JP2002138961A - Hermetic compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hermetic compressor for accurately detecting an oil level value of a sealed vessel without being influenced by refrigerant pressure, a refrigerant temperature and a foaming phenomenon in the sealed vessel by using a light detector for receiving a light beam from a light emitting element by a light receiving element, and detecting the oil level value by passing or shielding a light beam of a float floating on an oil surface. SOLUTION: An oil level detector 16 having an oil equalizing pipe 14 communicating with a bottom surface of an oil reservoir 12 in a lower part and having a pressure equalizing pipe 15 communicating with an oil level upper part of the oil reservoir 12 in an upper part, is arranged in the outer peripheral vicinity of the sealed vessel 1. The oil level detector 16 is composed of a pair of light detecting means 17A and 17B arranged on a side wall of the oil level detector 16, and detecting the light by receiving the light projected from one by the other, the float 18 capable of shielding the projected light by vertically moving by a fluctuation in an oil level of the oil level detector 16, and a judging means for judging the height of the oil level 16a when the light is not detected by the light detecting means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic compressor used for an air conditioner or the like, and more particularly to an oil level detector capable of accurately detecting the oil level of lubricating oil.

[0002]

2. Description of the Related Art Conventionally, as a technique for detecting the oil level of a compressor of this type, for example, there is a technique disclosed in Japanese Patent Application Laid-Open No. 3-225090. 4 and 5, in the closed container 21, a compression unit 22 including a rotary compression mechanism is provided on the bottom side, and an electric motor 23 for driving the compression unit 22 is provided on the top. 24 is the main shaft of the electric motor 23, 25 is the main bearing, 26 is the cylinder of the compression unit, 27 is the sub shaft,
28 is a secondary bearing. 29 is a lubricating oil, which is a sealed container 21
It is stored at the bottom. 29a is a lubricating oil surface. The lubricating oil 29 is sucked upward during the operation of the compressor, and circulates in the sealed container 21 to lubricate the compression part 22 and the sliding part.

In the closed container 21, means for detecting the oil level of the lubricating oil 29 by a change in the capacitance of an oil level detector 30 is provided. As shown in FIG. 5, the bottom surface of the flange portion of the conductive sub-bearing 28 is parallel to the lubricating oil surface 29a and located at the lubricating oil depletion level b.
The bottom surface of the flange portion is used as one electrode of a pair of parallel electrodes constituting the oil level detector 30. The lower electrode, which is the other electrode, is provided on the bottom surface of the flange portion of the sub-bearing 28 via the insulating spacer 31.
33 are installed. Thus, the oil level detector 30
Are installed in parallel with the oil surface 29a at the lubricating oil depletion level b.

[0004] The sub-bearing 28 is a closed container via a cylinder 26.
Because it is electrically connected to 21, one electrode is electrically connected to the sealed container 21, so the output terminal 34 for taking out the detection output of the oil level detector 30 to the outside of the compressor is A single terminal connected to the lower electrode is used. In the above configuration, the capacitance value of the oil level detector 30 and the lubricating oil level 29a have an inverse relationship, and particularly near the depletion level b, the capacitance value changes greatly and the detection sensitivity increases. Therefore, it is possible to accurately detect the depletion level, which is the limit for reducing the lubricating oil.

However, the above means cannot determine the maximum level (upper limit) of the oil level. In addition, if the lubricating oil decreases and the refrigerant dissolved in the lubricating oil boils due to the heat generated by the compressor, causing the lubricating oil to foam, the oil level detector may malfunction due to the foaming phenomenon. There is. In particular, in a multi-air conditioner using a plurality of compressors and operating a plurality of indoor units, it is necessary to detect the upper and lower limits of the oil level of each compressor and control the oil amount of each compressor.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and uses a photodetector that receives a light beam from a light emitting element by a light receiving element and passes a light beam of a float floating on an oil surface. Alternatively, a hermetic compressor that can accurately detect the oil level of a closed container without being affected by the refrigerant pressure, the refrigerant temperature, and the foaming phenomenon in the closed container by detecting the oil level by shielding. It is intended to provide.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a compression section for compressing a refrigerant in a closed container having an oil reservoir for storing lubricating oil at a bottom portion,
An electric motor that drives the compression unit, a shaft that transmits a rotational force of the electric motor to the compression unit, and that has a lubricating oil supply path, and an oil supply pipe that suctions lubricating oil from the oil reservoir; A hermetic compressor comprising an oil pump for supplying lubricating oil to the sliding portion through the lubricating oil supply path, near the outer periphery of the hermetic container, provided at a lower portion with an oil equalizing pipe communicating with the oil reservoir bottom surface. An oil level detector provided with an equalizing tube communicating with an upper part of the oil level of the oil reservoir is provided at an upper part, and the oil level detector is provided on a side wall of the oil level detector in a vertical direction, and light is emitted from one side. A plurality of pairs of light detection means for performing light detection by receiving light on the other side, a float which moves up and down due to a change in the oil level of the oil level detector, and which can block the light projection; If no light is detected by the means, the height of the oil level It is composed of a determining means for determining.

The light detecting means is constituted by a light emitting element for emitting light and a light receiving element for receiving light.

[0009] Further, the light emitting device is configured such that an LED (light emitting diode) is used and the light receiving device is a photodiode.

The light emitting element and the light receiving element are housed in separate holders, respectively, and a glass material is mounted on the front surface of the holder.

[0011] Further, the holder portion is screwed to the side wall of the oil level detector.

[0012] Further, stoppers are provided above and below the inside of the oil level detector for regulating the range of movement of the float.

Further, the inside of the closed container is configured to have a high pressure or a low pressure.

Further, the compressor is constituted by a scroll compressor.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as examples. 1 and 2, an electric motor 2 and a compression unit 3 are arranged in a closed container 1, and the compression unit 3 is provided with a fixed scroll 4 and an orbiting scroll 5 in which a spiral wrap is erected on the inner surface of a head plate. Are engaged with each other to form a compression chamber 6, and the orbiting scroll 5
The shaft 9 having the lubricating oil supply passage 8 penetrating the center thereof is formed by forming a crankshaft 7 into which the turning drive shaft 5a is inserted, and a frame 10 supporting the crankshaft 7 is hermetically sealed. Constructs a compressor.

A lubricating oil 12a is sucked from an oil pump 11 for supplying lubricating oil to the sliding portion of the compression unit 3 through the lubricating oil supply path 8 and an oil reservoir 12 provided at the bottom of the closed vessel 1. And an oil supply pipe 13 leading to the oil pump 11.

In the vicinity of the outer periphery of the closed vessel 1, an oil level provided with an equalizing pipe 14 communicating with the bottom surface of the oil sump 12 at the lower part, and a pressure equalizing pipe 15 communicating with an upper part of the oil level of the oil sump 12 at the upper part. The light level detector 16 is provided on a side wall of the oil level detector 16, and light emitted from a light emitting element 17 a using an LED (light emitting diode) is emitted from one side, and a photodiode is emitted from the other side. A pair of photodetectors 17 that detect light by receiving light with the used light receiving element 17b, and an oil level 16 of the oil level detector 16
The float 18 moves up and down due to the variation of a, and enables the light projection to be blocked, and a determination unit that determines the height of the oil level 16a when the light detector 17 does not detect light. It is configured.

The upper photodetector 17 for detecting the upper limit of the oil level 16a is arranged in the vertical direction of the oil level detector 16 in the vertical direction of the oil level detector 16.
A and a lower photodetector 17B for detecting the lower limit. Further, the light emitting element 17a and the light receiving element 17b
Are housed in individual holders 17c and 17d, respectively, and glass materials 17e and 17f are mounted on the front surfaces of the holders 17c and 17d. These glass materials 17e and 17f transmit light,
Refrigerant or lubricating oil is prevented from directly contacting 17a and light receiving element 17b. Further, the holders 17c and 17d are mounted on the side wall of the oil level detector 16 by screwing,
The installation work is made easy.

Further, stoppers 18a are provided above and below the inside of the oil level detector 16 for restricting the moving range of the float 18, respectively. Further, the inside of the sealed container 16 is configured to have a high pressure or a low pressure.

FIG. 3 is a control block diagram according to the present invention. The light beams emitted from the light emitting element 17a1 (for the upper limit value) and the light beam emitted from the light emitting element 17a2 (for the lower limit value) travel straight in the air or in the lubricating oil when the float 18 is not on the straight.
Light is received by b1 (for the upper limit) and the light receiving element 17b2 (for the lower limit). If the float 18 is located straight on the projected light beam, the light beam is blocked and is not received by the light receiving element. The output side of the light receiving elements 17b1 and 17b2 is connected to the oil level determination means 19 of the control unit A composed of a microcomputer, and the level of the oil level is determined based on the presence or absence of the output voltage of the light receiving elements 17b1 and 17b2. Output to output terminal B. That is, when there is no output voltage from the light receiving element 17b1, the oil level is the upper limit value, and when there is no output voltage from the light receiving element 17b2, the oil level is the lower limit value. When both the light receiving elements 17b1 and 17b2 have an output voltage, the oil level is between the upper limit and the lower limit.

In the above construction, the internal pressure of the oil level detector 16 is maintained at the same pressure as the internal pressure of the closed vessel 1 by the equalizing pipe 15, and the oil level of the oil level 16a is controlled by the oil leveling pipe 14. Depending on the oil level of the closed container 1, the closed container 1
And fluctuates so as to have the same oil level. When the float 18 floating on the oil surface 16a blocks the light emission of the lower photodetector 17B, the judging means for judging the height of the oil surface 16a detects and judges the oil surface as the lower limit. Also, the upper photodetector
When the 17A light is blocked, the oil level is detected and determined as the upper limit. Since the light beam from the light emitting element 17a is substantially transparent to the lubricating oil, the light beam is received by the light receiving element 17b as straight traveling light in the lubricating oil as in air. As a result, the light beam is not affected by the refrigerant pressure, the refrigerant temperature, the foaming phenomenon, and the like in the sealed container 1, and the oil level value of the sealed container 1 can be accurately detected.

[0022]

As described above, in the present invention, the oil level is detected by passing or blocking the float light beam floating on the oil surface by using the light detector which receives the light beam from the light emitting element by the light receiving element. By doing so, the hermetic compressor can accurately detect the oil level of the hermetic container without being affected by the refrigerant pressure, the refrigerant temperature, the foaming phenomenon, and the like in the hermetic container.

[Brief description of the drawings]

FIG. 1 is a transverse sectional view of a hermetic compressor showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part showing an embodiment of the present invention.

FIG. 3 is a control block diagram of the present invention.

FIG. 4 is a cross-sectional view of a hermetic compressor showing a conventional example.

FIG. 5 is an enlarged cross-sectional view of a main part in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed container 2 Electric motor 3 Compression part 4 Fixed scroll 5 Orbiting scroll 5a Orbital drive shaft 6 Compression chamber 7 Crankshaft 8 Lubricating oil supply line 9 Shaft 10 Main frame 11 Oil pump 12 Oil reservoir 13 Oil supply pipe 14 Equivalent pipe 15 Equalizing pipe 16 Oil level detector 16a Oil level 17A, 17B Light detector 17a, 17a1, 17a2 Light emitting element (LED) 17b, 17b1, 17b2 Light receiving element (photodiode) 18 Float 18a Stopper 19 Control unit

Claims (8)

[Claims] 1. A compression unit for compressing a refrigerant, an electric motor for driving the compression unit, and a torque of the electric motor transmitted to the compression unit in a closed container having an oil reservoir for storing lubricating oil at a bottom. A shaft provided with a lubricating oil passage, and an oil pump provided with an oil supply pipe for sucking lubricating oil from the oil reservoir, and supplying lubricating oil to the sliding portion of the compression section through the lubricating oil passage. In the hermetic compressor, an oil level provided near the outer periphery of the hermetic container is provided at a lower portion with an equalizing pipe communicating with the oil sump bottom surface, and at an upper portion is provided with an equalizing pipe communicating with an oil level upper portion of the oil sump. A plurality of pairs of light detection means for providing a detector, the oil level detector is provided on the oil level detector side wall in a vertical direction, and performs light detection by receiving light emitted from one side with the other; It moves up and down due to the fluctuation of the oil level of the oil level detector, A float which allows shield light, when the light detection is not performed by the light detecting means, the hermetic compressor characterized by comprising is composed of a determining means for determining the height of the oil surface. 2. The hermetic compressor according to claim 1, wherein said light detecting means comprises a light emitting element for projecting light and a light receiving element for receiving light. 3. The hermetic compressor according to claim 2, wherein an LED (light emitting diode) is used for the light emitting element, and a photodiode is used for the light receiving element. 4. The hermetic compressor according to claim 2, wherein the light emitting element and the light receiving element are respectively housed in separate holders, and a glass material is mounted on a front surface of the holder. . 5. The apparatus according to claim 4, wherein the holder is screwed onto a side wall of the oil level detector.
The hermetic compressor as described. 6. The hermetic compressor according to claim 1, wherein stoppers are provided above and below the inside of the oil level detector, respectively, for restricting a movement range of the float. 7. The hermetic compressor according to claim 1, wherein the inside of the hermetic container is set to a high pressure or a low pressure. 8. The hermetic compressor according to claim 1, wherein said compressor is a scroll compressor.