Rotor shaft arrangement for an electric machine

Abstract

The invention relates to a rotor shaft arrangement (1) for an electric machine (2), comprising a rotor shaft (4) able to rotate about a rotor axis (3), comprising a shaft channel (5), formed in the rotor shaft (4), for fluidically cooling a component of the electric machine (2), comprising a supply inlet (6), provided at one of the shaft ends (4e), for supplying fluid to the shaft channel (5), wherein the shaft channel (5) has front shaft outlets (7) at a first distance (d1) from the supply inlet (6) and rear shaft outlets (8) at a greater distance (d2) from the supply inlet (6), wherein the cooling fluid is able to be guided towards a channel circumferential wall (5U) of the shaft channel (5) by way of a distributor element (10), wherein the distributor element (10) is a separate shaft insert that is inserted into the shaft channel (5) at one of the shaft ends (4e) of the rotor shaft (4), wherein the rotor shaft (4) has a shaft opening (4h) into the shaft channel (5) at one of the shaft ends (4e), characterized in that the distributor element (10) is arranged and fastened in the shaft opening (4h) and has a supply inlet (6) that comprises a feed section (6C) for the insertion of a static feed pipe (11) in order to feed in the cooling fluid and multiple first inlet openings (6.1), wherein the first inlet openings (6.1) open into the shaft channel (5) at an oblique or vertical angle with respect to the rotor axis (3). (figure 1)

Description

[0001] Description

[0002] title

[0003] Rotor shaft arrangement of an electric machine

[0004] State of the art

[0005] The invention relates to a rotor shaft arrangement of an electric machine according to the preamble of the main claim.

[0006] A rotor shaft arrangement of an electric machine is already known from DE102014107845 A1, comprising a rotor shaft rotatable about a rotor axis, a shaft channel formed in the rotor shaft for fluid cooling of a component of the electric machine, and a supply inlet provided at a first shaft end for supplying fluid to the shaft channel. The shaft channel has front shaft outlets at a first distance from the supply inlet and rear shaft outlets at a greater distance from the supply inlet. The cooling fluid can be directed to a channel circumferential wall of the shaft channel by means of a funnel-shaped distribution element, wherein the distribution element is a separate shaft insert that is inserted into the shaft channel of the rotor shaft at one of the shaft ends of the rotor shaft. The rotor shaft has a shaft opening into the shaft channel at one of its shaft ends.

[0007] Advantages of the invention

[0008] In contrast, the rotor shaft arrangement of an electric machine according to the invention, with the characterizing features of the main claim, has the advantage that an open hydraulic cooling system can be formed by means of the distribution element, which allows the intake of air from the environment to limit the cooling fluid volume flow. This ensures that the front shaft outlets are reliably and adequately supplied with cooling fluid. Furthermore, the manufacturing costs of the rotor shaft arrangement can be reduced. This is achieved according to the invention by arranging and fixing the distribution element in the shaft opening and having a supply inlet comprising a feed section for inserting a static feed tube for supplying the cooling fluid and several first inlet openings, wherein the first inlet openings open into the shaft channel at an oblique or perpendicular angle to the rotor axis.

[0009] In particular, the first inlet openings are positioned in such a way that the cooling fluid encounters the channel's circumferential wall upstream of or at the front shaft outlets. This ensures a reliable supply of cooling fluid to the front shaft outlets. The cooling fluid then forms a film on the channel's circumferential wall.

[0010] The distribution element is mechanically coupled to the rotor shaft by its mounting in the shaft opening. An annular gap, particularly for air intake, must be provided between the feed section of the rotating distribution element and the static feed pipe to form the open hydraulic cooling system.

[0011] The measures listed in the dependent claims enable advantageous further developments and improvements of the rotor shaft arrangement of an electric machine specified in the main claim.

[0012] The feed section of the distribution element leads into the first inlet openings of the distribution element.

[0013] It is further advantageous if the first inlet openings of the distribution element are arranged circumferentially at a distance from each other, in particular at equal distances, wherein the number of first inlet openings corresponds in particular to the number of front shaft outlets. In this way, the cooling fluid can be distributed uniformly on the channel's circumferential wall, so that a stable film can be generated on the channel's circumferential wall and the front shaft outlets distributed around the circumference of the shaft channel can be supplied uniformly with cooling fluid.

[0014] It is highly advantageous if the shaft channel has a channel diameter to accommodate the distribution element and if the radially outermost edges of the first inlet openings located on an end face of the distribution element lie on a circle with a circle diameter where the ratio of circle diameter to channel diameter is between 0.5 and 1, particularly between 0.8 and 1. In this way, the cooling fluid in the first embodiment can be supplied sufficiently close to the channel's circumferential wall to generate a stable film on the channel's circumferential wall. The resulting film allows the front shaft outlets to be supplied with cooling fluid at a constant rate over time.

[0015] It is also advantageous if the supply inlet has a second inlet opening for supplying fluid, particularly to the rear shaft outlets, which extends axially with respect to the rotor axis and radially within the first inlet openings, especially centrally on the rotor axis. In this way, the coolant flow rate supplied to the feed section of the supply inlet is divided into a first partial flow to the first inlet openings and a second partial flow to the second inlet opening. A distribution of the coolant flow rate is thus integrated into the distribution element.

[0016] Furthermore, it is advantageous if a channel constriction, particularly a stepped one, is formed in the shaft channel downstream of the front shaft outlets to generate and accumulate a wall film at the front shaft outlets, especially by means of an inserted distribution pipe or by a step in the channel's circumferential wall. In this way, a stable wall film is generated at the front shaft outlets, ensuring a reliable and constant supply of cooling fluid to the front shaft outlets.

[0017] Furthermore, it is advantageous if a distributor pipe is inserted into the shaft channel, forming an annular channel between the shaft channel and the distributor pipe, the distributor pipe opening into the annular channel via a pipe inlet and a distributor opening between the pipe ends, the annular channel leading to the rear shaft outlets. In this way, the cooling fluid flow can be divided a further time to supply the first and second rear shaft outlets with cooling fluid.

[0018] It is advantageous if the rear shaft outlets comprise first and second rear shaft outlets, wherein the first and second rear shaft outlets are spaced apart axially with respect to the rotor axis, in particular by a distance greater than the axial length of a rotor body mounted on the rotor shaft. In this way, the first and second rear shaft outlets can be formed on the two end faces of the rotor body, thereby achieving good cooling of a component of the electric machine.

[0019] In an advantageous embodiment, the front shaft outlets can be provided for cooling an inductive transformer for powering a rotor winding, for cooling a winding head of the rotor winding or a stator winding of a stator, or for supplying fluid to cooling channels in a rotor body arranged on the rotor shaft. The rear shaft outlets can advantageously be provided for cooling a winding head of the rotor winding or a stator winding of a stator, or for supplying fluid to cooling channels in a rotor body arranged on the rotor shaft. The front and rear shaft outlets are, in particular, distributed around the circumference of the channel wall. The rotor body can, in particular, be a rotor lamination stack comprising a rotor winding or permanent magnets.

[0020] The invention further relates to an electric machine with a rotor shaft arrangement according to the invention.

[0021] drawing

[0022] Exemplary embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description.

[0023] They show:

[0024] Fig. 1 shows a first embodiment of a rotor shaft arrangement of an electric machine according to the invention.

[0025] Fig. 2 shows a distribution element according to the invention as shown in Fig. 1.

[0026] Fig. 3 shows a second embodiment of a rotor shaft arrangement of an electric machine according to the invention and

[0027] Fig. 4 shows a distribution element according to the invention as shown in Fig. 3. Description of exemplary embodiments.

[0028] Fig. 1 shows a first embodiment of a rotor shaft arrangement of an electric machine according to the invention.

[0029] The rotor shaft arrangement 1 of an electric machine 2 according to the invention comprises a rotor shaft 4 rotatable about a rotor axis 3, a shaft channel 5 formed in the rotor shaft 4 for fluid cooling of a component of the electric machine 2, and a supply inlet 6 provided at a first shaft end 4e for supplying fluid to the shaft channel 5. The rotor shaft arrangement 1 forms a rotor of the electric machine 2.

[0030] The wave channel 5 has front wave outlets 7 at a first distance d1 from the supply inlet 6 and rear wave outlets 8 at a greater distance d2 from the supply inlet 6 than d1. The front wave outlets 7 are, for example, distributed over the circumference of the channel's circumferential wall 5U. Likewise, the rear wave outlets 8 are, for example, distributed over the circumference of the channel's circumferential wall 5U.

[0031] The cooling fluid can be directed to a channel circumferential wall 5U of the shaft channel 5 by means of a distribution element 10. The distribution element 10 is a separate shaft insert that is inserted into the shaft channel 5 of the rotor shaft 4 at one of the shaft ends 4e of the rotor shaft 4. The rotor shaft 4 has a shaft opening 4h into the shaft channel 5 at one of its shaft ends 4e.

[0032] According to the invention, the distribution element 10 is arranged and fastened in the shaft opening 4h and has a supply inlet 6 comprising a feed section 6C for inserting a static feed tube 11 for supplying the cooling fluid and several first inlet openings 6.1, wherein the first inlet openings 6.1 open into the shaft channel 5 at an oblique (Fig. 1) or perpendicular (Fig. 3) angle to the rotor axis 3, in particular such that the cooling fluid impinges on the channel circumferential wall 5u of the shaft channel 5 upstream of or at the front shaft outlets 7. In both embodiments, the shaft channel 5 is widened at the shaft opening 4h relative to an adjacent channel section of the shaft channel 5 to accommodate the distribution element 10.

[0033] The feed section 6C of the distribution element 10 opens into the first inlet openings 6.1 of the distribution element 10. The distribution element 10 is, for example, cylindrical in shape.

[0034] According to the first embodiment, the first inlet openings 6.1 lead into an end face of the distribution element 10.

[0035] In the wave channel 5, a channel constriction 12 can be formed downstream of the front wave outlets 7 to generate and / or accumulate a wall film at the front wave outlets 7. According to the first embodiment, the channel constriction 12 is formed by a distributor pipe 15 inserted into the wave channel 5.

[0036] In both embodiments, the distributor pipe 15 is inserted into the shaft channel 5, forming an annular channel 16 between the shaft channel 5 and the distributor pipe 15. The distributor pipe 15 opens into the annular channel 16 via a pipe inlet 17 and at least one distributor opening 18 provided on the pipe shell between the pipe ends 15e. The annular channel 16 leads to the rear shaft outlets 8.

[0037] According to the first embodiment, the pipe inlet 17 of the distributor pipe 15 is arranged downstream of the front shaft outlets 7 and upstream of the first rear shaft outlets 8.1.

[0038] In the first embodiment, the distributor pipe 15 is arranged behind the front shaft outlets 7 in the direction of flow, so that there is an axial distance between the distributor element 10 and the distributor pipe 15.

[0039] The front shaft outlets 7 can be provided for cooling an inductive transformer 22 for supplying energy to a rotor winding of the rotor 1, for cooling a winding head of a rotor winding of the rotor 1 and / or a stator winding of a stator of the electric machine 2 or for supplying fluid to cooling channels in a rotor body 14 arranged on the rotor shaft 4.

[0040] The rear shaft outlets 8 can comprise first and second rear shaft outlets 8.1 and 8.2. The first and second rear shaft outlets 8.1 and 8.2 are spaced axially with respect to the rotor axis 3, in particular by a distance d5 that is greater than the axial length of a rotor body 14 arranged on the rotor shaft 4. The first rear shaft outlets 8.1 and 8.2 face the distribution element 10 and are thus located closer to the distribution element 10.

[0041] The rear shaft outlets 8, 8.1, 8.2 can be provided for cooling a winding head of a rotor winding of the rotor 1 and / or a stator winding of a stator of the electric machine 2 or for supplying fluid to cooling channels in the rotor body 14 arranged on the rotor shaft 4.

[0042] The supply inlet 6 of the distribution element 10 has at least one, in particular a single, second inlet opening 6.2 for supplying fluid, especially to the rear shaft outlets 8. The second inlet opening 6.2 of the supply inlet 6 of the distribution element 10 extends axially with respect to the rotor axis 3 and is arranged radially within the first inlet openings 6.1, in particular centrally on the rotor axis 3. According to the first embodiment, the second inlet opening 6.2 opens directly into the shaft channel 5.

[0043] The first inlet openings 6.1 together form a flow cross-section that is smaller than the flow cross-section of the feed section 6C of the supply inlet 6 and / or the feed pipe 11. The second inlet opening 6.2 according to the first embodiment has a flow cross-section that is smaller than the flow cross-section of the feed section 6C of the supply inlet 6 and / or the feed pipe 11.

[0044] Fig. 2 shows a distribution element 10 according to the invention as shown in Fig. 1.

[0045] The first inlet openings 6.1 of the supply inlet 6 of the distribution element 10 are arranged in the circumferential direction with respect to the rotor axis 3 at a distance, in particular at the same distance, from each other, wherein the number of first inlet openings 6.1 corresponds in particular to the number of front shaft outlets 7.

[0046] The wave channel 5 has a channel diameter d3 for receiving the distribution element 10. For the first embodiment, the radially outermost edges of the first inlet openings 6.1 located on an end face of the distribution element 10 lie on a circle with a circle diameter d4, wherein the ratio of circle diameter d4 to channel diameter d3 has a value between 0.5 and 1, in particular between 0.8 and 1.

[0047] Fig. 3 shows a second embodiment of a rotor shaft arrangement of an electric machine according to the invention.

[0048] According to the second embodiment, the first inlet openings 6.1 open at a perpendicular angle to the rotor axis 3 into an annular gap 20 formed between the shaft channel 5 and the distribution element 10.

[0049] According to the second embodiment, the distribution pipe 15 is arranged with one pipe end 15e in the second inlet opening 6.2 of the distribution element 10. In the second embodiment, the pipe inlet 17 of the distribution pipe 15 is narrower than in the first embodiment to achieve the same volume flow through the second inlet opening 6.2 in both embodiments. The opening of the pipe inlet 17 is smaller than the second inlet opening 6.2 of the distribution element 10. According to the second embodiment, the pipe inlet 17 of the distribution pipe 15 has a flow cross-section that is smaller than the flow cross-section of the feed section 6C of the supply inlet 6 and / or the feed pipe 11.

[0050] According to the second embodiment, the channel constriction 12 is formed by a step 21 in the channel circumferential wall 5U.

[0051] According to the second embodiment, the first inlet openings 6.1 lead into an outer circumference of the distribution element 10.

[0052] Fig. 4 shows the distribution element according to Fig. 3 according to the invention.

Claims

Claims 1. Rotor shaft arrangement (1) of an electric machine (2) with a rotor shaft (4) rotatable about a rotor axis (3), with a shaft channel (5) formed in the rotor shaft (4) for fluid cooling of a component of the electric machine (2), with a supply inlet (6) provided at one of the shaft ends (4e) for supplying fluid to the shaft channel (5), wherein the shaft channel (5) has front shaft outlets (7) at a first distance (d1) from the supply inlet (6) and rear shaft outlets (8) at a greater distance (d2) from the supply inlet (6), wherein the cooling fluid can be directed to a channel circumferential wall (5U) of the shaft channel (5) by means of a distribution element (10), wherein the distribution element (10) is a separate shaft insert which is inserted into the shaft channel (5) at one of the shaft ends (4e) of the rotor shaft (4), wherein the rotor shaft (4) is (4e) has a wave opening (4h) into the wave channel (5), characterized in thatthat the distribution element (10) is arranged and fastened in the shaft opening (4h) and has a supply inlet (6) comprising a feed section (6C) for inserting a static feed tube (11) for supplying the cooling fluid and several first inlet openings (6.1), wherein the first inlet openings (6.1) open into the shaft channel (5) at an oblique or perpendicular angle to the rotor axis (3), in particular such that the cooling fluid impinges on the channel circumferential wall (5U) of the shaft channel (5) upstream of the front shaft outlets (7) or at the front shaft outlets (7).

2. Rotor shaft arrangement according to claim 1, characterized in that the feed section (6C) of the distribution element (10) opens into the first inlet openings (6.2) of the distribution element (10).

3. Rotor shaft arrangement according to one of the preceding claims, characterized in that the first inlet openings (6.1) of the distribution element (10) are arranged circumferentially at a distance, in particular at the same distance, from each other, wherein the number of first inlet openings (6.1) corresponds in particular to the number of front shaft outlets (7).

4. Rotor shaft arrangement according to one of the preceding claims, characterized in that the shaft channel (5) has a channel diameter (d3) for receiving the distribution element (10) and that the radially outermost edges of the first inlet openings (6.1) located on an end face of the distribution element lie on a circle with a circle diameter (d4), wherein a ratio of circle diameter (d4) to channel diameter (d5) has a value between 0.5 and 1, in particular between 0.8 and 1.

5. Rotor shaft arrangement according to one of the preceding claims, characterized in that the supply inlet (6) has a second inlet opening (6.2) for fluid supply, in particular to the rear shaft outlets (8), which extends axially with respect to the rotor axis (3) and radially within the first inlet openings (6.1), in particular centrally on the rotor axis (3).

6. Rotor shaft arrangement according to one of the preceding claims, characterized in that a channel constriction (12) is formed in the shaft channel (5) downstream of the front shaft outlets (7) for generating and accumulating a wall film at the front shaft outlets (7), in particular by an inserted distributor pipe (15) or by a step (21) in the channel circumferential wall (5U).

7. Rotor shaft arrangement according to one of the preceding claims, characterized in that a distributor pipe (15) is inserted into the shaft channel (5), which forms an annular channel (16) in the shaft channel (5) between the shaft channel (5) and the distributor pipe (15), wherein the distributor pipe (15) opens into the annular channel (16) via a pipe inlet (17) and a distributor opening (18) between the pipe ends (15e), wherein the annular channel (16) leads to the rear shaft outlets (8).

8. Rotor shaft arrangement according to one of the preceding claims, characterized in that the rear shaft outlets (8) comprise first and second rear shaft outlets (8.1, 8.2), wherein the first and second rear shaft outlets (8.1, 8.2) are spaced apart in the axial direction with respect to the rotor axis (3), in particular by a distance (d5) which is greater than an axial length of a rotor body (14) arranged on the rotor shaft (4).

9. Rotor shaft arrangement according to one of the preceding claims, characterized in that a. the front shaft outlets (7) are for cooling an inductive transformer (22) for supplying energy to a rotor winding, for cooling a a. the winding head of the rotor winding or a stator winding of a stator or for supplying fluid to cooling channels in a rotor body (14) arranged on the rotor shaft (4), and / or b. the rear shaft outlets (8) for cooling a winding head of the rotor winding or a stator winding of a stator or for Fluid supply to cooling channels in a rotor body (14) arranged on the rotor shaft (4) are provided.

10. Electric machine (2) with a rotor shaft arrangement (1) according to one of the preceding claims.

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