JPH0210320Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a protection device for a rotary compressor, and particularly relates to the arrangement structure of heat-sensitive elements constituting the protection device.

(b) Prior Art Conventionally, a protection device for a rotary compressor has been constructed by providing a thermally responsive protector or the like on the surface of a sealed case or inside an electrical box. However, with such a configuration, when the electric motor generates heat and the temperature of the discharged gas rises when the compressor runs out of gas or is overloaded, a sealed case is required for this temperature to be transmitted to the thermally responsive protector. Since the protector takes a considerable amount of time to accurately sense the temperature and operate after the entire body has been heated, there was a problem that the protector's operation was delayed.

(c) Purpose of the invention This invention was developed in view of these points, and its purpose is to prevent delays in the operation of the rotary compressor protection device, and to accurately detect the temperature of the compressed refrigerant. It has been made possible.

(d) Structure of the invention This invention is a rotary compressor in which a motor part and a compressor part are housed in a sealed case, and the gas compressed by the compressor part is heat-exchanged by the motor part and then discharged outside the sealed case. A bypass pipe is provided on the outer wall of the sealed case to once discharge the gas compressed by the compressor part outside the sealed case, and then return it back into the sealed case between the electric motor part and the compressor part, In addition, a heat-sensitive element is attached to this bypass pipe,
This heat-sensitive element detects the temperature of the gas passing through the bypass pipe before it is affected by the electric motor, thereby shortening the operating time of the protection device.

(e) Examples Examples of the present invention will be described below based on the drawings.

1 has an electric motor section 3 and a compressor section 4 in a sealed case 2.
This is a rotary compressor that houses. 5 is a suction pipe having an accumulator 6 in its pipe line. 7
is a discharge pipe that leads the discharged gas inside the sealed case 2 to the outside of the case.

8 is a U-shaped bypass pipe attached to the outer wall of the closed case 2. This bypass pipe is
After the gas discharged from the compressor section 4 is once led out of the sealed case 2, it is returned to the inside of the case 2 between the electric motor section 3 and the compressor section 4. Reference numeral 9 denotes a positive temperature coefficient thermistor attached to the bypass pipe 8 by a fixing band 10. This thermistor is connected to the power supply circuit of the compressor 1, and when the heat detected by the thermistor becomes higher than the set value, the compressor 1
is set to stop.

Moreover, FIG. 3 shows another embodiment,
The protection device 11 is composed of a positive temperature coefficient thermistor 9, a pipe-shaped holder 13 for storing the thermistor, and a heat transfer putty 14 buried in the gap between the holder and the thermistor 9. It is attached to the bypass pipe 8 with a band 12.

Furthermore, FIG. 4 also shows another embodiment in which a positive temperature coefficient thermistor 9 is attached to a bypass pipe 8 via an S-shaped clip 15.

(f) Consideration of the invention As described above, according to the present invention, the gas compressed in the compressor section is once discharged outside the sealed case, and then returned to the sealed case between the electric motor section and the compressor section. Since a heat-sensitive element is attached to the return bypass pipe, it is possible to detect the temperature of the gas which is not affected by the temperature of the electric motor section, and it is possible to ensure protection in the event of gas starvation or overload operation. This can prevent delays in element operation.

[Brief explanation of drawings]

Fig. 1 is a front view of a rotary compressor showing one embodiment of the present invention, Fig. 2 is an enlarged view of the main part of the protection device in Fig. 1, and Fig. 3 is a vertical cross-section of the main part of the protection device showing another embodiment. The top view and FIG. 4 are plan sectional views of essential parts of a protection device showing still another embodiment. 1... Rotary compressor, 2... Sealed case, 3...
Electric motor section, 4...Compressor section, 8...Bypass pipe,
9...Positive characteristic thermistor.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A motor section and a compressor section are housed in a sealed case, and the gas compressed by the compressor section is subjected to heat exchange in the motor section before being discharged outside the sealed case. In the rotary compressor, the outer wall of the hermetic case is provided with a gas compressor, after which the gas compressed in the compressor section is once discharged outside the hermetic case, and is then inserted into the hermetic case between the electric motor section and the compressor section. A protection device for a rotary compressor, characterized in that a bypass pipe for returning the air is provided, and a heat-sensitive element is attached to the bypass pipe. (2) The protection device for a rotary compressor according to claim (1) of the utility model registration, characterized in that the heat-sensitive element is a positive temperature coefficient thermistor.