Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K37/00—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors
  • H02K37/10—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors of permanent magnet type
  • H02K37/12—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors of permanent magnet type with stationary armatures and rotating magnets
  • H02K37/125—Magnet axially facing armature
• • G—PHYSICS
  • G04—HOROLOGY
  • G04C—ELECTROMECHANICAL CLOCKS OR WATCHES
  • G04C13/00—Driving mechanisms for clocks by primary clocks
  • G04C13/08—Secondary clocks actuated intermittently
  • G04C13/10—Secondary clocks actuated intermittently by electromechanical step advancing mechanisms
  • G04C13/11—Secondary clocks actuated intermittently by electromechanical step advancing mechanisms with rotating armature
• • G—PHYSICS
  • G04—HOROLOGY
  • G04C—ELECTROMECHANICAL CLOCKS OR WATCHES
  • G04C15/00—Clocks driven by synchronous motors
• • 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
  • H02K21/24—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets axially facing the armatures, e.g. hub-type cycle dynamos

Definitions

• This invention relates to polyphase motors with ai ⁇ mantle rotor having on each of its two faces N / 2 pairs of poles.
• a first type is that for which the rotor has N pairs of poles, these pairs being defined, for example, by axes of magnetization which are parallel to the axis of rotation of the rotor, so that the latter has N poles on each of its two faces.
• a second type is that for which the rotor has, on each of its two faces, N / 2 pairs of poles, these pairs being defined, for example, by magnetization curves which are contained in planes parallel to the axis of rotation of the rotor, so that the latter also has N poles on each of its two faces.
• the engine of the present invention essentially belongs to this second type.
• the main object of the invention is to create an energy efficient polyphase motor, using existing materials, which can be manufactured by industrial processes and the number of phases as well as the range of powers can be very wide, without modifying the engine design.
• it also aims to create a mo- multi-phase tor which can be easily adapted to the step by step mode
• the field of application of the engine according to the present invention is therefore very wide.
• This engine can be used, in particular, in drive systems for office automation, robotics, the aeronautical and space industry, photographic equipment, timepieces.
• the motor according to the present invention is suitable for all systems using the digital technique, and, more particularly, for all those where the criteria of space, efficiency, power and speed are determining.
• the subject of the invention is a polyphase motor which is characterized by the structure defined by claim 1, certain special embodiments of which are defined by claims 2 to 14, which can be adapted to the stepping mode, using the means defined by claims 15 and 16 and which can be mounted in the manner defined by claim 17.
• Fig. 1 is a view in the direction of the axis of rotation of the rotor
• Fig. 2 shows the watch in parts, to illustrate its structure
• Fig. 3 is a section illustrating the positioning of the stators
• Fig. 4 is a section illustrating the mounting of the rotor
• Fig. 5 is a perspective view of the rotor of the first variant
• Fig. 6 is a plan view of a part of the second variant
• Figs. 7 and 8 are linear sequences of the engine, which illustrate its mode of operation. - 3 -
• the motor shown has a rotor 1, each of the two faces of which has a number N of poles equal to eight.
• the number m of the phases of this motor is equal to two.
• the offset between these two phases is equal to ⁇ .
• the rotor 1 is made of ferromagnetic material such as samarium-cobalt, the coercive field of which is high and the density low.
• Each of its two faces has N / 2 pairs of poles. On each face, these poles are distributed regularly around the axis of rotation of the rotor and they are alternately of opposite names. In addition, the poles on one side are located exactly opposite the poles of the same name on the other side.
• a stator is mounted opposite each of the faces of the rotor: a first a and a second b.
• the stators a, b form two phases r and s.
• Each phase r, s is composed of two pole pieces 2, 3, coplanar with each of the two stators a, b and the two pole pieces 2, 3 of each of the phases r, s of the stator a respectively have the same shape as the two pole pieces 2, 3 of each of the two phases r, s of the stator b.
• the pole pieces 2, 3 of the stator b are superimposed on the pole pieces, 3 of the same shape of the stator a.
• each phase thus has two pairs of pole pieces of the same shape facing each other and two pairs of coplanar pole pieces nested one inside the other.
• the pole pieces are made of ferromagnetic material with a low coercive field and high saturation induction. They have poles 5 (Fig. 1) which, to facilitate the explanations, are designated by p 1? p 2> ..., p 9 in Fig. 2,
• FIG. 1 This figure shows that the poles p-,, p, of the pole pieces 3 of of phase r of the stators a, b, the poles P2, p 4 of the pole pieces 2 of this same phase r of the stators a, b, the poles p,, p politicianof the pole pieces 3 of phase s of the stators a, b and the pole p_ of the pole pieces 2 of this phase s of the stators a, b respectively have the same angular extension.
• poles p- and Pq of the pole pieces 2 of phase s of the stators a, b are fractional.
• the sum of the angular extensions of these two fractional poles is at least approximately equal to the angular extension of an entire pole.
• 1 N phase are integers; they are - in number per pole piece and are spaced by an angular interval at least approximately equal to twice that existing between the adjacent poles of each face of the rotor.
• poles of the two remaining pole pieces there are
• the phases r, s are offset relative to each other by an angle ⁇ of 22.5 °.
• the offset ⁇ can be made different from - -.
• the sum of the angular extensions of the fractional poles remains at least approximately equal to the angular extension of an entire pole, but these fractional poles no longer all have the same angular extension.
• each pole piece of the stator a is magnetically connected to the pole piece of the stator b which is opposite it.
• These magnetic links are such that, for each phase, the two outer pole pieces 3 are connected to one end of a noau yau 6, the other end of which is connected to the two inner pole pieces. 2 of the same phase.
• the two outer pole pieces 3 are connected to the end A of the core 6 of this phase, the other end B of which is connected to the two inner pole pieces 2 of this same phase.
• the two outer pole pieces 3 are connected to the end D of the core 6 of this phase, the other end C of which is connected to the two inner pole pieces 2.
• the core 6 of each phase is made of ferromagnetic material with low coercive field and high saturation induction.
• a coil 7 is wound around the core of each phase. The assembly is mounted as illustrated in FIG. 3.
• the stator a rests against a piece of non-ferromagnetic material 8.
• the pole pieces 2, 3 of the respective stators a, b are positioned by four screw feet 9. Two of these screw feet have a shoulder 10 , against which the pole pieces of the stator bear b.
• Two spacers 11, made of soft ferromagnetic material, are interposed in the space between each of the ends of the core and each pole piece of the stator b.
• the device described ensures, on the one hand, the correct positioning in their planes of the pole pieces, thanks to the screw feet, and, on the other hand, the correct positioning in height of these pole pieces, thanks to the shoulders 10 and the spacers. 11.
• the rotor 1 is mounted as illustrated in FIG. 4. It pivots in bearings 12 with low contact friction. These bearings are preferably made in ruby.
• a pinion 13 is integral with the shaft 1a of the rotor in order to transmit the rotations of the latter to a first mobile
• the rotor is made in two parts separated by a disk 1b of soft ferromagnetic material.
• Each part of this rotor has N axes of magnetization of alternately opposite directions. These magnetization axes are parallel to the axis of rotation of the rotor and they are regularly distributed around the latter.
• the poles of the external face of one of the parts of the rotor are directly opposite those of the same name on the external face of the other
• the motor comprises a soft, fixed fer ⁇ romagnetic disc, which is mounted in place of a stator.
• This disc has openings 15, which are arranged so as to réali ⁇ ser a positioning torque.
• Figs. 7 and 8 illustrate the operation of the engine. These are linear expansions of it. More particularly, these are schematic sections of the engine previously unwound in a linear fashion.
• the phase shift r, s is 22.5 °.
• pairs of poles of the rotor 1 are located exactly opposite the poles p-,, p 2 , Pj and p, of the phase r of the stators a, b.
• This figure shows that the fluxes from the poles of the face of the rotor facing the stator a are collected by the poles p-, and p, of the pole piece 3 of this stator a, from where they are routed to the core 6 of phase r, which they travel from A to B. They then close by passing through the poles p 2 and p 4 of the pole piece 2 of the stator a.
• the fluxes coming from the face of the rotor facing the stator b they are collected by the poles p, and p, of the pole piece 3 of the stator b, then conveyed to the core 6 of phase r, which they travel through. also from A to B before closing through the poles p 2 and p. of pole piece 2 of stator b. In the considered position of the rotor, the flux of the rotor through the core 6 of phase r is therefore maximum.
• the position of the rotor in which its flux through the core 6 of phase s is maximum is that of FIG. 8.
• the two fractional poles Pc and pg each collect, for each face of the rotor, a flux equal to 1 / m times the flux collected by an entire pole, or 1/2 of that of an entire pole in the example shown.
• the rotor l 'of the variant shown in FIG. 5 comprises two magnetic parts. Unlike the rotor of the embodiment described above, the magnetization of these two parts is axial, and therefore easier to produce, and a soft ferro-magnetic disk 1b is fixed between them. As the poles of these two parts facing each other have the same name, the operation of the motor according to this variant is the same as that of the embodiment described above.
• Another variant (not shown) of the motor according to the invention consists in shifting identically both the poles of one of the faces of the rotor and those of the stator opposite these poles relative to the poles of the other face of the rotor and the stator opposite this other face.
• the operation of the engine is the same as that of the embodiment described above.
• the motor according to the invention would still operate if one of the sta ⁇ tors was removed.
• the rotor could have N / 2 pairs of poles only on its face opposite the remaining stator. As the flux passing through the cores would be halved, the efficiency of the engine would naturally be worse.
• Fig. 6 shows such a disc, which has openings 15, in order to create a positioning torque.
• These open tures are in number equal to that of the poles of one of the faces of the rotor and are arranged in a circular crown concentric with the rotor, in which they are distributed in a regular manner.
• the period of the positioning torque is equal to 2 ⁇ r / N. It would however also be possible to create a positioning torque of period 4 ⁇ r / N by removing one of the openings 15 both.
• a phase shift between the positioning torque and the mutual torques could be created by shifting the openings 15 relative to the radial sections of the sinuous iron 4 of the stator. Such a phase shift could also be created by shifting the poles of one of the faces of the rotor relative to those of the other face, the openings 15 then being arranged symmetrically with respect to the radial sections of the sinuous air gap of the stator.
• the number of motor phases according to the invention can be very wide without modifying the motor design, since it suffices that the re-
• N lation m -y-— be satisfied for n integer. In other words, it suffices to increase the number N of poles per face of the rotor to increase the number m of phases.
• the engine according to the invention also has the advantage of offering a very wide range of powers, without having to modify the design of the engine. Without going into the details of the theory, it is, indeed, intuitive to notice that the mechanical power of a motor of this type is an increasing function of the number of pairs of poles of the rotor as well as of the diameter of the latter.
• the motor according to the invention finally has the advantage of lending itself to operating mode step by step, since the disc of FIG. 6 introduces the positioning torque necessary for this operating mode.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Permanent Magnet Type Synchronous Machine (AREA)
• Iron Core Of Rotating Electric Machines (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4270347

Family Applications (1)

Country Status (4)

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• 1984
  • 1984-07-30 EP EP84902779A patent/EP0151159A1/de not_active Withdrawn
  • 1984-07-30 JP JP59502889A patent/JPS60501933A/ja active Pending
  • 1984-07-30 WO PCT/CH1984/000119 patent/WO1985000705A1/fr not_active Application Discontinuation
  • 1984-07-30 US US06/720,409 patent/US4680494A/en not_active Expired - Lifetime

Non-Patent Citations (1)

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