Mahindra JINMA-200 Operation Manual page 30

reducing axial displacement and increasing supporting rigidity of the spiral bevel gears under
operation. After operation for a period, as the conical bearings wears, the former preload will
disappear gradually, and moving clearance will occur between the two conical bearings when
the two moving clearance is more than 0.1 mm, the conical bearings should be preloaded
again.
A. Preload adjustment of second shaft conical bearing
Adjust the screwing tightness of the locking nut (11) near the bearing until the torsional
friction torque of the second shaft (9) is 0.7-1.1 N.m. After adjustment, insert locking slice
(12), then tightly screw the second locking nut (11).
B. Preload adjustment of differential conical bearing
Insert the adjusting shims (5) in same quantities between the two sides of transmission
box (2) and the bearing seats (4) of conical bearings, then tightly screw the bolts (6) of the
bearing seats; and turn second shaft (9), if the torsional torque is 0.4-0.76 N.m more than that
of the condition that the differential is not mounted, then the preload is suitable. In such case,
any axial displacement of the crown gear should not exist with the axially applied thrust.
2) Adjustment of meshing prints and backlash of the spiral bevel gears
A. Standard of meshing backlash and meshing print
The required mesh backlash is 0.1-0.25 mm. The ideal mesh prints distribute in the
middle of the working teeth surface and are slightly near the small end of the teeth; meshing
prints are like spots; meshing print height is not less than 50% of tooth height, the length of
meshing print is not less than 60% of tooth length.
B. Inspection of mesh backlash and mesh print
a. Inspection of mesh backlash
There are two methods of inspection: One is dial gauge inspection. During measuring,
put contact terminal on the teeth surfaces of big ends of bevel gear, and fix bevel pinion,
swing bevel gear in rotating direction; if the reading of the dial gauge is 0.14-0.3mm(circular
clearance), the backlash is correct. The other method is as follows: Using a lead wire of 15-
20mm long and 0.5mm thick or a fuse bent into "
teeth surfaces of the bevel gear and pinion(i.e. between the convex surface of the bevel pinion
and the concave surface of the bevel gear) and rotate the gear pair, then the thickness of the
extruded part where the lead slice is near the big ends of the gears is the vertical gear
backlash. The gear backlash should be among the range of 0.1-0.25mm(vertical backlash). It
is better to measure three or more points well distributed along the circumference of the bevel
gear and take the average value of measuring the gear backlash in the three or more points.
b. Inspection of mesh print
∽
" shape, put it between the unmeshed
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