EP2472116B1

EP2472116B1 - Hermetic compressor

Info

Publication number: EP2472116B1
Application number: EP11195144.8A
Authority: EP
Inventors: Jinsoo Kim; Jonghun Ha; Jangwoo Lee; Minchul Yong; Seungmock Lee
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2010-12-29
Filing date: 2011-12-22
Publication date: 2015-10-21
Anticipated expiration: 2031-12-22
Also published as: EP2472116A2; KR20120076164A; KR101718037B1; ES2551406T3; EP2472116A3

Description

This specification relates to a hermetic compressor, and particularly, to a hermetic compressor capable of reducing vibration of the compressor due to an accumulator.
In general, a hermetic compressor has a structure that a driving motor and a compression unit are installed within an inner space of a hermetic container. The hermetic compressors may be classified into a reciprocal type, a rotary type, a scroll type and the like according to a mechanism of compressing a refrigerant. Also, the hermetic compressors may be classified into a high pressure type and a low pressure type according to a mechanism of sucking a refrigerant or a mechanism of discharging a compressed refrigerant. That is, for the low pressure type hermetic compressor, a suction pipe is connected to the inner space of the hermetic container and a discharge pipe is connected to the compression unit such that the inner space of the hermetic container is filled with a sucked refrigerant in a low pressure state. On the contrary, for the high pressure type hermetic compressor, the suction pipe is connected directly to the compression unit and the discharge pipe is connected to the inner space of the hermetic container such that the inner space of the hermetic container is filled with a discharged refrigerant in a high pressure state. In regard of the high pressure type hermetic compressor, a refrigerant, which is introduced into the compressor via an evaporator, may be mixed with not only a gas refrigerant but also a liquid refrigerant left without being evaporated. Accordingly, an accumulator for separating and evaporating the liquid refrigerant is typically installed at a suction side of the compressor. However, the accumulator is connected to the hermetic container from the outside via a refrigerant pipe, accordingly, it is vulnerable to vibration of the compressor. Consequently, as the vibration of the compressor is increased, the increased vibration is transferred to an overall outdoor unit via the refrigerant pipe, thereby increasing noise of the outdoor unit.
FIG. 1 is a longitudinal sectional view showing an accumulator connected to a twin type rotary compressor according to the related art.
As shown in FIG. 1, in the structure of the related art twin type rotary compressor, an accumulator 1 is connected to a hermetic container 5 of the compressor by a plurality of L- shaped connection pipes 2 and 3 and a bracket 4. The connection pipes 2 and 3 are welded onto a lower end of the accumulator 1 and the bracket 4 is welded onto an upper end portion of the accumulator 1.
The connection pipes 2 and 3 are inserted into a housing 6, which defines a hermetic space of the accumulator 1, by a predetermine depth, and the bracket 4 is coupled to an outer circumferential surface of the housing 6.
A holder 7 for supporting the connection pipes 2 and 3 is coupled to an inner circumferential surface of the housing 6. The holder 7 is formed in an annular shape such that the outer circumferential surfaces of the connection pipes 2 and 3 can be closely adhered onto an inner circumferential surface of the holder 7 to be supported thereby.
The holder 7 is installed at a position as high as the middle of the housing 6 so as to stably support the connection pipes 2 and 3.
However, in the related art hermetic compressor, as the bracket 4 to support the accumulator 1 onto the hermetic container 5 of the compressor and the holder 7 to support the connection pipes 2 and 3 are spaced apart from each other by a predetermined interval L1, a mount stiffness for the accumulator 1 is lowered. Accordingly, vibration increases in the accumulator 1, which causes a stress to be concentrated onto a suction side of the accumulator 1 and a coupled portion of a suction pipe 8. Consequently, the suction pipe 8 is severely vibrated, and thereby a panel or pipe of an outdoor unit is vibrated more severely, resulting in increasing vibration noise of the entire outdoor unit.
JP 2005 054 741 discloses the features of the preamble of claim 1.
Therefore, an object of the invention is to provide a hermetic compressor capable of reducing vibration of an accumulator, and accordingly reducing vibration of a suction pipe connected to the accumulator, thereby resulting in reduction of vibration noise of an outdoor unit. This object is achieved with the subject-matter of the claims.
The basic idea of the invention is to raise a mount stiffness of support members, which support a hermetic container and the accumulator of the compressor.
There is provided a hermetic compressor according to claim 1.
Further scope of applicability of the present application will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the scope of the invention will become apparent to those skilled in the art from the detailed description.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments and together with the description serve to explain the principles of the invention.
In the drawings:

FIG. 1 is a longitudinal sectional view of an accumulator connected to a twin-type rotary compressor according to the related art;
FIG. 2 is a longitudinal sectional view of a twin-type rotary compressor having an accumulator connected thereto according to the present disclosure;
FIG. 3 is a sectional view taken along the line 'I-I' of FIG. 2;
FIG. 4 is a longitudinal sectional view showing the accumulator applied to the twin-type rotary compressor;
FIG. 5 is a graph showing changes in vibration of a refrigerant pipe when central lines of a holder and a bracket in each circumferential direction are aligned to each other and when they are not aligned to each other, in a hermetic compressor according to the present disclosure;
FIG. 6 is a graph showing changes in vibration according to a position of central lines in the hermetic compressor; and
FIG. 7 to 10 are graphs showing a vibration noise reduction effect of an outdoor unit having the compressor mounted therein.

Description will now be given in detail of a hermetic compressor according to an exemplary embodiment of a twin-type rotary compressor, with reference to the accompanying drawings. For the sake of brief description with reference to the drawings, the same or equivalent components will be provided with the same reference numbers, and description thereof will not be repeated.
FIG. 2 is a longitudinal sectional view of a twin-type rotary compressor having an accumulator connected thereto according to the present disclosure, and FIG. 3 is a sectional view taken along the line 'I-I' of FIG. 2.
As shown in FIGS. 1 and 2, in a twin-type rotary compressor 10 according to an exemplary embodiment, a suction side of the compressor 10 may be connected to an outlet side of an evaporator and simultaneously a discharge side thereof may be connected to an inlet side of the condenser so as to configure a part of a refrigerating cycle in form of a closed loop sequentially connected to a condenser, an expansion apparatus and the evaporator. An accumulator 20, which separates a refrigerant transferred from the evaporator to the compressor into a gas refrigerant and a liquid refrigerant, may be connected between the outlet side of the evaporator and the suction side of the compressor.
The compressor 10 may include a driving motor 12 installed at an upper side within an inner space of a hermetic container 11 to generate a driving force, and a first compression unit 13 and a second compression unit 14 installed at a lower side within the inner space of the hermetic container 11 to compress a refrigerant by the driving force generated from the driving motor 12.
The inner space of the hermetic container 11 may be maintained in a discharge pressure state by a refrigerant discharged from the first compression unit 13 and the second compression unit 14 or a refrigerant discharged from the first compression unit 13.
The driving motor 12 may include a stator 121 fixed onto an inner circumferential surface of the hermetic container 11, a rotor 122 rotatably disposed in the stator 121, and a crankshaft 123 shrink-fitted into the rotor 122 to be rotatable together with the rotor 122. The driving motor 12 may be a constant speed motor or an inverter motor. However, in regard of a fabricating cost, the driving motor 12 may idle one of the first compression unit 13 and the second compression unit 14, if necessary, to change an operation mode of the compressor even with using the constant speed motor.
The first compression unit 13 may include a first cylinder 131 to define a first compression space V1, a first rolling piston 132 eccentrically coupled to the crankshaft 123 to compress a refrigerant with orbiting in the first compression space V1, a first vane (not shown) coupled to the first cylinder to be movable in a radial direction and having a sealing surface at one side thereof contactable with an outer circumferential surface of the first rolling piston 132 such that the first compression space V1 can be partitioned into a first suction chamber and a first discharge chamber, and a vane spring (not shown) implemented as a compression spring to elastically support a rear side of the first vane.
The second compression unit 14 may include a second cylinder 141 installed below the first cylinder 131 to define a second compression space V2 isolated from the first compression space V1, a second rolling piston 142 eccentrically coupled to the crankshaft 123 to compress a refrigerant with orbiting in the second compression space V2, a second vane (not shown) coupled to the second cylinder 141 to be movable in a radial direction, and contactable with an outer circumferential surface of the second rolling piston 142 such that the second compression space V2 can be partitioned into a second suction chamber and a second discharge chamber, or spaced from the outer circumferential surface of the second rolling piston 142 such that the second suction chamber and the second discharge chamber can communicated with each other, and a vane spring (not shown) implemented as a compression space to support a rear side of the second vane.
Here, the first compression unit 13 and the second compression unit 14 may be connected to the accumulator 20 via a first connection pipe 23 and a second connection pipe 24, respectively.
In the meantime, an upper bearing plate (hereinafter, referred to as an upper bearing) 151 which supports the crankshaft 123 may cover an upper side of the first cylinder 131, and a lower bearing plate (hereinafter, referred to as a lower bearing) 152 which supports the crankshaft 123 may cover a lower side of the second cylinder 141. An intermediate plate 153, which defines the first compression space V1 and the second compression space V2 together with both of the bearings 151 and 152, may be installed between the lower side of the first cylinder 131 and the upper side of the second cylinder 141.
Hereinafter, description will be given of a process that a refrigerant is compressed in each compression space in the rotary compressor.
That is, when the rotor 122 rotates as power is applied to the stator 121 of the driving motor 12, the crankshaft 123 rotates together with the rotor 122 to transfer a rotational force of the driving motor 12 to the first and second compression units 13 and 14. In the first and second compression units 13 and 14, the first rolling piston 132 and the second rolling piston 142 eccentrically rotate in the first and second compression spaces V1 and V2, respectively, thereby defining the first compression space V1 and the second compression space V2, which have a phase difference of 180° from each other, in cooperation with the first vane (not shown) and the second vane (not shown).
Accordingly, as volumes of the first compression space V1 and the second compression space V2 change, a suction force is generated such that a refrigerant can alternately be sucked into the first compression space V1 and the second compression space V2 from the evaporator of the refrigerating cycle apparatus. Here, the sucked refrigerant is first introduced into the accumulator 20, which is installed outside the hermetic container 11 to be connected to each of the compression spaces V1 and V2, prior to being sucked into the first and second compression spaces V1 and V2. The refrigerant introduced into the accumulator 20 is separated into a gas refrigerant and a liquid refrigerant. Afterwards, the gas refrigerant is directly introduced into each of the first compression space V1 and the second compression space V2, while the liquid refrigerant is evaporated in the accumulator 20 to be converted into the gas refrigerant, thereafter being introduced into each of the first compression space V1 and the second compression space V2.
Here, vibration may be generated in the compressor during the process that the rotational force is generated in the driving motor 12 or the process that the refrigerant is sucked and discharged. The vibration may be transferred to the accumulator 20 via the first connection pipe 23 and the second connection pipe 24 to be increased along a refrigerant pipe connected to the accumulator 20. Therefore, in order for the vibration generated within the compressor to be offset or attenuated in the accumulator 20, the accumulator 20 should be supported with an enhanced mount stiffness.
However, in the related art, a holder as a first support member to fix connection pipes to the accumulator and a bracket as a second support member to fix the accumulator to the compressor have been located at non-overlapped positions, which results in distribution of the mount stiffness. Accordingly, the overall mount stiffness for the accumulator has been lowered and thereby vibration noise of the compressor including the accumulator has been increased.
Therefore, in the present disclosure, a height, i.e. the vertical position, at which the holder and the bracket overlap (are aligned to) each other may be adjusted. A central line of the holder in a circumferential direction and a central line of the bracket in a circumferential direction are disposed to be aligned to each other and simultaneously the central lines are located at a position as high as the (vertical) middle of the accumulator, namely, within a range of 0.3 - 0.6 times of an entire length (height) of the accumulator from a top of the accumulator. Preferably, the range is from 0.3 ∼ 0.5 times of said entire length, and most preferably 0.4 times of said entire length.
FIG. 4 is a longitudinal sectional view showing an accumulator applied to the twin-type rotary compressor.
The accumulator 20 according to this exemplary embodiment may have a hermetic inner space formed by a housing 21. The housing 21 may include an upper housing 211 and a lower housing 212, which are coupled to form the hermetic inner space.
Here, a coupled portion 213 where the upper housing and the lower housing are coupled to each other may preferably be located within a range of 0.3 - 0.6 times of the entire length of the accumulator from the top of the accumulator 20, which may result in reduction of vibration noise. Preferably, the range is from 0.3 ∼ 0.5 times of said entire length, and most preferably 0.4 times of said entire length. The coupled portion 213 may preferably be located between the top of the accumulator 20 and a holder 25 to be explained later.
An inlet side connection pipe 22 to guide a refrigerant from the evaporator to the inner space of the housing 21 may be connected to an upper side of the upper housing 211, and a plurality of outlet side connection pipes 23 and 24 to guide a refrigerant into each of the compression units 13 and 14 may be connected to a lower side of the lower housing 212.
The plurality of outlet side connection pipes 23 and 24 may have a shape like an alphabet 'L.' Upper ends of the respective connection pipes 23 and 24 may be inserted into the inner space of the housing 21 by a predetermined height. The outlet side connection pipes 23 and 24 may be supported on the lower housing 212 by the holder 25 at the middle portions thereof.
A plurality of through holes 212a and 212b, in which the plurality of outlet side connection pipes 23 and 24 are inserted, may be formed through the lower end of the lower housing 212. Supporting portions 212c and 212d may protrude from circumferences of the plurality of through holes 212a and 212b, respectively, by a predetermined height so as to support the outlet side connection pipes 23 and 24.
A bracket 26, by which the accumulator 20 is fully fixed onto the hermetic container 11 of the compressor, may be fixed onto an outer circumferential surface of the housing 21. Both ends of the bracket 26 may be welded onto the outer circumferential surface of the hermetic container 11 of the compressor 10 and the outer circumferential surface of the housing 21 of the accumulator 20, or clamped thereon by use of separate coupling members (not shown).
The holder 25 has a (imaginary) central line CL lying in a horizontal plane, i.e. in a plane being perpendicular to the longitudinal axis of the accumulator 20, and extending radially with respect to the accumulator 20. The central line CL is central with respect to the height of the holder 25. The bracket 26 also has a (imaginary) central line CL lying in a horizontal plane, i.e. in a plane being perpendicular to the longitudinal axis of the accumulator 20, and extending radially with respect to the accumulator 20. The central line CL is central with respect to the height of the bracket 26. Here, the holder 25 and the bracket 26, as aforementioned, may be disposed such that central lines CL thereof overlap (i.e. are coincident) or intersect each other and simultaneously a distance H of the central line CL from the top of the accumulator 20 can be in a range of a middle height of the accumulator 20, namely, located within a range of 0.3 - 0.6 times of the entire length L2 of the accumulator 20 from the top of the accumulator 20. Preferably, the range is from 0. 3 - 0.5 times of said entire length, and most preferably 0.4 times of said entire length.
Typically, in a compressor or an outdoor unit employing the compressor, a high peak mode (peak noise) is generated by resonance in a frequency domain corresponding to a harmonic element of an operational frequency of the compressor. FIG. 5 shows a graph showing an analysis result of changes in peak noise, which is exhibited in a frequency of approximately 192 Hz when the compressor runs in an operational frequency of approximately 48 Hz. As shown in the graph, when the holder 25 and the bracket 26 are spaced apart from each other by a predetermined interval as shown in the related art, a pipe vibration acceleration has been almost 20m/s². On the contrary, it can be noticed that when the holder 25 and the bracket 26 are aligned to each other as shown in the present disclosure, the pipe vibration acceleration is lowered by about 67% of the related art, namely, lowered to almost 6m/s².
Also, FIG. 6 shows a graph showing an analysis result of changes in vibration measured with changing a position of the central lines of the holder and the bracket from the top of the accumulator, in a state that the two central lines are aligned to each other. As can be seen in FIG. 6, the vibration acceleration increases when the central line CL is closer to the top or bottom of the accumulator 20, while decreasing when the central line CL is closer to the center of the accumulator 20. Especially, when the central line CL is located within a range of 0.3 - 0.6 times of the entire length of the accumulator from the top of the accumulator, the pipe vibration acceleration becomes lower than approximately 10m/s², whereby vibration noise of the compressor and the outdoor unit having the compressor can be reduced that much. Preferably, the range is from 0. 3 - 0.5 times of said entire length, and most preferably 0.4 times of said entire length.
FIGS. 7 to 10 are graphs each showing a vibration noise reduction effect in an outdoor unit having the compressor. FIGS. 7 and 8 show the vibration noise reduction effect at front and lower sides of the outdoor unit in a cooling condition, and FIGS. 9 and 10 show the vibration noise reduction effect at front and lower sides of the outdoor unit in a heating condition.
Referring to those graphs, the outdoor unit having the compressor, in which the bracket for supporting the accumulator and the holder for supporting the connection pipes are disposed at almost the same position and the bracket and the holder are installed within the range (namely, 0.3 - 0.6 times of the length of the accumulator), exhibits more reduction of vibration noise at the front and lower sides in both the cooling and heating modes.
As described above, the holder for supporting the connection pipes and the bracket for supporting the accumulator at the hermetic container of the compressor may be fixed onto the same position and the holder and the bracket may be disposed as high as the middle of the accumulator, so as to reduce vibration, which is generated in the compressor and increased and transferred along a refrigerant pipe via the accumulator, resulting in reduction of vibration noise generated from the compressor and the outdoor unit having the compressor.
The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present disclosure. The present teachings can be readily applied to other types of apparatuses. This description is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments.
As the present features may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.

Claims

A hermetic compressor comprising:
a hermetic container (11);

compression units (13, 14) installed within the hermetic container (11) to compress a refrigerant;

an accumulator (20) installed outside the hermetic container (11) and having a hermetic inner space;

connection pipes (23, 24) inserted into the inner space of the accumulator (20) to connect the inner space to a suction side of the compression units (13, 14);

a first supporting member (25) fixed onto an inner circumferential surface of the accumulator (20) to support the connection pipes (23, 24); and

a second supporting member (26) fixed onto an outer circumferential surface of the hermetic container (11) and an outer circumferential surface of the accumulator (20),

characterized in that the first supporting member (25) has a central line (CL) lying in a horizontal plane and extending radially with respect to the accumulator (20) and being central with respect to the height of the first supporting member (25),

wherein the second supporting member (26) has a central line (CL) lying in a horizontal plane and extending radially with respect to the accumulator (20) and being central with respect to the height of the second supporting member (26),

wherein said central lines (CL) overlap or intersect with each other, and

wherein the central lines (CL) are located relative to the top of the accumulator (20) within a range of 0.3 ∼ 0.6 times of an entire length (L2) of the accumulator (20) from a top of the accumulator (20).
The compressor of claim 1, wherein the accumulator (20) comprises an upper housing (211) and a lower housing (212) coupled to each other forming said hermetic inner space,
wherein a coupled portion (213) between the upper housing (211) and the lower housing (212) is located relative to the top of the accumulator (20) within a range of 0.3 ∼ 0.6 times of the entire length of the accumulator (20) from the top of the accumulator (20).
The compressor of claim 2, wherein the coupled portion (213) is located between the top of the accumulator (20) and the first supporting member (25).
The compressor of any of claims 1 to 3, wherein the first supporting member (25) and the second supporting member (26) are disposed such that the central lines (CL) thereof are aligned to each other.
The compressor of any one of claims 1 to 4, wherein the range is from 0. 3 ∼ 0.5 times of said entire length (L2).
The compressor of any of claims 1 to 5, wherein the range is 0.4 times of the entire length (L2).
The compressor of any of claims 1 to 6, wherein through holes (212a, 212b) for insertion of the connection pipes (23, 24) therethrough are formed through a lower end of the accumulator (20),
wherein supporting portions (212c, 212d) to support the connection pipes (23, 24) protrude vertically from circumferences of the respective through holes (212a, 212b).
The compressor of claim 7, wherein the through holes (212a, 212b) are provided in plurality, and the connection pipes (23, 24) are inserted into the plurality of through holes (212a, 212b), respectively.