JPH07180687A - Closed type motor-driven compressor - Google Patents

Abstract

PURPOSE:To enable operation without stopping the operation of a compressor even during overload operation and control the coil temperature positively by self-containing a sensor capable of detecting the coil temperature of the stator of a motor element. CONSTITUTION:A closed type motor-driven compressor is provided with a compressor element 6 and a motor 1 element inside, and has the coil 2 of the stator of the motor 1 element, and a temperature sensor 7. This sensor 7 is wound in together with the coil 2, on the coil 2 or between the coils 2 by a binding string. The temperature of the coil 2 is positively detected by thus self- containing the sensor 7 capable of detecting the stator coil temperature of the motor 1 element, and the rotating speed of the motor 1 is reduced through a control circuit. The load of the compressor is thereby reduced, and the temperature of the coil 2 is lowered without stopping the operation of the compressor, that is, the coil temperature can be controlled positively so as to lengthen the service life of the motor 1.

Description

Detailed Description of the Invention

[0001]

[Industrial field of application] It is mainly used for car air-conditioning compressors.

[0002]

2. Description of the Related Art Conventionally, this type of hermetic electric compressor (hereinafter referred to as a compressor) has a thermostat installed between coils as a main coil temperature protection method, and when the coil temperature exceeds a preset value, the thermostat is turned on. Operate to turn off the circuit
Then, the compressor operation was only stopped.

[0003]

In the conventional compressor, as shown in FIGS. 6 and 7, when the coil temperature rises in order to prevent the coil 2 from burning in the electric motor 1 during overload operation, the coil 2 will be damaged. The energization of the electric motor 1 can be stopped by operating the thermostat 3 which is wound,
With the discharge temperature thermistor 5 installed on the discharge pipe 4,
When the discharge temperature is higher than the reference value, the power supply to the electric motor 1 is stopped, the rotation frequency of the electric motor 1 is decreased, the discharge temperature is decreased, and the abnormal coil temperature rise protection is performed.

However, the following problems exist in the above structure. For example, when the thermostat 3 is operated to stop the energization of the electric motor 1, it takes about ten minutes before the thermostat 3 is restored and the operation is started. That is, since the air conditioner is stopped for more than a dozen minutes, in the case of a car air conditioner, etc., depending on the inside and outside air conditions, the inner surface of the window glass may become cloudy, which may seriously hinder driving. Or
The feeling as a car air conditioner was extremely bad.

When the discharge temperature sensor is used to stop the energization of the electric motor 1 or reduce the rotation frequency to reduce the load, the coil 2 is cooled by the compressed gas during normal compressor operation, and the discharge gas is discharged. The difference between the temperature of the coil 2 and the temperature of the coil 2 is within 5 to 10 deg. However, the difference between the actual coil temperature and the discharge temperature greatly varies depending on the load condition, and therefore the coil temperature actually exceeds the reference value. In some cases, the life of the electric motor 1 is remarkably reduced and the coil 2 is burned.

[0006]

In order to solve the above-mentioned problems, the present invention is characterized in that a sensor capable of detecting the coil temperature of the stator of the electric motor element is built in the compressor.

[0007]

According to the present invention, by incorporating a sensor capable of detecting the coil temperature of the stator of the electric motor element, it is possible to operate the compressor without stopping the operation even during overload operation. The window glass will not fog, which will seriously hinder driving, and the feeling as a car air conditioner will not be extremely bad.
Since the coil temperature is reliably controlled, the life of the electric motor is extended and the reliability of the compressor is improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
This will be described in 3, 4, and 5.

FIG. 3 is a refrigeration cycle diagram of a general heat pump air conditioner. In the cooling operation, the refrigerant gas adiabatically compressed by the compressor is in a high temperature and high pressure gas state and is condensed in the outdoor heat exchanger to be in a high temperature and high pressure liquid state. Further, it is squeezed by an expansion valve to become a low-temperature and low-pressure liquid, which is evaporated in an indoor heat exchanger and returns to a compressor as a low-temperature and low-pressure gas.

1 and 2 show a compressor, which is internally provided with a compressor element 6 and an electric motor 1 element. Reference numeral 2 denotes a stator coil of an electric motor element, and a temperature detection sensor 7 (hereinafter, referred to as a sensor) is wound around the coil 2 or between the coils 2 with a binding thread together with the coil 2. During normal compressor operation,
The coil 2 is cooled by the compressed gas, and the temperature difference between the discharge gas and the coil 2 is within about 5 to 10 deg. However, during overload operation or when the compression ratio is large,
Since the gas circulation amount is extremely reduced and the stator coil 2 is not sufficiently cooled by the discharge gas, the difference between the discharge temperature and the coil temperature may be 20 deg or more. Even in that case, the temperature detection sensor 7 is provided on the coil 2 or
Since it is caught between the coils 2, the coil 2 is securely
Is detected and the rotation speed of the electric motor 1 is reduced through the control circuit, the load on the compressor is reduced and the temperature of the coil 2 is lowered without stopping the operation of the compressor.

For this reason, for example, the inner surface of the window glass of an automobile becomes fogged, which seriously hinders driving.
The feeling as a car air conditioner is not extremely deteriorated, and the coil temperature is reliably controlled, so that the life of the electric motor 1 is extended and the reliability of the compressor is improved.

Further, as shown in FIGS. 4 and 5, the sensor 7 may be connected in series with the thermostat 8 and may be installed between the coils or on the surface thereof.

[0013]

According to the present invention, by incorporating a sensor capable of detecting the coil temperature in the stator of the electric motor element, it is possible to operate the compressor without stopping it even during overload operation. The window glass will not fog, which will seriously hinder driving, and the feeling as a car air conditioner will not be extremely bad.
Since the coil temperature is reliably controlled, the life of the electric motor is extended and the reliability of the compressor is improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a compressor showing a first embodiment of the present invention.

FIG. 2 is an electric circuit diagram of the compressor showing the first embodiment of the present invention.

[Fig. 3] General heat pump refrigeration cycle diagram

FIG. 4 is a sectional view of a compressor showing a second embodiment of the present invention.

FIG. 5 is an electric circuit diagram of a compressor showing a second embodiment of the present invention.

FIG. 6 is a sectional view of a compressor showing a conventional example.

FIG. 7 is an electric circuit diagram of a compressor showing a conventional example.

[Explanation of symbols]

 1 Electric Motor 2 Coil 3 Thermostat 4 Discharge Pipe 5 Discharge Temperature Thermistor 6 Compressor Element 7 Temperature Detection Sensor

Claims (6)

[Claims] 1. A compressor element and an electric motor element are incorporated.
A hermetic electric compressor, comprising a sensor capable of detecting a coil temperature of a stator of the electric motor element in the hermetic electric compressor. 2. The hermetic electric compressor according to claim 1, wherein the sensor is a thermistor. 3. The hermetic electric compressor according to claim 1, wherein the sensor is a thermocouple thermometer. 4. The hermetic electric compressor according to claim 1, wherein the sensor is a pressure type thermometer. 5. The hermetic electric compressor according to claim 1, wherein the sensor is installed in the coil of the stator of the electric motor element or on the surface of the coil. 6. A sensor and a thermostat are connected in series, and between the coils of the stator of the electric motor element,
Alternatively, the hermetic electric compressor according to claim 1, wherein the electric compressor is installed on the surface of the coil.