JP6068419B2 - Fully closed rotating electrical machine - Google Patents

Description

  The present invention relates to a fully-closed rotating electrical machine including an internal fan and a cooler.

  A fully-closed rotating electrical machine includes a rotor, a stator, and usually a cooler. The rotor usually has a rotor shaft that rotates about its axis and a rotor core that is provided on the outer side in the radial direction of the rotor shaft. The stator has a cylindrical stator core in which ferromagnetic steel plates are laminated in the axial direction, and a stator coil wound around a tooth portion formed on the stator core.

  During the load operation, the copper loss mainly occurs in the stator coil, and the iron loss mainly occurs in the stator core. Thus, it is necessary to cool the stator in order to protect the stator coil and the like against heat generated by iron loss and copper loss generated in the stator.

  A cooler cover containing a cooler is attached to the frame that houses the rotor core and the stator. The cooler cover forms a sealed space with the frame. In the cooler, the cooling medium from the outside flows inside the cooling pipe, and the cooling gas outside the cooling pipe cooled by the cooling medium flows in the sealed space. A cooling gas such as air is driven by an internal fan mounted on the rotor shaft and circulates in the sealed space (Patent Document 1).

Japanese Utility Model Publication No. 61-149957

  FIG. 7 is a cross-sectional view of the portion of the inner fan 15 of the conventional fully-closed rotating electric machine. FIG. 8 is a plan sectional view of the upper part of the cooler 41. The cooling gas in the sealed space 45 is driven by the rotation of the inner fan 15 attached to the rotor shaft, and moves from the frame 30 into the cooler cover 43. At this time, the gas driven by the inner fan fan 15 flows out of the inner fan fan 15 approximately symmetrically in the circumferential direction around the rotation axis.

  As a result, the velocity component in the direction from the frame 30 to the cooler cover 43 is not uniform. For this reason, the velocity distribution of the cooling gas flowing through the cooling pipe 42 is not uniform, and the heat exchange amount is also distributed. Such a state causes a decrease in cooling performance in the cooler.

  An object of this invention is to improve the cooling performance in the cooler of a fully-closed rotary electric machine.

In order to achieve the above-described object, a fully-closed rotating electrical machine according to the present invention includes a rotor shaft that is rotatably supported around a horizontally extending main shaft and extends in the main shaft direction, and is fixed to a radially outer side of the rotor shaft. And a rotor core that extends in the main axis direction, a stator core that is arranged radially outside the rotor core and extends in the main axis direction, and a stator that is wound around the stator core A stator having a coil, a frame for housing the rotor core and the stator, and a circulating fluid for cooling the stator and the rotor core in the frame as a pipe jacket cooling side fluid from the outside A cooler in which a plurality of cooling pipes extending in the direction of the main axis using external air as a cooling fluid in the pipe is arranged in parallel, and is attached to the upper part of the frame to form a sealed space together with the frame. A cooler inlet side opening provided below a region including one end in the direction of the main shaft to flow in from the inside of the frame, and the main shaft to flow out into the frame A cooler cover communicating with the frame by a cooler outlet side opening provided below a region including the other end of the direction, and a main shaft direction of the rotor core on the lower side of the cooler inlet side opening An inner fan that is attached to the rotor shaft in the outer portion and circulates the circulating fluid in the sealed space; and is provided in the cooler cover and above the cooler, and the velocity distribution of the circulating fluid the and an adjustment fan for generating a rotating flow of the circulating fluid around a vertical axis in order to equalize the rotational direction of the adjusting fan viewed the adjustment fan from above, the rotation of said fan fan The rotational direction of the inner fan fan viewed from the opposite side of the core and wherein the reverse der Rukoto.
The fully-closed rotating electrical machine according to the present invention includes a rotor shaft that is rotatably supported around a horizontally extending main shaft and extends in the main shaft direction, and is fixed to the radially outer side of the rotor shaft and extends in the main shaft direction. A stator having a rotor core, a stator core disposed radially outside the rotor core and extending in the main axis direction, and a stator coil wound around the stator core A frame that houses the rotor core and the stator, and a circulating fluid that cools the stator and the rotor core in the frame is a pipe jacket cooling side fluid, and external air from the outside is a cooling side in the pipe A cooler in which a plurality of cooling pipes extending in the direction of the main shaft as a fluid are arranged in parallel, and is attached to the upper part of the frame to form a sealed space together with the frame, including the cooler, A cooler inlet side opening provided below a region including one end portion in the direction of the main shaft in order to flow in from the inside of the frame, and the other end portion in the direction of the main shaft in order to flow out into the frame A cooler cover that communicates with the frame by a cooler outlet side opening provided below a region including the rotor shaft, and the rotor shaft at a portion below the cooler inlet side opening and outside the rotor core in the main axis direction And an internal fan that circulates the circulating fluid in the sealed space, and an adjustment that is provided in the cooler cover and is provided above the cooler to generate a rotating flow of the circulating fluid around a vertical axis. A plurality of adjusting fans, and each of the adjusting fans is arranged in a direction perpendicular to the longitudinal direction of the cooling pipe, and each of the adjusting fans is arranged with the cooling pipe. When divided into groups of cooling pipes provided below the position, the groups of cooling pipes adjacent to each other are formed so that the pressure loss of the circulating fluid is sequentially reduced. To do.

  ADVANTAGE OF THE INVENTION According to this invention, the cooling performance in the cooler of a fully enclosed rotary electric machine can be improved.

It is a longitudinal cross-sectional view of the fully-closed rotary electric machine which concerns on 1st Embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. FIG. 3 is a plan sectional view taken along the line III-III in FIG. 1. It is a longitudinal cross-sectional view of the fully-closed rotary electric machine which concerns on 2nd Embodiment. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4. FIG. 6 is a plan sectional view taken along line VI-VI in FIG. 4. It is a cross-sectional view in the portion of the internal fan of the conventional fully-closed rotating electrical machine. It is a top sectional view of the upper part of the cooler of the conventional fully-closed rotating electrical machine.

  Hereinafter, a fully-closed rotating electrical machine according to an embodiment of the present invention will be described with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

[First Embodiment]
FIG. 1 is a longitudinal sectional view of a fully-closed rotating electrical machine according to the first embodiment. 2 is a cross-sectional view taken along the line II-II in FIG. 3 is a cross-sectional plan view taken along line III-III in FIG.

  The fully-closed rotating electrical machine 100 includes a rotor 10, a stator 20, a frame 30, a bearing bracket 36, a cooler 41, and a cooler cover 43 that houses the cooler 41. The rotor 10 includes a rotor shaft 11 that is rotatably supported around a main shaft and extends in the horizontal direction, and a rotor core 12 that is provided on the radially outer side of the rotor shaft 11. The stator 20 includes a cylindrical stator core 21 provided on the outer side in the radial direction of the rotor core 12, and a stator coil 22 provided along a slot formed on the surface of the stator core 21 in the main axis direction. Have The rotor core 12 and the stator 20 are housed in a frame 30.

  The rotor shaft 11 is supported by bearings 35 on both outer sides in the main axis direction of the rotor core 12. The fixed portions of the bearing 35 are fixedly supported by bearing brackets 36, respectively. The bearing bracket 36 is fixedly supported by the frame 30. A cooler cover 43 is mounted on the upper portion of the frame 30. The frame 30, the bearing brackets 36 on both sides, and the cooler cover 43 form a sealed space 45. The atmosphere in the frame 30 and the atmosphere in the cooler cover 43 communicate with each other through the cooler inlet side opening 31 and the cooler outlet side opening 32.

  The cooler 41 has a plurality of cooling pipes 42. Each cooling pipe 42 extends in the main axis direction in parallel with each other. Each cooling pipe 42 is connected to the cooler cover 43 at both ends, and the inside of the cooling pipe 42 is open to the outside. The outside of the cooling pipe 42 is joined to the cooler cover 43 by welding. The outside of the cooling pipe 42 is a part of the sealed space 45, and the cooling pipe 42 is a part of the elements constituting the sealed space 45.

  An outer fan fan 44 is attached to the rotor shaft 11 outside the frame 30. The outer fan cover 44a on the suction side of the outer fan fan 44 is provided with a suction port (not shown). The external fan 44 sucks air in the external atmosphere, that is, external air, from a suction port formed in the external fan cover 44 a, and sends the sucked external air into the cooling pipe 42. The outer fan cover 44a serves as a guide to the inlet of the cooling pipe 42 for sucked outside air. The external air flowing into each cooling pipe 42 is discharged from the end of the cooling pipe 42 after cooling the circulating fluid by heat exchange with the circulating fluid (for example, air) flowing outside the cooling pipe 42. Here, the circulating fluid is a cooling gas that circulates in the sealed space 45.

  An inner fan 15 is attached to the outer side in one axial direction of the rotor core 12 of the rotor shaft 11. A partition plate 37 a is provided around the inner fan 15. The partition plate 37 a divides the inside of the frame 30 into a suction side and a discharge side of the inner fan 15. Further, a partition plate 37b is provided on the opposite side in the axial direction across the partition plate 37a and the rotor core 12, and the rotor core side and the outside thereof are separated.

  The inner fan 15 rotates with the rotation of the rotor shaft 11, sucks the circulating fluid on the rotor core 12 side, and discharges it to the outside in the main axis direction. This circulating fluid is transferred from the frame 30 to the cooler cover 43 side via the cooler inlet side opening 31. The circulating fluid transferred to the cooler cover 43 side is cooled while passing through the outside of the cooling pipe 42 by the cooler 41, and then transferred from the cooler cover 43 side into the frame 30 through the cooler outlet side opening 32. Is done. The circulating fluid transferred into the frame 30 flows into the rotor core 12 and the stator 20 to cool them, and then flows into the inner fan 15 again.

  An adjustment fan 61 is provided in the space above the cooler 41. The adjusting fan 61 is provided at a position close to the cooler inlet side opening 31 in the main axis direction from the longitudinal center of the cooling pipe 42. The adjustment fan 61 is fixedly supported on the upper surface of the cooler cover 43 and rotates around the vertical axis. The rotation direction of the adjustment fan 61 (see FIG. 3) viewed from above is counterclockwise, and the inner fan fan 15 (see FIG. 2) viewed from the opposite side of the rotor core 12 is rotated. The direction of rotation is opposite to the clockwise direction.

  Next, the operation of the fully-closed rotating electrical machine according to the present embodiment configured as described above will be described. The circulating fluid that has flowed out of the inner fan fan 15 into the space opposite to the rotor core 12 flows into the cooler cover 43 from the space via the cooler inlet side opening 31.

  As shown in FIG. 2, the case where the inner fan 15 rotates in the clockwise direction when viewed from the opposite side of the rotor core 12 (FIG. 1) in the axial direction is considered. The circulating fluid passing through the inner fan 15 flows out in the direction in which the radial direction component and the rotational direction component are combined. The flow velocity distribution when flowing out of this space and passing through the cooler inlet side opening 31 is not uniform because it is affected by the rotation direction of the inner fan 15. That is, the flow rate when the direction in which the outflow direction from the internal fan 15 faces the direction of the cooler inlet side opening 31 (left side in FIG. 2) passes through the cooler inlet side opening 31 is higher.

  As shown in FIG. 3, the circulating fluid that has flowed into the cooler 41 through the cooler inlet side opening 31 similarly has a velocity distribution in a direction perpendicular to the traveling direction. Here, the flow of the circulating fluid is a flow in the main axis direction in the cooler cover 43, that is, in the flow path outside the cooling pipe 42 in the cooler 41 and the space above the cooler 41.

  This flow passes around the adjustment fan 61. When the adjustment fan 61 is viewed from above, the adjustment fan 61 rotates counterclockwise. By this rotation, a flow component in the counterclockwise direction is generated around the adjusting fan 61. The flow component of the circulating fluid in the counterclockwise direction acts in a direction that reduces non-uniformity in the flow rate distribution of the circulating fluid that has passed through the cooler inlet side opening 31 and entered the cooler 41. As a result, the flow of the circulating fluid downstream from the periphery of the adjusting fan 61 reduces non-uniformity in the velocity distribution in the direction perpendicular to the main axis direction.

  For this reason, since the flow rate is low, the amount of heat exchange between the external air flowing inside the cooling pipe 42 and the circulating fluid flowing outside the cooling pipe 42 is low, so that the cooling efficiency of the entire cooler 41 is low. Improved cooling efficiency.

  As described above, according to the present embodiment, the cooling efficiency in the cooler 41 of the fully-closed rotating electrical machine 100 can be improved.

[Second Embodiment]
FIG. 4 is a longitudinal sectional view of a fully-closed rotating electrical machine according to the second embodiment. FIG. 5 is a cross-sectional view taken along line VV in FIG. 6 is a cross-sectional plan view taken along line VI-VI in FIG.

  This embodiment is a modification of the first embodiment. In the second embodiment, two adjustment fans 62a and 62b are provided. The adjustment fan 62a and the adjustment fan 62b are arranged side by side in the horizontal direction perpendicular to the main shaft. The rotational direction (FIG. 6) when the adjustment fans 62 a and 62 b are viewed from above is opposite to the rotational direction (FIG. 5) of the internal fan 15 when the internal fan 15 is viewed from the opposite side of the rotor core 12.

  Now, let us consider a case where the rotation direction of the inner fan 15 as viewed from the opposite side of the rotor core 12 is clockwise as in the first embodiment. In this case, the rotation direction when the adjustment fans 62a and 62b are viewed from above is counterclockwise.

  The cooling pipe 42a and the cooling pipe 42b are divided into two groups in a horizontal direction perpendicular to the main axis. The group of the cooling pipes 42a is a group arranged below the adjustment fan 62a. The group of the cooling pipes 42b is a group arranged below the adjustment fan 62b. Due to the effect that the rotation direction of the adjustment fan 62a is opposite to the rotation direction of the inner fan fan 15, the distribution in the direction perpendicular to the main axis direction of the flow rate of the circulating fluid passing through the region of the adjustment fan 62a is averaged. . Further, due to the effect that the rotation direction of the adjustment fan 62b is opposite to the rotation direction of the inner fan fan 15, the distribution of the flow rate of the circulating fluid passing through the region of the adjustment fan 62b in the direction perpendicular to the main axis direction is averaged. Is done.

  Moreover, the mutual pitch of the group of the cooling pipes 42b is larger than the mutual pitch of the group of the cooling pipes 42a. That is, the flow rate of the circulating fluid outside the cooling pipe 42b is smaller than the flow resistance of the flow path, and is larger than the flow rate of the circulating fluid outside the cooling pipe 42a.

The heat transfer coefficient U in the radial direction in the cooling pipe, the heat transfer coefficient hi inside the cooling pipe, the heat conductivity λ of the cooling pipe, and the heat transfer coefficient ho outside the cooling pipe have the following relationship (1). . Where t is the thickness of the cooling pipe.
1 / U = 1 / hi + t / λ + 1 / ho (1)

  Here, since the fluid inside and outside the cooling pipe is a gas, the thermal resistance component due to the thermal conductivity of the second term on the right side is generally negligible compared to the first and third terms. Here, in the case of forced convection, the heat transfer coefficient is generally proportional to, for example, about 0.5 to 0.8 power of the flow velocity. Therefore, when the flow rate of the external air inside the cooling pipe is sufficiently larger than the flow rate of the circulating fluid outside the cooling pipe, the inner heat transfer coefficient hi is sufficiently larger than the outer heat transfer coefficient ho. Therefore, the inner thermal resistance, which is the reciprocal number of each, is smaller than the outer thermal resistance.

  From the above, if the flow rate of the inner external air is sufficiently larger than the flow rate of the outer circulating fluid, 1 / U is approximately equal to 1 / ho, that is, the radial heat transfer rate U is equal to the outer heat transfer rate ho. It can be said that they are almost equal. That is, the heat passage rate U of the cooling pipe is almost determined by the flow velocity outside the cooling pipe. Since the flow rate of the circulating fluid outside the cooling pipe 42b is larger than the flow rate of the circulating fluid outside the cooling pipe 42a, the heat passing rate in the cooling pipe 42b is higher than the heat passing rate in the cooling pipe 42a. Bigger than.

  The amount of heat exchange between the external air inside the cooling pipe 42b and the circulating fluid outside the cooling pipe 42b in the cooling pipe 42b depends on the temperature and flow velocity of the external air, the temperature and flow velocity of the circulating fluid, and the heat transfer area of the cooling pipe 42b. Dependent. Due to the difference in pitch, the heat transfer area of the entire group of cooling pipes 42b is smaller than the heat transfer area of the entire group of cooling pipes 42a. On the other hand, since the flow rate of the circulating fluid outside the cooling pipe 42b is larger than the flow rate of the circulating fluid outside the cooling pipe 42a, the heat transfer coefficient outside the cooling pipe 42b is larger than the heat transfer coefficient outside the cooling pipe 42a.

  As described above, when the cooling pipe 42b is compared with the cooling pipe 42a, the heat transfer area is reduced, but the outer heat transfer coefficient is increased. Overall, the heat exchange amount of the group of the cooling pipes 42b and the cooling The amount of heat exchange in the group of tubes 42a is substantially equal.

  As described above, in the fully-closed rotating electrical machine according to the present embodiment, the cooling performance can be ensured by eliminating the uneven distribution of the heat exchange amount in the cooler 41 and averaging the distribution.

  As a modification of the present embodiment, the pressure loss of the circulating fluid outside the cooling pipe 42b can be reduced by reducing the pipe diameter of the cooling pipe 42b instead of increasing the pitch of the group of the cooling pipes 42b. Good. External air passing through the inside of each of the cooling pipe 42 a and the cooling pipe 42 b is supplied by an external fan 44. For this reason, the flow rate of the external air inside the cooling tube 42a and the cooling tube 42b is generally sufficiently larger than the flow rate of the circulating fluid outside the cooling tube 42a and the cooling tube 42b.

  For this reason, the reduction of the heat transfer area by reducing the diameter of the cooling pipe 42b is set so as to compensate for the increase in the heat transfer rate U due to the increase in the flow velocity outside the cooling pipe. The same effect as that of the second embodiment can be obtained.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described, embodiment is shown as an example and is not intending limiting the range of invention. The embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. The embodiments and the modifications thereof are included in the scope of the invention and the scope of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Rotor, 11 ... Rotor shaft, 12 ... Rotor iron core, 15 ... Inner fan fan, 20 ... Stator, 21 ... Stator iron core, 22 ... Stator coil, 30 ... Frame, 31 ... Opening at cooler inlet side 32 ... Cooler outlet side opening, 35 ... Bearing, 36 ... Bearing bracket, 37a, 37b ... Partition plate, 41 ... Cooler, 42, 42a, 42b ... Cooling pipe, 43 ... Cooler cover, 44 ... Outer fan 44a ... Outer fan cover, 45 ... Sealed space, 61, 62a, 62b ... Adjusting fan, 100 ... Fully-closed rotating electrical machine

Claims (2)

A rotor shaft rotatably supported around a horizontally extending main shaft and extending in the main shaft direction; and a rotor core fixed to a radially outer side of the rotor shaft and extending in the main shaft direction;
A stator having a stator core that is arranged on the radially outer side of the rotor core and extends in the main axis direction, and a stator coil wound around the stator core;
A frame for housing the rotor core and the stator;
A circulating fluid that cools the stator and the rotor core in the frame is a pipe jacket cooling side fluid, and external air from the outside is a pipe cooling side fluid, and a plurality of cooling pipes extending in the direction of the main shaft are arranged in parallel. And arranged coolers,
It is attached to the upper part of the frame to form a sealed space together with the frame, and is provided below a region including one end in the direction of the main shaft for containing the cooler and flowing in from the frame. A cooler inlet side opening, and a cooler cover communicating with the frame by a cooler outlet side opening provided below a region including the other end in the direction of the main shaft for flowing out into the frame; ,
An inner fan fan that is attached to the rotor shaft at a lower portion of the rotor core on the principal axis direction of the rotor core and circulates the circulating fluid in the sealed space;
An adjusting fan that is provided in the cooler cover and is provided above the cooler and that generates a rotating flow of the circulating fluid around a vertical axis in order to uniformize a velocity distribution of the circulating fluid;
Equipped with a,
The rotational direction of the adjusting fan viewed adjusting fan from above, the direction of rotation of said fan fan viewed from the opposite side of said inner fan fan the rotor core all characterized reverse der Rukoto Closed rotary electric machine. A rotor shaft rotatably supported around a horizontally extending main shaft and extending in the main shaft direction; and a rotor core fixed to a radially outer side of the rotor shaft and extending in the main shaft direction;
A stator having a stator core that is arranged on the radially outer side of the rotor core and extends in the main axis direction, and a stator coil wound around the stator core;
A frame for housing the rotor core and the stator;
A circulating fluid that cools the stator and the rotor core in the frame is a pipe jacket cooling side fluid, and external air from the outside is a pipe cooling side fluid, and a plurality of cooling pipes extending in the direction of the main shaft are arranged in parallel. And arranged coolers,
It is attached to the upper part of the frame to form a sealed space together with the frame, and is provided below a region including one end in the direction of the main shaft for containing the cooler and flowing in from the frame. A cooler inlet side opening, and a cooler cover communicating with the frame by a cooler outlet side opening provided below a region including the other end in the direction of the main shaft for flowing out into the frame; ,
An inner fan fan that is attached to the rotor shaft at a lower portion of the rotor core on the principal axis direction of the rotor core and circulates the circulating fluid in the sealed space;
An adjusting fan that is provided in the cooler cover and is provided above the cooler and generates a rotating flow of the circulating fluid around a vertical axis;
With
A plurality of adjustment fans are provided, and each of the adjustment fans is arranged in a direction perpendicular to the longitudinal direction of the cooling pipe,
When the cooling pipes are divided into groups of cooling pipes provided below the positions where the adjustment fans are provided, the pressure loss of the circulating fluid sequentially decreases between the adjacent cooling pipe groups. All-closing rotary electric machine you characterized in that it is formed as.

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