Abstract:
According to the present invention an expandable joint is made without removable bearing caps by preassembling eccentric bushings onto the hinge pin. The expandable joint has a hinge type construction, but with the journals for each side of the hinge being spaced apart so that the distance between the two sides of the hinge changes with rotation of the hinge pin. The expandable joint of the present invention is assembled by sliding the hinge pin into the hinged joint with the eccentric bushings attached. Once the hinge pin is in place, the eccentric bushings are locked in place with fasteners so that they do not rotate. After the eccentric bushings are locked in place, the hinge pin can be turned to expand the joint. The expandable joint is intended for use in variable compression ratio engines, where expansion of the joint changes the compression ratio of the engine.

Description:
[0001]    This application relates to Provisional Application No. 62/176,649 having a filing date of Feb. 24, 2015, and Provisional Application No. 62/230,277 having a filing date of Jun. 1, 2015, and Provisional Application Docket No. VC3-00C having a filing date of Feb. 1, 2016 and a US Express Mail No. EK 886663519 US with a Provisional Application No. not yet assigned. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Prior art variable compression ratio engines have eccentric hinge pin expandable joints. These engines have hinge pins with off-set journals bearing for adjusting engine compression ratio. The prior art engines employ removable bearing caps for assembly of the eccentric hinge pins in the engine. A problem with these engines is that they would be expensive to manufacture and expensive to assemble due to the large number of bearing caps that need to be bolted together. A second problem is low mechanical stiffness and strength. The problem of low strength and stiffness is compounded in engines where the parting line of the bearing cap is oriented vertically rather than horizontally for best supporting the high mechanical forces encountered in internal combustion engines. 
         [0003]    Eichi Kamiyama shows in U.S. Pat. No. 7,806,092 a variable compression ratio engine having an eccentric hinge pin assembly 25c, 25c1, 25c2, 25c3 and 25c4 retained in crankcase bearing caps 25a, 25a2 and jug bearing caps or bearing blocks 25b. Crankcase bearing caps 25a2 are bolted to crankcase 21, and jug bearing caps or bearing blocks 25b are bolted to jug 23. A problem with the invention taught in U.S. Pat. No. 7,806,092 is that it is expensive to manufacture and expensive to assemble due to the large number of bearing caps that need to be bolted to the jug and crankcase. A second problem is low mechanical stiffness and strength. 
         [0004]    Per Gillbrand shows in U.S. Pat. No. 5,611,301 a variable compression ratio engine having an eccentric hinge pin 44 and removable bearing caps 46 and links 41. These components collectively result in a relatively large, heavy and expensive engine. 
       SUMMARY OF THE INVENTION 
       [0005]    According to the present invention an expandable joint is made without removable bearing caps by preassembling eccentric bushings onto the hinge pin. 
         [0006]    The expandable joint has a hinge type construction, but with the journals for each side of the hinge being spaced apart so that the distance between the two sides of the hinge changes with rotation of the hinge pin. 
         [0007]    The expandable joint of the present invention is assembled by sliding the hinge pin into the hinged joint with the eccentric bushings attached. Once the hinge pin is in place, the eccentric bushings are locked in place with fasteners so that they do not rotate. After the eccentric bushings are locked in place, the hinge pin can be turned to expand the joint. 
         [0008]    The expandable joint is intended for use in variable compression ratio engines, where expansion of the joint changes the compression ratio of the engine. A major benefit of the present invention is that it is robust and can support the large forces encountered in internal combustion engines. Another benefit of the present invention is that removable bearing caps are not required, resulting in a lower cost and a smaller size than expandable joints used in prior art variable compression ratio engines. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0009]      FIG. 1  is intended to schematically illustrate an expandable joint according to the present invention. 
           [0010]      FIG. 2  shows an eccentric bushing having upper and lower halves according to the present invention. 
           [0011]      FIG. 3  shows an eccentric bushing having a contiguous metal structure according to the present invention. 
           [0012]      FIG. 4  shows a primary journal eccentric according to the present invention. 
           [0013]      FIG. 5  is similar to  FIG. 1 , but shows one hinge pin not slid into the eccentric hinged joint. 
           [0014]      FIG. 6  is an exploded view of the present invention showing the eccentric hinged joint of the present invention unassembled. 
           [0015]      FIG. 7  is intended to illustrate a partially assembled hinge pin. 
           [0016]      FIG. 8  is intended to illustrate an assembled hinge pin. 
           [0017]      FIG. 9  is intended to illustrate a variable compression ratio engine having assembled hinge pins. 
           [0018]      FIG. 10  is a detailed view of a compression fastener. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0019]      FIGS. 1 through 6  are intended to schematically illustrate a portion of a variable compression ratio engine  1  having an expandable joint or eccentric hinged joint  2  according to the present invention.  FIG. 1  provides a cutaway view of the variable compression ratio engine having the eccentric hinged joint according to the present invention.  FIG. 5  is similar to  FIG. 1  but one hinge pin has not yet been slid into the engine.  FIG. 6  is an exploded view of the present invention that shows the hinged joint unassembled. 
         [0020]    Eccentric hinged joint  2  has a primary or first bearing housing  4  having a plurality of primary journal bearings  6 , and a second bearing housing  8  having a plurality of secondary journal sockets  10 . 
         [0021]    Eccentric hinged joint  2  has a hinge pin  12  having a plurality of primary journals  14  and a plurality of secondary journals  16 . The primary journals  14  define a first journal axis  18  and the secondary journals  16  define a second journal axis  20 , second journal axis  20  being offset from said first journal axis  18 . 
         [0022]    According to the preferred embodiment of the present invention, eccentric hinged joint  2  further includes one or more eccentric bushings  22 . The eccentric bushings  22  are located in secondary journal sockets  10  after assembly of the eccentric hinged joint  2 . 
         [0023]    The primary journals  14  are rotatably mounted in the primary journal bearings  6 , and the secondary journals  16  are rotatably mounted in the eccentric bushings  22  for providing eccentric motion of the eccentric hinged joint  2 . 
         [0024]    Referring now to  FIG. 1 , only a lower portion  6   a  of primary journal bearing  6  is shown in order to make visible primary journal  14 . 
         [0025]    The eccentric hinged joint  2  further includes eccentric bushing retaining means  24  for preventing movement of the eccentric bushings  22  in the secondary journal sockets  10  after assembly of the eccentric hinged joint  2 . In more detail, the bushing retaining means  24  secure or fixes the offset location of the eccentric bushing  22  in the secondary journal sockets  10 , and in more detail bushing retaining means  24  fixes the location of bushing minor axis  42  in second bearing housing  8 . The eccentric bushing retaining means  24  may optionally be a threaded fastener  26 , a compression fastener  26   b,  a pin, a key, adhesive, solder, braze, weld, an interference fit, a combination of the above or other functional means. Retaining means  24  may be located above secondary journal socket  10  as shown, or optionally below or to the side of secondary journal socket  10 . 
         [0026]      FIGS. 1 and 5  show a portion of a variable compression ratio engine  1  having two eccentric hinged joints  2  of similar construction. The two eccentric hinged joints  2  rotate in the same direction and in phase to adjust the compression ratio of variable compression ratio engine  1 . A single eccentric hinged joint  2  according to the present invention may be used in other types of variable compression ratio engines. 
         [0027]      FIGS. 1, 2 and 6  shows an eccentric bushing  22  having an upper bushing half  28  and a lower bushing half  30 . A subset of eccentric bushings  22  are assembled eccentric bushings  22   a.  The bushing has separable halves to permit assembly on secondary journals  16  between two larger diameter primary journals  14 . Referring now to  FIGS. 1 through 6 , eccentric bushing  22  has a bushing outer surface  36  that is seated in secondary journal sockets  10  located in secondary bearing housings  8 . Eccentric bushing  22  optionally has a threaded hole, a pin hole, a socket, flat, keyway or other functional means  34  for receiving bushing retaining means  24 . Bushing outer surface  36  defines a bushing major axis  38 . Eccentric bushing  22  further has a bushing inner bearing surface  40  that bears on secondary journals  16  located on hinge pin  12 . Bushing inner surface  40  defines a bushing minor axis  42 , bushing minor axis  42  being offset from bushing major axis  38 . 
         [0028]    In the embodiment of the present invention shown in  FIGS. 1 through 6  the diameter of bushing outer surface  36  is approximately the same as the diameter of primary journals  14 . Additionally, in the embodiment of the present invention shown in  FIGS. 1 through 6 , the distance between bushing major axis  38  and bushing minor axis  42  is equal to or approximately equal to the distance between first journal axis  18  and second journal axis  20 , thereby enabling the outer surface of primary journals  14  to be generally aligned with bushing outer surface  36 , and thereby enable hinge pins  12 , with eccentric bushings  22  attached, to axially slide into primary journal bearings  6  and secondary journal sockets  10 , and thereby provide for assembly of eccentric hinge joint  2 , and in more detail without need for removable bearing caps. 
         [0029]    According to the present invention, eccentric hinged joint  2  has at least one eccentric bushing  22  assembled onto hinge pin  12  between two primary journals  14 . 
         [0030]    Eccentric hinge joint  2  further has a first axial assembly clearance for slidably assembling an eccentric bushing  22  on hinge pin  12  through at least one primary journal bearing  6 . Eccentric hinge joint  2  further has a second axial assembly clearance for slidably assembling a primary journal  14  on hinge pin  12  through at least one secondary journal socket  10 . Preferably, according to the present invention, eccentric hinge joint  2  has a first axial assembly clearance for slidably assembling an eccentric bushing  22  on hinge pin  12  through at least one primary journal bearing  6 , and eccentric hinge joint  2  has a second axial assembly clearance for slidably assembling a primary journal  14  on hinge pin  12  through at least one secondary journal socket  10 . In more detail, second bearing housing  8  and secondary journal socket  10  have an internal diameter and primary journal  14  has an outer primary journal diameter, where the internal diameter is larger than the outer primary journal diameter, thereby providing assembly clearance for the primary journal  14  to pass through the secondary bearing housing  8  and secondary journal socket  10  for assembly of the eccentric hinged joint  2 . 
         [0031]    Eccentric bushing  22  also has an outer bushing diameter and primary journal  14  has an outer primary journal diameter. Preferably, according to the present invention, the outer bushing diameter is within 0.007 inches of the outer primary journal diameter thereby enabling hinge pin  12  to slide into hinged joint  2 . 
         [0032]    A significant benefit of the present invention is that removable bearing caps are not required for assembling the hinge pins in the engine. Referring now to  FIGS. 1, 5 and 6 , eccentric hinged joint  2  preferably has at least one primary bearing housing  4  having a contiguous metal or material structure surrounding at least one primary journal bearing  6  thereby providing a rigid and compact eccentric hinged joint  2 . Preferably at least one secondary bearing housing  8  has a contiguous metal or material structure surrounding at least one secondary journal socket  10  thereby providing a rigid and compact eccentric hinged joint. And preferably at least one primary bearing housing  4  has a contiguous metal or material structure surrounding at least one primary journal bearing  6 , and at least one secondary bearing housing  8  has a contiguous metal or material structure surrounding at least one secondary journal socket  10  thereby providing a rigid and compact eccentric hinged joint. 
         [0033]    According to the present invention, hinge pin  12  may be a contiguous metal shaft including at least on primary journal  14  and at least one secondary journal  16 . Assembled eccentric bushings  22   a  are typically employed in embodiments of the present invention having a secondary journal  16  located between two primary journals  14 , and in more detail when the secondary journal has a smaller diameter than the two outer primary journals. 
         [0034]    Referring now to  FIGS. 1, 2 and 3 , a subset of eccentric bushings  22  are assembled eccentric bushings having separable halves  22   a.  Assembled eccentric bushings  22   a  have separable bushing halves for assembly of eccentric bushings  22 , on secondary journals  16 . Eccentric bushings  22   a  preferably include alignment means for alignment of separable eccentric bushing halves, including upper bushing half  28  and lower bushing half  30 , in second journal sockets  10 , and also to hold the bearing halves together during assembly. The eccentric bushing  22   a  alignment means is preferably selected from the group consisting of bushing alignment pins  32 ; threaded fasteners; fractured surface alignment; adhesive; solder; brazing; welding or other functional means. Alignment pins  32  can be seen in  FIGS. 1 and 10 . 
         [0035]    Referring now to  FIGS. 3, 4, 7, 8 and 9  a subset of hinge pins  12  are assembled hinge pins  12   b.  A subset of primary journals  14  are primary journal eccentrics  14   b.  A subset of eccentric bushings  22  are full-round or contiguous metal structure eccentric bushings  22   b.    
         [0036]    Assembled hinge pin  12   b  has a central shaft  44  and at least one primary journal eccentric  14   b  rigidly assembled onto central shaft  44 . Hinge pin  12   b  further includes retaining means  45  for rigidly retaining primary journal eccentric  14   b  on central shaft  44 . Preferably the retaining means  45  is selected from a group consisting of an interference fit; a key; a pin; a threaded fastener; adhesive; solder; braze; weld, or other functional means.  FIGS. 7 and 8  are intended to illustrate primary retaining means  45 , and in more detail where primary journal eccentrics  14   b  are press fit or shrink fit onto central shaft  44 , or retained in place with an adhesive, solder, braze or weld.  FIG. 4  is intended to illustrate primary journal eccentric  14   b.  Primary journal eccentric  14   b  has a full-round or contiguous metal structure. 
         [0037]    Eccentric bushing  22   b  has a slip fit assembly onto central shaft  44 . Central shaft  44  has a secondary journal surface  16   b  for supporting eccentric bushings  22   b.    FIG. 3  is intended to illustrate an eccentric bushing  22   b  having a contiguous metal structure. Bushing inner bearing surface  40  bears on secondary journal surface  16   b  on central shaft  44 . 
         [0038]      FIG. 7  shows a partially assembled hinge pin  12   b,  and  FIG. 8  shows an assembled or largely assembled hinge pin  12   b.    FIGS. 7 and 8  show eccentric bushing  22   b  having a slip fit assembly onto said central shaft  44  between two primary journals eccentrics  14   b,  primary journal eccentrics  14   b  being rigidly assembled onto central shaft  44 .  FIG. 8  shows central shaft  44  and rigidly attached primary journal eccentrics  14   b  rotated relative to eccentric bushings  22   b  causing the outer diameters of the eccentric bushings  22   b  to fall out of alignment with the primary journal eccentrics  14   b,  as needed for adjusting the compression ratio of variable compression ratio engine  1 . 
         [0039]      FIG. 9  is intended to illustrate a variable compression ratio engine having assembled hinge pins  12   b  according to the present invention. Variable compression ratio engine  1  has a crankshaft  46 , a connecting rod  48  a piston  50 , a cylinder  52 , a camshaft drive chain  54 , a crankcase  56 , a cylinder jug  58  and a deck  60  for receiving a head gasket and cylinder head. 
         [0040]    Referring now to  FIG. 10 , a subset of bushing retaining means  24  are compression fasteners  26   b.  Compression fasteners  26   b  are threaded into secondary bearing housing  8 , and include a compression pin tip  62  for bearing down in socket  34 . Alignment of eccentric bushing  22  is provided by pin tip  62  registering in the mating hole of socket  34 . Compression fastener  26   b  bears down on upper bushing half  28 , and upper bushing half  28  in turn bears down on lower bushing half  30 , forcing lower bushing half  30  to be firmly seated in secondary journal socket  10 . 
         [0041]    According to an embodiment of the present invention, eccentric bushings  22  are mounted in first bearing housing  4 , and primary journal bearings  6  are mounted in second bearing housing  8 , and secondary journals  16  are repositioned to align with eccentric bushings  22 , and primary journals  14  are repositioned to align with journal bearings  6 , and retaining means  24  is repositioned to align with eccentric bushings  22 . 
         [0042]    The present invention is intended for use in variable compression ratio engines, but may also be used for other purposes where an expandable joint is needed.