JP2001119891A - Electric rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electric rotating machine cooled with gas by constituting an enclosed channel in which a sufficient air volume is ensured by making uniform the radial shift of a flow, flowing into a fan from the gap between a stator and a rotor, thereby preventing deceleration of the fan and resulting pressure variation. SOLUTION: The electric rotating machine has an enclosed ventilation passage for delivering temperature raised gas from a fan after cooling a stator and a rotor, cooling the temperature raised gas through a cooler and supplying the gas again to the stator and a rotor. A control structure for shifting a high speed flow to the outer diameter side of the fan with respect to the flow flowing into the fan is provided on a holding ring at the end of the rotor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine, and more particularly, to a shape of a rotor holding ring.

[0002]

2. Description of the Related Art FIG. 1 schematically shows a structure near a stator end of a generator for cooling with air or hydrogen. The ventilation structure shown in this figure is called a reverse flow system, and the stator 101
Then, the gas heated by cooling the rotor 102 is
08 and discharged through a cooler to lower the temperature, and then diverted and sent again to the stator and the rotor. At this time, of the gas sent to the stator side,
1 flows through the ventilation hole 104 inside the stator, and the gas 126 sent to the rotor side cools the field coil 112, passes through the ventilation hole 105 inside the rotor, and both of them pass between the stator and the rotor. Merges at the gap 103 and flows into the fan. Of the gas sent to the stator, the gas flowing to the armature end 106 flows into the fan after cooling the armature end. Immediately upstream of the fan, a retaining ring 107 for retaining the rotor in the circumferential direction against the centrifugal force is provided, so that the flow flowing into the fan is retained between the air gap 103 and the fan 108. It will flow along the ring.

[0003] In this reverse flow method, the stator can be cooled with cold gas immediately after leaving the gas cooler, so that the stator and the rotor are cooled by the gas discharged from the fan. It has the feature that the temperature rise of the child coil can be kept low. In order to perform high-efficiency cooling utilizing this feature, various devices have been conventionally devised.

For example, according to Japanese Patent Application Laid-Open No. H10-150740, a flow path for sending gas cooled by a cooler to a rotor side is thermally separated from a stator frame to increase the temperature of the stator cooling gas. The structure which prevents as much as possible is taken. Thereby, the advantage of the reverse flow method can be maximized and the cooling performance of the rotor can be improved, so that a highly reliable rotating electric machine can be provided.

[0005]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. H10-150740
Although the method described in the above publication pays attention to the temperature of the gas after leaving the cooler, it does not pay attention to the flow flowing into the fan. As shown in FIG. 2, in the gap 103, since the inflow from the stator side is larger than the inflow from the rotor side, the flow is pressed against the rotor side, and the velocity distribution 131 is strongly biased. I am carrying it.
This velocity distribution does not change qualitatively while flowing through the retaining ring 201, and the velocity distributions 132, 133, and 234 on the upstream, middle, and downstream sides of the retaining ring all have a distribution that is strongly biased toward the retaining ring. ing. Since this characteristic is maintained even in the velocity distribution 235 immediately before flowing into the fan, a strongly biased flow with a large velocity flows into the inner diameter side and a small velocity flows into the outer diameter side in the fan blades 108.

Incidentally, an axial flow type fan whose flow direction is parallel to the rotating shaft is generally designed on the assumption that a uniform speed flows into both the inner diameter side and the outer diameter side of the blade. Mounting angle and the like are determined. When there is a speed deviation between the inner diameter side and the outer diameter side, there is a design method that attempts to reduce the influence by twisting the blade, but the effect is limited to the case where the speed deviation is small. If the strongly skewed flow that is the subject of the current flows into the fan, the angle of the blade does not match the angle of the inflow flow, and at least the outer diameter side of the blade stalls and does not generate the specified static pressure difference In addition, turbulence associated with stall can create strong pressure fluctuations 240. At this time, not only does the cooling flow rate become insufficient due to the stall, the cooling reliability is reduced, but also there is a possibility that a problem in mechanical strength may occur due to strong pressure fluctuation.

It is an object of the present invention to provide a stator holding ring having a structure capable of producing an inflow with favorable conditions for a cooling fan, and to secure a sufficient cooling air flow.

[0008]

In order to achieve the above object, a rotating electric machine according to the present invention rotates on a radially inner side of a stator through a gap, and has a plurality of fields supported at both ends in a circumferential direction by holding rings. A rotor having magnetic coils, a stator having a number of radial cooling holes formed by alternately laminating laminated core blocks and spacers, and a gap between the stator and the rotor serving as a suction side,
A fan provided at both ends of the rotor having a space provided on the stator outer diameter side as a discharge side, and a heated gas after cooling the stator and the rotor is discharged from the fan, and a cooler is provided. Providing a closed ventilation path for cooling and sending it back to the stator and rotor, on the retaining ring at the rotor end,
A flow control structure is provided for sending a high-speed flow to the fan outer diameter side with respect to the fan inflow flow.

Further, in the flow control structure, it is preferable to provide a flow jumping guide ring whose cross-sectional radius gradually increases on the surface of the holding ring.

[0010] In the above flow control structure, it is preferable that a protrusion on one or more rings is provided on the surface of the retaining ring.

In the above flow control structure, it is preferable that a plurality of triangular blades are provided on the surface of the retaining ring in the circumferential direction.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of the vicinity of an end of a stator of a rotating electric machine according to the present invention. Fans 10 provided at both ends of the rotor
The gas 125 discharged by 8 is guided through the discharge flow path and reaches a space provided on the outer diameter side of the stator. The cooler provided here cools the gas, from which the flow is split and directed to the stator outer diameter side and the rotor end. Part of the gas led to the stator outer diameter side is the armature coil end 10.
6 is used for cooling. The remaining part flows through the ventilation holes 104 of the stator, cools the stator, and reaches the gap 103.

On the other hand, the cooling gas 126 guided to the rotor end by the flow path 113 cools the field coil 112 through the flow guide 114 and then enters the rotor, cools the rotor, and opens the ventilation hole 105. After that, the space 103 is reached. The gas flowing into the gap flows along the surface of the rotor holding ring 107, enters a fan flow path partitioned by the fan guide 110, is sucked by the fan, and is discharged downstream of the fan. Since the flow rate from the stator flowing into the gap is larger than the flow rate from the rotor, the flow is pressed against the rotor side and flows with a strongly biased velocity distribution 131 in the gap. This deviation in the velocity distribution is not eliminated even when the flow reaches the rotor holding ring, and the deviations 132 and 133 are maintained even when the flow reaches the upstream portion and the intermediate portion of the holding ring.

By providing a guide ring 301 for jumping up the flow as shown in FIGS. 1 and 3 on the retaining ring 107, the flow is directed to the outer diameter portion of the fan, and the velocity distribution having a bias in the downstream portion of the retaining ring. 134 is a more uniform fan inflow speed distribution 1 having a sufficient speed at the fan outer diameter portion.
It changes to 35. This allows the cooling fan to perform sufficient aerodynamic work without stalling, so that a highly reliable rotating electric machine having sufficient cooling performance can be realized.

FIG. 2 shows a case where a conventional rotor holding ring is used. In this case, the rotor holding ring 201
Does not have a flow control structure, and the flow with a strong bias flowing from the gap does not change the bias much, and the speed distribution with a large speed on the rotor side, respectively 132, 133, 234, and 235 flow into the fan. When a flow having a strong velocity deviation flows into the inner diameter side and the outer diameter side in this manner, at least the outer diameter side of the fan stalls, and the fan can no longer perform aerodynamic work sufficiently. In addition, a strong pressure fluctuation 240 occurs with the stall, which may adversely affect mechanical strength.

FIG. 3 shows a cross-sectional view of a rotor holding ring 107 provided with a flow jump ring 301 for preventing this. In the example of FIG. 1, a rotor holding ring 107 having this shape is provided.

FIG. 4 shows a protruding ring 402 which acts as a resistor to partially block the flow along the surface of the rotor retaining ring 401 and to flow the flow more toward the outer diameter, instead of directly jumping up the flow. 2 shows a rotor retaining ring provided. It is more effective to provide one or more protruding rings, but if the number is too large, the resistance to the flow becomes too large, which is counterproductive.

FIG. 5 shows a structure for equalizing the flow flowing into the fan with different ideas. In this embodiment, a plurality of longitudinal vortex generating blades 502 having a triangular wing shape are arranged on a rotor holding ring 501 in a circumferential direction.

FIGS. 6 and 7 show the principle of operation. The fan rotates at the same angular speed as the rotor, and the flow flowing into the fan has a swirl component that is dragged by the rotation of the rotor and the surface of the retaining ring, which is slower than the rotational speed of the rotor . Therefore, the vertical vortex generating blade 502 has a certain attack angle of 6
The flow relatively flows in at 05. At this time, as is well known from the wing theory of the aircraft, a vertical vortex 604 called a wing tip vortex is generated from the tip of the vertical vortex generating wing. This longitudinal vortex entrains the surrounding fluid with a strong entrainment action, and on one side creates a flow 606 that blows up the fluid on the inner diameter side of the retaining ring to the outer diameter side, and on the other side creates a flow 607 that blows down the fluid on the outer diameter side to the inner diameter side. create. Due to this mixing action, the speed deviation between the inner diameter side and the outer diameter side of the retaining ring is reduced, the fan inflow velocity distribution is made uniform, and the fan can perform aerodynamically sufficient work without stalling. Yes, and there is no strong pressure fluctuation caused by stall.

[0021]

According to the present invention, the unevenness of the radial velocity of the flow of the cooling gas on the surface of the rotor holding ring is reduced,
Since the fan stall and the accompanying pressure fluctuation can be prevented by equalizing the flow of the inflow of the fan, a rotating electric machine having a sufficient cooling air volume and high reliability can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the vicinity of an end of a stator in a rotating electric machine embodying the present invention.

FIG. 2 is a cross-sectional view near a stator end in a rotating electric machine according to a conventional technique.

FIG. 3 is a sectional view of a holding ring in the rotating electric machine embodying the present invention.

FIG. 4 is a sectional view of a holding ring in the rotary electric machine embodying the present invention.

FIG. 5 is a sketch of a retaining ring in the rotating electric machine embodying the present invention.

FIG. 6 is an operation principle diagram of a vortex generating blade on a retaining ring in the rotary electric machine embodying the present invention.

FIG. 7 is an operation principle diagram of a vortex generating blade on a retaining ring in the rotating electric machine embodying the present invention.

[Explanation of symbols]

101: stator, 102: rotor, 103: air gap, 10
4 ... stator ventilation hole, 105 ... rotor ventilation hole, 106 ... armature coil end, 107, 201, 401, 501 ... rotor holding ring, 108 ... cooling fan blade, 109 ... cooling fan ring, 110 ... fan Guide: 111: Fan support, 112: Field coil end, 113: Rotor cooling gas flow path, 114: Rotor cooling gas guide, 121:
Stator cooling gas flow, 122, 126: rotor cooling gas flow, 123: air gap discharge flow, 124: flow from the end of the armature coil, 125: cooling fan discharge flow
131: air gap end velocity distribution, 132: retaining ring upstream velocity distribution, 133: retaining ring intermediate velocity distribution,
134 ... speed distribution downstream of the retaining ring, 135, 235 ...
Cooling fan inflow velocity distribution, 234: retaining ring downstream velocity distribution, 240: pressure fluctuation, 301: flow jumping guide ring, 402: projecting ring, 502: longitudinal vortex generating blade,
601: Blade center line, 602: Relative velocity direction, 603: Relative inflow, 604: Blade tip vortex, 605: Attack angle, 606
… Upflow, 607… downflow.

Continued on the front page (72) Inventor Akiyoshi Iida 502, Kandachicho, Tsuchiura-shi, Ibaraki F-term in Hitachi Machinery Co., Ltd. F-term (reference) RR03 RR26 RR33 RR46 RR70

Claims (1)

[Claims] 1. A rotor having a plurality of field coils, which is rotated on the inner diameter side of a stator via a gap and both ends are supported in a circumferential direction by holding rings, and a laminated core block and spacers are alternately laminated. A stator having a number of radial cooling holes, and a fan provided at both ends of the rotor having a space between the stator and the rotor as a suction side and a space provided on the outer diameter side of the stator as a discharge side. In a rotating electric machine having a closed-type ventilation path, the heated gas after cooling the stator and the rotor is discharged from the fan, cooled by a cooler, and sent to the stator and the rotor again. A rotating electric machine characterized in that a flow control structure is provided on the holding ring of the portion, the flow control structure for drawing a high-speed flow toward the fan outer diameter side with respect to the fan inflow flow.