Stabilized bearing structure for supporting a crankshaft in an internal combustion engine, and engine including same

An internal combustion engine comprising:

• a crankcase;
• a crankshaft rotatably supported on the crankcase through a plurality of rotary bearings;
• a backlash-absorbing mechanism provided between an outer race of said rotary bearings and said crankcase;
• and
• a stabilized bearing structure for supporting said crankshaft;
• wherein said stabilized bearing structure comprises an axial movement restraining structure adjacent said outer race for limiting axial movement of said outer race relative to said crankcase;
• wherein said axial movement restraining structure comprises an engaging groove provided in an inner circumferential surface of said outer race;
• and a restraining clamp member operatively attached to a surface of said crankcase, wherein the restraining clamp member comprises a hook portion which engages with said engaging groove.

An internal combustion engine, comprising:

• a crankcase having a left half section and a right half section, each said half section having a respective journal wall, each of said journal walls having a bearing hole formed therein;
• a cylinder block fixedly connected to said crankcase;
• a piston reciprocally mounted in said cylinder block and operatively connected to said crankshaft;
• a rotary bearing journaled into each of said bearing holes of the respective journal walls;
• a crankshaft rotatably supported in the crankcase by said rotary bearings;
• a backlash-absorbing mechanism situated proximate a first of said rotary bearings and operatively attached to said crankcase for cushioning radial movement of an outer race of said first rotary bearing;
• and
• an axial movement restraining structure adjacent said outer race for limiting axial movement of said outer race relatively to said crankcase;
• wherein the outer race comprises an engagement portion which extends outwardly beyond a corresponding inner race and the engagement portion of the outer race is engaged by the axial movement restraining structure.

An internal combustion engine comprising:

• a crankcase having a left half section and a right half section, each said half section having a respective journal wall, each of said journal walls having a bearing hole formed therein;
• a cylinder block fixedly connected to said crankcase;
• a piston reciprocally mounted in said cylinder block and operatively connected to said crankshaft;
• a rotary bearing journaled into each of said bearing holes of the respective journal walls;
• a crankshaft rotatably supported in the crankshaft by said rotary bearings;
• a backlash-absorbing mechanism situated proximate a first of said rotary bearings and operatively attached to said crankcase for cushioning radial movement of an outer race of said first rotary bearing;
• and
• an axial movement restraining structure adjacent said outer race for limiting axial movement of said outer race relative to said crankcase;
• wherein said axial movement restraining structure comprises an engaging groove provided in an inner circumferential surface of said outer race;
• and a restraining clamp member operatively attached to a surface of said crankcase, wherein the restraining clamp member comprises a hook portion which engages with said engaging groove.