Abstract
An electric machine (EM) is arranged within a housing (GG). A stator (S) is electrically insulated with respect to the housing (GG). A stator laminated core (SB) is secured at the housing (GG) via multiple screws (SS) aligned in the axial direction. Electrically insulating spacers (SD) are arranged between the stator laminated core (SB) and the housing (GG). At least two centering pins (SC) are provided for centering the stator (S) in the housing (GG).
Claims
1-14: (canceled)
15. An electric machine (EM) arranged within a housing (GG), the electric machine comprising: a rotatably mounted rotor (R); a rotationally fixed stator (S) electrically insulated with respect to the housing (GG), the stator (S) comprising a stator laminated core (SB) and at least one stator winding (SW) arranged at the stator laminated core (SB), the stator laminated core (SB) secured at the housing (GG) via a plurality of screws (SS) aligned in an axial direction; a plurality of electrically insulating spacers (SD) arranged between the stator laminated core (SB) and the housing (GG); and at least two centering pins (SC) configured for centering the stator (S) in the housing (GG).
16. The electric machine (EM) of claim 15, wherein each of the centering pins (SC) is arranged: in a respective bore (GG2) in the housing (GG) at one end of each of the centering pins (SC); and in a respective centering receptacle (SBZ) in the stator laminated core (SB) at another end of each of the centering pins (SC).
17. The electric machine (EM) of claim 16, wherein the centering pins (SC) are metallic and an electrical insulation is formed between the centering pins (SC) and the stator laminated core (SB) by the respective centering receptacle (SBZ).
18. The electric machine (EM) of claim 17, wherein the respective centering receptacle (SBZ) comprises an electrically insulating sleeve (SBH) inserted into a respective recess (SB3) in the stator laminated core (SB).
19. The electric machine (EM) of claim 15, wherein the centering pins (SC) are made of an electrically insulating material.
20. The electric machine (EM) of claim 15, wherein at least one of the plurality of spacers (SD) has a through-hole (SDA2), and at least one of the centering pins (SC) is guided through the through-hole (SDA2).
21. The electric machine (EM) of claim 15, wherein at least one of the plurality of spacers (SD) is held in position by at least one of the centering pins (SC).
22. The electric machine (EM) of claim 15, wherein at least one of the spacers (SD) is clipped into the housing (GG).
23. The electric machine (EM) of claim 15, wherein at least one of the centering pins (SC) is integrally formed as one-piece of seamless material with at least one of the spacers (SD).
24. The electric machine (EM) of claim 15, wherein a mounting pin (SDM) is formed with at least one of the spacers (SD), the mounting pin (SDM) engaged with a receiving bore in the housing (GG).
25. The electric machine (EM) of claim 15, wherein at least one of the spacers (SD) is bonded onto the stator laminated core (SB) or onto the housing (GG).
26. The electric machine (EM) of claim 15, wherein an air gap is defined between the screws (SS) and the spacers (SD).
27. The electric machine (EM) of claim 26, wherein each of the screws (SS) is guided through a respective through-hole (SDA1) of the spacers (SD).
28. A drive unit (HY, HY2, G, EA) for a motor vehicle, comprising: the electric machine (EM) of claim 15, wherein the electric machine (EM) is configured for driving the motor vehicle.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Exemplary embodiments of the invention are described in detail with reference to the figures, wherein:
[0021] FIG. 1a through FIG. 1d show various configurations of a motor vehicle drive train;
[0022] FIG. 2a through FIG. 2c each show a schematic sectioning of a motor vehicle drive unit;
[0023] FIG. 3a and FIG. 3b each show a view of a spacer according to a first exemplary embodiment;
[0024] FIG. 4a and FIG. 4b each show a view of a spacer according to a second exemplary embodiment;
[0025] FIG. 5a and FIG. 5b each show a view of a spacer according to a third exemplary embodiment; and FIG. 6a and FIG. 6b each show a view of a spacer according to a fourth exemplary embodiment.
DETAILED DESCRIPTION
[0026] Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.
[0027] FIG. 1a shows a drive train of a motor vehicle. The drive train includes an internal combustion engine VM. The drive train includes a transmission G for adapting the rotational speed and torque output characteristics of the internal combustion engine VM to the driving resistances of the motor vehicle. The transmission G can be, for example, an automatic transmission, an automated transmission that includes one single launch clutch, a dual-clutch transmission, a CVT transmission, or a manually shifted transmission. The transmission G is connected, at the output end of the transmission G, to a differential gear AG, which distributes the drive power to driving wheels DW.
[0028] In the drive train according to FIG. 1a, a hybrid module HY is arranged between the internal combustion engine VM and the transmission G. The hybrid module HY includes an electric machine EM, by which the motor vehicle is drivable purely electrically or in a hybrid manner together with the internal combustion engine VM. The hybrid module HY can include a separating clutch (not shown in FIG. 1a), by which a torque transmission is engageable between the internal combustion engine VM and the electric machine EM.
[0029] FIG. 1b shows another configuration of a motor vehicle drive train. A hybrid module HY2 is provided in the motor vehicle drive train, the hybrid module HY2 being arranged at the output side of the transmission G, in contrast to the drive train according to FIG. 1a. The hybrid module HY2 also includes an electric machine EM, by which the motor vehicle is drivable purely electrically or in a hybrid manner together with the internal combustion engine VM.
[0030] FIG. 1c shows another configuration of a motor vehicle drive train. A hybrid module is not provided in the motor vehicle drive train. Instead, the electric machine EM is an integral part of the transmission G. A transmission G of this type is also referred to as a hybrid transmission.
[0031] FIG. 1d shows another configuration of a motor vehicle drive train, which, in contrast to the drive trains according to FIG. 1a through FIG. 1c, is a purely electric drive train without an internal combustion engine. An electric axle drive EA includes an electric machine EM, the drive power of which is distributed onto driving wheels DW of the motor vehicle via the differential gear AG. A drive train of this type could also include a transmission between the axle drive EA and the differential gear AG, for example, a 2-speed transmission. This type of electric axle drive EA could also be combined with a second axle that is driven by an internal combustion engine.
[0032] The hybrid modules HY, HY2, the hybrid transmission G, and the axle drive EA form drive units for the motor vehicle. FIG. 2a shows a schematic sectional view of a drive unit HY, HY2, G, EA of this type. The electric machine EM is arranged in a metallic housing GG and includes a rotationally fixed stator S and a rotor R. The rotor R is connected to a rotor shaft RW, which is mounted at the housing GG via a bearing WL. In this way, the rotor R, including the rotor shaft RW, can rotate about an axis RA.
[0033] The stator S includes a stator laminated core SB, at which at least one stator winding SW is arranged. The stator laminated core SB is secured at the housing GG via multiple screws SS, for example, via three screws SS. For this purpose, the stator laminated core SB has passage openings SB1, through which the screws SS are guided in the axial direction. Threaded holes GG1 are arranged in the housing GG, the threaded holes GG1 interacting with an external thread of the screws SS.
[0034] The stator S is electrically insulated from the housing GG in order to reduce the transmission of interference currents starting from the stator S via the housing GG and via the bearing WL to the rotor shaft RW. For this purpose, electrically insulating spacers SD are arranged between the stator laminated core SB and the housing GG. These spacers SD are made, for example, of ceramic or a high-pressure resistant plastic. Electrically insulating spacers SD2 are also arranged between a screw head of the screws SS and the stator laminated core SB.
[0035] FIG. 2b shows another schematic sectional view of the drive unit HY, HY2, G, EA. FIG. 2b shows the centering of the stator S in the housing GG. Two centering pins SC are provided for centering, only one of these two centering pins SC being shown in the representation according to FIG. 2b. One end of the centering pin SC is arranged in a bore GG2 in the housing GG and the other end of the centering pin SC is arranged in a centering receptacle SBZ in the stator laminated core SB. In this exemplary embodiment, the centering receptacle SBZ is formed by a recess SB2. The centering pins SC are made of an electrically insulating material, for example, of ceramic. The centering pins SC are fitted into the bores GG2 and into the recesses SB2. The bores GG2 and the centering receptacle SBZ have a low position tolerance with respect to the axis RA in order to ensure an air gap between the stator S and the rotor R that is as uniform as possible. In the exemplary embodiment according to FIG. 2b, the centering pin SC extends through the spacer SD. Various embodiments, which are described by way of example in FIG. 3a through FIG. 6b, are possible for this purpose.
[0036] FIG. 2c shows a schematic sectional view of the drive unit HY, HY2, G, EA according to another possible example embodiment. In this example embodiment, the centering pins SC are made of a metallic material, for example, of steel. The centering receptacle SBZ includes electrically insulating sleeves SBH for the electrical insulation between the centering pin SC and the stator laminated core SB, the electrically insulating sleeves SBH being inserted into one recess SB3 each of the stator laminated core SB. The axial distance between the stator laminated core SB and the housing GG is ensured by the spacers SD, which are not visible in the sectional view according to FIG. 2c.
[0037] FIG. 3a shows a top view of a spacer SD according to a first exemplary embodiment. The spacer SD is plate-shaped and has a through-hole SDA1 and a through-hole SDA2. In the installed condition, one of the screws SS extends through the through-hole SDA1. The through-hole SDA1 is larger than the diameter of the screws SS. Projections SDX are formed at two opposite edges of the spacer SD. The projections SDX are used for holding the spacer SD in the housing GG, so that the spacer SD remains securely in position during assembly before the stator laminated core SB is secured at the housing GG. Via the projections SDX, the spacer SD can be clipped into appropriate receptacles in the housing GG.
[0038] FIG. 3b shows a sectional view through the spacer SD through a cutting plane A-A indicated in FIG. 3a, the centering pin SC being additionally shown. The centering pin SC extends through the through-hole SDA2, the diameter of the centering pin SC being smaller than the through-hole SDA2. This is the case because the spacer SD is held in position by the projections SDX, and so an appropriate position compensation with respect to the position of the centering pin SC is necessary.
[0039] FIG. 4a shows a top view of a spacer SD according to a second exemplary embodiment. FIG. 4b shows a sectional view through the spacer SD through a cutting plane B-B indicated in FIG. 4a, the centering pin SC being additionally shown. In contrast to the exemplary embodiment according to FIG. 3a and FIG. 3b, the projections SDX are dispensed with. The through-hole SDA2 is smaller in this case, enabling the centering pin SC to be fitted into the through-hole SDA2. In this type of design, the centering pins SC can be initially inserted into the bores GG2 of the housing GG during assembly. Thereafter, the spacers SD are slid onto the centering pins SC and held in position by the centering pins SC.
[0040] FIG. 5a shows a top view of a spacer SC according to a third exemplary embodiment. FIG. 5b shows a sectional view through the spacer SD through a cutting plane C-C indicated in FIG. 5a. The spacer SD according to the third exemplary embodiment is formed as one piece with the centering pin SC and, therefore, the through-hole SDA2 is dispensed with. This type of spacer SD that includes the centering pin SC can be realized, for example, by a ceramic component.
[0041] FIG. 6a shows a top view of a spacer SD according to a fourth exemplary embodiment. FIG. 6b shows a sectional view through the spacer SD through a cutting plane D-D indicated in FIG. 6a. The spacer SD includes a mounting pin SDM in this case. The mounting pin SDM is arranged on the housing-side end face of the spacer SD. In the assembled condition, the mounting pin SDM has been inserted into an appropriate receiving bore in the housing GG to hold the spacer SD in position. As a result, the projections SDX can be dispensed with. An embodiment of the spacer SD including two mounting pins SDM is also conceivable to prevent the spacer SD from tilting.
[0042] Modifications and variations can be made to the embodiments illustrated or described herein without departing from the scope and spirit of the invention as set forth in the appended claims. In the claims, reference characters corresponding to elements recited in the detailed description and the drawings may be recited. Such reference characters are enclosed within parentheses and are provided as an aid for reference to example embodiments described in the detailed description and the drawings. Such reference characters are provided for convenience only and have no effect on the scope of the claims. In particular, such reference characters are not intended to limit the claims to the particular example embodiments described in the detailed description and the drawings.
REFERENCE CHARACTERS
[0043] VM internal combustion engine [0044] HY hybrid module [0045] HY2 hybrid module [0046] G transmission [0047] EA electric axle drive [0048] AG differential gear [0049] DW driving wheel [0050] EM electric machine [0051] S stator [0052] SB stator laminated core [0053] SB1 passage opening [0054] SBZ centering receptacle [0055] SB2 recess [0056] SB3 recess [0057] SW stator winding [0058] R rotor [0059] RW rotor shaft [0060] RA axis of rotation [0061] WL bearing [0062] GG housing [0063] GG1 threaded hole [0064] GG2 bore [0065] SS screw [0066] SC centering pin [0067] SD2 spacer [0068] SD spacer [0069] SDA1 through-hole [0070] SDA2 through-hole [0071] SDX projection [0072] SDM mounting pin
