CN1777753A

CN1777753A - Hermetic compressor

Info

Publication number: CN1777753A
Application number: CNA2005800000617A
Authority: CN
Inventors: 坪井康佑
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Refrigeration Devices Singapore Pte Ltd
Priority date: 2004-03-16
Filing date: 2005-01-12
Publication date: 2006-05-24
Anticipated expiration: 2025-01-12
Also published as: EP1727982A1; DE602005016904D1; US20060204373A1; JP2005264743A; JP4429769B2; KR20060061288A; KR100724843B1; WO2005088127A1; CN100445558C; EP1727982B1

Abstract

The present invention relates to a hermetic compressor that stores oil (106), and houses compression mechanism (105) that compresses a refrigerant gas, in housing (101). Piston (140) is formed with at least two grooves (144) that do not include the edges of top surface (142) and skirt surface (143), on outer circumferential surface (145) of the piston, where groove (144) communicates with the space in housing (101), at least near the bottom dead center. Such a makeup allows the sliding part to be supplied with oil through groove (144), increasing efficiency owing to high sealability and a low sliding loss.

Description

Hermetic compressor

Technical field

The present invention relates to a kind of hermetic compressor that is used for the refrigeration cycle refrigeration cycle of the refrigerator of refrigerating cabinet (as have).

Background technique

In recent years, the price of hermetic compressor significantly descends.Except reducing manufacture cost, reducing energy consumption is further requirement.Reduce cost and comprise increase output, need improve sliding characteristics and reduce energy consumption.In order to address these problems, the translator of Japanese of PCT publication number 2004-501320 (hereinafter being referred to as file 1) discloses a kind of hermetic compressor, wherein improved the profile of piston,, thereby obtained more high efficiency with the slip loss between minimizing piston and the cylinder.At this, the improvement of sliding characteristics mainly refers to the coefficient of reducing friction.

Hereinafter, above-mentioned conventional hermetic compressor is described with reference to the accompanying drawings.

Fig. 8 is the file 1 described perspective view that is used for the piston of conventional hermetic compressor.In Fig. 8, piston 1 comprises: be formed at the sealing surfaces 3 of external peripheral surface 2 with contact cylinder inner circumferential surface; At least two guide surfaces 4, it is formed at the part of external peripheral surface 2 with contact cylinder inner circumferential surface, and is roughly parallel to the moving direction of piston 1 and extends; And the cutting part 5 that does not contact with the cylinder inner circumferential surface, it is characterized in that, two lines that are connected to the central axis of air cylinder 6 of piston 1 by two

border

4a and 4b with guide surface 4 are 40 ° or littler at the angle 4ab that the piston radial direction forms, and are preferably 30 ° or littler.

The following describes the work of above-mentioned hermetic compressor.

When operation, piston 1 to-and-fro motion.At close lower dead center place, the part of the piston skirt side of piston 1 departs from cylinder.By guide surface 4 guiding, piston 1 can enter cylinder smoothly.But because above-mentioned conventional piston has than sealing surfaces 3 more near the cutting part 5 (zone of the external peripheral surface of piston 1) of piston skirt side, so in other words, the downside among Fig. 8 is not cylindrical but multistage shape.In this case, can not keep stable, and therefore can not use and through feed centerless grinding machine, reduce productivity at the honing stone that adds man-hour rotation.

In addition, use above-mentioned conventional piston, piston 1 can only cause piston to be easy to tilt with respect to the direction of cylinder by in the gap adjustment between the inner circumferential surface of the external peripheral surface 2 of short part upper piston 1 and cylinder between the top surface edge of sealing surfaces 3 and the lower limb with respect to the vertical position of cylinder.Therefore, can leak a large amount of refrigeration agents, reduce refrigerating capacity, thereby also reduced efficient.

Summary of the invention

According to the present invention, in hermetic compressor, have at least two grooves to be formed at the outside piston perimeter surface, wherein this groove does not communicate with the upper surface and the skirt surface of piston, and simultaneously at least near the spatial communication in lower dead center place and the housing.Because be essentially columniform external peripheral surface on piston head and the skirt side, this structure can be stablized the honing stone of rotation in course of working; Can prevent that piston is with respect to cylinder direction vertical tilt; And by groove to sliding parts for machine oil.

Said structure provides high productivity, refrigerating capacity and high efficiency for hermetic compressor.

Description of drawings

Fig. 1 is the longitudinal sectional drawing according to the hermetic compressor of first exemplary embodiment of the present invention.

Fig. 2 is the perspective view according to the piston that is used for hermetic compressor of first exemplary embodiment of the present invention.

Fig. 3 is a feature chart, and it shows according to the refrigerating capacity of the hermetic compressor of first exemplary embodiment of the present invention and the coefficient of performance (C.O.P).

Fig. 4 is the longitudinal sectional view according to the hermetic compressor of second exemplary embodiment of the present invention.

Fig. 5 is the perspective view according to the piston that is used for hermetic compressor of second exemplary embodiment of the present invention.

Fig. 6 is the longitudinal sectional view according to the hermetic compressor of the 3rd exemplary embodiment of the present invention.

Fig. 7 is the perspective view according to the piston that is used for hermetic compressor of the 3rd exemplary embodiment of the present invention.

Fig. 8 is the perspective view that is used for the piston of conventional hermetic compressor.

Embodiment

The present invention provides a kind of high production rate, high refrigerating capacity and high efficiency hermetic compressor by suppressing the freezing medium leakage between piston and the cylinder.

Can in housing, store machine oil according to hermetic compressor of the present invention, and in housing, be mounted with the compressing mechanism that is used for compression refrigerant gas.This compressing mechanism is equipped with: the bent axle that perpendicular is provided with, and it has main shaft part and eccentric axial portion; Form the block of cylinder; Pistons reciprocating in cylinder; The connector that connects eccentric axial portion and piston; The oil supply structure of machine oil is provided for the outside piston perimeter surface.Be formed with groove on the external peripheral surface of piston, this groove is not connected with the upper surface and the skirt surface of piston, and wherein when piston is positioned near the lower dead center, the interior space of this groove and housing is connected.At this, groove does not communicate with piston upper surface and skirt surface and is meant that two grooves are independently formed in the external peripheral surface of piston separately, but does not comprise the edge on upper surface and skirt surface.In other words, groove is not the zone that is formed on apart from upper surface and skirt surface predetermined width, and meaning has promptly kept the outer circumferential shape of piston.Owing to be essentially columniform external peripheral surface at piston upside and skirt side, this structure can be stablized the honing stone of rotation in course of working.In addition, regulated on the direction of piston in the disalignment inclination at top surface edge and skirt side margin place, thereby suppressed this inclination with respect to the cylinder axis axle direction.In addition, can provide machine oil to sliding parts, thereby obtain high productivity, refrigerating capacity and high efficiency by groove.

In addition, in hermetic compressor according to the present invention, the zone of groove account for outside piston perimeter surface zone half or more.This has suppressed the seepage of coolant gas between piston and the cylinder.In addition, the bulk zone does not contact with cylinder, thereby has significantly reduced the slip loss that occurs between piston and the cylinder.In addition, can provide machine oil for very large-scale outer surface of piston by groove, thereby improve efficient.

In addition, in hermetic compressor according to the present invention, bent axle has the second axle part coaxial with main shaft part, and eccentric shaft is sandwiched between the second axle part and the main shaft part.Compressor also comprises second bearing that pivotally supports the second axle part.This structure has prevented that bent axle from tilting from Vertical direction, and is in substantially parallel relationship to the direction of cylinder axis by the piston that connector is connected to bent axle.When piston when lower dead center moves on to top dead center, this structure has prevented the edge and the cylinder EDGE CONTACT of the groove of skirt side, the running of having stablized piston.This structure has further suppressed the seepage of refrigeration agent, has improved refrigerating capacity and efficient, and has reduced noise.

In addition, in hermetic compressor according to the present invention, for when the outside piston perimeter surface is launched the shape of time slot in the plane, comprise not have to form and the shape of the line that piston skirt is surperficial parallel in the shape of this groove of skirt side.When piston when lower dead center moves to top dead center, such structure makes the edge of groove of skirt side as the vertically-guided part between piston and the cylinder, thus the running of stable plunger, to reduce noise.

In addition, hermetic compressor according to the present invention is by a plurality of frequency of okperation VFC, and this frequency of okperation comprises at least one frequency or lower frequency.Even less machine oil is provided in the low cruise process, by in groove, storing machine oil, use this frequency and can suppress freezing medium leakage, further improved refrigerating capacity and efficient.

In addition, use R600a as its refrigeration agent according to hermetic compressor of the present invention.Utilize this refrigeration agent can prevent that piston from tilting with respect to the direction of cylinder direction in the disalignment.Compare with the compressor that uses conventional R134a, use the compressor of R600a to need bigger cylinder capacity, the external diameter of piston is bigger, so that the seepage of refrigeration agent can become is big.Because the present invention has prevented piston and leaned to cylinder, suppressed freezing medium leakage, and improved refrigerating capacity and efficient.

In addition, according to hermetic compressor of the present invention, can select the machine oil of viscosity from VG10 to VG5.Use the conventional compressor of low viscosity machine oil can cause a large amount of refrigerant gas seepages, and STRUCTURE DEPRESSION of the present invention the seepage of refrigeration agent, further improved refrigerating capacity and efficient.

Hereinafter, illustrate with reference to the accompanying drawings according to exemplary embodiments more of the present invention.

First exemplary embodiment

Fig. 1 is the longitudinal sectional view according to the hermetic compressor of first exemplary embodiment.Fig. 2 is the perspective view according to the piston of the hermetic compressor of first exemplary embodiment.Fig. 3 shows the feature chart of the refrigerating capacity and the coefficient of performance (C.O.P.).C.O.P. the efficient of representing compressor, i.e. the ratio of the input power (W) of refrigerating capacity (W) and compressor electric element, higher refrigerating capacity can improve C.O.P..

In Fig. 1 and 2, housing 101 holds electric element 104, this electric element 104 comprises: stator 102 and rotor 103, and by for example using control circuit, they can be by a plurality of frequency of okperation frequency conversion drive (inverter-drive) that comprise power line frequency or lower frequency; With by electric element 104 compressor driven structures 105.In addition, store machine oil 106 in the housing 101.

The refrigeration agent that is used for this compressor is R600a, and it is a kind of natural carbon water refrigeration agent, and less for the influence of global warming.Machine oil 106 is ISO VG10 combinations to the machine oil of ISO VG5, and its viscosity is lower, has compatibility each other.

Bent axle 110 perpendicular are installed, and it comprises: press fit has the main shaft part 111 of rotor 103; Off-centre is formed on the eccentric axial portion 112 on the main shaft part 111; And with the second axle part 113 of main shaft part 111 coaxial settings, and eccentric axial portion 112 is clipped between main shaft part 111 and the second axle part 113.

Oil supply structure 120 comprises: be fixed on oil awl (the oil cone) 122 of main shaft part 111 bottoms, a wherein oily end of boring is at machine oil 106 split sheds, and the other end is communicated with fuel supply line 121; With the fuel supply line 121 that is formed on bent axle 110 inside, wherein this fuel supply line is communicated with oil awl 122, and at the open-topped of eccentric axial portion 112.

Block 130 has and is roughly columniform cylinder 131, and pivotally supports main shaft portion 111 main bearing 132 and pivotally support second bearing 133 of the second axle part 113.The top of cylinder 131 is provided with shutter (dash board) 134, and is provided with notch 135 at the top edge of bent axle 110 sides, and provides chamfered part 136 at the outer circumferential edges place of bent axle 110 sides.

Piston 140 can reciprocatingly be inserted in the cylinder 131 of block 130, is connected to eccentric axial portion 112 by connector 141.

Piston 140 also is equipped with at least two grooves 144 on the external peripheral surface 145 of piston, this groove is not communicated with the upper surface 142 and the skirt surface 143 of piston 140.Be meant the surface that moves back and forth direction perpendicular to piston at this upper surface 142 and skirt surface 143, as shown in Figure 1, and external peripheral surface 145 refers to be parallel to a reciprocating side.Upper surface 142 and skirt surface 143 correspond respectively to the top dead center surface and the lower dead center surface of piston 140.When the external peripheral surface with piston launched in the plane, groove 144 was quadrilateral basically.For example, the position of the skirt side margin 441 of groove 144 be on piston 140 with arrow T direction apart from skirt surperficial 143 about 2mm.Groove 144 upper edge 442 are placed on the arrow S direction from the position of upper surface 142 about 7mm to 8mm.The degree of depth of groove 144 be apart from the external peripheral surface 145 of piston 140 for 0.1mm to 0.5mm.

When the part of the groove 144 of piston 140 skirt sides is projected near the housing 101 of lower dead center when inner from cylinder 131, this part of groove 144 is exposed in the housing 101 near in the space of lower dead center.In this position, groove 144 is communicated with housing 101 inner spaces.Groove 144 is made into to make its gross area to surpass half of external peripheral surface 145 areas of piston 140.

Hereinafter, to the operation and the operation of the hermetic compressor of structure describe as mentioned above.

Rotor 103 turning crankshafts 110 of electric element 104, and rotatablely moving of eccentric axial portion 112 is sent to piston 140 by connector 141, cause piston to-and-fro motion in cylinder 131.This motion is extracted refrigerant gas out and is compressed and deliver to cylinder 131 inside from the cooling system (not shown), and then is discharged into cooling system.

Simultaneously, the centrifugal force that the rotation of the oil awl 122 that utilizes bent axle 110 to rotate to cause produces, oil supply structure 120 raises the machine oil in the fuel supply line 121 106, and near the second axle part 113 top ends machine oil 106 being sprayed into housing 101.The machine oil 106 of ejection strikes shutter 134, the notch 135 of passing through, and on the external peripheral surface 145 and chamfered section 136 attached to piston.Along with the to-and-fro motion of piston 140, the machine oil 106 that adheres to infiltrates the external peripheral surface 145 and the groove 144 of piston, as the oiling agent between outside piston perimeter surface 145 and the cylinder 131.

In this case, when piston 140 when lower dead center (S direction end) moves to top dead center (T direction end), flock together attached to machine oil on the chamfered section 136 106 and the edge 441 of the machine oil 106 that infiltrates groove 144, be stored in edge near the groove 144 of piston 140 by groove 144 skirt sides.When piston 140 moves on to lower dead center from top dead center, the athletic meeting of piston 140 makes the machine oil 106 that is stored between cylinder 131 and the outside piston perimeter surface 145 be introduced to gap between piston 140 and the cylinder 131, can be full of machine oil 106 in whole gap, thereby improve sealing near upper surface 142 places.In addition, provide machine oil 106 very on a large scale by what groove 144 can be given outside piston perimeter surface 145, so that more effectively supply machine oil 106.

When piston 140 was positioned at position near top dead center, because compressed refrigerant, cylinder 131 inside were in high pressure, and this refrigeration agent is released subsequently.At this moment, the pressure difference between housing 101 and the cylinder 101 reaches maximum value, and like this, a large amount of coolant gas leaks from the gap location between cylinder 131 and the piston 140.In addition, because the distribution of pressure can take place in flowing of the refrigeration agent that generates in the cylinder 131, therefore can produce a power and make piston 140 lean to cylinder 131.

But according to first exemplary embodiment, piston 140 utilizes two edges and towards the internal surface of cylinder 131, in two one another is near skirt surface 143 near upper surface 142, so just can regulating piston 140 so that suppress this inclination.Therefore, the gap between cylinder 131 and the outside piston perimeter surface 145 can obtain the restriction, suppressed refrigeration agent from cylinder 131 to housing 101 internal leak, thereby improved refrigerating capacity.Simultaneously, groove 144 does not contact cylinder 131, has reduced the slip loss.This interactional effect has improved efficient.Be more preferably, therefore the area of groove 144 has increased the area that does not contact with cylinder 131 greater than half of external peripheral surface 145 areas of piston, has suppressed the seepage of the gap location refrigeration agent between piston 140 and the cylinder 131 simultaneously.This structure has greatly reduced the slip loss that occurs between piston 140 and the cylinder 131.

When in manufacture process, grinding piston 140, edge 441 along 144 skirt sides from skirt surface 143 to groove, and from groove 144 upper edge 442 to the zone of upper surface 142 that substantially is the external peripheral surface 145 of columniform piston, therefore the less influence that is subjected to groove 144 of honing stone can process reposefully.So, even use to be fit to through feeding centerless grinding machine and also obtaining accurate processing and high production rate of mass production.

If there is not the second axle part 113, when the eccentric axial portion 112 of bent axle 110 applied compressive load, bent axle 110 can tilt at piston 140.Therefore, piston 140 vertically tilts, and particularly for the piston 140 according to this exemplary embodiment, the edge of the edge of skirt side bump cylinder 131 may send noise.

But in first exemplary embodiment, bent axle 110 comprises the second axle part 113 with main shaft part 111 coaxial settings, and wherein eccentric axial portion 112 is clipped between main shaft part 111 and the second axle part 113; And second bearing 133 is pivotally supported the second axle part 113, and has suppressed the inclination of bent axle 110.So the piston 140 that bent axle 110 is connected with connector 141 is roughly remained on the direction with cylinder 131 parallel to an axiss.Therefore, when piston 140 when lower dead center moves on to top dead center, avoided being arranged on the edge of cylinder 131 of skirt side margin bump bent axle 110 sides of the groove 144 on piston 140 skirt surfaces.This has just suppressed impact noise, and has stablized the motion of piston 140, has suppressed the seepage of refrigeration agent, and has improved refrigerating capacity and efficient.

In addition, when under comprising a plurality of frequency of okperation of power line frequency or lower frequency at least, carrying out frequency conversion drive, the to-and-fro motion of piston 140 has reduced from be sprayed onto the amount of the machine oil 106 of housing 101 inside near the second axle part 113 tops slower in service slack-off.This can make a large amount of refrigeration agents from the gap location seepage between outside piston perimeter surface 145 and the cylinder 131.Simultaneously, in first exemplary embodiment, groove can store machine oil 106 for 144 kinds therein, keeps higher refrigerating capacity and efficient.

The R134a refrigeration agent that is used for refrigerator with routine is compared, and the density of R600a refrigeration agent is lower.If require refrigerating capacity and the compressor that uses the R134a refrigeration agent to be in peer-level, the external diameter of cylinder capacity that the hermetic compressor of use R600a refrigeration agent need be bigger and bigger piston 140.So, under the situation of using the R600a refrigeration agent,, leak into housing 101 inside from cylinder 131 so may have more refrigeration agents because the area of pipeline is bigger.But, suppressed the direction inclination of piston 140 according to the hermetic compressor of first exemplary embodiment, thereby prevented R600a refrigeration agent seepage, and improved efficient with respect to cylinder 131.

The low viscosity machine oil of ISO viscosity from VG10 to VG5 can be used as machine oil 106.Generally, low viscosity machine oil can reduce the slip loss, and the gap location of machine oil 106 between cylinder 131 and outside piston perimeter surface 145 becomes discontinuous simultaneously, causes seal break-off and refrigeration agent to leak in the housing 101.But this first exemplary embodiment can store machine oil 106 in groove 144, and machine oil 106 is provided can for the gap between cylinder 131 and the piston 140, prevents to seal destroyed and the refrigeration agent seepage, has improved efficient.

Then, the improved efficiency according to the hermetic compressor of first exemplary embodiment is described.

In Fig. 3, the right longitudinal axis is represented the refrigerating capacity of compressor, and the left longitudinal axis is represented the coefficient of performance (W/W) feature.The compressor of the conventional compressor and first exemplary embodiment all uses the R600a refrigeration agent.The operating frequency of reciprocating motion of the pistons is 50Hz.Operating temperature is-25 °, and as vapourizing temperature, condensing temperature is 55 °, and this is the general conditions of refrigerator operation.

Fig. 3 clearly show that and uses the compressor of first exemplary embodiment to improve refrigerating capacity, C.O.P. and efficient.

Second exemplary embodiment

Fig. 4 is the longitudinal sectional drawing according to the hermetic compressor of second exemplary embodiment of the present invention.Fig. 5 is the perspective view according to the piston of the hermetic compressor use of second exemplary embodiment.At this, for parts identical in first exemplary embodiment, provided identical reference character, and omitted its detailed description.

In Figure 4 and 5, housing 101 has held by electric element 104 compressor driven structures 205.

The piston 240 that is included in the compressing mechanism 205 is equipped with two grooves 244 at least, and this groove is not communicated with the upper surface 242 and the skirt surface 245 of piston 240 on the external peripheral surface 245 of piston.Be not communicated with mutually between the groove 244.

Observe from the top of piston 240, groove 244 is at least near the spatial communication in lower dead center place and the housing 101, and the right side is wideer than the left side.As shown in Figure 5, if the external peripheral surface of piston 245 is unfolded in the plane, the line that the edge 246 of groove 244 skirt sides forms is crooked or inclination, thereby forms the line of the line parallel that forms with piston 240 skirts surface 243.Fig. 5 shows an example, wherein is processed to crooked shape at skirt side margin 246, and this curved shape has predetermined curvature in the lower left corner of figure.At this, this shape is not limited to the curved shape of certain curvature, also can be the straight line that tilts.

Below, the operation and the operation of hermetic compressor with said structure described.

The rotor 103 of electric element 104 clockwise rotates bent axle 110, and rotatablely moving of eccentric axial portion 112 is sent to piston 240 by connector 141, makes piston 240 to-and-fro motion in cylinder 131.

The skirt side margin 246 of piston 240 is crooked, thereby does not have to form the line that is parallel to piston 240 skirt surfaces 243.Because this structure, when piston 240 when lower dead center moves on to top dead center, be arranged on the continuous steerable part of the skirt side margin 246 of the lip-deep groove 244 of piston 240 skirts as cylinder 131 edges of bent axle 110 1 sides.This effect has prevented that skirt side margin 246 from periodically clashing into the edge of cylinder 131, has stablized the operation of piston 240, and has suppressed the appearance of noise.Except this advantage, observe from the top of Fig. 5, the right side broad of groove 244, therefore can be by groove 244 for bigger because side pressure zone easy to wear provides machine oil 106, thereby improve reliability.

In addition, according to the compressor of second exemplary embodiment, bent axle 110 comprises the second axle part 113 with main shaft part 111 coaxial settings, and eccentric axial portion 112 is clipped between main shaft part 111 and the second axle part 113, and second bearing 133 is pivotally supported the second axle part 113.Simultaneously, even without the second axle part 113 and second bearing 133 are provided, in other words, have only main bearing 132 pivotally to support bent axle 110, even and because the tilt piston 240 of Vertical direction can be with respect to the direction vertical tilt of cylinder 131, the described structure in second exemplary embodiment can be brought same effect and effect.

The 3rd exemplary embodiment

Fig. 6 is the longitudinal sectional drawing according to the hermetic compressor of the 3rd exemplary embodiment of the present invention.Fig. 7 is the perspective view according to the piston of the hermetic compressor use of the 3rd exemplary embodiment.

At this, for parts same in first exemplary embodiment, provide same reference character, and omit its detailed description.

In Fig. 6 and 7, housing 101 has held by electric element 104 compressor driven structures 305.

The piston 340 that is included within the compressing mechanism 305 is equipped with two grooves 344 at least, and this groove is not communicated with the upper surface 342 and the skirt surface 343 of piston 240 on outside piston perimeter surface 345.

Groove 344 is at least near the spatial communication in lower dead center place and the housing 101.Shown in Fig. 6 and 7, the shape of groove 344 is arches, and upside is broadened.Fig. 7 shows the shape of the skirt side margin 346 of groove 344.This shape does not have to form the line that is parallel to skirt surface 343, and this shape is the arch that predetermined curvature is arranged.At this, this shape is not limited to the arc of certain curvature, also can be the straight line that tilts.

Below, operation and the operation to this hermetic compressor describes according to the 3rd exemplary embodiment.

Rotor 103 turning crankshafts 110 of electric element 104, and rotatablely moving of eccentric axial portion 112 be sent to piston 340 by connector 141, makes piston 340 to-and-fro motion in cylinder 131.

The skirt side margin 246 of piston 340 does not have to form the line that is parallel to piston 340 skirt surfaces 343.Because this structure, when piston 340 when lower dead center moves to top dead center, the skirt side margin 346 of the lip-deep groove 344 of skirt that is arranged on piston 340 is continuously as the targeting part at cylinder 131 edges of bent axle 110 1 sides.This effect has prevented that skirt side margin 346 from periodically clashing into the edge of cylinder 131, has stablized the operation of piston 340, and has suppressed the noise that bump causes.Except this advantage, machine oil 106 accumulates in the top of piston 340 along the skirt side margin 346 of groove 344, has further improved sealability.

In addition, in compressor according to the 3rd exemplary embodiment, bent axle 110 comprises the second axle part 113 with main shaft part 111 coaxial settings, and eccentric axial portion 112 is clipped between main shaft part 111 and the second axle part 113, and second bearing 133 is pivotally supported the second axle part 113.Simultaneously, even without the second axle part 113 and second bearing 133 are set, in other words, have only main bearing 132 pivotally to support bent axle 110, even and because the tilt piston 240 of Vertical direction can be with respect to the direction vertical tilt of cylinder 131, the described structure of the 3rd exemplary embodiment can be brought same effect and effect.

To those skilled in the art, clearly can make multiple change to the above embodiment of the present invention.But scope of the present invention should be determined by following claim.

Industrial applicibility

As mentioned above, according to hermetic compressor of the present invention can boost productivity, efficient, And reliability, so it also can be used for air-conditioning and with the Combined type electric refrigerator of refrigerating chamber.

Claims

1. hermetic compressor comprises:

Compressing mechanism, it comprises:

Vertically disposed bent axle, it has main shaft part and eccentric axial portion;

Cylinder;

Pistons reciprocating in cylinder, and this piston comprises all upper surface and skirt surface perpendicular to vibration-direction, and the external peripheral surface that is parallel to vibration-direction;

Connector, it connects described eccentric axial portion and described piston; With

Oil supply structure is used to the outer surface of described piston that machine oil is provided,

Wherein said piston has at least two grooves on its external peripheral surface, described groove is separate and be formed on the part of described circumferential surface, do not comprise the edge of described upper surface and the edge on described skirt surface, and when described piston was positioned at lower dead center, described groove communicated with space in the housing;

Electric element; With

Housing, it holds described compressing mechanism and described electric element.

2. hermetic compressor as claimed in claim 1, wherein said groove can be stored machine oil therein.

3. hermetic compressor as claimed in claim 1, the area of wherein said groove are not less than half of external peripheral surface area of described piston.

4. hermetic compressor as claimed in claim 1, wherein said bent axle also comprises the second axle part coaxial with main shaft part, and described eccentric axial portion is clipped between described the second axle part and the described main shaft part, and described compressor also comprises second bearing of pivotally supporting described the second axle part.

5. hermetic compressor as claimed in claim 1, wherein when the external peripheral surface of described piston launched in the plane, the edge shape of described groove skirt side comprised the shape that does not have to form the line that is parallel to the skirt surface.

6. hermetic compressor as claimed in claim 5, the shape of wherein said groove skirt side margin comprises the curved shape with predetermined curvature.

7. by frequency conversion drive, described frequency of okperation comprises power line frequency or lower frequency at least under a plurality of frequency of okperation for hermetic compressor as claimed in claim 1, wherein said electric element.

8. hermetic compressor as claimed in claim 1, wherein said compressing mechanism comprises a kind of refrigerant gas, and described refrigerant gas is R600a.

9. hermetic compressor as claimed in claim 1, wherein said machine oil are selected from the machine oil of ISO viscosity VG10 to VG5, and comprise VG10 and VG5.