JP2007309186A - Hermetic compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that difference in current value between at the time of full load operation and at the time of controlled operation is generated since load torque to a motor is different between at the time of full load operation and at the time of controlled operation and that it is difficult to prevent excessive rise of temperature in a compressor in a multiple cylinder type hermetic compressor mounting a three-phase motor and by making capacity variable between the full load operation and the controlled load operation. <P>SOLUTION: A first relay performing continuous open close action with corresponding to current and temperature of a contact part in the three-phase motor, a second and a third relay performing continuous open close action with corresponding to temperature in other two phases are provided. Consequently, the first relay is operated during full load operation and the second and third relay are operated during controlled operation to prevent excessive rise of temperature. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention has two cylinder chambers, a so-called capability that enables selection between an operation in which two chambers are compressed simultaneously and an operation in which the compression action in one of the cylinder chambers is interrupted to reduce the compression work. The present invention relates to a hermetic compressor that can be made variable and that has a protective device that prevents an excessive temperature rise.

  A general hermetic compressor has a structure in which a motor part and a compression mechanism part connected to the motor part are accommodated in a hermetic case, and gas compressed by the compression mechanism part is once discharged into the hermetic case. It is an internal high-pressure type. The compression mechanism unit has a piston housed in a cylinder chamber provided in the cylinder. The cylinder is provided with a vane chamber in which the vane is slidably accommodated. The tip edge of the vane is pressed and urged by a compression spring so as to protrude toward the cylinder chamber and elastically contact the peripheral surface of the piston.

  Therefore, the cylinder chamber is divided into two chambers along the direction of rotation of the piston by the vanes. The suction part communicates with one chamber side, and the discharge part communicates with the other chamber side. A suction pipe is connected to the suction part, and the discharge part is opened in the sealed case.

  By the way, a two-cylinder type rotary hermetic compressor having two sets of cylinders at the top and bottom is generally used. In such a compressor, a cylinder that always performs a compression action, and a compression- If a cylinder capable of switching the stop can be provided, the usable capacity range is expanded, which is advantageous.

  For example, in Patent Document 1, two cylinder chambers are provided, and if necessary, the vanes of one of the cylinder chambers are forcibly separated from the rollers, and the compression operation is interrupted by increasing the pressure of the cylinder chamber. A technique characterized by comprising a high-pressure introduction means is disclosed.

2. Description of the Related Art Conventionally, as shown in FIG. 2, a protection device for preventing an excessive temperature rise of a compressor has a relay that opens and closes continuously in response to temperature and current at the middle contact portion of a three-phase motor inside the compressor. It was.
JP-A-1-247786

  However, in the above-described conventional excessive temperature rise protection device, the relay operates during full load operation, but during control load operation, the load torque to the motor decreases, so the current in the compressor motor section decreases, and the temperature inside the compressor The relay did not turn off even when

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide a rotary hermetic compressor capable of preventing an excessive temperature rise in the compressor even during a controlled load operation and improving reliability.

  In order to satisfy the above object, the present invention is connected to the first relay that opens and closes according to the temperature and current, and is connected to the two phases of the motor three-phase winding. The second and third relays that perform the opening / closing operation according to the above are installed.

  The hermetic compressor of the present invention provides a hermetic compressor that can prevent an excessive temperature rise of the compressor during full load operation and control load, and can improve the safety and reliability of the compressor. it can.

  1st invention installs the relay 1 which respond | corresponds to temperature and an electric current in the contact part in a three-phase motor, and the 1st relay which opens and closes according to temperature, and two phases of the winding of three phases, respectively By installing the relay 2 and the relay 3 that are connected and perform switching operation according to the temperature, the relay 1 is activated during full load operation, and the relay 2 and the relay 3 are activated during control load, and the compressor is overheated. The rise can be prevented.

  In the second aspect of the present invention, the second relay and the third relay are arranged in contact with the motor, whereby the quick response to the motor temperature can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by embodiment described below.

(Embodiment 1)
FIG. 2 is a connection diagram of a conventional compressor protection device. When the compressor 9 is operated at full load operation, an increase in the internal temperature of the compressor can be prevented by turning off the relay 1.

  However, at the time of control load operation of the compressor 9 of the multi-cylinder type hermetic compressor whose capacity can be changed between full load operation and control load operation, the load torque is small and the motor current value becomes low. There is a disadvantage that the internal temperature rise cannot be prevented.

  FIG. 1 is a connection diagram of a compressor protection device according to the present invention. In the figure, 1 is a first relay that responds to temperature and current in the compressor 9, 5 is a second relay that responds to temperature, and 6 is a third relay that responds to temperature.

  When the load of the refrigeration cycle during operation increases during full load operation, the internal temperature of the compressor 9 increases. In this case, the first relay 5 is turned off by the current value and the temperature, and the excessive temperature rise is suppressed. Since the current value is small at the time of control load, the first relay 1 does not react, and the second relay 3 and the third relay 4 that react only to the temperature rise are turned off to suppress the excessive temperature rise.

  As described above, the compressor protection device according to the present invention can prevent an excessive temperature rise in a multi-cylinder hermetic compressor whose capacity can be varied between full load operation and control load operation. And reliability can be improved.

Connection diagram showing an embodiment of the present invention Connection diagram showing a conventional compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st relay 2 Bimetal 3 2nd relay 4 3rd relay 5 Winding U phase 6 Winding V phase 7 Winding W phase 8 Power supply 9 Sealed compressor

Claims (5)

A multi-cylinder type housing a three-phase motor unit and a compression mechanism unit connected to the three-phase motor unit in a hermetically sealed case, the capacity of which is variable in two stages of full load operation and control load operation. A hermetic compressor, which is installed at the middle contact portion of the three-phase motor and is connected to two phases of the three-phase windings and a first relay that opens and closes according to temperature and current, A hermetic compressor comprising second and third relays that open and close according to the operation. The hermetic compressor according to claim 1, wherein the second and third relays are disposed in contact with the motor windings. The hermetic compressor according to claim 1, wherein the second and third relays are disposed in contact with the discharge gas atmosphere or the discharge gas atmosphere components. The hermetic compressor according to claim 1, wherein HCFC, HFC or the like not containing chlorine is used as a refrigerant. The hermetic compressor according to claim 1, wherein a natural refrigerant such as carbon dioxide or ammonia is used as a refrigerant.

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