Abstract:
Disclosed is a scroll compressor. As two side surfaces of a rotation preventing member are formed to be flat with keys, the rotation preventing member, a main frame, and an orbiting scroll may be easily processed and partial frictions and noise due to the keys may be prevented. Furthermore, since the orbiting scroll is entirely and stably supported by a ring portion of the rotation preventing member, the occurrence of a tilting moment of the orbiting scroll may be reduced. This may enhance the stability and the performance of the scroll compressor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present disclosure relates to subject matter contained in priority Korean Application No. 10-2011-0065638, filed on Jul. 1, 2011, which is herein expressly incorporated by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an orbiting scroll, and more particularly, to a rotation preventing member of a scroll compressor. 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, a compressor is an apparatus for compressing fluid such as a refrigerant gas, and may be classified into a rotary compressor, a reciprocating compressor, a scroll compressor, etc. according to a fluid compression method. 
         [0006]    This scroll compressor indicates a compressor of a high efficiency and low noise, the compressor widely applied to an air conditioning system. In this scroll compressor, a plurality of compression chambers are formed between two scrolls as the two scrolls perform an orbital motion with respect to each other. While continuously moving toward the center, these compression chambers have a deceased volume. Accordingly, a refrigerant is sucked, compressed and then is discharged. 
         [0007]      FIG. 1  is a longitudinal sectional view illustrating one example of a scroll compressor in accordance with the conventional art, and  FIG. 2  is a perspective view illustrating a state that an Oldham&#39;s ring has been separated from a main frame and an orbiting scroll of  FIG. 1 . 
         [0008]    As shown, in the conventional scroll compressor, a main frame  2  and a sub frame  3  are disposed at an inner space  11  of a casing  1  with a predetermine gap therebetween in a horizontal direction. A driving motor  4  for generating a rotational force is installed between the main frame  2  and the sub frame  3 . To the center of a rotor  42  of the driving motor  4 , coupled is a crankshaft  5  passing through the main frame  2 , and configured to transmit a rotational force of the driving motor  3  to an orbiting scroll  7  to be later explained by being coupled thereto. The main frame  2  is forcibly-coupled to the casing  1 , and the sub frame  3  is integrally formed with the casing  1 . 
         [0009]    A fixed scroll  6  is fixedly-installed above the main frame  2 , and the orbiting scroll  7  is coupled to the fixed scroll  6  to form a pair of compression chambers (P) which consecutively move, by being engaged with the fixed scroll  5 . Between the orbiting scroll  7  and the main frame  2 , installed is an Oldham&#39;s ring  8  for allowing the orbiting scroll  7  to perform an orbital motion with preventing a rotation of the orbiting scroll  7 . 
         [0010]    A suction pipe  12  and a discharge pipe  13  are coupled to the casing  1 . The suction pipe  12  is directly communicated with a suction ort (not shown) via the casing  1 , whereas the discharge pipe  13  is communicated with the inner space  11  of the casing  1 . A discharge port  63  of the fixed scroll  6  for containing therein a discharge refrigerant is communicated with the inner space  11  of the casing  1 . 
         [0011]    A shaft accommodating hole  21  for supporting a crankshaft  5  in a radius direction is formed at the center of the main frame  2 , and a first bearing  22  for supporting the crankshaft  5  in a radius direction is installed at the shaft accommodating hole  21 . 
         [0012]    The crankshaft  5  is forcibly-inserted into the rotor  42  of the driving motor  4 , and upper and lower sides thereof are supported by the main frame  2  and the sub frame  3 , respectively. Inside the crankshaft  5 , an oil passage  51  is long formed along a shaft direction so that oil of the casing  1  may be sucked to be used to lubricate each bearing surface. 
         [0013]    A fixed wrap  62  which forms a pair of compression chambers (P) is formed on a bottom surface of an end plate  61  of the fixed scroll  6  in an involute shape. A suction port (not shown) directly connected to the suction pipe  13  and sucking a refrigerant into the compression chambers (P) is formed on a side surface of the end plate  61 . At the center of an upper surface of the end plate  61 , formed is the discharge port  63  through which a compression gas compressed in the compression chambers (P) is discharged to the inner space  11  of the casing  1 . On an upper surface of the fixed scroll  6 , provided is a check valve  9  opening or closing the discharge port  63  and preventing backflow of a refrigerant gas. 
         [0014]    On an upper surface of an end plate  71  of the orbiting scroll  7 , an orbiting wrap is formed in an involute shape so as to form the pair of compression chambers (P) together with the fixed wrap  62  of the fixed scroll  6 . At the center of a bottom surface of the end plate  71 , formed is a boss portion  73  coupled to the crankshaft  5  and receiving a driving force of the driving motor  4 . On an inner circumferential surface of the boss portion  73 , installed is a second bearing  74  for supporting the crankshaft  5  and the boss portion  73  in a radius direction. 
         [0015]    As shown in  FIG. 2 , a body of the Oldham&#39;s ring  8 , a ring portion  81  is formed in a ring shape. At two sides of an upper surface of the ring portion  81 , first keys  82  are radially formed so as to be slidably inserted into first key recesses  75  provided on a bottom surface of the end plate  71  of the orbiting scroll  7 . At two sides of a bottom surface of the ring portion  81 , second keys  83  are formed so as to be slidably inserted into second key recesses  23  of the main frame in a direction perpendicular to the first keys  82 . 
         [0016]    Unexplained reference numeral  31  denotes a third bearing for supporting the crankshaft in a radius direction, and  41  denotes a stator of the driving motor. 
         [0017]    The conventional scroll compressor is operated as follows. 
         [0018]    Once power is applied to the driving motor  4 , the orbiting scroll  7  performs an orbital motion on an upper surface of the main frame  2  by the Oldham&#39;s ring  8  by an eccentric distance while the crank shaft  5  rotates together with the rotor  42  of the driving motor  4 . And, the pair of compression chambers (P) which consecutively move are formed between the fixed wrap  62  and an orbiting wrap  72 . The compression chambers (P) move toward the center by the continuous orbital motion of the orbiting scroll  7 , thus to have a decreased volume. Accordingly, a refrigerant is sucked, compressed and then is discharged. 
         [0019]    The first keys  82  and the second keys  83  of the Oldham&#39;s ring  8  disposed between an upper surface of the main frame  2  and a bottom surface of the orbiting scroll  7  are slidably inserted into the first key recesses  75  of the orbiting scroll  7  and the second key recesses  23  of the main frame  2 , respectively, in a direction perpendicular to each other. This may prevent the orbiting scroll  7  having received a rotational force of the driving motor  4  from rotating with respect to the fixed scroll  6 . 
         [0020]    However, in the conventional scroll compressor, processing the Oldham&#39;s ring  8  is difficult due to the first keys  82  and the second keys  83 . Besides, the first key recesses  75  and the second key recesses  23  for slidably inserting the first keys  82  and the second keys  83  have to be formed at the orbiting scroll  7  and the main frame  2 , respectively. This may increase the fabrication costs of the orbiting scroll  7  and the main frame  2 . 
         [0021]    Besides, since the orbiting scroll  7  is supported by the main frame  2  by the first keys  82  and the second keys  83  of the Oldham&#39;s ring  8 , a supportable area may be narrowed. If a tilting moment may occur at the orbiting scroll  7 , the Oldham&#39;s ring  8  may be easily inclined to tilt the orbiting scroll  7 . This may lower the stability and the performance of the scroll compressor, and may increase partial frictions and noise between the orbiting scroll  7  and the main frame  2  or between the orbiting scroll  7  and the fixed scroll  6 . 
       SUMMARY OF THE INVENTION 
       [0022]    Therefore, an object of the present invention is to provide a scroll compressor capable of facilitating fabrications due to a simplified structure of a rotation preventing member, and capable of reducing fabrication costs of the rotation preventing member and components contacting the rotation preventing member. 
         [0023]    Another object of the present invention is to provide a scroll compressor capable of effectively overcoming a tilting moment occurring at an orbiting scroll. 
         [0024]    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 scroll compressor, comprising: a rotation preventing member disposed between a fixed member and a movable member, and configured to prevent a rotation of the movable member, and configured to allow the movable member to perform an orbital motion with respect to the fixed member, wherein the rotation preventing member comprises a ring portion formed in a ring shape; one or more first sliding surfaces formed on an inner circumferential surface or an outer circumferential surface of the ring portion in a first direction, and slidably coupled to the movable member; and a second sliding surface formed, in a second direction, on one of the inner circumferential surface and the outer circumferential surface of the ring portion where the first sliding surface is not formed, and slidably coupled to the fixed member, wherein a virtual line extending from the first sliding surface and a virtual line extending from the second sliding surface are formed to cross each other. 
         [0025]    According to another aspect of the present invention, there is provided a scroll compressor, comprising: a frame fixedly-installed at an inner space of a casing; a fixed scroll fixedly-installed at the frame; an orbiting scroll installed to be movable with respect to the fixed scroll, and coupled to a rotor of a driving motor; and a rotation preventing member disposed between the frame and the orbiting scroll or between the fixed scroll and the orbiting scroll, and configured to prevent a rotation of the orbiting scroll, wherein a first guide surface is formed at the frame or the fixed scroll, a second guide surface is formed at the orbiting scroll, a first sliding surface is formed on one of an inner circumferential surface and an outer circumferential surface of the rotation preventing member so as to slidably contact the first guide surface, and a second sliding surface is formed on another surface so as to slidably contact the second guide surface. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a longitudinal sectional view illustrating one example of a scroll compressor in accordance with the conventional art; 
           [0027]      FIG. 2  is a perspective view illustrating a state that an Oldham&#39;s ring has been separated from a main frame and an orbiting scroll of  FIG. 1 ; 
           [0028]      FIG. 3  is a longitudinal sectional view illustrating one example of a scroll compressor according to the present invention; 
           [0029]      FIG. 4  is a perspective view illustrating a state that a rotation preventing member has been separated from a main frame and an orbiting scroll of the scroll compressor of  FIG. 3 ; 
           [0030]      FIG. 5  is a perspective view illustrating a state that a rotation preventing member has been interposed between a main frame and an orbiting scroll of the scroll compressor of  FIG. 3 ; 
           [0031]      FIG. 6  is a sectional view taken along line ‘I-I’ in  FIG. 5 , which illustrates a state that a rotation preventing member has been interposed between a main frame and an orbiting scroll; 
           [0032]      FIG. 7  is a planar view illustrating processes that an orbiting scroll of the scroll compressor of  FIG. 3  is prevented from rotating by a rotation preventing member; and 
           [0033]      FIG. 8  is a longitudinal sectional view illustrating another embodiment of an installation position of a rotation preventing member of the scroll compressor of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. It will also be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 
         [0035]    Description will now be given in detail of a drain device and a refrigerator having the same according to an embodiment, with reference to the accompanying drawings. 
         [0036]    Hereinafter, a scroll compressor of the present invention will be explained in more details with reference to the attached drawings. 
         [0037]      FIG. 3  is a longitudinal sectional view illustrating one example of a scroll compressor according to the present invention,  FIG. 4  is a perspective view illustrating a state that a rotation preventing member has been separated from a main frame and an orbiting scroll of the scroll compressor of  FIG. 3 ,  FIG. 5  is a perspective view illustrating a state that a rotation preventing member has been interposed between a main frame and an orbiting scroll of the scroll compressor of  FIG. 3 , and  FIG. 6  is a sectional view taken along line ‘I-I’ in  FIG. 5 , which illustrates a state that a rotation preventing member has been interposed between a main frame and an orbiting scroll. 
         [0038]    As shown, a scroll compressor having a rotation preventing member according to the present invention comprises a main frame  120  fixedly-installed at an inner space  111  of a hermetic casing  110 , and a sub frame  130  fixed to one side of the main frame  120  in a horizontal direction. The sub frame  130  may be coupled to an inner circumferential surface of the casing  110 , or may be integrally formed with the casing  110 . 
         [0039]    A shaft accommodating hole  121  for supporting a crankshaft  150  to be later explained in a radius direction is formed at the center of the main frame  120 , and a first bearing  122  for supporting the crankshaft  150  in a radius direction is installed at the shaft accommodating hole  121 . 
         [0040]    A driving motor  140  is fixedly-installed between the main frame  120  and the sub frame  130  at the inner space  112  of the casing  110 . A coil may be wound on a stator  141  of the driving motor  140  in a concentrated manner. The driving motor  140  may be implemented as a constant motor having the same rotation speed of a rotor  142 . Alternatively, the driving motor  140  may be implemented as an inverter motor having a variable rotation speed of the rotor  142  with consideration of multi functions of a refrigerating apparatus to which the scroll compressor is applied. A crank shaft  150  rotatably coupled to an orbiting scroll  170  to be later explained and transmitting a rotational force of the driving motor  140  to the orbiting scroll  170  is coupled to the rotor  142  of the driving motor  140 . The crankshaft  150  is supported by the main frame  120  and the sub frame  130  fixedly-installed at right and left sides of the casing  110 . 
         [0041]    A fixed scroll  160  is fixedly-coupled to one side surface of the main frame  120 . The fixed scroll  160  is provided with an end plate  161  of a disc shape so as to be fixed to the main frame  120 , and a fixed wrap  162  for forming compression chambers (P) is formed on a bottom surface of the end plate  161 . A suction recess (not shown) directly connected to a suction pipe  113  is formed at the edge of the end plate  161 , and a discharge port  163  is formed at the center of the end plate  161 . 
         [0042]    The orbiting scroll  170  which forms a pair of compression chambers (P) together with the fixed scroll  160  is installed between an upper surface of the main frame  120  and a bottom surface of the fixed scroll  160 . The orbiting scroll  170  is provided with an end plate of a disc shape so as to perform an orbital motion between the main frame  120  and the fixed scroll  160 . An orbiting wrap  172  which forms the compression chambers (P) by being engaged with the fixed wrap  162  is formed at one side surface of the end plate  171 . A boss portion  173  coupled to the crankshaft  150  is protruding from another side surface of the end plate  171 . 
         [0043]    A rotation preventing member  180  for preventing a rotation of the orbiting scroll  170  but allowing only an orbital motion with a rotational force received from the driving motor  140  is installed between the orbiting scroll  170  and the main frame  120 . 
         [0044]    As shown in  FIGS. 4 to 6 , the rotation preventing member  180  is provided with a ring portion  181  having a predetermined thickness and width, and formed in a ring shape. At one side surface of the main frame  120 , i.e., at the periphery of the shaft accommodating hole  121 , formed is a mounting portion  123  stepped from a thrust bearing surface in a ring shape, such that the rotation preventing member  180  is inserted thereinto to be movable on a plane. The mounting portion  123  consists of a bottom surface  1231  on which the rotation preventing member  180  is disposed, and a side wall surface  1232  extending from the bottom surface  1231  to a direction of the thrust bearing surface and which constitutes an inner circumferential surface of the mounting portion  123  such that a first guide surface  125  to be later explained is formed. 
         [0045]    Two side surfaces of the ring portion  181  in an axial direction, i.e., a first thrust surface  182  and a second thrust surface  183  sliding-contacting the mounting portion  123  of the main frame  120  and a thrust surface  175  of the orbiting scroll  170  are not provided with additional keys respectively, but are formed to be flat. 
         [0046]    One side surface of the ring portion  181  in an axial direction is provided with a first thrust surface  182  contacting the main frame  120 , and another side surface of the ring portion  181  in an axial direction facing the first thrust surface  182  is provided with a second thrust surface  183  contacting the orbiting scroll  170 . Accordingly, the mounting portion  123  of the main frame  120  and the thrust surface  175  of the orbiting scroll  170  facing the first thrust surface  182  and the second thrust surface  183 , respectively are formed to be flat without additional key recesses. 
         [0047]    First sliding surfaces  184  are formed at both sides of an outer circumferential surface of the ring portion  181 , so as to slide on a plane to a first direction, with respect to an inner circumferential surface of the mounting portion  123  of the main frame  120 , i.e., the side wall surface  1232 . And, first guide surfaces  125  are formed at both sides of an inner circumferential surface of the mounting portion  123  so that the first sliding surfaces  184  of the rotation preventing member  180  may slide on a plane to a first direction. The first guide surfaces  125  are formed in parallel on a plane to a first direction (upper and lower directions in  FIG. 6 ). As shown in  FIGS. 5 and 6 , the first sliding surfaces  184  and the first guide surfaces  125  may be formed to have an overlapped height based on a horizontal section, more preferably, may be formed on the same plane. Here, a virtual line extending from the first guide surface  125  and a virtual line extending from the second guide surface  176  to be later explained may be formed to cross each other. 
         [0048]    Second sliding surfaces  185  are formed at both sides of an inner circumferential surface of the ring portion  181 , so as to slide on a plane to a second direction, with respect to the orbiting scroll  170 . And, second guide surfaces  176  are formed at both sides of an outer circumferential surface of a boss portion  173  of the orbiting scroll  170 , so that the second sliding surfaces  185  of the rotation preventing member  180  may slide on a plane to a second direction. The second guide surfaces  176  are formed in parallel on a plane to a second direction (right and left directions in  FIG. 6 ). As shown in  FIGS. 5 and 6 , the second sliding surfaces  185  and the second guide surfaces  126  may be formed to have an overlapped height with the first sliding surfaces  184  and the first guide surfaces  125 , based on a horizontal section, more preferably, may be formed on the same plane. 
         [0049]    A virtual line extending from the second sliding surfaces  185  are formed in a direction perpendicular to a virtual line extending from the first sliding surfaces  184 . However, the A virtual line extending from the second sliding surfaces  185  may not be necessarily formed in a direction perpendicular to the A virtual line extending from the first sliding surfaces  184 , but may be formed to be crossed to the A virtual line extending from the first sliding surfaces  184 . 
         [0050]    The first sliding surfaces  184  are formed to have a length shorter than that of the first guide surfaces  125 , whereas the second sliding surfaces  185  are formed to have a length shorter than that of the second guide surfaces  126 . This may prevent a rotation of the orbiting scroll  170  as the rotation preventing member  180  performs a sliding motion with respect to the main frame  120  and the orbiting scroll  170 . 
         [0051]    As shown in  FIG. 6 , a plurality of the first sliding surfaces  184  are formed to be symmetrical to each other based on a first direction center line of the ring portion  181 . And, a plurality of the second sliding surfaces  185  are formed to be symmetrical to each other based on a second direction center line of the ring portion  181 . 
         [0052]    Unexplained reference numeral  112  denotes a suction pipe,  113  denotes a discharge pipe,  122 ,  131  and  174  indicate bearings, and  190  denotes a check valve. 
         [0053]    The operation of the scroll compressor will be explained as follows. 
         [0054]    Once power is supplied to the driving motor  140 , the crankshaft  150  rotates together with the rotor  142  to transmit a rotational force to the orbiting scroll  170 . 
         [0055]    Then, the orbiting scroll  170  performs an orbital motion on a thrust bearing surface of the main frame  120  by an eccentric distance, by the rotation preventing member  180 . As a result, a pair of compression chambers (P) which consecutively move are formed between the fixed wrap  162  and the orbiting wrap  172 . 
         [0056]    Due to a continuous orbital motion of the orbiting scroll  170 , the compression chambers (P) move to the center to have a decreased volume. Accordingly, a refrigerant sucked to the compression chambers (P) through the suction pipe  113  is compressed, and then is discharged to the inner space of the casing  110  through the discharge port  163  communicated with the final compression chamber. The discharged refrigerant is moved to a refrigerating cycle through the discharge pipe  114 . 
         [0057]    The rotation preventing member  180  of a ring shape is provided between the main frame  120  and the orbiting scroll  170 , thereby preventing a rotation of the orbiting scroll  170  which receives a rotational force from the driving motor  140 , but allowing only an orbital motion of the orbiting scroll  170 . 
         [0058]      FIG. 7  is a planar view illustrating processes that the orbiting scroll of the scroll compressor of  FIG. 3  is prevented from rotating by the rotation preventing member. 
         [0059]    As shown in  FIG. 7 , the orbiting scroll  170  is rotatably coupled to the crankshaft  150  in a state eccentric from the center of the crankshaft  150 , and receives a rotational force from the crankshaft  150 . Therefore, the orbiting scroll  170  tends to rotate as well as to perform an orbital motion centering around the crankshaft  150 , on an upper surface of the main frame  120 . 
         [0060]    The first sliding surfaces  184  are formed, in parallel, on two outer sides of the rotation preventing member  180  inserted into the mounting portion  123  of the main frame  120  in the form of straight lines. And, the first guide surfaces  125  are formed, in parallel, on two sides of an inner circumferential surface of the mounting portion  123 . This may prevent a rotation of the orbiting scroll  160 , and cause the orbiting scroll  170  to slide to the first direction where the first sliding surfaces  184  and the first guide surfaces  125  are formed, i.e., the upper and lower directions. 
         [0061]    At the same time, the second sliding surfaces  185  are formed in parallel, in the form of straight lines, on an inner circumferential surface of the rotation preventing member  180 , in a direction perpendicular to the first sliding surfaces  184 . And, the second guide surfaces  176  are formed in parallel, in the form of straight lines, on an outer circumferential surface of the boss portion  173  inserted into the mounting portion  123  together with the rotation preventing member  180 , in correspondence to the second sliding surfaces  185 . This may prevent a rotation of the orbiting scroll  170 , and may cause the orbiting scroll  170  to slide to the second direction where the second sliding surfaces  185  and the second guide surfaces  176  are formed, i.e., the right and left directions. 
         [0062]    Under these configurations, as shown in  FIGS. 7A to 7D , the orbiting scroll  170  does not perform a rotation by the rotation preventing member  180 , but performs an orbital motion despite a rotational force received from the driving motor  140 . In  FIG. 7 , Oa indicates the center of the crankshaft, and Ob indicates the center of the boss portion of the orbiting scroll. 
         [0063]    In the conventional art, a plurality of keys are formed on upper and lower surfaces of the rotation preventing member, and key recesses are formed at the main frame and the orbiting scroll. This may cause a difficulty in fabricating the rotation preventing member, and may cause an unstable behavior of the orbiting scroll. However, in the present invention, upper and lower surfaces of the rotation preventing member are not formed to be flat, but are formed to be provided with sliding surfaces. This may prevent a rotation of the orbiting scroll, thereby facilitating a processing of the oration preventing member. Furthermore, even if a tilting moment occurs at the orbiting scroll, the rotation preventing member is not inclined. This may effectively prevent tilting of the orbiting scroll, and thus reduce partial frictions and noise. 
         [0064]    Another embodiment of the scroll compressor according to the present invention will be explained as follows. 
         [0065]    In the aforementioned embodiment, the rotation preventing member is installed between the main frame and the orbiting scroll. However, in this embodiment, as shown in  FIG. 8 , the rotation preventing member  180  may be installed between the fixed scroll  160  and the orbiting scroll  170 . 
         [0066]    In this case, the ring portion  181  of the rotation preventing member  180  may be formed in a ring shape, and the first thrust surface  182  and the second thrust surface  183  are formed on upper and bottom surfaces of the ring portion  181 , respectively. The first sliding surfaces  184  and the second sliding surfaces  185  may be formed on an outer side surface and an inner side surface of the ring portion  181 , respectively. A mounting portion  165  may be formed on a thrust bearing surface of the fixed scroll  160 , and a first guide surface  166  may be formed on an inner circumferential surface of the mounting portion  165 . And, a mounting portion  177  may be formed on a thrust bearing surface of the orbiting scroll  170  in the form of a boss portion, and a second guide surface  178  may be formed on an outer circumferential surface of the mounting portion  177 . 
         [0067]    In this embodiment, the scroll compressor has the same configuration and effects as those of the aforementioned embodiment, except that the rotation preventing member is disposed between the fixed scroll and the orbiting scroll. This may allow the orbiting scroll to have a more stable behavior by being stably supported by the main frame.