JP2009141985A - Rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating electric machine has a simple structure and can efficiently cooling a bracket and a bearing. <P>SOLUTION: The rotating electric machine is provided with: a casing 3 surrounding a stator; a bracket 5 surrounding a bearing 4 pivotally supporting a rotor shaft 2 provided on an end of the casing; a fan provided on the rotor shaft and circulating a cooling gas in the casing; and a gas cooler for cooling the cooling gas forced by the fan. The rotating electric machine is further provided with a blowing path forming member 8 for forming a blowing path 7 of the cooling gas along an internal surface 5a of the bracket arranged at an internal B side of the bracket; and a blow guiding member 9 for guiding the cooling gas cooled by the gas cooler. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine having a gas cooler inside a casing surrounding a stator.

  In a rotating electric machine, particularly a large rotating electric machine such as a turbine generator, the temperature of a stator winding, a stator core, and the like rises due to electrical loss and mechanical loss. In such a rotating electrical machine, the cooling gas in the rotating electrical machine is circulated by a fan attached to the rotor and cooled by a gas cooler in order to cool the temperature rising portion. For example, the first ventilation path forming means provided between the fan in the casing and the gas cooler for guiding the cooling gas sent from the fan to the gas cooler, and the cooling gas exiting the gas cooler for the stator core A second ventilation path forming means for guiding the cooling gas to the radial cooling passage; a third ventilation path forming means for guiding the cooling gas to the end of the stator core; and a fourth for guiding the cooling gas that has cooled the stator core to the fan. There is one provided with ventilation path forming means (see, for example, Patent Document 1). Further, in a rotating electrical machine in which one of the stator frame and the bearing bracket that covers the stator winding end is made of magnetic metal, the magnetic metal part is covered from the inside with a shield plate made of a highly conductive metal plate, There is a shield passage through which a cooling medium is passed, and a pipe for supplying and discharging the cooling medium is provided in the refrigerant path to prevent overheating of a bracket or the like (see, for example, Patent Document 2).

JP-A-6-261500 (first page, FIG. 1) JP 59-37864 A (first page, FIG. 1)

  In order to reduce the manufacturing cost by reducing the size of a rotating electrical machine in recent years, reducing the manufacturing cost by simplifying the structure, and reducing the generation loss for increasing the efficiency, it is required to cool the bearing temperature with a simple structure. For this purpose, it is necessary to prevent the in-machine surface of the bracket holding the bearing from being overheated by the high temperature gas. In the conventional technology such as the above-mentioned Patent Document 1, since the high-temperature cooling gas flows on the machine inner surface of the bracket, there is a problem that the bracket and the bearing are overheated. Further, the conventional technique such as Patent Document 2 has a problem that the shield plate and the refrigerant passage are structurally complicated.

  The present invention has been made to solve the above-described problems of the prior art, and an object thereof is to provide a rotating electrical machine that has a simple structure and can efficiently cool a bracket and a bearing.

  A rotating electrical machine according to the present invention includes a casing that surrounds a stator, a bracket that surrounds a bearing that supports a rotor shaft provided at an end of the casing, and the rotor shaft that is provided on the rotor shaft. In a rotating electrical machine having a fan for circulating a cooling gas in a casing and a gas cooler for cooling a cooling gas energized by the fan, cooling along a machine inner surface of the bracket provided on the machine inner side of the bracket An air passage forming member that forms a gas air passage and a wind guide member that guides a part of the cooling gas cooled by the gas cooler to the air passage are provided.

  In this invention, the cooling gas cooled by the gas cooler is guided by the air guide member to the air passage along the machine inner surface of the bracket formed by the air passage forming member, so the structure is simple, The bracket can be efficiently cooled.

Embodiment 1 FIG.
1 and 2 are diagrams for explaining a main part of the rotating electrical machine according to the first embodiment of the present invention, and FIG. 1 is a main part longitudinal section schematically showing one axial end (left end) of the rotating electrical machine. FIG. 2 is a front view schematically showing the upper half of the bracket as viewed from the direction of arrow A in FIG. Note that the same reference numerals denote the same or corresponding parts throughout the drawings. In the figure, a rotating electrical machine 1 is arranged so as to surround a cylindrical rotor core (not shown) that generates a magnetic field or eddy current fixed to a predetermined portion of a rotor shaft 2 and the rotor core. A cylindrical stator (not shown) including a provided stator core and windings is provided. The casing (frame) 3 is provided so as to surround a stator (not shown), and brackets 5 that support bearings 4 that support the rotor shaft 2 are provided at both axial ends of the casing 3. A housing 6 that surrounds the stator and the rotor core is formed by the casing 3 and the bracket 5, and the inside B and the outside C are separated by the housing 6.

  In addition, oil retaining rings 10 a and 10 b fixed to the radially inner peripheral side of the bracket 5 are respectively enclosed on both sides in the axial direction of the bearing 4 through a small gap with respect to the outer peripheral surface of the rotor shaft 2. It is provided so that the lubricating oil of the bearing 4 is prevented from scattering. Then, a predetermined portion of the rotor shaft 2 cools heating members such as the windings and iron cores in the machine B, keeps the rotor and stator within an allowable temperature, and circulates a cooling gas for improving the reliability of the equipment. A cooling mechanism including a fan (not shown) and a gas cooler (not shown) for cooling the cooling gas that has become high temperature is provided. As the cooling gas, for example, hydrogen gas or air having excellent cooling performance is used and is hermetically housed in the machine B, but the type of gas is not particularly limited. In addition, the cooling gas ventilation path is provided in the radial direction inside the stator core, and is further provided in the axial direction along the stator coil mounted in the slot of the stator core. Since these can be preferably used without any particular limitation, they are not shown together with a fan, a gas cooler and the like.

  An air passage forming member 8 made of a donut plate-like air guide plate that forms an air passage 7 for the cooling gas along the inboard surface 5a of the bracket 5 is provided on the in-machine B side of the bracket 5 and is not shown. There is provided at least one air guide member 9 composed of a pipe that bypasses the cooling gas cooled by the gas cooler and guides it to the air passage 7. The air path forming member 8 is fixed to the machine inner surface 5a of the bracket 5 so that the air path forming member 8 is spaced from the machine inner surface 5a of the bracket 5 by several mm to several tens of mm. An outlet portion 7a for the in-machine B of the air passage 7 is formed at the end on the inner peripheral side. The air guide member 9 is connected on the outer peripheral side of the air passage forming member 8 so as to communicate with the air passage 7. The thickness, shape, number, and the like of the air guide member 9 can be appropriately changed according to the temperature of the bracket 5 and the cooling gas, the air flow rate, the pressure loss, and the like.

  Moreover, although the general structural rolled steel (SS400), stainless steel, etc. can also be used for the air path formation member 8 and the baffle member 9, it is more to use materials with high heat insulation, such as an epoxy resin, for example. Preferably, the use of materials with low thermal insulation properties such as copper and aluminum should be avoided. In the case of a material composed of a material with high heat insulation, heat from the high-temperature gas on the in-machine B side with respect to the bracket 5 can be shielded and an improvement in the cooling performance of the bracket 5 can be expected. The cooling gas cooled by the vessel reaches the air path 7 of the bracket 5 and is heated by a high temperature atmosphere of, for example, about 100 degrees Celsius. It is not preferable.

  Next, the operation of the first embodiment configured as described above will be described. When the rotating electrical machine 1 is operated, a fan (not shown) rotates with the rotation of the rotor shaft 2 and energized with a cooling gas such as air or hydrogen enclosed in the machine, and cooled by the gas cooler. Most of the generated cooling gas takes heat from the stator and the rotor, which are heat sources, and cools the stator and the rotor. The high-temperature cooling gas returns to the gas cooler (not shown) interposed in the circulation path, exchanges heat, and releases the heat in the machine B to the machine C. The cooling gas that has released the heat becomes a low temperature, and circulates in the machine B again in a predetermined route. A part of the cooling gas cooled by the gas cooler is fed into the air passage 7 formed by the air passage forming member 8 through the air guide member 9 which is a bypass passage, and the bracket 5 is passed through the in-machine B. Cool from the side. The air passage forming member 8 also serves to insulate the high temperature gas in the casing 3 so as not to contact the machine inner surface 5 a of the bracket 5.

  At this time, when the pressure in the high-temperature atmosphere on the in-machine B side of the bracket 5 is α and the pressure in the air guide member 9 is β, α <β is satisfied. In the vicinity of the bracket 5 on the side B in the machine, a cooling gas having a high temperature of about 100 degrees Celsius just before heat exchange with the gas cooler flows, but the cooling gas fed into the air passage 7 as described above is sent to the bracket 5. By cooling the machine inner surface 5a, the temperature of the bracket 5 is also kept below a predetermined temperature to prevent overheating of the bearing 4, and oil retaining rings 10a, 10b fixed to the radially inner peripheral side of the bracket 5 are provided. Further, it is possible to prevent the outer peripheral surface of the rotor shaft 2 from being damaged due to contact.

  As described above, according to the first embodiment, the air passage forming member 8 forms the air passage 7 along the machine inner surface 5a of the bracket 5, and the cooling gas cooled by the gas cooler in the air passage 7 is formed. Since a part of is bypassed and guided by the air guide member 9, the bracket 5 can be efficiently cooled. Therefore, overheating of the bearing 4 is prevented, and there is no possibility that the oil retaining rings 10a and 10b come into contact with the rotor shaft 2 and are damaged. In addition, since the air passage forming member 8 is provided close to the machine inner surface 5a of the bracket 5 and the pipe-like air guide member 9 is connected, the structure is simple and is not bulky. It is easy to install, and there is no fear that the apparatus will be enlarged. Furthermore, it is not necessary to install a fan, fins, or the like on the outside C side, and the bearing temperature is prevented from increasing without increasing the size, thereby ensuring the reliability of the bearing and extending the life.

Embodiment 2. FIG.
FIG. 3 is a front view showing the upper half of the bracket part, which is the main part of the rotating electrical machine according to the second embodiment of the present invention, when viewed from the inside of the machine. In the figure, the air passage forming member 8 is composed of a plurality (10 in this example) of air guide plates 81 divided in the circumferential direction, and a plurality of air guide members 9 corresponding to each of the air guide plates 81 are provided from the cooler. The cooling air is supplied to each air passage 7. A gap D is formed between the air guide plates 81 adjacent in the circumferential direction. Since other configurations such as the distance between the machine inner surface 5a (not shown) of the bracket 5 and the wind guide plate 81, the configuration of the wind guide member 9, and the like are the same as those in the first embodiment, description thereof will be omitted.

In the second embodiment configured as described above, the air passage forming member 8 is divided into a plurality of portions in the circumferential direction, and the cooling air is supplied from the air guide member 9 for each air passage 7 inside the divided air guide plate 81. Therefore, the cooling air flows uniformly over the entire machine inner surface 5a of the bracket 5, the bracket 5 is cooled more uniformly than in the first embodiment, and the cooling effect can be enhanced. .
The gap D between the adjacent air guide plates 81 may be closed. Further, although the air passage forming member 8 is divided into a plurality of portions in the circumferential direction, the air passage forming member 8 made of a single air guide plate as in the first embodiment has a radial direction on the surface facing the inboard surface 5a. A partition plate may be provided, and the air path may be divided into a plurality of parts in the circumferential direction.

Embodiment 3 FIG.
FIG. 4 is a front view showing an upper half portion of a bracket portion, which is a main part of a rotating electrical machine according to Embodiment 3 of the present invention, when viewed from the inside of the machine. In the drawing, the air passage forming member 8 is composed of a plurality of ventilation pipes 82 meanderingly fixed to the machine inner surface 5 a of the bracket 5, and the internal space of the ventilation pipe 82 forms the air passage 7. The plurality of ventilation pipes 82 are juxtaposed in the circumferential direction on the inner surface 5 a of the bracket 5, and pipe-like air guide members 9 are connected to one end portion of each ventilation pipe 82 on the outer peripheral side in the radial direction. The other end 82a on the radially inner peripheral side of the ventilation pipe 82 is open to the inside of the machine. Other configurations are the same as those of the second embodiment except that a ventilation pipe is used instead of the air guide plate, and thus the description thereof is omitted.

  In the third embodiment configured as described above, the ventilation pipe 82 through which the cooling gas flows is meandered and fixed to the machine inner surface 5a of the bracket 5, so that it is fed from the wind guide member 9. The time for the cooling gas to contact the bracket 5 can be increased, and more heat can be taken from the bracket 5. In this case, unlike the case of the air guide plate, it is preferable to use a material having a high thermal conductivity such as copper or aluminum as the material of the ventilation pipe 82 in this case. In addition, although the case where a plurality of the ventilation pipes 82 meandering in the radial direction on the inner surface 5a is provided in the circumferential direction has been described, the present invention is not necessarily limited thereto. Alternatively, the length of the air passage 7 may be extended in a shape other than meandering. For example, it may be fixed spirally to the machine inner surface 5a or meandering in the circumferential direction. Further, the ventilation tube 82 may be a flat tube having a uniform tube diameter, for example, a flat tube, a bellows tube, or a tube having irregularities. As a modification, for example, a meandering groove is provided on the machine inner surface 5a and covered with a plate material, a hole serving as an inlet for cooling air is provided at a position corresponding to one end portion of the groove in the plate material, and the other end portion is provided. A similar effect can be expected by providing a hole serving as an outlet for cooling air at the corresponding position.

Embodiment 4 FIG.
FIG. 5 is a longitudinal sectional view of a main part schematically showing one axial end portion (left end portion) of a rotating electrical machine according to Embodiment 4 of the present invention. In the figure, a groove-like unevenness 5 b is provided on the surface on the machine inner side of the bracket 5. Since other configurations are the same as those of the first embodiment, description thereof is omitted.
In the fourth embodiment configured as described above, since the machine-inside surface of the bracket 5 is formed by the unevenness 5b, the surface area is increased with a simple structure, and the cooling gas supplied from the air guide member 9 is used. When the air flows through the air passage 7, the contact area with the cooling gas increases, and the heat dissipation effect can be further improved. Accordingly, a large amount of heat can be taken from the bracket 5, and the structure is simpler than that of the third embodiment, so that the manufacture is also easy. Note that the unevenness 5b is not necessarily limited to the groove shape, and may be of any other shape as long as it increases the surface area.
Needless to say, the inventions described in the first to fourth embodiments can be modified or changed as appropriate.

The principal part longitudinal cross-sectional view which shows typically the axial direction one end part (left side end part) of the rotary electric machine which concerns on Embodiment 1 of this invention. The front view which shows typically the upper half part of the bracket seen from the arrow A direction of FIG. The front view which shows the upper half part when the bracket part which is the principal part of the rotary electric machine by Embodiment 2 of this invention is seen from the machine inner side. The front view which shows the upper half part when the bracket part which is the principal part of the rotary electric machine by Embodiment 3 of this invention is seen from the machine inner side. The principal part longitudinal cross-sectional view which shows typically the axial direction one end part (left side end part) of the rotary electric machine by Embodiment 4 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Rotating electrical machine, 2 Rotor shaft, 3 Casing (frame), 4 Bearing, 5 Bracket, 5a Machine inner surface, 5b Concavity and convexity, 6 Housing, 7 Air passage, 7a Outlet part, 8 Air passage formation member, 81 Air guide plate 82 Ventilation pipe, 9 Air guide member, 10a, 10b Oil retaining ring, B Inside the machine, C Outside the machine, D Gap.

Claims (6)

  A casing that surrounds the stator, a bracket that surrounds a bearing that supports the rotor shaft provided at the end of the casing, and a cooling gas in the casing that is provided on the rotor shaft are circulated. In a rotating electrical machine including a fan to be cooled and a gas cooler that cools the cooling gas energized by the fan, a cooling gas air path is formed along the inner surface of the bracket provided on the inner surface of the bracket. A rotating electrical machine comprising: an air passage forming member; and an air guide member that guides a part of the cooling gas cooled by the gas cooler to the air passage.   The rotating electrical machine according to claim 1, wherein the air passage forming member is formed of an air guide plate provided at an interval on an inner surface of the bracket.   The rotating electrical machine according to claim 2, wherein the air guide plate is divided into a plurality of portions in the circumferential direction, and the ventilation member is provided for each of the divided air guide plates.   The rotating electrical machine according to any one of claims 1 to 3, wherein unevenness is provided on an inner surface of the bracket.   2. The rotating electrical machine according to claim 1, wherein the air path forming member is a ventilation pipe fixed so as to meander on the inner surface of the bracket.   The rotating electrical machine according to any one of claims 1 to 5, wherein the air guide member comprises a pipe.

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