Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
  • F04C18/30—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
  • F04C18/34—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members
  • F04C18/356—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the outer member
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
  • F04C29/0042—Driving elements, brakes, couplings, transmissions specially adapted for pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
  • F04C23/008—Hermetic pumps

Definitions

• the present invention relates to compressors and, particularly, to rotary compressors.
• the compression mechanism includes an eccentric positioned within a cylindrical compression chamber.
• a vane extending from the cylindrical wall of the compression chamber contacts a roller positioned around the eccentric and divides the compression chamber into compression and suction pockets.
• the roller move through the compression chamber, the compression pocket decreases in volume to compress a working fluid contained therein.
• the suction pocket is increasing in volume and drawing working fluid into the suction pocket.
• counterweight must be used to keep the crankshaft and other components of the compressor in balance.
• the size of the eccentric and its corresponding counterweight also increase.
• two counterweights may be used.
• a first counterweight is positioned at the end of the crankshaft opposite the eccentric and on the same side as the eccentric, while a second counterweight is position between the eccentric and the first counterweight on the opposite side of the crankshaft as the eccentric and the first counterweight.
• the mass-eccentricity of the second counterweight must be equal to the sum of the mass-eccentricities of the first counterweight and the eccentric and the roller.
• the present invention relates to compressors and, particularly, to rotary compressors.
• the eccentric on the crankshaft of a rotary compressor, as well as the roller that surrounds the eccentric is replaced by an elongated, preferably elliptical, cam that acts as a double eccentric.
• the elliptical cam provides for inherent balancing of the crankshaft and other components of the compressor, eliminating the need to use
• the elliptical cam is symmetrical, resulting in equal inertial forces acting on opposing sides of the elliptical cam. This allows the elliptical cam to maintain its balance throughout its rotation, even when operating at a high rate of revolution. Additionally, because pressure forces from the compression pockets are equal and opposite in direction, bearing loads are reduced which allows for the use of a smaller bearing. This, in turn, reduces the viscous frictional losses associated with shearing of oil in the bearings, which increases mechanical efficiency.
• eliminating the use of counterweights in the rotary compressor of the present invention decreases the overall height and size of the compressor. Additionally, it allows for the rotary compressor to be utilized to compress larger volumes of working fluid and also eliminates the need to provide a roller surrounding an eccentric on the crankshaft.
• the present invention includes an open suction pressure channel that extends along an inner surface of the compression mechanism of the compressor to draw suction pressure working fluid into the opposing working pockets defined by the elliptical cam.
• a cross passage is formed through the elliptical cam to draw suction pressure working fluid into the opposing working pockets defined by the elliptical cam.
• the outboard journal bearing is eliminated and the crankshaft of the compressor includes only a single journal bearing, i.e., the main bearing, which is positioned between the cylinder and the motor. Elimination of the outboard journal reduces the viscous friction losses of the compressor and increases mechanical efficiency. Also, because the outboard journal consists of precisely machined surfaces, its elimination reduces the cost of manufacturing the compressor.
• the present invention provides a rotary compressor having an outer hermetic housing, a motor and a cylinder having an inner cylindrical surface including a plurality of slots formed therein, the inner cylindrical surface defining a substantially cylindrical bore.
• a crankshaft includes an elongate cam, either integral therewith or attached thereto, which is rotatably disposed within the cylinder block such that the outer surface of the elongate cam contacts the inner cylindrical surface of the cylinder block at two circumferentially spaced positions to form a pair of working pockets.
• First and second vanes are positioned at least partially within the slots in the cylinder block and biased inwardly to contact the outer surface of the elongate cam.
• An outboard thrust bearing is positioned adjacent the cylinder block and a main bearing positioned adjacent the cylinder block at an axial end thereof and at least partially defining a discharge port in fluid communication with the working pockets at certain rotation angles of the elongate cam.
• a suction pressure inlet is in communication with the working pockets at certain angles of rotation of the cam to supply suction pressure working fluid into the working pockets.
• the present invention provides a rotary compressor having an outer hermetic housing, a motor and a cylinder having an inner cylindrical surface including a plurality of slots, the inner cylindrical surface defining a substantially cylindrical bore.
• a crankshaft having an elongate cam thereon is rotatably disposed within the cylinder block such that the outer surface of the cam contacts the inner surface of the cylinder block at two circumferentially spaced positions to form a pair of working pockets.
• First and second vanes at least partially positioned within the slots are biased inwardly to contact the outer surface of the elongate cam.
• An outboard thrust bearing is positioned adjacent the cylinder block and defines a suction pressure passage therein, the suction pressure passage in simultaneous fluid
• a main bearing is provided adjacent the cylinder and at least partially defines a discharge port in fluid communication with the working pockets at certain rotation angles of the elongate cam.
• FIG 1 is a perspective view of a rotary compressor in accordance with an embodiment of the present invention.
• Fig. 2 is a plan view thereof
• Fig. 3 is a sectional view thereof taken along one A-A of Fig. 2 and viewed in the direction of the arrows, wherein the section is taken through the suction port;
• Fig. 4 is a sectional view thereof taken through the vanes
• Fig. 5 is a sectional view thereof taken through the discharge ports
• FIG. 6 is a transverse sectional view of the compressor taken through the cylinder
• Fig. 7 is a perspective view of the outboard thrust bearing showing the suction panel
• Fig. 8 is a perspective view of the main bearing
• FIG. 9 is a perspective view of an alternative crankshaft and cam design.
• Fig. 10 is a sectional view of the alternate embodiment.
• Fig. 1 illustrates the rotary compressor 10 forming one embodiment of the present invention.
• Compressor 10 includes an outer hermetic housing 12 including center portion 14 to which upper and lower caps 16 and 18 are connected, such as by welding.
• a conventional suction accumulator 20 having inlet 22 and outlet suction line 24 is connected to the center portion 14 of compressor 10 by means of mounting strap 26.
• Compressed refrigerant is discharged from high pressure housing 12 through discharge line 28.
• Compressor 10 may be a component of a heating and/or cooling circuit and functions to compress the working fluid, such as a refrigerant, which may be a hydrofluorocarbon, chlorofluorocarbon,
• hydrochlorofluorocarbon or carbon dioxide refrigerant, for example.
• motor 30 and compression mechanism 32 are mounted within hermetic housing 12.
• Oil sump 41 (Fig. 3) is formed in the lower portion of hermetic housing 12.
• the motor includes stator 34 and rotor 36.
• Compression mechanism 32 comprises a cylinder 34 that is rigidly connected to the inner surface 35 of housing center section 14, a main bearing 36 fastened to cylinder 34 by means of a plurality of screws 38 and an outboard thrust bearing 40 connected to cylinder 34 by means of a plurality of screws 42.
• Suction line 24 extends through the center section 14 of housing 12 and is sealably joined to cylinder block 34 in communication with suction port 44 which opens into the wall of cylinder bore 50.
• An elongate cam 46 which is preferably elliptical, is preferably integrally connected with crankshaft 14, although alternatively it may be a separate element connected by any suitable means.
• Shaft 64 is rotationally secured to rotor 28 and, as shown in Fig. 6, cam 46 is in sealing engagement with the bore 50 of cylinder 34.
• Oil passage 52 Extending through elliptical cam 46 and up through shaft 48 is oil passage 52.
• Oil paddle 54 extends from oil passage 52 of elliptical cam 46 and is configured to draw oil upward and into passageway 52 that is in combination with passages 56 in elliptical cam 46.
• Passages 56 extend through elliptical cam 46 and direct oil into main bearing 36 between elliptical cam 46 and rotor 28 of motor 30.
• the journal surface of crankshaft 48 may include a spiral groove (not shown).
• passages 56 may extend into crankshaft 48 and exit crankshaft 48 at a point above main bearing 36 allowing oil exiting passages 56 to pass along the journal surface and through main bearing 36.
• passages 56 may be in fluid communication with radial discharge passages (not shown) that are positioned above or within main bearing 36.
• oil passage 52 may extend through the entire length of crankshaft 48 as shown.
• Oil passage 92 extends from the oil passage 52 of crankshaft 48 to the outboard thrust bearing surface of thrust bearing 40.
• slots 58 are formed in cylinder block 34 and have vanes 60 positioned therein.
• Springs 62 bias vanes 60 radially inwardly toward the center of cylinder 34 during start-up of the compressor. After start-up, discharge pressure working fluid is used to bias vanes 60 radially inwardly.
• Cylinder 34 includes an inner cylindrical surface defining cylinder bore 50 for rotation of elliptical cam 46 therein.
• elliptical cam 46 By utilizing elliptical cam 46, the need for a roller is eliminated. As a result, any potential wear that may occur between the contact surfaces of the roller and an eccentric is also eliminated. Additionally, elliptical cam 46 is symmetrical and provides for proper balancing of crankshaft 48 and the other rotating components of the compressor while eliminating the need to use counterweights. As a result, the overall height of the compressor utilizing elliptical cam 46 may be reduced.
• vanes 60 are biased toward the center of cylinder bore 50 where they contact exterior surface 66 of elliptical cam 46. Vanes 60 may be coated with a ceramic or other material to lessen the friction generated between vanes 60 and the exterior surface 66 of cam 46.
• the contact of the outer surface 66 of elliptical cam 46 with the inner cylindrical surface of bore 50 at two circumferentially spaced positions and the biasing of vanes 60 against surface 66 forms two working pockets 68 that are defined by vanes 60, elliptical cam 46 and cylinder 34.
• working pockets 68 are sealed on opposite axial sides thereof by outboard bearing 40 and main bearing 36.
• Outboard bearing 40 includes thrust surfaces 70, 71 upon which elliptical cam 46 is supported. During rotation of crankshaft 48, elliptical cam 46 bears against and rotates on thrust surfaces 70, 71.
• the surface of elliptical cam 46 that contacts surfaces 70, 71 as well as surfaces 70, 71 and thrust surface 72 (Fig. 8) of main bearing 36 are finely machined surfaces that cooperate to seal working pockets 68.
• outboard bearing 40 includes suction pressure channel 74 formed therein.
• Channel 74 extends around oil passage 76 formed by boss 73 in outboard bearing 40 and is formed as an open channel that is in fluid communication with bore 50 in cylinder 34.
• suction pressure working fluid passes through suction port 44 in block 34 to enter the proximal working pocket 68 and suction pressure channel 74.
• suction pressure working fluid is drawn through suction pressure channel 74, passing under elliptical cam 46, around aerodynamically shaped diverters 78, to enter distal working pocket 68.
• Discharge pressure working fluid flows past motor 30 and out discharge line 28.
• main bearing 36 may be provided with a suction pressure channel 88 that extends between working pockets 68 and around boss 90 (Fig. 8).
• cross passages 94 extending through elliptical cam 96 of crankshaft 98 allow for suction pressure working fluid received through suction port 44 to pass between working pockets 68. Specifically, such pressure working fluid as received through suction port 44 enters the proximal working pocket 68 and then passes through cross passages 94 into the distal working pocket 68.
• cross passages 94 are oriented at a slight angle relative to the major chord of the ellipse defined by elliptical cam 96 so that cross passages 94 are never in fluid communication with the discharge side of the contact points between cam 96 and bore 50.
• Passages 94 and suction pressure channel 70 may possibly be used in conjunction with one another or, alternatively, employed separately.
• suction pressure channel 74 is present and passages 94 are absent.
• passages 94 are present and suction pressure channel 74 is absent.
• elongate cam 46 also eliminates the need for an outboard journal bearing.
• the outboard journal extends around the oil paddle and through an opening in the outboard bearing.
• the interaction of the journal with the portion of the outboard bearing that defines the opening prevents off- centered movement of the crankshaft and eccentric during rotation of the crankshaft.
• the interaction of opposing pressure forces on exterior surface 66 of cam 46 substantially eliminates the need for an outboard journal on crankshaft 48.
• the need to create a correspondingly highly machined journal and outboard bearing 40 is also eliminated.
• the cost of manufacturing a rotary compressor in accordance with this embodiment of the invention is substantially reduced.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
• Gears, Cams (AREA)
• Rotary Pumps (AREA)
• Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=43780601

Family Applications (1)

Country Status (7)

Families Citing this family (5)

Family Cites Families (16)

• 2010
  • 2010-09-24 BR BR112012006836A patent/BR112012006836A2/pt not_active IP Right Cessation
  • 2010-09-24 CA CA2774105A patent/CA2774105A1/en not_active Abandoned
  • 2010-09-24 WO PCT/US2010/050102 patent/WO2011038174A2/en active Application Filing
  • 2010-09-24 US US12/889,508 patent/US20110076169A1/en not_active Abandoned
  • 2010-09-24 EP EP10819498A patent/EP2483563A2/en not_active Withdrawn
  • 2010-09-24 CN CN2010800428315A patent/CN102597525A/zh active Pending
  • 2010-09-24 IN IN2106DEN2012 patent/IN2012DN02106A/en unknown

Non-Patent Citations (1)

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