JP2001099070A - Refrigeration air conditioning compressor - Google Patents

Abstract

(57) [Problem] To provide a refrigeration air-conditioning compressor that detects the properties of refrigerant-mixed lubricating oil at various points of a sliding portion of the compressor and controls the operation so as to protect the compressor according to the lubricating oil failure. I do. SOLUTION: Fixed scroll 4, orbiting scroll 5,
A compression mechanism 2 having an Oldham ring 10 and the like, and an electric motor 3 having a rotating shaft 9 for eccentrically orbiting the orbiting scroll 5, and a bearing 21 for supporting the rotating shaft 9 between the scrolls 4 and 5 and the sliding portion of the Oldham ring 10. In a refrigerating air-conditioning compressor for supplying a refrigerant-mixed lubricating oil to a lubricating unit, etc., an ultrasonic probe 19 (a, e, d, g) is arranged at each lubricating point, and measuring means for measuring the ultrasonic intensity transmitted and received by each ultrasonic probe Calculate the ultrasonic attenuation rate from the output of, the calculated ultrasonic attenuation rate, and the relationship between the ultrasonic propagation distance in the lubricant oil and the bubble content rate of the lubricant and the ultrasonic attenuation rate, the bubble attenuation rate It is provided with arithmetic means for calculating the rate, and control means for controlling so as to reduce the number of revolutions of the electric motor 3 when the bubble content rate is equal to or more than a predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a displacement type refrigerating and air-conditioning compressor for use in refrigerators, air conditioners, and the like, and in particular, detects the state of lubricating oil in the compressor locally and compresses the lubricating oil when defective. The present invention relates to a positive displacement refrigeration / air-conditioning compressor that controls so as to protect the compressor.

[0002]

2. Description of the Related Art In a refrigerating air-conditioning compressor, lubricating oil is usually used to prevent seizure of a sliding portion or to reduce wear. However, such a refrigeration / air-conditioning compressor has the following problems. At the time of pressure change and temperature change inside the casing, the amount of refrigerant dissolved in the lubricating oil changes, so that the viscosity of the lubricating oil changes greatly, and when the refrigerant excessively dissolved in the lubricating oil separates from the lubricating oil. Generates bubbles in oil. The lubricating oil containing the bubbles generally has poor lubricity, and as a result, there is a fear that poor lubrication may occur in the sliding portion. When such poor lubrication occurs, abrasion occurs on the sliding portion, leading to a decrease in performance, an increase in noise, a decrease in reliability, and the like. Further, there is a fear that the sliding portion may be burned or malfunctioned. Therefore, if the amount of air bubbles mixed into the lubricating oil during the operation of the compressor can be grasped, the operation of the refrigeration / air-conditioning compressor is stopped before the lubricating ability of the lubricating oil is impaired, or the rotational speed of the shaft is changed to prevent poor lubrication. Can be avoided. In addition, from the viewpoint of reliability evaluation, an abnormal lubrication state with a fear of failure can be found without waiting for a failure in a long-term test of the compressor.

As means for detecting the occurrence of poor lubrication in a sliding portion, means for detecting using an acoustic emission (AE) signal as described in JP-A-8-151992, and JP-A-10-288182. As described in the gazette, means for detecting using an energization signal is known. Since the AE signal and the energization signal are generated only when the sliding surfaces come into contact with each other, it is difficult to predict the occurrence of wear beforehand.

As an example of measuring the inside of a compressor using ultrasonic waves, as described in Japanese Patent Application Laid-Open No. 6-94687, refrigerant mixed into lubricating oil in an oil sump inside the compressor from outside the compressor. There are devices for measuring quantities. However, with this device, it is difficult to measure accurately because the sensitivity of the measured ultrasonic signal varies depending on the material and surface roughness of the compressor container, and it detects the entry of air bubbles into the lubricating oil at the sliding part. However, it was very difficult to predict poor lubrication of the compressor.

[0005]

Conventionally, in a refrigerating and air-conditioning compressor, it has been difficult to avoid a decrease in reliability such as insufficient lubrication due to the generation of air bubbles and increased wear due to local poor lubrication. Was.

In addition, it is difficult to check the lubricating oil during operation, and it is necessary to periodically stop the operation to check the lubricating oil and sliding parts.

Therefore, the present invention provides a refrigerating and air-conditioning compressor to which a device for controlling the operation of a compressor in accordance with lubricating oil failure by grasping the state of lubricating oil in a sliding portion while the compression operation is continued is provided. The purpose is to realize.

[0008]

In order to achieve the above object, a refrigerating and air-conditioning compressor according to the present invention comprises a compression mechanism in a closed container and an electric motor for driving the compression mechanism via a rotating shaft. In a refrigeration / air-conditioning compressor that supplies refrigerant-mixed lubricating oil to lubricating points such as a sliding part of a movable member and a bearing part that supports a rotating shaft of an electric motor, ultrasonic waves are periodically generated at or near each lubricating point. Each ultrasonic probe which is transmitted and received after propagating through the lubricating oil by a predetermined distance, measuring means for measuring the intensity of the ultrasonic wave transmitted from each ultrasonic probe and the intensity of the received ultrasonic wave, and the measured ultrasonic wave Calculate the ultrasonic attenuation rate of the reception intensity with respect to the transmission intensity from the transmission intensity and the reception intensity of the transmission intensity, the calculated ultrasonic attenuation rate, the ultrasonic wave propagation distance in the lubricating oil, the bubble content of the lubricating oil, and the Relationship with sound attenuation And calculating means for determining the bubble content of the lubricating oil at each lubricating point, and reducing or stopping the rotation speed of the motor when the bubble content determined by the calculating means is greater than a predetermined value at any of the lubricating points. And control means for performing the control.

In another refrigeration / air-conditioning compressor, an ultrasonic probe is installed in the same manner as in the above-mentioned refrigeration / air-conditioning compressor, and measuring means for measuring the time required from transmission to reception of each ultrasonic probe is provided. The required time, the ultrasonic wave propagation distance in the lubricating oil determined in advance, and the required propagation time. The control means for controlling the rotational speed of the electric motor to be reduced or stopped when the lubricating oil viscosity determined by the arithmetic means is lower than a predetermined value. Are provided.

In each of the refrigerating and air-conditioning compressors described above, the amount of air bubbles or the amount of lubrication present in the refrigerant oil existing in the sliding portion depends on the intensity or sound speed of the ultrasonic wave propagating in the lubricating oil containing the refrigerant or air bubbles. An oil viscosity is calculated, and an abnormal state such as an abnormally low viscosity state or an oil film rupture state is detected, and the compressor is controlled to avoid a poor lubrication state.

As a sliding portion which is a lubricating portion of the refrigerating and air-conditioning compressor, for example, in a scroll compressor, a sliding formed by a lower surface of a fixed scroll and an upper surface of an orbiting scroll eccentrically rotated with respect to the fixed scroll. There is a sliding portion formed by a key and a key groove in an Oldham ring having a key / key groove sliding mechanism that operates linearly to prevent rotation of the orbiting scroll during eccentric orbiting. Further, in a rotary compressor, there is a slide bearing provided on both end surfaces of a cylinder accommodating an eccentric shaft portion and supporting a rotary shaft connected to the eccentric portion by a slide bearing.

The ultrasonic probe installed in the sliding portion is embedded in a stationary member opposite to the movable member of the sliding portion, and the ultrasonic wave transmitted from the ultrasonic probe is transmitted to the movable member via lubricating oil. It is preferable to arrange so as to reflect from the side member and return.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a refrigeration / air-conditioning compressor according to the present invention will be described in detail with reference to FIGS.

FIG. 1 is a longitudinal sectional view of a scroll compressor according to a first embodiment of the present invention, and FIG. 2 is a sectional view of FIG. 1A-A. This scroll compressor sucks refrigerant gas used for air conditioning, compresses it, and supplies it as high-temperature and high-pressure refrigerant gas for air conditioning. This scroll compressor is roughly classified into a cylindrical hermetic container 1 and a container 1
A compression mechanism 2 for generating compressed air therein, an electric motor 3 for driving the compression mechanism 2, and a lubrication oil for storing a refrigerant mixed lubricating oil to be supplied to each sliding surface formed between components and members constituting the compression mechanism 2. It comprises an oil reservoir 16 and ultrasonic probes installed at various points in a lubricating oil circulation path from the lubricating oil reservoir 16 to each sliding surface of the compression mechanism 2 to detect the properties of the lubricating oil. The closed container 1 houses the compression mechanism 2 in the upper part, the electric motor 3 in the middle part, and the lubricating oil reservoir 16 in the lower part.

The compression mechanism 2 has a spiral wrap 4
a scroll 5 having a fixed scroll 4 and a wrap 5b meshing with the wrap 4b of the fixed scroll 4 to form a compression chamber between the two wraps 4b and 5b;
An Oldham ring 10 that assembles the orbiting scroll 4 and the orbiting ring 5 so that the orbiting scroll 5 rotates without rotating with respect to the fixed scroll 4, and a frame that holds the fixed scroll 4, the orbiting scroll 5, and the Oldham ring 10 in predetermined positions. And 8.

The components constituting the compression mechanism 2 will be described in more detail. The fixed scroll 4 includes a head plate 4a and a wrap 4b formed in an involute curve or a curve similar to the involute curve in a concave portion formed at a lower portion (back side) of the head plate 4a. On the other hand, the orbiting scroll 5 has a spiral wrap 5b that meshes with the wrap 4b of the fixed school 4 protruding from the upper surface of the end plate 5a, and has a hole in the lower surface of the end plate 5a for inserting the eccentric shaft portion at the tip of the rotating shaft 9 of the electric motor 3. The boss 5c is protruded, and is configured to turn while sliding on the peripheral portion of the upper surface of the end plate 5a with the lower surface of the fixed scroll 4. The frame 8 is a container having a downwardly tapered shape. The fixed scroll 4 is fixed to the upper surface with bolts, the orbiting scroll 5 and the Oldham ring are housed in the internal space, and the main shaft directly connected to the rotating shaft of the electric motor 3 is provided in the lower part. 9 is configured by installing a rolling bearing 21
And it is itself fixed in the container 1. The Oldham ring 10 is fitted with a key groove 5 d formed in the orbiting scroll 5 and a key groove 8 a formed in the frame 8 so as not to rotate the orbiting scroll 5 eccentric to the fixed scroll 4. One key for rotating axis 9
Are arranged symmetrically with respect to the eccentric axis of the key, so that the key groove and the key slide to perform a linear reciprocating motion.

The refrigerant gas compressed by the compression mechanism 2 is
The suction port 7 of the fixed scroll 4 in the container 1 from the refrigeration cycle system outside the closed container 2 through the suction pipe 11 provided in the container 2.
Wrap 4b of both scrolls 4 and 5,
It is compressed in a compression chamber formed between 5b, and is discharged from a discharge port 6 formed in the center of the end plate 4a of the fixed scroll 4 to a discharge chamber 12 on the upper part of the closed container 1. Discharge chamber 12
High-temperature and high-pressure refrigerant gas discharged into the lower chamber formed between the frame 8 and the sealed container 1 through the passage,
Then, it is supplied to the refrigeration cycle system through a discharge pipe 13 provided on the outer wall of the closed container 1.

On the other hand, a pressure intermediate between the suction pressure and the discharge pressure acts on a space (back pressure chamber) 14 surrounded by the back surface of the orbiting scroll 5 and the frame 8. At this intermediate pressure, a fine hole (back pressure hole) 15 is provided in the end plate 5 a of the orbiting scroll 5, and the gas under compression inside the scroll is guided to the space (back pressure chamber) 14 through the fine hole 15, and The gas is made to act on the back of 5. By the gas from this back,
The orbiting scroll 5 is pressed against the fixed scroll 4 to seal the respective compression chambers and also seal the outer mirror plate surfaces of the scroll members 4 and 5.

The refrigerant mixed lubricating oil in the oil reservoir 16 at the bottom of the closed casing 1 is attached below the rotating shaft 9 of the electric motor 3 due to the pressure difference between the discharge pressure outside the frame 8 and the pressure in the back pressure chamber 14 inside the frame 8. From the supplied oil supply pipe 17, through a fuel supply hole 9 a penetrating the axis of the rotary shaft 9 and a fuel supply hole branched from the fuel supply hole 9 a in the radial direction of the rotary shaft 9, the rolling bearing 21 in the frame 8 and the Oldham ring Oil is supplied to sliding parts such as keys and key grooves and both scrolls 4 and 5. The lubricating oil discharged from each sliding portion passes from the back pressure chamber 14 of the frame 8 to the fixed scroll 4 via the back pressure hole 15 provided in the end plate 5a of the orbiting scroll 5 and the compression chamber between the two scrolls 4, 5. End plate 4
The liquid is discharged into the discharge chamber 12 from the discharge port 6 provided at the position a. At this time, the lubricating oil is discharged with the refrigerant gas. The refrigerant gas and the lubricating oil flow from the discharge chamber 12 toward the electric motor unit 3 along the closed container 1 by a passage and a guide (not shown), and the lubricating oil separated by the coil end 3a above the electric motor unit 3 The refrigerant gas flows to the lower oil reservoir 16, while the refrigerant gas flows along the inner wall of the container 1 and is sent out from the discharge pipe 13 to the refrigeration cycle system.

The lubrication of the sliding part of the Oldham ring 10 is as follows.
Due to the differential pressure between the inside and outside of the frame 8, the oil from the oil reservoir 16 passes through the oil supply hole 9 a of the main shaft 9 and is used for lubrication of the slewing bearing, and the lubricating oil dropped on the balance weight 18 of the frame 8 enters the back pressure chamber 14 of the frame 8. It is done by being splashed,
A fluid oil film is formed on the sliding portion of the key / key groove.

As an ultrasonic probe 19 for detecting the properties of the refrigerant-mixed lubricating oil (ultrasonic probes are collectively denoted by reference numeral 19), an ultrasonic probe 19g is arranged on a rolling bearing 21 that supports the rotating shaft of the electric motor 3. The ultrasonic probe 19b is provided in the lubricating oil flow path near the bearing 21, and the ultrasonic probes 19d and 19e are provided in the sliding portion of the Oldham ring 10 in the key / key groove, and the end plate 4b of the fixed scroll 4 and the orbiting scroll 5 are provided. The ultrasonic probe 19a is arranged on the sliding portion of the end plate 5b, the ultrasonic probe 19h is arranged on the bottom of the back pressure chamber 14 in the frame 8, and the ultrasonic probe 19c is arranged in the lubricating oil reservoir 16 on the bottom of the container 1. . Place it at any other location. The ultrasonic probe 19 measures the amount of foam in the lubricating oil or the viscosity of the lubricating oil at various points in the lubricating oil path in the scroll compressor. The ultrasonic probe 19 is attached using an insulating adhesive, and the outer periphery is insulated.

When an ultrasonic probe is installed for measuring a lubricating oil interposed in a sliding portion (for example, a sliding portion between a key of the Oldham ring 10 and a key groove of the frame 8), as shown in FIG. Keyway 8a for resting the sensor surface of the probe
The measurement is performed by exposing on the side sliding surface, or as shown in FIG. 4, without exposing the sensor surface, the wall portion 8b is provided between the surface of the ultrasonic probe 19e and the surface of the key portion 10b of the Oldham ring. There is a method of performing measurement via the. When the former is executed, higher sensitivity is obtained than when the latter is executed.
When measuring by exposing the ultrasonic probe surface on the sliding surface, the sensor surface of the ultrasonic probe is at the same position as the sliding surface or at a position dug several micrometers to several tens of micrometers below the sliding surface. It is desirable to install in By selecting the optimal mounting position of the ultrasonic probe, the ultrasonic probe is protected even if the fluid film between the sliding surfaces breaks, and more reliable measurement is not affected by accidental contact of the sliding surface Can be realized. Further, the ultrasonic sensor 19 which detects the contact between the two members sliding with each other.
Since the cause of poor lubrication can be specified from the part, a highly reliable compressor can be realized.

When the ultrasonic probe 19 is provided on the sliding portion in the scroll compressor, the ultrasonic probe 19e is provided on the sliding portion of the Oldham ring 10 as shown in FIGS.
Is embedded in one side surface of the key groove 8a, and the sensor surface is disposed so as to be at right angles to the sliding direction of the key groove, and one sliding surface of the key 10b is used as a reflection surface.
Ultrasonic probe 19 installed on the other side of keyway 8a
f is also set in the same manner as the ultrasonic probe 19e, and the key 10b
Is used as a reflection surface. Keyway 8a
The ultrasonic probe 19d installed on the lower surface of the key is a key 10b
And the bottom surface of the key 10b is used as a reflection surface.

In the rolling bearing 21 for supporting the rotating main shaft 9 of the electric motor 3, an ultrasonic probe 19g is provided on the frame 8 side so as to face the end face of the thrust bearing member of the rolling bearing 21. 19g
Uses the end face of the thrust bearing member as a reflection surface. Further, the lubricating oil in the lubricating oil path leading to the rolling bearing 21, that is, the rotating main shaft 9 of the electric motor 3 and the frame 8 passing therethrough
An ultrasonic probe 19b is installed on the frame 8 side in a direction perpendicular to the surface of the rotating spindle 9 in order to check the lubricating oil flowing in the gap between the holes provided in the spindle 9 and the ultrasonic probe 19b. Is used as a reflection surface. These ultrasonic probes 19b and 19g detect the lubrication failure caused by the entry of air bubbles into the lubricating oil fluid film in the sliding portion of the bearing 21 or the insufficient oil amount in the sliding portion.

When the ultrasonic probe 19 is attached to the lubricating oil reservoir 16 or a place where the lubricating oil is stored, as shown in FIG. 5, the two ultrasonic probes 19i and 19j are opposed to each other on a straight line at a certain distance. Is defined as a transmitting-side ultrasonic probe and the other as a receiving-side ultrasonic probe, and is installed so that lubricating oil to be measured flows between these two probes, or one ultrasonic probe as shown in FIG. Similarly, the reflection surface 19c and the reflection surface 20 are installed so as to be linearly opposed to each other at a fixed distance, and the lubricating oil to be measured flows between the ultrasonic probe 19c and the reflection surface 20. As in the lubricating oil reservoir 16, an ultrasonic probe 19h and a reflecting surface facing the ultrasonic probe 19h are provided also in the back pressure chamber 14 of the frame 8. The ultrasonic probe 19h measures the state of bubbles and the viscosity in the lubricating oil in the back pressure chamber 14, and the ultrasonic probe 19c measures the state of the lubricating oil in the oil reservoir 16.
Since the amount of air bubbles and the viscosity in the lubricating oil are simultaneously measured by one measuring means, it is predicted in advance that the lubrication state will be deteriorated due to the increase in the amount of air bubbles in the lubricating oil and the extremely low viscosity.

Next, a rotary compressor according to a second embodiment of the refrigerating and air conditioning compressor of the present invention will be described with reference to FIG. This rotary compressor is functionally composed of a vertical cylindrical hermetic container, a compression mechanism for compressing the refrigerant gas in the hermetic container, an electric motor driving the compression mechanism, and components and members constituting the compression mechanism. It is composed of a lubricating oil reservoir for storing refrigerant mixed lubricating oil supplied to the sliding surfaces, and an ultrasonic probe for detecting the properties of the lubricating oil on each sliding surface. In the closed container, an electric motor, a compression mechanism, and a lubricating oil reservoir are installed in order from the top.

The electric motor 47 has a rotating shaft 4 extending downward.
Two. The compression mechanism includes an eccentric shaft portion 42a formed near the lower end of the rotary rotating shaft 42, a roller 46 to which eccentric rotation is given by the eccentric shaft portion 42a, and a cylinder 45 that stores the eccentric shaft portion 42a and the roller 46;
A main bearing member 41 (journal slide bearing) serving as an upper lid of the cylinder 45 and supporting the rotary shaft 42, and a sub-bearing member 44 (journal slide bearing) serving as a lower lid of the cylinder 45 and supporting a tip end of the rotary shaft 42.
It is composed of The refrigerant-mixed lubricating oil in the lubricating oil reservoir is supplied to the bearing members 41 and 44 through branch holes radially branched from an axial hole formed in the axis of the rotary shaft 42, and the sliding portions of each bearing member are lubricated. A fluid oil film is formed by the oil to ensure smooth lubrication.

The ultrasonic probe 19 is, as shown in FIG.
The ultrasonic probe 19k is installed at a position on the compression chamber 43 side of the main bearing member 41, and the ultrasonic probe 19l is installed at a position near the compression chamber 43 side on the auxiliary bearing member 44.
An ultrasonic probe 19m is installed on the lower end side of the main bearing member 41, and an ultrasonic probe 19n is installed on the upper end side of the main bearing member 41. These ultrasonic probes measure the amount of bubbles in the lubricating oil between the sliding surfaces of each bearing member and the rotating shaft 42.

The ultrasonic probe for detecting the properties of the lubricating oil can be applied to a reciprocating compressor in addition to a scroll compressor and a rotary compressor.

Next, the relationship between the bubbles in the lubricating oil and the ultrasonic intensity, sound speed, and the like, and the control for protecting the various compressors using the relationship will be described. The HFC-based refrigerant is mixed, and an ultrasonic wave having a frequency of 10 MHz is emitted into ether-based lubricating oil containing air bubbles, and the amount of air bubbles and the intensity (reception intensity) of the ultrasonic wave propagated in the oil over a distance of 5 mm. Sought a relationship. As a result, as shown in FIG.
It tends to decrease as the amount of bubbles increases. Here, the reception intensity of the ultrasonic wave in the lubricating oil without bubbles was set to 100. The attenuation rate of the ultrasonic wave is calculated by dividing a value obtained by subtracting the receiving intensity of the lubricating oil containing bubbles from the receiving intensity of the lubricating oil without bubbles by the receiving intensity of the lubricating oil without bubbles. Further, under the same conditions, the relationship between the viscosity of the lubricating oil and the speed of sound of ultrasonic waves in the oil was obtained. As a result, the sound speed of the ultrasonic wave tends to increase as the viscosity of the lubricating oil mixed with the refrigerant increases, as shown in FIG. This tendency is not largely affected by changes in temperature or pressure. When a frequency other than 10 MHz is used, although not shown, the characteristics of bubbles in the lubricating oil differ depending on the frequency of the ultrasonic wave transmitted from the ultrasonic probe. If a high frequency ultrasonic wave of 5 MHz or more is used, even bubbles having a small diameter can be detected sensitively, and the intensity of the reflected wave is greatly reduced even for a small amount of bubbles. In addition, when an ultrasonic wave having a low frequency of several hundred kHz or less is used, a decrease in the intensity of the reflected wave is reduced, which is suitable for measurement of lubricating oil containing a large amount of bubbles.

As shown in FIG. 10, the arithmetic and control unit 30 comprises a measuring circuit 31, an arithmetic circuit 32 and a control means 33. The measuring circuit 31 periodically operates each ultrasonic probe 19, and measures the intensity and the reflection time of the ultrasonic wave emitted from the ultrasonic probe 19 which is reflected and returned from the output of the ultrasonic probe 19, and the value is measured. Is given to the arithmetic circuit 32. The arithmetic circuit 32 determines the intensity and lubrication of the ultrasonic wave transmitted through the lubricating oil of the refrigerant mixture as shown in FIG. 8 for each ultrasonic probe installed in the compressor for refrigeration and air conditioning in accordance with the propagation distance of the ultrasonic wave. The relationship with the amount of air bubbles contained in the oil and the attenuation rate are stored in advance, and the attenuation rate is calculated from the intensity of the ultrasonic wave given from each ultrasonic probe periodically during the operation of the compressor, and from this attenuation rate The value corresponding to the bubble amount (%) in the oil is output. The arithmetic circuit 32
Similarly, for each ultrasonic probe, the relationship between the sound speed of ultrasonic waves propagating in the lubricating oil mixed with the refrigerant and the viscosity of the lubricating oil is stored in advance as shown in FIG. The value of the viscosity of the lubricating oil is output based on the sound speed of the ultrasonic wave given from each ultrasonic probe.

The control means 33 changes the operating frequency of the compressor based on the signal from the arithmetic circuit 32 and controls the motor unit 3. In general, when the pressure load is excessively large, poor lubrication often occurs. Therefore, the rotation frequency is reduced to reduce the load.

If the refrigeration cycle has a pressure load detection mechanism and it can be determined that the excessive pressure load is not the cause of the lubricating oil failure, the compressor speed is increased for the purpose of increasing the sliding speed and increasing the film formation. In some cases, increasing the frequency is appropriate. If the difference between the discharge pressure and the suction pressure of the compressor is small, it may be determined that the inability to supply the required amount of oil is the cause of poor lubrication.In this case, increase the rotation speed and reduce the pressure difference. Enlarge. In some cases, the operation of the compression mechanism 2 is temporarily stopped to eliminate poor lubrication.

For each ultrasonic probe, display means for displaying the input signal to the arithmetic unit, the contents of the arithmetic operation, and the output signal from the arithmetic unit may be provided. This makes it possible to continuously and quantitatively determine factors such as the local bubble amount and viscosity in the refrigerant-mixed lubricating oil at the sliding portion during compressor operation, and to evaluate the wear state that has conventionally been caused by long-term continuous operation tests. Therefore, it is possible to easily grasp the lubrication state of each sliding portion, which has been confirmed by the above, so that it is possible to improve the reliability of the refrigeration / air-conditioning compressor.

[0035]

According to the present invention, the state of the lubricating oil in the sliding section in the compressor is quantitatively grasped by the parameters such as the amount of air bubbles and the viscosity in the lubricating oil mixed with the refrigerant while the operation is continued. A refrigeration / air-conditioning compressor capable of controlling operation to protect the compressor in response to lubricating oil failure can be realized.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a scroll compressor according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a configuration diagram of a detection unit that does not expose an ultrasonic probe to a sliding surface.

FIG. 5 is a configuration diagram of a detection unit using two ultrasonic probes in a back pressure chamber and an oil sump.

FIG. 6 is a configuration diagram of a detection unit using one ultrasonic probe and a reflection surface in a back pressure chamber and an oil sump.

FIG. 7 is a sectional view showing a rotary compressor according to an embodiment of the present invention.

FIG. 8 is a graph showing a relationship between a bubble content in a lubricating oil mixed with a refrigerant and an ultrasonic attenuation rate.

FIG. 9 is a graph showing the relationship between the viscosity of lubricating oil mixed with a refrigerant and the speed of sound of ultrasonic waves in the oil.

FIG. 10 is a diagram illustrating a configuration of an arithmetic and control unit that processes a signal from an ultrasonic probe installed in a compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed container 2 Compression mechanism 3 Electric motor 4 Fixed scroll 5 Orbiting scroll 8 Frame 8a Frame side keyway 8b Ultrasonic probe protection wall 9 Main shaft 9a Oil supply hole 10 Oldham ring 10b Oldham ring side key part 16 Lubricating oil reservoir 19a-19h Ultrasonic wave Probe 20 Reflecting surface 21 Thrust bearing member 22 Sub bearing member 30 Arithmetic controller 31 Measurement circuit 32 Arithmetic circuit 33 Control means 40 Closed vessel 41 Main bearing member 42 Rotating shaft 43 Compression chamber 44 Sub bearing member 45 Cylinder 46 Roller 47 Motor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme Court ゛ (Reference) F25B 49/02 550 F25B 49/02 550 560 560 (72) Inventor Muneo 502 Kandatecho, Tsuchiura City, Ibaraki Prefecture Address Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Yuichi Yanase 502, Kantachi-cho, Tsuchiura-shi, Ibaraki Prefecture Machinery Laboratory, Hitachi, Ltd. (72) Yoshiki Fujimoto 390, Muramatsu, Shimizu-shi, Shizuoka Hitachi Air Conditioning Co., Ltd. 3H003 AA05 AB03 AC03 BD00 BD02 3H029 AA02 AA14 AB03 BB50 BB60 CC51 CC62 3H045 AA05 AA09 AA12 AA27 BA43 BA44 CA00 DA02 DA07

Claims (5)

[Claims] 1. A compression mechanism and an electric motor for driving the compression mechanism via a rotary shaft in a closed container, wherein a sliding portion of a movable member constituting the compression mechanism and a bearing portion for supporting the rotary shaft are provided. In a refrigerating air-conditioning compressor that supplies a refrigerant mixed lubricating oil to a lubricating point, each ultrasonic probe that periodically transmits ultrasonic waves at or near each lubricating point and receives after propagating through a predetermined distance in the lubricating oil, Measuring means for measuring the intensity of the ultrasonic wave transmitted by the ultrasonic probe and the intensity of the received ultrasonic wave, and calculating the ultrasonic attenuation rate of the reception intensity with respect to the transmission intensity from the transmission intensity and the reception intensity of the measured ultrasonic wave,
From the calculated ultrasonic attenuation rate and the relationship between the ultrasonic propagation distance in the lubricating oil, the previously determined ultrasonic wave propagation distance, the air bubble content of the lubricating oil, and the ultrasonic attenuation rate, determine the air bubble content of the lubricating oil at each lubricating point. Calculating means, and control means for controlling so as to reduce or stop the rotation speed of the electric motor when the bubble content calculated by the calculating means is larger than a predetermined value at any of the lubrication points. Refrigeration air conditioning compressor. 2. A compression mechanism and an electric motor for driving the compression mechanism via a rotary shaft in a closed container, wherein a sliding portion of a movable member constituting the compression mechanism and a bearing portion for supporting the rotary shaft are provided. In a refrigerating air-conditioning compressor that supplies a refrigerant-mixed lubricating oil to a lubricating point, each ultrasonic probe that periodically transmits ultrasonic waves at or near each of the lubricating points and receives after propagating a predetermined distance in the lubricating oil, Measuring means for measuring the required time from transmission to reception of each ultrasonic probe, and the measured required time, from the relationship between the ultrasonic propagation distance and the required propagation time in the lubricating oil and the required lubricating oil viscosity,
Calculating means for calculating the lubricating oil viscosity of each lubricating point; and control means for controlling to reduce or stop the rotation speed of the electric motor when the lubricating oil viscosity obtained by the calculating means is lower than a predetermined value. Refrigeration and air conditioning compressor. 3. An Oldham ring having a fixed scroll, an orbiting scroll that eccentrically turns with respect to the fixed scroll, a key / keyway sliding mechanism that operates linearly to prevent rotation of the orbiting scroll during the eccentric turning, and the fixed scroll. A compression mechanism composed of the orbiting scroll and a frame for holding the Oldham ring in a predetermined position, and an electric motor having a rotating shaft for eccentrically orbiting the orbiting scroll, provided in a closed container, Supplies refrigerant-mixed lubricating oil to lubricating points such as a sliding part on which the upper surfaces of the orbiting scrolls slide together, a key / key groove sliding part of the Oldham ring, and a bearing part installed in the frame and supporting the rotary shaft. Refrigeration and air-conditioning compressors periodically transmit ultrasonic waves at or near each lubrication point and Each ultrasonic probe to be received after propagating by a distance, and measuring means for measuring the intensity of the ultrasonic wave transmitted from each ultrasonic probe and the intensity of the received ultrasonic wave, and from the measured transmission intensity and reception intensity of the ultrasonic wave, Calculate the ultrasonic attenuation rate of the reception intensity with respect to the transmission intensity, the calculated ultrasonic attenuation rate, and the relationship between the ultrasonic propagation distance and the bubble content rate of the lubricant oil and the ultrasonic attenuation rate determined in advance. And calculating means for calculating the bubble content of the lubricating oil at each lubricating point, and reducing or stopping the rotation speed of the electric motor when the bubble content determined by the calculating means is a predetermined value or more at any of the lubricating points. Refrigeration and air-conditioning compressor provided with control means for performing such control. 4. An ultrasonic probe installed at a lubricating point which is the sliding portion is embedded in a stationary member which is a counterpart of a movable member of the sliding portion, and ultrasonic waves transmitted from the ultrasonic probe use lubricating oil. The refrigeration / air-conditioning compressor according to claim 1, 2 or 3, wherein the compressor is arranged so as to be reflected from the movable side member and returned. 5. A compression mechanism having a cylinder, an eccentric shaft portion housed in the cylinder, and respective slide bearings installed at both ends of the cylinder, and a rotation connected to the eccentric shaft portion and supported by the slide bearing. An electric motor having a shaft, and in a refrigerating air-conditioning compressor for supplying a refrigerant-mixed lubricating oil to the sliding bearing, an ultrasonic probe embedded in the sliding surface of each sliding bearing, and the rotation transmitted from each ultrasonic probe and the rotation Measuring means for measuring the transmission intensity and the reception intensity of the ultrasonic wave reflected from the shaft surface and returning through the refrigerant-mixed lubricating oil; and the ultrasonic attenuation of the reception intensity with respect to the transmission intensity from the transmission intensity and the reception intensity of the measured ultrasonic wave Calculate the rate, the calculated ultrasonic attenuation rate, and the relationship between the ultrasonic propagation distance in the lubricating oil and the relationship between the bubble content of the lubricating oil and the ultrasonic attenuation rate determined in advance, the position of each ultrasonic probe Calculating means for calculating the bubble content of the lubricating oil in the motor, and control means for controlling to reduce or stop the rotation speed of the electric motor when the bubble content determined by the calculating means is equal to or more than a predetermined value. A refrigeration and air conditioning compressor.