JPS6020748A - Ac generator for vehicle - Google Patents

Abstract

PURPOSE:To improve the cooling efficiency of a rectifier by flowing air between the fins of the rectifier. CONSTITUTION:When a fan is rotated, air is sucked from a suction window 2'b of a frame. This air is fed from a suction window 61a of a rear cover into the interior of a cover to contact with inner peripheral side fins 37, flowed to the outer periphery between the fins 37 and the cover 6 to further contact with part 36' of the outer peripheral side fins, flowed to the inner peripheral side between the fins 36 and 37, and guided to the frame suction window 2'b. Thus, since the fins 37 can heat sink from both front and back surfaces, the surface area can be reduced, the air is contacted with the fins 36 and the part lapped with the fins 37, thereby effective cooling can be performed.

Description

[Detailed description of the invention] The present invention particularly relates to a rectifying device for an alternator for a vehicle.

The most important point in achieving compact size, light weight, and high output is improving cooling performance, but in particular, heat generation due to diode loss during rectification increases in proportion to the output direction, and semiconductors are sensitive to heat. Improving the cooling efficiency of the rectifier is essential for achieving compactness and high output.

The purpose of the present invention is to greatly improve the cooling performance of the rectifier, and to achieve this by particularly improving the way the air flows.

First, an overview of one embodiment will be explained. A ball core 10' having a centrifugal fan 11' on the side surface of the ball core and a stator 8 are arranged inside the frame. The rotor is rotatably supported by a pair of bearings 15.degree. 15', and has a slip ring 18 on the side opposite to the fan of the bearings 15'.

A cylindrical slip ring cover 2'd is formed as a part of the frame at the center of the frame 2' to surround the slip ring. A flow device is arranged outside the frame 2'. The rectifier has a roughly horseshoe shape with positive and negative 1
It has a pair of plate-like two-layer structure, and the fan-side fins are shifted toward the inner and outer peripheries so that they are on the outer periphery, and each fin is arranged with appropriate gaps for airflow. The outer fins 36 are provided on the inner periphery of the rear cover 61 that surrounds the entire flow straightening device, and the inner fins 37 are provided on the outer periphery of the slip ring cover 2'd with a slight gap G1. G2.

When the fan rotates, air is sucked into the frame through the intake window 2'b of the frame. This wind blows through the intake window 6 of the rear cover.
It enters the inside of the cover from 1a and hits the inner fin 37,
It flows toward the outer periphery between the fins 37 and the cover 61, then hits a portion 36' of the outer fin, flows toward the inner periphery between the fins 36 and 37, and is guided to the frame suction window 2'b.

As a result, the inner fins 37 can radiate heat from both the front and back sides, so the surface area can be drastically reduced, and the outer fins 36 and the portions where they overlap with the inner fins 37 are also exposed to air, making them more effective. can be cooled to

One embodiment will be described in more detail below. The vehicle alternator 1 (FIG. 1) has an outer shell, a fixed part that rotates once, and a bearing part. The outer shell generally consists of a pair of bowl-shaped frames 2.2', said frames 2,2'
' is a plurality of stud bolts 3 at the circumference of the opening.
and are connected to each other by a nut 4.

The left frame 2 has a cylindrical part, a frusto-conical part and a flange part extending from said cylindrical part. On the frames 2 and 2', there are mounting holes 2a for attaching the generator 1 to the support structure of the vehicle.

2'a is formed.

The truncated conical part of the frame 2 has a cylindrical bearing box 5 in the center, and in the middle there is a shroud 2b for guiding ventilation, which will be described below, and an air supply provided radially inward of the shroud 2b. The shroud 2b has a suction window 2c, and a discharge window (not shown) that is provided radially outward of the shroud 2b and discharges cooled air.

The right frame 2' consists of a cylindrical part and a frusto-conical part. At the center of the truncated conical portion of the frame 2', a cylindrical bearing box 6 pressed from a steel plate is fixed to the frame 2' together with a rectifier assembly (to be described later) by bolts 7. There is. Further, the frame 2' has an air intake window 2' provided radially inward of the shroud for guiding ventilation.
b, and an air discharge window 2'C are formed.

The fixed part of the generator l consists of a stator 8, and the stator 8 has a stator core 8a fixed to the inner periphery of the cylindrical part of the frame 2 by press fitting or the like, and a stator coil 8b wound around the stator core 8a. .

The rotating part of the generator 1 includes a shaft 9 and a pair of claw-shaped ball cores 10 fixed to the shirt 1-9 and rotating together.
10', a pair of centrifugal cooling fans 11.11' fixed to respective sides of the ball core 10.10', and a pulley 22 fixed to one end of the shaft 9.

A conventional rotor coil 12 is arranged in a recess formed between a pair of ball cores 10, 10'.

The cooling fan 11.11' has an outer diameter smaller than the inner diameter of the stator 8, and has respective blades 11a, ll'a.
The ball cores 10 and 10' are arranged concentrically around the shaft 9, facing in the opposite direction to the ball core 10, 10', and are fixed to the side surface of the ball core.

The blades 11a, ll'a of the cooling fan 11.11' face the respective shrouds 2b, 2b' of the frames 2, 2' with a suitable gap therebetween.

Pulley 22 is nut 13. It is fixed to the shaft 9 by a washer 14, and rotational power is transmitted from an engine (not shown). A pair of bearings j5.15' constituting the bearing portion of the generator 1 are each attached to a bearing box 5.6, and support the shaft 9 in a rotatable manner. On both sides of one bearing 15 are collars 16 and 17.
is fitted coaxially to the shaft 9, and positions the bearing 15 with a gap from the ball core 10 and the pulley 22.

In this way, the gap between the bearings 15, 15' is made relatively small, making it possible to increase the critical speed of the shaft 9 above the normal rotational speed. The slip ring 18 is attached to one end of the shaft 9 on the outside of the right frame 2' and the bearing 15', and is fixed to the shaft 9 while being electrically insulated from the shaft 9.

Figures 2-4 show the rectifier assembly. The horseshoe-shaped cooling fins 36 and 37 have a two-layer structure with a plurality of insulating spacers 40 interposed therebetween so that air flow between the cooling fins is smooth. One of the cooling fins 36 has an appropriately rising bent portion 36' on its outer edge, and the other cooling fin 37 has an appropriately rising bent portion 37' on its inner edge.

A plurality of diodes 42, 43, for example four each, are connected to the cooling fins 36, 43 near the bends 36', 37'.
37 in a known manner, and as viewed from the front and back as shown in FIGS. 2 and 3, eight diodes 42. 4g are mechanically arranged without overlapping.

A terminal block 35 made of insulating resin is attached to a cooling fin 36, and a plurality of terminals 41, for example, 41 m long, are fixed to the terminal block 35 by insert molding and connected to diodes 42, 43.

In more detail, we will add a description of the structure that forms the main part of this case.

At the center of the truncated conical portion of the frame 2' mentioned above, a slip ring 18 is covered (a cylindrical slip ring cover 2'd is formed integrally with the frame 2', and a roughly bowl-shaped rear cover described later is provided). 61 and the slip ring cover 2'd is sealed by a gasket 60 made of a sealing member such as rubber.This protects the slip ring 18 from water, dust, etc. .

FIG. 1 shows the assembly of the rectifier parts. cooling fin 36
．． The bent portions 36' and 37' of 37 are bent toward the rear cover 61, respectively. Further, the cooling fins 36 and 37 are fixed together with the carrier cover 61 by bolts and nuts 62. Bent portion 36 of fin 36
There is a minimum gap G which can maintain an electrically insulated state between the slip ring cover 2'd and the slip ring cover 2'd. Further, there is also a minimum gear G2 between the bent portion 37' of the fin 37 and the rear cover 61 to maintain electrical insulation. A suction window 61a for sucking in cooling air is appropriately opened in the rear cover 61.

In the generator 1 shown in FIG. 1, current is supplied to the rotor coil 12 through the brushes and slip ring 18, and the generator 1 shown in FIG.
An alternating voltage of a magnitude controlled by the regulator F is induced in the stator coil 8b, and its output current is rectified by the rectifier.

Here, a detailed explanation of the above-mentioned operation similar to that of the conventional device will be omitted, and the unique operation according to the present invention will be explained below.

When the fan 11'' attached to the ball core 10' rotates with the rotation of the shaft 9, cooling air SL+32 is sucked into the rectifier section through the plurality of suction windows 61a formed in the rear cover 61.

The cooling air S2 sucked in from near the center of the rear cover 61 hits the first stage fins 37, and the air near the bent portions 37' flows radially through the bent portions 37' to cool the fins 37. The wind S3 that has cooled the fins 37 flows into the space between the fins 36 and 37 through the bent portion 36' of the second stage fin 36, together with the wind Sl taken in through the intake window 61a opened on the outer periphery, and the reaction force of the fin 37 is It flows toward the center while cooling the side of the bar and the side of the fin 37 of the fin 36.

Next, this wind flows along the slip ring cover 2'd.
A suction window 2'd provided in the frame 2' (this figure is cut away at the rectifier installation part, so the window 2'd here is
Although not shown in the drawings, a window 2'b is arranged on the same circumferential diameter on the other side of the rectifier mounting part. ) as a flow S4, passes through the fan blade 11'a, cools the stator coil 8b, and flows into the discharge window 2' of the frame 2'.
The hot air S5 is discharged from C to the outside.

In this way, the present invention improves the cooling efficiency by a large 1+ by allowing air to flow through the rectifying device section in a manner similar to the figure 2.

Next, other embodiments will be described.

As shown in FIG. 5, the first stage fins 36 are arranged on the outer periphery side, and a bent part 36' is provided on the outer periphery.
A minimum gap G2 is formed between the 6' and the rear cover 61, and the second stage fin 37 is arranged on the inner circumferential side (shaft side), and a bent part 37' is provided on the inner circumferential side. The minimum gear G1 is formed between the bent portion 37 and the slip ring cover 2'd, and the fins 36, 37
The same effect can be obtained even if the structure is configured so that wind flows between them.

As described above, the present invention has the following effects.

(1) By flowing air between the fins of the rectifying device, heat can be radiated from both the front and back surfaces of the fins, so cooling efficiency can be greatly improved, and the fins themselves can be made smaller.

(2) Since each fin has a bent part, and the gap between each bent part and the slip ring cover and rear cover is minimized, most of the cooling air sucked into the cover is directed to the fins. In this way, leakage air that adversely affects cooling can be reduced to a minimum.

(3) By bending the fins, wind can be collected near the diodes attached to the central portion of each fin, and the heat source (diode) can be efficiently cooled.

(4) Since the fins are arranged in two layers on a plane perpendicular to the shaft, the surface area can be maximized in a limited space, and foreign objects such as flying stones can be directly prevented from rotating the fan. This prevents them from entering the inside of the frame.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing an embodiment of the generator of the present invention, Fig. 2 is a fin arrangement diagram seen from the direction of the arrow ■ in Fig. 1, and Fig. 3 is a diagram of the arrangement of fins seen from the direction of the arrow ■ in Fig. 1. FIG. 4 is a sectional view taken along IV-IV in FIG. 2, and FIG. 5 is a partial sectional view of a rectifier section showing another embodiment. 2'...Frame, 61...Rear cover, 36.3
7...Cooling fin, 42.43...Diode, 9
...shaft, 36', 37'...bending part, G
I. G2... extremely small gap. Representative Patent Attorney Takashi Okabe

Claims (1)

[Scope of Claims] A pair of cooling fins provided in the space between the frame and the palm bar and having a roughly horseshoe shape with different average radii, and a plurality of diodes of different polarity arranged in the same direction on one side of each of the cooling fans. and the pair of cooling fins are electrically insulated from each other, and a ventilation gap is provided between each cooling fin, and one cooling fin is arranged to be partially overlapped with the other cooling fin. In the system, each of the cooling fins is arranged on a plane perpendicular to a shaft serving as a generator input shaft, and the cooling fins are arranged on the inner circumferential side of the cooling fins, and the cooling fins are arranged on the inner circumferential side of the cooling fins that are located on the outer circumferential side. Each of the fins is provided with a bent portion in a direction opposite to the wind flow on the outer peripheral side thereof, and each of the bent portions is arranged with an extremely small gap between the frame and the rear cover,
An alternator for a vehicle, characterized in that cooling air flows between the cooling fins.