JPH0454072B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an oil lubrication mechanism for a compressor incorporated in an air conditioner, a refrigerator, or the like.

[Technical background of the invention and its problems]

Compressors built into air conditioners, refrigerators, etc. house an electric motor and a compression mechanism in a sealed casing, and transmit the driving force from the electric motor to the compression mechanism via a rotating shaft. There is. The lower end of the rotating shaft is immersed in lubricating oil in an oil reservoir formed at the bottom of the closed casing, and an oil pump is formed at the bottom of the shaft. This oil pump performs a pumping action as the rotating shaft rotates, and this pumping action supplies lubricating oil stored in an oil reservoir to each sliding part such as the rotating shaft bearing to lubricate it. .

A conventional oil lubrication mechanism for a compressor is constructed as shown in FIG. 6, and an oil pump 2 is formed in a lower part of a rotating shaft 1. The oil pump 2 has a spiral blade 4 interposed in a hollow part 3 at the lower end of the shaft, and the lower end of the shaft is covered with a pump cover 6 fixed to a sub-bearing 5 (Japanese Patent Application Laid-Open No. 54-1999).
(See Publication No. 139104).

By the way, when the lower end of the rotating shaft 1 is covered with the pump cover 6, a space 7 is formed between the lower end surface of the rotating shaft 1 and the pump cover 6, and the lubricating oil guided into this space 7 is absorbed by the rotating shaft. 1 rotates at a speed close to the shaft rotational speed, generating a vortex. Therefore, it is difficult for lubricating oil to flow into the oil suction port 8 at the lower end of the rotating shaft 1, and the amount of lubricating oil pumped up by the oil pump 2 is small.

In addition, when the pump cover 6 is placed in close contact with the lower end surface of the rotating shaft in order to prevent the adverse effects of eddy currents, the lower end surface of the rotating shaft and the pump cover 6
Since the lubricating oil is gasified by the sliding frictional heat generated between the rotary shaft 1 and the rotary shaft 1, it becomes impossible to replenish the lubricating oil into the lower end hollow portion 3 of the rotary shaft 1, and there is a possibility that the lubricating oil cannot be refilled.

[Purpose of the invention]

The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide an oil lubrication mechanism for a compressor that reliably supplies a sufficient amount of lubricating oil to the hollow portion at the lower end of a rotating shaft and improves the oil lubrication function. With the goal.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention immerses the lower end of a rotating shaft that transmits driving force from an electric motor to a compression mechanism in lubricating oil stored in the inner bottom of a sealed casing. A hollow part for the oil pump is formed at the bottom,
In an oil lubrication mechanism for a compressor in which the lower end of the shaft is covered with a pump cover having an oil introduction hole, the pump cover is provided with a vortex flow suppressing protrusion extending toward the lower end surface of the rotating shaft on its inner surface, and the vortex flow suppressing protrusion is The tip is inserted into a hollow portion at the lower end of the rotating shaft.

[Embodiments of the invention]

An embodiment of the oil lubrication mechanism for a compressor according to the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a hermetic casing of a vertical rotary hermetic electric compressor, and inside the hermetic casing 10, an electric motor 11 is housed in the upper part, and a compression mechanism 12 is housed in the lower part. The driving force from the electric motor 11 is transmitted to the compression mechanism 1 via the rotating shaft 13.
2 to drive this compression mechanism 12. The rotating shaft 13 is the compression mechanism 1
The lower end of the shaft is immersed in lubricating oil in an oil reservoir 16 formed at the inner bottom of the sealed casing 10.

On the other hand, a hollow portion 17 extending in the axial direction is formed at the center of the lower part of the rotating shaft 13, as shown in FIG. A spiral blade 18 is interposed within this hollow portion 17, and an oil pump 19 is configured. The lower end of the spiral blade 18 is inserted so as to substantially coincide with the lower end of the rotary shaft 13. The oil pump 19 performs a pumping action by the rotation of the rotating shaft 13,
Lubricating oil is supplied from the oil port 20 to the lubrication groove 21 (first
(see figure) to lubricate each lubricating part such as the main bearing 14 and sub-bearing 15.

The lower end of the rotating shaft 13 is connected to the pump cover 2
Covered by 3. The pump cover 23 is held by a bearing cover 24 fixed to the sub-bearing 15. Pump cover 23 is oil sump 1
The rotary shaft 13 has an oil introduction hole 25 for guiding the lubricating oil in the rotary shaft 13 into the rotary shaft 13. The oil introduction hole 25 faces the lower end hollow part 17 of the rotary shaft 13, and
The diameter is smaller than 7. This prevents the lubricating oil supplied to the hollow portion of the rotary shaft 13 from escaping downward as the rotary shaft 13 rotates.

Furthermore, a plate-shaped eddy current suppressing protrusion 27 is formed on the inner surface of the pump cover 23 . Eddy flow suppression protrusion 2
7 extends toward the lower end surface of the rotary shaft 13 and is erected so as to straddle the oil introduction hole 25 . The plate surface of the vortex suppressing projection 27 is formed to be substantially perpendicular to the rotational direction of the rotary shaft 13, thereby preventing the generation of vortices due to the lubricating oil. Also,
The upper end portion of the eddy current suppressing projection 27 is inserted into the lower end hollow portion 17 of the rotary shaft 13 . At this time, it is sufficient that the amount of overlap between the upper end of the eddy current suppressing projection 27 and the lower end hollow portion 17 of the rotary shaft 13 is about 0 to several mm. By inserting the upper end of the eddy current suppressing protrusion 27 into the lower end hollow part 17 of the rotating shaft 13, very viscous lubricating oil and rotating shaft 13 can be removed.
This is effective in guiding the lubricating oil when the rotational speed of the rotary shaft 13 is high, and the lubricating oil can be smoothly and smoothly guided into the hollow portion 17 of the rotating shaft 13.

Next, the effect will be explained.

For example, during normal compressor operation, such as during cooling/heating operation, the oil level of the lubricating oil stored in the oil reservoir 16 is located above the lower end surface of the rotating shaft 13. When the rotary shaft 13 rotates, the oil pump 19 is activated and performs a pumping action. Due to the pumping action of this oil pump 19, lubricating oil is scraped up from the lower end of the rotating shaft 13.
While the lower hollow part 17 of the rotating shaft 13 is filled with lubricating oil, this lubricating oil passes through the oil port 20 to the main bearing 14, sub-bearing 15,
It is supplied to sliding parts such as the crank part, and lubricates each sliding part. The lubricating oil that has lubricated the sliding part is released to the outside of the sliding part and enters the oil reservoir 1 at the bottom of the sealed casing 10.
6.

At this time, the lower end of the rotating shaft 13 is covered with a pump cover 23, and a vortex suppressing protrusion 27 is formed on the pump cover 23 to extend toward the lower end surface of the shaft and to be inserted into the lower end hollow portion 17 of the rotating shaft 13. Therefore, the lubricating oil guided to the lower end hollow portion 17 of the rotary shaft 13 is hardly subjected to rotational movement due to shaft rotation, and is smoothly supplied. In this case, the lubricating oil tries to make a rotational movement following the rotation of the rotating shaft 13.
Its rotational movement is regulated by the plate surface of the eddy current suppressing protrusion 27, thereby preventing the generation of eddy currents. Therefore, the lubricating oil is smoothly guided to the lower end hollow part 17 of the rotating shaft 13, and the guided lubricating oil is sufficiently scraped up by the spiral blade 18 of the oil pump 19, and a sufficient amount of lubricating oil is supplied. Ru. Therefore, the oil level formed in the hollow part 17 of the rotating shaft 13, as shown by the solid line a in FIG. 3, is significantly higher than the oil level of the conventional oil lubrication mechanism shown by the broken line b. The pumping function of the oil pump 19 is improved accordingly.

In addition, during transient operating conditions such as starting the compressor in a sleep state (starting with refrigerant mixed in the lubricating oil) or during defrosting operation, the oil level of the lubricating oil may temporarily drop. Although the level of the lubricating oil may be below the lower end surface of the rotating shaft, in this case, if the lubricating oil level returns to normal, the lubricating oil flowing into the lower end hollow portion 17 of the rotating shaft 13 will flow through the vortex flow suppressing protrusion 2 of the pump cover 23.
7, the rotational movement is necessarily restricted, so that lubricating oil can be smoothly and stably supplied to the hollow portion 17 at the lower end of the shaft. Therefore, the hollow portion 17 of the rotating shaft 13 is quickly replenished with lubricating oil.

Next, the first modification of the pump cover is shown in Fig. 4A.
This will be explained with reference to B.

In one embodiment of the present invention, an example has been described in which the pump cover 23 is held by the elastic force of the bearing cover 24, but as shown in FIGS. It may be directly fitted onto the outside and fixed. In this case, the same effects as those described in the embodiment shown in FIG. 2 can be obtained.

Further, the pump cover 23B may have a structure shown in FIGS. 5A and 5B. That is, pump cover 2
A plurality of vortex flow suppressing protrusions 27B, for example, two protruding blades 2, are formed so as to straddle the oil introduction hole 25 of 3B.
7a, 27b, each protruding blade 27a, 2
7b is cut diagonally upward so as to be inclined upward along the rotational direction A of the rotary shaft 13.

The vortex flow suppressing protrusion 27B actively utilizes the viscosity of the lubricating oil, and by installing the protruding blades 27a and 27b at an angle, the lubricating oil guided from the oil inlet hole 25 can absorb the rotation of the rotating shaft 13. This actively generates an upward spiral flow. This upward spiral flow pushes the lubricating oil upward and guides it into the hollow portion at the lower end of the shaft.

Note that the eddy current suppressing protrusion may have a cross structure in which two plates are crossed with each other.
The pump cover may be fixed to a stationary part such as the bottom wall of the closed casing. Furthermore, the present invention can be applied not only to rotary type compressors but also to reciprocating type compressors.

〔Effect of the invention〕

As described above, the oil lubrication mechanism for the compressor according to the present invention is provided with a vortex suppressing protrusion that extends toward the lower end surface of the rotating shaft and is inserted into the hollow portion at the lower end of the rotating shaft on the inner surface of the pump cover. ,
Even when the rotating shaft is rotationally driven, especially when the rotating shaft rotates at high speed or the viscosity of the lubricating oil is high, the lubricating oil near the lower end of the shaft hardly rotates, and the generation of vortices can be actively prevented. Therefore, the lubricating oil introduced from the oil introduction hole of the pump cover is guided by the eddy flow suppressing protrusion and smoothly flows into the hollow portion at the lower end of the shaft. Therefore, a sufficient amount of lubricating oil can be reliably supplied to the hollow part for the oil pump at the bottom of the rotating shaft, and the oil lubrication function of the oil pump can be greatly improved, thereby improving the reliability of the compressor. can be done.

In addition, even if the lubricating oil level in the sealed casing falls below the lower end surface of the rotating shaft for some reason,
If the oil level recovers, the generation of vortices can be effectively prevented, and a sufficient amount of lubricating oil can be quickly and stably supplied again.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a partial cross-sectional view showing the main parts of the oil lubrication mechanism for a compressor according to the invention, and FIG. FIGS. 4A and 4B are a partial sectional view showing the state of the lubricating oil level in the hollow part; FIGS. A plan view showing a second modification of the pump cover, FIG.
A sectional view taken along the line V-V in Figure A, and FIG. 6 is a partial sectional view showing an oil lubrication mechanism of a conventional compressor. 10... Sealed casing, 11... Electric motor, 1
2... Compression mechanism, 13... Rotating shaft, 14...
...Main bearing, 15...Sub bearing,
17... Hollow part for oil pump, 18... Spiral vane, 19... Oil pump, 23, 23A, 23
B...Pump cover, 25...Oil introduction hole, 27,
27B... Eddy flow suppression protrusion, 27a, 27b... Protrusion blade.

Claims (1)

[Claims] 1. The lower end of a rotating shaft that transmits driving force from an electric motor to a compression mechanism is immersed in lubricating oil stored at the bottom of a sealed casing, and an oil pump is installed at the bottom of the rotating shaft. In the oil lubrication mechanism for a compressor, the lower end of the shaft is covered with a pump cover having an oil introduction hole, and the pump cover has a vortex flow suppressing projection extending toward the lower end surface of the rotating shaft on its inner surface. established,
An oil lubrication mechanism for a compressor, characterized in that the tip of the vortex suppressing protrusion is inserted into a hollow portion at the lower end of the rotating shaft. 2. The oil lubrication mechanism for a compressor according to claim 1, wherein the eddy current suppressing protrusion is plate-shaped and provided so as to straddle the oil introduction hole of the pump cover. 3. The oil lubrication mechanism for a compressor according to claim 2, wherein the eddy current suppressing protrusion is erected on the inner surface of the pump cover so that the plate surface is substantially orthogonal to the rotation direction of the rotating shaft. 4. The oil lubrication mechanism for a compressor according to claim 2, wherein the eddy current suppressing protrusion has a plurality of protruding vanes, and each protruding vane is cut upward obliquely along the rotational direction of the rotary shaft. 5. The oil lubrication mechanism for a compressor according to claim 1, wherein the pump cover is fixed to a stationary part such as a sub-bearing, and the oil introduction hole thereof is smaller in diameter than the hollow part at the lower end of the rotating shaft.