Iranian Classification Society Rules
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Section 8 Bearings of Rudder Stocks
801. Minimum bearing surface
The bearing surface (defined as the projected area : bearing length × outside diameter of sleeve) is not to be less than that obtained from the following formula :
mm
: reaction force in bearing (N).
: allowable surface pressure (N mm
) as given in Table 4.1.6. When verified by tests, however,
value different from those in this Table may be taken.
Table 4.1.6
Bearing material |
(N mm |
Lignum vitae | 2.5 |
White metal (oil-lubricated) | 4.5 |
Synthetic materials with hardness between 60 and 70, Shore HSD(1) | 5.5 |
Steel(2), bronze and hot pressed bronzegraphite materials | 7.0 |
NOTE: (1) Indentation hardness test at the temperature of 23℃ and humidity of 50 %, according to a recog- nized standard. Synthetic bearings are to be of approved type. (2) Stainless and wear-resistant steel in an approved combination with a stock liner. | |
802. Length of bearings
The length of the bearing surface is not to be greater than 1.2
= diameter obtained from the external surface of the sleeve of rudder stocks
803. Bearing clearances
For metal bearings clearances are not to be less than /1000+1.0 (mm ) in the
: the internal diameter of bush (mm ).
804. Thickness of bush and sleeve
The thickness of any bush or sleeve t is not to be less than that obtained from the following for- mula :
mm
However, not to be less than
as follows.
= 8 mm for metallic materials and synthetic materials.
= 22 mm for lignum vitae.
Pt 4 Hull Equipment
Ch 1 Rudders Pt 4, Ch 1
