JPH0713411Y2 - Water-cooled alternator for internal combustion engines - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an alternator for an internal combustion engine, which is widely used as a generator for an automobile, and particularly, forcibly generates heat on the stator side by using cooling water. The present invention relates to improvement of a water-cooled alternator having a cooling structure.

[Technical Background of the Invention and its Problems] The power generation efficiency of the alternator decreases when the rotor or stator becomes hot due to heat generated by the exciting current or the generated current. Therefore, some forced cooling structure is provided.

In a general alternator, a fan is provided on its rotation shaft, and this fan blows air inside to cool the fan.
This cooling by air works well for heat generation of the rotor, but is not so effective for heat generation of the stator.

Therefore, in some alternators designed to further enhance the cooling effect, a cooling water passage is formed around the outer periphery of the stator core, and cooling water is circulated in this passage to forcibly cool the stator core.

However, in a conventional water-cooled alternator, a donut-shaped water jacket that constitutes the cooling water passage by itself is fitted around the outer periphery of the stator core, and the outer surface of the water jacket and the outer peripheral surface of the stator core are in contact with each other. (For example, Jitsukai Sho 60-11653). The area of the outer peripheral surface of the stator core is not very large, and this surface is not in direct contact with the cooling water, but only in contact with the outer surface of the water jacket that contains the cooling water, so the cooling efficiency is very high. However, the cooling effect that was expected was not obtained despite the troublesome addition of a water cooling structure.

[Object of the Invention] The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a water-cooled alternator for an internal combustion engine, which is capable of effectively cooling the stator side with cooling water. It is in.

[Summary of the Invention] In order to achieve the above object, the present invention has a cylindrical stator core, a fin for heat dissipation, and a cooling water passage for forcibly cooling the stator core. A strip-shaped member having a predetermined width and having wide portions larger than the predetermined width at predetermined intervals,
The thickness is laminated in the height direction of the cylinder, which is spirally wound so that the width becomes the wall thickness of the cylinder, and the fin is a portion of the predetermined width of the strip-shaped member and the wide portion. A step is formed on the outer periphery of the stator core and directly faces the cooling water passage.

[Embodiment of the Invention] FIG. 1 shows the structure of a water-cooled alternator according to an embodiment of the present invention. The outer case of this alternator has a front cover 10, a rear cover 12, and a water jacket 14.
It is composed by. The rotating shaft 16 is supported in the case by a front bearing 18 and a rear bearing 20.

A rotor 22 around which a field coil is wound and a fan 24 for air cooling are attached to the rotary shaft 16. A pulley 26 for transmitting the rotational force of the internal combustion engine to the rotary shaft 16 is attached to the case protruding end of the rotary shaft 16. A slip ring 40 and the like are also attached to the rotary shaft 16.

The front cover is located so as to surround the rotor 22.
A stator 32 is attached between the 10 and the rear cover 12. The stator 32 is formed by winding a stator coil 30 around the inner peripheral side of a cylindrical stator core 28. Stator coil
30 is connected to the IC regulator 42 mounted in the case.

The jacket 14 is an annular component that surrounds the outer periphery of the stator core 28. The water jacket 14 does not form a cooling water passage by itself, and the space between the water jacket 14 and the stator core 28 serves as the cooling water passage 34. Two water pipes 36 and 38 are connected to the water jacket 14, and the cooling water of the internal combustion engine is also circulated and supplied to the passage 34 through these pipes.

As described above, the first characteristic feature of this embodiment is that the outer periphery of the stator core 28 forms a part of the cooling water passage 34, and the outer surface of the stator core 28 faces the passage 34. Is. That is, the stator core 28
The outer peripheral surface of is in direct contact.

The second characteristic point is that a large number of fins 28a are integrally formed on the outer peripheral surface of the stator core 28, and the formation portion of the fins 28a faces the cooling water passage 34. Due to the fins 28a, the surface area of the outer peripheral surface of the stator core 28 becomes extremely large, and the cooling water comes into contact there.

As will be described later with reference to FIG. 2, the third characteristic point is that since the stator core 28 is made of a continuous member, heat conduction in the axial direction (cylindrical height direction) of the stator core can be secured to some extent. Even if the stator core 28 is locally heated or cooled, the temperature gradient in the axial direction within the stator core 28 does not increase, and the temperature of the stator core 28 can be reduced as a whole.

Due to the above-mentioned three characteristic points, the stator 32, which generates heat during the operation of the alternator, is extremely effectively cooled by the cooling water supplied to the passage 34, and the decrease in heat generation efficiency due to heating is prevented.

The fin 28a shown in FIG. 1 has an intermittent spiral shape on the outer peripheral surface of the stator core 28. Fin of this structure
FIG. 2 shows the detailed structure of the stator core 28 with 28a and the manufacturing method thereof.

As shown in FIG. 2A, a strip-shaped magnetic material 50 as shown in FIG. 2B is laminated such that the thickness of the material 50 is laminated in the height direction of the cylinder and the width of the material 50 is The stator core described above is formed by densely winding spirally so as to have a cylindrical wall thickness. Here, the material forming the inner peripheral side of the stator core
The edge portion of 50 is called an inner edge portion, and the edge on the side forming the outer peripheral surface of the stator core is called an outer peripheral edge portion.

Comb-shaped unevenness is formed on the inner edge of the material 50. By winding the material 50 in a spiral shape so that the unevenness is aligned,
The irregularities form the slots 50b around which the stator coil is wound.

The outer edge of the material 50 is not aligned and the spacing H1
A wide portion 50a having a wide width is provided every other length H2. The width of the wide portion 50a is D2, the width of the portion of length H1 is D1, and a step of Δd is generated at the boundary portion between the two. That is, the wide portion 50a projects outward by Δd from the other portions.

When this material 50 is spirally wound as described above, the peripheral surface of the wound cylindrical core does not become a uniform cylindrical surface, but a wide portion.
Unevenness occurs due to 50a. The wide portion 50a becomes a convex portion. This convex portion is the fin 28a shown in FIG.

The length H2 of the wide portion 50a is set to the length of one round of the outer circumference of the stator core 28. The interval H1 between the wide portions 50a is an integral multiple of H2. If the thickness of the material 50 is small, increase H1 and
If thick, H1 may be equal to H2.

Then, one spiral fin formed by one wide portion 50a is formed so as to go around the stator coil.
The space between the fins is determined by the thickness of the material 50 and H1.

According to the above structure and manufacturing method, since the stator core 28 with the fins 28a as shown in FIG. 1 is formed by the belt-shaped member, the material yield is good, and accordingly, the stator core 28 can be mass-produced at low cost. You can

[Effects of the Invention] As described in detail above, in the water-cooled alternator for an internal combustion engine according to the present invention, a fin for heat radiation is integrally formed on the outer peripheral surface of the stator core, and the fin-formed portion is cooled. Since it faces the inside of the water passage, the heat dissipation area is expanded and the cooling water comes into direct contact therewith. Moreover, the stator core is made of a series of members, so the cooling effect is much more than the conventional one. It becomes higher, and it is possible to reliably prevent a decrease in power generation efficiency due to heating.

[Brief description of drawings]

FIG. 1 is a sectional view of an alternator according to an embodiment of the present invention, and FIG. 2 is a view showing a concrete structural example of a stator core with fins in the same embodiment and a manufacturing method thereof. 10 ... Front cover, 12 ... Rear cover 14 ... Water jacket, 16 ... Rotating shaft 22 ... Rotor, 28 ... Stator core 28a ... Fins, 30 ... Stator coil 32 ... Stator, 34 ... Cooling water passage 36, 38 ... Water piping 50 ... Strip Magnetic material 50a ... Wide part that becomes fin

Claims (1)

[Scope of utility model registration request] 1. A stator core having a cylindrical shape, fins for heat radiation, and a cooling water passage for forcibly cooling the stator core, wherein the stator core has a predetermined width and is spaced at predetermined intervals. A strip-shaped member having a wide portion larger than a predetermined width,
The thickness is laminated in the height direction of the cylinder, which is spirally wound so that the width becomes the wall thickness of the cylinder, and the fin is a portion of the predetermined width of the strip-shaped member and the wide portion. A water-cooled alternator for an internal combustion engine, which is formed on the outer periphery of the stator core by a step and directly faces the cooling water passage.