Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
  • F04B39/0027—Pulsation and noise damping means
  • F04B39/0055—Pulsation and noise damping means with a special shape of fluid passage, e.g. bends, throttles, diameter changes, pipes
  • F04B39/0066—Pulsation and noise damping means with a special shape of fluid passage, e.g. bends, throttles, diameter changes, pipes using sidebranch resonators, e.g. Helmholtz resonators
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B35/00—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for
  • F04B35/04—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for the means being electric
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
  • F04B39/0027—Pulsation and noise damping means
  • F04B39/0033—Pulsation and noise damping means with encapsulations
  • F04B39/0038—Pulsation and noise damping means with encapsulations of inlet or outlet channels
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
  • F04B39/0027—Pulsation and noise damping means
  • F04B39/0055—Pulsation and noise damping means with a special shape of fluid passage, e.g. bends, throttles, diameter changes, pipes
  • F04B39/0061—Pulsation and noise damping means with a special shape of fluid passage, e.g. bends, throttles, diameter changes, pipes using muffler volumes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
  • F04B39/10—Adaptations or arrangements of distribution members
  • F04B39/1066—Valve plates

Definitions

• the present invention refers to a suction muffler for a refrigeration compressor, particularly of the type used in small refrigeration systems, such as refrigerators, freezers, water fountains, refrigerated counters, and which is provided in the region where the refrigerant gas is admitted to the hermetic compressor.
• compressors of the refrigeration systems present, at the suction side thereof, an acoustic dampening system or suction muffler provided inside the shell and which conducts the gas coming from the suction line of said refrigeration systems to a suction valve that is conventionally disposed to provide the selective and automatic opening of a respective suction orifice of a valve plate in which the suction and discharge valves of the compressor are usually mounted.
• the suction muffler has, several important functions to the adequate operation of the compressor, such as: to direct the gas, to attenuate the noise resulting from pulsation provoked by suction, to thermally insulate the gas being drawn into the cylinder, and to control the dynamics of the suction valve.
• the present refrigeration compressors use the suction muffler of the volume-tube type.
• This type of suction muffler usually consists of a sequence of volumes interconnected by tubes which conduct the gas coming from the suction line directly to the suction valve. At present, said tubes presenting open ends for the passage of refrigerant gas.
• Gas displacement produces pulses, generating noises that are propagated in a direction that is opposite to the gas flow toward the suction valve.
• the influence of the suction muffler on the performance of the compressor is highly important and the dimensioning of both the inner volumes and the length of the tubes of the suction muffler determine, to a great extent, the efficiency of the compressor.
• the known suction mufflers of the volume-tube type have the disadvantage of presenting noise peaks in the specific operational modes of said tubes .
• a suction muffler for a refrigeration compressor mounted within a shell
• said suction muffler comprising a hollow body defining at least one dampening chamber that carries a gas inlet duct having an inlet opening external to the dampening chamber and an outlet opening in the interior of the dampening chamber, and a gas outlet duct presenting an inlet opening in the interior of the dampening chamber and an outlet opening external to said dampening chamber, at least one of the gas inlet and gas outlet ducts presenting at least one closed end, and one of the inlet and outlet openings being positioned at a certain distance from said closed end, along the respective duct, smaller than the distance of said opening in relation to the other opening of the same duct and in a region of the latter presenting a minimum acoustic pressure for a determined frequency, the dimensioning of said duct and of the cross section of the first of said openings being achieved so as to minimize the gas pulsation noises inside the su
• the dimensioning of said gas duct and of the cross section of said opening is achieved so as to minimize the gas pulsation noises inside the suction muffler which are generated upon the closing and opening of the suction valve.
• the region of minimum acoustic pressure is represented as a nodal point of the acoustic mode of the duct.
• Figure 1 illustrates, schematically and partially, a longitudinal sectional view of a compressor carrying a suction muffler
• Figure 2 illustrates, schematically, a partial cross- sectional upper plan view of a suction muffler constructed according to the present invention, presenting a dampening chamber carrying a gas inlet duct and a gas outlet duct of the suction muffler;
• Figure 3 illustrates, schematically, a longitudinal sectional view of a construction for a suction muffler of the present invention, according to line III-III of figure 2, presenting a dampening chamber carrying a gas inlet duct of the suction muffler;
• Figure 4 illustrates, schematically, another longitudinal sectional view of the suction muffler of the present invention, according to line IV-IV of figure 2, showing the gas outlet duct of the suction muffler;
• Figure 5 illustrates, schematically, a longitudinal sectional view of another construction for a suction muffler of the present invention, presenting two dampening chambers carrying respective gas inlet and gas outlet ducts of the suction muffler; and
• Figure 6 illustrates, schematically, a graph showing the attenuation curve obtained, for frequency 2kHz, with a muffler construction of the prior art (full lines) and with the construction of the present invention (broken lines) .
• a compressor of the type used in refrigeration systems comprising, inside a hermetic shell 1, a motor- compressor assembly having a cylinder block in which is defined a cylinder 2 lodging, at one end, a piston 3, and having an opposite end closed by a cylinder cover 4 defining, therewithin, a suction chamber (not illustrated) and a discharge chamber 5 in selective fluid communication with a compression chamber 6 defined inside the cylinder 2 between a top portion of the piston 3 and a valve plate 7 provided between the opposite end of the cylinder 2 and the cylinder cover 4, through a suction orifice 7a and a discharge orifice 7b, which are respectively closed by suction and discharge valves 8a, 8b.
• the gas drawn by the compressor and coming from a suction line (not illustrated) of the refrigeration system to which the compressor is coupled reaches the interior of the shell 1 through the suction muffler, generally provided inside said shell 1 and maintained in fluid communication with the interior of the suction chamber of the compressor.
• the suction muffler of the present invention comprises a hollow body 10, which is generally made of a material of low thermal conductivity, such as plastic, defining at least one dampening chamber 13, for example internal to said hollow body 10 and carrying a gas inlet duct 20 having an inlet opening 21 external to the dampening chamber 13 and an outlet opening 22 in the interior of the dampening chamber 13 and a gas outlet duct 30 presenting an inlet opening 31 in the interior of the dampening chamber 13 and an outlet opening 32 external to said dampening chamber 13.
• a hollow body 10 which is generally made of a material of low thermal conductivity, such as plastic, defining at least one dampening chamber 13, for example internal to said hollow body 10 and carrying a gas inlet duct 20 having an inlet opening 21 external to the dampening chamber 13 and an outlet opening 22 in the interior of the dampening chamber 13 and a gas outlet duct 30 presenting an inlet opening 31 in the interior of the dampening chamber 13 and an outlet opening 32 external to said dampening chamber 13.
• At least one of the gas inlet and gas outlet ducts 20, 30 presents at least one closed end 23, 33, one of the inlet and outlet openings 21, 22, 31, 32 being positioned at a certain distance from the closed end 23, 33, along the respective duct 20, 30, smaller than the distance of said opening in relation to the other opening of the same duct 20, 30 and in a region thereof presenting a minimum acoustic pressure for a determined frequency, the dimensioning of said duct 20, 30 and of the cross section of the first of said openings 21, 31; 22, 32, being achieved in such a way as to minimize the gas pulsation noises inside the suction muffler.
• each closed end 23, 33 is submitted to. the same gas pressure reigning in said region of minimum acoustic pressure.
• the suction muffler presents a dampening chamber 13 provided with a gas inlet duct 20 having its inlet opening 21 in fluid communication with the gas supply to the compressor, connected to the suction line of the refrigeration system to which the compressor is coupled and its outlet opening 22 in fluid communication with a suction side of the compressor, for example, directly connected to the suction orifice 7a of the valve plate 7 of the compressor.
• the outlet opening 32 of the gas outlet duct 30 of a first dampening chamber 13 is maintained in fluid communication with the suction orifice 7a through another dampening chamber 14 , as for example illustrated in figure 5, said other dampening chamber 14 having another gas outlet duct 40 having an inlet opening 41 opened to the interior of said other dampening chamber 14 and an outlet opening 42 connected to the suction orifice 7a.
• the suction muffler comprises a hollow body 10 defining two dampening chamber 13, 14, for example, internal to said hollow body 10 and separated from each other by a common wall 15.
• each of the gas ducts 20, 30, 40 presents a geometry defined so that at least one of its inlet and outlet openings 21, 22, 31, 32, 41, 42 is positioned at a certain distance from each closed end 23, 33 of the same duct 20, 30, 40, along this duct 20, 30, 40, smaller than the distance of said opening in relation to the other opening of the same duct 20, 30, 40 and in a region thereof presenting a minimum acoustic pressure for a determined frequency, the dimensioning of said duct 20, 30, 40 and of said cross section of the first of said openings 21, 31; 22, 32; 41, 42, being defined so as to minimize the gas pulsation noises in the interior of the suction muffler, the distance between the medium line of the first of said openings 21, 31; 22, 32; 41, 42 and the closed end 23, 33 of the same duct 20, 30, 40, in which is provided said closed end 23, 33, being greater than half the diameter of said opening 21, 31; 22, 32; 41, 42.
• the hollow body 10 of the suction muffler presents, internally, only one dampening chamber 13, to the interior of the latter projecting the outlet opening 22 of the gas inlet duct 20 and the inlet opening 31 of the gas outlet duct 30.
• the gas inlet duct 20 has a closed end 23 located closer to the inlet opening 21 of said gas inlet duct 20 and defined in a nodal region of minimum acoustic pressure.
• the gas outlet duct 30 may or may not have a closed end.
• Figure 4 illustrates a construction in which the gas outlet duct 30, illustrated in figure 2, has a closed end 33 provided closer to the inlet opening 31 of said gas outlet duct 30.
• each gas inlet and gas outlet duct 20, 30, 40 may present at least one respective closed end 23, 33 in each dampening chamber 13, 14.
• the gas inlet duct 30 presents a closed end 33 in the interior of the dampening chamber 13, closer to the inlet opening 31 of said gas inlet duct 30.
• the closed end may be also provided adjacent to the outlet opening of the same gas duct .
• the opening defined in the region of minimum acoustic pressure is one of the inlet and outlet openings 21, 22, 31, 32, 41, 42 of each gas inlet and gas outlet duct 20, 30, 40 inside the hollow body 10, in a respective dampening chamber 13, 14.
• an acoustic mode is determined to have a certain attenuated frequency, said attenuation occurring in the region of the gas duct or ducts 20, 30, 40 having a minimum acoustic node, that is, in the regions with minimum pressure.
• the pressures reigning in each of the gas ducts 20, 30, 40 of the suction muffler are the stationary or acoustic pressures presenting regions of minimum and maximum pressure. Once the minimum pressure regions are determined, one can determine the region to provide said inlet opening
• Each gas duct 20, 30, 40 provided with an opening or openings in nodal regions, presents each respective closed end 23, 33 constructed in such a way as to avoid any direct communication of the gas with the interior of the hollow body 10 of said suction muffler.
• an inner sidewall portion of the hollow body 10 defines a cover portion in which is tightly fitted the closed end 23, 33 of a gas duct 20, 30, 40, said cover portion being retained therein by appropriate retaining means, such as glue, clamps, projections or by interference.
• each closed end 23, 33 incorporates the respective cover, which is for example defined as a single piece with the remaining of the respective body of the gas duct 20, 30, 40, for example by injection, jointly with the formation of the duct in a single piece, or by over-injection.
• the gas duct 20, 30, 40 carries and secures a cover closing an adjacent closed end 23, 33.
• the closed end 23, 33 is defined in a plane intercepted by the direction of the gas flow passing through the opening defined in a nodal region of minimum acoustic pressure of the respective gas duct 20, 30, 40, said opening positioning allowing the pressure to be taken at a point of minimum acoustic pressure, generating high acoustic attenuation in a determined frequency band, as illustrated in figure 6.
• the closed end 23, 33 is defined in a plane parallel to the direction of the gas flow passing through the first of said openings 21, 31; 22, 32, 42 of one of the first, second and third gas ducts 20, 30, 40, said opening positioning also allowing the pressure to be taken at a point of minimum acoustic pressure, generating high acoustic attenuation in a determined frequency band, as illustrated in figure 6.
• Specific aspects of the invention are shown in the figures of the drawings for convenience only, as each aspect can be combined with other aspects according to the invention. Other embodiments will be recognized as possible by those skilled in the art and should be included in the scope of the claims. Accordingly, the description above should be construed as illustrative and not as limitative of the scope of protection of the invention. All such obvious modifications and alterations are found in the scope of protection defined in the appended claims.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Compressor (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=36930331

Family Applications (1)

Country Status (8)

Cited By (2)

Families Citing this family (11)

Citations (4)

Family Cites Families (1)

• 2005
  • 2005-05-03 BR BRPI0501740-8A patent/BRPI0501740A/pt not_active IP Right Cessation
• 2006
  • 2006-05-02 US US11/912,233 patent/US20090038329A1/en not_active Abandoned
  • 2006-05-02 JP JP2008509271A patent/JP2008540891A/ja active Pending
  • 2006-05-02 KR KR1020077024609A patent/KR20080005930A/ko not_active Application Discontinuation
  • 2006-05-02 MX MX2007013709A patent/MX2007013709A/es unknown
  • 2006-05-02 WO PCT/BR2006/000085 patent/WO2006116830A1/en not_active Application Discontinuation
  • 2006-05-02 EP EP06721643A patent/EP1877664A1/en not_active Withdrawn
  • 2006-05-02 CN CNA200680015020XA patent/CN101171424A/zh active Pending

Patent Citations (4)

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