SELF-VENTILATED ELECTRODYNAMIC ROTARY MACHINE

Abstract

A self-ventilated electrodynamic rotary machine includes a housing configured to at least partially axially enclose the rotary machine, and a fan connected in a rotationally fixed manner to a shaft on a ventilation side of the rotary machine and configured to generate a main cooling air flow when the shaft rotates about an axis. The fan includes a cover which is configured to direct the main cooling air flow onto the housing and is structured to improve cooling of the housing. An air guide element is detachably fixed to the cover to generate an additional cooling air flow. The air guide element, when viewed in a circumferential direction, has a segmented design and is configured as separate part for retrofitting to the cover depending on a thermal requirement of the rotary machine. --,

Claims

1-10. (canceled)

11. A self-ventilated electrodynamic rotary machine, comprising: a housing configured to at least partially axially enclose the rotary machine; a fan connected in a rotationally fixed manner to a shaft on a ventilation side of the rotary machine and configured to generate a main cooling air flow when the shaft rotates about an axis, said fan comprising a cover which is configured to direct the main cooling air flow onto the housing and is structured to improve cooling of the housing; and an air guide element detachably fixed to the cover to generate an additional cooling air flow, said air guide element, when viewed in a circumferential direction, having a segmented design and configured as separate part for retrofitting to the cover depending on a thermal requirement of the rotary machine.

12. The self-ventilated electrodynamic rotary machine of claim 11, wherein the air guide element comprises ridges and air guide surfaces located between the ridges, with openings located between the air guide surfaces.

13. The self-ventilated electrodynamic rotary machine of claim 12, wherein the air guide surfaces are angled with respect to the axis.

14. The self-ventilated electrodynamic rotary machine of claim 11, wherein the air guide element includes segments of axially different extents and/or different numbers of openings.

15. The self-ventilated electrodynamic rotary machine of claim 11, further comprising a plurality of said guide element of segmented design, with the guide elements disposed axially along the housing.

16. The self-ventilated electrodynamic rotary machine of claim 11, further comprising a structure at an axial end of the cover to reduce an inner radius of the cover.

17. The self-ventilated electrodynamic rotary machine of claim 16, wherein the structure is configured in one of two ways, a first way in which the structure is a reducing element provided at least in one section of the cover in a circumferential direction of the cover, a second way in which the axial end of the cover is inclined radially to the axis.

18. The self-ventilated electrodynamic rotary machine of claim 11, wherein the cover has an essentially pot-shaped configuration.

19. The self-ventilated electrodynamic rotary machine of claim 11, wherein the cover has an inner radius which is larger than an outer radius of the housing.

20. The self-ventilated electrodynamic rotary machine of claim 11, wherein the housing includes at least one section provided with fins.

Description

[0036] The invention as well as further advantageous embodiments of the invention will now be explained in more detail by means of exemplary embodiments illustrated in principle in the drawings wherein:

[0037] FIG. 1 shows a longitudinal section through a dynamoelectric machine,

[0038] FIG. 2 shows a detailed representation,

[0039] FIGS. 3 to 7 show partial perspective views,

[0040] FIG. 8 shows a partial longitudinal section through the dynamoelectric machine,

[0041] FIG. 9 shows a partial cross-section of the dynamoelectric machine,

[0042] FIG. 10 shows a perspective view of a dynamoelectric machine,

[0043] FIG. 11 shows a top view of a part of a dynamoelectric machine.

[0044] FIG. 1 shows a longitudinal section through a dynamoelectric rotary machine 1 illustrated in principle, in particular an asynchronous motor with squirrel cage rotor. The dynamoelectric machine 1 has a stator 14 which is of laminated design and has winding overhangs of a winding system 15 at its end faces. The stator 14 is inserted in a housing 6, in particular such that heat is transferred from the stator 14 to the housing 6. Distributed around its outer circumference, the housing 6 has essentially radially projecting fins 13 which are used to cool the electrical machine 1.

[0045] The energized winding system 15 of the stator 14 sets up an electromagnetic interaction with a rotor 16 via an air gap 17, causing a shaft 9 to rotate about an axis 10. The shaft 9 is positioned on the housing 6 via bearings 11 and associated end shield 12. On the shaft 9, a fan 2 is non-rotatably connected to the shaft 9. This fan 2 has essentially radially extending fan blades 4. The fan 2 draws in an air flow axially via apertures 5 in a cover 3, which air flow is then deflected by the fan blades 4 and with the aid of the cover 3, so that a main cooling air flow 7 is established essentially axially along the fins 13.

[0046] However, after exiting the cover 3, cooling air gradually escapes radially from the fin region of the housing 6 and thus loses its cooling function. The loss of cooling air increases sharply as it passes axially along the fins 13 to the drive side, so that the amount of cooling air that still has a cooling effect on the drive side is very small.

[0047] This premature removal of the cooling air flow from the housing surface is now avoided, as shown in FIG. 2, by reducing the inner radius of the cover 3 at its axial end and/or by the air guide elements 18, thereby significantly improving cooling.

[0048] The reduction of the inner radius at the axial end of the cover 3 can also be created by an additional reducing element positioned in or on the cover 3. Said reducing element is wedge-shaped when viewed in cross-section.

[0049] By means of air guide elements 18, which are already provided in one piece on the cover 3 or can be fitted by additional means, an additional cooling air flow 8 is generated during operation of the fan 2, said cooling air flowing via the openings 21 to the housing surface and/or between the fins 13.

[0050] Even in the case of a one-piece cover 3, only certain angular sections around the cover 3 can be occupied by the air guide elements 18. There are therefore covers 3 in which only a predeterminable angular section is occupied, and there are also covers 3 in which air guide elements 18 occupy the entire circumference.

[0051] In the case of separate air guide elements 18 segmented in the circumferential direction, these can be positioned on the cover 3 and/or on the housing 6.

[0052] The air guide element 18 has axially extending ridges 23 on which air guide surfaces 26 are disposed. Between the air guide surfaces 26 in the axial direction are openings 21 which allow the additional cooling air flow 8 during operation of the electrodynamic rotary machine 1. The air guide surfaces 26 essentially follow the contour of the housing 6, in other words, viewed in the circumferential direction, the curvature of the respective air guide surfaces 26 has a radius dependent on the diameter of the housing 6.

[0053] FIG. 3 shows a plurality of separate air guide elements 18 disposed on the cover 3. Not all the angular sections are occupied in the circumferential direction.

[0054] In another detailed view, FIG. 4 shows the cover 3 with a segmented air guide element 18 attached to the cover 3 by means of an e.g. detachable clip connection in a recess of the cover 3.

[0055] The ridges 23 project axially in the direction of the ventilation side for mechanical and/or flow-related reasons, as can also be seen in particular from FIG. 5.

[0056] FIG. 6 shows a segment of an air guide element 18 on the cover 3, having two rows of three air guide surfaces 26 each disposed axially one behind the other which have openings 21 between the axial end of the cover and the first air guide surface 26 or between the air guide surfaces 26.

[0057] FIG. 7 shows in particular the angle of inclination of the air guide surfaces 26 with respect to the axis 10. This results in the injector effect so that, in addition to a main cooling air flow 7, an additional cooling air flow 8 is generated which contributes to the cooling of the machine 1.

[0058] The angling of the air guide surfaces 26 is preferably taken into account in the manufacture of the cover 3 if the cover 3 and air guide elements 18 are made in one piece, e.g. by injection molding or 3D printing.

[0059] If the air guide elements 18 are manufactured separately and are to be clipped onto the cover 3, the angle can be taken into account during manufacture. Having separate air guide elements 18 means that they are also interchangeable, thereby obtaining axially longer air guide elements 18 and/or obtaining a different angle of the air guide surfaces 26.

[0060] FIG. 8 shows in principle how the segmented air guide elements 18 can be attached to the cover 3, e.g. by a hook engaging in a recess at the axial end of the cover 3. The air guide surfaces 26 rest on or are slightly spaced from the fins 3. The ridges 23 rest on the cover 3.

[0061] The resting of the air guide surfaces 26 on the fins can also be seen in FIG. 9.

[0062] FIG. 10 shows a cover 3 with air guide elements 18, wherein an angular segment on the cover 3 is not occupied by the air directing element 18.

[0063] FIG. 11 shows a top view of an air guide element 18 on the cover 3 and a section of the dynamoelectric machine 1 with the housing 6 to be cooled or more specifically the fins 13.