Mini fan

• US 20060153677A1
• Filed: 05/11/2004
• Published: 07/13/2006
• Est. Priority Date: 07/16/2003
• Status: Active Grant

• Current Assignee: Ebm-Papst St Georgen GmbH & Company KG (Ebm-Papst Mulfingen GmbH & Company KG)
• Original Assignee: Ebm-Papst St Georgen GmbH & Company KG (Ebm-Papst Mulfingen GmbH & Company KG)
• Inventors: Winkler, Wolfgang Arno, Rapp, Nils
• Granted Patent: US 8,915,721 B2
• Time in Patent Office: Days
• US Class Current: 415/220
• CPC Class Codes: F04D 25/062 Details of the bearings
• CPC Class Codes: F04D 29/057 hydrostatic; hydrodynamic
• CPC Class Codes: F04D 29/063 specially adapted for elastic fluid pumps
• CPC Class Codes: F04D 29/646 Mounting or removal of fans

Abstract

A mini-fan has a drive motor having an external rotor (222) and an internal stator (244). The external rotor (222) is equipped with a rotor shaft (234) that has a necked down portion (258) in the region of its free end (235). The mini-fan (216) has a bearing tube (238) on whose outer side the internal stator (244) is mounted and in whose interior is arranged a bearing arrangement (236) in which the rotor shaft (234) is rotatably supported. A closure arrangement (262) serves to close off the bearing tube (238) in liquid-tight fashion at one end, and is equipped, in the region of the necked down portion (258) of the rotor shaft (234), with at least one resilient securing member (260) that engages into that necked down portion (258) and secures the rotor shaft (234) against being pulled out of the bearing arrangement (236).

Claims

1. A mini-fan that comprises:

a drive motor having an external rotor (222) and an internal stator (244), which external rotor is equipped with a rotor shaft (234) that is equipped with a necked down portion (258) adjacent its free end (235);

a bearing tube (238) on whose outer side the internal stator (244) is mounted, and in whose interior is arranged a bearing arrangement (236) in which the rotor shaft (234) is rotatably supported;

a closure arrangement (62;

262) that closes off the bearing tube (238) in liquid-tight fashion at one end, and is equipped adjacent the necked down portion (258) of the rotor shaft (234) with at least one resilient securing member (260) that engages into that necked down portion (258) of the rotor shaft (234) and secures the rotor shaft (234) against being pulled out of the bearing arrangement (236).

2. The mini-fan according to claim 1, wherein

the closure arrangement is implemented as a cover (62) that is made from a thermoplastic that is at least partially transparent to laser light, that cover (62) being attached by means of a substantially liquid-tight welded join (100, 102).

3. The mini-fan according to claim 2 which comprises

a housing having a flange (78);

and wherein

the welded join (100, 102) is provided at a location at which the cover (62) at least partly overlaps a portion of that flange (78).

4. The mini-fan according to claim 2, which further comprises

a housing having a flange (78), wherein

the bearing tube (38) is held between the closure arrangement implemented as a cover (62) and a portion of that flange (78).

5. The mini-fan according to claim 2, wherein

the bearing tube (38) is pressed in substantially liquid-tight fashion into an opening (80) formed in the flange (78).

6. The mini-fan according to claim 5, wherein

the bearing tube (38) consists essentially of metal, and is epilam-coated on its side that is pressed into the flange opening (80).

7. The mini-fan according to claim 3, wherein

the bearing tube (38) is equipped with a radial projection (82) that is held in positively engaged fashion between the closure arrangement (62) and a portion of the flange (78).

8. The mini-fan according to claim 7, wherein the radial projection is implemented as a flange (82).

9. The mini-fan according to claim 8, wherein the flange (82) is provided on an end portion of the bearing tube (38).

10. The mini-fan according to claim 1, wherein the rotor shaft (34;

234) comprises

a free end (35;

235), facing away from the rotor (22;

222), on which a tracking cap (68;

268) is formed for axial support;

and wherein a support surface (66;

266) for that tracking cap is provided on the closure arrangement (62;

262).

11. The mini-fan according to claim 10, wherein

the support surface is implemented as a depression (66;

266) and is equipped with a lubricant (110).

12. The mini-fan according to claim 1,

wherein the at least one resilient securing member (60;

260) protrudes into the necked down portion (58;

258) of the rotor shaft (34;

234) without touching it.

13. The mini-fan according to claim 12, wherein

there is provided, adjacent the free end of the shaft (34;

234), a spreading member (35;

235) that is implemented to deflect the at least one resilient securing member (60;

260) in a radial direction upon installation of the shaft (34;

234).

14. The mini-fan according to claim 10, wherein

the tracking cap (68;

268) is acted upon by a magnetically generated force urging said rotor shaft in a direction toward the closure arrangement (62;

262).

15. The mini-fan according to claim 1, wherein

the closure arrangement is implemented as a plug that is mounted in an opening of the bearing tube.

16. The mini-fan according to claim 15, wherein

the closure arrangement is pressed in liquid-tight fashion into the opening of the bearing tube (238).

17. The mini-fan according to claim 15, wherein

at a transition point (271, 283) between the bearing tube (238) and plug (262), there is implemented on one of those parts an annular ridge (284, 285) and on the other part an annular groove (272, 273) complementary thereto, which together form a latching connection when the plug (262) is installed.

18. The mini-fan according to claim 15, wherein

the bearing tube (238) has a larger inside diameter at its portion (271) provided for reception of the plug (262) than at its portion (240) provided for reception of the bearing arrangement (236).

19. The mini-fan according to claim 1, wherein

the bearing tube (238) comprises a portion (278) that protrudes away from the rotor (222) and is implemented for installation in an opening (280) of a component (217).

20. The mini-fan according to claim 1, wherein the internal stator (44;

244) comprises a lamination stack (45;

245) on which is arranged a coil former (46;

246) having a stator winding (247), and mounted on that coil former is at least one rigid electrical conductor (132;

288) that is electrically connected to the stator winding (247) and extends substantially parallel to the rotation axis (41;

241) of the mini-fan.

21. The mini-fan according to claim 20,

wherein the bearing tube (238) comprises an outwardly protruding flange (239) that is equipped with an orifice (292) for the passage of the rigid electrical conductor (288).

22. The mini-fan according to claim 1,

wherein the internal stator (44;

244) comprises a lamination stack (45;

245) and the external rotor (22;

222) comprises a permanent magnet (28;

228) coacting with the internal stator, which magnet is offset relative to the lamination stack (45;

245) of the internal stator (44;

244) in such a way that a magnetic force is generated which acts upon the tracking cap (68;

268) in a direction toward the support surface (66;

266).

23. The mini-fan according to claim 1,

wherein an end portion (32;

232) of the shaft (34;

234) is joined to a fan wheel (26;

226);

and near a transition from the shaft (34;

234) to the fan wheel (26;

226);

a surface (112;

312) is provided which extends approximately radially and is located inside the bearing tube (38;

238), so that lubricant (110) thrown off from that surface upon rotation of the fan wheel is thrown into the interior of the bearing tube (38;

238).

24. The mini-fan according to claim 23, wherein the approximately radially extending surface (112;

312) is implemented in undercut fashion.

25. The mini-fan according to claim 23,

wherein the bearing tube (38;

238) comprises, in the region of its end facing away from the cover (62;

262), an inwardly protruding portion (114;

314).

26. The mini-fan according to claim 25,

wherein the inwardly protruding portion (114;

314) is separated from the fan wheel (26;

226) at least locally by a gap (116;

316) that is implemented in the manner of a capillary gap, in order to reduce the emergence of lubricant (110) through that gap.

27. The mini-fan according to claim 25,

wherein the inwardly protruding portion is implemented, on its side facing toward the closure arrangement (62;

262), in the manner of an undercut (114;

314).

28. The mini-fan according to claim 1,

wherein a sintered bearing (36;

236) is provided in order to support the shaft (34;

234), which bearing is arranged in the bearing tube (38;

238) that comprises on its inner side a portion (138) of reduced diameter, for reception of the sintered bearing (36;

236).

35. The mini-fan according to claim 5,

wherein the bearing tube (38) is formed with a constriction (37) in which a sintered bearing (36) is mounted.

36. The mini-fan according to claim 35, wherein the inner side (40) of the constriction (37) has a better-machined surface than other, unconstricted portions of the inner side of the bearing tube (38).

29. A mini-fan having a housing (74) that is equipped with a flange portion (78) that in turn comprises a flange opening (80),

having a cover (62) for closing off that flange opening (80),

further having a join (100, 102) provided between the flange portion (78) and the cover (62),

and having a bearing tube (38) in which a bearing arrangement (36) for a shaft (34) of the fan is located;

the bearing tube (38) being held in positively engaged fashion between the cover (62) and flange portion (78).

30. The mini-fan according to claim 29,

wherein the bearing tube (38) is pressed in substantially liquid-tight fashion into the flange opening (80).

31. The mini-fan according to claim 29,

wherein the bearing tube (38) is equipped with a flange (39) that is held in positively engaged fashion between the cover (62) and the flange portion (78).

32. The mini-fan according to claim 29,

wherein the join between the flange portion (78) and cover (62) is implemented as a welded join (100, 102).

33. The mini-fan according to claim 29,

wherein the shaft (34) of the fan comprises a free end (35);

and a holding apparatus (60) that is implemented to retain that free end (35) is provided on the cover (62).

34. The mini-fan according to claim 29, wherein

the shaft (34) of the fan has a free end (35) that is equipped with a tracking cap (68) associated with which is a corresponding depression (66) in the cover (62), which depression forms, together with the tracking cap (68), a bearing for the shaft (34).

37. A mini-fan, having a fan wheel (22) that is equipped with a shaft (34) for support thereof,

having a sintered bearing (36) to support that shaft (34),

having a bearing tube (38) for reception and retention of the sintered bearing (36), which bearing tube comprises, on its inner sides a portion (37) having a reduced inside diameter, in which portion the sintered bearing (36) is mounted.

38. The mini-fan according to claim 37,

wherein the sintered bearing (36) comprises a portion (42) having an enlarged outside diameter, which outside diameter corresponds approximately to the reduced inside diameter of the bearing tube (38) in order to permit mounting of the sintered bearing (36) in the bearing tube (38) in the region of that portion (42) having an enlarged outside diameter.

39. The mini-fan according to claim 37,

wherein the bearing surfaces (48, 50) of the sintered bearing (36) are located substantially outside the portion (42) having an enlarged inside diameter.

40. The mini-fan according to claim 37,

wherein the bearing surfaces (48, 50) of the sintered bearing (36) are located substantially at locations that are located outside the locations at which the sintered bearing (36) is held in the bearing tube (38).

41. The mini-fan according to claim 37,

wherein the shaft (34) comprises a free end (35) facing away from the fan wheel (22),

and near this free end (35), at least one closure member (62) is provided which seals that end (39) of the bearing tube (38) in substantially liquid-tight fashion.

42. The mini-fan according to claim 41,

wherein a lubricant supply (64) is provided in the region of the sealed end (39) of the bearing tube (38).

43. The mini-fan according to claim 41,

wherein the shaft (34) is equipped in the region of its free end (35) with a tracking cap (68), associated with which in the closure member (62) is a corresponding running surface (66) that, together with the tracking cap (68), forms an axial bearing for the shaft (34).

44. The mini-fan according to claim 37,

wherein the shaft (34) comprises a free end (35) facing away from the fan wheel (22),

and in the region of that free end (35) an annular groove (58) is provided into which protrudes, in the assembled state, a resilient latching member (60) that is mechanically connected to the housing of the mini-fan and counteracts pulling of the installed shaft (34) out of the sintered bearing (36).

45. The mini-fan according to claim 44,

wherein the resilient latching member (60) is implemented integrally with a closure member (62) which serves to close off the bearing tube (38) in substantially liquid-tight fashion.