JP2020120518A - Stator of rotary electric machine - Google Patents

Abstract

To provide a stator of a rotary electric machine which sufficiently transmits heat generated in a coil to a stator core.SOLUTION: A coil 18 passes through a slot 16 and is wound around teeth 14. In the slot 16, a resin sheet 20 is arranged between a stator core 10 and a coil 18 which contains an oil absorptive polymer and absorbs oil and thereby is swollen. The resin sheet 20 absorbs the oil and is swelled, and the swollen resin sheet embeds a gap between the coil 18 and the stator core 10.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a stator of a rotary electric machine.

In a stator of a rotary electric machine, a coil is generally wound around a stator core. Various techniques for fixing a coil to a stator core are known.

For example, Patent Document 1 describes a method of fixing a coil to a stator core using a material having foamability. In this method, a foamable material is arranged between the stator core and the coil, and the material is expanded to fill the gap between the coil and the stator core, thereby fixing the coil to the stator core.

Japanese Unexamined Patent Publication No. 2018-129991

By the way, the coil generates heat when energized. In order to suppress the temperature rise of the coil, it is conceivable to transfer the heat generated in the coil to the stator core.

When the foamable material described in Patent Document 1 is used, an air insulation layer formed by foaming is formed between the coil and the stator core. Since the air heat insulating layer is a layer containing air, it generally has poor thermal conductivity. Therefore, the presence of the air insulation layer may not adequately transfer the heat generated in the coil to the stator core.

An object of the present disclosure is to sufficiently transfer heat generated in a coil in a stator of a rotating electric machine to a stator core.

A stator of a rotating electric machine according to the present disclosure includes a stator core having a plurality of teeth protruding inward in a radial direction from an inner peripheral surface of an annular yoke, and a stator core having slots formed between the teeth, and the teeth passing through the slots to the teeth. It has a wound coil and a resin sheet which is arranged between the stator core and the coil in the slot, contains an oil-absorbing polymer, and swells by absorbing oil.

In the above configuration, the resin sheet that contains the oil-absorbing polymer and absorbs oil to swell is arranged between the coil and the stator core. The resin sheet absorbs oil and swells, thereby filling the gap between the coil and the stator core. Since oil easily transfers heat, the heat generated in the coil can be sufficiently transferred to the stator core through the swollen resin sheet.

According to the stator of the rotary electric machine according to the present disclosure, the heat generated in the coil can be sufficiently transmitted to the stator core.

It is a front view which shows a stator core. It is a sectional view showing a part of stator. It is a sectional view showing a part of stator. It is a flowchart which shows the fixing method of a coil.

The stator of the rotary electric machine according to this embodiment will be described below. The rotating electric machine includes a rotor and a stator arranged on the outer peripheral side of the rotor with a predetermined gap. The stator has a stator core and a coil wound around the stator core. The rotary electric machine is, for example, a motor/generator that functions as an electric motor and a generator.

FIG. 1 shows a stator core 10. The stator core 10 includes a substantially annular yoke 12 and a plurality of teeth 14 that protrude radially inward from the inner peripheral surface of the yoke 12 and are provided at intervals in the circumferential direction. A slot 16 which is a space for accommodating a part of the coil is formed between the adjacent teeth 14. The direction along the central axis of the annular ring of the stator core 10 is the axial direction, the direction orthogonal to the central axis is the radial direction, and the direction around the central axis is the circumferential direction.

The stator core 10 may be, for example, a laminated steel plate manufactured by laminating a plurality of electromagnetic steel plates (for example, silicon steel plates) in the thickness direction, or a powder compact formed by press-molding insulating coated magnetic particles It may be a magnetic core.

The coil is wound around the tooth 14 through the slot 16. The coil winding method may be distributed winding, concentrated winding, or another winding method. A coil formed by conductor segments may be used as the coil.

Hereinafter, the stator according to the present embodiment will be described in detail with reference to FIGS. 2 and 3. 2 and 3 are cross-sectional views showing a part of the stator. 2 and 3 show a part of the cross section of the stator taken along a plane perpendicular to the axial direction.

As shown in FIGS. 2 and 3, a part of the coil 18 is arranged in the slot 16. Further, as shown in FIG. 2, a resin sheet 20 containing an oil-absorbing polymer is arranged in the slot 16 between the stator core 10 and the coil 18. That is, the resin sheet 20 is arranged between the inner wall surface of the slot 16 and the coil 18. The resin sheet 20 may be arranged over the entire length of the slot 16 in all directions, or may be partially arranged. Further, the resin sheet 20 may be arranged so as to partially surround the coil 18 in the slot 16, or may be arranged so as to surround the entire coil 18. Although only one slot 16 is shown in FIG. 2, the coil 18 and the resin sheet 20 are arranged in each slot 16.

The resin sheet 20 is a sheet that absorbs oil such as transmission oil and swells. As the oil-absorbing polymer, for example, Aqua N-Cap manufactured by Meito Ka Co., Ltd. is used.

When oil is supplied to the resin sheet 20 with the resin sheet 20 arranged as shown in FIG. 2, the resin sheet 20 absorbs the oil and swells.

FIG. 3 shows the resin sheet 22 after swelling. The swollen resin sheet 22 fills the gap between the stator core 10 and the coil 18, and the coil 18 is fixed to the stator core 10. Further, since the resin sheet 22 is not a foamable member, a space containing air is not formed in the resin sheet 22. Therefore, the heat generated in the coil 18 can be easily transferred to the stator core 10 via the resin sheet 22. That is, in the foamable sheet, since the sheet is inflated by the air having low thermal conductivity, the heat generated in the coil 18 is difficult to be transferred to the stator core 10. In the present embodiment, since the resin sheet 22 is inflated with oil having a thermal conductivity higher than that of air, the heat generated in the coil 18 is easily transferred to the stator core 10 as compared with the case where a foamable sheet is used.

When foreign matter such as water is mixed into the rotating electric machine, the rotating electric machine may break down. However, since the material used for swelling the resin sheet 22 is transmission oil, it does not cause a failure of the rotating electric machine. By the way, when the rotary electric machine is used, the transmission oil flows in the rotary electric machine.

Hereinafter, a method of fixing the coil 18 will be described with reference to FIG. FIG. 4 shows a flowchart showing the fixing method.

The coil 18 is fixed by a first step (S01) of manufacturing the resin sheet 20, a second step (S02) of placing the resin sheet 20 in the slot 16, and a third step (S02) of placing the coil 18 in the slot 16. S03) and a fourth step (S04) of causing the resin sheet 20 to absorb the transmission oil and swelling the resin sheet 20.

The first step (S01) will be described in detail. An oil-absorbing polymer (for example, the above-mentioned Aqua N-cap) is added to raw rubber of heat-resistant silicone and kneaded. Then, the rubber containing the oil-absorbent polymer is formed into a sheet by a roll and heated to be cured. The cured resin sheet is cut into sheets having dimensions that can be placed in the slots 16. Thereby, the resin sheet 20 is manufactured.

The second step (S02) will be described in detail. The resin sheet 20 manufactured in the first step is placed in the slot 16 while ensuring a space in which the coil 18 is placed in the slot 16. The resin sheet 20 may be arranged in contact with the inner wall surface of the slot 16, or may be arranged apart from the inner wall surface. Further, the resin sheet 20 may be adhered to the inner wall surface of the slot 16.

The third step (S03) will be described in detail. The coil 18 is wound around the stator core 10 while being arranged in the slot 16 so that the resin sheet 20 is arranged between the stator core 10 and the coil 18. For example, as shown in FIG. 2, the coil 18 is arranged in the slot 16 so that the coil 18 is surrounded by the resin sheet 20.

The fourth step (S04) will be described in detail. With the coil 18 and the resin sheet 20 arranged in the slot 16, the transmission oil is applied to the resin sheet 20 by spraying or the like. The stator on which the resin sheet 20 is arranged may be immersed in the transmission oil. When the resin sheet 20 absorbs the transmission oil, the resin sheet 20 swells. As shown in FIG. 3, the swollen resin sheet 22 fills the gap between the coil 18 and the stator core 10, and as a result, the coil 18 is fixed to the stator core 10. As a result, the stator according to this embodiment is manufactured.

As described above, according to the stator of this embodiment, since the resin sheet 20 that absorbs oil and swells is used, the heat generated in the coil 18 is transferred to the stator core 10 through the swollen resin sheet 22. Can be fully communicated.

10 stator cores, 12 yokes, 14 teeth, 16 slots, 18 coils, 20, 22 resin sheets.

Claims (1)

A stator core having a plurality of teeth projecting radially inward from the inner peripheral surface of the annular yoke and slots formed between the teeth;
A coil wound around the tooth through the slot,
A resin sheet disposed between the stator core and the coil in the slot, containing an oil-absorbing polymer, and swelling by absorbing oil,
A stator of a rotating electric machine, comprising:

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