JPS6112465B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating electric machine with an internal cooling system, especially a radial flow is used to cool the stator core, and a gear pick-up method is used to cool the rotor at the same time. This is related to rotating electric machines. The first cooling device for this type of rotating electric machine
In the conventional example, the gas that passes through the cooler flows along the casing end wall, is pressurized by a fan, and is discharged toward the rotor end winding.Some of the gas cools the rotor end winding, and the other gas cools the rotor end winding. is designed to cool the stator core and rotor body and return to the cooler. Further, in the second conventional example, the cooling gas flow of the first conventional example is reversed. That is, the gas exiting the cooler is divided into two flow paths, one of which cools the stator core and the rotor body, and then is collected near the rotor end turns. The other flow path is provided along the casing end wall, through which the gas that cools the rotor end winding flows into the end winding, is cooled, and is then discharged to the outside, causing the stator core to rotate. It is configured so that it merges with the gas that has cooled the main body, is sucked into the fan, is pressurized, and returns to the cooler. However, in the first conventional example, since the flow resistance at the end windings of the rotor is extremely large, most of the gas is used to cool the stator core and the rotor body. The gas flow entering is negligible. Therefore, the temperature increase at the end windings of the rotor significantly impedes capacity increase. Furthermore, since the gas is discharged into a large space by the fan, the dynamic pressure is not recovered and is lost, making it impossible to obtain high pressure. In the second conventional example, the gas flow that cools the rotor end winding exits the cooler, changes its direction by 180 degrees, flows through a flow path provided along the casing end wall, and then cools the rotor end. Since it reaches the wound portion, the flow loss is extremely large. Therefore, as in the case of the first prior art, the gas flow flowing through the rotor end turns is small and the temperature of the end turns becomes significantly high. The present invention provides a rotating electric machine equipped with an improved cooling device that effectively utilizes the pressure before and after the fan and improves cooling of the rotor end winding by providing a gas flow path with less flow loss. This is what we provide. In the rotating electrical machine of the present invention, the flow of cooling gas is divided into two parts. One flow portion is pressurized by a fan after leaving the cooler and is supplied to cool the stator core and rotor body. The other flow portion, after being pressurized by the fan, immediately flows into the end winding of the rotor, cools it, and then is discharged to the fan inlet. At the inlet of the fan, the flow joins with the other flow that has passed through the cooler and is cooled, and then is again pressurized by the fan and circulated through the end windings of the rotor to perform a cooling effect. DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a rotating electric machine according to the present invention will be described in detail below with reference to the drawings. The drawing shows, in cross section, the structure of one end of the upper half of a hydrogen gas-cooled generator as a rotating electric machine. The generator has an airtight casing 1 containing a hydrogen cooling gas, in which a stator core 2, a rotor 5 having a body portion 4 separated from the stator core 2 by a gas cap 3, and a cooler 6 are installed. exists. The stator core 2 is provided with radial cooling passages 7 and 8 at appropriate intervals, and has a groove for housing the main armature winding 9 which is cooled by a liquid cooling system separate from the present invention. ing. Further, the stator core 2 is provided with circumferential inlet chambers 10 and outlet chambers 11 that face and alternately surround the cooling passages 7 and 8. The rotor 5 has at either end an end turn 14 including an end turn 13 held in place by a retaining ring 12, and the rotor 5 also supports a set of fans 15, which Gas is guided to 15 by fixed vanes 16 . The main body portion 4 of the rotor 5 faces the radial cooling passages 7 and 8 and is spaced apart in the axial direction into a plurality of zones, and this portion is cooled by taking gas from the gas gap 3 using a gap pickup method. This is accomplished by passing internal diagonal cooling passages through the rotor windings to axially spaced areas along the gas gap. The end winding part 14 has a centrifugal blower blade 17 at the end of the retaining ring 12 whose discharge side is connected to the inlet area 1 of the fan 15.
The end winding 13 is cooled by the centrifugal blower blade 17 . The cooler 6 is arranged in a passage 21 provided in the casing 1 between the flow guide wall 19 and the flow dividing wall 20 . The inlet of this cooler 6 communicates with the armature end region 22 and the outlet chamber 11 provided in the circumferential direction of the stator core 2, and the outlet communicates with the inlet region 18 of the fan 15. The outlet passage 23 of the fan 15 is formed by the casing end wall 1a, the flow guide wall 19, and the flow dividing wall 24, and communicates with the inlet chamber 10 provided in the circumferential direction of the stator core 2. The flow dividing wall 24 also has an opening 24a, which leads the gas to an end chamber 27 that communicates with the end turn 14 via a rotor shaft opening 25 and a shaft longitudinal passage 26. The flow of cooling gas in the rotating electric machine of the present invention will be explained according to the illustrated example. The first flow is Juan 15
After being pressurized by the flow, it flows into the end wall 27 through the opening 24a of the flow dividing wall 24, passes through the rotor shaft longitudinal passage 26 from the rotor shaft opening 25, and is provided to the end turn 14 . be done. Here, the gas flows through the end-turn internal passage (not shown) and the end-turn
14 is discharged into the fan inlet area 18 by the centrifugal blower blades 17, and a part flows from the gas gap 3 to the armature end area 22 to cool the main armature winding 9 and is discharged to the inlet of the cooler 6. released to the side. After being pressurized by the fan 15, the second gas flow passes through the passage 23 and is distributed to the circumferential inlet chambers 10 that alternately surround the stator core 2 by a plurality of circumferentially provided pipes 28. , radial cooling passage 7
through which it flows into gas gap 3. The gas now flows through one section of the rotor body 4 through internal diagonal cooling passages of the rotor windings, into other axially spaced sections along the gas gap 3 and back into the gas gap 3; Collected through the radial cooling passages 8 into the inlet chamber 10 and the circumferential outlet chamber 11 surrounding the stator core 2 alternately, the stator core 2 and the rotor 5 are collected.
cooling. The gas collected in the outlet chamber 11 is
The cooler 6 is connected by a large number of pipes 29 provided in the circumferential direction.
is cooled by the cooler 6 together with the gas discharged from the armature end region 22 , and the passage 2
1 to the inlet area 18 of the fan 15. The second gas stream cooled by the cooler 6 is
End turn 14 at inlet area 18 of fan 15
After cooling the first gas flow by combining with the first gas flow discharged from the first gas flow, the first gas flow is again pressurized by the fan 15 and circulated, thereby performing a cooling effect. According to the present invention, the gas flow path leading from the fan outlet to the rotor end winding is shortened to reduce flow loss, and the gas flowing through the rotor end winding is immediately discharged to the fan inlet, thereby reducing the pressure before and after the fan. Since the gas flow rate is effectively utilized for cooling the end winding, the flow rate of gas flowing through the end winding is significantly increased, and the end winding can be effectively cooled. In addition, by reversing the gas flow, a considerable amount of the dynamic pressure that was previously lost is recovered as static pressure, making it possible to obtain large pressure and perform effective cooling. I can do it.

[Brief explanation of drawings]

The figure shows, in cross section, one end of the upper half of a hydrogen gas cooled generator as an example of the rotating electric machine of the present invention. 1...Airtight casing, 2...Stator core, 5
... rotor, 6 ... cooler, 7, 8 ... radial cooling passage, 14 ... end winding section, 15 ... fan,
18 ... Entrance area of the fan, 21 ... Passage, 23
...exit passage.

Claims (1)

[Claims] 1 An airtight casing filled with cooling gas,
It has a stator core having a cooling passage in the radial direction, and a rotor having a main body portion and an end winding portion that are cooled by the fan action of cooling gas supply and exhaust holes provided on the outer circumferential surface, In a rotating electric machine of the type in which a fan is provided for circulating cooling gas, the rotary electric machine is arranged in a passage that directly communicates with the fan inlet area in the casing, and is used to cool the gas guided to the fan inlet area. cooler and
an opening provided in the rotor shaft near the fan outlet; and a first channel for directing cooled gas to the rotor end winding through a shaft longitudinal passage provided in the rotor shaft that communicates with the opening. a cooling gas flow path, and a second cooling gas flow path that guides the cooled gas from the fan outlet to the stator core cooling passage, and the gas flow cooled through the cooler and the rotor. A rotating electric machine characterized in that the rotating electric machine is configured such that the gas flow discharged from the end winding portion merges at the fan inlet.