JPS6299695A - Rotary compressor - Google Patents

Abstract

PURPOSE:To effectively reduce the noise of a compressor by providing the inlets of a valve and a discharge hole near a middle and a quadrisection position between both the ends of a discharge chamber respectively to diminish the occurrence of an air column resonance in the discharge chamber. CONSTITUTION:Since communication in the circumferential direction of a discharge chamber 14 is checked by bringing a portion 13a on the inside periphery of the side plane of a discharge cover 13 into contact with the outside periphery of a bearing journal 12a or approaching them each other, the occurrence of an air column resonance in a double cylindrical cavity is prevented. In addition to that, since a valve hole 12b and a discharge port 15 both provided on a bearing 12 are located near a middle and a quadrisection position between both the ends 14a, 14b of the discharge chamber 14 respectively, either the valve hole 12b or the discharge port 15 is situated near the node of a space natural vibration mode with 1-3 nodes in circumferential direction, and the discharge chamber 14 is therefore hardly affected by the air column resonance of a lower natural vibration mode. Furthermore, since the discharge port 15 is provided on the bearing 12, the discharge chamber 14 can be freely formed in its length to produce excellent noise reduction effect.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary compressor used in a freezing and refrigeration system.

BACKGROUND OF THE INVENTION In recent years, compressors used in refrigerators and freezers have been shifting from reciprocating types to rotary types from the viewpoint of saving energy and space. These rotary compressors usually have a high pressure side inside a closed case, and the refrigerant compressed in the cylinder is once discharged into the shell interior space before being discharged from the compressor into the refrigeration system.

As a result, the pressure pulsation component of the refrigerant generated by the refrigerant being compressed within the cylinder is transmitted to the shell interior space with almost no attenuation, causing atmospheric resonance in the shell interior space, and further vibrating the shell and producing loud noise. Occur.

Therefore, conventional methods have been used to attenuate the pressure pulsations of the refrigerant by providing a silencing structure immediately after the refrigerant compressed in the cylinder is discharged from the cylinder, and then providing a discharge chamber.

An example of the conventional rotary compressor mentioned above will be described below with reference to the drawings. FIGS. 4 and 5 show an example of the conventional rotary compressor.

In the figure, 1 is a rotary compressor, 2 is a closed case, and 3 is a rotary compressor.
is fixed to the sealed case 2 by a stator through a shrink fit. 4
is connected to the crankshaft 5 by a rotor. 6 is a piston, and 7 is a cylinder. 8 is a bearing on the rotor side, which is fixed to the sealed case 2 by welding. 9 is a bearing at the end of the shaft, and 9b is a recess into which a valve (not shown) is mounted. Reference numeral 10a denotes a substantially double cylindrical discharge chamber provided on the outer periphery of the journal portion 9a of the bearing 9, and is constructed by fixing a cup-shaped discharge cover 10 to the bearing 9. The discharge cover 10 has a discharge chamber 10a.
A discharge hole 10b is provided which communicates with the space 11 inside the sealed case.

The operation of the rotary compressor configured as above will be described below.

The refrigerant gas compressed in the cylinder T is discharged into the discharge chamber 1.
0a, and is further discharged from the discharge hole 10b provided in the discharge cover 10 into the internal space 11 of the sealed case. Therefore, the discharge chamber IQa mainly acts as an expansion type muffler, and the refrigerant flows into the discharge chamber 10.
Since the pressure pulsation component of the refrigerant is attenuated when passing through a, the pressure pulsation component of the refrigerant discharged into the closed case inner space 11 is reduced, and the generation of noise can be reduced.

Problems to be Solved by the Invention However, in the above configuration, since the discharge chamber 10a has a substantially double cylindrical spatial shape, resonance of the double cylindrical cavity occurs within the discharge chamber 10a, and these resonances Loud noises may occur at high frequencies.

In view of the above problems, the present invention provides an extremely effective noise reduction effect without reducing the efficiency of the compressor.

Means for Solving the Problems In order to solve the above problems, the rotary compressor of the present invention includes a bearing having a valve hole and a discharge hole, and a part of the outer periphery of the journal part and the inner periphery of the cup-shaped side surface of this bearing. are in contact with or in close proximity to each other, and form a discharge chamber with the contact portion or the adjacent portion as both ends with the bearing, and the valve hole or the discharge hole is located approximately in the middle of both ends of the discharge chamber, and A discharge cover is provided in which the discharge hole or the valve hole is positioned approximately midway between the valve hole or the discharge hole and one end of the space.

Effect: With the above-described configuration, the present invention reduces the number of natural vibration modes of the cavity in the audible region that generate air column resonance in the discharge chamber, and reduces the number of air column resonances of low-order natural vibration modes that occur in the circumferential direction. By preventing the occurrence of noise and obtaining a silencing effect in a lower frequency range, an extremely effective silencing effect can be obtained.Example: Refer to the figure below for a rotary compressor according to an embodiment of the present invention. I will explain while doing so. In addition, to avoid duplication of explanation,
The same parts as in the conventional example are given the same reference numerals, and the explanation will be omitted.

1 to 3 show an embodiment of a rotary compressor of the present invention. In the figure, 12 is a bearing at the end of the shaft, and 12a is the outer circumference of the journal of the bearing 12.

12b is a valve hole, 12c is a valve, and 12d is a convex portion for mounting the valve 12c. 13 is a cup-shaped discharge cover, and a part 13a of the inner periphery of the side surface is connected to the outer periphery 12 of the journal.
The discharge chamber 14 is formed with the bearing 12 and in contact with or in close proximity to the bearing 12. 15 is a discharge hole provided in the bearing 12, with an inlet 15a and an outlet 15b.

The valve hole 12b is provided near an intermediate position between both ends 14a and 14b of the discharge chamber 14, and the inlet portion 15a of the discharge hole 15 is provided between both ends 14a and 14b of the discharge chamber 14.
It is provided near the intermediate position of 4b.

The operation of the rotary compressor configured as described above will be explained below with reference to FIGS. 1 to 3.

The refrigerant compressed within the cylinder 7 is discharged into the discharge chamber 14 through the valve hole 12b, and then discharged into the cylinder internal space 11 through the discharge hole 15 provided in the bearing 12. In this process, the pressure pulsations of the refrigerant generated within the cylinder 7 are attenuated mainly by the expansion-type silencing effect in the discharge chamber 14. Further, the discharge chamber 14 includes a part 13a of the inner periphery of the side surface of the discharge cover and an outer periphery 1 of the bearing journal part.
By contacting or being close to 2a, communication in the circumferential direction is prevented, so that air column resonance in the double cylindrical cavity does not occur. Further, the valve hole 12b and the inlet 15a of the discharge hole are located at both ends 14a and 1 of the discharge chamber, respectively.
Because it is near the middle position of 4b and the position where it is divided into % equal parts,
Either the valve hole 12b or the discharge hole inlet 15a is located near the node of the spatial natural vibration mode of 1 to 3 nodes in the circumferential direction, and the influence of the air column resonance of the low-order natural vibration mode. hard to receive. Furthermore, since the valve hole 15 is provided in the bearing 12, it can be of any length, so that the length can be set to a sufficiently low frequency limit value that limits the lower limit frequency of the silencing effect. Therefore, a wide silencing effect can be obtained.

Therefore, the influence of air column resonance in the audible band within the discharge chamber is small, and a wide and effective sound damping effect can be obtained.

As described above, according to this embodiment, by bringing the journal portion outer periphery 12a of the bearing 12 into contact with or close to the part 13a of the side inner periphery of the cup-shaped discharge cover 13, the side inner periphery of the discharge cover 13 is A part 13a of the both ends 14a,
14b is formed, a valve hole 12b is provided at a position approximately midway between both ends 14a and 14b of this discharge chamber 14, and a valve hole 12b is provided at a position approximately midway between this valve hole 12b and the end 14b of the discharge chamber 14. Hole 15
By providing this, it is possible to reduce the occurrence of air column resonance that occurs within the discharge chamber, and also to lower the lower limit frequency of the silencing effect, resulting in a silencing effect in the low frequency range, resulting in extremely wide and effective compression. Machine noise can be reduced.

Effects of the Invention As described above, the present invention provides a rotary compressor in which an electric compression element is housed in a sealed case. A part of the parts contacts or is close to each other, and forms a discharge chamber with the contact part or the adjacent part as both ends with the bearing, and the valve hole or the discharge hole is provided at a position approximately halfway between both ends of the discharge chamber. By further providing a discharge cover in which the discharge hole or the valve hole is positioned approximately midway between the valve hole or the discharge hole and one end of the discharge chamber, air generated in the discharge chamber can be prevented. By reducing the occurrence of column resonance and obtaining a silencing effect in a lower frequency range, a very wide and effective reduction in compressor noise can be achieved.

[Brief explanation of drawings]

FIG. 1 shows a bearing for a rotary compressor showing an embodiment of the present invention.
An exploded perspective view showing the discharge cover, Fig. 2 is a sectional view of essential parts of the same compressor, Fig. 3 is a sectional view of the same compressor, and Fig. 4 shows the bearing and discharge cover of a conventional rotary compressor. The exploded perspective view and FIG. 5 are sectional views of the same compressor. 7... Cylinder, 12... Bearing, 12b...
... Valve hole, 13 ... Discharge cover, 1
4. River: discharge chamber, 15: discharge hole. Name of agent: Patent attorney Toshio Nakao and 1 other person/
5--U excavation λb Fig. 2 14--U excavation λb

Claims (1)

[Claims] A sealed case housing an electric compression element, a bearing having a valve hole and a discharge hole of the electric compression element, and an outer periphery of a journal part of this bearing and a part of an inner periphery of a cup-shaped side surface are in contact with or close to each other, and the bearing A discharge chamber is formed with the contact portion or the adjacent portion as both ends, and the valve hole or the discharge hole is located approximately midway between the both ends of the discharge chamber, and the valve hole or the discharge hole and the A rotary compressor comprising a discharge cover in which the discharge hole or the valve hole is located approximately in the middle of one end of a discharge chamber.