JPH01104983A - Airtight electric compressor - Google Patents

Abstract

PURPOSE: To prevent mechanical deterioration due to poor lubrication by forming a bowl in the lower portion of an impervious chamber, arranging a thief hole on an oil pump above the bowl and arranging a means for detecting the existence of a coolant. CONSTITUTION: An electrical compressor 1 comprises an impervious chamber 2 containing an electrical compressor system 3. The lower portion 10 of the chamber 2 constitutes a bowl designed for receiving lubricant. An oil pump 8 has a thief hole 9 above a bottom 7 of the bowl, disposed from the bottom 7 at a determined distance. The electrical compressor 1 has a means 15 for detecting the existence of a coolant liquid 12 in the bowl 10. A first and second electrodes 16, 17 are combined with a first and second inputs 40, 41 of an detect and control device 50 by a cross member 19. The detect and control device 50 comprises a detector 18, a power 28 and an alarm device 30. Thus it is possible to prevent mechanical deterioration due to poor lubrication.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hermetic electric compressor □ of the type used for example for refrigeration, air conditioning or in heat pumps. The present invention particularly relates to means for preventing deterioration in the shield machine due to poor lubrication.

prior art The airtight motorized compression condyle device has an impermeable case.

The impermeable case is an electric compressor, such as an electric compressor of the electric motor type, in which a crankshaft is used to drive the compression device, and the compression device consists of, for example, a connecting rod and a piston that move within a cylinder, and which open a compression chamber. Configure. The compression chamber alternately opens on the one hand into a suction circuit through which it draws the refrigerant fluid in the gas phase, and on the other hand into a supply circuit through which the compressor leaves the impermeable case and connects it to a gas-tight electric compressor. The refrigerant fluid circulates within the mating parts, in which the refrigerant fluid is in either a gas or liquid phase. The refrigerant fluid returns to the hermetic electric compressor in gaseous form.

It should be noted that gas entering a hermetic electric compressor generally spreads through the impermeable casing before being sucked into the suction tube when the compression chamber is under reduced pressure.

The lower portion of the impermeable case generally constitutes a basin containing lubricating oil. Oil is extracted, for example, by a spiral oil pump, which is usually fixed at the end of a crankshaft which is itself rotatably connected to the rotor of the motor. To this end, the rotor and the crankshaft are arranged along a vertical axis of rotation, the crankshaft being configured to receive the pump and to transmit oil to the parts to be lubricated.

Due to the presence of refrigerant liquid within the case, lubrication of moving parts poses an unresolved problem under certain environmental conditions.

Especially to! IJ slippage is likely to occur after an extended outage, during which time a portion of the refrigerant contained within the system may migrate to the electric compressor pan. This development generally occurs according to two main causes. That is, the oil contained in a pan absorbs refrigerant to varying degrees depending on temperature and pressure conditions (i.e., the oil and refrigerant are miscible), thus dissolving a variable amount of refrigerant and dissolving one type of refrigerant in the pan. Creates a reduced pressure state.

- When the compressor is cooler than the rest of the entire circuit, refrigerant is drawn towards the compressor.

Therefore, when the oil is saturated with refrigerant, the refrigerant will precipitate in liquid form at the bottom of the case or pan of the airtight electric compressor because its density is higher than that of the mixture of oil and refrigerant. When the level of the refrigerant liquid reaches the lower end of the oil pump, i.e. the level at which this pump takes its sample, the possibility of a "stuck" type accident is extremely high upon restart due to the low lubrication properties of the refrigerant liquid. Become.

To prevent this type of accident, auxiliary machinery is usually used. These include, for example, suction-operated liquid storage bottles, which trap the refrigerant liquid. Furthermore, a device for heating the dish portion may be used. This heating device operates before the compressor is restarted. The temperature increase causes the refrigerant liquid to evaporate, resulting in no removal and is often subject to limitations in practice.

In addition, routine heating of the pan for a predetermined period of time prior to restarting the hermetic electric compressor is particularly advantageous in that the heating time is long enough to receive large seedling refrigerant liquid within the pan. In many cases, even after taking into account the compressor's special environmental conditions, the level of extraction by the oil pump is still and refrigerant liquid.Therefore, when the compressor is restarted, this mixture still has lubricating power.

SUMMARY OF THE INVENTION The invention relates to a gas-tight electric compressor which is easy to apply and which comprises new measures making it possible to eliminate the above-mentioned drawbacks when emitting at least one signal.

Said signal may, for example, make it possible to prevent the start-up of the compressor, or make it possible for this compressor to restart in full safely, or even make it possible to start auxiliary machinery, for example for heating the pan. Make it familiar.

According to the present invention, a gas-tight electric compressor is disclosed comprising an impermeable chamber containing an electric rfO compressor device, the electric compressor device including an oil pump, and the lower part of the chamber forming a dish. , the oil pump has at least one sampling hole positioned above the bottom of the pan at a predetermined distance from the bottom, the chamber further containing lubricating oil and refrigerant liquid, and the airtight electric compressor is above the bottom of the pan. and means for detecting the presence of a refrigerant liquid in liquid form within the refrigerant.

The invention will now be better understood from the following description, which is given by way of non-limiting example and with reference to the accompanying drawings, in which: FIG.

Specific example Figure 1 shows the airtight electricity of the present invention! 1 is a schematic diagram of an lJ compressor 1. FIG. The electric compressor t51 consists of a gas-tight chamber or case 2 containing an electric compressor device 3, itself signpost-shaped, represented in FIG. 1 by a rectangular parallelepiped. The electric compressor arrangement 3 is known per se and has parts (not shown) mounted in a conventional manner. These parts drive the movement of the piston in the cylinder, for example via a crankshaft. This type of crank/shaft 4
extends beyond the lower end 5 of the motorized compression a device 3, a portion of which is shown. The lower part 10 of the chamber 2 constitutes a dish designed to contain lubricating oil.

The end 6 of the crankshaft 4 supported toward the bottom 7 of the dish 10 forms an oil pump 8 fixedly connected to the crankshaft 4 . The oil pump 8 is of standard type, for example a centrifugal pump, and has a sampling hole 9.

When the hermetic electric compressor 1 is in normal operating condition, this lubricating oil is present in the pan 10 at a distance from the bottom 7 of this pan 10 which is, in principle, greater than the distance between the sampling hole 9 of the oil pump 8 and the bottom 7. up to a height (not shown).

Thus, for example, assuming that the sampling hole 9 is contained within a sampling surface 11 (indicated by a dashed diagram), this sampling surface 11 is at a level N1 lower than the level reached by the lubricating oil. This oil can therefore be extracted by the oil pump 8.

However, as explained in the preface, the environmental conditions of the hermetic electric compressor 1 are such that the pan 10 is the refrigerant liquid 12 and the oil/refrigerant liquid mixture 1! l!
113 may be included. Since the oil/refrigerant liquid mixture has a lower density than the refrigerant liquid 12, the refrigerant liquid is deposited on the bottom 7 of the pan 10, and the oil/refrigerant liquid mixture 13 is located on top of the refrigerant liquid 12. This arrangement is shown in FIG. 1, and it is also this arrangement that shows that the refrigerant liquid 12 has a second level N2 that is higher than the second level N2 of the collected blood 11. The consequence of this is that if the oil pump 8 were to enter operation under these conditions, it would be the refrigerant liquid 12 that the pump would sample, and not the oil/refrigerant liquid mixture 13. For this reason, it becomes decisive that the electric pressure [13] gets stuck and stops.

According to one feature of the invention, the hermetic electric compressor t11 includes means for detecting the presence or absence of refrigerant liquid 12 in the pan 10, in order to prevent the hermetic electric compressor n1 from returning to operation under these circumstances. There is.

In a first variant of the invention, this detection is carried out at a level close to the level corresponding to the appearance of a definite danger, i.e. at a first level N
This is done at a third level N3, which is lower than 1 and close to it.

In the non-limiting example described here, the means 15 for detecting the presence of a refrigerant liquid comprises a pair of electrodes 16 .
7 and secondly a detection and control ll located outside the chamber 2.
device 50. First and second electrodes 16.17
are coupled to the first and second power sources 40, 41 of the detection and control device 50 using insulating and impermeable cross members 19, respectively.

In the first specific example, the detection of the presence of the refrigerant liquid 12
and the difference in electrical resistivity between the oil/refrigerant liquid mixture 13.

Most refrigerant fluids or coolants are hydrocarbon chlorofluoride derivatives. Coolants of this type are for example DLIPON
They are well known as R12, R22, R502 marketed by TDE NEMOUR8.

For example, refrigerant R22 is approximately 101
It has a resistivity that is 2 times lower. The electrical resistivity of commonly used lubricating oils is approximately 1014 Ω-α. The electrical resistivity occurring between the ends 21 of the electrodes 16.17 that are bent towards each other therefore varies considerably depending on whether these electrode ends 20.21 are immersed in the oil/refrigerant liquid 13 or in the refrigerant liquid 12. do.

As a non-limiting example, mutually facing electrode ends 20.21 each have an area of 1 cA (not shown) and
(not shown), the resistance is considered to have a distance of M
When E is filled with centering fluid mixture 13 on the third level N3, it increases by a much larger ratio than a. Hence the detection and control device! 50 is, for example, a detector 18, a power supply 28
and an alarm device 31 can be designed in a particularly Qillill way.

In the described non-limiting example, the detector 18 includes an electromagnetic relay 23 with a coil 24, the first end 25 of which is connected to the second human power 41.
The second end 26 is connected to the second electrode 17 using the power source 2.
It is connected to the terminal 27 of 8. A second end 29 of the power source 28 is connected to the first electrode 16 via a first power source 40 . In the non-limiting example shown, the electromagnetic relay 23 has contacts 30 that are open unless the proper current flows through the coil 24.

In order to move the contact 30, the electromagnetic relay 23 is activated under a voltage of 24 volts provided by the power supply 28, for example 0,00
Assume that a current of 5 amps is required. When the oil/refrigerant liquid mixture 13 replaces the refrigerant 12, i.e. in a near-regular state, when it is occupied within the coil 24, the electrical resistance exhibited by '##4#E decreases and thus It is approximately 100 ohms, causing a voltage drop of approximately 0.5 volts, and contacts 30 are actuated. Contact point 30
can be connected, for example, to an alarm device 31, by means of which the refrigerant liquid 12 is detected at a level close to the sampling surface 11.
indicates the existence of

The alarm device 31 can actuate, in a known manner, a control device for reheating the containment chamber 10, for example an alarm bell or a gas-tight electric pressure $Iiii□1 restart inhibit device.

Of course, in the spirit of the invention, the detector 18 can perform other functions, and also in a standard manner per se, if for example the mutually facing electrode ends 20,21 have a much smaller area than that mentioned above. or even if the liquid refrigerant has a higher electrical resistivity than the cold WR22, for example one or more current amplifiers can be used. ' Fig. 2 shows a second modification of the hermetic electric compressor 1 of the present invention, which is of a different type from the first in that the presence of the refrigerant liquid 12 is detected near the bottom 7 of 1 m 1 o. It is a schematic diagram.

In the described non-limiting example, electrodes 16.17 are shown on the inner side 44 of the dish 10, and the detection and control Il device 5
0 in the same way as in the example above.

However, in this second type the electrodes 16,17 are closer to the bottom 7 of the dish than the claw holes 9 in the bottom 7 of the dish.

With such an electrode arrangement [16, 17, this refrigerant liquid 1
It becomes possible to detect the presence of refrigerant liquid 12 in dish 10 when the amount of refrigerant liquid 12 is still small, ie shortly after the ffI oil begins to be saturated with refrigerant.

The refrigerant liquid remains at the bottom 7 of the pan 10, thus supporting the oil/refrigerant liquid mixture 13 collected in large groups below the sampling surface 11, and the holes 9 of the oil pump 8 are pumped into the oil/refrigerant liquid mixture 13. .

Under these conditions, the heating of the pan 10 can be controlled, for example while allowing the restart of the hermetic electric compressor 1, thus avoiding wasting time and furthermore allowing the heating of the pan as well as the refrigerant mixed with lubricating oil. The refrigerant liquid 12 contained in the bottom 7 can be evaporated.

Of course, the arrangement of this second modification and the first modification shown in FIG.
A variant arrangement also allows for more complete safety at the same time.

FIG. 3 is a partial schematic diagram of the hermetic electric compressor 1 according to the invention, in which the pan 10 is shown in order to explain an embodiment that makes it possible to particularly economize on electrodes.

In the non-limiting example of the present invention, the first electrode 16 is mounted on the interior side surface 44 of the dish 10 as in the previous example, except that in this new embodiment the first electrode 16 is bent back to The extreme end 20 faces towards the side 44 of the ff110.

In this case, the inner wall 45 of the dish 1G is formed with a second electrode on either the third level N3 or the fourth level N4, which is close to the sampling surface 11 and the bottom 7 of m10, respectively.

The operation can be the same as in FIG. 1, with the first end 1
6 and the dish 10 are respectively connected to the first and second human power 40.41 of the detection and control device 50.

FIG. 4 is a schematic diagram of a dish 10 similar to that of FIG.
2 shows an example of forming the plates of a capacitor in contact with the liquid to be identified within the capacitor.

In the described non-limiting example, the first electrode and the second electrode 16.
17 is mounted on the side 44 of the dish 10 in the same way as in the previous example, and also detects and controls! ! Also coupled to device 50. The first and second electrodes 16,17 each include an insulated electrode body 52. These insulated electrode bodies 52.5
? Each has a metal plate 54,55 at its tip. The metal plates 54.55 are substantially planar and the dielectric is formed via the ME contained between the two plates 54.55. The dielectric consists of either an oil/refrigerant liquid mixture 13 (not shown) or a refrigerant liquid 12, depending on the level of refrigerant liquid as previously explained.

In the non-limiting example described, the plate 54.55 is attached to the bottom 7
and are arranged on both sides of the third level N3 close to the collection surface 11. However, in accordance with the spirit of the invention, the electrodes 54,55 have a different orientation, and the bottom 7
It will be appreciated that it is also quite possible to be placed at a different level, for example closer to the fourth level N4.

In order to further save electrodes, as explained in connection with FIG.
It should be noted that the second capacitor plate may be formed by the plate 10 itself.

Taking cold W R22 as an example, its relative dielectric constant ε1 or dielectric constant in the liquid state is the relative dielectric constant E of the lubricating oil when the oil/refrigerant liquid mixture 13 containing almost no refrigerant and the refrigerant liquid 1
2 corresponds to the change in the total capacitance of capacitor C when it is filled one after another with 2. This type of capacitance change is much larger than that which can be easily detected by standard means.

In the non-limiting example described, the detection and control device 50 is itself an oscillator 6 with a standard oscillator circuit (not shown).
0, and a capacitor C is inserted here. The oscillator 60 is coupled to a pulse generator 61 and supplies this pulse generator with, for example, a sine signal S1 of a frequency F related to the value of the capacitor C, from which the pulse generator 61 reciprocally receives the same signal S1 in succession at a frequency F. A second signal S2 consisting of a width pulse (not shown) is sent out. Signal S2 is integrated circuit 6
3, the circuit itself delivers a third @bow S3 corresponding to a voltage (not shown), the amplitude of which varies with frequency F. The third signal S3 is e.g.
4, the comparator is also in standard form, and the dielectric of capacitor C is either oil/refrigerant liquid mixture 13 or refrigerant liquid 1.
The fourth signal S4 or the fifth signal S5 is sent out depending on which of the two signals S4 and S5 is composed of. This fourth and fifth signal S
4, S5 is added to the above alarm device 31. This latter embodiment of the detection and control device 50 is given as a non-limiting example; it is possible for a person skilled in the art to detect changes in the capacitance of the capacitor C by various methods known per se. It is.

[Brief explanation of the drawing]

Is Figure 1 airtight according to the present invention? Schematic diagram of ailJ compressor, 2nd
The figure is a schematic diagram of an airtight electric compressor as a second modification of the present invention, and FIG. 3 is a schematic diagram of the dish portion shown in FIG. 1 and a specific example of the electrodes shown in FIGS. 1 and 2. Schematic diagram representing m
FIG. 4 is a schematic diagram showing the outline of the pan shown in FIG. 1 and a specific example based on a change in capacity used to detect the presence or absence of a refrigerant liquid. 1...Airtight electric compressor, 2...Impermeable chamber, 3...Electric compressor@place, 7...
...Bottom of Tsukuda, 8...Oil pump, 9
......Sampling hole, 10...Casing,
50...Detection and control device. Agent Patent Attorney Takeshi Funayama 2 sides 1 dispute (oldness, 2 sentences 7: ”-L) FIGj procedural amendment writing method) % formula % 1. Indication of case 1988 Patent Application No. 182772
No. 2, Title of the invention Airtight electric compressor 3. Relationship to the amended person's case Name of patent applicant Name Ruunite Ermedik Nis.A.
1) Add appropriate drawings clearly drawn in black as shown in the attached sheet. (No change in content)

Claims (9)

[Claims] (1) An airtight electric compressor comprising an impermeable chamber containing an electric compressor device, the electric compressor device including an oil pump, a lower portion of the chamber forming a pan, and an oil pump in the pan. at least one sampling hole positioned above and at a predetermined distance from the bottom; said chamber further contains lubricating oil and refrigerant liquid; further comprising means for detecting the presence of a refrigerant liquid, said means being coupled to a detection and control device located within the pan and sensing the presence of a refrigerant liquid within a space formed between the two electrodes. a gas-tight electric compressor, the space being formed at a level between the sampling hole and the bottom of the dish, the level at which the space is located being closer to the bottom than the sampling hole. (2) The hermetic electric compressor according to claim 1, wherein the level at which the space is located is close to the bottom of the pan. (3) A hermetic electric compressor according to claim 1, wherein the detection and control device has a detector coupled to the electrode pair, the detector sensing the electrical sensitivity exhibited by the space. (4) The hermetic electric compressor according to claim 3, wherein the detector has an electromagnetic relay device connected in series with the electrode pair and the power source. (5) The hermetic electric compressor according to claim 1, wherein the electrode pair includes a first electrode mounted within a dish, and further wherein the second electrode is formed by an inner wall of the dish. (6) electrode pairs constitute two plates of a capacitor on both sides of said space, and further a detection and control device is sensitive to changes in the capacitance of the capacitor;
An airtight electric compressor according to claim 1. 7. The hermetic electric compressor of claim 6, wherein the sensing and control device includes an oscillator coupled to a capacitor, the oscillator delivering a signal with a frequency that varies with the capacitance of the capacitor. (8) The hermetic electric compressor according to claim 6, wherein the change in capacitance of the capacitor is caused by a change in the relative permittivity of its dielectric. (9) The hermetic electric compressor according to claim 1, wherein the detection and control device has an alarm device.