JPH05332265A - Scroll type compressor - Google Patents

Abstract

PURPOSE:To eliminate a need for a delivery valve and to improve performance of a compressor by providing a circuit to perform short-circuit between the arbitrary terminals of the fixed winding of a stator when energization to an electric motor is stopped and arranging an electric load device on the circuit. 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. A plurality of stator windings Mc are arranged as the electric motor M to a stator Mb, and a DC brushless motor having a permanent magnet is used in the rotor Ma. Further, a circuit 102 is provided for performing short- circuit between the arbitrary terminals of the stator winding Mc of the stator Mb when energization to the electric motor M is stopped, and an electric load device 104 is arranged on the circuit 102. This constitution prevents reverse rotation of a rotary shaft 5 when energization is stopped and an outage occurs, resulting in elimination of a need for a delivery valve and improvement of performance of a compressor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type compressor.

[0002]

2. Description of the Related Art FIG. 2 is a vertical sectional view of a conventional scroll type compressor, and FIG. 3 is an electric circuit diagram of a motor drive section of the same compressor. In FIG. 3, the interior of the hermetically sealed housing 8 of the scroll compressor 201 is partitioned by the discharge cover 31 into a high pressure side 44 and a low pressure side 45. Low voltage side 4
5, a scroll type compression mechanism C is arranged in the upper part and an electric motor M is arranged in the lower part.
Are interlockingly connected to each other via. As the electric motor M, a DC brushless motor including a rotor Ma having a permanent magnet and a stator Mb having a stator winding Mc connected in three phases is used, and the stator Mb is fixed via the motor driving means 101. A rotating magnetic field is generated by switching the energization to the child winding Mc, and the rotor M
The rotation shaft 5 is rotated by rotating a. 100 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 that is erected on the inner surface of the end plate 21, and a drive bush 54 is rotated inside a boss 23 that is erected on the outer surface of the end plate 21 via an orbiting bearing 73. 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 at an angle of 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 floatably mounted on a frame 6 via a support spring 32 arranged on the outer periphery of the end plate 11.
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 caused to rotate 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 84.
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 orbital movement of the orbiting scroll 2, the air 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.

[0009]

In the above-mentioned conventional scroll type compressor, the discharge valve 17 is installed in the discharge port 13 to open and close the discharge valve 17, but this causes a discharge pressure loss, so that the compressor of the compressor is not used. It has the drawback of reduced performance. Therefore, it is preferable to eliminate the discharge valve 17, but
When the power supply to the electric motor M is cut off due to a stop of power supply or a power failure, the reverse rotation of the rotary shaft 5 causes a problem such as running out of oil in the sliding portion.

The present invention solves the above-mentioned drawbacks of the prior art and eliminates the need for a discharge valve by providing means for preventing reverse rotation of the rotating shaft when the power supply is stopped or when a power failure occurs, thereby improving the performance of the compressor. Is.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a plurality of fixing members are fixed to a stator 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 compressor using a DC brushless motor having a child winding and a rotor having a permanent magnet, a short circuit occurs between any terminals of the stator winding of the stator when power supply to the electric motor is stopped. The present invention relates to a scroll-type compressor, which is characterized in that a circuit for providing the electric load is provided on the circuit.

[0012]

Since the present invention has the above-mentioned structure, the following effects are produced. That is, when the power supply to the electric motor is stopped, the terminals of the stator windings of the stator are short-circuited to form a closed circuit. Further, at this time, the rotating shaft and the rotor rotate in reverse due to the gas flowing in the compression mechanism in the opposite direction. The induced voltage generated by the rotation of the rotor causes a current to flow in the circuit and is consumed by the electric loader. That is, the electric motor acts as a generator and generates a braking force by converting the rotational kinetic energy of the rotor through the electric loader. Therefore, the braking force suppresses reverse rotation of the rotor and the rotating shaft. Therefore, the discharge valve becomes unnecessary.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an electric circuit diagram of a motor drive unit in an embodiment of the scroll compressor of the present invention. In the figure, Mc is a stator winding provided on the stator Mb, and 10
2 is an inter-terminal connection circuit formed by connecting between the terminals of the same stator winding Mc, 103 is a relay provided on the circuit, 104 is an electric loader provided on the circuit,
The relay 103 and the electric load device 104 are connected in series.

The relay 103 separates its contacts when the electric motor M is energized to open the circuit 102, and closes the contacts when the energization is stopped to short-circuit the terminals of the stator winding Mc to form a closed circuit 102. It is supposed to do. Electric loader 10
Reference numeral 4 is for converting the current flowing through the circuit 102 into energy such as heat and light, and in this example, a resistor is used. Note that the circuit 102 can be provided between other terminals as well. It is also possible to provide a plurality.

Further, in the scroll compressor of this embodiment, the discharge valve 17 for opening and closing the discharge port 13 is not installed. Structures other than those described above are similar to those shown in FIG.
3 and is similar to the conventional one shown in FIG. 3, and the corresponding members are designated by the same reference numerals and the description thereof will be omitted.

In this device, when the electric motor M is energized, the contacts of the relay 103 are separated and the circuit 102 is open, and the motor driving means 101 is the same as described in the conventional example.
A rotating magnetic field is generated by switching the energization of the stator winding Mc of the stator Mb via the rotor, thereby rotating the rotor Ma and rotating the rotating shaft 5.

On the other hand, when the driving of the motor is stopped, or when the power supply to the electric motor M is stopped due to the disconnection of the connection outlet or the power failure, the contact of the relay 103 is closed to form the closed circuit 102. .. At this time, in the housing of the compressor, the rotating shaft 5 and the rotor Ma are reversely rotated by the gas flowing in the opposite direction from the high pressure side 44 to the low pressure side 45 through the compression mechanism C. A current flows through the circuit 102 due to the induced voltage generated therewith, and is consumed as Joule heat by the resistor 104. That is, the electric motor M acts as a generator and generates braking force by converting the rotational kinetic energy of the rotor Ma into Joule heat. Therefore, the braking force suppresses the reverse rotation of the rotor Ma and the shaft 5, and as a result, running out of oil in the sliding portion due to the reverse rotation of the rotary shaft 5 is avoided.

According to this embodiment, a circuit for forming a closed circuit is provided by short-circuiting between arbitrary terminals of the stator winding when energization of the electric motor is stopped, and an electric loader is provided on this circuit. Since the electric motor is provided with the electric motor, the electric motor acts as a generator to suppress the reverse rotation of the rotating shaft in the event of a power failure or the like, so that the oil supply to the sliding portion due to the reverse rotation is avoided. As a result, the discharge valve is not required, so the discharge pressure loss can be reduced and the performance of the compressor can be improved.

[0019]

In the scroll type compressor of the present invention, a circuit is provided for short-circuiting any terminals of the stator winding of the stator when the electric motor is de-energized, and an electric load is provided on this circuit. Since the device is provided, reverse rotation of the rotating shaft is prevented when the power is stopped or when a power failure occurs, which eliminates the need for a discharge valve and improves the performance of the compressor.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a motor drive unit according to an embodiment of the present invention.

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

FIG. 3 is an electric circuit diagram 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 stator winding 5 rotating shaft 8 sealed housing 13 discharge port 17 discharge valve 101 motor drive means 102 terminal connection circuit 103 relay 104 electric loader 201 scroll type Compressor

Claims (1)

[Claims] 1. A DC brushless motor having a stator having a plurality of stator windings 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 such a scroll compressor, a circuit that short-circuits between arbitrary terminals of the stator winding of the stator when the power supply to the electric motor is stopped is provided, and an electric loader is provided on this circuit. A scroll type compressor characterized in that