JPH0534892B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotor for a vehicle alternator, and more particularly to an improvement in the pole core portion of this rotor.

Conventionally, the rotor of a vehicle alternator has been equipped with a plurality of claw-shaped pole core parts protruding in the axial direction on the outer periphery as described in Japanese Patent Laid-Open No. 58-79455 to improve cooling efficiency. The pair of rotor cores thus formed are configured by being fitted onto a shaft such that an excitation coil fixed to a yoke is held between the pair of rotor cores, and the pole core portions of the pair of rotor cores are arranged so as to face each other and mesh with each other. death,
Some have cooling air passages formed along the sides of the pole core.

In recent years, such rotating electricity has been made faster by increasing the pulley ratio in order to achieve smaller size, lighter weight, and higher output. When the pole core rotates, centrifugal wind is generated, which generates pulsating pressure fluctuations between the stator and the pole core, which interferes with the unevenness of the teeth on the inner circumference of the stator and generates wind noise. This wind noise has become particularly loud for the reasons mentioned above.

The present invention has been made in view of the above points, and is designed to eliminate interference noise between the pole core and the stator, reduce noise in the high-speed rotation range, and prevent the ventilation inside the rotor for cooling from being impaired. The object of the present invention is to provide a rotor for a vehicle alternator.

In order to achieve the objects of the present invention, the rotor of the vehicle alternator of the present invention is provided with a pair of Lundell type pole cores having a plurality of claws arranged so as to alternately mesh with each other, and an excitation coil inside the pole core. A rotor for a vehicle alternator comprising a rotor wound with teeth and a stator having teeth arranged radially opposite to the rotor. Equipped with a ring,
The ring includes a first plate portion which is arranged between each pawl of the pole core and makes the outer circumference of the rotor into a cylindrical shape with no unevenness, and a first plate portion which is placed along the back side of each pawl of the pole core and which makes the outer circumference of the rotor have a cylindrical shape with no unevenness. the first
and a second plate portion connecting the plate portions of the pole core, and a space is formed between the inner circumferential surface of the ring and the excitation coil to allow ventilation in the axial direction between the claws of the pole core. This is a characteristic feature.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a vehicle alternator to which the present invention is applied. In this figure, a pair of frames 9 and 9' forming the outer shell of the generator are both substantially bowl-shaped, and their openings are The sides are directly joined and fixed to each other by a plurality of pairs of stud bolts 10 and nuts 8 (only one pair is shown). A stator 2, which is a stator, is press-fitted into the inner periphery of the frame 9 using the stud bolts 10. The stator 2 includes a stator core 2-a and a stator coil 2-b wound around the stator core 2-a. The stator core 2-a includes a plurality of conventionally known teeth (magnetic pole teeth) as shown in FIG.
on the inner periphery in the radial direction. Both frames 9,
At the center of the side surface of 9' are cylindrical bearing boxes 19, 19' that protrude toward the inside of the generator.
bearings 11 and 11' are formed, respectively.
is attached, and the shaft 4 is rotatably supported by both bearings 11, 11'. A pair of Lundell-type claw-shaped pole cores 1 and 1' forming a rotor are mechanically fixed to the shaft 4 so as to be located inside the stator 2.
The claws 1-p, 1-p' of the pole cores 1, 1' are designed to prevent magnetic flux leakage between the claws and to effectively supply magnetic flux to the stator 2, as shown in FIG. For each outer diameter width m and n,
It is formed so that the inner diameter widths m' and n' are small.
Stators 2 are provided on both sides of the pole cores 1 and 1'.
a centrifugal cooling fan 7 with a diameter smaller than the inner diameter of the
7' is concentric with the shaft 4, blades 7-a, 7-
It is tightly fixed to the pole cores 1, 1' by appropriate means with a' facing in the opposite direction to the pole cores 1, 1'. Furthermore, the fan 7 cools the rotor coil 5, which is an excitation coil.
In order to force cooling air into the pole cores 1, 1', the blades 7-a are tilted forward in the direction of rotation to form a mixed flow type.

On both sides of the pair of end frames 9, 9', there are shrouds 9-a, 9 that face the blades 7-a, 7-a' of the fans 7, 7' with appropriate gaps. -a' are formed, and the shrouds 9-a, 9-a' serve as guide plates for the fans 7, 7'. In addition, both end frames 9,
Suction windows 9-b and 9-b' are formed near the bearings 11 and 11' on both sides of the stator coil so that cooling air is sucked into the frame by fans 7 and 7'. Discharge windows 9-c and 9-c' are formed on the outer periphery of 2-b to discharge hot air after cooling (discharge window 9-c' is not shown).

Pulley 1 placed outside the end frame 9
2 is coupled to the shaft 4 by pressing the nut 13 against the bearing 11. Therefore, the pulley 12 transmits the rotation of the engine (not shown) to the shaft 4, causing it to rotate.

A diode fin 14 provided with a diode (not shown) is provided on the outer side of the outer frame formed by the end frames 9, 9' opposite to the side of the pulley 12;
Brush 15 that supplies exciting current to rotor coil 5
A brush holder 15 that holds -a inside, and an IC regulator (not shown) that adjusts the output voltage.
Each electrical functional component is fixed to the frame 9' together with the rear cover 16. The rear cover 16 is
the diode fin 14, the brush holder 15,
It is formed to surround the regulator, and regulator cooling holes and diode cooling holes are appropriately opened on the side surface.

In the vehicle alternator having the above configuration, a non-magnetic material is used in the space between the pawls 1-p and 1-p' of the pole cores 1, 1' and between the pawl backs 1-b and the rotor coil 5. A resin ring 3 is attached as shown in FIGS. 4 and 5. This resin ring 3
has a shape as shown in FIGS. 3 and 6, and includes a first plate portion, that is, an outer peripheral curved surface plate 3-c, and a second plate portion, that is, a nail back plate 3-b and a nail side plate 3-. It is integrally molded with a. The outer circumference curved plate 3-c is
The outer circumferential space between adjacent claws 1-p and 1-p' of a pole core 1 is filled to make the outer circumference of the pole core a uniform cylindrical shape without unevenness. In addition, the nail back plate 3-b and the nail side plate 3-a are attached to the nail 1-
It has a shape that wraps around the back of the nail 1-b and both sides 1-a of the nail, respectively, and connects the outer peripheral curved plate 3-c. Furthermore, a pleated rib 3-d extends from the claw back plate 3-b toward the center of the rotor coil 5. This rib 3-d
The ribs are spaced apart from adjacent ribs by 30° as shown in FIG. A pair of pole cores 1, 1'
side surfaces 1-c, 1-c' of the nail base (not shown)
and the end surfaces 3-f and 3-f' of the nail back plate,
The resin ring 3 is fixed in the axial direction, and the rib 3-d is mechanically fixed in a compressed state with an interference between the outermost diameter of the rotor coil 5 and the back surface 1-b of the pole core. The axial width of the resin ring 3 is determined by the unevenness of the outer periphery of the pole core claws 1-p, 1-p' at least in the portion facing the teeth 2-a of the stator 2 when installed between the pole cores 1, 1'. It is sufficient as long as it disappears. The outer circumferential curved plate 3-c and the rotor coil 5 are shaped so as to have a space 3-e between them.
A part of the centrifugal air generated by the centrifugal fans 7-a and 7-a' can flow through this space 3-e.

Next, the operation of the above vehicle alternator will be explained. A current is supplied to the rotor coil 5 via the brush 15-a and the slip ring, and the rotor coil 5 is rotated via the pulley 12, so that an alternating current voltage is induced in the stator coil 2-b.
Since the power generation system in which the power is rectified by a rectifier and the output voltage is controlled by a regulator is well known, the details will be omitted and the operation unique to the present invention will be explained.

When the shaft 5 rotates, the pole cores 1, 1'
The cooling fans 7-a, 7-a' on both sides of the fan rotate,
External cold air is sucked in through the suction windows 9-b, 9-b', cools the bearings 11, 11', cools the stator coil 2-b, and is discharged as hot air to the outside through the discharge window 9-c. Also, a part of the cold air is pushed toward the pole cores 1 and 1', receives heat from the rotor coil 5, and then continues to the stator coil 2-
b is cooled and discharged as hot air from the discharge window 9-c.

When the above-mentioned cold air passes through the pole cores 1 and 1', centrifugal wind is generated due to the fan action of the side surface 1-a of the pole core claw 1-p, as speeds have increased in recent years. However, pulsating pressure fluctuations occurred between the stator 2 and the pole cores 1, 1', and interference noise was generated due to the unevenness formed by the stator teeth 2-a' and the slots. Since the resin ring 3 is installed in the space between the adjacent pole core claw side surfaces 1-a, the outer periphery of the pole core claws 1-p, 1-p' has a cylindrical shape with no unevenness, so the pole core No centrifugal wind is generated due to the fan effect of the side surface 1-a, and no interference noise is generated between this centrifugal wind and the unevenness of the stator tooth 2-a'.

In addition, the nail back plate 3-b of the resin ring 3 is
Since the pole core pawl backs 1-2 are covered, the outer periphery of the rotor coil 5 and the inner periphery of the pawl of the pole core 1 can be insulated, and the space factor of the rotor coil 5 can be increased. Since it is sandwiched between the two pole cores 1 and 1' and between the pole core pawl back 1-b and the rotor coil 5 with an interference,
In addition to ensuring reliable positioning, the outer circumference curved plate 3-b is integrally molded so that the claw back plate 3-b is in contact with the pole core claw back 1-b.
c is prevented from scattering due to centrifugal force.

Furthermore, when the rotor coil 5 rotates, the resin ring 3 has a space 3e inside the outer peripheral curved plate 3-c against the wind passing between the pole core claws 1-p and 1-p' by the cooling fan 7. Therefore, it is possible to ventilate the rotor coil 5 in the axial direction as in the conventional case, and the rotor coil 5 can be cooled. Moreover, nail 1-p, 1-
Due to the centrifugal fan action of p', the wind that has flowed into the rotor coil 5 is scattered toward the stator 2 side, and the pole core claws 1-p, 1- p', and the rotor coil 5 can be effectively cooled.

In the above embodiment, the ring 3 is molded from resin, but it is also formed from a non-magnetic metal such as aluminum die-casting, aluminum, or stainless steel into a similar shape by press molding or cold forging, and is electrically insulating. A similar effect can be obtained by painting with paint.

In addition, the pole core claw 1-p provided on the ring 3,
The rib 3-d for pressing 1-p' does not have to have the two-part shape shown, but may have an integral shape or a multi-part shape. Ring 3 itself
In the above embodiments, it is integrally molded, but it may be installed in separate pieces.

Furthermore, the front fan 7 for cooling the rotor coil 5 may be a centrifugal type fan with mixed flow.

As described above, the rotor of the vehicle alternator according to the present invention is made of non-magnetic material such that at least the outer peripheral part of the rotor facing the teeth of the stator has a smooth cylindrical shape between the claws of the pole core. Since a ring consisting of a body is installed, the interference noise between the pole core and the teeth of the stator, which conventionally occurs, is eliminated, and noise in the high-speed rotation range can be reduced. In addition, by using the above ring,
Air from the cooling fan flows between the pole cores, which has the excellent effect of removing heat inside the rotor generated by the rotor coil.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the whole of a vehicle alternator as an embodiment of the present invention, FIG. 2 is a plan view of the claws of the pole cores of the stator and rotor, viewed in the P direction in FIG. 3 is a perspective view of the ring body installed between the pole cores of the rotor, FIG. 4 is a perspective view of the rotor with the ring installed, and FIG. 5 is a sectional view taken along the line - in FIG. 4, 6 is a partial side view of the ring body, FIG. 7 is a sectional view taken along the line - in FIG. 6, and FIG. 8 is a sectional view taken along the line - in FIG. 7. 1, 1'...Pole core, 1-p, 1-p'...Claw,
2... Stator (stator), 2-a... Teeth, 3
...Ring, 5...Exciting coil.

Claims (1)

[Claims] 1 A pair of Lundell type pole cores having a plurality of claws are arranged so as to mesh with each other alternately, a rotor having an excitation coil wound inside the pole core, and a rotor arranged radially opposite to the rotor. A rotor for an alternator for a vehicle comprising a stator having teeth with teeth, and a rotor of a non-magnetic material attached to the pole core, the ring being disposed between each pawl of the pole core, a first plate portion having a cylindrical outer circumferential portion with no unevenness;
a second plate portion arranged along the back side of each pawl of the pole core to connect the first plate portion arranged between the pawls, and a second plate portion connecting the inner peripheral surface of the ring and the excitation coil A rotor for an alternator for a vehicle, characterized in that a space is formed between the pawls of the pole core to allow ventilation in the axial direction.