Rotor assembly for an electric excited synchronous motor (EESM)
A rotor assembly for an electric excited synchronous motor (EESM) comprises: a rotor shaft, a rotor core with windings, a first and a second fluid guide element arranged at the ends of the rotor core, wherein the rotor shaft comprises an axial bore and a plurality of radial bores, wherein the rotor core includes a plurality of inlet openings fluidically connected to the radial bores, and axial channels extending axially to first and second outlet openings of the rotor core, wherein the first and second fluid guide elements are fluidically connected to the outlet openings of the rotor core and comprise a fluid structure configured to receive cooling fluid from the rotor core and guide same to escape openings arranged in circumferential direction between two circumferentially adjacent winding ends of the rotor.
1 . A rotor assembly for an electric excited synchronous motor (EESM), comprising:
a rotor shaft,
a rotor core connected to the rotor shaft and including a plurality of circumferentially distributed pole portions, with respective windings being received around the pole portions, wherein the windings have first winding ends that project axially from a first end face of the rotor core and, on the opposite side, second winding ends that project axially from a second end face of the rotor core;
a first fluid guide element arranged at a first end of the rotor core;
a second fluid guide element arranged at a second end of the rotor core;
wherein the rotor shaft comprises an axial bore and, extending therefrom, a plurality of radial bores arranged in an axially central region of the rotor shaft;
wherein the rotor core includes a plurality of inlet openings that are fluidically connected to the radial bores of the rotor shaft, and axial channels that extend from the inlet openings axially to first outlet openings at the first end face of the rotor core and to second outlet openings at the second end face of the rotor core;
wherein the first fluid guide element is fluidically connected to the first outlet openings of the rotor core and comprises a fluid structure that is configured to receive cooling fluid from the first outlet openings of the rotor core and guide the cooling fluid to first escape openings arranged in circumferential direction between two circumferentially adjacent first winding ends; and
wherein the second fluid guide element is fluidically connected to the second outlet openings of the rotor core and comprises a fluid structure that is configured to receive cooling fluid from the second outlet openings of the rotor core and guide the cooling fluid to second escape openings arranged in circumferential direction between two circumferentially adjacent second winding ends;
wherein the first fluid guide element includes a first ring portion and a plurality of first winding support portions radially projecting from the first ring portion, with first head portions forming enlarged ends of the first winding support portions, wherein the first end windings embrace the first winding support portions; and
wherein the second fluid guide element includes a second ring portion and a plurality of second winding support portions radially projecting from the second ring portion, with second head portions forming enlarged ends of the second winding support portions, wherein the second end windings embrace the second winding support portions.
2 . The rotor assembly of claim 1 , further comprising a supply element to direct cooling fluid into the axial bore of the rotor shaft.
3 . The rotor assembly of claim 1 , wherein at least some of the plurality of radial bores of the rotor shaft are arranged in a plane that lies axially within a central portion of the rotor core.
4 . The rotor assembly of claim 1 , wherein the number of radial bores and axial channels of the rotor core corresponds with the number of pole portions.
5 . The rotor assembly of claim 1 , wherein the axial channels are arranged radially inside the pole portions that receive the windings.
6 . The rotor assembly of claim 1 ,
wherein the first fluid guide element includes a first annular channel fluidically connected with the first outlet openings of the rotor core, and, at an inner circumferential face of the first fluid guide element, a plurality of first fluid pockets fluidically connected to the first annular channel, wherein the first escape openings are fluidically connected with the first fluid pockets respectively; and/or
wherein the second fluid guide element includes a second annular channel fluidically connected with the second outlet openings of the rotor core, and, at an inner circumferential face the second fluid guide element, a plurality of second fluid pockets fluidically connected to the second annular channel, wherein the second escape openings are fluidically connected with the second fluid pockets respectively.
7 . The rotor assembly of claim 6 ,
wherein the first escape openings of the first fluid guide element have an axial extension that is at least 0.25 times an axial length of the first end windings projecting from the first end face of the rotor core; and
wherein the second escape openings of the second fluid guide element have an axial extension that is at least 0.25 times an axial length of the second end windings projecting from the second end face of the rotor core.
8 . The rotor assembly of claim 1 , wherein at least one of the first fluid guide element and the second fluid guide element is made of a non-conducting material that is different from a material of the rotor core.
9 . The rotor assembly of claim 1 ,
wherein a first end ring is provided at the first side of the rotor core and a second end ring is provided at the opposite second side, wherein the first end ring and the second end ring are clamped axially against each other by a plurality of clamping elements respectively extending between two circumferentially adjacent windings; and
wherein at least one of the first end ring and the second end ring comprises a flange portion for supporting the clamping elements and a jacket portion surrounding the end windings, wherein the end ring comprises a plurality of outlet openings.
10 . The rotor assembly of claim 9 ,
wherein the outlet openings of the first and second end ring are arranged circumferentially offset relative to the escape openings of the respective fluid guide element.
11 . The rotor assembly of claim 9 , wherein at least one of the first and second end ring includes a plurality of ribs that extend axially between two circumferentially adjacent end windings.
12 . The rotor assembly of claim 9 , wherein the end ring is made of non-ferromagnetic material.
13 . The rotor assembly of claim 1 , wherein winding slots are formed in the rotor core respectively between two pole portions adjacent in circumferential direction, with a wedge element arranged respectively between two windings adjacent in circumferential direction.
14 . The rotor assembly of claim 1 , in an electric excited synchronous motor (EESM) comprising:
a housing,
a stator arranged in the housing and comprising a stator core and windings, wherein the rotor assembly is rotatably supported in the housing about an axis of rotation.
15 . A rotor assembly for an electric excited synchronous motor (EESM), comprising:
a rotor shaft,
a rotor core connected to the rotor shaft and including a plurality of circumferentially distributed pole portions, with respective windings being received around the pole portions, wherein the windings have first winding ends that project axially from a first end face of the rotor core and, on the opposite side, second winding ends that project axially from a second end face of the rotor core;
a first fluid guide element arranged at a first end of the rotor core;
a second fluid guide element arranged at a second end of the rotor core;
wherein the rotor shaft comprises an axial bore and, extending therefrom, a plurality of radial bores arranged in an axially central region of the rotor shaft;
wherein the rotor core includes a plurality of inlet openings that are fluidically connected to the radial bores of the rotor shaft, and axial channels that extend from the inlet openings axially to first outlet openings at the first end face of the rotor core and to second outlet openings at the second end face of the rotor core;
wherein the first fluid guide element is fluidically connected to the first outlet openings of the rotor core and comprises a fluid structure that is configured to receive cooling fluid from the first outlet openings of the rotor core and guide the cooling fluid to first escape openings arranged in circumferential direction between two circumferentially adjacent first winding ends;
wherein the second fluid guide element is fluidically connected to the second outlet openings of the rotor core and comprises a fluid structure that is configured to receive cooling fluid from the second outlet openings of the rotor core and guide the cooling fluid to second escape openings arranged in circumferential direction between two circumferentially adjacent second winding ends; and
wherein at least one of the first fluid guide element and the second fluid guide element is made of a non-conducting material that is different from a material of the rotor core.
16 . A rotor assembly for an electric excited synchronous motor (EESM), comprising:
a rotor shaft,
a rotor core connected to the rotor shaft and including a plurality of circumferentially distributed pole portions, with respective windings being received around the pole portions, wherein the windings have first winding ends that project axially from a first end face of the rotor core and, on the opposite side, second winding ends that project axially from a second end face of the rotor core;
a first fluid guide element arranged at a first end of the rotor core;
a second fluid guide element arranged at a second end of the rotor core;
wherein the rotor shaft comprises an axial bore and, extending therefrom, a plurality of radial bores arranged in an axially central region of the rotor shaft;
wherein the rotor core includes a plurality of inlet openings that are fluidically connected to the radial bores of the rotor shaft, and axial channels that extend from the inlet openings axially to first outlet openings at the first end face of the rotor core and to second outlet openings at the second end face of the rotor core;
wherein the first fluid guide element is fluidically connected to the first outlet openings of the rotor core and comprises a fluid structure that is configured to receive cooling fluid from the first outlet openings of the rotor core and guide the cooling fluid to first escape openings arranged in circumferential direction between two circumferentially adjacent first winding ends;
wherein the second fluid guide element is fluidically connected to the second outlet openings of the rotor core and comprises a fluid structure that is configured to receive cooling fluid from the second outlet openings of the rotor core and guide the cooling fluid to second escape openings arranged in circumferential direction between two circumferentially adjacent second winding ends;
wherein a first end ring is provided at the first side of the rotor core and a second end ring is provided at the opposite second side, wherein the first end ring and the second end ring are clamped axially against each other by a plurality of clamping elements respectively extending between two circumferentially adjacent windings; and
wherein at least one of the first end ring and the second end ring comprises a flange portion for supporting the clamping elements and a jacket portion surrounding the end windings, wherein the end ring comprises a plurality of outlet openings.