JP2008029102A - Rotator for vehicle alternator and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle alternator which can favorably prevent the crack of an axial projection which projects axially along the bottom of a trough between claw-shaped magnetic poles from the flange part of the resin bobbin of a field coil, and its manufacturing method. <P>SOLUTION: A spacer 56, which is rich in flexibility and has necessary heat resistance, is inserted into the space between axial projection 55, which projects outward in its axial direction while facing the surface of a trough bottom 26 at the disc parts 22 of the field cores 2 and 3 from a resin bobbin 5, and the trough bottom 26 at the disck parts 22. Hereby, it can prevent the crack of the axial projection 55 of the resin bobbin 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicular AC generator rotor mounted on a passenger car, a truck, or the like, and a method for manufacturing the same, and more particularly to an improvement in a resin bobbin.

  A Landel-type rotor core (field core) of an AC generator for a vehicle has a substantially U-shaped valley bottom located between the claw-shaped magnetic poles adjacent in the circumferential direction and present at the radially innermost side. . The field iron core is equipped with a field coil wound around a resin bobbin. For example, as disclosed in Patent Documents 1 and 2 below, the resin bobbin includes a winding drum portion around which a field coil is wound, a flange portion extending radially outward from both ends of the winding drum portion, and a flange portion. And an axial protrusion extending outward in the axial direction along the surface of the valley bottom of the field core.

  More specifically, the resin bobbin of Patent Document 1 has an axial projecting portion facing the bottom of the other valleys except the two coil wire lead-out portions. In Patent Document 2, the coil wire lead-out portions at the two locations also have axial protrusions. This axial projecting portion increases the creeping discharge distance between the field coil and the field iron core, so that water (especially, electrolytes such as car shampoo and snowmelt salt water) intrudes from the field coil and the field coil. It has a function of preventing deterioration of electrical insulation performance with the magnetic core.

The field coil is subjected to a resin-impregnated tree treatment in order to improve the electrical insulation and mechanical strength of the field coil. More specifically, after the assembly of the rotor is completed, a powder or liquid thermosetting resin is dropped from above the heated rotor and cured to impregnate the field coil, and the field coil After fixing with the resin bobbin, the rotor is cooled, and the resin impregnation process between the field coils and between the field coil and the resin bobbin is completed. As the thermosetting resin, it is usual to employ a heat resistant resin such as an epoxy resin.
JP-A-8-331786 JP 2002-335661 A

  The present inventors have noticed for the first time that the above-described thermosetting resin impregnation treatment may cause a crack in the axial protrusion of the resin bobbin. This problem will be described below.

  The ductility (that is, the elastic modulus) of a thermosetting resin (impregnated resin) such as epoxy used for impregnation and fixing to a field coil wound around a resin bobbin is excellent in deformability such as nylon. It is much smaller than that of a resin bobbin formed of a soft resin.

  In the thermosetting resin impregnation treatment described above, the liquid thermosetting resin (impregnating resin) penetrates between the surface of the valley bottom between the claw-shaped magnetic pole portions and the axial protrusion of the resin bobbin facing it, and the shaft There is a possibility that the directional protruding portion is firmly fixed to the surface of the valley bottom by the impregnated resin portion cured.

  It has been found that when the axial protrusion is fixed to the valley bottom of the field core by the cured thermosetting resin (impregnation resin), cracks may occur in the axial protrusion. More specifically, when the thermosetting resin is dropped onto the heated field coil of the rotor, polymerized and solidified, and then cooled, the thermal expansion coefficient of the thermosetting resin is much larger than that of the field core. The thermosetting resin solidified between the bottom portion of the iron core and the axial projecting portion is given a large pulling force from the bottom portion, and there is a possibility that a crack will occur. At this time, if the axial protruding portion of the resin bobbin is fixed to the thermosetting resin, it is necessary to consider the possibility of cracking in the axial protruding portion.

  This problem will be described in more detail.

  As described above, the ductility (deformability) of the axially protruding portion of the resin bobbin is significantly superior to the thermosetting resin that is fixed thereto. However, after a crack occurs in the thermosetting resin in the state where both are integrated, the tensile stress of the thermosetting resin and the axial protruding portion is applied to the portion of the axial protruding portion adjacent to the crack portion (the crack adjacent portion). Will concentrate, and there is a possibility that a crack will occur in the adjacent portion of the crack. This state is shown in FIG. If such a crack occurs in the axial projecting portion, the creeping discharge distance between the field coil and the field iron core is shortened, and there is a concern that the electric insulation of the field coil is lowered.

  The present invention has been made in view of the above-mentioned problems, and it is possible to satisfactorily generate cracks in the axial protruding portion that protrudes in the axial direction from the flange portion of the resin bobbin of the field coil along the valley bottom portion between the claw-shaped magnetic pole portions. It is an object of the present invention to provide a rotor for a vehicle alternator that can be prevented and a method for manufacturing the same.

  Each of the inventions for solving the above-mentioned problems includes a boss portion fitted to the rotating shaft, a plurality of radially projecting column portions, and a plurality of recesses radially inwardly positioned between the column portions. A disk portion having trough portions alternately in the circumferential direction and extending radially outward from the axial outer end portion of the boss portion, and a plurality of claw-shaped magnetic poles individually extending in the axial direction from the tip of the column portion And the innermost portion in the radial direction of each trough is a field iron core that forms a substantially U-shaped trough bottom, a resin bobbin fitted to a boss portion of the field iron core, and the resin bobbin The resin bobbin includes: a field coil to be wound; and a thermosetting impregnated resin portion that is thermally cured after being attached to the field coil and the resin bobbin fitted in the field iron core. Includes a cylindrical winding drum portion around which the field coil is wound, and a pair of flanges protruding radially outward from both ends of the winding drum portion. And an axially protruding portion extending outward in the axial direction from the flange portion along the surface of the valley bottom portion of the field core, and the impregnated resin portion after thermosetting is the resin It is applied to the rotor of a vehicle alternator having characteristics that are inferior in deformability to a bobbin. The structure of the rotor of this type of vehicle alternator is widely mass-produced and is well known.

  1st invention is a thermosetting resin which suppresses formation of the said impregnation resin part in the clearance gap between the said axial direction protrusion part of the said resin bobbin, and the said valley bottom part of the said field iron core which faces this axial direction protrusion part It has an intrusion suppression structure.

  That is, according to this 1st invention, the clearance gap between the axial direction protrusion part of the resin bobbin which protrudes an axial direction outer side along the substantially U-shaped part (valley bottom part) between claw-shaped magnetic pole parts, and a valley bottom part Since the thermosetting resin (impregnation resin) has a structure that prevents the penetration of the resin, the cracks in the axial projecting portion can be satisfactorily prevented.

  In a preferred manufacturing method, the thermosetting resin intrusion suppressing structure is made of a softer material than the resin bobbin, and at least an electrically insulating spacer inserted in the gap before the heat curing treatment of the impregnated resin portion. Consists of. In this way, since the spacer that is more flexible than the axial protrusion is disposed in the gap between the axial protrusion and the valley bottom, the axial protrusion is made of the field core by the thermosetting resin (impregnation resin). It is possible to satisfactorily prevent cracks from being fixed to the bottom of the valley. As this soft spacer, for example, silicon rubber which is an electrically insulating member excellent in heat resistance and flexibility is suitable.

  In a preferred manufacturing method, the thermosetting resin invasion suppressing structure is configured to face the surface of the axial protruding portion of the resin bobbin and the axial protruding portion at least before the deposition of the impregnated resin portion. It is comprised by the film of the low friction coefficient formed in at least one of the surface of the said valley bottom part of a field iron core. In this way, the bondability between the axially protruding portion and the impregnated resin portion made of thermosetting resin can be reduced, so that even if a crack occurs in the impregnated resin portion, the tensile stress of the impregnated resin causes the axial protrusion in the vicinity of the crack. When it concentrates on a part, thereby, a slip arises between an axial direction protrusion part and impregnation resin, and the crack generation | occurrence | production of an axial direction protrusion part can be prevented.

  In a preferred aspect, the thermosetting resin intrusion suppressing structure is located at a peripheral edge of the axial protrusion of the resin bobbin and protrudes toward the valley bottom of the field iron core to adhere to the surface of the valley bottom By doing so, it is comprised by the rib which suppresses formation of the said impregnation resin part in the said clearance gap. In this way, when the field coil is impregnated with the thermosetting resin liquid, it is possible to satisfactorily prevent the thermosetting resin liquid from entering the gap between the axial protrusion and the valley bottom. In addition, a rib may be provided in the perimeter part whole periphery of an axial direction protrusion part, and may be provided partially. In the latter case, it is a matter of course that it is preferable to arrange the ribs at a site where the impregnating resin easily enters.

  According to a second aspect of the present invention, the axial protruding portion of the resin bobbin is thicker than the disk portion of the insulating bobbin, and is three times or more as thick as a gap between the valley bottom portion and the axial protruding portion. It is characterized by being formed. That is, according to the present invention, the axial protrusion is much thicker than in the prior art, and is formed to have a thickness of three times or more the gap between the valley bottom and the axial protrusion. As a result, even if a crack occurs in the impregnated resin portion made of thermosetting resin that has entered the gap between the axial protrusion and the valley bottom, the axial protrusion is transmitted from the impregnated resin portion to the axial protrusion. Therefore, the generation of cracks can be prevented. Moreover, since this thickening is only the axial protrusion of the resin bobbin, an increase in the amount of resin used in the resin bobbin can be suppressed.

  The third invention is characterized in that the axial protrusion of the resin bobbin has a bellows shape that periodically changes with the width of the gap. In this way, even if a crack occurs in the impregnated resin portion made of a thermosetting resin fixed to the axial protruding portion, it is possible to satisfactorily prevent the crack from spreading to the axial protruding portion.

  A preferred embodiment of the rotor of the vehicle alternator of the present invention will be described below. However, the present invention should not be construed as being limited to the following embodiments, and the technical idea of the present invention may be realized by combining other technologies.

(First embodiment)
The rotor of the vehicle alternator of the first embodiment will be described with reference to FIGS. FIG. 1 is an axial sectional view of the rotor, FIG. 2 is an enlarged perspective view of a main part of the rotor shown in FIG. 1, and FIG. 3 is a front view of a resin bobbin around which a field coil is wound.

(Rotor structure)
As shown in FIG. 1, the rotor is rotatably supported by a frame (not shown) of the vehicle alternator and is driven by an in-vehicle engine (not shown). The rotor is wound around the rotating shaft 1, the field iron cores 2 and 3 fitted to the rotating shaft 1 adjacent to each other in the axial direction, and the field iron cores 2 and 3 wound around the resin bobbin 5. Field coils 4 and cooling fans 9 and 10 fixed to the end faces of the field iron cores 2 and 3. The field iron cores 2 and 3 are commonly referred to as Landel-type pole cores, and although well known, the shape will be briefly described.

  The field iron core 2 includes a boss portion 21 fitted and fixed to the rotating shaft 1, a disk portion 22 extending radially outward from the axial outer end portion of the boss portion 21, and a radial outer end of the disk portion 22. And a plurality of claw-shaped magnetic pole portions 23 extending in the axial direction from the portion. The field core 3 also has the same structure as the field core 2.

  The disk portion 22 has a plurality of pillar portions 24 projecting radially, and a plurality of trough portions 25 located between the pillar portions 24 and recessed radially inwardly in the circumferential direction. The magnetic pole portion 23 extends in the axial direction from the radially outer end of the column portion 24. A radially innermost portion of each valley portion 25 is a substantially U-shaped (or substantially V-shaped) valley bottom portion 26.

  As is well known, the pair of field iron cores 2 and 3 are assembled in a state where the claw-shaped magnetic pole portions 23 are alternately meshed. A resin bobbin 5 around which a field coil 4 is wound is fitted into the boss portion 21 in a space surrounded by the boss portion 21, the disk portion 22, and the claw-shaped magnetic pole portion 23 of the field iron cores 2 and 3. Contained.

  The resin bobbin 5 has a cylindrical winding drum portion 51 around which the field coil 4 is wound, and a pair of flange portions 52 that extend radially outward from both axial ends of the winding drum portion 51.

  One of the pair of flange portions 52 is shown in FIG. The flange portion 52 has a total of eight groove portions 52A that are recessed radially inward at a constant circumferential pitch. Of the flange portion 52, the portion other than the groove portion 52A is bent by the radially inner surface of the claw-shaped magnetic pole portion 23 as shown in FIG.

  Reference numeral 53 denotes a lead wire locking portion where the winding start end 300 of the field coil 4 is locked, and 54 denotes a lead wire locking portion where the winding end end of the field coil 4 is locked. The portions 53 and 54 are formed in the radially innermost portion of the pair of groove portions 52A that are rotationally symmetrical to each other in the groove portion 52A of the flange portion 52. Further, an axial projecting portion 55 projects from the radially innermost portion of the remaining six groove portions 52A out of the total eight groove portions 52A of the flange portion 52 outward in the axial direction.

  The other of the pair of flange portions 52 has the same shape as one of the pair of flange portions 52 described above except that an axial protrusion 55 is provided instead of the lead wire locking portions 53 and 54. . The groove portion 52A of the flange portion 52 is arranged at the same position in the circumferential direction as the valley portion 25 of the disk portion 22 of the field iron cores 2 and 3, and the axial protruding portion 55 of the resin bobbin 5 is located on the valley bottom portion 26 of the valley portion 25. Projecting outward in the axial direction.

  Further, in this embodiment, as shown in FIG. 2, a substantially U-shaped spacer 56 is inserted in the gap between the axial protrusion 55 and the valley bottom 26 of the valley 25. The spacer 56 is molded from an electrically insulating resin material that is at least more deformable than the resin bobbin 5. Since resin such as nylon is adopted as the resin bobbin 5, it is preferable to adopt heat resistant rubber such as silicon rubber as the spacer 56 in consideration of heat generation of the field coil 4 and the like. It is not limited.

(Manufacturing process)
Next, the rotor manufacturing process will be described.

  As described above, the resin bobbin 5 around which the field coil 4 is wound is fitted to the boss portion 21, and the pair of field iron cores 2 and 3 are attached in a state where the claw-shaped magnetic pole portions 23 are alternately meshed. Fit and fix on the rotating shaft 1. The spacer 56 is inserted before the next thermosetting resin liquid is dropped, preferably when the resin bobbin 5 is attached.

  Next, for example, an unpolymerized epoxy resin liquid (thermosetting resin referred to in the present invention) is applied to the outer peripheral surface of the field coil 4 while the rotor is slowly rotated in a heated state (preferably 130 to 180 ° C.). Let it drip. The epoxy resin liquid is impregnated between the windings of the field coil 4 and between the field coil 4 and the resin bobbin 5, and then is cured by polymerization to cover the field coil 4, and the field coil 4 and the resin bobbin. 5 is integrated. Thereafter, the rotor is gradually cooled to complete the manufacture of the rotor.

(effect)
According to the rotor of the above-described embodiment, the gap between the axially protruding portion 55 of the resin bobbin 5 and the surface of the valley bottom portion 26 of the disk portion 22 of the field iron cores 2 and 3 can be larger than that of the resin bobbin 5. Since the spacer 56 made of heat-resistant resin or heat-resistant rubber having excellent flexibility is inserted, the axially projecting portion 55 is flexible, particularly through the impregnated resin portion that is inferior in ductility. Therefore, it is possible to satisfactorily solve the problem that the cracks generated in the impregnated resin portion spill over the protruding portion 55 in the axial direction.

(Second Embodiment)
The rotor of the vehicle alternator of the second embodiment will be described below. In the rotor of this embodiment, in the first embodiment shown in FIGS. 1 to 3, the spacer 56 is omitted, and instead, the surface of the axial protrusion 55 or the surface of the valley bottom 26 has a low friction coefficient coating ( (Not shown). This deposition is performed before the thermosetting resin liquid is dropped.

  The low friction coefficient film may be a liquid film or a powder film in addition to a solid film. For example, a silicon resin film or the like may be used, or molybdenum disulfide or lubricating oil may be applied. In this way, the bond strength between the axial protruding portion 55 and the impregnated resin portion can be greatly reduced, so that the impregnated resin portion cracks and the tensile stress of the impregnated resin portion passes through the low coefficient of friction coating. Therefore, when trying to concentrate on the axial protrusion 55 in the vicinity of the crack, the axial protrusion 55 slides and displaces on the low-friction coefficient film, so that breakage of the axial protrusion 55 can be satisfactorily suppressed.

(Third embodiment)
The rotor of the vehicle alternator of the third embodiment will be described with reference to FIG. In the rotor of this embodiment, in the first embodiment shown in FIGS. 1 to 3, the spacer 56 is omitted. Instead, as shown in FIG. 4, the peripheral edge of the axial protrusion 55 and the valley bottom 26. A rib 56 that protrudes toward the surface (more precisely, toward the surface 24A of the column portion 24 facing the valley bottom portion 26) is provided. FIG. 4 is a view of the axial protrusion 55 and the disk portion 22 as viewed from the axially outer side of the rotor in the axial direction, and the axial protrusion 55 is shown in cross-section.

  In this embodiment, the rib 56 protrudes from the radially outermost portion of the peripheral edge portion of the axial protrusion portion 55, and the tip thereof is in close contact with the surface 22 </ b> A of the disk portion 22 facing the valley bottom portion 26. Since nylon, which is the material of the resin bobbin 5, has elasticity, it is easy to press the rib 56 against the surface 22A of the disk portion 22 by using this elasticity. As a result, the rib 56 can satisfactorily prevent the thermosetting resin liquid from entering the gap S between the axial protrusion 55 and the surface 22A of the disk portion 22. In this embodiment, as shown in FIG. 4, the ribs 56 are provided only on the radially outermost part of the peripheral edge of the axial protrusion 55, but the ribs 56 are provided on the entire peripheral edge of the axial protrusion 55. Accordingly, the penetration of the thermosetting resin liquid into the gap S between the axial projecting portion 55 and the surface 22A of the disk portion 22 can be further prevented.

  Preferably, the size t of the gap S between the axial protrusion 55 and the surface 22A of the disk portion 22 is set to be larger than the thickness of the axial protrusion 55. By doing so, since the width of the gap S is large, even if the thermosetting resin liquid enters, the integration of the axial protruding portion 55 and the surface 22A of the disk portion 22 can be suppressed.

(Modification)
A modification of the rib 56 described in the third embodiment is shown in FIG. The rib 550 of this embodiment is a tongue-like body that extends radially outward from the radially outermost portion of the peripheral edge of the axial protrusion 55 while contacting the surface 24A of the pillar 24. In this way, the adhesion between the rib 56 and the surface 24A of the column portion 24 is further increased, and the rib 550 is gradually thinned toward the tip, further improving the flexibility. Intrusion of the thermosetting resin liquid into the gap S can be prevented even better.

(Fourth embodiment)
The rotor of the vehicle alternator of the fourth embodiment will be described with reference to FIG. FIG. 4 is a view of the axial protrusion 55 and the disk portion 22 as viewed from the axially outer side of the rotor in the axial direction, and the axial protrusion 55 is shown in cross-section.

  In the rotor of this embodiment, the spacer 56 is omitted in the first embodiment shown in FIGS. 1 to 3, and instead the thickness of the axial protrusion 55 is changed to the disk of the resin bobbin 5 as shown in FIG. 6. More than twice the thickness of the portion 22, preferably 4 to 10 times.

  Further, the thickness of the axial protruding portion 55 is at least 5 times the minimum value of the gap S between the valley bottom portion (more precisely, the surface 22A of the disk portion 22) and the axial protruding portion 55, preferably 10 times or more. It is said that. Reference numeral 57 denotes a thermosetting resin reservoir groove that is located at the tip end portion (radially outermost portion) of the axial projecting portion 55 and is recessed facing the surface 22A of the disk portion 22.

  In this way, since the axial protrusion 55 of the resin bobbin 5 is formed thick, the crack resistance strength can be improved. As a result, the surface of the axial protrusion 55 and the disk portion 22 can be improved. Even if a crack occurs in the impregnated resin portion that has entered and solidified between 22A and 22A, the crack of the impregnated resin portion can be prevented from spreading to the axial protrusion 55.

  Further, the thermosetting resin liquid storage groove 57 stores the intruding thermosetting resin liquid, and has an effect of preventing the axially protruding portion 55 and the surface 22A of the disk portion 22 from being completely fixed by the impregnated resin portion. Play.

(Fifth embodiment)
The rotor of the vehicle alternator of the fifth embodiment will be described with reference to FIG. FIG. 7 is a view of the axial protrusion 55 and the disk portion 22 as viewed from the outside in the axial direction of the rotor in the axial direction, and the axial protrusion 55 is shown in cross section.

  In the rotor of this embodiment, the spacer 56 is omitted in the first embodiment shown in FIGS. 1 to 3, and instead, the axial protrusion 55 is formed in a corrugated shape as shown in FIG. 6. The point is its characteristic.

  In this way, the axial projecting portion 55 is not fixed to the surface 22A of the disk portion 22 through the impregnating resin portion over a large area at the same time. It is possible to satisfactorily prevent the protrusion 55 from cracking, and to provide a plurality of isolated thermosetting resin reservoir grooves 57 between the axial protrusion 55 and the surface 22A of the disk portion 22, respectively. This is effective in preventing cracks.

It is an axial sectional view showing the rotor of the first embodiment. It is a principal part expansion perspective view of the rotor shown in FIG. It is a front view which shows the resin bobbin by which the field coil was wound. It is a front view which shows the axial direction protrusion part and disc part in 3rd Embodiment. It is a front view which shows the modification of the rib of 3rd Embodiment. It is a front view which shows the axial direction protrusion part and disc part in 4th Embodiment. It is a front view which shows the axial direction protrusion part and disc part in 5th Embodiment. It is a model perspective view which shows the conventional axial direction protrusion part and disk part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating shaft 2 Field iron core 3 Field iron core 4 Field coil 5 Resin bobbin 9 Cooling fan 21 Boss part 22 Disk part 22A Disk part surface 23 Claw-shaped magnetic pole part 24 Column part 24A Column part surface 25 Valley part 26 Valley bottom Part 51 Winding body part 52 Flange part 52A Groove part of flange part 53 Leader line locking part 55 Axial protruding part 56 Spacer 56 Rib 57 Thermosetting resin reservoir groove 550 Rib

Claims (6)

Boss portions fitted to the rotation shaft, a plurality of radially projecting column portions, and a plurality of trough portions that are located between the column portions and are recessed radially inward are alternately arranged in the circumferential direction. Each of the troughs includes a disk part extending radially outward from the axially outer end of the boss part and a plurality of claw-shaped magnetic poles individually extending in the axial direction from the tip of the pillar part. The innermost portion in the radial direction of the magnetic field core that forms a substantially U-shaped valley bottom,
A resin bobbin fitted to the boss of the field core;
A field coil wound around the resin bobbin;
A thermosetting impregnated resin portion formed by being thermally cured after being attached to the field coil and the resin bobbin fitted in the field core;
With
The resin bobbin includes a cylindrical winding body around which the field coil is wound,
A pair of flange portions projecting radially outward from both ends of the winding drum portion, and an axial projecting portion extending axially outward from the flange portion along the surface of the valley bottom of the field core And
In the rotor of the vehicle alternator, the impregnated resin portion after thermosetting has a property that is inferior in deformability to the resin bobbin,
A vehicular AC generator rotor having a thermosetting resin invasion suppressing structure that suppresses intrusion of the impregnating resin into a gap between the axial protrusion and the valley bottom. In the manufacturing method of the rotor of the vehicle alternator according to claim 1,
The thermosetting resin invasion suppression structure is
A method of manufacturing an AC generator for a vehicle, which is made of a material softer than the resin bobbin and has an electrically insulating spacer inserted in the gap before at least the heat curing treatment of the impregnated resin portion. In the manufacturing method of the rotor of the vehicle alternator according to claim 1,
The thermosetting resin invasion suppression structure is
A low-friction coating made of a material having a lower friction coefficient than the resin bobbin and applied to at least one of the surface of the axially protruding portion and the surface of the valley bottom before the application of the impregnated resin portion. A method for manufacturing a rotor of a vehicle alternator. In the rotor of the vehicle alternator according to claim 1,
The thermosetting resin invasion suppression structure is
A vehicular AC generator rotor having ribs that protrude from a peripheral edge of the axial protrusion toward the bottom of the valley and prevent the impregnation resin from entering the gap. Boss portions fitted to the rotation shaft, a plurality of radially projecting column portions, and a plurality of trough portions that are located between the column portions and are recessed radially inward are alternately arranged in the circumferential direction. Each of the troughs includes a disk part extending radially outward from the axially outer end of the boss part and a plurality of claw-shaped magnetic poles individually extending in the axial direction from the tip of the pillar part. The innermost portion in the radial direction of the magnetic field core that forms a substantially U-shaped valley bottom,
A resin bobbin fitted to the boss of the field core;
A field coil wound around the resin bobbin;
A thermosetting impregnated resin portion formed by being thermally cured after being attached to the field coil and the resin bobbin fitted in the field core;
With
The resin bobbin includes a cylindrical winding body around which the field coil is wound,
A pair of flange portions projecting radially outward from both ends of the winding drum portion, and an axial projecting portion extending axially outward from the flange portion along the surface of the valley bottom of the field core And
In the rotor of the vehicle alternator, the impregnated resin portion after thermosetting has a property that is inferior in deformability to the resin bobbin,
The axial protruding portion of the resin bobbin is thicker than the disk portion of the insulating bobbin, and is formed to have a thickness more than three times the gap between the valley bottom portion and the axial protruding portion. An AC generator rotor for a vehicle. Boss portions fitted to the rotation shaft, a plurality of radially projecting column portions, and a plurality of trough portions that are located between the column portions and are recessed radially inward are alternately arranged in the circumferential direction. Each of the troughs includes a disk part extending radially outward from the axially outer end of the boss part and a plurality of claw-shaped magnetic poles individually extending in the axial direction from the tip of the pillar part. The innermost portion in the radial direction of the magnetic field core that forms a substantially U-shaped valley bottom,
A resin bobbin fitted to the boss of the field core;
A field coil wound around the resin bobbin;
A thermosetting impregnated resin portion formed by being thermally cured after being attached to the field coil and the resin bobbin fitted in the field core;
With
The resin bobbin includes a cylindrical winding body around which the field coil is wound,
A pair of flange portions projecting radially outward from both ends of the winding drum portion, and an axial projecting portion extending axially outward from the flange portion along the surface of the valley bottom of the field core And
In the rotor of the vehicle alternator, the impregnated resin portion after thermosetting has a property that is inferior in deformability to the resin bobbin,
The vehicular alternator rotor according to claim 1, wherein the axial protrusion of the resin bobbin has a bellows shape that periodically changes with the width of the gap.

Images