JP2001082335A - Electric motor for compressor, and compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly efficient electric motor for a compressor by a method wherein a leak current flowing to a compressor case through lubrication oil and a refrigerant, adhered to a winding during operation of the electric motor for a compressor, and a leak current flowing to a stator core through an insulation member are reduced without reducing the efficiency of the motor by reducing the diameter of a winding. SOLUTION: This electric motor for a compressor comprises a rotor integrally mounted on a rotary shaft; and a stator situated with a narrow gap between the outer peripheral surface of the rotor and the stator. A ratio between the lengths in an axial direction of the rotor between the coil end of the stator and a stator core is set to 0.6 or less. Volume resistance of an insulation member is set to 1×108 ω or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor motor incorporated in a compressor mounted on an air conditioner or the like,
In particular, it relates to the structure of the stator of the electric motor.

[0002]

2. Description of the Related Art As shown in FIG. 1, a compressor 1 mounted on an air conditioner includes an electric motor unit 2 and a compression unit 11. The motor unit 2 includes a rotor 4 integrally attached to the rotating shaft 3 and a stator 5 disposed with a small gap from the outer peripheral surface of the rotor 4.

FIG. 10 is an assembly view of a conventional stator. FIG. 11 is a sectional view taken along the line AA in FIG. FIG. 12 is a partially enlarged view of FIG. FIG.
As shown in FIG. 5, the stator 5 is formed by fitting an insulating member 7 to a stator core 6 in which electromagnetic steel sheets are laminated, and winding a winding 8 thereon.

In the stator 5, the length of the stator core 6 in the same direction as the axial direction of the rotating shaft 3 is t, and similarly, a coil end is formed by extending a winding 8 at the upper and lower ends of the stator 5. 9
Assuming that the length of the coil end portion 9 composed of 1 and the coil end 92 is h, the ratio (h / t) between the coil end portion 9 and the stator core 6 was larger than 0.6. Where h
Is the total length of the coil end portion (the sum of the length h1 of the coil end 91 and the length h2 of the coil end 92).

In general, a polyester film is used for the insulating member 7, and its volume resistance is 1 × 10 ⁸ Ω.
It was smaller.

When the electric motor 2 is driven, the current flowing through the winding 8 passes through the following two paths and becomes a leakage current. 1) It flows into the compressor case 10 through the lubricating oil or refrigerant attached to the winding 8. 2) Flow through the stator core 6 through the insulating material 7 between the stator core 6 and the winding 8.

In such a conventional configuration, since the coil end portion 9 occupies a large proportion, a large amount of lubricating oil or refrigerant adheres to the winding 8, and the current flowing to the winding is likely to leak. In addition, since the volume resistance of the material used for the insulating member 7 is small,
The insulation was incomplete and leaked to the stator core 6.

[0008]

In the above-described conventional configuration, measures have been taken to reduce the diameter of the winding in order to reduce the leakage current.

However, measures to reduce the diameter of the winding have problems such as an increase in copper loss and a decrease in the efficiency of the motor.

The present invention has been made in consideration of the above circumstances, and has as its object to provide a compressor motor and a compressor with reduced leakage current and high efficiency.

[0011]

According to a first aspect of the present invention, there is provided a motor having a stator core having a winding extending at an upper end and a lower end of the stator with respect to a length in the same direction as the rotation axis. The ratio of the length of the protruding coil end in the same direction as the rotation axis direction is 0.6 or less, and the volume resistance of an insulating member that insulates between the stator and the winding is 1 × 10 ^8. Ω
That is all.

According to a second aspect of the present invention, in the first aspect of the present invention, the ratio of the thickness of the insulating member in the cross section of the stator core to the length of the contact portion between the stator core and the insulating member is 7 × 10.
^-4 .

According to a third aspect of the present invention, in the first or second aspect, the volume resistivity of the insulating member is 1 × 10
^{It is 14} Ωm or more.

According to a fourth aspect of the present invention, in any one of the first to third aspects, a resin molding material is used for the insulating member.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, the stator is formed in an annular shape in which a plurality of magnetic pole teeth are radially installed along the inner peripheral portion at predetermined intervals. The stator core and the winding wound around the magnetic pole teeth of the stator core via an insulating member are configured such that the windings are concentrated winding.

According to a sixth aspect of the present invention, there is provided a compressor for mounting a compressor motor according to any one of the first to fifth aspects of the present invention to compress a refrigerant, wherein an HFC-based refrigerant is used as the refrigerant to be compressed. It has a configuration.

According to the above construction, the leakage current flowing through the lubricating oil or the refrigerant adhered to the winding can be reduced.

According to the second aspect of the invention, in addition to the first aspect, the leakage current flowing through the stator core via the insulating member can be further reduced.

According to the third aspect of the invention, in addition to the first and second aspects, the leakage current can be reduced with a small number of insulating members.

According to the fourth aspect of the invention, in addition to the first to third aspects, the volume resistivity can be easily set to 1 × 10 ¹⁴ Ωm or more.

According to the fifth aspect of the present invention, in addition to the first to fourth aspects of the present invention, it is easy to reduce the length h of the coil end by concentrating the winding, and thus h / h. t
Can be 0.6 or less.

According to the sixth aspect of the present invention, the configuration of the compressor motor according to the present invention prevents an increase in leakage current even when using HFC refrigerant which tends to increase leakage current with respect to HCFC refrigerant. can do.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, a first embodiment of the electric motor according to the present invention will be described.

The present embodiment is applied to a compressor used in an air conditioner or the like. The structure of the compressor is the same as that shown in FIG. Description is omitted.

FIG. 2 is an assembly view of the stator 5 used in the electric motor unit 2 according to the present embodiment. FIG. 3 is a sectional view taken along the line AA in FIG. FIG. 4 is a partially enlarged view of FIG. FIG. 5 shows a top view of the stator 5.

The stator 5 has a plurality of magnetic pole teeth 1 along the inner circumference.
Reference numeral 2 denotes an annular stator core 6 radially installed at a predetermined interval, and a winding 8 wound around magnetic pole teeth 12 of the core via an insulating member 7.

If the lengths of the coil end portion 9 and the stator core 6 in the same direction as the rotation axis are h and t, respectively, the ratio (h / t) is formed to be 0.6 or less. Note that h
Is the total length of the coil end portion 9 (the sum of the length h1 of the coil end 91 and the length h2 of the coil end 92).

FIG. 6 shows the relationship between h / t and leakage current. h
In the range where / t is large, the proportion occupied by the coil end portion 9 is large, so that the amount of the lubricant or coolant adhering to the winding 8 and flowing to the case 10 increases. Conversely, the leakage current decreases as h / t decreases.

FIG. 7 shows the relationship between the volume resistance of the insulating member 7 and the leakage current when h / t is set to 0.5. FIG. 7 shows that the leakage current can be reduced when the volume resistance of the insulating member 7 is designed to be 1 × 10 ⁸ Ω or more. This tendency is the same when h / t is 0.6 or less.

Therefore, the volume resistance of the insulating material 8 is set to 1 × 10 ⁸ Ω so that the leakage current can be reduced even when h / t is 0.6 or less.
Design above.

Next, a second embodiment of the compressor according to the present invention will be described.
The state will be described. As shown in FIG.
W is the thickness of the insulating material 7 in the A-A section, and the stator core is
Let L be the length of the contact portion between 6 and the insulating member 7. here,
The length L of the contact portion is the total contact portion if there are multiple insulating materials.
The total length of the minutes (L = L₁+ L₂+ L ₃+ ... +
L_n).

FIG. 8 shows the relationship between W / L and leakage current. From FIG. 8, it can be seen that the ratio of the reduction of the leakage current is large when the W / L is 7 × 10 ⁻⁴ or more.

In FIG. 8, h / t is equal to 0.
8, the tendency in FIG. 8 is that h / t is 0.
The same applies to a range of 6 or less. Therefore, it is formed so that the ratio (W / L) of W to L is 7 × 10 ⁻⁴ or more.

Next, a description will be given of a third embodiment of the compressor according to the present invention. FIG. 7 shows the relationship between the volume resistivity and the leakage current. The volume resistivity than 9 It can be seen that the proportion of the reduction of the leakage current from the place became ¹ × 10 1 ⁴ Ωm or more is increased. In FIG. 9, h /
In the case where t is 0.5, the tendency in FIG.
The same applies to the case where t is 0.6 or less. Therefore,
By designing the volume resistivity of the insulating material 8 to be 1 × 10 ¹⁴ Ωm or more, the leakage current can be reduced with a small amount of insulating material.

In the embodiment of the present invention, the insulating material 8
Resin molding material was used, but polyphenylene sulfide (PPS), nylon (PA),
Examples thereof include polybutylene laphthalate (PBT) and liquid crystal polymer (LCD). By using these materials for the insulating material 8, the volume resistivity can be formed to be 1 × 10 ¹⁴ Ωm or more.

Further, in the first to third embodiments, even if an HFC refrigerant having a tendency to increase the leakage current with respect to the HCFC refrigerant is used, the structure of the electric motor for a compressor according to the present invention allows the leakage of the HFC refrigerant. An increase in current can be prevented.

It should be noted that the effect of reducing the leakage current can be obtained in the case where the HCFC-based refrigerant is used, similarly to the case where the HFC-based refrigerant is used.

Further, in the present invention, a compressor having a rotary type compression mechanism has been described. However, the present invention is not limited to this. For example, a compressor having a scroll type compressor may be used.

[0039]

As described above, according to the present invention,
Without reducing the efficiency of the motor,
Leakage current flowing to the compressor case via lubricating oil or refrigerant attached to the windings and leakage current flowing to the stator core via the insulating member can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a compressor according to the present invention.

FIG. 2 is an assembly view of a stator of the compressor electric motor according to the present invention.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a partially enlarged view of FIG. 3;

FIG. 5 is a top view of the stator according to the first embodiment.

FIG. 6 is a graph showing the relationship between h / t and leakage current.

FIG. 7 is a graph showing the relationship between the volume resistance of the insulating member and the leakage current when h / t is set to 0.5.

FIG. 8 is a graph showing the relationship between W / L and leakage current.

FIG. 9 is a graph showing the relationship between volumetric efficiency and leakage current.

FIG. 10 is an assembly view of a conventional stator.

FIG. 11 is a sectional view taken along line AA in FIG. 10;

FIG. 12 is a partially enlarged view of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Compressor 2 ... Electric motor part 11 ... Compression part 3 ... Rotating shaft 4 ... Rotor 5 ... Stator 12 ... Magnetic pole teeth 6 ... Stator iron core 7 ... Insulating member 8 ... Winding 9 ... Coil end parts 91 and 92 ... Coil end

Claims (6)

[Claims] 1. A motor for a compressor comprising: a rotor integrally mounted on a rotating shaft; and a stator disposed with a small gap from an outer peripheral surface of the rotor. The ratio of the length in the same direction as the axial direction of the rotor with respect to the length in the same direction as the axial direction of the rotor and the length of the coil end in which the winding extends at the upper and lower ends of the stator in the same direction as the axial direction is 0.6 or less. And a volume resistance of an insulating member that insulates between the stator and the winding is 1 × 10 ⁸ Ω or more. 2. A ratio of a thickness of said insulating member in a cross section of said stator core to a length of a contact portion between said stator core and said insulating member is set to 7 × 10 ^−4. 2. The electric motor for a compressor according to 1. 3. A volume resistivity of the insulating member is 1 × 10 ^14.
The motor for a compressor according to claim 1 or 2, wherein the resistance is not less than Ωm. 4. The electric motor for a compressor according to claim 1, wherein a resin molding material is used for said insulating member. 5. The stator of the compressor motor according to claim 1, wherein the stator includes an annular stator core in which a plurality of magnetic pole teeth are radially arranged along an inner peripheral portion at predetermined intervals. The motor for a compressor according to any one of claims 1 to 4, comprising a winding wound around the magnetic pole teeth via an insulating member, wherein the winding is a concentrated winding. 6. A compressor for mounting a compressor motor according to any one of claims 1 to 5 for compressing a refrigerant, wherein an HFC-based refrigerant is used as the refrigerant to be compressed. Machine.