The production tolerances of the drive pinion gear and ring gear are designed so that perfect operation is guaranteed with an accurate adjustment of gear backlash and friction value of the tapered roller bearings.
The contact pattern of the ring gear and pinion should, however, also always be checked as an additional inspection.
1 Determine contact pattern by a comparison with the examples on the contact pattern shown in the following, carry out the remedial action listed if necessary.
W33.30-0020-01
An ideal contact pattern is rarely obtained in practice. It is, however, important to ensure that the contact pattern on the tooth face does not extend to the outside edge of the tooth at any point.
Shown: Ideal contact pattern
W33.30-0021-01
Cause: The installed dimension of the drive pinion gear is too small.
Remedy: Increase the installed dimension of the drive pinion gear slightly and the test of gear backlash, re-adjust gear backlash if necessary.
Shown: Contact pattern on foot of tooth flank (unacceptable contact pattern)
W33.30-0022-01
Cause: The installed dimension of the drive pinion gear is too large.
Remedy: Reduce the installed dimension of the drive pinion gear slightly and repeat the test of gear backlash, re-adjust gear backlash if necessary.
Shown: Contact pattern on head of tooth flank (unacceptable contact pattern)