JP7265894B2 - Oil sensor unit and compressor - Google Patents

Description

The present invention relates to an oil sensor unit and a compressor.

The compressor includes an oil sensor that detects the level of oil (lubricating oil) accumulated in the bottom of the compressor housing (see, for example, Patent Document 1).
In Patent Document 1, a capacitance type oil sensor provided at the bottom of the housing of the compressor, a capacitance measurement determination device provided outside the compressor, and a device used to compare the output values of the oil sensor. and a reference capacitor provided within the capacitance measuring and determining device.

The oil sensor has two metal plates facing each other with a gap therebetween. The capacitance measurement determination device is electrically connected to the oil sensor via a cable. The capacitance measurement determination device measures the capacitance of the oil sensor.
In Patent Document 1, whether or not the oil sensor is immersed in oil is determined by comparing the magnitude of the first capacitance of the reference capacitor with the magnitude of the second capacitance of the total of the cable and the oil sensor. make a judgment as to whether

Chinese Patent Application Publication No. 102213214

By the way, electrostatic capacitance (parasitic capacitance) is generated between the ground and the cable due to disturbance caused by the path of the cable, people, objects, and the like.
Therefore, when using the compressor of Patent Document 1 described above, the capacitance of the cable is included in the second capacitance. Therefore, it was difficult to accurately determine the presence or absence of oil based on the oil sensor.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an oil sensor unit and a compressor that can accurately determine the presence or absence of oil using an oil sensor.

In order to solve the above-described problems, an oil sensor unit according to an aspect of the present invention accommodates a compression portion that compresses a refrigerant, is provided at the bottom of a housing in which oil is stored at the bottom, and includes a first reference capacitor. and an oil sensor having an oil detection sensor, a first cable electrically connected to the first reference capacitor, and the first cable electrically connected to the oil detection sensor. A second cable that has the same structure as the first cable and is routed along the same route as the first cable so that the capacitance is equal to that of the first cable, and is connected to the capacitance measurement unit , a storage unit storing a determination reference value used when determining the presence or absence of the oil, a calculation unit, and a capacitance measurement determination device having a determination unit, wherein the first reference capacitor is a first cathode plate, a first anode plate arranged to face the first cathode plate with a first gap interposed therebetween, and a first anode plate arranged to close the first gap and having a known capacitance , and the capacitance has a first solid dielectric that is not easily affected by the oil, and the oil detection sensor section includes a second cathode plate and a second gap into which the oil or air flows. a second anode plate facing the second cathode plate via a second anode plate, and the capacitance measurement unit measures the capacitance of the first cable and the capacitance of the first reference capacitor; and a second capacitance including the capacitance of the second cable equal to the capacitance of the first cable and the capacitance of the oil detection sensor unit. and the calculating unit subtracts the capacitance of the first solid dielectric from the first capacitance, thereby equaling the capacitance of the second cable. Acquiring the capacitance of the first cable and subtracting the capacitance of the first cable from the second capacitance to acquire the capacitance of the oil detection sensor unit, The determination unit determines whether or not the oil is present in the second gap by comparing the capacitance of the oil detection sensor acquired by the calculation unit with the determination reference value.

According to the present invention, by routing the first cable and the second cable having the same structure along the same route, the disturbance received by the first cable and the second cable become equal. It becomes possible to equalize the capacitance and the second capacitance.
For this reason, an oil sensor having the first reference capacitor and the oil detection sensor unit configured as described above, and an electrostatic capacitance having the capacitance measurement unit, the storage unit, the calculation unit, and the determination unit configured as described above. and a measurement determination device, obtaining the capacitance of the first cable by subtracting the capacitance of the first solid dielectric from the first capacitance, and obtaining the capacitance of the first cable from the second capacitance By subtracting the capacitance of the first cable, it is possible to obtain the capacitance of the oil detection sensor that does not include the capacitance of the second cable.
As a result, it is possible to determine the presence or absence of oil based on the determination reference value and the capacitance of the oil detection sensor section that does not include the capacitance of the second cable. It is possible to accurately determine the presence or absence of oil in the second gap of the sensor section.

In the oil sensor unit according to the aspect of the present invention, the storage unit stores data indicating a relationship between the capacitance of the oil detection sensor unit and the dilution ratio of the refrigerant contained in the oil. The capacitance measurement and determination device is electrically connected to the storage unit and the calculation unit, and is included in the oil based on the data and the capacitance of the oil detection sensor unit It may have a dilution rate acquisition unit that acquires the dilution rate of the refrigerant.

By having the storage unit and the dilution ratio acquisition unit configured in this way, the capacitance of the oil detection sensor unit that does not include the capacitance of the second cable and the capacitance of the oil detection sensor unit The dilution ratio of the refrigerant contained in the oil can be obtained based on the data indicating the relationship between the capacity and the dilution ratio of the refrigerant contained in the oil.

Further, in the oil sensor unit according to the aspect of the present invention, two each of the first and second cables are provided, and the oil sensor includes the first cathode plate and one of the first cathode plates. a first cathode terminal connected to one cable; a first anode terminal electrically connected to the first anode plate and also connected to the other first cable; a second cathode terminal electrically connected to the cathode plate and connected to one of the second cables; and a second cable electrically connected to the second anode plate and to the other of the second cables. and a second anode terminal connected.

A first cathode terminal, a first anode terminal, a second cathode terminal, and a second anode terminal configured as described above are provided, and these terminals are connected to the first cable or the second cable. By doing so, information on the first and second capacitances can be transmitted to the capacitance measurement determination device.

Further, in the oil sensor unit according to the aspect of the present invention, the first cathode plate is formed integrally with the second cathode plate at the tip of the second cathode plate, and the first One cable is provided, two second cables are provided, and the oil sensor is electrically connected to the first anode plate and also to the first cable. a connected first anode terminal; a cathode terminal electrically connected to the second cathode plate and the first cathode plate; and a cathode terminal connected to one of the second cables; and a second anode terminal electrically connected to the anode plate and connected to the other second cable.

Thus, by forming the first cathode plate at the tip of the second cathode plate so as to be integrated with the second cathode plate, one cathode terminal and one of the second cables can be connected to the second cathode plate. It can be used as a common cathode terminal and cable for the cathode plate and the first cathode plate. As a result, the number of constituent elements of the oil sensor unit can be reduced.

Further, in the oil sensor unit according to the aspect of the present invention, the oil sensor has a second reference capacitor, is electrically connected to the second reference capacitor, and A third cable that has the same configuration as the first and second cables and is routed along the same route as the first and second cables so that the capacitance is equal to that of the cable; The second reference capacitor includes a third cathode plate, a third anode plate opposed to the third cathode plate with a third gap therebetween, and arranged to close the third gap. and having a second solid dielectric whose capacitance is known and whose capacitance is not easily affected by the oil, and wherein the capacitance measurement unit measures the capacitance of the first cable and the capacitance of the first reference capacitor, the capacitance of the second cable equal to the capacitance of the first cable, and the oil detection sensor unit and a third cable capacitance equal to the capacitance of the first cable and the capacitance of the second reference capacitor. and the capacitance of the first cable obtained by subtracting the capacitance of the first solid dielectric from the first capacitance. an average capacitance that is the average of the capacitance and the capacitance of the third cable obtained by subtracting the capacitance of the second solid dielectric from the third capacitance; and acquires the capacitance of the oil detection sensor unit by subtracting the average capacitance from the second capacitance, and the determination unit obtains the oil obtained by the calculation unit The presence or absence of the oil in the second gap may be determined based on the capacitance of the detection sensor section.

As described above, by routing the first to third cables having the same structure along the same route, the disturbance received by the first to third cables becomes equal. 2 and the third capacitance can be made equal.
For this reason, a second reference capacitor, a capacitance measurement unit, and a determination unit are provided, and the first capacitance obtained by subtracting the capacitance of the first solid dielectric from the first capacitance and the third cable capacitance obtained by subtracting the capacitance of the second solid dielectric from the third capacitance. By acquiring the capacitance, it becomes possible to improve the reliability of the average capacitance used as the capacitance of the second cable.
This makes it possible to improve the reliability of the capacitance of the oil detection sensor section obtained by subtracting the average capacitance from the second capacitance.
Then, by determining whether or not there is oil in the second gap based on the highly reliable capacitance of the oil detection sensor portion, it is possible to improve the accuracy of determining whether or not there is oil.

Further, in the oil sensor unit according to the aspect of the present invention, two each of the first to third cables are provided, and the oil sensor includes the first cathode plate and one of the first cathode plates. a first cathode terminal connected to one cable; a first anode terminal electrically connected to the first anode plate and also connected to the other first cable; a second cathode terminal electrically connected to the cathode plate and connected to one of the second cables; and a second cable electrically connected to the second anode plate and to the other of the second cables. a connected second anode terminal; a third cathode terminal electrically connected to the third cathode plate and connected to one of the third cables; and a third anode terminal connected in common and connected to the other third cable.

A first cathode terminal, a first anode terminal, a second cathode terminal, a second anode terminal, a third cathode terminal, and a third anode terminal configured as described above are provided, and these terminals and By connecting the first to third cables, information on the first to third capacitances can be transmitted to the capacitance measurement determination device.

Further, in the oil sensor unit according to the aspect of the present invention, the first cathode plate is formed integrally with the second cathode plate at the tip of the second cathode plate, and the third cathode plate is formed integrally with the second cathode plate. The cathode plate is formed integrally with the first cathode plate at the tip of the first cathode plate, the first cable and the third cable are provided one by one, and the second Two cables are provided, and the oil sensor is electrically connected to the first anode plate, and includes a first anode terminal connected to the first cable, and the first to a cathode terminal electrically connected to a third cathode plate and connected to one of the second cables, and a cathode terminal electrically connected to the second anode plate and to the other of the second cables There may be a connected second anode terminal and a third anode terminal electrically connected to the third anode plate and connected to the third cable.

Thus, the first cathode plate is formed at the tip of the second cathode plate so as to be integrated with the second cathode plate, and the tip of the first cathode plate is formed so as to be integrated with the first cathode plate. By forming the third cathode plate in the second cathode plate, it becomes possible to use the second cathode terminal and the second cable as common terminals and cables for the first to third cathode plates. This eliminates the need for the first cathode terminal, the first cable, the third cathode terminal, and the third cathode plate, thereby reducing the number of components of the oil sensor unit.

In order to solve the above problems, a compressor according to one aspect of the present invention includes the above oil sensor unit, the housing, and the compression section.

According to the present invention, it is possible to accurately determine the presence or absence of oil, so that the compressor can be stably operated.

According to the present invention, it is possible to accurately determine the presence or absence of oil using the oil sensor.

It is a sectional view showing a schematic structure of a compressor concerning a 1st embodiment of the present invention. It is the figure which expanded the part enclosed by the area|region A among the compressors shown in FIG. FIG. 5 is an enlarged view for explaining an oil sensor unit according to a second embodiment of the invention; FIG. 5 is a graph showing the relationship between the capacitance of the oil detection sensor and the dilution rate of the refrigerant contained in the oil. FIG. 11 is an enlarged view for explaining an oil sensor unit according to a third embodiment of the invention; FIG. 11 is an enlarged view for explaining an oil sensor unit according to a fourth embodiment of the invention; FIG. 11 is an enlarged view for explaining an oil sensor unit according to a modification of the fourth embodiment of the invention; FIG. 11 is an enlarged view for explaining an oil sensor unit according to a fifth embodiment of the invention;

Embodiments to which the present invention is applied will be described in detail below with reference to the drawings.

(First embodiment)
A compressor 10 according to a first embodiment will be described with reference to FIGS. 1 and 2. FIG. In FIG. 1, the Z direction is the direction in which the housing 21 extends (vertical direction), _O1 is the axis of the housing 21, the rotary shaft main body 23A of the rotary shaft 23, and the discharge pipe 29 (hereinafter referred to as "axis _O1 "); ₂ indicates the axis of the eccentric shaft portion 23B (hereinafter referred to as "axis O ₂ ").
In FIG. 1, as an example of the compressor 10, a hermetic electric rotary compressor used in an air conditioner, a refrigeration system, or the like is illustrated. In FIG. 2, the same components as those of the structure shown in FIG. 1 are denoted by the same reference numerals.

The compressor 10 includes an oil sensor unit 20, a compressor body 11, an accumulator 13, a bracket 14, a suction pipe 15, first cables 16A and 16B, second cables 17A and 17B, static A capacitance measurement determination device 18 and a display device 19 are provided.
The oil sensor unit 20 includes first cables 16A and 16B, second cables 17A and 17B, a capacitance measurement determination device 18, a display device 19, an oil sensor 30 constituting the compressor main body 11, have

The compressor main body 11 has a housing 21 , a rotating shaft 23 , an upper bearing 24 , a lower bearing 25 , an electric motor 27 , a compression section 28 , a discharge pipe 29 and an oil sensor 30 .

The housing 21 has a housing body 31 , a lid portion 32 and a bottom portion 33 .
The housing body 31 has a cylindrical shape and extends in the Z direction. The upper end and lower end of the housing body 31 are open ends. First and second openings 31A and 31B are formed in the lower portion of the housing body 31 .

The first opening 31A is formed so as to face the outer peripheral surface of the cylinder 45 housed inside the housing 21 . The tip of the suction pipe 15 is inserted into the first opening 31A.
The second opening 31B is formed to be positioned directly above the cylinder 45. As shown in FIG. The second opening 31B is an opening for arranging the oil sensor 30 .

The lid portion 32 is provided on the housing body 31 so as to cover the upper end of the housing body 31 . A through hole 32A is formed in the lid portion 32 . The axis of the through hole 32A coincides with the axis _O1 . 32 A of through-holes are holes for inserting the discharge pipe 29. As shown in FIG.
The bottom portion 33 is provided on the housing body 31 so as to cover the lower end of the housing body 31 .

An oil reservoir 36 is formed at the bottom of the housing 21 by accumulating oil 35 (lubricating oil). A liquid surface 36a of the oil reservoir 36 is positioned above the compression portion 28 when the oil 35 is initially filled. Thereby, the compression part 28 is driven in the oil reservoir 36 .
The housing 21 configured as described above hermetically seals the internal space, and accommodates the rotating shaft 23 , the upper bearing 24 , the lower bearing 25 , the electric motor 27 , and the compression section 28 .

The rotating shaft 23 has a rotating shaft body 23A and an eccentric shaft portion 23B. Rotating shaft main body 23A
The rotary shaft main body 23A extends in the Z direction inside the housing 21 . The rotary shaft main body 23A is configured to be rotatable around the axis _O1 .
The eccentric shaft portion 23B is provided on the lower end side of the rotary shaft main body 23A. The axis _O2 of the eccentric shaft portion 23B is arranged at a position offset from the axis _O1 . The eccentric shaft portion 23B forms part of the compression portion 28 .

The upper bearing 24 is provided on the upper surface of the compression portion 28 . The upper bearing 24 is bolted to a cylinder 45 that constitutes the compression portion 28 .
The lower bearing 25 is provided on the lower surface of the compression portion 28 . Thereby, the upper bearing 24 and the lower bearing 25 are arranged so as to sandwich the compression portion 28 in the Z direction. The lower bearing 25 is bolted to a cylinder 45 that constitutes the compression portion 28 .
The upper bearing 24 and the lower bearing 25 configured as described above support the rotating shaft main body 23A in a state in which the rotating shaft main body 23A is rotatable around the axis _O1 .

The electric motor 27 is arranged centrally within the housing 21 in the Z direction. The electric motor 27 has a rotor 41 and a stator 42 .
The rotor 41 is fixed to the outer peripheral surface of the rotating shaft main body 23A positioned above the compression portion 28 .
The stator 42 is fixed to the inner peripheral surface 31 a of the housing body 31 so as to surround the outer peripheral surface of the rotor 41 .

A cable 43 is connected to the electric motor 27 configured as described above. The electric motor 27 is connected via a cable 43 to a power source (not shown). The electric motor 27 rotates the rotating shaft 23 with electric power supplied from the power supply.

The compression part 28 is provided at the bottom inside the housing 21 located below the electric motor 27 . The compression portion 28 has a cylinder 45 , an eccentric shaft portion 23</b>B, and a piston rotor 47 .

The cylinder 45 has a compression chamber 45A, a suction hole 45B, and a discharge hole (not shown).
45 A of compression chambers are formed in the center part of the cylinder 45. As shown in FIG. The compression chamber 45A accommodates the eccentric shaft portion 23B and the piston rotor 47 .
The suction hole 45B is a hole for allowing the refrigerant to flow into the compression chamber 45A. Refrigerant compressed by the compression section 28 is discharged to a discharge hole (not shown).

The cylinder 45 is provided with a blade (not shown) that divides the compression chamber 45A into two. The cylinder 45 is formed with blade grooves (not shown) extending in the radial direction.
The blade is slidably guided on the inner surface of the blade groove. The blades are held so as to move toward and away from the piston rotor 47 . The radially outer proximal end of the blade is elastically pressed by a compression spring (not shown), and the distal end of the blade is always pressed against the outer peripheral surface of the piston rotor 47 .

The discharge pipe 29 is fixed to the lid portion 32 with its upper end disposed outside the housing 21 and its lower end inserted into the through hole 32A. The discharge pipe 29 discharges the compressed refrigerant containing the oil 35 to the outside of the housing 21 .

The oil sensor 30 is fixed to the housing 21 while being inserted into the second opening 31B. Accordingly, the oil sensor 30 is arranged at the bottom of the housing 21 .
The oil sensor 30 includes a fixing member 49, a first reference capacitor 51, an oil detection sensor portion 52, a first cathode terminal 54, a first anode terminal 55, and a second cathode terminal 56. and a second anode terminal 57 .

The fixing member 49 is arranged to close the second opening 31B and is fixed to the housing body 31 . The fixing member 49 has an inner surface 49 a and an outer surface 49 b arranged in the radial direction of the housing 21 .
The inner surface 49 a is arranged inside the housing 21 . The outer surface 49b is arranged outside the housing 21 .

The first reference capacitor 51 has a first cathode plate 61 , a first anode plate 62 and a first solid dielectric 63 .
The first cathode plate 61 is partially embedded in the fixing member 49 from the inner surface 49a side, and is supported by the fixing member 49 . The first cathode plate 61 protrudes radially inward of the housing body 31 from the inner surface 49a.

The first anode plate 62 is supported by the fixing member 49 by being partially embedded from the inner surface 49 a side of the fixing member 49 located above the first cathode plate 61 . The first anode plate 62 protrudes radially inward of the housing body 31 from the inner surface 49a.
The lower surface 62a of the first anode plate 62 faces the upper surface 61a of the first cathode plate 61 while being separated from the first cathode plate 61 in the Z direction.

A first gap 64 is formed between the upper surface 61 a of the first cathode plate 61 and the lower surface 62 a of the first anode plate 62 . The first cathode plate 61 and the first anode plate 62 are made of metal plates.

The first solid dielectric 63 is arranged to block the first gap 64 while being adhered to the upper surface 61 a of the first cathode plate 61 and the lower surface 62 a of the first anode plate 62 . The first solid dielectric 63 is a dielectric that has a known capacitance and whose capacitance is less affected by the oil 35 .
As the material of the first solid dielectric 63, it is possible to use, for example, ceramics or resin with small changes in temperature characteristics.

The oil detection sensor section 52 has a second cathode plate 66 and a second anode plate 67 .
The second cathode plate 66 is partially embedded in the fixing member 49 from the inner surface 49a side, and is supported by the fixing member 49 . The second cathode plate 66 protrudes radially inward of the housing body 31 from the inner surface 49a.

The second anode plate 67 is partially embedded in the fixing member 49 located above the second cathode plate 66 from the inner surface 49a side, and is supported by the fixing member 49 .
The second anode plate 67 extends radially inward of the housing body 31 from the inner surface 49a.
A lower surface 67a of the second anode plate 67 of the second anode plate 67 faces the upper surface 66a of the second cathode plate 66 while being separated from the second cathode plate 66 in the Z direction. The second cathode plate 66 and the second anode plate 67 are made of metal plates.

A second gap 68 is formed between the upper surface 66 a of the second cathode plate 66 and the lower surface 67 a of the second anode plate 67 .
As shown in FIG. 2 , when the liquid surface 36 a of the oil sump 36 is above the oil detection sensor portion 52 , the oil 35 forming the oil sump 36 is arranged in the second gap 68 . Refrigerant supplied to the compression section 28 is dissolved in the oil 35 .
On the other hand, when the liquid surface 36 a of the oil reservoir 36 is below the oil detection sensor portion 52 , air is arranged in the second gap 68 .

The first cathode terminal 54 is partially embedded in the fixing member 49 from the outer surface 49b side, and is supported by the fixing member 49 . The first cathode terminal 54 extends radially outward of the housing body 31 from the outer surface 49b. The first cathode terminal 54 is electrically connected to the first cathode plate 61 inside the fixing member 49 .
The first cathode terminal 54 is electrically connected to the capacitance measurement determination device 18 via the first cable 16A (one first cable).

The first anode terminal 55 is partially embedded in the fixing member 49 from the outer surface 49b side, and is supported by the fixing member 49 . The first anode terminal 55 extends radially outward of the housing body 31 from the outer surface 49b. The first anode terminal 55 is electrically connected to the first anode plate 62 inside the fixing member 49 .
The first anode terminal 55 is electrically connected to the capacitance measurement determination device 18 via the first cable 16B (the other first cable).

The second cathode terminal 56 is partially embedded in the fixing member 49 from the outer surface 49b side, and is supported by the fixing member 49 . The second cathode terminal 56 extends radially outward of the housing body 31 from the outer surface 49b. The second cathode terminal 56 is electrically connected to the second cathode plate 66 inside the fixing member 49 .
The second cathode terminal 56 is electrically connected to the capacitance measurement determination device 18 via a second cable 17A (one second cable).

The second anode terminal 57 is supported by the fixing member 49 by being partially embedded in the fixing member 49 from the outer surface 49b side. The second anode terminal 57 extends radially outward of the housing body 31 from the outer surface 49b. The second anode terminal 57 is electrically connected to the second anode plate 67 inside the fixing member 49 .
The second anode terminal 57 is electrically connected to the capacitance measurement determination device 18 via a second cable 17B (the other second cable).

The accumulator 13 is provided beside the compressor body 11 . A side wall of the accumulator 13 is connected with a bracket 14 connected with the housing body 31 .
The accumulator 13 is thereby supported by the housing 21 via the bracket 14 . The accumulator 13 separates the refrigerant into gas phase refrigerant and liquid phase refrigerant.

The intake tube 15 has a first portion 15A, a second portion 15B, and a third portion 15C located between the first portion 15A and the second portion 15B.
The first portion 15A is arranged within the accumulator 13 . The first portion 15A has an inlet 15Aa for introducing gas phase refrigerant.

The second portion 15B is fixed to the compressor main body 11 while being inserted into the suction hole 45B through the first opening 31A. The second portion 15B has an outlet port 15Ba for leading the gas-phase refrigerant to the compression chamber 45A.
The third portion 15C is arranged outside the housing 21 and the accumulator 13 and is L-shaped.

The first cable 16A is a ground cable and is arranged outside the housing 21 . The first cable 16A has one end connected to the first cathode terminal 54 and the other end connected to the capacitance measurement determination device 18 .
The first cable 16B is a sensor cable and is arranged outside the housing 21 . The first cable 16B has one end connected to the first anode terminal 55 and the other end connected to the capacitance measurement determination device 18 .
The first cables 16A and 16B have the capacitance of the first cables 16A and 16B (hereinafter referred to as “capacitance C _C1 ”) and the known capacitance of the first reference capacitor 51 (hereinafter referred to as “ Information necessary for measuring the first capacitance (hereinafter referred to as "first capacitance C ₁ ") including the capacitance C _R1 ") is transmitted to the capacitance measurement determination device 18 do.

The second cable 17A is a ground cable and is arranged outside the housing 21 . The second cable 17A has one end connected to the second cathode terminal 56 and the other end connected to the capacitance measurement determination device 18 . The second cable 17A has the same structure as the first cable 16A and is routed along the same route as the first cable 16A.
The second cable 17B is a sensor cable and is arranged outside the housing 21 . The second cable 17B has one end connected to the second anode terminal 57 and the other end connected to the capacitance measurement determination device 18 .
The second cables 17A and 17B are second cables including the capacitance C _C2 of the second cables 17A and 17B and the capacitance of the oil detection sensor section 52 (hereinafter referred to as “capacitance C _S ”). (hereinafter referred to as “second capacitance C ₂ ”) is transmitted to the capacitance measurement determination device 18 .

The second cable 17B has the same structure as the first cable 16B and is routed along the same route as the first cable 16B.
In this way, the second cables 17A, 17B are of the same construction as the first cables 16A, 16B and routed along the same route as the first cables 16A, 16B. The disturbances received by the cables 16A, 16B, 17A and 17B are equal. Therefore, the capacitance C _C1 of the first cables 16A and 16B and the capacitance of the second cables 17A and 17B (hereinafter referred to as “capacitance C _C2 ”) can be made equal.
Therefore, the following formula (1) holds.
C _C2 =C _C1 (1)

The capacitance measurement determination device 18 is provided outside the compressor main body 11 . The capacitance measurement determination device 18 has a capacitance measurement section 18A, a storage section 18B, a calculation section 18C, and a determination section 18D.

Based on the information transmitted from the first and second cables 16A, 16B, 17A, and 17B, the capacitance measurement unit 18A measures the capacitance _CC1 of the first cable and the capacitance of the first reference capacitor 51. including the known capacitance C _R1 and the first capacitance C ₁ , the second cable capacitance C _C2 (=C _C1 ), and the oil detection sensor unit capacitance C _S A second capacitance is measured.
The first capacitance _C1 has the relationship of the following equation (2).
C ₁ =C _C1 +C _R1 (2)
The second capacitance _C2 has the relationship of the following equation (3).
C ₂ =C _C2 +C _S (3)

The storage unit 18B is electrically connected to the determination unit 18D. The storage unit 18B stores a determination reference value (e.g., the value of the capacitance between the second cathode plate 66 and the second and the value of the capacitance when only air exists between the anode plate 67 and the positive plate 67).

The calculation unit 18C subtracts the capacitance _CR1 of the first solid dielectric from the first capacitance _C1 , as shown in the following equation (4), to obtain the capacitance of the second cables 17A and 17B Obtain the capacitance C _C1 of the first cable 16A, 16B equal to the capacitance C _C2 .
Since the specific values of the capacitances C _{1 and} C _R1 described in the following equation (4) are known at this stage, the capacitance C _C1 can be obtained.
C _C1 =C ₁ -C _R1 (4)
The above formula (4) is a modified formula of the above formula (2).

Further, the calculation unit 18C subtracts the capacitance C _C1 (=C _C2 ) of the first cables 16A and 16B from the second capacitance C ₂ as shown in the following equation (5). Acquire the capacitance _CS of the oil detection sensor.
C _S =C ₂ -C _C1 (5)
The above formula (5) is a formula obtained by modifying the above formula (3) after replacing C _C2 in the above formula (3) with C _C1 .
Since the specific numerical values of the capacitances C2 _{and C1} shown in the above equation (5) are known at this stage, the capacitance _Cs of the oil detection sensor section 52 can be obtained.
The capacitance _Cs of the oil detection sensor section 52 obtained by such a method does not include the capacitances _Cc2 of the second cables 17A and 17B.

The determination unit 18D compares the capacitance C _S of the oil detection sensor unit 52 acquired by the calculation unit 18C with the determination reference value stored in the storage unit 18B, thereby determining the difference between the second cathode plate 66 and the second cathode plate 66. It is determined whether or not oil exists in the second gap 68 formed between the anode plate 67 (determination of the presence or absence of oil).

The capacitance measuring/determining device 18 configured as described above is electrically connected to the display device 19 . The capacitance measurement determination device 18 transmits information about the determination result of the determination section 18D to the display device 19 .

The display device 19 is provided outside the compressor body 11 . The display device 19 has a display screen 19A. The display device 19 causes the display screen 19A to display the determination result of the determination section 18D.
By displaying the determination result of the determination unit 18D on the display screen 19A in this manner, the operator can easily recognize the remaining amount of the oil sump 36 in real time.
In addition, since the operator can easily recognize the remaining amount of the oil sump 36 in real time, the stop time of the compressor 10 (compressor main body 11) when the oil 35 becomes low can be shortened. can do.

According to the oil sensor unit 20 of the first embodiment, the oil sensor 30 having the above-described first reference capacitor 51 and oil detection sensor section 52, the above-described capacitance measurement section 18A, storage section 18B, By providing the capacitance measuring/determining device 18 having the computing unit 18C and _{the determining unit 18D, the capacitance CR1 of} the first solid dielectric 63 is subtracted from the first capacitance C1, By obtaining the capacitance C _C1 of the first cables 16A and 16B and subtracting the capacitance C _C1 of the first cables 16A and 16B _from the second capacitance C2, the second cable 17A _{, 17B} .

As a result, the presence or absence of oil can be determined based on the capacitance _CS of the oil detection sensor portion 52, which does not include the capacitance _CC2 of the second cables 17A and 17B, and the determination reference value. It becomes possible.
Therefore, the presence or absence of the oil 35 in the second gap 68 can be accurately determined.

Further, according to the compressor 10 of the first embodiment, by providing the oil sensor unit 20 configured as described above, it is possible to accurately determine the presence or absence of oil. can be run by

In FIG. 2, as an example, the case where the oil detection sensor section 52 is arranged below the first reference capacitor 51 is illustrated, but the position where the oil detection sensor section 52 is arranged is , but not limited to the positions shown in FIG.
For example, the oil detection sensor section 52 may be arranged above the first reference capacitor 51 , or the oil detection sensor section 52 may be arranged next to the first reference capacitor 51 .

(Second embodiment)
An oil sensor unit 75 of a second embodiment will be described with reference to FIGS. 3 and 4. FIG. In FIG. 3, the same components as those of the structure shown in FIG. 2 are denoted by the same reference numerals. In FIG. 4, a straight line L1 indicates the capacitance when the second gap 68 is filled only with air, and a straight line L2 indicates the capacitance when the second gap 68 is filled only with oil 35. It shows the relationship between the dilution ratio of the refrigerant contained in the oil 35 and the capacitance of the oil detection sensor section 52 . A straight line L2 is a straight line drawn by a linear function.

The oil sensor unit 75 has the same configuration as the compressor 10 except that it has a capacitance measurement determination device 76 instead of the capacitance measurement determination device 18 that constitutes the oil sensor unit 20 of the first embodiment. It is

In addition to the capacitance measurement unit 18A, the storage unit 18B, the calculation unit 18C, and the determination unit 18D that constitute the capacitance measurement determination device 18 of the first embodiment, the capacitance measurement determination device 76 has a dilution rate It is configured in the same manner as the capacitance measurement determination device 18 except that it has an acquisition unit 18E.

Data indicating the relationship between the capacitance _CS of the oil detection sensor unit 52 and the dilution ratio of the refrigerant contained in the oil 35 is stored in the storage unit 18B of the capacitance measurement determination device 76 .
As the data, for example, the graph shown in FIG. 4 can be exemplified.

The dilution ratio acquisition section 18E is electrically connected to the storage section 18B, the calculation section 18C, and the determination section 18D. Information on the electrostatic capacity _CS of the oil detection sensor section 52 acquired by the calculation section 18C is transmitted to the dilution rate acquisition section 18E.
The dilution rate acquisition unit 18E determines the amount of oil contained in the oil 35 located in the second gap 68 based on the data stored in the storage unit 18B (see FIG. 4) and the capacitance _CS of the oil detection sensor unit 52. Gets the dilution ratio of the refrigerant used.

Here, how the dilution rate acquisition unit 18E acquires the dilution rate will be described using the graph shown in FIG.
For example, when the value of the capacitance C _S of the oil detection sensor unit 52 acquired by the calculation unit 18C is C _SA (for example, 4 pF), the determination unit 18D determines that the second gap 68 is filled with air. be judged. In this case, the dilution rate acquisition unit 18E does not perform the process of acquiring the dilution rate.

When the capacitance C _S of the oil detection sensor unit 52 acquired by the calculation unit 18C is C _SB (for example, 5 pF), the determination unit 18D determines that the second gap 68 is filled with the oil 35. Therefore, the dilution rate acquisition unit 18E performs a process of acquiring the dilution rate. As shown in FIG. 4, the dilution ratio of the refrigerant in the oil 35 obtained by this process is 0%.

When the capacitance C _S of the oil detection sensor unit 52 acquired by the calculation unit 18C is C _SC , the determination unit 18D determines that the second gap 68 is filled with the oil 35, so the dilution ratio is acquired. The unit 18E performs a process of acquiring the dilution ratio. As shown in FIG. 5, the dilution ratio of the refrigerant in the oil 35 obtained by this process is D%.

When the capacitance C _S of the oil detection sensor unit 52 acquired by the calculation unit 18C is C _SD (for example, 20 pF), the determination unit 18D determines that the second gap 68 is filled with the oil 35. Therefore, the dilution rate acquisition unit 18E performs a process of acquiring the dilution rate. As shown in FIG. 5, the dilution ratio of the refrigerant in the oil 35 obtained by this process is 100%.
By such a method, the dilution rate acquisition unit 18E acquires the dilution rate of the refrigerant in the oil 35. FIG.

According to the oil sensor unit 75 of the second embodiment, by including the storage unit 18B and the dilution rate acquisition unit 18E configured as described above, the capacitance _C2 of the second cables 17A and 17B is not included. Based on the capacitance _CS of the oil detection sensor portion 52 and data indicating the relationship between the capacitance _CS of the oil detection sensor portion 52 and the dilution ratio of the refrigerant contained in the oil 35, the oil 35 It is possible to obtain the dilution ratio of the refrigerant contained in .

(Third embodiment)
An oil sensor unit 80 according to a third embodiment will be described with reference to FIG. In FIG. 5, the same components as those of the structure shown in FIG. 2 are denoted by the same reference numerals.

The oil sensor unit 80 is configured in the same manner as the oil sensor unit 20 except that it has an oil sensor 81 instead of the oil sensor 30 that constitutes the oil sensor unit 20 of the first embodiment.

The oil sensor 81 has the first cathode plate 61 formed at the tip of the second cathode plate 66 so as to be integrated with the second cathode plate 66 , and the first anode terminal 55 and the first anode plate 62 . is provided, and the first cathode terminal 54 is removed from the constituent elements.

According to the oil sensor unit 80 of the third embodiment, by forming the first cathode plate 61 at the tip of the second cathode plate 66 so as to be integrated with the second cathode plate 66, the second As a common terminal and cable for the cathode plate 66 and the second cathode plate 66, it is possible to use the second cathode terminal 56 and the second cable 17A. As a result, the number of constituent elements of the oil sensor unit 80 can be reduced.

Note that the capacitance measurement/determination device 76 described in the second embodiment may be provided instead of the capacitance measurement/determination device 18 constituting the oil sensor unit 80 of the third embodiment. In this way, the oil sensor unit 80 has the capacitance measuring/determining device 76, so that the dilution ratio of the refrigerant in the oil 35 can be obtained.

(Fourth embodiment)
An oil sensor unit 90 of a fourth embodiment will be described with reference to FIG. In FIG. 6, the same components as those of the structure shown in FIG. 2 are denoted by the same reference numerals.

The oil sensor unit 90 has an oil sensor 91 in place of the oil sensor 30 that constitutes the compressor 10 of the first embodiment, and further includes a third cathode terminal 93, a third anode terminal 94, and a third cable. It is configured in the same manner as the oil sensor unit 20 except that it has 96A and 96B.

The oil sensor 91 is configured in the same manner as the oil sensor 30 except that a second reference capacitor 100 is added to the configuration of the oil sensor 30 .

The second reference capacitor 100 is arranged below the oil detection sensor section 52 arranged below the first reference capacitor 51 .
The second reference capacitor 100 has a third cathode plate 101 , a third anode plate 102 and a second solid dielectric 104 .

A portion of the third cathode plate 101 is embedded in the fixing member 49 from the inner surface 49a side, thereby being supported by the fixing member 49 . The third cathode plate 101 protrudes radially inward of the housing body 31 from the inner surface 49a.

The third anode plate 102 is supported by the fixing member 49 by partially embedding it from the inner surface 49a side of the fixing member 49 located above the third cathode plate 101 . The third anode plate 102 protrudes radially inward of the housing body 31 from the inner surface 49a.
The lower surface 102a of the third anode plate 102 faces the upper surface 101a of the third cathode plate 101 while being separated from the third cathode plate 101 in the Z direction.

A third gap 105 is formed between the upper surface 101 a of the third cathode plate 101 and the lower surface 102 a of the third anode plate 102 . The third cathode plate 101 and the third anode plate 102 are made of metal plates.

The second solid dielectric 104 is arranged to close the third gap 105 while being adhered to the upper surface 101 a of the third cathode plate 101 and the lower surface 102 a of the third anode plate 102 . The second solid dielectric 104 is a dielectric that has a known capacitance and whose capacitance is less susceptible to oil.
The material of the second solid dielectric 104 may be the same as or different from the material of the first solid dielectric 63 .
As the material of the second solid dielectric 104, it is possible to use, for example, ceramics or resin with small changes in temperature characteristics.

A third cable 96A is provided outside the housing 21 . The third cable 96</b>A has one end electrically connected to the third cathode terminal 93 and the other end connected to the capacitance measurement determination device 18 . The third cable 96A has the same structure as the first and second cables 16A, 17A and is routed along the same route as the first and second cables 16A, 17A.

A third cable 96B is provided outside the housing 21 . The third cable 96B has one end electrically connected to the third anode terminal 94 and the other end connected to the capacitance measurement determination device 18 . The third cable 96B has the same structure as the first and second cables 16B, 17B and is routed along the same route as the first and second cables 16B, 17B.

The third cables 96A and 96B configured as described above combine the capacitance of the third cables 96A and 96B (hereinafter referred to as “capacitance C _C3 ”) and the known capacitance of the second reference capacitor 100 . Information necessary for measuring a third capacitance (hereinafter referred to as “third capacitance C ₃ ”) including capacitance (hereinafter referred to as “capacitance C _R2 ”) is obtained by capacitance measurement. It is transmitted to the determination device 18 .
As described above, since the third cables 96A, 96B are routed along the same route as the first and second cables 16A, 16B, 17A, 17B, the first and second cables 16A, 16B, The disturbances received by 17A and 17B are equal. Therefore, it is possible to equalize the capacitance C _C3 of the third cable, the second capacitance C _C2 , and the first capacitance C _C1 .
Therefore, the following formula (6) holds.
C _C3 =C _C1 =C _C2 (6)

Here, processing performed by the capacitance measurement unit 18A, the calculation unit 18C, and the determination unit 18D that configure the capacitance measurement determination device 18 will be described.
The capacitance measurement unit 18A measures a first capacitance C1 including the capacitance _C1 of the first cables 16A and 16B and the capacitance _C11 of the first reference capacitor ₅₁ , A second capacitance C2 including the capacitance C _R2 of the second cables 17A, 17B equal to the capacitance C _C1 of the cables 16A, 16B of the second cable 16A, 16B and the capacitance C _S of the oil detection sensor unit ₅₂ and the capacitance C R1 _of the second reference capacitor 100 and the capacitance C _R3 of the third cables 96A, 96B equal to the capacitance C _C1 of the first cables 16A, 16B. Measure the capacitance _C3 .

The first capacitance _C1 can be expressed as the above equation (2). The second capacitance _C2 can be expressed as the above equation (3).
The third capacitance _C3 can be expressed as the following equation (7).
C ₃ =C _C3 +C _R2 (7)

The calculation unit 18C calculates the capacitance _C1 of the first cable obtained by subtracting the capacitance _CR1 of the first solid dielectric 63 from the first capacitance C1, and the capacitance _C1 of the third cable. and the capacitance C _C3 of the third cables 96A and _96B obtained by subtracting the capacitance C _R2 of the second solid dielectric 104 from the capacitance C3. The capacitance C _C3 is obtained by the following formula (8).
C _C3 =C ₁ -C _R2 (8)

Further, the calculation unit 18C acquires an average capacitance _CCAVE , which is the average value of the capacitances _CC1 and _CC3 , based on the following equation (9).
C _CAVE =(C _C1 +C _C3 )/2 (9)

Further, as shown in the following equation (10), the calculation unit 18C subtracts the average capacitance C _CAVE from the second capacitance C ₂ to obtain the capacitance C _S of the oil detection sensor unit 52. get.
C _S =C ₂ -C _CAVE (10)

The determination unit 18D determines whether or not the oil 35 is present in the second gap 68 based on the capacitance _CS of the oil detection sensor unit 52 acquired by the calculation unit 18C.

According to the oil sensor unit 90 _{of the fourth embodiment, the first cable 16A obtained by subtracting the capacitance CR1 of} the first solid dielectric 63 from the first capacitance C1, 16B capacitance C _C1 and the capacitance of the third cables 96A, 96B obtained by subtracting the capacitance C _R2 of the second solid dielectric 104 _from the third capacitance C3. It is possible to improve the reliability of the average capacitance C _CAVE used as the capacitance C _C2 of the second cables 17A and 17B by obtaining the average capacitance C _CAVE that is the average value of C C3 _and C C3. becomes.

Accordingly, by subtracting the average capacitance C _CAVE from the second capacitance C ₂ , the capacitance C _S of the oil detection sensor portion 52 is obtained, and the capacitance C S of the oil detection sensor portion 52 is obtained. By determining the presence or absence of the oil 35 in the second gap 68 based on the capacity _CS , the accuracy of the determination can be improved.

Note that the capacitance measurement/determination device 76 described in the second embodiment may be provided instead of the capacitance measurement/determination device 18 constituting the oil sensor unit 90 of the fourth embodiment. In this way, the oil sensor unit 90 has the capacitance measurement/determination device 76, so that the dilution ratio of the refrigerant in the oil 35 can be obtained.

Also, in FIG. 6, as an example, a case where the oil detection sensor unit 52 is arranged between the first reference capacitor 51 and the second reference capacitor 100 in the Z direction will be described. However, the positions of the first reference capacitor 51, the second reference capacitor 100, and the oil detection sensor section 52 are not limited to the positions shown in FIG.

For example, like the oil sensor 111 constituting the oil sensor unit 110 of the modified example of the fourth embodiment shown in FIG. may be arranged, or the first and second reference capacitors 51 and 100 may be arranged below the oil detection sensor section 52 . Also, the first reference capacitor 51 , the second reference capacitor 100 , and the oil detection sensor section 52 may be arranged in the circumferential direction of the housing body 31 .

(Fifth embodiment)
An oil sensor unit 120 according to a fifth embodiment will be described with reference to FIG. In FIG. 8, the same components as those of the structure shown in FIG. 6 are denoted by the same reference numerals.

The oil sensor unit 120 is configured in the same manner as the oil sensor unit 90 except that it has an oil sensor 121 instead of the oil sensor 91 that constitutes the oil sensor unit 90 of the fourth embodiment.

The oil sensor 121 has the first cathode plate 61 formed at the tip of the second cathode plate 66 so as to be integrated with the second cathode plate 66 , and the first cathode plate 61 at the tip of the first cathode plate 61 . 61, wirings 125 and 126 are provided, and the first cathode terminal 54 and the third cathode terminal 93 are removed from the constituent elements. It is configured in the same manner as the oil sensor 91 described in the embodiment.

The wiring 125 has one end connected to the first anode plate 62 and the other end electrically connected to the first anode terminal 55 .
The wiring 126 has one end connected to the third anode plate 102 and the other end electrically connected to the third anode terminal 94 .

According to the oil sensor unit 120 of the fifth embodiment, the first cathode plate 61 is formed at the tip of the second cathode plate 66 so as to be integrated with the second cathode plate 66. By forming the third cathode plate 101 at the tip of the cathode plate 61 so as to be integrated with the first cathode plate 61, the first cathode plate 61, the second cathode plate 66, and the third cathode plate 101 are combined. As a common terminal and cable, it becomes possible to use the second cathode terminal 56 and the second cable 17A. This eliminates the need for the first cathode terminal 54, the first cable 16A, the third cathode terminal 93, and the third cathode plate 101 shown in FIG. can be reduced.

The capacitance measurement/determination device 76 described in the second embodiment may be provided instead of the capacitance measurement/determination device 18 constituting the oil sensor unit 120 of the fifth embodiment. In this way, the oil sensor unit 120 has the capacitance measuring/determining device 76, so that the dilution ratio of the refrigerant in the oil 35 can be obtained.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the invention described in the scope of the claims. Transformation and change are possible.

DESCRIPTION OF SYMBOLS 10... Compressor 11... Compressor main body 13... Accumulator 14... Bracket 15... Suction pipe 15A... First part 15Aa... Inlet 15Ba... Outlet 15B... Second part 15C... Third part 16A, 16B... Third part 1 cable 17A, 17B ... second cable 18, 76 ... capacitance measurement determination device 18A ... capacitance measurement unit 18B ... storage unit 18C ... calculation unit 18D ... determination unit 18E ... dilution ratio acquisition unit 19 ... display device DESCRIPTION OF SYMBOLS 20,75,80,90,110,120... Oil sensor unit 21... Housing 23... Rotating shaft 23A... Rotating shaft main body 23B... Eccentric shaft part 24... Upper bearing 25... Lower bearing 27... Electric motor 28... Compression part 29... Discharge pipe 30, 81, 91, 111, 121 Oil sensor 31 Housing body 31a Inner peripheral surface 31A First opening 31B Second opening 32 Lid 32A Through hole 33 Bottom 35 Oil 36 Oil reservoir 36a Fluid surface 41 Rotor 42 Stator 43 Cable 45 Cylinder 45A Compression chamber 45B Suction hole 47 Piston rotor 49 Fixing member 49a Inner surface 49b Outer surface 51 First reference Capacitor 52... Oil detection sensor portion 54... First cathode terminal 55... First anode terminal 56... Second cathode terminal 57... Second anode terminal 61... First cathode plate 61a, 66a, 101a... Upper surface 62a, 67a, 102a Lower surface 62 First anode plate 63 First solid dielectric 64 First gap 66 Second cathode plate 67 Second anode plate 68 Second gap 85 , 125, 126... Wiring 93... Third cathode terminal 94... Third anode terminal 100... Second reference capacitor 101... Third cathode plate 102... Third anode plate 104... Second solid dielectric A... Area _O1 , _O2 ... Axis

Claims (8)

an oil sensor that accommodates a compression section that compresses a refrigerant and is provided at the bottom of a housing in which oil is stored at the bottom, and has a first reference capacitor and an oil detection sensor section;
a first cable electrically connected to the first reference capacitor;
It is electrically connected to the oil detection sensor unit, has the same structure as the first cable so that the capacitance is equal to that of the first cable, and has the same route as the first cable. a routed second cable;
A capacitance that is connected to the first and second cables and has a capacitance measurement unit, a storage unit that stores a determination reference value used when determining the presence or absence of the oil, a calculation unit, and a determination unit. a measurement determination device;
with
The first reference capacitor includes a first cathode plate, a first anode plate opposed to the first cathode plate with a first gap interposed therebetween, and arranged to close the first gap. having a first solid dielectric with a known capacitance, said capacitance being insensitive to said oil;
The oil detection sensor unit has a second cathode plate, and a second anode plate arranged opposite the second cathode plate with a second gap through which the oil or air flows,
The capacitance measurement unit measures a first capacitance including the capacitance of the first cable and the capacitance of the first reference capacitor, and the capacitance of the first cable. measuring a second capacitance including the same capacitance of the second cable and the capacitance of the oil detection sensor unit;
The computing unit subtracts the capacitance of the first solid dielectric from the first capacitance to obtain the capacitance of the first cable equal to the capacitance of the second cable. and obtain the capacitance of the oil detection sensor unit by subtracting the capacitance of the first cable from the second capacitance,
The determination unit compares the capacitance of the oil detection sensor acquired by the calculation unit with the determination reference value to determine whether or not the oil is present in the second gap. The storage unit stores data indicating a relationship between the capacitance of the oil detection sensor unit and the dilution ratio of the refrigerant contained in the oil,
The capacitance measurement determination device is electrically connected to the storage unit and the calculation unit, and dilutes the refrigerant contained in the oil based on the data and the capacitance of the oil detection sensor unit. 2. The oil sensor unit according to claim 1, further comprising a dilution ratio obtaining section for obtaining the ratio. Two each of the first and second cables are provided,
The oil sensor includes a first cathode terminal connected to the first cathode plate and one of the first cables;
a first anode terminal electrically connected to the first anode plate and connected to the other first cable;
a second cathode terminal electrically connected to the second cathode plate and connected to one of the second cables;
a second anode terminal electrically connected to the second anode plate and connected to the other second cable;
The oil sensor unit according to claim 1 or 2, comprising: The first cathode plate is formed integrally with the second cathode plate at the tip of the second cathode plate,
One first cable is provided,
Two of the second cables are provided,
the oil sensor is electrically connected to the first anode plate and a first anode terminal connected to the first cable;
a cathode terminal electrically connected to the second cathode plate and the first cathode plate and connected to one of the second cables;
a second anode terminal electrically connected to the second anode plate and connected to the other second cable;
The oil sensor unit according to claim 1 or 2, comprising: The oil sensor has a second reference capacitor,
The first and second cables are electrically connected to the second reference capacitor and have the same configuration as the first and second cables so that the capacitance is equal to that of the first and second cables. a third cable routed along the same route as the first and second cables;
The second reference capacitor includes a third cathode plate, a third anode plate opposed to the third cathode plate with a third gap therebetween, and arranged to close the third gap. having a second solid dielectric with a known capacitance, said capacitance being less susceptible to said oil;
The capacitance measurement unit measures a first capacitance including the capacitance of the first cable and the capacitance of the first reference capacitor, and the capacitance of the first cable. A second capacitance including the same capacitance of the second cable and the capacitance of the oil detecting sensor unit, and a third cable capacitance equal to the capacitance of the first cable. and a third capacitance including the capacitance of the second reference capacitor, and
The computing unit obtains the capacitance of the first cable obtained by subtracting the capacitance of the first solid dielectric from the first capacitance, and the third capacitance. Acquire an average capacitance that is the average value of the capacitance of the third cable obtained by subtracting the capacitance of the second solid dielectric from the second static obtaining the capacitance of the oil detection sensor by subtracting the average capacitance from the capacitance;
2. The oil sensor unit according to claim 1, wherein the determination section determines presence or absence of the oil in the second gap based on the capacitance of the oil detection sensor section acquired by the calculation section. Two each of the first to third cables are provided,
The oil sensor includes a first cathode terminal connected to the first cathode plate and one of the first cables;
a first anode terminal electrically connected to the first anode plate and connected to the other first cable;
a second cathode terminal electrically connected to the second cathode plate and connected to one of the second cables;
a second anode terminal electrically connected to the second anode plate and connected to the other second cable;
a third cathode terminal electrically connected to the third cathode plate and connected to one of the third cables;
a third anode terminal electrically connected to the third anode plate and connected to the other third cable;
6. The oil sensor unit according to claim 5, comprising: The first cathode plate is formed integrally with the second cathode plate at the tip of the second cathode plate,
The third cathode plate is formed integrally with the first cathode plate at the tip of the first cathode plate,
Each of the first and third cables is provided one by one,
Two of the second cables are provided,
the oil sensor is electrically connected to the first anode plate and a first anode terminal connected to the first cable;
a cathode terminal electrically connected to the first to third cathode plates and connected to one of the second cables;
a second anode terminal electrically connected to the second anode plate and connected to the other second cable;
a third anode terminal electrically connected to the third anode plate and connected to the third cable;
6. The oil sensor unit according to claim 5, comprising: the oil sensor unit according to any one of claims 1 to 7;
the housing;
the compression section;
Compressor with

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