JPS59159638A - Ac generator for vehicle - Google Patents

Abstract

PURPOSE:To reduce the entire temperature of a stator coil by forming coil strands in an approximately flat shape by axially displacing the strands at the coil end, and forming a gap between units. CONSTITUTION:A stator core 7 is secured to a housing 2 on the outer periphery of a field rotor 4 having a pawl-shaped pole, a stator coil 1 is wound on the core 7, and cooling fans 3a, 3b are formed on both end faces of the rotor 4. When phase coil units are respectively contained in slots, strands are displaced axially of the rotor and wound in a flat shape, resin plates 8 are disposed between the phase units before forming the inner and outer diameters and the end heights of the wound coil, the plates are removed after the coil is shaped, thereby forming gaps 9 between the units. In this manner, a ventilating resistance is reduced to increase the air flow rate, thereby reducing the entire temperature of a stator coil.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an alternator for a vehicle, and more particularly to an improved structure of a stator coil.

In the conventional stator coil winding method for vehicle AC generators, the height of the coil end is the first phase and the second phase.

Normally, the third phase coils are wound indiscriminately at almost the same height, and the outermost third phase coil in the slot is the innermost first phase coil. It is in a state where it is hidden. However, in the conventional structure of an internal fan type vehicle alternator that has a fan on the end face of the rotor for cooling, the cooling passage is sucked in from the front and rear sides in the axial direction and discharged in the radial direction. The stator coil on the inner diameter side, which is closer to the fan, is directly hit by the cooling air and is cooled down considerably. On the other hand, the stator coil on the outer diameter side is hidden by the coil on the inner diameter side, so the cooling air does not hit it at all, and the temperature is very low. Because of this, it is necessary to decide on a wire type and wire diameter that can withstand the temperature on the outer diameter side, which has the disadvantage of increasing costs.

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, an object of the present invention is to provide an alternator for a vehicle in which a stator coil is configured so that the flow of cooling air from a fan to the stator coil efficiently cools the coil. It is something to do.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention shown in the drawings will be described.

FIG. 1 is a vertical cross-sectional view of a main part of an alternator embodying the present invention. A stator core 7 is fixed to a housing 2 around the outer periphery of a field rotor 4 having claw-shaped magnetic poles. is wound around the rotor 4, and cooling fans 3a and 3b are provided on both end surfaces of the rotor 4. The detailed configuration of the stator coil 1 is as follows. Firstly, it is a three-phase all-node concentrated winding system, with each phase's coil uni-node 1a, 1. b, lc are housed in the slots of the stator core in order as shown in FIG. 2, and the outermost layer coil unit,
It forms a middle layer coil unit and an inner layer coil unit. Second, when each phase coil unit is stored in the slot, each strand is shifted in the axial direction of the rotor as shown in FIG. 4, and wound in an aligned flat shape as shown in FIG. ing. Thirdly, the coil wound in a flat shape,
Before forming the inner and outer diameters and end height, Fig. 5 (a), (
As shown in b), a resin plate 8 is placed between each phase coil unit, and this plate is removed after coil molding, thereby forming a gap rJ19 between each phase coil unit.

Next, the operation of the vehicular alternator having the stator coil configured as described above will be explained.

When the field rotor 4 rotates, three-phase power is generated in the stator coil 1, and DC output is supplied to the outside through a three-phase full-wave rectifier (not shown), and a load current flows through the stator coil 1, causing copper loss. However, the cooling air 6 taken in from outside the alternator by the fans 3a + 3b provided on both end faces of the rotor 4 is twisted and agitated by the rotation of the rotor 4, as shown in FIG. It is pushed out while being twisted in the same direction as the rotational direction 6' of the rotor, hits the end of the stator coil 1, cools the coil, and is then discharged to the outside through discharge ports 3a and 3b provided in the housing 2. At this time, the stator coil 1 is arranged so that the projected area of the coil end portion viewed from the inner diameter side of the fan (rotor side) is as large as possible as shown in FIG. The coil units are arranged and staggered in a flat shape as shown in FIG. 6 flows to the outside through the gap 9 along the side surface of the flat coil end. For this reason, the cooling air hits most of the surface area of the stator coil strands, and the temperature of the coil ends drops significantly.

The results of experimentally confirming the cooling effect of the stator coil of the vehicle alternator according to the present invention are shown in FIG. 7 as a temperature rise characteristic diagram of the stator coil, where A is for the conventional case and B is for the stator coil. In the case where the coils are formed into aligned flat windings, C shows the case of the present invention in which the stator coils are formed into aligned flat windings and gaps are provided between the coil units. As shown in the figure, the present invention has a temperature reduction effect of about 40°C at the maximum temperature.

Note that in order to form the gap 9 between the coil units, the method shown in FIG. 6 (
al, (as shown in bl, each coil unit may be covered with a resin cap 10, then molded, and then removed. In addition, in the above embodiment, after storing the coil unit in the stator slot, the gap 9 is closed. Although it is forming,
Each coil unit may be molded in advance so that there is a gap between the coil units, and then stored in the slot.

As described above, in the vehicular alternator according to the present invention, in an internal fan type vehicular alternator in which a cooling fan is provided on the end face of the field rotor, a coil end portion is provided for each phase unit of the stator coil. Since each coil wire is axially shifted from each other and formed into a generally flat shape, and a gap is formed between each unit, each phase coil can be uniformly cooled to the same level, and each phase coil can be cooled uniformly to the same level. The gap between the units reduces ventilation resistance and increases the air volume, which has a great effect of reducing the overall temperature of the stator coil.

[BRIEF DESCRIPTION OF THE DRAWINGS] The attached drawings show an embodiment of the vehicular alternator according to the present invention, and FIG. 1 is a vertical cross-sectional view of a main part of the vehicular alternator embodying the present invention, and FIG. 1 is a schematic diagram of the stator coil end viewed from the axial direction of the stator core, FIG. 3 is a schematic diagram of the stator coil end viewed from the outer periphery to the inner periphery of the stator core in FIG. 1, and FIG. I-
A vertical cross-sectional view along line 1, Figure 5+8) is a schematic diagram of a resin plate, and Figure 5 fbl shows a method of forming gaps between each phase coil unit using the plate shown in Figure 5 fa1. Pattern diagram,
Figure 6(a) is a schematic diagram of the resin cap, Figure 6(b)
Figure 6 (a1) is a schematic diagram showing a method of forming gaps between each phase coil unit using the camp shown in Figure 7. Figure 7 is a temperature rise characteristic diagram of the stator coil, which shows the difference between the conventional stator coil winding method. It is a diagram showing a comparison between the case of the winding method, the case of aligned flat winding, and the winding method of the present invention. 1... Stator coil, 2... Housing, 3a. 3b... Cooling fan, 4 ...field rotor, la, l
b. 1c...Coil unit of each phase, 9...Gap formed between coil units of each phase, 6...Arrow indicating the direction of cooling air, 6''...Arrow indicating the rotation direction of the field rotor Representative Patent Attorney Takashi Okabe Figure 1 Figure 5 (a)

Claims (1)

[Claims] In an internal fan type vehicle alternator in which a cooling fan is installed on the end face of the field rotor, the coil wires are shifted from each other in the axial direction at the coil end of the unit for each phase of the stator coil, resulting in a roughly flat shape. An alternator for a vehicle, wherein the alternating current generator is formed such that a gap is formed between each of the units.