Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K49/00—Dynamo-electric clutches; Dynamo-electric brakes
  • H02K49/10—Dynamo-electric clutches; Dynamo-electric brakes of the permanent-magnet type
  • H02K49/104—Magnetic couplings consisting of only two coaxial rotary elements, i.e. the driving element and the driven element
  • H02K49/106—Magnetic couplings consisting of only two coaxial rotary elements, i.e. the driving element and the driven element with a radial air gap

Definitions

• the invention relates to a permanent magnet coupling for the synchronous transmission of rotational movements with a first rotor and a second rotor, which are each covered with permanent magnets and form an inner rotor and an outer rotor, wherein associated permanent magnets of the first rotor and the second rotor in the circumferential direction extend over the same angular range.
• Permanent magnetic couplings enable a wear-free and non-contact transmission of torques across the air gap.
• the term air gap refers to the distance formed between the rotors, in which, for example, a split pot can be provided, which allows a leak-free seal between the inner rotor and outer rotor.
• permanent magnet couplings can be used with a split pot, for example in pumps, with the leakage-free torque transmission even with polluting, toxic or otherwise dangerous substances increased security is ensured by the spatial separation.
• permanent magnet clutches enable a wear-free torque limitation, wherein the inner rotor and the outer rotor move synchronously up to a predetermined rotational moment and wherein the permanent magnet coupling slips when the predetermined limit value is reached.
• the present invention is based on a permanent-magnet coupling known from practice, which is completely covered with permanent magnets on its inner rotor and its outer rotor, wherein the successive permanent magnets each have an opposite magnetization direction on each of the rotors (FIGS. 1 a and 1 b).
• All magnets have the same extent in the circumferential direction, so cover the same angle.
• With respect to the magnetic forces between inner rotor and outer rotor results in a minimum, when at the air gap each north pole of the inner rotor, a south pole of the outer rotor and each south pole of the inner rotor is opposite to a north pole of the outer rotor.
• the individual permanent magnets may be arc-shaped, wherein the permanent magnets of the outer rotor are correspondingly larger because of the enlarged diameter. Due to the dense packing of mutually aligned permanent magnets, a high torque can be transmitted in a compact design.
• the permanent magnets of inner rotor and outer rotor are each arranged on a rotor carrier, which is also provided for the magnetic flux as a reflux element.
• the clutch slips ie the rotor provided as output can no longer follow the driven rotor.
• the slippage is due to the magnetic forces acting and eddy currents associated with significant heat generation, which increases with the duration of slippage and with the speed of the permanent magnet coupling. Depending on the particular type of permanent magnet coupling, this results in a maximum slip duration or maximum rotational speed which limits the range of use and which may not be exceeded during operation in order to avoid overheating. andreyevsky ⁇ honke
• a permanent magnet coupling is known in which an equidistant distance is provided in the circumferential direction between each adjacent permanent magnet of the outer rotor. This distance results from the fact that the permanent magnets of the outer rotor have approximately the same extent as the permanent magnets of the inner rotor. In the usual way, the same number of permanent magnets is provided on the inner rotor and the outer rotor, wherein during the synchronous movement of each permanent magnet of the inner rotor is associated with a permanent magnet of the outer rotor. Because of the incomplete coverage of the outer rotor, the maximum torque to be transmitted is comparatively low.
• the invention has for its object to provide a permanent magnet coupling, which has a lower tendency to overheat in a compact design and a high maximum torque to be transmitted when slipping.
• the object is achieved in that on the first rotor, starting from a complete occupancy with permanent magnets in the circumferential direction by omitting part of the permanent magnets unfilled gaps are formed and that the first rotor and the second rotor have a different number of permanent magnets.
• all the magnets expediently have the same extent in the circumferential direction, ie they cover the same angular range. Due to the different diameters of the inner rotor and the outer rotor, the respective magnets are generally of different sizes. In the context of the invention, full coverage is also understood to mean embodiments in which a small intermediate space or web remains between adjacent magnets. A web may in particular be provided to hold the permanent magnets safely. In an arcuate configuration of the magnets according to the curvature at the air gap between the first rotor and andre jewski ⁇ honke
• the magnets which are successive in the circumferential direction can also abut one another directly against the second rotor.
• successive permanent magnets preferably have a respective opposite magnetization direction on the second rotor.
• all circumferentially successive permanent magnets may each have a respective opposite magnetization direction, wherein the intermediate spaces then each extend over an angular range which corresponds to the extension of two or at least an even number of permanent magnets of the first rotor.
• the respective adjacent permanent magnets at the first rotor in an otherwise alternate orientation of the permanent magnets at the intermediate spaces, the respective adjacent permanent magnets have a same magnetization direction, wherein the spaces each extend over an angular range, which is the extension of a permanent magnet or an odd number of permanent magnets of the first rotor corresponds.
• the rotor provided with unfilled gaps can form the inner rotor or the outer rotor without restriction, wherein expediently the empty gaps are to be provided on the respective driven rotor in order to achieve the described ventilation effect during the slipping.
• FIG. 1 b shows a perspective view of the known permanent magnet coupling according to FIG. 1 a
• FIGS. 2 to 4 show alternative embodiments of permanent magnet couplings according to the invention.
• Figures 1 a and 1 b show a known from the prior art permanent magnet coupling in plan view and in a perspective view.
• the permanent magnet coupling comprises a first rotor 1 a and a second rotor 1 b, which are each covered with permanent magnets 2 a, 2 b and form an inner rotor and an outer rotor.
• the first rotor 1 a and the second rotor 1 b each have twelve permanent magnets 2 a, 2 b, which are arranged around the circumference with an alternating magnetization direction.
• Permanent magnets 2a, 2b are arcuately formed according to the curvature of the air gap 3 formed between the rotors 1 a, 1 b and thereby form substantially closed rings.
• the permanent magnets 2a, 2b of the first rotor 1 a and of the second rotor 1 b are arranged on rotor supports 4 a, 4 b, which are also provided as reflux elements of the magnetic flux.
• Fig. 2 shows a permanent magnet coupling according to the invention, in which the first rotor 1 a forms the driven outer rotor.
• the inner rotor is formed as a second rotor 1 b as described above, alternate on the outer rotor with a total of only six permanent magnets 2a around the circumference pairs of oppositely poled Permanentmag Neten 2a m with unausgefl between Räu men 5 from, wel che each ü Extend over an angular range corresponding to the extension of two permanent magnets 2a of the first rotor 1 a.
• the inner rotor 1 b as the second rotor 1 b, the movement of the driven first rotor no longer follow, resulting in a significant heat development. Due to the unfilled gaps 5 but strong air turbulence is generated, which cause good cooling and uniform heat distribution, so that overheating of the permanent magnet andre jewski ⁇ honke
• FIG. 3 shows an alternative embodiment in which, in an otherwise comparable construction of the inner rotor is driven and corresponding to the first, provided with gaps 5 rotor 1a of the permanent magnet coupling according to the invention forms. Also in this embodiment, in contrast to the second rotor 1b with twelve permanent magnets 2b, the first rotor 1a has only six permanent magnets 2a, which are arranged in three groups of two oppositely oriented permanent magnets 2a.
• FIG. 4 shows an alternative embodiment of the invention, in which on the first rotor 1a, here by way of example the inner rotor, gaps 5 are provided which extend only over the angular range of a permanent magnet 2a of the first rotor 1a. Because of the otherwise mutual orientation of the magnetization direction, therefore, the magnetization directions of the respective permanent magnets 2a adjacent to one of the interstices 5 are the same.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Permanent Field Magnets Of Synchronous Machinery (AREA)

Applications Claiming Priority (2)

Publications (1)

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Country Status (7)

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• 2010
  • 2010-01-19 DE DE202010001180U patent/DE202010001180U1/de not_active Expired - Lifetime
• 2011
  • 2011-01-19 CN CN201180006453.XA patent/CN102714455B/zh not_active Expired - Fee Related
  • 2011-01-19 BR BR112012017659A patent/BR112012017659A2/pt not_active Application Discontinuation
  • 2011-01-19 US US13/520,637 patent/US20120280586A1/en not_active Abandoned
  • 2011-01-19 WO PCT/EP2011/050639 patent/WO2011089131A2/de active Application Filing
  • 2011-01-19 EP EP11701488A patent/EP2526612A2/de not_active Withdrawn
  • 2011-01-19 JP JP2012549339A patent/JP6007107B2/ja not_active Expired - Fee Related

Non-Patent Citations (2)

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