JPS62170796A - Rotary compressor - Google Patents

Abstract

PURPOSE:To prevent occurrence of noise due to the vibration of an enclosed casing by forming a plurality of axial ribs having different axial positions for splitting a circumference unevenly onto the outer circumference at the tubular section of the enclosed casing formed by the tubular section and cup type cover sections. CONSTITUTION:An enclosed casing 22 for an enclosed rotary compressor is formed by jointing a tubular section 23 and the cup type cover sections 24, 25. Axial ribs 23c, 23d are formed on the outer circumference of said tubular section 23 at the positions for splitting the circumference unevenly. Said axial ribs 23c, 23d include two types of ribs, i.e. one type of ribs extending from the vicinity of one end section to the side nearer to the other end section then the central portion and the other type of ribs extending from the vicinity of the other end section to the side nearer to one end section than the central portion. Since the vibration frequency of the enclosed casing 22 is sifted to the high region side and the vibration in the audible frequency region is reduced, occurrence of uncomfortable noise can be prevented.

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 refrigeration systems have been shifting from reciprocating type to bi-vane type compressors from the viewpoint of energy saving and space saving. These rotary compressors are typically
The electric compression element is fixed to the closed case by shrink fitting or welding the electric motor stator and bearing or cylinder. Therefore, the vibrations generated by the electric compression element are transmitted to the sealed case without being absorbed by the spring or the like, which may cause the sealed case to vibrate and generate large noise.

An example of the conventional rotary compressor mentioned above will be described below with reference to the drawings.

FIG. 4 shows an example of a conventional rotary compressor.

In the figure, 1 is a rotary compressor.

2 is an electric motor, 3 is a stator, 4 is a rotor, and 5 is a winding of the stator. 6 is a compression element, 7 is a crankshaft fixed to the rotor 4, 8 and 9 are bearings that support the crankshaft 7, 1o is a cylinder, and 11 is a piston that is slidable around the crank portion 7a of the crankshaft. .

In the 12Fi discharge cover, 14 is an oil supply pipe that includes a spring 13 connected to the crankshaft 7. 15
is a sealed case made of three rigid materials, which includes a cylindrical part 16 with a thickness of 2.5mm and a cup-shaped part with a thickness of 3wn, which internally fixes the stator 3 and the bearing 8.
It consists of lid parts 17 and 18. 19 is a suction pipe, 20 is a discharge pipe, and 21 is refrigerating machine oil.

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

Mainly, refrigerant pressure pulsations and mechanical vibrations caused by compression of the refrigerant in the cylinder 10 vibrate each component and propagate through the bearing 8 or the refrigerant in the closed case 14 and are transmitted to the closed case 14. Unfortunately, the sealed case 15 vibrates and generates noise.

Problems to be Solved by the Invention The sealed case 15 undergoes rigid body vibration without deformation in the frequency range up to I KHz-2 KHz, but undergoes elastic vibration accompanied by deformation in the frequency range above that.

The sealed case 15 includes the stator 3 and the bearing 10 in the cylindrical part 16.
is internally fixed, elastic vibration accompanied by deformation of the circular cross section of the sealed case 15 occurs in the high frequency range of 5 KHz or higher, and in the frequency range of 2 to 5 KHz, as shown in Fig. 5. The main vibration is elastic vibration accompanied by axial deformation.

In addition, in FIG. 5, A shows an undeformed shape, and B shows a deformed shape.

Therefore, between 2 and 5 kHz, vibrations occur mainly due to the deformation of the axial cross section of the sealed case, and above 5 kHz, noise is generated due to vibrations accompanied by the deformation of the circular cross section of the sealed case.

In view of the above-mentioned problems, the present invention provides an extremely effective compressor noise reduction effect without reducing compressor efficiency and without substantially impairing the compactness of the compressor.

Means for Solving the Problems In order to solve the above problems, the rotary compressor of the present invention has the following features:
The cylindrical part of the sealed case has a plurality of ribs in the axial direction that protrude toward the outer circumference at positions that unevenly divide the circumference and extend from the vicinity of one end to the center and the other end, and a circular rib that does not overlap with these ribs. It is provided with a plurality of six pages of ribs in the axial direction that protrude in the outer circumferential direction at positions that divide the circumference unevenly and extend from near the other end to the center and toward the one end.

Function The present invention aims at reducing noise in the audible frequency range by shifting vibrations accompanied by deformation of the axial cross-section of the sealed case and vibrations accompanied by deformation of the circular cross-section to a high frequency range, using the above-described configuration. .

EXAMPLE Hereinafter, a rotary compressor according to an example of the present invention will be described with reference to the drawings. 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, 22 is a closed case made of steel, 23 is a cylindrical part with a thickness of 2.5 mm, and 24.25 is a cup-shaped lid part with a thickness of 3 mm. The cylindrical portion 23 is provided with four ribs 23c that protrude toward the outer circumference at positions that divide the circumference unevenly and extend from near one end 23a to the other end 23b from the center. . These ribs 23c extend around the cylindrical portion 23 in a 6:4:5:36 direction in the circumferential direction.
Arranged to divide the page proportions unevenly.

Further, the cylindrical portion 23 is provided with four ribs 23d that protrude in the outer circumferential direction at positions that divide the circumference unevenly and extend from near the end 23b to the center toward the end 23a.

These ribs 23d divide the cylindrical portion 23 unevenly in the circumferential direction in the opposite direction from the ribs 23c at a ratio of 6:4:5:3, and are arranged so as not to overlap with the ribs 23c.

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

Mainly, refrigerant pressure pulsations and mechanical vibrations caused by compression of the refrigerant within the cylinder 10 vibrate each component and propagate through the bearing 8 or the refrigerant within the closed case 22 and are transmitted to the closed case 22. Therefore, the sealed case 22 vibrates and generates noise.

The sealed case 22 performs rigid body vibration without deformation in a frequency range of 1 to 2 kHz, but performs elastic vibration with deformation in a frequency range higher than that. In the sealed case 22, the stator 3 and the bearing 1o are internally fixed in the cylindrical part 23, so the elastic vibration is mainly due to axial deformation at low frequencies, and as the frequency increases, Some appear due to deformation of the circular cross section. However, since the cylindrical portion 23 is provided with ribs 23C and 23d in the axial direction, the closed case 22
Since the ribs 23C and 223d are rigidly strong against deformation in the axial cross section, the natural frequency due to the deformation in the axial cross section becomes higher than in the case where there is no rib 23C223d.

Further, since the ribs 23C223d are arranged so as to divide the circumference unevenly, the vibration due to the deformation of the circular cross section cannot take a perfectly axially symmetrical mode, so that the natural frequency becomes high.

Moreover, since the ribs 23C and 23d are arranged so that the circumferential cross section is divided into different sections without overlapping each other, the vibrations due to the circular cross-sectional deformation on the end 23a side and the end 23b side are transmitted to the other end. It is difficult to excite vibration due to the circular cross-sectional deformation on the portions 23b and 23a sides, and a damping effect is exerted, so that the amplitude of the circular cross-sectional deformation is extremely small for the same excitation force.

As described above, according to this embodiment, the cylindrical portion 23 of the sealed case 22 has protrusions in the outer circumferential direction at positions that divide the circumference unevenly, and extends from near the end 23a to the other end 23b from the center. A plurality of consecutive ribs 23c in the axial direction and these ribs 2
3c, but protrudes in the outer circumferential direction at a position that divides the circumference unevenly, and from near the end 23b to the center from the end 23a.
By providing a plurality of ribs 2sd in the axial direction connected to the side, it is possible to shift the natural frequency due to deformation of the axial cross section and circular cross section of the sealed case 22 to a high frequency region, and reduce the natural vibration mode in the audible frequency region. , Furthermore, the damping effect can reduce the vibration amplitude due to the deformation of the circular cross section, without compromising the compressor efficiency.
Still, compressor noise can be stably reduced without compromising the compactness of the compressor.

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 plurality of ribs extending in the axial direction from near one end to the center from the other end, and a plurality of ribs that do not overlap with these ribs and protrude in the outer circumferential direction at positions that unevenly divide the circumference from near the other end to the center. By providing a plurality of ribs in the axial direction connected to the one end side, the natural frequency due to the deformation of the axial cross section of the sealed case and the deformation of the circular cross section is shifted to a higher frequency region, and the natural vibration mode in the audible frequency region is shifted. Furthermore, the damping effect can reduce the vibration amplitude due to the deformation of the circular cross section, stabilizing the compressor noise without compromising the compressor efficiency or almost impairing the compactness of the compressor. It is intended to reduce the

[Brief explanation of drawings]

Fig. 1 is a perspective view of a cylindrical part of a sealed case of a rotary compressor showing an embodiment of the present invention, Fig. 2 is a sectional view taken along line 1-1' in Fig. 4 is a sectional view of a conventional rotary compressor, and FIG. 5 is a diagram showing natural vibration modes due to deformation of the axial cross section of the closed case of the same compressor. 10 Beno 3... Stator, 8... Bearing, 22...
... Sealed case, 23 ... Cylindrical part, 23
C...Rib, 23d...Rib.

Claims (1)

[Claims] Both ends are circular, and a plurality of ribs in the axial direction protrude toward the outer circumference at positions that unevenly divide the circumference and extend from the vicinity of one end to the center and the other end, and these ribs do not overlap and are circular. A sealed case is formed by a substantially cylindrical portion having a plurality of ribs in the axial direction protruding toward the outer circumference at positions that divide the circumference unevenly and extending from near the other end to the central portion toward the one end, and a cup-shaped lid portion. A rotary compressor with an electric compression element formed and housed within this closed case.