EP0857872A2 - Compresseur à plateau en biais à capacité variable - Google Patents

Compresseur à plateau en biais à capacité variable Download PDF

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Publication number
EP0857872A2
EP0857872A2 EP98102453A EP98102453A EP0857872A2 EP 0857872 A2 EP0857872 A2 EP 0857872A2 EP 98102453 A EP98102453 A EP 98102453A EP 98102453 A EP98102453 A EP 98102453A EP 0857872 A2 EP0857872 A2 EP 0857872A2
Authority
EP
European Patent Office
Prior art keywords
chamber
cylinder
pressure
plate
crank chamber
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.)
Withdrawn
Application number
EP98102453A
Other languages
German (de)
English (en)
Other versions
EP0857872A3 (fr
Inventor
Masaaki Fujita
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sanden Corp
Original Assignee
Sanden Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sanden Corp filed Critical Sanden Corp
Publication of EP0857872A2 publication Critical patent/EP0857872A2/fr
Publication of EP0857872A3 publication Critical patent/EP0857872A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • 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
    • F04B27/1804—Controlled by crankcase pressure
    • 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
    • F04B27/1804—Controlled by crankcase pressure
    • F04B2027/184—Valve controlling parameter
    • F04B2027/1845—Crankcase pressure

Definitions

  • This invention relates to a variable-displacement swash-plate compressor typically used in an automotive air conditioner to compress a refrigerant gas and, in particular, to a crank chamber pressure control system in such a variable-displacement swash-plate compressor.
  • a conventional variable-displacement swash-plate compressor (hereinafter simply referred to as a compressor) comprises a cylinder housing having a crank chamber and a plurality of cylinder bores. A plurality of pistons are slidably fitted into the cylinder bores, respectively.
  • a piston drive mechanism is disposed in the crank chamber and comprises a drive shaft, a swash plate coupled to the drive shaft with a variable slant angle to be rotatable together with the drive shaft.
  • a motion converting mechanism is coupled between the swash plate and the pistons for converting a rotary motion of the swash plate into a linear reciprocating motion of each of the pistons.
  • a cylinder head is mounted on the cylinder housing and has a suction chamber selectively communicating with the cylinder bores for introducing a fluid to be compressed into the each of the cylinder bores and a discharge chamber selectively communicating with the cylinder bores for allowing the fluid compressed within the cylinder bores to discharge thereinto.
  • the compressor has a crank chamber pressure control system for controlling an inner pressure of the crank chamber to control the slant angle of the swash plate to thereby control a fluid displacement volume of the compressor.
  • the crank chamber pressure control system comprises a pressure detecting chamber formed in the cylinder head and communicating with the crank chamber through a communicating path, and a pressure detector disposed in the pressure detecting chamber for detecting the inner pressure of the crank chamber.
  • JP-A-4 183980 discloses such a variable-displacement swash-plate compressor wherein the crank pressure detecting chamber contains a fluid flow control valve therein and is also connected with the suction chamber through a connecting hole.
  • the fluid flow control valve detects a pressure difference between the crank chamber pressure through the communicating path and a suction pressure through the connecting hole.
  • the fluid flow control valve opens to allow the fluid from the crank chamber into the suction chamber when the pressure difference exceeds a predetermined threshold level.
  • the fluid flow control valve is described to be provided with a threshold level adjusting mechanism including an electric solenoid. The threshold level is adjusted by controlling a level of a current flowing through the solenoid.
  • crank chamber detector detects a threshold value of the crank chamber pressure
  • the cylinder block In order to form the communication path between the crank chamber in the cylinder housing and the pressure detecting chamber in the cylinder block, the cylinder block is machined to form a hollow space connecting with the crank chamber, while the cylinder head is also machined to form a small hole to extend to the pressure detecting chamber.
  • the hollow space and the small hole must accurately be interconnected to each other without fluid leakage when the cylinder head is assembled and mounted onto the cylinder housing.
  • the machining of the cylinder housing and the cylinder head for forming the hollow space and the small hole is complicated and is difficult. This is a cause of a high cost of the compressor.
  • a variable-displacement swash-plate compressor comprising a cylinder housing having a plurality of cylinder bores and a crank chamber in which a swash plate is disposed and coupled to a drive shaft with a variable slant angle to be rotated together, a motion converting mechanism coupling between the swash plate and pistons slidably fitted into the cylinder bores for converting a rotary motion of the swash plate into a linear reciprocating motion to reciprocatingly drive the pistons within the cylinder bores, a cylinder head mounted on the cylinder housing and having a suction chamber and a discharge chamber selectively connected to the cylinder bores, and a crank chamber pressure control system for controlling an inner pressure of the crank chamber to control the slant angle of the swash plate to thereby control a fluid displacement volume of the compressor, the crank chamber pressure control system comprising a pressure detecting chamber formed in the cylinder head and communicating with the crank chamber through a communicating path, and a pressure detector disposed
  • variable-displacement swash-plate compressor hereinafter simply referred to as a compressor
  • the compressor comprises a cylinder housing 100 having a cylinder block 101 and a front housing 102 coupled to the cylinder block 101 to close one open end of the cylinder block 101, and a rear housing or cylinder head 131 coupled to the cylinder housing 100 via a valve plate 130 to close the other open end of the cylinder block 101.
  • a drive shaft 109 is inserted in the cylinder housing 100 on its center axis and extending in an axial direction.
  • a swash plate 113 is attached to the drive shaft 109.
  • the cylinder block 101, the front housing 102, and the rear housing 131 are integrally coupled by a plurality of bolts 129 (only one bolt being illustrated in Fig. 1).
  • the front housing 102 has a generally funnel-shaped section.
  • the front housing 102 has a cylindrical protruding portion 102a protruding outwards from its center, and an axial first through-hole 102b extending through the protruding portion 102a in the axial direction.
  • the drive shaft 109 is inserted via a shaft seal member 106.
  • the drive shaft 109 is also inserted into a second through-hole 105 formed in the front housing 102 on its center axis and continuous from the first through-hole 102b in the axial direction.
  • the drive shaft 109 is supported by a first bearing 107 arranged in the second through-hole 105.
  • the other end of the drive shaft 109 is inserted into a third through-hole 126 formed in the cylinder block 101 on its center axis and is supported by a second bearing 128 arranged in the third through-hole 126.
  • the front housing 102 and the cylinder block 101 define a space which serves as a crank chamber 110.
  • An intermediate portion of the drive shaft 119 is located within the crank chamber 110.
  • a disk-shaped rotor 111 is fixed on an outer periphery of the drive shaft 109 at the side of the front housing 102.
  • the rotor 111 has a pair of rotor arms 111a protruding in a radial direction, or upwards in the figure.
  • the swash plate 113 is attached to the rotor 111 through a hinge mechanism 112.
  • the hinge mechanism 112 is formed by a combination of the rotor arms 111a and swash plate arms 113a of the swash plate 113 which are coupled to the rotor arms 113a via pins 111b.
  • a boss 120 is formed at the center of the swash plate 113.
  • the boss 120 has an aperture 114 formed on its center axis.
  • the drive shaft 109 extends through the apperture 114.
  • the swash plate 113 is rendered variable in its inclination angle or a slant angle with respect to the drive shaft 109.
  • a swing plate or a wobbling plate 116 as a motion converting mechanism is slidably attached through a thrust and radial bearings 117 and 118.
  • a spherical portion 115a at one end of each of a plurality of piston rods 115 is slidably coupled by a ball joint mechanism.
  • each piston rod 115 has an outer surface of a convex spherical shape and is slidably received in each of a plurality of spherical recesses 116a formed in the swing plate 116 substantially in conformity with the convex spherical shape of the spherical portion 115a.
  • a balance ring 121 of an annular shape is attached to the boss 120 located at the center of the swash plate 113.
  • the balance ring 121 performs rotary motion together with the swash plate 113.
  • the swing plate 116 is clamped between the swash plate 113 and the balance ring 121.
  • a guide bar 124 is arranged in a lower portion of the crank chamber 110 in parallel to the drive shaft 109.
  • the guide bar 124 has one end and the other end supported by the front housing 102 and the cylinder block 101, respectively.
  • the guide bar 124 is clamped by a pair of clamping portions 125 of the swing plate 116.
  • the swing plate 116 is prevented from rotation (around itself) and performs swinging or wobbling motion alone.
  • a plurality of cylinder bores 122 are formed at an equiangular interval around the drive shaft 109.
  • a plurality of pistons 123 are received in one-to-one correspondence to be slidable and linearly reciprocable in the axial direction.
  • the pistons 123 are coupled to the piston rods 115 in one-to-one correspondence. Specifically, each piston 123 is coupled to a spherical portion 115b formed at the other end of the piston rod 115 by a ball joint mechanism.
  • the rear housing 131 coupled to the cylinder housing 100 via the valve plate 130 has a suction chamber (first pressure chamber) 132 and a discharge chamber (second pressure chamber) 133 separated by a first partition wall 131a also illustrated in Fig. 2.
  • the valve plate 130 has a suction port 134 and a discharge port 135.
  • the rear housing 131 further has a third pressure chamber 140 as a pressure detecting chamber separated from the suction chamber 132 and the discharge chamber 133 by a second partition wall 131d.
  • the third pressure chamber 140 is connected with the suction chamber 132 through a hole formed in the partition therebetween.
  • a volume control valve with a bellows valve 142 is accommodated in the third pressure chamber 140.
  • the bellows valve 142 is disposed in a lower portion of the third pressure chamber 140 with an upper portion thereof being a space for containing a fluid flow control valve described in the preamble.
  • the third pressure chamber 140 is also communicated with the crank chamber 110 through a communicating path 156, so that the bellows valve 142 detects a pressure difference between the crank chamber pressure and the suction pressure. When the pressure difference exceeds a predetermined level, the bellows valve 142 opens to allow a fluid to flow from the crank chamber to the suction chamber to control the crank chamber pressure.
  • the slant angle of the swash plate 113 and the swing plate 116 is varied to change reciprocating strokes of pistons, so that fluid compression capacity is changed.
  • the compressor has a communicating member 155 providing the communicating path 156.
  • the communicating member 155 has an axial through-hole penetrating therethrough for the communicating path 156 and is formed as a part assembled into the compressor.
  • the communicating member 155 is disposed to bridge across the cylinder block 101 and the rear housing 131, specifically, pressure regions I and II in the crank chamber 110 and the interior of the rear housing 131.
  • the pressure region I is the crank chamber 110 and the other pressure region II is a rear cavity 145 in the third through-hole 126 supporting the drive shaft 109.
  • the pressure region II is communicated with the crank chamber 110 through a clearance formed in the bearing 128 supporting the drive shaft 109.
  • the communicating member 155 has a bolt-like shape and a head portion formed at its one end and located in the pressure region cavity 145 and an extending portion extending through the valve plate 130 and then through the discharge chamber 133.
  • the extending portion is formed or threaded on its outer surface.
  • the other end of the communicating member 155 is fitted to the second partition wall 131d separating the third pressure chamber 140 where the volume control valve 142 is accommodated.
  • the communicating member 155 serves to establish communication between the pressure regions I and II of the crank chamber 110 and the third pressure chamber 140 of the rear housing 131.
  • the second partition wall 131d separating the third pressure chamber 140 and the discharge chamber 133 is provided with a fluid communication hole 131c for connecting third pressure chamber 140 and the communicating path 156 of the communicating member 155.
  • the communicating member 155 holds a retainer 160 supported by a nut 161 and pressed against the valve plate 130 within the discharge chamber 133.
  • the valve plate 130 and the retainer 160 are clamped between the head portion of the communicating member 155 and the nut 161 engaged with the threaded portion of the communicating member 155.
  • the valve plate 130 has suction valves (not shown) for controlling open and close of the suction ports 134 and discharge valves (not shown) for controlling open and close of the discharge ports 135.
  • the retainer 160 is for retaining the discharge valves so as to suppressing the valves from over-deformation.
  • the other end of the communicating member 155 is fitted in the second partition wall 131d of the third pressure cahmber 140. Specifically, the other end of the communicating member 155 is fitted into a recess 131b formed in the second partition wall 131d with a seal member 163 interposed between an outer peripheral surface of the other end of the communicating member 155 and an inner peripheral surface of the recess 131b.
  • the other end of the communicating member 155 may be brought into tight contact with the second partition wall 131d of the third pressure chamber 140 and sealed by a seal member.
  • crank chamber pressure control mechanism comprising the third pressure chamber 140, the pressure detector 142 therein, and the communicating member 155, it is possible to control the crank chamber pressure to thereby control the volume of the discharge gas in dependence upon thermal load inside and outside the car, an air-conditioning mode, a car speed, and the like.
  • a control valve in a fluid flow from the discharge chamber to the crank chamber through another communicating hole connecting therebetween upon detection of the pressure difference by the pressure detector (142) contained in the third pressure chamber 140.
  • the pressure detector which, in turn, controls the control valve to open so that the discharge gas is introduced into the crank chamber 110.
  • the internal pressure of the crank chamber 110 is increased to reduce the inclination angle of the swash plate 113. In this manner, the discharge volume is decreased.
  • variable-displacement swash-plate compressor (hereinafter simply referred to as a compressor) according to a second embodiment of this invention.
  • This compressor is similar to the compressor shown in Figs. 1 and 2 except a difference in the motion converting mechanism. Therefore, similar parts are designated by like reference numerals as those depicted in Figs. 1 and 2 and description thereto will be omitted for the purpose of simplification of the description.
  • a swash plate 213 is attached to the rotor 111 through a hinge mechanism 212.
  • the swash plate 213 is formed with a center aperture 214 through which the drive shaft 109 extends.
  • the hinge mechanism 212 By the hinge mechanism 212, the swash plate 213 is rendered variable in its inclination angle with respect to the drive shaft 109.
  • the swash plate 213 has an outer peripheral end 213c slidably inserted between a pair of shoes 265 as a motion converting mechanism.
  • the shoes 265 have an outer surface of a convex spherical shape and are slidabiy received in a recess 270 formed in a piston 223.
  • the recess 270 has a shape substantially in conformity with the convex spherical shape of the shoes 265.
  • the compressor according to the second embodiment is similar in operation to the first embodiment. Specifically, the bellows valve 142 in the third pressure chamber 140 detects a pressure difference between the crank chamber pressure and the suction pressure. Then, the crank chamber pressure is controlled in the similar manner as described in connection with the embodiment of Figs. 1 and 2. Thus, the slant angle of the swash plate 213 is controlled in response to the gas pressure in the crank chamber 110 and is moved leftwards and rightwards along the drive shaft 109 to be settled at a slant angle corresponding to the crank chamber pressure.
  • the compressor in each of the first and the second embodiments uses the single-headed piston
  • this invention is also applicable to a compressor of a double-headed piston type wherein the cylinder housing has two sets of cylinder bores disposed at opposite sides of the crank chamber, two sets of pistons being disposed at opposite sides of the swash plate and slidably fitted into corresponding ones of the cylinder bores, and two sets of cylinder heads mounted on opposite ends of the cylinder housing, respectively.
  • the third pressure chamber and the crank chamber are made to communicate with each other via the communicating path in the communicating member.
  • the gas passage of an essential and sufficient length can be assured between the third pressure chamber and the crank chamber.
  • the above-mentioned structure requires less complicated mechanical machining of the cylinder block and the cylinder head for forming the gas passage and less strict accuracy of the machining.
  • the compressor can be compact in size and easy in manufacture. It is noted here that the communicating member can be easily assembled and positioned at its location because it is threaded and engaged with a nut in the compressor.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
EP98102453A 1997-02-12 1998-02-12 Compresseur à plateau en biais à capacité variable Withdrawn EP0857872A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP9027522A JPH10220351A (ja) 1997-02-12 1997-02-12 可変容量斜板式圧縮機
JP27522/97 1997-02-12

Publications (2)

Publication Number Publication Date
EP0857872A2 true EP0857872A2 (fr) 1998-08-12
EP0857872A3 EP0857872A3 (fr) 1999-01-13

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Family Applications (1)

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EP98102453A Withdrawn EP0857872A3 (fr) 1997-02-12 1998-02-12 Compresseur à plateau en biais à capacité variable

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EP (1) EP0857872A3 (fr)
JP (1) JPH10220351A (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4073603A (en) * 1976-02-06 1978-02-14 Borg-Warner Corporation Variable displacement compressor
US4848101A (en) * 1986-03-19 1989-07-18 Diesel Kiki Co., Ltd. Method and system for controlling capacity of variable capacity wobble plate compressor
EP0486257A1 (fr) * 1990-11-16 1992-05-20 Sanden Corporation Compresseur à plateau en biais avec mécanisme de contrôle de capacité
EP0498552A1 (fr) * 1991-01-28 1992-08-12 Sanden Corporation Compresseur à plateau en biais avec mécanisme à déplacement variable

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4073603A (en) * 1976-02-06 1978-02-14 Borg-Warner Corporation Variable displacement compressor
US4848101A (en) * 1986-03-19 1989-07-18 Diesel Kiki Co., Ltd. Method and system for controlling capacity of variable capacity wobble plate compressor
EP0486257A1 (fr) * 1990-11-16 1992-05-20 Sanden Corporation Compresseur à plateau en biais avec mécanisme de contrôle de capacité
EP0498552A1 (fr) * 1991-01-28 1992-08-12 Sanden Corporation Compresseur à plateau en biais avec mécanisme à déplacement variable

Also Published As

Publication number Publication date
EP0857872A3 (fr) 1999-01-13
JPH10220351A (ja) 1998-08-18

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