] FIG. 7 shows schematically a cylindrical continuous hairpin winding 117, 137 according to a first exemplary embodiment as used, for example in the first or second rotating electromechanical machine 110, 130. As is shown, all the phase windings U1, V1, W1, U2, V2, W2 have input leads on the same side of the continuous hairpin winding 117, 137 and within the same relatively small azimuthal angular range, which is beneficial for electrically connecting the continuous hairpin winding, for example to a power source and/or a motor controller. Further, the opposite ends of the wires from the input leads are also in the same area, allowing for a star-ground or a delta connection between the phase windings U1, V1, W1, U2, V2, W2 to be easily formed. Each phase winding U1, V1, W1 of the first set and each corresponding phase winding of the second set U2, V2, W2 have the same phase. Such an optimally shaped continuous hairpin winding 117, 137 is required in particular for the electromechanical machine 110, 130 having a very small gap 124 between the continuous hairpin winding 117, 137 and the respective rotor 120, 140. Having a small gap is obviously advantageous for achieving a higher electromagnetic efficiency and in particular for embodiments where the electromechanical apparatus 100.
[0096] In an embodiment, the continuous hairpin winding 117, 137 can be potted with a curable potting material. A strong mechanical and thermal bond of the hairpin winding 117, 137 to the lamination stack 114, 134 is advantageous for the reliable transfer of the torque and to the optimal conduct of the heat. It further provides further structural support and increases the electrical insulation between the wires, and improves heat transport away from the wires.
[0097] FIG. 8 shows schematically a block diagram of a transmission unit 10 according to an exemplary embodiment. The transmission unit 10 comprises the electromechanical apparatus 100 with the first and second rotating electromechanical machine 110, 130 arranged coaxially and interleaving with respect to each other.
[0098] FIG. 8 further shows the input shaft 160 and the output shaft 170. The transmission unit 10 further comprises an electrical component 300 configured to receive electric current, generated during operation of the first or second rotating electromechanical machine 110, 130, and configured to transmit electric current to the other of the first or second rotating electromechanical machine 110, 130, to drive an output shaft 170. The electrical component 300 comprises, according to this embodiment, a converter 302, which is configured to transform the received electric current having first electric properties, in particular a first AC frequency, to the desired electric current having second electric properties, in particular a second AC frequency, for the rotating electromechanical machine 110, 130, configured to drive the output shaft 170 as desired.
[0099] The transmission unit 10, according to this embodiment, further comprises a control unit 304 for controlling the properties of the electric current transmitted to the first or second rotating electromechanical machine 110, 130 such that a desired transmission ratio between the first rotor 120 of the first rotating electromechanical machine 110 and the second rotor 140 of the second rotating electromechanical machine 130 is realized. The transmission ratio is, for example, the ratio of the rotational speed of the output shaft 170 to the rotational speed of the input shaft 160. The electrical component 300 is, according to this embodiment, configured to modify the properties of the electric current, which is transmitted to the rotating electromechanical machine 110, 130 working in engine mode, for example, by changing the frequency. The desired transmission ratio is, for example, determined by input parameters received by the control unit 304, and which are transformed by the control unit 304 into control commands for the electrical component 300.
[0100] The transmission unit 10 as shown in FIG. 8 further shows a transmission unit battery 303 configured to store and provide electric energy for the transmission unit 10. The transmission unit 10 is configured to transfer mechanical input energy received via the input shaft 160 of the electromechanical apparatus 100 into mechanical output energy transmitted via the output shaft 170 of the electromechanical apparatus 100 to different parts of a vehicle, like a drivetrain of the vehicle. The desired properties of the mechanical output energy can be realized by modifying of the electrical properties of the electric current, which is supplied to the rotating electromechanical machine 110, 130 of the electromechanical apparatus 100 working in engine mode.
[0101] The transmission unit battery 303, which is electrically connected with the electromechanical apparatus 100, can be configured such that at least a portion of the electric current, which is produced by the rotating electromechanical machine 110, 130 working in generator mode, is at least temporarily transferred to the transmission unit battery 303. Alternatively or in addition, the transmission unit battery 303 can further be configured such that at least a portion of the electric current, which is needed by the rotating electromechanical machine 110, 130 working in engine mode, is at least temporarily provided by the transmission unit battery 303. According to this embodiment, the transmission unit battery 303 is configured to work as an electric buffer for the transmission unit 10.
[0102] FIG. 9 shows schematically a vehicle 400 comprising the transmission unit 10 according to an exemplary embodiment. The vehicle 400 comprises additionally an internal combustion engine 401, a vehicle battery 402 and a drivetrain 403. The internal combustion engine 401 is according to this embodiment mechanically connected to the input shaft 160 of the transmission unit 10 and configured to drive the first or second rotating electromechanical machine 110, 130 working in generator mode. The output shaft 170 of the transmission unit 10 is mechanically connected to the drivetrain 403. The transmission unit 10 replaces for example a conventional gearbox. The transmission unit 10 may be installed in the vehicle 400 as replacement kit. In another embodiment, the transmission unit 10 is installed directly during manufacturing of the vehicle 400.
LIST OF REFERENCE SIGNS
[0103] 10 transmission unit [0104] 100 electromechanical apparatus [0105] 110 first rotating electromechanical machine [0106] 112 first stator [0107] 113 first stator shell [0108] 114 first lamination stack [0109] 115 helical wound strip [0110] 1151 main surface [0111] 1152 side surface [0112] 1153 insulation coating [0113] 116 first coil [0114] 117 first continuous hairpin winding [0115] 1171 first winding layer [0116] 1172 second winding layer [0117] 118 first magnets [0118] 120 first rotor [0119] 121 first rotor shell [0120] 122 common axis of rotation [0121] 124 axially extending gap [0122] 130 second rotating electromechanical machine [0123] 132 second stator [0124] 133 second stator shell [0125] 134 second lamination stack [0126] 135 second helical wound strip [0127] 136 second coil [0128] 137 second continuous hairpin winding [0129] 138 second magnets [0130] 140 second rotor [0131] 141 second rotor shell [0132] 150 support [0133] 151 first bearing [0134] 152 second bearing [0135] 153 third bearing [0136] 160 input shaft [0137] 170 output shaft [0138] 176 interleaving region [0139] 180 gear stage [0140] 200 first machine thickness [0141] 201 second machine thickness [0142] 202 overall thickness, radial thickness of electromechanical apparatus [0143] 210 cavity, hollow inner machine volume [0144] 300 electrical component [0145] 302 converter, AC-AC converter [0146] 303 transmission unit battery [0147] 304 control unit [0148] 400 vehicle [0149] 401 internal combustion engine [0150] 402 vehicle battery [0151] U1, U2, V1, V2, W1, W2 phase windings
