|Title of Invention||
A REFRIGERANT COMPRESSOR
|Abstract||In a refrigerant compressor (20), a discharge valve assembly (43) which reduces reexpansion volume. The present invention provides a discharge valve assembly (43) for reciprocating, rotary, and scroll types of compressors, and includes a spherical valve member (44) that engages and penetrates a discharge port (40) provided on a compressor cylinder head (38), valve plate or scroll plate. The discharge port is formed in the cylinder head or scroll plate and is dimensioned such that the spherical member penetrates and substantially fills the discharge port. The reexpansion volume within the discharge port is thereby reduced. To maintain engagement of the spherical member with the discharge port, an elastically deformable arm (46) having an aperture (48) is positioned to hold the spherical member in the discharge port. The arm is elastically deformable to allow the spherical valve member to move out of engagement with the discharge port during the compression phase of the compressor. To prevent the spherical member from being discharged along with the compressed refrigerant, a rigid stop plate (50) is disposed adjacent the deformable arm to engage the spherical member during the compression phase and thereby limit the movement of the spherical valve member.|
COMPRESSOR BALL VALVE
The present invention relates to refrigerant compressors, and, more particularly, to discharge valve assemblies for refrigerant compressors.
Refrigerant compressors are known of various types, such as reciprocating, rotary, and scroll. All such compressors have as a fundamental function the compressing of refrigerant fluids. Refrigerant compressors of the reciprocating piston type include at least one cylinder in which a piston reciprocatingly moves to both draw fluid into the cylinder, and compress the fluid before discharge. It is therefore necessary to provide a means for regulating the inflow and outflow of the fluid to and from the cylinder.
Rotary type refrigerant compressors include a roller or piston which rotates or orbits within a cylinder, a sliding vane divides the area defined by the rotary piston and the cylinder wall into a compression chamber and a suction chamber. The rotary piston is rotated beyond a top dead center position to a point where the compression chamber is at a maximum, and to a point just prior to the top dead center position, where the compression chamber is at a minimum. As the rotary piston is rotated beyond the top dead center position it begins to compress refrigerant fluid contained in the compression chamber. One rotary compressor is disclosed in U.S. Letters Patent No. 5,339,652 (Dreaming) and is incorporated herein by reference. As with the reciprocating typ6 compressor, it is necessary to provide a means for regulating the inflow and outflow of the and from the cylinder.
To regulate the inflow and outflow of a compressed fluid in reciprocating and rotary compressor applications, a discharge valve in communication with the compression chamber is provided in a cylinder head, or in a valve plate for reciprocating type compressors, adjacent the cylinder. In reciprocating type compressors a wide
variety of discharge valve types are used, including flat leaf spring type valves. Typically in a rotary compressor application a flat leaf spring type valve member is biased toward a valve seat, as the volume of fluid is compressed an increasing force is created within the compression chamber. At a certain point, the force becomes sufficient to overcome the biasing force of the leaf spring, thereby cause the valve member to become unseated and permitting compressed refrigerant fluid to enter a discharge chamber.
A problem with such valve arrangements is that they are traditionally disposed wholly external the discharge port. This results in a volume of fluid within the discharge port which is never compressed by the piston. This volume of fluid is defined by the thickness of the cylinder head or valve plate. This results in the occurrence of an undesirable re-expansion volume of fluid during each compression cycle. A valve member is needed that extends at least partially into the discharge valve port to reduce the reexpansion volume.
Valve arrangements have been devised to provide a means of regulating the outflow of the fluid from the compressor cylinder while reducing the reexpansion volume. U.S. Patent No. 5,346,373, discloses a reciprocating type refrigeration compressor having a discharge valve poppet characterized by a spherical head which is spring biased so as to seal ably seat against a valve seat which is ftprmed in a discharge port of the compressor valve plate. A flat leaf spring and a rigid stop member bias the valve poppet toward the v live seat and limit the displacement of the valve poppet during the compression stroke, respectively. The discharge port is formed in a separate valve plate, not the cylinder head, adding expense and assembly time to the resulting compressor. Moreover, the piston includes a concaved recess to receive the spherical head, which also adds to manufacturing expense while decreasing the cylinder volume.
In rotary applications a flat leaf spring is biased toward a discharge port/valve seat provided in the cylinder' head. The leaf spring is disposed over and outside of the discharge port. Although this is a simple arrangement keeping the cost of manufacturing low, it does not address the undesired effect of inefficient re-expansion volume. Again, a valve member is needed that extends at least artfully into the discharge valve port to reduce the reexpansion volume.
v^ Although the nature of a scroll type compressor does not necessitate a valve at the discharge of the compressor mechanism, enhanced noise qualities have been achieved with the use of discharge valves. One beneficial effect of utilizing discharge valves in scroll compressors is the substantial elimination of reverse orbiting which occurs upon the termination of compressor operation. Without a discharge valve, compressed fluid, at a higher pressure than the suction pressure refrigerant or partially compressed refrigerant, rushes into the orbiting scroll mechanism causing a reverse orbiting of the scroll mechanism. This creates an undesired "whizzing" noise which is preferably ruminated. Accordingly, discharge valves are also applicable in scroll applications, although for a different function than that required in reciprocating or rotary compressors.
The present invention utilizes a discharge ball valve for use in refrigerant compressors of the reciprocating, rotary and scroll types. The present ball valve addresses the above-identified needs by providing a ball valve assembly having a ball valve member which is positioned at least partially within a discharge port formed directly in a cylinder head. A separate valve plate is therefore not necessary, thus resulting in a less expensive compressor. In addition, by positioning the ball valve member within the discharge port, which is .configured to most effectively receive the ball valve member, re-
expansion volume is reduced, thereby enhancing compressor efficiency.
The present invention as illustrated in the drawings provides a discharge ball valve assembly for use in a rotary compressor wherein the compressor includes at least one cylinder having a rotary piston or roller rotatingly disposed therein. A discharge port, preferably have a partially chamfered or spherical shape, is formed directly in the cylinder head of the compressor so as to provide a valve seat. The discharge port/valve seat receives a spherical valve member which engages the discharge port/valve seat.
An plastically deformable arm with a cut-out, preferably circular, engages and captures the spherical valve member such that the spherical valve member in part protrudes through the cut-dot. The elastically deformable arm biases the spherical valve renumber into penetrating and sealing contact with the discharge port to reduce re-expansion volume. The ball valve assembly is configured such that the spherical ball member is retained in engagement with the cut-out and is prevented from becoming dislodged and discharged into the discharge chamber.
During the suction phase of the rotary piston within the cylinder, or the suction stroke in the case of a reciprocating piston, the elastic arm biases the spherical valve member into engagement with the discharge port During the compression phase of the rotary piston, the force of the compressed refrigerant within the cylinder will at some point overcome the biasing force of the elastically deformable arm to unseat the spherical valve member from engagement with the discharge port, thereby allowing the compressed refrigerant to be discharged.
To maintain alignment of the spherical valve member with the discharge port and to prevent the spherical valve member from being displaced from its engagement with the elastic arm, a rigid stop plate
is positioned adjacent the elastically deformable arm such that the spherical valve member protrudes through the elastically deformable arm at the cut-out and contacts the rigid stop plate during the compression phase. The movement of the spherical valve member is therefore limited by the rigid stop plate and the valve member is thereby retained in engagement with the cut-out.
floe advantage of the present invention is that re-expansion volume within the discharge port is reduced.
Another advantage of the present invention is that the ball valve member is maintained in proper position due to the cut-out within the elastically deformable arm.
Another advantage of the present invention is that the movement of the ball valve member is limited by the rigid stop plate.
Yet another advantage of the present invention is that the discharge port/valve seat is formed directly in the cinder head and d6es not necessitate the use of a separate valve plate. The present invention is therefore less expensive and easier to manufacture than prior art compressors.
The present invention, in one form thereof, provides a refrigerant compressor comprising a compressor mechanism, a discharge chamber, and a discharge valve assembly. The compressor mechanism defines a compression chamber for compressing refrigerant fluid. The discharge chamber receives compressed fluid from the compression chamber. The discharge valve assembly is disposed intermediate the compression chamber and the discharge chamber and comprises a spherical valve member, a discharge port providing a seat for the valve member, an elastically deformable arm, and a rigid stop. The spherical valve member is seated against the discharge port adjacent the discharge chamber and is dimensioned to
partially penetrate and seal the discharge port, thereby reducing re-expansion volume.
The elastically deformable arm includes an aperture for partially receiving the valve member, and engages and bias the spherical valve member into engagement with the discharge port. The arm is adapted to elastically deform and thereby allow the valve member to move out of engagement with the discharge port during discharge of fluid from the compression chamber to the discharge chamber. The rigid stop is positioned over the spherical valve member and the deformable arm such that movement of the spherical valve member is limited by the rigid stop during discharge to thereby maintain alignment of the spherical valve member with the discharge port.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
Fig. 1 is a partial sectional view of a rotary compressor incorporating the discharge ball valve assembly of the present invention;
Fig. 2A is an alleged partial sectional view of the ball valve assembly of Fig. 1 in the closed position;
Fig. 2B is an enlarged partial sectional view of the ball valve assembly of Fig. 1 in |he open position; and
Fig. 3 is a plan view of the deformable arm of the ball valve
assembly of Fig. 1.
Corresponding reference characters medicate corresponding
parts throughout the several views. The exemplification set out therein illustrates one embodiment of the invention and such
1. A refrigerant compressor (20), comprising: a compressor mechanism (26) defining a compression chamber for compressing refrigerant fluid; a discharge chamber (57) receiving compressed refrigerant fluid from said compression chamber; and a discharge valve assembly (43) disposed intermediate said compression chaffier and said discharge chamber, said discharge valve assembly characterized by: a discharge port (40); a spherical valve member (44) seated against said discharge port, said spherical valve member dimensioned to partially penetrate and seal said discharge port; an elastically deformable arm (46) having an aperture (48) partially receiving said spherical valve member therein, said arm engaging said spherical valve member and biasing said spherical valve member into engagement with said discharge port, said arm adapted to deform and thereby allow said spherical valve member to move out of engagement with said discharge port during a compression phase; kind a rigid stop (50) disposed adjacent said spherical valve member said arm, and limiting the movement of said spherical valve member during the compression phase, thereby maintaining alignment of said spherical valve member with said discharge port.
2. The compressor of Claim 1 characterized in that said arm aperture is a circular cut-out.
3. The compressor of Claim 1 characterized in that said deformable arm is manufactured from spring steel.
4. The compressor of Claim 1 characterized in that said deformable arm is manufactured from heat resistant plastic.
5. The compressor of Claim 1 characterized in that said deformable arm has a substantially planar surface, and said rigid stop is a rigid plate having an actuate surface (54).
6. The compressor of Claim 5 characterized in that said compressor mechanism comprises a cylinder head (38), and wherein
said deformable arm and said rigid plate are fastened to said cylinder
head, said arm and said plate being in contact where said arm and
said plate are fastened to said cylinder head, said arcuate rigid plate
curving away from said deformable arm proximate said spherical
valve member. i
7. The compressor of Claim 1 characterized in that said
disclose port is chamfered at a surface adjacent said discharge
chamber to provide a seat (56) for said spherical valve member.
8. The compressor of Claim 1 characterized in that said
compressor mechanism (26) includes a cylinder (34) receiving a
piston (36) and a cylinder head (38) in which said discharge port (40)
is formed therethrough, and said cylinder and said cylinder head
define said compression chamber,
9. The compressor of Claim 1 characterized in that said
compressor is a rotary refrigerant compressor which comprises a
cylinder block (33) having a bore (39) defining a cinder (34), a
rotary piston (36) received in said cylinder, a vane glidingly received
in! said cylinder block and engaging said piston, and a cylinder head
(3^) having said discharge port formed therethrough and defining
said discharge chamber, and wherein said cylinder, said vane, said
piston, and said cinder head define said compression chamber.
|Indian Patent Application Number||2515/MAS/1997|
|PG Journal Number||20/2006|
|Date of Filing||04-Nov-1997|
|Name of Patentee||TECUMSEH PRODUCTS COMPANY|
|Applicant Address||100 EAST PATTERSON STREET , TECUMSEH , MICHIGAN 49286 ,USA|
|PCT International Classification Number||F04C18/356|
|PCT International Application Number||N/A|
|PCT International Filing date|