Electric drive device for a vehicle

Abstract

Electric drive device (1) for a vehicle (100), the electric drive device (1) comprising: – an electric machine (14) having a stator (15a) and a rotor (15b); – a main shaft arrangement (5) attached to the rotor (15b) in a torque-proof manner and extending along a main axis (6); – a link shaft (7) extending along a link axis (8); – a first housing part (2) having a jacket section (9) accommodating the electric machine (14), a first extended section (10) extending radially with regard to the main axis (6) away from the jacket section (9) on a first axial side (12) of the jacket section (9), a second extended section (11) extending radially with regard to the main axis (6) away from the jacket section (9) on a second axial side (13) of the jacket section (9), a first axial opening (23) forming a margin (24) of the jacket section (9) and the first extended section (10) on the first axial side (12) and a second axial opening (25) forming a margin (26) of the jacket section (9) and the second extended section (11) on the second axial side (13); – a second housing part (3) forming a drive end shield for the main shaft arrangement (5) and covering the first axial opening (23); – a third housing part (4) forming a non-drive end shield for the main shaft arrangement (5) and covering the second axial opening (25); and – a gearbox (16) configured to transmit a rotating movement of the main shaft arrangement (5) to the link shaft (7) and being accommodated in the jacket section (9), the first extended section (10) and in the second housing part (4); wherein the first housing part (2) further comprises a stiffening section (30), which extends axially with regard to the link axis (9) from the first extended section (10) to the second extended section (11) and which projects radially beyond the link shaft (7).

Description

[0001] Electric drive device for a vehicle

[0002] The present invention relates to an electric drive device for a vehicle.

[0003] EP 3 530 987 A1 discloses an integrated drive system for a vehicle comprising an electric machine and a gearbox. The electric machine and the gearbox are arranged in a multi-part housing. Further, the arrangement comprises a shaft attached to a rotor of the electric machine and a side shaft coupled with the gearbox.

[0004] Electric drive devices for a vehicle with a main shaft arrangement and a link shaft coupled by a gearbox to the main shaft arrangement can be arranged in a housing formed by multiple housing parts. Typically, the link shaft extends in parallel to the main shaft and partially outside the housing so as to allow access to the link shaft.

[0005] It is an object of the present invention to provide an electric drive device with a main shaft arrangement and a link shaft coupled by to gearbox to the main shaft arrangement with improved mechanical stability.

[0006] The above object is solved by an electric drive device for a vehicle, the electric drive device comprising: an electric machine having a stator and a rotor; a main shaft arrangement attached to the rotor in a torque-proof manner and extending along a main axis; a link shaft extending along a link axis; a first housing part having a jacket section accommodating the electric machine, a first extended section extending radially with regard to the main axis away from the jacket section on a first axial side of the jacket section, a second extended section extending radially with regard to the main axis away from the jacket section on a second axial side of the jacket section being opposite to the first axial side, a first axial opening forming a margin of the jacket section and the first extended section on the first axial side and a second axial opening forming a margin of the jacket section and the second extended section on the second axial side; a second housing part forming a drive end shield for the main shaft arrangement and covering the first axial opening; a third housing part forming a non-drive end shield for the main shaft arrangement and covering the second axial opening; and a gearbox configured to transmit a rotating movement of the main shaft arrangement to the link shaft and being accommodated in the jacket section, the first extended section and in the second housing part; wherein the first extended section and the second extended section each comprise a link shaft opening, through which the link shaft extends; wherein the first housing part further comprises a stiffening section, which extends axially with regard to the link axis from the first extended section to the second extended section and which projects radially beyond the link shaft.

[0007] The electric drive device for a vehicle comprises an electric machine, a main shaft arrangement, a link shaft, a first housing part, a second housing part, a third housing part and a gearbox.

[0008] The electric machine has a stator and a rotor. The main shaft arrangement is attached to the rotor in a torque-proof manner. The main shaft extends along a main axis. The link shaft link shaft extends along a link axis.

[0009] The first housing part has a jacket section, a first extended section, a second extended section, a first axial opening and a second axial opening. The jacket section accommodates the electric machine. The first extended section extends radially with regard to the main axis away from the jacket section on a first axial side of the jacket section. The second extended section extends radially with regard to the main axis away from the jacket section on a second axial side of the jacket section. The second axial side is opposite to the first axial side. The first axial opening forms a margin of the jacket section and the first extended section on the first axial side. The second axial opening forming a margin of the jacket section and the second extended section on the second axial side.

[0010] The second housing part forms a drive end shield for the main shaft arrangement and covers the first axial opening. The third housing part forms a non-drive end shield for the main shaft arrangement and covers the second axial opening. The gearbox is configured to transmit a rotating movement of the main shaft arrangement to the link shaft. The gearbox is accommodated in the jacket section, the first extended section and in the second housing part.

[0011] The first extended section and the second extended section each comprise a link shaft opening. The link shaft extends through the link shaft openings. The first housing part further comprises a stiffening section. The stiffening section extends axially with regard to the link axis from the first extended section to the second extended section. The stiffening section projects radially beyond the link shaft.

[0012] The invention is based upon the consideration that the extended sections as such form a mechanically weakness of the first housing part, when the second and third housing parts are attached thereto to cover the axial openings. Advantageously, providing the stiffening section between the extended sections part increases the stiffness of the entire housing structure of the electric drive device. Therein, a more robust operation of the electric drive device is possible.

[0013] The main shaft arrangement may be realized by a single shaft or multiple shafts being connected with each other. Preferably, the main axis and the link axis extend in parallel.

[0014] The third housing part may also comprise a link shaft opening, through which the link shaft may extend.

[0015] Preferably, the second and third housing parts are fastened to the first housing part, e.g., by means of screws extending into the first housing part. The housing parts are preferably made of metal. The jacket section may have a substantially hollow cylindrical accommodation space for the stator and the rotor.

[0016] Preferably, the stiffening section comprises a first accommodating subsection extending from a position between the jacket section and the link shaft on one side of a plane that lies on the link axis. Further, the stiffening section may comprise a second accommodating subsection extending from a position between the jacket section and the link shaft on the other side of the plane.

[0017] Advantageously, the stiffening section comprises a connection subsection extending radially with regard to the main axis away from the jacket section. Therein, the first accommodating subsection and the second accommodating subsection may extend away from the connection subsection at the position between the link shaft and the jacket section.

[0018] In a preferred design, the accommodating subsections and the first and second extended sections enclose an accommodation space, which accommodates the link shaft partially. The first and second extended section may further delimit a service opening for accessing the accommodation space. The service opening allows better serviceability of the link shaft.

[0019] In detail, the first accommodating subsection and / or the second accommodating subsection may have the shape of a hollow cylinder sector partially surrounding the link shaft.

[0020] Preferably, the first housing part is provided with multiple mounting openings configured to fasten the electric drive device to a supporting structure of the vehicle, the mounting openings being arranged around the stiffening section. In particular, the mounting openings may be arranged around the service opening.

[0021] Further, the first housing part may be provided with process fastening openings configured to fasten the electric drive device on a test bench, the process fastening openings being arranged around the stiffening section. In particular, the process fastening openings may be arranged around the service opening. Further, process fastening openings may be provided at the jacket section of the first housing part. With regard to the electric drive according to the invention, the stiffening section may comprise drainage holes. The drainage holes prevent that condensed water accumulates on one side of the first housing part. In detail, the first accommodating subsection may be provided with the drainage holes. Alternatively or additionally, the connection subsection may be provided with the drainage holes.

[0022] In a preferred embodiment of the electric drive device according to the invention, the gearbox is configured to receive a drive shaft extending along the link axis and to transmit the rotating movement of the main shaft arrangement to the drive shaft. Further, the first housing part may have a drive shaft opening, through which the link axis extends. The gearbox may comprise a differential gear that couples the link shaft and the drive shaft. The differential gear may further be configured to support the link shaft and the drive shaft the housing parts. Typically, the differential gear is accommodated in the first extended section and in the second housing part.

[0023] Also, the electric drive device may comprise the drive shaft received by the gearbox. The drive shaft may extending through the drive shaft opening of the second housing part.

[0024] The electric drive device may further comprise a bearing arranged in the third housing part and configured to support the main shaft arrangement and / or a bearing arranged in the second housing part and configured to support the main shaft arrangement. A further bearing configured to support the main shaft arrangement may be arranged inside the jacket section.

[0025] The electric drive device may further comprise a bearing arranged in the third housing part and configured to support the link shaft. The link shaft may further be supported by the gearbox, e.g., by the afore-said differential gear.

[0026] Preferably, the electric drive device according to the invention further comprises an inverter device attached to the third housing part on a side opposite to the first housing part. Further, the inverter device may comprise a housing structure formed with a cut-out so that the cut-out partially surrounds the link axis so as to allow access to the link shaft.

[0027] The invention may further refer to an electric vehicle comprising an electric drive device according to the invention. The electric drive device may be configured to drive the vehicle.

[0028] The electric drive device may form an electric axle of the vehicle.

[0029] The vehicle may be a battery electric vehicle (BEV) or a fuel cell driven vehicle. The vehicle may further be a hybrid vehicle, which additionally comprises a combustion engine.

[0030] Further details and advantages of the invention are disclosed in the following, wherein reference is made to the drawings. The drawings show schematically:

[0031] Fig. 1 a perspective view of an embodiment of the electric drive device according to the invention;

[0032] Fig. 2 a schematic diagram of further components arranged inside the housing parts;

[0033] Fig. 3 and 4 each a perspective view of the first housing part of the electric drive device;

[0034] Fig. 5 a top view of the first housing part; and

[0035] Fig. 6 a principle drawing of an embodiment of the vehicle according to the invention.

[0036] Fig. 1 is a perspective view of an embodiment of an electric drive device 1 . The electric drive device 1 comprises a first housing part 2, a second housing part 3, a third housing part 4 and a main shaft arrangement 5, which is hidden in Fig. 1 . The housing parts 2, 3, 4 accommodate the main shaft arrangement 5 (see Fig. 2), which extends along a main axis 6. Further, the electric drive device comprises a link shaft 7, which is partially visible in Fig. 1 and extends along a link axis 8. In the present embodiment, the axes 6, 8 extend in parallel.

[0037] The first housing part 2 comprises a jacket section 9, a first extended section 10 and a second extend section 11 . The first and second extended section 10, 11 extend radially with regard to the main axis 6 away from the jacket section 9.

[0038] Therein, the first extended section 10 extends away on a first axial side 12 of the jacket section 9 and the second extended section 11 extends away on a second axial side 13 of the jacket section 9.

[0039] Fig. 2 is a schematic diagram of further components arranged inside the housing parts 2, 3, 4.

[0040] The electric drive device 1 further comprises an electric machine 14 having a stator 15a and a rotor 15b. The electric machine may be a permanent magnet or electrically excited synchronous machine or an induction motor. The main shaft arrangement 5 is attached to the rotor 15b in a torque-proof manner.

[0041] The electric machine 14 is accommodated in the jacket section 9. Further, the electric drive device 1 comprises a gearbox 16 configured to transmit a rotating movement of the main shaft arrangement 5 to the link shaft 7. The gearbox 16 is accommodated in the jacket section 9, the first extended section 10 and in the second housing part 3.

[0042] Further, the second housing part 3 forms a drive end shield for the main shaft arrangement 5. Thereto, a first bearing 17 supporting the main shaft arrangement 5 is arranged in the second housing part 3. The third housing part 4 forms a non- drive end shield for the main shaft arrangement 6. Thereto, a second bearing 18 supporting the main shaft arrangement 5 is arranged in the third housing part 4. A third bearing 19 supporting the main shaft arrangement 6 is arranged inside the jacket section 9.

[0043] As can be seen further in Fig. 2, a bearing 20 supporting the link shaft 7 is arranged in the third housing part 4. Therein, the link shaft 7 is further supported by the gearbox 16, in particular by a differential gear 21 of the gear box 16.

[0044] The gearbox 16 is further configured to receive a drive shaft 22, which is an optional component of the electric drive device 1 . The drive shaft 22 extends along the link axis 8. The gearbox 16 is configured to transmit the rotating movement of the main shaft arrangement 5 to the drive shaft 22. The drive shaft 22 can be received in the differential gear 21 . Access to the drive shaft 22 is possible via a drive shaft opening (hidden in Fig. 1 ) in the second housing part 3.

[0045] Fig. 3 to Fig. 5 each show the first housing part 2, wherein Fig. 3 is a perspective view from the first axial side 12, Fig. 3 is a perspective view from the second axial side 13 and Fig. 5 is a top view.

[0046] The first housing part 2 has a first axial opening 23 forming a margin 24 of the jacket section 9 and the first extended section 10 on the first axial side 12. A second axial opening 25 of the jacket section 9 forms a margin 26 and the second extended section 11 on the second axial side 13. As can be seen together with Fig.

[0047] 1 , the second housing part 3 covers the first axial opening 23 and the third housing part 4 covers the second axial opening 25. In particular detail, the second and third housing parts 3, 4 are fastened on the axial openings 23, 25, e.g., by screws.

[0048] Further, the first extended section 10 comprises a link shaft opening 27 and the second extended section 11 comprises a link shaft opening 28. A link shaft opening 29 of the third housing part 4 is indicated in Fig. 1 as well. The link shaft 7 extends through the link shaft openings 27, 28, 29. As can be further seen in Fig. 1 , Fig. 3 and Fig. 4, the first housing part 2 comprises a stiffening section 30, which extends axially with regard to the link axis 8 from the first extended section 10 to the second extended section 12 and which projects radially beyond the link shaft 7.

[0049] In particular detail, the stiffening section 30 comprises a first accommodating subsection 31 and a second accommodating subsection 32. The accommodating subsection 31 , 32 extend from a position between the jacket section 9 and the link shaft 7 on opposite sides of a plane that lies on the link axis 8. The accommodating subsections 31 , 32 have the shape of a hollow cylinder sector partially surrounding the link shaft 7. The accommodating subsections 31 , 32 and the first and second extended sections 10, 11 enclose an accommodation space 34, which accommodates the link shaft 7 partially, and delimit a service opening 35 for accessing the accommodation space 34.

[0050] As can be seen best in Fig. 5, the stiffening section 30 further comprises a connection subsection 33 extending radially with regard to the main axis 6 away from the jacket section 9. The first accommodating subsection 31 and the second accommodating subsection 32 extend away from the connection subsection 33 at the position between the link shaft 7 and the jacket section 9.

[0051] Additionally, the first housing part 9 is provided with multiple mounting openings 36 configured to fasten the electric drive device 1 to a supporting structure of a vehicle 100 (see Fig. 6). the mounting openings 36 are arranged around the service opening 35.

[0052] Further, the first housing part 9 is provided with process fastening openings 37 configured to fasten the electric drive device 1 on a test bench (not shown). The process fastening openings 37 are arranged around the service opening 35. Further process fastening openings 38, which are arranged at other positions of the first housing part 9, are shown in Fig. 1 , Fig. 3, Fig. 4 and Fig. 5. Moreover, the stiffening section 30 comprises drainage holes 39, 40. Therein, the first accommodating subsection 31 is provided with the drainage holes 39 and the e.g., connection subsection 33 is provided with the drainage holes 40.

[0053] Again with reference to Fig. 1 , the electric drive device 1 further comprises an inverter device 41 attached to the third housing part 4 on a side opposite to the first housing part 2. The inverter device 41 comprises a housing structure 42 formed with a cut-out 43 so that the cut-out 43 partially surrounds the link axis 8 so as to allow access to the link shaft 7.

[0054] Fig. 6 is a principle drawing of a vehicle 100 comprising the electric drive device 1 according the embodiment described afore. The vehicle 100 is a battery electric vehicle (BEV). Alternatively, the vehicle 100 further comprises a combustion engine (not shown) and is a hybrid vehicle.

Claims

Claims1 . Electric drive device (1 ) for a vehicle (100), the electric drive device (1 ) comprising: an electric machine (14) having a stator (15a) and a rotor (15b); a main shaft arrangement (5) attached to the rotor (15b) in a torque-proof manner and extending along a main axis (6); a link shaft (7) extending along a link axis (8); a first housing part (2) having(i) a jacket section (9) accommodating the electric machine (14),(ii) a first extended section (10) extending radially with regard to the main axis (6) away from the jacket section (9) on a first axial side(12) of the jacket section (9),(iii) a second extended section (11 ) extending radially with regard to the main axis (6) away from the jacket section (9) on a second axial side(13) of the jacket section (9) being opposite to the first axial side (12),(iv) a first axial opening (23) forming a margin (24) of the jacket section(9) and the first extended section (10) on the first axial side (12) and(v) a second axial opening (25) forming a margin (26) of the jacket section (9) and the second extended section (11 ) on the second axial side (13); a second housing part (3) forming a drive end shield for the main shaft arrangement (5) and covering the first axial opening (23);- a third housing part (4) forming a non-drive end shield for the main shaft arrangement (5) and covering the second axial opening (25); and a gearbox (16) configured to transmit a rotating movement of the main shaft arrangement (5) to the link shaft (7) and being accommodated in the jacket section (9), the first extended section (10) and in the second housing part (4); wherein the first extended section (10) and the second extended section (11) each comprise a link shaft opening (27, 28), through which the link shaft (7) extends;wherein the first housing part (2) further comprises a stiffening section (30), which extends axially with regard to the link axis (9) from the first extended section (10) to the second extended section (1 1 ) and which projects radially beyond the link shaft (7).

2. Electric drive device according to claim 1 , wherein the stiffening section (30) comprises a first accommodating subsection (31 ) extending from a position between the jacket section (9) and the link shaft (7) on one side of a plane that lies on the link axis (8).

3. Electric drive device according to claim 2, wherein the stiffening section (30) comprises a second accommodating subsection (32) extending from a position between the jacket section (9) and the link shaft (7) on the other side of the plane.

4. Electric drive device according to claims 3, wherein the stiffening section (30) comprises a connection subsection (33) extending radially with regard to the main axis (6) away from the jacket section (9), the first accommodating subsection (31 ) and the second accommodating subsection (32) extending away from the connection subsection (33) at the position between the link shaft (7) and the jacket section (9).

5. Electric drive device according to claim 3 or 4, wherein the accommodating subsections (31 , 32) and the first and second extended sections (10, 1 1 ) enclose an accommodation space (34), which accommodates the link shaft (7) partially, and delimit a service opening (35) for accessing the accommodation space (34).

6. Electric drive device according to any of claims 2 to 5, wherein the first accommodating subsection (31 ) and / or the second accommodating (32) subsection have the shape of a hollow cylinder sector partially surrounding the link shaft (7).

7. Electric drive device according to any of the preceding claims, wherein the first housing part (2) is provided with multiple mounting openings (36) configured to fasten the electric drive device (1 ) to a supporting structure of the vehicle (100), the mounting openings (36) being arranged around the stiffening section (30).

8. Electric drive device according to any of the preceding claims, wherein the first housing part (2) is provided with process fastening openings (37) configured to fasten the electric drive device (1 ) on a test bench, the process fastening openings (37) being arranged around the stiffening section (30).

9. Electric drive device according to any of the preceding claims, wherein the stiffening section (30) comprises drainage holes (39, 40).

10. Electric drive device according to claim 9, when being dependent on claim 2, wherein the first accommodating subsection (31 ) is provided with the drainage holes (39).11 . Electric drive device according to claim 9 or 10, when being dependent on claim 4, wherein the connection subsection (33) is provided with the drainage holes (40).

12. Electric drive device according to any of the preceding claims, wherein the gearbox (16) is configured to receive a drive shaft (22) extending along the link axis (8) and to transmit the rotating movement of the main shaft arrangement (5) to the drive shaft (22).

13. Electric drive device according to claim 12, further comprising the drive shaft (22) received by the gear box (16).

14. Electric drive device according to any of the preceding claims, further comprising a bearing (17) arranged in the second housing part (3) and configured to support the main shaft arrangement (5) and / or a bearing (18) arranged in the third housing part (4) and configured to support the main shaft arrangement (5) and / or a bearing (20) arranged in the third housing part (4) and configured to support the link shaft (7).

15. Electric drive device according to any of the preceding claims, further comprising an inverter device (41 ) attached to the third housing part (4) on a side opposite to the first housing part (2), the inverter device (41 ) comprises a housing structure (42) formed with a cut-out (43) so that the cut-out (43) partially surrounds the link axis (8) so as to allow access to the link shaft (7).

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