JP3306361B2 - Refrigerant compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a refrigerant compressor,
In particular, the present invention relates to a refrigerant compressor capable of handling a new refrigerant.

[0002]

2. Description of the Related Art As a refrigerant for a compressor such as an air conditioner,
CFC-based and HCFC-based CFCs that have been used in the past have caused the ozone layer to be destroyed, and the use of alternative CFC-based refrigerants has been demanded. I have. In addition, an inverter is used as a drive power supply for a DC brushless motor that drives a compressor such as an air conditioner, and its control method is more efficient than a conventional PWM (pulse width modulation) control method.
It has shifted to the AM (pulse amplitude modulation) control method.

[0003] Even when a new refrigerant is used for the refrigerant compressor, it is necessary to suppress the leakage current of the electric motor to within a specified value (1.0 mA). In the combination, the leakage current increases more than before, and when the DC brushless motor for driving the compressor is driven and controlled by the PAM control system for high efficiency operation, the leakage current increases due to the high voltage. However, it was difficult to suppress the content within the specified value.

Further, the insulating paper in the winding groove of the electric motor is attacked by the new refrigerant, so that the insulating effect is reduced, and
This is also a cause of an increase in relative permittivity and leakage of harmonic components of the inverter power supply due to capacitance, thereby increasing leakage current.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned problems, and an inverter-driven compression compressor using a new refrigerant comprising a combination of an HFC-based refrigerant and an ether-based or ester-based lubricant. Select the most suitable magnet material for the rotor of a DC brushless motor for motors, reduce the stacking height of the core, reduce the volume of the motor, the amount of copper wire used, and reduce the dielectric constant of the groove insulating film. It is an object of the present invention to provide a refrigerant compressor using a DC brushless electric motor for a compressor capable of supporting a new refrigerant, by suppressing the leakage current to within a specified value by reducing the capacitance by using the same.

[0006]

According to a first aspect of the present invention, there is provided a refrigerant compressor in which a compression element and a DC brushless motor for driving the compression element are enclosed in a closed container. A refrigerant compressor in which a single HFC-based refrigerant or a mixed refrigerant thereof and an ether-based or ester-based lubricating oil are sealed in the hermetically sealed container, wherein the DC brushless motor has a surface Perform processing
A rare earth magnet using a magnet material that does not
It is configured to be driven by the inverter power supply.

As described above, the DC brushless motor for a compressor according to the present invention provides a conventional ferrite as a rotor magnet even when HFC-based refrigerants such as R410A and R407C and ether-based or ester-based lubricating oil are used as new refrigerants. Although the price per unit weight is higher than that of a magnet, its BH
By using a rare earth magnet consisting of neodymium, ferrite, iron, and boron, the product is extremely large, reducing the stacking height of the core, reducing the volume of the motor and the amount of copper wire used, and reducing the leakage current to the specified value. Can be suppressed within.

[0008]

Further, by employing a rare earth magnet in the iron core of the rotor, a strong magnetic force can be obtained.
The magnet material that is not subjected to the surface treatment can be used as it is, which facilitates the production and the management of the magnet material.

[0010] A refrigerant compressor according to a second aspect of the present invention has a stator and a rotor, and has an HF such as R410A or R407C.
A rotary or scroll refrigerant compressor using a C-based refrigerant and an ether-based or ester-based lubricating oil, wherein a rotor has a rare earth magnet in an iron core, and a PEN film, a PPS film, or an aramid as an insulating paper for an electric motor. A composite paper product or a combination thereof with a PET film is used, and the slot insulating paper or the wedge insulating paper of the winding is mainly made of a material other than the PET film, and is driven by an inverter power supply.

Thus, for example, a PEN film, a PPS film or a composite of aramid paper having a relative dielectric constant of less than 3.1 at 25 ° C. and 1 KHz, or a combination thereof with a PET film is used as the groove insulating paper for the winding. The use of slot insulation paper or wedge insulation paper for windings other than PET film mainly reduces the capacitance by using groove insulation paper with a small relative dielectric constant, and leaks harmonic components of the inverter power supply. And the leakage current can be suppressed.

According to a third aspect of the present invention, there is provided a refrigerant compressor having a stator and a rotor, and an HF compressor such as R410A or R407C.
A rotary or scroll refrigerant compressor using a C-based refrigerant and an ether-based or ester-based lubricating oil. The rotor has a rare-earth magnet in the iron core, is driven by an inverter power supply, and the control method of the inverter is PAM control. Alternatively, the PWM control and the PAM control are used in combination.

In this way, by controlling the operation of the inverter of the DC brushless motor for the compressor corresponding to the new refrigerant by using the PAM control or the combination of the PWM control and the PAM control, it is possible to control the leakage current within a specified value and to achieve high efficiency at a high voltage. Can be driven by

According to a fourth aspect of the present invention, there is provided a refrigerant compressor having a stator and a rotor, and an HF such as R410A or R407C.
A rotary or scroll refrigerant compressor using a C-based refrigerant and an ether-based or ester-based lubricating oil, wherein a rotor has a rare earth magnet in an iron core, and a stator winding has an intermediate magnetic pole (image pole) type. It is wound and is configured to be driven by an inverter power supply.

Since the stator winding of the motor is formed by winding of the image pole type, the leakage current of the motor tends to increase in proportion to the surface area of the winding. Thus, the leakage current can be reduced.

According to a fifth aspect of the present invention, there is provided a refrigerant compressor having a stator and a rotor, and an HF compressor such as R410A or R407C.
A rotary or scroll refrigerant compressor using a C-based refrigerant and an ether-based or ester-based lubricating oil, wherein the rotor has a rare-earth magnet in an iron core, is driven by an inverter power supply, and operates at a rated operating frequency of the compressor. The rated speed of the motor is set at a position shifted from the peak value of the leakage current.

Thus, since the operating frequency-leakage current curve of the DC brushless motor for the compressor has a peak value,
By avoiding the peak, the leakage current can be suppressed within a specified value.

[0018]

Embodiments of the present invention will be described below. FIG. 1 is a typical block diagram of a drive circuit of a commonly used DC brushless motor for a compressor.
In the figure, 1 is a DC power supply obtained by rectifying an AC power supply, 2 is a permanent magnet rotor, 3 is an inverter that supplies electric power for causing a stator 4 to generate a rotating magnetic field, and 6 is a rotor position detecting means. is there. The element constituting the inverter 3 includes six transistors Tr1 to Tr6.

The control circuit 5 is a control circuit for outputting a signal for controlling the energization of the transistors Tr1 to Tr6 constituting such an inverter 3 in a predetermined order, and detects the rotational position of the permanent magnet rotor. Means 6 detects the current, sets the timing of energization to the stator windings, and controls the energization to the stator windings.

FIG. 2 shows an example of a refrigerant compressor according to the present invention. The figure is a cross-sectional view, 21 is a stator core of the motor, 22 is a stator winding, 23 is a coil end of the stator winding, 24 is a rotor shaft, 25 is a cup fixed to the compressor, 26 is A cylinder block of a compressor (not shown),
27 is a storage case of the compressor.

FIG. 3 is a sectional view of the electric motor, and the same components as those in FIG. 2 are denoted by the same reference numerals. The stator winding 22 has three phases of A, B, and C phases. The windings of each layer are wound by an intermediate magnetic pole method called an image pole method, and an L coil having a long winding width and an M coil having a short winding width are used.
The coil is wound in two layers.

Further, four flat rare earth magnets 28 made of neodymium or the like are arranged in the iron core of the rotor 2. The plate-shaped rare-earth magnet 28 has a stronger magnetic force than a normal magnet, so that a magnet material that is not subjected to corner chamfering and surface treatment can be used as it is, thereby facilitating manufacturing and controlling the magnet material. Becomes easier.

In the DC brushless motor for a compressor having such a configuration, a new refrigerant replacing the conventional refrigerant is as follows.
As a result of experiments, the present applicant has found that it is effective to use an HFC-based refrigerant and an ether-based or ester-based lubricating oil. In particular, polyol ester oil for R134a, polyvinyl ether oil for R410A or R407C, and either polyol ester oil or polyvinyl ester oil for R404A are preferable. On the other hand, it was also found that this new refrigerant tends to increase the leakage current of the compression motor.

An inverter, which is a drive power source of a DC brushless motor for driving a compressor such as an air conditioner,
More efficient PAM from M (pulse width modulation) control method
(Pulse amplitude modulation) When switching to the control method or the combination of the PWM control method and the PAM control method, efficient operation is achieved, but the leakage current of the compression motor increases due to the high voltage, and the leakage current increases more and more. Has to be controlled within a specified value (1.0 mA), and adjustment during that time is required.

In order to solve this problem, according to the present invention, the leakage current depends on the volume of the motor even when HFC refrigerants such as R410A and R407C and ether or ester lubricating oil are used as the new refrigerant. Therefore, as a rotor magnet of a DC brushless motor for an inverter driven compressor, the price per unit weight is higher than that of a normal ferrite magnet, but its BH product is much larger, such as neodymium, ferrite, By using a rare-earth magnet made of iron, boron, or the like, the volume of the motor could be reduced by reducing the stack height of the core, and as a result, the leakage current could be reduced.

Further, in the present invention, as described above, the stator winding of the electric motor is formed by an intermediate magnetic pole (image pole) type winding. Next, the image pole type winding of the stator winding will be briefly described with reference to FIGS. In FIG.
Symbolically described are examples of an image pole system in which four poles form four poles (abbreviated as IP in the figure), an image pole system in which three poles form six poles, and an image pole system in which four poles form eight poles. The figure is shown.

For example, an image pole system in which four poles are formed by two poles will be described. A stator winding 22L having a long winding width of the A-phase wound at an opposing position in FIG. 3,
The stator winding 22M having a short winding width is opposed to be excited to have the same polarity to generate a magnetic flux, and the same poles N collide with each other. Is virtually generated, and 4
A pole is formed.

As a result, the leakage current of the motor tends to increase in proportion to the surface area of the winding, so that the image pole method results in a stator winding having half the desired number of poles and reduces the amount of copper wire used. Since it is possible, the number of windings and the number of windings are reduced to reduce the leakage current, and as a result, the leakage current can be suppressed within a specified value.

Also, HFCs such as R410A, R407C, etc.
Insulating paper in the winding groove of the motor is attacked by a new refrigerant that uses a system refrigerant and ether-based or ester-based lubricating oil, deteriorating insulation, lowering the insulation effect, and increasing the relative dielectric constant. Harmonic components of the inverter power supply leaked due to the capacitance, which also increased the leakage current.

Therefore, in order to solve this problem, PEN (polyethylene naphthalate) is used as insulating paper for a motor.
Film or PPS (polyphenylene sulfide) film or composite of aramid paper or PET and PET
(Polyethylene terephthalate) used in combination with film, slot insulation paper or wedge insulation paper for winding is PE
Those other than the T film were mainly used.

That is, for example, a PEN film, a PPS film or a composite of aramid paper having a relative dielectric constant of less than 3.1 at 25 ° C. and 1 KHz, or a combination thereof with a PET film is used for the groove insulating paper of the winding. The use of slot insulation paper or wedge insulation paper for windings other than PET film mainly reduces the capacitance by using groove insulation paper with a small relative dielectric constant, and leaks harmonic components of the inverter power supply. And it was possible to suppress the leakage current.

Further, HFCs such as R410A, R407C, etc.
When a DC brushless motor for a rotary or scroll compressor using a system refrigerant and an ether-based or ester-based lubricating oil is driven by an inverter power supply, as shown in the operating frequency-leakage current curve of FIG. Since it was found that a peak value of the leakage current exists in a specific range of the rated operating frequency, the peak is avoided by setting the rated speed of the motor at a position shifted from the peak value of the leakage current and operating the motor. And the leakage current can be suppressed to within a specified value.

[0033]

As described above, according to the present invention, R410A,
In a refrigerant compressor using a DC brushless motor driven by an inverter using a new refrigerant in which an HFC-based refrigerant such as R407C and an ether-based or ester-based lubricant are combined, the inverter is controlled by PAM or PWM control and PAM.
The operation is controlled as a combined use of control, and by adopting rare earth magnets for the magnet material of the motor rotor, the core lamination height is reduced, the volume of the motor and the amount of copper wire used are reduced, and the leakage current is within the specified value. Operation at high voltage and high efficiency.

Further, by using a groove insulating film having a small relative dielectric constant to reduce the capacitance, the leakage current can be suppressed within a specified value, and the stator winding of the motor is formed by an image pole type winding. As a result, the leakage current of the motor tends to increase in proportion to the surface area of the winding,
The number and amount of windings can be reduced to reduce leakage current. Furthermore, since the operating frequency-leakage current curve of the DC brushless motor for a compressor has a peak value, by operating while avoiding the peak, the leakage current can be suppressed within a specified value.

[Brief description of the drawings]

FIG. 1 is a block diagram of a drive circuit of a DC brushless motor for a compressor.

FIG. 2 is a layout diagram of a refrigerant compressor.

FIG. 3 is a sectional view of a DC brushless motor for a compressor according to the present invention.

FIG. 4 is an illustration of a symbolic image pole system.

FIG. 5 is an operating frequency-leakage current curve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 DC power supply 2 Permanent magnet rotor 3 Inverter 4 Stator 5 Control circuit 6 Rotor position detecting means 21 Stator core 22 Stator winding 23 Coil end 24 Rotor shaft 25 Cup 26 Cylinder block 27 Storage case 28 Flat plate Rare earth magnet

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F04C 29/00 F04C 29/00 U (72) Inventor Kazuhiko Arai 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. 56) References JP-A-7-264889 (JP, A) JP-A-9-233882 (JP, A) JP-A-9-256954 (JP, A) JP-A-63-45478 (JP, A) JP 63-45477 (JP, A) JP-A-3-118749 (JP, A) International Publication No. 92/7409 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 29/00 F04B 39/00 F04B 39/00 106 F04B 49/06 341 F04C 29/00 H02K 21/00

Claims (5)

(57) [Claims] 1. A compression element and a DC brushless motor for driving the compression element are enclosed in a sealed container.
A refrigerant compressor in which an FC-based single refrigerant or a refrigerant mixture thereof and an ether-based or ester-based lubricating oil are sealed in the closed container, wherein the DC brushless electric motor has a rotor iron core having a surface treatment. Rare earth magnets using non-performing magnet materials
A refrigerant compressor in which a stone is inserted and driven by an inverter power supply. 2. A PEN film, a PPS film or a composite of aramid paper or a combination thereof with a PET film as an insulating paper of an electric motor, and a slot insulating paper or a wedge insulating paper of a winding is mainly made of a material other than the PET film. The refrigerant compressor according to claim 1, wherein the refrigerant compressor is used. 3. The refrigerant compressor according to claim 1, wherein the control system of the inverter for driving the motor is PAM control or a combination of PWM control and PAM control. 4. The motor according to claim 1, wherein the stator winding is a winding of an intermediate magnetic pole (image pole) type.
A refrigerant compressor according to any of the preceding claims. 5. A compression element and a DC brushless motor for driving the compression element are enclosed in a sealed container.
A refrigerant compressor comprising an FC-based single refrigerant or a mixed refrigerant thereof, and an ether-based or ester-based lubricating oil sealed in the closed container, wherein the DC brushless electric motor includes a rotor core having a rare-earth magnet inside. A refrigerant compressor, wherein the rated speed of the electric motor is set at a position where the rated operating speed of the compressor is shifted from the peak value of the leakage current while being driven by an inverter power supply.