Classifications

• • 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
  • H02K5/173—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using bearings with rolling contact, e.g. ball bearings
  • H02K5/1732—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using bearings with rolling contact, e.g. ball bearings radially supporting the rotary shaft at both ends of the rotor
• • 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

• the present invention relates to an electric motor comprising both a stator and at least one rotary member comprising a rotor part essentially in the form of a flat annu ⁇ disk mounted rotatably with respect to the stator by means of at least one bearing. with balls comprising at least two coaxial bearing rings forming ball raceways, at least one of these bearing rings having a planar annular surface perpendicular to the axis of rotation.
• the disc-shaped rotor part is arranged very precisely relative to the stator.
• the position of the annular disc must be defined with great precision with respect to the parts of the stator with which this disc cooperates, and this in particular as regards the position of the disc in the axial direction and with regard to relates to the orientation of the plane of the disc which must be strictly perpendicular to the axis of rotation.
• annular disc-shaped part of the rotary member is fixed thereto by means of a support piece mounted on the motor shaft, so that the dimensional and positional tolerances of this part are added to the sets of ball bearings. Furthermore, it is difficult by means of such a support piece to ensure a plane of rotation exactly perpendicular to the motor shaft.
• the present invention aims to provide an engine of the type mentioned above, the construction of which is simple and economical and which makes it possible to achieve very great precision in defining the position of the disc-shaped rotor part relative to the stator.
• the motor according to the invention is characterized in that the rotor part is fixed on a rolling part, directly, so that respective flat annular surfaces are in contact with each other, or indirectly, via a support part having a planar annular surface in contact with the planar annular surface of said rolling part, and in contact with said rotor part, or via a support part in the form of a flat annular disc of which one or more flat annular surfaces are in contact with the respective flat annular surfaces of said rotor part and said rolling part.
• the stator comprises two parts, each forming a magnetic circuit with an air gap, and being coupled with at least one control coil, as well as two rotary members cooperating respectively with each of these stator parts.
• FIG. 1 is a view in axial section of a two-stage two-phase synchronous motor
• Figure 2 is a sectional view along line II-II of the
• FIG. 3 is a view in partial axial section of a motor similar to that of FIG. 1 comprising a double ball bearing, with a common ring,
• FIG. 4 is a view in partial axial section of another alternative embodiment of the motor of FIG. 1 comprising two juxtaposed ball bearings,
• FIG. 5 is a view in partial axial section of an alternative embodiment similar to that of FIG. 4 comprising a ball bearing with three rings and a single row of balls,
• FIG. 6 is a view in axial section of a two-phase synchronous motor having two rotary members resiliently coupled in the axial direction
• FIG. 7 is a view in partial axial section of an alternative embodiment of the engine according to FIG. 6,
• FIG. 8 is a view in partial axial section of another embodiment of the engine of FIG. 6, and
• FIG. 9 is a view in partial axial section of another alternative embodiment of the engine according to FIG. 6.
• the motor shown in FIG. 1 is a two-stage motor, each of which comprises a respective stator part 1,2 and a corresponding rotary member 3,4.
• Each rotary member comprises a respective rotor part 5, 6, in the form of a thin, planar annular disc, made of a magnetizable material such as samarium-cobalt.
• These discs are magnetized parallel to their axis so as to present on each of their flat surfaces alternately positive and negative magnetic poles, distributed regularly along an annular zone of each surface. They are glued or fixed in some other appropriate manner on a portion of 7.8 * corresponding support also having a disc-shaped annular plane.
• the support discs are in turn fixed, for example by welding, on the cheeks of respective inner rings 9, 10 of two ball bearings, the corresponding outer rings of which are designated by 11 and 12 respectively, the rows of balls of each bearings being designated by 13 and 14.
• the inner rings of the two ball bearings are mounted on an axis 15 of the motor so as to be integral with this axis in their final position determined during the assembly of the motor.
• the two stator parts 1,2 of the motor of FIG. 1 each comprise a corresponding electrical control coil 16 and 17, of annular shape, arranged coaxially with respect to the axis of the motor. Each coil is coupled with a magnetic circuit comprising two annular parts designated 18.19 and 20.21 respectively. These annular parts are made of a material of very good magnetic permeability, and they are in two-by-two contact along peripheral plane contact zones 22 and 23 so that the magnetic resistance also remains low at this location.
• the parts 18 to 21 each have an inner annular part comprising a series of teeth, such as 24, distributed over the entire circumference so as to form in each of the stator parts a variable annular air gap along this circumference .
• the axial section of the magnetic circuits thus has a C shape and an annular zone of each rotor part is disposed in the respec ⁇ tive air gap formed by these magnetic circuits.
• the external parts 18 and 21 of the magnetic circuits are mounted on the corresponding external rings 11 and 12 of the ball bearings of the motor.
• a support plate 25 is also
• the internal parts 19 and 20 of the two stator parts 1 and 2 are in contact along an annular cylindrical surface 26 perpendicular to the axis of the motor.
• An intermediate piece with parallel flat surfaces could be arranged, according to an alternative embodiment, between the parts 19 and 20, so that these parts would be spaced apart while preserving the parallelism of their flat annular surfaces such as the surface 26.
• carcass parts such as 27 in which the control coils are housed, and a separation piece 28, made of plastic, which can be placed between the two rotor parts to facilitate mounting of the engine.
• FIG. 2 shows the configuration of certain elements of the motor in section along the line II-II of FIG. 1, and in particular the teeth 24 oriented radially and arranged essentially regularly along the inner periphery of the visible annular part 19.
• FIG. 3 shows an alternative embodiment which uses, instead of two separate ball bearings, two combined roule ⁇ ments having one of their bearing rings in common.
• the stator parts designated respectively by 31 and 32, have a configuration similar to that of FIG. 1 and are mounted on the common ring 33 of the combined ball bearings.
• Two inner rings 34 and 35 cooperate with the common ring by means of two rows of balls 36, 37.
• the rings 34 and 35 are in contact with one another along an annular surface 38 and each comprise a respective support part 39, 40 having planar annular support surfaces perpendicular to the axis of rotation of the motor.
• Annular rotor parts 41, 42 are mounted on these support parts so as to be arranged in the air gaps of the two stator parts.
• the assembly of the rings 34 and 35 is carried out so that the two combined ball bearings have practically no resulting play.
• the motor axis and the engine support parts are no longer shown in Figure 3 and in some of the following figures.
• FIG. 4 illustrates an embodiment which differs essentially from the examples of FIGS. 1 and 3 by the presence of two juxtaposed ball bearings which each include a first rolling ring 43,44 and a second rolling ring 45, 46 cooperating with two rows of respective balls 47,48.
• the two bearings are mounted side by side so that the assembly has no resulting play.
• the rotor parts 49, 50 are fixed to the cheeks formed by the front surfaces of the rings 45, 46 by means of corresponding support discs 51, 52.
• the stator parts shown in FIG. 4 each have two annular sheet metal parts 53, 54 and 55, 56, formed so as to present a housing for the control coils 57, 58 and opposite teeth, similar to those of the figure. 1, such as the teeth designated by 59.
• the parts 54 and 55 are fixed to the outer rings 43 and 44 of the juxtaposed ball bearings, by means of a common support piece 60 which can be welded to the pieces 54, 55, 44 and 43 so as to make these integral.
• a pin 61 can be mounted inside the rings 45 and 46 of the ball bearings, as shown in the figure.
• FIG. 5 shows an alternative embodiment of the engine of Figure 4 in which a single bearing with a row of balls and three bearing rings is used in place of the two juxtaposed bearings of Figure 4.
• An outer ring of the bearing designated by 62 cooperates, via a row of balls 63, with two inner rings 64,65 juxtaposed axially, the whole of the bearing being adjusted so that it presents practically no play.
• the rotor parts and stator can be fixed, in a similar manner to that of the previous examples, respectively to the inner rings and the outer ring of this bearing.
• the support part 60 of Figure 4 has been deleted, but the other parts of the rotor and stator parts, are similar to those of Figure 4 and have been designated by the same reference figures.
• Figure 5 further shows two closure parts 66,67 placed on the stator parts so as to protect the interior of the motor.
• the shaft 61 shown is constituted by a long, cut pinion which, owing to the fact that it is centered by its teeth ends, ensures very good mounting precision with respect to the ball bearing.
• Figure 6 shows, in section along an axial plane, another two-phase synchronous motor, comprising two separate rotary members 71 and 72, arranged coaxially opposite one another.
• Each of these rotary members comprises a respective magnetic annular disc 73, 74, fixed by one of its flat surfaces on an annular flat surface, such as 75, of a corresponding rolling part 76, 77, forming part of a rolling bearing.
• respective axial balls 78, 79 respective axial balls 78, 79.
• the two rolling parts 76 and 77 are coupled by means of a coupling device, constituted, in the present example, by two spring washers 80 and 81, which are housed in a corresponding recess of each rolling part, to tend to separate these two parts in the axial direction.
• the two outer bearing parts, designated by 82, 83 form axial stops, by means of the ball bearings, for the inner bearing parts 76 and 77, so that the position of the two rotor parts relative to the stator is defined, without play, by the. two ball bearings.
• Coupling in the circumferential direction that is to say in the direction of rotation, can be ensured by welding the two washers with each other during their mounting, and by welding each them on the corresponding bearing part. In some cases, the friction of the spring washers and / or a notching of these may be sufficient to ensure that the two rolling parts are integral in their rotation.
• the stator 84 of the motor comprises two annular electric coils 85 and 86, which are each coupled with a corresponding magnetic circuit 87 and 88.
• Each magnetic circuit is formed by two parts 89, 90 and 91, 92 made, for example, of a material magnetically permeable frit. These parts have an annular shape and are in contact along a respective flat annular zone 93, 94 with low magnetic resistance.
• Rooms 89 to 92 on the other hand, each have an annular part provided with a series of teeth such as 95, distributed over the entire circumference, so as to form a variable air gap cooperating with the magnetized zones of the corresponding disc 73 or 74.
• the position of the magnetized discs 73 and 74 in the gaps of the magnetic circuits 87 and 88 is defined by the dimensions of the two ball bearings 78 and 79, and by the flat contact surfaces of the parts 89 to 92.
• the corresponding dimensions can be produced with all the desired precision and in a very economical manner, so that the arrangement described makes it possible to obtain in an extremely advantageous manner an excellent centering in the axial direction and a very good parallelism of the rotor parts with respect to the air gaps.
• Figures 7, 8 and 9 show alternative embodiments of the motor of Figure 6.. ' .
• a first stator part comprises a pole part 96, made of a sintered material, having an annular shape and forming the toothing 95, and a pole part 97, forming the opposite toothing. These two pole parts are magnetically connected to each other by annular connection parts 98 and 99, formed according to the sectional view of FIG. 7, for example by stamping, and joined together and to parts 96 and 97, for example by welding.
• the electric coil, designated here by 100 is closely surrounded by the corresponding magnetic circuit, so as to reduce losses and to make optimum use of the available volume.
• a second part of stator 101 is produced in a similar manner to the first.
• Organs rotary 71, 72 are similar to those of Figure 6, and are designated by the same reference numerals.
• the variant embodiment according to FIG. 8 comprises removable radial ball bearings 102, 103.
• one of the rolling parts 104 or 105 of each rotary member 106, 107 carries a corresponding magnetic disc 108, 109, this disc being fixed on a surface perpendicular to the axis of rotation.
• the device for coupling the two rotary members and the two stator parts are produced in a similar manner to FIG. 7, and the corresponding parts are designated by the same reference numerals as in this figure.
• FIG. 9 shows another alternative embodiment of the motor of FIG. 6, in which support parts 110, 111 are used for fixing the magnetized rotor parts 112, 113 to the corresponding rolling parts 114, 115
• the rolling parts each have an annular planar surface in contact with a first zone of an annular plane surface 116, 117 of the respective support part 110, 111, and a second zone of these same surfaces 116, 117 is in contact with one of the flat surfaces of the annular discs 112, 113.
• the coupling between the two rotary members is carried out in the axial direction by two spring washers 80, 81, as in the examples of Figures 6 to 8, while a pin 118 is provided in the example of Figure 9 to ensure coupling in the circumferential direction.
• This pin is arranged so as not to hinder the separation of the two rotary members under the effect of the springs 80, 81.
• the magnetic circuits of the motor of FIG. 9 each comprise annular, toothed polar parts, similar to parts 96, 97 of FIG. 7, and annular connection parts 119, 120, formed and assembled according to the section view of FIG. 9, so as to ensure "very low magnetic resistance and good dimensional accuracy in the axial direction.
• the present motor can be produced in the form of an extremely flat and small assembly, the useful parts of which occupy a minimum volume.
• the efficiency reaches an optimal value, all the more since, in the two-phase versions shown, the entire circumference of the magnetic disc cooperates with polar parts of the stator.
• the two rotary members or the two stator parts can moreover be easily adjusted in their mutual angular position before their final immobilization, by welding or gluing for example.
• the excellent definition of the position of the magnetically active part of the rotor with respect to the stator parts with which they cooperate is a decisive advantage, obtained in a relatively simple manner and economic.
• the precision of the ball bearings is found, thanks to the flat contact surfaces between the bearing part, the possible support part and the corresponding magnetized rotor part, at the air gaps of the stator parts.
• a motor of which a single rotary member carries a magnetic disc can be designed in a similar manner to the motor shown, and various embodiments of rotary members, in particular rotary members axially displaceable relative to each other and provided with coupling devices, as well as alternative embodiments of the stator parts and ball bearings, can be envisaged by the skilled person. It should be noted, on the other hand, that the present principle of mounting of the rotary member, although it is particularly

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Motor Or Generator Frames (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

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• 1984
  • 1984-11-29 WO PCT/CH1984/000188 patent/WO1985002503A1/fr not_active Application Discontinuation
  • 1984-11-29 EP EP84904086A patent/EP0165257A1/de not_active Withdrawn
  • 1984-11-29 FR FR8418211A patent/FR2555835A1/fr not_active Withdrawn
  • 1984-11-29 KR KR1019850700143A patent/KR850700189A/ko not_active Application Discontinuation

Non-Patent Citations (1)

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