WO2008072810A1

WO2008072810A1 - Oil separator for reciprocating compressor having insulation function

Info

Publication number: WO2008072810A1
Application number: PCT/KR2006/005469
Authority: WO
Inventors: Geonho Lee; Haksoo Kim; Kibeom Kim; Ikseo Park; Kijung An; Frank Obrist; Christian Schmaelzle; Peter Giese; Stefan Kroess
Original assignee: Doowon Technical College; Doowon Electronic Co., Ltd.; Obrist Engineering Gmbh
Priority date: 2006-12-14
Filing date: 2006-12-14
Publication date: 2008-06-19
Also published as: KR101089963B1; KR20090089429A

Abstract

Provided is an oil separator for a reciprocating compressor having an insulation function, the compressor including: a housing, a cylinder block having a plurality of cylinder bores, pistons reciprocally accommodated in the cylinder bores, a piston drive means for driving the pistons, a piston connection shaft connected to the pistons, a valve apparatus installed opposite to bottoms of the pistons and having suction ports and discharge ports, and a suction chamber and a discharge chamber formed at the housing with the valve apparatus interposed therebetween, characterized in that the oil separator includes: an inner recess having a gas discharge port; a peripheral recess formed around the inner recess and in fluid communication with the discharge port; and an oil discharge port for communicating the inner recess with the exterior, wherein the oil separator is installed in the discharge chamber. Therefore, it is possible to increase efficiency of the compressor and maintain durability by separating oil from coolant introduced into the discharge chamber. In addition, coolant sucked from the suction chamber is not thermally affected by coolant discharged through the discharge port to maintain high volume efficiency of the compressor.

Description

OIL SEPARATOR FOR RECIPROCATING COMPRESSOR HAVING INSULATION FUNCTION

Technical Field

[1] The present invention relates to an oil separator for a reciprocating compressor having an insulation function, and more particularly, to an oil separator for a reciprocating compressor capable of maintaining the entire performance by separating oil before coolant discharged from a discharge chamber is discharged to the exterior of the compressor and providing insulation performance.

[2]

Background Art

[3] A reciprocating compressor includes a piston, a piston drive apparatus, a cylinder block, and a valve, and is widely used as a compressor for an air conditioner of a vehicle.

[4] Recently, a swash plate type compressor is widely used as a typical example of the reciprocating compressor. The swash plate type compressor can vary inclination of a swash plate depending on variation of thermal load to control strokes of pistons, thereby obtaining precise movement control. In addition, as the inclination is continuously varied, it is possible to reduce abrupt torque variation of an engine caused by the compressor to improve ride comfort of a vehicle even during operation of the compressor.

[5] The reciprocating compressor repeatedly performs sucking coolant from a suction chamber, compressing the coolant using pistons, discharging the compressed coolant to a discharge chamber, and transporting the coolant to the following cooling cycle.

[6] In this process, since the coolant discharged to the discharge chamber contains a small amount of oil, the oil should be separated from the coolant before the coolant is discharged. If the oil exists in the cooling cycle, flow resistance may increase, thermal transfer may be degraded, and the entire system efficiency may be lowered.

[7] Japanese Patent Publication No. 2004-036583 discloses a typical example of an oil separator for separating oil from coolant, which will be briefly described with reference to FIGS. IA and IB below.

[8] First, a swash plate type compressor disclosed in Japanese Patent Publication No.

2004-036583 includes a front housing 1, a rear housing 3, a cylinder block 2 disposed between the front housing 1 and the rear housing 3, pistons 7 reciprocating in cylinder bores 2a of the cylinder block 2, a rotary shaft 4 passing through the front housing 1 an d disposed in the housings 1 and 3 to transmit rotational force from an external power source to drive the pistons 7, a swash plate 6 connected to the pistons 7 and installed at the rotary shaft 4 in a tilted manner, and a swash plate chamber 36 for accommodating the swash plate 6. [9] Meanwhile, an oil separator 26 is installed adjacent to a discharge chamber 33 of the rear housing 3. The oil separator 26, which uses centrifugal force, is installed at the rear housing 3 and passes through a valve plate 20. [10] Of course, separated oil is supplied to a part, in which lubrication is needed, through a passage 27, and gaseous coolant joins a coolant cycle through a coolant outlet 54. [11] However, in the conventional swash plate type compressor, the oil separator 26 is installed through the valve plate 20, and disposed adjacent to the discharge chamber

33, not in the discharge chamber 33. As a result, the valve plate 20 must have a shape conforming to the oil separator 26, and have a separate space for installing the oil separator 26. [12] Therefore, it was also difficult to assemble and manufacture the conventional compressor. [13] In addition, since the discharged coolant is in direct contact with the rear housing 3, the temperature of suction gas sucked into the suction chamber 32 may be increased to decrease volume efficiency of the compressor. [14]

Disclosure of Invention

Technical Problem

[15] An object of the present invention is to provide an oil separator for a reciprocating compressor having an insulation function capable of maintaining the entire performance by separating oil before coolant discharged from a discharge chamber is discharged to the exterior of the compressor.

[16] Another object of the present invention is to provide an oil separator for a reciprocating compressor having an insulation function capable of readily assembling and manufacturing the oil separator.

[17] Still another object of the present invention is to provide an oil separator for a reciprocating compressor having an insulation function capable of maintaining original volume efficiency by preventing the discharged coolant from thermally affecting a suction coolant gas.

[18]

Technical Solution

[19] An aspect of the invention provides an oil separator for a reciprocating compressor having an insulation function, the compressor including: a housing, a cylinder block having a plurality of cylinder bores, pistons reciprocally accommodated in the cylinder bores, a piston drive means for driving the pistons, a piston connection shaft connected to the pistons, a valve apparatus installed opposite to bottoms of the pistons and having suction ports and discharge ports, and a suction chamber and a discharge chamber formed at the housing with the valve apparatus interposed therebetween, characterized in that the oil separator includes: an inner recess having a gas discharge port; a peripheral recess formed around the inner recess and in fluid communication with the discharge port; and an oil discharge port for communicating the inner recess with the exterior, wherein the oil separator is installed in the discharge chamber.

[20] In this process, the inner recess may be separated from the peripheral recess by a guide wall, and the inner and peripheral recesses may be in communication with each other through a coolant introduction groove formed at a tip of the guide wall or a coolant introduction hole formed at a side surface of the guide wall.

[21] The coolant introduction groove may be inclined in a flow direction of coolant.

[22] When seen in an axial direction, the coolant introduction groove may include an inlet port having a smoothly curved shape.

[23] In addition, the coolant introduction hole may be inclined in a flow direction of coolant.

[24] Further, when seen in an axial direction, the coolant introduction hole may include an inlet port having a smoothly curved shape.

[25] In addition, when seen in an axial direction, the guide wall may have a circular shape.

[26] Further, a center of the inner recess may be eccentric to a center of the gas discharge port.

[27] In this case, the inlet port of the coolant introduction groove or the coolant introduction hole may be formed at a wide part of the peripheral recess.

[28] The inner recess may have the same center as the peripheral recess.

[29] Meanwhile, the gas discharge port may project from a bottom of the inner recess to the valve apparatus.

[30] In this case, when seen in an axial direction, the gas discharge port may have a circular shape.

[31] In addition, the oil separator may have a projection at its outer bottom to be inserted into a groove formed inside the rear housing.

[32] In this case, the projection may have a hollow structure in communication with the gas discharge port.

[33] In addition, when seen in an axial direction, the oil separator may have prominences and depressions formed therearound at predetermined intervals, and the rear housing may have prominences and depressions to be inserted into the prominences and depressions of the oil separator. [34] Meanwhile, the oil separator may be formed of an insulating material.

[35] In addition, the insulating material may include polyetheretherketone (PEEK).

[36]

[37]

Brief Description of the Drawings

[38] The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[39] FIG. IA is a longitudinal cross-sectional view of a conventional swash plate type compressor;

[40] FIG. IB is a detailed cross-sectional view of an oil separator of FIG. IA;

[41] FIG. 2 is a longitudinal cross-sectional view of a reciprocating compressor having an oil separator formed of an insulating material in accordance with the present invention;

[42] FIG. 3 is a longitudinal cross-sectional view of an assembled structure of an oil separator and a rear housing of FIG. 2;

[43] FIG. 4 is an exploded perspective view of the oil separator and the rear housing of

FIG. 3;

[44] FIGS. 5 A and 5B are a perspective view and a front view showing an exemplary embodiment of the oil separator of FIG. 4, respectively;

[45] FIGS. 6 A and 6B are a perspective view and a front view showing another exemplary embodiment of the oil separator of FIG. 4, respectively; and

[46] FIG. 7 is a perspective view of still another exemplary embodiment of an oil separator formed of an insulating material in accordance with the present invention. Best Mode for Carrying Out the Invention

[47] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

[48] FIG. 2 is a longitudinal cross-sectional view of a reciprocating compressor having an oil separator formed of an insulating material in accordance with the present invention, FIG. 3 is a longitudinal cross-sectional view of an assembled structure of an oil separator and a rear housing of FIG. 2, FIG. 4 is an exploded perspective view of the oil separator and the rear housing of FIG. 3, FIGS. 5 A and 5B are a perspective view and a front view showing an exemplary embodiment of the oil separator of FIG. 4, respectively, FIGS. 6 A and 6B are a perspective view and a front view showing another exemplary embodiment of the oil separator of FIG. 4, respectively, a center of which is in an eccentric position, and FIG. 7 is a perspective view of still another exemplary embodiment of an oil separator formed of an insulating material in accordance with the present invention, in which a coolant introduction hole is formed at a side surface of a guide wall.

[49] First, a reciprocating compressor 1000 in accordance with the present invention includes a housing 100, a cylinder block 110 having a plurality of cylinder bores 110a, a drive shaft 140 rotatably supported by the cylinder block 110, a swash plate 150 connected to the drive shaft 140 and rotatably installed to vary its inclination, pistons 200 reciprocally accommodated in the cylinder bores 110a by slide movement with the swash plate 150, a suction/discharge valve apparatus 300 installed opposite to a bottom surface of the piston 200, and a suction chamber 131 and a discharge chamber 132 formed at the housing 100 and having the suction/discharge valve apparatus 300 interposed therebetween.

[50] The housing 100 includes a front housing 120 and a rear housing 130, interposing the cylinder block 110 therebetween.

[51] In addition, the rear housing 130 has the suction chamber 131 and the discharge chamber 132. A valve plate 330 has suction ports 331 for communicating the cylinder bores 110a with the suction chamber 131, and discharge ports 332 for communicating the cylinder bores 110a with the discharge chamber 132.

[52] Further, the suction ports 331 and the discharge ports 332 formed at the valve plate

330 include suction valves and discharge valves for opening and closing the suction ports 331 and the discharge ports 332 in response to pressure variation depending on reciprocation of the pistons 200, respectively.

[53] The cylinder block 110 has eight cylinder bores 110a. Coolant introduced from the suction chamber 131 by the pistons 200 reciprocating through the cylinder bores 110a is continuously compressed.

[54] The drive shaft 140 is rotatably supported by the front housing 120 and the cylinder block 110 through the medium of a bearing 400.

[55] Further, the swash plate 150 is slidably coupled with the pistons 200 by shoes 201.

[56] Furthermore, the swash plate 150 has connection projections 155 formed at its front and rear parts. Connection links 600 are interposed between the connection projections 155 and the drive shaft 140, which are connected to each other by hinge pins 610. Therefore, the connection links 600 and the connection projections 155, and the connection links 600 and the drive shaft 140 can be hinged to each other.

[57] Meanwhile, an oil separator 700 in accordance with the present invention is installed in the discharge chamber 132 of the rear housing 130.

[58] Specifically, since coolant discharged into the discharge chamber 132 of the rear housing 130 contains a small amount of oil, the oil should be separated by the oil separator using centrifugal force to supply only pure gaseous coolant through a cooling cycle. [59] For this purpose, the oil separator 700 in accordance with the present invention includes an inner recess 710 having a gas discharge port 711, a peripheral recess 720 formed around the inner recess 710 and in fluid communication with the discharge port 332; and an oil discharge port 730 for communicating the inner recess 710 with the exterior.

[60] The oil separator 700 in accordance with the present invention has a circular shape when seen in an axial direction, and a bowl shape when seen in a side view.

[61] First, coolant discharged through the discharge port 332 of the rear housing 130 is introduced into the peripheral recess 720 of the oil separator 700, and then introduced into the inner recess 710. For this purpose, a coolant introduction groove 741 is formed at a tip of a guide wall 740 between the inner recess 710 and the peripheral recess 720 to cross the guide wall 740.

[62] In addition, as shown in FIG. 7, a coolant introduction hole 742 may be formed at a side surface of the guide wall 740.

[63] Of course, while a predetermined gap may be entirely formed between the guide wall 740 and the valve assembly 300 to introduce coolant, it is difficult to sufficiently apply centrifugal force to the coolant.

[64] Especially, the coolant introduction groove 741 and the coolant introduction hole

742 may be inclined in a circumferential moving direction of coolant. In this case, since coolant can be smoothly introduced from the peripheral recess 720 to the inner recess 710 in a tangential direction of a circumference of the guide wall 740 (strictly, in a slightly inclined tangential direction), it is possible to apply large centrifugal force to the coolant.

[65] In addition, when seen in an axial direction, since an inlet port 714a of the coolant introduction groove 741 and an inlet port of the coolant introduction hole 742 may have a smoothly curved shape (a predetermined radius of curvature R), it is possible to more smoothly introduce coolant.

[66] Further, the inlet port 714a of the coolant introduction groove 741 or the inlet port of the coolant introduction hole 742 may have the largest cross-sectional area such that coolant can be smoothly introduced.

[67] Furthermore, when seen in an axial direction, the guide wall 740 may have a circular shape to allow coolant to be smoothly introduced.

[68] In FIGS. 6A, 6B and 7, while the coolant introduction groove 741 and the coolant introduction hole 742 are solely formed in a circumferential direction of the guide wall 740, it is also possible to form at least two coolant introduction grooves or holes.

[69] Meanwhile, the center of the inner recess 710 may be eccentric to the center of the gas discharge port 711. In this case, the width of a coolant path may be varied depending on the eccentricity to maximize oil separation performance. [70] In addition, since the wider the width of the coolant path, the larger the pressure, when the coolant introduction groove 741 or the coolant introduction hole 742 is formed at this point, it is possible to more smoothly introduce coolant.

[71] Of course, even though the inner recess 710 has the same center as the peripheral recess 720, it is possible to separate oil using centrifugal force.

[72] Meanwhile, the gas discharge port 711 may project from the bottom of the inner recess 710 toward the valve apparatus 300. In this case, it is possible to prevent the separated fine oil from being discharged with the coolant gas through the gas discharge port 711 along the bottom of the inner recess 710.

[73] In addition, when seen in an axial direction, the gas discharge port 711 may have a circular shape to smoothly apply centrifugal force to coolant.

[74] Further, a projection 770 (see FIG. 3) is formed at an outer bottom of the oil separator 700 and inserted into a groove 139 formed inside the rear housing 130. The projection 770 may have a hollow structure in communication with the gas discharge port 711, for the convenience of manufacturing.

[75] In addition, when seen in an axial direction, the oil separator 700 has prominences and depressions 790 formed therearound at predetermined intervals, and the rear housing 130 also has prominences and depressions 138 formed therein such that the prominences and depressions 790 of the oil separator 700 are inserted, thereby facilitating an assembly process and preventing shaking during operation.

[76] Meanwhile, the oil separator 700 may be formed of an insulating material such as

PEEK. Of course, other insulating materials such as synthetic resin, etc., may be used.

[77] Since the oil separator 700 is formed of an insulating material, coolant sucked from the suction chamber 131 may almost not be thermally affected by coolant discharged through the discharge port 332 to obtain predetermined volume efficiency.

[78] Hereinafter, operations of peripheral parts of the oil separator 700 formed of an insulating material in accordance with the present invention will be described in brief.

[79] First, when a compressor 1000 operates, a pulley P connected to an engine (not shown) rotates, and a drive shaft 140 connected to the pulley P rotates.

[80] As the drive shaft 140 rotates, a swash plate 150 rotates in a tilted manner, and pistons 200 slide along the swash plate 150 to perform compression of coolant.

[81] Specifically, coolant introduced through a suction port 331 of a valve apparatus 300 is compressed in cylinder bores 1 Ia by the pistons 200, and the compressed coolant is introduced into a peripheral recess 710 of an oil separator 700 formed of an insulating material through a discharge port 332 of the valve apparatus 300.

[82] Then, the coolant is introduced into an inner recess 720 from the peripheral recess

710 through a coolant introduction groove 741 or a coolant introduction hole 742 formed at a guide wall 740 to apply centrifugal force to the coolant. [83] At this time, oil having large density is collected onto a side bottom of the inner recess 710 disposed at an outer side of the gas discharge port 711, and continuously flows toward a control valve 800 through an oil discharge port 730. [84] The oil passing through the control valve 800 is supplied to each part of the compressor through a swash plate chamber 120a or an inner part of a drive shaft 140 by an oil pump 910. [85] While the above constitution is described as an exemplary embodiment of the present invention, it will be apparent to those skilled in the art that the oil separator may be adapted to various general reciprocating compressors including a piston, a cylinder block, a piston drive means, a housing, and a valve apparatus, in addition to the swash plate type compressor. [86]

Industrial Applicability [87] As can be seen from the foregoing, it is possible to increase efficiency of a compressor and maintain durability by separating oil from coolant introduced into a discharge chamber. [88] In addition, a coolant introduction groove may be formed at a tip of a guide wall or a coolant introduction hole may be formed at a side surface of the guide wall to allow smooth introduction of coolant. [89] Further, the coolant introduction groove and the coolant introduction hole may have a specific structure to more smoothly introduce coolant. [90] Furthermore, the center of an inner recess may be eccentric to the center of a gas discharge port to generate a pressure difference, thereby facilitating introduction of coolant through the coolant introduction groove. [91] In addition, the gas discharge port may project from the bottom of the inner recess to a valve to prevent oil from being discharged with coolant gas after separating the oil. [92] Further, since the oil separator is formed of an insulating material, coolant sucked from a suction chamber may not be thermally affected by coolant discharged through a discharge port to maintain high volume efficiency of the compressor. [93] Furthermore, a projection may be formed at an outer bottom of the oil separator to be inserted into a groove formed inside a rear housing to facilitate an assembly process and increase assembly integrity. [94] While this invention has been described with reference to exemplary embodiments thereof, it will be clear to those of ordinary skill in the art to which the invention pertains that various modifications may be made to the described embodiments without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. [95]

Claims

[1] An oil separator for a reciprocating compressor having an insulation function, the compressor comprising: a housing, a cylinder block having a plurality of cylinder bores, pistons reciprocally accommodated in the cylinder bores, a piston drive means for driving the pistons, a piston connection shaft connected to the pistons, a valve apparatus installed opposite to bottoms of the pistons and having suction ports and discharge ports, and a suction chamber and a discharge chamber formed at the housing with the valve apparatus interposed therebetween, characterized in that the oil separator comprises: an inner recess having a gas discharge port; a peripheral recess formed around the inner recess and in fluid communication with the discharge port; and an oil discharge port for communicating the inner recess with the exterior, wherein the oil separator is installed in the discharge chamber.

[2] The oil separator according to claim 1, wherein the inner recess is separated from the peripheral recess by a guide wall, and the inner and peripheral recesses are in communication with each other through a coolant introduction groove formed at a tip of the guide wall or a coolant introduction hole formed at a side surface of the guide wall.

[3] The oil separator according to claim 2, wherein the coolant introduction groove is inclined in a flow direction of coolant.

[4] The oil separator according to claim 3, wherein, when seen in an axial direction, the coolant introduction groove has an inlet port having a smoothly curved shape.

[5] The oil separator according to claim 2, wherein the coolant introduction hole is inclined in a flow direction of coolant.

[6] The oil separator according to claim 3, wherein, when seen in an axial direction, the coolant introduction hole has an inlet port having a smoothly curved shape.

[7] The oil separator according to any one of claims 2 to 6, wherein, when seen in an axial direction, the guide wall has a circular shape.

[8] The oil separator according to claim 7, wherein a center of the inner recess is eccentric to a center of the gas discharge port.

[9] The oil separator according to claim 8, wherein the inlet port of the coolant introduction groove or the coolant introduction hole is formed at a wide part of the peripheral recess.

[10] The oil separator according to claim 7, wherein the inner recess has the same center as the peripheral recess. [11] The oil separator according to any one of claims 3 to 6, wherein the gas discharge port projects from a bottom of the inner recess to the valve apparatus. [12] The oil separator according to claim 11, wherein, when seen in an axial direction, the gas discharge port has a circular shape. [13] The oil separator according to claim 2, wherein the oil separator has a projection at its outer bottom to be inserted into a groove formed inside the rear housing. [14] The oil separator according to claim 13, wherein the projection has a hollow structure in communication with the gas discharge port. [15] The oil separator according to any one of claims 1 to 6, wherein, when seen in an axial direction, the oil separator has prominences and depressions formed therearound at predetermined intervals, and the rear housing has prominences and depressions to be inserted into the prominences and depressions of the oil separator. [16] The oil separator according to any one of claims 1 to 6, wherein the oil separator is formed of an insulating material. [17] The oil separator according to claim 16, wherein the insulating material comprises polyetheretherketone (PEEK).