Liquid-cooled rotor for an electromechanical energy converter

Abstract

The invention relates to a liquid-cooled rotor for an electromechanical energy converter, the liquid-cooled rotor (1) being supported in a manner rotatable about a rotor axis (9) and having a rotor shaft (2) which is at least partially embodied as a hollow shaft and has an open first axial end (2a), and the liquid-cooled rotor (1) further having a liquid guide device (3) which extends into the rotor shaft (2) through the open first axial end (2a), a liquid annular space (5) being produced between the liquid guide device (3) and the rotor shaft (2) in a radial direction (4), and the liquid guide device (3) further having an inner space (3a) for guiding liquid and a liquid inlet opening (3b) into the inner space (3a), the liquid inlet opening (3b) being provided on a first axial end (3c) of the liquid guide device (3), characterized in that the liquid guide device (3) is received indirectly or directly in the rotor shaft (2) on a second axial end (3d) opposite the first axial end (3c) of the liquid guide device (3) and is thus guided relative to the rotor shaft (2), and the liquid guide device (3) has at least one liquid outlet opening (3e) through which the inner space (3a) of the liquid guide device (3) is fluidically connected to the liquid annular space (5), and the liquid outlet opening (3e) is provided between the first and second ends (3c, 3d) of the liquid guide device (3) in an axial direction.

Description

TECHNICAL FIELD

[0001] The present invention relates to a liquid-cooled rotor of an electromechanical energy converter. DE 10 2016 218 823 A1 relates to a cooling system for an electromechanical machine and thereby is in the same technical field as the subject matter of the present invention. US 2008 / 0272661 A1 relates to a liquid-cooled rotor arrangement. BACKGROUND

[0002] The invention is then described by means of an electric machine in a motor vehicle, which is not to be understood as a restriction of the invention to this application. For mobile applications, such as in a motor vehicle, the aim is to achieve a high power density of the electric machine. In order to achieve the maximum possible power density, the rotor in the electric machine is actively cooled, for example by means of a water lance or an oil lance. This is of particular significance in asynchronous electric machines and in externally excited synchronous electric machines. Insufficient cooling leads to an early degradation of the drive. A water lance requires a costly slip ring seal at the rotor inlet of the cooling channel. As an alternative to water lance cooling, the rotor can be cooled by means of oil cooling with transmission oil. In order to generate a cooling oil flow through the rotor, an oil pump is provided, a mechanical oil pump showing a loss power which increases with the rotational speed, which can adversely affect the efficiency of the drive. Furthermore, an oil pump usually requires an electrical pump control, which can increase the error susceptibility and thereby adversely affect the system reliability. SUMMARY

[0003] The task of the present invention is to specify a liquid-cooled rotor of an electromechanical energy converter with improved operating characteristics and an electromechanical energy converter with such a rotor, which task is solved by the subject matter of the present invention.

[0004] In the sense of the present invention, a liquid-cooled rotor for an electromechanical energy converter is to be understood as a rotor for an electric motor, a generator or an electric motor / generator, which rotor can be temperature-regulated and in particular cooled with a liquid medium. Preferably, the liquid for temperature regulation is a lubricating material and preferably engine oil or transmission oil. Depending on the construction type of the electromechanical energy converter, the rotor is configured as an electrically passive or electrically active element, wherein the present invention can be applied independently of this characteristic. The liquid-cooled rotor has a rotor shaft, which in the case of an engine-type operation constitutes a drive power output and in the case of a generator-type operation constitutes a drive power input (torque, rotational speed), and which is supported in a rotatable manner about a rotor axis. Furthermore, the rotor shaft constitutes at least in sections a hollow shaft and has an open first axial end. Furthermore, the liquid-cooled rotor has a liquid guiding device, which is designed to guide a liquid, which is provided for temperature-regulating the rotor.

[0005] The liquid guiding device extends through the first axial end of the opening of the rotor shaft into the hollow shaft section of the rotor shaft. Figuratively speaking, the rotor shaft and the liquid guiding device form at least partially two tubular members which are inserted into one another, wherein the rotor shaft surrounds the liquid guiding device. The rotor shaft and the liquid guiding device are preferably materially bonded to one another and are preferably configured in one piece.

[0006] A liquid annular space is formed at least partially between the liquid guiding device and the rotor shaft in the radial direction. By this, the possibility is functionally achieved to introduce liquid into the rotor shaft via the liquid guiding device (the radially inner tube member) and to lead the liquid out of the rotor shaft again via the annular gap formed locally between the rotor shaft and the liquid guiding device, the so-called liquid annular space. For the configuration of this functionality, the liquid guiding device has an inner space for guiding the liquid and a liquid inlet opening into the inner space, which is provided on the first axial end of the liquid guiding device.

[0007] The liquid guiding device extends in the axial direction along the rotor shaft line up to its second axial end. That is, the second axial end of the liquid guiding device is opposite the first axial end thereof.

[0008] The liquid guiding device is received in the rotor shaft indirectly or directly, in particular axially at the second end of the liquid guiding device or with the second axial end of the liquid guiding device. In a preferred embodiment, the rotor shaft has a rotor shaft end section, with which the rotor shaft is preferably closed. It is further preferred that the rotor shaft end section is received in or on the rotor shaft and it is further preferred that the rotor shaft end section is configured in one piece with the rotor shaft or is preferably connected with the rotor shaft.

[0009] In a further preferred embodiment, the liquid guiding device is received with its second axial end in the rotor shaft end section and the liquid guiding device is thus received indirectly with respect to the rotor shaft at least in the region of its second axial end. In particular, by this configuration a modular construction of the rotor shaft with the rotor shaft end section and the liquid guiding device can be achieved. It is further preferred that the liquid guiding device is received on its second axial end in the rotor shaft end section in such a way that the liquid guiding device is fluid-tightly closed on this end.

[0010] In a further preferred embodiment, the liquid guiding device has a support section on its second axial end. The support section is preferably understood to be a section of the liquid guiding device which extends radially outward, preferably from the second axial end of the liquid guiding device, through a liquid annular space which is formed between the liquid guiding device and the rotor shaft. It is further preferred that the liquid guiding device is supported and preferably centered with respect to the rotor shaft, in particular in the region of the second axial end of the liquid guiding device, via the support section. In particular, the liquid guiding device is directly received with respect to the rotor shaft by means of the support section. In particular, a direct and thereby precise centering of the liquid guiding device in the rotor shaft can be achieved by means of the support section. In a preferred embodiment, the support section fluid-tightly encloses the liquid interior space of the liquid guiding device with respect to the liquid annular space. In particular, by means of this design it can be achieved that the liquid reaches the liquid annular space from the liquid interior space only through the one or more liquid discharge openings and that a precise metering of the liquid flow into the liquid annular space can be achieved.

[0011] In a further preferred embodiment, the support section has at least one support section gap or a plurality of support section gaps, through which the liquid annular space is fluidically connected to the liquid interior space of the liquid guiding device. In particular, by means of at least one such support section gap it can be achieved that the liquid flows from the second axial end of the liquid guiding device into the liquid annular space. In particular, the at least one support section gap or its size is coordinated with the liquid discharge opening or its size, so that by this coordination a determined induced flow of the liquid through the liquid annular space is predetermined.

[0012] Further, the liquid guiding device is received in the region of its second axial end or with its second axial end in a rotor shaft end section. It is preferred that the rotor shaft end section is formed in one piece with the rotor shaft or is connected to the rotor shaft as a separate component. It is further preferred that the liquid guiding device is centered with respect to the rotor shaft and further preferably with respect to the rotational axis by means of the rotor shaft end section. It is further preferred that by means of the rotor shaft end section a preferably radially more uniform liquid annular space is obtained.

[0013] The liquid guiding device furthermore has at least one liquid discharge opening, preferably a plurality of liquid discharge openings. Such a liquid discharge opening is here understood in particular as a recess in the liquid guiding device, through which the interior space of the liquid guiding device is fluidically connected to the liquid annular space. Furthermore, the at least one liquid discharge opening and preferably all liquid discharge openings are arranged in the axial direction between the first and second end of the liquid guiding device. In particular, the possibility of a "free" positioning of the liquid discharge opening, in particular in the axial direction, opposite the discharge of the liquid through the axial end of the liquid guiding device, which is known from the prior art, enables a simple possibility of guiding the liquid out of the liquid guiding device at the point of need and thus enables an improved cooling and thus an improved operating behavior. It is further preferred that a plurality of liquid discharge openings are arranged and preferably spaced apart from one another in the axial direction, i.e. along the axis of rotation.

[0014] In a preferred embodiment, the liquid guiding device has a liquid guiding tube and an output shaft member. In particular, by the liquid guiding device consisting of a plurality of components, a desired configuration of the liquid guiding device can be achieved. The output shaft member is preferably non-rotatably connected to the rotor shaft and preferably has at least one bearing seat for receiving a bearing device for rotatably bearing the rotor shaft. It is further preferred that the output shaft member is completely configured as a hollow shaft member.

[0015] It is further preferred that the liquid inlet opening is arranged on a first axial end of the output shaft member and the liquid guiding tube is arranged on a second axial end of the output shaft member, in particular opposite the first axial end. The liquid guiding tube is thereby preferably arranged with the first axial end on the second axial end of the output shaft member. The liquid guiding tube is preferably received with the second axial end on the rotor shaft end section and this second axial end of the liquid guiding tube thereby forms the second axial end of the liquid guiding device. This second axial end of the liquid guiding tube is preferably not arranged in the rotor shaft end section, but rather a support section is preferably arranged on this second axial end of the liquid guiding tube and this second axial end of the liquid guiding tube further preferably thereby forms the second axial end of the liquid guiding device. The liquid guiding tube is preferably funnel-shaped expanded in the region of the support section, and it is further preferred that this expanded region of the liquid guiding tube is supported relative to the rotor shaft, so that the liquid guiding tube is directly received in the rotor shaft in the region of its second axial end.

[0016] It is further preferred that the liquid guide tube, in particular without taking the support section into account, is configured as an at least substantially cylindrical component, preferably as a circular-cylindrical component. It is preferred that the at least one liquid discharge opening extends radially outward through a wall of the liquid guide tube, wherein the wall can be understood as a lateral surface of the liquid guide tube. As stated, the at least two-piece design of the liquid guide device in particular results in the possibility of configuring the liquid guide device as desired.

[0017] In a preferred embodiment, the liquid guide device and preferably the output shaft component are received in the rotor connection region in the rotor shaft. It is preferred that at least one liquid guide channel is provided in the rotor connection region, which can be understood as a free space provided radially between the rotor shaft and the liquid guide device. The liquid-cooled rotor preferably has a plurality of such liquid guide channels. In particular, the at least one liquid guide channel is configured such that, with the liquid guide channel, a liquid annular space, in particular a gap between the rotor shaft and the liquid guide device in the region of the liquid guide tube, is fluidically connected to the environment surrounding the liquid-cooled rotor. Depending on the structural form of the electric machine in which the liquid-cooled rotor is used, the environment surrounding the rotor can be an interior space of a housing. In particular, by means of this rotor connection region between the liquid guide device and the rotor shaft, it is possible to achieve a simple outflow of liquid from the liquid annular space and thereby an improved cooling effect.

[0018] In a preferred embodiment, the rotor connection region has at least one torque transmission region and at least one centering region. In particular by this configuration, the centering is functionally separated from the torque transmission and a centering with high precision and a torque transmission (from the rotor shaft to the liquid guide device, in particular the output shaft component) can be achieved. It is preferred that the torque transmission region and the centering region are arranged spaced apart from one another in the axial direction. It is further preferred that the torque transmission region is configured as a hub connection having a form-fit connection. The hub connection preferably has toothings which are embedded into one another, wherein a tooth gap is preferably provided in the toothings, so that a liquid guide channel is configured in this region by means of the tooth gap.

[0019] It is further preferred that, in order to constitute the liquid guiding channel, a recess is provided in the centering region. It is preferred that the centering region is constituted by a shaft section on the liquid guiding device and a bore section or recess section in the rotor shaft, wherein the shaft section together with the bore section has a corresponding centering functionality for the rotor connection region. It is preferred that, in particular, the flattening or the flattening section is to be understood as a recess in this sense, further, the recess is to be understood as a slot-like recess in the centering region in the rotor shaft or in the liquid guiding device. In particular, by this design of the liquid guiding channel, a high accuracy can be achieved with the centering region and a good torque transmissibility can be achieved with the torque transmission region, and further, thus a small structural space requirement for the liquid guiding channel can be achieved by the rotor connection region.

[0020] Further, an electromechanical energy converter is proposed, which has a liquid-cooled rotor in one of the previously described configurations. In such an electromechanical energy converter, the rotor shaft is rotatably supported in the housing device. Further, an energy converter rotor is connected non-rotatably with the rotor shaft, which rotor can have one or more windings or other magnetic or non-magnetic components, depending on the configuration of the electromechanical energy converter, wherein the present application can be applied independently of the configuration of the rotor. Further, an output pinion is provided on the rotor shaft, which output pinion is preferably designed for the transmission of drive power in the form of rotational speed and torque from or to the rotor shaft. The output pinion is preferably provided on the liquid guiding device and preferably on the output shaft component and is preferably connected in one piece with the output shaft component.

[0021] Further, an electromechanical energy converter is proposed, which has a liquid-cooled rotor in one of the previously described configurations. In such an electromechanical energy converter, the rotor shaft is rotatably supported in the housing device. Further, an energy converter rotor is connected non-rotatably with the rotor shaft, which rotor can have one or more windings or other magnetic or non-magnetic components, depending on the configuration of the electromechanical energy converter, wherein the present application can be applied independently of the configuration of the rotor. Further, an output pinion is provided on the rotor shaft, which output pinion is preferably designed for the transmission of drive power in the form of rotational speed and torque from or to the rotor shaft. The output pinion is preferably provided on the liquid guiding device and preferably on the output shaft component and is preferably connected in one piece with the output shaft component.

[0022] Furthermore, an output pinion is provided on the liquid-cooled rotor, which output pinion engages with a counter gear for power transmission. The counter gear is at least partially surrounded by a liquid collection section of the liquid transport device in the radial direction or in the circumferential direction. That is, the liquid collection section is thus at least partially delimited by the circumference or the peripheral surface of the counter gear. The liquid collection section is preferably configured such that the counter gear is immersed in the liquid, which is received in the liquid collection section. It is further preferred that the liquid collection section is configured such that at least one tangent to the circumference of the counter gear runs in the region of the liquid collection section in the direction of the first axial end of the liquid guiding device. In particular, the direction of the tangent can be understood here as the tangent being projected into a plane running through the first axial end of the liquid guiding device, which plane is arranged orthogonally to the rotational axis, and the tangent running in this plane in the direction of the first axial end of the liquid guiding device.

[0023] In other words, with the counter gear, a liquid flow in the direction from the liquid collection section towards a liquid inlet opening, which is provided in the first axial end of the liquid guiding device, can be generated preferably in the preferred direction of rotation. In particular, with this design of the application, in the planned operation of the electromechanical energy converter, a targeted transport of liquid from the liquid collection section towards the liquid inlet opening and thus, in particular, a high-efficiency cooling of the liquid-cooled rotor can be achieved in the direction of rotation of the counter gear, preferably in the preferred direction of rotation.

[0024] In a preferred embodiment of the application, in the planned installation position of the electromechanical energy converter, the output pinion is at least partially covered in the axial direction at least partially or preferably completely by the liquid transport device. The liquid transport device preferably has a liquid collection section, which is arranged at least partially above the output pinion in the planned installation position, so that in the planned operation of the electromechanical energy converter, in which the output pinion rotates about the rotational axis, liquid that is centrifugally separated upwards by the output pinion or another gear is at least partially collected by the liquid collection section. In this regard, the upward direction also relates to the planned installation position of the electromechanical energy converter. In particular, with this design, it is possible to collect the liquid that is centrifugally separated upwards by the output pinion with the liquid collection section and to flow the liquid automatically, in particular, without a pump device, under the force of gravity of the liquid to predefined locations. In particular, the liquid transport takes place on the liquid transport device without pressure and preferably only under the force of gravity. In particular, with this design of the electromechanical energy converter, an automatic liquid movement for rotor cooling can be achieved, in particular, without additional energy consumption.

[0025] In one preferred embodiment of the application, a radially encircling and radially inwardly projecting plug-in section is formed at the liquid inlet opening. Preferably, this plug-in section is to be understood as a radial narrowing, preferably a radial narrowing at the liquid inlet opening. In particular, with the aid of such a plug-in section, liquid can only flow out of the liquid guiding device in the case where the liquid fill level exceeds the plug-in section, as a second possibility, liquid is discharged from the liquid guiding device via the liquid discharge opening. In particular, with the aid of the plug-in section, the preferred flow direction from the liquid inlet opening towards the liquid discharge opening is facilitated in the planned operation of the electromechanical energy converter. In particular, with the aid of the proposed plug-in section, the desired flow setting (from the liquid inlet opening towards the liquid discharge opening) is imposed on the liquid for cooling the liquid-cooled rotor in the liquid guiding device, without additional pump devices being required for this purpose.

[0026] In one preferred embodiment of the electromechanical energy converter, the liquid guiding device has a liquid guiding section. This liquid guiding section is preferably formed as a raised section of the liquid guiding device. This raised section preferably extends through the liquid inlet opening or into the liquid inlet opening in the axial direction. The liquid guiding section is arranged below the liquid collecting section in the planned installation position of the electromechanical energy converter, so that the liquid collected by the liquid collecting section flows under the force of gravity to the liquid guiding section. Preferably, an additional guiding element is provided, which improves the targeted flow of liquid from the liquid collecting section to the liquid guiding section. In particular, with this design, a pumpless flow from the liquid collecting section to the liquid guiding section can be achieved.

[0027] In one preferred embodiment, the liquid guiding section extends through the liquid inlet opening in the axial direction and beyond the plug-in section into the interior space of the liquid guiding device. In particular, with this design, a particularly large amount of the liquid collected in the liquid collecting section is used for cooling the rotor, since this liquid is deposited behind the plug-in section in the preferred flow direction.

[0028] Further preferably, the liquid delivery section is introduced into the liquid inlet opening in a non-fluidically sealed manner. In particular, in systems known in the art for rotor cooling that guide pressurized liquid into the rotor, the liquid path is fluidly sealed, because otherwise leakage would occur and a bypass of the liquid would form. In known systems, fluid sealing at the transition from the stationary liquid delivery device to the rotatably supported rotor is achieved with a partially worn and partially contacting sealing device at that transition. The present invention preferably proposes an open system at this transition, in which an open area remains in the inlet opening except for the liquid delivery section. Figuratively speaking, in this embodiment, the liquid delivery section does not completely fill the liquid inlet opening. In particular, this configuration enables a simple construction and high efficiency, because the sealing device between the liquid delivery section and the liquid inlet opening can be eliminated or can be constructed only partially, preferably in the form of a scraper ring or the like, and thus only small or no sealing loss occurs at this location. Attached Figure Description

[0029] The various features of the invention and its embodiments are then described in more detail with the aid of the accompanying drawings, in which:

[0030] Figure 1 A partial longitudinal sectional view of an electromechanical energy converter with a liquid-cooled rotor is shown.

[0031] Figure 2 A partial longitudinal sectional view is shown in the region of the output shaft with the output pinion of the liquid-cooled rotor;

[0032] Figure 3 An exploded perspective view of the liquid-cooled rotor is shown.

[0033] Figure 4 Two cross-sections of the liquid-cooled rotor in the connection area are shown;

[0034] Figure 5 Two longitudinal sectional views of a liquid-cooled rotor with a support section are shown;

[0035] Figure 6 A partial perspective view of a pair of gears having a preferred direction of rotation is shown. Detailed Implementation

[0036] exist Figure 1 A partial longitudinal sectional view of an electromechanical energy converter with a liquid-cooled rotor 1 is shown in the figure. Figure 2An enlarged view of the same embodiment, in particular of the output shaft member 3g, is shown in Fig. 3. The liquid-cooled rotor 1 is constructed in multiple parts, with the rotor shaft 2, which guides the energy converter rotor 11 and is supported in a manner rotatable about a rotor axis 9, and the liquid guide device 3, which itself has the output shaft member 3g and the liquid guide tube 3f as component parts, as main components.

[0037] The liquid guide tube 3f is received in its first axial end 3fI in the second axial end 3gII of the output shaft member 3g and in its second axial end 3fII in the rotor shaft end section 2b of the rotor shaft 2. The liquid guide tube 3f is understood to be a so-called oil lance. The rotor shaft end section 2b encloses the second axial end 3fII of the liquid guide tube 3f and positions the liquid guide tube 3f in this region relative to the rotor shaft 2. The liquid guide tube 3f has a plurality of liquid discharge openings 3e on its tube wall, which are directed away from both the first axial end 3fI and the second axial end 3fII of the liquid guide tube 3f in the axial direction 10. In this multiple-part embodiment of the liquid guide device 3 (output shaft member 3g, liquid guide tube 3f), the second axial end 3d of the liquid guide device 3 and the second axial end 3fII of the liquid guide tube 3f coincide or correspond to one another, and the same applies to the first axial end 3b of the liquid guide device 3 and the first axial end 3gI of the output shaft member 3g.

[0038] The liquid-cooled rotor 1 is supported in the housing device 0 in a manner rotatable about the rotation axis 9, in particular via the groove ball bearing 15, the radial direction 4 being orthogonal to the rotation axis 9.

[0039] In the intended operation of the electromechanical energy converter, the electromechanical energy converter outputs drive power (rotational speed, torque) via the output pinion 12 to a further gearwheel (not shown), which is formed in one piece with the output shaft member 3g. The gearwheel stage (output pinion 12, further gearwheel) is oil-lubricated. By the rotational movement of the output pinion and / or the further gearwheel, oil is centrifuged therefrom. The centrifuged oil is at least partially collected by the liquid transport device 13. The liquid transport device 13 has for this purpose a liquid collection section 13a. The liquid collection section 13a at least partially covers the output pinion 12 in the axial direction 10 and is arranged in the shown intended installation position of the electromechanical energy converter, which corresponds to the shown position, above the liquid entry opening 3b. The oil collected in the liquid collection section 13a flows downward, i.e. in the direction of the liquid entry opening 3b, under the influence of gravity. The liquid transport device 13 additionally has a liquid transport section 13b, which can be formed as a bearing cover or housing member. The liquid transport section 13b extends in the axial direction 10 through the liquid entry opening 3b and the collected oil is thereby transported via the liquid transport device 13 to the interior space 3a of the liquid guide device. This transport takes place as stated under the influence of gravity and thereby without pressure, so that a sealing device at the transition of the rotatably supported liquid-cooled rotor 1 to the stationary and fixedly mounted liquid transport device 13 of the housing is superfluous.

[0040] At the first axial end 3c, i.e. at the liquid entry opening 3b, a plug-in section 14 is formed. The plug-in section 14 is a radially circumferentially and radially inwardly projecting region in the output shaft member and prevents the oil from flowing out of the output shaft member in the direction from the liquid entry opening 3b to the liquid discharge opening 3e in the reverse direction. The liquid transport section 13b projects in the axial direction 10 beyond this plug-in section 14, so that the oil can reliably be conducted out of the liquid transport section behind the plug-in section 14 into the interior space 3a.

[0041] By the rotation of the liquid-cooled rotor 1, the oil introduced via the liquid transport device 13 is discharged from the interior space 3a of the liquid guide tube 3f radially outwardly through the liquid discharge opening 3e. Thus, by the centrifugal force, a preferred direction for the transported oil from the liquid entry opening 3b to the liquid discharge opening 3e is formed in the liquid guide device 3 into its interior space 3a.

[0042] The oil reaches the liquid annular space 5 between the liquid guide tube 3f and the rotor shaft 2 from the liquid discharge opening 3e under the effect of centrifugal force. The liquid guide channel 7, through which the liquid, i.e. currently the oil, is discharged from the liquid annular space 5 to the environment surrounding the liquid-cooled rotor 1, extends through the connecting region 6 in which the output shaft member 3g is connected to the rotor shaft 2 by means of the centring region 6a and the torque transmission region 6b. The torque transmission region 6b is configured as a hub connection with a toothed portion. The centring region is configured as a substantially cylindrical shaft section or hub section, wherein the shaft section has a flattened region which is to be understood in this sense as a recess, so that the liquid guide channel 7 extends through the torque transmission region 6b and the centring region 6a on the one hand through the mentioned regions.

[0043] In Figure 2 It can be seen in particular in that the liquid delivery section 13b of the liquid delivery device 13 extends into the interior space 3a beyond the plug-in section 14 in the axial direction 10, which interior space is formed in the output shaft member 3g and the liquid guide tube 3f. The plug-in section 14 extends radially inwardly into the interior space 3a, but is spaced apart from the liquid delivery section, so that no frictional losses occur between the output shaft member 3g with the plug-in section 14 and the liquid delivery device 13 with the liquid delivery section 13b.

[0044] In Figure 3 A perspective exploded view of the individual components of the liquid-cooled rotor 1 is shown in Figure 1 and 2 The rotor shaft end section 2b can receive a further bearing for rotatably supporting the liquid-cooled rotor 1 and is connected to the rotor shaft 2 in the assembled state. The rotor shaft 2 is substantially configured as a hollow shaft. The liquid guide tube is received in the output shaft member 3g with its first axial end 3fI and in the rotor shaft end section 2b with its second axial end 3fII. With these two receptions, the liquid guide tube 3f can be held centred with respect to the rotor shaft 2 and with respect to the axis of rotation 9. The liquid guide tube 3f has a liquid discharge opening 3e through which the liquid guided in the liquid guide tube 3f can be discharged as intended from the liquid guide tube.

[0045] The output shaft member 3g has an output pinion 12 which is embodied as a cutaway toothed portion. The output shaft member 3g pushes with its second axial end 3gII into the rotor shaft 2 and is connected to this in the connecting region. The plug-in section is formed in the output shaft member 3g by a separate component and more precisely by a plug-in section ring 14a which is to be pressed into it on the first axial end 3gI of the output shaft member 3g.

[0046] In Figure 4Two cross-sectional views (II, IV) and two enlarged detail views (I, III) of these cross-sectional views (II, IV) are shown, which lead through the connecting region in different axial positions, here detail view I belongs to cross-sectional view II and detail view III belongs to cross-sectional view IV.

[0047] In cross-sectional view II the cross-section of the torque transmission region 6b is shown, here the rotational axis 9 is cut orthogonally. The liquid guiding tube 3f is visible as an annular surface. The output shaft member 3g has an outer toothing, which is engaged into an inner toothing in the rotor shaft 2 for torque transmission. In these mutually engaged toothing (inner toothing / outer toothing) the liquid guiding channel 7 or several such channels are constituted. In detail view I, which belongs to this cross-sectional view II, it is visible that with regard to the outer toothing of the output shaft member 3g there are notches on each tooth tip and each tooth root, through which notches liquid can flow through the torque transmission region 6b, so that these notches form the liquid guiding channel in the torque transmission region 6b.

[0048] In cross-sectional view IV the cross-section of the centering region 6a is shown, here the rotational axis 9 is cut orthogonally. The output shaft member 3g has an essentially circular outer surface, which is engaged into a circular inner surface in the rotor shaft 2 for centering and thus centers the output shaft member 3g with regard to the rotor shaft 2. In these mutually engaged surfaces (inner surface / outer surface) the liquid guiding channel 7 or currently two such channels are formed through gaps in the outer surface of the output shaft member 3g. In detail view III, which belongs to this cross-sectional view IV, it is visible that the outer surface of the output shaft member 3g is flattened, in particular through the gaps. Through this flattening notches are obtained, which are visible in detail view III, which form the liquid guiding channel 7, through which liquid can flow through the centering region 6a. In other words, through this gap or flattening the liquid guiding channel 7 is formed in the centering region 6a.

[0049] In other words, the cooling design for the rotor of the electromechanical energy converter is premised on the fact that the components of the drive device, which introduce losses, are spatially arranged in the vicinity of the transmission construction space. It is proposed to use the transmission oil as liquid for cooling the liquid-cooled rotor. The idea of the proposed design is to utilize the oil flow in the transmission based on the gear motion in such a way that the oil is transported into the liquid-cooled rotor of the electromechanical energy converter without an oil pump, i.e. passively. The components of the proposed invention are here in particular:

[0050] 1. Oil transport from the axially open shaft end into the rotating hollow shaft region, in particular into the liquid guiding device.

[0051] 2. Oil is transported through the hollow shaft region (into which the oil has been fed) and the so-called oil lance, in particular the liquid guide tube, based on centrifugal acceleration.

[0052] 3. Oil is discharged from the oil lance, in particular the liquid guide tube, into the rotor shaft radially outside, on which the heat input occurs as a result of the conversion of electrical power (voltage, current) into mechanical power (rotational speed, torque).

[0053] 4. The oil flows back into the transmission space (in which the output pinion is arranged, in particular), i.e. into the environment surrounding the liquid-cooled rotor.

[0054] The oil feed to the output pinion can take place actively, i.e. in particular by means of an electrical or mechanical oil pump, but is usually implemented passively on account of efficiency and cost advantages, in particular oil immersion lubrication. The output shaft member 3g is positioned in an oil chamber of the transmission, whereby the transmission oil based on the gear motion is sprayed in the environment. The transmission oil sprayed onto the bearing cap with the liquid feed device 13 remains attached there and flows based on gravity and, if necessary, in conjunction with the oil guide geometry on the housing side into the liquid feed section 13b, which is configured as a drip tray. The output shaft member 3g and the liquid guide tube 3f are currently configured as separate components, but can also be configured in one piece with one another.

[0055] On account of the rotational motion of the output shaft member 3g together with the rotor shaft 2 in the planned operation of the electromechanical energy converter and the oil lance, i.e. the liquid guide tube 3f, guided therein, there is a high centrifugal force on the radius of the inner wall of the liquid guide tube 3f, which causes the oil introduced to adhere to the inner wall. The axial extension associated therewith of the oil leads to an oil feed along the output shaft member 3g and the liquid guide tube 3f, i.e. in the interior space 3. The plug-in section 14 directly below the drip tray of the liquid feed section 13b in the region of the open shaft end, i.e. of the liquid entry opening 3b, prevents the oil from flowing back out into the transmission space, i.e. into the environment 8 surrounding the liquid-cooled rotor 1, so that the oil is fed in the axial direction towards the other end of the oil lance, i.e. towards the liquid discharge opening 3e and thereby towards the energy converter rotor.

[0056] If the oil in the liquid guide tube 3f reaches the liquid discharge opening 3e, the oil is sprayed from the oil lance (liquid guide tube 3f) into the rotor shaft 2, which is configured as a hollow shaft, and thereby into the liquid annular space 5. On account of the centrifugal acceleration in the rotating rotor shaft 2, the oil adheres to the inner wall radially outside the rotor shaft 2. There the oil receives heat from the energy converter rotor 11 and contributes to the cooling of the energy converter rotor.

[0057] The oil flow in the proposed embodiment flows through the toothing of the torque transmission region 6b and the flattening in the centering region 6a, i.e. the oil flows back into the transmission space through one or more liquid guide channels thus formed. The oil is hereby transported back to the point from which it was previously taken away and thus currently concerns a closed oil circuit.

[0058] The oil flow in this case additionally lubricates possible toothing. The rotor shaft 2 and the output shaft member 3g are currently configured as separate members, which can also be implemented in one piece. In the case of a one-piece construction (rotor shaft 2 and output shaft member 3g configured in one piece), at least one liquid guide channel can be formed through a radial gap or a radial hole through the one-piece member, wherein the radial gap leads from the liquid annular space back to the environment 8 surrounding the liquid-cooled rotor, in particular to the transmission space.

[0059] In Figure 5 a first variant of a liquid-cooled rotor with a support section (fluid-tight support section) is shown in Figure 5 a and a liquid-cooled rotor with a support section (support section with support section gap) is shown in Figure 5 b. Reference is also made to the explanations of the liquid-cooled rotor according to Figures 1 to 4 so that the differences of the embodiments shown in Figure 5 are then mainly discussed.

[0060] In the embodiment of the liquid-cooled rotor 1 shown in Figure 5 a, the liquid guide tube 3f is received in a fluid-tight support section 16a configured as a cover. The fluid-tight support section 16a centers the liquid guide tube 3f with respect to the rotor shaft 2 and fluid-tight closes the second axial end 3fll of the liquid guide tube 3f. In the embodiment shown, the discharge of liquid from the liquid guide tube 3f via the liquid discharge opening 3e can be achieved. An embodiment is shown in which the fluid-tight support section 16a is attached to the liquid guide tube 3f as a separate member, but the support section can also be configured in one piece with the liquid guide tube 3f.

[0061] In Figure 5 b, an embodiment of the application is shown in which the support section 16b is provided with support section gaps 16c. With these support section gaps 16c, a liquid flow from the second axial end 3fll of the liquid guide tube 3f into the liquid annular space 5 can be achieved. Via the configuration of one support section gap 16c or multiple support section gaps, the amount of liquid reaching the liquid annular space 5 on this path can be structurally adjusted.

[0062] In Figure 6A partial perspective view of the housing device 0 together with the mating gear 17 is shown in Fig. 1. The mating gear 17 engages for power transmission with an output pinion 12 (not shown) of a liquid-cooled rotor 1 (not shown), the mating gear 17 being at least partially surrounded here in the peripheral direction by the liquid section 13a.

[0063] In the planned operation, the mating gear 17 rotates in the preferred direction of rotation 18, the mating gear 17 being immersed in the liquid collected in the liquid collection section 13a here. The liquid collection section 13a is formed by the guide element 20 and the housing device 0. By the rotational movement of the mating gear 17 in the preferred direction of rotation 18, the liquid is transported from the liquid collection section 13a in the direction of the tangent 19 onto the mating gear 17 and thereby towards the liquid delivery section 13b.

[0064] In particular, the liquid is transported from the liquid collection section 13a in the direction of the tangent 19 onto the mating gear 17, since the mating gear 17 is partially surrounded in the radial direction by the liquid collection section 13a. The liquid collection section 13a is arranged here such that the tangent 19 runs in the liquid collection section 13a in the direction of the first axial end of the liquid guide device (not shown). The liquid delivery section 13b projects in the assembled state into the liquid guide device (not shown). Thus, as shown in Fig. 1, in the planned operation of the electromechanical energy converter with the liquid-cooled rotor, the liquid is transported from the liquid collection section 13a in the preferred direction of rotation 18 of the mating gear 17 to the liquid entry opening 3b, in particular for cooling the liquid-cooled rotor 1 in operation, and the liquid-cooled rotor 1 is thus cooled by the liquid without an additional pump. Figures 1 to 5

[0065] Briefly, the present application proposes two possibilities, namely how the liquid, in particular the transmission oil, can get from the liquid collection section into the liquid guide device and how the liquid can contribute there, in particular to the cooling of the liquid-cooled rotor. On the one hand it is possible to use these effects individually, and on the other hand it is possible to use them in combination. One of the available effects is the force of gravity, the other is the transport action of the gear, in particular the mating gear. That is, on the one hand the liquid collection section can be arranged at least partially geodetically above the liquid entry opening in the planned installation position of the electromechanical energy converter (force of gravity), and on the other hand the liquid collection section can be arranged such that the tangent in the liquid collection section onto the mating gear points in the direction of the liquid entry opening (transport action of the mating gear).

[0066] List of reference signs

[0067] ​

Claims

1. Liquid-cooled rotor for an electromechanical energy converter, the liquid-cooled rotor (1) being supported in a manner rotatable about a rotor axis (9) and having a rotor shaft (2), which is at least partially configured as a hollow shaft and has an open first axial end (2a), and the liquid-cooled rotor (1) further having a liquid guide device (3), which extends into the rotor shaft (2) through the open first axial end (2a), creates a liquid annular space (5) between the liquid guide device (3) and the rotor shaft (2) in a radial direction (4), and further has an inner space (3a) for guiding liquid and a liquid inlet opening (3b) into the inner space (3a), which is provided on a first axial end (3c) of the liquid guide device (3), characterized in that the liquid guide device (3) is received indirectly or directly in the rotor shaft (2) on a second axial end (3d) opposite the first axial end (3c) of the liquid guide device (3) and is thus guided relative to the rotor shaft (2), and in that the liquid guide device (3) has at least one liquid discharge opening (3e) through which the inner space (3a) of the liquid guide device (3) is fluidically connected to the liquid annular space (5), and in that the liquid discharge opening (3e) is arranged in the axial direction between the first axial end (3c) and the second axial end (3d) of the liquid guide device (3), the liquid guide device (3) has a liquid guide tube (3f) and an output shaft member (3g), and the liquid inlet opening (3b) is arranged on a first axial end of the output shaft member (3g), and the liquid guide tube (3f) is arranged on a second axial end of the output shaft member (3g), and the liquid guide tube (3f) is received on the output shaft member (3g) with a first axial end, and the at least one liquid discharge opening (3e) extends through a wall of the liquid guide tube (3f), wherein the output shaft member is non-rotatably connected relative to the rotor shaft, and the output shaft member is completely configured as a hollow shaft member. the liquid guide tube (3f) is received on a rotor shaft end section (2b) with a second axial end (3fll) of the liquid guide tube (3f). the output shaft member (3g) is received in the rotor shaft (2) in a rotor connection region (6), and in the rotor connection region (6) there is arranged at least one liquid guide channel (7) with which the liquid annular space (5) is fluidically connected to an environment (8) surrounding the liquid-cooled rotor (1).

2. The liquid-cooled rotor according to claim 1, characterized in that the connection region (6) has a torque transmission region (6b) and a centering region (6a), and the torque transmission region (6b) and the centering region (6a) are spaced apart from one another along the rotor axis (9) in the axial direction (10), and 3. The liquid-cooled rotor according to claim 1 or 2, characterized in that the centering region (6a) is configured as a hollow centering region. ​ 4. The liquid-cooled rotor of claim 3, wherein ​ The liquid guiding channel (7) is configured as a gap on the rotor shaft (2) or on the output shaft member (3g) in the centering region (6a).

5. Electromechanical energy converter having a liquid-cooled rotor (1), characterized in that The liquid-cooled rotor (1) is supported in a manner rotatable about a rotor axis (9) and has a rotor shaft (2) which is at least partially configured as a hollow shaft and has an open first axial end (2a), and the liquid-cooled rotor (1) furthermore has a liquid guiding device (3) which extends into the rotor shaft (2) through the open first axial end (2a), creates a liquid annular space (5) between the liquid guiding device (3) and the rotor shaft (2) in a radial direction (4), and furthermore has an inner space (3a) for guiding liquid and a liquid inlet opening (3b) into the inner space (3a), which liquid inlet opening (3b) is provided on a first axial end (3c) of the liquid guiding device (3), which liquid guiding device (3) is received indirectly or directly in the rotor shaft (2) on a second axial end (3d) opposite the first axial end (3c) of the liquid guiding device (3) and is thus guided relative to the rotor shaft (2), and which liquid guiding device (3) has at least one liquid outlet opening (3e) through which the inner space (3a) of the liquid guiding device (3) is fluidically connected to the liquid annular space (5), and which liquid outlet opening (3e) is provided in the axial direction between the first axial end (3c) and the second axial end (3d) of the liquid guiding device (3), The liquid-cooled rotor is rotatably supported in a housing device (0), the energy converter rotor (11) is connected to the rotor shaft (2) in a manner that is not rotatable relative to it, and An output pinion (12) is provided on the liquid-cooled rotor (1), and In the intended installation position of the electromechanical energy converter, the output pinion (12) meshes with a counter gear for power transmission, which counter gear is at least partially surrounded in the radial direction by a liquid collection section (13a) of a liquid delivery device (13), and the liquid collection section (13a) is configured such that at least one tangent on the counter gear runs in the direction of the first axial end of the liquid guiding device in the liquid collection section (13a), so that in the intended operation, liquid can be delivered from the liquid collection section (13a) to the liquid inlet opening (3b) by the counter gear in the direction of rotation of the counter gear.

6. The electromechanical energy converter of claim 5, wherein A radially encircling and radially inwardly projecting plug-in section (14) is configured on the liquid inlet opening (3b).

7. The electromechanical energy converter according to claim 6, characterized in that The liquid delivery device (13) has a liquid delivery section (13b), The liquid delivery section (13b) is configured as a raised section on the liquid delivery device (13), and the liquid delivery section extends into the liquid guiding device (3) through the liquid entry opening (3b) in the axial direction (10).

8. The electromechanical energy converter according to claim 7, characterized in that The liquid delivery section (13b) extends into the interior space (3a) of the liquid guiding device (3) beyond the blocking section (14) in the axial direction (10).

9. The electromechanical energy converter according to any one of claims 5 to 8, characterized in that, The liquid guiding device (3) has a liquid guiding tube (3f) and an output shaft member (3g), and The liquid entry opening (3b) is provided on a first axial end of the output shaft member (3g), and the liquid guiding tube (3f) is provided on a second axial end of the output shaft member (3g), and The liquid guiding tube (3f) is received on the output shaft member (3g) with a first axial end, and The at least one liquid discharge opening (3e) extends through a wall of the liquid guiding tube (3f).

10. The electromechanical energy converter according to claim 9, characterized in that The liquid guiding tube (3f) is received on the rotor shaft end section (2b) with a second axial end (3fII) of the liquid guiding tube (3f).

11. The electromechanical energy converter according to claim 9, characterized in that The output shaft member (3g) is received in the rotor connection region (6) in the rotor shaft (2), and In the rotor connection region (6) at least one liquid guiding channel (7) is provided with which the liquid annular space (5) is fluidically connected with an environment (8) surrounding the liquid-cooled rotor (1).

12. The electromechanical energy converter according to claim 11, characterized in that The connection region (6) has a torque transmission region (6b) and a centering region (6a), and the torque transmission region (6b) and the centering region (6a) are spaced apart from one another in the axial direction (10) along the rotor axis (9), and The liquid guiding channel (7) is configured as a recess on the rotor shaft (2) or on the output shaft member (3g) in the centering region (6a).

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