WO2008143370A1

WO2008143370A1 - A housing unified with oil separating structure for reciprocating compressor

Info

Publication number: WO2008143370A1
Application number: PCT/KR2007/002483
Authority: WO
Inventors: Geonho Lee; Haksoo Kim; Kibeom Kim; Ikseo Park; Kijung An; Frank Obrist; Christian Schmaelzle; Peter Giese
Original assignee: Doowon Technical College; Doowon Electronic Co., Ltd.; Obrist Engineering Gmbh
Priority date: 2007-05-22
Filing date: 2007-05-22
Publication date: 2008-11-27
Also published as: KR101328855B1; KR20100017213A

Abstract

Provided is a housing integrated with an oil separating structure for a reciprocating compressor including a housing having a suction chamber and a discharge chamber, a cylinder block coupled with the housing and having a plurality of cylinder bores, pistons reciprocally accommodated in the cylinder bores, piston drive means for driving the pistons, and a valve apparatus opposite to bottoms of the pistons and having a suction port and a discharge port in communication with the suction chamber and the discharge chamber, characterized in that: the oil separating structure has an inner recess having a gas discharge port formed at its bottom, a peripheral recess formed around the inner recess and in communication with the discharge chamber, and an oil discharge port in communication with the inner recess in a circulation manner, which are integrally formed with each other; and the discharge chamber rather than the suction chamber is disposed adjacent to a center thereof. Therefore, since the oil is separated from the coolant introduced into the discharge chamber and reused, it is possible to increase efficiency and maintain durability of the compressor. In addition, since the oil separating structure is integrally formed with the housing, there is no need to provide a separate component for separating oil, and the housing can be readily formed to reduce manufacturing cost.

Description

A HOUSING UNIFIED WITH OIL SEPARATING STRUCTURE FOR RECIPROCATING COMPRESSOR

Technical Field

[1] The present invention relates to a housing integrated with an oil separating structure for a reciprocating compressor, and more particularly, to a housing integrated with an oil separating structure for a reciprocating compressor capable of maintaining the entire performance of a reciprocating compressor by separating oil before discharging a coolant from a discharge chamber to the exterior of the compressor and simultaneously providing insulation performance

[2]

Background Art

[3] A general reciprocating compressor, which is widely used as a compressor of an air-conditioner for an automobile, commonly includes a piston, a piston driving apparatus, a cylinder block, a valve, and so on.

[4] Recently, a swash plate type compressor has been widely used as a typical example of a reciprocating compressor. In the swash plate type compressor, an inclination angle of a swash plate is varied depending on variation of thermal load to control a stroke of a piston, thereby accomplishing precise movement control. At the same time, the inclination angle is continuously varied to reduce an abrupt torque variation of an engine due to the compressor, thereby improving ride quality of a vehicle even during operation of the compressor.

[5] Such a reciprocating compressor repeats a process of sucking a coolant from a suction chamber to compress the coolant using the piston, and discharging the compressed coolant to a discharge chamber to transmit the coolant to the subsequent 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 to discharge the coolant only. When oil exists in a cooling cycle, a flow path resistance may be increased, thermal transfer may be interfered with, and efficiency of the entire system may be decreased.

[7] Typical constitution of an oil separator for separating oil from a coolant is disclosed in Japanese Laid-open Patent Publication No. 2004-36583, which will be described with reference to FIGS. IA and IB.

[8] First, the compressor disclosed in the above publication is a swash plate type compressor, which includes a front housing 1, a rear housing 3, a cylinder block 2 disposed between the front housing 1 and the rear housing 3, a plurality of pistons 7 reciprocating in cylinders 2a of the cylinder block 2, a rotary shaft 4 passing through a front part of the housings 1 and 3 and disposed in the housings 1 and 3 to transmit a rotational movement from external power to drive the piston 7, a swash plate 6 connected to the plurality of pistons 7 and disposed on 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 a centrifugal force, is installed at the rear housing 3 and passes through a valve plate 20.

[10] The separated oil is supplied to a portion to be lubricated through a flow path 27, and a gas coolant joins a cooling cycle through a coolant outlet 54.

[H]

Disclosure of Invention Technical Problem

[12] However, in the conventional swash plate type compressor, the oil separator 26 is installed through the valve plate 20 and adjacent to the discharge chamber 33, not in the discharge chamber 33. That is, the valve plate 20 must have a structure conforming to the oil separator 26, and must have a separate space for installing the oil separator 26.

[13] Therefore, assembly and manufacture of the conventional compressor can be very troublesome and difficult.

[14] In addition, since the discharged coolant is in direct contact with the rear housing 3, the temperature of a gas sucked into a suction chamber 32 may be increased, which thereby decreases volume efficiency of the compressor.

[15] An object of the present invention is to provide a housing integrated with an oil separating structure for a reciprocating compressor capable of separating oil before a coolant discharged from the compressor is discharged from a discharge chamber to the exterior, thereby maintaining the entire performance of the compressor.

[16] Another object of the present invention is to provide a housing integrated with an oil separating structure for a reciprocating compressor capable of readily assembling and manufacturing the compressor.

[17] Still another object of the present invention is to provide a housing integrated with an oil separating structure for a reciprocating compressor capable of preventing the discharged coolant from thermally affecting the sucked coolant gas, thus maintaining original volume efficiency of the compressor.

[18]

Technical Solution [19] An aspect of the invention provides a housing integrated with an oil separating structure for a reciprocating compressor comprising a housing having a suction chamber and a discharge chamber, a cylinder block coupled with the housing and having a plurality of cylinder bores, pistons reciprocally accommodated in the cylinder bores, piston drive means for driving the pistons, and a valve apparatus opposite to bottoms of the pistons and having a suction port and a discharge port in communication with the suction chamber and the discharge chamber, characterized in that: the oil separating structure has an inner recess having a gas discharge port formed at its bottom, a peripheral recess formed around the inner recess and in communication with the discharge chamber, and an oil discharge port in communication with the inner recess in a circulation manner, which are integrally formed with each other; and the discharge chamber rather than the suction chamber is disposed adjacent to a center thereof.

[20] In this process, the inner recess may be partitioned from the peripheral recess by a guide wall, and the inner recess may be in communication with the peripheral recess through a coolant introduction groove formed at a tip of the guide wall.

[21] In this case, the coolant introduction groove may have a slope in a direction of movement of the coolant.

[22] In addition, when seen from an axial direction, the coolant introduction groove may have a smoothly curved inlet.

[23] Meanwhile, the inner recess may be partitioned from the peripheral recess by a guide wall, and the inner recess may be in communication with the peripheral recess through a coolant introduction hole formed at the side of the guide wall.

[24] In this case, the coolant introduction hole may have a slope in a direction of movement of the coolant.

[25] In addition, when seen from an axial direction, the coolant introduction hole may have a smoothly curved inlet.

[26] The gas discharge port may project from the bottom of the inner recess toward the valve apparatus.

[27] When seen from an axial direction, the guide wall may have a circular shape.

[28] The inner recess may be aligned to the gas discharge port in an eccentric manner.

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

[30] The inner recess may be aligned to the peripheral recess in a concentric manner.

[31] Meanwhile, when seen from an axial direction, the gas discharge port may have a circular shape. Brief Description of the Drawings

[33] 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:

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

[35] FIG. IB is a specific cross-sectional view of an oil separating structure of FIG. IA;

[36] FIG. 2 is a longitudinal cross-sectional view of a reciprocating compressor including a housing integrally formed with an oil separating structure in accordance with an exemplary embodiment of the present invention;

[37] FIGS. 3A, 3B and 3C are a perspective view, a front view, and a longitudinal cross- sectional view of a housing integrally formed with an oil separating structure in accordance with an exemplary embodiment of the present invention, respectively; and

[38] FIGS. 4A and 4B are a perspective view and a front view of a housing integrally formed with an oil separating structure in accordance with another exemplary embodiment of the present invention, respectively.

[39]

Best Mode for Carrying Out the Invention

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

[41] Exemplary embodiments of the present invention will now be described with reference to FIGS. 2 to 4.

[42] 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 rotatably connected to the drive shaft 140 to vary its inclination angle, pistons 200 reciprocally accommodated in the cylinder bores 110a by a slidable movement with respect to the swash plate 150, a suction/discharge valve apparatus 300 installed opposite to bottoms of the pistons 200, and a suction chamber 131 and a discharge chamber 132 formed at the housing 100 through the medium of the suction/discharge valve apparatus 300. A shoe 201 is installed between the swash plate 150 and the pistons 200.

[43] The drive shaft 140, the swash plate 150, and the shoe 201 constitute a piston drive mechanism of the present invention.

[44] The housing 100 includes a front housing 120 and a rear housing 130 with the cylinder block 110 interposed therebetween.

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

[46] In addition, a suction valve and a discharge valve are installed at the suction port

331 and the discharge port 332 formed at the valve plate 330 to open/close the suction port 331 and the discharge port 332 depending on pressure variation due to reciprocation of the pistons 200.

[47] The cylinder block 110 has eight cylinder bores 110a, and the pistons 200 reciprocating through the cylinder bores 110a continuously compress the coolant introduced from the suction chamber 131.

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

[49] In addition, the swash plate 150 is slidably engaged with the pistons 200 through the medium of the shoe 201.

[50] Further, connection projections 155 are formed at a front and a rear of the swash plate 150, and connection links 600 are connected between connection projections 155 and the drive shaft 140 by hinge pins 610. Therefore, the connection links 600 and the connection projections 155, and the connection links 600 and the drive shaft 140 may be hinged to each other.

[51] Meanwhile, according to the present invention, the rear housing 130 is integrally formed with an oil separating structure.

[52] Therefore, according to the present invention, a small amount of oil contained in the coolant sucked from the suction chamber 131 of the rear housing 130 is separated by the oil separating structure so that only a pure gas coolant circulates through a coolant cycle. The oil separating structure in accordance with an exemplary embodiment of the present invention centrifuges the coolant in a misty state to separate oil and a gas coolant.

[53] For this purpose, the oil separating structure 700 integrally formed with the rear housing 130 in accordance with the present invention has an inner recess 710 having a gas discharge port 711 formed in an axial direction of the piston, a peripheral recess 720 formed around the inner recess 710 and in communication with the discharge port 332, and an oil discharge port 730 for communicating the inner recess 710 with the exterior.

[54] A guide wall 740 is formed between the inner recess 710 and the peripheral recess

720. In addition, a coolant introduction groove 741 is formed to cross a tip of the guide wall 740. Therefore, a coolant in the peripheral recess 720 is smoothly introduced into the inner recess 710 through the coolant introduction groove 741.

[55] Alternatively, as shown in FIG. 4, a coolant introduction hole 742 is formed through the guide wall 740 to introduce a coolant from the peripheral recess 720 into the inner recess 710. [56] The coolant introduction groove 741 or the coolant introduction hole 742 may have a slope in a circumferential moving direction of the coolant such that the coolant can be smoothly introduced in a tangential direction (actually, slightly sloped to a normal direction) of the circumference from the peripheral recess 720 to the inner recess 710, thereby providing a high centrifugal force to the coolant.

[57] Moreover, when seen from an axial direction, an inlet 741a of the coolant introduction groove 741 or an inlet of the coolant introduction hole 742 has a smoothly curved shape (a radius of curvature = R) to enable smoother introduction of the coolant. [58] In addition, the inlet 741a of the coolant introduction groove 741 or the inlet of the coolant introduction hole 742 may have a largest width to smoothly introduce the coolant. [59] Further, when the guide wall 740 has a circular shape, seen from an axial direction, the coolant can be more smoothly introduced. [60] While the coolant introduction groove 741 or the coolant introduction hole 742 is solely formed to cross the guide wall 740, at least two grooves or holes may be formed. [61] Meanwhile, the inner recess 710 may be aligned to the gas discharge port 711 in an eccentric manner. As a result, a width of a coolant path is varied due to the eccentric manner of alignment to maximize an oil separating function. [62] In addition, the more the width of the coolant path widens, the more the pressure is increased, and the coolant introduction groove 741 may be formed at the coolant path having the largest width to more smoothly introduce the coolant. [63] The inner recess 710 may be aligned to the peripheral recess 720 to separate oil using a centrifugal force. [64] Meanwhile, the gas discharge port 711 may project from a bottom of the inner recess 710 toward the valve apparatus 300. As a result, it is possible to prevent a small amount of separated oil from being discharged together with the coolant gas through the gas discharge port 711 along the bottom of the inner recess 710. [65] In addition, when seen from an axial direction, the gas discharge port 711 may have a circular shape that smoothly centrifuges the coolant. [66] Hereinafter, operation of the compressor including an oil separating structure integrated housing in accordance with the present invention will be briefly described with reference to FIG. 3. [67] First, when the compressor 1000 is operated, a pulley P connected to an engine (not shown) is rotated to rotate the drive shaft 140 installed at the pulley P. [68] The drive shaft 140 rotates the swash plate 150 in a tilted manner to slidably re- ciprocate the pistons 200 to compress the coolant.

[69] Specifically, the coolant introduced through the suction port 331 of the valve apparatus 300 is compressed in the cylinder bores 110a by the pistons 200, and the compressed coolant is introduced into the peripheral recess 710 of the oil separating structure integrated housing 130 through the discharge port 332 of the valve apparatus 300.

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

710 through the coolant introduction groove 741 formed at the guide wall 740 to apply centrifugal force to the coolant.

[71] At this time, a large density of oil is collected on an outer side of the bottom of the inner recess 710 outside the gas discharge port 711, and the oil is continuously moved to a control valve 800 through an oil discharge port 730.

[72] The oil passed through the control valve 800 is supplied through a swash plate chamber 120a and the interior of the drive shaft 140 by an oil pump 910.

[73] The above constitution of the swash plate type compressor is described for an illustrative purpose only, and another general reciprocating compressor including a piston, a cylinder block, a piston drive mechanism, a housing, and a valve apparatus can be adapted by those skilled in the art.

[74]

Industrial Applicability

[75] As can be from the foregoing, it is possible to separate oil from a coolant introduced into a discharge chamber to increase efficiency and maintain durability of a compressor.

[76] In addition, since an oil separating structure is integrally formed with a housing, there is no need to prepare a separate component for separating oil, and the housing can be readily formed to reduce manufacturing cost of the compressor.

[77] Further, a coolant introduction hole or a coolant introduction groove is formed at a guide wall or a tip of the guide wall to smoothly introduce a coolant.

[78] Furthermore, a specific shape of a coolant introduction groove or a coolant introduction hole is formed to more smoothly introduce a coolant.

[79] In addition, an inner recess is aligned to a gas discharge port in an eccentric manner to generate a pressure difference such that a coolant can be more smoothly introduced through the coolant introduction groove or the coolant introduction hole.

[80] Further, the gas discharge port projects from a bottom of the inner recess toward a valve to prevent oil from being partially discharged together with a coolant gas after the oil separation.

[81] Although a few exemplary embodiments of the present invention have been shown and described above, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.

Claims

[1] A housing integrated with an oil separating structure for a reciprocating compressor comprising a housing having a suction chamber and a discharge chamber, a cylinder block coupled with the housing and having a plurality of cylinder bores, pistons reciprocally accommodated in the cylinder bores, piston drive means for driving the pistons, and a valve apparatus opposite to bottoms of the pistons and having a suction port and a discharge port in communication with the suction chamber and the discharge chamber, characterized in that: the oil separating structure has an inner recess having a gas discharge port formed at its bottom, a peripheral recess formed around the inner recess and in communication with the discharge chamber, and an oil discharge port in communication with the inner recess in a circulation manner, which are integrally formed with each other; and the discharge chamber rather than the suction chamber is disposed adjacent to a center thereof.

[2] The housing according to claim 1, wherein the inner recess is partitioned from the peripheral recess by a guide wall, and the inner recess is in communication with the peripheral recess through a coolant introduction groove formed at a tip of the guide wall.

[3] The housing according to claim 2, wherein the coolant introduction groove has a slope in a direction of movement of the coolant.

[4] The housing according to claim 3, wherein, when seen from an axial direction, the coolant introduction groove has a smoothly curved inlet.

[5] The housing according to claim 1, wherein the inner recess is partitioned from the peripheral recess by a guide wall, and the inner recess is in communication with the peripheral recess through a coolant introduction hole formed at the side of the guide wall.

[6] The housing according to claim 5, wherein the coolant introduction hole has a slope in a direction of movement of the coolant.

[7] The housing according to claim 6, wherein, when seen from an axial direction, the coolant introduction hole has a smoothly curved inlet.

[8] The housing according to any one of claims 1 to 7, wherein the gas discharge port projects from a bottom of the inner recess toward the valve apparatus.

[9] The housing according to claim 8, wherein, when seen from an axial direction, the guide wall has a circular shape.

[10] The housing according to claim 8, wherein the inner recess is aligned to the gas discharge port in an eccentric manner. [11] The housing according to claim 10, wherein the inlet of the coolant introduction groove or the coolant introduction hole is formed at a wider part of the peripheral recess. [12] The housing according to claim 8, wherein the inner recess is aligned to the peripheral recess in a concentric manner. [13] The housing according to claim 12, wherein, when seen from an axial direction, the gas discharge port has a circular shape.