JP2017175788A - Brushless rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling performance of an exciting device of a brushless rotary electric machine having a rotary rectifier.SOLUTION: A brushless rotary electric machine 100 comprises: a rotor 10 having a rotor shaft 11 and a rotor core 12; a stator 20 having a stator core 21 and a stator winding 22; an exciting device 50 having a rotary rectifier 51; a frame 30; a cooler 41; a cooler cover 42; an exciting device cooler 61 including the exciting device 50; a branched pipe 62 connecting the exciting device cooler 61 and the cooler cover 42 together; a return pipe 63 connecting the exciting device cooler 61 and the frame 30 together; an inner fan 15; an exciting device cooling acceleration machine 70 provided on the branched pipe 62 and performing cooling of gas for cooling; and a connection pipe 74 coupling the branched pipe 62 and the exciting device cooling acceleration machine 70 together. The exciting device cooling acceleration machine 70 is constituted in such a way that a part of the gas for cooling supplied via the connection pipe 74 is used for gas on cooling side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a brushless rotating electrical machine.

  In a synchronous rotating electric machine, an armature winding is usually provided on the stator side and a field winding is provided on the rotor side. The DC power to the field winding provided in the rotor is usually supplied from a rectifier provided on the stationary side via a brush. Since this brush requires maintenance and replacement, there is known a technique for making the brushless by using a method in which the rectifier of the exciter is rotated together with the rotor in order to eliminate the need for the brush.

Japanese Patent No. 5605777 JP-A-8-251871

  The rotary rectifier or the like is usually provided at the extended portion by extending the rotor shaft of the rotor. Usually, the stationary part of the exciter is also provided in the vicinity of the rotary rectifier.

  In order to cool the rotor and the stator of the rotating electrical machine, a cooling gas circulates in a circulation channel in the machine of the rotating electrical machine. In order to cool the heat generated by the rectifier of the exciter, a branched flow path is formed so that a part of the cooling gas is used by branching from the circulation flow path in the rotating electric machine (Patent Document). 1, 2).

  Therefore, it is necessary to cool the heat generated by the rectifier of the exciter without impairing the cooling function of the rotor and stator of the rotating electrical machine. For this reason, the cooling with respect to heat_generation | fever of the rectifier etc. of an efficient excitation device is calculated | required.

  Accordingly, an object of the present invention is to improve the cooling performance of an excitation device in a brushless rotating electrical machine having a rotary rectifier.

  In order to achieve the above object, a brushless rotating electrical machine according to the present invention includes a rotor shaft that is rotatably supported around a main shaft and extends in the main shaft direction, and is fixed to the outer side in the radial direction of the rotor shaft. A rotor having an extended rotor core, a rotor winding penetrating through the rotor core, a stator core that is disposed radially outside the rotor core and extends in the main axis direction, and the fixing thereof A stator having a stator winding wound around a core of the core, an excitation device having a rotary rectifier that rotates with the rotor shaft, a frame for housing the rotor core and the stator, A cooler that cools a cooling gas that cools the stator and the rotor core; and a sealed space that is attached to an upper portion of the frame to form a sealed space together with the frame. And a cooler cover that communicates with the frame by a cooler inlet opening for allowing the cooling gas to flow into the frame and a cooler outlet opening for allowing the cooling gas to flow into the frame; The exciter cover that includes the exciter and forms a part of the sealed space, the branch pipe that connects the exciter cover and the cooler cover, and the exciter cover and the frame are connected. A return pipe, an inner fan that is attached to the rotor shaft and circulates the cooling gas in the sealed space, and an excitation device cooling accelerator that is provided in the branch pipe and cools the cooling gas in the branch pipe And a connecting pipe that connects the branch pipe and the excitation device cooling accelerator, and the excitation device cooling accelerator is configured to supply the cooling gas supplied through the connection pipe. Parts is configured to be used in the cooling side of the gas of the exciter cooling promotion machine, characterized in that.

  ADVANTAGE OF THE INVENTION According to this invention, in the brushless rotary electric machine which has a rotary rectifier, the improvement of the cooling performance of an exciting device can be aimed at.

1 is an elevational sectional view of a brushless rotating electrical machine according to an embodiment of the present invention. 1 is an enlarged sectional view showing an excitation device cooling accelerator for a brushless rotating electrical machine according to an embodiment of the present invention.

  Hereinafter, a brushless rotating electrical machine according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an elevational sectional view of a brushless rotating electrical machine according to an embodiment of the present invention. The brushless rotating electrical machine 100 includes a rotor 10, a stator 20, and an excitation device 50.

  The rotor 10 includes a rotor shaft 11 that extends in the direction of the rotation axis and is rotatably supported, a rotor core 12 that is disposed radially outside the rotor shaft 11 and is coupled to the rotor shaft 11, and the rotor core 12. And a rotor winding 13 penetrating therethrough. An inner fan 15 is attached to the rotor shaft 11 and rotates with the rotation of the rotor shaft 11. A partition plate 15 a is provided in the radial direction of the inner fan 15. The inner fan 15 sucks the cooling gas on the outer side in the axial direction of the inner fan 15 and the partition plate 15a, that is, the bearing 32 side, and pushes it out to the rotor core 12 and the stator 20 side.

  The stator 20 is arranged on the outer side in the radial direction of the rotor core 12 and is formed on the surface of the stator core 21 on the inner side in the radial direction with an interval in the circumferential direction. And a stator winding 22 installed in a plurality of extended slots (not shown).

  The exciter 50 includes a rotary rectifier 51, an exciter rotating unit 52, and an exciter fixing unit 53. The rotation rectifier 51 and the exciter rotating unit 52 are attached to the rotor shaft 11 and rotate together with the rotor shaft 11. The exciter fixing part 53 is stationary and fixed outside the exciter rotating part 52 in the radial direction so as to face the exciter rotating part 52 in the radial direction.

  For example, when the brushless rotating electrical machine 100 is a generator, it operates as follows. That is, DC power is supplied to the exciter fixing unit 53 from a power source (not shown). As a result, the exciter fixing part 53 becomes an electromagnet. In addition, the exciter fixing part 53 is not limited to an electromagnet using a coil. For example, when it is not necessary to control the field current of the brushless rotating electrical machine 100, that is, the current flowing through the coil of the rotor 10, a permanent magnet may be used.

  When the exciter rotating unit 52 rotates around the rotation axis inside the DC field by the exciter fixing unit 53, an AC induction is generated in the exciter rotating unit winding (not shown) of the exciter rotating unit 52. An electromotive force is generated. The AC power generated in the exciter rotating part winding is converted into DC power by the rotary rectifier 51 and applied to the rotor winding (field winding) 13 provided on the rotor core 12 that also rotates around the rotation axis. Supplied. This field generates an induced electromotive force in the stator winding 22, that is, the armature winding.

  The stator 20 and the rotor core 12 are accommodated in the frame 30. Bearing brackets 34 are connected to both ends of the frame 30 in the axial direction. Each of the bearing brackets 34 supports the bearing 32. The bearing 32 supports the rotor shaft 11 to be rotatable. The exciter 50 is accommodated in the exciter cover 61.

  An air supply pipe 31 passes through the frame 30. The penetrating part is processed to be leak tight. An end of the air supply pipe 31 in the frame 30 is open to the suction side of the inner fan 15. The other end of the air supply pipe 31 is open to the outside air outside the frame 30. Note that the other end of the supply pipe 31 may be connected to a pressure source such as a compressor or a blower (not shown).

  That is, in the nozzle 75 (FIG. 2) attached to the header 73 (FIG. 2) to be described later, the pressure of the cooling gas in the nozzle 75 is set high enough to eject the cooling gas from the nozzle 75. Specifically, a pressure obtained by adding the head to the suction pressure of the inner fan 15 and subtracting the pressure loss from the inner fan 15 to the branch pipe 62 is the pressure at the communication pipe 74 inlet. If the pressure at the inlet of the connecting pipe 74 is equal to or greater than the pressure loss from the inlet of the connecting pipe 74 to the outlet of the nozzle 75 described later, and a pressure sufficiently higher than the pressure higher than the atmospheric pressure, the cooling gas is supplied from the nozzle 75 described later. It is possible to erupt. This pressure can be adjusted by the suction pressure of the inner fan 15.

  A cooler 41 is provided on the upper portion of the frame 30. The cooler 41 is accommodated in the cooler cover 42. The cooler 41 has a cooling pipe (not shown), and the cooling gas flowing outside the cooling pipe is cooled by the cooling medium flowing inside the cooling pipe.

  The frame 30, the bearing bracket 34, the exciter cover 61, and the cooler cover 42 are joined together to form a sealed space as a whole. The space in the frame 30 and the space in the cooler cover 42 communicate with each other through the cooler inlet opening 43 and the cooler outlet opening 44. The space in the frame 30 and the space in the exciter cover 61 are communicated by a branch pipe 62 and a return pipe 63.

  The branch pipe 62 is provided with an exciting device cooling accelerator 70. Further, a connecting pipe 74 extending from the branch pipe 62 to the exciter cooling accelerator 70 is provided.

  As the rotor shaft 11 rotates, the inner fan 15 rotates and drives the cooling gas in the frame 30. The cooling gas is pushed out in the radial direction and flows into the cooler cover 42 from the cooler inlet opening 43. The cooling gas flowing into the cooler cover 42 is cooled by the cooler 41, then flows out of the cooler 41, and flows into the frame 30 through the cooler outlet opening 44. The cooling gas flowing into the frame 30 cools the rotor 10 and the stator 20 while passing through the rotor 10 and the stator 20 and then flows into the inner fan 15 side.

  A part of the cooling gas flowing out of the cooler 41 flows into the branch pipe 62 and flows into the exciter cover 61 to cool the heat generating part including the rotary rectifier 51, and from the return pipe 63. Returning to the frame 30, the cooling gas flows into the frame 30 from the cooler outlet opening 44 and merges.

  FIG. 2 is an enlarged sectional view showing an excitation device cooling accelerator of the brushless rotating electrical machine according to the embodiment of the present invention. The exciter cooling accelerator 70 includes a central duct 71, a jet pump guide pipe 72, and a header 73.

  The central duct 71 is a straight pipe whose both ends are open, and is provided in the middle of the branch pipe 62. Both ends of the central duct 71 are connected to the branch pipe 62. The cross section of the central duct 71 has the same shape as the branch pipe 62. At both ends of the central duct 71, connection flanges 71a are provided. Connection flanges are also provided at the connection portions of the branch pipe 62 with the central duct 71.

  A plurality of fins 76 extending in the radial direction and extending in the flow direction of the central duct 71 are attached to the outer surface of the central duct 71. The plurality of fins 76 are provided at intervals in the circumferential direction of the central duct 71.

  The material of the central duct 71 and the fin 76 is a good thermal conductor compared to the material of the branch pipe 62. That is, the material of the branch pipe 62 is usually an iron-based material, for example. On the other hand, the material of the central duct 71 and the fin 76 is a good thermal conductor such as copper or aluminum.

  A jet pump guide pipe 72 is provided outside the central duct 71 in the radial direction. Both ends of the jet pump guide pipe 72 are opened, and the inner diameter is gradually increased along the flow direction of the central duct 71, and then the inner diameter gradually increases after reaching the minimum diameter.

  The header 73 is provided at the inlet of the jet pump guide pipe 72 outside the central duct 71 in the radial direction, and is formed so as to surround the central duct 71 on the entire circumference. The header 73 is provided with a plurality of nozzles 75. Each of the nozzles 75 is arranged so that the gap 72a between the central duct 71 and the jet pump guide pipe 72 is directed to the narrowest part on the downstream side in the flow direction of the central duct 71.

  A connecting pipe 74 is connected to the header 73. In addition, although the example which the connection pipe 74 has couple | bonded with the header 73 in one place is shown, the connection pipe 74 branches into two, for example, and each is 180 degree | times in the circumferential direction, for example in the header 73 mutually It may be connected at a distant position, or may be connected after branching to three or more.

  During rotation of the rotor shaft 11, the pressure in the brushless rotating electrical machine 100 is in a state where cooling gas can be ejected from the nozzle 75. When the cooling gas is ejected from each nozzle 75, the ambient air is drawn in by the action of the jet pump. The gap 72a is narrowed in the middle, and the flow velocity is increased and the static pressure is reduced at this portion, so that the effect of drawing ambient ambient air further increases.

  As a result, in the gap 72a between the central duct 71 and the jet pump guide pipe 72, a mixed gas of cooling gas and outside air flows. In addition, although the cooling gas flows out from the nozzle 75, the inventory of the cooling gas in the sealed space is reduced, but that amount flows into the sealed space from the air supply pipe 31 and is replenished. In the case of a supply method, replenishment may be performed automatically according to the pressure in the machine. Or the system of adjusting the fixed amount manually as a fixed amount of supply may be used.

  Therefore, the temperature of the cooling gas corresponding to the mixing ratio and the gas having the average temperature of the outside air pass outside the central duct 71. Heat exchange occurs between the cooling gas flowing inside the central duct 71 and the mixed gas flowing outside the central duct 71. The heat transfer surfaces at this time are the outer surface of the central duct 71 and the fins 76. As a result, the cooling gas flowing inside the central duct 71 is cooled and flows into the exciter cover 61 with the temperature lowered. For this reason, the cooling efficiency of the rotary rectifier 51 and the like in the exciter cover 61 is improved.

  As described above, according to the present embodiment, in the brushless rotating electrical machine 100 having the rotary rectifier 51, the cooling performance of the excitation device 50 can be improved.

  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. Furthermore, these 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. These embodiments and their modifications are included in the scope and gist 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 core, 13 ... Rotor winding, 15 ... Inner fan, 15a ... Partition plate, 20 ... Stator, 21 ... Stator iron core, 22 ... Stator winding , 30 ... Frame, 31 ... Supply pipe, 32 ... Bearing, 34 ... Bearing bracket, 41 ... Cooler, 42 ... Cooler cover, 43 ... Cooler inlet opening, 44 ... Cooler outlet opening, 50 ... Excitation device, 51 Rotating rectifier 52 Exciter rotating unit 53 Exciter fixing unit 61 Exciter cover 62 62 Branch pipe 63 Return pipe 70 Exciter cooling accelerator 71 Central duct 71a Flange 72 ... Jet pump guide pipe, 72a ... Gap, 73 ... Header, 74 ... Connecting pipe, 75 ... Nozzle, 76 ... Fin, 100 ... Brushless rotating electrical machine

Claims (5)

A rotor shaft that is rotatably supported around the main shaft and extends in the main shaft direction, a rotor core that is fixed radially outside the rotor shaft and extends in the main shaft direction, and a rotor that passes through the rotor core A rotor having windings;
A stator core disposed on the outer side in the radial direction of the rotor core and extending in the main axis direction, and a stator winding wound around the stator core;
An excitation device having a rotary rectifier rotating with the rotor shaft;
A frame for housing the rotor core and the stator;
A cooler for cooling a cooling gas for cooling the stator and the rotor core in the frame;
A cooling space that is attached to an upper part of the frame to form a sealed space together with the frame, encloses the cooler, and allows the cooling gas to flow in from the frame; and A cooler cover in communication with the frame by a cooler outlet opening for flow into the frame;
An exciter cover that encloses the exciter and forms part of the sealed space;
A branch pipe connecting the exciter cover and the cooler cover;
A return pipe connecting the exciter cover and the frame;
An inner fan attached to the rotor shaft and circulating the cooling gas in the sealed space;
An excitation device cooling accelerator provided in the branch pipe for cooling the cooling gas in the branch pipe;
A connecting pipe connecting the branch pipe and the excitation device cooling accelerator;
With
The excitation device cooling accelerator is configured such that a part of the cooling gas supplied via the connecting pipe is used as a gas on the cooling side of the excitation device cooling accelerator.
This is a brushless rotating electrical machine. The exciter cooling accelerator is
A central duct through which the cooling gas, which is a medium to be cooled, passes;
A pipe disposed outside the central duct in the radial direction and having an inlet and an outlet open. A jet pump guide tube formed to increase;
Have
The connecting pipe is radially outside the central duct and opens to the inlet of the jet pump guide pipe.
The brushless rotating electrical machine according to claim 1.   The brushless rotating electrical machine according to claim 2, wherein the material of the central duct is a good conductor that is more thermally than the thermal conductivity of the branch pipe.   The exciter cooling accelerator spreads radially on the outer surface of the central duct, extends along the flow direction of the central duct, and is spaced apart from each other in the circumferential direction. The brushless rotating electrical machine according to claim 2, further comprising a plurality of fins that are typical good conductors. The exciter cooling accelerator further includes a header provided with a plurality of nozzles and provided at an inlet of the jet pump guide tube,
The connecting pipe is connected to the header and opens into the header;
The plurality of nozzles open toward the downstream side in the flow direction of the central duct in the jet pump guide pipe.
The brushless rotating electrical machine according to any one of claims 2 to 4, wherein the brushless rotating electrical machine is provided.

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