Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H57/00—General details of gearing
  • F16H57/0018—Shaft assemblies for gearings
  • F16H57/0025—Shaft assemblies for gearings with gearing elements rigidly connected to a shaft, e.g. securing gears or pulleys by specially adapted splines, keys or methods
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N15/00—Other power-operated starting apparatus; Component parts, details, or accessories, not provided for in, or of interest apart from groups F02N5/00 - F02N13/00
  • F02N15/006—Assembling or mounting of starting devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D1/00—Couplings for rigidly connecting two coaxial shafts or other movable machine elements
  • F16D1/06—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end
  • F16D1/064—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end non-disconnectable
  • F16D1/068—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end non-disconnectable involving gluing, welding or the like
• • 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
  • H02K7/10—Structural association with clutches, brakes, gears, pulleys or mechanical starters
  • H02K7/116—Structural association with clutches, brakes, gears, pulleys or mechanical starters with gears

Definitions

• the present invention relates to a rotor armature shaft of a rotary electric machine.
• the invention relates more particularly to an armature shaft for an electric motor of a motor vehicle starter.
• a motor vehicle starter comprises,
• an electric motor whose rotor, which serves to drive the starter launcher in rotation, comprises an armature shaft of the type comprising a central section which receives a magnetic circuit, and two front and rear end sections constituting guide pins for rotating the shaft.
• the armature shaft can drive the launcher directly in rotation, or by means of a reduction gear, and it then comprises a toothed pinion which is linked in rotation to the shaft, which is arranged axially in the vicinity of the 'axial end before the central section of the armature shaft.
• the teeth constituting the input pinion of the reduction gear receive a heat and / or chemical treatment.
• the shaft is machined from a bar to obtain a cylinder whose stage profile comprises different sections of distinct diameters.
• the toothing of the pinion is then cut into the corresponding section and it is heat treated.
• the bearing surfaces of the end pins are adjusted to guarantee a
• the operation of quenching the teeth during the process of making the shaft results in sudden heating and cooling which can cause deformations leading for example to the appearance of an unbalance phenomenon of the rotor from which it results. vibrations and noise during engine operation, as well as premature wear of the end bearings.
• the quenching zone of the teeth stops in portions of reduced diameter and, if the quenching is too deep, the shaft is locally weakened and this results in a risk of breakage, in particular under the effect of the shocks caused during starter operation. In such a design, it is therefore necessary to master with great precision the quenching process which is therefore particularly complex and calls for costly installations requiring delicate adjustments.
• machining the shaft with its pinion in one piece is particularly expensive because it requires removing a large part of the material. of the starting bar whose diameter is at least equal to the outside diameter of the pinion. It is of course possible to start from a forged blank to limit the machining time, but the cost of the shaft is further increased.
• French patent application No. 85 16177 has proposed a structure of an armature shaft in which the toothed pinion is produced in the form of an independent element or component which is attached to the shaft.
• the pinion has a toothing in its internal bore which makes it possible to make a connection and a fixing by local deformation of the complementary zone of the shaft during the axial fitting of the pinion on the shaft, with the press.
• the invention provides an armature shaft in which the toothed pinion, produced in the form of an element attached to the shaft, is fixed to the latter by welding.
• each of the two parts that is to say the shaft itself and its toothed pinion, can be produced according to an optimized means of production, then they are assembled by a continuous or discontinuous weld bead.
• the sprocket has a central hole which is traversed axially by a section of the shaft;
• Said rear portion of the front journal is a portion whose diameter is intermediate between that of the journal and that of the central section;
• the front transverse face of the attached pinion is offset axially rearward relative to the annular transverse face of the front end of the central section;
• the attached pinion is fixed to the shaft by an annular welding bead, complete or partial, of axial orientation formed at the front axial end of the central hole of the pinion; the attached pinion is fixed to the shaft by an annular welding bead, complete or partial, of radial orientation formed in line with the rear transverse face of the pinion;
• the front pin and the toothed pinion are made in a single piece attached to the front axial end of the central section to which it is fixed by welding;
• the insert is fixed to the central section by an annular welding bead, complete or partial, of radial orientation formed in line with the transverse face of the axial end before the central section;
• the rear transverse face of the pinion comprises, at least one frustoconical central part to facilitate the radial welding operation;
• - central hole has two bores of different diameters, the bore of larger diameter forming a recess.
• the pinion extends in the form of a section which carries the bore forming the recess.
• the weld produced is of good quality because the pinion does not undergo clamping stresses on the shaft at the weld.
• the recess provides mechanical decoupling between the pinion and the shaft at the weld.
• the toothing of the pinion undergoes a physical and / or chemical treatment operation before it is welded to the shaft.
• the invention also relates to a motor vehicle starter, the electric motor of which comprises a rotor, the armature shaft of which conforms to the teachings of the invention.
• FIG. 1 is a schematic view in partial axial section, which shows a motor vehicle starter whose electric motor comprises an armature shaft equipped with a toothed output gear;
• FIG. 2 is an exploded perspective view of the axial front half of an armature shaft produced in accordance with the teachings of the invention illustrated in association with its output pinion;
• FIG. 3 is a view, in partial axial section, which illustrates the first embodiment of the invention shown in Figure 2, after mounting and fixing of the pinion reported by welding;
• Figures 4 and 5 are views similar to that of Figure 3 which illustrate a second embodiment of the invention in which the toothed pinion is made in one piece with the front axial end journal of the shaft armature;
• Figure 6 is a view similar to that of Figure 3 which illustrates a third embodiment of the invention.
• Figure 7 is a view similar to that of Figure 3 which illustrates a third embodiment of the invention.
• FIG. 1 shows a motor vehicle starter which, in a known manner, consists essentially of an electric motor 12 which is capable of rotating a starter launcher 14 which is coaxial with the axis of rotation XX of the motor 12 and which is capable of being driven axially forwards, that is to say to the left when considering FIG. 1, by a fork or control lever 1 16 under the action an electromagnetic contactor 18 which also controls the electrical supply to the motor 12.
• a fork or control lever 1 16 under the action an electromagnetic contactor 18 which also controls the electrical supply to the motor 12.
• the fork 1 16 is connected to articulation with a movable core (not referenced) that comprises the contactor 18.
• This contactor also comprises a winding, a fixed core, a rod coupled to a movable contact and a fixed contact (not referenced).
• the winding is activated and the movable core moves, as well as the fork 1 16, by actuating the movable contact, via its rod, after a stroke, until the contact of fixed and mobile contacts, which allows the electric motor 12 to be supplied.
• the motor 12 comprises a rotor 14 which comprises a magnetic circuit 16 and a collector 19 which are both mounted by axial fitting, on the central section axially notched 20 of the armature shaft 22 of the rotor 14.
• the armature shaft 22 is produced in one piece by machining and it comprises, on either side of the central section of large diameter 20, a front axial end trunnion 24 and a rear axial end trunnion 26 which enable the armature shaft 20 to be guided in rotation in complementary front and rear bearings.
• the armature shaft 22 comprises a toothed pinion 28 which is disposed axially between the front axial end of the central section 20 and the front pin 24 and which constitutes the input pinion of a reduction gear 30, here of the planetary gear type, which is interposed between the armature shaft 20 and the launcher 14.
• the toothed pinion 28 is produced in the form of a component attached to the shaft 22.
• the front pin 24 has a rear portion 32 whose diameter is intermediate between the outside diameter of the pin 24 and the outside diameter of the main section 20 and which constitutes a cylindrical portion for mounting the pinion 28 which for this purpose comprises a central hole or bore 34 of internal diameter complementary to the external diameter of the portion 32.
• the bearing 32 like the bore 34, is smooth and the mounting of these two elements is of the tight or just sliding type so as to ensure the coaxiality of the pinion 28 relative to the shaft 22.
• the pinion 28 is fixed to the shaft 22 by welding.
• a first annular weld bead 36 which is complete or partial and which is a bead of axial orientation formed at the axial end before the bore 34.
• the welding of the pinion 28 on the shaft 22 can also be carried out (by means of a second annular welding bead 40, complete or partial, which is here of radial orientation and which is formed in line with the rear transverse face 42 of the toothed pinion 28.
• the rear transverse face 42 is here inclined, that is to say that its surface is frustoconical.
• the toothed pinion 28 is produced integrally in one piece with the front axial end pin 24 and it is these two pieces 24-28 which are fixed to the front axial end 44, 46 of the central section 20 of the armature shaft 22 by means of a welding operation by a bead 40 of radial orientation.
• the third embodiment represented in FIG. 6 constitutes a variant of the first embodiment represented in FIGS. 2 and 3 in which the central bore 34 of the pinion 28 is crossed axially by the front axial end of the central section 20 of the armature shaft 22, the welding of the two parts being carried out by means of an annular welding bead 36 of axial orientation.
• This design is advantageous when the pinion 28 is of large diameter relative to the shaft and it is advantageous to have the diameter of the bore 34 of the pinion directly equal to the largest diameter of the shaft so as to limit the machining.
• the front end transverse face 46 of the central section 20 is axially aligned with the front transverse face 43 of the pinion 28, but it is also possible to shift the pinion 28 axially towards the rear. so as to have a most suitable abutment face 46, taking into account the geometry and the characteristics of the material chosen.
• the fourth embodiment represented in FIG. 7 also constitutes a variant of the first embodiment represented in FIGS. 2 and 3 in which the central bore 34 of the pinion 28 is axially crossed by the front axial end of the central 20 of the armature shaft 22.
• the bore is made in two parts, on the one hand, a first part 34 which is mounted clamped on the cylindrical bearing surface 32 for centering the pinion 28 on the cylindrical bearing surface 32, and on the other hand, a bore 34 'of diameter greater than the first bore 24 so as to constitute a recess or recess 70 between this second bore and the cylindrical bearing 32.
• the pinion 28 extends rearward in the form of a section 71 which carries the bore 34 'forming the recess 70.
• the welding is carried out at the recess 70 at the rear end of the section 7.1.
• This section can be cylindrical or frustoconical. It is possible to form a chamfer 44 at the axial front end 46 of the central section of the shaft 22 to facilitate the welding operation and the quality of the weld 40.
• the weld 40 is produced at level of the recess 70.
• the welding is carried out in an area devoid of constraints related to tightening which provides a good quality weld free of cracks. The recess thus produced achieves local decoupling between the shaft 22 and the pinion 28 promoting good welding.
• welding by laser or electron beam is particularly well suited to the design according to the invention which is not however limited to these types of welding.
• the invention also makes it possible to choose with the greatest latitude the materials suitable for the design of each of the parts constituting the complete armature shaft.
• this zone is eliminated and it is thus possible to reduce the length and the weight of the starter.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Power Engineering (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
• Manufacture Of Motors, Generators (AREA)
• Synchronous Machinery (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=8855942

Family Applications (1)

Country Status (5)

Families Citing this family (6)

Family Cites Families (5)

• 2000
  • 2000-10-31 FR FR0013980A patent/FR2816126B1/fr not_active Expired - Fee Related
• 2001
  • 2001-10-31 BR BR0107393-1A patent/BR0107393A/pt not_active IP Right Cessation
  • 2001-10-31 EP EP01983659A patent/EP1252703A1/de not_active Withdrawn
  • 2001-10-31 WO PCT/FR2001/003376 patent/WO2002037647A1/fr active Application Filing
  • 2001-10-31 HU HU0203948A patent/HUP0203948A2/hu unknown

Non-Patent Citations (1)

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