Abstract:
Provided is a hermetic scroll compressor comprising: an upper frame which supports an upper side of a driving shaft and has an oil pocket at a center portion thereof so that oil can be accumulated therein; a fixed scroll fixed to the upper frame; an orbiting scroll which is revolved between the fixed scroll and the upper frame so as to compress fluid; an Oldham ring having two upper keys inserted into a side of the orbiting scroll and two lower keys inserted into a side of the upper frame; a lower key groove formed at the upper frame so that the lower key is accommodated therein so as to be linearly reciprocated; and an oil supplying structure formed at a body of the upper frame so as to supply the oil from the oil pocket to the lower key groove. The friction generated between the orbiting scroll and the thrust surface of the upper frame can be minimized.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a hermetic scroll compressor, and more particularly, to a scroll compressor adapted to smoothly supply oil to a thrust surface of an upper frame and a lower key portion of an Oldham ring to prevent components from being worn by friction and also prevent generation of frictional heat.  
         [0003]     2. Description of the Related Art  
         [0004]     Generally, a compressor is a means for converting mechanical energy into compressive energy, and largely classified into a reciprocating type, a scroll type, a centrifugal type and a vane type. Particularly, a scroll compressor is widely used in an air conditioner and a refrigerator.  
         [0005]     Further, the scroll compressor can be classified into a low-pressure scroll compressor and a high-pressure scroll compressor.  
         [0006]     In detail, the scroll compressor is classified into the low-pressure scroll compressor and the high-pressure scroll compressor according as whether a casing thereof is filled with suction gas or exhaust gas.  
         [0007]     In addition, the scroll compressor is formed with a spiral scroll wrap, and performs a compressing action by a relative motion between a fixed scroll fixed regardless of rotation of a driving shaft and an orbiting scroll revolved by the rotation of the driving shaft.  
         [0008]     The typical related art low-pressure scroll compressor includes a driving motor having a rotor and a stator, a driving shaft which is rotated by rotation of the driving motor and has an eccentric portion at an upper portion thereof, and an upper frame which is fitted to an upper side of the driving shaft so as to support the driving shaft and has an oil pocket at an edge portion of a center groove.  
         [0009]     The related art low-pressure scroll compressor further includes a scroll compressing portion having an orbiting scroll which is positioned at an upper side of the upper frame, for compressing sucked coolant by an orbiting motion, a fixed scroll which is engaged with the orbiting scroll and fixed to the upper side of the upper frame, and a Oldham ring which allows the orbiting scroll to be orbited in the fixed scroll.  
         [0010]     In the above-mentioned scroll compressor, oil is accumulated in the oil pocket formed at the upper frame. The accumulated oil is infiltrated into a fractional portion between a lower surface of the orbiting scroll and the thrust surface of the upper frame by the revolution of the orbiting scroll. Thus, a contact surface is lubricated.  
         [0011]     The scroll compressor operated by the above-mentioned operating principle is described in U.S. Pat. No. 6,685,441 filed by the applicant of the present invention.  
         [0012]     However, when the related art scroll compressor as described above is overloaded during a compressing process, the orbiting scroll is tightly contacted with the thrust surface. As the result, the oil from the oil pocket cannot be sufficiently supplied to the fractional portion between the orbiting scroll and the upper frame.  
         [0013]     Furthermore, the oil cannot be smoothly supplied to a fractional surface between the orbiting scroll and an upper key of an Oldham ring, and also to a fractional surface between a lower key of the Oldham ring and the upper frame.  
         [0014]     As described above, since the oil cannot be sufficiently supplied to the fractional portions, there are some problems that components are severely worn by fraction and a change in oil characteristic is occurred by fractional heat.  
         [0015]     In addition, there is a further problem that noise and vibration is generated by the fraction.  
       SUMMARY OF THE INVENTION  
       [0016]     Accordingly, the present invention is directed to a scroll compressor that substantially obviates one or more problems due to limitations and disadvantages of the related art.  
         [0017]     An object of the present invention is to provide a scroll compressor with an improved upper frame structure, which is smoothly lubricated even when a compressing portion of the scroll compressor is overloaded.  
         [0018]     Another object of the present invention is to provide a scroll compressor in which components is prevented from being worn by friction, and generation of frictional heat as well as generation of noise and vibration is also prevented.  
         [0019]     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.  
         [0020]     To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a hermetic scroll compressor comprising: an upper frame which supports an upper side of a driving shaft and has an oil pocket at a center portion thereof so that oil can be accumulated therein; a fixed scroll fixed to the upper frame; an orbiting scroll which is revolved between the fixed scroll and the upper frame so as to compress fluid; an Oldham ring having two upper keys inserted into a side of the orbiting scroll and two lower keys inserted into a side of the upper frame; a lower key groove formed at the upper frame so that the lower key is accommodated therein so as to be linearly reciprocated; and an oil supplying structure formed at a body of the upper frame so as to supply the oil from the oil pocket to the lower key groove.  
         [0021]     In another aspect of the present invention, there is provided a hermetic scroll compressor comprising: an upper frame which supports an upper side of a driving shaft; a scroll compressing portion disposed at the upper frame so as to be revolved to compress fluid; an oil supplying structure formed at a body of the upper frame so as to supply the oil to the scroll compressing portion; and an oil supplying portion having an oil passage formed along an inner portion of a driving shaft so as to supply the oil to the oil supplying structure, and an oil feeder for pushing up the oil to the oil passage.  
         [0022]     In yet another aspect of the present invention, there is provided a hermetic scroll compressor comprising: an upper frame which supports an upper side of a driving shaft and has an oil storing portion at a center portion thereof so that oil can be accumulated therein; at least one or more scroll member which is revolved on the upper frame so as to compress fluid; an Oldham ring having at least one upper key coupled to the scroll member and at least one lower key inserted into a side of the upper frame; and an oil supplying structure formed at a side of the upper frame so as to supply oil from the oil storing portion to a surface of the lower key.  
         [0023]     In still another aspect of the present invention, the hermetic scroll compressor further comprises an Oldham ring having an upper key protruded on an upper side surface thereof and a lower key protruded on a lower side surface thereof; and an upper frame having a lower key groove in which the lower key is accommodated to be reciprocated, an oil pocket formed at a center portion thereof to accumulate oil, and an oil groove and oil hole for supplying the oil from the oil pocket to the lower key groove.  
         [0024]     It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:  
         [0026]      FIG. 1  is a cross-sectional view of a low-pressure scroll compressor with an oil supplying structure according to the present invention;  
         [0027]      FIG. 2  is a perspective view showing a coupling structure of an orbiting scroll, an Oldham ring and an upper frame in the scroll compressor according to the present invention;  
         [0028]      FIG. 3  is a plan view of the upper frame having an oil groove according to the present invention;  
         [0029]      FIG. 4  is a cross-sectional view of a hermetic scroll compressor according to another embodiment of the present invention;  
         [0030]      FIG. 5  is a perspective view of an upper frame having an oil hole according to the present invention;  
         [0031]      FIG. 6  is an plan view of the upper frame;  
         [0032]      FIG. 7  is a cross-sectional view of a scroll compressor according to yet another embodiment of the present invention;  
         [0033]      FIG. 8  is a perspective view of an upper frame of the scroll compressor according to the present invention; and  
         [0034]      FIG. 9  is a plan view of the upper frame. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0035]     Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. However, the spirit of the invention is not limited to the embodiments, but other embodiments may be easily proposed within the scope of the invention or other retrograde inventions by adding, changing or deleting other components.  
         [0036]     First Embodiment  
         [0037]     Referring to  FIG. 1 , a scroll compressor includes a driving motor  70  having a rotor  71  and a stator  72 , a driving shaft  79  which is rotated by rotation of the driving motor  70  and has an eccentric portion  74  at an upper portion thereof, and an upper frame  40  which is fitted to an upper side of the driving shaft  79  so as to support the driving shaft  79  and has an oil pocket  78  at an edge portion of a center groove.  
         [0038]     The scroll compressor further includes a suction portion having a suction pipe  93  for introducing fluid from an outside and a suction chamber  94 . In detail, a sliding bush  73  is inserted onto an outer surface of the eccentric portion  74  so as to be surface-contacted with the eccentric portion  74 .  
         [0039]     The scroll compressor further includes a scroll compressing portion having an orbiting scroll  60  which is positioned at an upper side of the upper frame  40 , for compressing coolant sucked through the suction pipe  93  by an orbiting motion, a fixed scroll  80  which is engaged with the orbiting scroll  60  and fixed to the upper side of the upper frame  40 , and a Oldham ring  2  which allows the orbiting scroll  60  to be orbited in the fixed scroll  80 .  
         [0040]     In addition, the scroll compressor further includes an exhaust portion having an exhaust port  90  which vertically passes through a center portion of the fixed scroll  80 , an exhaust chamber  91  which is formed at an uppermost portion of the compressor and communicated with the exhaust port  90 , and an exhaust pipe  92  which is disposed at one side of the exhaust chamber  91  so as to exhaust accumulated coolant.  
         [0041]     Moreover, the scroll compressor further includes an oil supplying portion having an oil passage  76  formed along an inner portion of the driving shaft  79 , and an oil feeder  75  for feeding oil to the oil passage  76 .  
         [0042]     Hereinafter, an operation of the scroll compressor as described above will be described.  
         [0043]     First, low-pressure coolant, which undergoes an expansion process, is introduced through the suction pipe  93  to the suction chamber  94 . The introduced coolant is moved to the scroll compressing portion. The coolant is compressed in the scroll compressing portion and changed into high-pressure coolant side of the shell  110 . The high-pressure coolant is moved through the exhaust port  90  to the exhaust chamber  91  and then exhausted through the exhaust pipe  92  to an outside.  
         [0044]     Meanwhile, while the compression process is performed, the oil stored in a lower chamber of the compressor is pushed up by the oil feeder  75  rotated with rotation of the driving shaft  79 . The oil is raised along the oil passage  76  to an upper end of the driving shaft  79  and spouted to an upper side of the eccentric portion  74 . The spouted oil is run down along a gap between the eccentric portion  74  and the sliding bush  73 , thereby functioning as lubricating oil. Then, the oil is accumulated in the oil pocket formed at the upper frame  40 . The accumulated oil is infiltrated into a fractional portion between a lower surface of the orbiting scroll  60  and a thrust surface of the upper frame  40  by revolution of the orbiting scroll. Thus, a contact surface is lubricated.  
         [0045]      FIG. 2  is a perspective view showing a coupling structure of an orbiting scroll, an Oldham ring and an upper frame in the scroll compressor according to the present invention.  
         [0046]     Referring to  FIG. 2 , the scroll compressor of the present invention comprises the upper frame  40 , the orbiting scroll  60  disposed at the upper side of the upper frame  40 , the thrust surface  41  contacted with the lower surface of the orbiting scroll  60  and the Oldham ring fitted to the upper frame  40 . At a body of the Oldham ring  50 , there are provided an upper key  52  which is protruded upward, and a lower key  51  which is protruded downward. An upper key groove  61  is formed on the lower surface of the orbiting scroll  60  so that the upper key  52  of the Oldham ring  50  is accommodated therein. A lower key groove  42  is formed on an outer circumferential surface of the thrust surface  41  of the upper frame  40  so that the lower key  51  of the Oldham ring  50  is accommodated therein. The oil pocket  44  for accumulating the oil is formed at a center portion of the upper frame  40 . An oil groove  43  is formed to be extended from the oil pocket  44  to the lower key groove  42 .  
         [0047]     Hereinafter, an operation and function of the scroll compressing portion will be described.  
         [0048]     The oil movement from the lower chamber of the scroll compressor to the oil pocket  44  is the same as in  FIG. 1 . Therefore, the description thereof will be omitted.  
         [0049]     The oil accumulated in the oil pocket  43  is moved along the oil groove  43  formed on the thrust surface  41  in a direction of the outer circumferential surface of the upper frame  40 . The oil in the oil groove  43  is evenly spread on the entire thrust surface  41  by the orbiting scroll revolved at the upper side of the upper frame  40 .  
         [0050]     Further, the oil flown along the oil groove  43  is finally moved to the lower key groove  42 . Then, the oil is drenched to the lower key groove  42  and the lower key  51  of the Oldham ring  50 , thereby functioning as the lubricating oil.  
         [0051]     Meanwhile, a shape of the oil groove  43  is not limited to the embodiment. The oil groove  43  can have any shape for allowing the oil to be smoothly moved.  
         [0052]     Further, a depth of the oil groove  43  is not limited to any particular value.  
         [0053]      FIG. 3  is a plan view of the upper frame having an oil groove according to the present invention.  
         [0054]     Referring to  FIG. 3 , one end of the oil groove  43  is started from an outer circumferential surface of the oil pocket  44 , and the other end is connected to the lower key groove  42 . Therefore, the oil accumulated in the oil pocket  44  is moved along the oil groove  43  to the lower key groove  42 .  
         [0055]     Second Embodiment  
         [0056]      FIG. 4  is a cross-sectional view of a hermetic scroll compressor according to another embodiment of the present invention.  
         [0057]     Referring to  FIG. 5 , the upper frame  40  according to the present invention comprises a thrust surface  41  which is contacted with a lower surface of an orbiting scroll  60 , a lower key groove  42  which is accommodated in an Oldham ring (not shown) so as to be linearly reciprocated, and an oil pocket  44  formed at a center portion of the upper frame  40  so that the oil is accommodated therein.  
         [0058]     In order for the oil from the oil pocket  44  to be run to the lower key  42 , there is provided an oil hole  45  formed to penetrate from one end to the other end of the lower key  42 .  
         [0059]      FIG. 5  is a perspective view of an upper frame having an oil hole according to the present invention, and  FIG. 6  is a plan view of the upper frame.  
         [0060]     Referring to  FIGS. 5 and 6 , the oil hole  45  of the present invention is formed at a desired depth from an upper side surface of the upper frame  40 . One end of the oil hole  45  is connected with the oil pocket  44 , and the other end is connected with the lower key groove  42 . Therefore, the oil accommodated in the oil pocket  44  is run along the oil hole  45  and arrived at the lower key groove  42 . At the lower key groove  42 , lubricating action is smoothly achieved, while the lower key  51  of the Oldham ring  50  is reciprocated. Further, the oil is evenly spread over the thrust surface  41 .  
         [0061]     Meanwhile, a diameter of the oil hole  45  and the depth of the oil hole  45  from the thrust surface  41  are not limited to particular values.  
         [0062]     Third Embodiment  
         [0063]      FIG. 7  is a cross-sectional view of a scroll compressor according to yet another embodiment of the present invention.  
         [0064]     Referring to  FIG. 7 , an upper frame of a scroll compressor according to the present invention comprises a oil groove  43  formed at an upper side surface thereof, and an oil hole  45  formed at a position which is below a bottom surface of the oil groove  43  in a desired length.  
         [0065]     Therefore, the oil in the oil pocket  44  is run along the oil groove  43  and the oil hole  45  to the lower key groove  42 .  
         [0066]      FIG. 8  is a perspective view of an upper frame of the scroll compressor according to the present invention, and  FIG. 9  is a plan view of the upper frame.  
         [0067]     Referring to  FIGS. 8 and 9 , the oil accumulated in the oil pocket  44  is moved along the oil hole  45  to the lower key groove  42 . Thus, the oil can be more rapidly spread in comparison with in the related art scroll compressor in which the oil is spread through the thrust surface  41  to the lower key groove  42 . The oil groove  43  and the oil hole  45  are formed together in the upper frame  40 . Therefore, the oil moved along the oil groove  43  functions as lubricating oil on the thrust surface, and the oil moved along the oil hole  45  functions as the lubricating oil between the lower key  51  and the lower key groove  42  of the upper frame  40 .  
         [0068]     Furthermore, although an overload is applied to an upper portion of the orbiting scroll  60 , the lubricating action of the oil is not influenced.  
         [0069]     Since the hermetic scroll compressor according to the present invention is provided with the oil groove and/or the oil hole on the upper frame, the oil can be smoothly supplied between the thrust surface of the upper frame and the lower surface of the orbiting scroll, through the overload is applied to the compressor.  
         [0070]     Accordingly, since the oil can be smoothly supplied, wear of components, fractional heat, noise and vibration due to the friction can be effectively reduced or eliminated.  
         [0071]     Furthermore, since the oil is rapidly supplied to the key portion of the Oldham ring, the Oldham ring can be smoothly reciprocated, thereby reducing the noise and vibration.  
         [0072]     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.