US20170009758A1 - Sealed compressor and refrigeration device - Google Patents
Sealed compressor and refrigeration device Download PDFInfo
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- US20170009758A1 US20170009758A1 US15/113,272 US201515113272A US2017009758A1 US 20170009758 A1 US20170009758 A1 US 20170009758A1 US 201515113272 A US201515113272 A US 201515113272A US 2017009758 A1 US2017009758 A1 US 2017009758A1
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- piston
- cylinder
- shaft
- sealed compressor
- shaft portion
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Classifications
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- 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
- F04B39/0094—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 crankshaft
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- 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
- F04B15/00—Pumps adapted to handle specific fluids, e.g. by selection of specific materials for pumps or pump parts
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- 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
- F04B17/00—Pumps characterised by combination with, or adaptation to, specific driving engines or motors
- F04B17/03—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors
-
- 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
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- 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
- F04B39/0005—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 adaptations of pistons
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- 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
- F04B39/0005—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 adaptations of pistons
- F04B39/0022—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 adaptations of pistons piston rods
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- 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
- F04B39/12—Casings; Cylinders; Cylinder heads; Fluid connections
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B31/00—Compressor arrangements
- F25B31/02—Compressor arrangements of motor-compressor units
- F25B31/023—Compressor arrangements of motor-compressor units with compressor of reciprocating-piston type
Definitions
- the present invention relates to a sealed compressor capable of reducing sliding loss of a piston, and a refrigeration device including this sealed compressor.
- a type of sealed compressors developed under these circumstances decreases distortion of a reciprocating piston produced within a compression chamber during a compression stroke to reduce sliding loss and improve efficiency (for example, see PTL 1).
- FIG. 8 is a longitudinal cross-sectional view of a conventional sealed compressor.
- FIG. 9 is a cross-sectional view illustrating a main part around a piston of the conventional sealed compressor during a compression stroke.
- FIG. 10 is a cross-sectional view illustrating the main part around the piston of the conventional sealed compressor during a suction stroke.
- sealed container 301 of the conventional sealed compressor contains electric element 304 including stator 302 and rotor 303 , and compression element 305 driven by electric element 304 .
- Shaft 310 includes main shaft portion 311 , and eccentric shaft portion 312 eccentrically disposed at one end of main shaft portion 311 .
- Rotor 303 is fixed to main shaft portion 311 .
- Cylinder block 314 includes substantially cylindrical cylinder 315 , and bearing portion 320 .
- Piston 323 is reciprocatively inserted into cylinder 315 .
- Valve plate 350 is attached to an end surface of cylinder 315 .
- Cylinder 315 and piston 323 constitute compression chamber 316 .
- piston pin 325 attached to piston 323 is positioned in parallel with eccentric shaft portion 312 .
- Bearing portion 320 supporting main shaft portion 311 of shaft 310 constitutes a cantilever bearing.
- Connecting rod 326 is composed of large-hole end portion 328 , small-hole end portion 329 , and rod portion 330 .
- Large-hole end portion 328 engages with eccentric shaft portion 312 .
- Small-hole end portion 329 connects with piston 323 via piston pin 325 .
- Eccentric shaft portion 312 and piston 323 connect with each other via connecting rod 326 and piston pin 325 .
- shaft center C indicates a shaft center of piston 323
- shaft center D indicates a shaft center of cylinder 315 .
- piston 323 is pressed toward eccentric shaft portion 312 by a compression load applied to compress the refrigerant gas.
- shaft 310 is tilted within bearing portion 320 .
- shaft center C of piston 323 is also tilted in accordance with the tilt of shaft 310 .
- shaft center D of cylinder 315 is disposed in a tilted position in correspondence with the tilt of shaft center C of piston 323 . This structure decreases distortion of piston 323 within cylinder 315 during the compression stroke, thereby reducing sliding loss to achieve higher efficiency.
- piston 323 is pulled toward cylinder 315 by a suction load applied to suck refrigerant gas during a suction stroke of the reciprocating movement of piston 323 as illustrated in FIG. 10 .
- shaft 310 is tilted toward cylinder 315 .
- shaft center C of piston 323 deviates from shaft center D of cylinder 315 disposed in a tilted position beforehand.
- shaft center C of piston 323 is further tilted in such a manner as to press a tip end of piston 323 against a bottom of compression chamber 316 . This condition produces distortion of piston 323 , and increases input accordingly.
- the present invention solves the aforementioned conventional problems by providing a highly efficient sealed compressor capable of preventing input increase by reducing distortion produced by a tilt of a piston during a suction stroke.
- a sealed compressor includes a sealed container that contains an electric element, and a compression element driven by the electric element.
- the compression element includes a shaft that includes a main shaft portion, and an eccentric shaft portion integrally movable with the main shaft portion, and further includes a bearing portion that supports the main shaft portion of the shaft to constitute a cantilever bearing.
- the compression element further includes a cylinder that compresses gas, a piston reciprocatively inserted into the cylinder, and a connecting rod that connects the eccentric shaft portion with the piston.
- An angle a 1 formed by a first center line indicating a shaft center of the bearing portion, and a second center line indicating a shaft center of the cylinder, and an absolute value c 1 of an angle of a tilt of the shaft with respect to the bearing portion satisfy equation (1).
- An outer circumferential surface of the piston includes a seal portion producing a clearance from an inner circumferential surface of the cylinder, and forming a sliding surface, an extension portion disposed in a rear of the seal portion, and forming a sliding surface, and a non-sliding portion disposed in the rear of the seal portion, and not forming a sliding surface.
- a side extension portion constituting a sliding surface is disposed in the rear of the seal portion forming a sliding surface of the piston even in a state of large deviation between the shaft center of the cylinder and the shaft center of the piston during a suction stroke.
- This structure eliminates a sliding surface in the vertical up-down direction. Accordingly, local distortion of the piston in the vertical up-down direction decreases at the time of a tilt of the piston.
- the sealed compressor according to the present invention reduces local distortion produced during a suction stroke of a piston for prevention of input increase, thereby improving efficiency.
- FIG. 1 is a longitudinal cross-sectional view of a sealed compressor according to a first exemplary embodiment of the present invention.
- FIG. 2 is an enlarged cross-sectional view of a main part of the sealed compressor according to the first exemplary embodiment of the present invention when a compression load is applied during a compression stroke.
- FIG. 3 is an enlarged cross-sectional view of the main part of the sealed compressor according to the first exemplary embodiment of the present invention when a suction load is applied during a suction stroke.
- FIG. 4 is a cross-sectional view of a cylinder and a piston, as viewed from above, of the sealed compressor according to the first exemplary embodiment of the present invention.
- FIG. 5 is a longitudinal cross-sectional view of the cylinder and the piston of the sealed compressor according to the first exemplary embodiment of the present invention.
- FIG. 6 is a cross-sectional view of a main part illustrating a positional relationship between a bearing portion and the cylinder of the sealed compressor according to the first exemplary embodiment of the present invention.
- FIG. 7 is a schematic cross-sectional view of a refrigerator according to a second exemplary embodiment of the present invention.
- FIG. 8 is a longitudinal cross-sectional view of a conventional sealed compressor.
- FIG. 9 is a cross-sectional view of a main part around a piston during a compression stroke of the conventional sealed compressor.
- FIG. 10 is a cross-sectional view of the main part around the piston during a suction stroke of the conventional sealed compressor.
- FIG. 1 is a longitudinal cross-sectional view of a sealed compressor according to a first exemplary embodiment of the present invention.
- FIG. 2 is an enlarged cross-sectional view of a main part of the sealed compressor when a compression load is applied during a compression stroke.
- FIG. 3 is an enlarged cross-sectional view of the main part of the sealed compressor when a suction load is applied during a suction stroke.
- FIG. 4 is a cross-sectional view of a cylinder and a piston, as viewed from above, of the sealed compressor.
- FIG. 5 is a longitudinal cross-sectional view of the cylinder and the piston of the sealed compressor.
- FIG. 6 is a cross-sectional view of a main part illustrating a positional relationship between a bearing portion and the cylinder of the sealed compressor.
- sealed container 101 contains electric element 104 including stator 102 and rotor 103 , and compression element 105 driven by electric element 104 .
- Lubricant 106 is stored in an inner bottom of sealed container 101 .
- An interior of sealed container 101 is filled with hydrocarbon type R600a refrigerant 106 .
- Lubricant 102 that is low-viscosity oil in a range from VG3 to VG10 is sealed into the bottom of sealed container 101 .
- Electric element 104 includes rotor 103 and stator 102 , and is driven by an inverter (not shown) at a plurality of driving frequencies including at least a driving frequency equal to or higher than a power supply frequency.
- a maximum driving frequency for driving electric element 104 is set to 80 Hz.
- Electric element 104 is driven at a driving frequency equal to or higher than a minimum driving frequency of 17 Hz.
- Shaft 110 includes main shaft portion 111 , and eccentric shaft portion 112 eccentrically disposed at one end of main shaft portion 111 and integrally movable with main shaft portion 111 .
- Rotor 103 is fixed to main shaft portion 111 .
- Lubrication path 113 is provided within shaft 110 and in a surface of shaft 110 . A lower portion of lubrication path 113 is extended to reach a predetermined depth of lubricant 106 for immersion in lubricant 106 .
- Cylinder block 114 includes cylinder 115 having a cylindrical shape (including a substantially cylindrical shape), and bearing portion 120 .
- Bearing portion 120 supporting main shaft portion 111 of shaft 110 constitutes a cantilever bearing.
- Piston 123 is reciprocatively inserted into cylinder 115 .
- Valve plate 150 is attached to an end of cylinder 115 .
- Cylinder 115 and piston 123 form compression chamber 116 .
- Piston pin 125 attached to piston 123 is positioned in parallel with eccentric shaft portion 112 .
- seal portion 123 a and extension portion 123 b are formed on an outer circumferential surface of piston 123 .
- Seal portion 123 a has a cylindrical sliding surface configured to produce a small clearance from an inner circumferential surface of cylinder 115 .
- Extension portion 123 b has sliding surfaces disposed on both side surfaces of piston 123 in the rear of seal portion 123 a. Each sliding surface of extension portion 123 b has a radius same as a radius of seal portion 123 a, and is extended in an axial direction of piston 123 while maintaining a fixed width.
- Non-sliding portion 123 c is formed in each of vertically upper and lower surfaces of piston 123 in the rear of seal portion 123 a.
- Each of non-sliding portions 123 c has a larger clearance from the inner circumferential surface of cylinder 115 , thereby constituting a portion not slidable.
- connecting rod 126 is composed of large-hole end portion 128 , small-hole end portion 129 , and rod portion 130 .
- Large-hole end portion 128 engages with eccentric shaft portion 112 .
- Small-hole end portion 129 connects with piston 123 via piston pin 125 .
- Eccentric shaft portion 112 and piston 123 connect with each other via connecting rod 126 and piston pin 125 .
- shaft 110 , connecting rod 126 , piston pin 125 , and piston 123 constituting a part of compression element 105 are assembled such that shaft center 144 of main shaft portion 111 of shaft 110 , and shaft center C of reciprocating piston 123 form an angle of ⁇ /2 (rad).
- a structure assembled in this manner achieves smoothest operation and reduces driving loss. Accordingly, this exemplary embodiment is constructed in a similar manner.
- piston 123 is sized to have a diameter of 26 mm, a full length of 23 mm, and axial lengths of 8 mm and 15 mm for seal portion 123 a and extension portion 123 b, respectively.
- Each radius clearance between the inner circumferential surface of cylinder 115 and the sliding surface of seal portion 123 a, and between the inner circumferential surface of cylinder 115 and the sliding surface of extension portion 123 b is set to 0.005 mm.
- a radius clearance between the inner circumferential surface of cylinder 115 and non-sliding portion 123 c is set to 0.5 mm.
- first center line 141 indicating a shaft center of bearing portion 120
- second center line 142 indicating a shaft center of cylinder 115 as illustrated in FIG. 6 .
- An angle formed by first center line 141 and second center line 142 is defined as angle a 1 .
- An absolute value of an angle of a tilt of shaft 110 with respect to bearing portion 120 produced by a diameter clearance between bearing portion 120 and main shaft portion 111 is defined as value c 1 (rad).
- Cylinder block 114 (cylinder 115 ) is constructed such that angle a 1 and value c 1 satisfy the following equation (1).
- piston 123 starts reciprocating movement within cylinder 115 .
- This reciprocating movement of piston 123 sucks refrigerant gas from a cooling system (not shown) having a freezing cycle, and supplies the refrigerant gas into compression chamber 116 .
- the refrigerant gas is compressed in compression chamber 116 , and again discharged to the cooling system.
- Lubricant 106 stored in the bottom of sealed container 101 passes through lubrication path 113 , flows upward by the pumping operation, and horizontally scatters toward the entire circumference within sealed container 101 . Scattered lubricant 106 reaches piston pin 125 , piston 123 and the like to lubricate piston pin 125 , piston 123 and the like.
- a compression load during compression of refrigerant gas is generally supported only on one side of main shaft portion 111 of shaft 110 .
- shaft 110 is tilted within the diameter clearance between main shaft portion 111 and bearing portion 120 when a compression load is applied during a compression stroke as illustrated in FIG. 2 .
- the valve plate 150 side of piston 123 is tilted upward from a horizontal line.
- valve plate 150 side of shaft center D of cylinder 115 is tilted beforehand in the upward direction from the horizontal line in consideration of the tilt of piston 123 .
- an intersection O is defined at an intersection of first center line 141 indicating the shaft center of bearing portion 120 and second center line 142 indicating the shaft center of cylinder 115 .
- Absolute value c 1 is defined as an absolute value of an angle of a tilt of shaft 110 with respect to bearing portion 120 produced by the diameter clearance between bearing portion 120 and main shaft portion 111 .
- cylinder 115 is disposed such that angle a 1 formed by first center line 141 indicating the shaft center of bearing portion 120 and second center line 142 indicating the shaft center of cylinder 115 satisfy equation (1).
- angle a 1 expressed by equation (1) is determined as a design value of the angle of the shaft center of cylinder 115 according to this exemplary embodiment.
- Angle a 1 is so designed as to approximate an actual value based on absolute value c 1 of the angle of the tilt of shaft 110 with respect to bearing portion 120 . Accordingly, distortion between piston 123 and cylinder 115 more securely decreases.
- shaft 110 is tilted within the diameter clearance between main shaft portion 111 and bearing portion 120 when suction force is applied to piston 123 during the suction stroke as illustrated in FIG. 3 .
- assembly is determined such that the angle of shaft center C of piston 123 with respect to shaft center 144 of main shaft portion 111 of shaft 110 becomes ⁇ /2 (rad) at the time of a tilt of shaft 110 within the diameter clearance of bearing portion 120 .
- the valve plate 150 side of piston 123 is tilted downward from the horizontal line in this state.
- deviation is produced from shaft center D of cylinder 115 designed in consideration of the tilt of piston 123 during the compression stroke.
- shaft center C of piston 123 tilts and deviates downward from shaft center D of cylinder 115 when a suction load is applied to piston 123 during the suction stroke.
- a maximum tilt amount of seal portion 123 a in the radial direction produced at shaft center deviation angle ⁇ of piston 123 is expressed as (axial length L of seal portion 123 a ) ⁇ sin ( ⁇ ) as illustrated in FIG. 5 .
- an axial full length of piston 123 is set to a length of seal portion 123 a to secure sealing and sliding reliability.
- the radius clearance of seal portion 123 a i.e., 0.005 mm in this exemplary embodiment, is the minimum clearance in clearances produced by components of compression element 105 .
- the maximum tilt amount of seal portion 123 a in the radial direction during the suction stroke becomes larger than 0.005 mm, the radius clearance of seal portion 123 a. Accordingly, distortion is produced between E part of piston 123 on the compression chamber 116 side, and F part of piston 123 on the eccentric shaft portion 112 side.
- the sliding portion of piston 123 is composed of seal portion 123 a, and extension portion 123 b provided on both sides of piston 123 for supporting side pressure.
- F part corresponds to non-sliding portion 123 c having a radius clearance of 0.5 mm, which is sufficiently larger than 0.005 mm of the radius clearance of the seal portion. Accordingly, no contact is produced between F part of piston 123 and the inner circumferential surface of cylinder 115 .
- the maximum tilt amount L ⁇ sin ( ⁇ ) of seal portion 123 a in the radial direction produced at shaft center deviation angle a becomes smaller than 0.005 mm of the radius clearance in the vicinity of E part as a result of small length L of seal portion 123 a.
- the suction force generated during the suction stroke is considerably smaller than the compression load, wherefore the tilt angle of piston 123 becomes smaller during the suction stroke than the compression stroke.
- Distortion between piston 123 and cylinder 115 also becomes smaller during the suction stroke than the compression stroke. Accordingly, distortion between piston 123 and cylinder 115 during the suction stroke effectively decreases.
- efficiency improves by reduction of sliding loss produced between piston 123 and cylinder 115 during both the compression and suction strokes.
- the sealed compressor includes sealed container 101 that contains electric element 104 , and compression element 105 driven by electric element 104 .
- Compression element 105 includes shaft 110 that includes main shaft portion 111 , and eccentric shaft portion 112 integrally movable with main shaft portion 111 , and further includes bearing portion 120 that supports main shaft portion 111 of shaft 110 to constitute a cantilever bearing.
- Compression element 105 further includes cylinder 115 that compresses gas, piston 123 reciprocatively inserted into cylinder 115 , and connecting rod 126 that connects eccentric shaft portion 112 with piston 123 .
- An outer circumferential surface of piston 123 includes seal portion 123 a producing a clearance from an inner circumferential surface of cylinder 115 , and forming a sliding surface, extension portion 123 b disposed in a rear of seal portion 123 a, and forming a sliding surface, and non-sliding portion 123 c disposed in the rear of seal portion 123 a, and not forming a sliding surface.
- This structure reduces sliding loss of piston 123 and cylinder 115 during both the compression and suction strokes, thereby improving efficiency.
- Extension portion 123 b has a radius same as a radius of seal portion 123 a, and forms the sliding surface that supports side pressure. This structure reduces local distortion of the piston, thereby preventing input increase and improving efficiency.
- Electric element 104 is driven at a plurality of rotation speeds by an inverter circuit.
- This structure prevents distortion of the piston within the cylinder even under a driving condition of low-speed rotation where a lubricant film thickness decreases on the sliding surface of the piston as a result of a small lubricant supply amount to the piston.
- This structure also prevents distortion of the piston within the cylinder during the suction stroke under a driving condition of high-speed rotation where the tilt of the piston increases due to a high compression ratio. Accordingly, efficiency improves.
- FIG. 7 is a schematic cross-sectional view of a refrigerator according to a second exemplary embodiment of the present invention. Described herein is a refrigerator presented as an example of a refrigeration device.
- the refrigerator illustrated in FIG. 7 includes the sealed compressor described in the first exemplary embodiment.
- heat insulating box 180 includes inner box 182 , outer box 184 , and heat insulating walls.
- Inner box 182 is produced by vacuum forming of a resin material such as ABS (Acrylonitrile Butadiene Styrene).
- Outer box 184 is made of a metal material such as pre-coated steel sheet.
- the heat insulating walls are produced by filling foamed heat insulating material 186 into a space defined by inner box 182 and outer box 184 .
- Heat insulating material 186 is made of rigid urethane foam, phenol foam, styrene foam or the like. It is more preferable to use hydrocarbon cyclopentane for a foamed material in view of prevention of global warming.
- Heat insulating box 180 is divided into a plurality of heat insulating sections.
- a revolving-type door is provided in an upper part, while drawer-type compartments are provided in lower part of heat insulating box 180 .
- the plurality of heat insulating sections include refrigerating compartment 188 , a pair of drawer-type switching compartment 190 and ice compartment 192 disposed side by side, drawer-type vegetable compartment 194 , and drawer-type freezing compartment 196 in this order from above.
- a heat insulating door is attached to each of the respective heat insulating sections via a gasket. These doors are composed of refrigerating compartment revolving door 198 , switching compartment drawer door 200 , ice compartment drawer door 202 , vegetable compartment drawer door 204 , and freezing compartment drawer door 206 in this order from above.
- Outer box 184 of heat insulating box 180 includes recessed portion 208 corresponding to a recessed rear part of a top surface of outer box 184 .
- sealed compressor 210 In a freezing cycle, sealed compressor 210 , a condenser (not shown) provided on a side or other portions of heat insulating box 180 , capillary 212 corresponding to a decompressor, a drier (not shown) for removing moisture, evaporator 216 , and suction piping 218 are connected in an annular shape. Sealed compressor 210 corresponds to the sealed compressor described in the first exemplary embodiment, and is elastically supported on recessed portion 208 . Evaporator 216 is disposed in a rear of vegetable compartment 194 and freezing compartment 196 . Cooling fan 214 is provided in the vicinity of evaporator 216 .
- a temperature of refrigerating compartment 188 is generally determined in a range from 1° C. to 5° C., with a lower limit set above a freezing temperature for refrigerating storage.
- Temperature setting of switching compartment 190 is changeable by a user within a predetermined temperature zone, ranging from a freezing compartment temperature zone to a refrigerating compartment or vegetable compartment temperature zone.
- Ice compartment 192 is an independent ice storage compartment. Ice compartment 192 includes a not-shown automatic ice making device to automatically produce ice and store the produced ice. A temperature of ice compartment 192 is set in the freezing temperature zone for storage of ice. However, the temperature of ice compartment 192 may be set at a freezing temperature in a range from ⁇ 18° C. to ⁇ 10° C. for storage of ice, which temperature is relatively higher than the freezing temperature zone.
- a temperature of vegetable compartment 194 is often set at a temperature equivalent to the temperature range of refrigerating compartment 188 , or at a temperature ranging from 2° C. to 7° C., which is slightly higher than the temperature range of refrigerating compartment 188 . Freshness of leafy vegetables continues longer as the temperature of vegetable compartment 194 decreases toward a lower limit above a freezing temperature.
- a temperature of freezing compartment 196 is generally set in a range from ⁇ 22° C. to ⁇ 18° C. for freezing storage. However, the temperature of freezing compartment 196 may be set in a low temperature range from ⁇ 30° C. to ⁇ 25° C. for improvement of a freezing storage state.
- heat insulating box 180 may be integrally formed by filling foamed heat insulating material 186 to reduce costs and improve heat insulation performance.
- Heat insulating box 180 formed by filling foamed heat insulating material 186 exhibits approximately twice the heat insulation performance of a structure formed of a heat insulating material such as styrene foam. Accordingly, heat insulating box 180 thus constructed is allowed to increase a storage volume by reduction of thicknesses of partitioning parts.
- Cooling operation starts and stops in response to signals generated from a temperature sensor (not shown) and a control board based on the set temperatures within the refrigerator.
- Sealed compressor 210 performs predetermined compression operation in accordance with instructions of cooling operation.
- Discharged high-temperature and high-pressure refrigerant gas is condensed and liquefied at the condenser (not shown) while releasing heat, and decompressed by capillary 212 to become low-temperature and low-pressure liquid refrigerant.
- the generated liquid refrigerant reaches evaporator 216 .
- the refrigerant gas within evaporator 216 is evaporated and gasified by heat exchange with air inside the refrigerator in accordance with operation of cooling fan 214 .
- Low-temperature cooling air after heat exchange is distributed by a damper (not shown) or the like to cool the respective compartments.
- cylinder block 114 includes bearing portion 120 and cylinder 115 disposed such that first center line 141 indicating the shaft center of bearing portion 120 and second center line 142 indicating the shaft center of cylinder 115 cross each other as described in the first exemplary embodiment.
- Angle a 1 (rad) formed by first center line 141 and second center line 142 , and absolute value c 1 (rad) of the angle of the tilt of shaft 110 with respect to bearing portion 120 produced by the diameter clearance between bearing portion 120 and main shaft portion 111 satisfy equation (1).
- Piston 123 includes cylindrical seal portion 123 a constituting a sliding surface and producing a uniform clearance between an outer circumferential surface of piston 123 and an inner circumferential surface of cylinder 115 .
- Piston 123 further includes extension portion 123 b disposed in the rear of seal portion 123 a, having a radius same as a radius of seal portion 123 a, and constituting a sliding surface for supporting side pressure.
- piston 123 which includes extension portion 123 b constituting a sliding surface for supporting side pressure in the rear of cylindrical seal portion 123 a providing a sliding surface of piston 123 , and eliminates a sliding surface in the vertical up-down direction.
- This structure decreases local distortion of piston 123 , thereby reducing sliding loss for improvement of efficiency of sealed compressor 210 . As a result, reduction of power consumption of the refrigerator is achievable.
- the refrigerator in this exemplary embodiment is a refrigeration device including the sealed compressor according to the first exemplary embodiment. Accordingly, the refrigeration device provided herein realizes reduction of power consumption.
- the sealed compressor according to the present invention improves efficiency by reduction of sliding loss of a piston, and therefore is applicable not only to a household electric refrigerator, but also to a refrigeration device for an air conditioner, a vending machine, or various other apparatuses.
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Abstract
Description
- The present invention relates to a sealed compressor capable of reducing sliding loss of a piston, and a refrigeration device including this sealed compressor.
- There has been a recent demand for higher efficiency of a sealed compressor included in a refrigerator or other refrigeration devices with an aim to reduce power consumption.
- A type of sealed compressors developed under these circumstances decreases distortion of a reciprocating piston produced within a compression chamber during a compression stroke to reduce sliding loss and improve efficiency (for example, see PTL 1).
- A conventional sealed compressor is hereinafter described with reference to the drawings.
FIG. 8 is a longitudinal cross-sectional view of a conventional sealed compressor.FIG. 9 is a cross-sectional view illustrating a main part around a piston of the conventional sealed compressor during a compression stroke.FIG. 10 is a cross-sectional view illustrating the main part around the piston of the conventional sealed compressor during a suction stroke. - As illustrated in
FIGS. 8 through 10 , sealedcontainer 301 of the conventional sealed compressor containselectric element 304 includingstator 302 androtor 303, andcompression element 305 driven byelectric element 304. Shaft 310 includesmain shaft portion 311, andeccentric shaft portion 312 eccentrically disposed at one end ofmain shaft portion 311.Rotor 303 is fixed tomain shaft portion 311. -
Cylinder block 314 includes substantiallycylindrical cylinder 315, and bearingportion 320. Piston 323 is reciprocatively inserted intocylinder 315.Valve plate 350 is attached to an end surface ofcylinder 315.Cylinder 315 andpiston 323 constitutecompression chamber 316. - As illustrated in
FIG. 9 ,piston pin 325 attached topiston 323 is positioned in parallel witheccentric shaft portion 312. Bearingportion 320 supportingmain shaft portion 311 ofshaft 310 constitutes a cantilever bearing. - Connecting
rod 326 is composed of large-hole end portion 328, small-hole end portion 329, androd portion 330. Large-hole end portion 328 engages witheccentric shaft portion 312. Small-hole end portion 329 connects withpiston 323 viapiston pin 325.Eccentric shaft portion 312 andpiston 323 connect with each other via connectingrod 326 andpiston pin 325. - In the drawing, shaft center C indicates a shaft center of
piston 323, while shaft center D indicates a shaft center ofcylinder 315. - Operation of the conventional sealed compressor thus constructed is hereinafter described. When
electric element 304 is turned on,rotor 303 causes rotation ofshaft 310. Rotational movement ofeccentric shaft portion 312 produced in accordance with rotation ofshaft 310 is transmitted topiston 323 via connectingrod 326. As a result,piston 323 starts reciprocating movement withincylinder 315. This reciprocating movement ofpiston 323 sucks refrigerant gas from a cooling system (not shown) having a freezing cycle, and supplies the refrigerant gas intocompression chamber 316. The refrigerant gas is compressed incompression chamber 316, and again discharged to the cooling system. - During a compression stroke of the reciprocating movement of
piston 323,piston 323 is pressed towardeccentric shaft portion 312 by a compression load applied to compress the refrigerant gas. As a result,shaft 310 is tilted within bearingportion 320. In this case, shaft center C ofpiston 323 is also tilted in accordance with the tilt ofshaft 310. Accordingly, for alignment between shaft center C ofpiston 323 and shaft center D ofcylinder 315 during the compression stroke, shaft center D ofcylinder 315 is disposed in a tilted position in correspondence with the tilt of shaft center C ofpiston 323. This structure decreases distortion ofpiston 323 withincylinder 315 during the compression stroke, thereby reducing sliding loss to achieve higher efficiency. - In the conventional sealed compressor, however,
piston 323 is pulled towardcylinder 315 by a suction load applied to suck refrigerant gas during a suction stroke of the reciprocating movement ofpiston 323 as illustrated inFIG. 10 . In this case,shaft 310 is tilted towardcylinder 315. As a result, shaft center C ofpiston 323 deviates from shaft center D ofcylinder 315 disposed in a tilted position beforehand. Particularly when the suction load increases under severe driving conditions including a high compression ratio, shaft center C ofpiston 323 is further tilted in such a manner as to press a tip end ofpiston 323 against a bottom ofcompression chamber 316. This condition produces distortion ofpiston 323, and increases input accordingly. - PTL 1: Japanese Translation of PCT Publication No. 2011-508840
- The present invention solves the aforementioned conventional problems by providing a highly efficient sealed compressor capable of preventing input increase by reducing distortion produced by a tilt of a piston during a suction stroke.
- A sealed compressor according to the present invention includes a sealed container that contains an electric element, and a compression element driven by the electric element. The compression element includes a shaft that includes a main shaft portion, and an eccentric shaft portion integrally movable with the main shaft portion, and further includes a bearing portion that supports the main shaft portion of the shaft to constitute a cantilever bearing. The compression element further includes a cylinder that compresses gas, a piston reciprocatively inserted into the cylinder, and a connecting rod that connects the eccentric shaft portion with the piston. An angle a1 formed by a first center line indicating a shaft center of the bearing portion, and a second center line indicating a shaft center of the cylinder, and an absolute value c1 of an angle of a tilt of the shaft with respect to the bearing portion satisfy equation (1). An outer circumferential surface of the piston includes a seal portion producing a clearance from an inner circumferential surface of the cylinder, and forming a sliding surface, an extension portion disposed in a rear of the seal portion, and forming a sliding surface, and a non-sliding portion disposed in the rear of the seal portion, and not forming a sliding surface.
-
a1=π/2+c2 (1) - In this structure, a side extension portion constituting a sliding surface is disposed in the rear of the seal portion forming a sliding surface of the piston even in a state of large deviation between the shaft center of the cylinder and the shaft center of the piston during a suction stroke. This structure eliminates a sliding surface in the vertical up-down direction. Accordingly, local distortion of the piston in the vertical up-down direction decreases at the time of a tilt of the piston.
- The sealed compressor according to the present invention reduces local distortion produced during a suction stroke of a piston for prevention of input increase, thereby improving efficiency.
-
FIG. 1 is a longitudinal cross-sectional view of a sealed compressor according to a first exemplary embodiment of the present invention. -
FIG. 2 is an enlarged cross-sectional view of a main part of the sealed compressor according to the first exemplary embodiment of the present invention when a compression load is applied during a compression stroke. -
FIG. 3 is an enlarged cross-sectional view of the main part of the sealed compressor according to the first exemplary embodiment of the present invention when a suction load is applied during a suction stroke. -
FIG. 4 is a cross-sectional view of a cylinder and a piston, as viewed from above, of the sealed compressor according to the first exemplary embodiment of the present invention. -
FIG. 5 is a longitudinal cross-sectional view of the cylinder and the piston of the sealed compressor according to the first exemplary embodiment of the present invention. -
FIG. 6 is a cross-sectional view of a main part illustrating a positional relationship between a bearing portion and the cylinder of the sealed compressor according to the first exemplary embodiment of the present invention. -
FIG. 7 is a schematic cross-sectional view of a refrigerator according to a second exemplary embodiment of the present invention. -
FIG. 8 is a longitudinal cross-sectional view of a conventional sealed compressor. -
FIG. 9 is a cross-sectional view of a main part around a piston during a compression stroke of the conventional sealed compressor. -
FIG. 10 is a cross-sectional view of the main part around the piston during a suction stroke of the conventional sealed compressor. - Exemplary embodiments according to the present invention are hereinafter described with reference to the drawings. The present invention is not limited to the exemplary embodiments presented herein.
-
FIG. 1 is a longitudinal cross-sectional view of a sealed compressor according to a first exemplary embodiment of the present invention.FIG. 2 is an enlarged cross-sectional view of a main part of the sealed compressor when a compression load is applied during a compression stroke.FIG. 3 is an enlarged cross-sectional view of the main part of the sealed compressor when a suction load is applied during a suction stroke.FIG. 4 is a cross-sectional view of a cylinder and a piston, as viewed from above, of the sealed compressor.FIG. 5 is a longitudinal cross-sectional view of the cylinder and the piston of the sealed compressor.FIG. 6 is a cross-sectional view of a main part illustrating a positional relationship between a bearing portion and the cylinder of the sealed compressor. - As illustrated in
FIGS. 1 through 6 , sealedcontainer 101 containselectric element 104 includingstator 102 androtor 103, andcompression element 105 driven byelectric element 104.Lubricant 106 is stored in an inner bottom of sealedcontainer 101. - An interior of sealed
container 101 is filled with hydrocarbontype R600a refrigerant 106.Lubricant 102 that is low-viscosity oil in a range from VG3 to VG10 is sealed into the bottom of sealedcontainer 101. -
Electric element 104 includesrotor 103 andstator 102, and is driven by an inverter (not shown) at a plurality of driving frequencies including at least a driving frequency equal to or higher than a power supply frequency. A maximum driving frequency for drivingelectric element 104 is set to 80 Hz.Electric element 104 is driven at a driving frequency equal to or higher than a minimum driving frequency of 17 Hz. -
Shaft 110 includesmain shaft portion 111, andeccentric shaft portion 112 eccentrically disposed at one end ofmain shaft portion 111 and integrally movable withmain shaft portion 111.Rotor 103 is fixed tomain shaft portion 111.Lubrication path 113 is provided withinshaft 110 and in a surface ofshaft 110. A lower portion oflubrication path 113 is extended to reach a predetermined depth oflubricant 106 for immersion inlubricant 106. -
Cylinder block 114 includescylinder 115 having a cylindrical shape (including a substantially cylindrical shape), and bearingportion 120.Bearing portion 120 supportingmain shaft portion 111 ofshaft 110 constitutes a cantilever bearing. -
Piston 123 is reciprocatively inserted intocylinder 115.Valve plate 150 is attached to an end ofcylinder 115.Cylinder 115 andpiston 123form compression chamber 116. -
Piston pin 125 attached topiston 123 is positioned in parallel witheccentric shaft portion 112. As illustrated inFIGS. 4 and 5 ,seal portion 123 a andextension portion 123 b are formed on an outer circumferential surface ofpiston 123.Seal portion 123 a has a cylindrical sliding surface configured to produce a small clearance from an inner circumferential surface ofcylinder 115.Extension portion 123 b has sliding surfaces disposed on both side surfaces ofpiston 123 in the rear ofseal portion 123 a. Each sliding surface ofextension portion 123 b has a radius same as a radius ofseal portion 123 a, and is extended in an axial direction ofpiston 123 while maintaining a fixed width.Non-sliding portion 123 c is formed in each of vertically upper and lower surfaces ofpiston 123 in the rear ofseal portion 123 a. Each ofnon-sliding portions 123 c has a larger clearance from the inner circumferential surface ofcylinder 115, thereby constituting a portion not slidable. - As illustrated in
FIG. 2 , connectingrod 126 is composed of large-hole end portion 128, small-hole end portion 129, androd portion 130. Large-hole end portion 128 engages witheccentric shaft portion 112. Small-hole end portion 129 connects withpiston 123 viapiston pin 125.Eccentric shaft portion 112 andpiston 123 connect with each other via connectingrod 126 andpiston pin 125. - In general,
shaft 110, connectingrod 126,piston pin 125, andpiston 123 constituting a part ofcompression element 105 are assembled such thatshaft center 144 ofmain shaft portion 111 ofshaft 110, and shaft center C ofreciprocating piston 123 form an angle of π/2 (rad). A structure assembled in this manner achieves smoothest operation and reduces driving loss. Accordingly, this exemplary embodiment is constructed in a similar manner. - According to this exemplary embodiment,
piston 123 is sized to have a diameter of 26 mm, a full length of 23 mm, and axial lengths of 8 mm and 15 mm forseal portion 123 a andextension portion 123 b, respectively. Each radius clearance between the inner circumferential surface ofcylinder 115 and the sliding surface ofseal portion 123 a, and between the inner circumferential surface ofcylinder 115 and the sliding surface ofextension portion 123 b is set to 0.005 mm. A radius clearance between the inner circumferential surface ofcylinder 115 andnon-sliding portion 123 c is set to 0.5 mm. - Considered herein is a projection surface extending in parallel with
first center line 141 indicating a shaft center of bearingportion 120, and in parallel withsecond center line 142 indicating a shaft center ofcylinder 115 as illustrated inFIG. 6 . An angle formed byfirst center line 141 andsecond center line 142 is defined as angle a1. An absolute value of an angle of a tilt ofshaft 110 with respect to bearingportion 120 produced by a diameter clearance between bearingportion 120 andmain shaft portion 111 is defined as value c1 (rad). Cylinder block 114 (cylinder 115) is constructed such that angle a1 and value c1 satisfy the following equation (1). -
a1=π/2+c1 (1) - Operation of the sealed compressor thus constructed is hereinafter described. When
electric element 104 is turned on,rotor 103 causes rotation ofshaft 110. Rotational movement ofeccentric shaft portion 112 produced in accordance with rotation ofshaft 110 is transmitted topiston 123 via connectingrod 126. - As a result,
piston 123 starts reciprocating movement withincylinder 115. This reciprocating movement ofpiston 123 sucks refrigerant gas from a cooling system (not shown) having a freezing cycle, and supplies the refrigerant gas intocompression chamber 116. The refrigerant gas is compressed incompression chamber 116, and again discharged to the cooling system. - Pumping operation produced by rotation of
shaft 110 starts at a lower end oflubrication path 113.Lubricant 106 stored in the bottom of sealedcontainer 101 passes throughlubrication path 113, flows upward by the pumping operation, and horizontally scatters toward the entire circumference within sealedcontainer 101.Scattered lubricant 106 reachespiston pin 125,piston 123 and the like to lubricatepiston pin 125,piston 123 and the like. - Distortion of the piston is hereinafter described.
- In a sealed compressor including a cantilever bearing structure, a compression load during compression of refrigerant gas is generally supported only on one side of
main shaft portion 111 ofshaft 110. In this case,shaft 110 is tilted within the diameter clearance betweenmain shaft portion 111 and bearingportion 120 when a compression load is applied during a compression stroke as illustrated inFIG. 2 . Accordingly, in the assembly setting π/2 (rad) for the angle of shaft center C ofpiston 123 with respect toshaft center 144 ofmain shaft portion 111, thevalve plate 150 side ofpiston 123 is tilted upward from a horizontal line. - According to this exemplary embodiment, the
valve plate 150 side of shaft center D ofcylinder 115 is tilted beforehand in the upward direction from the horizontal line in consideration of the tilt ofpiston 123. - Accordingly, when a compression load is applied to
piston 123 during the compression stroke, shaft center D ofcylinder 115 is aligned with shaft center C ofpiston 123 as illustrated inFIG. 2 . As a result, distortion ofreciprocating piston 123 decreases. - As illustrated in
FIG. 6 , an intersection O is defined at an intersection offirst center line 141 indicating the shaft center of bearingportion 120 andsecond center line 142 indicating the shaft center ofcylinder 115. Absolute value c1 is defined as an absolute value of an angle of a tilt ofshaft 110 with respect to bearingportion 120 produced by the diameter clearance between bearingportion 120 andmain shaft portion 111. In this case,cylinder 115 is disposed such that angle a1 formed byfirst center line 141 indicating the shaft center of bearingportion 120 andsecond center line 142 indicating the shaft center ofcylinder 115 satisfy equation (1). - More specifically, angle a1 expressed by equation (1) is determined as a design value of the angle of the shaft center of
cylinder 115 according to this exemplary embodiment. Angle a1 is so designed as to approximate an actual value based on absolute value c1 of the angle of the tilt ofshaft 110 with respect to bearingportion 120. Accordingly, distortion betweenpiston 123 andcylinder 115 more securely decreases. - On the other hand,
shaft 110 is tilted within the diameter clearance betweenmain shaft portion 111 and bearingportion 120 when suction force is applied topiston 123 during the suction stroke as illustrated inFIG. 3 . According to this exemplary embodiment, assembly is determined such that the angle of shaft center C ofpiston 123 with respect toshaft center 144 ofmain shaft portion 111 ofshaft 110 becomes π/2 (rad) at the time of a tilt ofshaft 110 within the diameter clearance of bearingportion 120. Accordingly, thevalve plate 150 side ofpiston 123 is tilted downward from the horizontal line in this state. As a result, deviation is produced from shaft center D ofcylinder 115 designed in consideration of the tilt ofpiston 123 during the compression stroke. - As apparent, shaft center C of
piston 123 tilts and deviates downward from shaft center D ofcylinder 115 when a suction load is applied topiston 123 during the suction stroke. In this case, a maximum tilt amount ofseal portion 123 a in the radial direction produced at shaft center deviation angle α ofpiston 123 is expressed as (axial length L ofseal portion 123 a)×sin (α) as illustrated inFIG. 5 . - In a typical sealed compressor for use in applications similar to a use application of this exemplary embodiment, an axial full length of
piston 123 is set to a length ofseal portion 123 a to secure sealing and sliding reliability. The radius clearance ofseal portion 123 a, i.e., 0.005 mm in this exemplary embodiment, is the minimum clearance in clearances produced by components ofcompression element 105. In this case, the maximum tilt amount ofseal portion 123 a in the radial direction during the suction stroke becomes larger than 0.005 mm, the radius clearance ofseal portion 123 a. Accordingly, distortion is produced between E part ofpiston 123 on thecompression chamber 116 side, and F part ofpiston 123 on theeccentric shaft portion 112 side. - According to this exemplary embodiment, however, the sliding portion of
piston 123 is composed ofseal portion 123 a, andextension portion 123 b provided on both sides ofpiston 123 for supporting side pressure. In this case, F part corresponds tonon-sliding portion 123 c having a radius clearance of 0.5 mm, which is sufficiently larger than 0.005 mm of the radius clearance of the seal portion. Accordingly, no contact is produced between F part ofpiston 123 and the inner circumferential surface ofcylinder 115. - Moreover, the maximum tilt amount L×sin (α) of
seal portion 123 a in the radial direction produced at shaft center deviation angle a becomes smaller than 0.005 mm of the radius clearance in the vicinity of E part as a result of small length L ofseal portion 123 a. - In this case, distortion at E part of
piston 123 decreases even when a suction load is applied during the suction stroke. - Accordingly, distortion between
piston 123 andcylinder 115 decreases during the suction stroke, as well as during the compression stroke. - Furthermore, the suction force generated during the suction stroke is considerably smaller than the compression load, wherefore the tilt angle of
piston 123 becomes smaller during the suction stroke than the compression stroke. Distortion betweenpiston 123 andcylinder 115 also becomes smaller during the suction stroke than the compression stroke. Accordingly, distortion betweenpiston 123 andcylinder 115 during the suction stroke effectively decreases. - According to this exemplary embodiment, therefore, efficiency improves by reduction of sliding loss produced between
piston 123 andcylinder 115 during both the compression and suction strokes. - As described above, the sealed compressor according to this exemplary embodiment includes sealed
container 101 that containselectric element 104, andcompression element 105 driven byelectric element 104.Compression element 105 includesshaft 110 that includesmain shaft portion 111, andeccentric shaft portion 112 integrally movable withmain shaft portion 111, and further includes bearingportion 120 that supportsmain shaft portion 111 ofshaft 110 to constitute a cantilever bearing.Compression element 105 further includescylinder 115 that compresses gas,piston 123 reciprocatively inserted intocylinder 115, and connectingrod 126 that connectseccentric shaft portion 112 withpiston 123. Angle a1 formed byfirst center line 141 indicating a shaft center of bearingportion 120, andsecond center line 142 indicating a shaft center ofcylinder 115, and absolute value c1 of an angle of a tilt ofshaft 110 with respect to bearingportion 120 satisfy equation (1). An outer circumferential surface ofpiston 123 includesseal portion 123 a producing a clearance from an inner circumferential surface ofcylinder 115, and forming a sliding surface,extension portion 123 b disposed in a rear ofseal portion 123 a, and forming a sliding surface, andnon-sliding portion 123 c disposed in the rear ofseal portion 123 a, and not forming a sliding surface. - This structure reduces sliding loss of
piston 123 andcylinder 115 during both the compression and suction strokes, thereby improving efficiency. -
Extension portion 123 b has a radius same as a radius ofseal portion 123 a, and forms the sliding surface that supports side pressure. This structure reduces local distortion of the piston, thereby preventing input increase and improving efficiency. -
Electric element 104 is driven at a plurality of rotation speeds by an inverter circuit. - This structure prevents distortion of the piston within the cylinder even under a driving condition of low-speed rotation where a lubricant film thickness decreases on the sliding surface of the piston as a result of a small lubricant supply amount to the piston. This structure also prevents distortion of the piston within the cylinder during the suction stroke under a driving condition of high-speed rotation where the tilt of the piston increases due to a high compression ratio. Accordingly, efficiency improves.
-
FIG. 7 is a schematic cross-sectional view of a refrigerator according to a second exemplary embodiment of the present invention. Described herein is a refrigerator presented as an example of a refrigeration device. The refrigerator illustrated inFIG. 7 includes the sealed compressor described in the first exemplary embodiment. - As illustrated in
FIG. 7 , heat insulatingbox 180 includesinner box 182,outer box 184, and heat insulating walls.Inner box 182 is produced by vacuum forming of a resin material such as ABS (Acrylonitrile Butadiene Styrene).Outer box 184 is made of a metal material such as pre-coated steel sheet. The heat insulating walls are produced by filling foamedheat insulating material 186 into a space defined byinner box 182 andouter box 184. Heat insulatingmaterial 186 is made of rigid urethane foam, phenol foam, styrene foam or the like. It is more preferable to use hydrocarbon cyclopentane for a foamed material in view of prevention of global warming. - Heat insulating
box 180 is divided into a plurality of heat insulating sections. A revolving-type door is provided in an upper part, while drawer-type compartments are provided in lower part ofheat insulating box 180. The plurality of heat insulating sections include refrigeratingcompartment 188, a pair of drawer-type switching compartment 190 and ice compartment 192 disposed side by side, drawer-type vegetable compartment 194, and drawer-type freezing compartment 196 in this order from above. A heat insulating door is attached to each of the respective heat insulating sections via a gasket. These doors are composed of refrigeratingcompartment revolving door 198, switching compartment drawer door 200, ice compartment drawer door 202, vegetablecompartment drawer door 204, and freezingcompartment drawer door 206 in this order from above. -
Outer box 184 ofheat insulating box 180 includes recessedportion 208 corresponding to a recessed rear part of a top surface ofouter box 184. - In a freezing cycle, sealed
compressor 210, a condenser (not shown) provided on a side or other portions ofheat insulating box 180, capillary 212 corresponding to a decompressor, a drier (not shown) for removing moisture,evaporator 216, and suction piping 218 are connected in an annular shape.Sealed compressor 210 corresponds to the sealed compressor described in the first exemplary embodiment, and is elastically supported on recessedportion 208.Evaporator 216 is disposed in a rear ofvegetable compartment 194 and freezingcompartment 196. Coolingfan 214 is provided in the vicinity ofevaporator 216. - Operation and effect of the refrigerator thus constructed are hereinafter described.
- Initially, temperature setting and cooling system for the respective heat insulating sections are described.
- A temperature of refrigerating
compartment 188 is generally determined in a range from 1° C. to 5° C., with a lower limit set above a freezing temperature for refrigerating storage. - Temperature setting of switching compartment 190 is changeable by a user within a predetermined temperature zone, ranging from a freezing compartment temperature zone to a refrigerating compartment or vegetable compartment temperature zone.
- Ice compartment 192 is an independent ice storage compartment. Ice compartment 192 includes a not-shown automatic ice making device to automatically produce ice and store the produced ice. A temperature of ice compartment 192 is set in the freezing temperature zone for storage of ice. However, the temperature of ice compartment 192 may be set at a freezing temperature in a range from −18° C. to −10° C. for storage of ice, which temperature is relatively higher than the freezing temperature zone.
- A temperature of
vegetable compartment 194 is often set at a temperature equivalent to the temperature range of refrigeratingcompartment 188, or at a temperature ranging from 2° C. to 7° C., which is slightly higher than the temperature range of refrigeratingcompartment 188. Freshness of leafy vegetables continues longer as the temperature ofvegetable compartment 194 decreases toward a lower limit above a freezing temperature. - A temperature of freezing
compartment 196 is generally set in a range from −22° C. to −18° C. for freezing storage. However, the temperature of freezingcompartment 196 may be set in a low temperature range from −30° C. to −25° C. for improvement of a freezing storage state. - The respective compartments are sectioned by the heat insulating walls to efficiently maintain different temperature settings. However, heat insulating
box 180 may be integrally formed by filling foamedheat insulating material 186 to reduce costs and improve heat insulation performance. Heat insulatingbox 180 formed by filling foamedheat insulating material 186 exhibits approximately twice the heat insulation performance of a structure formed of a heat insulating material such as styrene foam. Accordingly, heat insulatingbox 180 thus constructed is allowed to increase a storage volume by reduction of thicknesses of partitioning parts. - Operation of the freezing cycle is hereinafter described.
- Cooling operation starts and stops in response to signals generated from a temperature sensor (not shown) and a control board based on the set temperatures within the refrigerator.
Sealed compressor 210 performs predetermined compression operation in accordance with instructions of cooling operation. Discharged high-temperature and high-pressure refrigerant gas is condensed and liquefied at the condenser (not shown) while releasing heat, and decompressed bycapillary 212 to become low-temperature and low-pressure liquid refrigerant. The generated liquid refrigerant reachesevaporator 216. - The refrigerant gas within
evaporator 216 is evaporated and gasified by heat exchange with air inside the refrigerator in accordance with operation of coolingfan 214. Low-temperature cooling air after heat exchange is distributed by a damper (not shown) or the like to cool the respective compartments. - In
sealed compressor 210 of the refrigerator performing the foregoing operation,cylinder block 114 includes bearingportion 120 andcylinder 115 disposed such thatfirst center line 141 indicating the shaft center of bearingportion 120 andsecond center line 142 indicating the shaft center ofcylinder 115 cross each other as described in the first exemplary embodiment. Angle a1 (rad) formed byfirst center line 141 andsecond center line 142, and absolute value c1 (rad) of the angle of the tilt ofshaft 110 with respect to bearingportion 120 produced by the diameter clearance between bearingportion 120 andmain shaft portion 111 satisfy equation (1).Piston 123 includescylindrical seal portion 123 a constituting a sliding surface and producing a uniform clearance between an outer circumferential surface ofpiston 123 and an inner circumferential surface ofcylinder 115.Piston 123 further includesextension portion 123 b disposed in the rear ofseal portion 123 a, having a radius same as a radius ofseal portion 123 a, and constituting a sliding surface for supporting side pressure. - In this structure, a sliding area in a tilted state of
piston 123 decreases even when deviation between the shaft center ofcylinder 115 and the shaft center ofpiston 123 increases during the suction stroke. This effect is produced by the configuration ofpiston 123 which includesextension portion 123 b constituting a sliding surface for supporting side pressure in the rear ofcylindrical seal portion 123 a providing a sliding surface ofpiston 123, and eliminates a sliding surface in the vertical up-down direction. - This structure decreases local distortion of
piston 123, thereby reducing sliding loss for improvement of efficiency of sealedcompressor 210. As a result, reduction of power consumption of the refrigerator is achievable. - As described above, the refrigerator in this exemplary embodiment is a refrigeration device including the sealed compressor according to the first exemplary embodiment. Accordingly, the refrigeration device provided herein realizes reduction of power consumption.
- As described above, the sealed compressor according to the present invention improves efficiency by reduction of sliding loss of a piston, and therefore is applicable not only to a household electric refrigerator, but also to a refrigeration device for an air conditioner, a vending machine, or various other apparatuses.
- 101 Sealed container
- 102 Stator
- 103 Rotor
- 104 Electric element
- 105 Compression element
- 106 Lubricant
- 110 Shaft
- 111 Main shaft portion
- 112 Eccentric shaft portion
- 113 Lubrication path
- 114 Cylinder block
- 115 Cylinder
- 116 Compression chamber
- 120 Bearing portion
- 123 Piston
- 123 a Seal portion
- 123 b Extension portion
- 123 c Non-sliding portion
- 125 Piston pin
- 126 Connecting rod
- 128 Large-hole end portion
- 129 Small-hole end portion
- 130 Rod portion
- 141 First center line
- 142 Second center line
- 144 Shaft center
- 150 Valve plate
- 180 Heat insulating box
- 182 Inner box
- 184 Outer box
- 186 Heat insulating material
- 188 Refrigerating compartment
- 190 Switching compartment
- 192 Ice compartment
- 194 Vegetable compartment
- 196 Freezing compartment
- 198 Refrigerating compartment revolving door
- 200 Switching compartment drawer door
- 202 Ice compartment drawer door
- 204 Vegetable compartment drawer door
- 206 Freezing compartment drawer door
- 208 Recessed portion
- 210 Sealed compressor
- 212 Capillary
- 214 Cooling fan
- 216 Evaporator
- 218 Suction piping
Claims (4)
a1=π/2+c1 (1), and
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014-033746 | 2014-02-25 | ||
JP2014033746 | 2014-02-25 | ||
PCT/JP2015/000651 WO2015129184A1 (en) | 2014-02-25 | 2015-02-13 | Sealed compressor and refrigeration device |
Publications (1)
Publication Number | Publication Date |
---|---|
US20170009758A1 true US20170009758A1 (en) | 2017-01-12 |
Family
ID=54008522
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/113,272 Abandoned US20170009758A1 (en) | 2014-02-25 | 2015-02-13 | Sealed compressor and refrigeration device |
Country Status (5)
Country | Link |
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US (1) | US20170009758A1 (en) |
JP (1) | JPWO2015129184A1 (en) |
CN (1) | CN106062363A (en) |
DE (1) | DE112015000951T5 (en) |
WO (1) | WO2015129184A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20210340967A1 (en) * | 2018-11-08 | 2021-11-04 | Panasonic Appliances Regrigeration Devices Singapore | Refrigerant compressor and refrigeration apparatus using the same |
Citations (6)
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US2587246A (en) * | 1949-11-28 | 1952-02-26 | Tresco Inc | Hermetic refrigeration compressor |
US3419207A (en) * | 1966-09-13 | 1968-12-31 | Hintze Rudolf | Small hermetic compressor |
US20040241013A1 (en) * | 2001-12-17 | 2004-12-02 | Park Kyoung Jun | Crank shaft in dual capacity compressor |
US20090101442A1 (en) * | 2004-12-14 | 2009-04-23 | Makoto Katayama | Hermetic compressor |
US20120107148A1 (en) * | 2010-10-27 | 2012-05-03 | Samsung Electronics Co., Ltd. | Hermetic compressor |
US20120183419A1 (en) * | 2009-10-27 | 2012-07-19 | Panasonic Corporation | Hermetic compressor |
Family Cites Families (5)
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---|---|---|---|---|
JP2005264740A (en) * | 2004-03-16 | 2005-09-29 | Matsushita Electric Ind Co Ltd | Hermetic compressor |
JP4595408B2 (en) * | 2004-07-08 | 2010-12-08 | パナソニック株式会社 | Compressor |
KR101245024B1 (en) * | 2008-05-12 | 2013-03-18 | 파나소닉 주식회사 | Closed type compressor and freezing apparatus using the same |
JP5212148B2 (en) * | 2009-02-04 | 2013-06-19 | パナソニック株式会社 | Hermetic compressor and refrigeration system |
JP5579676B2 (en) * | 2011-08-23 | 2014-08-27 | 日立アプライアンス株式会社 | Hermetic compressor and refrigerator using the same |
-
2015
- 2015-02-13 CN CN201580010415.XA patent/CN106062363A/en active Pending
- 2015-02-13 JP JP2016505029A patent/JPWO2015129184A1/en active Pending
- 2015-02-13 US US15/113,272 patent/US20170009758A1/en not_active Abandoned
- 2015-02-13 DE DE112015000951.5T patent/DE112015000951T5/en not_active Withdrawn
- 2015-02-13 WO PCT/JP2015/000651 patent/WO2015129184A1/en active Application Filing
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
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US2587246A (en) * | 1949-11-28 | 1952-02-26 | Tresco Inc | Hermetic refrigeration compressor |
US3419207A (en) * | 1966-09-13 | 1968-12-31 | Hintze Rudolf | Small hermetic compressor |
US20040241013A1 (en) * | 2001-12-17 | 2004-12-02 | Park Kyoung Jun | Crank shaft in dual capacity compressor |
US7100743B2 (en) * | 2001-12-17 | 2006-09-05 | Lg Electronics Inc. | Crank shaft in dual capacity compressor |
US20090101442A1 (en) * | 2004-12-14 | 2009-04-23 | Makoto Katayama | Hermetic compressor |
US20120183419A1 (en) * | 2009-10-27 | 2012-07-19 | Panasonic Corporation | Hermetic compressor |
US20120107148A1 (en) * | 2010-10-27 | 2012-05-03 | Samsung Electronics Co., Ltd. | Hermetic compressor |
Also Published As
Publication number | Publication date |
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JPWO2015129184A1 (en) | 2017-03-30 |
WO2015129184A1 (en) | 2015-09-03 |
CN106062363A (en) | 2016-10-26 |
DE112015000951T5 (en) | 2016-11-03 |
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