Electric motor

Abstract

The present invention relates to an electric motor having a sheath (1) for forming a main cavity of the electric motor, into which a coolant is introduced for cooling the components of the electric motor, the electric motor having a rotor (3) and a stator (2) with first and second stator end windings, the electric motor further having an impeller (31) for forcing the coolant into the area of ​​the end windings.

Description

[Technical field]

[0001] The present invention relates to an electric motor of the wet rotor type for the traction drives of electric vehicles, which is cooled directly by a dielectric coolant, in particular oil, in that at least one rotor and at least a part of the windings are exposed to the coolant delivered by the rotor of the electric motor. [Background technology]

[0002] US Patent No. 5,399,633 discloses a rotor for use with direct cooling, in which a cast filling body is used to direct the flow of coolant towards the head of the windings, and oil is discharged from the rotor through a number of radial bores and / or radial passages formed by the cast filling body and the shaft journal on both sides of the rotor. Patent document 2 shows an electric motor having a rotor and a stator. The rotor has end plates with holes for guiding a coolant. Further electric motors are known from US Pat. No. 5,399,623, US Pat. No. 5,499,633, US Pat. No. 5,523,367, US Pat. No. 5,523,675, and US Pat. No. 5,523,675. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] European Patent Application Publication No. 3507889 [Patent Document 2] US Patent Application Publication No. 2009 / 0173352 [Patent Document 3] European Patent Application Publication No. 3495157 [Patent Document 4] US Patent Application Publication No. 2019 / 027987 [Patent Document 5] DE 102009029716 [Patent Document 6] International Publication No. 2018 / 225877 [Patent Document 7] JP 2011-254571 A Summary of the Invention [Problem to be solved by the invention]

[0004] With this known solution, the driving force for utilizing the coolant flow generated by the shaped packing is weak, since the flow generated by the packing is not controlled (regulated) and is constantly blocked by the recirculating coolant particles.

[0005] SUMMARY OF THE DISCLOSURE The object of the present invention is therefore to propose an improved, or at least an alternative, embodiment for utilizing a coolant flow, which overcomes the above-mentioned drawbacks. [Means for solving the problem]

[0006] This object is achieved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject matter of the dependent claims.

[0007] According to the present invention, Electric motors Independent Components is Partition wall Have , this partition is fixed to the end plate of the sheath of the electric motor in the area of ​​the circulation chamber. The impeller of the rotor of the electric motor is used in the function of a pump for delivering a coolant (cooling liquid) by the cooling system of the electric motor, thus making use of the coolant flow movement regulated by means of the partition element in the area of ​​the circulation chamber.

[0008] Cooling the stator and windings of an electric motor with an impeller in combination with a partition wall significantly and effectively improves the cooling performance, and therefore the continuous performance, of the electric motor.

[0009] In the present invention, the compound word "first / second" is used for the sake of simplicity. In the context of the present invention, the individual terms "first" and "second" of the compound word "first / second" are always connected with "and / or". Thus, there may be a "first" element and / or a "second" element of the rotor. In this case, each "first" element only relates to a further "first" element of the rotor or to a first axial end of the rotor, and each "second" element only relates to a further "second" element of the rotor or to a second axial end of the rotor. If the individual terms "first" and "second" are not used in the compound word "first / second", they should be understood according to this usage. Furthermore, in the present invention, the terms "axial" and "radial" always relate to the axis of rotation.

[0010] In an advantageous embodiment, the rotor of the electric motor comprises a hollow shaft and a rotor core. The hollow shaft is a two-part hollow structure, adapted to be assembled with the hollow shaft core and a corresponding support body, adapted to support the rotor core in position. In an advantageous embodiment, the hollow shaft and the corresponding rotor core are cylindrical bodies having a first end and an opposite second end of the hollow shaft. In an advantageous embodiment, the hollow shaft has an inlet opening for introducing a coolant into a main cavity of the hollow shaft, the hollow shaft having a number of channels for discharging the coolant from the hollow shaft to an inlet region of the impeller. The rotor core comprises a cylindrical body, the cylindrical body further comprising a number of layered metal sheets formed of magnetic steel, the rotor core having a first adjacent front face on a first side of the rotor core and a second adjacent front face on a second (opposite) side of the rotor core, at least one side of the rotor core comprising a feature of the impeller. The rotor core further comprises an impeller with a number of blades to assist the flow of coolant in the sheath of the electric motor. In an advantageous embodiment, the channels for ejecting the coolant from the hollow shaft are arranged in the area close to the outer periphery of the hollow shaft, more precisely in the area of ​​the interference-fit connection between the hollow shaft core and the corresponding support body, the number of channels being preferably equal to the number of blades of the impeller and the positions of the channels being aligned with respect to the leading edges of the corresponding blades.

[0011] In an advantageous embodiment, the electric motor further comprises a sheath and a stator with a number of wires to form the windings. The stator is a cylinder including a laminated stator core and further comprises a first end of the stator core and an opposite second end. The windings further comprise winding heads (heads of windings, head windings) on both sides of the stator core. Accordingly, an internal volume in the form of a main cavity of the electric motor is provided and is bounded by the sheath, the stator and the rotor. The main cavity of the electric motor comprises at least two sub-cavities for coolant circulation, the first coolant circulation chamber being a cavity bounded by the sheath, the first side of the stator and the first side of the rotor and further comprising a first winding head. Similarly, the second coolant circulation chamber is a cavity bounded by the sheath, the second side of the stator and the second side of the rotor and further comprising a second winding head.

[0012] In an advantageous embodiment, the oil introduced into the main cavity of the electric motor circulates against the rotor with the aid of an impeller, the sheath further comprising a dividing wall for dividing the coolant circulation chamber into zones including the impeller inlet zone, the impeller air gap zone, the impeller outlet zone and the injection zone, the remaining part of the coolant circulation chamber being considered as the winding head circulation zone. The dividing wall has a first boundary surface facing the rotor, more precisely the impeller, and a second boundary surface facing the sheath of the electric motor. 。 stomach In order to improve the hydraulic performance of the impeller, the air gap between the impeller and the sheath is reduced by a first interface of the partition wall, thereby providing a gap zone with a distance between the partition wall and the impeller of between 0.2 mm and 10 mm, and the impeller outlet zone forms an opening through which oil is discharged from the impeller into the remainder of the coolant circulation chamber, and the circulation of the coolant in the coolant circulation chamber is driven by the flow of coolant coming from the impeller outlet zone. According to the present inventionThe second boundary surface of the partition wall has a number of spacers, which form gaps for providing an injection zone and are used to inject the coolant again in the region of the impeller inlet zone. Advantageously, the flow of the coolant in the circulation chamber of the electric motor is regulated and circulated, which reduces the hydraulic losses caused by the impeller and significantly improves the cooling performance of the cooling system.

[0013] In one embodiment, and particularly one alternative embodiment, the partition wall also has a central opening which further includes a plurality of grooves and / or openings through which the coolant is directed from the injection zone to the impeller inlet zone.

[0014] Other important features and advantages of the present invention will become apparent from the appended claims, the drawings, and the following description of the figures based on the accompanying drawings.

[0015] It goes without saying that the features mentioned above and those to be described below can be used not only in the respective combinations specified, but also in other combinations or alone without departing from the scope of the invention.

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention are illustrated in the drawings and described in more detail below, where like reference numbers indicate identical or similar or functionally identical elements.

[0017] Each figure is a schematic diagram. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 shows a cross-sectional view of an electric motor having a partition wall according to an advantageous embodiment of the invention. [Diagram 2] FIG. 2 is a perspective view of a partition wall according to an advantageous embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 1 shows a cross-section of an electric motor with a partition wall 4 according to an advantageous embodiment of the invention. The electric motor comprises a sheath 1, a stator 2 and a rotor 3. The rotor 3 further comprises an impeller 31, with a first coolant circulation chamber 1A formed on a first side of the stator 2 and the rotor 3, respectively, or a second coolant circulation chamber 1B formed on a second side of the stator 2 and the rotor 3, respectively. In an advantageous embodiment, the partition wall 4 separates the first coolant circulation chamber 1A into an impeller inlet zone 31A, an impeller air gap zone 41, an impeller outlet zone 31B and an injection zone 41, the remaining part of the first coolant circulation chamber 1A being considered as the head circulation zone of the windings.

[0020] FIG. 2 is a perspective view of a partition wall 4 according to an advantageous embodiment of the invention, which has a number of spacers 4A, which form gaps for providing an injection zone 41, which are used to reinject coolant in the region of the impeller inlet zone 43.

[0021] All parts of the electric motor, especially the partition wall 4, are shown and described herein in the best possible form, however, different shapes / sizes / configurations are also possible, and the coolant is preferably oil, air or a mixture of oil and air.

Claims

1. An electric motor having a sheath (1) for forming a main cavity of the electric motor, and a coolant being introduced into the sheath for cooling components of the electric motor, comprising a stator (2) having a first stator end winding and a second stator end winding, and a rotor (3), further having an impeller (31) for feeding the coolant into a region of the end winding, characterized in that the electric motor further has a partition wall (4) for partitioning a first coolant circulation chamber (1A) and / or a second coolant circulation chamber (1B) into zones including an impeller inlet zone (31A), an impeller air gap zone (41), an impeller outlet zone (31B), and an injection zone (41), the partition wall (4) being an independent component having a plurality of spacers (4A) for providing the zones which is an electric motor.

2. The electric motor according to claim 1, wherein the main cavity of the electric motor has a first coolant circulation chamber (1A) in a region of the first stator end winding and a second coolant circulation chamber (1B) in a region of the second end winding.

3. The electric motor according to claim 1 or 2, wherein the remaining part of the first coolant circulation chamber (1A) and / or the remaining part of the second coolant circulation chamber (1B) are used for cooling the electric motor by circulation of the coolant.

4. The electric motor according to claim 1 or 2, wherein the partition wall (4) has a central opening and a plurality of grooves and / or openings, and the coolant is introduced from the injection zone to the impeller inlet zone through the central opening and the grooves and / or openings.

5. The electric motor according to claim 1 or 2, wherein the rotor (3) has a hollow shaft (32) and a rotor core, the hollow shaft (32) being a two-part hollow structure having a hollow shaft core and a corresponding support body, configured to be assembled and configured to support the rotor core at a predetermined position.

6. The electric motor according to claim 5, The electric motor is characterized in that the hollow shaft (32) and the rotor core are cylindrical bodies having a first end portion and a second end portion on both sides of the hollow shaft (32).

7. In the electric motor according to claim 5, the hollow shaft (32) has an inlet opening (1AO) for introducing a coolant into the main cavity (7) of the hollow shaft (32), and the hollow shaft (32) has a plurality of flow paths for discharging the coolant from the hollow shaft (32) to the inlet region of the impeller (31). The electric motor is characterized by this.

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