Classifications

• • 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
  • H02K1/2786—Outer rotors
  • H02K1/2787—Outer rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
  • H02K1/2789—Outer rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets
  • H02K1/2791—Surface mounted magnets; Inset magnets
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
  • H02K21/12—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets
  • H02K21/22—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating around the armatures, e.g. flywheel magnetos
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
  • H02K7/18—Structural association of electric generators with mechanical driving motors, e.g. with turbines
  • H02K7/1807—Rotary generators
  • H02K7/1846—Rotary generators structurally associated with wheels or associated parts

Definitions

• the present invention relates to electric motors for use on a rear wheel hub of a two-wheeler with an outer rotor connected to a rim.
• the electric motors are preferably designed in the form of brushless, electronically commutated electric motors, so-called PMSM motors.
• Such electric motors have an axle-fixed internal stator arrangement with a high number of slots of usually more than 51.
• the rotor of these electric motors is firmly connected to the rim of the rear wheel and usually has a ring mounted on a yoke ring of permanent magnets, in particular rare earth permanent magnets, with a high number of poles.
• a drive motor for a drive wheel of a two-wheeler comprising:
• the permanent magnets are arranged with a tangential polarity direction between the rotor poles of the rotor assembly.
• the runner can be given a pronounced salience.
• An idea of the above rotor arrangement is to arrange the permanent magnets spoke-shaped. Two adjacent permanent magnets each include a rotor pole.
• a holding element made of paramagnetic material arranged on an outer lateral surface of the rotor arrangement can be provided in order to ensure a magnetic separation between the rotor poles.
• the rotor arrangement has no return region.
• the rotor poles terminate with their radially inner ends flush with the radially inner ends of the permanent magnets or protrude inwardly beyond the radially inner ends of the permanent magnets.
• the pole faces of the permanent magnets can abut against tangentially oriented side faces of the rotor poles.
• a drive system for a two-wheeler includes the above drive motor provided inside a rim body.
• a method for operating the above drive motor wherein the stator coils according to a predetermined Commutation scheme are driven to generate a stator magnetic field that interacts with an exciting magnetic field generated by the permanent magnets to cause a driving torque, wherein the stator magnetic field is generated so that an angle between the exciting magnetic field and the stator magnetic field corresponds to more than 90 ° electrical rotor position.
• Figure 1 is a cross-sectional view of a section through a
• Figure 2 is a diagram showing load / speed characteristics of an electric motor without salience and an electric motor with salience with different Vorkommut istswinkeln the control.
• Figure 1 shows a cross-sectional view of a section through an electric motor 1 as a drive motor for a gearless drive a rear wheel of a two-wheeler.
• the cross section is transverse to the axial direction.
• the electric motor 1 is an electronically commutated external rotor motor with a rotor assembly 2 as an external rotor and a
• Stator arrangement 3 as an inner stator.
• the rotor assembly 2 is formed annular or circular cylindrical and rotatably supported about a rear wheel axle of the bicycle.
• the rotor assembly 2 is with Permanent magnets 21 are formed between which rotor poles 22 are arranged.
• the permanent magnets 21 have a Polungsraum in the tangential direction, so that the magnetic poles bear against radially extending side surfaces of the rotor poles 22.
• the rotor poles 22 terminate at their radially outer end substantially flush with the radially outer ends of the permanent magnets 21, so that a substantially circular lateral surface of the rotor assembly 2 is formed.
• the circular lateral surface is connected via a holding element 4 of paramagnetic, ie non-conductive, material with a (not shown) rim body 5 of the drive wheel.
• the rotor poles 22 may terminate substantially flush with the radially inner ends of the permanent magnets 21 at their radially inner end facing an air gap 6 of the electric motor 1, so that a substantially circular inner circumferential surface of the rotor assembly 2 is formed.
• the rotor poles 22 may project with their radially inner end over the radially inner end of the permanent magnets 21 and partially overlap the permanent magnets 21 at their edges. In this way, Polkumble 24 can be formed, which allow improved flow distribution in the air gap 6.
• the stator assembly 3 Inside the rotor assembly 2, the stator assembly 3 is provided, the axis fixed, d. H. not rotatable, connected to the bicycle.
• Stator assembly 3 is provided with stator teeth 31.
• the stator teeth 31 are surrounded by stator coils 32, which can be energized to provide a stator magnetic field according to a commutation pattern. Possible commutation patterns are sinusoidal commutation or block commutation, although other types of commutation are conceivable.
• the stator teeth 31 are connected to one another via a magnetic return region 33 close to the axis.
• the stator arrangement 3 is arranged in the interior of the rotor arrangement 2 such that both arrangements are separated from one another by the air gap 6.
• the rotor assembly 2 is mounted about a rotation axis (not shown), so that the width of the air gap 6 is substantially constant over the entire circumferential direction.
• the permanent magnets 21 are preferably formed as ferrite magnets, but may also be provided as rare-earth permanent magnets or the like.
• the rotor poles 22 are formed of soft magnetic material, such as electrical steel, in particular in lamellar construction.
• the q-axis describes the direction of a magnetic flux through the stator coils 32 perpendicular to the exciting field generated by the permanent magnets 21 and the d-axis the direction of the magnetic flux of the exciting magnetic field.
• the stator 3 does not generate any flux component in a d-direction, but only in a q-direction, so that the stator magnetic field leads the exciter magnetic field essentially by 90 ° electrical rotor position.
• the engine torque provided by the electric motor 1 is as follows:
• L d , L q correspond to the instantaneous virtual stator inductances in the d- or q- direction, Z P to the number of pole pairs of the external rotor 2, ⁇ ⁇ to the magnetic flux of the field magnet field and l q to the current through the stator coils 32.
• the virtual inductances L d and L q result after a backward calculation from a ring integral along the considered magnetic fluxes.
• the magnetic permeability of ferromagnetic materials is almost equal to that of air, so that the virtual stator inductances L d and L q are nearly equal in surface mount type permanent magnets 21. It is irrelevant whether the surface magnets are spaced apart or, as currently customary in wheel hub drives, mounted flush with each other.
• the rotor arrangement 2 described above has a salience, since the virtual inductances L d and L q provide different values, in particular also depending on the operating state of the electric motor 1, in particular its speed and rotor position. If a phase-advance angle that is time-invariant from the perspective of the rotor-fixed coordinate system is selected for a distinctly salient electric motor 1, which makes the component of the motor current I d unequal to 0, the operating variables flux, phase voltage, motor torque, electrical speed and sum of the phase currents result as follows:
• M Mi 3/2 x Z p ( ⁇ ⁇ x Iq + (L d - L d) x Iq xl d) wherein in each case l d, l q the effective stator phase, U d, U q induced phase voltages, D L of electrical rotation speed and M M i correspond to the internal engine torque.
• a control with a pre-commutation is added to the permanent magnet excitation of the electric motor 2, further a component L d xl d -
• the stator current in the d-direction l d is less than zero and thereby reduces the excitation flux of the magnetic field generated by the permanent magnets 21 in d Direction and thus the induced counter electromotive voltage, whereby the electric motor 2 higher speeds are possible. It is thus intended to control the above electric motor 2 in such a way that the stator magnetic field leads in addition to the angle leading the 90 ° electrical rotor position by a further pre-commutation angle.
• the pre-commutation angle can be selected depending on the operating point or fixed.
• FIG 2 are different load / speed characteristics curves for an electric motor without a saliente rotor arrangement (curve K1) and for electric motors with salient rotor arrangement and Vorkommut istswinkeln of 0 °, 20 ° and 40 ° (curves K2, K3, K4) for the control the stator coils shown.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Permanent Magnet Type Synchronous Machine (AREA)
• Permanent Field Magnets Of Synchronous Machinery (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=49989695

Family Applications (1)

Country Status (4)

Citations (2)

Family Cites Families (5)

• 2013
  • 2013-02-07 DE DE102013202011.2A patent/DE102013202011A1/de active Pending
• 2014
  • 2014-01-13 CN CN201480007787.2A patent/CN104995821B/zh active Active
  • 2014-01-13 WO PCT/EP2014/050434 patent/WO2014121976A2/de active Application Filing
  • 2014-01-13 EP EP14700588.8A patent/EP2954609A2/de not_active Withdrawn

Patent Citations (2)

Non-Patent Citations (1)

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