Hermetic compressor
View Patent ↗A hermetic compressor includes a housing accommodating a motor and a compressing mechanism driven by the motor, refrigerating machine oil, which is pooled in the housing, for lubricating the compressing mechanism, refrigerant gas sealed into the housing and to be refrigerant forming a refrigerating cycle, and an oil surface sensor including a thermistor having a given length. A part of the oil surface sensor is impregnated into the refrigerating machine oil, and the sensor senses a temperature immediately after energizing the thermistor and a rate of change in temperature onward, so that a position of an oil surface is detected.
1. A hermetic compressor system comprising:
a housing accommodating a motor and a compressing mechanism driven by the motor;
refrigerating machine oil, pooled in the housing, for lubricating the compressing mechanism;
refrigerant gas sealed into the housing and acting as a refrigerant in a refrigerating cycle;
an oil surface sensor including a thermistor having a length;
an insulator;
a holder for holding the oil surface sensor, the holder including a first portion mounted to an external surface of a side wall of the compressing mechanism and a second portion extending outwardly from the external surface of the side wall of the compressing mechanism, the second portion of the holder extending around the insulator;
a comparator which compares a stored temperature of the thermistor and a stored rate of change in temperature of the thermistor after energizing the thermistor to a subsequent temperature of the thermistor and a subsequent rate of change in temperature of the thermistor; and
a processor which determines what portion of the length of the thermistor extends into the refrigerating machine oil based on the compared results.
2. The hermetic compressor system of claim 1 , wherein the oil surface sensor is formed of a cylindrical single thermistor.
3. The hermetic compressor system of claim 1 , wherein the oil surface sensor is coupled to a signal line at an upper end of the oil surface sensor and a lower end of the oil surface sensor, respectively, for taking out a signal.
4. The hermetic compressor system of claim 1 , wherein the oil surface sensor is placed in a direction at right angles to the oil surface.
5. The hermetic compressor system of claim 1 , wherein the oil surface sensor is placed such that a first section of the oil surface sensor touches the refrigerating machine oil and a second section of the oil surface sensor touches the refrigerant gas.
6. The hermetic compressor system of claim 1 , wherein the holder is fixed to the compressing mechanism.
7. The hermetic compressor system of claim 6 , wherein the insulator is between the thermistor and the holder.