US20060078452A1

US20060078452A1 - Oil discharge reducing device for scroll compressor

Info

Publication number: US20060078452A1
Application number: US11/034,821
Authority: US
Inventors: Jin-Sung Park; Dong-Koo Shin; Cheol-Hwan Kim; Hyo-Keun Park; Yang-Hee Cho; In-Hwe Koo; Nam-Kyu Cho
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2004-10-07
Filing date: 2005-01-14
Publication date: 2006-04-13
Also published as: JP2006105123A; DE102005000899B4; DE102005000899A1; JP4680614B2

Abstract

An oil discharge reducing device for a scroll compressor comprises: a refrigerant guiding mechanism for guiding a refrigerant gas of high pressure discharged through a discharge opening of the fixed scroll to a rotor of the driving motor; and an oil separating mechanism penetrated through the rotor and for separating oil contained in the refrigerant gas by a centrifugal force caused by the rotation of the rotor while the refrigerant gas guided by the refrigerant guiding mechanism cools the driving motor as it flows though the driving motor. According to this, an amount of oil leaked to outside of the compressor is minimized, and the driving motor constituting the compressor can be effectively cooled.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a scroll compressor, and more particularly to, an oil discharge reducing device for a scroll compressor which minimizes a quantity of oil flowing out of the compressor and effectively cools a driving motor constituting the compressor.
2. Description of the Background Art
Generally, a scroll compressor is changed in volume as it moves relative to a plurality of compression chambers formed by two scrolls along with the circling motion-of the two scrolls being contacted, and the scroll compressor sucks, compresses and discharges gas according to a change in volume of the compression chambers.
The scroll compressor is classified into a low pressure type in which the inside of a casing is kept at a low pressure, i.e., a suction pressure, and a high pressure type in which the inside of a casing is kept at a high pressure, i.e., a discharge pressure.
FIG. 1 is a sectional view illustrating one example of a high pressure scroll compressor.
As illustrated therein, the high pressure scroll compressor comprises: a casing 16 provided with a suction pipe 11 and a discharge pipe 12; a main frame 20 and a sub frame 30 secured and coupled to the casing 10 at a predetermined vertical interval; a fixed scroll 40 secured and coupled to the casing 10 so as to be located in the upper side of the main frame 20; a orbiting scroll 50 located between the fixed scroll 40 and the main frame 20 so as to be swivellingly engaged with the fixed scroll 40; an Oldham's ring 60 located between the orbiting scroll 50 and the main frame 20 for preventing the rotation of the orbiting scroll 50; a driving motor secured and coupled to the casing 10 for generating a driving force so as to be located between the main frame 20 and the sub frame 30; and a rotary shaft 70 for transmitting the driving force of the driving motor to the orbiting scroll 50.
The bottom face of the casing 10 is filled with oil. The suction pipe 11 and the discharge pipe 12 are located in the same direction, and the discharge pipe 12 is located in the lower side of the fixed scroll 40.
The main frame 20 includes: a shaft insertion hole 22 formed at a frame body portion 21 having a predetermined shape and for having the rotary shaft 70 penetrated and inserted thereinto; a boss insertion groove 23 extending from the axial insertion hole 22 and having a larger inner diameter than the shaft insertion hole 22 has; a bearing surface 24 formed on the top surface of the frame body portion 21 and for supporting the orbiting scroll 50; a back pressure space groove 25 formed in a predetermined shape at the frame body portion 21 and forming a pressure space along with the backside of the orbiting scroll 50; and a flow channel groove 26 formed on the outer surface of the frame body portion 21 and forming a gas pathway along with the casing 10.
The fixed scroll 40 includes a body portion 41 formed in a predetermined shape, a wrap 42 formed on one surface of the body portion 41 in an involute curve having a predetermined thickness and height, a discharge opening 43 penetrated at the center of the body portion 41, a suction port 44 formed at one side of the body portion 41 and a flow channel groove 45 formed on the outer surface of the fixed scroll 40 and for flowing gas through along with the casing 10. The suction pipe 11 provided at the casing 10 is inserted and coupled to the suction port.
The orbiting scroll 50 includes a disc portion 51 having a predetermined thickness and area, a wrap 52 formed on one surface of the disc portion 51 in an involute curve having a predetermined thickness and height, and a boss portion 53 formed at the center of the other side of the disc portion 51.
The orbiting scroll 50 is coupled between the fixed scroll 40 and the main frame 20 so that the wrap 52 is engaged with the fixed scroll wrap 42, the boss portion 53 is inserted into the boss insertion groove 23 of the main frame 20 and one surface of the disc portion 51 is supported by the bearing surface 24 of the main frame 20.
The rotary shaft 70 is provided with an eccentric portion 71. One side of the rotary shaft 70 is penetrated and inserted into the shaft insertion hole 22 of the main frame 20 to couple the eccentric portion 71 to the boss portion 53 of the orbiting scroll 50, and the other side thereof is supported by the sub frame 30.
The driving motor includes a stator 80 provided with a coil C and secured and coupled to the casing 10 and a rotor 90 rotatably coupled to the inside of the stator 80. A gas pathway through which gas flows is formed on the outer circumferential surface of the stator 80 along with the casing 10.
Unexplained reference numeral B represents bushes, 100 represents an oil feeder mounted to the rotary shaft 70 and 110 represents a balance weight.
The operation of the compression mechanism of the high pressure scroll compressor as set forth above will be described below.
When a power is applied to the scroll compressor, the rotor 90 is rotated by an interaction between the stator 80 and rotor 90 constituting the driving motor, and the rotary force of the rotor 90 is transmitted to the orbiting scroll 50 through the rotary shaft 70. With the transmission of the rotary force of the rotary shaft 70 to the orbiting scroll 50, the orbiting scroll 50 coupled to an eccentric portion 71 of the rotary shaft orbits around the axis of the rotary shaft 70. The orbiting scroll 50 orbits as being prevented from rotation by the Oldham's ring 60.
With the orbiting scroll 50 orbiting, as the wrap 52 of the orbiting scroll orbits engaged with the wrap 42 of the fixed scroll, a plurality of compression pockets P formed by -the wrap 52 of the orbiting scroll and the wrap 42 of the fixed scroll moves to the center parts of the fixed scroll 40 and orbiting scroll 50, and at the same time, as their volume changes, sucks and compresses gas and discharges it through the discharge opening 43 of the fixed scroll.
At this time, the gas is sucked into the suction port 44 of the fixed scroll through the suction pipe 11 and the gas flown into the suction port 44 is sucked to the compression pockets P.
A refrigerant gas of high temperature and high pressure state discharged through the discharge opening 43 of the fixed scroll, as shown in FIG. 2, passes through the flow channel groove 45 of the fixed scroll and the flow channel groove 26 of the main frame to flow to the lower side of the main frame 20. Most of the refrigerant gas of high pressure flown into the lower side is discharged through the discharge pipe 12, and some parts of the refrigerant gas passes through the pathway between the stator 80 and the casing 90 to flow to the lower side of the driving motor and the refrigerant gas moved to the lower side of the driving motor moves again to the upper side through the pathway between the stator 80 and the casing 10. In this procedure, the driving motor is cooled. The refrigerant gas cooling the driving motor is discharged out through the discharge pipe 12. The refrigerant gas of high temperature and high pressure discharged through the discharge pipe 12 circulates in a cooling cycle system.
Meanwhile, with the rotation of the rotary shaft 70, the oil filled in the bottom face of the casing 10 is fed by the oil feeder 100 coupled to the rotary shaft 70 and by a centrifugal force of the rotary shaft 70, to thus be flown to the upper side through the oil flow channel 72 of the rotary shaft. The oil flown to the upper side through the oil flow channel 72 of the rotary shaft is ejected to the boss insertion groove 23 of the main frame, and the oil ejected to the boss insertion groove 23 is supplied between parts where relative motion occurs. The oil supplied between the parts is recovered to the bottom face of the casing 10 through the shaft insertion hole 22.
In the high pressure scroll compressor as set forth above, however, while the refrigerant gas of high temperature and high pressure discharged through the discharge opening 43 of the fixed scroll passes through the casing 10 and then is discharged through the discharge pipe 12, some parts of the oil recovered to the bottom face of the casing 10 after being ejected through the oil flow channel 72 are mixed with the refrigerant gas of high temperature and then directly discharged out through the discharge pipe 12. Due to this, since an excessive amount of oil filled in the casing 10 is excessively flown out into the cooling cycle system and this leads to a shortage of oil in the casing 10, the oil cannot be smoothly supplied to the parts which relative motion occurs between and an excessive amount of oil is flown out into the cooing cycle system, thereby deteriorating the efficiency of the cooling cycle system.
Further, since some parts of the refrigerant gas flow through the pathway formed by the outer circumferential surface of the driving motor stator 80 and the inner circumferential surface of the casing 10, the driving motor cannot be cooled effectively.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide an oil discharge reducing device for a scroll compressor which prevents the shortage of oil in the compressor and increases the efficiency of a cooling cycle system including the compressor by minimizing the amount of oil flowing out of the compressor.
Another object of the present invention is to provided an oil discharge reducing device for a scroll compressor which effectively cools a driving motor constituting the compressor.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an oil discharge reducing device for a scroll compressor, the scroll compressor comprising: a casing filled with oil at the bottom face thereof; a driving motor mounted to the casing and for generating a rotary force; a main frame secured and coupled to the casing; a fixed scroll located at a predetermined interval from the main frame; and a orbiting scroll located between the fixed scroll and the main frame, and interlocked with the fixed scroll, wherein the oil discharge device comprises: a refrigerant guiding mechanism for guiding a refrigerant gas of high pressure discharged through a discharge opening of the fixed scroll to a rotor side of the driving motor; and an oil separating mechanism penetrated through the rotor and for separating oil contained in the refrigerant gas by a centrifugal force caused by the rotation of the rotor while the refrigerant gas guided by the refrigerant guiding mechanism cools the driving motor as it flows though.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
In the drawings:
FIG. 1 is a sectional view illustrating one example of a high pressure scroll compressor;
FIG. 2 is a sectional view illustrating an operating state of the high pressure scroll compressor;
FIG. 3 is a sectional view of a high pressure scroll compressor provided with an oil discharge reducing device for a scroll compressor according to one embodiment of the present invention;
FIG. 4 is an exploded perspective view illustrating a rotor of a driving motor constituting the high pressure scroll compressor;
FIG. 5 is a plane view illustrating the rotor of the driving motor constituting the high pressure scroll compressor;
FIG. 6 is a sectional view illustrating an oil separating plate constituting the oil discharge reducing device for a scroll compressor according to the present invention;
FIGS. 7 and 8 are front sectional and plane sectional views illustrating a through flow channel constituting the oil discharge reducing device for a scroll compressor according to the present invention;
FIG. 9 is a partial sectional view illustrating a modified example of the through flow channel; and
FIG. 10 is a sectional view of the high pressure scroll compressor illustrating an operating state of the oil discharge reducing device for a scroll compressor according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an oil discharge reducing device for a scroll compressor according to the present invention will be described in detail according to an embodiment illustrated in the accompanying drawings.
FIG. 3 is a sectional view of a high pressure scroll compressor provided with an oil discharge reducing device for a scroll compressor according to one embodiment of the present invention. The same reference numerals are given with respect to the same parts as in the prior art.
As illustrated therein, the high pressure scroll compressor comprises: a casing 10 provided with a suction pipe 11 and a discharge pipe 12; a main frame 20 and a sub frame 30 secured and coupled to the casing 10 at a predetermined vertical interval; a fixed scroll 40 secured and coupled to the casing 10 so as to be located in the upper side of the main frame 20; a orbiting scroll 50 located between the fixed scroll 40 and the main frame 20 so as to be swivellingly engaged with the fixed scroll 40; an Oldham's ring 60 located between the orbiting scroll 50 and the main frame 20 for preventing the rotation of the orbiting scroll 50; a driving motor secured and coupled to the casing 10 for generating a driving force so as to be located between the main frame 20 and the sub frame 30; and a rotary shaft 70 for transmitting the driving force of the driving motor to the orbiting scroll 50.
The bottom face of the casing 10 is filled with oil. The suction pipe 11 and the discharge pipe 12 are located in the same direction, and the discharge pipe 12 is located in the lower side of the fixed scroll 40.
The main frame 20 includes: a shaft insertion hole 22 formed at a frame body portion 21 having a predetermined shape and for having the rotary shaft 70 penetrated and inserted thereinto; a boss insertion groove 23 extending from the axial insertion hole 22 and having a larger inner diameter than the shaft insertion hole 22 has; a bearing surface 24 formed on the top surface of the frame body portion 21 and for supporting the orbiting scroll 50; and a back pressure space groove 25 formed in a predetermined shape at the frame body portion 21 and forming a pressure space along with the backside of the orbiting scroll 50; and a flow channel groove 26 formed on the outer surface of the frame body portion 21 and forming a gas pathway along with the casing 10.
The fixed scroll 40 includes a body portion 41 formed in a predetermined shape, a wrap 42 formed on one surface of the body portion 41 in an involute curve having a predetermined thickness and height, a discharge opening 43 penetrated at the center of the body portion 41, a suction port 44 formed at one side of the body portion 41 and a flow channel groove 45 formed on the outer surface of the fixed scroll 40 and for flowing gas through along with the casing 10. The suction pipe 11 provided at the casing 10 is inserted and coupled to the suction port.
The orbiting scroll 50 includes a disc portion 51 having a predetermined thickness and area, a wrap 52 formed on one surface of the disc portion 51 in an involute curve having a predetermined thickness and height, and a boss portion 53 formed at the center of the other side of the disc portion 51.
The orbiting scroll 50 is coupled between the fixed scroll 40 and the main frame 20 so that the wrap 52 is engaged with the fixed scroll wrap 42, the boss portion 53 is inserted into the boss insertion groove 23 of the main frame 20 and 10o one surface of the disc portion 51 is supported by the bearing surface 24 of the main frame 20.
The rotary shaft 70 is provided with an eccentric portion 71. One side of the rotary shaft 70 is penetrated and inserted into the shaft insertion hole 22 of the main frame 20 to couple the eccentric portion 71 to the boss portion 53 of the orbiting scroll 50, and the other side thereof is supported by the sub frame 30.
The driving motor includes a stator 80 provided with a coil C and secured and coupled to the casing 10 and a rotor 90 rotatably coupled to the inside of the stator 80. Gas pathways through which gas flows are formed by the outer circumferential surface of the stator 80 and the casing 10.
Preferably, the driving motor is a synchronous reluctance motor that generates a rotary force by a reluctance torque.
The high pressure scroll compressor is provided with a refrigerant guiding mechanism for guiding a refrigerant gas of high pressure discharged through the discharge opening 43 of the fixed scroll to the rotor 90 side of the driving motor and an oil separating mechanism penetrated through the rotor 90 and for separating oil contained in the refrigerant gas by a centrifugal force caused by the rotation of the rotor 90 while the refrigerant gas guided by the refrigerant guiding mechanism cools the driving motor as it flows though.
The refrigerant guiding mechanism includes a first flow pathway f1 formed at one side of the fixed scroll 40 and a second flow pathway f2 penetrated through the main frame 20 so that the refrigerant having passed through the first flow pathway f1 faces the upper side of the rotor 90.
The first flow pathway f1 is preferably a flow channel groove that is formed on the outer circumferential surface of the body portion 21 of the fixed scroll to form a flow channel along with the casing 10. The second flow pathway f2 includes a first vertical hole 27 vertically formed on the outer circumferential surface of the main frame 20 so as to be communicated with the first pathway f1, a horizontal hole 28 horizontally formed extended from the first vertical hole 27 and a second vertical hole 29 vertically formed extended from the horizontal hole 28.
A guide member 120 for guiding the refrigerant gas flown out through the second flow pathway f2 to the upper side of the rotor 90 is located on the lower surface of the main frame 20 and in the upper side of the rotor 90. The guide member 120 is formed in a cylindrical shape and the second vertical hole 29 is located l the guide member 120. The guide member 120 is preferably formed integral with the main frame 20.
The oil separating mechanism is a through flow channel that is penetrated through the rotor 90 in its lengthwise direction.
As illustrated in FIGS. 4 and 5, the rotor 90 is a cylindrical laminated body with multiple round thin sheets. The rotor 90 includes a rotor body 91 provided with a plurality of slots S penetrated in a circular arc shape along a circumferential direction, an upper end ring 92 coupled to the top surface of the rotor body 91 and a lower end ring 93 coupled to the lower surface of the rotor body 91. As for the slots S, the top surface of the rotor body 91 is partitioned off into four regions and a plurality of slots S are formed at each of the partitioned four regions. The curvilinear direction of the slots S is opposite to the curvilinear direction of the outer circumferential surface of the rotor body 91. The plurality of slots S forms a poles to the rotor 90 when the driving motor is operated.
The upper end ring 92 and lower end ring 93 are formed in a ring shape having a predetermined thickness and width.
The upper end ring 92 and lower end ring 93 are provided with a balance weight 110 the rotation balance of the rotary body including the rotary shaft 70.
The through flow channel includes a plurality of first holes H1 penetrated through the upper end ring 92 and communicated with the slots S and a plurality of second holes H2 penetrated through the upper end ring 93 and communicated with the slots S.
The number of the first holes H1 is four, and each of the four first holes H1 is located at one of the slots S located at each of the layout four regions partitioned off from the rotor body 91. The first holes HI are located at the center of the slots S.
The second holes H2 are consist of four gas discharge holes h2 and eight oil discharge holes h3. Each of the four gas discharge holes h2 are located at one of the slots S located at each of the four regions partitioned off from the rotor body 91. And, the eight oil discharge holes h3 are located both opposite ends of slots S where the gas discharge holes h2 are located.
As illustrated in FIG. 6, an oil separating plate 130 is formed on the lower surface of the lower end ring 93 which is partitioned off into the gas discharge holes h2 and the oil discharge holes h3 for preventing gas and oil from being mixed. The oil separating plate 130 is formed in a cylindrical shape having a predetermined length. The oil separating plate 130 may be formed integral with the lower end ring 93, or may be coupled to the lower end ring 93 by separate manufacturing.
In case that the first holes H1 formed at the upper end ring 92 and the second holes H2 formed at the lower end ring 93 are overlapped with the balance weight 110 coupling to the upper end ring 92 and lower end ring 93, a through hole is formed at the balance weight 110 according to the position of the first holes H1 and second holes H2.
In another embodiment of the through flow channel, as shown in FIGS. 7 and 8, the through flow channel consists of a plurality of oil separating grooves penetrated in the lengthwise direction of the rotor 90 on the inner circumferential surface of the shaft insertion hole h1 of the rotor into which the rotary shaft 70 is press fit.
The oil separating grooves 94 are formed on the inner circumferential surface of the rotor shaft insertion hole h1 at a predetermined interval in the circumferential direction, and their sections are formed in a constant manner.
In a modified example of the oil separating plate 94, as illustrated in FIG. 9, the oil separating grooves 94 are formed in a manner that the area gradually increases so that the inlet side has a smaller section and the outlet side has a larger section.
Unexplained reference numeral B represents bushes, 100 represents an oil feeder mounted to the rotary shaft 70 and H3 represents a molding aperture.
The operational effects of the compression mechanism of the high pressure scroll compressor as set forth above will be described below.
When a power is applied to the scroll compressor, the rotor 90 is rotated by an interaction between the stator 80 and rotor 90 constituting the driving motor, and the rotary force of the rotor 90 is transmitted to the orbiting scroll 50 through the rotary shaft 70. With the transmission of the rotary force of the rotary shaft 70 to the orbiting scroll 50, the orbiting scroll 50 coupled to an eccentric portion 71 of the rotary shaft orbits around the axis of the rotary shaft 70. The orbiting scroll 50 orbits as being prevented from rotation by the Oldham's ring 60.
With the orbiting scroll 50 orbiting, as the wrap 52 of the orbiting scroll orbits engaged with the wrap 42 of the fixed scroll, a plurality of compression pockets P formed by the wrap 52 of the orbiting scroll and the wrap 42 of the fixed scroll moves to the center parts of the fixed scroll 40 and orbiting scroll 50, and at the same time, as their volume changes, sucks and compresses gas and discharges it through the discharge opening 43 of the fixed scroll.
At this time, the gas is sucked into the suction port 44 of the fixed scroll through the suction pipe 11 and the gas flown into the suction port 44 is sucked to the compression pockets P.
Meanwhile, with the rotation of the rotary shaft 70, the oil filled in the bottom face of the casing 10 is fed by the oil feeder 100 coupled to the rotary shaft 70 and by a centrifugal force of the rotary shaft 70, to thus be flown to the upper side through the oil flow channel 72 of the rotary shaft and ejected to the boss insertion groove 23 of the main frame, and the oil ejected to the boss insertion groove 23 is supplied between parts where relative motion occurs. Some parts of the oil supplied between the parts are recovered to the bottom face of the casing 10 and others are mixed with the refrigerant gas of high temperature and high pressure discharged to the discharge opening 43.
As illustrated in FIG. 10, the refrigerant gas of high temperature and high pressure discharged through the discharge opening 43 of the fixed scroll flows to the rotor 90 side of the driving motor through the first flow pathway f1 of the fixed scroll and the second flow pathway f2 of the main frame. At this time, the guide member 120 located between the main frame 20 and the driving motor suppresses the refrigerant gas from being diffused in the casing 10.
The refrigerant gas flown to the rotor 90 side flows through the first holes H1, slots S and second holes H2 constituting the through flow channel by a suction force generated from the through flow channel side by the rotation of the rotor 90 to thus be flow to the lower side of the driving motor. In the procedure in which the refrigerant gas passes through the slots S, as the oil mixed in the refrigerant gas is separated from the slots S by a centrifugal force, the oil is discharged through the oil discharge holes H3 constituting the second holes H2, and the refrigerant gas from which the oil is separated flows to the lower side of the driving motor through the gas discharge holes h2.
The procedure of separating the oil and the refrigerant gas from the slots S will be described in more detail. Since the slots S are formed in a circular arc shape, if the refrigerant gas mixed with oil flows into the slots S while the rotor 90 is rotating, the oil mixed in the refrigerant gas gathers to both opposite ends of the slots S along the inner walls of the slots S located in the outer side by a centrifugal force caused by the rotation of the rotor 90, to thus be dropped down. The oil dropping to both opposite ends of the slots S flows to the lower side through the oil discharge holes h3 located at both opposite ends of the slots S. The refrigerant gas from which the oil is separated is discharged through the gas discharge holes h2 located on the same line as the first holes H1.
The oil discharged through the oil discharge holes h3 cools the driving motor as it is ejected to the coil C and the stator 80 by a rotary force of the rotor 90, and the oil having cooled the driving motor is recovered to the bottom face of the casing 10.
The refrigerant gas having flow to the lower side of the driving motor through the gas discharge holes h2 is discharged through the discharge pipe 12 while flowing to the upper side of the driving motor through the pathway formed by the outer circumferential surface of the stator 80 and the casing 10.
If the oil separating plate 130 is coupled to the lower end ring 93, the oil separating plate 130 minimizes the mixing of the oil ejected through the oil discharge holes h3 and the refrigerant gas flowing through the gas discharge holes h2.
Meanwhile, in yet another embodiment of the through flow channel, in case that a plurality of oil separating grooves 94 is formed on the inner circumferential surface of the shaft insertion hole h1, the oil mixed in the refrigerant gas flowing into the oil separating grooves 94 gathers in the inner walls of the oil separating grooves 94 by a centrifugal force caused from the rotary force of the rotor 90 and is dropped down along the inner walls. If the section of the oil separating grooves 94 becomes larger, the separation of the oil is accomplished more effectively. Meanwhile, the refrigerant gas from which the oil is separated flows to the lower side of the driving motor through the oil separating grooves 94.
As explained above, in the oil discharge reducing device for a scroll compressor according to the present invention, since the refrigerant gas discharged through the discharge opening 43 of the fixed scroll is discharged to the discharge pipe 12 through the refrigerant guiding mechanism and the oil separating mechanism penetrated through the rotor 90 of the driving motor, the driving motor is cooled effectively by the refrigerant gas mixed with the oil.
As the refrigerant gas mixed with the oil passes through the oil separating mechanism, the oil mixed in the refrigerant gas is effectively separated by a rotary force of the rotor 90, thereby minimizing the amount of oil discharged through the discharge pipe 12 along with the refrigerant gas. Further, the oil separated from the refrigerant gas is ejected to the driving motor to thus intensively cool the driving motor, thus increasing the cooling efficiency of the driving motor still more.
Since the amount of oil mixed in the refrigerant gas discharged into the cooling cycle system through the discharge pipe 12 is minimized, this prevents the system efficiency from being deteriorated due to an excessive amount of oil accumulated in the cooling cycle system, and furthermore the shortage of oil filled in the casing 10 of the compressor is suppressed to increase the reliability of the compressor.

Claims

1. An oil discharge reducing device for a scroll compressor, the scroll compressor comprising: a casing filled with oil at the bottom face thereof; a driving motor mounted to the casing and for generating a rotary force; a main frame fixed and coupled to the casing; a fixed scroll located at a predetermined interval from the main frame; and a orbiting scroll positioned between the fixed scroll and the main frame, and interlocked with the fixed scroll,

wherein the oil discharge device comprises:

a refrigerant guiding mechanism for guiding a refrigerant gas of high pressure discharged through a discharge opening of the fixed scroll to a rotor of the driving motor; and

an oil separating mechanism penetrated through the rotor and for separating oil contained in the refrigerant gas by a centrifugal force caused by the rotation of the rotor while the refrigerant gas guided by the refrigerant guiding mechanism cools the driving motor as it flows though the driving motor.

2. The device of claim 1, wherein the refrigerant guiding mechanism comprises a first flow pathway formed at one side of the fixed scroll and a second flow pathway penetrated through the main frame so that the refrigerant having passed through the first flow pathway faces the upper side of the rotor.

3. The device of claim 1, wherein the second flow pathway comprises a first vertical hole vertically formed on the outer circumferential surface of the main frame so as to be communicated with the first pathway, a horizontal hole horizontally formed extended from the first vertical hole and a second vertical hole vertically formed extended from the horizontal hole.

4. The device of claim 2, wherein a guide member for guiding the refrigerant gas flown out through the second flow pathway to the upper side of the rotor is located on the lower surface of the main frame and in the upper side of the rotor.

5. The device of claim 4, wherein the guide member is formed in a cylindrical shape.

6. The device of claim 4, wherein the guide member is formed integral with the main frame.

7. The device of claim 1, wherein the oil separating mechanism is a through flow channel penetrated through the rotor in that is penetrated through the rotor in its lengthwise direction.

8. The device of claim 7, wherein the rotor is composed of: a rotor body constructed as a cylindrical laminated body that a plurality of circular thin plates are laminated, having a plurality of slots penetrated as a circular arc shape along a circumferential direction of the laminated body, and having a shaft insertion hole at a center of the laminated body; and an upper end ring and a lower end ring coupled to both sides of the rotor body, and the through flow channel is composed of: a plurality of first holes penetrated through the upper end ring and communicated with the slots; and a plurality of second holes penetrated through the lower end ring and communicated with the slots.

9. The device of claim 8, wherein the rotor is formed poles by the plurality of slots when the driving motor is operated.

10. The device of claim 8, wherein the first holes are positioned at the center of the slots.

11. The device of claim 8, wherein the second holes are consist of gas discharge holes located at the center of the slots and oil discharge holes located at both ends of the slots, respectively.

12. The device of claim 11, wherein the gas discharge holes and the first holes are positioned on the same line, respectively.

13. The device of claim 11, wherein an oil separating plate is formed on the lower surface of the lower end ring which is partitioned off into the gas discharge holes and the oil discharge holes for preventing gas and oil from being mixed.

14. The device of claim 13, wherein the oil separating plate is formed in a cylindrical shape having a predetermined length.

15. The device of claim 7, wherein the through flow channel consists of a plurality of oil separating grooves penetrated in the lengthwise direction of the rotor on the inner circumferential surface of the shaft insertion hole of the rotor into which the rotary shaft is pressingly fit.

16. The device of claim 15, wherein the sections of the oil separating grooves are formed in a constant manner.

17. The device of claim 15, wherein the oil separating grooves are formed in a manner that the sectional area gradually increases so that the outlet side is larger than the inlet side.