EP1491769B1 - A device having a pulsation reducing structure and a passage forming body - Google Patents
A device having a pulsation reducing structure and a passage forming body Download PDFInfo
- Publication number
- EP1491769B1 EP1491769B1 EP04014847A EP04014847A EP1491769B1 EP 1491769 B1 EP1491769 B1 EP 1491769B1 EP 04014847 A EP04014847 A EP 04014847A EP 04014847 A EP04014847 A EP 04014847A EP 1491769 B1 EP1491769 B1 EP 1491769B1
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- EP
- European Patent Office
- Prior art keywords
- passage
- gas
- restricting
- combined
- compressor
- 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.)
- Expired - Fee Related
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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
- 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
- F04C29/06—Silencing
- F04C29/068—Silencing the silencing means being arranged inside the pump housing
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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
- F04B27/1081—Casings, housings
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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
- F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
- F04B39/0027—Pulsation and noise damping means
- F04B39/0055—Pulsation and noise damping means with a special shape of fluid passage, e.g. bends, throttles, diameter changes, pipes
Definitions
- the present invention relates to a device having a pulsation reducing structure.
- the present invention also pertains to a passage forming body and a compressor.
- Document EP-A-1 270 947 discloses a scroll compressor comprising a gas passage, a pulsation source connected to the gas passage, a muffler for reducing the pulsation whereby a combined passage is located in the gas passage, the combined passage including a restricting passage and a pressure restoring passage which are connected in series.
- Document EP-A-0 940 581 discloses a variable displacement compressor having cylinder bores and a crankcase which are formed in a housing, single-ended pistons fitted in the cylinder bores, and a cam plate provided in the crankcase, and the displacement capacity of the compressor is varied by controlling the angle of inclination of the cam plate in accordance with a difference between the internal pressure of the crankcase and a suction pressure present on both sides of each single-ended piston.
- a damping or muffler chamber is provided downstream of an output channel through which a refrigerant gas discharged from the cylinder bores passes.
- a check valve which opens and closes in accordance with a pressure difference between upstream and downstream sides of the output channel is provided in the output channel, upstream of the sound-deadening chamber. The device reduces the effects of pressure pulsations caused by the compression motion of the compressor and caused by the valve body of the open/close device hunting, has no bad effects on the external refrigerant circuit connected to the compressor, and increases the reliability of the lip
- EP-A-1 270 945 discloses a swash plate type compressor used for the air conditioner of an automobile, and more particularly, a compressor having a structure where pulsation pressure caused during refrigerants are compressed and discharged is reduced, thereby permitting the noise at the time of driving to be substantially reduced.
- the compressor according to the present invention can embody the structure by distributing and discharging refrigerant that has been compressed by a plurality of pistons and discharged from a plurality of bores into at least two discharge holes, wherein a frequency of the pulsation pressure is increased in proportion to the number of the discharge holes but a strength of the pulsation pressure is decreased in inverse proportion to the number of the discharge holes. Therefore, the driving noise of the compressor that is formed in proportion to the strength of the pulsation pressure is considerably decreased.
- an oil separator is located in a front housing member.
- An oil separating chamber which forms part of the oil separator, is connected to a discharge chamber defined at the back of a fixed scroll.
- the oil separating chamber accommodates a cylindrical member, which forms part of the oil separator.
- Refrigerant gas in the discharge chamber is introduced into the oil separating chamber.
- Lubricant oil included in the refrigerant gas introduced into the oil separating chamber is separated from the refrigerant gas.
- the cylindrical member which forms part of the oil separator, also functions to reduce pulsation of discharged gas.
- the inner diameter of the cylindrical member needs to be reduced to obtain sufficient pulsation reducing effect.
- the inner diameter of the cylindrical member is excessively reduced, a great pressure loss is generated. Therefore, it is difficult to reduce the inner diameter of the cylindrical member to obtain sufficient pulsation reducing effect.
- the present invention provides a device having a pulsation reducing structure that obtains sufficient pulsation reducing effect and suppresses pressure loss in devices having a gas passage.
- the present invention also pertains to a passage forming body and a compressor.
- the present invention provides a device having a pulsation reducing structure.
- the device includes a gas passage, a pulsation source connected to the gas passage, a muffler for reducing the pulsation and a combined passage located in the gas passage. Pulsation of gas spreads from the pulsation source to the gas passage.
- the muffler is located in a part of the gas passage.
- the combined passage is located upstream or downstream of the muffler with respect to a flowing direction of gas.
- the combined passage includes a restricting passage and a pressure restoring passage.
- the restricting passage and the pressure restoring passage are connected in series.
- the pressure restoring passage is located downstream of the restricting passage with respect to the flowing direction of gas and its cross-sectional area is gradually increased in the flowing direction of gas.
- the muffler is located between the pulsation source and the combined passage in the gas passage.
- a passage forming body having a plurality of combined passages is provided.
- the combined passages are arranged in parallel.
- Each combined passage includes a restricting passage and a pressure restoring passage.
- the restricting passage is combined with the pressure restoring passage in series and the cross-sectional area of pressure restoring passage is gradually increased in the flowing direction of gas.
- present invention may be applicable to provide a scroll compressor.
- the compressor includes a compression mechanism including a movable scroll and a fixed scroll, the scrolls defining a compression chamber, a discharge chamber for receiving gas discharged from the compression chamber, a discharge gas passage for guiding discharge gas from the discharge chamber to the outside of the compressor.
- a restricting passage is located in the discharge gas passage.
- a pressure restoring passage is located in the discharge gas passage. The pressure restoring passage is connected to the restricting passage in series and located downstream of the restricting passage with respect to a flowing direction of gas.
- a scroll compressor 10 includes a rear housing member 12 and a front housing member 31.
- a shaft support member 13 and a fixed scroll 11 are inserted in and fixed to the rear housing member 12.
- the front housing member 31 is secured to the rear housing member 12 and the fixed scroll 11.
- the rear housing member 12 and the front housing member 31 form a housing of a device, which is the scroll compressor 10.
- the rear housing member 12 and the shaft support member 13 rotatably support a rotary shaft 14 by means of radial bearings 15, 16.
- the rotary shaft 14 extends through the shaft support member 13 and projects toward the fixed scroll 11.
- An eccentric shaft 17 is formed integrally with the end of the rotary shaft 14 that projects from the shaft support member 13.
- the axis of the eccentric shaft 17 located at a position decentered from the axis of the rotary shaft 14.
- the eccentric shaft 17 supports a bush 18 to which a balance weight 19 is integrally formed.
- the bush 18 supports a movable scroll 20 by means of a radial bearing 21 such that the movable scroll 20 faces the fixed scroll 11.
- the movable scroll 20 rotates relative to the fixed scroll 11.
- the radial bearing 21 is accommodated in a cylindrical portion 221, which projects from the rear surface of a movable scroll base plate 22 of the movable scroll 20.
- the fixed scroll 11 includes a fixed scroll base plate 23 and a fixed volute portion 24.
- the movable scroll 20 includes the movable scroll base plate 22 and a movable volute portion 25.
- the fixed scroll base plate 23, the fixed volute portion 24, the movable scroll base plate 22, and the movable volute portion 25 define sealed spaces S0 and S1.
- the movable scroll 20 orbits as the eccentric shaft 17 rotates. Centrifugal force created by the orbital movement of the movable scroll 20 is cancelled by the balance weight 19.
- Columnar anti-rotation pins 27 (three or more) are fixed to the movable scroll base plate 22.
- the shaft support member 13 has circular anti-rotation bores 131, the number of which is the same as the anti-rotation pins 27.
- the anti-rotation bores 131 are arranged in the circumferential direction of the shaft support member 13. The end of each anti-rotation pin 27 is inserted in the corresponding anti-rotation bore 131.
- a stator 29 is secured to the inner circumferential surface of the rear housing member 12.
- a rotor 30 is secured to the rotary shaft 14. When electricity is supplied to a stator coil 291 of the stator 29, the rotor 30 and the rotary shaft 14 rotate integrally.
- the stator 29 and the rotor 30 construct an electric motor.
- the movable scroll 20 orbits as the eccentric shaft 17 rotates integrally with the rotary shaft 14.
- An inlet 26 is formed in a circumferential wall of the rear housing member 12 and a circumferential wall 111 of the fixed scroll 11.
- refrigerant gas in an external refrigerant circuit which is not shown, is introduced into a suction chamber 112 inside the circumferential wall 111 through the inlet 26.
- the refrigerant gas introduced into the suction chamber 112 flows into the sealed spaces S0, S1 between the fixed scroll base plate 23 and the movable scroll base plate 22 from the periphery of the fixed scroll 11 and the movable scroll 20.
- Lubricant oil is included in a refrigeration circuit, which includes the compressor 10, and flows with refrigerant gas.
- each anti-rotation pin 27 slides along the circumferential surface of the corresponding anti-rotation bore 131.
- the movable scroll 20 is prevented from rotating while being permitted to orbit.
- the sealed spaces S1, S0 move toward the center of the scrolls 11, 20, while the volume of each sealed space S1, S0 decreasing.
- a discharge chamber 32 is formed in the front housing member 31.
- the refrigerant gas compressed by the decrease in the volume of the sealed spaces S1, S0 is discharged to the discharge chamber 32 through a discharge port 231, which is formed in the fixed scroll base plate 23, while flexing a discharge valve flap 33.
- a retainer 34 limits the opening degree of the discharge valve flap 33.
- a compression reaction force in the sealed spaces S1, S0 that acts on the movable scroll 20 is received by the shaft support member 13.
- An outlet 311 is formed in the circumferential wall of the front housing member 31.
- a pipe 35 is fitted to the outlet 311. That is, the pipe 35 is formed separately from the front housing member 31, which defines the discharge chamber 32 and the outlet 311.
- the pipe 35 includes a fitting portion 351, a restrictor 38, and a diffuser 39.
- the restrictor 38, the diffuser 39, and the fitting portion 351 are arranged in series in this order along a flowing direction of refrigerant gas from the discharge chamber 32 to the outside of the compressor 10 via the outlet 311.
- a restricting passage 381 in the restrictor 38 and a pressure restoring passage 391 in the diffuser 39 are connected in series in this order from the discharge chamber 32 toward the outside of the compressor 10.
- the cross-sectional area of the pressure restoring passage 391 is greater than the cross-sectional area of the restricting passage 381.
- the pipe 35 is fitted to the outlet 311 with the fitting portion 351.
- the inner diameter of the fitting portion 351 is greater than the inner diameter of the diffuser 39 and the restrictor 38.
- the inner diameter of the restrictor 38 is constant.
- the inner diameter of the diffuser 39 gradually increases from the end close to the restrictor 38 toward the end close to the fitting portion 351. That is, the pressure restoring passage 391 is widened in the flowing direction of refrigerant gas.
- the widening angle ⁇ 1 (see Fig. 1(b)) of the pressure restoring passage 391 of the diffuser 39 is less than or equal to 20 degrees.
- the refrigerant gas When refrigerant gas is discharged into the discharge chamber 32 through the discharge port 231 while flexing the discharge valve flap 33, the refrigerant gas collides with the inner wall of the front housing member 31, or the refrigerant gas changes the flowing direction and flows toward the pipe 35. Therefore, the lubricant oil included in the refrigerant gas is separated from the refrigerant gas. The lubricant oil separated from the refrigerant gas is stored at the bottom of the discharge chamber 32. The bottom of the discharge chamber 32 is connected to a back pressure chamber 37 located at the back of the movable scroll base plate 22 via a return passage 36.
- the lubricant oil stored at the bottom of the discharge chamber 32 is supplied to the back pressure chamber 37 through the return passage 36 and used to lubricate the radial bearings 16 and 21.
- Refrigerant gas in the discharge chamber 32 flows to the external refrigerant circuit through the pipe 35.
- the pipe 35 is suspended in the outlet 311 such that the lower end of the pipe 35 is separate from the inner wall of the front housing member 31 and projects in the discharge chamber 32. That is, part of the pipe 35 is located inside the discharge chamber 32.
- This structure effectively prevents lubricant oil adhered to the inner wall of the front housing member 31 from entering the pipe 35 by the operation of the refrigerant gas. That is, the pipe 35 functions as an oil separator, which separates lubricant oil from refrigerant gas.
- the discharge port 231 and the discharge chamber 32 are part of a gas passage in the compressor 10.
- the discharge chamber 32 functions as a muffler that is part of the gas passage.
- the restricting passage 381 in the restrictor 38 and the pressure restoring passage 391 in the diffuser 39 form a combined passage 40 located downstream of the muffler, which is the discharge chamber 32 in this embodiment, in respect to the gas passage.
- the pressure restoring passage 391, which forms part of the combined passage 40, is located downstream of the restricting passage 381.
- the fixed scroll 11, the movable scroll 20, and the sealed spaces S0, S1 form a pulsation source.
- the pulsation of discharge gas spreads from the pulsation source to the external refrigerant circuit via the discharge chamber 32 and the combined passage 40.
- the discharge chamber 32 (muffler) and the restricting passage 381 reduce the pulsation of discharge gas.
- the muffler which is the discharge chamber 32 in this embodiment, is located between the pulsation source and the combined passage 40 in respect to the gas passage.
- the first embodiment has the following advantages.
- a cylinder block 41, a front housing member 42, and a rear housing member 43 form a housing of a device, which is a piston type variable displacement compressor 44 in the second embodiment.
- the front housing member 42 and the cylinder block 41 define a control pressure chamber 421.
- the front housing member 42 and the cylinder block 41 rotatably support a rotary shaft 45.
- a rotary support 46 is fixed to the rotary shaft 45, and a swash plate 47 is supported on the rotary shaft 45.
- the swash plate 47 is permitted to incline with respect to and slide along the rotary shaft 45.
- Guide holes 461 are formed in the rotary support 46 and guide pins 48 are connected to the swash plate 47.
- Each guide pin 48 is fitted to one of the guide holes 461 to form a hinge mechanism.
- the hinge mechanism permits the swash plate 47 to tilt with respect to the axial direction of the rotary shaft 45 and rotate integrally with the rotary shaft 45.
- the rotary support 46 determines the maximum inclination of the swash plate 47.
- the swash plate 47 shown by a solid line in Fig. 2(a) is in the maximum inclination state.
- the swash plate 47 shown by a chain double-dashed line in Fig. 2(a) is in the minimum inclination state.
- Cylinder bores 411 extend through the cylinder block 41. Each cylinder bore 411 accommodates a piston 49. The rotation of the swash plate 47 is converted to reciprocation of the pistons 49 by means of shoes 50. Thus, each piston 49 reciprocates in the corresponding cylinder bore 411.
- a suction chamber 431 and a discharge chamber 432 are defined in the rear housing member 43.
- Suction ports 511 are formed in a valve plate 51 and a valve flap plate 53.
- Discharge ports 512 are formed in the valve plate 51 and a valve flap plate 52.
- Suction valve flaps 521 are formed on the valve flap plate 52, and discharge valve flaps 531 are formed on the valve flap plate 53.
- the discharge chamber 432 is connected to the control pressure chamber 421 with a supply passage 54.
- the control pressure chamber 421 is connected to the suction chamber 431 with a release passage 55. Refrigerant in the control pressure chamber 421 flows to the suction chamber 431 through the release passage 55.
- An electromagnetic control valve 56 is located in the supply passage 54.
- the control valve 56 is closed when de-excited and prevents refrigerant from passing through. In this state, refrigerant is not supplied from the discharge chamber 432 to the control pressure chamber 421 via the supply passage 54. Refrigerant in the control pressure chamber 421 flows to the suction chamber 431 through the release passage 55. Therefore, the pressure in the control pressure chamber 421 decreases. Therefore, the inclination angle of the swash plate 47 increases. The compressor displacement increases, accordingly.
- the control valve 56 is open when excited and permits refrigerant through. In this state, refrigerant is supplied from the discharge chamber 432 to the control pressure chamber 421 via the supply passage 54. Therefore, the pressure in the control pressure chamber 421 increases. Accordingly, the inclination angle of the swash plate 47 decreases, which decreases the compressor displacement.
- a muffler 57 is formed on the circumferential surface of the cylinder block 41 and the circumferential surface of the front housing member 42.
- the muffler 57 has a cylindrical portion 58.
- the cylindrical portion 58 is formed integrally with the cylinder block 41.
- the muffler 57 is connected to the discharge chamber 432 via a discharge passage 59.
- the muffler 57 is connected to the control pressure chamber 421 via an oil passage 60.
- a pipe 61 is accommodated in and fitted to the cylindrical portion 58.
- the pipe 61 includes a nozzle 62, a restrictor 63, and a diffuser 64.
- the nozzle 62, the restrictor 63, and the diffuser 64 are arranged in series in this order along a direction from the muffler 57 toward the outside of the compressor 44 via the interior of the cylindrical portion 58.
- an introduction passage 621 in the nozzle 62, a restricting passage 631 in the restrictor 63, and a pressure restoring passage 641 in the diffuser 64 are connected in series in this order from the muffler 57 toward the outside of the compressor 44.
- the inner diameter of the nozzle 62 gradually decreases from the end close to the muffler 57 toward the restrictor 63.
- a small diameter portion of the introduction passage 621 is connected to the restricting passage 631. That is, the introduction passage 621 is tapered toward the restricting passage 631. In other words, assuming that the introduction passage 621 is the inlet of the restricting passage 631, the inlet is widened in a direction opposite to the flowing direction of refrigerant gas.
- the inner diameter of the restrictor 63 is constant, and the inner diameter of the diffuser 64 gradually increases from the end close to the restrictor 63 toward the end close to the outside of the compressor 44.
- the widening angle ⁇ 1 (see Fig. 2(b)) of the diffuser 64 is less than or equal to 20 degrees.
- the widening angle ⁇ 2 (see Fig. 2(b)) of the nozzle 62 is greater than the widening angle ⁇ 1 of the diffuser 64.
- the inner circumferential surface of the nozzle 62 is connected to the inner circumferential surface of the cylindrical portion 58 in a bent state as shown by an acute angle ⁇ in Fig. 2(b). That is, there is no step having a substantially right angle between the inner circumferential surface of the nozzle 62 and the inner circumferential surface of the cylindrical portion 58.
- the refrigerant gas When refrigerant gas is discharged into the muffler 57 through the discharge passage 59, the refrigerant gas collides with the inner wall of the muffler 57, or the refrigerant gas changes the flowing direction and flows toward the cylindrical portion 58. Therefore, the lubricant oil included in the refrigerant gas is separated from the refrigerant gas.
- the passage of refrigerant gas extending from the muffler 57 to the cylindrical portion 58 narrows in the cylindrical portion 58. This prevents lubricant oil from entering the cylindrical portion 58. That is, the cylindrical portion 58 functions as an oil separator, which separates lubricant oil from refrigerant gas.
- the lubricant oil separated from the refrigerant gas is stored at the bottom of the muffler 57. Refrigerant gas in the muffler 57 flows to the external refrigerant circuit, which is not shown, through the pipe 61.
- the discharge passage 59 and the muffler 57 are part of the gas passage in the variable displacement compressor 44.
- the restricting passage 631 in the restrictor 63 and the pressure restoring passage 641 in the diffuser 64 form a combined passage 65 located downstream of the muffler 57 in respect to the gas passage.
- the pressure restoring passage 641, which forms part of the combined passage 65, is located downstream of the restricting passage 631.
- the pipe 61 is located in the cylindrical portion 58 to permit refrigerant gas to flow through the combined passage 65.
- the pistons 49 and the cylinder bores 411 construct a pulsation source.
- the pulsation of discharge gas spreads from the pulsation source to the external refrigerant circuit via the discharge chamber 432, the discharge passage 59, the muffler 57, and the combined passage 65.
- the muffler 57 and the restricting passage 631 reduce the pulsation of discharge gas.
- the muffler 57 is located between the pulsation source and the combined passage 65 in respect to the gas passage.
- the second embodiment has the same advantages as the advantages (1-1), (1-4), and (1-5) of the first embodiment.
- the pipe 61 can be fitted to the cylindrical portion 58 by setting the outer diameter of the pipe 61 in accordance with the inner diameter of the cylindrical portion 58.
- the size and the shape of the pipe 61 to which the combined passage 65 is formed can be selected in accordance with the shape of the pipe used for the gas passage (the cylindrical portion 58 in the second embodiment). Therefore, the pipe 61 is a favorable place for forming the combined passage 65.
- the pipe 61 is accommodated in the cylindrical portion 58. Therefore, if there is a step having a substantially right angle at the inlet of the pipe 61, the step generates a great passage resistance with respect to the refrigerant gas.
- the passage resistance causes pressure loss.
- the inner circumferential surface of the nozzle 62 is connected to the inner circumferential surface of the cylindrical portion 58 at an acute angle ⁇ . Therefore, the passage resistance applied to the refrigerant gas that flows into the pipe 61 is small.
- Fig. 3 shows a third embodiment of the present invention.
- a pipe 61A includes a pressure restoring passage 641A, which is formed by smoothly connecting the inner circumferential surface of a diffuser 64A to the inner circumferential surface of the restrictor 63.
- the widening angle ⁇ 3 of the pressure restoring passage 641A which forms part of a combined passage 65A, represents the angle at the maximum diameter portion of the pressure restoring passage 641A.
- the widening angle ⁇ 3 of the pressure restoring passage 641A is less than or equal to 20 degrees.
- the combined passage 40 which includes the restricting passage 381 and the pressure restoring passage 391, is directly formed in the front housing member 31.
- the fourth embodiment has the same advantages as the advantages (1-1), (1-4), and (1-5) of the first embodiment.
- FIG. 5(a) an inlet 28 is formed in the circumferential wall of the rear housing member 12 and the circumferential wall 111 of the fixed scroll 11.
- a columnar passage forming body 66 is fitted in the inlet 28.
- a plurality of Combined passages 67 are formed in the passage forming body 66 and are arranged in parallel.
- refrigerant gas in the external refrigerant circuit which is not shown, is introduced into the suction chamber 112 via the combined passages 67.
- the suction chamber 112 serves as a muffler, which forms part of the gas passage in the compressor 10.
- the combined passages 67 are located upstream of the suction chamber 112 in respect to the gas passage.
- each combined passage 67 has a pressure restoring passage 671, a restricting passage 672, and an introduction passage 673.
- the pressure restoring passage 671 is located downstream of the restricting passage 672.
- the restricting passage 672 is located downstream of the introduction passage 673.
- the diameter of the introduction passage 673 gradually decreases from the end close to the external refrigerant circuit (outside of the compressor 10) toward the restricting passage 672.
- a small diameter portion of the introduction passage 673 is connected to the restricting passage 672.
- the pulsation source is formed by the fixed scroll 11, the movable scroll 20, and the sealed spaces S0, S1.
- the pulsation of suction gas spreads from the pulsation source to the external refrigerant circuit via the suction chamber 112 and the combined passages 67.
- the suction chamber 112 and the restricting passages 672 reduce the pulsation of suction gas.
- each restricting passage 672 the pressure of refrigerant gas decreases as the flow rate of refrigerant gas increases.
- the pressure of refrigerant gas that has moved from the restricting passage 672 to the corresponding pressure restoring passage 671 increases as the flow rate of refrigerant gas decreases in the pressure restoring passage 671. That is, the pressure restoring passage 671 restores the pressure of refrigerant gas that has passed through the restricting passage 672.
- the pressure of refrigerant gas can be reduced in each restricting passage 672 by an amount that can be restored in the corresponding pressure restoring passage 671. Therefore, the cross-sectional area of each restricting passage 672 can be reduced to increase the pulsation reducing effect of the suction gas.
- each pressure restoring passage 671 when several combined passages 67 are arranged in parallel, the cross-sectional area of each restricting passage 672 can be reduced. This permits the length of each pressure restoring passage 671 to be shortened. Shortening the pressure restoring passages 671 shortens the combined passages 67. Shortening the combined passages 67 contributes to minimizing the size of the passage forming body 66. That is, the structure of arranging several combined passages 67 in parallel is advantageous in suppressing the size of the compressor 10 to which the passage forming body 66 is mounted.
- the invention may be embodied in the following forms.
- the present invention may be applied to compressors other than a scroll compressor and a piston type variable displacement compressor.
- the present invention may be applied to a swash plate type compressor or a vane type compressor.
- the present invention may be applied to devices that are equipped with a muffler as part of a gas passage in an exhaust system attached to a vehicle engine.
- the combined passage in which the restricting passage and the pressure restoring passage are connected in series is provided downstream of the muffler in respect to the gas passage.
- the pipe may be deformed by applying pressure on the outer circumferential surface of the pipe.
- the restricting passage and the pressure restoring passage may be formed in the pipe by such deformation.
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- Mechanical Engineering (AREA)
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- Applications Or Details Of Rotary Compressors (AREA)
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- Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
Description
- The present invention relates to a device having a pulsation reducing structure. The present invention also pertains to a passage forming body and a compressor.
- Document EP-A-1 270 947 discloses a scroll compressor comprising a gas passage, a pulsation source connected to the gas passage, a muffler for reducing the pulsation whereby a combined passage is located in the gas passage, the combined passage including a restricting passage and a pressure restoring passage which are connected in series.
- Document EP-A-0 940 581 discloses a variable displacement compressor having cylinder bores and a crankcase which are formed in a housing, single-ended pistons fitted in the cylinder bores, and a cam plate provided in the crankcase, and the displacement capacity of the compressor is varied by controlling the angle of inclination of the cam plate in accordance with a difference between the internal pressure of the crankcase and a suction pressure present on both sides of each single-ended piston. A damping or muffler chamber is provided downstream of an output channel through which a refrigerant gas discharged from the cylinder bores passes. A check valve which opens and closes in accordance with a pressure difference between upstream and downstream sides of the output channel is provided in the output channel, upstream of the sound-deadening chamber. The device reduces the effects of pressure pulsations caused by the compression motion of the compressor and caused by the valve body of the open/close device hunting, has no bad effects on the external refrigerant circuit connected to the compressor, and increases the reliability of the lip seal.
- EP-A-1 270 945 discloses a swash plate type compressor used for the air conditioner of an automobile, and more particularly, a compressor having a structure where pulsation pressure caused during refrigerants are compressed and discharged is reduced, thereby permitting the noise at the time of driving to be substantially reduced. The compressor according to the present invention can embody the structure by distributing and discharging refrigerant that has been compressed by a plurality of pistons and discharged from a plurality of bores into at least two discharge holes, wherein a frequency of the pulsation pressure is increased in proportion to the number of the discharge holes but a strength of the pulsation pressure is decreased in inverse proportion to the number of the discharge holes. Therefore, the driving noise of the compressor that is formed in proportion to the strength of the pulsation pressure is considerably decreased.
- In a scroll compressor disclosed in Japanese Laid-Open Patent Publication No. 2002-285981, an oil separator is located in a front housing member. An oil separating chamber, which forms part of the oil separator, is connected to a discharge chamber defined at the back of a fixed scroll. The oil separating chamber accommodates a cylindrical member, which forms part of the oil separator. Refrigerant gas in the discharge chamber is introduced into the oil separating chamber. Lubricant oil included in the refrigerant gas introduced into the oil separating chamber is separated from the refrigerant gas.
- The cylindrical member, which forms part of the oil separator, also functions to reduce pulsation of discharged gas.
- The inner diameter of the cylindrical member needs to be reduced to obtain sufficient pulsation reducing effect. However, if the inner diameter of the cylindrical member is excessively reduced, a great pressure loss is generated. Therefore, it is difficult to reduce the inner diameter of the cylindrical member to obtain sufficient pulsation reducing effect.
- Accordingly, it is an objective of the present invention to provide a device having a pulsation reducing structure that obtains sufficient pulsation reducing effect and suppresses pressure loss in devices having a gas passage. The present invention also pertains to a passage forming body and a compressor.
- To achieve the above-mentioned objective, the present invention provides a device having a pulsation reducing structure. The device includes a gas passage, a pulsation source connected to the gas passage, a muffler for reducing the pulsation and a combined passage located in the gas passage. Pulsation of gas spreads from the pulsation source to the gas passage. The muffler is located in a part of the gas passage. The combined passage is located upstream or downstream of the muffler with respect to a flowing direction of gas. The combined passage includes a restricting passage and a pressure restoring passage. The restricting passage and the pressure restoring passage are connected in series. The pressure restoring passage is located downstream of the restricting passage with respect to the flowing direction of gas and its cross-sectional area is gradually increased in the flowing direction of gas. The muffler is located between the pulsation source and the combined passage in the gas passage.
- According to another aspect of the invention, a passage forming body having a plurality of combined passages is provided. The combined passages are arranged in parallel. Each combined passage includes a restricting passage and a pressure restoring passage. In each combined passage, the restricting passage is combined with the pressure restoring passage in series and the cross-sectional area of pressure restoring passage is gradually increased in the flowing direction of gas.
- In addition, present invention may be applicable to provide a scroll compressor. The compressor includes a compression mechanism including a movable scroll and a fixed scroll, the scrolls defining a compression chamber, a discharge chamber for receiving gas discharged from the compression chamber, a discharge gas passage for guiding discharge gas from the discharge chamber to the outside of the compressor. A restricting passage is located in the discharge gas passage. A pressure restoring passage is located in the discharge gas passage. The pressure restoring passage is connected to the restricting passage in series and located downstream of the restricting passage with respect to a flowing direction of gas.
- Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
- The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
- Fig. 1(a) is a cross-sectional view illustrating a compressor according to a first embodiment of the present invention;
- Fig. 1(b) is an enlarged partial cross-sectional view of Fig. 1(a);
- Fig. 2(a) is a cross-sectional view illustrating a compressor according to a second embodiment of the present invention;
- Fig. 2(b) is an enlarged partial cross-sectional view of Fig. 2(a);
- Fig. 3 is an enlarged partial cross-sectional view illustrating a third embodiment of the present invention;
- Fig. 4 is a partial cross-sectional view illustrating a fourth embodiment of the present invention;
- Fig. 5(a) is a partial cross-sectional view illustrating a fifth embodiment of the present invention;
- Fig. 5(b) is a side view illustrating a
passage forming body 66 shown in Fig. 5(a); and - Fig. 5(c) is a cross-sectional view taken along line VC-VC in Fig. 5(b).
- In the drawings, like numerals are used for like elements throughout.
- A first embodiment of the present invention will now be described with reference to Figs. 1(a) and 1(b).
- As shown in Fig. 1(a), a
scroll compressor 10 includes arear housing member 12 and afront housing member 31. Ashaft support member 13 and afixed scroll 11 are inserted in and fixed to therear housing member 12. Thefront housing member 31 is secured to therear housing member 12 and the fixedscroll 11. Therear housing member 12 and thefront housing member 31 form a housing of a device, which is thescroll compressor 10. Therear housing member 12 and theshaft support member 13 rotatably support arotary shaft 14 by means ofradial bearings - The
rotary shaft 14 extends through theshaft support member 13 and projects toward thefixed scroll 11. Aneccentric shaft 17 is formed integrally with the end of therotary shaft 14 that projects from theshaft support member 13. The axis of theeccentric shaft 17 located at a position decentered from the axis of therotary shaft 14. Theeccentric shaft 17 supports abush 18 to which abalance weight 19 is integrally formed. Thebush 18 supports amovable scroll 20 by means of aradial bearing 21 such that themovable scroll 20 faces the fixedscroll 11. Themovable scroll 20 rotates relative to the fixedscroll 11. Theradial bearing 21 is accommodated in acylindrical portion 221, which projects from the rear surface of a movablescroll base plate 22 of themovable scroll 20. - The fixed
scroll 11 includes a fixedscroll base plate 23 and a fixedvolute portion 24. Themovable scroll 20 includes the movablescroll base plate 22 and amovable volute portion 25. The fixedscroll base plate 23, the fixedvolute portion 24, the movablescroll base plate 22, and themovable volute portion 25 define sealed spaces S0 and S1. Themovable scroll 20 orbits as theeccentric shaft 17 rotates. Centrifugal force created by the orbital movement of themovable scroll 20 is cancelled by thebalance weight 19. - Columnar anti-rotation pins 27 (three or more) are fixed to the movable
scroll base plate 22. Theshaft support member 13 has circular anti-rotation bores 131, the number of which is the same as the anti-rotation pins 27. The anti-rotation bores 131 are arranged in the circumferential direction of theshaft support member 13. The end of eachanti-rotation pin 27 is inserted in the corresponding anti-rotation bore 131. - A
stator 29 is secured to the inner circumferential surface of therear housing member 12. Arotor 30 is secured to therotary shaft 14. When electricity is supplied to astator coil 291 of thestator 29, therotor 30 and therotary shaft 14 rotate integrally. Thestator 29 and therotor 30 construct an electric motor. - The
movable scroll 20 orbits as theeccentric shaft 17 rotates integrally with therotary shaft 14. Aninlet 26 is formed in a circumferential wall of therear housing member 12 and acircumferential wall 111 of the fixedscroll 11. As themovable scroll 20 orbits, refrigerant gas in an external refrigerant circuit, which is not shown, is introduced into asuction chamber 112 inside thecircumferential wall 111 through theinlet 26. The refrigerant gas introduced into thesuction chamber 112 flows into the sealed spaces S0, S1 between the fixedscroll base plate 23 and the movablescroll base plate 22 from the periphery of the fixedscroll 11 and themovable scroll 20. Lubricant oil is included in a refrigeration circuit, which includes thecompressor 10, and flows with refrigerant gas. - As the
movable scroll 20 orbits, the circumferential surface of eachanti-rotation pin 27 slides along the circumferential surface of the corresponding anti-rotation bore 131. Themovable scroll 20 is prevented from rotating while being permitted to orbit. As themovable scroll 20 orbits, the sealed spaces S1, S0 move toward the center of thescrolls - A
discharge chamber 32 is formed in thefront housing member 31. The refrigerant gas compressed by the decrease in the volume of the sealed spaces S1, S0 is discharged to thedischarge chamber 32 through adischarge port 231, which is formed in the fixedscroll base plate 23, while flexing adischarge valve flap 33. Aretainer 34 limits the opening degree of thedischarge valve flap 33. A compression reaction force in the sealed spaces S1, S0 that acts on themovable scroll 20 is received by theshaft support member 13. - An
outlet 311 is formed in the circumferential wall of thefront housing member 31. Apipe 35 is fitted to theoutlet 311. That is, thepipe 35 is formed separately from thefront housing member 31, which defines thedischarge chamber 32 and theoutlet 311. As shown in Fig. 1(b), thepipe 35 includes afitting portion 351, a restrictor 38, and adiffuser 39. The restrictor 38, thediffuser 39, and thefitting portion 351 are arranged in series in this order along a flowing direction of refrigerant gas from thedischarge chamber 32 to the outside of thecompressor 10 via theoutlet 311. In other words, a restrictingpassage 381 in the restrictor 38 and apressure restoring passage 391 in thediffuser 39 are connected in series in this order from thedischarge chamber 32 toward the outside of thecompressor 10. The cross-sectional area of thepressure restoring passage 391 is greater than the cross-sectional area of the restrictingpassage 381. - The
pipe 35 is fitted to theoutlet 311 with thefitting portion 351. The inner diameter of thefitting portion 351 is greater than the inner diameter of thediffuser 39 and therestrictor 38. The inner diameter of the restrictor 38 is constant. The inner diameter of thediffuser 39 gradually increases from the end close to the restrictor 38 toward the end close to thefitting portion 351. That is, thepressure restoring passage 391 is widened in the flowing direction of refrigerant gas. The widening angle θ1 (see Fig. 1(b)) of thepressure restoring passage 391 of thediffuser 39 is less than or equal to 20 degrees. - When refrigerant gas is discharged into the
discharge chamber 32 through thedischarge port 231 while flexing thedischarge valve flap 33, the refrigerant gas collides with the inner wall of thefront housing member 31, or the refrigerant gas changes the flowing direction and flows toward thepipe 35. Therefore, the lubricant oil included in the refrigerant gas is separated from the refrigerant gas. The lubricant oil separated from the refrigerant gas is stored at the bottom of thedischarge chamber 32. The bottom of thedischarge chamber 32 is connected to aback pressure chamber 37 located at the back of the movablescroll base plate 22 via areturn passage 36. The lubricant oil stored at the bottom of thedischarge chamber 32 is supplied to theback pressure chamber 37 through thereturn passage 36 and used to lubricate theradial bearings discharge chamber 32 flows to the external refrigerant circuit through thepipe 35. - The
pipe 35 is suspended in theoutlet 311 such that the lower end of thepipe 35 is separate from the inner wall of thefront housing member 31 and projects in thedischarge chamber 32. That is, part of thepipe 35 is located inside thedischarge chamber 32. This structure effectively prevents lubricant oil adhered to the inner wall of thefront housing member 31 from entering thepipe 35 by the operation of the refrigerant gas. That is, thepipe 35 functions as an oil separator, which separates lubricant oil from refrigerant gas. - As shown in Figs. 1(a) and 1(b), the
discharge port 231 and thedischarge chamber 32 are part of a gas passage in thecompressor 10. Thedischarge chamber 32 functions as a muffler that is part of the gas passage. The restrictingpassage 381 in the restrictor 38 and thepressure restoring passage 391 in thediffuser 39 form a combinedpassage 40 located downstream of the muffler, which is thedischarge chamber 32 in this embodiment, in respect to the gas passage. Thepressure restoring passage 391, which forms part of the combinedpassage 40, is located downstream of the restrictingpassage 381. The fixedscroll 11, themovable scroll 20, and the sealed spaces S0, S1 form a pulsation source. The pulsation of discharge gas spreads from the pulsation source to the external refrigerant circuit via thedischarge chamber 32 and the combinedpassage 40. The discharge chamber 32 (muffler) and the restrictingpassage 381 reduce the pulsation of discharge gas. The muffler, which is thedischarge chamber 32 in this embodiment, is located between the pulsation source and the combinedpassage 40 in respect to the gas passage. - The first embodiment has the following advantages.
- (1-1) In the restricting
passage 381, the pressure of refrigerant gas is reduced as the flow rate of refrigerant gas increases. On the other hand, the pressure of refrigerant gas that has moved from the restrictingpassage 381 to thepressure restoring passage 391 increases as the flow rate of refrigerant gas is reduced in thepressure restoring passage 391. That is, thepressure restoring passage 391 restores the pressure of refrigerant gas that has passed through the restrictingpassage 381. The pressure of refrigerant gas can be reduced in the restrictingpassage 381 by an amount that can be restored in thepressure restoring passage 391. Therefore, the cross-sectional area of the restrictingpassage 381 can be reduced to increase the pulsation reducing effect of the discharge gas. - (1-2) The
pipe 35, which is provided with the combinedpassage 40, is fitted to theoutlet 311 of thefront housing member 31. In this case, thepipe 35 may be press-fitted or adhered with an adhesion to theoutlet 311. Thepipe 35 is fitted to a gas passage (theoutlet 311 in this embodiment) the diameter of which is greater than or equal to the maximum outer diameter of thediffuser 39 by adjusting the outer diameter of thefitting portion 351 to the diameter of the gas passage. Thepipe 35 is easily formed by, for example, press working. Therefore, the size and the shape of thepipe 35 to which the combinedpassage 40 is formed can be selected in accordance with the shape of a pipe used for the gas passage (theoutlet 311 in this embodiment). Thus, the restrictingpassage 381 and thepressure restoring passage 391 are also easily formed. Therefore, thepipe 35 is a favorable place for forming the combinedpassage 40. - (1-3) The
pipe 35 functions also as the oil separator. Forming the combinedpassage 40 in thepipe 35, which functions as the oil separator, reduces the number of parts as compared to a case in which a pipe dedicated for pulsation reduction is used. This contributes to reducing the cost. Since a space for the pipe dedicated for pulsation reduction is unnecessary, the size of thecompressor 10 is prevented from being increased. - (1-4) In restoring the pressure in the
pressure restoring passage 391, it is important that the flow of refrigerant gas through thepressure restoring passage 391 does not separate from the inner surface of thediffuser 39. The structure of setting the widening angle θ1 of thepressure restoring passage 391 to be less than or equal to 20 degrees is effective in preventing the refrigerant gas flow from separating from the inner surface. - (1-5) The
compressor 10 that causes pulsation of discharge gas is a device that includes the muffler, which is thedischarge chamber 32 in this embodiment, as part of a gas passage. The present invention is suitable forsuch compressor 10. - A pulsation reduction structure according to a second embodiment of the present invention will now be described with reference to Figs. 2(a) and 2(b).
- As shown in Fig. 2(a), a
cylinder block 41, afront housing member 42, and arear housing member 43 form a housing of a device, which is a piston typevariable displacement compressor 44 in the second embodiment. Thefront housing member 42 and thecylinder block 41 define acontrol pressure chamber 421. Thefront housing member 42 and thecylinder block 41 rotatably support arotary shaft 45. - A rotary support 46 is fixed to the
rotary shaft 45, and aswash plate 47 is supported on therotary shaft 45. Theswash plate 47 is permitted to incline with respect to and slide along therotary shaft 45. Guide holes 461 are formed in the rotary support 46 and guide pins 48 are connected to theswash plate 47. Eachguide pin 48 is fitted to one of the guide holes 461 to form a hinge mechanism. The hinge mechanism permits theswash plate 47 to tilt with respect to the axial direction of therotary shaft 45 and rotate integrally with therotary shaft 45. - When the center of the
swash plate 47 moves toward the rotary support 46, the inclination of theswash plate 47 increases. The rotary support 46 determines the maximum inclination of theswash plate 47. Theswash plate 47 shown by a solid line in Fig. 2(a) is in the maximum inclination state. When the center of theswash plate 47 moves toward thecylinder block 41, the inclination of theswash plate 47 decreases. Theswash plate 47 shown by a chain double-dashed line in Fig. 2(a) is in the minimum inclination state. - Cylinder bores 411 (only one is shown) extend through the
cylinder block 41. Each cylinder bore 411 accommodates apiston 49. The rotation of theswash plate 47 is converted to reciprocation of thepistons 49 by means ofshoes 50. Thus, eachpiston 49 reciprocates in the corresponding cylinder bore 411. - A
suction chamber 431 and adischarge chamber 432 are defined in therear housing member 43.Suction ports 511 are formed in avalve plate 51 and avalve flap plate 53.Discharge ports 512 are formed in thevalve plate 51 and avalve flap plate 52. Suction valve flaps 521 are formed on thevalve flap plate 52, and discharge valve flaps 531 are formed on thevalve flap plate 53. As eachpiston 49 moves from the top dead center to the bottom dead center (from the right side to the left side in Fig. 2(a)), refrigerant gas in thesuction chamber 431 is drawn into the correspondingsuction port 511 while flexing thesuction valve flap 521 to enter the associatedcylinder bore 411. When eachpiston 49 moves from the bottom dead center to the top dead center (from the left side to the right side in Fig. 2(a)), refrigerant in the corresponding cylinder bore 411 is discharged to thedischarge chamber 432 via thecorresponding discharge port 512 while flexing thedischarge valve flap 531. - The
discharge chamber 432 is connected to thecontrol pressure chamber 421 with asupply passage 54. Thecontrol pressure chamber 421 is connected to thesuction chamber 431 with arelease passage 55. Refrigerant in thecontrol pressure chamber 421 flows to thesuction chamber 431 through therelease passage 55. - An
electromagnetic control valve 56 is located in thesupply passage 54. Thecontrol valve 56 is closed when de-excited and prevents refrigerant from passing through. In this state, refrigerant is not supplied from thedischarge chamber 432 to thecontrol pressure chamber 421 via thesupply passage 54. Refrigerant in thecontrol pressure chamber 421 flows to thesuction chamber 431 through therelease passage 55. Therefore, the pressure in thecontrol pressure chamber 421 decreases. Therefore, the inclination angle of theswash plate 47 increases. The compressor displacement increases, accordingly. Thecontrol valve 56 is open when excited and permits refrigerant through. In this state, refrigerant is supplied from thedischarge chamber 432 to thecontrol pressure chamber 421 via thesupply passage 54. Therefore, the pressure in thecontrol pressure chamber 421 increases. Accordingly, the inclination angle of theswash plate 47 decreases, which decreases the compressor displacement. - A
muffler 57 is formed on the circumferential surface of thecylinder block 41 and the circumferential surface of thefront housing member 42. Themuffler 57 has acylindrical portion 58. Thecylindrical portion 58 is formed integrally with thecylinder block 41. Themuffler 57 is connected to thedischarge chamber 432 via adischarge passage 59. Themuffler 57 is connected to thecontrol pressure chamber 421 via anoil passage 60. Apipe 61 is accommodated in and fitted to thecylindrical portion 58. - As shown in Fig. 2(b), the
pipe 61 includes anozzle 62, a restrictor 63, and adiffuser 64. Thenozzle 62, the restrictor 63, and thediffuser 64 are arranged in series in this order along a direction from themuffler 57 toward the outside of thecompressor 44 via the interior of thecylindrical portion 58. In other words, anintroduction passage 621 in thenozzle 62, a restrictingpassage 631 in the restrictor 63, and apressure restoring passage 641 in thediffuser 64 are connected in series in this order from themuffler 57 toward the outside of thecompressor 44. The inner diameter of thenozzle 62 gradually decreases from the end close to themuffler 57 toward therestrictor 63. A small diameter portion of theintroduction passage 621 is connected to the restrictingpassage 631. That is, theintroduction passage 621 is tapered toward the restrictingpassage 631. In other words, assuming that theintroduction passage 621 is the inlet of the restrictingpassage 631, the inlet is widened in a direction opposite to the flowing direction of refrigerant gas. - The inner diameter of the restrictor 63 is constant, and the inner diameter of the
diffuser 64 gradually increases from the end close to the restrictor 63 toward the end close to the outside of thecompressor 44. The widening angle θ1 (see Fig. 2(b)) of thediffuser 64 is less than or equal to 20 degrees. The widening angle θ2 (see Fig. 2(b)) of thenozzle 62 is greater than the widening angle θ1 of thediffuser 64. The inner circumferential surface of thenozzle 62 is connected to the inner circumferential surface of thecylindrical portion 58 in a bent state as shown by an acute angle α in Fig. 2(b). That is, there is no step having a substantially right angle between the inner circumferential surface of thenozzle 62 and the inner circumferential surface of thecylindrical portion 58. - When refrigerant gas is discharged into the
muffler 57 through thedischarge passage 59, the refrigerant gas collides with the inner wall of themuffler 57, or the refrigerant gas changes the flowing direction and flows toward thecylindrical portion 58. Therefore, the lubricant oil included in the refrigerant gas is separated from the refrigerant gas. The passage of refrigerant gas extending from themuffler 57 to thecylindrical portion 58 narrows in thecylindrical portion 58. This prevents lubricant oil from entering thecylindrical portion 58. That is, thecylindrical portion 58 functions as an oil separator, which separates lubricant oil from refrigerant gas. The lubricant oil separated from the refrigerant gas is stored at the bottom of themuffler 57. Refrigerant gas in themuffler 57 flows to the external refrigerant circuit, which is not shown, through thepipe 61. - The
discharge passage 59 and themuffler 57 are part of the gas passage in thevariable displacement compressor 44. The restrictingpassage 631 in the restrictor 63 and thepressure restoring passage 641 in thediffuser 64 form a combinedpassage 65 located downstream of themuffler 57 in respect to the gas passage. Thepressure restoring passage 641, which forms part of the combinedpassage 65, is located downstream of the restrictingpassage 631. Thepipe 61 is located in thecylindrical portion 58 to permit refrigerant gas to flow through the combinedpassage 65. - The
pistons 49 and the cylinder bores 411 construct a pulsation source. The pulsation of discharge gas spreads from the pulsation source to the external refrigerant circuit via thedischarge chamber 432, thedischarge passage 59, themuffler 57, and the combinedpassage 65. Themuffler 57 and the restrictingpassage 631 reduce the pulsation of discharge gas. Themuffler 57 is located between the pulsation source and the combinedpassage 65 in respect to the gas passage. - The second embodiment has the same advantages as the advantages (1-1), (1-4), and (1-5) of the first embodiment. The
pipe 61 can be fitted to thecylindrical portion 58 by setting the outer diameter of thepipe 61 in accordance with the inner diameter of thecylindrical portion 58. The size and the shape of thepipe 61 to which the combinedpassage 65 is formed can be selected in accordance with the shape of the pipe used for the gas passage (thecylindrical portion 58 in the second embodiment). Therefore, thepipe 61 is a favorable place for forming the combinedpassage 65. - In the second embodiment, the
pipe 61 is accommodated in thecylindrical portion 58. Therefore, if there is a step having a substantially right angle at the inlet of thepipe 61, the step generates a great passage resistance with respect to the refrigerant gas. The passage resistance causes pressure loss. However, the inner circumferential surface of thenozzle 62 is connected to the inner circumferential surface of thecylindrical portion 58 at an acute angle α. Therefore, the passage resistance applied to the refrigerant gas that flows into thepipe 61 is small. - Fig. 3 shows a third embodiment of the present invention. As shown in Fig. 3, a
pipe 61A includes apressure restoring passage 641A, which is formed by smoothly connecting the inner circumferential surface of adiffuser 64A to the inner circumferential surface of therestrictor 63. In this case, the widening angle θ3 of thepressure restoring passage 641A, which forms part of a combinedpassage 65A, represents the angle at the maximum diameter portion of thepressure restoring passage 641A. The widening angle θ3 of thepressure restoring passage 641A is less than or equal to 20 degrees. - A fourth embodiment will now be described with reference to Fig. 4.
- The combined
passage 40, which includes the restrictingpassage 381 and thepressure restoring passage 391, is directly formed in thefront housing member 31. - The fourth embodiment has the same advantages as the advantages (1-1), (1-4), and (1-5) of the first embodiment.
- A fifth embodiment will now be described with reference to Figs. 5(a), 5(b), and 5(c). As shown in Fig. 5(a), an
inlet 28 is formed in the circumferential wall of therear housing member 12 and thecircumferential wall 111 of the fixedscroll 11. A columnarpassage forming body 66 is fitted in theinlet 28. A plurality of Combinedpassages 67 are formed in thepassage forming body 66 and are arranged in parallel. As themovable scroll 20 orbits, refrigerant gas in the external refrigerant circuit, which is not shown, is introduced into thesuction chamber 112 via the combinedpassages 67. Thesuction chamber 112 serves as a muffler, which forms part of the gas passage in thecompressor 10. The combinedpassages 67 are located upstream of thesuction chamber 112 in respect to the gas passage. - As shown in Figs. 5 (a), 5(b), and 5(c), each combined
passage 67 has apressure restoring passage 671, a restrictingpassage 672, and anintroduction passage 673. Thepressure restoring passage 671 is located downstream of the restrictingpassage 672. The restrictingpassage 672 is located downstream of theintroduction passage 673. The diameter of theintroduction passage 673 gradually decreases from the end close to the external refrigerant circuit (outside of the compressor 10) toward the restrictingpassage 672. A small diameter portion of theintroduction passage 673 is connected to the restrictingpassage 672. As described above, the pulsation source is formed by the fixedscroll 11, themovable scroll 20, and the sealed spaces S0, S1. The pulsation of suction gas spreads from the pulsation source to the external refrigerant circuit via thesuction chamber 112 and the combinedpassages 67. Thesuction chamber 112 and the restrictingpassages 672 reduce the pulsation of suction gas. - In each restricting
passage 672, the pressure of refrigerant gas decreases as the flow rate of refrigerant gas increases. On the other hand, the pressure of refrigerant gas that has moved from the restrictingpassage 672 to the correspondingpressure restoring passage 671 increases as the flow rate of refrigerant gas decreases in thepressure restoring passage 671. That is, thepressure restoring passage 671 restores the pressure of refrigerant gas that has passed through the restrictingpassage 672. The pressure of refrigerant gas can be reduced in each restrictingpassage 672 by an amount that can be restored in the correspondingpressure restoring passage 671. Therefore, the cross-sectional area of each restrictingpassage 672 can be reduced to increase the pulsation reducing effect of the suction gas. - If a single combined passage is used at the
inlet 28, the difference between the diameter of the restricting passage and the diameter of part of the gas passage upstream of the restricting passage becomes great, and the restricting effect of the restricting passage is increased. In this case, the length of the pressure restoring passage needs to be increased. However, when several combinedpassages 67 are arranged in parallel, the cross-sectional area of each restrictingpassage 672 can be reduced. This permits the length of eachpressure restoring passage 671 to be shortened. Shortening thepressure restoring passages 671 shortens the combinedpassages 67. Shortening the combinedpassages 67 contributes to minimizing the size of thepassage forming body 66. That is, the structure of arranging several combinedpassages 67 in parallel is advantageous in suppressing the size of thecompressor 10 to which thepassage forming body 66 is mounted. - The invention may be embodied in the following forms.
- The present invention may be applied to compressors other than a scroll compressor and a piston type variable displacement compressor. For example, the present invention may be applied to a swash plate type compressor or a vane type compressor.
- The present invention may be applied to devices that are equipped with a muffler as part of a gas passage in an exhaust system attached to a vehicle engine. In this case, the combined passage in which the restricting passage and the pressure restoring passage are connected in series is provided downstream of the muffler in respect to the gas passage. The pipe may be deformed by applying pressure on the outer circumferential surface of the pipe. The restricting passage and the pressure restoring passage may be formed in the pipe by such deformation.
- The present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.
Claims (17)
- A device having a pulsation reducing structure, the device comprising:a gas passage (311);a pulsation source (11, 20 50, S1) connected to the gas passage, wherein pulsation of gas spreads from the pulsation source to the gas passage; anda muffler (32, 57) for reducing the pulsation, wherein the muffler is located in a part of the gas passage,wherein a combined passage (40, 65) is located in the gas passage upstream or downstream of the muffler with respect to a flowing direction of gas, said combined passage including a restricting passage (381, 631) and a pressure restoring passage (391, 641), the restricting passage and the pressure restoring passage being connected in series, wherein the pressure restoring passage is located downstream of the restricting passage with respect to the flowing direction of gas, and wherein the muffler is located between the pulsation source and the combined passage in the gas passage,characterized in that
the cross-sectional area of the pressure restoring passage is gradually increased in the flowing direction of gas. - The device according to claim 1, characterized in that the cross-sectional area of the pressure restoring passage (391, 641) is greater than the cross-sectional area of the restricting passage (381, 631).
- The device according to claim 1 or 2,
characterized in that the pressure restoring passage (391, 641) is widened in the flowing direction of gas. - The device according to claim 1 or 3,
characterized in that the widening angle of the pressure restoring passage (391, 641) is less than or equal to 20 degrees. - The device according to any one of claims 1 to 4,
characterized in that the combined passage (40, 65) is defined by a pipe (35,61) located in the gas passage. - The device according to claim 5, characterized by a housing that defines the gas passage, wherein the pipe (35,61) is formed separately from the housing.
- The device according to claim 5 or 6,
characterized in that at least part of the pipe (35,61) is located in the muffler (32, 57). - The device according to claim 7, characterized in that the pipe (35,61) also functions as an oil separator, which separates oil from gas flowing through the gas passage.
- The device according to any one of claims 5 to 8,
characterized in that the pipe includes an introduction passage, the introduction passage being located upstream of the restricting passage (381, 631) with respect to the flowing direction of gas, wherein the introduction passage is connected to the restricting passage in series, and the introduction passage is tapered toward the restricting passage. - The device according to any one of claims 1 to 9,
characterized in that an inlet of the restricting passage (381, 631) is widened in a direction opposite to the flowing direction of gas. - The device according to any one of claims 1 to 10,
characterized in that the combined passage (40, 65) is one of a plurality of combined passages, wherein the combined passages are arranged in parallel. - The device according to any one of claims 1 to 11,
characterized in that the device is a compressor for a vehicle air conditioner. - The device according to any one claims 1 to 11,
characterized in that the device is provided in an exhaust system attached to a vehicle engine. - A passage forming body in a pulsation reducing structure of a compressor being characterized by having a plurality of combined passages (67), the combined passages being arranged in parallel, wherein each combined passage includes a restricting passage (672) and a pressure restoring passage (671), wherein in each combined passage, the restricting passage is combined with the pressure restoring passage in series, and wherein the cross-sectional area of the pressure restoring passage is gradually increased in the flowing direction of gas.
- The device according to any one of claims 1 to 13,
characterized in that the device is a scroll compressor (10), comprising:a compression mechanism which functions as the pulsation source, wherein the compression mechanism including a movable scroll (20) and a fixed scroll (11), the scrolls defining a compression chamber;a discharge chamber (32) for receiving gas discharged from the compression chamber; anda discharge gas passage which functions as the gas passage, wherein the discharge gas passage guides discharge gas from the discharge chamber to the outside of the compressor. - The device according to any one of claims 1 to 13, characterized in that the device is a scroll
compressor (10), comprising:a compression mechanism which functions as the pulsation source, wherein the compression mechanism including a movable scroll (20) and a fixed scroll (11), the scrolls defining a compression chamber;a suction chamber for temporarily storing gas before the gas is drawn into the compression chamber; anda suction gas passage which functions as the gas passage, wherein the suction gas passage guides gas into the suction chamber from the outside of the compressor,wherein the suction gas passage includes a suction restricting passage, which functions as the restricting passage, and a suction pressure restoring passage, which functions as the pressure restoring passage. - The device according to any one of claims 1 to 13,
characterized in that the device is a piston type compressor (44), comprising:a compression chamber, which functions as the pulsation source,a discharge chamber into which gas compressed in the compression chamber is discharged, anda discharge gas passage which functions as the gas passage, wherein the discharge gas passage guides gas from the discharge chamber to the outside of the compressor, the discharge gas passage including the muffler (57), the restricting passage (631), and the pressure restoring passage (641).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2003184113 | 2003-06-27 | ||
JP2003184113A JP2005016454A (en) | 2003-06-27 | 2003-06-27 | Pulsation reduction structure in equipment with gas passage |
Publications (2)
Publication Number | Publication Date |
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EP1491769A1 EP1491769A1 (en) | 2004-12-29 |
EP1491769B1 true EP1491769B1 (en) | 2006-08-16 |
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EP04014847A Expired - Fee Related EP1491769B1 (en) | 2003-06-27 | 2004-06-24 | A device having a pulsation reducing structure and a passage forming body |
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US (1) | US20050002800A1 (en) |
EP (1) | EP1491769B1 (en) |
JP (1) | JP2005016454A (en) |
DE (1) | DE602004001929T2 (en) |
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JP2005171859A (en) * | 2003-12-10 | 2005-06-30 | Sanden Corp | Compressor |
JP2006275022A (en) * | 2005-03-30 | 2006-10-12 | Anest Iwata Corp | Scroll fluid machine with muffling device |
JP4621054B2 (en) * | 2005-03-30 | 2011-01-26 | アネスト岩田株式会社 | Scroll fluid machine with silencer |
JP4758767B2 (en) * | 2006-01-10 | 2011-08-31 | サンデン株式会社 | Compressor |
US7794591B2 (en) | 2007-03-23 | 2010-09-14 | Zodiac Pool Systems, Inc. | Pool filter |
US7815796B2 (en) * | 2007-03-23 | 2010-10-19 | Zodiac Pool Systems, Inc. | Pool filter |
US7951293B2 (en) * | 2007-10-05 | 2011-05-31 | Zodiac Pool Systems, Inc. | Methods and apparatus for a pool treatment and water system |
KR100873366B1 (en) | 2007-12-26 | 2008-12-10 | 학교법인 두원학원 | A pulsation reducing type compressor |
US20090175739A1 (en) * | 2008-01-07 | 2009-07-09 | Kanwal Bhatia | Dual drive compressor |
US8516661B2 (en) * | 2009-04-29 | 2013-08-27 | Zodiac Pool Systems, Inc. | Retainer band for use in fluid-handling vessels |
JP5692177B2 (en) | 2012-07-19 | 2015-04-01 | 株式会社豊田自動織機 | Compressor |
BE1021301B1 (en) * | 2013-09-05 | 2015-10-26 | Atlas Copco Airpower, Naamloze Vennootschap | COMPRESSOR DEVICE |
JP6187266B2 (en) * | 2014-01-08 | 2017-08-30 | 株式会社豊田自動織機 | Electric compressor |
JP6396712B2 (en) * | 2014-07-31 | 2018-09-26 | 日立ジョンソンコントロールズ空調株式会社 | Refrigeration equipment |
WO2016130156A1 (en) * | 2015-02-13 | 2016-08-18 | GM Global Technology Operations LLC | Natural gas fueled vehicle |
KR102291952B1 (en) * | 2015-03-04 | 2021-08-23 | 한온시스템 주식회사 | A eccentric bush assembling structure of a scroll compressor |
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US3193193A (en) * | 1958-03-13 | 1965-07-06 | Carrier Corp | Compressor muffler construction and method for muffling compressor discharge gases |
US4477229A (en) * | 1982-08-25 | 1984-10-16 | Carrier Corporation | Compressor assembly and method of attaching a suction muffler thereto |
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JP3513836B2 (en) * | 1994-02-23 | 2004-03-31 | 株式会社豊田自動織機 | Compressor |
JP3820766B2 (en) * | 1998-03-06 | 2006-09-13 | 株式会社豊田自動織機 | Compressor |
JP2000337255A (en) * | 1999-05-26 | 2000-12-05 | Toyota Autom Loom Works Ltd | Damping device and suction structure of compressor |
US6315536B1 (en) * | 1999-11-18 | 2001-11-13 | Copeland Corporation | Suction inlet screen and funnel for a compressor |
KR100576631B1 (en) * | 1999-12-21 | 2006-05-04 | 한라공조주식회사 | Compressor having structure to reduce pulsation pressure |
JP3721933B2 (en) * | 2000-04-17 | 2005-11-30 | 株式会社デンソー | Compressor |
JP4399994B2 (en) * | 2000-11-17 | 2010-01-20 | 株式会社豊田自動織機 | Variable capacity compressor |
JP2003013872A (en) * | 2001-06-28 | 2003-01-15 | Toyota Industries Corp | Scroll type compressor and its refrigerant compressing method |
-
2003
- 2003-06-27 JP JP2003184113A patent/JP2005016454A/en active Pending
-
2004
- 2004-06-24 EP EP04014847A patent/EP1491769B1/en not_active Expired - Fee Related
- 2004-06-24 DE DE602004001929T patent/DE602004001929T2/en not_active Expired - Fee Related
- 2004-06-24 US US10/877,664 patent/US20050002800A1/en not_active Abandoned
Also Published As
Publication number | Publication date |
---|---|
JP2005016454A (en) | 2005-01-20 |
EP1491769A1 (en) | 2004-12-29 |
DE602004001929T2 (en) | 2007-03-01 |
US20050002800A1 (en) | 2005-01-06 |
DE602004001929D1 (en) | 2006-09-28 |
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