Swash plate type compressor

• US 5,478,212 A
• Filed: 09/30/1994
• Issued: 12/26/1995
• Est. Priority Date: 03/04/1992
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation), Nippon Soken, Inc. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation), Nippon Soken, Inc. (DENSO Corporation)
• Inventors: Nakashima, Masafumi, Sakai, Takeshi, Inagaki, Mitsuo, Saiki, Manabu
• Primary Examiner(s): Thorpe, Timothy S.
• Assistant Examiner(s): Korytnyk, Peter G.
• Application Number:
  US08/316,032
• Time in Patent Office: 452 Days
• Field of Search: 417/269, 417/222.1, 417/222.2, 417/270, 91/499
• US Class Current: 417/269
• CPC Class Codes: F04B 27/1018 Cylindrical distribution members
• CPC Class Codes: F04B 39/08 Actuation of distribution members
• CPC Class Codes: F04B 49/225 with throttling valves or valves varying the pump inlet opening or the outlet opening
• CPC Class Codes: F05C 2253/12 Coating

Abstract

A swash plate type variable capacity compressor having rotary valves that rotate together on a rotating shaft. The rotary valves are arranged on the shaft in such a manner that, upon one complete rotation, the rotary valves are connected, in sequential manner, for respective rotating angles, with circumferentially spaced piston chambers via respective intake passageways on the rotary valves. The arrangement between the intake passageways and the piston chamber changes in accordance with the axial position of the rotary valves on the shaft. Control of the rotating angle varies the effective volume of the piston chambers, thereby continuously varying the compressor capacity.

Claims

1. A variable capacity swash plate type compressor comprising:

a rotating shaft adapted for connection to a source of a rotating movement;

a cylinder block rotatably connected to said rotating shaft, said cylinder block forming a plurality of circumferentially spaced cylinder bores each extending parallel to an axis of said rotating shaft;

a plurality of double headed pistons axially and slidably stored in respective ones of said plurality of circumferentially spaced cylinder bores, each of said plurality of double headed pistons forming on sides thereof axially spaced first and second piston chambers;

a swash plate fixedly connected to said rotating shaft and connected to said plurality of double headed pistons to obtain an axial reciprocal movement of each of said plurality of double headed pistons upon rotation of said rotating shaft;

each of said first and second piston chambers having a volume which alternately increases and decreases upon said axial reciprocal movement of a corresponding one of said plurality of double headed pistons;

said cylinder block forming therein an intake pressure chamber that is connected to a source of a medium to be compressed, and forming therein axially spaced first and second outlet pressure chambers for removing said medium as compressed;

intake means for controlling an introduction of said medium from said intake pressure chamber to said first and second piston chambers; and

discharge means for controlling a discharge of said medium from said first and second piston chambers to said first and second outlet pressure chambers;

said intake means comprising;

axially spaced first and second rotary valves, said first rotary valve being axially slidable with respect to said rotating shaft while rotating together with said rotating shaft, and said second rotary valve always being at a fixed position of said rotating shaft, and

axial position control means for controlling an axial position of said first rotary valve on said rotating shaft;

said first and second rotary valves providing successive control of a communication between said intake pressure chamber and said first and second piston chambers, respectively, at a respective range of a rotating angle within one complete rotation of said first and second rotary valves, said rotating angle of said first rotary valve varying in accordance with said axial position of said first rotary valve as controlled by said axial position control means; and

valve means, responsive to axial movement of said first rotary valve, for selectively controlling an introduction of said medium to said second piston chamber, so that a capacity of said compressor changes between a first mode wherein said medium to be compressed is only introduced to said first piston chamber, and a second mode wherein said medium to be compressed is introduced to said first and second piston chambers.

2. A compressor according to claim 1, wherein said valve means is movable together with said axial movement of said first rotary valve, and selectively controls said introduction of said medium to said second piston chamber.

3. A compressor according to claim 1, wherein said valve means is stationary with respect to said cylinder block, creating a relative axial movement between said valve means and said first rotary valve.

4. A compressor according to claim 3, wherein said valve means comprises:

a valve member having a valve portion which cooperates with said first rotary valve and a fixed portion in face to face contact with said rotating shaft, and

fixed connecting means for fixedly connecting said fixed portion of said valve member with said rotating shaft while allowing said medium to be introduced to said second piston chamber.

5. A compressor according to claim 4, wherein said fixed connecting means comprises a spring arranged between said fixed portion of said valve member and said first rotary valve.

6. A compressor according to claim 3, wherein said valve means further comprises means for controlling an amount of said medium introduced to said second piston chamber in accordance with said relative axial movement between said valve means and said first rotary valve.

7. A compressor according to claim 1, further comprising a pair of axially spaced apart slide bearings having a sleeve shape to rotatably support said rotating shaft to said cylinder block, said pair of axially spaced apart slide bearings including respective openings for allowing said introduction of said medium to said first and second piston chambers, respectively.

8. A compressor according to claim 1, wherein said first and second rotary valves are made from materials having different coefficients of thermal expansion such that a first coefficient of thermal expansion of said first and second rotary valves is larger than a second coefficient of thermal expansion of respective valve cylinders so as to prevent, during a normal operation, an outer diameter of said first and second rotary valves from exceeding an inner diameter of said respective valve cylinders.

9. A variable capacity swash plate type compressor comprising:

a rotating shaft adapted for connection to a source of a rotating movement;

a cylinder block rotatably connected to said rotating shaft, said cylinder block forming a plurality of circumferentially spaced cylinder bores each extending parallel to an axis of said rotating shaft;

a plurality of pistons axially and slidably stored in the respective ones of said plurality of circumferentially spaced cylinder bores and forming a respective piston chamber on a respective side of each of said plurality of pistons;

a swash plate fixedly connected to said rotating shaft and connected to said plurality of pistons to obtain an axial reciprocal movement of each of said plurality of pistons upon rotation of said rotating shaft;

each of said respective piston chambers having a volume which alternately increases and decreases upon said axial reciprocal movement of a corresponding one of said plurality of pistons;

said cylinder block forming therein an intake pressure chamber that is connected to a source of a medium to be compressed, and forming therein an outlet pressure chamber for removing said medium as compressed;

intake means for controlling an introduction of said medium from said intake pressure chamber to said piston chambers, said intake means comprising a rotary valve that is rotatable with said rotating shaft; and

discharge means for controlling a discharge of said medium from said piston chambers to said outlet pressure chamber;

said rotary valve and a valve cylinder for said rotary valve being made from materials having different coefficients of thermal expansion, such that a first coefficient of thermal expansion of said rotary valve is larger than a second coefficient of thermal expansion of said valve cylinder so as to prevent, during a normal operation, an outer diameter of said rotary valve from exceeding an inner diameter of said valve cylinder.

10. A compressor according to claim 9, wherein:

said valve cylinder is made of an aluminum based alloy material; and

said rotary valve is made of a plastic material.

11. A compressor according to claim 10, wherein a clearance between said rotary valve and said valve cylinder is in a range equal to or larger than 15 μ

m and smaller than 30 μ

m.

12. A compressor according to claim 9, wherein said intake means comprises:

a rotary valve that is axially slidable with respect to said rotating shaft while rotating together with said rotating shaft; and

axial position control means for controlling an axial position of said rotary valve on said rotating shaft;

said rotary valve providing successive control of a communication between said intake pressure chamber and said piston chambers at a respective range of a rotating angle within one complete rotation of said rotary valve, said rotating angle being controlled in accordance with said axial position of said rotary valve as controlled by said axial position control means.

13. A variable capacity swash plate type compressor comprising:

a rotating shaft adapted for connection to a source of a rotating movement;

a cylinder block rotatably connected to said rotating shaft, said cylinder block forming a plurality of circumferentially spaced cylinder bores each extending parallel to an axis of said rotating shaft;

a plurality of pistons axially and slidably stored in respective ones of said plurality of circumferentially spaced cylinder bores forming a respective piston chamber on respective sides of said plurality of pistons;

a swash plate fixedly connected to said rotating shaft and connected to said plurality of pistons to obtain an axial reciprocal movement of each of said plurality of pistons upon rotation of said rotating shaft;

each of said piston chambers having a volume which alternately increases and decreases upon said axial reciprocal movement of a corresponding one of said plurality of pistons;

said cylinder block forming therein an intake pressure chamber that is connected to a source of a medium to be compressed, and forming therein an outlet pressure chamber for removing said medium as compressed;

intake means for controlling an introduction of said medium from said intake pressure chamber to said piston chambers; and

discharge means for controlling a discharge of said medium from said piston chambers to said outlet pressure chamber;

said intake means comprising;

a rotary valve that is axially slidable with respect to said rotating shaft while rotating together with said rotating shaft, and

axial position control means for controlling an axial position of said rotary valve on said rotating shaft;

said rotary valve providing successive control of a communication between said intake pressure chamber and said piston chambers at a respective range of a rotating angle within one complete rotation of said rotary valve, said rotating angle being controlled in accordance with said axial position of said rotary valve as controlled by said axial position control means, and

said rotary valve and a valve cylinder for said rotary valve being made from materials having different coefficients of thermal expansion such that a first coefficient of thermal expansion of said rotary valve is larger than a second coefficient of thermal expansion of said valve cylinder so as to prevent, during a normal operation, an outer diameter of said rotary valve from exceeding an inner diameter of said valve cylinder.