Oil seal

Abstract

According to the present invention, a variable compression ratio machine having main bearings mounted in an eccentric carrier or support includes an oil seal located primarily in a main bearing cap for minimizing leakage of pressurized main bearing oil. The seal is located generally in a first main bearing fastener socket or fastener access cutout in order to minimize structurally compromising the bearing cap, and a portion of the fastener socket preferably is used as an oil passageway as well as for wrench access to the fastener. The oil seal and oil circuit of the present invention enable the size of the eccentric support to be minimized while also providing highly effective oil sealing. In more detail, a significant advantage of the present invention is that highly effective oil sealing is attained without compromising the size or structural integrity of the bearing cap. A second significant advantage of the present invention is that it can be manufactured and assembled at low cost. The oil sealing system of the present invention is robust and highly reliable.

1 . An oil circuit for a variable compression ratio mechanism having a range of compression ratio settings, and having an oil supply, a housing and at least one cylinder mounted in the housing, a piston mounted for reciprocating movement in the cylinder, a crankshaft defining an axis about which the crankshaft rotates, and a connecting rod connecting the piston to the crankshaft, said variable compression ratio mechanism further having at least one eccentric support for supporting the crankshaft about the rotational axis of the crankshaft, the eccentric support being mounted in the housing for pivoting relative to the housing about a pivot axis, the pivot axis being substantially parallel to and spaced from the rotational axis of the crankshaft, and main bearings mounted in the eccentric support for supporting the crankshaft,
 said eccentric support further including a bearing cap and a plurality of fasteners for retaining the crankshaft in the eccentric support, said bearing cap further including a bearing socket for retaining one or more of said main bearings in the eccentric support,   said eccentric support further having a first fastener access cutout,   a housing oil feed line in said housing, said housing oil feed line having an upstream end, said upstream end being in fluid communication with the oil supply, and a down stream end, said down stream end being in fluid communication with said first fastener access cutout,   wherein said oil circuit further has an eccentric oil feed line in said eccentric support, said eccentric oil feed line having an upstream end, said upstream end being connected to said first fastener access cutout, and a down stream end, said down stream end being in fluid communication with said main bearings,   wherein said oil supply is in fluid communication with said first fastener access cutout through said housing oil feed line, and said first fastener access cutout is in fluid communication with said main bearings through said eccentric oil feed line,   wherein said oil circuit further has a sealing curtain area around said first fastener access cutout, and sealing means for providing a small curtain area for providing minimal oil leakage between said housing oil feed line and said eccentric oil feed line, thereby providing an oil supply circuit for delivering oil from the oil supply to the main bearings with minimal oil leakage.   
   
   
       2 . The oil circuit of  claim 1  further including an oil seal for substantively minimizing leakage of oil between the housing oil feed line and the eccentric oil feed line, said seal being mounted on said eccentric support. 
   
   
       3 . The oil circuit of  claim 1  further including an oil seal for substantively minimizing leakage of oil between the housing oil feed line and the eccentric oil feed line, said seal being located generally in said first fastener access cutout. 
   
   
       4 . The oil circuit of  claim 3 , wherein said first fastener access cutout includes retaining means for retaining said oil seal in location. 
   
   
       5 . The oil circuit of  claim 3 , further having a first fastener socket, and said oil seal further includes a boss, said boss being positioned in said first fastener socket for retaining said oil seal in position for oil sealing. 
   
   
       6 . The oil circuit of  claim 5 , wherein the upstream end of said eccentric oil feed line is in fluid communication with said first fastener socket, and said boss has a cutaway section to permit flow of oil from the housing oil feed line to the eccentric oil feed line,
 said upstream end of said housing oil feed line being in fluid communication with the oil supply, and said down stream end of said housing oil feed line being in fluid communication with said first fastener socket,   said upstream end of said eccentric oil feed line being in fluid communication with said first fastener socket, and said down stream end of said eccentric oil feed line being in fluid communication with said main bearings,   wherein said oil supply is in fluid communication with said first fastener socket through said housing oil feed line, and said first fastener socket is in fluid communication with said main bearings through said eccentric oil feed line, thereby providing an oil supply circuit for delivering oil from the oil supply to the main bearings.   
   
   
       7 . The oil circuit of  claim 1 , further having a first fastener socket,
 wherein said oil circuit has a primary oil flow pathway from said oil supply to said main bearings at all of said compression ratio settings, said primary oil flow pathway including a first pathway section from said oil supply to said first fastener socket and a second pathway section from said fastener socket to said main bearings, thereby providing a streamline flow passageway with minimal pressure loss.   
   
   
       8 . The oil circuit of  claim 5 , wherein the upstream end of said eccentric oil feed line bypasses said first fastener socket. 
   
   
       9 . The oil circuit of  claim 2  wherein said oil seal is made out of a compressive material for provide seating contact between said oil seal and said housing. 
   
   
       10 . The oil circuit of  claim 2  further including a spring for providing sealing contact between said oil seal and said housing. 
   
   
       11 . The oil circuit of  claim 10  wherein said spring is located in said first fastener socket for providing sealing contact between said oil seat and said housing. 
   
   
       12 . The oil circuit of  claim 1 , where in said first fastener access cutout is located in said bearing cap. 
   
   
       13 . The oil circuit of  claim 1 , further including eccentric support outer bearings, and bleed holes for release of oil from the oil supply circuit for lubricating the eccentric support outer bearings. 
   
   
       14 . The oil circuit of  claim 12 , wherein said bearing cap has a parting surface and a normal imaginary plane, said normal imaginary plane being normal to said parting surface, the rotational axis of the crankshaft being entirely within said imaginary plane,
 said bearing cap having a minor half located on one side of said normal imaginary plane, and a major half located on the other side of said normal imaginary plane, said major half of said bearing cap being generally larger than said minor half of said bearing cap,   wherein said first fastener access cutout is located in said major half of said bearing cap, for providing both a small eccentric support and a first fastener access cutout long enough for an open oil circuit at all compression ratio settings.   
   
   
       15 . The oil circuit of  claim 14 , wherein said connecting rod advances from the region adjacent to said minor half of said bearing cap to the region adjacent to said major half of said bearing cap, thereby providing a crankshaft rotational direction yielding an eccentric support that is stiff and compact while also having a first fastener access cutout and an eccentric oil feed line drilled hole. 
   
   
       16 . The oil circuit of  claim 1  wherein said sealing means includes a small curtain area circumference and a small assembly tolerance between said housing and said outer bearing surface. 
   
   
       17 . The oil circuit of  claim 1 , further having a first compression ratio setting, a first fastener line of action and a first flow stream segment, said flow stream segment being generally aligned with said first fastener line of action at said first compression ratio setting. 
   
   
       18 . The oil circuit of  claim 17 , further including an oil seal for substantively minimizing leakage of oil between the housing oil feed line and the eccentric oil feed line, wherein said first flow stream segment passes through said oil seal. 
   
   
       19 . The oil circuit of  claim 1 , further having a first fastener socket, wherein said eccentric oil feed line is connected to said first fastener socket downstream of said first fastener access cutout.