JP2002031072A - Rotary compressor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To suppress the vibration of a drive motor caused by cantilever. SOLUTION: A rotary type compressor 4 and a drive motor for driving the compressor 4 are housed in a sealed container 3 provided with a gas refrigerant suction pipe 1 and a discharge pipe 2, and are provided in a rotary for a vehicle mounted refrigerator. In the compressor, the compressor 4 is driven by a permanent magnet type synchronous motor 20, and a rotor 23 of the permanent magnet type synchronous motor 20 is embedded in a rotor core 24 laminated with a magnetic thin plate material and the rotor core 24. The permanent magnet type synchronous motor 20 is configured to suppress the vibration of the open side rotor shaft 6 even if the rotor shaft 6 of the permanent magnet type synchronous motor 20 has a cantilever structure on the compressor 4 side. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor, and more particularly to a drive motor for driving a compressor housed in a closed container of a refrigerator mounted on a vehicle such as an automobile operated by a DC power supply such as a battery of 12 V or 24 V. By using a neodymium-based permanent magnet type synchronous motor, the efficiency of the motor has been improved, the rotating shaft has been shortened and the size and weight have been reduced, and the vibration of the drive motor caused by the cantilever of the rotor shaft has been suppressed. The present invention relates to a rotary compressor applicable to a refrigerator mounted on a vehicle.

[0002]

2. Description of the Related Art Conventionally, a hermetic rotary compressor for cooling a refrigerator mounted on an automobile, for example, using a battery voltage of DC 12V or 24V as a power source, as shown in FIG. 2 is provided in a closed container 3 provided with, for example, a rotary type compressor 4 and a drive motor for driving the compressor 4, and compresses a gas refrigerant introduced into the closed container 3 from the suction pipe 1 into a high-pressure compressor. And discharged from the discharge pipe 2 to an external refrigerating device.

At this time, an induction motor 5 is conventionally used as a drive motor for driving the compressor 4. The induction motor 5 is rotated by using a battery voltage DC12V or 24V mounted on an automobile as a driving power source, and the induction motor 5 is driven. The crankshaft 7 of the compressor 4 is fixed to the rotor shaft 6 in which the rotor shaft 6 is cantilevered only on the compressor 4 side, and the rotation of the induction motor 5 is transmitted to the crankshaft 7 to drive the compressor 4. Was like that.

FIG. 6 shows a principle diagram of an induction motor represented by an equivalent schematic circuit. In general, a cage-type rotor having a rotor structure shown in FIG. 7 is often used in a relatively small-capacity induction motor. Therefore, the drive motor for driving the compressor 4 of the conventional refrigerator mounted on an automobile is also a cage-type rotor. Of the induction motor 5 was used.

The stator 8 of the induction motor 5 has a stator winding (primary winding) for generating a rotating magnetic field or an alternating magnetic field.
When an exciting current flows through the stator winding 9, an induced electromotive force is generated in the short-circuit wire (conductor) 11 of the rotor 10, and the current flowing through the stator winding 9 is reduced. Due to a 90 ° phase difference generated between the current flowing through the short-circuit wire 11 of the rotor 10 and a rotation torque is generated in the rotor 10, and the rotor 10 of the induction motor 5 rotates.

The rotary type compressor 4 has been widely used in the past. For example, the structure of the rotary type compressor 4 is such that a roller inserted into an eccentrically rotating crankshaft 7 has an inner peripheral surface in a cylinder chamber. The cylinder chamber is divided into two parts by vanes that are eccentric along and are pressed by a spring so as to contact the rollers. Then, the refrigerant gas from the refrigeration cycle is sucked into the cylinder chamber from the suction pipe 1, and then the refrigerant gas in the cylinder chamber is compressed by the eccentric rotation of the crankshaft 7 and the rollers, and the refrigerant gas is pressurized to a predetermined pressure. Then, the discharge valve is pushed open and discharged into the space in the closed container 3. Thereafter, the discharged high-pressure compressed refrigerant gas is supplied to the closed container 3
It is sent out of the rotary compressor from the discharge pipe 2 in the inside, that is, outside the hermetic container 3, and reaches the inside of the refrigeration cycle of the refrigerator. A cooling action is performed in the refrigeration cycle, and the refrigerant is again sucked into the cylinder chamber from the suction pipe 1.
Compression and discharge are performed.

The induction motor 5 is supplied with a voltage of DC 12 V or 24 V of a battery mounted on a vehicle. This battery voltage is converted into an AC voltage having a predetermined frequency by an appropriate converter, and is supplied to the induction motor 5.

FIG. 8 shows a characteristic diagram of a rotary compressor using a conventional cage rotor induction motor, wherein the diameter of the closed vessel 3 is S ₀ , its length is L ₀ , and the input voltage DC12V is constant. When the rotation speed is constant at 3000 rpm, the horizontal axis represents torque, and the vertical axis represents input current I ₀ , output P ₀ , and efficiency η ₀ , respectively. Note that the efficiency at the time of rating η ₀ =
59%.

[0009]

In the induction motor 5 as a drive motor for driving the compressor 4, an exciting current flows through a stator winding 9 wound around a stator 6 in order to obtain a rotational torque. An electromotive force is induced in the short-circuited wire 11 and a short-circuit current is caused to flow through the short-circuited wire 11, so that the efficiency is poor, the starting current (rush current) is large, and the rated current is increased to about six times. Therefore, under a limited energy source such as a battery or the like as a power source, the discharge is fast and unsuitable.

Further, in order to form the rotor 10 in a cage shape, the rotor core is die-cast and the short-circuit wire 1
1 must be buried, and short-circuit rings 12 must be provided at both ends of the rotor 10. The die cost and the processing cost by die-casting the rotor core are increased, and the shape of the rotor 10 is increased. There were drawbacks.

In addition, the rotor shaft 6 of the rotor 10 of the induction motor 5 fixed to the crankshaft 7 of the compressor 4 has a cantilever holding structure only on the compressor 4 side, and the rotation axis length of the rotor 10 , The open side rotor shaft 6 of the rotor 8 is easily vibrated greatly, and the rotor 10
And the inner peripheral surface of the stator 8 is in contact with the inner peripheral surface of the stator 8.

In addition, from the viewpoint of use as a refrigerator mounted on a vehicle such as an automobile, it is strongly desired to reduce the size and weight of the refrigerator without reducing the internal volume of the refrigerator. Had been requested.

The present invention has been made in view of the above points, and uses a permanent magnet type synchronous motor composed of a neodymium permanent magnet as a drive motor for driving a rotary type compressor having a cantilever structure. As a result, the drive motor is made more efficient and smaller and lighter, and the length of its rotating shaft is shortened. Thus, even if the compressor is a cantilevered structure only on the compressor 4 side, the vibration of the rotor shaft of the drive motor is suppressed and the vehicle is mounted An object of the present invention is to provide a rotary compressor adapted to a refrigerator for use in a vehicle.

[0014]

In order to solve the above-mentioned problems, a rotary compressor according to the present invention comprises a rotary compressor and a compressor in a sealed container provided with a gas refrigerant suction pipe and a discharge pipe. A drive motor that drives the compressor is housed, and in a rotary compressor of a refrigerator mounted on a vehicle, the compressor is driven by a permanent magnet type synchronous motor,
The rotor of the permanent magnet type synchronous motor includes a rotor core laminated with a magnetic thin plate material and a neodymium permanent magnet embedded in the rotor core, and a rotor shaft of the permanent magnet type synchronous motor is provided. Is characterized in that the vibration of the open-side rotor shaft is suppressed even in a cantilever structure on the compressor side.

Since a neodymium-based permanent magnet type synchronous motor is used, its high efficiency makes it possible to reduce the size and weight of the rotating shaft as well as to suppress and reduce the vibration of the open-side rotor shaft of the cantilever drive motor. It becomes a rotary compressor suitable for a refrigerator mounted on a vehicle.

[0016]

FIG. 1 is a sectional view showing an embodiment of a rotary compressor according to the present invention.

In FIG. 5, the same components as those in FIG. 5 are denoted by the same reference numerals, and a permanent magnet type synchronous motor 20 is used as a drive motor for driving the compressor 4. The permanent magnet type synchronous motor 20 includes a stator 21 on which a stator winding 9 for generating a rotating magnetic field or an alternating magnetic field is wound.
And a rotor 23 in which a permanent magnet 22 is embedded to form a magnetic pole on a rotor core laminated with a magnetic thin plate material.

FIG. 2 shows a principle diagram of a permanent magnet type synchronous motor represented by an equivalent schematic circuit. The rotor structure of a rotor 23 used in the permanent magnet type synchronous motor 20 is as follows.
This is shown in FIG.

As shown in FIGS. 1 and 3, the rotor 23 is provided with a neodymium-magnesium (Nd-M) on a rotor core 24 formed by punching a thin sheet of a magnetic material into a predetermined shape and laminating it.
g) A structure is provided in which a permanent magnet 22 made of a magnetic material is fitted and mounted. The permanent magnet 22 fitted and mounted on the laminated rotor core 24 is not limited to the shape shown in FIG. 3, but includes various other shapes.

When an exciting current flows through the stator winding (primary winding) 9, rotating N and S poles are generated on the stator 21 side, and the rotating N and S poles on the stator 21 side are connected to each other. Permanent magnet 22
, An attraction / repulsion action occurs between the N and S poles of the rotor 23, and the rotor 23 of the permanent magnet type synchronous motor 20 rotates.

Since a neodymium-magnesium permanent magnet 22 having high energy is used for the rotor 23, the electric power supplied to the permanent magnet type synchronous motor 20 is limited to the stator winding 9 on the stator 21 side. And the current is small, so that the efficiency is high.

In addition, since the rotor 23 has a structure in which the permanent magnets 22 are fitted and mounted on the laminated rotor cores 24, the structure is simple and the balance is easy to take.
Manufacturing costs can be kept low. Neodymium requires only a small amount.

The permanent magnet type synchronous motor 20 is supplied with a DC voltage of 12 V or 24 V of a battery mounted on an automobile. This battery voltage is converted into an AC voltage having a predetermined frequency by an appropriate converter, and is supplied to the permanent magnet type synchronous motor 20.

FIG. 4 is a characteristic diagram of a rotary compressor using the permanent magnet type synchronous motor of the present invention.
When the diameter S ₁ of the closed container 3 is of a conventional 5 same S ₁ =
S ₀ , the length is L ₁ , the input voltage is constant at 12 V DC and the rotation speed is 3000 rpm, the horizontal axis represents torque, and the vertical axis represents input current I ₁ , output P ₁ , and efficiency η ₁ , respectively. The efficiency at the time of rating η ₁ = 86%.

This characteristic is based on the fact that a neodymium-magnesium permanent magnet 22 having high energy is used for the rotor 23, and the thickness of the stator of the drive motor for driving the rotary type compressor 4 is increased. The ratio T ₁ / T ₀ between the thickness T ₁ of the stator 21 of the permanent magnet type synchronous motor 20 of the present invention and the thickness T ₀ of the stator 8 of the conventional induction motor 5 is 1 /. 2.

Accordingly, the ratio of the length L ₁ of the closed vessel 3 of the rotary compressor of the present invention to the length L ₀ of the closed vessel 3 of the conventional rotary compressor is as small as L ₁ / L ₀ = 0.8. That is, the size and weight of the rotary compressor can be reduced.

Since the permanent magnet type synchronous motor 20 for driving the rotary type compressor 4 can be reduced in size and weight, the rotation of the rotor 23 of the permanent magnet type synchronous motor 20 when the diameter is the same as that of the conventional drive motor. The shaft length can be shortened, and the vibration of the open-side rotor shaft 6 of the cantilevered permanent magnet synchronous motor 20 fixed to the crankshaft 7 of the compressor 4 can be reduced. As a result, the permanent magnet type synchronous motor 20 is prevented from deteriorating its durability and its life is extended.

[0028]

As described above, according to the present invention, a drive motor for driving a rotary compressor having a cantilever structure is provided.
The use of a permanent magnet synchronous motor composed of neodymium-based permanent magnets suppresses and reduces the vibration of the open-side rotor shaft of the drive motor that drives the compressor. In addition, the size and weight can be reduced, the number of processing steps can be reduced, and the material cost can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a principle diagram of a permanent magnet type synchronous motor represented by an equivalent schematic circuit.

FIG. 3 is an explanatory view of a rotor structure of a rotor of a permanent magnet type synchronous motor.

FIG. 4 is a characteristic diagram of one embodiment of a rotary compressor using the permanent magnet type synchronous motor of the present invention.

FIG. 5 is a sectional view of one embodiment of a conventional rotary compressor.

FIG. 6 is a principle diagram of an induction motor represented by an equivalent schematic circuit.

FIG. 7 is an explanatory view of a rotor structure of a cage rotor of an induction motor.

FIG. 8 is a characteristic diagram of a rotary compressor using a conventional induction motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Suction pipe 2 Discharge pipe 3 Airtight container 4 Compressor 5 Induction motor 6 Rotor shaft 7 Crankshaft 8 Stator 9 Stator winding 10 Rotor 11 Short-circuit wire 12 Short-circuit ring 20 Permanent-magnet synchronous motor 21 Stator 22 Permanent Magnet 23 Rotor 24 Rotor core

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H029 AA15 AA21 AB03 BB23 CC07 CC27 CC38 5H607 AA00 AA04 BB07 BB09 BB14 CC05 DD19 FF07 5H621 BB07 BB10 HH01 JK13 JK19 5H622 CA02 CA07 CA10 CA13 CB03 DD02 PP03 PP11 PP11

Claims (1)

[Claims] In a rotary compressor of a refrigerator mounted on a vehicle, a rotary compressor and a drive motor for driving the compressor are housed in a sealed container provided with a suction pipe and a discharge pipe for a gas refrigerant. The compressor is driven by a permanent magnet type synchronous motor, and the rotor of the permanent magnet type synchronous motor is composed of a rotor core laminated with a magnetic thin plate material and a neodymium permanent magnet embedded in the rotor core. A rotary compressor, comprising: a rotor for a permanent magnet type synchronous motor, wherein a vibration of an open-side rotor shaft is suppressed even if a rotor shaft of the compressor is cantilevered on a compressor side.