Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
  • H02K11/01—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for shielding from electromagnetic fields, i.e. structural association with shields
  • H02K11/014—Shields associated with stationary parts, e.g. stator cores
  • H02K11/0141—Shields associated with casings, enclosures or brackets
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
  • H02K11/40—Structural association with grounding devices
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
  • H02K5/16—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields

Definitions

• the invention relates to a DC motor, with a stator and a rotor unit which is rotatably connected to an electrically conductive shaft which is rotatably mounted in at least one fixed sintered bearing, and with a shield against high-frequency electromagnetic fields.
• a generic DC motor is known for example from DE 1 638 216 A1. It is also known, on the rotor unit opposite end face of the stator, ie in the region of a bottom or base plate of the stator, an electrically connected to ground metal plate for
• EC Electronically Commutated
• BLDC Brushless Direct Current
• EC Electronically Commutated
• BLDC Brushless Direct Current
• the opposite further shielding can be realized by a metallic rotor mounted close to the stator.
• a metallic rotor mounted close to the stator.
• it is not sufficient to surround the components to be shielded with conductors, but they must be contacted at ground potential. Otherwise, in the worst case, it may happen that the shield, even in the function of an antenna, inputs or decouples high-frequency energy and thus aggravates the interference problem.
• the required electrical connection to the rotating rotor shielding is not readily possible. Although it can be done in a known manner via a sliding contact, but this requires additional components and is considered problematic in terms of life.
• Device in particular a circuit which is surrounded by a conductive cap, known to arrange flat areas of the cap electrically isolated at a small distance parallel to a flat region of a conductor of a reference potential, so that a capacitive coupling of the cap to the reference potential arises.
• the object of the invention is achieved by the DC motor according to claim 1. Further advantageous embodiments of the invention will become apparent from the dependent claims and the description.
• the shielding of the rotor unit is conductively connected to the shaft for connecting a conductive shield formed on the rotor unit to a defined electrical potential.
• the sintered bearing is conductively connected to the potential, so that a capacitive coupling of the shielding of the rotor unit to the potential is produced via the electrically at least partially insulating oil-filled bearing gap arranged between the shaft and the sintered bearing.
• the invention is based on the idea to use by means of the sintered bearing, especially in the high-frequency range electrically conductive connection, namely a capacitive electrical coupling to electrically connect the rotating shaft to a fixed bearing bush and thus ultimately the rotor shield electrically to the Contact reference potential.
• electrically conductive connection namely a capacitive electrical coupling to electrically connect the rotating shaft to a fixed bearing bush and thus ultimately the rotor shield electrically to the Contact reference potential.
• the rotor unit comprises a cup-shaped metallic pole housing forming the shield, so that the rotor unit essentially forms itself the shield in this area of the motor.
• the shaft is rotatably mounted in a first and second, axially spaced sintered bearing, which are each conductively connected to the defined potential, so that two parallel capacitive couplings of the wave arise to the potential.
• the higher capacitance allows the high-frequency noise generated by the motor, which couple into the rotor shield, to be better dissipated via the capacitive coupling to the ground potential.
• a metal plate connected to the defined potential is provided for further shielding of the motor in the axial direction opposite the shielding of the rotor unit, which is arranged on the end face of the stator unit facing away from the rotor unit and which has at least one connection device a terlager is conductively connected to produce the capacitive coupling. This allows the complete shielding of the motor.
• connection means comprise a pin, preferably integrally connected to the metal plate, extending in the axial direction from the metal plate through the stator unit into the region of de - Ren the rotor unit facing end side extends.
• This pin opens up the possibility of easy contacting of the upper sintered bearing.
• the pin is enveloped near its free end with a dome-shaped plastic extrusion, so that moisture can not penetrate into the motor from its free end.
• a fan is rotatably attached to the shaft outside of the rotor unit, so that the DC motor is designed or used as a blower motor with integrated commutation.
• the DC motor is designed or used as a blower motor with integrated commutation.
• FIG. 1 shows a perspective, partially cut-away view of a DC motor according to the invention with a fan wheel
• FIG. 2 shows the DC motor according to FIG. 1, without a fan wheel, but with a cut stator and rotor unit, FIG.
• FIG. 3 shows a perspective view of a housing flange made of plastic with dome-shaped pins
• FIG. 4 shows a view of a metal plate with a pin connected to the shield in the axial direction for the electrical connection of the metal plate to a sintered bearing
• FIG. 5 shows a perspective view of components of the shielding of the DC motor according to the invention
• FIG. 6 shows an enlarged partial view of the components of FIG. 5.
• FIG. 1 shows a section through the air duct 4 of an embodiment of the DC motor according to the invention.
• a preferred use of the flat-type DC motor is in use as a fan for the air conditioning of a motor vehicle.
• a corresponding fan 2 is attached to the rotating shaft 3, which sucks in air from the exterior of the vehicle via the air duct 4.
• the rotatably mounted on the shaft 3 arranged rotor unit 1 consists of a metallic cup-shaped pole housing, on the inside of which magnets are attached, which in operation of the electric motor in a conventional manner interact with the coils of the stator 5, which, in the pot of Rotor unit 1 and arranged on the
• Housing flange 6 is attached.
• the formed as a dome-shaped bush bearing sintered bearings 8 and 9 sit in the so-called insulating mask of the stator 5, wherein in each case a clamping glasses 10 and 11 is provided which presses the respective sintered bearing in the respective seat.
• the known sintered bearings are plain bearings, which consist for example of sintered iron, a very porous material that can accommodate a large amount of lubricant (oil) during operation.
• FIG. 1 a circuit board with the commutation electronics for the BLDC motor is arranged below the housing flange 6, a circuit board with the commutation electronics for the BLDC motor is arranged below the housing flange 6, a circuit board with the commutation electronics for the BLDC motor is arranged. Recognizable in Figure 1 are also connection pins 7, which forward the commutation signals from the electronics to the coils of the stator 5. In Figure 3, the housing flange 6 is shown alone, with four (two for each terminal pin 7 of the two coils) with the
• Plastic of the flange 6 overmolded dome 12 are provided. Recesses for the dome-like plastic encapsulations 12 are provided in the stator unit 5, so that the stator unit 5 can be placed (elastically) on the domes 12, the area around the connection pins 7 being sealed in a moisture-tight manner by the domes 12. Without the dome 12, an undesirable Tes penetration of moisture from the sucked outside air in the DC motor practically unavoidable.
• Shaft 3 is possible because there is an oil-filled bearing gap between the two conductive parts, which indeed contains more or less metallic abrasion, but does not permit sufficient ohmic connection, in particular not in all operating states.
• a capacitive coupling, in particular via the first, upper sintered bearing 8, is realized instead.
• a pin 14 which is integrally connected to the metal plate 13, is provided, which extends axially into the region of the end face of the stator unit 5 facing the rotor unit 1. Also, this pin 14 is, as seen in Figure 3, provided with a dome-shaped plastic extrusion 12.
• the electrical contacting is advantageously carried out on the clamping goggles 10 of the sintered bearing 8, that is, over the way: electrical contact, clamping gland, sintered bearing, lubricating gap, shaft, rotor unit (pole housing), cf. FIG. 5 and FIG.
• the connecting device from the reference plate placed on the metal plate 13 to the outer surface of the sintered bearing 8, or the clamping glasses 10, comprises, in addition to the pin 14, an axially disposed first contact spring 15 which is resiliently applied to the first sintered bearing 8, in particular on a conductive first clamping glasses 10, which presses the first bearing 8 in his seat.
• a second axially extending contact spring 16 electrically and mechanically connected, in the region of its free end resiliently on the second sintered bearing 9, in particular on a conductive second clamping glasses 11th is present, which presses the second bearing 9 in its seat.
• the connection direction for electrical connection of the rotor unit 1 facing ends of the pin 14 and the first contact spring 15 comprises a strand 17, see Figure 6.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Motor Or Generator Frames (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=48190990

Family Applications (1)

Country Status (5)

Families Citing this family (8)

Citations (1)

Family Cites Families (22)

• 2012
  • 2012-05-25 DE DE102012208847A patent/DE102012208847A1/de active Pending
• 2013
  • 2013-04-29 CN CN201380026981.0A patent/CN104303402B/zh active Active
  • 2013-04-29 US US14/401,865 patent/US9673686B2/en active Active
  • 2013-04-29 WO PCT/EP2013/058895 patent/WO2013174626A1/de active Application Filing
  • 2013-04-29 EP EP13719115.1A patent/EP2856620A1/de not_active Withdrawn

Patent Citations (1)

Non-Patent Citations (1)

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