This application claims priority to Korean Application No. 10-2008-0101334, filed in Korea on Oct. 15, 2008, the entirety of which is incorporated herein by reference.
1. Field
A scroll compressor and a refrigerating machine including the same are provided.
2. Background
Scroll compressors compress refrigerant gas by varying a volume of a compression chamber formed by an inter-engaged pair of scrolls. The scroll compressor is efficient, low in vibration and noise, small in size and light in weight, as compared to a reciprocating compressor or a rotary compressor. Scroll compressors have widely been used in a number of different applications, such as, for example, air conditioners. Improved lubrication to the friction parts of the compressor would further enhance performance, reliability and efficiency of both the compressor and the end application in which it is installed.
The embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein:
Scroll compressors may be divided into high pressure type scroll compressors and low pressure type scroll compressors based on a pressure of a refrigerant provided to an inside of a casing. That is, the low pressure type scroll compressor may be configured such that a suction pipe communicates with an inner space of a casing and a discharge pipe communicates with a discharge side of a compression device, thereby indirectly introducing refrigerant into a compression chamber. On the other hand, the high pressure type scroll compressor may be configured such that a suction pipe directly communicates with a suction side of the compression device and a discharge pipe communicates with the inner space of the casing, thereby directly introducing refrigerant into the compression chamber. For the high pressure type scroll compressor, refrigerant discharged from the compression device may be held in the inner space of the casing.
The high pressure type scroll compressor may use a back pressure scheme to seal a space between a fixed scroll and an orbiting scroll. For instance, a back pressure chamber may be formed at a space defined by the orbiting scroll, a main frame supporting the orbiting scroll, and the fixed scroll, to maintain an intermediate pressure. Oil drawn in through an oil channel of a shaft coupled to the orbiting scroll may pass through a bearing surface between the main frame and the orbiting scroll via an oil reservoir of the main frame, and be introduced into the back pressure chamber. While passing through the bearing surface between the main frame and the orbiting scroll, the oil may be decompressed to arrive at the intermediate pressure environment of the back pressure chamber. Since the pressure of the back pressure chamber is higher than that of the suction chamber, the pressure differential drives the oil in the back pressure chamber into the suction chamber through a bearing surface between the fixed scroll and the orbiting scroll, and into the compression chamber. During this process, the bearing surface between the fixed scroll and the orbiting scroll becomes lubricated, thereby reducing frictional losses.
However, when the scroll compressor is initially operated or is operated in a low-speed operation mode, oil may sometimes not be sufficiently supplied to the back pressure chamber, resulting in an insufficient pressure differential between the back pressure chamber and the suction chamber. Accordingly, oil cannot be smoothly introduced into the bearing surface between the scrolls, thereby lowering compressor efficiency due to frictional losses. In addition, when the scroll compressor is normally operated, in particular, in a high-speed operation mode, oil may be excessively introduced into the back pressure chamber, thereby applying an excessive pushing force on the orbiting scroll against the fixed scroll. Accordingly, the space between the fixed scroll and the orbiting scroll is compressed, an oil passage cannot be formed therebetween, thus lowering compressor efficiency due to frictional losses.
As shown in
The hermetic inner space of the casing 10 may be divided into an upper space S1 and a lower space S2 by the main frame 20 and the fixed scroll 40. In such a high pressure scroll compressor, the upper space S1 and the lower space S2 maintain a high pressure state, and oil is provided at a bottom portion of the lower space S2 of the casing 10. The gas suction pipe SP may penetrate the casing 10 into the upper space S1, and a gas discharge pipe DP may communicate with the lower space S2 of the casing 10.
A shaft receiving hole 21 may be formed through a center of the main frame 20, and an oil reservoir 22 may be formed at an upper end of the shaft receiving hole 21. A back pressure groove 23 may be formed at an edge of an upper surface of the main frame 20 so as to partially define a back pressure chamber S3. An intermediate pressure may be maintained in the back pressure chamber S3 by mixing refrigerant with oil. The sealing groove 24, which allows the oil contained in the oil reservoir 22 to be maintained at a high pressure, may be formed in a ring shape at an inner side of the back pressure groove 23 to receive the sealing member 70 therein. The back pressure chamber S3 may be defined by the back pressure groove 23 of the main frame 20, a plate portion 41 of the fixed scroll 40, and a plate portion 51 of the orbiting scroll 50.
The driving motor 30 may include a stator 31 that receives external power fixed to an inner portion of the casing 10, a rotor (not shown) disposed inside the stator 31 with a gap therebetween that rotates while interacting with the stator 31, and a drive shaft 32 coupled to the rotor so as to transmit a rotational force from the driving motor 30 to the orbiting scroll 50. An oil supply channel 32a may extend through the drive shaft 32 in a shaft direction, and an oil pump (not shown) may be installed at a lower end of the oil supply channel 32a.
The fixed scroll 40 may include a fixed wrap 42 involutely formed at a lower surface of the plate portion 41 to form one pair of compression chambers P, an inlet 43 formed at a side surface of the plate portion 41 and in direct communication with the gas suction pipe SP, and a discharge port 44 formed at the center of an upper surface of the plate portion 41 through which compressed refrigerant may be discharged to the upper space S1 of the casing 10.
The orbiting scroll 50 may include an orbiting wrap 52 involutely formed on an upper surface of the plate portion 51 to form one pair of compression chambers P together with the fixed wrap 42 of the fixed scroll 40, and a boss portion 53 formed at the center of a lower surface of the plate portion 51 so as to receive a driving force from the driving motor 30 through its coupling to the drive shaft 32.
In certain embodiments, the fixed scroll 40 and the orbiting scroll 50 may be asymmetrical with each other. For example, a length of the wrap of the orbiting scroll 50 may be longer than that of the fixed scroll 40 by approximately 180°. In alternative embodiments, the fixed scroll 40 and the orbiting scroll 50 may be symmetrical with each other and have substantially the same length of each wrap of the scrolls.
Operation of a scroll compressor as embodied and broadly described herein will now be discussed.
When power is supplied to the driving motor 30 and the drive shaft 32 rotates together with the rotor, a rotation force is transferred to the orbiting scroll 50. The orbiting scroll 50, having received the rotation force, performs an orbiting motion on an upper surface of the main frame 20. One pair of compression chambers P are consecutively moved between the orbiting wrap 52 of the orbiting scroll 50 and the fixed wrap 42 of the fixed scroll 40. As the orbiting scroll 50 continuously performs the orbiting motion, the compression chambers P move inward and are decreased in volume, thereby compressing a refrigerant held therein.
In this condition, the oil pump (not shown) installed at the lower end of the drive shaft 32 starts pumping oil contained in the casing 10, and the oil is drawn upward through the oil supply channel 32a of the drive shaft 32. Some of the oil is supplied to the shaft receiving hole 21 of the main frame 20, while some of the oil is dispersed at the upper end of the drive shaft 32 and then passes through a bearing surface Fs1 between the main frame 20 and the orbiting scroll 50, and is introduced into the back pressure chamber S3. The oil in the back pressure chamber S3 serves to support the orbiting scroll 50 such that the orbiting scroll 50 is lifted toward the fixed scroll 40. Then, each end of the fixed wrap 42 and the orbiting wrap 52 closely contacts its respective plate portion 51, 41 of the scrolls, thereby sealing the compression chamber P.
In order for the orbiting scroll 50 to smoothly perform an orbiting motion while being engaged with the fixed scroll 40, oil may be smoothly supplied onto the bearing surface Fs2 between the fixed scroll 40 and the orbiting scroll 50. Further, in order to prevent a leakage of a refrigerant between the fixed wrap 42 and the orbiting wrap 52 or between each wrap 42, 52 and its respective plate portion 51, 41 in the compression chamber P, a certain amount of oil may continuously be supplied to the compression chamber P. However, when the compressor is initially operated or is in a low-speed operation mode, an amount of oil supplied may be relatively small, thereby requiring more oil to be introduced into the back pressure chamber S3. Thus, the amount of oil introduced into the bearing surface Fs2 between the scrolls 40, 50 or the amount of oil supplied to the compression chamber P would be insufficient. On the contrary, when the compressor is normally operated or is in a high-speed operation mode, an amount of oil supplied may be relatively large, thereby providing too much lift to the orbiting scroll 50 and causing excessive contact between the fixed scroll 40 and the orbiting scroll 50, thus causing a shortage of oil in the compression chambers P.
In consideration of these types of problems, an oil supply channel through which some oil may be allowed to be introduced into the suction chamber before the oil moves from the oil reservoir 22 to the back pressure chamber S3 may be provided.
For example, referring to
For instance, the outermost edge of the orbiting wrap 52 may be, approximately, positioned in a compression chamber range (C) as shown in
A plurality of oil pockets 56 may be formed on a lower surface of the orbiting scroll 50 (i.e., the first bearing surface Fs1) along a circumferential direction such that oil contained inside the sealing member 70 flows to an outside thereof. The oil pockets 56 may have the same interval therebetween, and/or the same size. In certain embodiments, as shown in
As shown in
In certain embodiments, the first groove 46 may be formed in the range of 150°(β) in an orbiting direction of the orbiting scroll, if an area where a frictional resistance is highest on the second bearing surface Fs2 (i.e., the center of the inlet 43 of the fixed scroll 40) is assumed to be at 0°. The first groove 46 may have a diameter greater than that of the oil supply hole 55 so as to maintain communication with the oil supply hole 55, and the second groove 47 may be formed in a circular arc shape.
The second groove 47 may be formed such that an interval between an inner circumferential surface at an end thereof and an inner circumferential surface of the fixed wrap 42 is less than a thickness of the fixed wrap 42. This enables the oil to be smoothly introduced into the compression chamber P from the second groove 47. Further, the second groove 47 may extend toward the suction chamber, thereby deflating the oil supply groove using a pressure difference.
A process of supplying oil to the second bearing surface in a scroll compressor as embodied and broadly described herein will now be discussed in detail.
When the drive shaft 32 is rotated, the oil pump (not shown) provided at the lower portion of the drive shaft 32 pumps oil from the bottom of the casing 10 into an upper portion thereof. Some of the oil is directed into the oil reservoir 23 of the main frame 20. As shown in
And, the oil held in the back pressure chamber S3 is supplied to the second bearing surface Fs2 between the fixed scroll 40 and the orbiting scroll 50 through a channel that connects the back pressure chamber S3 to the second bearing surface Fs2, i.e., a fourth channel, due to the pressure differential, and mixed with the oil introduced through the second and third channels, thereby lubricating the second bearing surface Fs2.
Then, the oil, having lubricated the second bearing surface Fs2, is introduced into the suction chamber. The oil is then introduced into the compression chamber P together with the refrigerant, to prevent leakage of the refrigerant from the compression chamber P.
Thus, even if the compressor is initially driven or is in the low-speed operation mode, oil may be supplied to the second bearing surface Fs2 before filling the back pressure chamber S3, thereby preventing an oil shortage at the second bearing surface Fs2. In addition, even if there is excessive contact at the second bearing surface Fs2 when the compressor is normally operated or is in the high-speed operation mode, the oil may be smoothly supplied to the second bearing surface Fs2 through the oil supply hole 55 and the oil supply groove 45.
If the scroll compressor as embodied and broadly described herein is applied to a refrigerating machine, efficiency of the refrigerating machine may be enhanced.
Therefore, compressor efficiency can be enhanced by effectively preventing frictional losses and refrigerant leakage in the compressor, and energy efficiency of a refrigerating machine utilizing such a compressor may also be enhanced.
A scroll compressor as embodied and broadly described herein may be widely used in a refrigerating machine, such as, for example, an air conditioner, a refrigerator/freezer, and the like.
A scroll compressor that is capable of preventing a lowering of compressor efficiency due to a frictional loss by smoothly supplying oil between a fixed scroll and an orbiting scroll regardless of its mode of operation (e.g., an initial operation or a low-speed operation and a normal operation or a high-speed operation) and that capable of enhancing performance of the compressor, and a refrigerating machine having the same are provided.
A scroll compressor as embodied and broadly described herein may include a casing having a hermetic inner space; a frame fixed to the casing and having a back pressure groove at an edge thereof; a fixed scroll fixed to the frame and having an involute wrap at one side surface thereof; and an orbiting scroll disposed between the frame and the fixed scroll, having an involute wrap for forming a pair of compression chambers consecutively moved while performing an orbiting motion by being engaged with a wrap of the fixed scroll, and supported in a shaft direction by a pressure of the back pressure groove, wherein an oil supply hole, through which oil is guided from a space between the frame and the orbiting scroll to a space between the fixed scroll and the orbiting scroll, is formed at the orbiting scroll, and an oil supply groove formed to be always communicated with the oil supply hole is formed at the fixed scroll.
In certain embodiments, a scroll compressor is provided in which a crank shaft of a driving motor is supported by a shaft receiving hole of a frame, a fixed scroll is fixed to the frame, an orbiting scroll coupled to the crank shaft and forming a pair of compression chambers consecutively moved while performing an orbiting motion by being engaged with the fixed scroll is orbitably disposed between the frame and the fixed scroll, and a back pressure chamber is formed on a rear surface of the orbiting scroll so as to support the orbiting scroll in a shaft direction by a pressure of the back pressure chamber, the scroll compressor comprising: a first channel through which oil sucked through the crank shaft is guided to a back pressure chamber through a space between the frame and the orbiting scroll, a second channel through which the oil flowing through the first channel is guided to a space between the fixed scroll and the orbiting scroll, a third channel through which oil in the second channel is widely spread on a bearing surface between the space the fixed scroll and the orbiting scroll, and a fourth channel through which the oil in the back pressure chamber is guided to the bearing surface between the fixed scroll and the orbiting scroll.
A refrigerating machine as embodied and broadly described herein may include a compressor; a condenser connected to a discharge side of the compressor; an expander connected to the condenser; and an evaporator connected to the expander and connected to a suction side of the compressor, wherein the compressor is configured such that an oil supply hole is formed at the orbiting scroll and an oil supply groove is formed at the fixed scroll.
Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” “alternative embodiment,” “certain embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment as broadly described herein. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, numerous variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
Number | Date | Country | Kind |
---|---|---|---|
10-2008-0101334 | Oct 2008 | KR | national |
Number | Name | Date | Kind |
---|---|---|---|
4462772 | Hazaki et al. | Jul 1984 | A |
4743181 | Murayama et al. | May 1988 | A |
5427511 | Caillat et al. | Jun 1995 | A |
5548973 | Komine et al. | Aug 1996 | A |
5660539 | Matsunaga et al. | Aug 1997 | A |
5951271 | DuMoulin et al. | Sep 1999 | A |
6619062 | Shibamoto et al. | Sep 2003 | B1 |
6655172 | Perevozchikov et al. | Dec 2003 | B2 |
7044723 | Morozumi et al. | May 2006 | B2 |
7322809 | Kitaura et al. | Jan 2008 | B2 |
20050053508 | Morozumi et al. | Mar 2005 | A1 |
Number | Date | Country |
---|---|---|
1118842 | Mar 1996 | CN |
1132826 | Oct 1996 | CN |
1339087 | Mar 2002 | CN |
10 2005 00146 | Sep 2005 | DE |
0 679 809 | Nov 1995 | EP |
0 911 526 | Apr 1999 | EP |
1 544 467 | Jun 2005 | EP |
62-178791 | Aug 1987 | JP |
63131889 | Jun 1988 | JP |
05133355 | May 1993 | JP |
Number | Date | Country | |
---|---|---|---|
20100092321 A1 | Apr 2010 | US |