JPH08219565A - Overload protector of closed type electric compressor - Google Patents

Abstract

PURPOSE: To prevent overload protection of a closed type electric compressor from occurring with a simple structure and circuit without burning a motor of the closed type electric compressor even when the amount of a refrigerant of air conditioning equipment is lowered. CONSTITUTION: A thermal reactor 3 has a directly/indirectly hated type thermosensitive overload protector 2 comprising a bimetallic contact 2a and a resistance 2b in a series circuit and is molded integrally. In a bleeding overload of a small-current air conditioning equipment, the thermal reactor 3 works by an outer temperature of a closed type electric compressor 1 even under a small current value to open an electric circuit to the closed type electric compressor 1 thereby preventing the burning of the closed type electric compressor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overload protection device for a hermetic electric compressor.

[0002]

2. Description of the Related Art A conventional closed type electric compressor overload protection device for an air conditioner will be described with reference to the drawings.

In FIG. 5, reference numeral 101 denotes a hermetic electric compressor in which an electric element and a compression element are formed inside an airtight container.
A motor 02 is an electric element. A power supply terminal 103 and an overload protection device 10 are provided on the outside of the hermetic compressor 102.
4 is attached by a terminal cover 105.

In FIG. 6, a motor 102 has a main winding 10
2a, an auxiliary winding 102b and a rotor (not shown). Further, 104 is an overload protection device formed of a normally closed bimetal 104a, and the motor 102 is formed by being connected to an AC power supply 106, a driving capacitor 107, and the overload protection device 104.

The operation of the above arrangement will be described. When the AC power supply 106 is turned on, current flows through the motor 102, the overload protection device 104, and the operating capacitor 107, and the hermetic electric compressor 101 enters a steady operation state. However, during operation of the hermetic electric compressor 101, for example, an overload state occurs, and an overcurrent occurs in the hermetic electric compressor 101 or an abnormal temperature occurs in the outer shell, so that the hermetic electric compressor 10
The bimetal 104a of the overload protection device 104 attached to the outer shell of No. 1 is thermally deformed and inverted to cut off the current to the motor 102 to stop the operation of the hermetic electric compressor 101.

[0006]

However, in the above-mentioned conventional overload protection device for a hermetic electric compressor, since there is only one bimetal, when the air conditioner is filled with a prescribed amount of refrigerant and is in an overload state. Although it is possible to protect the hermetic electric compressor to some extent, when the amount of refrigerant becomes less than the specified amount or when the voltage is low, the overload protection device does not operate because the current value flowing in the hermetic electric compressor is small and The motor of the type electric compressor was sometimes burned out.

The present invention solves the above-mentioned problems of the conventional example, and can protect the motor of a hermetic electric compressor without burning it even when the amount of refrigerant in the air conditioner becomes small or at a low voltage, and is compact. Is an overload protection device for the hermetic electric compressor.

[0008]

In order to solve the above-mentioned problems, the present invention is directed to a direct-acting device including a thermal response device provided on the outer shell of a hermetic electric compressor and operating according to the compressor surface temperature, a bimetal contact, and a resistor. This is a temperature-sensing overload protection device of the indirectly heated type that is made into a series circuit and integrally molded. In addition, a direct heat type temperature-sensitive overload protection device consisting of a thermal actuator, a bimetal contact, and a resistor is made into a series circuit, and is made a parallel circuit with an internal auxiliary winding circuit of a hermetic electric compressor.

Further, it comprises a heat responsive device which is provided in parallel with the internal auxiliary winding circuit of the hermetic electric compressor and operates according to the winding temperature, and a bimetal contact and a resistor which are provided on the outer shell of the hermetic electric compressor. A direct thermal type temperature-sensitive overload protection device is a series circuit in which the load resistor and an electromotive terminal pin are provided in parallel with the bimetal contact.

[0010]

According to the present invention, the thermal responsive device is a direct thermal type temperature-sensitive overload protection device consisting of a bimetal contact and a resistor formed in a series circuit and integrally formed, and when a small current air conditioner is out of gas and overloaded. In the above, even if the current value is small, the thermal response device operates due to the outer temperature of the hermetic electric compressor to open an electric circuit to the hermetic electric compressor to prevent the hermetic electric compressor from burning.

Further, according to the present invention, a direct thermal type temperature sensitive type overload protection device consisting of a thermal actuator, a bimetal contact and a resistor is formed into a series circuit, and the internal auxiliary winding circuit and the parallel circuit of the hermetic electric compressor are formed. As a result, even when the high current air conditioner loses gas and is overloaded, the outer temperature rises and the thermal response device operates, causing the current to flow between the hermetic electric compressor and the load resistor, reversing the bimetal contact, and hermetic electric compression. The electric circuit to the machine is opened to prevent burnout of the hermetic electric compressor.

Further, according to the present invention, by disposing the thermal actuator inside the hermetic electric compressor, the temperature of the motor winding can be detected more accurately and the protection of the hermetic electric compressor can be improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An overload protection device for a hermetic electric compressor according to an embodiment of the present invention will be described below with reference to the drawings.

Since the method of mounting the overload protection device is the same as that of the conventional example, the description thereof will be omitted. In FIG. 1, reference numeral 1 denotes a motor of a small hermetic electric compressor, which includes a main winding 1a, an auxiliary winding 1b, and a rotor (not shown). Reference numeral 2 is a direct-heat type temperature-sensitive overload protection device integrally formed by forming a normally closed bimetal contact 2a, a resistor 2b, and a thermal response device 3 that operates according to the outer temperature of the hermetic electric compressor in a series circuit. Is.

When a current flows through the bimetal contact 2a, heat is generated. When the current exceeds a preset value and reaches a predetermined temperature, the bimetal contact 2a operates and opens, and the resistor 2b is energized to generate heat. Bimetal contact 2a
The bimetal contact 2a is also activated and opened by heating the. The thermal actuator 3 shuts off the circuit to the motor 1 when the temperature exceeds the set temperature.

The operation of the above arrangement will be described. In a small air conditioner such as a dehumidifier, when the AC power supply 4 is turned on, a current flows through the motor 1, the temperature-sensitive overload protection device 2, and the operating capacitor 5, and the hermetic electric compressor 1 enters a steady operation state. Since the thermal actuator 3 integrally formed in the temperature-sensitive overload protection device 2 and connected in series is an air conditioner for small current, it can be miniaturized.

When the hermetic electric compressor is in operation, for example, an overload condition occurs, an overcurrent flows through the motor 1, and the bimetal contact 2a of the overload protection device 2 becomes higher than a preset value and reaches a predetermined temperature. By reversing, the current to the motor 1 is cut off and the operation of the hermetic electric compressor is stopped. When the amount of refrigerant is less than the predetermined amount, the bimetal contact 2a does not generate heat because the current value flowing through the bimetal contact 2a is small, but the main winding 1a and the auxiliary winding 1b of the motor 1 rise in temperature. At this time, the thermal response device 3 is aware of the outer temperature of the hermetic electric compressor of the small air conditioner, and when the temperature exceeds the set temperature of the thermal response device 3, the thermal response device 3 is opened and the circuit to the motor 1 is opened. Shut off to protect the hermetic electric compressor.

FIG. 2 shows a bimetal contact 2a and a resistor 2b.
FIG. 3 is an external view of a direct-heat type temperature-sensitive overload protection device 2 integrally formed with a thermal response device 3 that operates according to the outer temperature of the hermetic electric compressor in a series circuit.

In FIG. 3, reference numeral 1 is a motor of a hermetic electric compressor of a home air conditioner. It consists of a main winding 1a, an auxiliary winding 1b, and a rotor (not shown). Reference numeral 2 denotes a normally closed bimetal contact 2a in series with the motor 1, and a thermal response device 3 and a resistor 2b which operate according to the outer temperature of the hermetic electric compressor are formed in parallel with the auxiliary winding 1b in a parallel circuit. It is a direct heat type temperature-sensitive overload protection device.

When a current flows through the bimetal contact 2a, heat is generated, and when the current exceeds a preset value and reaches a predetermined temperature, the bimetal contact 2a operates and opens. When the temperature exceeds the set temperature, the thermal actuator 3 is closed to energize the resistor 2b to generate heat, and the heat causes the bimetal contact 2a to be heated and the bimetal contact 2a to operate and open. This cuts off the circuit to the motor 1.

The operation of the above configuration will be described. In the domestic air conditioner, when the AC power supply 4 is turned on, a current flows through the motor 1, the temperature-sensitive overload protection device 2, and the operating capacitor 5, and the hermetic electric compressor 1 enters a steady operation state.

When the hermetic electric compressor is in operation, for example, an overload state occurs, an overcurrent flows through the motor 1, and the bimetal contact 2a of the overload protection device 2 exceeds a preset temperature and reaches a predetermined temperature. By reversing, the current to the motor 1 is cut off and the operation of the hermetic electric compressor is stopped. When the amount of refrigerant is less than the predetermined amount, the bimetal contact 2a does not generate heat because the current value flowing through the bimetal contact 2a is small, but the main winding 1a and the auxiliary winding 1b of the motor 1 rise in temperature. At this time, the heat response device 3 is aware of the outer temperature of the hermetic electric compressor, and when the temperature exceeds the set temperature of the heat response device 3, the heat response device 3 is closed and a small current flows through the resistor 2b to generate heat. As a result, the bimetal contact 2a is heated and the bimetal contact 2a operates and opens. This shuts off the motor circuit to protect the hermetic electric compressor.

In FIG. 4, the thermal actuator 3 is installed inside the motor 1 to improve the protection effect implemented in FIG.

[0024]

As is apparent from the above description, the present invention does not increase the size of the temperature-sensitive overload device and protects it from the usual overload and when the amount of refrigerant is less than a predetermined amount. It is possible to protect the windings from burning.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view of a temperature-sensitive overload protection device of the present invention.

FIG. 3 is a circuit diagram showing an embodiment of the present invention.

FIG. 4 is a circuit diagram showing an embodiment of the present invention.

FIG. 5 is a cross-sectional view of a conventional hermetic electric compressor.

FIG. 6 is a circuit diagram showing a conventional example.

[Explanation of symbols]

 1 Motor 2 Temperature-sensitive overload protection device 2a Bimetal contact 2b Resistance 3 Thermal response device

Claims (3)

[Claims] 1. A hermetic electric compressor provided with a single-phase motor having a main winding and an auxiliary winding, and a thermal responsive device provided on the outer shell of the hermetic electric compressor and operating according to the compressor surface temperature. A direct-heat type temperature-sensitive overload protection device consisting of a bimetal contact and a resistor is formed into a series circuit and integrally molded, and the heat-responsive device causes the hermetically-sealed electric compression device to handle abnormal heat generation of the hermetically-sealed electric compressor. A protective device for a hermetic electric compressor that controls the operation of the machine. 2. A direct-heat type temperature-sensitive overload protection device comprising a thermal actuator, a bimetal contact, and a resistor formed in a series circuit to form a parallel circuit with an internal auxiliary winding circuit of a hermetic electric compressor. Item 1. A protective device for a hermetic electric compressor according to item 1. 3. A hermetic electric compressor provided with a single-phase motor having a main winding and an auxiliary winding, and an internal auxiliary winding circuit of the hermetic electric compressor provided in parallel with each other according to the winding temperature. A direct thermal type temperature-sensitive overload protection device consisting of a thermal response device that operates and a bimetal contact and a resistor provided on the outer shell of the hermetic electric compressor is connected in parallel with the bimetal contact to the load resistor and the electromotive force. A protection device for a hermetic electric compressor, wherein terminal pins are provided to form a series circuit, and the hermetic electric compressor is controlled by the heat responsive device to abnormal heat generation of the hermetic electric compressor.