Patent Application
20090031753
The present application claims priority to Korean Applications No. 10-2007-0076579, filed on Jul. 30, 2007, Korean Application No. 10-2007-0139286, filed on Dec. 27, 2007, and Korean Application No. 10-2008-0070336, filed on Jul. 18, 2008, which are herein expressly incorporated by reference in their entireties.
1. Field of the Invention
The present invention relates generally to a compressor, and, more particularly, to an oil recollecting apparatus of a compressor capable of separating and recollecting oil from a refrigerant discharged from a compressing unit.
2. Description of Related Art
A compressor is a device for converting kinetic energy into compression energy of a compressive fluid. A hermetic compressor is configured such that a motor for generating a driving force and a compression unit for compressing fluid by the driving force received from the motor are all installed in an inner space of a hermetically sealed container.
When the hermetic compressor is provided as a component in a refrigerant compression refrigeration cycle, a certain amount of oil is stored in the hermetic compressor in order to cool the motor of the compressor or smooth and seal the compression unit. However, when the compressor is driven, the refrigerant discharged from the compressor into the refrigeration cycle includes oil mixed in with the refrigerant. Part of the oil discharged into the refrigeration cycle is not recollected to the compressor but remains in the refrigeration cycle, thereby causing a decrease in the amount of oil in the compressor. This may result in decrease in compressor reliability and also degradation of heat-exchange capability of the refrigeration cycle due to the oil remaining in the refrigeration cycle.
Accordingly, in the related art, an oil separator is disposed at a discharge side of the compressor to separate oil from the discharged refrigerant, and such separated oil is recollected to a suction side of the compressor, thereby avoiding the lack of oil in the compressor and also maintaining the heat-exchange capability of the refrigeration cycle.
However, when recollecting oil separated by the oil separator into the suction side of the compressor, the high pressure refrigerator is also recollected together with the oil, which results in decreasing the amount of refrigerant circulating in the refrigeration cycle, thereby lowering a cooling capability of the compressor. In addition, temperature of suction gas in the compressor is increased to thereby raise temperature of discharge gas. Accordingly, the reliability of the compressor is degraded. Also, as the temperature increases, a specific volume of the sucked refrigerant is increased, so as Lo decrease he actual amount of the sucked refrigerant, thereby degrading the cooling capability.
Specifically, during a low speed operation of the compressor, the lack of oil pumped causes cooling refrigerant gas to be more recollected than oil, whereby the amount of refrigerant circulating in the refrigeration cycle is decreased. Accordingly, the cooling capability of the compressor is further degraded.
Therefore, in order to solve those problems of the related art compressor, an object of the present invention is to provide a compressor having an oil recollecting apparatus for recollecting oil separated from a refrigerant discharged from a compressing unit.
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 a compressor having a compressor main body including a casing defining an inner space, a suction pipe corrected to the casing, a discharge pipe connected to the casing, a motor located at the inner space of the casing, a compressing unit driven by the motor to compress a refrigerant, an oil separating unit configured to separate oil from the refrigerant discharged from the compressing unit, and an oil recollecting unit configured to pump the oil separated by the oil separating unit and recollect the separated oil into the compressor main body.
According to a different aspect of the present invention, there is provided a compressor having a casing having an inner space, a suction pipe connected to the casing, a discharge pipe connected to the casing, a motor located in the inner space of the casing to generate a driving force, a compressing unit driven by the motor to compress a refrigerant, an oil separating unit configured to separate oil from the refrigerant discharged out of the compressing unit, and an oil recollecting unit including an oil recollecting pump driven by a rotation force of the motor to pump oil separated by the oil separating unit.
According to yet another aspect of the present invention, there is provided a compressor having a casing having an inner space, a suction pipe connected to the casing, a discharge pipe connected to the casing, a motor located in the inner space of the casing to generate a driving force, a compressing unit driven by the motor to compress a refrigerant, an oil separating unit configured to separate oil from the refrigerant discharged out of the compressing unit, and an oil recollecting unit. The oil recollecting unit includes an oil recollecting pipe for connecting the oil separating unit to the casing and an oil recollecting pump cooperating with the oil recollecting pipe to pump oil separated by the oil separating unit.
Further scope of applicability of the present application will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the detailed description.
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:
Description will now be given in detail of the present invention, with reference to the accompanying drawings. Although the description of the present invention is given with reference to scroll compressors, the present invention is not limited to scroll compressors, but can be equally applied to other so-called hermetic compressors, such as rotary compressors, having a motor and a compressing unit disposed in the same casing.
As shown in
The inner space of the casing 10 is configured to hold a refrigerant at a suitable discharge pressure. A suction pipe SP is formed through one side of the casing 10 to be in communication with a suction chamber formed by the fixed scroll 31 and the orbiting scroll 32. A discharge pipe DP is connected to another side of the casing 10 to guide a refrigerant discharged out of the inner space of the casing 10 to a refrigeration cycle.
The motor 20 may be a constant speed motor rotating at a uniform speed, or an inverter motor rotating at variable speed depending on the needs of a refrigerating device to which the compressor is applied. A crankshaft 23 of the motor 20 is supported by a main frame 11 and a sub-frame 12 fixedly installed at both upper and lower ends of the casing 10.
An oil passage 23a is formed through the crankshaft 23 in an axial direction. An oil supplying pump 25 for pumping oil contained in the casing 10 is disposed below the oil passage 23a, in particular, below the crankshaft 23. A displacement pump may be used as the oil supplying pump 25 as shown in
The compressing unit 30, as shown in
Operation of the compressor will be described with reference to the above configuration. When power is applied to the motor 20, the crankshaft 23 rotates together with a rotor 22 to forward such rotational force to the orbiting scroll 32. The orbiting scroll 32 receiving the rotational force applied is then orbited by the Oldham ring 33 on an upper surface of the main frame 11, thereby forming a pair of compression chambers P which are continuously moved between the fixed wrap 31a of the fixed scroll 31 and the orbiting wrap 32a of the orbiting scroll 32. Such compression chambers P are then moved to the center by the continuous orbiting motion of the orbiting scroll 32 such that their capacities decrease to thereby compress a sucked refrigerant. The compressed refrigerant is continuously discharged to an upper space S1 of the casing 10 through the discharge opening 31c of the fixed scroll 31 and then moved down to a lower space S2 of the casing 10, thereby being discharged into a refrigeration cycle system through the refrigerant discharge pipe DP. The compressed refrigerant may be moved from upper space S1 to lower space S2 using various approaches, such as, for example providing a passage (not shown) through the fixed scroll 31 and/or main frame 11.
At the same time that the crankshaft 23 is rotated, the oil supplying pump 25 disposed below the crankshaft 23 pumps oil contained in the casing 10 using a variable capacity formed between the inner gear and outer gear of the oil supplying pump 25. Oil is sucked toward an upper end through the oil passage 23a of the crankshaft 23 and the oil is partially supplied to respective bearing surfaces of the sub-frame 12 and the main frame 11, and partially supplied to the compression chambers P through a bearing surface between the main frame 11 and the orbiting scroll 12 at the upper end of the crankshaft 23 so as to seal or smooth the compression chambers P.
An oil recollecting pump 52 coupled to the crankshaft 23 configured to operate in cooperation with the oil supplying pump 25 is also provided. The oil recollecting pump 52 pumps and recollects oil separated from a refrigerant discharged out of the compressing unit. A detailed description thereof will now be given.
As shown in
As shown in
The oil separating unit 40 may use various methods for separating oil. For example, a mesh screen may be installed inside the oil separator 41 to thereby separate oil from a refrigerant, or the discharge pipe DP may be connected to the oil separator 41 at an incline such that a refrigerant rotates in a form of cyclone to thereby separate relatively heavy oil from the refrigerant.
The oil recollecting unit 50 may include the oil recollecting pipe 51 connected to the oil separating unit 40 to guide oil, and an oil recollecting pump 52 installed at the oil recollecting pipe 51 to pump oil from the oil separator 41. One end of the oil recollecting pipe 51 is connected to the lower end of the oil separator 41, and the other end thereof penetrates through the casing 10 to be connected to an inlet of the oil recollecting pump 52. The oil recollecting pipe 51 may be a metallic pipe having a suitable strength so as to stably support the oil separator 41. Also, the oil recollecting pipe 51 may be curved through an angle so that the oil separator 41 is oriented parallel with the casing 10, thus to reduce a vibration of the compressor.
The oil recollecting pump 52 may be installed above or below the oil supplying pump 25 to be driven by a driving force from the motor 20. For example, as shown in
In the scroll compressor according to this exemplary embodiment, the oil separator 41 separates oil from a refrigerant discharged out of the inner space of the casing 10. Such separated oil is recollected into the inner space of the casing 10 via the oil recollecting pump 52, or may be directly be supplied into the oil passage 23a of the crankshaft 23. For example, oil introduced into the compression chamber P is discharged together with a refrigerant to be introduced into the oil separator 41 via the discharge pipe DP. Such oil and refrigerant are separated from each other in the oil separator 41. The separated refrigerant then flows up to a condenser of the refrigeration cycle via the refrigerant pipe RP whereas the separated oil is collected at the bottom of the oil separator 41. As the crankshaft 23 of the motor 20 rotates, the inner gear of the oil recollecting pump 52 rotates so as to configure a variable capacity between the inner gear and the outer gear, thereby generating a pumping force. The oil separated by the oil separator 41 is pumped by such pumping force. The oil pumped by the oil recollecting pump 52 is recollected into the inner space of the casing 10 through the oil recollecting pipe 51 and the oil recollecting pump 52. Such recollected oil is accordingly re-supplied to each bearing surface and the compression chamber P by the oil supplying pump 52 via the oil passage 23a of the crankshaft 23. This process may be continuously repeated as the crankshaft 23 rotates.
An oil supplying hole 14 for injecting oil into the inner space of the casing 10 may be formed at a lower portion of the casing 10. When a plurality of compressors are used, the oil supplying hole 14 may be used as an oil equalizing hole to place the plurality of compressors in communication with each other in order to match liquid-level heights of each of the compressors.
While the first exemplary embodiment of the compressor includes an oil supplying pump, a second exemplary embodiment is provided where a single oil recollecting pump is used to perform the function of the oil supplying pump. For example, the second exemplary embodiment of the scroll compressor may be implemented as follows. As shown in
The scroll compressor in accordance with this exemplary embodiment is similar to that of the aforesaid embodiment in the basic configuration and operations, and accordingly a detailed description thereof will not be repeated. However, the inlet of the oil recollecting pump 52 is divided into the first inlet 52a and the second inlet 52b. Accordingly, oil separated by the oil separator 41 is sucked through the first inlet 52a while oil collected at the bottom of the casing 10 is sucked through the second inlet 52b. Such oils sucked through the first and second inlets 52a and 52b are all collected into the oil passage 23a of the crankshaft 23 to be supplied to each bearing surface or the compression chamber P.
Still another embodiment of a scroll compressor according to the present invention will be described hereafter. While the aforementioned exemplary embodiments are configured such that the oil recollecting pump is installed inside the casing or coupled to the motor to use the driving force of the motor, a third exemplary embodiment of the scroll compressor, as shown in
According to yet another exemplary embodiment of the present invention, the oil separating unit may be located at the inside of the casing of the compressor. For example, as shown in
A guide cover 15 having a certain inner space to accommodate a discharge side of the compressing unit 30 is installed between the compressing unit 30 and the oil separating unit 240. An inlet side fluid passage (not shown) is formed at a portion of the compressing unit 30 which is accommodated in the guide cover 15, whereas an outlet side fluid passage (not shown) is formed at a portion of the compressing unit 30 which is not accommodated in the guide cover 15. Accordingly, refrigerant and oil discharged from the compression chamber P is allowed to flow toward a lower space S2 of the casing 10, namely, toward the motor 20 and then to flow toward an upper space S1 of the casing 10, in particular, toward the oil separating cap 241.
The discharge pipe DP for guiding the refrigerant separated by the oil separating cap 241 to the refrigeration cycle is connected to another side wall surface of the oil separating cap 241. The discharge pipe DP is then connected to the refrigeration cycle through the casing 10. An oil recollecting pipe 251 for guiding oil separated by the oil separating cap 241 to the bottom of the casing 10 is connected to a lower end of the oil separating cap 241. An oil recollecting pump 252 for pumping oil separated by the oil separating cap 241 is located at an outlet of the oil recollecting pipe 251.
The oil separating pipe 242 includes an inlet in communication with the upper space S1 of the casing 10 and an outlet in communication with the inner space of the oil separating cap 241. The oil separating pipe 242 may be formed to be curved or bent, as shown in
The inlet of the oil recollecting pipe 251, as shown in
The oil recollecting pump 252 may be a trochoid gear pump having inner gear and outer gear as described above. In particular, the inner gear may be configured as same as in the aforementioned embodiments, such as being coupled to the crankshaft 23 of the motor 20.
In general, the operation of this exemplary embodiment of the present invention, the process in which oil is separated from the refrigerant to be recollected is the same or similar to those described above, so a detailed explanation thereof will not be repeated. However, because the oil separating unit 240 is installed inside the casing 10, the flow direction of the refrigerant and oil is different from that in the previous embodiments. That is, refrigerant and oil, after being discharged from the compression chamber P into the inner space of the guide cover 15, flow to the lower space S2 via the inlet side fluid passage. Thereafter, the refrigerant and oil flow to the upper space S1 through the outlet side fluid passage. The refrigerant and oil are then introduced into the oil separating cap 241 through the oil separating pipe 242 to orbit inside the oil separating cap 241. Accordingly, the refrigerant and the oil are separated from each other. Afterwards, the separated refrigerant then flows to the refrigeration cycle through the discharge pipe DP whereas the separated oil is recollected to the oil passage 23 a of the crankshaft 23 through the oil recollecting pipe 251 by a pumping force of the oil recollecting pump 252. This process may be continuously repeated as the crankshaft 23 rotates.
In still another exemplary embodiment of the present invention, as shown in
As a result of one or more of the exemplary embodiments, oil separated by the oil separator is recollected by the oil recollecting pump. The recollected oil is mixed with a refrigerant again, whereby it is allowed to prevent a backflow of such oil into the compressor. Accordingly, the reduction of the amount of refrigerant circularly supplied into the refrigeration cycle can be avoided, thereby preventing a degradation of a cooling capacity of the compressor beforehand. Also, the simplification of the oil recollecting unit allows the decrease of manufacturing cost. In addition, as the driving force of the motor may be used to drive the oil recollecting pump, the configuration of the compressor can be further simplified.
The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present disclosure. The present teachings can be readily applied to other types of apparatuses. This description is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments.
As the present features may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2007-0076579 | Jul 2007 | KR | national |
| 10-2007-0139286 | Dec 2007 | KR | national |
| 10-2008-0070336 | Jul 2008 | KR | national |
