JP2001157425A - Alternator - Google Patents

Abstract

(57) [Summary] An alternator is realized by a rotor in which pressed cores are stacked. SOLUTION: A stator core 36 around which an armature winding 38 is wound, a rotor core 56 formed by laminating a disc-shaped sheet core having a concave portion for forming a pole piece, and a ring having the same outer periphery as the rotor core 56 A rotor core 57 in which sheet-shaped sheet cores are stacked, and a ring body 58 in which sheet rings of non-magnetic material are stacked between the rotor cores 56, 57, and the rotor cores 56, 57 and the ring body 58 are integrated. Rotor 5 having a cavity 76 formed therein.
3. Holding the stator core 36 and bearing 5
A front bracket 51 that rotatably supports the rotor 53 via a cantilever via the rotor 55, an excitation winding 37 disposed in a cavity 76 of the rotor 53, and an excitation core that fixes the excitation winding 37 to the front bracket 51 side. 77 and the front bracket 51 are provided with a fixed rear cover 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alternator, particularly to a brushless alternator, and more particularly to an alternator having a simplified rotor core structure capable of pressing a rotor core constituting a rotor.

[0002]

2. Description of the Related Art Conventionally, an alternator rotor has a structure shown in FIG.
And it was assembled.

[0003] In the partial cross-sectional view of the rotor of the conventional alternator shown in FIG. 12, a knurl 2 is cut in a shaft 1, and a rotor core 3 is fixed to a portion where the knurl 2 is cut. The rotor core 4 is fixed and assembled via a non-magnetic ring 7 so as to be assembled. Excitation windings are mounted in the internal space where the two rotor cores 3 and 4 are combined, as will be described later with reference to FIG. Are not shown.

The two rotor cores 3, 4 are forged,
As shown in FIG. 12, a plurality of claw-shaped pole pieces 5 are formed, and a portion called a boss portion 6 having a hole to be pressed into the shaft 1 is formed at the center of one rotor core 3. ing. The other rotor core 4 is welded via a non-magnetic ring 7 to be connected to the rotor core 3. At this time, the claw-shaped pole pieces 5 of the two rotor cores 3 and 4 are connected in a mutually engaged manner, and the combined body of the rotor core 3 and the rotor core 4 is
The rotor core 3 was assembled as a rundle type rotor 8 of an alternator, which was press-fitted using a hole provided at the center of the boss 6 of the rotor core 3 and the knurl 2 cut into the shaft 1.

FIG. 13 is a sectional view of a conventional alternator.

In FIG. 1, a conventional alternator 30 using the above-mentioned Landel rotor 8 has the following structure. That is, the front bracket 33 is provided on both sides of the stator core 36 around which the armature winding 38 is wound.
And the rear bracket 34 are fixed, and the ball bearing 40 and the roller bearing 31 mounted on the front bracket 33 and the rear bracket 34 respectively form the Landel-type rotor 8 described above to form the stator core 36.
Is rotatably supported inside.

In the rotor 8 omitted in FIG. 12, two rotor cores 3 and 4 and a boss 6 are combined.
As shown in FIG. 13, an exciting winding 37 is wound around the space between the rotor cores 3 and 4 via the exciting core 9, and the exciting core 9 is mounted on the rear bracket 34. Fixed.

Further, a pulley 32 for rotating the rotor 8 is provided on the shaft 1.
A centrifugal fan 39 is attached to the front bracket 33 side. The rear bracket 34 is covered with a rear cover 35 having an air hole for taking in outside air.
The outside air on the side of the rear cover 35 is taken into the alternator 30 by a centrifugal fan 39 attached to the engine 2, and each component in the alternator 30 is air-cooled.

Since the conventional alternator 30 is configured in this manner, when an exciting current flows through the exciting winding 37, the magnetomotive force causes (a) the claw-shaped pole piece 5 of the rotor core 3, (b) the (C) the air gap between the pole piece 5 and the teeth of the stator core 36 facing the position, (c) the teeth of the stator core 36 facing the claw-shaped pole piece 5 of the rotor core 3, and (d) the stator cores 36 and (e). ) Rotor core 4 located adjacent to the claw-shaped pole piece 5 of rotor core 3
Core 36 positioned opposite to claw-shaped pole piece 5
(F) the rotor core 3
C) the claw-shaped pole piece 5 of the rotor core 4 located next to the claw-shaped pole piece 5; (g) the air gap between the rotor core 4 and the outer peripheral surface of the excitation core 9;
(I) the excitation core 9, (j) the air gap between the inner peripheral surface of the excitation core 9 and the boss 6 provided on the rotor core 3, (k) the rotor core (including the boss 6) 3, (l The magnetic flux flows in that direction through the magnetic circuit of the first claw-shaped pole piece 5 of the rotor core 3.

[0010]

However, in the conventional alternator rotor structure, since the rotor cores 3 and 4 are forged and the boss portion 6 is provided on the rotor core 3, the weight is heavy. In addition, since the two rotor cores 3 and 4 are combined and welded via the non-magnetic ring 7, the processing takes time. For this reason, reduction of the production cost of the rotor 8 has been strongly desired.

The present invention has been made in view of the above points, and has been modified from the conventional structure of a Landel type rotor in which two rotor cores formed by forging are welded and combined via a non-magnetic ring, and are punched out by a press. It is an object of the present invention to provide an alternator provided with a rotor that can be mass-produced in a short period of time by using a structure in which a magnetic pole is formed based on a sheet-shaped core member and that can reduce the manufacturing cost.

[0012]

In order to solve the above-mentioned object, an alternator according to the present invention has a stator core on which an armature winding is wound, and a plurality of recesses for forming pole pieces on the outer periphery. A first rotor core formed by laminating a plurality of disc-shaped sheet cores made of a magnetic material having a shape; and a second rotor core formed by laminating a plurality of ring-shaped sheet cores formed of a magnetic material having the same outer periphery as the first rotor core. A ring body formed by laminating a plurality of nonmagnetic material seat rings disposed between the first rotor core and the second rotor core, wherein the first rotor core, the second rotor core, and the ring body are stacked. And a rotor that rotates inside the stator core through an air gap and has a cavity formed inside, and holds the stator core and rotatably supports the rotor through bearings. That the front bracket, and an annular excitation winding which is disposed in the cavity of the rotor, characterized in that a exciting core for fixing the exciting coil to the front bracket side.

In the rotor, the pole pieces of the rotor cores are stacked linearly or obliquely in the axial direction of the rotor.

The exciting core is provided with a projection for holding an exciting winding and passing a magnetic flux, and the two bearings are mounted on a shaft at a predetermined distance from each other. A structure is employed in which the rotor is rotatably and cantilevered by two bearings.

Further, the rotor may have a structure in which both the disc-shaped sheet core of the first rotor core and the ring-shaped sheet core of the second rotor core are formed as one piece.

A plurality of recesses for forming magnetic pole pieces are formed on the outer periphery of the disk-shaped sheet core, and a ring-shaped sheet core having the same outer circumference as the disk-shaped sheet core is used. Since the rotor configuration is such that the seat ring is interposed, it is possible to press the rotor core of the rotor and the like, and by improving the rotor core structure, an alternator having a reduced weight and a simplified configuration is realized.

[0017]

FIG. 1 is a sectional view showing one embodiment of an alternator according to the present invention.

In FIG. 1, a stator core 36 around which an armature winding 38 is wound is composed of a front bracket 51 and a rear cover 5 attached to the front bracket 51.
2 and so on. A rotor 53 is rotatably supported by a cantilever structure inside two stators 54 and 55 provided on the front bracket 51 and separated by a predetermined distance L via an air gap inside the stator core 36. The reason for adopting the cantilever structure will be described later in detail.

As shown in FIGS. 2 and 3, the rotor 53 includes rotor cores 56 and 57 made of a magnetic material, a ring body 58 made of a non-magnetic material, and a side plate 60 with a fan 59.
However, it has a structure in which it is integrated by welding with nonmagnetic rivets, screws, electron beams, and the like, and is fixed to the shaft 61.

The rotor core 56 is formed by laminating a predetermined number of disk-shaped sheet cores 62 made of a magnetic material such as an iron plate, an electromagnetic steel plate, or a silicon steel plate having the shape shown in FIG. In the core shape of the sheet core 62, a plurality of concave portions 64 for forming the pole pieces 63 are formed at equal intervals on the outer periphery, and a shaft hole 65 is provided at the center thereof. In order to reduce the weight, a plurality of lightening holes 66 are formed in a range where the magnetic influence is small. The hole 67 is a hole for a rivet or a hole for a screw. The hole 67 is unnecessary when the fixing method is welding as described above.

The rotor core 57 is formed by laminating a predetermined number of ring-shaped sheet cores 68 made of a magnetic material such as an iron plate, an electromagnetic steel plate, and a silicon steel plate having the shape shown in FIG.
The outer shape of the core of the sheet core 68 is the same as that of the sheet core 62 of the rotor core 56, a plurality of recesses 70 for forming the pole pieces 69 are formed at equal intervals on the outer circumference, and a large hole is formed at the center thereof. 71 are provided. The hole 72 is a hole for the rivet or a hole for a screw. This hole 7
No. 2 is unnecessary when the fixing method is welding as described above.

The ring body 58 made of the non-magnetic material is shown in FIG.
A predetermined number of sheet rings 73 of a non-magnetic material such as aluminum and stainless steel having the shape shown in FIG. The shape of the seat ring 73 is such that the outer diameters of the recesses 6 are formed in the seat cores 62 and 68 respectively.
The bottom diameter of the sheet core 68 is the same as or smaller than the bottom diameter of the large hole 71 of the sheet core 68. The hole 74 is a hole for the rivet or a hole for a screw.

The sheet core 62 forming the rotor core 56, the sheet ring 73 forming the ring body 58, and the sheet core 68 forming the rotor core 57 are punched out from a strip-shaped or roll-shaped member, respectively. The two sheet cores 62 and 68 are
Since the outer peripheral shape is the same, the latter sheet core 68
After punching the former sheet core 62 (except for the hole 67), the large hole 71 and the hole 72 of the latter sheet core 68 are used.
Can be punched by a progressive press method.

In the rotor 53 shown in FIGS. 1 and 2, the rotor core 56 is formed by stacking five sheet cores 62, the ring body 58 is formed by stacking three sheet rings 73, and the rotor core 57 is formed by forming five sheet cores. An example in which the cores 68 are stacked and integrated with one side plate 60 is shown as an example. When assembling the rotor 53, the magnetic pole pieces 63 of the rotor core 56 are aligned with the concave portions 70 of the rotor core 57, and the concave portions 64 of the rotor core 56 are aligned and integrated with the magnetic pole pieces 69 of the rotor core 57, respectively. Is done.

As described above, since the core member of the rotor 53 can be removed by pressing, the rotor 53 can be formed in a more flexible shape. Compared with the conventional rotor-type rotor 8 shown in FIG. 12, which is formed by combining two rotor cores 3 and 4 formed by forging, the weight thereof can be remarkably reduced.

Focusing on the reduction of the weight of the rotor 53, the method of fixing the excitation winding 37 to the front bracket 51 side, which will be described next, uses the spacing L provided on the front bracket 51 as described above in the present invention. The two rotors 54 and 55 rotatably support the reduced rotor 53 in a cantilever structure. 2 at this time
The distance L between the bearings 54 and 55 is determined by the output of the alternator, that is, the size of the rotor 53 and other conditions. Since the rotor 53 has a cantilever structure and is rotatably supported by the front bracket 51, the conventional rear bracket 34 (see FIG. 13) is not required, and the weight can be further reduced.

The rotor 53 has a shaft 61 having an inner diameter formed by a rotor core 57 and a ring body 58.
An annular space having an inner diameter of the rotor core 57 and the ring body 58 as an outer diameter, that is, a cavity 76 is formed.

An annular (toroidal) excitation winding 37 is disposed in the cavity 76, and the excitation winding 37 is held by an excitation core 77 and an excitation winding holding ring 78. The excitation winding 37 is fixed to the front bracket 51 via the same.

FIG. 7 is an exploded explanatory view of an embodiment of a method of fixing the excitation winding.

As shown in the drawing, the annular (donut-shaped) excitation winding 37 is provided with a fitting step 79, is wound around a winding frame, and is solidified by varnish processing.

The fitting step 7 provided on the exciting winding 37
An annular (doughnut-shaped) excitation core 77 of a magnetic material into which the excitation winding 37 is fitted by using the projections 9 is a projection that forms a receiving groove 80 for receiving the excitation winding 37, that is, an annular wrap projection 81. Have. The excitation core 77
Further, a fitting groove 83 is provided, and an exciting winding holding ring 78 made of a magnetic material having a flange 82 is fitted into the fitting groove 83.

When the exciting winding 37 is inserted into the exciting winding holding ring 78, the exciting winding holding ring 78 is inserted into the fitting groove 83.
And the excitation winding 37 is fixed to the excitation core 77. A hole 84 that is continuous with the fitting groove 83 and has a diameter slightly larger than the diameter of the shaft 61 is provided in the excitation core 77.

The excitation core 77 is provided with a plurality of screw holes 85, and the excitation winding 3
The excitation core 77 to which is fixed is fixed to the front bracket 51 with screws 86 (see FIG. 1) using the screw holes 85.

The inner diameter of the exciting winding holding ring 78 is the same as the diameter of the hole 84 of the exciting core 77 and is slightly larger than the diameter of the shaft 61.

A pulley 32 for rotating the rotor 53 is provided on the shaft 61, and a centrifugal fan 39 is attached to the pulley 32 on the front bracket 51 side. The centrifugal fan 39 attached to the pulley 32 cooperates with the fan 59 of the side plate 60 constituting the rotor 53 to take in the outside air on the rear cover 35 side into the alternator 30 via the rear cover 52 having the air hole. The hot air that has cooled the rotor 53 and the like is discharged to the outside air through the air holes of the front cover 87 attached to the front bracket 51. Reference numeral 88 denotes a mounting leg, and various mounting legs 88 are fixed to the front bracket 51 as shown by a dotted line in accordance with a mounting partner.

FIG. 8 is a partial sectional view illustrating the flow of magnetic flux.

In FIG. 3, when an exciting current flows through the exciting winding 37 in a certain direction, for example,
(A) Magnetic pole piece 63 of rotor core 56 laminated, (b)
An air gap between the pole piece 63 and the teeth of the stator core 36 at the position facing the stator core, and (c) the stator core 3 at a position facing the stacked pole piece 63 of the rotor core 56.
6, (d) stator core 36, (e) rotor core 5
6, the stacked pole pieces 69 of the rotor core 57 located adjacent to the stacked pole pieces 63 (in FIGS. 1, 2 and 8, the stacked magnetic pole pieces of the rotor core 56 are easy to understand. Although the piece 63 and the pole piece 69 on which the rotor core 57 is stacked are drawn at the same height, the height is correctly the bottom diameter of the stacked recess 70 of the rotor core 57 (see FIG. 5), and And (f) the ring body 58 of the pole piece 63 on which the rotor core 56 is laminated. Stacked pole pieces 69 of the rotor core 57 located adjacent to and separated by
(G) rotor core 57, (h) outer peripheral surface X of excitation core 77 facing the inner diameter surface of sheet core 68 including the inner diameter surface of sheet core 68 on which rotor core 57 is stacked and wrap projection 81 of excitation core 77. (I) the exciting core 77, (j) the air gap between the inner peripheral surface Y of the exciting core 77 (including the inner peripheral surface Y of the exciting winding holding ring 78) and the shaft 61, k) the shaft 61, (l) the rotor core 56, (m) and the first rotor core 5
In the magnetic circuit of the stacked pole pieces 63, magnetic flux flows in that direction.

In this case, the pole piece 63 of the rotor core 56 laminated is magnetized to the N pole, and the laminated pole piece 69 of the rotor core 57 is magnetized to the S pole. That is, as can be understood from the above description of the flow of the magnetic flux, the rotor core 56,
The magnetic reluctance of the portion of each of the stacked concave portions 64 and 70 of the rotor 57 is large, and almost no magnetic flux flows through the stacked concave portions 64 and 70, and conversely, the stacked magnetic pole pieces 63 and 70 of the rotor cores 56 and 57. Since the magnetic resistance of the portion 69 is small, a magnetic flux flows and is magnetized as described above.

When the exciting current flows in the exciting winding 37 in the opposite direction, the magnetomotive force causes the magnetic flux to flow through the magnetic circuit in the above-described order in reverse, and the laminated magnetic pole piece 63 of the rotor core 56 is magnetized to the S pole. The stacked pole pieces 69 of the rotor core 57 are magnetized to the N pole. That is, it can be seen that the rotor 53 is configured to perform the same function as the conventional rotor 8.

Here, paying attention to the wrap projection 81 formed on the excitation core 77, the formation of the wrap projection 81 causes a magnetic flux to flow through the wrap projection 81 as indicated by an arrow A, and It is understood that the wrap portion of the magnetic path is effectively expanded compared to when the convex portion 81 is not formed. Thus, the thickness of the exciting core 77 and the stacked thickness of the rotor core 57 can be reduced without reducing the magnetic flux density force by the exciting winding 37, the core thickness of the rotor 53 can be reduced, and the rotor 53 can be reduced in weight. In addition, the overall length of the alternator 30 can be reduced and its weight can be reduced.

FIG. 9 is a sectional view of another embodiment of the rotor.

The rotor 53 shown in the drawing has the same structure as that shown in FIG. 2, but the sheet cores 62, 68 of the rotor cores 56, 57 are skewed in the same direction in the axial direction of the shaft 61. It has a laminated structure in which cooling air is easily passed.

FIG. 10 is an explanatory view of one embodiment of the rotation direction of the skewed rotor core and the flow of the wind.

The rotor cores 56 and 57 are skewed by shifting and stacking the sheet cores 62 and 68. The hatched portions are the stacked magnetic pole pieces 63 and 69, and the unhatched portions are the stacked concave portions 64 and 70. The rotor 53 is rotated in the direction of the arrow.

By skewing the rotor 53 in this manner, the flow of the wind in the direction of arrow F is assisted, the flow of the wind becomes similar to that of the conventional alternator 30, and the method of cutting off the magnetic flux (shown by the arrow K) Can be.

FIG. 11 is a sectional view of another embodiment of the alternator according to the present invention.

In the figure, the difference from the one in FIG. 1 is the rotor 89, and the rotor core 9 constituting the rotor 89 is different.
0, 91 and a ring body 92 are different, and the others are the same.

The rotor cores 90 and 91 each consist of one disc-shaped core and one ring-shaped core punched by a press, and the black portions are the outer pole pieces,
The white portion is the outer concave portion. As the ring body 92, a seat ring punched by two presses is used, and these rotor cores 9 are formed in accordance with the output of the alternator 30.
0, 91 and the thickness of the ring body 92 are determined.

The operation of the alternator 30 shown in FIG. 11 is the same as that of FIG.

[0050]

As described above, according to the present invention, a plurality of recesses for forming magnetic pole pieces are formed on the outer periphery of a disc-shaped sheet core constituting a rotor, and the outer periphery is formed with a disc-shaped sheet core. Since the rotor configuration is such that a ring-shaped sheet core having the same shape is used and a sheet ring made of a non-magnetic material is interposed therebetween, it is possible to press the rotor core of the rotor. Because the rotor core can be pressed, it is possible to manufacture a rotor core that supports a large number of magnetic circuits by combining the number of cores of the pressed rotor core, etc., without requiring special technology, and reduce the cost of the rotor. .

Since the weight of the rotor core is reduced, the bearing of the rotor can have a cantilever structure, and a rear bracket is not required, thereby realizing an alternator having a simplified configuration.

Since the excitation winding is housed in the excitation core, and the excitation core is provided with a projection for passing a magnetic flux,
The size of the rotor can be reduced, and the alternator can be downsized by the cantilever structure of the bearing of the rotor.

If the stacked rotor cores have a skewed structure, the skew of the rotor cores improves the flow of the wind of the rotor, and can suppress the temperature rise of the alternator.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of an alternator according to the present invention.

FIG. 2 is a sectional view of one embodiment of a rotor.

FIG. 3 is a left side view of FIG. 2;

FIG. 4 is an explanatory view of a shape of an embodiment of a sheet core constituting a rotor core.

FIG. 5 is an explanatory view of a shape of an embodiment of a sheet core constituting a rotor core.

FIG. 6 is an explanatory view of the shape of an embodiment of a seat ring constituting a ring body.

FIG. 7 is an exploded explanatory view of an embodiment of a method of fixing an excitation winding.

FIG. 8 is a partial cross-sectional view illustrating a flow of a magnetic flux.

FIG. 9 is a sectional view of another embodiment of the rotor.

FIG. 10 is a diagram illustrating an example of a rotation direction of a skewed rotor core and a flow of wind.

FIG. 11 is a sectional view of another embodiment of the alternator according to the present invention.

FIG. 12 is a partial sectional view of a rotor of a conventional alternator.

FIG. 13 is a sectional view of a conventional alternator.

[Explanation of symbols]

 Reference Signs List 1 shaft 2 knurl 3, 4 rotor core 5 magnetic pole piece 6 boss 8 rotor 9 excitation core 30 alternator 36 stator core 37 excitation winding 38 armature winding 51 front bracket 53 rotor 54, 55 bearing 56, 57 rotor core 58 ring body 61 shaft 63 magnetic pole piece 64 concave part 66 lightening hole 68 sheet core 69 magnetic pole piece 70 concave part 73 seat ring 76 cavity 77 exciting core 81 lap convex part 89 rotor 90, 91 rotor core 92 ring body

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H002 AA07 AB08 AC03 AC06 AE07 AE08 5H605 AA08 BB01 BB10 CC02 CC09 DD09 EA01 EB10 GG04 GG06 5H619 AA05 BB02 BB15 PP02 PP05 PP06 PP10 PP13

Claims (6)

[Claims] 1. A first laminate comprising: a stator core on which an armature winding is wound; and a plurality of disk-shaped sheet cores made of a magnetic material having a plurality of recesses formed on an outer periphery thereof for forming pole pieces. A first rotor core, a second rotor core in which a plurality of ring-shaped sheet cores whose outer periphery is made of a magnetic material having the same shape as the first rotor core are laminated, and a non-rotor core disposed between the first rotor core and the second rotor core. A ring body in which a plurality of sheet rings made of a magnetic material are stacked, wherein the first rotor core, the second rotor core, and the ring body are stacked and integrated to form a cavity inside the stator core. A rotor that rotates through an air gap; a front bracket that holds a stator core and rotatably supports the rotor through a bearing; and an annular excitation disposed in the cavity of the rotor. An alternator comprising: a magnetic winding; and an excitation core for fixing the excitation winding to a front bracket side. 2. The alternator according to claim 1, wherein the rotor has a structure in which the pole pieces of each rotor core are linearly stacked in the axial direction of the rotor. 3. The alternator according to claim 1, wherein the rotor has a structure in which the pole pieces of each of the rotor cores are stacked obliquely in the axial direction of the rotor. 4. The alternator according to claim 1, wherein the excitation core has a structure for holding an excitation winding and having a projection for passing a magnetic flux. 5. The bearing according to claim 1, wherein two bearings are mounted on the shaft at a predetermined distance from each other, and the two bearings rotatably support the rotor in a cantilever manner. The alternator according to claim 1. 6. The alternator according to claim 1, wherein the rotor has a structure in which both a disc-shaped sheet core of the first rotor core and a ring-shaped sheet core of the first rotor core are constituted by one piece.