>> Electric equipment and capital repairs of engines
>> Capital repairs of engines
>> Conrod bearings
Conrod bearings demountable, consist of two inserts. On engines of some modifications the inserts of bearings established in a rod and in a cover of a rod are interchanged. On some engines in the insert established in a rod there are lubricant openings. At installation of inserts in a rod and in a cover of their edge act a little, when tightening bolts of a cover inserts are densely fixed in the place. For fixing on an insert the ledge is provided.
It is forbidden to file the sites of inserts supporting the demountable planes of a rod and a conrod cover, the demountable planes and also to enclose under a laying insert.
Inserts of conrod bearings
1 – an insert with lubricant openings and a flute
2 – to combine
3 – an insert without lubricant opening and a flute (as a rule, is established in a rod cover)
Marking of connecting rods
And – 0,125 mm
In – 0,25 mm
With – 0,375
The dimensional group of an insert is put in the form of a letter in the specified places.
If on inserts there are damages, then they should be replaced repair. At satisfactory condition of inserts it is necessary to check a gap between a conrod neck. Existence on the surface of a conrod neck of development at the edges of an insert it is necessary to proshlifovat necks or to replace a bent shaft.
With deep wear of conrod necks the bent shaft should be replaced as regrinding of necks will reduce durability of a bent shaft.
Check of a condition of conrod bearings and their replacement
Rods should be stored together with covers. At installation be convinced of the correct orientation of covers. Adjusting tags on a rod and a cover have to be combined and sent to one party.
Definition of a gap in conrod bearings by means of a plastic calibration wire of "Plastigauge"
In the spare part inserts standard and the repair sizes are delivered. The gap between necks and inserts is checked by means of a plastic calibration wire which keeps within on a conrod neck. Range of the measured gap by means of a wire of 0,025-0,080 mm.
| PERFORMANCE ORDER
| 1. Clear conrod bearings from a prileganiye to a rod and to a cover, and also reciprocal surfaces in rods and conrod covers. Dry wipe rods and inserts of bearings with the fabric which is not leaving pile. Lay on conrod bearings pieces of a calibration plastic wire along an axis of a bent shaft on the center of a conrod neck. Establish a rod cover with an insert and tighten nuts of bolts with the set moment. Rotation of a bent shaft at the same time is not allowed.
| 2. Uncover, not to remove the crushed pieces of a wire.
| 3. Determine a gap in the conrod bearing by the maximum width of the crushed wire, having compared to a scale on packing.
|4. Compare the received value to standard. If the gap exceeds 0,076 mm, then conrod bearings should be replaced. If bearings in satisfactory condition and knocks from a bent shaft were not noted, then bearings can be not changed.
|5. When replacing bearings at first it is recommended to establish new standard inserts, and again to check a gap in plastic caliber. If the gap does not meet standard, then install repair bearings of the closest dimensional group and again check a gap. The dimensional group of inserts is stamped on its reverse side.
After assembly check an axial side play of a rod on a neck of a bent shaft. If the side play is less than norm or is absent, then either the wrong selection of an insert, or a rod bend is the reason.