Motor

Abstract

The invention relates to an electric machine (10) comprising a rotor (12) arranged on a rotor shaft (11) and a support ring (14) arranged on an end face of the rotor (12), at least one guide channel (34) arranged in the support ring (14) having a collector structure (44).

Description

Technical Field

[0001] The invention relates to a motor, which comprises a rotor arranged on a rotor shaft and a supporting ring arranged on an end surface of the rotor. A guide channel arranged in the supporting ring has a current collecting structure. Background Art

[0002] Electric machines can be used as working machines for electrically drivable motor vehicles, such as electric vehicles and hybrid vehicles. Various types of electric machines can be used here, which usually have a stator mounted in a fixed position and a rotor mounted movably relative to the stator. In current-excited electric machines, the active part has a magnetic field generating system, for example in the form of a current-carrying winding, which is held by an iron core in order to generate a magnetic flux.

[0003] Such windings heat up during operation of the electric machine, which results in local hot spots, for example, due to an uneven temperature distribution in the winding. Since the heating of the electric machine has a negative impact on efficiency and continuous output (continuous output power), solutions for cooling the electric machine are known. For example, in order to cool the rotor, a cooling jacket can be arranged around the rotor, through which a coolant flows, or the rotor can have a shaft, which is designed as a hollow shaft and through which a coolant flows. Summary of the invention

[0004] The object of the present invention is to improve the cooling of an electric machine.

[0005] This object is achieved by an electric machine having the features of claim 1. The dependent claims relate to advantageous developments of the invention.

[0006] According to a first aspect, an electric motor is proposed, comprising a rotor arranged on a rotor shaft and a support ring arranged on an end surface of the rotor, at least one guide channel arranged in the support ring having a collecting structure, which is configured to guide fluid discharged from the rotor shaft to the end surface of the support ring.

[0007] The support ring can be arranged and / or fastened on the rotor and / or on the rotor shaft, whereby heat transfer can take place between the support ring and the corresponding component of the electric machine. In particular, the support ring comprises aluminum or is made of aluminum in order to support heat transfer between the fluid, the support ring and in particular other components, in particular when the support ring is connected to the rotor or other components of the electric machine in a heat-conducting manner.

[0008] The fluid discharged from the rotor shaft can be received by the guide channel and conveyed to the collecting structure, in particular by means of centrifugal force. By arranging the collecting structure to guide the fluid to the end face of the support ring, the heat generated in the rotor can be absorbed and transported away by the fluid. This can improve the coolability of the rotor and thus adjust a uniform temperature level. For example, the fluid can be conveyed or guided along the end face of the support ring or the rotor facing and / or facing away from the rotor. In this case, the fluid can flow essentially radially on the end face to the outside.

[0009] The coolant can be directed directly on the location to be cooled or very close to the location to be cooled. Thus, in particular, a coolant flow can be generated which ensures heat dissipation.

[0010] In order to cool the electric machine, the rotor shaft is designed as a rotating hollow shaft through which a fluid flows and, for example, can be designed as a rotating hollow shaft through which a fluid or a cooling medium flows, around which the rotor or a support ring is arranged in a rotationally fixed manner. The fluid is, in particular, a non-conductive coolant, such as oil. The fluid can be taken from a coolant circuit or a lubricant circuit in order not to impair the function of the electric machine, in particular when it comes into direct contact with live parts.

[0011] The rotor shaft can have at least one outlet or at least one outlet opening for discharging coolant from the hollow rotor shaft. During the rotational movement of the rotor, the fluid can be transported radially outward from the rotor shaft by centrifugal force in order to wet the machine parts and thus enable heat transfer. The one or more guide channels of the support ring can be assigned to the outlet or outlet opening in order to receive the fluid from the rotor shaft and discharge it onto the end face of the support ring or onto a collecting structure arranged there.

[0012] The electric motor can be used, for example, as an electric traction machine for an electrically operable motor vehicle. The electric motor is in particular configured as a current-excited synchronous motor (SSM) or an asynchronous motor (ASM). The electric motor can have a stator supported in a fixed position and a rotor supported movably, in particular rotatably, relative to the stator. The rotor has a rotor iron, which can be formed, for example, by a rotor laminated core composed of axially stacked laminations. In addition, the rotor can have an electrically conductive winding, which is configured to generate or excite a magnetic flux to conduct an electric current. For example, in a current-excited synchronous motor, the winding can be configured as an energized excitation coil.

[0013] The interior of the electric machine is defined by the housing. Therefore, the fluid or coolant can be located in the interior of the electric machine and it can be referred to as a wet electric machine, in particular a wet electric motor. In particular, the rotor and the stator are also arranged in the interior and the fluid can interact directly with the components of the electric machine to be cooled in the interior of the electric machine.

[0014] In addition, the present invention is based on the following idea: by means of a collecting structure, the fluid or coolant discharged from the rotor shaft is guided to the end face of the support ring or through the support ring or its end face, and in particular the suction effect caused by the centrifugal force can be used to continuously change the position of the fluid during the rotational movement of the rotor. By establishing a thermal connection between the fluid and the support ring and / or the component to be cooled, such as the rotor, the heat generated during operation can be discharged and taken away from the system. In this case, the support ring can be arranged on the axial end of the rotor, on which in particular the winding heads of the rotor winding can be arranged, which winding heads can form hot spots during the operation of the rotor. In some embodiments, two support rings can be provided, which can be arranged on two oppositely arranged end faces of the rotor.

[0015] By arranging or designing the manifold structure, for example, the mass flow of the fluid that is or should be guided through the end face of the support ring can be predetermined. As a result, the temperature distribution in the motor can be made uniform and / or local hot spots can be avoided. As a result, for example, the efficiency and / or the continuous power of the motor can be increased. In addition, the targeted guidance of the fluid to a predetermined area of ​​the support ring can relieve the load on the coolant pump arranged outside the motor, so that the coolant pump can be smaller and lighter.

[0016] In one embodiment, the support ring is arranged on the rotor shaft by means of a hub and the at least one guide channel is arranged on the hub of the support ring. In this case, the hub is formed on the radial inner part of the support ring and has a predetermined length in the axial direction so as to enable a secure fit on the rotor shaft and / or the reception or delivery of the rotor shaft fluid. For this purpose, the hub has an inner diameter, which in particular substantially corresponds to the outer diameter of the rotor shaft so that it can be fixed on the rotor shaft. The at least one guide channel or multiple guide channels of the support ring are in particular assigned to one or more fluid outlets of the rotor shaft or are arranged adjacent to these fluid outlets so as to enable fluid guidance through the one or more guide channels.

[0017] By means of a substantially annular disk-shaped design, the support ring can be arranged axially on the end face of the rotor in order to enable a space-saving arrangement and to keep the axial dimensions of the electric machine small. In some embodiments, the support ring extends radially up to the outer diameter of the rotor shaft, thereby providing a maximum area of ​​the end face for fluid guidance to improve the cooling performance.

[0018] In one embodiment, the at least one guide channel is arranged in the region between the hub and the end face of the support ring, the guide channel in particular opening into the collecting structure in the plane of the support ring. The collecting structure can be configured in this transition region, in particular on the end face and / or on the hub side, so that the fluid is guided, for example, through the guide channel arranged in the hub in the direction of the end face of the support ring and can be collected there in the collecting structure. As a result, in particular due to cohesive forces, the fluid can be collected in the radial inner region of the support ring in order to subsequently flow or be guided on the surface of the end face of the support ring, in particular due to adhesive forces, in order to cool the surface.

[0019] In one embodiment, the at least one guide channel forms an acute angle with the rotor axis. This can reduce the acceleration of the fluid so as to support the fluid to be collected at the end of the guide channel. In addition, the fluid can be guided in the direction towards the end face of the support ring so as to support the collection and guidance of the fluid on the end face. In some embodiments, additionally or alternatively, the guide channel can form an acute angle with the radial direction of the support ring so as to adjust the flow direction and / or flow velocity of the fluid.

[0020] In one embodiment, the collecting structure is designed as a recess in the support ring. The recess can be provided to collect the fluid discharged from the rotor shaft and guide the fluid to the end face of the support ring, for example, by means of rounded and / or radially oriented transition surfaces. The fluid thus captured or collected can be guided to the end face or flow along the end face in order to be able to achieve heat exchange there.

[0021] For this purpose, the recess can, for example, have a structure facing away from the rotor shaft or the rotor shaft outlet, which structure is particularly in the form of a notch, a cavity or a groove, which is provided to collect the fluid flowing through the one or more guide channels in the radial direction or to prevent the fluid from splashing when leaving the one or more guide channels and missing the end face of the support ring or reaching the end face only to an undesirable extent.

[0022] In some embodiments, the collecting structure may be configured as a protrusion, in particular in the form of a wall, a dam, a slope or a lip, so as to collect the fluid and / or guide the fluid to the end surface of the support ring.

[0023] In one embodiment, the recess is arranged at the radially outer end of the guide channel so as to collect the fluid on the end face, in particular, facing away from the rotor. By collecting the fluid by means of the collecting structure, it is possible to at least partially avoid the fluid from running or flying past the support ring, thereby improving the cooling efficiency. In addition, the fluid flow on the end surface can be made uniform so as to achieve uniform cooling of the support ring.

[0024] In one embodiment, the recess is arranged offset relative to the guide channel in the opposite direction of rotation of the rotor. The collecting structure or the recess can be arranged to influence the trajectory of the fluid flow of the discharged fluid in a predetermined direction so as to guide it to the target area, in particular to the end face of the support ring. By the offset arrangement or asymmetric design of the recess or the collecting structure, a fluid flow optimized in the direction of rotation can be achieved on the end face.

[0025] In other embodiments, the recesses or collecting structures may be arranged uniformly or symmetrically around the outlet of the one or more guide channels to allow uniform or similar fluid distribution on the end surface of the support ring in both possible rotation directions when the motor is running.

[0026] In one embodiment, a plurality of guide channels are arranged rotationally symmetrically on the support ring. In particular, six or twelve guide channels can be arranged on the hub of the support ring, for example, in order to achieve an optimized fluid flow for a rotor having six windings. Furthermore, every two guide channels can be assigned to a collecting structure or lead into it, in order to be able to supply the collecting structure in a rotationally optimized manner. In this case, the pair of guide channels can have different angles and / or different cross sections relative to the rotor axis or the radial direction of the support ring, in order to improve the fluid guidance.

[0027] According to another aspect, a support ring for an electric machine is provided, which is provided for use in an electric machine described in the present application. In particular, the support ring is designed in the manner described in the present application, in particular as disclosed in the embodiments and / or examples for the electric machine described in the present application. With the aid of such a support ring, uniform cooling of the electric machine can be achieved.

[0028] The embodiments and advantages described in this application apply correspondingly to a motor vehicle having such an electric machine.

[0029] Other features of the invention are apparent from the claims, the drawings and the description of the drawings. The features and feature combinations mentioned above in the specification and the features and feature combinations mentioned below in the description of the drawings and / or shown individually in the drawings can be used not only in the respectively given combination but also in other combinations or individually. Other advantages and application possibilities of the invention are apparent from the following description in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic cross-sectional view showing an exemplary embodiment of an electric machine according to the invention;

[0031] Figure 2 A schematic diagram showing an exemplary embodiment of a support ring according to the present invention;

[0032] Figure 3A schematic diagram shows another exemplary embodiment of a support ring according to the invention. DETAILED DESCRIPTION

[0033] Figure 1 A schematic sectional view shows a detail of an exemplary embodiment of an electric machine 10 according to the invention.

[0034] The electric machine 10 has a rotor 12 , a stator 13 and a flow element 14 , which are arranged on a rotor shaft 11 . The rotor shaft 11 has a cavity 15 through which a fluid can flow and from which a fluid F or coolant (indicated by arrows) can exit the rotor shaft 11 via an outlet 16 .

[0035] The support ring 14 is arranged on the rotor shaft 11 by means of the hub 24 and can be connected to the end face 22 of the rotor 12 in a heat-conducting manner. The guide channel 34 or its collecting structure 44 arranged in the support ring 14 is provided for guiding the fluid F (especially the fluid F that leaves and flows through the guide channel 34 due to the centrifugal force generated during the movement of the rotor) to the end face 54 of the support ring 14. The guide channel 34 is arranged in the area between the hub 24 and the end face 54 of the support ring 14 and opens into the collecting structure 44 arranged on the radial outer end of the guide channel 34. Here, the guide channel 34 encloses an acute angle α with the rotor axis A (in the figure, the angle α is drawn relative to the wall of the rotor shaft 11 for better readability).

[0036] The collecting structure 44 is designed as a recess in the support ring 14 and is provided for collecting the fluid F emerging from the rotor shaft 11 in order to conduct the fluid to the end face 54 of the support ring 14 so that it can be cooled in a targeted manner.

[0037] Figure 2 A schematic diagram of an exemplary embodiment of a support ring 14 for an electric machine 10 according to the invention is shown.

[0038] The support ring 14 is basically constructed as an annular disk with a hub 24 and has a collecting structure 44 on the transition between the hub 24 and its end face 54, which is used to collect the fluid F flowing out of the rotor shaft 11 and guide it to the end face 54 of the support ring 14. For this purpose, every two guide channels 34 lead into a collecting structure 44 constructed as a recess in the support ring 14. The recess is symmetrically arranged around the guide channel 34. A radial collecting wall 18 is constructed on the hub side in the support ring 14 through the recess 44, which can be used to capture the fluid F ejected from the guide channel 34 due to the rotational movement caused by operation and thus prevent uncontrolled outflow. In addition, a collecting bottom 28 axially set back relative to the end face 54 is also constructed on the end face through the recess 44, which helps to collect the fluid F. The recess or collecting structure 44 and / or its collecting wall 18 and / or collecting bottom 28 can have, for example, rounded and / or radially oriented transition surfaces in order to guide the fluid F to the end face 54 of the support ring 14 .

[0039] Figure 3 A schematic diagram shows a further exemplary embodiment of a support ring 14 according to the invention for an electric machine 10 , which substantially corresponds to Figure 2 Support ring 14.

[0040] The support ring 14 has a guide channel 34, which is provided for guiding the fluid flow F in the radial direction so as to enable heat transfer to the fluid F on the end face 54 of the support ring 14. A collecting structure 44 is assigned to each guide channel 34 distributed radially, especially symmetrically, on the hub 24, so as to guide the fluid F discharged from the rotor shaft 11 to the end face 54 of the support ring 14. The collecting structure 44, which is configured as a recess, is arranged offset relative to the guide channel 34, and the first collecting structure 44a is arranged in the first rotation direction D. a and the second current collecting structure 44a in the second rotation direction D b The recess 44 is arranged offset relative to the corresponding guide channel 34 or its outlet. This can be configured in particular in the following manner, that is, the recess 44 is arranged offset relative to the corresponding guide channel 34 in the direction of rotation D a , D b The opposite side has a ratio D a , D b This allows for a larger collection volume on the pump. This allows for a fluid distribution that matches the direction of rotation. Reference numerals list

[0041] 10 Motor

[0042] 11 Rotor shaft

[0043] 12 rotors

[0044] 13 Stator

[0045] 14 Support ring

[0046] 15 Cavity

[0047] 16Exit

[0048] 18 Collector wall

[0049] 22 End face of rotor

[0050] 24 hub

[0051] 28 collector bottom

[0052] 34 Guide Channel

[0053] 44 Current collecting structure

[0054] 54 end face

[0055] A rotor axis

[0056] D a , D b Direction of rotation

[0057] F Fluid

[0058] α angle

Claims

1. An electric motor (10), comprising a rotor (12) arranged on a rotor shaft (11) and a support ring (14) arranged on an end face of the rotor (12), wherein at least one guide channel (34) arranged in the support ring (14) has a flow collecting structure (44), the flow collecting structure being configured to guide a fluid (F) discharged from the rotor shaft (11) to the end face (54) of the support ring (14).

2. The electric machine (10) according to claim 1, wherein: The support ring (14) is arranged on the rotor shaft (11) by means of a hub (24), and the at least one guide channel (34) is arranged on the hub (24) of the support ring (14).

3. The electric machine (10) according to the preceding claim, wherein: The at least one guide channel (34) is arranged in the region between the hub (24) and an end face (54) of the support ring (14).

4. The electric machine (10) according to any one of the preceding claims, wherein: The at least one guide channel (34) encloses an acute angle (α) with the rotor axis (A).

5. The electric machine (10) according to any one of the preceding claims, wherein: The current collecting structure (44) is designed as a recess in the support ring (14).

6. The electric machine (10) according to the preceding claim, wherein The recess is arranged at the radially outer end of the guide channel (34).

7. The electric machine (10) according to any one of the two preceding claims, wherein: The recess is opposite to the direction of rotation (D a , D b ) is arranged offset relative to the guide channel (34).

8. The electric machine (10) according to any one of the preceding claims, wherein: A plurality of guide channels (34) are arranged rotationally symmetrically on the support ring (14). 9 . A support ring ( 14 ) for an electric machine ( 10 ), the support ring being provided for use in an electric machine ( 10 ) according to claim 1 .

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