Patent Publication Number: US-7594803-B2

Title: Orbit control device for a scroll compressor

Description:
FIELD OF THE INVENTION 
     The invention relates to a scroll compressor and more particularly to an orbit control device for a scroll compressor including a support plate having at least one support hole, a guide plate having at least one guide hole, and at least one pin, wherein an outer surface of the pin travels adjacent an inner surface of the guide hole to militate against a deviation from a desired path of travel by the orbit scroll. 
     BACKGROUND OF THE INVENTION 
     Presently, there are scroll compressors which use a pair of spiral involutes formed on a pair of plates. One plate is typically fixed, and the other plate travels in orbiting pattern in respect of the fixed plate, thereby gradually compressing a fluid. The fluid is eventually discharged through a discharge port. Known scroll compressors rely on various orbit control structures which enable the orbiting scroll to maintain a desired trajectory for efficient operation. The known orbit control structures include a ball coupling ring, an eccentric motion bearing, an Oldham coupling, a pin and barrel, and a pin and ring, for example. 
     One such control structure is disclosed in U.S. Pat. No. 5,147,192, hereby incorporated herein by reference in its entirety. The &#39;192 patent describes a scroll compressor including an orbit scroll having a first forming plate affixed thereto and a fixed plate having a second forming plate affixed thereto. The forming plates face one another and include a plurality of circular recesses formed therein on each of the facing surfaces. The recesses are formed in an annular pattern. A coupling lug is disposed between each facing pair of recesses. The recesses can be formed in the fixed plate and the orbit scroll. 
     U.S. Pat. No. 5,456,584, hereby incorporated herein by reference in its entirety, discloses an anti-rotation mechanism for a scroll compressor. The mechanism includes a fixed ring attached to a race and a rear housing. A moveable ring is affixed to a pressure receiving wall of an orbit scroll. Both the fixed ring and the moveable ring include a plurality of circular holes formed therein. The holes are adapted to receive one of a plurality of cylindrical pins therein. Alternatively, the mechanism includes a plurality of pins, each having two ends protruding from a moveable ring. The pins cooperate with a plurality of holes formed in a moveable plate and a fixed pressure-receiving wall. 
     In U.S. Pat. No. 6,264,444, hereby incorporated herein by reference in its entirety, a scroll compressor is disclosed which includes an orbital rotating mechanism disposed at an end of an orbit scroll. The mechanism includes a plurality of guide holes formed in a front housing and a pressure receiving plate. The plate is disposed between the orbit scroll and the front housing. A plurality of pins is attached to the back surface of the orbit scroll. The pins are adapted to be received in the guide holes. An outer peripheral surface of each of the pins makes sliding contact with an inner peripheral surface of each of the guide holes. 
     Although the aforementioned structures operate effectively, the structures require numerous parts. Additionally, the structures are difficult to manufacture, costly, heavy, and lack durability. 
     It would be desirable to produce an orbit control device for a scroll compressor wherein a cost, complexity, and weight thereof are minimized and a durability thereof is maximized. 
     SUMMARY OF THE INVENTION 
     In concordance and agreement with the present invention, an orbit control device for a scroll compressor wherein a cost, complexity, and weight thereof are minimized and a durability thereof is maximized, has surprisingly been discovered. 
     In one embodiment, an orbit control device for the scroll compressor comprises at least one pin adapted to be joined with an orbit scroll; a support plate including at least one support hole formed therein; and a guide plate disposed adjacent the support plate, the guide plate including at least one guide hole formed therein substantially aligned with the support hole formed in the support plate and having a diameter larger than a diameter of the pin, the pin received in the support hole of the support plate and the guide hole of the guide plate, wherein an inner surface forming the guide hole of the guide plate guides a path of movement of the pin 
     In another embodiment, a scroll assembly for the scroll compressor comprises a fixed scroll having a spiral involute disposed thereon; an orbit scroll having at least one aperture formed therein and a spiral involute disposed thereon adapted to cooperate with the spiral involute of the fixed scroll; and an orbit control device. The orbit control device further comprises a support plate disposed adjacent the orbit scroll, the support plate including at least one support hole formed therein; a guide plate disposed adjacent the support plate, the guide plate including a guide hole formed therein substantially aligned with the support hole of the support plate and having a diameter larger than a diameter of the support hole of the support plate; and at least one pin disposed in the aperture of the orbit scroll and adapted to be received in the support hole of the support plate and the guide hole of the guide plate, wherein an inner surface forming the guide hole of the guide plate abuts the pin to guide a path of movement of the orbit scroll. 
     In another embodiment, the scroll compressor comprises a housing forming a hollow interior; and a scroll assembly disposed in the hollow interior of the housing, the scroll assembly including a fixed scroll having a spiral involute, an orbit scroll having an annular array of apertures formed therein and a spiral involute adapted to cooperate with the involute of the fixed scroll to compress a fluid, and an orbit control device. The orbit control device further comprises a support plate disposed adjacent the orbit scroll and having an annular array of support holes formed therein; a guide plate having an annular array of guide holes formed therein, wherein the pins travel around an inner surface of the guide hole at least one spaced apart pin disposed in the back of the orbit scroll; and a plurality of pins disposed in the apertures of the orbit scroll, the pins adapted to be received in the support holes of the support plate and the guide holes of the guide plate, wherein an inner surface forming the guide holes of the guide plate abut the pins to guide a path of movement of the orbit scroll. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects and advantages of the invention will become readily apparent to those skilled in the art from reading the following detailed description of the invention when considered in the light of the accompanying drawings, in which: 
         FIG. 1  is a cross-sectional view of a scroll compressor including an orbit control device according to an embodiment of the invention; 
         FIG. 2  is an exploded perspective view of the orbit control device for the scroll compressor illustrated in  FIG. 1 ; and 
         FIG. 3  is a cross-sectional view of the orbit control device for the scroll compressor illustrated in  FIGS. 1 and 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
     The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the present invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. It is understood that materials other than those described can be used without departing from the scope and spirit of the invention. 
       FIG. 1  shows a scroll compressor  10  according to an embodiment of the invention. The scroll compressor  10  includes a housing assembly having a first housing shell  12 , a second housing shell  14 , and a scroll assembly  16 . The first housing shell  12  and the second housing shell  14  cooperate to form a hollow chamber therebetween. The first housing shell  12  can be produced from any conventional material such as aluminum, for example. Although the first housing shell  12  has a substantially circular cross-sectional shape, other cross-sectional shapes can be used as desired. The first housing shell  12  has a radially outwardly extending peripheral flange  13  formed thereon. 
     The second housing shell  14  can be produced from any conventional material such as aluminum, for example. Although the second housing shell  14  has a substantially circular cross-sectional shape, other cross-sectional shapes can be used as desired. A radially outwardly extending peripheral flange  15  is formed on the second housing shell  14 . The flange  15  is adapted to cooperate with the flange  13  of the first housing shell  12  to form a substantially fluid tight seal. The flange  13  of the first housing shell  12  and the flange  15  of the second housing shell  14  can be joined using bolts, screws, clips, and the like, for example. 
     The scroll assembly  16  includes a fixed scroll  18 , an orbit scroll  20 , and an orbit control device  52 . The fixed scroll  18  has a substantially circular cross-sectional shape, although other cross-sectional shapes can be used as desired. The fixed scroll  18  includes a base plate  22  having a first face  24  and a second face  26 . A spiral involute  28  extends laterally outwardly from the second face  26  of the base plate  22 . The base plate  22  is secured to the first housing shell  12  using any conventional means of attachment such as pins, screws, bolts, and the like, for example. In the embodiment shown, the fixed scroll  18  is formed from aluminum. However, it is understood that other conventional materials can be used if desired. 
     The orbit scroll  20  has a substantially circular cross-sectional shape. It is understood that other cross-sectional shapes can be used as desired. The orbit scroll  20  includes a base plate  32  having a first face  34 , a second face  36 , and a hub  40  adapted to receive a bearing  42  therein. The second face  36  includes a spiral involute  38  laterally outwardly extending therefrom. The spiral involute  38  of the orbit scroll  20  is received in and engages the spiral involute  28  of the fixed scroll  18  to define a plurality of compression chambers  46  therebetween. It is understood that wraps of the involutes  28 ,  38  can be shifted, maximized, or minimized, as desired. The second shell housing  14  and the end plate  32  of the orbit scroll  20  define a crank chamber  48  therebetween. A crank mechanism  50  is disposed in the crank chamber  50 . In the embodiment shown, the orbit scroll  20  is formed from aluminum. However, it is understood that other conventional materials can be used if desired. 
       FIG. 2  illustrates the orbit control device  52 . The orbit control device  52  includes the orbit scroll  20 , a support plate  56 , a guide plate  60 , and the second shell housing  14 . An annular array of pins  54  is press fit into apertures  64  formed in the second face  36  of the orbit scroll  20  and extend laterally outwardly therefrom, although other attachment methods and structures can be used as desired. As shown, the pins  54  have a substantially circular cross-sectional shape. It is understood that the pins  54  can have other cross-sectional shapes as desired. The pins  54  can be produced from any conventional material such as rolled steel, for example. 
     The support plate  56  is substantially disk shaped with a central aperture  66  formed therein. Any conventional material can be used to produce the support plate  56  such as steel, copper alloys, and cast iron, for example. An annular array of support holes  58  is formed in the support plate  60 . The holes  58  are substantially aligned with the pins  54  and permit the pins  54  to extend therethrough. In the embodiment shown, a diameter of the support holes  58  is slightly larger than a diameter of the pins  54 . Although the support plate  56  shown is held in place by an interference fit between the pins  54  and the support holes  58 , the support plate  56  may be affixed to the orbit scroll  20  by any conventional means, such as pins, screws, and the like, for example. The support plate  56  includes a first face  68  and a second face  70 . The first face  68  is adapted to seat adjacent the second face  36  of the orbit scroll  20 . The second face  70  can include an applied coating such as polytetrafluoroethylene (PFTE) and molybdenum disulfide (MoS 2 ), for example, or a surface modification adapted to minimize friction, if desired. 
     The guide plate  60  is substantially disk shaped and includes a central aperture  76  formed therein. An annular array of guide holes  62  is formed in the guide plate  60 . In the embodiment shown, a diameter of each of the guide holes  62  is larger than a diameter of each of the support holes  58  and a diameter of each of the pins  54 . However, other diameters can be used as desired. The pins  54  extend through the guide holes  62 . The number of pins  54 , and the corresponding number of the support holes  58  and the guide holes  62 , can be increased or decreased depending upon a load on the scroll compressor  10 , material properties of the materials used to produce components of the scroll compressor  10 , or other design considerations. A cam surface  78  surrounding the guide holes  62  guide a path of the orbit scroll  20 . 
     A first face  74  of the guide plate  60  may include a plurality of spaced apart indentations  72  formed therein. In the embodiment shown, an annular array of indentations  72  is formed, each indentation  72  having an oblong shape. However, it is understood that more or fewer indentations, indentations having different shapes, and indentations formed in different patterns can be used without departing from the scope and spirit of the invention. It is further understood that the indentations  72  can be formed elsewhere on the guide plate  60 , as desired. The indentations  72  are formed to collect and disperse a lubricant, such as oil, for example, over respective mating faces  70 ,  74  of the support plate  56  and the guide plate  60 . 
     The guide plate  60  is secured to the second housing shell  14  using pins  80  as shown in  FIG. 3 . It is understood that other means of attachment can be used such as screws, and the like, for example. The guide plate  60  can be produced from any conventional material known in the art such as steel, a copper alloy, and cast iron, for example. The guide plate  60  may be produced from a harder material than the support plate  56 , if desired, in order to control wear patterns and wear characteristics of the plates  56 ,  60 . The guide plate  60  can also include an applied coating such as polytetrafluoroethylene (PFTE) and molybdenum disulfide (MoS 2 ), for example, or a surface modification, if desired. The second face  70  of the support plate  56  slidably contacts the first face  74  of the guide plate  60 . 
     In operation, the crank mechanism  50  disposed in the crank chamber  48  causes the orbit scroll  20  to revolve in a desired path, as is known in the art. The cam surfaces  78  cooperate with the pins  54  of the orbit scroll  20  to militate against a deviation from the desired path. More specifically, as the orbit scroll  20  revolves, an outer surface of the pins  54  slidably contacts the cam surface  78  of the guide holes  62 . Accordingly, the orbit scroll  20  is caused to revolve within limitations provided by the cam surfaces  78 . Thus, the desired path of the orbit scroll  20  is controlled by the diameter of the guide holes  62 . The support plate  56  militates against undesirable wear of the orbit scroll  20  and the pins  54 . Additionally, when the indentations  72  are provided, a lubricant is collected in and dispersed from the indentations  72  to minimize heated generated due to contact between the plates  56 ,  60  and further militate against undesirable wear. 
     From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions in accordance with the scope of the appended claims.