2.10.2. Check of technical condition and repair

Bent shaft. Examine a bent shaft. Cracks in any place of a bent shaft are not allowed. On the surfaces interfaced to working edges of epiploons scratches, zaboina and risks are not allowed.

Fig. 2.42. Admissible beats of the main surfaces of a bent shaft

Establish a bent shaft by extreme radical necks on two prisms (fig. 2.42) and check the indicator a beating:
– radical necks and a landing surface under the leading gear wheel of the oil pump (no more than 0,03 mm);
– a landing surface under a flywheel (no more than 0,04 mm);
– a landing surface under pulleys and the surfaces which are interfaced to epiploons (no more than 0,05 mm).
Measure diameters of radical and conrod necks. Necks should be ground if their wear is more than 0,03 mm or ovality of necks more than 0,03 mm, and also if on necks there are teases and risks.

Fig. 2.41. Main sizes of a bent shaft

Grind necks with reduction of diameter to the next repair size (see fig. 2.41).
When grinding maintain the sizes of galtel of necks similar specified fig. 2.41 for the normal sizes of a bent shaft. Ovality and conicity of radical and conrod necks after grinding has to be no more than 0,005 mm.
Shift of axes of conrod necks from the plane passing through axes of conrod and radical necks after grinding has to be within ±0,35 mm. For check establish a shaft by extreme radical necks on prisms and expose a shaft so that the axis of a conrod neck of the first cylinder was in the horizontal plane passing through axes of radical necks. Then the indicator check shift in the vertical direction of conrod necks of 2, 3 and 4 cylinders of rather conrod neck of the 1st cylinder.
Прошлифовав necks, polish them by means of diamond paste or GOI paste.
After grinding and the subsequent operational development of necks remove caps of oil channels, and then process nests of caps a mill And. 94016/10, put on a spindle And. 94016. Carefully wash out a bent shaft and its channels for removal of the remains of an abrasive and blow compressed air. Mandrel And. 86010 press new caps and fuller everyone in three points a center punch.
On the first cheek of a bent shaft mark the size of reduction of radical and conrod necks (for example, K 0,25; Ш 0,50).
Inserts. On inserts it is impossible to make any subracing operations. At teases, risks, or peelings replace inserts new.
The gap between inserts and necks of a bent shaft is checked calculation (having measured details). Conveniently for check of a gap to use the calibrated plastic wire. In this case check method following:
– carefully clear working surfaces of inserts and the corresponding neck and put a piece of a plastic wire on its surface;
– establish on a neck a rod with a cover or a cover of the radical bearing (depending on a type of the checked neck) and tighten nuts or bolts of fastening. Nuts of conrod bolts tighten the moment of 51 N · m (5,2 kgfs · l), and bolts of fastening of covers of radical bearings the moment of 80,4 N · m (8,2 kgfs · l);


Fig. 2.43. Measurement of a gap in the conrod bearing: 1 – the flattened calibrated plastic wire; 2 – insert; 3 – rod cover; 4 – a scale for measurement of a gap

– uncover also on the scale put on packing, determine the size of a gap (fig. 2.43) by flattening of a wire.
The nominal settlement gap makes 0,02–0,07 mm for conrod and 0,026–0,073 mm for radical necks. If the gap is less limit (0,1 mm for conrod and 0,15 mm for radical necks), then it is possible to use these inserts again.
At a gap bigger limit replace on these necks inserts new.
If necks of a bent shaft are worn-out and are ground to the repair size, then replace inserts repair (the increased thickness).
Persistent half rings. As well as on inserts, on half rings it is impossible to make any subracing operations. At teases, risks or peelings replace half rings new.
Half rings are replaced also if the axial gap of a bent shaft exceeds the most admissible – 0,35 mm. Select new half rings nominal thickness or increased by 0,127 mm to receive an axial gap within 0,06–0,26 mm.


Fig. 2.19. Check of an axial free wheeling of a bent shaft

The axial gap of a bent shaft is checked by means of the indicator as it is described in subsection. "Assembly of the engine" (see fig. 2.19).

Fig. 2.44. Flywheel: 1 – surface adjacent to a flange of a bent shaft; 2 – the place of check of a surface for coupling fastening; 3 – the place of check of a beating of a basic surface of the conducted disk stsepleniya2-39 copy.jpg

Flywheel. Check a condition of a gear rim and in case of damage of teeths replace a flywheel. If the flywheel has colors of a pobezhalost it is necessary to check a rim tightness on a flywheel for surfaces of 3 (fig. 2.44). The rim should not be turned at torque of 590 N · by m (60 kgfs · l) or to move in the axial direction under effort of 3,9 kN (400 kgfs).
On the surface of 1 flywheel adjacent to a flange of a bent shaft, and on a surface 3 under the conducted clutch plate scratches and teases are not allowed. The admission of not planeness of a surface 3 makes 0,06 mm.
Scratches and teases on a surface 3 remove with a pro-point, removing a layer of metal no more than 1 mm thick. At the same time pierce as well a surface 2, without mentioning a gear rim and maintaining the size (0,5 ±0,1) mm. At a pro-point it is necessary to provide parallelism of surfaces 2 and 3 concerning a surface 1. Admission of not parallelism of 0,1 mm.
Establish a flywheel on a mandrel, aligning it on a landing opening with the emphasis on a surface 1, and check a beating of the planes 2 and 3. In the places specified by shooters fig. 2.44, the indicator should not show the beats exceeding 0,1 mm.