Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K9/00—Arrangements for cooling or ventilating
  • H02K9/02—Arrangements for cooling or ventilating by ambient air flowing through the machine
  • H02K9/04—Arrangements for cooling or ventilating by ambient air flowing through the machine having means for generating a flow of cooling medium
  • H02K9/06—Arrangements for cooling or ventilating by ambient air flowing through the machine having means for generating a flow of cooling medium with fans or impellers driven by the machine shaft

Definitions

• the invention relates to an electrical machine according to the preamble of spoke 1.
• the object of the invention is to design a generator of the generic type in such a way that the heat dissipation is improved.
• This configuration has the effect that the heat conduction is drastically improved due to the larger transition area from the rotor to the cooling air via the fan wheel.
• the temperatures in the excitation winding and the temperatures in the area of the electrodes are reduced, so that a performance advantage of the generator can be achieved.
• the surface of the The rotor is thus enlarged by the surface of the fan wheel, which means that a greater heat flow can be achieved.
• At least one fan wheel and the rotor are connected to one another by welding over a large area.
• the welding ensures a cost-effective, good heat-conducting and safe connection of the fan wheel to the rotor.
• the at least one air wheel and the rotor prefferably be connected to one another at least along an arc of a part circle, the connection also being able to be implemented over a large area.
• the fan wheel is thus attached to the rotor over a large area in order to reduce the thermal resistance. Better cooling of the rotor is made possible by the increase in the cross-sectional area for the heat conduction.
• the at least one fan wheel and the rotor are preferably ultrasonically welded to one another. Ultrasonic welding can significantly increase the welding area and thus also the thermal contact area between the air wheel and the rotor in comparison to other welding processes at low costs.
• the at least one fan wheel consists of an aluminum alloy.
• the use of fan wheels made of an aluminum alloy has the advantage that the heat conduction in the fan wheel itself is considerably improved compared to steel fan wheels. This is due to the higher coefficient of thermal conductivity. Furthermore, due to the material combination of aluminum and steel Ultrasonic welding possible.
• the use of fan wheels made of an aluminum alloy suppresses the stray magnetic flux between the two claw poles by the non-magnetic fan wheel.
• a fan wheel is provided on the opposite end faces of the rotor.
• the arrangement of the fan wheels on both sides ensures efficient cooling of the rotor.
• FIG. 2 shows an enlarged detail of the view according to FIG. 1 on the drive-side fan wheel
• Fig. 3 is a plan view of a fan wheel.
• An electrical machine in this exemplary embodiment a generator 1, has in a housing 2, consisting of two housing halves 3 and 4, a rotor 6 which is rotatably mounted about an axis of rotation 5.
• a three-part housing 2 is also possible.
• the rotor 6 is supported by two ball bearings 7 and 8, the ball bearing 7 being larger in the front housing half 3 and designed as a fixed bearing.
• the ball bearing 8 is located in the rear half of the housing 4 and forms the floating bearing.
• the front housing half 3 is a bearing plate for the ball bearing 7 and the rear Housing half 4 formed as a bearing plate for the ball bearing 8. Outside the housing half 3, at the end of the rotor shaft 9, a pulley 10, fastened by a nut 11, is attached to drive the rotor 6.
• a slip ring arrangement 12 is provided at the rear end of the rotor shaft 9.
• the Sc eifringan extract 12 comprises 9 carbon brushes 13 on the rotor shaft.
• the carbon brushes 13 interact in a known manner with slip rings 27.
• a slip ring or brushless design is also possible.
• the rotor 6 comprises on the rotor shaft 9 in the middle region a rotor winding 14, which corresponds to an excitation winding, on a core piece 15 and two claw pole plates 16 directly adjacent to the rotor winding 14 with intermeshing claw pole fingers 17.
• the two housing halves 3 and 4 connected to one another by screws 18, fix a stator winding 19 running around the inside of the housing.
• fan wheels 21 made of an aluminum alloy on the outer end faces 20 of the claw pole plates.
• the fan wheels 21 can be pushed onto the rotor shaft 9 due to a central bore 22.
• the end faces 20 of the claw pole plates 16 are then ultrasonically welded to the fan disk 23 of the fan wheel 21.
• the fan wheels 21 have individual, radially projecting fan blades 24 on the outside.
• the fan blade 24 comprises an axially oriented projecting fan blade 28, the fan blade 24 and the fan blade 28 being formed in one piece.
• the fan blade 24 is inclined at an angle W with respect to the bore axis 29.
• the angle W is preferably 25 °.
• the fan blade 28 has a recess 30 on its end face.
• fan wheels 21 made of steel can also be used.
• fan wheels 21 made of steel laser welding When using fan wheels 21 made of steel laser welding required.
• the use of aluminum alloy fan wheels 21 is preferable since aluminum has a higher coefficient of thermal conductivity and also prevents the magnetic leakage flux between the claw poles via the non-magnetic fan wheel 21.
• the welding takes place in an area concentric to the shaft axis 5 with an inner diameter D and a width B. The welding is ring-shaped in this area.
• the annulus area of the weld is 706.9 mm for each fan wheel, an inner diameter of 40 mm and an annulus width of 5 mm being taken as a basis.
• Other types of connections are also possible.
• the basis for a connection is good conductivity.
• Solder connections or adhesive connections can be used.
• the connection between the fan wheel 21 and the rotor 6 can also be made on a partial arc. A square design of the connecting surface is also possible.
• the fan wheel 21 in the front housing half 3 is provided with recesses 26 at the end of the fan disk 23 for attachment the outer end faces 20 of the claw pole plates 16.
• the mode of operation of the generator according to the invention is identical to the mode of operation of known generators.
• the flowing currents in the stator winding 19 and in the rotor winding 14 cause a strong heat build-up in the housing 2 of the generator 1.
• an air flow is axially applied through slots in the housing for cooling. sucks and is blown radially outwards at the front winding head of the stator winding through external housing slots.
• cooling by means of fan wheels takes place, on the one hand, by the supply of cooling air and, on the other hand, by the removal of the heat generated.
• the fan wheels are attached to the claw-pole end faces by means of spot or spot welding.
• the prior art shows that typically only the slip ring-side fans are attached to the claw-pole boards. This attachment is usually carried out by 12 welding points, each with a diameter of 5 mm. This results in a total welding area of 235.6 m 2 . This small area creates a high thermal resistance between the fan and the claw pole. In comparison with the generator 1 according to the invention, the connection area is made smaller by a factor of 6.
• the air wheel 21 can also be arranged between the claw-pole boards 16, in which case the fan wheel 21 is then welded to the inside of the claw-pole board 16.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Motor Or Generator Cooling System (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=7676101

Family Applications (1)

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Citations (2)

Family Cites Families (15)

• 2001
  • 2001-03-02 DE DE10110129A patent/DE10110129A1/de not_active Withdrawn
• 2002
  • 2002-02-14 BR BR0207793-0A patent/BR0207793A/pt not_active IP Right Cessation
  • 2002-02-14 JP JP2002570376A patent/JP2004521591A/ja not_active Abandoned
  • 2002-02-14 US US10/469,461 patent/US6841901B2/en not_active Expired - Fee Related
  • 2002-02-14 EP EP02708244A patent/EP1374372A1/de not_active Ceased
  • 2002-02-14 MX MXPA03007854A patent/MXPA03007854A/es unknown
  • 2002-02-14 WO PCT/DE2002/000518 patent/WO2002071576A1/de not_active Ceased

Patent Citations (2)

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