JPH0718425B2 - Scroll compressor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vertical hermetic scroll compressor, and in particular, it is suitable for a scroll compressor that supplies oil to each bearing and a sliding portion through an oil supply hole provided in a rotary shaft. It is about structure.

An oil supply structure of a conventional hermetic scroll compressor will be described with reference to FIGS. 1 to 3.

In the closed container 1, a compressor section is arranged in an upper part and an electric motor section 2 is arranged in a lower part. The compressor section has a fixed scroll 3 having a spiral disc-shaped groove on a thick disk, a bearing boss, It is composed of an orbiting scroll 4 in which a spiral-shaped projection is provided on an integrated flat plate, and the electric motor unit 2 is composed of a stator having a stator winding and a rotor which is a rotor.
Is transmitted to the orbiting scroll 4 via the eccentric portion 6a. The orbiting scroll 7 is prevented from rotating by the orbiting mechanism 7 composed of an Oldham ring and an Oldham key. Therefore, the orbiting scroll 4 makes an orbiting motion with the rotation of the shaft 6, and the gas flowing through the suction pipe 8 from the refrigerant gas suction chamber 10 provided in the peripheral portion of the fixed scroll 3 is fed to the fixed scroll 3 and the orbiting scroll. After sealing in the sealed space formed between the 4 and 4, the sealed space shrinks and moves to the center while compressing the gas, and the sealed space opens near the center to the discharge port 11 provided at the center of the fixed scroll. The discharge port
From 11, the compressed gas is discharged into the closed container 1. The discharged compressed gas passes through the discharge passage 12 provided on the outer periphery of the fixed scroll 3 and the frame 5, flows around the electric motor unit 2, and is then discharged from the compressor through the discharge pipe 9 provided in the closed container. .

On the other hand, the shaft 6 is supported by a bearing boss 17 provided on the frame 5, and the eccentric portion 6a is inserted in the orbiting scroll bearing portion. The lower ends of the eccentric oil supply holes 19 and 20 in the shaft 6 provided for oil supply to the respective bearings open to the shaft lower cavity 21, and the eccentric oil supply hole 19 is located above the bearing boss 17 of the frame 5 in the middle. It is opened to the main bearing portion, and at the upper portion, it is opened to the upper end 6b of the eccentric portion 6a of the shaft 6 and the bearing surface side 6c of the orbiting scroll bearing. Further, the upper portion of the eccentric oil supply hole 20 is opened to the lower main bearing portion of the bearing boss 17. Further, the flat plate portion of the orbiting scroll 4 is provided with an oil feed hole 16 having one end opening to the shaft upper cavity 15 in the orbiting scroll bearing boss and the other end opening to the orbiting scroll outer peripheral end plate surface 4a. At the lower end of the shaft 6, a fuel filler port 22
When the compressor is stopped, there is an oil surface of the oil sump 14 below the opening end inside the shaft lower cavity 21 of the shaft eccentric oil supply holes 19 and 20 when the compressor is stopped.
It has a structure where an oil-free space is formed inside. Oil sump
The gas pressure in the space around the electric motor unit 2 acts on the oil surface of 14.

In this way, the shaft lower cavity 21 communicates with the space around the electric motor portion 2 in the hermetic container from the lower main bearing portion gap of the frame bearing boss 17 through the eccentric oil supply hole 20 on the one hand, and the oil supply hole 19 on the other hand. Through the gap between the end plate surface 4a where the oil feeding hole 16 of the orbiting scroll is opened and the fixed scroll plane, the suction chamber 10
In the hermetic scroll compressor configured to communicate with the above, as the pressure of the suction chamber 10 becomes lower than the pressure of the surrounding space of the electric motor part 2 due to the activation of the compressor, the shaft upper cavity 15 and the shaft lower part 15 Since the gas in the cavity 21 is sucked into the suction chamber 10 side, the pressure in the cavity inside the shaft decreases, and the centrifugal force along the cap slope above the oil filler port 22 inside the shaft lower cavity 21 accompanying the rotation. With the above action, the oil level in the shaft lower cavity 21 is raised to guide the oil to the eccentric oil supply holes 19 and 20, and the oil is supplied to each bearing and the orbiting scroll outer peripheral end plate portion.

However, at the time of start-up, there is an oil-free space in the shaft lower cavity 21 and the eccentric oil supply holes 19 and 20 communicate with each other through the space, so that the eccentric oil supply hole 20 is lower than the lower main bearing of the bearing boss 17. The gas in the space around the electric motor section 2 flows into the lower shaft cavity 21 through the passage, and the pressure drop in the lower shaft cavity 21 is hindered, and the cap slopes above the oil filler port 22 are continuously connected in the circumferential direction. However, the effect of centrifugal force could not be expected sufficiently, therefore the oil level in the shaft lower cavity 21 did not rise, and there was a problem that oil could not be guided to the eccentric oil supply holes 19 and 20. . Further, even when refueling is performed, oil is supplied to each bearing after filling the shaft lower cavity 21, so that refueling to each bearing is delayed.

As described above, in the conventional device, there is a risk that the bearing may become astringent due to insufficient lubrication.

The present invention has been invented in view of the above, and improves oil supply to each bearing and the orbiting scroll end plate sliding portion to prevent seizure accidents, and particularly improves oil supply performance during compressor operation including at startup. The purpose is to let.

In order to achieve the above-mentioned object, the present invention provides claims 1
The gist is the scroll compressor described in the section.

Hereinafter, some embodiments of the present invention will be described. In these embodiments, the structure of the compressor is the same as the above-mentioned conventional example except for the shaft lower structure described below.

Prior to the description of the embodiments of the present invention, embodiments of the prior invention by the present inventors will be described with reference to FIGS. 4 to 6. In the figure, the oil feed holes 24 and 25 provided in the shaft 23 are horizontally long grooves 26 forming a centrifugal pump portion formed in the lower end of the shaft 23.
And a fluid oil hole 27 is provided in the central lower surface wall of the laterally long groove 26 to communicate with the oil reservoir 14. Similar to the conventional eccentric oil supply hole 19, the oil supply hole 25 is opened in the upper main bearing portion of the bearing boss 17 of the frame 5 at an intermediate portion. Oil feed hole 25
Like the conventional eccentric oil supply hole 19 (see FIG. 2), the eccentric portion has an opening at the upper end of the eccentric portion, or a hole provided in the eccentric portion in the radial direction is formed in the orbiting scroll bearing boss. The structure is such that it is communicated with the shaft upper cavity 15 by opening it on the bearing surface side and interposing a gap between the bearing portions. Further, the upper portion of the oil feed hole 24 is opened to the lower main bearing portion of the bearing boss 17 of the frame 5, like the conventional eccentric oil feed hole 20.

When the compressor is started, the gas in the oil feed hole 25 in the shaft 23 is sucked to the suction chamber 10 side through the gap of the orbiting scroll end plate portion 4a, and the gas pressure in the oil feed hole 25 is increased around the electric motor portion 2. Since the pressure is lower than the pressure in the space, the oil level in the oil feed hole 25 rises. Further, the rotation of the shaft 23 causes a centrifugal force to act on the oil in the horizontally elongated groove 26 forming the centrifugal pump section, which raises the oil level in the oil feed holes 24 and 25. As for the oil pressure, the oil level rises rapidly due to the effect of the pressure drop and the action of centrifugal force, and the flame
Oil is sent to the upper main bearing of the bearing boss portion 17 and the bearing surface of the orbiting scroll bearing boss and the orbiting scroll end plate surface. On the other hand, regarding the oil feed hole 24, since the oil feed hole 24 communicates with the surrounding space of the electric motor section 2 through the bearing gap of the lower main bearing provided in the bearing boss 5 of the frame 5, The gas pressure in the holes 24 is higher than the gas pressure in the oil feeding holes 25, but is almost equal to the gas pressure acting on the oil surface of the oil reservoir 14, and the lower ends of the oil feeding holes 24, 25 are Since it is below the oil level, the gas from the motor part surrounding space does not flow from the oil feed hole 24 to the oil feed hole 25 at the lower part of the shaft as in the conventional structure, and the action of centrifugal force is sufficiently exerted. Oil is supplied to the lower main bearing provided on the bearing boss of the frame 5 through the oil feed hole 24. In addition, since the volume of the long groove 26 at the bottom of the shaft is small, the time until the bearings and the orbiting scroll end plate surface are refueled is further shortened, and the lubrication delay time at startup and the lack of lubrication amount are eliminated. The pump characteristics are improved, and the reliability of the bearing and the sliding surface of the end plate is greatly improved.

Two embodiments of the present invention will be described below with reference to FIGS. 7, 8, 9 and 10. In both of these embodiments, the oil feeding holes 2 and 25 respectively corresponding to the oil feeding holes 24 and 25 of the prior invention.
At the bottom of the shaft 28 having 9,30, the lower end opening 33 has an oil sump 14
A cylindrical oil supply cap 31 that is open below the oil surface is fixed, and the lower end of the shaft 28 is located above the oil surface of the oil sump 14.

In the embodiment of FIGS. 7 and 8, oil pumping pipes 35, 36 extending from the oil pumping holes 29, 30 are connected to the lower ends of the oil pumping holes 29, 30, and these pumping pipes 35, 36 are provided along the inner surface of the fuel cap 31. By bending in the circumferential direction and opening the open end into the oil sump 14 (below the oil level), the oil feed holes 29 and 30 are extended and communicated with the oil sump 14, and in the rotational direction of the shaft 28 described above. By bending the pumping oil pipe, the structure takes into consideration the effect of a viscous pump in addition to the centrifugal pump action.

In the embodiment of FIGS. 9 and 10, the oil pumping hole 29 opened at the lower end of the shaft 28 and the oil pumping pipe having one end opened in the oil sump 14 are provided.
By fixing 34, bending the middle of the oil pump pipe 34 in the radial direction, and opening it with a gap near the inner surface of the oil supply cap 31, the oil feed hole 29 is communicated via oil and also functions as a centrifugal pump. , Again, the garbage that tries to enter the oil pump pipe 34
Since it is blown off by centrifugal force, it has a structure that prevents dust from entering the oil feed hole.

Also in the embodiments shown in FIGS. 7 to 8 and 9 to 10, respectively, the oil supply hole 30 has the oil supply operation based on the pressure difference and the oil supply operation by the centrifugal force in the embodiment of the preceding invention. This is similar to the case of the oil feed hole 24.

As described above, according to the present invention, the lower ends of the two oil feed holes provided in the shaft are communicated with each other only through the oil in the oil sump, so that the compressor is operated even when the compressor is started. Oil can be stably supplied to each bearing portion and the orbiting scroll end plate sliding portion, a seizure accident due to insufficient oil supply can be prevented, and a mechanical loss can be reduced.

[Brief description of drawings]

1, 2, and 3 are a vertical cross-sectional view of a conventional scroll compressor, an elevational view showing a partial cross-section of a shaft, and a III-III cross-sectional view of the shaft, respectively. FIG. 5 is a vertical cross-sectional view of a scroll compressor having an oil supply structure according to an embodiment of the invention preceding the present invention, FIG. 5 is a cross-sectional view of the lower portion of the shaft indicated by A in FIG. 4, and FIG. VI-VI cross-sectional view, FIG. 7 and FIG. 8 are cross-sectional views of the structure of the lower portion of the shaft in one embodiment of the present invention and VIII-VIII cross-sectional views, and FIG. 9 and FIG. 13A and 13B are a cross-sectional view and a cross-sectional view taken along the line XX of the lower portion of the shaft in yet another embodiment of the present invention. 14 …… Oil sump, 23 …… Shaft 24,25 …… Oil feed hole, 26 …… Horizontal groove 27 …… Opening, 28 …… Shaft 29,30 …… Oil feed hole, 31 …… Cap 33 …… Opening , 35,36 …… Oil pumping pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Sakae Hazaki, Sakae, Hasaki, 502 Jinritsu-cho, Tsuchiura-shi, Ibaraki Machinery Research Institute, Hiritsu Manufacturing Co., Ltd. (72) Naoshi Uchikawa, 390 Muramatsu, Shimizu-shi, Shizuoka Hitachi, Ltd. Shimizu, Hitachi In the factory (56) References JP-A-58-214692 (JP, A)

Claims (2)

[Claims] 1. A hermetically sealed container having a gas compressor section formed by meshing a fixed scroll and an orbiting scroll as an upper portion, and an electric motor section coupled to a shaft for orbiting the orbiting scroll as compared with the gas compressor section. An oil sump is arranged in the lower part below the electric motor part, and from the oil sump to the bearing part or sliding part that communicates with the upper part of each of the two oil feed holes extending axially from the lower end of the shaft in the shaft. Oil is supplied through the oil feeding hole, and the gas pressure acting on the upper portion of the oil feeding hole via the bearing portion or the sliding portion is one during the operation of the gas compressor portion. In a scroll compressor in which the oil pressure in the hole is approximately equal to the oil surface pressure in the oil sump and the pressure in the other oil supply hole is lower than the oil surface pressure in the other, a cylinder that opens below the oil surface in the oil sump -Shaped cap is fixed to the bottom of the shaft, The lower end opening of the oil feeding hole of the oil feeding hole is located on the oil surface in the cap, and at least the lower end opening of the oil feeding hole where the gas pressure acting on the upper portion of the oil feeding hole becomes high is stored in the cap. Is connected to an oil feed pipe as an extension passage whose tip opens below the oil surface of the cylindrical cap, and the oil feed pipe is bent in the radial direction of the cylindrical cap and opens near the opposing inner surface of the cap. Characteristic scroll compressor. 2. The oil feed pipe as the extension passage is bent in the radial direction of the cylindrical cap, and is bent along the inner side of the cylindrical cap in the rotational direction of the shaft. A scroll compressor according to claim 1.