JPS62186090A - Rotary type compressor - Google Patents

Abstract

PURPOSE:To prevent the generation of noise in an audio-frequency region, by a method wherein a closed case is formed with an approximately cylindrical part, having plural axial ribs, which are protruded in the direction of a center in positions, in which a periphery is divided unequally, and extended in succes sion to both ends, and a cup-shaped cover part. CONSTITUTION:Plural axial ribs 24c, which are protruded in the direction of a center in positions, in which a periphery in unequally divided, and extended in succession to both end parts 24a and 24b, are formed in the outer periphery of an approximately cylinder part 24 with which a closed case 23 is formed together with cup-shaped cover parts 25 and 26. Since the periphery is unequally divided by means of the ribs 24c, this constitution prevents vibration due to deformation of the approximately cylindrical part 24 from forming a mode symmetrical about a shaft, and increases the natural frequency thereof, resulting in reduction of the generation of noise in an audio frequency region.

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 types to rotary types from the standpoint of energy and space savings. These rotary compressors typically have an electric compression element fixed to a 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 not absorbed by springs, etc., and are transmitted to the sealed case.
The closed case sometimes vibrates and generates a large noise. Hereinafter, an example of the above-mentioned conventional rotary compressor will be explained 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, 10 is a cylinder, and 11 is a piston that is slidable around the crank portion 7a of the crankshaft. .

12 is a discharge cover, and 14 is an oil supply pipe that includes a spring 13 connected to the crankshaft 7. Reference numeral 15 denotes a sealed case made of rigid material, which includes a cylindrical part 16 with a thickness of 2.6 mm and a cup-shaped thickness 3 for internally fixing the stator 3 and the bearing 8.
It consists of lid parts 17 and 18 of g. 19 is a suction pipe, 2o 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. Therefore, the sealed case 15 vibrates 9 and generates noise.

Problems to be Solved by the Invention The sealed case 16 undergoes rigid body vibration without deformation in the frequency range from IKHz to 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 6 KHz, the vibration as shown in Fig. 6 occurs. 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 substantially impairing the compactness of the upper compressor, which is designed to improve compressor efficiency.

Means for Solving the Problems In order to solve the above problems, the rotary compressor of the present invention has a shaft in the cylindrical part of the sealed case that protrudes toward the center at positions that divide the circumference unevenly and is connected to both ends. It is equipped with a plurality of ribs in different directions.

This aims to reduce noise in the audible frequency range.

EXAMPLE Hereinafter, a rotary compressor according to an example of the present invention will be described with reference to the drawings. In order 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 the present reciprocating rotary compressor. In the figure, 22 is a stator with a cylindrical outer circumference, 23 is a sealed case made of steel, 24 is a cylindrical part with a thickness of 2.5 cm, and 26° is a cup-shaped lid part with a thickness of 3 cm. be. The cylindrical portion 24 is provided with six ribs 24c in the axial direction that protrude toward the center at positions that unevenly divide the circumference and are continuous to both end portions 24a and 24b. These ribs 24C are 9:3:8 in the circumferential direction of the cylindrical portion 24.
:4 near=5.

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 23 to the closed case 23. Therefore, the sealed case 23 vibrates and generates noise.

The sealed case 23 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. The sealed case 23 has the stator 22 and the bearing 1o in the cylindrical part 24.
is internally fixed, so at low frequencies, elastic vibrations are mainly due to deformation in the axial direction, and as the frequency increases, deformation of the circular cross section appears. However, since the cylindrical portion 24 is provided with the ribs 24c in the axial direction, the sealed case 24 has greater rigidity against deformation in the axial cross section. The natural frequency becomes higher.

Further, since the ribs 24c 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.

As a result, the number of natural vibration modes in the audible frequency range is reduced, and noise is reduced.

Furthermore, even if the outer peripheral shape of the stator 23 is circular,
The ribs 24c ensure a flow path for refrigerating machine oil and refrigerant, so there is no need to provide a cutout in the stator 22 for the flow of refrigerating machine oil and refrigerant, unlike in the past.In addition to improving motor efficiency, it is possible to The cross-sectional area of the flow path can be widened, and the motor can be cooled effectively.

As described above, according to this embodiment, both ends 24a of the cylindrical portion 24 of the closed case 230 protrude toward the center at positions that divide the circumference unevenly.

By providing a plurality of ribs 24c in the axial direction connected to 24b, the natural frequency due to the deformation of the axial cross section and circular cross section of the sealing case 223 is shifted to a higher frequency region of the sieve nose 11, and the natural vibration mode in the audible frequency region is shifted. By reducing the number of motors, compressor efficiency can be improved by improving motor efficiency, compressor reliability can be improved by improving motor cooling, and compressor 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. By providing multiple ribs in the axial direction that connect at both ends, it is possible to increase the natural frequency due to the deformation of the axial cross section and circular cross section of the sealed case, improving efficiency and reliability while reducing compressor noise. can be reduced.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the cylindrical part of the sealed case of a rotary compressor showing an embodiment of the present invention, Fig. 2 is a front view of the cylindrical part of the compressor, and Fig. 3 is a sectional view of the compressor. , FIG. 4 is a sectional view of a conventional rotary compressor, and FIG. 5 is a diagram showing the natural vibration mode due to deformation of the axial cross section of the closed case of the same compressor. 8...Bearing, 22...Stator, 23
... Sealed case, 24 ... Cylindrical part, 2
4c...Rib. Name of agent: Patent attorney Toshio Nakao and 1 other personz4
---Cylindrical part Fig. 1 24cm Soft Fig. 2 8-11 Glaze holder η--Stage O - Sealed case 24- Cylindrical part 24cm--Tub Fig. 3 Fig. 4 Fig. 5

Claims (1)

[Claims] An airtight case is formed by a substantially cylindrical part having a plurality of ribs in the axial direction that protrude toward the center at positions that divide the circumference unevenly and are connected to both ends, and a cup-shaped lid part, and an electrically powered A rotary compressor that houses compression elements.