JP3034661B2 - Hermetic electric compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic electric compressor, which is mainly used for air conditioning or refrigeration, and is particularly suitable for improving the performance of a refrigeration cycle and ensuring the reliability of the compressor. It relates to a compressor.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. FIG. 4 is a longitudinal sectional view of a conventional hermetic scroll compressor, FIG. 5 is a system diagram of a refrigeration cycle having a conventional oil separator, and FIG. 6 shows an example of a discharge pipe of the conventional hermetic scroll compressor. It is principal part sectional drawing. FIG.
In the scroll compressor shown in FIG. 1, a compression mechanism 7 is accommodated in an upper portion of a closed container 9 and an electric motor 8 is accommodated in a lower portion. A lubricating oil 10 for lubricating a sliding portion of the compression mechanism 7 is sealed in the closed container 9 and stored in a closed container bottom 9a.

The compression mechanism 7 has a fixed scroll 7a, a revolving scroll 7b, a frame 14, a crankshaft 11, and an Oldham ring 7c as main components. Electric motor 8
Is composed of a stator 8a and a rotor 8b. The stator 8a is fixed in the closed container 9 by shrink fitting or the like, and the rotor 8b is fixed to the crankshaft 11 by press fitting or the like. The outer periphery of the frame 14 is fixed to the closed casing 9 and has a bearing for receiving the rotation of the crankshaft 11. The fixed scroll 7a is fastened to the frame 14.

The fixed scroll 7a and the revolving scroll 7b each have a spiral wrap standing upright on a base plate, and the wraps are engaged with each other inward to form a compression chamber. . An eccentric portion of the crankshaft 11 is rotatably fitted into the boss portion of the revolving scroll 7b, and rotation is prevented by the Oldham ring 7c to perform revolving action. The fixed scroll is activated by the revolution of the revolving scroll 7b.
Refrigerant gas sucked from a suction port (not shown) of the nozzle 7a is gradually compressed in the compression chamber.

[0005] The lubricating oil 10 is supplied to the bearing portion 12a and the crank portion 1 by the rotation of the crank shaft 11 directly connected to the rotor 8b.
After the oil is supplied to 2b and the like, the oil is discharged from the discharge port 13 and returns to the closed container bottom 9a again, but a part thereof becomes spray oil due to the stirring of the rotor 8b of the electric motor unit. The refrigerant gas enters the compression mechanism 7 from the suction pipe 4b, is compressed and discharged from the discharge port 13 into the closed container 9, and is sent out from the discharge pipe 4a to the refrigeration cycle together with the sprayed lubricating oil.

The conventional refrigeration cycle shown in FIG. 5 includes a compressor 1, heat exchangers 2a and 2b, an expansion mechanism 3, and a piping system 4 connecting these, and circulates refrigerant. Oil separation
The compressor 5 separates the spray lubricating oil discharged together with the refrigerant from the discharge pipe 4a of the compressor 1 and includes a bypass pipe 6 that quickly returns only the lubricating oil component to the compressor side (inside). I have. This eliminates the shortage of lubricating oil inside the compressor and improves the reliability of the compressor, prevents the circulation of lubricating oil to the heat exchanger, and allows the lubricating oil to adhere to the inner wall of the heat exchanger pipe and transfer heat. The efficiency of the refrigeration cycle is prevented from lowering, thereby reducing the efficiency.

[0007]

In the above prior art, an oil separator circuit for returning the lubricating oil sent from the compressor discharge pipe to the refrigerating cycle to the compressor promptly is provided outside the compressor. There has been a problem that the cycle configuration is complicated and large and the cost is high. Therefore, without providing this oil separator circuit, the discharge pipe 4A protrudes near the center of the container as shown in FIG.
In some cases, countermeasures such as reducing the amount of lubricating oil by increasing the refrigerant component to be sent out of the compressor, such as centrifugal separation of a lubricating oil component having a high density due to the swirling flow, may be taken.

In this case, since the lubricating oil separated by centrifugation is re-sprayed by the electric motor rotor, the gas-liquid separation capacity between the lubricating oil and the refrigerant is not sufficient, and the lubricating oil inside the compressor is insufficient, and the compression oil is compressed. There was a problem that the reliability of the machine was reduced. In addition, the lubricating oil may circulate to the heat exchanger, causing the lubricating oil to adhere to the inner wall of the heat exchanger pipe, lowering the heat transfer coefficient, and lowering the efficiency of the refrigeration cycle. Further, there is a problem that a space for disposing the discharge pipe up to the upper portion of the rotor is required, which leads to an increase in the size of the compressor.

Further, as another example of the gas-liquid separation inside the compressor, a technique described in, for example, JP-A-58-160587 is known. In this technology, a gas-liquid separation blade is provided above a rotor of an electric motor unit, and a partition plate is provided at an upper portion of the electric motor unit to almost completely separate the electric motor and the compression mechanism unit, and a discharge pipe communicates with a space above the partition plate. It is a thing. Here, the partition plate has an outer periphery in contact with the inner wall of the sealed container and an inner periphery in contact with the bearing boss. In this conventional technique, there is a problem that the internal configuration of the compressor becomes complicated and the cost increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and is intended to reduce the amount of lubricating oil sent from a compressor discharge pipe to a refrigeration cycle in a compact, low-cost, and reliable manner. It is an object of the present invention to provide a hermetic electric compressor capable of increasing the efficiency of a heat exchanger of a refrigeration cycle and securing the amount of oil in the compressor to increase the reliability of the compressor.

[0011]

In order to achieve the above object, a closed electric compressor according to the present invention comprises a motor and a compression mechanism connected to the motor by a crankshaft in a closed container. in sealed electric compressor accommodating a compressor
Between the structure and the coil end of the motor,
Has electrical insulation properties formed in a cylindrical part concentric with the axis
A shield ring is provided, and the suction port of the discharge pipe is
It is arranged inside the gang .

[0012]

The function of the above technical means is as follows. That is, by the above-described configuration, the inside of the shielding ring is in a state where the spray oil mist is hard to enter from the outside,
Since the suction port of the discharge pipe is located inside the shielding ring, the lubricating oil component sent out from the discharge pipe to the refrigeration cycle is reliably separated and quickly returned to the inside of the compressor to improve the reliability of the compressor. In addition, the oil separator circuit on the refrigeration cycle side can be eliminated, and the simplification, downsizing, and low cost of the in-machine configuration can be realized.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. [Embodiment 1] FIG. 1 is a sectional view of a main part of a hermetic scroll compressor according to an embodiment of the present invention. In the figure, components having the same reference numerals as those in FIG. In the embodiment shown in FIG. 1, a shielding ring 15 made of sheet metal is disposed between a frame 14 which is a part of the compression mechanism 7 and a stator coil end 8c which is a part of the electric motor, so that the discharge pipe 4a is formed. The suction port is provided inside the shielding ring 15. More specifically, the shielding ring 15 is formed by curling the tip of the ring into a flared shape, and forming a main portion in a cylindrical portion concentric with the axis in the axial direction of the compressor. In this configuration, the flare-shaped curled portion secures an insulation distance from the stator coil end 8c.

According to the present embodiment, the lubricating oil discharged together with the discharge gas from the discharge port 13 becomes spray oil, and the notch groove provided on the outer periphery of the frame 14 and the fixed scroll constituting the compression mechanism 7. When falling into the electric motor room through the block 16, the shield ring 15 is obstructed by the shield ring 15, so that the spray oil does not easily enter the shield ring 15 from the outside and the density of the spray oil can be kept low. . here,
Since the suction port of the discharge pipe 4a is located inside the shielding ring 15, the lubricating oil sent from the discharge pipe 4a to the refrigeration cycle is greatly reduced, and the lubricating oil is quickly returned to the inside of the compressor. Nature can be secured. Further, the structure of the gas-liquid separation means in the compressor is simple, and the oil separator circuit on the refrigeration cycle side is eliminated, so that simplification, downsizing and low cost can be realized.

[Embodiment 2] FIG. 2 is a sectional view of a main part of a hermetic scroll compressor according to another embodiment of the present invention.
In the figure, the same reference numerals as those in FIG. 4 denote the same parts, and a description thereof will be omitted. In the embodiment of FIG. 2, a shielding ring 17 having electrical insulation properties is disposed between a frame 14 which is a part of the compression mechanism 7 and a stator coil end 8c which is a part of the electric motor. The suction port 4a is disposed inside the shielding ring 17. More specifically, the shielding ring 17 is made of a material having an electrical insulating property, the tip of the ring is curled in a flared shape, and the main part is formed in a cylindrical part concentric with the axis in the axial direction of the compressor. The cylindrical portion is attached to the outer peripheral portion of the frame 14 so that the flare-shaped curled portion is close to the stator coil end 8c.

According to the embodiment shown in FIG. 2, since the shield ring 17 is made of a material having an electrical insulating property, the gap between the shield ring 17 and the motor coil end 8c can be made sufficiently small. The effect of the shielding ring can be further enhanced. Therefore, the lubricating oil discharged together with the discharge gas from the discharge port 13 becomes spray-like oil, and passes through the notch 16 provided on the outer periphery of the compression mechanism 7,
When falling into the motor room, the inside of the shielding ring 17 becomes more difficult for the spray oil to enter from the outside than in the first embodiment, and the density of the spray oil can be kept low. In addition, it is possible to more reliably prevent the lubricating oil from being sent to the refrigeration cycle and to secure the lubricating oil to be supplied to the compression mechanism.

[Embodiment 3] FIG. 3 is a sectional view of a main part of a hermetic scroll compressor according to still another embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 4 denote the same parts, and a description thereof will be omitted. In the embodiment of FIG. 3, a main part is provided between a frame 14 which is a part of the compression mechanism 7 and a rotor end ring 19 which is a part of the electric motor, and a main part is a cylindrical part concentric with the axis in the axial direction of the compressor. Shield ring 1 formed on
8 and the shield ring bottom surface 18a is attached close to the rotor end ring 19, and the frame 14 and the shield ring 1
8 and a ring bottom surface 18a, a small space 20 is formed, and a suction port of the discharge pipe 4a is disposed inside the small space 20.

According to the embodiment shown in FIG. 3, the lubricating oil discharged together with the discharge gas from the discharge port 13 becomes a spray-like oil, and passes through the notch 16 provided on the outer periphery of the compression mechanism 7.
After dropping into the motor chamber, the suction ring 18 is sucked into the discharge pipe because the gap between the rotor end ring 19 rotating at high speed and the shield ring bottom 18a is narrow.
The small space 20 pertaining to the inside is in a state where the spray oil hardly enters from the outside, and the density of the spray oil can be kept low. Since the suction port of the discharge pipe 4a is disposed inside the shielding ring 18, that is, in the small space 20, the lubricating oil sent from the discharge pipe 4a to the refrigeration cycle is greatly reduced, and the lubricating oil is quickly introduced into the compressor. The compressor can be returned to ensure the reliability of the compressor. Further, the structure of the gas-liquid separation means in the compressor is simple, and the oil separator circuit on the refrigeration cycle side is eliminated, so that simplification, downsizing and low cost can be realized.

In each of the above embodiments, an example of a hermetic scroll compressor has been described. However, the present invention is not limited to a scroll compressor, but may be another hermetic electric compressor, for example, a hermetic rotary compressor. It goes without saying that it also applies to.

[0020]

As described above in detail, according to the present invention, the amount of lubricating oil sent from the compressor discharge pipe to the refrigeration cycle is reduced at a low cost, and the heat of the refrigeration cycle is reduced. While increasing the efficiency of the exchanger,
It is possible to provide a hermetic electric compressor that can increase the reliability of the compressor by securing the amount of oil in the compressor.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a hermetic scroll compressor according to one embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a hermetic scroll compressor according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view of a main part of a hermetic scroll compressor according to still another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a conventional hermetic scroll compressor.

FIG. 5 is a system diagram of a refrigeration cycle having a conventional oil separator.

FIG. 6 is a sectional view of a main part showing an example of a discharge pipe of a conventional hermetic scroll compressor.

[Explanation of symbols]

 Reference numeral 4a Discharge pipe 7 Compression mechanism 9 Sealed container 11 Crankshaft 14 Frame 8c Stator coil end 15 Shielding ring 17 Shielding ring 18 Shielding ring 19 Rotor end ring

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor: Shigeru Kawanami 800, Tomita, Odaimachi, Ohiramachi, Shimotsuga-gun, Tochigi Prefecture Inside the Tochigi Plant of Hitachi, Ltd. (72) Inventor Tatsuya Wakana 709-2, Tomita, Ohira-machi, Ohira-machi, Shimotsuga-gun, Tochigi Prefecture Inside Hitachi Tochigi Electronics Co., Ltd. (56) References JP-A-57-212389 (JP, A) 58-160587 (JP, A) JP-B 53-8041 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F04C 23/00-29/10 331 F04C 18/02 311

Claims (1)

(57) [Claims] 1. A hermetic electric compressor in which an electric motor and a compression mechanism connected to the electric motor by a crankshaft are accommodated in a closed container, wherein a compressor shaft is provided between the compression mechanism and a coil end of the electric motor. A hermetic electric compressor in which a shield ring having electrical insulation properties is formed in a cylindrical portion concentric with the axis in the center direction, and a suction port of a discharge pipe is disposed inside the shield ring.