ELECTRICAL MOTOR HAVING RADIALLY OFFSET COOLING STREAM AND COOLING METHOD

• US 20110254391A1
• Filed: 11/24/2009
• Published: 10/20/2011
• Est. Priority Date: 12/23/2008
• Status: Active Grant

• Current Assignee: Flender GmbH (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Schonbauer, Norbert, Memminger, Oliver, Senninger, Karl, Elender, Gunther
• Granted Patent: US 8,686,607 B2
• Time in Patent Office: Days
• US Class Current: 310/52
• CPC Class Codes: H02K 1/32 with channels or ducts for flow of cooling medium
• CPC Class Codes: H02K 9/18 wherein the external part of the closed circuit comprises a heat exchanger structurally associated with the machine casing

Abstract

The rotor of an electrical motor should be designed simply and able to be efficiently cooled. To this end, the invention relates to an electrical motor having a rotor that has at least one radial cooling slot (16) and axially running cooling channels. The first cooling channels (18) run having their central axis at a different radial height opposite the axis of the rotor (11) than the second cooling channels (19). A spacer (29) is arranged in the at least one radial cooling slot (16) by means of which a first cooling stream (28) can be conducted from one of the first cooling channels (18) into one of the second cooling channels (19). A second partial package (T2) in the flow direction can also be supplied with cool air in this way if it flows through the first partial package (T1) in a cool region, such as near the shaft.

Claims

1-12. -12. (canceled)

13. An electrical machine, comprising:

a rotor defining a rotor axis and having a single radial cooling slot to divide the rotor in midsection, said rotor including axial cooling ducts which issue into the radial cooling slot, said cooling ducts having first, second and third cooling ducts, each defined by a central axis, wherein the central axis of the first cooling duct extends in closer radial proximity to the rotor axis than the central axis of the second cooling duct; and

a spacer arranged in the radial cooling slot and constructed to route a first cooling stream from the first cooling duct to the second cooling duct,

wherein a second cooling stream is introducible into the third cooling duct and directed radially to the outside by the spacer, with the third cooling duct defined by a central axis which extends coaxially to the second cooling duct.

14. The electrical machine of claim 13, wherein the spacer includes a plurality of disks, each having a passage opening, wherein the passage openings of the disks are arranged to deflect the first cooling stream in a radial direction.

15. The electrical machine of claim 13, further comprising permanent magnets to excite the rotor.

16. The electrical machine of claim 13, further comprising short-circuiting bars received in the rotor.

17. The electrical machine of claim 13, wherein the rotor has a laminated core comprised of a first core element which includes the first cooling duct and a second core element which includes the second cooling duct, said first core element being arranged offset in a circumferential direction relative to the second core element.

18. A method for cooling a rotor of an electrical machine, comprising the steps of:

introducing a first cooling stream axially into the rotor in a direction of a central line which extends at a first radial level in relation to an axis of the rotor;

deflecting the first cooling stream in midsection of the rotor in a single radial cooling slot in a radial direction to flow in relation to the axis of the rotor at a second radial level which differs relative to the first radial level;

introducing a second cooling stream axially into the rotor at the second radial level; and

routing the second cooling stream radially to the outside in midsection of the rotor.