JPH09247879A - Salient-pole type electric rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce fatigue of a rotating shaft including its load by suppressing pulsation torque during starting by forming a magnetic pole head with a highly conductive magnetic pole piece and a high permeability magnetic pole piece jointed to both the sides of said pole piece. SOLUTION: A center portion of a magnetic pole head 2A of a magnetic pole copper 14 and end portions at both the sides are provided with a material having a high permeability, end portions are overlapped at the both sides of the central portion and welded, and the mutual components of a boundary portion are diffused by heat treatment with a high temperature high pressure vessel thereby creating sloped continuous characteristics. In an early period of staring, both of a vertical shaft magnetic flux and a lateral shaft magnetic flux pass an outer peripheral shallow portion of a magnetic pole head, but the magnetic flux passes the interior of the magnetic pole head 2A as a synchronous speed comes closer. Moreover, most of the lateral magnetic flux passes through a material having a high conductivity constituting the central portion of a magnetic pole head 2A, so that the impedance of a lateral shaft circuit decreases and a current increases, As a result, the resistance of the lateral shaft decreases and the lateral shaft current increase, so that the pulsation torque during starting is suppressed and the fatigue of the rotating shaft including the load can be decreased.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a salient pole type rotating electric machine.

[0002]

2. Description of the Related Art FIG. 10 is a perspective view showing an example of a rotor of a synchronous motor as a conventional salient-pole type rotary electric machine. In FIG. 10, a field winding 6 is attached to a magnetic pole barrel 1 that is provided so as to radially project in the axial direction with respect to the center of a rotor 9. The field winding 6 inserted into each pole cylinder 1 is
Each side surface is pressed by a plurality of coil pressers 10 fixed by bolts between them.

At the outer peripheral end of each magnetic pole barrel, a magnetic pole head 2B made of forged steel, which is substantially arcuate when viewed in the axial direction and is rectangular when viewed in the direction orthogonal to the axial direction, is formed in a counterbore formed in the outer circumference. It is fixed with the high tension bolt inserted. Rotor 9
Inner fans 11 are press-fitted on both sides of the field winding 6.

In the synchronous motor configured as described above, as is well known, at the time of starting, by the excitation of the armature winding on the stator side (not shown), the current flowing by the electromotive force induced in each pole piece 2B is used. , Start as an induction motor.

When the number of rotations of the rotor approaches the synchronous speed, the field winding 6 is DC-excited and synchronously drawn. At the time of starting, the magnetic pole head 2B has a higher resistance than the rotor bar of the induction motor, and therefore exhibits high starting characteristics.

By the way, in the synchronous motor configured as described above, at the time of starting, the magnetic flux generated in the armature winding (not shown) and passing through the magnetic pole head 2B is generated as shown in FIGS.
It becomes as shown in.

Of these, FIG. 11 shows the direct-axis magnetic flux in the case of a slip of 1 with an arrow, which is a loop that divides into the left and right at the central portion of the magnetic pole head 2B and returns to the armature side, and further the surface of the magnetic pole head 2B. It has passed and has reached the armature 8.

In FIG. 12, the horizontal axis magnetic flux in the case of a slip of 1 is indicated by arrows. From one side of the magnetic pole piece 2 to the surface of the magnetic pole head 2B to the other side of the magnetic pole head 2B to the armature side. It becomes a loop back.

[0009]

However, in the salient pole type rotating electric machine configured as described above, as shown in FIGS. 11 and 12, the paths of the magnetic flux are asymmetrical between the straight axis and the horizontal axis. , The pulsating torque is generated during the start due to the difference in impedance between the direct-axis circuit and the horizontal-axis circuit, and the pulsating torque causes torsional torque in the rotor 9, which not only causes torsional vibration of the rotor, but also The rotating shaft of the load connected to the rotor 9 may also vibrate.

Then, during a long-term operation, the rotor 9 and the joints connected to the rotor 9 and the rotating shaft of the load may be fatigued by the above-mentioned torsional vibration, and the service life may be shortened. is there. Therefore, an object of the present invention is to provide a salient pole type rotating electric machine capable of suppressing the pulsating torque at the time of starting and reducing the fatigue of the rotating shaft including the load.

[0011]

A salient pole type rotating electric machine according to a first aspect of the present invention is a salient pole type rotating electric machine in which a magnetic pole head is fixed to a tip of a magnetic pole barrel to which a field winding is mounted. It is characterized in that the magnetic pole head is formed of a highly conductive magnetic pole piece and a high magnetic permeability magnetic pole piece joined to both sides thereof.

Further, the salient pole type rotating electric machine according to the present invention is characterized in that a connecting member for connecting both ends of the highly conductive magnetic pole piece is interposed between the magnetic pole head and the magnetic pole barrel. And

Further, the salient pole type rotating electric machine according to a third aspect of the present invention is characterized in that a first short-circuit member for connecting the ends of the connecting member is provided.

Further, the salient pole type rotating electric machine according to the invention of claim 4 is characterized in that second short-circuit members for connecting the ends of the magnetic pole heads are provided at both ends of the magnetic pole heads.

By such means, in the present invention, the horizontal axis resistance is reduced and the horizontal axis current is increased.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a salient-pole type rotary electric machine of the present invention will be described below with reference to the drawings. FIG. 1 is a partial longitudinal sectional view showing a first embodiment of a salient pole type rotating electric machine of the present invention, and FIG. 2 is a partial explanatory view of FIG.

In FIG. 1, the difference from the conventional salient pole type rotating electric machine is that the material having high conductivity for the central portion 2a of the magnetic pole head 2A will be described later in detail, and the broken line A in the graph of FIG. The end portions 2b on both sides of the magnetic pole head 2A are provided as shown in FIG.
On the other hand, the material having the high magnetic permeability shown by the broken line B in FIG. 2 is formed in the same process as described below, and the rest is the same as the salient pole type rotating electric machine shown in FIG. Therefore, the same elements as those in FIG. 10 are designated by the same reference numerals.

That is, in the above-described magnetic pole head 2A, the end portions 2b are overlapped and welded on both sides of the central portion 2a, and then heat-treated in a high temperature and high pressure vessel to diffuse the mutual components at the boundary portion, and the two components shown in FIG. As shown by broken lines A and B, the characteristics are continuous and inclined.

In the salient pole type rotary electric machine constructed as described above, in the initial stage of starting, as shown in the explanatory views shown in FIGS. 11 and 12, the direct-axis magnetic flux (FIG. 11) and the horizontal-axis magnetic flux are shown. In both cases (Fig. 12), the shallow portion of the outer circumference of the magnetic pole head is passed as in the conventional case.

However, as the synchronous speed approaches, the magnetic flux passes through the inside of the magnetic pole head 2A as shown by the direct-axis magnetic flux 12 shown in FIG. 3 and the horizontal-axis magnetic flux 13 shown in FIG. Moreover, as shown in FIG. 4, most of the horizontal axis magnetic flux 13 passes through the material having high conductivity which constitutes the central portion of the magnetic pole head 2A, and as a result, the impedance of the horizontal axis circuit decreases and the current increases.

The direct-axis magnetic flux 12 shown in FIG. 3 is linked to the field coil, and is directly connected to the field coil connected to the discharge resistor connected via the brush and the slip ring by the discharge resistor (not shown). The induced current of the shaft circuit flows.

As described above, the magnetic flux passes through the central portion of the magnetic pole piece and the field coil as the synchronous speed approaches, but the resistance value of the horizontal axis circuit becomes smaller than that of the conventional salient pole type rotating electric machine. Therefore, the pulsating torque can be reduced.

Incidentally, the pulsating torque generated until reaching the synchronous speed is expressed by the following equation.

[Equation 1]

Here, ω _{0 is a} synchronous speed, Φ _{d is a} direct axis magnetic flux vector, Φ _{q is a} horizontal axis magnetic flux vector, i _{d is a} direct axis current vector, and i _{q is a} horizontal axis current vector. Since the value on the right side of the equation (1) decreases due to the increase in the horizontal axis current described above, the pulsating torque (T _P1 ) also decreases.

FIG. 5 is a partial vertical sectional view showing a second embodiment of the salient pole type rotating electric machine of the present invention, which is a view corresponding to FIG.
FIG. 6 is a cross-sectional view taken along line CC of FIG. 5 and FIG. 6 are different from FIG. 1 in that the short-circuit plates described below are provided at the central portions of both side surfaces of each magnetic pole cylinder 1 in the axial direction and the facing surface of the magnetic pole head 2A. That is, both ends of the short circuit plate 1 are connected.

That is, a shallow U-shaped groove is formed in the center of each magnetic pole cylinder 1 on both the magnetic pole head side and both sides in the axial direction. Into each of these grooves, short-circuit plates 4A and 4B formed from a copper plate in the shape of a strip plate are inserted and bonded to each magnetic pole barrel 1 with an adhesive. Of these, inserted on both sides in the axial direction of the magnetic pole barrel 1. The end of the short circuit plate 4B on the axial center side is fixed by a bolt 5 having a threaded portion coated with Loctite (adhesive for loosening prevention). The ends of the short-circuit plates 4B on the axial center side are brazed to annular short-circuit rings provided on both sides of the magnetic pole barrel 1.

In the salient pole type rotating electric machine configured as described above, the resistance value of the circuit of the horizontal axis circuit is set to the short-circuit rings 4A and 4B.
Further, the value of the cross current vector i _q shown in the equation (1) can be increased and the pulsating torque can be further reduced.

FIG. 7 is a connection diagram showing an equivalent circuit of a direct axis at the time of starting, where r _{a is} the resistance of the armature winding, and r _{kd is} the resistance.
Resistance of braking winding of direct axis, r _f : Resistance of field winding, j
X _e : leakage reactance of armature, jX _f : leakage reactance of field winding, jX _kd : reactance of damping winding of direct axis.

On the other hand, FIG. 8 is a connection diagram showing an equivalent circuit on the horizontal axis at the time of starting, where jX _{aq is the} horizontal axis armature reaction reactance, and jX _{kq is the} horizontal axis damping winding reactance.

Next, FIG. 9 is a longitudinal sectional view showing a third embodiment of the salient pole type rotating electric machine of the present invention, and is a view corresponding to FIGS. 1 and 5. 9 is different from FIGS. 1 and 5 in that both side surfaces of each magnetic pole head 2A are short-circuited by an arc-shaped short-circuit piece 7.

That is, the central portions of arc-shaped short-circuit pieces 7 made of a copper plate are fixed to both sides of each magnetic pole head 2A by bolts. Both ends of these short-circuit pieces 7 are overlapped with each other and connected by a pair of bolts 5.

In the salient pole type rotating electric machine constructed as described above, it is not necessary to form the U-shaped groove on the outer circumference of the magnetic pole barrel 1 shown in FIG. The both ends of the short-circuit piece 7 may be connected by brazing at a stage before being assembled.

[0033]

As described above, according to the first aspect of the present invention,
In a salient-pole rotating electric machine in which the magnetic pole head is fixed to the tip of the magnetic pole body to which the field winding is mounted, the magnetic pole head is formed of a highly conductive magnetic pole piece and high permeability magnetic pole pieces joined to both sides of the magnetic pole piece. Since the resistance of the horizontal axis is reduced and the current of the horizontal axis is increased, it is possible to obtain the salient-pole rotating electric machine that can suppress the pulsating torque at the start and reduce the fatigue of the rotating shaft including the load. .

According to the second aspect of the present invention, the resistance on the horizontal axis is reduced by interposing the connecting member for connecting both ends of the highly conductive magnetic pole piece between the magnetic pole head and the magnetic pole barrel. Since the horizontal axis current is reduced and the horizontal axis current is increased, it is possible to obtain a salient-pole rotating electric machine that can suppress the pulsating torque at the time of starting and reduce the fatigue of the rotating shaft including the load.

According to the third aspect of the invention, since the first short-circuit member for connecting the ends of the connecting member is provided, the resistance on the horizontal axis is reduced and the current on the horizontal axis is increased. It is possible to obtain a salient-pole rotating electric machine that can suppress the pulsating torque at the time of starting and reduce the fatigue of the rotating shaft including the load.

Further, according to the fourth aspect of the present invention,
By providing the second short-circuit member for connecting the ends of the magnetic pole head to both ends of the magnetic pole head, the resistance of the horizontal axis is reduced and the current of the horizontal axis is increased, so that the pulsating torque at the start is suppressed and the load is included. It is possible to obtain a salient-pole type rotary electric machine that can reduce fatigue of the rotating shaft.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view showing a first embodiment of a salient-pole rotating electric machine of the present invention.

FIG. 2 is a graph showing the operation of FIG.

FIG. 3 is a partially enlarged explanatory view showing the action of the salient pole type rotating electric machine of the present invention, showing the direction of the direct-axis magnetic flux when the slip is 0.02.

FIG. 4 is a partially enlarged detailed view showing the action of the salient pole type rotating electric machine of the present invention, which is different from FIG. 3 and shows the direction of the horizontal axis magnetic flux when the slip is 0.02.

FIG. 5 is a partial vertical cross-sectional view showing a second embodiment of the salient pole type rotating electric machine of the present invention.

FIG. 6 is a sectional view taken along line CC of FIG. 5;

FIG. 7 is a connection diagram showing the operation of the salient pole type rotating electric machine of the present invention, showing a direct-axis circuit.

FIG. 8 is a connection diagram different from FIG. 7 showing the operation of the salient pole type rotating electric machine of the present invention, showing a horizontal axis circuit.

FIG. 9 is a partial vertical cross-sectional view showing a third embodiment of a salient pole type rotating electrical machine of the present invention.

FIG. 10 is a partial perspective view showing an example of a conventional salient pole type rotating electric machine.

FIG. 11 is an explanatory view showing the action of this type of salient pole type rotating electric machine, showing the direction of the direct-axis magnetic flux.

FIG. 12 is an explanatory diagram showing the action of this type of salient pole type rotating electric machine, showing the direction of the horizontal axis magnetic flux.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic pole barrel, 2 ... Magnetic pole head, 2a ... Center part, 2b ... End part, 3,5 ... Bolt, 4A, 4B ... Short-circuit plate, 6 ... Field coil, 7 ... Short-circuit piece, 8 ... Armature, 9 ... Rotor, 10 ... Coil retainer, 11 ... Inner fan, 12 ... Direct axis magnetic flux, 13 ... Horizontal axis magnetic flux.

Claims (4)

[Claims] 1. A salient-pole rotating electric machine in which a magnetic pole head is fixed to the tip of a magnetic pole barrel to which a field winding is mounted, wherein a high-conductivity magnetic pole piece and high-permeability magnetic pole pieces bonded to both sides of the magnetic pole piece are used. A salient-pole type rotating electric machine having a magnetic pole head. 2. Between the pole head and the pole barrel,
2. The salient pole type rotating electric machine according to claim 1, further comprising a connecting member for connecting both ends of the highly conductive magnetic pole piece. 3. The salient-pole rotating electric machine according to claim 2, further comprising a first short-circuit member that connects the ends of the connecting member. 4. The salient-pole rotating electric machine according to claim 1, wherein second short-circuit members that connect the ends of the magnetic pole heads are provided at both ends of the magnetic pole heads.