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
  • H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
  • H02K11/21—Devices for sensing speed or position, or actuated thereby
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
  • H02K1/22—Rotating parts of the magnetic circuit
  • H02K1/27—Rotor cores with permanent magnets
  • H02K1/2706—Inner rotors
  • H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
  • H02K1/2726—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of a single magnet or two or more axially juxtaposed single magnets
  • H02K1/2733—Annular magnets
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
  • H02K1/22—Rotating parts of the magnetic circuit
  • H02K1/28—Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures
  • H02K1/30—Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures using intermediate parts, e.g. spiders
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K29/00—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices
  • H02K29/06—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with position sensing devices
  • H02K29/08—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with position sensing devices using magnetic effect devices, e.g. Hall-plates, magneto-resistors

Definitions

• Magnetic Wheel for an electric motor, comprising a shaft and a disc made of a magnetic particles contained plastic, wherein the disc is arranged on a carrier hub and the carrier hub is pressed with the shaft.
• Such magnetic wheels are used in brushless DC motors as part of position sensors and are therefore known.
• the disk of the magnetic wheel is produced by injection molding a plastic containing iron particles onto the carrier hub.
• the carrier hub is a closed ring made of a suitable material such as steel or brass. Subsequently, the carrier hub is pressed with the molded disc onto the shaft.
• the disadvantage of this design is that due to manufacturing tolerances of the shaft when pressing the carrier hub sometimes considerable stresses in the carrier hub occur, which reduce the life of the magnetic wheel. In particularly bad cases, magnetic wheel damage can occur, which can lead to malfunctions in the position sensor.
• the invention is therefore an object of the invention to provide a magnetic wheel, in the production-related stresses do not lead to an impairment of individual components.
• the carrier hub is formed as a slotted ring, around which the disc is molded by injection molding.
• the slotted design of the carrier hub allows a much better response to tolerances of the shaft.
• the carrier hub thereby surrounds the shaft as a kind of spring and can thereby widening at larger shaft diameters. In this way, stresses in the carrier hub are significantly reduced, which increases the life of the magnetic wheel. Due to the greater toughness of the plastic, the expansion of the carrier hub does not significantly increase the stresses in the disk.
• Another advantage is that due to the slotted carrier hub and larger manufacturing tolerances in the shaft diameter and the hub bore are allowed, which simplifies the production.
• the production is very cost-effective when the ring for the carrier hub is rolled from strip material.
• the ring for the carrier hub can be in another embodiment, as before, a turned or stamped part, in which a slot is introduced. This is particularly advantageous if the ring is still processed before encapsulation.
• An intimate connection of carrier hub and disc is achieved with a notch in the form of at least one imprint, preferably in the form of a Rändeis.
• the notch is particularly easy to produce in another embodiment, if it is a single recess in the carrier hub, which is arranged opposite the slot. A single recess is often sufficient due to the low torque to be transmitted. It is also advantageous that so wide areas of the carrier hub are present, which allow a relative movement of plastic and carrier hub.
• two to four recesses can be arranged in the carrier hub, which are arranged symmetrically to the slot.
• the invention is explained in detail. It shows in:
• FIG. 1 shows a magnetic wheel in half section
• Figures 2, 3 further embodiments of the carrier hub.
• the magnetic wheel 1 consists of a shaft 2, which may be the shaft of an electronically commutated electric motor, and a disc 3 made of ferrite-bonded plastic.
• the synthetic material is molded onto a carrier hub 4 by means of injection molding.
• the carrier hub has a slot 5, which is arranged in the cutting plane for better visibility. Opposite of the slot 5 and thus at a distance of 180 °, the carrier hub 4 radially outwardly a notch 6 in the form of a recess 8. In the injection molding of the ferrite-bound plastic, this fills the notch 6 and thereby produces an intimate bond with the carrier hub 4.
• the carrier hub 4 When pressing the carrier hub 4 with the disc 3 on the shaft 2, the carrier hub 4 can expand, where it is in the areas right and left of the slot 5 can come to relative movements between the carrier hub 4 and disc 3.
• the carrier hub 4 is shown without the disc and the shaft. 2 shows the carrier hub 4 with a notch 6 in the form of two knurls 7.
• the knurls 7 are arranged in a region which is symmetrically opposite the slot 5 and extends over 60 °.
• the knurls 7 each extend over a range of 20 ° and have a distance of 20 ° from each other.
• the knurls 7 thus have a distance from the slot 5 of 150 °.
• the carrier hub 4 in Fig. 3 has a notch 6 in the form of three symmetrically to the slot 5 arranged recesses 8, which have a distance of 30 ° to each other.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)
• Permanent Field Magnets Of Synchronous Machinery (AREA)
• Brushless Motors (AREA)
• Iron Core Of Rotating Electric Machines (AREA)
• Injection Moulding Of Plastics Or The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=47501241

Family Applications (1)

Country Status (7)

Families Citing this family (6)

Family Cites Families (20)

• 2011
  • 2011-12-20 DE DE102011089243A patent/DE102011089243A1/de active Pending
• 2012
  • 2012-12-19 US US14/366,191 patent/US9882456B2/en active Active
  • 2012-12-19 WO PCT/EP2012/076069 patent/WO2013092653A2/de active Application Filing
  • 2012-12-19 CN CN201280062426.9A patent/CN104040852B/zh active Active
  • 2012-12-19 EP EP12809792.0A patent/EP2795772A2/de not_active Withdrawn
  • 2012-12-19 JP JP2014547948A patent/JP6066128B2/ja active Active
  • 2012-12-19 KR KR1020147015924A patent/KR20140117357A/ko not_active Application Discontinuation

Non-Patent Citations (2)

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