Patent Publication Number: US-2003223894-A1

Title: Inleakageproof structure for escape opening of a coil-type compressor

Description:
BACKGROUND OF THE INVENTION  
       [0001] The present invention is related to an inleakageproof structure for escape opening of a coil-type compressor. The inleakageproof structure includes an annular oil groove formed on outer wall face of a fixed coiled body around the escape opening. An oil liquid exhausted from the escape opening is contained in the oil groove. By means of capillarity of the oil liquid in the oil groove, the oil liquid automatically seals a gap between the valve plate and the outer wall face of the fixed coiled body to avoid the problem of inleakage.  
       [0002]FIG. 4 shows a conventional coil-type compressor. A fixed coiled body  81  and a movable coiled body  82  are disposed in a housing  8 . The fixed coiled body  81  is formed with an escape opening  811  for the compressed gas to escape into the compressed gas chamber  84 . A resilient valve plate  83  is disposed on outer wall face of the fixed coiled body  81  corresponding to the escape opening  811 . In normal state, the valve plate  83  resiliently seals the escape opening  811 .  
       [0003] When the movable coiled body  82  is rotated relative to the fixed coiled body  81  to compress the gas, the compressed high pressure gas will push away the valve plate  83  to unblock the escape opening  811 . At this time, the high pressure gas can escape from the escape opening  811 . After escaping, the valve plate  83  due to its own resilience again seals the escape opening  811 .  
       [0004] A minor gap inevitably exists between the valve plate  83  and the wall face  812  around the escape opening  811  due to precision of the processed surface. As a result, the high pressure gas in the compressed gas chamber  84  will flow back through the gap between the valve plate  83  and the escape opening  811 . This leads to a problem of inleakage. Furthermore, the rotational speed of the compressor is up to several thousand rpm. That is, the valve plate  83  will open and close several thousand times per minute. As a result, after a period of use, the valve plate  83  will deform and can hardly fully seal the escape opening  811 . Under such circumstance, the high pressure gas in the compressed gas chamber  84  will flow through the gap between the valve plate  83  and the escape opening  811  back into the space between the fixed coiled body  81  and the movable coiled body  82  as shown in FIG. 5. This leads to more serious problem of inleakage. Accordingly, the efficiency of the compressor will be reduced.  
       SUMMARY OF THE INVENTION  
       [0005] It is therefore a primary object of the present invention to provide an inleakageproof structure for escape opening of a coil-type compressor. The inleakageproof structure includes an annular oil groove formed on outer wall face of a fixed coiled body around the escape opening. An oil liquid exhausted from the escape opening is contained in the oil groove. By means of capillarity of the oil liquid in the oil groove, the oil liquid automatically seals a gap between the valve plate and the outer wall face of the fixed coiled body to avoid the problem of inleakage.  
       [0006] It is a further object of the present invention to provide the above inleakageproof structure in which due to surface tension, the level of the oil liquid in the oil groove is slightly higher than the outer wall face of the fixed coiled body. Accordingly, when the valve plate is closed to a position near the outer wall face, due to capillarity, the oil liquid will be attracted to attach to the valve plate so as to previously seal the escape opening. Accordingly, the possibility of backflow of the high pressure gas is minified.  
       [0007] The present invention can be best understood through the following description and accompanying drawings wherein: 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0008]FIG. 1 is a sectional view of the present invention;  
     [0009]FIG. 2 is a sectional view according to FIG. 1, showing that the valve plate is slightly opened;  
     [0010]FIG. 3 is an enlarged view showing that the oil liquid in the oil groove seals the gap between the valve plate and the outer wall face of the fixed coiled body of the present invention;  
     [0011]FIG. 4 is a sectional view of a conventional coil-type compressor; and  
     [0012]FIG. 5 is an enlarged view showing the inleakage of high pressure gas existing in the conventional coil-type compressor. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0013] Please refer to FIGS.  1  to  3 . The present invention provides an inleakageproof structure for escape opening of a coil-type compressor  1 . A fixed coiled body  11  and a movable coiled body  12  are disposed in the compressor  1 . The fixed coiled body  11  is formed with an escape opening  111 . A valve plate  13  is disposed on outer wall face  112  of the fixed coiled body  11  corresponding to the escape opening  111 . The outer wall face  112  is formed with an annular oil groove  113  around the escape opening  111  within a range covered by the valve plate  13 . The oil liquid exhausted from the escape opening  111  is contained in the oil groove  113 . By means of capillarity of the oil in the oil groove  113 , the oil will automatically seal the gap between the valve plate  13  and the outer wall face  112 . In addition, a stop board  14  is disposed on the fixed coiled body  11 , whereby the valve plate  13  is sandwiched between the stop board  14  and the fixed coiled body  11 . The stop board  14  serves to restrict the extent to which the valve plate  13  is opened. After the movable coiled body  12  is rotated relative to the fixed coiled body  11  to compress the gas, the high pressure gas pushes away the valve plate  13  to unblock the escape opening  111 . At this time, the high pressure gas can escape from the escape opening  111  and go into the compressed gas chamber  15 . After escaping, the valve plate  13  due to its own resilience again seals the escape opening  111  to avoid backflow of the high pressure gas.  
     [0014] The oil groove  113  around the escape opening  111  contains therein an oil liquid A (such as freezing oil) exhausted from the escape opening  111 . Due to surface tension, the level of the oil liquid A will be slightly higher than the outer wall face  112 . Accordingly, before the valve plate  13  fully contacts with the outer wall face  112 , the valve plate  13  will first contact with the oil liquid A in the oil groove  113  as shown in FIG. 2. By means of capillarity of the oil liquid A, the oil liquid A will seal the minor gap between the valve plate  13  and the outer wall face  112 . Accordingly, the escape opening  111  is previously sealed to minify the possibility of backflow of the high pressure gas in the compressed gas chamber  15 . Furthermore, in the case that the valve plate  13  deforms after a period of use, under the capillarity, the oil liquid A in the oil groove  113  will automatically seal the enlarged gap between the valve plate  13  and the outer wall face  112  as shown in FIG. 3. Accordingly, the high pressure gas in the compressed gas chamber  15  is prevented from flowing back into the space between the fixed coiled body  11  and the movable coiled body  12  so that the problem of inleakage is avoided.  
     [0015] The above embodiment is only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiment can be made without departing from the spirit of the present invention.