JP3305002B2 - Brushless rotary electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless rotary electric machine having an improved structure of a permanent magnet generator overhanged on a rotary shaft of a main synchronous machine.

[0002]

2. Description of the Related Art FIG.
This will be described with reference to FIG. The main synchronous machine rotating shaft (1) protrudes from the main synchronous machine bearing stand (2), and overhangs the armature (3) of the rotary armature type AC exciter. The armature (3) is an armature core (5) equipped with an armature winding (4).
Is shrink-fitted to a sleeve (6), and the sleeve (6) is fitted to the main synchronous machine rotating shaft (1). A rotary rectifier (8) is incorporated in the inner periphery of the collar of the outer iron holding plate (7).

The exciter field winding (9) is incorporated in a field iron core (11) mounted inside a magnet frame (10). The magnet frame (10) is mounted on an exciter stand (12) overhanged on the bearing stand (2). Both ends of the magnet frame (10) have an armature (3) of the exciter and a rectifier (8). ) And an exciter cover (13) covering the rotor (20) of the permanent magnet generator.

[0004] As shown by an arrow in FIG. 4, the cooling gas is taken out from a cooler (not shown) in the stator frame of the main synchronous machine, and is taken in through an exciter stand (12). The rotary rectifier and a permanent magnet generator described later are cooled and returned to the main synchronous machine stator frame (15) via the exhaust duct (14).

[0005] A rotor (20) of a permanent magnet generator is assembled at the shaft end of the exciter through a connecting shaft (21). The permanent magnet generator has a permanent magnet (22) mounted inside a rotor (20), and a stator (23) inserted inside the rotor (20) to form an outer rotor.

[0006]

In the conventional structure as described above, the axial dimension becomes longer, the weight of the connecting shaft and the rotor of the permanent magnet generator is applied to the tip of the overhang, and the deflection of the shaft becomes large. Therefore, the rotation frequency and the natural frequency of bending of the overhang portion became close to each other, and there was a concern that a vibration problem might occur.

[0007] An object of the present invention is to reduce the axial length of the overhang portion by incorporating a permanent magnet generator into an exciter core mounting cylinder, thereby eliminating the possibility of vibration, and
An object of the present invention is to provide a brushless rotating electric machine that is lightweight and compact.

[0008]

In order to achieve the above object, the present invention provides a rotating armature type AC excitation which is overhanged and directly connected to a rotating shaft of a main synchronous machine outside a bearing stand of the main synchronous machine. In a brushless rotating electric machine having a machine armature, a rotary rectifier, and a permanent magnet generator, the rotor of the permanent magnet generator is mounted as an outer rotor on the inner periphery of the mounting cylinder of the armature core of the AC exciter. .

[0009]

In the structure constructed as described above, the rotor of the permanent magnet generator is integrated with the armature core of the AC exciter, so that the number of components is small, the manufacturability and economy are excellent, and
The size of the overhang portion in the axial direction is shortened, the natural frequency is high, and there is no danger of vibration. Therefore, it is possible to provide a highly reliable and compact brushless rotary electric machine.

In the case where a nonmagnetic comb-shaped ring whose inner peripheral surface is slightly smaller in diameter than the inner peripheral surface of the permanent magnet is interposed between the permanent magnets and the root portion of the comb is disposed on the shaft end side, the stator core is replaced with This prevents the iron core from directly hitting the permanent magnet during insertion, improving the ease of assembly. Furthermore, if the position of the bolt for attaching the magnetic ring is located at the central back of the strip-shaped permanent magnet in the same direction width, the efficiency of the permanent magnet generator is improved without being affected by an increase in magnetic resistance.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, the armature (3) of the AC exciter is directly connected to the main synchronous machine rotating shaft (1) at a position exiting from the main synchronous machine bearing stand (2). The armature (3) has an armature core (5) on the exciter core mounting body (40).
Is shrink-fitted, and the armature winding (4) is placed in the iron core (5).
It is received by the iron core holding plate (7) and fixed by the bind wire (42).

The field winding (9) is connected to the magnet frame (1).
0) is mounted on the field core (11).

The rotary rectifier (8) is mounted inside the iron core holding plate (7), and converts the AC output of the armature winding (4) into DC. The DC output from the rotary rectifier (8) is connected to a field winding (not shown) of the main synchronous machine via a connection conductor (43).
Connected to the center hole conductor (44) connected to.

The rotor (20) of the permanent magnet generator comprises a magnetic ring (45) and a strip-shaped permanent magnet (46), and the magnetic ring (45) is fitted inside the exciter core mounting cylinder (40). , Hexagonal bolts (47), and formed in an outer rotor shape.

The stator winding (48) of the permanent magnet generator is housed in a stator core (49) and inserted inside the rotor, and the stator core (49) is connected to a stator supporting pipe (5).
0), and the pipe (50) is attached to the gantry (5).
Fixed to 1).

The entire exciter, rotary rectifier, and permanent magnet generator are covered with an exciter cover (52), and are cooled by bypassing the cooling gas of the main synchronous machine.

The permanent magnet generator will be described in more detail with reference to FIGS. A plurality of (in this case, eight) strip-shaped permanent magnets (46) are attached to the inside of the magnetic ring (45) at predetermined intervals in the circumferential direction with a high-temperature, high-strength adhesive. A non-magnetic comb-shaped ring (53) made of aluminum is press-fitted between the parentheses. The inner diameter of the comb-shaped ring (53) is smaller by 0.2 to 1.0 mm in diameter than the inner peripheral surface of the strip-shaped permanent magnet (46). The magnetic ring (45) is provided with four bolt holes (54) on the center line (55) of the circumferential width of the strip-shaped permanent magnet (46).

Next, the operation of the above embodiment will be described. According to the present embodiment, since the permanent magnet generator is incorporated in the inner diameter of the armature of the AC exciter, the brushless rotating electric machine is downsized, the natural frequency is increased, and high reliability is achieved. Also, by making the inner diameter of the non-magnetic comb-shaped ring (53) slightly smaller than the inner peripheral surface of the strip-shaped permanent magnet (46), the stator core (49) can be inserted into the stator core (49) when the stator is inserted or disassembled. 46)
To prevent direct contact with the
3) The root portion of the comb (53a) is formed in a ring shape. By arranging the root portion of the comb (53a) on the shaft end side,
Although the impact is particularly likely to be applied when the stator core (49) is inserted, the entire end face of the strip-shaped permanent magnet (46) is covered and mechanically protected. Further, since the bolt hole (54) of the magnetic ring (45) is provided at the central back of the strip-shaped permanent magnet (46) in the circumferential direction, the amount of magnetic flux passing through the bolt hole (54) is small, and the magnetic resistance increases. Improve the efficiency of permanent magnet generator without being affected.

[0019]

As described above, according to the present invention, since the rotor of the permanent magnet generator is incorporated into the inner diameter of the armature of the AC exciter and integrated with the armature core, the number of components is small. To provide a highly reliable, lightweight and compact brushless rotating electric machine with excellent manufacturability, economic efficiency, and reduced axial dimension of the overhang portion, high natural frequency and no risk of vibration. be able to.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a main part of a rotor of the permanent magnet generator of FIG.

FIG. 3 is an elevational view as viewed from an arrow A in FIG. 2;

FIG. 4 is a vertical sectional view of a main part of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main synchronous machine rotating shaft 2 ... Main synchronous machine bearing stand 3 ... Armature of rotary armature type AC exciter 5 ... Armature core 8 ... Rotary rectifier 20 ... Permanent magnet generator rotor 40 ... Mounting body

Claims (1)

(57) [Claims] 1. An armature of a rotary armature type AC exciter, which is overhanged and directly connected to a rotating shaft of a main synchronous machine outside a bearing stand of the main synchronous machine, a rotary rectifier, and a permanent magnet generator. Permanent magnets between permanent magnets in brushless rotating electrical machines
Non-magnetic comb-shaped phosphorus with a slightly smaller inner diameter than the inner diameter
With the base of the comb on the shaft end side
Install the bolts in the same width as the strip-shaped permanent magnet.
A brushless rotary electric machine having a central back portion, wherein a rotor of a permanent magnet generator is an outer rotor type and is mounted on an inner peripheral portion of a mounting cylinder of an armature core of an AC exciter.