CA2040721A1 - Hermetically sealed scroll type refrigerant compressor with an improved lubricating mechanism - Google Patents
Hermetically sealed scroll type refrigerant compressor with an improved lubricating mechanismInfo
- Publication number
- CA2040721A1 CA2040721A1 CA002040721A CA2040721A CA2040721A1 CA 2040721 A1 CA2040721 A1 CA 2040721A1 CA 002040721 A CA002040721 A CA 002040721A CA 2040721 A CA2040721 A CA 2040721A CA 2040721 A1 CA2040721 A1 CA 2040721A1
- Authority
- CA
- Canada
- Prior art keywords
- drive shaft
- scroll
- pin member
- compressor
- housing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
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
- F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
- F04C29/02—Lubrication; Lubricant separation
- F04C29/028—Means for improving or restricting lubricant flow
-
- 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
- F04C18/02—Rotary-piston pumps specially adapted for elastic fluids of arcuate-engagement type, i.e. with circular translatory movement of co-operating members, each member having the same number of teeth or tooth-equivalents
- F04C18/063—Rotary-piston pumps specially adapted for elastic fluids of arcuate-engagement type, i.e. with circular translatory movement of co-operating members, each member having the same number of teeth or tooth-equivalents with coaxially-mounted members having continuously-changing circumferential spacing between them
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Rotary Pumps (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
Abstract
HERMETICALLY SEALED SCROLL TYPE REFRIGERANT
COMPRESSOR WITH AN IMPROVED LUBRICATING MECHANISM
ABSTRACT OF THE DISCLOSURE
A hermetically sealed scroll type compressor includes a lubri-cating mechanism. The compressor includes a hermetically sealed housing and a motor driven drive shaft supported by a plurality of plain bearings in an inner block member. The drive shaft is provided with pin member at its upper end. The axis of pin member is radially offset from the axis of the drive shaft. The pin member is opera-tively connected to an orbiting scroll which orbits within a fixed scroll. A rotation preventing device prevents rotation of the orbiting scroll. The drive shaft includes an axial bore extending from a lower end thereof to a lower end of the pin member. A centrifugal pump is provided at a lower end of the axial bore, and immersed in the lubri-cating oil pump at an inner bottom of the housing. A throttling device, such as an orifice tube, penetrates through the pin member.
The lubricating oil at the inner bottom of the housing is supplied to the frictional surfaces of the slidable members of the compressor by operation of the centrifugal pump supplying lubricating oil through the axial bore and the orifice tube. The frictional surfaces can thereby receive a sufficient, but not excessive, amount of the lubri-cating oil at any rotational speed of the drive shaft so that the fric-tional surfaces are effectively lubricated.
COMPRESSOR WITH AN IMPROVED LUBRICATING MECHANISM
ABSTRACT OF THE DISCLOSURE
A hermetically sealed scroll type compressor includes a lubri-cating mechanism. The compressor includes a hermetically sealed housing and a motor driven drive shaft supported by a plurality of plain bearings in an inner block member. The drive shaft is provided with pin member at its upper end. The axis of pin member is radially offset from the axis of the drive shaft. The pin member is opera-tively connected to an orbiting scroll which orbits within a fixed scroll. A rotation preventing device prevents rotation of the orbiting scroll. The drive shaft includes an axial bore extending from a lower end thereof to a lower end of the pin member. A centrifugal pump is provided at a lower end of the axial bore, and immersed in the lubri-cating oil pump at an inner bottom of the housing. A throttling device, such as an orifice tube, penetrates through the pin member.
The lubricating oil at the inner bottom of the housing is supplied to the frictional surfaces of the slidable members of the compressor by operation of the centrifugal pump supplying lubricating oil through the axial bore and the orifice tube. The frictional surfaces can thereby receive a sufficient, but not excessive, amount of the lubri-cating oil at any rotational speed of the drive shaft so that the fric-tional surfaces are effectively lubricated.
Description
2 ~
HERMETICALLY SEALED SCROLL TYPE REFRIGERANT
COMPRESSOR WITH AN IMPROVED LUBRICATING MECHANISM
B~C:KGROUND OF THE INVENTION
Field of the Invention This inventioD relates to a hermetically sealed scroll type refrigerant compressor, and more particularly to a lubricating mecha-nism thereof.
Descri~ion of the Prior Art Japanese Patent Application Publication No. 60-73~0~3 dis-closes a hermetically sealed scroll type refrigerant compressor which is designe~ such that the longitudinal axis of ~he drive shaft is gener-ally perpendicular to a horizontal plane when the compressor is installed. Therefore, in general, the compressor can b~e called a verti-cally installed type scroll refrigerant compressor. The compressor includes a hermetically sealed housing in which a compression mecha-nism having fixedi and orbiting scrolls, a driving mechanism having a motor and a motor driven drive shaft, and a rutation preventing device for preventing rotatioD of the orbiting scroll during orbital motion are contained. The fixe~ scroll includes a circular end plate which divides the cavity defined by the housing into suction and dis-charge chamber sections. The suction chamber section contains the driving mechanism, the ro~ation preventing mechanism and the spiral elements of the fixed and orbiting scrolls.
The drive shaft includes an axial condui~. The axis of the con-duit is radially offset from the axis of ~he drive shaft. The drive shaft is provided with a centrifugal pump at its lower end. The centrifugal pump is immersed in a reservoir of lubricating oil which accumulates at the inner bottom portion of the housing.
2.~
In operation, refrigerant gas flowing from an external îluid circuit flows into the suction chamber section through an inlet port disposed through a side wall of the housing. The refrigerant gas is taken into a pair of outer fluid pockets which are defined by the spiral elements. The refrigerant gas is compressed inwardly toward a cen-tral fluid pocket due to orbital motion of the orbiting scroll. As the refrigerant gas moves towards the central fluid pocket, it undergoes a volume reduction and compression and is discharged into the dis-charge chamber section through a hole extending through the circular end plate of the fixed scroll. The compressed refrigerant gas in the discharge chamber section flows out of the compressor and to the external fluid circuit through an outlet port which is disposed through an upper end of the housing. After circulating through the external fluid circuit, the refrigerant gas which exits through the outlet port returns ~o the compressor through the inlet porl.
Furthermore, lubrica~ing oil which accumulates at the inner bottom end portion of the housing flows upwardly through the axial conduit by operation of the centrifugal pump. The pump operates during rotation of the drive shaft. The lubricating oil which has upwardly passed over the axial conduit flows through other conduits and into frictional surfaces of the slidable members of the compres-sor, such as the rotation preventing mechanism and the bearings rotatably supporting the drive shaft, in order to lubricate them.
As mentioned above, in this prior art, the lubricating oil at the inner bottom portion of the housing is supplied to the frictional sur-faces of the slidable members of the compressor through the axial conduit and the other conduits by use o~ the centrifugal pump. How-ever, the flow rate of the lubricating oil which has passed through the axial conduit and the other conduits quadratically increases in accor-dance with the increase in rotational speed of the drive shaft. This increase in flow rate occurs because the hydraulic resistance which is generated at the axial conduit and the other conduits when the lubri-cating oil passes therethrough is negligible.
Accordingly, when the capability of the centrifugal pump is designed so as to be able to supply a sufficient amolmt of the 3 2 ~
lubricating oil to the frictional surfaces of the slidable members of the compressor during low rotational speeds of the drive shaft, an excessive amount of the lubricating oil is supplied to the fri~tional surfaces during high rotational speeds of the drive shaft. Therefore, during high rotational speeds OI the drive shaft, viscous drag of the lubricating oil generated between the frictional surfaces increases greatly so that the frictional surfaces do not smoothly slide relative to each other. In addition, when an excessive amount of the lubricating oil is supplie~ to the frictional surfaces between the fixed and orbiting scrolls, an excessive amount of the lubricating oil is taken into the fluid pockets of the scrolls together with the refrigerant, and exits to the fluid circuit via a compression and discharge process of the refrigerant. Therefore, the ratio of the amount of the lubricating oil to the amount of the refrigerant in the circulation of the fluid circuit increases. As a result, the heat exchangeability of the evaporator forming a part of the fluid circuit decreases. On the other hand, when the capability of the centrifugal pump is designed so as to be able to supply a sufficient, but not an excessive, amount of lubricating oil to the frictional surfaces during high rotational speeds of the drive shaft, an insufficient amount of the lubricating oil is supplied to the frictional surfaces during low ro~ational speeds of the c!rive shaft.
Therefore, the frictional surfaces may seize in the low rotational speeds of the drive shaft due to the lack of lubricating oil.
- In order to resolve these defects, Japanese Patent Application Publication No. 63-90,684 discloses a vertically installed type scroll refrigerant compressor. A construction of this compressor is substan-tially similar to the construction of the compressor disclosed in the Japanese '083 publieation, except for the lubricating oil pumping device which is disposed at the lower end of the drive shaft. The pumping device therein includes a centri~ugal pump and a positive-displacement pump, wherein the displacement linearly increases in accordance with the increase in rotational speed of the drive shaft.
By a combination of the centrifugal pump and the positive-displace-ment pump, a sufficient, but not excessive, amount of the lubricating oil is supplied to the frictional surfaces even though the drive shaft 2 ~
- ~ -rotates at any rotational speed. Accordingly, the above-mentioned defects can be resolved.
However, in this prior art, the pumping device is comprised of a large number of component parts. This construction requires a complicated assembling process and a resultant increased manufac-turing cost.
SUM~IARY OF THE~ INVENTION
Accordingly, it is an object of the present invention to provide a hermetically sealed scroll type refrigerant compressor which includes a simply structured lubricating mechanism for effectively lubricating the frictional surfaces of the slidable members thereof at any rotational speed of the drive shaf t.
A scroll type compressor with a hermetically sealed housing includes fixed and orbiting scrolls disposed within ~he housing. The fixed scroll comprises a first end plate from which a first spiral ele-ment extends. The orbiting scroll cornprises a second end plate from which a second spiral element extends. The first and second spiral elements interfit at an angular and radial of gset to form a plurality of line contacts which define at least one pair of sealed off fluid pockets.
A drive mechanism includes a drive shaft which is rotatably supported in the housing, and a pin member which is integrated with one end of the drive shaft. The axis of the pin member is radially offset from the axis of the drive shaft. The pin member is rotatably connected to the orbiting scroll to effect orbital motion of the orbit-ing scroll. A rotation preventing device, such as an Oldham coupling mechanism, prevents rotation of the orbiting scroll during its orbital motion. With this con~truction, the volume of the fluid pockets changes to compress refrigerant fluid within the pockets. The longi-tudinal axis of the drive shaft is generally perpendicular to a horizon-tal plane, when the compressor is installed. A motor is associated with the drive shaft so as to rotate the drive shaft.
An axial bore is formed through the drive shaft. One end of the axial bore, opposite to the orbiting scroll, is immersed in lubricat-ing oil which accumulates at an inner bottom portion of the housing.
2 ~
A throttling device, such as an orifice tube, penetrates through the pin member and is fluidly coupled with the a~nal ~ore. A centrifugal pump which operates during rotation of the drlve shaf t is provided at the one end of the ax~al bore. The pump operates to conduct the lubricating oil at the inner bottom portion of the housing to the fric-tional surfaces of the slidable members of the compressor via an or~-~ice tube.
BR~ElF DESCRIPTIONQF THE DRAWING
The drawing is a vertical section view of a vertically installed type scroll refrigerant compressor in accordance with one embodi-ment of the present invention.
DETAILl~D DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the drawing, a vertically installed type scroll refrigerant compressor in accordance with one embodiment of the present invention is shown. Compressor 1n includes casing 11 com-prising cylindrical portion 12 and a pair of shallow cup-shaped por-tions 13 and 14 hermetically fixecl to both ends of cylindrical portion 12, fixed and orbiting scrolls 20 and 30, inner block member 40 and motor 50.
Cylindrical portion 12 includes annular flanges 121 and 122 projecting radially outward f rom upper and lower ends thereof, respectively. Shallow cup~haped portion 13 includes annular ~lange 131 projecting radially outward from an opening end thereof, and shallow cup~haped portion 14 includes annular flange 141 projecting radially outward from an opening end thereof. Flange 131 is hermeti-cally and releasably secured to flange 121 by a plurality of screws 200 and O-ring seal 201. Flange 141 is hermetically and releasably secured to flange 122 by a plurality of screws 22û and O-ring seal 221.
With this construction, cylindrical portion 12 and the pair of shallow cup-shaped portions 13 and 14 can be disassembled when necessary.
Cylindrical portion 12 further includes a plurality of projections 123 projecting radially inward from the upper end thereof.
Fixed scroll 20 includes circular end plate 21 and spiral ele-ment or wrap 22 extending downwardly from the lower end surface of circular end plate 21. Circular end plate 21 is forcibly inserted into ~ ~ ~L
an inner peripheral wall OI shallow cup-shaped portion 13. O-ring seal 210 is disposed between the outer peripheral surface of circular end plate 21 and the inner peripheral wall of shallow cup-shaped por-tion 13 to seal the mating surface therebetween. The cavity defined by casing 11 is thereby divided into first and second cavities 60 and 61 by circular end plate 21 of fixed scroll 20. Axial hole 24 is formed in circular end plate 21 at the central location to link cavity 60 and a late~mentioned central fluid pocket 71b. Axial hole 24 is covered by one way valve 25 disposed on the upper end surface of circular end plate 21. Curved plate 251 of rigid material, such as steel"s disposed on one way valve 25 to prevent excessive bending of one way valve 25. Curved plate 251 and one way valve 25 are firmly secured to cir-cular end plate 21 at their one end by screw 26. Circular end plate 21 is provided with annular wall 211 projecting downwardly frorn the peripheral end surface thereof. Radial hole 23 is formed in annular wall 211. Annular Ilange 211a projects radially outward from a lower end of arlnular wall 211. Orbiting scroll 30 includes circular end plate 31 and spiral element or wrap 32 extending upwardly from one end surface of circular Pnd plate 31. Spiral element 22 of fixed scroll 20 and spiral element 32 of orbiting scroll 30 interfit at an angular and radial o~fset to form a plurality of line contacts which define at least one pair of sealed off fluid pockets ~1 therebetween. Annular projec-tion 33 projects axially from the other end surface of circular end plate 31. Shallow depression 34 is also formed at the other end sur-face of circular end plate 31 at a central location, and is linked to radial conduit 101 formed in circular end plate 31. Radial conduit 101 extends in one direction to the outer peripheral surface of circular end plate 31; but the outer radial end ~hereof is blocked by plug 102.
The outer radial portion of conduit 101 is linked through axial short path 103 to annular groove 104 formed at one end surface of circular end plate 31 at a peripheral location. Radial conduit 101, axial short path 103 and annular groove 104 conduct the lubricating oil in shallow depression 34 to the mating surfaces between annular wall 21 of fixed scroll 20 and circular end plate 31 of orbiting scroll 30.
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Inner block member 40 includes central portion 41, first axial annular wall ~12 projecting upwardly from central portion 41 at a peripheral loca~ion, and secon~ axial annular wall 43 projecting down-wardly from central portion 41 at a peripheral location. Axial annu-lar projection 44 projects downwardly from central portion 41 at a central location. First axial annular wall 42 is secured by a plurality o~ screws 400 to flange 211a of annular wall 211. A plurality of elon-gated screws 400a secure flange 211a to a plurality of projections 123 through first axial annular wall 42. Inner block member 40 and fixed scroll 20 are thereby firmly secured to cylindrical portion 12 of casing 11.
Motor 50 includes stator 51 which is firmly secured to a lower end of second axial annular wall ~3 by a plurality of screws S00.
Rotor 52 of motor 50 is disposed within stator S1 and is fixed to drive shaft 15 extending therethrough. Wires 110 from stator 51 are con-nected with terminals 111 which are connected to an external elec^
tric source (not shown). Hermetic seal base 120 is insulated from ter-minals 111 and hermetically fi~ed to opening 12g which is formed in cylindrical portion 12.
Drive shaft 15 exten~s through axial annular projection 4~.
Axial annular projection 44 e~tends within an opening in rotor 52.
Drive shaft 15 is rotatably supported within axial annular projection 44 through upper and lower fixed plain bearings 15a and 15b disposed between the exterior surface of drive shaft 15 and the interior sur-face of axial annular projection 44. Driv~ shaft 15 extends through central portion 41 of inner block member 40. Pin member 16 is inte-grated with and projects axially from the upper end surface of drive shaft 15. The axis of pin member 16 is radially offset ~rom the axis of drive shaft 15. Pin member 16 is rotatably disposed within axial annu-lar projec~ion 33 of orbiting scroll 30 through fixed plain bearing 16a.
Drive shaft 15 includes axial bore 151 extending from an opening at the lower end surface of drive shaft 15 and terminating at the lower end portion of pin member 16. A plurality of radial bores 152 extend through drive shaft 15 at lncations within annular projection 44.
Centrifugal pump 1~ includes annular cylinder 171 and annular truncated cone 172. Annular cylinder 171 is firmly secured to the outer peripheral surface of the lower end portion of drive shaft 15 at its upper end by welding or by a plurality OI fastening devices, such as screws (not shown). Annular truncated cone 17~ is integrated with the lower end of annular cylinder 171 and gradually narrows down-wardly. Centrifugal pump 17 is immersed in a reservoir of lubricating oil which accumulates at the inner bottom portion of casing 11.
A throttling device, such as orifice tube 1~, penetrates through pin member 16 so as to link shallow depression 34 to axial hole 151.
Balance weight 35 is integrated with a lower end portion of pin member lB and serves to average the torque of drive shaft 15 acting on pin member 16 during rotation. Balanc~ weight 35 includes annular disk portion 35a and crescent-shaped portion 35b which is integrated with the upper surface of annular disk portion 35a. Needle thrust bearing 81 is disposed between the end surface of axial annular pro-jection 33 and the upper end surface of annular disk portion 35a.
Needle thrust bearing 82 is disposed b~tween the lower end surface of annular disk portion 35a and an upper surface of central portion 41 of inner block member 40. Balance weight 35 is thereby rotatably sup-ported by bearings 81 and 82.
Rotation preventing device 19, for example an Oldham cou-pling mechanism, is disposed between the lower peripheral surface of circular end plate 31, exterior of annular projection 33, and the upper surface of inner block member 40 to prevent rotation of orbiting scroll 30 during its orbital motion. Rotation preventing device 19 and pin member 16, as well as spiral elements 22 and 3~, are all contained in cavity 61.
In operation, stator 51 generates a magnetic field, causing rotation of rotor 52 to thereby rotate drive shaft 15. The rotation of drive shaft 15 is converted into the orbital motion of orbiting scroll 30 by pin member 16. The rotational motion of orbiting scroll 30 is pre-vented by rotation preventing device 19. Refrigerant gas is intro-duced into cavity 61 from the external refrigeration circuit through suction gas inlet pipe 90~ The refrigerant gas is then taken into the - 9 -.
outer fluid pockets ~la between fixed scroll 20 and orbiting scroll 30 through hole 23, The refrigerant gas is compressed inwardly toward the central fluid pocket 71b of spiral elements 22 and 32 due to the orbi~al motion of orbi~ing scroll 30. As the refrigerant gas moves towards the central fluid pocket 71b, it undergoes a ~olume reduction and compression. The refrigerant gas is discharged ~rom the central fluid pocke~ 71b to cavity 60 through hole 24 with the bending of one way valve 25. Compressed refrigerant gas in cavity 60 flows out of the cornpressor to the external refrigerant circuit through discharge gas outlet pipe 91.
Lubricating oil which accumulates at the inner bottom portion of casing 11 flows upwardly through axial bore 151 by virtue of the operation of centrifugal pump 17 which operates during rotation of drive shaft lS. A small part of the lubricating oil which flows upwardly through axial bore 151 further flows into the gap between fixed plain bearings 15a9 15b and the exterior surface of drive shaft 15 to lubricate the contact surfaces by virtue of the centrifugal force generated by rotation of drive shaft 15 during operation of the com-pressor. A large part of the lubricating oil which flows upwardly through axial bore 151 further flows through orifice tube 18. The lubricating oil which has passed through orifice tube 18 is supplied to fiY~ed plain bearings 16a, needle thrust bearings 81 and 82, and the mating surfaces between annular wall 211 of fixed scroll 20 and circu-lar end plate 31 of orbiting scroll 30 in order to lubricate them.
Furthermore, the flow rate of the lubricating oil which flows through axial bore 151 quadratically incrsases in accordance with the increase in rotational speed of drive shaft 15. When the lubricating oil which flows through axial bore 151 further flows through orifice tube 18, hydraulic ~riction generated at orifice tube 18 quadratically increases in accordance with increase in flow rate of the lubricating oil which flows through axial bore 151. Accordingly, the increase in the flow rate of the lubricating oil which is passed through orifice tube 18 is sufficiently reduced due to the quadratic increase in hydraulic friction genera~ed at orifice tube 1~, even though the flow rate of the lubricating oil which f lows through axial bore 151 2 ~ r~ 2 1 quadratically increases in accordance with increase in the rotational speed of drive shaft 15. Therefore, if the diameter and length of ori fice tube 18 are appropriately designed, the flow rate of the lubricat-ing oil which is passed through orifice tube 1~ varies within a narrow range of values. This allows the frictional surfaces of the above-mentioned slidable members of the compressor to receive a sufficient, but not excessive, amount of the lubricating oil even though drive shaft 15 rotates at any rotational speed.
Furthermore, in the above embodiment, although orifice tube 18 is used as a throttling device, a porous metal member or an aper-ture having a throttling portion can also be used as the throttling device in this invention. Such throttling devices can be positioned at any location along axial bore 151 of drive shaft 15.
As mentioned above, in this invention, the frictional surfaces of the slidable members of the compressor can receive an appropriate amount of the lubricating oil even though the drive shaft rotates at any rotational speed. Moreover, the lubricating mechanism is struc-tured by a simple combination of the throttling device and the cen-trifugal pump. Accordingly, the defects experienced in the compres-sor of the Japanese '083 and '684 Publications are eliminated.
This invention has been described in detail in connection with the preferred embodiments. These embodirnents, however, are merely for example only and the invention is not restricted thereto.
It will be understood by those skilled in the art that other variations and modifications can easily be made within the scope of thi~s inven-tion defined by the claims.
HERMETICALLY SEALED SCROLL TYPE REFRIGERANT
COMPRESSOR WITH AN IMPROVED LUBRICATING MECHANISM
B~C:KGROUND OF THE INVENTION
Field of the Invention This inventioD relates to a hermetically sealed scroll type refrigerant compressor, and more particularly to a lubricating mecha-nism thereof.
Descri~ion of the Prior Art Japanese Patent Application Publication No. 60-73~0~3 dis-closes a hermetically sealed scroll type refrigerant compressor which is designe~ such that the longitudinal axis of ~he drive shaft is gener-ally perpendicular to a horizontal plane when the compressor is installed. Therefore, in general, the compressor can b~e called a verti-cally installed type scroll refrigerant compressor. The compressor includes a hermetically sealed housing in which a compression mecha-nism having fixedi and orbiting scrolls, a driving mechanism having a motor and a motor driven drive shaft, and a rutation preventing device for preventing rotatioD of the orbiting scroll during orbital motion are contained. The fixe~ scroll includes a circular end plate which divides the cavity defined by the housing into suction and dis-charge chamber sections. The suction chamber section contains the driving mechanism, the ro~ation preventing mechanism and the spiral elements of the fixed and orbiting scrolls.
The drive shaft includes an axial condui~. The axis of the con-duit is radially offset from the axis of ~he drive shaft. The drive shaft is provided with a centrifugal pump at its lower end. The centrifugal pump is immersed in a reservoir of lubricating oil which accumulates at the inner bottom portion of the housing.
2.~
In operation, refrigerant gas flowing from an external îluid circuit flows into the suction chamber section through an inlet port disposed through a side wall of the housing. The refrigerant gas is taken into a pair of outer fluid pockets which are defined by the spiral elements. The refrigerant gas is compressed inwardly toward a cen-tral fluid pocket due to orbital motion of the orbiting scroll. As the refrigerant gas moves towards the central fluid pocket, it undergoes a volume reduction and compression and is discharged into the dis-charge chamber section through a hole extending through the circular end plate of the fixed scroll. The compressed refrigerant gas in the discharge chamber section flows out of the compressor and to the external fluid circuit through an outlet port which is disposed through an upper end of the housing. After circulating through the external fluid circuit, the refrigerant gas which exits through the outlet port returns ~o the compressor through the inlet porl.
Furthermore, lubrica~ing oil which accumulates at the inner bottom end portion of the housing flows upwardly through the axial conduit by operation of the centrifugal pump. The pump operates during rotation of the drive shaft. The lubricating oil which has upwardly passed over the axial conduit flows through other conduits and into frictional surfaces of the slidable members of the compres-sor, such as the rotation preventing mechanism and the bearings rotatably supporting the drive shaft, in order to lubricate them.
As mentioned above, in this prior art, the lubricating oil at the inner bottom portion of the housing is supplied to the frictional sur-faces of the slidable members of the compressor through the axial conduit and the other conduits by use o~ the centrifugal pump. How-ever, the flow rate of the lubricating oil which has passed through the axial conduit and the other conduits quadratically increases in accor-dance with the increase in rotational speed of the drive shaft. This increase in flow rate occurs because the hydraulic resistance which is generated at the axial conduit and the other conduits when the lubri-cating oil passes therethrough is negligible.
Accordingly, when the capability of the centrifugal pump is designed so as to be able to supply a sufficient amolmt of the 3 2 ~
lubricating oil to the frictional surfaces of the slidable members of the compressor during low rotational speeds of the drive shaft, an excessive amount of the lubricating oil is supplied to the fri~tional surfaces during high rotational speeds of the drive shaft. Therefore, during high rotational speeds OI the drive shaft, viscous drag of the lubricating oil generated between the frictional surfaces increases greatly so that the frictional surfaces do not smoothly slide relative to each other. In addition, when an excessive amount of the lubricating oil is supplie~ to the frictional surfaces between the fixed and orbiting scrolls, an excessive amount of the lubricating oil is taken into the fluid pockets of the scrolls together with the refrigerant, and exits to the fluid circuit via a compression and discharge process of the refrigerant. Therefore, the ratio of the amount of the lubricating oil to the amount of the refrigerant in the circulation of the fluid circuit increases. As a result, the heat exchangeability of the evaporator forming a part of the fluid circuit decreases. On the other hand, when the capability of the centrifugal pump is designed so as to be able to supply a sufficient, but not an excessive, amount of lubricating oil to the frictional surfaces during high rotational speeds of the drive shaft, an insufficient amount of the lubricating oil is supplied to the frictional surfaces during low ro~ational speeds of the c!rive shaft.
Therefore, the frictional surfaces may seize in the low rotational speeds of the drive shaft due to the lack of lubricating oil.
- In order to resolve these defects, Japanese Patent Application Publication No. 63-90,684 discloses a vertically installed type scroll refrigerant compressor. A construction of this compressor is substan-tially similar to the construction of the compressor disclosed in the Japanese '083 publieation, except for the lubricating oil pumping device which is disposed at the lower end of the drive shaft. The pumping device therein includes a centri~ugal pump and a positive-displacement pump, wherein the displacement linearly increases in accordance with the increase in rotational speed of the drive shaft.
By a combination of the centrifugal pump and the positive-displace-ment pump, a sufficient, but not excessive, amount of the lubricating oil is supplied to the frictional surfaces even though the drive shaft 2 ~
- ~ -rotates at any rotational speed. Accordingly, the above-mentioned defects can be resolved.
However, in this prior art, the pumping device is comprised of a large number of component parts. This construction requires a complicated assembling process and a resultant increased manufac-turing cost.
SUM~IARY OF THE~ INVENTION
Accordingly, it is an object of the present invention to provide a hermetically sealed scroll type refrigerant compressor which includes a simply structured lubricating mechanism for effectively lubricating the frictional surfaces of the slidable members thereof at any rotational speed of the drive shaf t.
A scroll type compressor with a hermetically sealed housing includes fixed and orbiting scrolls disposed within ~he housing. The fixed scroll comprises a first end plate from which a first spiral ele-ment extends. The orbiting scroll cornprises a second end plate from which a second spiral element extends. The first and second spiral elements interfit at an angular and radial of gset to form a plurality of line contacts which define at least one pair of sealed off fluid pockets.
A drive mechanism includes a drive shaft which is rotatably supported in the housing, and a pin member which is integrated with one end of the drive shaft. The axis of the pin member is radially offset from the axis of the drive shaft. The pin member is rotatably connected to the orbiting scroll to effect orbital motion of the orbit-ing scroll. A rotation preventing device, such as an Oldham coupling mechanism, prevents rotation of the orbiting scroll during its orbital motion. With this con~truction, the volume of the fluid pockets changes to compress refrigerant fluid within the pockets. The longi-tudinal axis of the drive shaft is generally perpendicular to a horizon-tal plane, when the compressor is installed. A motor is associated with the drive shaft so as to rotate the drive shaft.
An axial bore is formed through the drive shaft. One end of the axial bore, opposite to the orbiting scroll, is immersed in lubricat-ing oil which accumulates at an inner bottom portion of the housing.
2 ~
A throttling device, such as an orifice tube, penetrates through the pin member and is fluidly coupled with the a~nal ~ore. A centrifugal pump which operates during rotation of the drlve shaf t is provided at the one end of the ax~al bore. The pump operates to conduct the lubricating oil at the inner bottom portion of the housing to the fric-tional surfaces of the slidable members of the compressor via an or~-~ice tube.
BR~ElF DESCRIPTIONQF THE DRAWING
The drawing is a vertical section view of a vertically installed type scroll refrigerant compressor in accordance with one embodi-ment of the present invention.
DETAILl~D DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the drawing, a vertically installed type scroll refrigerant compressor in accordance with one embodiment of the present invention is shown. Compressor 1n includes casing 11 com-prising cylindrical portion 12 and a pair of shallow cup-shaped por-tions 13 and 14 hermetically fixecl to both ends of cylindrical portion 12, fixed and orbiting scrolls 20 and 30, inner block member 40 and motor 50.
Cylindrical portion 12 includes annular flanges 121 and 122 projecting radially outward f rom upper and lower ends thereof, respectively. Shallow cup~haped portion 13 includes annular ~lange 131 projecting radially outward from an opening end thereof, and shallow cup~haped portion 14 includes annular flange 141 projecting radially outward from an opening end thereof. Flange 131 is hermeti-cally and releasably secured to flange 121 by a plurality of screws 200 and O-ring seal 201. Flange 141 is hermetically and releasably secured to flange 122 by a plurality of screws 22û and O-ring seal 221.
With this construction, cylindrical portion 12 and the pair of shallow cup-shaped portions 13 and 14 can be disassembled when necessary.
Cylindrical portion 12 further includes a plurality of projections 123 projecting radially inward from the upper end thereof.
Fixed scroll 20 includes circular end plate 21 and spiral ele-ment or wrap 22 extending downwardly from the lower end surface of circular end plate 21. Circular end plate 21 is forcibly inserted into ~ ~ ~L
an inner peripheral wall OI shallow cup-shaped portion 13. O-ring seal 210 is disposed between the outer peripheral surface of circular end plate 21 and the inner peripheral wall of shallow cup-shaped por-tion 13 to seal the mating surface therebetween. The cavity defined by casing 11 is thereby divided into first and second cavities 60 and 61 by circular end plate 21 of fixed scroll 20. Axial hole 24 is formed in circular end plate 21 at the central location to link cavity 60 and a late~mentioned central fluid pocket 71b. Axial hole 24 is covered by one way valve 25 disposed on the upper end surface of circular end plate 21. Curved plate 251 of rigid material, such as steel"s disposed on one way valve 25 to prevent excessive bending of one way valve 25. Curved plate 251 and one way valve 25 are firmly secured to cir-cular end plate 21 at their one end by screw 26. Circular end plate 21 is provided with annular wall 211 projecting downwardly frorn the peripheral end surface thereof. Radial hole 23 is formed in annular wall 211. Annular Ilange 211a projects radially outward from a lower end of arlnular wall 211. Orbiting scroll 30 includes circular end plate 31 and spiral element or wrap 32 extending upwardly from one end surface of circular Pnd plate 31. Spiral element 22 of fixed scroll 20 and spiral element 32 of orbiting scroll 30 interfit at an angular and radial o~fset to form a plurality of line contacts which define at least one pair of sealed off fluid pockets ~1 therebetween. Annular projec-tion 33 projects axially from the other end surface of circular end plate 31. Shallow depression 34 is also formed at the other end sur-face of circular end plate 31 at a central location, and is linked to radial conduit 101 formed in circular end plate 31. Radial conduit 101 extends in one direction to the outer peripheral surface of circular end plate 31; but the outer radial end ~hereof is blocked by plug 102.
The outer radial portion of conduit 101 is linked through axial short path 103 to annular groove 104 formed at one end surface of circular end plate 31 at a peripheral location. Radial conduit 101, axial short path 103 and annular groove 104 conduct the lubricating oil in shallow depression 34 to the mating surfaces between annular wall 21 of fixed scroll 20 and circular end plate 31 of orbiting scroll 30.
2 ~
Inner block member 40 includes central portion 41, first axial annular wall ~12 projecting upwardly from central portion 41 at a peripheral loca~ion, and secon~ axial annular wall 43 projecting down-wardly from central portion 41 at a peripheral location. Axial annu-lar projection 44 projects downwardly from central portion 41 at a central location. First axial annular wall 42 is secured by a plurality o~ screws 400 to flange 211a of annular wall 211. A plurality of elon-gated screws 400a secure flange 211a to a plurality of projections 123 through first axial annular wall 42. Inner block member 40 and fixed scroll 20 are thereby firmly secured to cylindrical portion 12 of casing 11.
Motor 50 includes stator 51 which is firmly secured to a lower end of second axial annular wall ~3 by a plurality of screws S00.
Rotor 52 of motor 50 is disposed within stator S1 and is fixed to drive shaft 15 extending therethrough. Wires 110 from stator 51 are con-nected with terminals 111 which are connected to an external elec^
tric source (not shown). Hermetic seal base 120 is insulated from ter-minals 111 and hermetically fi~ed to opening 12g which is formed in cylindrical portion 12.
Drive shaft 15 exten~s through axial annular projection 4~.
Axial annular projection 44 e~tends within an opening in rotor 52.
Drive shaft 15 is rotatably supported within axial annular projection 44 through upper and lower fixed plain bearings 15a and 15b disposed between the exterior surface of drive shaft 15 and the interior sur-face of axial annular projection 44. Driv~ shaft 15 extends through central portion 41 of inner block member 40. Pin member 16 is inte-grated with and projects axially from the upper end surface of drive shaft 15. The axis of pin member 16 is radially offset ~rom the axis of drive shaft 15. Pin member 16 is rotatably disposed within axial annu-lar projec~ion 33 of orbiting scroll 30 through fixed plain bearing 16a.
Drive shaft 15 includes axial bore 151 extending from an opening at the lower end surface of drive shaft 15 and terminating at the lower end portion of pin member 16. A plurality of radial bores 152 extend through drive shaft 15 at lncations within annular projection 44.
Centrifugal pump 1~ includes annular cylinder 171 and annular truncated cone 172. Annular cylinder 171 is firmly secured to the outer peripheral surface of the lower end portion of drive shaft 15 at its upper end by welding or by a plurality OI fastening devices, such as screws (not shown). Annular truncated cone 17~ is integrated with the lower end of annular cylinder 171 and gradually narrows down-wardly. Centrifugal pump 17 is immersed in a reservoir of lubricating oil which accumulates at the inner bottom portion of casing 11.
A throttling device, such as orifice tube 1~, penetrates through pin member 16 so as to link shallow depression 34 to axial hole 151.
Balance weight 35 is integrated with a lower end portion of pin member lB and serves to average the torque of drive shaft 15 acting on pin member 16 during rotation. Balanc~ weight 35 includes annular disk portion 35a and crescent-shaped portion 35b which is integrated with the upper surface of annular disk portion 35a. Needle thrust bearing 81 is disposed between the end surface of axial annular pro-jection 33 and the upper end surface of annular disk portion 35a.
Needle thrust bearing 82 is disposed b~tween the lower end surface of annular disk portion 35a and an upper surface of central portion 41 of inner block member 40. Balance weight 35 is thereby rotatably sup-ported by bearings 81 and 82.
Rotation preventing device 19, for example an Oldham cou-pling mechanism, is disposed between the lower peripheral surface of circular end plate 31, exterior of annular projection 33, and the upper surface of inner block member 40 to prevent rotation of orbiting scroll 30 during its orbital motion. Rotation preventing device 19 and pin member 16, as well as spiral elements 22 and 3~, are all contained in cavity 61.
In operation, stator 51 generates a magnetic field, causing rotation of rotor 52 to thereby rotate drive shaft 15. The rotation of drive shaft 15 is converted into the orbital motion of orbiting scroll 30 by pin member 16. The rotational motion of orbiting scroll 30 is pre-vented by rotation preventing device 19. Refrigerant gas is intro-duced into cavity 61 from the external refrigeration circuit through suction gas inlet pipe 90~ The refrigerant gas is then taken into the - 9 -.
outer fluid pockets ~la between fixed scroll 20 and orbiting scroll 30 through hole 23, The refrigerant gas is compressed inwardly toward the central fluid pocket 71b of spiral elements 22 and 32 due to the orbi~al motion of orbi~ing scroll 30. As the refrigerant gas moves towards the central fluid pocket 71b, it undergoes a ~olume reduction and compression. The refrigerant gas is discharged ~rom the central fluid pocke~ 71b to cavity 60 through hole 24 with the bending of one way valve 25. Compressed refrigerant gas in cavity 60 flows out of the cornpressor to the external refrigerant circuit through discharge gas outlet pipe 91.
Lubricating oil which accumulates at the inner bottom portion of casing 11 flows upwardly through axial bore 151 by virtue of the operation of centrifugal pump 17 which operates during rotation of drive shaft lS. A small part of the lubricating oil which flows upwardly through axial bore 151 further flows into the gap between fixed plain bearings 15a9 15b and the exterior surface of drive shaft 15 to lubricate the contact surfaces by virtue of the centrifugal force generated by rotation of drive shaft 15 during operation of the com-pressor. A large part of the lubricating oil which flows upwardly through axial bore 151 further flows through orifice tube 18. The lubricating oil which has passed through orifice tube 18 is supplied to fiY~ed plain bearings 16a, needle thrust bearings 81 and 82, and the mating surfaces between annular wall 211 of fixed scroll 20 and circu-lar end plate 31 of orbiting scroll 30 in order to lubricate them.
Furthermore, the flow rate of the lubricating oil which flows through axial bore 151 quadratically incrsases in accordance with the increase in rotational speed of drive shaft 15. When the lubricating oil which flows through axial bore 151 further flows through orifice tube 18, hydraulic ~riction generated at orifice tube 18 quadratically increases in accordance with increase in flow rate of the lubricating oil which flows through axial bore 151. Accordingly, the increase in the flow rate of the lubricating oil which is passed through orifice tube 18 is sufficiently reduced due to the quadratic increase in hydraulic friction genera~ed at orifice tube 1~, even though the flow rate of the lubricating oil which f lows through axial bore 151 2 ~ r~ 2 1 quadratically increases in accordance with increase in the rotational speed of drive shaft 15. Therefore, if the diameter and length of ori fice tube 18 are appropriately designed, the flow rate of the lubricat-ing oil which is passed through orifice tube 1~ varies within a narrow range of values. This allows the frictional surfaces of the above-mentioned slidable members of the compressor to receive a sufficient, but not excessive, amount of the lubricating oil even though drive shaft 15 rotates at any rotational speed.
Furthermore, in the above embodiment, although orifice tube 18 is used as a throttling device, a porous metal member or an aper-ture having a throttling portion can also be used as the throttling device in this invention. Such throttling devices can be positioned at any location along axial bore 151 of drive shaft 15.
As mentioned above, in this invention, the frictional surfaces of the slidable members of the compressor can receive an appropriate amount of the lubricating oil even though the drive shaft rotates at any rotational speed. Moreover, the lubricating mechanism is struc-tured by a simple combination of the throttling device and the cen-trifugal pump. Accordingly, the defects experienced in the compres-sor of the Japanese '083 and '684 Publications are eliminated.
This invention has been described in detail in connection with the preferred embodiments. These embodirnents, however, are merely for example only and the invention is not restricted thereto.
It will be understood by those skilled in the art that other variations and modifications can easily be made within the scope of thi~s inven-tion defined by the claims.
Claims (6)
1. In a scroll type compressor with a hermetically sealed housing, said compressor comprising a fixed scroll disposed within said housing, said fixed scroll having a first end plate from which a first spiral element extends, an orbiting scroll having second end plate from which a second spiral element extends, said first and second spiral elements interfitting at an angular and radial offset to form a plurality of line contacts which define at least one pair of sealed off fluid pockets, a drive mechanism operatively connected to said orbit-ing scroll to effect orbital motion of said orbiting scroll, rotation pre-venting means for preventing rotation of said orbiting scroll during orbital motion whereby the volume of said fluid pockets changes to compress refrigerant fluid within said pockets, said drive mechanism including a drive shaft rotatably supported within said housing, said drive shaft including a bore formed therein, one end of said bore immersed in lubricating oil which accumulates at an inner bottom portion of said housing, the improvement comprising:
said bore including throttling means and centrifugal force generating means which is provided at said one end of said bore, said centrifugal force generating means operating during rotation of said drive shaft so as to conduct the lubricating oil at said inner bot-tom portion of said housing through said bore.
said bore including throttling means and centrifugal force generating means which is provided at said one end of said bore, said centrifugal force generating means operating during rotation of said drive shaft so as to conduct the lubricating oil at said inner bot-tom portion of said housing through said bore.
2. The scroll type compressor of claim 1 wherein said throttling means is positioned at any location along said bore.
3. The scroll type compressor of claim 2 wherein said throttling means includes an orifice tube.
4. The scroll type compressor of claim 3, wherein said driving mechanism further includes a pin member which axially projects from one end of said drive shaft, the axis of said pin member is radially offset from the axis of said drive shaft, said pin member is rotatably connected to said orbiting scroll, said bore is axially formed through said drive shaft from said one end of said drive shaft to the other end of said drive shaft, and said orifice tube penetrates through said pin member.
5. The scroll type compressor of claim 2 wherein said throttling means includes a porous metal member.
6. The scroll type compressor of claim 2 wherein said throttling means includes an aperture having a throttling portion.
5. The scroll type compressor of claim 1 wherein the longi-tudinal axis of said drive shaft is generally perpendicular to a horizon-tal plane when the compressor is installed.
5. The scroll type compressor of claim 1 wherein the longi-tudinal axis of said drive shaft is generally perpendicular to a horizon-tal plane when the compressor is installed.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JPP99414/2 | 1990-04-17 | ||
| JP2099414A JPH041485A (en) | 1990-04-17 | 1990-04-17 | Scroll compressor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2040721A1 true CA2040721A1 (en) | 1991-10-18 |
Family
ID=14246819
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002040721A Abandoned CA2040721A1 (en) | 1990-04-17 | 1991-04-17 | Hermetically sealed scroll type refrigerant compressor with an improved lubricating mechanism |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0452896B1 (en) |
| JP (1) | JPH041485A (en) |
| KR (1) | KR100192699B1 (en) |
| AU (1) | AU640218B2 (en) |
| CA (1) | CA2040721A1 (en) |
| DE (1) | DE69101168T2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100924895B1 (en) | 2002-05-24 | 2009-11-02 | 파나소닉 주식회사 | Scroll compressor |
| JP2005083290A (en) * | 2003-09-10 | 2005-03-31 | Fujitsu General Ltd | Scroll compressor |
| WO2006068664A2 (en) | 2004-07-13 | 2006-06-29 | Tiax Llc | System and method of refrigeration |
| DE102019005095A1 (en) * | 2019-07-23 | 2021-01-28 | KSB SE & Co. KGaA | Pump arrangement with a lubrication and cooling system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0673083A (en) * | 1992-08-28 | 1994-03-15 | Takara Shuzo Co Ltd | New glucide hydrolase inhibitor |
-
1990
- 1990-04-17 JP JP2099414A patent/JPH041485A/en active Pending
-
1991
- 1991-04-12 AU AU74389/91A patent/AU640218B2/en not_active Ceased
- 1991-04-16 KR KR1019910006065A patent/KR100192699B1/en not_active IP Right Cessation
- 1991-04-17 EP EP91106116A patent/EP0452896B1/en not_active Expired - Lifetime
- 1991-04-17 CA CA002040721A patent/CA2040721A1/en not_active Abandoned
- 1991-04-17 DE DE69101168T patent/DE69101168T2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| KR920005749A (en) | 1992-04-03 |
| DE69101168D1 (en) | 1994-03-24 |
| EP0452896A1 (en) | 1991-10-23 |
| DE69101168T2 (en) | 1994-07-21 |
| EP0452896B1 (en) | 1994-02-16 |
| AU7438991A (en) | 1991-11-07 |
| JPH041485A (en) | 1992-01-06 |
| KR100192699B1 (en) | 1999-06-15 |
| AU640218B2 (en) | 1993-08-19 |
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| EEER | Examination request | ||
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