JPH0118860Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a hermetic compressor, in particular, a partition wall is provided in the casing to form a motor chamber and a crank chamber, and the motor is placed in the motor chamber, and the motor shaft is placed in the crank chamber. The present invention relates to a hermetic compressor in which a compression element having a crankshaft connected to the motor chamber is installed, and a passage opening into the crank chamber is opened into the motor chamber via a pressurizing mechanism.

Conventionally, this type of compressor has been used, for example, in the
87406, and as shown in Fig. 3, a passage b opening into the crank chamber a is opened into the motor chamber e via a centrifugal pipe d hanging vertically near the boss portion of the motor shaft c. , as shown in FIG. 4, an oil guide hole g is provided in the partition wall f extending from an oil supply point for supplying oil to the bearing portion of the motor shaft c, and the oil guide hole g
is connected to the ejector i that opens to the crank chamber a through an oil pipe h, and an oil return hole k is bored in the casing j on the motor chamber e side,
It has been proposed that the oil return hole k is configured to communicate with the side portion of the ejector i via an oil pipe l.

With such a configuration, the pressure in the motor chamber e is kept higher than the pressure in the crank chamber a, and together with the action of the ejector i, the lubricating oil accumulated at the bottom of the motor chamber e is removed from the crank chamber. It had been returned to Room A.

However, there was not enough space in the crank chamber a, and it was difficult to provide a sufficient length for the injection nozzle of the ejector i, and there were also restrictions on the mounting position of the ejector i. It is. If the length of the ejector nozzle of the ejector i was not sufficient, there was a problem in that almost no ejector effect could be obtained even though the ejector i was installed.

The present invention was devised in view of the above-mentioned circumstances, and its purpose is to inject the injection nozzle of the ejector located above the oil level in the crank chamber.
By opening below the oil level in the crank chamber, a sufficient ejector effect can be obtained even if the length of the injection nozzle is shortened, reducing restrictions on the mounting position of the ejector, and even when the compressor is stopped. The object of the present invention is to provide a hermetic compressor that prevents lubricating oil from flowing into the motor chamber from the crank chamber even during operation.

Therefore, the configuration of the present invention is such that a return passage for lubricating oil is provided in the bottom wall of the crank chamber, one end of which opens at the bottom of the motor chamber, and an injection nozzle is provided for injecting the oil pressure-fed from the oil supply pump. An ejector is provided above the oil level of the crank chamber, the other end of the return passage is connected to the suction port of the ejector, and an injection nozzle of the ejector is connected to the oil level of the crank chamber. The ejector is opened downward so that a sufficient ejector effect can be exerted even if the length of the ejector nozzle is short.

Embodiments of the present invention will be described below based on the drawings.

In the figure, 1 is a casing, and the casing 1
A partition wall 2 is provided inside the casing 1, and a motor chamber 3 and a crank chamber 4 are formed in the casing 1. A motor 31 is housed in the motor chamber 3, and a compression element 41 is housed in the crank chamber 4.

The motor 31 includes a stator 32 and a rotor 33.
The rotation of the motor 31 is caused by the motor shaft 34.
and is transmitted to pistons 43 and 44 via a crankshaft 42 connected to the motor shaft 34. Also,
The compression element 41 includes the crankshaft 42 and pistons 43 and 44, and a cylinder 4.
5, 46 and head covers 47, 48 of the cylinders 45, 46, the refrigerant gas sucked into the cylinders 45, 46 is transferred to the head covers 47, 46.
48 and a discharge pipe (not shown) to the outside of the machine. Further, the crankshaft 42 and the motor shaft 34 are provided with a passage 51 that opens into the crank chamber 4 at one end and opens into the motor chamber 3 at the other end. A pressurizing mechanism consisting of a centrifugal pipe 52 is interposed in the opening on the third side, and the passage 51 opens to the motor chamber 3 side via the pressurizing mechanism.

Therefore, in this embodiment, a lubricating oil return passage 12 having a horizontal part 12a and a vertical part 12b is provided in the bottom wall 11 of the casing 1 in the crank chamber 4, and one end thereof is connected to the motor chamber 3.
The oil return hole 13 is opened at the bottom of the side casing 1, while the other end is opened at the side of the ejector 6, which opens below the surface of the lubricating oil o stored at the bottom of the crank chamber 4. be.

The ejector 6 includes an ejector main body 61 bored in the casing 1 and an injection nozzle 62 connected and fixed to the front of the ejector main body 61. The ejector main body 61 includes a receiving port 63 for receiving oil pressure-fed from the lubricating oil supply pump 7 through the oil passage 81, and the return passage 1.
It is provided with a suction port 64 that sucks the two lubricating oils, and a discharge port 65 that merges and discharges the respective oils. Further, the injection nozzle 62 is curved downward so as to open below the surface of the lubricating oil o.

Further, in FIG. 1, a centrifugal oil supply pump 7 is installed inside the end of the casing 1 on the left side of the crankshaft 42, and the pump 7 allows
Lubricating oil is supplied to each bearing portion through an oil passage 8 bored through the crankshaft 42 and motor shaft 34. Further, while the ejector 6 is located near the pump 7, an oil passage 81 is provided in the vicinity of the end of the casing 1, as described above, in addition to the oil passage 8 that supplies lubricating oil to each of the bearings. The oil passage 81 is provided in parallel with the oil passage 81 to supply lubricating oil from the pump 7 to the receiving port 63 of the ejector 6.

In the embodiment configured as described above, due to the action of the pressurizing mechanism 52, when the motor 31 is operated, the pressure in the motor chamber 3 becomes higher than the pressure in the crank chamber 4. The lubricating oil that flows into the bottom of the casing 1 on the motor chamber 3 side together with the inflow of refrigerant gas and is stored therein flows into the ejector 6 from the oil return hole 13 via the return passage 12. Coupled with the ejector effect of the oil pumped from the pump 7 to the ejector 6, the motor chamber 3
The lubricating oil stored at the bottom of the side casing 1 can be strongly returned to the crank chamber 4 side. Moreover, since the injection nozzle 62 is opened below the surface of the lubricating oil o, the ejector effect in the ejector main body 61 can be sufficiently exerted even if the length of the injection nozzle 62 is shortened. That is, in general, if the length of the injection nozzle is short, the ejector effect cannot be obtained because air, etc. is drawn in quickly at the opening of the ejector 6, and the pressure inside the ejector 6 cannot be lowered. ing. However, when the injection nozzle 62 is opened into the lubricating oil o as in this embodiment, even if the length of the injection nozzle 62 is shortened by preventing air from being entrained, the ejector effect cannot be sufficiently exerted. Therefore, there are fewer restrictions on the mounting position of the ejector 6. Moreover, since the lubricating oil o is directly cooled by the vaporized refrigerant discharged from the ejector 6, the problem of oil temperature rise can be solved and deterioration of the oil can be prevented. Furthermore, the return passage 12
is installed inside the bottom wall 11 of the casing 1, and is provided with an oil pipe configured separately from the casing 1 to guide oil from the oil return hole 13 to the ejector 6. There is no need, and
Oil is supplied from the pump 7 to the rear of the ejector 6 through an oil passage 81 bored near the end of the casing 1, and is also provided separately from the casing 1. There is no need to install oil piping, and the structure is simplified.
Therefore, manufacturing becomes easier and costs can be reduced.

Furthermore, the lubricating oil flowing through the return passage 12 is heated by exchanging heat with the high-temperature lubricating oil o stored at the bottom of the casing 1 on the side of the crank chamber 4 while flowing through the return passage 12. This makes it easy to separate the refrigerant mixed into the lubricating oil.
Since the refrigerant in the lubricating oil is injected from the ejector 6 and depressurized in this easy-to-separate state, the refrigerant in the lubricating oil is vaporized at the same time as it is injected from the ejector 6, and the lubricant is stored in the crank chamber 4. The lubricating oil is returned without being dissolved in the oil o, and the lubricating oil is returned to the lubricating oil o stored on the crank chamber 4 side in a state containing almost no refrigerant.

On the other hand, the lubricating oil o stored in the casing 1 on the side of the crank chamber 4 is efficiently cooled by the low-temperature lubricating oil flowing through the return passage 12, and is also affected by the heat of vaporization of the refrigerant when it is discharged from the ejector 6. Since the lubricating oil is cooled even when the lubricating oil is wet, the temperature of the lubricating oil O can be prevented from rising as described above, and deterioration of the lubricating oil can be prevented.

Moreover, since the ejector 6 is located near the pump 7, the oil passage 81 can be shortened, thereby reducing the pressure loss due to the passage of the oil passage 81, thereby increasing the ejector effect of the ejector 6. Therefore, the lubricating oil on the motor chamber 3 side can be more strongly returned to the crank chamber 4 side.

In the embodiment described above, the return passage 12 is connected to the bottom wall 1 of the casing 1 on the side of the crank chamber 4.
1, but the structure is not limited to this, and oil piping may be provided separately.

As is clear from the above description, in the hermetic compressor of the present invention, a lubricating oil return passage is provided in the bottom wall of the crank chamber, one end of which opens at the bottom of the motor chamber, and the lubricating oil is fed under pressure from the oil supply pump. An ejector equipped with an injection nozzle for injecting oil is provided, this ejector is installed above the oil level of the crank chamber, the other end of the return passage is connected to the suction port of the ejector, and Since the injection nozzle is opened below the oil level in the crank chamber, in addition to the differential pressure between the motor chamber and the crank chamber, the lubricating oil in the motor chamber is drained by the action of the ejector installed above the oil level in the crank chamber. Since the lubricating oil can be returned to the oil in the crank chamber and the differential pressure is used, the lubricating oil can be easily injected by the ejector, and can be injected even if the length of the injection nozzle is shortened. Moreover, since there is no entrainment of air in the injection nozzle, the ejector effect of the injection nozzle can be fully exerted, and restrictions on the mounting position of the ejector can be reduced. Furthermore, since the ejector with the injection nozzle opening below the oil level in the crank chamber is installed above the oil level in the crank chamber, the compressor stops and the pressure difference between the motor chamber and the crank chamber disappears. Even if the oil level in the crank chamber is higher than the bottom of the motor chamber, the lubricating oil in the crank chamber does not flow back into the motor chamber, and since oil is injected into the oil in the crank chamber during operation, there is no ejector in the crank chamber. Therefore, less mist-like oil is generated, and the pressurizing mechanism prevents mist-like oil from flowing into the motor chamber through the passage. Therefore, there is no excess oil in the motor chamber, the motor can be protected, and there is no shortage of oil in the crank chamber.

Furthermore, by directly mixing the lubricating oil that accumulates at the bottom of the motor chamber, which is returned together with the refrigerant from the evaporator in the air conditioner and accumulates at the bottom of the motor chamber, which is lower in temperature than the lubricating oil that accumulates in the crank chamber, with the lubricating oil in the crank chamber. It is expected that the lubrication performance will improve due to the decrease in oil temperature.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view showing an embodiment of the present invention;
3 is an enlarged sectional view of the main part, FIG. 3 is a vertical sectional view of the main part showing a conventional example, and FIG. 4 is an enlarged sectional view taken along the line A--A in FIG. 3. 1... Casing, 2... Partition wall, 3... Motor room, 4... Crank room, 6... Ejector,
12... Return passage, 31... Motor, 34... Motor shaft, 41... Compression element, 42... Crankshaft, 51... Passage, 52... Pressure mechanism.

Claims (1)

[Scope of utility model registration request] A partition wall is provided in the casing to form a motor chamber and a crank chamber, and a motor is placed in the motor chamber.
Further, the crank chamber is equipped with a compression element having an oil supply pump and a crankshaft connected to the motor shaft, and a closed compression type in which a passage opening into the crank chamber is opened into the motor chamber via a pressurizing mechanism. In the engine, a return passage for lubricating oil is provided in the bottom wall of the crank chamber, one end of which opens at the bottom of the motor chamber, and an ejector is provided with an injection nozzle for injecting oil pressure-fed from the oil supply pump. , the ejector is provided above the oil level of the crank chamber, the other end of the return passage is connected to the suction port of the ejector, and an injection nozzle of the ejector is opened below the oil level of the crank chamber. This hermetic compressor is characterized by: