JPS5963395A - Valve cover for rotary compressor - Google Patents

Abstract

PURPOSE:To attenuate pressure pulsation of discharged gas by providing a closing wall for closing the hollow section of a valve cover spaced a predetermined distance from a discharge port in the valve cover and a seal member in the fit portion of the valve cover and a main bearing. CONSTITUTION:Compressed gas discharged from a discharge port 5 into a hollow chamber 7 along with pressure pulsation collides with a closing wall 17 while vibtating in the hollow chamber 7 to flow so that energy loss is produced and the pulsation is quickly attenuated. Thus, noises based on the pulsation are attenuated, and further noise leakage from the fit portions 8, 9 of the valve cover 4 and a main bearing 1 is prevented by seal members 15, 16 while vibration itself of the valve cover 4 is attenuated by the seal members 15, 16.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary compressor, and particularly to a compressor that accelerates the attenuation of pressure pulsations in compressed gas discharged into a compressor and prevents pulp force and noise from leaking outside. The present invention relates to a valve cover for a rotary compressor that can prevent noise and improve quietness as much as possible.

[Technical background of the invention and its problems]

Generally, in a rotary compressor, as shown in FIGS. 1 and 2, an upper wall 3 of a cylinder chamber 2 is attached to the outer circumference of a main bearing 1
A groove 4 is provided to cover the valve cover 4, and an annular hollow chamber 7 containing a discharge port 5 and a discharge valve 6 is formed inside the valve cover 4.

This annular hollow chamber 7 surrounds the outer periphery of the main bearing 1 and communicates with it, and compressed gas with strong pressure pulsations is discharged from the discharge port 5 into the hollow chamber γ.

The discharged compressed gas vibrates within the hollow chamber 7 due to its pressure pulsations, and since the hollow chamber 7 is formed into an annular shape, the vibrations propagate through the chamber many times, causing damage to the valve cover 4 and the main bearing 1.
The leakage from the fitting portions 8 and 9 of the valve cover 4 was transmitted through the valve cover 4, causing noise.

3 and 4 show the propagation direction of the pressure pulsation, where LH is the propagation path length in the cross-sectional height direction of the hollow chamber 7, LR is the propagation path length in the same cross-sectional width direction, and LC is an annular shape. Regarding the propagation path length in the circumferential direction of the hollow chamber 7, the main propagation direction is the circumferential direction having the maximum path length.

The primary pressure pulsation frequency f in this case is expressed by the following equation: n1
approximated.

f-%≠CAo (a) However, C is the speed of sound, and for example, when the compressed gas is a refrigerant, it is a value determined by its concentration and pressure. λ is the wavelength of the pressure pulsations.

According to experimental data using conventional products, '121'6H
When does the noise z reach its peak sound pressure level t? 4) Also, the pressure pulsation frequency was measured to be 1218 Hz. The circumferential propagation path length LC of the conventional product used in this experiment was 0.13771 and the sound velocity C was 151 ml.
When sec is substituted into the above equation (a), the frequency becomes f 嬌' 5X, 13-1 ICiOHz, which almost agrees with the experimental data.

[Purpose of the invention]

The present invention has been devised in order to improve the problems by paying attention to the above-mentioned circumstances.

An object of the present invention is to provide a pulp cover for a rotary compressor that can speed up the attenuation of the pressure pulsation of compressed gas discharged into the valve cover, prevent noise from leaking outside the valve cover, and increase the quietness as much as possible. Our goal is to provide the following.

[Summary of the invention]

The present invention provides a closing wall that closes the cross section of the hollow chamber in the annular hollow chamber within the valve cover at a predetermined distance from the discharge port, and also includes a 7-hole member at the fitting portion between the valve cover and the main bearing. By providing this, the above-mentioned purpose is achieved.

[Embodiments of the invention]

Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

As shown in FIGS. 5 and 6, the valve cover for a rotary compressor according to the present invention has its inner peripheral end 12 fitted onto the outer peripheral surface 11 of the journal portion 10 of the main bearing 1. Further, the outer peripheral end 13 of the valve cover 4 is connected to the ring chamber tenth wall 3 of the main bearing 1.
It is fitted onto the outer peripheral end 14 of. The fitting parts 8 and 9 between the pulp cover 4 and the main bearing 1 are made of plastic or asbestos or the like and are molded into a sill-like shape 7.
- A control member 15,16 is provided. In this case, the standard thickness tinm of the seal members 15 and 16 is within the range expressed by the following formula.

(x+0.1)mm≦t≦(2X+0.1)mm
--(o) However, x mm is the gap between the fitting parts 8 and 9 of the pulp cover 4 and the main bearing 1, respectively.

The annular hollow chamber 7 inside the valve cover 4 is designed to accommodate the gloss of the main bearing 1.
The grooves formed along the outer circumferential surface 11 of the null part 10 do not communicate with each other, and are kept at a predetermined distance along the circumferential direction from the discharge port 5 (in the height direction and width direction of the cross section of the hollow chamber). A closing wall 17 is provided to close the cross section of the hollow chamber at a position separated by a distance (a distance greater than the propagation path length). In this embodiment, one part of the mounting part 18 for bolts etc. for fixing the pulp cover 4 to the cylinder chamber upper wall part 3 is enlarged, and its inner wall surface 19 is attached to the outer peripheral surface 11 of the glossy tool part 10. A closing wall 17 is formed by joining.

Next, the operation of the present invention will be explained.

When the compressor is operated, the gas compressed in the cylinder chamber 2 is discharged from the discharge port 5 into the hollow chamber 7 with pressure pulsations. In the process of flowing while vibrating in the hollow chamber γ, this compressed gas collides with the closing wall 17, causing energy loss, and the pulsation can be quickly attenuated.

Therefore, the noise due to pulsation is also reduced by the sound member n1 and the seal member 1.
5.16, the fitting part 8 between the valve cover 4 and the main bearing 1
, 9 is also prevented, and the sealing member 1
5.16 can also dampen the vibration of the pulp cover 4 itself.

By the way, FIG. 7 is a model of the pulp cover 4, the closing wall 17, and the discharge port 5 shown in FIG.
It is set at 0. In this way, the pressure pulsation distribution between α0 from the discharge port 5 to the closing wall 17 at a certain time will be as shown in Fig. 8, with the maximum pressure at the discharge port 5 position and the minimum pressure at the closing wall 17 position. becomes. Therefore,
A pressure pulsating wave of 1 (λ is the wavelength) is present between α0 and α0. This means that 36% of the pressure pulsating waves with λ of 4 exist between the total propagation path lengths LC in the circumferential direction.

That is, the wavelength λ of the pressure pulsating wave in this case can be expressed as follows. Substituting λ into the above equation (a), we get n. In this case, C and Lc of the formula are set under the same conditions as above (
C==151 ml sec, Lc” 0.1
3? When substituting n) and comparing it with the case of the conventional product, the graph shown in Figure 9 (the solid line is this example, the broken line is the conventional example), and the absolute value of α1α1 is from 50° to 180°'=
! By providing the closing wall 17 at an arbitrary position between 1 and 2, the frequency of pressure pulsation can be freely determined up to about three times the total frequency. Therefore, the pulp cover 4 and the pull member 15.16
By setting α to a frequency that makes effective use of the silencing characteristics, a very effective sound reduction effect can be obtained.

In this example, an example was given in which the closing wall was molded integrally with the pulp cover, but this closing wall was formed from a separate assembly of metal or plastic, and was inserted as a filler into the conventional annular hollow chamber. Of course, the same action and effect will not be obtained even if it is fitted.

In addition, it is thought that the coefficient of performance of the compressor will decrease as the air volume inside the pulp cover becomes smaller, but the closure wall according to the present invention does not have a very large volume and has little effect on the coefficient of performance. It can be ignored.

〔Effect of the invention〕

As is clear from the above explanation, the following excellent effects can be achieved by the present invention.

1. By causing the pulsating gas flow to collide with the closing wall, the pulsation is quickly attenuated and noise is reduced.

2. The volume occupied by the closing wall inside the annular hollow chamber is small, and the decrease in the hollow chamber volume is small, so there is almost no decrease in the coefficient of performance of the compressor.

3. The pulsation frequency can be set depending on the installation position of the closing wall, and the characteristics of the sound deadening material can be fully utilized.

4. - Generic sound Rn- can be prevented from occurring from the gap between the club cover and the main bearing.

5. The lubricating oil is no longer blown up due to leaking gas from the gap between the pulp cover and the main bearing9, and the amount of oil discharged can be reduced.

6 The structure is simple and can be easily adopted.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the conventional valve force/g, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Figs. 3 and 4 respectively show the propagation path of n pressure pulsation. The plan view shown and IV in FIG.
5 is a plan view showing one embodiment of the pulp cover according to the present invention, and FIG. 6 is a view taken along line Vl-V in FIG.
7 is a plan view modeled on FIG. 5, FIG. 8 is a graph showing the pressure pulsation distribution between α0 in FIG. 7, and FIG. 9 is a cross-sectional view of the closing wall. It is a graph diagram showing the relationship between position and pressure pulsation frequency, and comparison with the pressure pulsation frequency in a conventional example. In the figure, 1 is the main bearing, 2 is the cylinder chamber, 3 is the upper wall of the cylinder chamber, 4 is the valve force, 5 is the discharge port, 7 is the annular hollow chamber, 8 is the inner peripheral end of the pulp cover and the gloss - a fitting part with the outer circumferential surface of the null part, a fitting part with the outer circumferential edge of the 9-bar group cupper and the outer circumferential edge of the upper wall of the 7-ring chamber, 10 is a glossy null part;
l1id its outer peripheral surface, 12 is the inner peripheral end of the pulp cover, 13
14 is the outer peripheral end of the upper wall of the cylinder chamber, 15° and 16 are sealing members, and 11 is a closing wall. Representative Patent Attorney Nobuo Kinutani Figure 1 Figure 3 Figure 4 Figure 5 B Figure 6 Figure 7 Figure 8

Claims (1)

[Scope of Claims] 1. In a valve cover that is fitted onto a main bearing that integrally constitutes a gloss portion for a main shaft of a rotary compressor and an upper wall of a cylinder chamber including a discharge port, the inner periphery of the valve cover is The ends are fitted to the outer circumferential surface of the glossy part and the outer circumferential ends are fitted to the outer circumferential ends of the upper wall of the cylinder chamber, thereby partitioning the inner part of the valve cover and the outer part of the main bearing. A valve cover for a rotary compressor, characterized in that an annular hollow chamber is provided with a closing wall that closes a cross section of the hollow chamber. 2. The above-mentioned patent, wherein the closing wall is provided at a distance from the position of the discharge port in the circumferential direction of the hollow chamber, which is larger than the height and width of the cross-section of the hollow chamber. A valve cover for a rotary compressor according to claim 1. 3. The valve cover for a rotary compressor according to claim 1, wherein the closing wall is integrally molded with the valve cover by press working or the like. 4. A valve cover for a rotary compressor according to claims 1 and 2, wherein the closing wall is formed of a filling material such as metal or plastic.