Permissible runout of the main surfaces of the crankshaft
Diameters of connecting rod journals, mm
Rated | reduced | |||
0,25 | 0,50 | 0,75 | 1,0 | |
47,814 | 47,564 | 47,314 | 47,064 | 46,814 |
47,834 | 47,584 | 47,334 | 47,084 | 46,834 |
Diameters of main journals, mm
Rated | reduced | |||
0,25 | 0,50 | 0,75 | 1,0 | |
50,775 | 50,525 | 50,275 | 50,025 | 49,775 |
50,795 | 50,545 | 50,295 | 50,045 | 49,795 |
Examination
1. Install the crankshaft on two prisms and check with an indicator:
- beating of the main journals (maximum allowable 0.03 mm);
- runout of seating surfaces under the sprocket and gearbox input shaft bearing (maximum allowable 0.04 mm);
- offset of the axes of the connecting rod journals from the plane passing through the axes of the connecting rod and main journals (maximum allowable±0.35 mm);
- non-perpendicularity with respect to the axis of the crankshaft of the end surface of the flange. When turning the shaft, an indicator mounted on the side at a distance of 34 mm from the axis of the shaft should not show runouts of more than 0.025 mm.
2. Cracks are not allowed on the main, connecting rod journals and on the cheeks of the crankshaft. If they are found, replace the shaft.
3. On the surfaces of the crankshaft, mating with the working edges of the seals, scratches, nicks and risks are not allowed.
4. Measure the diameters of the main and connecting rod journals. The necks should be ground if their wear is more than 0.03 mm or the ovality of the necks is more than 0.03 mm, and also if there are scratches and marks on the necks.
Neck grinding
1. Grind main and connecting rod journals, reducing by 0.25 mm so as to obtain, depending on the degree of wear, diameters corresponding to the values (see table. Diameters of connecting rod journals, mm and tab. Diameters of main journals, mm) and neck fillet radii as indicated (see fig.