US20090148313A1 - Variable capacity compressor - Google Patents
Variable capacity compressor Download PDFInfo
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- US20090148313A1 US20090148313A1 US12/326,503 US32650308A US2009148313A1 US 20090148313 A1 US20090148313 A1 US 20090148313A1 US 32650308 A US32650308 A US 32650308A US 2009148313 A1 US2009148313 A1 US 2009148313A1
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- Prior art keywords
- pivot
- tilting plate
- pistons
- rotor
- link
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/10—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis having stationary cylinders
- F04B27/1036—Component parts, details, e.g. sealings, lubrication
- F04B27/1054—Actuating elements
- F04B27/1072—Pivot mechanisms
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B25/00—Multi-stage pumps
- F04B25/04—Multi-stage pumps having cylinders coaxial with, or parallel or inclined to, main shaft axis
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/14—Control
- F04B27/16—Control of pumps with stationary cylinders
- F04B27/18—Control of pumps with stationary cylinders by varying the relative positions of a swash plate and a cylinder block
Definitions
- the present invention relates to a variable capacity compressor for varying its discharging capacity of a piston by adjusting a tilted angle of a tilting plate (swash plate, wobble plate).
- a conventional variable capacity compressor is disclosed in Japanese Patent Application Laid-Open Number 2006-233855.
- the variable capacity compressor 100 includes a housing 101 .
- the housing 101 is assembled primarily of a cylinder block 101 a , a front head 101 b provided at one end of the cylinder block 101 a and a rear head 101 c provided at another end of the cylinder block 101 a via a valve plate 102 .
- a drive shaft 103 is provided at the center of the housing 101 . Both ends of the drive shaft are rotatably supported by the housing 101 via radial bearings 104 and 105 .
- cylinder bores 106 are formed on a circumference with the drive shaft 103 as the center.
- a piston 107 capable of reciprocating is provided in each of the cylinder bores 106 .
- a crank chamber 108 is provided within the front head 101 a , which communicates with the cylinder bores 106 .
- crank chamber 108 Within the crank chamber 108 , provided are a rotor 109 fixed on an outer circumferential surface of the drive shaft 103 , a sleeve 110 provided slidably on the outer circumferential surface of the drive shaft 103 , a journal 112 provided outside the sleeve 110 and linked with the rotor 109 via a link 111 and a tilting plate 113 fixed on an outer circumferential surface of the journal 112 .
- the pistons 107 are coupled to an outer circumference of the tilting plate 113 via pairs of shoes 114 .
- First and second springs S 1 and S 2 are provided at both sides of the sleeve 110 .
- the tilting plate 113 will be returned to its initial position due to a balance between elastic forces of the first and second springs S 1 and S 2 after a shutdown.
- the pistons 107 are reciprocated within the cylinder bores 106 , respectively, due to the rotor 109 , the tilting plate 113 and so on.
- a reciprocating stroke amount of the pistons 107 is varied due to a tilted angle of the tilting plate 113 .
- a suction chamber 120 and a discharge chamber 121 are provided within the rear head 101 c.
- the valve plate 102 is interposed between the cylinder head 101 a and the rear head 101 c . Therefore, the cylinder bores 106 and the chambers 120 and 121 are partitioned by the valve plate 102 .
- the tilting plate 113 swings to reciprocate the pistons 107 on the drive shaft 103 being rotated.
- Refrigerant is supplied into the cylinder bore 106 from the suction chamber 120 during a suction stroke of the piston 107 .
- the supplied refrigerant is compressed and discharged into the discharge chamber 121 during a compression stroke of the piston 107 .
- the discharged refrigerant is circulated in a refrigerating cycle to be served for air-conditioning or the like and returned to the capacity variable compressor 100 .
- a pressure in the crank chamber 108 is made low when thermal load for the refrigerating cycle becomes large during the capacity variable compressor 100 driving. As a result, a balance will be disrupted between a counter-clockwise moment (to move the tilting plate 113 in FIG. 5 ) due to a crank chamber pressure (a back pressure of the pistons 107 ) and the elastic force of the first spring S 1 and a clockwise moment due to a front pressure of the pistons 107 and the elastic force of the second spring S 2 . Thereby, the clockwise moment becomes large to increase the tilted angle of the tilting plate 113 , so that the link 111 swings in an arrowed direction a in FIG. 5 until the both moments are balanced.
- the pressure in the crank chamber 108 is made high when the thermal load for the refrigerating cycle becomes small.
- the balance will be disrupted between the counter-clockwise moment due to the crank chamber pressure (the back pressure of the pistons 107 ) and the elastic force of the first spring S 1 and the clockwise moment due to the front pressure of the pistons 107 and the elastic force of the second spring S 2 .
- the counter-clockwise moment becomes large to decrease the tilted angle of the tilting plate 113 , so that the link 111 swings in an arrowed direction b in FIG. 5 until the both moments are balanced.
- the second pivot 111 b is moved in the arrowed direction b from the large capacity state [ FIG.
- the rotor 109 and the journal 112 are connecting each other with the link 111 as shown in FIGS. 6A and 6B in the conventional capacity variable compressor 100 .
- Such a linkage with the link 111 can serve lower frictions than a linkage with an elongate hole and a pin slidable within the elongate hole.
- the link 111 is provided in a pair and a first pivot 111 a is also provided in a pair as shown in FIGS. 6A and 6B . However, they are referred as the “link 111 ” and the “first pivot 111 a ” hereinafter.
- the first pivot 111 a (connecting the rotor 109 and the link 111 ) and the second pivot 111 b (connecting the journal 112 and the link 111 )
- the first pivot 111 a is arranged near the rotor 109 (on the side of the rotor 109 )
- the second pivot 111 b is arranged near the journal 112 (on the side of the journal 112 ) in the above-mentioned conventional capacity variable compressor 100 . Therefore, with respect to head clearance, there is a tendency indicated by a characteristic line of a conventional example in FIG. 4 at a time when the tilted angle of the tilting plate 113 is small (within a small discharge amount range of the piston 107 ) as shown in FIG.
- An object of the present invention is to provide a capacity variable compressor that can restrain a sudden cut-off of the discharge flow amount within the small discharge amount range as much as possible and can sustain the tilted angle of the tilting plate stably.
- An aspect of the present invention is to provide a capacity variable compressor that includes a housing within which a plurality of cylinder bores and a crank chamber communicating with the plurality of cylinder bores are provided; a drive shaft rotatably supported within the housing; a rotor fixed with the drive shaft; a link for linking the rotor and a journal; a tilting plate capable of changing a tilted angle thereof by a movement of the journal; and a plurality of pistons capable of reciprocating within the plurality of cylinder bores, respectively, due to a swinging rotation of the tilting plate.
- the tilted angle of the tilting plate is changed due to a rotation of the rotor by way of the link.
- Each reciprocating stroke of the plurality of pistons is adjusted according to the tilted angle of the tilting plate.
- the link is linked with the rotor via a first pivot and linked with the journal via a second pivot.
- An arrangement of the first and second pivot is set so that each head clearance of the plurality of pistons decreases as a discharge capacity decreases toward a minimum value thereof within a small discharge capacity range.
- the head clearance reduces as the capacity decreases toward its minimum value within the small discharge capacity range, it can be prevented as much as possible that the discharge flaw amount is cut off abruptly and the tilted angle of the tilting plate can be sustained stably.
- a ratio of a head clearance B at the top dead center of the piston to a stroke A of the piston shall be defined as a stroke ratio B/A, and the arrangement of the first and second pivot is set so that the stroke rate B/A is made constant or decreases as the discharge capacity decreases within the small discharge capacity range.
- the stroke rate is made constant or decreases as the capacity decreases within the small discharge capacity range of the pistons, it can be prevented firmly that the discharge flaw amount is cut off abruptly and the tilted angle of the tilting plate can be sustained stably.
- the link is configured so that the first pivot is arranged nearer to the journal than the second pivot and the second pivot is arranged nearer to the rotor than the first pivot.
- the head clearance reduces as the capacity decreases toward its minimum value within the small discharge capacity range, it can be prevented as much as possible that the discharge flaw amount is cut off abruptly and the tilted angle of the tilting plate can be sustained stably.
- FIG. 1 is an overall cross-sectional view of a variable capacity compressor according to an embodiment of the present invention
- FIG. 2A is a plan view of a linkage in the variable capacity compressor according to the embodiment of the present invention.
- FIG. 2B is a side view of the linkage in the variable capacity compressor according to the embodiment of the present invention.
- FIG. 3A is an explanatory diagram showing a stroke ratio under a mid capacity setting
- FIG. 3B is an explanatory diagram showing a stroke ratio under a small capacity setting
- FIG. 4 is a characteristic line chart showing relations between a discharge capacity and a head clearance in the variable capacity compressor according to the embodiment of the present invention
- FIG. 5 is an overall cross-sectional view of a conventional variable capacity compressor
- FIG. 6A is a plan view of a linkage in the conventional variable capacity compressor
- FIG. 6B is a side view of the linkage in the conventional variable capacity compressor.
- FIG. 7 is a cross-sectional view of primary elements when a stroke is zero.
- a variable capacity compressor 1 includes a housing 2 .
- the housing 2 is configured to be assembled of a cylinder block 2 a , a front head 2 b provided at one end of the cylinder block 2 a and a rear head 2 c provided at another end of the cylinder block 2 a via a valve plate 3 .
- a drive shaft 4 penetrating an after-mentioned crank chamber 10 is provided within the cylinder block 2 a and the front head 2 b . Both ends of the drive shaft 4 are rotatably supported by the cylinder block 2 a and the front head 2 b via radial bearings 5 and 6 . One end of the drive shaft 4 is projected outward from the front head 2 b and a pulley 7 is fixed on the projected end to receive engine rotation. The drive shaft 4 is configured to rotate by receiving a drive force from the pulley 7 fixed on its one end.
- Cylinder bores 8 are formed within the cylinder block 2 a .
- the cylinder bores 8 are formed at even intervals on a circumference with the drive shaft 4 as the center.
- a piston 9 capable of reciprocating is provided in each of the cylinder bores 8 .
- the crank chamber 10 is provided within the front head 2 b , which communicates with the cylinder bores 8 .
- a rotor 11 fixed on an outer circumferential surface of the drive shaft 4
- a sleeve 12 provided slidably on the outer circumferential surface of the drive shaft 4
- a journal 13 provided outside the sleeve 12
- a link 14 connecting the journal 13 and the rotor 11
- a tilting plate 15 fixed on an outer circumferential surface of the journal 13 and rear ends of the pistons 9 , each coupled to an outer circumference of the tilting plate 15 via a pair of shoes 16 .
- An outer circumferential surface of the sleeve 12 is formed almost spherical to smoothly guide a transition of the tilted angle of the tilting plate 13 .
- First and second springs S 1 and S 2 are provided at both sides of the sleeve 12 .
- the tilting plate 15 will be returned to its initial position due to a balance between elastic forces of the first and second springs S 1 and S 2 after a shutdown. A linkage with the link 14 will be explained later in detail.
- a suction chamber 20 and a discharge chamber 21 for refrigerant gas are provided within the rear head 2 c .
- the suction chamber 20 is connected to an outlet of an evaporator in a refrigerating cycle.
- the discharge chamber 21 is connected to an inlet of a condenser in the refrigerating cycle.
- the cylinder bores 8 and the chambers 20 and 21 are partitioned by the valve plate 3 .
- Discharge holes 22 are provided on the valve plate 3 within partitioning areas between the bores 8 and the discharge chamber 21 .
- a discharge valve is provided at each of the discharge holes 22 .
- Suction holes (not shown) are provided on the valve plate 3 within partitioning areas between the bores 8 and the suction chamber 20 .
- a suction valve (not shown) is provided at each of the suction holes.
- an extraction path (not shown) is provided between the crank chamber 10 and the suction chamber 20 , which is always opened.
- An intake path 23 is provided between the crank chamber 10 and the discharge chamber 21 .
- a pressure control valve 24 is provided on the intake path 23 . The pressure control valve 24 is configured to control a pressure within the crank chamber 10 by adjusting its valve opening.
- the link 14 is connected with the rotor 11 via the first pivot 14 a and connected with the journal 13 via the second pivot 14 b .
- the first pivot 14 a is arranged near the journal 13 (on the side of the journal 13 ) and the second pivot is arranged near the rotor 11 (on the side of the rotor 11 ).
- the link 14 is linked with the arrangement of the first and second pivot 14 a and 14 b being reversed as compared with the above-mentioned conventional example.
- head clearance decreases as the capacity (tilted angle) decreases toward its minimum value within a small discharge amount range of the pistons 9 (equal-to or less-than 40% capacity, equal-to or less-than 8 degrees tilting plate angle) as shown by a characteristic line of the present invention in FIG. 4 .
- a ratio of a head clearance B at the top dead center (TDC) of the piston 9 to a stroke A of the piston 9 shall be defined as a stroke ratio B/A, as shown in FIG. 3 .
- the arrangement of the first and second pivots 14 a and 14 b is set so that the stroke rate is made constant or decreases as the capacity decreases within the small discharge capacity range of the piston 9 .
- the tilting plate 15 rotates due to the rotational force of the drive shaft 4 .
- the pistons 9 reciprocate within the cylinder bores 8 .
- the suction holes (not shown) are opened due to a pressure reduction within the cylinder bores 8 .
- the refrigerant gas is supplied from the suction chamber 20 to cylinder bores 8 .
- the suction holes (not shown) are closed and the refrigerant gas within the cylinder bores 8 is compressed adiabatically by the pistons 9 .
- the compressed refrigerant gas with high-temperature and high-pressure is discharged from the discharge holes 22 to the discharge chamber 21 .
- the discharged refrigerant gas with high-temperature and high-pressure is discharged from the capacity variable compressor 1 via the outlet port (not shown).
- the discharged refrigerant gas is circulated in the refrigerating cycle to be served for air-conditioning or the like and returned to the capacity variable compressor 1 again.
- a pressure in the crank chamber 10 is made low when thermal load for the refrigerating cycle becomes large during the capacity variable compressor 1 driving. As a result, a balance will be disrupted between a counter-clockwise moment (to move the tilting plate 15 in FIG. 1 ) due to the crank chamber pressure (a back pressure of the pistons 9 ) and the elastic force of the first spring S 1 and a clockwise moment due to a front pressure of the pistons 9 and the elastic force of the second spring S 2 . Thereby, the clockwise moment becomes large to increase the tilted angle of the tilting plate 15 , so that the link 14 swings in an arrowed direction a in FIGS. 1 and 2B until the both moments are balanced.
- the second pivot 14 b is moved in the arrowed direction a from the small capacity state toward the large capacity state [ FIG. 1 ]. In FIG. 1 , the second pivot 14 b is already moved to the limit of the arrowed direction a.)
- Such swinging of the link 14 makes the tilted angle of the tilting plate 15 large.
- the reciprocating stroke amount of the pistons 9 is made large when the tilted angle of the tilting plate 15 is made large. Thereby, a discharge amount of the refrigerant is made large, so that a cooling performance or the like is enhanced.
- the pressure in the crank chamber 10 is made high when the thermal load for the refrigerating cycle becomes small.
- the balance will be disrupted between the counter-clockwise moment due to the crank chamber pressure (the back pressure of the pistons 9 ) and the elastic force of the first spring S 1 and the clockwise moment due to the front pressure of the pistons 9 and the elastic force of the second spring S 2 .
- the counter-clockwise moment becomes large to decrease the tilted angle of the tilting plate 15 , so that the link 14 swings in an arrowed direction b in FIGS. 1 and 2B until the both moments are balanced.
- the second pivot 14 b is moved in the arrowed direction b from the large capacity state [ FIG.
- the head clearance is made smaller as the capacity (tilted angle) decreases toward its minimum value. Therefore, it can be prevented firmly that the discharge flaw amount is cut off abruptly and the tilted angle of the tilting plate 15 can be sustained stably.
- the stroke rate is hardly influenced even if the head clearance B is somewhat large within a mid discharge capacity range as shown in FIG. 3A because the stroke A is large.
- the stroke rate is greatly influenced by alteration of the head clearance B within the small discharge capacity range as shown in FIG. 3B because the stroke A is small.
- the refrigerant discharge may be cut off abruptly if the stroke rate became large.
- the stroke rate is set not more than a certain value in the present embodiment, it can be prevented firmly that the discharge flaw amount is cut off abruptly.
Abstract
A variable capacity compressor includes: cylinder bores; a drive shaft; a rotor fixed with the drive shaft; a link for linking the rotor and a journal; a tilting plate capable of changing its tilted angle; and pistons capable of reciprocating within the cylinder bores along with a rotation of the tilting plate. Each reciprocating stroke of the pistons is adjusted according to the tilted angle of the tilting plate. The link is linked with the rotor via a first pivot and linked with the journal via a second pivot. An arrangement of the first and second pivot is set so that each head clearance of the pistons decreases as a discharge capacity decreases toward its minimum value within a small discharge capacity range. According to the compressor, it can be prevented that the discharge flaw amount is cut off abruptly and the tilted angle can be sustained stably.
Description
- 1. Field of the Invention
- The present invention relates to a variable capacity compressor for varying its discharging capacity of a piston by adjusting a tilted angle of a tilting plate (swash plate, wobble plate).
- 2. Description of Related Art
- A conventional variable capacity compressor is disclosed in Japanese Patent Application Laid-Open Number 2006-233855.
- As shown in
FIG. 5 , thevariable capacity compressor 100 includes ahousing 101. Thehousing 101 is assembled primarily of acylinder block 101 a, afront head 101 b provided at one end of thecylinder block 101 a and arear head 101 c provided at another end of thecylinder block 101 a via avalve plate 102. - A
drive shaft 103 is provided at the center of thehousing 101. Both ends of the drive shaft are rotatably supported by thehousing 101 viaradial bearings - Within the
cylinder block 101 a,cylinder bores 106 are formed on a circumference with thedrive shaft 103 as the center. Apiston 107 capable of reciprocating is provided in each of thecylinder bores 106. Acrank chamber 108 is provided within thefront head 101 a, which communicates with thecylinder bores 106. Within thecrank chamber 108, provided are arotor 109 fixed on an outer circumferential surface of thedrive shaft 103, asleeve 110 provided slidably on the outer circumferential surface of thedrive shaft 103, ajournal 112 provided outside thesleeve 110 and linked with therotor 109 via alink 111 and atilting plate 113 fixed on an outer circumferential surface of thejournal 112. Thepistons 107 are coupled to an outer circumference of thetilting plate 113 via pairs ofshoes 114. First and second springs S1 and S2 are provided at both sides of thesleeve 110. Thetilting plate 113 will be returned to its initial position due to a balance between elastic forces of the first and second springs S1 and S2 after a shutdown. - On the
drive shaft 103 rotating, thepistons 107 are reciprocated within thecylinder bores 106, respectively, due to therotor 109, thetilting plate 113 and so on. A reciprocating stroke amount of thepistons 107 is varied due to a tilted angle of thetilting plate 113. - A
suction chamber 120 and adischarge chamber 121 are provided within therear head 101 c. - The
valve plate 102 is interposed between thecylinder head 101 a and therear head 101 c. Therefore, thecylinder bores 106 and thechambers valve plate 102. - According to the above-mentioned configuration, the tilting
plate 113 swings to reciprocate thepistons 107 on thedrive shaft 103 being rotated. Refrigerant is supplied into thecylinder bore 106 from thesuction chamber 120 during a suction stroke of thepiston 107. The supplied refrigerant is compressed and discharged into thedischarge chamber 121 during a compression stroke of thepiston 107. The discharged refrigerant is circulated in a refrigerating cycle to be served for air-conditioning or the like and returned to thecapacity variable compressor 100. - A pressure in the
crank chamber 108 is made low when thermal load for the refrigerating cycle becomes large during thecapacity variable compressor 100 driving. As a result, a balance will be disrupted between a counter-clockwise moment (to move thetilting plate 113 inFIG. 5 ) due to a crank chamber pressure (a back pressure of the pistons 107) and the elastic force of the first spring S1 and a clockwise moment due to a front pressure of thepistons 107 and the elastic force of the second spring S2. Thereby, the clockwise moment becomes large to increase the tilted angle of thetilting plate 113, so that thelink 111 swings in an arrowed direction a inFIG. 5 until the both moments are balanced. (Asecond pivot 111 b is moved in the arrowed direction a from a small capacity state [FIG. 7 ] to a large capacity state [FIG. 5 ].) Such swinging of thelink 111 makes the tilted angle of thetilting plate 113 large. The reciprocating stroke amount of thepistons 107 turns to be large when the tilted angle of thetilting plate 113 is made large. Thereby, a discharge amount of the refrigerant is made large, so that a cooling performance or the like is enhanced. - On the other hand, the pressure in the
crank chamber 108 is made high when the thermal load for the refrigerating cycle becomes small. As a result, the balance will be disrupted between the counter-clockwise moment due to the crank chamber pressure (the back pressure of the pistons 107) and the elastic force of the first spring S1 and the clockwise moment due to the front pressure of thepistons 107 and the elastic force of the second spring S2. Thereby, the counter-clockwise moment becomes large to decrease the tilted angle of thetilting plate 113, so that thelink 111 swings in an arrowed direction b inFIG. 5 until the both moments are balanced. (Thesecond pivot 111 b is moved in the arrowed direction b from the large capacity state [FIG. 5 ] to the small capacity state [FIG. 7 ].) Such swinging of thelink 111 makes the tilted angle of thetilting plate 113 small. The reciprocating stroke amount of thepistons 107 turns to be small when the tilted angle of thetilting plate 113 is made small. Thereby, the discharge amount of the refrigerant is made small, so that the cooling performance or the like is reduced. Thecapacity variable compressor 100 conserves energy according to the above-mentioned operation. - In addition, the
rotor 109 and thejournal 112 are connecting each other with thelink 111 as shown inFIGS. 6A and 6B in the conventionalcapacity variable compressor 100. Such a linkage with thelink 111 can serve lower frictions than a linkage with an elongate hole and a pin slidable within the elongate hole. Note that thelink 111 is provided in a pair and afirst pivot 111 a is also provided in a pair as shown inFIGS. 6A and 6B . However, they are referred as the “link 111” and the “first pivot 111 a” hereinafter. - However, with respect to the
first pivot 111 a (connecting therotor 109 and the link 111) and thesecond pivot 111 b (connecting thejournal 112 and the link 111), thefirst pivot 111 a is arranged near the rotor 109 (on the side of the rotor 109) and thesecond pivot 111 b is arranged near the journal 112 (on the side of the journal 112) in the above-mentioned conventionalcapacity variable compressor 100. Therefore, with respect to head clearance, there is a tendency indicated by a characteristic line of a conventional example inFIG. 4 at a time when the tilted angle of thetilting plate 113 is small (within a small discharge amount range of the piston 107) as shown inFIG. 7 . Then, the head clearance increases as the capacity decreases toward its minimum value. Since stroke becomes small as a matter of course, dead volume ratio to the discharge amount increases drastically. As a result, a discharge flow amount from thecylinder bores 106 is cut off abruptly as a certain tilted angle. Since the small discharge amount range is basically an unstable range due to a small discharge amount, the tilted angle of thetilting plate 113 cannot be sustained stably when the discharge flow amount changes rapidly as mentioned above. - An object of the present invention is to provide a capacity variable compressor that can restrain a sudden cut-off of the discharge flow amount within the small discharge amount range as much as possible and can sustain the tilted angle of the tilting plate stably.
- An aspect of the present invention is to provide a capacity variable compressor that includes a housing within which a plurality of cylinder bores and a crank chamber communicating with the plurality of cylinder bores are provided; a drive shaft rotatably supported within the housing; a rotor fixed with the drive shaft; a link for linking the rotor and a journal; a tilting plate capable of changing a tilted angle thereof by a movement of the journal; and a plurality of pistons capable of reciprocating within the plurality of cylinder bores, respectively, due to a swinging rotation of the tilting plate. The tilted angle of the tilting plate is changed due to a rotation of the rotor by way of the link. Each reciprocating stroke of the plurality of pistons is adjusted according to the tilted angle of the tilting plate. The link is linked with the rotor via a first pivot and linked with the journal via a second pivot. An arrangement of the first and second pivot is set so that each head clearance of the plurality of pistons decreases as a discharge capacity decreases toward a minimum value thereof within a small discharge capacity range.
- According to the above aspect of the present invention, since the head clearance reduces as the capacity decreases toward its minimum value within the small discharge capacity range, it can be prevented as much as possible that the discharge flaw amount is cut off abruptly and the tilted angle of the tilting plate can be sustained stably.
- It is preferable that a ratio of a head clearance B at the top dead center of the piston to a stroke A of the piston shall be defined as a stroke ratio B/A, and the arrangement of the first and second pivot is set so that the stroke rate B/A is made constant or decreases as the discharge capacity decreases within the small discharge capacity range.
- According to this, since the stroke rate is made constant or decreases as the capacity decreases within the small discharge capacity range of the pistons, it can be prevented firmly that the discharge flaw amount is cut off abruptly and the tilted angle of the tilting plate can be sustained stably.
- It is also preferable that the link is configured so that the first pivot is arranged nearer to the journal than the second pivot and the second pivot is arranged nearer to the rotor than the first pivot.
- According to this, since the head clearance reduces as the capacity decreases toward its minimum value within the small discharge capacity range, it can be prevented as much as possible that the discharge flaw amount is cut off abruptly and the tilted angle of the tilting plate can be sustained stably.
-
FIG. 1 is an overall cross-sectional view of a variable capacity compressor according to an embodiment of the present invention; -
FIG. 2A is a plan view of a linkage in the variable capacity compressor according to the embodiment of the present invention; -
FIG. 2B is a side view of the linkage in the variable capacity compressor according to the embodiment of the present invention; -
FIG. 3A is an explanatory diagram showing a stroke ratio under a mid capacity setting; -
FIG. 3B is an explanatory diagram showing a stroke ratio under a small capacity setting; -
FIG. 4 is a characteristic line chart showing relations between a discharge capacity and a head clearance in the variable capacity compressor according to the embodiment of the present invention; -
FIG. 5 is an overall cross-sectional view of a conventional variable capacity compressor; -
FIG. 6A is a plan view of a linkage in the conventional variable capacity compressor; -
FIG. 6B is a side view of the linkage in the conventional variable capacity compressor; and -
FIG. 7 is a cross-sectional view of primary elements when a stroke is zero. - Hereinafter, one embodiment according to the present invention will be explained with reference to drawings.
- As shown in
FIG. 1 , avariable capacity compressor 1 includes ahousing 2. Thehousing 2 is configured to be assembled of acylinder block 2 a, afront head 2 b provided at one end of thecylinder block 2 a and arear head 2 c provided at another end of thecylinder block 2 a via avalve plate 3. - A
drive shaft 4 penetrating an after-mentionedcrank chamber 10 is provided within thecylinder block 2 a and thefront head 2 b. Both ends of thedrive shaft 4 are rotatably supported by thecylinder block 2 a and thefront head 2 b viaradial bearings drive shaft 4 is projected outward from thefront head 2 b and apulley 7 is fixed on the projected end to receive engine rotation. Thedrive shaft 4 is configured to rotate by receiving a drive force from thepulley 7 fixed on its one end. - Cylinder bores 8 are formed within the
cylinder block 2 a. The cylinder bores 8 are formed at even intervals on a circumference with thedrive shaft 4 as the center. Apiston 9 capable of reciprocating is provided in each of the cylinder bores 8. - The
crank chamber 10 is provided within thefront head 2 b, which communicates with the cylinder bores 8. Within thecrank chamber 10, provided are arotor 11 fixed on an outer circumferential surface of thedrive shaft 4, asleeve 12 provided slidably on the outer circumferential surface of thedrive shaft 4, ajournal 13 provided outside thesleeve 12, alink 14 connecting thejournal 13 and therotor 11, a tiltingplate 15 fixed on an outer circumferential surface of thejournal 13 and rear ends of thepistons 9, each coupled to an outer circumference of the tiltingplate 15 via a pair ofshoes 16. - An outer circumferential surface of the
sleeve 12 is formed almost spherical to smoothly guide a transition of the tilted angle of the tiltingplate 13. First and second springs S1 and S2 are provided at both sides of thesleeve 12. The tiltingplate 15 will be returned to its initial position due to a balance between elastic forces of the first and second springs S1 and S2 after a shutdown. A linkage with thelink 14 will be explained later in detail. - On the
drive shaft 4 rotating, its rotation is transmitted to the tiltingplate 15 by therotor 11, thelink 14 and thejournal 13 to reciprocate thepistons 9 within the cylinder bores 8. In addition, each stroke of thepistons 9 is varied due to the tilted angle of the tiltingplate 15 to change a discharge amount of refrigerant. Mechanism for adjusting the tilted angle of the tiltingplate 15 will be explained later. - A
suction chamber 20 and adischarge chamber 21 for refrigerant gas are provided within therear head 2 c. Thesuction chamber 20 is connected to an outlet of an evaporator in a refrigerating cycle. Thedischarge chamber 21 is connected to an inlet of a condenser in the refrigerating cycle. In addition, the cylinder bores 8 and thechambers valve plate 3. Discharge holes 22 are provided on thevalve plate 3 within partitioning areas between thebores 8 and thedischarge chamber 21. A discharge valve is provided at each of the discharge holes 22. Suction holes (not shown) are provided on thevalve plate 3 within partitioning areas between thebores 8 and thesuction chamber 20. A suction valve (not shown) is provided at each of the suction holes. - Further, an extraction path (not shown) is provided between the
crank chamber 10 and thesuction chamber 20, which is always opened. Anintake path 23 is provided between thecrank chamber 10 and thedischarge chamber 21. Apressure control valve 24 is provided on theintake path 23. Thepressure control valve 24 is configured to control a pressure within thecrank chamber 10 by adjusting its valve opening. - Next, the linkage with the
link 14 will be explained. As shown inFIGS. 1 , 2A and 2B, thelink 14 is connected with therotor 11 via thefirst pivot 14 a and connected with thejournal 13 via thesecond pivot 14 b. Thefirst pivot 14 a is arranged near the journal 13 (on the side of the journal 13) and the second pivot is arranged near the rotor 11 (on the side of the rotor 11). Namely, thelink 14 is linked with the arrangement of the first andsecond pivot FIG. 4 . - A ratio of a head clearance B at the top dead center (TDC) of the
piston 9 to a stroke A of thepiston 9 shall be defined as a stroke ratio B/A, as shown inFIG. 3 . In the present embodiment, with respect to a decreasing tendency of the head clearance, the arrangement of the first andsecond pivots piston 9. - In the above configuration, on the
drive shaft 4 rotating, the tiltingplate 15 rotates due to the rotational force of thedrive shaft 4. Then, thepistons 9 reciprocate within the cylinder bores 8. During the suction stroke of the pistons 9 (stroke from TDC to BDC), the suction holes (not shown) are opened due to a pressure reduction within the cylinder bores 8. As a result, the refrigerant gas is supplied from thesuction chamber 20 to cylinder bores 8. - During the compression stroke of the pistons 9 (stroke from BDC to TDC), the suction holes (not shown) are closed and the refrigerant gas within the cylinder bores 8 is compressed adiabatically by the
pistons 9. The compressed refrigerant gas with high-temperature and high-pressure is discharged from the discharge holes 22 to thedischarge chamber 21. The discharged refrigerant gas with high-temperature and high-pressure is discharged from thecapacity variable compressor 1 via the outlet port (not shown). The discharged refrigerant gas is circulated in the refrigerating cycle to be served for air-conditioning or the like and returned to thecapacity variable compressor 1 again. - A pressure in the
crank chamber 10 is made low when thermal load for the refrigerating cycle becomes large during thecapacity variable compressor 1 driving. As a result, a balance will be disrupted between a counter-clockwise moment (to move the tiltingplate 15 inFIG. 1 ) due to the crank chamber pressure (a back pressure of the pistons 9) and the elastic force of the first spring S1 and a clockwise moment due to a front pressure of thepistons 9 and the elastic force of the second spring S2. Thereby, the clockwise moment becomes large to increase the tilted angle of the tiltingplate 15, so that thelink 14 swings in an arrowed direction a inFIGS. 1 and 2B until the both moments are balanced. (Thesecond pivot 14 b is moved in the arrowed direction a from the small capacity state toward the large capacity state [FIG. 1 ]. InFIG. 1 , thesecond pivot 14 b is already moved to the limit of the arrowed direction a.) Such swinging of thelink 14 makes the tilted angle of the tiltingplate 15 large. The reciprocating stroke amount of thepistons 9 is made large when the tilted angle of the tiltingplate 15 is made large. Thereby, a discharge amount of the refrigerant is made large, so that a cooling performance or the like is enhanced. - On the other hand, the pressure in the
crank chamber 10 is made high when the thermal load for the refrigerating cycle becomes small. As a result, the balance will be disrupted between the counter-clockwise moment due to the crank chamber pressure (the back pressure of the pistons 9) and the elastic force of the first spring S1 and the clockwise moment due to the front pressure of thepistons 9 and the elastic force of the second spring S2. Thereby, the counter-clockwise moment becomes large to decrease the tilted angle of the tiltingplate 15, so that thelink 14 swings in an arrowed direction b inFIGS. 1 and 2B until the both moments are balanced. (Thesecond pivot 14 b is moved in the arrowed direction b from the large capacity state [FIG. 1 ] toward the small capacity state.) Such swinging of thelink 14 makes the tilted angle of the tiltingplate 15 small. The reciprocating stroke amount of thepistons 9 turns to be small when the tilted angle of the tiltingplate 15 is made small. Thereby, the discharge amount of the refrigerant is made small, so that the cooling performance or the like is reduced. Thecapacity variable compressor 1 conserves energy according to the above-mentioned operation. - Next, explained will be an operation within the small discharge amount range of the
pistons 9. Within the small discharge amount range of thepistons 9, the head clearance is made smaller as the capacity (tilted angle) decreases toward its minimum value. Therefore, it can be prevented firmly that the discharge flaw amount is cut off abruptly and the tilted angle of the tiltingplate 15 can be sustained stably. - In the present embodiment, since the arrangement of the first and
second pivots piston 9, it can be prevented firmly that the discharge flaw amount is cut off abruptly and the tilted angle of the tiltingplate 15 can be sustained stably. Specifically, the stroke rate is hardly influenced even if the head clearance B is somewhat large within a mid discharge capacity range as shown inFIG. 3A because the stroke A is large. However, the stroke rate is greatly influenced by alteration of the head clearance B within the small discharge capacity range as shown inFIG. 3B because the stroke A is small. Therefore, within the small discharge capacity range, the refrigerant discharge may be cut off abruptly if the stroke rate became large. However, since the stroke rate is set not more than a certain value in the present embodiment, it can be prevented firmly that the discharge flaw amount is cut off abruptly.
Claims (3)
1. A variable capacity compressor comprising:
a housing within which a plurality of cylinder bores and a crank chamber communicating with the plurality of cylinder bores are provided;
a drive shaft rotatably supported within the housing;
a rotor fixed with the drive shaft;
a link for linking the rotor and a journal;
a tilting plate capable of changing a tilted angle thereof by a movement of the journal; and
a plurality of pistons capable of reciprocating within the plurality of cylinder bores, respectively, due to a swinging rotation of the tilting plate;
wherein
the tilted angle of the tilting plate is changed due to a rotation of the rotor by way of the link,
each reciprocating stroke of the plurality of pistons is adjusted according to the tilted angle of the tilting plate,
the link is linked with the rotor via a first pivot and linked with the journal via a second pivot, and
an arrangement of the first and second pivot is set so that each head clearance of the plurality of pistons decreases as a discharge capacity decreases toward a minimum value thereof within a small discharge capacity range.
2. The compressor according to claim 1 , wherein
a ratio of a head clearance B at the top dead center of the piston to a stroke A of the piston shall be defined as a stroke ratio B/A, and
the arrangement of the first and second pivot is set so that the stroke rate B/A is made constant or decreases as the discharge capacity decreases within the small discharge capacity range.
3. The compressor according to claim 1 , wherein
the link is configured so that the first pivot is arranged nearer to the journal than the second pivot and the second pivot is arranged nearer to the rotor than the first pivot.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2007315978A JP2009138629A (en) | 2007-12-06 | 2007-12-06 | Variable capacity compressor |
JP2007-315978 | 2007-12-06 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20090148313A1 true US20090148313A1 (en) | 2009-06-11 |
Family
ID=40379662
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/326,503 Abandoned US20090148313A1 (en) | 2007-12-06 | 2008-12-02 | Variable capacity compressor |
Country Status (5)
Country | Link |
---|---|
US (1) | US20090148313A1 (en) |
EP (1) | EP2067993A2 (en) |
JP (1) | JP2009138629A (en) |
KR (1) | KR20090060180A (en) |
CN (1) | CN101451517A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110038739A1 (en) * | 2009-08-17 | 2011-02-17 | Delphi Technologies, Inc. | Variable stroke compressor design |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6013768B2 (en) * | 2012-04-25 | 2016-10-25 | サンデンホールディングス株式会社 | Variable capacity compressor and manufacturing method thereof |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4112826A (en) * | 1977-05-02 | 1978-09-12 | General Motors Corporation | Variable displacement reciprocating piston machine |
US20070220859A1 (en) * | 2004-04-12 | 2007-09-27 | Calsonic Kansei Corporation | Link Mechanism and Variable Displacement Compressor |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002147345A (en) * | 2000-11-13 | 2002-05-22 | Seiko Instruments Inc | Variable displacement swash plate type compressor |
JP4649230B2 (en) * | 2005-02-24 | 2011-03-09 | カルソニックカンセイ株式会社 | Link mechanism and variable capacity compressor |
-
2007
- 2007-12-06 JP JP2007315978A patent/JP2009138629A/en active Pending
-
2008
- 2008-11-25 CN CNA2008101790365A patent/CN101451517A/en active Pending
- 2008-12-02 US US12/326,503 patent/US20090148313A1/en not_active Abandoned
- 2008-12-03 EP EP08021005A patent/EP2067993A2/en not_active Withdrawn
- 2008-12-05 KR KR1020080122829A patent/KR20090060180A/en not_active Application Discontinuation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4112826A (en) * | 1977-05-02 | 1978-09-12 | General Motors Corporation | Variable displacement reciprocating piston machine |
US20070220859A1 (en) * | 2004-04-12 | 2007-09-27 | Calsonic Kansei Corporation | Link Mechanism and Variable Displacement Compressor |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110038739A1 (en) * | 2009-08-17 | 2011-02-17 | Delphi Technologies, Inc. | Variable stroke compressor design |
US8196506B2 (en) * | 2009-08-17 | 2012-06-12 | Delphi Technologies, Inc. | Variable stroke compressor design |
Also Published As
Publication number | Publication date |
---|---|
KR20090060180A (en) | 2009-06-11 |
EP2067993A2 (en) | 2009-06-10 |
CN101451517A (en) | 2009-06-10 |
JP2009138629A (en) | 2009-06-25 |
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AS | Assignment |
Owner name: CALSONIC KANSEI CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MIYAJI, TOSHIKATSU;REEL/FRAME:021922/0693 Effective date: 20081031 |
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STCB | Information on status: application discontinuation |
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