Bearing oil feed device

Abstract

A partial groove 14 is formed in an inner circumferential surface of an upper side bearing member 11 of a main bearing 5 which pivotally supports a main shaft 3 A of a crankshaft 3, and a space D between an end portion of the partial groove 14 and each of crush reliefs 11 b formed at both ends in a circumferential direction of the upper side bearing member 11 is provided within a range of 2 mm≦D≦main shaft diameter/ 3. Further, a depth gradually decreasing portion 14 b having an arc-shaped section is formed at an end portion of the partial groove 14, and a radius r of the depth gradually decreasing portion 14 b is provided within a range of 0≦ r≦main bearing inner circumferential surface radius× 0.5. Further, in a connecting rod bearing 6, a lubricating oil discharge passage 23, which discharges a lubricating oil outside a connecting rod 4 when communicating with an internal passage 3 C formed in the crankshaft 3, is provided. An amount of the lubricating oil which is discharged from a sliding portion of the main bearing is suppressed, and damage to the main bearing and the connecting rod bearing due to a foreign substance in the lubricating oil can be prevented as much as possible.

1 . A bearing oil feed device, comprising a crankshaft including a plurality of main shafts and crankpins, a plurality of main bearings which are each configured by a semi-cylindrical upper side bearing member and lower side bearing member, and each pivotally supports the main shaft rotatably at a cylinder block, and a plurality of connecting rod bearings which each pivotally supports the crankpin rotatably at a connecting rod,
 in which a radial hole which communicates with a lubricating oil passage formed inside the cylinder block is formed in the upper side bearing member in the main bearing, and a lubricating oil which is supplied to a sliding portion of the main bearing and the main shaft via the radial hole is supplied to a sliding portion of the crankpin and the connecting rod bearing via an internal passage which is formed inside the crankshaft and is opened to the main shaft and the crankpin,   wherein a partial groove which is formed in a circumferential direction of an inner circumferential surface of the upper side bearing member in the main bearing, to which the radial hole is opened, and which communicates with an opening of the internal passage of the main shaft is formed,   a space D between an end portion of the partial groove and each of crush reliefs formed at both ends in a circumferential direction of the upper side bearing member is provided within a range of
   2mm≦D≦main shaft diameter/3  (1),
 
   a depth gradually decreasing portion which is formed to be arc-shaped in section seen from an axial direction of the upper side bearing member is formed at the end portion of the partial groove, and a radius r of the depth gradually decreasing portion is provided within a range of
   0≦r≦main bearing inner circumferential surface radius×0.5  (2),
 
   
       and
 a lubricating oil discharge passage which communicates with the internal passage formed in the crankshaft to discharge the lubricating oil is provided in the connecting rod bearing. 
 
     
     
         2 . A bearing oil feed device, comprising a crankshaft including a plurality of main shafts and crankpins, a plurality of main bearings which each pivotally supports the main shaft rotatably at a cylinder block, and are each configured by a semi-cylindrical upper side bearing member and lower side bearing member, and a plurality of connecting rod bearings which each pivotally supports the crankpin rotatably at a connecting rod,
 in which a radial hole which communicates with a lubricating oil passage formed inside the cylinder block is formed in the upper side bearing member in the main bearing, and a lubricating oil which is supplied to a sliding portion of the main bearing and the main shaft via the radial hole is supplied to a sliding portion of the crankpin and the connecting rod bearing via an internal passage which is formed inside the crankshaft and is opened to the main shaft and the crankpin,   wherein a partial groove which is formed in a circumferential direction of an inner circumferential surface of the upper side bearing member in the main bearing, to which the radial hole is opened, and which communicates with an opening of the internal passage of the main shaft is formed,   a space D between an end portion of the partial groove and each of crush reliefs formed at both ends in a circumferential direction of the upper side bearing member is provided within a range of
   2mm≦D≦main shaft diameter/3  (1),
 
   a depth gradually decreasing portion with a depth gradually decreasing is formed at the end portion of the partial groove, and an angle θ formed by the depth gradually decreasing portion and the inner circumferential surface of the upper side bearing member is provided within a range of
   0≧25°  (3),
 
   
       and
 a lubricating oil discharge passage which communicates with the internal passage formed in the crankshaft to discharge the lubricating oil is provided in the connecting rod bearing. 
 
     
     
         3 . The bearing oil feed device according to  claim 2 ,
 wherein the angle θ formed by the depth gradually decreasing portion and the inner circumferential surface of the upper side bearing member is provided within a range of
   30°≦θ≦45°.
 
   
     
     
         4 . The bearing oil feed device according to  claim 1 ,
 wherein the oil discharge passage in the connecting rod bearing is configured by a through-hole which penetrates to an outer circumferential surface from an inner circumferential surface of the connecting rod bearing, and a foreign substance discharge groove which is formed in the outer circumferential surface of the connecting rod bearing to communicate with the through-hole and communicate with at least one end surface of the connecting rod bearing.   
     
     
         5 . The bearing oil feed device according to  claim 1 ,
 wherein the oil discharge passage in the connecting rod bearing includes a foreign substance discharge groove which is formed in the inner circumferential surface of the connecting rod bearing and communicates with at least one end surface of the connecting rod bearing.