Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K3/00—Details of windings
  • H02K3/02—Windings characterised by the conductor material
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K3/00—Details of windings
  • H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
  • H02K3/12—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors arranged in slots
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K2213/00—Specific aspects, not otherwise provided for and not covered by codes H02K2201/00 - H02K2211/00
  • H02K2213/03—Machines characterised by numerical values, ranges, mathematical expressions or similar information
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K23/00—DC commutator motors or generators having mechanical commutator; Universal AC/DC commutator motors
  • H02K23/26—DC commutator motors or generators having mechanical commutator; Universal AC/DC commutator motors characterised by the armature windings

Definitions

• the invention relates to a motor starter of low power with optimized size.
• the invention finds a particularly advantageous, but not exclusive, application with starter systems so-called "stop and start” for stopping and restarting the engine of the vehicle according to particular traffic conditions.
• a starter provided with a launcher capable of transmitting a rotation energy of the starter to a crankshaft of the engine through a crown starting.
• This launcher is mounted on a drive shaft.
• a speed reducer is interposed between this drive shaft and the shaft of an electric machine.
• This electric machine comprises on the one hand, a rotor, also called armature and on the other hand, a stator, also called inductor, mounted coaxially around the rotor.
• the stator has several permanent magnets or coil poles (electromagnets).
• the rotor comprises a body in the form of a bundle of sheets and conductors forming the winding inserted in longitudinal notches formed at the outer periphery of the sheet bundle.
• the conductors have welded ends on the blades of a collector on which brushes are rubbed for feeding the winding.
• the thermal engines may have a reduced dimensioning because of the improvement of their efficiency or their combined use with an electric traction motor in the case of hybrid vehicles.
• Car manufacturers therefore need to reduce the size of corresponding starters with a reduced power requirement, and to reduce the size under the hood of the vehicle.
• the rotors are provided with a coil made of copper which has the advantage of having good electrical conductivity with respect to other materials, which reduces the size of the rotors.
• a more resistive material than copper, such as aluminum it is well known that this leads, for the same level of torque produced, to a longer electrical machine, so more voluminous.
• FIGS. 1A, 1A ', 1B, 1B' and 1C are curves which represent the armature length as a function of the pair and are Pareto fronts, ie join optimal definition points to the characteristics. different design. These characteristics are: the number of notches; conductor wire diameter; lead wire material; thickness of ferrite magnets; breech thickness.
• FIG. 1A shows a curve of a starter rotor whose conductor is made of aluminum. This curve shows the optimum points taking into account the 5 characteristics mentioned above. It can be seen that to have a smaller rotor length, it is preferable that the conductor is copper.
• the curve 1 B which is a curve prolonging that of 1 A towards the small powers, that when the torque is less than 55N.m is a maximum rotor torque 1 1, 9 Nm, the curve is flat, that is to say that the length for an optimum rotor remains at 100mm.
• the invention departs from the unexpected finding that, in a certain range of reduced power of the starter, it is the use of aluminum and non-copper conductors that ensures the desired electromechanical performance at minimum machine volume electric.
• FIG. 1C which represents the set of curves 1A, 1A ', 1B, 1B' for the power ranges of the range P1
• the search for an active volume The minimum torque induced armature leads to the use of a copper armature winding rather than aluminum.
• the length of an aluminum armature LAI is greater than the length LCu of a copper armature.
• FIG. 2 represents the evolution of a characteristic quantity defined as the integral J of the difference e between the active length of an armature in aluminum (LAI) and the active length of a copper armature (LCu) with the same product torque.
• Xkw of starter means the power of a maximum starter according to a supply law of a straight voltage / current characterized for OA a voltage of 1 1, 5V, with a source resistance of 10 mili OHm terminals of the starter. This measurement is made according to the ISO 8856 standard.
• the invention therefore relates to a starter for a motor vehicle comprising an electric machine provided with a rotor comprising:
• a collector comprising a set of electrically conductive blades
• the conductors inserted into the slots are aluminum-based for a starter having a power of less than 1 .3kW.
• the invention also relates to a starter for a motor vehicle comprising an electric machine provided with a rotor comprising:
• a collector comprising a set of electrically conductive blades
• notches arranged on an outer periphery of the rotor body, and a winding formed by a set of conductors inserted at least partly inside the notches and electrically connected to the collector blades,
• the conductors inserted in the notches are based on aluminum for a starter having a maximum torque of less than 10.82N.m according to a supply law of a straight voltage / current characterized for OA a voltage of 1 1, 5V, with a source resistance of 10 milli Ohm across the starter.
• a starter having its aluminum conductors having the same characteristics as a starter having its copper conductors (rotor length etc ..) will have a larger max torque.
• the conductor comprises an insulating layer directly on the aluminum-based core layer.
• the conductor comprises a single conductor core layer comprising a single aluminum-based alloy.
• the conductor comprises a single conductive core layer comprising a single alloy based on aluminum or only aluminum. According to one embodiment of these inventions, the conductor has its aluminum-based layer welded directly to the collector.
• the conductors inserted into the slots are based on aluminum for a power range of between 1 and 1.2 kW.
• portions of each conductor located inside said slots are made of an alloy consisting predominantly of aluminum.
• the conductors are pin-shaped.
• said electric machine comprises a stator having an outer diameter of the order of 60 mm.
• said rotor has an outer diameter of the order of 44mm.
• said rotor has a length of the order of 30 mm. In one embodiment, the rotor has between 2 and 29 notches.
• the rotor has 19 notches.
• said rotor comprises 23 notches.
• said rotor has 25 notches.
• said rotor comprises 29 notches.
• said electric machine comprises a stator provided with poles formed by permanent magnets.
• stator poles are six in number.
• the conductors have a diameter of between 1.5 and 2 millimeters, preferably between 1.5 and 1.9.
• FIGS. 1A, 1A 'and 1B, 1B' already described, show the evolution of the armature lengths of copper and aluminum as a function of the torque produced for a same outer diameter of the electric machine and the same electrical resistance;
• FIG. 1C shows the evolution of the armature lengths of copper and aluminum as a function of the torque produced for the same external diameter of the electric machine and the same electrical resistance;
• FIG. 2 already described, is a representation, obtained from the curves of FIG. 1, of the evolution of a characteristic quantity defined as the integral of the difference between the active length of an aluminum armature and the active length of a copper armature with the same torque produced.
• Figure 3 shows a longitudinal sectional view of a thermal engine starter according to the present invention.
• FIG. 4 represents a perspective view of a rotor used with the starter according to the invention
• Figure 5 shows a cross-sectional view of the two conductor layers positioned within the notches of the rotor.
• the starter 1 comprises a drive shaft 2, a launcher 3 mounted on the shaft 2 and an electric machine 5 operating in motor mode composed of an inductor stator 8 and an armature rotor 9 mounted coaxially along an axis X.
• the stator 8 surrounds the rotor 9 integral with a shaft 14.
• the machine 5 comprises a carcass 51 mounted on a metal support 12 of the starter 1 intended to be fixed on a part fixed of the motor vehicle.
• the stator 8 comprises in one embodiment a plurality of permanent magnets forming the poles of the stator 8 and carried by the inner periphery of the cylinder head 10. Alternatively, as shown in the embodiment of FIG.
• the poles are formed by windings 1 1 each positioned around a polar mass 15 integral.
• the polar masses 15 are fixed with bolts 16 to the bolt 10, here metallic, as described in the document FR261 1096.
• Each winding January 1 is composed of a continuous conductor wound around the polar mass in the direction of its thickness so as to form concentric contiguous turns of increasing diameter as better visible in Figures 2 to 5 of EP749194.
• the axis of each winding is radial with respect to the X axis of the rotor 9.
• a gear reduction gear 13 of the epicyclic gear type is preferably interposed between a rear end of the drive shaft 2 and the shaft 14 of the electric motor 5.
• Brooms 17 rub on conductive blades 18 of a collector 20 to supply the rotor winding.
• the brushes 17 belong to a brush holder 23 equipped with guiding cages and receiving brushes 17. These brushes 17 are biased towards the conductive blades 18 by resilient means 25 of the spring type.
• the brush holder 23 is secured to a rear flange 24 having in the central portion a housing for mounting a needle bearing. The bearing of the rear flange 24 is used for rotatably mounting one end of the shaft 14 of the electric motor 5.
• the starter 1 also comprises an electromagnetic contactor 29 extending parallel to the electric motor 5 by being radially implanted above it.
• the contactor 29 has a metal tank 30 carried by the support 12, and equipped with an excitation coil 33 provided with at least one winding. A shoulder of the tank 30 makes it possible to ensure the axial setting of a fixed core 34.
• Terminals 37, 38 are shaped to each form a fixed contact inside the tank 30.
• One of the terminals 37 is intended to be connected to the positive terminal of the vehicle battery, the other terminal 38 is connected at the input of the inductor winding of the stator 8 and the brushes 17 of positive polarities.
• a movable core 40 is attracted by magnetic attraction towards the fixed core 34 to, on the one hand, act after catching a game on a rod 41 carrying a contact mobile 42 to cause the closure of the contacts of the contactor 29 and power the electric motor 5 of the starter 1, and secondly, actuate a control lever 45 of the launcher 3.
• the drive shaft 2 is rotatably mounted in a front bearing 46 of the support 12.
• This bearing 46 is constituted by way of example by a needle bearing or alternatively by a plain bearing.
• This shaft 2 carries at the front a stop 48 adjacent to the bearing 46 to limit the movement of the launcher 3.
• the launcher 3 is slidably mounted on the drive shaft 2, and comprises a drive pinion 50, a driver 51 configured to be actuated by the pivoting control lever 45, and a freewheel device 52, for example of the roller type, installed between the driver 51 and the pinion 50.
• the upper end of the lever 45 is mounted in a known manner to articulation on a rod elastically connected to the movable core 40 via a spring, said spring against tooth, housed in the movable core 40.
• the driver 51 is internally provided with helical splines in complementary engagement with external helical teeth carried by the drive shaft 2.
• the launcher 3 is thus animated by a helical movement when it is moved. by the lever 45 in the direction of the stop 48 to come, via its pinion 50, in engagement with the starting ring of a heat engine 5.
• freewheel device 52 can be replaced by a conical clutch device or a clutch provided with several friction discs, as described in the document FR2978500.
• launcher 3 variant is implanted outside the support 12.
• FIG. 4 shows the rotor 9 comprising a body 91 mounted on the shaft 14 of axis X.
• This body 91 in the form of a bundle of sheets has an outer periphery of cylindrical shape.
• Notches 92 are formed longitudinally at the outer periphery of the body 91.
• a set of conductors 93 are threaded inside each of these notches 92.
• the ends of the conductors 93 are welded to the electrically conductive blades 18 of the collector 20.
• the blades 18 are made of copper.
• the blades 18 are carried by a support 94 of plastic material integral with the shaft 14.
• the support 94 of the The collector is, for good temperature resistance, thermosetting plastic material, such as a thermosetting phenolic plastic material, for example bakelite.
• the manifold 20 which has blades 18 extending longitudinally side by side on the outer periphery of the support 94 is of the "drum" type.
• the collector 20 used may be a flat type collector.
• each conductor 93 pin-shaped has two branches 931, 932 connected by a bottom 933 so as to form a U.
• the conductors 93 are based on aluminum.
• these conductors 93 are made of an alloy consisting mainly of aluminum, that is to say with an aluminum content greater than or equal to 50%. In an exemplary embodiment, this alloy consists almost exclusively of aluminum, that is to say that the aluminum content exceeds 90% and preferably 95%.
• the portions of each conductor 93 located inside the notches 92 corresponding to the branches 931, 932 are made of this alloy.
• the ends of the conductors 93 may however be made of copper to facilitate their welding on the blades 18 of the collector 20.
• Each conductor 93 is preferably coated with an electrically insulating layer, such as enamel.
• the conductors 93 are threaded inside the notches 92 on two distinct layers: the upper layer and the lower layer. If one of the branches 931, 932 is positioned in the lower layer then the other branch 931, 932 is in the upper layer and vice versa.
• the cross section of the conductors 93 may be round or square or rectangular.
• the portions of the conductors 93 projecting from the end faces of the body 91 of the rotor 9 form the buns of the winding.
• frets 96 are positioned respectively around the buns. As can be seen in FIG.
• a slot insulator 97 is positioned around the branches 931, 932 of the conductors.
• this insulator 97 has an S-shaped section. This insulation makes it possible not to harm the conductors 93 (coated with the thin layer of enamel) during their mounting in the package of laminations of the rotor 9 provided by definition of burrs and fluted for force fitting of the rotor plate package.
• the clearance between the insulation 97 and the edges of the notches 92 is filled by an impregnating varnish.
• the conductors 93 pin-shaped are replaced by winding son.
• the stator 8 which has six poles, has a yoke 10 having an outer diameter of about 60 mm.
• power of 1 kw we mean the power characteristic of a starter, a maximum power for a source of 1 1, 5V and Omiliohm.
• the rotor 9 has an outer diameter of about 44 mm and a length of about 30 mm.
• the rotor 9 has 25 notches and the armature leads 93 have a diameter of the order of 1 .6 mm.
• the current point / torque of the pinion is of the order of 600 A, we obtain a torque of the order of 15.0 N.m.
• Thickness of ferrite magnets is 5.9mm
• the thickness of the cylinder head is 2.2mm.
• the resistance stress of a 1 KW starter is about 7Milliohm while that of a 1KW power starter is about 5Milliohm.
• the stator 8 which has six poles, has a yoke 10 having an outer diameter of the order of 60mm.
• the rotor 9 has an outer diameter of about 44 mm and a length of about 30 mm.
• the rotor 9 has 25 notches and the armature leads 93 have a diameter of the order of 1 .9 mm.
• the current / torque of the pinion is of the order of 700 A
• the thickness of ferrite magnets is 5.9 mm
• the thickness of the yoke is 2.2 mm. It can be seen that the rotor having aluminum conductors is better for all starters below or equal to 1, 3kw or even if the length of the rotor is greater than 100mm as the performance / weight ratio.
• the rotor 9 has 23 or 29 notches.
• the rotor 9 has a conductor wire diameter of between 1.4 and 2.3.
• the stator comprises ferrite magnets to form the poles and the thickness is between 2 and 2.4mm.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Windings For Motors And Generators (AREA)
• Manufacture Of Motors, Generators (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=51063467

Family Applications (1)

Country Status (4)

Cited By (4)

Citations (6)

Family Cites Families (5)

• 2013
  • 2013-11-18 FR FR1361288A patent/FR3013532B1/fr not_active Expired - Fee Related
• 2014
  • 2014-11-18 WO PCT/FR2014/052951 patent/WO2015071618A1/fr active Application Filing
  • 2014-11-18 EP EP14809489.9A patent/EP3072218A1/fr not_active Withdrawn
  • 2014-11-18 CN CN201480061167.7A patent/CN105706338A/zh active Pending

Patent Citations (6)

Also Published As

Similar Documents

Legal Events