JP2009225515A - Core and stator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coil and a stator for rapidly dissipating heat generated in a coil. <P>SOLUTION: Grooves 14a, 14b opened on an inner surface 12a as a side surface of a rotor side are formed on both end surfaces (both end surfaces of a coil end side) of an axial direction z of a teeth portion 12. The grooves 14a, 14b extend to a yoke portion 11 and penetrate through an external peripheral surface 11a of the yoke portion 11. When the rotor rotates, a coolant flowing along the surface of the rotor flows into the grooves 14a, 14b of the teeth portion 12, and the heat is dissipated to the coolant from wall surfaces of the grooves 14a, 14b and also from the inner surface of a coil at the ceiling surfaces of the grooves 14a, 14b, and thus a heat dissipation performance is improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a core and a stator, and more particularly to measures for improving heat dissipation.

  In recent years, with the advancement of new technologies such as electric vehicles, hybrid vehicles, and robots, the performance required for the stators of rotating electric machines (motors and generators) for driving them has been advanced. For example, in an electric vehicle and a hybrid vehicle, a large current is required and downsizing is required.

  The stator includes a core and a coil wound around the core. To increase the current, it is required to increase the current flowing through the coil. However, when increasing the current flowing through the coil, the coil diameter is increased. Then, in order to increase the difficulty of coil winding due to the increased rigidity of the coil wire and the eddy loss, a structure in which a plurality of thin coils are wound around the core is often employed.

For example, as disclosed in Patent Document 1, a partition that divides a slot region into two partial slot regions is provided in an insulator laid in a slot region of a split core, and a coil is individually wound around each partial slot region. Therefore, there is one that attempts to realize a high-density coil structure.
Japanese Patent Laid-Open No. 11-27886

  In the stator having the structure as described in Patent Document 1, the main heat dissipation path of the heat generated from the coil is the coil, the mold resin of the coil, the core, and the refrigerant circulating in the rotating electrical machine from the rotor side surface of the core. It becomes a route to dissipate heat. However, if the coil structure in the stator is made compact and the current is increased, if a large amount of heat is generated in the coil, it becomes difficult to quickly transfer the heat to the rotor side surface of the core. There is a risk of degrading the reliability such as deteriorating the resin.

  An object of the present invention is to provide a core for quickly releasing the heat generated by a coil and a stator including the core.

  The core of the present invention is a stator core disposed around the rotor of a rotating electrical machine, and is formed by forming a groove opening on the side surface on the rotor side on the end surface of the tooth portion.

Thereby, in the rotating electrical machine to which the core is attached, when the rotor of the rotating electrical machine rotates, the refrigerant in the rotating electrical machine flows along the outer surface of the rotor and further flows into the groove of the tooth portion of the core. Therefore, even if the coil suddenly generates a large amount of heat due to an increase in current and density, not only from the rotor side surface of the core, but also from a part close to the coil via a shortened heat dissipation path. However, since the heat is radiated to the refrigerant, quick heat radiation is possible. Therefore, it is possible to prevent a decrease in reliability.
The core of the present invention may be a divided core obtained by dividing an annular core into a plurality of pieces, or may be a single core constituted by an annular core.

  Since the groove penetrates to the outer peripheral surface of the yoke portion, the flow of the refrigerant becomes smoother and the heat dissipation is further improved.

  Moreover, it is preferable that the said groove | channel is formed in the end surface by the side of the coil end of a teeth part, and it is more preferable that it is formed in the both end surfaces by the side of the coil end of a teeth part, respectively.

  The stator of the present invention is obtained by winding a coil around the tooth portion of the core, so that heat can be quickly dissipated even if a large amount of heat is generated due to a large current or high density. A stable stator is obtained.

  According to the core or stator of the present invention, even if a large amount of heat is generated due to a large current or a high density, a rapid decrease in reliability can be prevented by quickly dissipating heat.

  FIG. 1 is a perspective view showing the shape of a split core 10 in an embodiment of the invention. FIG. 2 is a front view of the split stator 30 according to the embodiment of the invention. FIG. 3 is a perspective view schematically showing the overall structure of the stator 40 according to the embodiment of the invention. FIG. 4 is a perspective view showing a main part of the motor 50 according to the embodiment of the invention.

  As shown in FIG. 4, the motor 50 includes a rotor 41 and a stator 40 surrounding the rotor 41. The rotor 41 is roughly a cylindrical body having a central axis parallel to the axial direction z shown in FIG. 4 and rotating in the circumferential direction θ. The stator 40 is configured by assembling the divided stator 30 in the circumferential direction θ, and is a cylindrical body that is separated from the rotor 41 by a substantially constant gap in the radial direction r. Therefore, the central axis of the stator 40 substantially coincides with the central axis of the rotor 41.

  As shown in FIG. 1, the split core 10 according to the present embodiment has a yoke portion 11 extending in the circumferential direction θ and a teeth portion 12 protruding in the radial direction r from the yoke portion 11 toward the rotor 41. Yes. In the present embodiment, the split core 10 adopts a so-called compacted core structure formed by compression molding magnetic powder having an insulating film, but adopts a laminated steel plate structure in which a large number of magnetic steel plates are laminated. May be.

  Here, as a feature of the present embodiment, grooves 14a and 14b that open to the inner side surface 12a that is the side surface on the rotor side are formed on both end surfaces (both end surfaces on the coil end side) of the tooth portion 12 in the axial direction z. Has been. The grooves 14 a and 14 b extend to the yoke portion 11 and further penetrate to the outer peripheral surface 11 a of the yoke portion 11.

  In the present embodiment, the dimension of the teeth part 12 and the yoke part 11 in the axial direction z is about 45 mm to 65 mm, the dimension of the yoke part 11 in the circumferential direction θ is about 30 mm to 40 mm, and the tooth part 12 The dimension of the circumferential direction θ at the tip of the teeth portion is about 15 mm to 25 mm, the size of the circumferential direction θ at the proximal end of the tooth portion 12 is about 20 mm to 30 mm, and the dimension of the yoke portion 11 in the radial direction r is 5 mm. The dimension of the tooth part 12 in the radial direction r is about 15 mm to 25 mm.

  The widths (dimensions in the circumferential direction θ) of the grooves 14a and 14b are about 5 mm to 10 mm, and the depths (dimensions in the axial direction z) are about 15 mm to 25 mm.

  As shown in FIG. 2, the split stator 30 has a coil 20 that surrounds the teeth portion 12 of the split core 10. The grooves 14 a and 14 b provided in the tooth portion 12 are covered with the coil 20.

Moreover, in this Embodiment, the coil 20 is molded by resin and is comprised as what is called a cassette coil. As a material for the mold resin, PPS resin (polyphenylene sulfide), LCP resin (liquid crystal polymer), epoxy resin, or the like is used.
However, instead of the cassette coil structure, a structure formed by winding the coil 20 around the outer periphery of the tooth portion 12 may be used.

  In the present embodiment, the coil 20 has a substantially circular cross section, but may be a rectangular wire or a structure in which a plurality of coil wires are assembled. Moreover, in the case of a flat wire, it may be wound along the outer peripheral surface of the tooth part 12, and may be what is called an edgewise shape.

  As shown in the enlarged sectional view of FIG. 4, when a current flows through the coil 20 and the rotor 41 rotates, the refrigerant flows along the surface of the rotor 41. Therefore, the heat generated in the coil 20 is released to the refrigerant from the inner side surface 12 a that is the side surface on the rotor side of the tooth portion 12 and the outer surface of the coil 20.

  Furthermore, in the present embodiment, the refrigerant also flows into the grooves 14a and 14b of the tooth portion 12. Therefore, the refrigerant also flows from the wall surfaces of the grooves 14a and 14b and the inner surface of the coil 20 corresponding to the ceiling surface of the grooves 14a and 14b. Heat is released. Accordingly, even when the heat of the coil 20 suddenly increases due to a sudden increase in the current of the coil 20 during acceleration of a vehicle equipped with the motor 50, the inner surface 12a of the tooth portion 12 and the outer surface of the coil 20 In addition, it is possible to quickly dissipate heat through a shortened heat dissipation path such as the wall surfaces of the grooves 14a and 14b and the inner surface of the coil 20. Therefore, deterioration of the coating insulating film of the coil wire can be prevented, and a decrease in reliability can be prevented.

  In addition, since the refrigerant flows from the grooves 14a and 14b to the end surface on the coil end side of the yoke portion 11 and the back surface of the coil 20, the heat dissipation function is further enhanced. Since the grooves 14 a and 14 b penetrate to the outer peripheral surface 11 a of the yoke portion 11, the heat dissipation function is further enhanced.

  However, the grooves 14 a and 14 b do not necessarily have to penetrate to the outer peripheral surface 11 a of the yoke portion 11. In the case of the structure shown in FIGS. 1 and 2, even if the grooves 14 a and 14 b do not penetrate, the refrigerant flows from the middle of the grooves 14 a and 14 b to the coil end side end surface of the yoke portion 11 and the back surface of the coil 20. is there.

(Modification 1)
FIG. 5 is a perspective view showing the shape of the split core 10 according to the first modification of the embodiment. In this modification, grooves 14c and 14d that branch from the grooves 14a and 14b and penetrate to the coil side surface 12b of the tooth portion 12 are formed. The rear sides of the grooves 14a and 14b are blocked and do not have to penetrate to the outer peripheral surface 11a of the yoke part 11.
In the present modification, the heat dissipation function is further improved by circulating the coolant through the grooves 14c and 14d.

(Modification 2)
FIG. 6 is a perspective view showing the shape of the split core 10 according to the second modification of the embodiment. In this modification, the yoke portion 11 has a structure protruding in the axial direction z from the tooth portion 12. Grooves 14e and 14f penetrating to the side surface 11d in the circumferential direction θ of the yoke portion 11 are formed in the upper end surface 11b and the lower end surface 11c of the yoke portion 11 in the axial direction z. In addition, the back of the grooves 14a and 14b is blocked and does not have to penetrate to the outer peripheral surface 11a of the yoke portion 11.

  In this modification, the refrigerant also flows into the grooves 14e and 14f, and in the annular stator 40 assembled with the split stator 30 (see FIGS. 3 and 4), the refrigerant circulates in the circumferential direction θ throughout the stator 40. Further, the heat dissipation function is improved.

(Other embodiments)
The cross-sectional shapes of the grooves 14a to 14f do not have to be rectangular as in the embodiment and the modifications thereof, and may be various shapes such as a semicircular shape.

  The grooves 14a to 14f do not need to be single on one surface as in the embodiment and the modifications thereof, and a plurality of grooves 14a to 14f may be formed on the same surface, for example, a plurality of thin grooves.

  Further, in the structure shown in FIGS. 1, 5, and 6, a groove connecting the two grooves 14a and 14b may be formed on the outer peripheral surface 11a of the yoke portion 11. In that case, the refrigerant can circulate around the split core 11 and the heat dissipation function is further improved.

  In the said embodiment and its modification, the structure which assembled the division | segmentation core 10 and the division | segmentation stator 30 cyclically | annularly was employ | adopted, However, You may employ | adopt a single core and a stator structure.

  In the above embodiment, the example in which the stator 40 is used as a part of the motor has been described. However, the stator 40 of the present invention can be used not only for the motor but also for general rotating electrical machines such as a generator.

  The structure of the embodiment of the present invention disclosed above is merely an example, and the scope of the present invention is not limited to the scope of these descriptions. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  The core and stator of the present invention can be used for motors and generators disposed in industrial motors, hybrid vehicles, electric vehicles, fuel cell vehicles, robots, and the like.

It is a perspective view which shows the shape of the division | segmentation core which concerns on embodiment. It is a front view of the division | segmentation stator which concerns on embodiment of invention. 1 is a perspective view schematically showing a structure of a stator according to an embodiment of the invention. It is a perspective view which shows the principal part of the motor which concerns on embodiment of invention. It is a perspective view which shows the shape of the division | segmentation core which concerns on the modification 1 of embodiment. It is a perspective view which shows the shape of the division | segmentation core which concerns on the modification 2 of embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Split core 11 Yoke part 11a Outer peripheral surface 11b Upper end surface 11c Lower end surface 11d Side surface 12 Teeth part 12a Inner side surface 12b Coil side surface 14a-14f Groove 20 Coil 30 Split stator 40 Stator 41 Rotor 50 Motor

Claims (5)

A stator core disposed around the rotor of the rotating electrical machine,
A yoke portion, and a teeth portion protruding from the yoke portion toward the rotor,
A core having a groove opened on a side surface on the rotor side is formed on an end surface of the tooth portion. The core of claim 1,
The groove penetrates to the outer peripheral surface of the yoke portion. The core according to claim 1 or 2,
The groove is a core formed on an end surface of the tooth portion on the coil end side. The core of claim 3,
The said groove | channel is the core currently formed in the both end surfaces by the side of the coil end of the said teeth part, respectively. A core according to any one of claims 1 to 4;
A coil wound around the teeth portion of the core;
Stator with.

Images