MXPA06003833A - Scroll machine - Google Patents

Abstract

A discharge valve assembly (12) is provided for preventing reverse rotation of a scroll compressor. The discharge valve assembly includes a cup-shaped valve member (104) slidably engaged with a central post of a retainer member (106). The cup-shaped valve member (104) includes notches in communication between the central post of the retainer (106) and the sidewalls of the cup-shaped valve member.

Description

SPIRAL MACHINE DESCRIPTION OF THE INVENTION The present invention relates to scroll compressors, and more particularly, to relief valves to prevent the reverse rotation of a scroll compressor in a forced stop. Spiral compressors have been widely used in many refrigerant compression applications. Spiral compressors are relatively efficient, and have been used increasingly in different applications. In a typical scroll compressor, the compression chambers are defined by two generally spiral wraps. The spiral wraps are formed into individual spiral members, and extend from a base plate. The spiral wraps are interconnected to define compression chambers. One of the spiral wraps is set in motion to orbit relative to the other, and the size of the compression chambers changes to compress the trapped coolant. As the compression chamber nears the end of its cycle, trapped gas is exposed to a discharge port. The trapped gas leaves the discharge port and moves through a regulating valve into a distribution chamber. The discharge regulator valve typically opens during the operation of the scroll compressor. The regulating valve closes the discharge port and desirably prevents backflow once the compressor stops. There is a phenomenon in spiral compressors known as reverse rotation. This occurs when the compressed gas moves back through the discharge port and into the compression chamber to move the compressor casings to each other in a reverse direction during a forced stop of the compressor. This is undesirable, and results in unwanted noise and potential damage to the compressor components. One method to minimize the amount of reverse rotation is to minimize the volume of compressed gas that will move between the spiral envelopes during a forced stoppage. The present invention provides a discharge valve that is designed to act quickly to close the discharge port during a forced shutdown of the compressor. A discharge valve, in accordance with the principles of the present invention, includes a valve seat having a seating surface which is oriented downstream to a discharge passage of the scroll compressor. A valve member having a body portion for coupling the seat surface of the valve seat to close the discharge passage is provided. The valve member includes a guide portion extending axially from the body portion. A retainer is slidably coupled with the guide portion of the valve member and includes at least one passage communicating with a space between the valve member and the retainer. In accordance with one aspect of the present invention, a guide portion of the valve member includes at least one notch portion in communication with the space between the valve member and the retainer. During the operation of the scroll compressor, the valve member is lifted from the valve seat and slidably moved relative to the retainer to an open position. During a forced stop, the discharge pressure in the discharge chamber acts on the valve member through at least one passage communicating with the space between the valve member and the retainer to cause the valve member to move. towards its closed position. The notched portions in the guide portion of the valve member dampen with respect to movement of the valve member between the open and closed positions. Additional areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, although they indicate the preferred embodiment of the invention, they are only intended for purposes of illustration and not to attempt to limit the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully understood from the detailed description and the accompanying drawings, in which: Figure 1 is a cross-sectional view of a coil compressor incorporated with a discharge valve, in accordance with the principles of the present invention; Figure 2 is a detailed cross-sectional view of the discharge valve shown in Figure 1; Figure 3 is an exploded perspective view of the components of the relief valve shown in Figure 2; Figure 4 is a cross-sectional view of a discharge valve according to an alternative embodiment of the present invention; Figure 5A is a cross-sectional view of a discharge valve according to an alternative embodiment of the present invention; Figure 5B is a top view of the valve retainer shown in Figure 5A; Figure 6A is a cross-sectional view of a discharge valve according to still another embodiment of the present invention; Figure 6B is a top view of the retainer shown in Figure 6A; Figure 7A is a cross-sectional view of yet another embodiment of the relief valve according to the principles of the present invention; Figure 7B is a plan view of the grooves formed in the cushion plate; Figure 8A is a cross-sectional view of yet another embodiment of the relief valve according to the principles of the present invention; Figure 8B is a plan view of the grooves formed in the damping plate in accordance with the principles of the present invention; Figure 9 is a cross-sectional view of a discharge valve according to an alternative embodiment of the present invention; Figure 10 is a perspective view of the valve member shown in Figure 9; Figure 11 is a cross-sectional view of a discharge valve according to an alternative embodiment of the present invention; Figure 12 is a perspective view of the valve member shown in Figure 11; Figure 13 is a cross-sectional view of a discharge valve according to an alternative embodiment of the present invention; Figure 14 is a cross-sectional view taken along line 14-14 of Figure 13; Figure 15A is a cross-sectional view of a discharge valve according to an alternative embodiment of the present invention with the valve member being shown in a fully open position; Figure 15B is a cross-sectional view of the relief valve shown in Figure 15A, with the valve member being shown in a partially closed position; and Figure 15C is a cross-sectional view of the relief valve shown in Figure 15A, with the valve member being shown in a fully seated position. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its application or its uses. To begin, it is noted that the embodiments of the compressor described herein are the subject of the commonly assigned US Patent No. 6, 139, 291 to Perezovchicov, a description of which is incorporated herein by reference. Referring now to the drawings in which like reference numbers designate similar or corresponding parts in all the various views, a spiral compressor 10 incorporating a discharge valve assembly 12 according to the present invention is shown in Figure 1. . The compressor 10 comprises a generally cylindrical watertight frame 14 having at its upper end thereof a lid 16 and at the lower end thereof a base 18. The lid 16 is provided with a refrigerant discharge fitting 20. Other main elements fixed to the frame 14 include a transversely extending partition or buffer plate 22 which is welded to the frame 14 around its periphery. A main support housing 24 is suitably secured to the frame 14 and a two-piece upper support housing 26 is suitably secured to the main support housing 24. A drive shaft or crankshaft 30 having an eccentric crankshaft journal 32 at the upper end thereof is rotatably articulated in a first support (not shown) in the main support housing 24 and a second support 36 in the support housing 26 higher. The crankshaft 30 has at the lower end an eccentric orifice of relatively large diameter communicating with an orifice 40 of smaller externally inclined diameter extending upwardly therefrom to the upper part of the crankshaft 30. The lower portion of the interior of the frame defines a lubricant crankcase that is filled with lubricating oil at a level slightly above the lower end of a rotor 46, and the eccentric orifice acts as a pump to pump the lubricating oil upward toward the crankshaft 30 and into the orifice 40 and finally to all the various portions of the compressor 10 that require lubrication. The crankshaft 30 is rotatably driven by an electric motor 48 which includes a stator 50, windings 52 passing therethrough, and a rotor 46 which adjusts by pressure on the crankshaft 30 and which has an upper counterweight and a lower counterweight ( not shown). An upper surface 58 of an upper support housing 26 is provided with a flat axial bearing surface on which is arranged an orbiting spiral member 60 having a spiral reef or sheath 62 extending upwardly from an end plate 64. Projecting downwardly from a bottom surface of the end plate 64 of the orbiting spiral member 60 is a cylindrical bushing 66 having an articulation support 68 therein, and which is rotatably disposed in a transmission bushing 70 having an orifice 72 internally in which the crankshaft journal 32 is operatively arranged. The crankshaft journal 32 has a surface that engages a flat surface (not shown) formed in a portion of the hole 72 to provide a radially compliant actuating arrangement, such as is shown in Assignee's North American Patent No. 4,877,382, description of the which is incorporated herein by reference. An Oldham coupling 76 is also provided and placed between the orbiting spiral member 60 and the upper support housing 26 and the orbiting spiral member 60 and a non-orbiting spiral member 80 is secured to prevent the rotary movement of the member 60. of orbiting spiral. The Oldham Coupling 76 is preferably of the type described in Assignee's North American Patent No. 5,320,506, a description of which is incorporated herein by reference. The non-orbiting spiral member 80 is provided with a shell 82 extending downwardly from an end plate 84 which is placed in a combination gear with a shell 62 of the orbiting spiral member 60. The non-orbiting coil member 80 has a centrally disposed discharge passage 86 communicating with an upwardly open recess 88 which in turn is in fluid communication with a shock absorbing chamber 90 defined by the cover 16 and division 22. A annular recess 92 is formed in a non-orbiting spiral member 80, within which a floating seal assembly 94 is disposed. The recesses 88, 92, and the floating seal assembly 94 cooperate to define an axial pressure bias chamber that receives the pressurized fluid which is compressed by the shells 62, 82 so that an axial biasing force is exerted on the member. 80 of non-orbiting spiral to thereby drive the tips of the respective shells 62, 82, within a sealing gear with opposite end plate surfaces 98, 100 and the end plates 64, 84, respectively. The floating seal assembly 94 is preferably of the type described in greater detail in U.S. Patent No. 5,156,539, a description of which is incorporated herein by reference. The non-orbiting coil member 80 is designed to be mounted in the main support housing 24 in a suitable manner such as in the manner provided in the aforementioned US Patents Nos. 4,877,382 or 5,102,316, descriptions of which are incorporated herein by reference. reference. The present invention is directed towards an assembly 12 of closed mechanical discharge valve that is disposed within a recess 88 that is formed in the non-orbiting spiral member 80. The discharge valve assembly 12 moves between a fully closed condition and a fully open condition during the regular state operation of the compressor 10. The valve assembly 12 will close during forced shutdown of the compressor 10. When the valve assembly 12 is completely closed, the recompression volume is minimized and the counterflow of the discharge gas through the spiral members 60, 80 is prohibited. The valve assembly 12 is normally closed as shown in Figure 2. The normally closed configuration of the valve assembly 12 requires a discharge force (i.e., a pressure differential) to open the valve assembly 12. The valve assembly 12 depends on the pressure within the shock absorber chamber 90 to cause the valve 12 to close. Referring now to Figures 2 and 3, the discharge valve assembly 12 includes a valve plate 102 that defines a valve seat disposed in an upwardly open recess 88 in the non-orbiting scroll member 80 adjacent to the discharge passage 86 . A valve member 104 is provided to enclose the passage through the valve plate 103. A retainer 106 is provided to retain and guide the movement of the valve member 104. The valve plate 102 defines a valve seat that includes a seat surface 108 having a frusto-conical shape and which is oriented in a downstream direction from the discharge port 86. The valve plate 102 includes the central opening 110 adjacent the seat surface 108. The seat surface 108 is disposed at approximately 50-60 degrees from the axis of the valve plate. A surface 112 upstream of the valve plate 102 is also angularly disposed relative to the axis of the valve plate 102 at about 50-60 degrees. The outer perimeter of the valve plate 102 includes a recessed portion 114. The valve member 104 is generally bell-shaped and includes a generally cylindrical side wall portion 116 and a base portion 118 enclosing a forward end of the cylindrical side wall 116. The base portion 118 includes a central hub 120 extending axially therefrom. The external perimeter of the base portion 118 includes a frustoconical surface 122 between the internal face of the base portion 118 and the cylindrical side wall 116. The frusto-conical portion 122 is disposed at about 50-60 of the central axis of the valve member. The cylindrical side wall 116 includes a plurality of equally spaced notches 124 (better seen in Figure 3) extending axially from a rear end 126 of the cylindrical side wall 116 in the direction of a front end 128 of the cylindrical side wall. In the embodiment shown in Figure 3, three notches 124 are provided.

Alternatively, slots 124 'may be provided in the side wall 116 as illustrated in Figures 9 and 10. As a further alternative, as shown in Figures 11 and 12, holes 124"may be provided in the side wall 116. The holes 124"can be molded or drilled. The slots 124 'and the holes 124"provide a rigid side wall 116 while providing ventilation passages therethrough. As yet a further alternative, as shown in Figures 13 and 14, the rod 134 of the retainer 106 can be provided with recesses 140 while the side walls 116 of the valve member 104 are not provided with any ventilation formation. The retainer 106 includes a cylindrical external side wall 130 and a retainer base portion 132 disposed at a rear end of the cylindrical external side wall 130. A central rod 134 extends axially from the retainer base portion 132 and includes a through hole 136 extending axially therethrough. The valve member 134 is slidably received in the central rod 134 of the retainer 106. Through the operation of the scroll compressor 10, the valve member 104 is opened by a gas flow from the scroll compressor. The valve member 104 slides freely on the rod 134 of the retainer 106. The ventilation formations 124, 124 ', 124' ', 140 provide ventilation to the space 138 between the valve member 104 and the rod 134 which defines a cavity of damping with the movement of the valve member 104. When the valve member 104 is open, the gas in the valve cavity 138 is compressed and depleted through the radial clearance of the restriction orifice 136 and the stem 134. This causes the pressure in the valve cavity to increase. , therefore the velocity of the valve and the impact on the retainer 106 are reduced. After the communication of the gas through the ventilation formations 124, 124 ', 124", 140 have been closed, the flow of Gas to or from the damping cavity is restricted by the radial clearance of the valve 104 and the rod 134. During a fraction of a revolution, when there is a negative pressure drop across the valve which causes the member valve stops working, the pressure in the valve cavity is reduced due to an increase in volume and pressure drop through the orifice 136 and the stem 134 of the radial clearance, reducing the speed of the valve and introducing a delay in the valve closure. With reference to Figure 4, an alternative embodiment of the discharge valve 4-10 is shown. The discharge valve 4-10 includes a valve seat 4-12 including a portion 4-14 of cylindrical side wall received in the recess 4-16 extending upwardly of the fixed spiral member 4-18. A valve member 4-20 is provided adjacent the valve seat 4-12 and a discharge passage 4-22. The valve member 4-20 includes a disc-shaped body portion 4-20a with a cylindrical wall portion 4-20b extending posteriorly. A plurality of notches 4-20c are provided in the cylindrical wall portion 4-20b. A valve retainer 4-24 including a bell-shaped body portion 4-24a having a shoulder portion 4-24b against which valve member 4-20 tops off. A spring 4-26 is provided in the bell-shaped body portion 4 -24a and displaces the valve member 4-20 against the valve seat 4-12. A 4-28 passage generally located centrally at the base of the bell-shaped portion 4-24a is provided. The retainer 4-24 includes a radially extending flange portion 4-24c. The flange portion 4-24c includes passages 4-30 circumferentially spaced around the flange 4-24c to allow passage of the compressed gas discharge therethrough. The retainer 4-24 is held in place by a clip 4-32 which is received in a slot 4-34 in the side wall of the recess 4-16. During operation, when valve member 4-20 begins to open, gases in volume 4-36 flow through notches 4-20c and port 4-28 to provide a rapid opening of the valve. When the notches 4-20c are closed by the bell-shaped body portion 4-24a of the valve retainer 4-24, the flow only passes through the orifice 4-28 and the radial clearance between valve 4-20 and retainer 4-24. The reduced flow provides more damping which reduces the impact between the valve member 4-20 and the shoulder 4-28b of the valve retainer 4-28. When the valve member 4-20 begins to close, the valve member 4-20 begins to move rapidly under the pressure of volume 4-36 and the spring 4-26. When the notches 4-20c open to allow a flow passage, the pressure in the volume 4-36 drops rapidly and reduces the force that is compressing the valve member 4-20 so that the impact of the member 4-20 of valve and seat 4-12 valve is reduced. With reference to Figures 5A-5B, another embodiment of the discharge valve member 5-10 will now be described. The discharge valve 5-10 includes a valve seat surface 5-12 disposed adjacent to the discharge opening 5-14. A valve member 5-16 is provided in the aperture recess portion 5-18 upwardly of the fixed spiral member 5-20. A valve retainer 5-22 is supported by a dividing plate 5-24. The retainer includes a cylindrical wall portion 5-22a having radially extending openings 5-26 extending therefrom. A radial rim 5-22b extends radially outward from the cylindrical side wall 5-22a which is disposed against the dividing plate 5-24. A radially extending inwardly extending portion 5-22c extends from the upstream end of the cylindrical side wall portion 5-22a and defines an opening 5-30 to receive a central tab portion 5-32 of the member 5-22c. -16 valve. The valve member 5-16 includes a portion 5-34 of a cylindrical outer wall having an inner surface receiving the outer surface of the retainer member 5-22. The valve member 5-16 is exposed to a counter-pressure through the retainer 5-22 which causes the valve member 5-16 to close when the compressor is interrupted. The space 5-40 between the valve member 5-16 and the internally extending flange portion 5-2c cushions the movement of the valve member 5-16 during pressure fluctuations. With reference to Figure 6A, the valve assembly 6-10 is substantially the same as the valve assembly 5-10 with the exception that the valve member 6-10 includes a sliding fit with the hole 5-30 in the valve assembly. valve retainer 5-22, and valve member 6-16 does not include an outer cylindrical surface such as the cylindrical surface 5-34 of valve member 5-16. With this arrangement, the sliding engagement of the valve member 6-16 and the retainer 5-22 cushions the movement of the valve member 6-16. With reference to Figures 7A-7B, another embodiment of the discharge valve 7-10 will now be described. The discharge valve 7-10 includes a valve seat surface 7-12 disposed adjacent the discharge opening 7-14 provided in the fixed spiral 7-16. A valve member 7-18 is provided in the recess portion 7-20 open upwardly of the fixed spiral member 7-16. A valve retainer 7-22 is supported by the buffer plate 7-24. The retainer 7-22 includes a portion 7-26 of elongated base attached to one end of the damping plate 7-24 and having at a second end thereof a radially extending portion 7-28 of flange. The radially extending flange portion 7-28 includes openings 7-30 extending therethrough. Valve member 7-18 includes a portion 7-30 of generally planar base with a cylindrical side wall 7-34 extending therefrom. The cylindrical side wall 7-34 is provided with recessed indentations 7-36 spaced around the cylindrical side wall. The radially extending flange portion 7-28 is received within the cylindrical extension side wall 7-34. of the valve member so that the valve member is able to move axially relative to the retainer 7-22. The valve member 7-18 is optionally provided with radially and internally extending projections 7-38 which retain the valve member 7-18 in the retainer 7-22 during the installation of the valve assembly 7-10. The retainer 7-22 has an end portion 7-40 which is received in an opening 7-42 and radially and externally flanged to retain the retainer 7-22 in the cushion plate 7-24. The cushion plate also includes the openings 7-44, as best illustrated in Figure 7B, to allow the discharge of compressed gas through the buffer plate 7-24. A sealing ring 7-46 is arranged between the fixed spiral 7-16 and the buffer plate 7-24. During operation, the space 7-50 between the valve member 7-18 and the retainer 7-22 dampens the movement of the valve member 7-18. With reference to Figures 8A-8B, valve assembly 8-10, - as shown, is substantially the same as valve assembly 7-10 as discussed above, with the exception that member 8-18 of valve further includes an axially extending tab 8-20 which is received in a recess 8-22 provided at the end of the retainer 8-24. The tab 8-20 includes radially extending projections 8-26 which engage the support portion 8-28 in the opening 8-22 of the retainer 8-24. With reference to Figures 15A-15C, where common reference numbers are used to represent common elements as described in Figures 2 and 3, the valve member 15-10 includes a generally cylindrical section 15-12 at the bottom of the valve member 15-10 which engages the cylindrical surface 110 of the valve seat 15-14 with a controlled clearance therebetween when the valve member 15-10 is approaching the valve seat 15-14. The valve seat 15-14 includes a cylindrical surface 15-16 on the top of the valve seat surface 15-18 of conical shape, which is coupled with the outer cylindrical surface 15-20 of the valve member 15-10. valve when valve member 15-10 is approaching seat 15-14. As a result, when surfaces 15-12, 110; 15-16, 1520 cylindrical fit, a seat cushion cavity 15-22, as shown in Figure 15B, is formed. When the member 15-10 is approaching the valve seat 15-14 and the cavity 15-22 is formed. The gas pressure in the cavity 15-22 is increasing due to its reduction in volume and the flow restriction for the gas to escape through clearances between the surfaces 15-20, 110; 15-16, 15-20 cylindrical respective. The raising of the pressure gas in the damping cavity 15-22 of the member reduces the velocity of the valve member during closing of the valve, reducing the impact velocity of the valve 15-10 and the seat coupling 15-14, therefore it reduces the stress induced by the impact, improving the reliability of the sound characteristics of the valve and the compressor. The description of the invention is only exemplary in nature and, thus, variations that do not deviate from the essence of the invention are intended to be within the scope of the invention. Such variations will not be taken as a separation of the spirit and scope of the invention.

Claims (19)

1. CLAIMS 1. A discharge valve for a scroll compressor, characterized in that it comprises: a valve seat surface facing downstream of a discharge passage of the scroll compressor; a valve member having a body portion for engaging the seating surface for closing the discharge passage, the valve member includes a guide portion extending axially from the body portion; and a retainer slidably engaging the guide portion of the valve member, the retainer includes at least one passage in communication with a space between the valve member and the retainer.
2. 2. The discharge valve according to claim 1, characterized in that the guide portion of the valve member includes at least one ventilation formation in communication with the space between the valve member and the retainer.
3. 3. The discharge valve according to claim 1, characterized in that the retainer includes an axially extending passage extending through and in communication with a space between the valve member and the retainer.
4. 4. The discharge valve according to claim 1, characterized in that the valve member has a cylindrical side wall that includes at least one ventilation formation in communication with the space between the valve member and the retainer.
5. 5. The discharge valve according to claim 1, characterized in that it further comprises a spring between the valve member and the retainer.
6. The discharge valve according to claim 1, characterized in that the retainer includes a cylindrical side wall portion having a plurality of openings extending radially therethrough.
7. The discharge valve according to claim 6, characterized in that the valve member includes a central tab portion received in the cylindrical side wall portion of the retainer.
8. The discharge valve according to claim 7, characterized in that the valve member includes an outer cylindrical side wall portion which is received in the retainer.
9. The discharge valve according to claim 1, characterized in that the retainer includes an elongated base portion and a radially extending flange portion that is received in a cylindrical sidewall portion of the valve member, the flange portion. radially extending includes at least one passage therethrough in communication with the space between the valve member and the retainer.
10. The discharge valve according to claim 9, characterized in that the elongated base portion of the retainer is mounted on a partition plate, the partition plate includes at least one discharge passage extending therethrough.
11. The discharge valve according to claim 1, characterized in that the retainer has a bell-shaped body portion for receiving the valve member therein.
12. The discharge valve according to claim 2, characterized in that at least one ventilation formation includes a notch in the valve member.
13. The discharge valve according to claim 4, characterized in that at least one ventilation formation includes a groove inside the cylindrical side wall.
14. The discharge valve according to claim 2, characterized in that at least one ventilation formation includes a hole in the valve member.
15. 15. A discharge valve for a scroll compressor, characterized in that it comprises: a valve seat surface arranged in a discharge passage of the scroll compressor, the valve seat surface facing downstream of the discharge passage; a valve member having a generally bell-shaped body with a cylindrical side wall and a base portion enclosing a leading end of the cylindrical side wall, the cylindrical side wall includes at least one vent formed in the cylindrical side wall; and a retainer having an outer cylindrical side wall and a base portion of the retainer disposed at a rear end of the outer cylindrical side wall, a central rod extending axially from the base portion of the retainer, the cylindrical side wall of the member of valve is slidably received in the central rod, the central rod includes a through hole extending axially therethrough.
16. 16. The discharge valve according to claim 15, characterized in that at least one ventilation formation includes a notch in the cylindrical side wall.
17. The discharge valve according to claim 15, characterized in that at least one ventilation formation includes a groove in the cylindrical side wall.
18. The discharge valve according to claim 15, characterized in that at least one ventilation formation includes a hole in the cylindrical side wall.
19. 19. A discharge valve for a scroll compressor, characterized in that it comprises: a valve seat including a conical seating surface facing downstream of a discharge passage of the scroll compressor and a first generally cylindrical wall section upstream of the conical seat surface and a second generally cylindrical wall section running below the conical seat surface; a valve member having a body portion including a seat coupling portion for coupling the conical seat surface to close the discharge passage, the valve member includes a first generally cylindrical portion extending axially rearwardly of the seat engaging portion and a second generally cylindrical portion extending axially forward of the seat engaging portion, wherein the seat engaging portion, the first generally cylindrical portion and the second generally cylindrical portion of the valve member cooperate with the conical seat surface, the first generally cylindrical wall section and the second generally cylindrical wall section form a seat cushion cavity while the valve member moves towards the valve seat.