US20070231167A1

US20070231167A1 - Reciprocating compressor

Info

Publication number: US20070231167A1
Application number: US11/407,352
Authority: US
Inventors: Hideaki Tsukamoto; Ryuji Watanabe; Tsuyoshi Ohyama
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 2006-03-31
Filing date: 2006-04-19
Publication date: 2007-10-04
Also published as: JP2007270765A; JP4902244B2; MXPA06004569A

Abstract

A reciprocating compressor is disclosed which has a valve construction using plural discharge ports, plural reed valves and plural valve backers to lower the discharge resistance and improve the compression efficiency. The reciprocating compressor (1000) has within a closed vessel (900) a reciprocating compressing section (300) for compressing a required fluid, the reciprocating compressing section (300) comprising a discharge unit for discharging the fluid and a valve assembly (500) for opening and closing the discharge unit, with a plurality of discharge ports (522A, 522B) being formed in the valve assembly, the valve assembly (500) comprising valve members (560), the valve members (560) comprising reed valves (530A, 530B) disposed correspondingly to the discharge ports (522A, 522B) and valve backers (540A, 540B) disposed respectively on back sides of the reed valves, a valve seat (520) having a recess for receiving the valve members therein, and valve members fixing means for urging end sides of the valve members to fix the valve members elastically to fixing portions (523A, 523B) of the recess.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a reciprocating compressor to be used, for example, for compressing a refrigerant in a home refrigerator. Particularly, the present invention is concerned with an improvement of a valve assembly portion which is for opening and closing a discharge unit in a compressing section.
2. Description of the Prior Art
A reciprocating compressor of this type has such a schematic construction as FIG. 1 which illustrates a compressor 1000.
In FIG. 1, the compressor 1000 comprises an assembly. According to the construction of this assembly, a motor section 200 is driven by electric power fed from a power dispatching section 100 which supplies electric power 101. A reciprocating compressing section 300 is connected to the motor section 200 to compress a refrigerant fluid which is introduced from an intake path 601 in an intake section 600 through a valve assembly 500. The refrigerant fluid thus compressed is discharged from a discharge path 701 in a discharge section 700. The assembly thus constructed is mounted and accommodated in the interior of a closed vessel 900 elastically by means of a buffer/support section 800.
Further, there is provided a construction whereby lubricating oil 401 stored in the bottom of the closed vessel 900 is circulated for lubrication to a mechanical kinetic portion between the motor section 200 and the reciprocating compressing section 300 by means of an oil feeder 400. Various proposals have been made about concrete structures of various portions in the above construction of the compressor (see Japanese Patent Publication No. H04(1992)-4894).
Since a piston reciprocates at a high speed of about 3,000 rpm, various improvements have been made in connection with the construction of the valve assembly 500. For example, there has been proposed a construction using a valve assembly, the valve assembly being provided with a thick plate as a restriction piece having an appropriate divergent angle, the restriction piece being disposed on a back side of a reed valve which is for opening and closing a discharge port, whereby not only the degree of opening of the reed valve is restricted but also the return speed of the reed valve is increased to improve the compressing efficiency (see Japanese Utility Model Publication No. H02(1990)-25986).
There also has been proposed a construction using a valve assembly wherein a reed valve and a plate spring as a restriction piece superimposed on a back side of the reed valve are disposed within a recess of a valve seat, and about half of a portion which covers a discharge port of the reed valve is covered with the restriction piece, whereby the reed valve opens while having a twisted surface, a fluid discharge direction is set toward an outlet by the twisted surface, and the closing speed is increased by a return stress of twist (see U.S. Pat. No. 4,723,896).
However, all of the above conventional valve assemblies adopt a valve construction comprising one discharge port, one reed valve for opening and closing the discharge port, and one restriction piece disposed on the back side of the reed valve. Therefore, in a compressor provided with such a valve assembly, the discharge resistance is still high, resulting in a lowering of the compression efficiency, and thus there has been room for improvement.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a reciprocating compressor using a valve construction provided with plural discharge ports, reed valves and restriction/repulsion pieces (hereinafter referred to as “valve backers”), thereby decreasing the discharge resistance and improving the compression efficiency.
For achieving the above-mentioned object, in one aspect of the present invention there is provided a reciprocating compressor having within a closed vessel a reciprocating compressing section for compressing a required fluid, the reciprocating compressing section comprising a discharge unit for discharging the fluid and a valve assembly for opening and closing the discharge unit, with a plurality of discharge ports being formed in the valve assembly, the valve assembly comprising valve members, the valve members comprising reed valves disposed correspondingly to the discharge ports and valve backers disposed respectively on back sides of the reed valves, a valve seat having a recess for receiving the valve members therein, and valve members fixing means for urging end sides of the valve members to fix the valve members elastically to fixing portions of the recess.
In a second aspect of the present invention there is provided, in combination with the above first aspect, a reciprocating compressor wherein the reed valves are each formed in a shape comprising fulcrum portions projecting to both sides in the associated one of the fixing portions, an intermediate portion projecting in a perpendicular or oblique direction with respect to a line joining the fulcrum portions, and a lid portion for closing the associated one of the discharge ports, the lid portion lying on the side opposite to the fulcrum portions with respect to the intermediate portion, the fulcrum portions, the intermediate portion and the lid portion being integral with one another, and the valve backers are each formed in a shape comprising the same fulcrum portions as those of each of the reed valves, an intermediate portion having a gradually narrowing portion projecting in an oblique direction with respect to a line joining the fulcrum portions, and an opposite end portion narrower than the lid portion of each of the reed valves, the fulcrum portions, the intermediate portion and the opposite end portion being integral with one another.
In a third aspect of the present invention there is provided, in combination with the above second aspect, a reciprocating compressor wherein the reed valves are disposed in such a manner that the lid portions of the reed valves are positioned centrally and the fulcrum portions of one of the reed valves and the fulcrum portions of the other reed valve are positioned outside the lid portions, and the valve backers are disposed in such a manner that the intermediate portions of the valve backers are positioned in directions different from each other with respect to the line joining the fulcrum portions.
In a fourth aspect of the present invention there is provided, in combination with the above second or third aspect, a reciprocating compressor wherein the valve members fixing means is formed in a shape comprising fixing portions for fixing the fulcrum portions of the valve members to the fixing portions of the recess and a spring portion for connecting the fixing portions of the valve members fixing means with each other and for urging the fulcrum portions of the valve members elastically to the fixing portions of the recess, the fixing portions and the spring portion being integral with each other.
Thus, the reciprocating compressor in the above first aspect of the present invention has within a closed vessel a reciprocating compressing section for compressing a required fluid, the reciprocating compressing section comprising a discharge unit for discharging the fluid and a valve assembly for opening and closing the discharge unit, with a plurality of discharge ports being formed in the valve assembly, the valve assembly comprising valve members, the valve members comprising reed valves disposed correspondingly to the discharge ports and valve backers disposed respectively on back sides of the reed valves, a valve seat having a recess for receiving the valve members therein, and valve members fixing means for urging end sides of the valve members to fix the valve members elastically to fixing portions of the recess.
With the valve members fixing means, the valve members can be fixed elastically to the fixing portions of the recess. Moreover, with the elasticity of the valve backers, restriction and repulsive return of the reed valves are performed to afford an effect of enhancing the efficiency of a pressurizing operation. Further, since the valve assembly adopted uses a valve construction provided with plural discharge ports and also provided correspondingly with reed valves and valve backers, there is attained an outstanding effect such that it is possible to lower the discharge resistance and improve the compression efficiency.
According to the reciprocating compressor in the above second aspect of the present invention, in combination with the above first aspect, the reed valves are each formed in a shape comprising fulcrum portions projecting to both sides in the associated one of the fixing portions, an intermediate portion projecting in a perpendicular or oblique direction with respect to a line joining the fulcrum portions, and a lid portion for closing the associated one of the discharge ports, the lid portion lying on the side opposite to the fulcrum portions with respect to the intermediate portion, the fulcrum portions, the intermediate portion and the lid portion being integral with one another, and the valve backers are each formed in a shape comprising the same fulcrum portions as those of each of the reed valves, an intermediate portion having a gradually narrowing portion projecting in an oblique direction with respect to a line joining the fulcrum portions, and an opposite end portion narrower than the lid portion of each of the reed valves, the fulcrum portions, the intermediate portion and the opposite end portion being integral with one another.
By disposing the fulcrum portions in the fixing portions of the recess through the valve members fixing means, it is possible to fix the valve members easily and positively. Besides, the reed valves when opened can each be allowed to perform such a motion as the letter S being stretched obliquely and the head portion twisted. In resistance to such a cubically complicated way of bending an internal stress is stored in the reed valves themselves and the valve backers, and with the resulting repulsive force it is possible to further increase the reed valve return speed, thus affording a further outstanding effect that the compression efficiency can be further improved.
According to the reciprocating compressor in the above third aspect of the present invention, in combination with the above second aspect, the reed valves are disposed in such a manner that the lid portions of the reed valves are positioned centrally and the fulcrum portions of one of the reed valves and the fulcrum portions of the other reed valve are positioned outside the lid portions, and the valve backers are disposed in such a manner that the intermediate portions of the valve backers are positioned in directions different from each other with respect to the line joining the fulcrum portions.
Since the reed valves open while being bent in opposite directions, the collision of refrigerant gases discharged from the reed valves is diminished and the discharge resistance is made still lower, thus affording a further outstanding effect that the compression efficiency can be further improved.
According to the reciprocating compressor in the above fourth aspect of the present invention, in combination with the above second or third aspect, the valve members fixing means is formed in a shape comprising fixing portions for fixing the fulcrum portions of the valve members to the fixing portions of the recess and a spring portion for connecting the fixing portions of the valve members fixing means with each other and for urging the fulcrum portions of the valve members elastically to the fixing portions of the recess, the fixing portions and the spring portion being integral with each other.
There can be obtained a further outstanding effect that the valve members can be fixed to the aforesaid recess easily and positively by one valve members fixing means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an entire construction common to both a reciprocating compressor according to an embodiment of the present invention and the prior art;
FIG. 2 is a sectional view showing an entire construction of the embodiment of the present invention in an exploded state;
FIG. 3 is a perspective view partly in section, showing an entire construction of the embodiment of the present invention in an assembled state of various constituent portions;
FIG. 4 is an enlarged diagram showing principal portions of FIG. 2 in detail;
FIG. 5 is an explanatory diagram showing an assembled state of various portions related to a valve assembly used in the embodiment of the present invention;
FIG. 6(A) is an explanatory plan view showing an assembled state of various portions related to the valve assembly in the embodiment of the present invention, FIG. 6(B) is an explanatory plan view showing in detail principal portions of reed valves and valve backers shown in FIG. 6(A), and FIG. 6(C) is an explanatory plan view showing a state in which valve backers are disposed on back sides of the reed valves respectively;
FIG. 7 is an explanatory sectional view taken on line A-A in FIG. 6(A); and
FIG. 8 is an explanatory diagram showing a state in which a valve backer is disposed on the back side of a reed valve.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

A reciprocating compressor according to an embodiment of the present invention will be described in detail hereinunder with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an entire construction common to both a reciprocating compressor according to an embodiment of the present invention, FIG. 2 is a sectional view showing an entire construction of the embodiment of the present invention in an exploded state, FIG. 3 is a perspective view partly in section, showing an entire construction in an assembled state of various constituent portions, FIG. 4 is an enlarged diagram showing principal portions of FIG. 2 in detail, FIG. 5 is an explanatory diagram showing an assembled state of various portions related to a valve assembly used in the embodiment of the present invention, FIG. 6(A) is an explanatory plan view showing an assembled state of various portions related to the valve assembly in the embodiment of the present invention, FIG. 6(B) is an explanatory plan view showing in detail principal portions of reed valves and valve backers shown in FIG. 6(A), and FIG. 6(C) is an explanatory plan view showing a state in which valve backers are disposed on back sides of the reed valves respectively, FIG. 7 is a sectional view taken on line A-A in FIG. 6(A), and FIG. 8 is an explanatory diagram showing a state in which a valve backer is disposed on the back side of a reed valve.
Functional portions represented by reference numerals are assembled by combinations indicated with fine lines and chain lines and are mounted and fixed or engaged using set screws and retaining springs. In the accompanying drawings, portions of the same reference numerals represent portions having the same functions, and portions of the same reference numerals as in FIG. 1 represent portions having the same functions as those of the portions of the same reference numerals illustrated in FIG. 1.
In FIGS. 1 to 3, a stator 210, a rotor 220, a rotatable shaft 230 and a bearing 240 are assembled together to constitute a motor section 200, which is connected to a power dispatching section 100. A buffer/support section 800 is constituted by a helical spring or the like.
A crescent balancing plate 231 is integrally formed at a lower end portion of the rotatable shaft 230 in the motor section 200 and an eccentric pin 310 is disposed on the side opposite to the crescent balancing plate 231, thereby constituting a motion mechanism for making the eccentric pin 310 perform a motion which describes a circular path.
A motion mechanism which is driven by the eccentric pin 310 to create a linear reciprocating motion is constituted within a T-shaped crank tube 330, and a piston 340 reciprocates within a cylinder bore of a cylinder 350 to effect a compression action. A reciprocating compressing section 300 is constituted by the portions from the eccentric pin 310 to the cylinder 350.
A valve assembly 500, which is mounted in contact with the cylinder 350, is mainly composed of a gasket 551, an intake-side valve member 510, a valve seat 520, two reed valves 530, two valve backers 540, valve members fixing means 570, and a gasket 550. These portions are sandwiched in between an end face 352 of the cylinder 350 which constitutes the reciprocating compressing section 300 and an end face 713 of a head muffler member 710 which constitutes a discharge section 700, and are then fixed with screws for assembly. Thus, the portions in question are held grippingly and fixed between the end face 352 of the cylinder 350 and the muffler member 710 of the discharge section 700.
The reference numeral 600 denotes an intake section. A refrigerant fluid introduced from an intake path 601 passes through a muffler (not shown) provided with a filter for filtering admixtures, etc. received in a conduit of an object of utilization, further passes through a resonance chamber, and is introduced into the valve assembly 500.
As the solvent used in this embodiment there is used an HFC refrigerant, e.g., R134a.
On the other hand, the refrigerant fluid after compression passes through the valve assembly 500 and then through plural mufflers 720 having resonance chambers adapted to resonate with a fluid vibration of a different frequency for deadening a sound, then passes through a path extending from a discharge pipe (not shown) to a discharge path 701. In this way there is constituted a discharge section 700.
After assembly of the above constituent portions, an upper vessel 920 of a closed vessel 900 is fitted in a lower vessel 910 in a hermetically sealed state, whereby there is provided an integrated, hermetically sealed, reciprocating compressor 1000, as shown in FIG. 3. In this state, lubricating oil 401 is charged through a charging pipe 402 into the lower vessel 910. An oil feeder 400 is constituted so as to suck up the lubricating oil 401 by high-speed rotation of the rotatable shaft 230 and circulate it to various constituent portions.
Numeral 360 denotes an intra-case discharge pipe for discharging a portion of the compressed refrigerant into the closed vessel 900 to increase the internal pressure to a high level.
Next, detailed portions of the valve assembly 500 will be described below with reference to FIGS. 4 to 8.
As shown in FIG. 4, the valve assembly 500, which is mounted in contact with the cylinder 350, is mainly composed of a gasket 551, an intake-side valve member 510, a valve seat 520, two reed valves 530A, 530B, two valve backers 540A, 540B, valve members fixing means 570, and a gasket 550.
These portions are sandwiched in between the end face 352 of the cylinder 350 which constitutes the reciprocating compressing section 300 and the end face 713 of the muffler 710 which constitutes the discharge section 700, and are then fixed with screws and assembled. Further, an intake path extending along an arrow from the right to the left in FIG. 4 and a discharge path extending along an arrow from the left to the right in the same figure are formed.
More specifically, there are provided two discharge ports 522A and 522B from which the refrigerant is discharged with a high-speed reciprocating motion of the piston 340 within the cylinder 350. The reed valves 530A and 530B are for opening and closing the discharge ports 522A and 522B and the valve backers 540A and 540B, which are for restriction and repulsion of openings of the reed valves 530A and 530B, are disposed respectively on back sides of the reed valves 530A and 530B to constitute valve members 560. The valve members 560 are received in predetermined positions (523A, 523B) of a recess 523 formed in the valve seat 520. Thereafter, end sides of the valve members 260 are urged by the valve members fixing means 570 to fix the valve members elastically to predetermined fixing portions (523A, 523B) of the recess 523 (see FIGS. 5 to 7).
The gasket 551 is interposed between the cylinder 350 and the intake-side valve element 510 and is formed by forming a resin plate, e.g., a fiber-filled butyl rubber plate, into the illustrated shape. The gasket 551 is provided on its outer periphery with a peripheral edge portion for closing the peripheral portion between it and the cylinder 350, as well as the intake-side valve element 510, and is also provided with an intake/discharge passage 551A.
The intake-side valve member 510 comprises a reed valve 511, the reed valve 511 being formed by forming a slit near the center of a planar plate spring, e.g., a stainless steel plate spring having both surfaces polished, and discharge holes 512A and 512B formed outside a base portion of the reed valve 511, the discharge holes 512A and 512B being a little larger than the discharge ports 522A and 522B of the valve seat 520.
The reed valves 530A and 530B are each formed by forming a planar plate spring, e.g., a thin stainless steel plate spring having both surfaces polished, into the illustrated shape. According to this shape, as shown in FIG. 6(B), two fulcrum portions 531 and 532 projecting to both sides are formed at one end corresponding to a lead valve fixing portion 535, an intermediate portion 533 extends along a center line (y) which is perpendicular to a center line (x) joining the two fulcrums, and a lid portion 534 having a diameter able to close the associated one of the discharge ports 522A and 522B is formed at an opposite end opposite to the one end with respect to the intermediate portion 533.
As shown in FIGS. 5 to 7, the reed valves 530A and 530B are disposed in the predetermined fixing portions (523A, 523B) of the recess 523 in such a manner that the lid portions 534 of the reed valves 530A and 530B are positioned centrally, while the fulcrum portions 531 and 532 of one reed valve 530A and the fulcrum portions 531 and 532 of the other reed valve 530B are positioned outside the lid portions 534. The valve backers 540A and 540B are disposed in such a manner that intermediate portions 543 of the valve backers 540A and 540B are positioned in different directions with respect to lines joining fulcrum portions 541 and 542 of the valve backers 540A and 540B.
A description will now be given about the valve backer 540A. According to the shape of the valve backer 540A, as shown in FIGS. 6(A) to 6(C), the intermediate portion 543 extends along a center line (z) which is oblique at an angle of θ relative to a center line (y) perpendicular to a center line (x) joining the fulcrum portions 541 and 542, and an opposite end portion 544 is formed on an opposite end side opposite to the fulcrum portions side with respect to the intermediate portion 543. FIG. 6(C) shows a state in which the valve backers 540A and 540B are disposed on back sides of the reed valves 530A and 530B respectively.
By so disposing the valve backers 540A and 540B, the reed valves 530A and 530B are lifted from below and bend in opposite directions and open in the illustrated state by virtue of a discharge pressure. Consequently, the collision between the refrigerant gas discharged from the reed valve 530A and that discharged from the reed valve 530B is diminished, whereby it is possible to further lower the discharge resistance and improve the compression efficiency.
The valve backers 540A and 540B are each formed by forming a planar plate spring, e.g., a thin stainless steel plate spring having both sides polished, into the illustrated shape. As is the case with the reed valves 530A and 530B, two fulcrum portions 541 and 542 projecting to both sides are formed at one end corresponding to a valve backer fixing portion 549 and an intermediate portion 543 extends in an oblique direction at a predetermined angle of θ as noted above relative to a line joining the two fulcrums, the intermediate portion 543 extending so as to become narrower gradually from base portions of the fulcrum portions 541 and 542 and form a tip end 544 on the opposite end side, the tip end 544 having a width of about half of the lid portion 534 in each of the reed valves 530A and 530B. The valve backer fixing portion 549 including the fulcrum portions 541 and 542 and the tip end 544 are formed so that their surfaces are parallel to each other, while the intermediate portion 543 is formed in a shape having surfaces curved along quadratic curves with a small curvature on a side 543-1 close to the valve backer fixing portion 549 and a large curvature on a side 543-2 close to the tip end 544.
According to this shape of the valve backers 540A and 540B, when the reed valves 530A and 530B are lifted from below in the illustrated state by virtue of a discharge pressure, they are deformed with elastic deformation of the valve backers 540A and 540B and along the shape of the valve backers. Moreover, the smaller width of the tip end 544 permits the reed valves 530A and 530B to be twisted more easily.
The valve members fixing means 570 is formed by forming a thick metallic plate, e.g., a stainless steel plate spring, into the illustrated shape and is made up of fixing portions 570A and 570B for fixing the fulcrum portions 531, 532, 541 and 542 of the valve members 560 to the fixing portions 523A and 523B of the recess 523 and a spring portion 570C for connecting the fixing portions 570A and 570B with each other and for urging the fulcrum portions 531, 532, 541 and 542 of the valve members 560 elastically to the fixing portions 523A and 523B of the recess 523, the fixing portions 570A, 570B and the spring portion 570C being integral with each other.
The fixing portions 570A and 570B of the valve members fixing means 570 are mounted from above the fulcrum portions 531, 532, 541 and 542 to the fixing portions 523A and 523B of the recess 523. In this way the valve members 560 can be fixed easily and positively by one valve members fixing means 570.
In this state, the valve assembly 500 is sandwiched and fixed between the end face 352 of the cylinder 350 and the head muffler member 710 in the discharge section 700, whereby the valve members 560 are prevented from dislodgment under vibration or the like.
The valve seat 520 is formed by forming a rather thick metallic plate, e.g., a stainless steel plate into the illustrated shape, which is in conformity with the profile of the fulcrum portions 531 and 532 of the reed valves 530A and 530B. According to the shape of the valve seat 520 there is formed a recess 523, the recess 523 comprising fixing portions 523A and 523B as a first recess in which the fulcrum portions 531, 532, 541, 542 of the reed valves 530A, 530B and the valve backers 540A, 540B enter in a mutually superimposed state and a second recess in which the other portions than the fulcrum portions of the reed valves 530A, 530B and the valve backers 540A, 540B enter, the first and the second recess being contiguous to each other. Further, discharge ports 522A and 522B are formed in the second recess in positions corresponding to the lid portions 534 of the reed valves 530A and 530B.
In the valve seat 520, the recess 523 is formed by stamping and both surfaces thereof are finished by polishing. The discharge ports 522A and 522B are formed with peripheral rib-like faces 522C, which are finished by polishing to form contact faces for the reed valves 530A and 530B. Further, an intake port 521 is formed in the planar portion free of the recess 523 in a position corresponding to the reed valve 511 of the intake-side valve member 510.
The gasket 550 is interposed between the valve seat 520 and the head muffler member 710 in the discharge section 700 and it is formed by forming a resin plate, e.g., a fiber-filled butyl rubber plate, into the illustrated shape. The gasket 550 is provided with a peripheral edge portion for closing the peripheral portion between the valve seat 520 and the head muffler member 710 and is also provided with a partitioning portion 554 for partition between an intake-side small chamber 558 and a discharge-side small chamber 559.
The head muffler member 710 in the discharge section 700 is formed by forming a rather thick metallic plate, e.g., a stainless steel plate, into the illustrated shape, in which a hole as a passage (not shown) leading to the discharge path 701 is formed.
The above constituent elements, that is, all of the gasket 551, intake-side valve member 510, valve seat 520, reed valves 530A, 530B, valve backers 540A, 540B, valve members fixing means 570, gasket 550, and head muffler member 710, are demagnetized to prevent mutual tacking in operation.
As shown in FIG. 6(A), the valve seat 520, the reed valve 530A (530B), and the valve backer 540A (540B), when assembled, are superimposed one on another in plan.
In the section of FIG. 6(A), that is, in a longitudinal section taken along the center of the reed valve 530A and that of the reed valve 530B, principal portions are as shown in FIG. 7. In the section of FIG. 6(A) taken on line A-A, the shape of the reed valves 530A, 530B and that of the valve backers 540A, 540B are in a pressure-free state. Further, in the valve members 560 constituted by the reed valves 530A, 530B and the valve backers 540A, 540B, the reed valve fixing portions 535 and the valve backer fixing portions 549 at one ends including the fulcrum portions 531, 532, 541 and 542 are held down by the valve members fixing means 570.
Since the valve backers 540A and 540B are disposed in the illustrated fashion, when the compressed fluid is discharged from the discharge ports 522A and 522B and a discharge pressure is imposed on the reed valves 530A and 530B, the reed valves are lifted from below in the illustrated state by virtue of the discharge pressure and exhibit a complicated way of bending in opposite directions.
This bending is a three-dimensionally complicated way of bending as if a cobra raised it head and twisted its neck, that is, a way of bending as if the letter S were drawn out thinly and the head thereof twisted. Consequently, an internal stress resistive to the bending is stored in the reed valves 530A, 530B and the valve backers 540A, 540B.
When a change is made from the discharge pressure to a counter pressure in this state, a restoring force which acts to correct the bending of the reed valves 530A, 530B and close the discharge ports 522A, 522B appears as a strong repulsive force due to the internal stress against the foregoing three-dimensionally complicated way of bending and acts as a force to straighten the foregoing S-bend. Consequently, the reed valves 530A and 530B perform such an abrupt operation as their tip portions, i.e., lid portions 534 are thrown against the discharge ports 522A and 522B. As a result, the reed valves 530A and 530B close the discharge ports 522A and 522B earlier than the counter pressure and operate so that the amount of the fluid returning to the discharge ports 522A and 522B under the counter pressure can be diminished to the extreme degree.
Thus, in such a closed type reciprocating compressor 1000, the valve members 260 can be fixed to the fixing portions 523A and 523B of the recess 523 easily and positively by the valve members fixing means 570 and restriction and repulsive return of the reed valves 530A and 530B are performed with the elasticity of the valve backers 540A and 540B to afford an effect of enhancing the efficiency of the pressurizing operation. Further, since the valve assembly 500 is of a valve construction including two discharge ports 522A, 522B, two reed valves 530A, 530B and two valve backers 540A, 540B, the discharge resistance is further lowered and the compression efficiency is improved. Consequently, when the reciprocating compressor 1000 is used as a compressor in a refrigerator, the coefficient of performance in the refrigerator is improved.
The above embodiment is for explaining the present invention and neither limits the claimed invention nor restricts the scope of claims. The constructions of various constituent portions in the present invention are not limited to those described in the above embodiment, but various modifications may be made within the technical scope described in the claims.
According to the reciprocating compressor of the present invention, the valve members can be fixed to the fixing portions of the recess in the valve seat easily and positively by one valve members fixing means. Besides, restriction and repulsive return of the reed valves are performed with the elasticity of the valve backers to afford an effect of enhancing the efficiency of the pressurizing operation. Moreover, since the valve assembly used a valve construction provided with plural discharge ports, plural reed valves and plural valve backers, the discharge resistance is further lowered and the compression efficiency is improved. When the reciprocating compressor is used as a compressor in a refrigerator, there is obtained an outstanding effect that the coefficient of performance in the refrigerator is improved. Thus, the reciprocating compressor of the present invention is high in its industrial utility.

Claims

1. A reciprocating compressor having within a closed vessel a reciprocating compressing section for compressing a required fluid,

said reciprocating compressing section comprising a discharge unit for discharging said fluid and a valve assembly for opening and closing said discharge unit, with a plurality of discharge ports being formed in said valve assembly,

said valve assembly comprising valve members, said valve members comprising reed valves disposed correspondingly to said discharge ports and valve backers disposed respectively on back sides of said reed valves, a valve seat having a recess for receiving said valve members therein, and valve members fixing means for urging end sides of said valve members to fix said valve members elastically to fixing portions of said recess.

2. The reciprocating compressor according to claim 1, wherein:

said reed valves are each formed in a shape comprising fulcrum portions projecting to both sides in the associated one of said fixing portions, an intermediate portion projecting in a perpendicular or oblique direction with respect to a line joining said fulcrum portions, and a lid portion for closing the associated one of said discharge ports, said lid portion lying on the side opposite to said fulcrum portions with respect to said intermediate portion, said fulcrum portions, said intermediate portion and said lid portion being integral with one another, and

said valve backers are each formed in a shape comprising the same fulcrum portions as those of each said reed valve, an intermediate portion having a gradually narrowing portion projecting in an oblique direction with respect to a line joining said fulcrum portions, and an opposite end portion narrower than said lid portion of each said reed valve, said fulcrum portions, said intermediate portion and said opposite end portion being integral with one another.

3. The reciprocating compressor according to claim 2, wherein said reed valves are disposed in such a manner that said lid portions of said reed valves are positioned centrally and said fulcrum portions of one of said reed valves and said fulcrum portions of the other reed valve are positioned outside said lid portions, and said valve backers are disposed in such a manner that said intermediate portions of said valve backers are positioned in directions different from each other with respect to said line joining said fulcrum portions.

4. The reciprocating compressor according to claim 2, wherein said valve members fixing means is formed in a shape comprising fixing portions for fixing said fulcrum portions of said valve members to said fixing portions of said recess and a spring portion for connecting said fixing portions of said valve members fixing means with each other and for urging said fulcrum portions of said valve members elastically to said fixing portions of said recess, said fixing portions and said spring portion being integral with each other.

5. The reciprocating compressor according to claim 3, wherein said valve members fixing means is formed in a shape comprising fixing portions for fixing said fulcrum portions of said valve members to said fixing portions of said recess and a spring portion for connecting said fixing portions of said valve members fixing means with each other and for urging said fulcrum portions of said valve members elastically to said fixing portions of said recess, said fixing portions and said spring portion being integral with each other.