WO2021223808A1

WO2021223808A1 - Electrical drive device and drive arrangement

Info

Publication number: WO2021223808A1
Application number: PCT/DE2021/100400
Authority: WO
Inventors: Jonas Kniel; Patrick Gramann
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2020-05-08
Filing date: 2021-05-03
Publication date: 2021-11-11
Also published as: DE102020112510A1

Abstract

The invention relates to an electrical drive device and to a drive arrangement for a motor vehicle. The electric rotary machine comprises a rotor (3,5) that is rotatable about an axis of rotation (1), a stator (4,6) that is statically arranged relative to the rotor as well as a fluid feeding device (20), which is arranged in a rotationally fixed manner, and a distribution device (30) which is flow-connected to the fluid feeding device (20), is rotatable relative to the fluid feeding device (20) and has at least one flow guide element (33) for distributing cooling fluid about the axis of rotation (1) to at least one component of the electric rotary machine. Optimal cooling of the electric rotary machine can be achieved in a structurally simple and cost-effective manner by way of the electrical drive device according to the invention and a drive arrangement equipped with said electrical drive device.

Description

Electric drive device and drive arrangement

The invention relates to an electric drive device and a drive arrangement for a motor vehicle.

Various electrical drive devices which are used in drive arrangements for motor vehicles are known from the prior art.

Such electrical drive devices usually comprise an electrical rotating machine with a rotor rotatable about a rotation axis and a stator arranged statically with respect to the rotor and a housing in which the electrical rotating machine is arranged or which is formed by the electrical rotating machine for housing the rotor. It is known to provide cooling of the stator and / or rotor of the electric rotating machine for the purpose of increasing efficiency.

DE 102015015797 A1 discloses an electrical machine with a rotor and a stator. The stator comprises at least one winding which has at least one surface facing the rotor, which can be acted upon by a cooling liquid sprayed outward from the rotor in the radial direction by rotating the rotor for cooling the winding.

EP 3059937 A1 describes a method for surface cooling of at least part of an electrical machine and a cooling device for carrying out the method. The cooling device is provided to form a high pressure flow and a low pressure flow for generating a coolant flow. The cooling device includes a nozzle that generates the high pressure flow, the high pressure flow being provided to run on a surface to be cooled of a rotor of the electrical machine using the Coanda effect and to carry along a low pressure flow according to the injection principle. WO 2016 132060 A1 describes an electric rotary machine with a stator with a stator body and a distributor circuit for receiving a cooling fluid for cooling the electric rotary machine.

The distributor circuit is designed to conduct a cooling fluid into an interior space of the electric rotary machine in which the stator is located. For this purpose, the distributor circuit has precisely one opening which faces a side surface of the stator body, so that the cooling fluid can be fed directly to the stator body.

JP 2016 149900 A discloses a cooling structure which comprises an electric rotating machine, a circulation path, a fluid tank, a return duct and a valve device.

The rotary electric machine comprises a rotor and a stator, the rotor being arranged in a rotor chamber and the stator being arranged in a stator chamber and these two chambers being separated from one another in a fluid-tight manner by a partition. The circulation path connects the fluid tank to the stator chamber and the return duct also connects the fluid tank to the stator chamber, the valve device being set up to control the volume flow in the return duct. The valve device controls depending on the fluid pressure prevailing in the stator chamber.

DE 102016 103408 A1 teaches a stator of an electric motor, comprising a stator core, a coil which is wound around teeth of the stator core, an outer cylinder which surrounds the teeth on their yoke, and a heat-conducting part which has an inner peripheral surface of the outer cylinder and a coil end of the coil is in contact.

With this structure, some of the heat that is generated at the coils during operation of the motor is conducted through the heat-conducting part to the outer cylinder and dissipated from the outer cylinder to the outside air. The coil of the motor is cooled accordingly via the heat-conducting part. A particularly efficient cooling of the electric rotary machine is usually achieved by fluid cooling. Oil is mostly used as a cooling fluid, which is directed to the rotor and / or the stator in order to dissipate heat there. Typically, this is done by directing the oil to the rotor and / or the stator using one of two methods.

In this case, a distribution device can be connected to a rotating component and, when rotating, use centrifugal force to fling the oil onto the rotor and / or the stator.

Alternatively, the distribution device is arranged on a stationary component in order to spray the oil onto the rotor and / or the stator from there in a nozzle-like manner. If the distribution device is configured as a nozzle, however, only a certain section is sprayed on the circumference of the rotor and / or stator, so that several nozzles must be provided distributed around the circumference for uniform cooling of the stator.

Proceeding from this, the present invention is based on the object of providing an electric drive device and a drive arrangement equipped therewith, which implement optimal cooling of the electric rotary machine in a structurally simple and cost-effective manner.

The object is achieved by the electrical drive device according to the invention according to claim 1. Advantageous refinements of the electric drive device are specified in subclaims 2 to 8. In addition, a drive arrangement for a motor vehicle, which has the electric drive device, is provided according to claim 9. Dependent claim 10 is directed to an advantageous embodiment of the electric drive device.

The features of the claims can be combined in any technically meaningful manner, in which case the explanations from the following description and features from the figures can also be used, which include additional embodiments of the invention. In the context of the present invention, the terms “axial” and “radial” always relate to the axis of rotation of the electric drive device.

The invention relates to an electric rotary machine with a rotor rotatable about an axis of rotation and a stator arranged statically with respect to the rotor, as well as a fluid supply device arranged non-rotatably. Furthermore, the electric rotary machine comprises a distribution device that is fluidically connected to the fluid feed device and rotatable relative to the fluid feed device with at least one flow guide element for distributing cooling fluid around the axis of rotation to at least one component of the electric rotary machine.

The cooling fluid is thus transported from the fluid supply device to the distribution device.

Although the present cooling is also partly based on centrifugal force-induced discharge of the cooling fluid, this cooling is not solely dependent on the effect of the centrifugal force, since even when static pressure is applied from the distribution device, cooling fluid is essentially on a stationary state with a corresponding arrangement of flow guide elements closed circumference around the axis of rotation can be applied. In one embodiment it is provided that the distribution device is set up to apply cooling fluid to the windings of the stator, in particular to the end windings of the windings.

Flow guiding elements of the distribution device are set up accordingly to apply cooling fluid to the surface of the electrical rotating machine by means of several spray jets or streams without the cooling fluid being passed or guided through a line element between the distribution device and the electrical rotating machine. In other words, the distribution device enables cooling fluid to be sprayed or flowed onto the electric rotary machine. The electric rotating machine can be either a synchronous motor or an asynchronous motor. According to one aspect of the invention, the distribution device is annular, the distribution device forming a circumferential groove, the interior of which is fluidically connected to the fluid supply device.

For an embodiment in which cooling fluid is to be discharged radially inward from the ring shape, it can be provided that at least one seal is arranged in the radially outer area in order to prevent centrifugal force-induced discharge on the radial outside. Accordingly, the cooling fluid can be applied over a closed circumference.

In this case, the fluid supply device is either arranged on the stator or is formed by it, or the fluid supply device is arranged on a housing of the electric rotary machine or is formed by this.

According to a supplementary embodiment, the distribution device can have a plurality of radially aligned flow guide elements for discharging the cooling fluid in a flow direction with a radial component.

The flow guide elements can in particular be several holes or also be designed as impact elements, e.g. by means of an axial toothing. Alternatively, however, it is also not ruled out that the distribution device axially forms a smooth edge from which cooling fluid is thrown off as a result of centrifugal force.

In a preferred embodiment, a respective flow guide element is formed by a bore. However, this does not rule out the use of alternative flow guide elements, such as guide surfaces or guide vanes formed on or by the distribution device.

According to a further supplementary aspect, the fluid supply device has a plurality of flow channels for conveying the cooling fluid to the distribution device. These flow channels can be arranged in a substantially regularly distributed manner on a circumference. In particular, these flow channels can run axially parallel. In an alternative embodiment, the fluid supply device is through only one flow channel is formed with which cooling fluid can be transferred to the distribution device.

In a special embodiment, the flow channel can form at least one outlet in the radial direction, for discharging the cooling fluid with at least one radial directional component.

The individual or respective flow channel forms one or more outlets for transferring the cooling fluid into the distribution device.

Furthermore, the electric drive device can comprise a control device with which the flow parameters of the cooling fluid can be set in such a way that a laminar flow can be achieved in the discharge of the cooling fluid.

This control device controls the pressure and / or the flow rate of the cooling fluid in such a way and the flow channel and the flow guide elements are designed in such a way that the cooling fluid can flow out onto the electric rotary machine with a laminar flow.

According to a further embodiment, the distribution device is connected to the rotor in a rotationally fixed manner. This embodiment is therefore set up in such a way that, as a result of centrifugal force, cooling fluid can be discharged when the rotor of the electric rotary machine rotates. However, the application of cooling fluid due to static pressure is also not excluded.

Furthermore, it is also not excluded that the electric rotary machine combines an internal rotor machine and an external rotor machine and the distribution device is connected or can be connected to a rotor of the internal rotor machine or the external rotor machine in a rotationally fixed manner, and is not connected to the other rotor in each case, but is designed to supply cooling fluid at least partially also to be supplied to the electric rotary machine, with the rotor of which the distributor device is not coupled. In particular, the distribution device can be arranged and configured in such a way that it can be used to cool the windings of the stator of the electric rotating machine.

The present invention is not restricted to this embodiment, but the distribution device can also be arranged and configured in such a way that it can be used to cool the windings of the rotor of the electric rotary machine.

In a particular embodiment, it is provided that the distribution device is arranged and designed in such a way that it can be used to cool the stator and the rotor of the electric rotary machine.

In particular in this embodiment, the distribution device can have a plurality of radially inwardly oriented flow guide elements for cooling an internal rotor rotor and a plurality of radially outwardly oriented flow guide elements for cooling the associated stator.

In a further embodiment, the distribution device is arranged and designed in such a way that it can be used to cool a plurality of stators, i.e. in the case of a combination of an internal rotor machine and an external rotor machine implemented in an axial position. For this purpose, too, it is advisable for the distribution device to have a plurality of flow guide elements oriented radially inward and a plurality of flow guide elements oriented radially outward for cooling the two stators.

The two stators of the two electric rotating machines can be integral components of a stator unit, via which the cooling fluid is optionally supplied.

The electrical rotary machine according to the invention has the advantage that the cooling fluid can be optimally distributed with little structural effort and with little energy requirement.

Furthermore, according to the invention, a drive arrangement for a motor vehicle is made available which has an electrical drive device according to the invention and an output device. The output device can in particular be a transmission, or else an internal combustion engine.

The output device can have a shaft, the distribution device being connected to the shaft in a rotationally fixed manner.

In the case of an output device designed as a gear, the relevant shaft can be a gear input shaft. If the output device is designed as an internal combustion engine, the connected shaft can be the crankshaft of the internal combustion engine or a shaft that is coupled to the crankshaft in a rotationally fixed manner.

Here, the rotary movement of the shaft ensures the rotation of the distribution device, so that when the shaft is decoupled from the rotor of the electric rotary machine and when the shaft rotates due to its coupling to a gearbox or an internal combustion engine, centrifugal force-related discharge of cooling fluid to the electric rotary machine is still ensured is.

The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way restricted by the purely schematic drawings, it being noted that the exemplary embodiments shown in the drawings are not restricted to the dimensions shown. It is shown in

Figure 1: a first embodiment of the electrical drive device in the area of fluid cooling,

FIG. 2: a second embodiment of the electric drive device in the area of fluid cooling,

FIG. 3: a third embodiment of the electric drive device in the area of fluid cooling, and in FIG

FIG. 4: a fourth embodiment of the electrical drive device in the area of fluid cooling. All 4 figures each show different embodiments of the electric rotary machine in the area of the application of the cooling fluid to at least one segment of the electric rotary machine.

The embodiment according to FIG. 1 comprises a statically fixed fluid supply device 20 with a flow channel 21 arranged essentially axially parallel to the axis of rotation 1.

The flow channel 21 ends in an outlet 22, which also extends axially parallel. Through this, cooling fluid reaches the distribution device 30, which here forms a laterally open groove 31 through a radially inner element 34 and a radially outer element 35. Both in the radially inner element 34 and in the radially outer element 35, a plurality of flow guide elements 33, which are essentially evenly distributed around the circumference, are arranged here in the form of bores. By means of these flow guide elements 33, when the distribution device 30 rotates, cooling fluid emerging can be distributed radially inward and also radially outward.

The distribution device 30 is driven in its rotary movement via a hub 40 which is connected to the shaft 50 shown here, which rotates about the axis of rotation 1. The shaft 50 can in particular be the shaft of an output device, not shown here, such as a transmission or an internal combustion engine. This results in the advantage that centrifugal force-induced distribution of the cooling fluid by means of the distribution device 30 can take place when the shaft 50 rotates, without the need to rotate a rotor of the electric rotary machine itself.

In order to ensure a centrifugal force-induced distribution of the cooling fluid also by means of the flow guide elements 33 on the radially inner element 34, the seal 32 shown here on the radially outer element 35 is integrated in order to prevent an unintentional escape of cooling fluid there.

FIG. 2 shows an embodiment which is simpler in comparison to FIG. 1, in which the distribution device 30 has only one radially outer element 35 in which flow guide elements 33 are arranged. In order to support or ensure the distribution of the cooling fluid on the radially outer side here, the outlet 22 is on Flow channel 21 directed radially outwards in order to supply the cooling fluid to the radially outer element 35 through the fluid supply device 20. Otherwise, as in the embodiment according to FIG. 1, the rotation of the distribution device 30 takes place via a hub 40 which is connected to a shaft 50.

FIG. 3 shows a section from an electric rotary machine which, with regard to the fluid supply device 20, is configured like the embodiment according to FIG. The electric rotary machine is designed here as an external rotor machine 8 which has a statically fixed stator 6 of the downstream machine 8 and, in this regard, has the rotor 5 of the downstream machine 8 radially on the outside. In the embodiment shown here, it is provided that the distribution device 30 or its radially outer element 35 is coupled in a rotationally fixed manner to the rotor 5 of the downstream machine 8 via the hub 40. At the same time, a non-rotatable coupling to the shaft 50, which rotates about the axis of rotation 1, takes place via the hub 40. This embodiment ensures that when the rotor 5 of the run-off machine 8 rotates, the distribution device 30 is entrained in the rotary movement, the distribution device 30 or its radially outer element 35 transferring the cooling fluid to the windings 10 or their end windings 11 in the stator 6 of the external rotor machine 8 applies.

FIG. 4 shows a section from an electric rotary machine which has an external rotor machine 8 and an internal rotor machine 7. This electric rotating machine accordingly comprises a rotor 3 of the internal rotor machine 7, a stator 4 of the internal rotor machine 7 that is statically fixed in this regard, a rotor 5 of the external rotor machine 8 and a stator 6 of the external rotor machine 8 that is statically fixed in this regard.

In the embodiment shown here, the distribution device 30 is designed similarly to the embodiment according to FIG. 1, namely in such a way that it comprises a radially inner element 34 and a radially outer element 35, which together form a groove 31.

The radially inner element 34 and the radially outer element 35 have respective flow guide elements 33 in the form of bores, whereby they are radially on both sides of the Fluid supply device 20 are arranged. The flow guide elements 33 in the radially inner element 34 guide cooling fluid onto the windings 10 and, in particular, onto the end winding 11 of the internal rotor machine 7.

Through the flow guide elements 33 in the radially outer element 35, cooling fluid is applied to the windings 10 and in particular to the end winding 11 of the external rotor

Machine 8 led. Here, too, equivalent to the embodiment according to FIG. 1, a seal 32 for the fluid supply device 20 is integrated on the radially outer element 35 to maintain a static pressure within the groove 31 in order to ensure the outflow of cooling fluid through the flow guide elements 33 in the radially inner element 34 of the distribution device 30th

In the embodiment shown here, it can be seen that the rotary drive of the distribution device 30 takes place via the hub 40, which is coupled to the rotor 5 of the downstream machine 8. Correspondingly, there is no rotationally fixed connection to the shaft 50, which leads to an output device. In this way, it is provided by this embodiment that it rotates the distribution device 30 together with the rotor 5 of the external rotor machine 8 and thus distributes cooling fluid due to centrifugal force when the downstream machine 8 is in operation.

With the electrical drive device according to the invention and a drive arrangement equipped with it, optimal cooling of the electrical rotating machine can be implemented in a structurally simple and cost-effective manner.

Reference list

I axis of rotation

3 rotor of the internal rotor machine 4 stator of the internal rotor machine

5 Rotor of the external rotor machine

6 stator of the external rotor machine

7 internal rotor machine

8 external rotor machine 10 winding

I I winding head

20 fluid supply device

21 flow channel

22 outlet 30 distribution device

31 groove

32 Seal

33 flow guide element

34 radially inner element 35 radially outer element

40 hub

50 wave

Claims

1. Electric rotary machine with a rotor (3,5) rotatable about an axis of rotation (1) and a stator (4,6) arranged statically with respect to the rotor (3,5), as well as a non-rotatably arranged fluid supply device (20) and one with the Fluid supply device (20) fluidically connected distribution device (30) rotatable relative to the fluid supply device (20) with at least one flow guide element (33) for distributing cooling fluid around the axis of rotation (1) to at least one component of the electrical rotating machine.

2. Electric rotary machine according to claim 1, characterized in that the distribution device (30) is annular, the distribution device (30) forming a circumferential groove (31), the interior of which is fluidically connected to the fluid supply device (20).

3. Electric rotary machine according to one of the preceding claims, characterized in that the fluid supply device (20) i) is arranged on the stator (4, 6) or is formed by this, or ii) is arranged on a housing of the electric rotary machine or by this is trained.

4. Electric rotary machine according to one of the preceding claims, characterized in that the distribution device (30) has a plurality of radially aligned flow guide elements (33) for discharging the cooling fluid in a flow direction with a radial component.

5. Electric rotary machine according to claim 4, characterized in that a respective flow guide element (33) is formed by a bore.

6. Electrical rotary machine according to one of the preceding claims, characterized in that the fluid supply device (20) has a plurality of flow channels (21) for conducting the cooling fluid to the distribution device (30).

7. Electric rotary machine according to one of the preceding claims, characterized in that the distribution device (30) has a plurality of radially inwardly oriented flow guide elements (33) and a plurality of radially outwardly oriented flow guide elements (33) for discharging the cooling fluid in flow directions with radially inward or radially outwardly aligned component.

8. Electric rotary machine according to one of the preceding claims, characterized in that the distribution device (30) is connected to the rotor (3, 5) in a rotationally fixed manner.

9. Drive arrangement for a motor vehicle with an electric rotary machine according to one of claims 1 to 8 and with an output device.

10. Drive arrangement according to claim 9, characterized in that the output device has a shaft (50), wherein the distribution device is connected to the shaft in a rotationally fixed manner.