TOS SUA 125 NUMERIC - Page 51

SUA 125 NUMERIC
34200003 TOS a.s. 02/2011
51
a
2
=14,6 . (
M
M N+
2
. Z
2
- 0,001)
According to fig. „a“ the value
M
M N+
1
=0,9
M
M N+
2
=0,88
Constants 14 and 14,6 mentioned in equations for a1 and a2 are determined from publication “SKF Bearings in machine
tools“.
The dependence of axial shift a1 or a2 on the basis of graphically found out value Z1 or Z2 (diagram fig. 5.5-b) is tabulated
in fig. 5.5.
Example:
front bearing - value read from the bearing diagram Z1=0,008 mm. Value of need axial shift of inner race of front radial
spindle bearing can be read in table (fig. 5.5) for required radial prestress: 0,003 mm.
a1=0,145 mm.
rear bearing - value read from the bearing diagram Z2=0,006 mm. The value of need axial shift of inner race of rear radial
spindle bearing can be read in table (fig. 5.5) for required clearance: 0,001 mm.
a2=0,065 mm.
Routine for setting up the radial spindle bearing (fig. 5.4).
When setting up the radial prestress of the front bearing 8, ensured by radial interference in front bearing ranges from
0,002 to 0,004 mm, the following procedure should be selected:
• unbolt headstock cover
• loosen the nut 4 after its unlock 3
• loosen screws 12
• release split distance ring 13 by shifting ring 11
• take out distance ring 13
• grind accurately distance ring 13 at the specific size which is necessary for securing the desired radial interference of the
front bearing - radial prestress
• insert the distance ring 13 into the same position on work spindle
• fit on inner race of the front radial bearing on the front conical bearing surface of spindle by means of nut 4 to fasten
distance ring 13
• shift ring 11 to the left hand position and tighten screws 12
• lock nut 4 by protecting pad
When setting up of the radial clearance of the rear bearing 5 of recommended range from 0 to 0,0025 mm, please follow
the instructions mentioned below:
• unbolt screws 10 and take off cover 9
• loosen nut 1 after its unlock
• take out split distance ring 14
• grind accurately distance ring 14 at the specific size which is necessary for securing the required radial clearance
• insert distance ring 14 into the same position on spindle
• fit on the inner race of the rear radial bearing on the rear conical bearing surface by means of nut 1 to fasten distance ring
14
• nut 1 fix with protecting pad 5
• fit on the cover 9 back and tighten screws 10.