JPH05332266A - Scroll type fluid machine - Google Patents

Abstract

PURPOSE:To perform re-starting immediately after a compressor is stopped once by providing a control device which is designed to intermittently feed a DC exciting current in a given amount, required for constrainment of a rotor, between the arbitrary terminals of the armature winding of a stator during the stop of a compressor. CONSTITUTION:An electric motor M is provided for driving a scroll type compression mechanism 201, contained in a closed housing 8, through a rotary shaft 5. An armature winding Mc is arranged as the electric motor M to a stator Mb, and a DC brushless motor having a permanent magnet is used in a rotor Ma. Further, a control device is provided for intermittently feeding a DC exciting current in a given amount, required for constrainment of the rotor Ma, between the arbitrary terminals of the armature winding Mc of the stator Mb when a compressor is stopped. Since the rotary shaft 5 is alternately stopped and reversed, pressures on the delivery side and the suction side of the compressor are rapidly uniformized with each other as the generation of abnormal noise and the occurrence of a reverse flow are suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type fluid machine used for compressors, expanders and the like.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view of a conventional scroll type compressor incorporated in a refrigeration system. FIG. 3 is a diagram showing a refrigerant circuit of a refrigerating apparatus configured by incorporating the same compressor and an electric circuit of a motor drive section of the same compressor.

In FIG. 3, a compressor 201 constitutes a refrigeration system together with a condenser 202, a diaphragm device 203 such as a capillary tube, and an evaporator 204.
The interior of the closed housing 8 of the compressor 201 is partitioned by the discharge cover 31 into a high pressure side 44 and a low pressure side 45. Inside the low-pressure side 45, a scroll type compression mechanism C is arranged at an upper part thereof and an electric motor M is arranged at a lower part thereof, which are interlockingly connected to each other via a rotary shaft 5. The electric motor M includes a rotor Ma and a rotor 3 each having a permanent magnet.
A DC brushless motor including a stator Mb having a phase-connected armature winding Mc is used, and a rotating magnetic field is generated by switching the energization of the stator Mb to the armature winding Mc via the energization switching unit 101. It is generated so that the rotor Ma is rotated and the rotating shaft 5 is driven. 105 is a power supply.

In FIG. 2, the scroll type compression mechanism C comprises a fixed scroll 1 and an orbiting scroll 2.
The fixed scroll 1 includes an end plate 11 and a spiral wrap 12 provided upright on the inner surface of the end plate 11. A discharge port 13 is provided at the center of the end plate 11, and the discharge port 13 is opened and closed. The discharge valve 17 is installed.
The orbiting scroll 2 is provided with an end plate 21 and a spiral wrap 22 which is erected on the inner surface of the end plate 21, and a drive bush 54 is rotated via a orbiting bearing 73 in a boss 23 which is erected on the outer surface of the end plate 21. The rotary shaft 5 is freely inserted and inserted into a slide hole 55 formed in the drive bush 54.
An eccentric pin 53 protruding from the upper end of is fitted slidably.

The fixed scroll 1 and the orbiting scroll 2 are eccentric with respect to each other by a predetermined distance, and are meshed with each other with an angle shifted by 180 degrees to form a plurality of closed spaces 24. The orbiting scroll 2 is a closed housing 8
A slidably supported on a frame 6 fixed inside and allowing rotation of the swivel scroll 2 between the swivel scroll 2 and the frame 6 but preventing the rotation thereof. The mechanism 3 is provided.

The fixed scroll 1 is capable of floating freely via a support spring 32 arranged on the outer periphery of the end plate 11 of the frame 6.
Supported by. On the back surface of the end plate 21 of the fixed scroll 1, a concentric cylindrical flange 15 centered on the center thereof,
16 is protruded upward, and is enclosed by the cylindrical flanges 38 and 39 protruded downward on the lower surface of the discharge cover 31 between these in a sealed and slidable manner. An intermediate pressure chamber 40 is formed, and the intermediate pressure chamber 40 communicates with the sealed space 24, which is in the middle of compressing gas, through a pressure guiding hole 41 formed in the end plate 11. A high pressure chamber 42 is formed on the inner peripheral side of the intermediate pressure chamber 40, and a low pressure chamber 43 is formed on the outer peripheral side.

The upper end of the rotary shaft 5 is supported by an upper bearing 71 provided on the frame 6, and the lower end thereof is supported by a lower bearing 72. The oil pump 5 is attached to the lower end of the rotary shaft 5.
1, the oil pump 51 is provided with an oil supply hole 52 formed in the rotary shaft 5 for lubricating oil stored in an oil sump 81 at the inner bottom of the closed housing 8 when the rotary shaft 5 is rotated in the forward direction. On the other hand, when the rotary shaft 5 is rotated in the opposite direction, the lubricating oil flows back from the oil supply hole 52 to the oil sump 81.

By driving the electric motor M, the orbiting scroll 2 is driven by a revolving orbiting mechanism including a rotating shaft 5, an eccentric pin 53, a drive bush 54, a boss 23, etc., and the orbiting scroll 2 is rotated by a rotation preventing mechanism 3. While being blocked, it makes a revolution revolving motion on a circular orbit having a radius of revolution revolution. Then, the gas is sucked into the suction pipe 82.
Through the low pressure side 45 and through the passage 61.
3 is sucked into the closed space 24. Then, as the volume of the closed space 24 decreases due to the orbiting motion of the orbiting scroll 2, the space reaches the center while being compressed, and the discharge valve 17 is pushed open from the discharge port 13 to enter the high pressure side 44 from the high pressure chamber 42. From here, it is discharged to the outside via the discharge pipe 83. At this time, the fixed scroll 1 is pressed against the orbiting scroll 2 by the back pressure load due to the gas pressure in the high pressure chamber 42 and the intermediate pressure chamber 40, and gas leakage from the sealed space 24 is suppressed. When the liquid is sucked into the closed space 24, the fixed scroll 1 floats and the liquid is released to prevent the scroll type compression mechanism C from being damaged.

At the same time, the lubricating oil in the oil sump 81 is sucked up by the oil pump 51, passes through the oil supply hole 52, and the eccentric pin 53, the upper bearing 71, the rotation preventing mechanism 3, and the slewing bearing 7 are provided.
After lubricating the sliding parts such as 3 and the like, they return to the oil sump 81 through a path not shown and are stored there. On the other hand, when the operation of the compressor is stopped, the discharge valve 17 is closed and the high pressure side 44
Therefore, the reverse flow of the gas into the compression mechanism C is prevented, and thus the reverse rotation of the rotary shaft 5 is prevented, and the situation where the sliding portion is out of oil is avoided. Further, generation of abnormal sound due to this reverse rotation is prevented.

[0010]

In the conventional scroll type compressor described above, the discharge port 1 is provided in order to prevent the reverse rotation of the rotary shaft 5 immediately after the compressor 201 is stopped.
Since the discharge valve 17 for opening and closing the compressor 3 is provided, when the compressor is once stopped, the pressures on the discharge side and the suction side of the compressor 201 are only gradually equalized through the expansion device 203. Therefore, there is a problem that it takes a long time to equalize the pressure and the compressor 201 cannot be immediately restarted.

The present invention aims to solve the above-mentioned drawbacks of the prior art and to provide a scroll type fluid machine which can be immediately restarted after being temporarily stopped.

[0012]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems. An electric motor for driving a scroll type compression mechanism housed in a hermetically sealed housing via a rotary shaft is used as a stator armature winding. In a scroll type fluid machine in which a DC brushless motor having a wire and a rotor having a permanent magnet is used, the rotor is constrained between arbitrary terminals of the armature winding of the stator when the compressor is stopped. The present invention relates to a scroll type fluid machine including a control device for intermittently supplying a constant amount of DC exciting current.

[0013]

Since the present invention has the above-mentioned structure, the following effects are produced. That is, when the operation of the compressor is stopped, a DC exciting current of a predetermined magnitude necessary for restraining the rotor is intermittently supplied to the armature winding of the stator so that the rotor is integrated with the rotor. The rotating shaft that has stopped and reverse rotation is alternately repeated, and both pressures are quickly equalized with the outflow of gas from the discharge side to the suction side of the compressor under this reverse rotation.

[0014]

FIG. 1 is a diagram showing a refrigerant circuit of a refrigeration system and an electric circuit of a motor drive section of a compressor in one embodiment of the present invention. In the figure, 103 is a controller that controls the energization of the armature winding Mc after the motor is stopped, and controls the energization switching means 101. Further, 104 is a device that issues an operation stop signal, 110 is an energization ON signal, and 111 is an energization OFF signal. Further, in the compressor 201, the discharge valve 17 that is conventionally provided for opening and closing the discharge port 13 is not provided. The parts other than the above are the same as those of the conventional technique, and therefore the description of the configuration will be omitted.

In this device, the operation stop signal device 104
Immediately after the compressor 201 is stopped by the operation stop signal from the
Outputs an energization ON signal 110 to the energization switching means 101 to energize a predetermined armature winding Mc with a direct current of a predetermined magnitude for a predetermined time. A predetermined direct current is applied to the armature winding Mc to generate a magnetic field in a fixed direction, and the rotor Ma is rotated.
Is stopped by the attraction action with the permanent magnet to stop the rotating shaft 5. Here, the electric current of a predetermined magnitude means that gas flows from the high-pressure side 44 into the compression mechanism C to prevent the rotating shaft 5 from rotating in the reverse direction, and a sufficient restraining torque is generated to restrain the rotor Ma. It is the electric current.

After a certain period of time, the controller 103 outputs an energization OFF signal 111 to the energization switching means 101 to stop energization. Therefore, the gas on the high pressure side 44 flows out to the low pressure side 45 via the compression mechanism C, and the rotating shaft rotates in the reverse direction. After that, the controller 103 turns on / off this energization.
The FF control is repeated a predetermined number of times. The predetermined number of repetitions is, for example, until the pressures on the high pressure side 44 and the low pressure side 45 become equal.

The selection of the armature winding Mc to be energized is as follows.
It may be random, or by selecting the phase to be energized and the direction of current, depending on the relationship between the direction of the magnetic pole generated by the armature winding Mc and the direction of the magnetic pole of the permanent magnet of the rotor Ma,
It is also possible to limit the stop position of the rotor Ma. Also,
It is possible to change it every time. In this way, the rotating shaft 5 alternately repeats stop and reverse rotation, and the pressures of both are quickly equalized as the gas flows from the high pressure side 44 to the low pressure side 45 under the reverse rotation.

It should be noted that when the rotating shaft 5 rotates in the reverse direction, abnormal noise is generated, and depending on the type of the oil pump 51, a backflow phenomenon of the lubricating oil from the sliding portion to the oil sump 81 occurs, but this reverse rotation is intermittent. The reverse rotation speed of the rotating shaft 5 can be suppressed to a small value by setting the time for energizing and stopping energizing the armature winding Mc by the controller 103 appropriately. Backflow can be suppressed.

In the present embodiment, when the operation of the compressor is stopped, a predetermined amount of direct current required to restrain the rotor between arbitrary terminals of the armature windings provided in the stator when the compressor is stopped Since the rotating shaft is alternately stopped and reversely rotated by providing a control device that intermittently supplies an exciting current, the pressure on the discharge side and suction side of the compressor is suppressed while suppressing abnormal noise and backflow of lubricating oil. Can be quickly equalized, and as a result, the time required to restart the compressor can be shortened.

[0020]

According to the scroll type fluid machine of the present invention, a predetermined amount of DC exciting current required to restrain the rotor between the arbitrary terminals of the armature winding of the stator is intermittently applied when the compressor is stopped. Since it is provided with the control device for supplying, it can be restarted immediately after being stopped once.

[Brief description of drawings]

FIG. 1 is a diagram showing an electric circuit of a refrigerant circuit of a refrigeration system and a motor drive unit of a compressor in one embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a conventional scroll compressor.

FIG. 3 is a diagram showing a refrigerant circuit of a refrigerating apparatus configured by incorporating the compressor and an electric circuit of a motor drive unit of the compressor.

[Explanation of symbols]

 C compression mechanism M electric motor (DC brushless motor) Ma rotor Mb stator Mc armature winding 5 rotating shaft 8 hermetically sealed housing 17 discharge valve 101 energization switching means 103 controller 104 operation stop signal device 105 power supply 110 energization ON signal 111 energization OFF signal

Claims (1)

[Claims] 1. A DC brushless motor having a stator having an armature winding and a rotor having a permanent magnet is used as an electric motor for driving a scroll type compression mechanism housed in a hermetically sealed housing via a rotary shaft. In a scroll type fluid machine, a control device that intermittently supplies a predetermined amount of DC exciting current required to restrain the rotor between arbitrary terminals of the armature winding of the stator when the compressor is stopped is provided. Scroll type fluid machine characterized by.