JP2013046554A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine capable of suppressing a temperature rise of a stator iron core coil and of achieving large capacity.SOLUTION: According to one embodiment, a rotary electric machine comprises: a stator frame 12; a stator 30 that has an annular stator iron core 32 disposed in the stator frame 12 in a coaxial manner and a plurality of iron core coils 34 installed to the stator iron core 32 and defines a cooling ventilation passage between an outer periphery of the stator iron core 32 and an inner surface of the stator frame 12; a rotatable rotor 40 disposed inside the stator iron core 32 in the coaxial manner; cooling fans 50a and 50b that are installed on the rotor 40 and integrally rotate with the rotor 40; fan covers 60a and 60b that cover axial direction ends of the stator 30 and the rotor 40 and the cooling fans 50a and 50b and are fixed to the stator frame 12; and air intake ports 62a and 62b that are formed at the fan covers 60a and 60b and positioned coaxial with the rotor 40. External diameters D1 of the air intake ports 62a and 62b of the fan covers 60a and 60b and internal diameters d of fins of the cooling fans 50a and 50b are formed so as to have substantially the same dimensions.

Description

  Embodiments of the present invention relate to a rotating electrical machine used for, for example, a hoisting machine of an elevator.

  For example, a rotating electrical machine used for a hoisting machine of an elevator includes a cylindrical stator core and a rotor that is rotatably supported inside the stator core. A plurality of slits are formed in the stator core, and stator coils are embedded in these slits.

  In recent years, in order to suppress the heat generation of the rotor and realize a more compact rotating electric machine, a permanent magnet type rotating electric machine configured by inserting a permanent magnet into a rotor core instead of a squirrel-cage rotor is increasing.

JP 2008-029150 A JP 2008-099491 A

  Usually, a rotary electric machine used for a hoisting machine or the like has a limitation in installation space, but more capacity is desired. When the rotating electrical machine is reduced in size, weight, and capacity, the heat generation density per unit volume increases. In particular, the temperature of the stator core coil rises, affecting the durability and reliability.

  Accordingly, an object of the present invention is to provide a rotating electrical machine capable of suppressing the temperature increase of the stator core coil and increasing the capacity.

  According to the embodiment, the rotating electrical machine has a stator frame, an annular stator core disposed coaxially in the stator frame, and a plurality of core coils attached to the stator core, A stator defining a cooling air passage between an outer periphery of the stator core and an inner surface of the stator frame; a rotatable rotor provided coaxially inside the stator core; and the rotation A cooling fan attached to the rotor and rotating integrally with the rotor, axial ends of the stator and the rotor, a fan cover that covers the cooling fan and is fixed to the stator frame, and the fan cover And the outside diameter of the air inlet of the fan cover and the inside diameter of the fin of the cooling fan are formed to have substantially the same dimensions.

FIG. 1 is a perspective view showing a rotating electrical machine according to the first embodiment. FIG. 2 is a longitudinal sectional view showing a flow of cooling air of the rotating electric machine. FIG. 3 is a longitudinal sectional view of the rotating electric machine. FIG. 4 is a perspective view showing a stator frame of the rotating electrical machine. FIG. 5 is a perspective view showing spacers (ribs) arranged between the stator frame and the stator core. FIG. 6 is a perspective view showing a stator core of the rotating electrical machine. FIG. 7 is a side view showing a stator frame and a stator core of the rotating electric machine. FIG. 8 is a perspective view showing a rotor of the rotating electrical machine. FIG. 9 is a diagram showing the relationship between the cooling temperature and the ratio between the diameter D of the air inlet of the fan cover and the inner diameter d of the cooling fan. FIG. 10 is a diagram showing the relationship between the ratio of the protruding length C of the iron core coil and the fin chord length L of the cooling fan and the cooling temperature. FIG. 11 is a perspective view showing a rotating electrical machine according to the second embodiment.

  Various embodiments will be described below with reference to the drawings. In addition, the same code | symbol shall be attached | subjected to a common structure through embodiment, and the overlapping description is abbreviate | omitted. In addition, each drawing is a schematic diagram for promoting the embodiment and its understanding, and its shape, dimensions, ratio, etc. are different from the actual device, but these are considered in consideration of the following description and known techniques. The design can be changed as appropriate.

(First embodiment)
1 shows a rotating electrical machine 10 according to the first embodiment, FIGS. 2 and 3 show longitudinal sections of the rotating electrical machine 10, and FIGS. 4 to 8 show various components of the rotating electrical machine 10. FIG. Yes.
As shown in FIGS. 1 to 3, the rotating electrical machine 10 includes a stator frame 12, a cylindrical stator 30 supported in the fixed frame, and a rotor 40 rotatably provided inside the stator. And cooling fans 50a and 50b formed on the rotor 40, and a pair of fan covers 60a and 60b covering both sides of the stator and the rotor.

  As shown in FIGS. 1, 4, and 7, the stator frame 12 includes a cylindrical frame 14 and an annular flange portion 16 formed integrally with the outer peripheral portion of the cylindrical frame. A pair of leg seats 18 are formed integrally with the lower portion of the flange portion 16. A plurality of exhaust holes 20, for example, rectangular exhaust holes 20 are formed in the cylindrical frame 14, and are provided at intervals along the circumferential direction. In addition, a small-diameter circular exhaust hole 22 is formed at the upper end of the cylindrical frame 14, that is, the upper end in the vertical direction. A plurality of reinforcing ribs 24 are integrally formed on the lower outer surface of the cylindrical frame 14 in the vicinity of the leg seat 18.

  As shown in FIGS. 1 to 7, the stator 30 includes a cylindrical stator core 32. The stator core 32 is configured by laminating a plurality of annular metal plates made of a magnetic material, for example, a silicon steel plate. A plurality of slots extending in the axial direction are formed in the inner peripheral portion of the stator core 32, and the stator core coil 34 is embedded in these slots. The coil ends of the iron core coil 34 project axially from both end faces of the stator iron core 32. A stator 30 is constituted by the stator core 32 and the stator core coil 34.

  The outer diameter Q2 of the stator core 32 is formed to be slightly smaller than the inner diameter Q1 of the cylindrical frame 14. The stator core 32 is coaxially disposed in the cylindrical frame 14, and a plurality of spacers 36 are fitted between the outer peripheral surface of the stator core 32 and the cylindrical frame 14. Each spacer 36 is formed in an elongated cylindrical shape (rib shape). A majority of the spacers 36 are formed with a recess 36a at the center thereof. These spacers 36 extend in the axial direction of the stator core 32, and are arranged side by side at a constant interval in the circumferential direction of the stator core 32. The spacer 36 having the recess 36 a is installed, for example, in a state where the recess 36 a side faces the inner peripheral surface of the cylindrical frame 14.

  In the embodiment, as shown in FIG. 6, the plurality of spacers 36 are fixed to the outer peripheral surface of the stator core 32, and the stator core 32 is fitted into the cylindrical frame 14 by press fitting or shrink fitting. The stator core 32 is coaxially fixed in the cylindrical frame 14. The stator core 32 is fixed and held in the cylindrical frame 14 by an iron core presser (not shown).

As shown in FIGS. 2 and 7, a cooling air passage 37 through which cooling air to be described later flows is formed by a gap between the outer peripheral surface of the stator core 32 and the inner peripheral surface of the cylindrical frame 14. Here, the spaces partitioned by the adjacent spacers 36 communicate with each other through the recesses 36 a of the spacers 36. The plurality of exhaust holes 20 and 22 are opened and communicated with the cooling air passage 37. Most of the exhaust holes 20 are provided in the cylindrical frame 14 between two adjacent spacers 36, and some of the exhaust holes 20 overlap the spacers and are formed in the cylindrical frame. 3. As shown in FIG. 8, the rotor 40 is composed of a rotating shaft 42, a cylindrical rotor core 44 fixed substantially in the center in the axial direction of the rotating shaft, and an iron core retainer (not shown) fixed to the rotating shaft. And have. The rotating shaft 42 extends coaxially with the stator core 32, and both axial ends thereof are rotatably supported by bearings (not shown). The rotor core 44 is coaxially positioned with a gap inside the stator core 32. A driving side end 42a of the rotating shaft 42 penetrates a fan cover described later and extends outside the machine.

  The rotor core 44 is configured by laminating a large number of annular metal plates made of a magnetic material, for example, a silicon steel plate, and a permanent magnet (not shown) is disposed therein. By energizing the stator core coil 34, the rotor core 44 rotates, and the rotating shaft 42 rotates together with the stator core. Thus, a permanent magnet type rotating electrical machine is configured. The rotor 40 may be cage-shaped to constitute an induction type rotating electrical machine.

  As shown in FIGS. 2, 3, and 8, a plurality of fins 52 are fixed to both end surfaces in the axial direction of the rotor core 44, and constitute cooling fans 50 a and 50 b, respectively. The fins 52 are each formed in a rectangular plate shape, and the plurality of fins 52 extend radially with respect to the rotation center of the rotor core 44 and are arranged at equal intervals in the circumferential direction. The inner diameters of the cooling fans 50a and 50b, that is, the inner diameters of the plurality of fins 52 are set to d, and the chord length of each fin 52, that is, the length along the axial direction of the rotor core 44 is set to L. Has been. The cooling fans 50a and 50b rotate together with the rotor 40, as will be described later, sucking outside air and ejecting it radially outward.

  As shown in FIGS. 1 to 3, the fan covers 60 a and 60 b are formed in a disc shape (substantially dish shape) whose outer peripheral portions are bent and bent inward. The fan covers 60a and 60b are made of metal, for example, a thin steel plate having a thickness of 3.2 mm. The fan cover 60 a has a peripheral edge fixed to the stator frame 12, arranged coaxially with the stator 30 and the rotor 40, and covers one end side of the stator 30 and the rotor 40. A space through which cooling air flows is formed between the fan cover 60 a and the stator 30 and the rotor 40. A circular air inlet 62 a is formed at the center of the fan cover 60. The air inlet 62 a is located coaxially with the rotor 40. The output side end of the rotating shaft 42 extends outside the machine through the air inlet 62a. The diameter of the air inlet 62a is set to D1.

  The other fan cover 60b is fixed to the stator frame 12 at its peripheral edge, and is disposed coaxially with the stator 30 and the rotor 40, and covers the other end of the stator 30 and the rotor 40. Yes. A space through which cooling air flows is formed between the fan cover 60 b and the stator 30 and the rotor 40. An annular air inlet 62 b is formed at the center of the fan cover 60. The air inlet 62b is positioned coaxially with the rotor 40. The inner diameter of the air inlet 62b is set to D2, and the outer diameter is set to D1.

  As shown in FIG. 2, when the cooling fans 50a and 50b rotate together with the rotor 40, outside air (cooling air) is sucked into the apparatus from the intake ports 62a and 62b of the fan covers 60a and 60b, and is radiated by the cooling fans 50a and 50b. Sent out of the direction. The cooling air passes through the coil end of the stator core coil 34 and cools it, and then flows through the cooling air passage 37 between the stator core 32 and the cylindrical frame 14 to cool the stator core 32. Thereafter, the cooling air is exhausted from the exhaust hole 20 to the outside of the machine. In this manner, by applying cooling air to the iron core coil (copper loss) 34 and the stator iron core (iron loss) 32 that are generated heat sources, heat is radiated to the outside air, and the temperature rise of these heat sources is suppressed.

  1) In this embodiment, as shown in FIG. 3, the diameters D1 of the air inlets 62a and 62b of the fan covers 60a and 60b and the inner diameters d of the cooling fans 50a and 50b are formed to be substantially equal. For example, when the diameter D1 of the intake ports 62a and 62b is 300 mm, the inner diameter d of the cooling fans 50a and 50b is formed to be equal to the diameter D1 with an error of about ± 20 mm (1 to 6%).

  Thus, by setting the diameter D1 of the intake ports 62a and 62b and the inner diameter d of the cooling fans 50a and 50b to be substantially the same size, the surrounding air is sucked from the inner diameter d of the cooling fans 50a and 50b by centrifugal force. At that time, the air volume depends on the diameter D of the air inlets 62a and 62b of the fan covers 60a and 60b. As a result of experimental analysis and computer simulation flow analysis to clarify this phenomenon, as shown in FIG. 9, the diameter D of the intake ports 62a and 62b and the inner diameter d of the cooling fan are the same dimension (d / D = 1). As a result, the air volume is maximized and the overall temperature of the rotating electrical machine is reduced. Since the cooling air flows to the maximum extent, the heat of the stator core 32 and the iron core coil 34 can be efficiently dissipated to the cooling air, and the temperature rise can be suppressed.

  2) According to the present embodiment, as shown in FIG. 3, the distance B between the coil end of the iron core coil 34 projecting axially from the stator iron core 32 and the fan covers 60a, 60b is set to about 10 cm. The distance E between the fins 52 of the cooling fans 50a and 50b and the inner surface of the fan cover is smaller than the chord length L of the fins 52 (L> E), and is set to 20% or less of the length L, for example. .

  For example, when a thin steel plate having a thickness of 3.2 mm is used for the fan covers 60a and 60b, approximately 10 cm or more is required to maintain an insulation distance from the coil end. The positional relationship between the coil end and the cooling fans 50a and 50b is separated in the radial direction. Therefore, if the distance E between the cooling fans 50a and 50b and the fan covers 60a and 60b is too large, the air volume is reduced.

  3) According to the present embodiment, the length C of the coil end projecting in the axial direction of the stator core 32 is L / C = 0.8 to 0.7 with respect to the chord length L of the fin 52. Is set. In this case, the surrounding air is sucked in by the centrifugal force from the cooling fans 50a and 50b, and the cooling air hits the coil end. At that time, the cooling air spreads from the outer shape of the cooling fans 50a and 50b toward the coil end, and the range is approximately 1.25 to 1.40 times. In this range, the air volume is maximized and the overall temperature of the rotating electrical machine is reduced. FIG. 10 shows the result of simulation of the relationship between L / C and iron core coil temperature. From this figure, by setting L / C = 0.8 to 0.7, the cooling air flows to the maximum, the heat of the stator core 32 and the iron core coil 34 is radiated to the cooling air, and the temperature rises. It turns out that it can suppress.

  4) According to the present embodiment, as shown in FIG. 3, the stator with respect to the suction area S of the air inlet 62b defined by the outer diameter D1 and the inner diameter D2 of the air inlet 62b formed in the fan cover 60b. The thickness h of the spacer 36 is set so that the relationship between the outer diameter Q2 of the iron core and the area G of the cooling ventilation path 37 defined by the inner diameter Q1 of the cylindrical frame 14 is G = 1.1 to 1.3S. Has been. In this case, the surrounding air is sucked by the centrifugal force from the cooling fans 50 a and 50 b and is discharged from the exhaust hole 20 through the cooling air passage 37.

  Here, the area on the exhaust side (area of the cooling air passage 37) is set to about 1.1 to 1.3 times the area on the inflow side (area of the intake port 62b). It was found that the air volume of the cooling air is maximized within this range, and the overall temperature of the rotating electrical machine 10 is reduced. Since the cooling air flows to the maximum, the heat of the stator core 32 and the iron core coil 34 can be radiated to the cooling air, and the temperature rise of the stator iron core 32 and the iron core coil can be suppressed.

  5) According to the present embodiment, the plurality of exhaust holes 20 and 22 are arranged in the cylindrical frame 14 of the stator frame 12 as shown in FIGS. The annular bending stiffness with the cylindrical frame 14 can be balanced. When the exhaust holes 20 and 22 are provided in the cylindrical frame 14, the annular bending rigidity of the cylindrical frame is reduced. However, since the annular bending rigidity is large between the two flange portions 16, if the high strength position of the flange portion 16 and the position of the exhaust hole 20 in the circumferential direction coincide with each other, the exhaust hole 20 is cylindrical. The reduction in the strength of the frame is compensated, and the annular bending rigidity of the stator frame 12 is totally increased due to the barannes. Therefore, the annular bending rigidity of the stator core 32 can be improved.

  Further, when the rotating electrical machine 10 is stopped, dust may enter from the exhaust hole. However, the exhaust hole 22 provided in the upper part in the vertical direction of the cylindrical frame 14 is formed with a small diameter, so that intrusion of dust is suppressed. be able to.

  In the rotating electrical machine configured as described above, the airflow characteristics of the cooling fans 50a and 50b are improved by optimizing the configuration of each part as described in 1) to 5) above, and the temperature of the entire rotating electrical machine is increased. Can be suppressed. Cooling air generated from the cooling fan around the outer shape of the coil end and stator core effectively flows depending on the distance from the fan cover, improving the cooling performance for stator cores and core coils that rise in temperature. And the temperature rise is suppressed. Thereby, the rotary electric machine which can suppress the temperature rise of a stator core coil and can aim at large capacity | capacitance is obtained.

  In addition, the current flowing through the iron core coil can be increased as the temperature decreases, and the output of the rotating electrical machine can be further increased, so that the heat generation density per unit volume can be increased despite the fact that the capacity can be increased. A small rotating electric machine can be provided. Furthermore, by optimizing the positions of the exhaust holes and the number of exhaust holes, the rigidity of the stator core can be improved, and the cooling performance is improved while maintaining the structural rigidity.

  In the first embodiment, the rotating electrical machine 10 is configured to satisfy all of the above-described 1) to 5), but is not limited thereto, and may include at least one of the above-described 1) to 4). Even in this case, a rotating electrical machine capable of suppressing the temperature rise of the stator core coil and increasing the capacity can be obtained.

Next, a rotating electrical machine according to another embodiment will be described.
In the embodiments described below, the same parts as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

(Second Embodiment)
FIG. 11 shows a rotating electrical machine according to the second embodiment. In the second embodiment, the rotating electrical machine 10 includes a forced suction blower 70 connected to at least one exhaust hole 20. For example, the blower 70 is attached to the cylindrical frame 14 of the stator frame 12 via an air passage 72 and communicates with the exhaust hole 20 via the air passage 72.

  By forcibly sucking the cooling air from the inside of the rotating electrical machine 10 by the blower 70, more cooling air can be supplied to the stator core 32 and the iron core coil 34, and the temperature rise can be further suppressed. Accordingly, it is possible to further increase the capacity of the rotating electrical machine. Other configurations of the rotating electrical machine 10 are the same as those of the rotating electrical machine according to the first embodiment described above.

Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.
For example, the shape of the fin constituting the cooling fan is not limited to the above-described embodiment, and can be variously changed. In the cooling fan, the plurality of fins are directly fixed to the stator core. However, the cooling fan may be separately configured by fixing the fins to the support disk. The cooling fan is not limited to both ends of the rotor in the axial direction, and may be provided at least on one side. The rotating electrical machine according to the present invention is not limited to a hoisting machine for an elevator, and can be applied to various rotating electrical machines.

DESCRIPTION OF SYMBOLS 10 ... Rotary electric machine, 12 ... Stator frame, 14 ... Cylindrical frame, 16 ... Flange part,
20, 22 ... exhaust holes, 30 ... stator, 32 ... stator core, 34 ... iron core coil,
36 ... Spacer, 37 ... Cooling ventilation path, 40 ... Rotor, 42 ... Rotating shaft,
44 ... Rotor core, 50a, 50b ... Cooling fan, 52 ... Fin,
60a, 60b ... fan cover, 62a, 62b ... air intake

Claims (5)

A stator frame;
An annular stator core disposed coaxially in the stator frame, and a plurality of core coils attached to the stator core, and between the outer periphery of the stator core and the inner surface of the stator frame A stator that defines a cooling air passage,
A rotatable rotor coaxially provided inside the stator core;
A cooling fan attached to the rotor and rotating integrally with the rotor;
Axial ends of the stator and rotor, and a fan cover that covers the cooling fan and is fixed to the stator frame;
An air inlet formed on the fan cover and positioned coaxially with the rotor,
A rotating electrical machine in which an outer diameter of an air inlet of the fan cover and an inner diameter of a fin of the cooling fan are formed to have substantially the same dimension. The iron core coil has a coil end protruding in the axial direction from an axial end of the stator core, and the distance between the coil end and the fan cover is 10 cm or more,
The rotating electrical machine according to claim 1, wherein a distance between the fin of the cooling fan and the inner surface of the fan cover is formed to be equal to or less than a chord length of the fin. The iron core coil has a coil end protruding in an axial direction from an axial end of the stator core, and an axial protruding length C of the coil end and a chord length L of the fin are:
The rotating electrical machine according to claim 1, wherein the rotating electrical machine is formed so as to satisfy a relationship of L / C = 0.8 to 0.7.   The area of the air inlet of the fan cover, the area S of the cooling ventilation path, and the area G of the cooling ventilation path are formed so as to satisfy a relationship of G = 1.1 to 1.3S. 4. The rotating electrical machine according to claim 1. A plurality of spacers provided between the outer peripheral surface of the stator core and the inner peripheral surface of the stator frame at intervals in the circumferential direction;
5. The rotating electrical machine according to claim 1, wherein the stator frame has an exhaust hole that is formed between the plurality of spacers and opens to the cooling air passage.

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