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vesconite.com > Design technical information > Bearing groove design |
Bearing
groove design
Vesconite is an internally lubricated bearing material
that has an ability to run without lubrication in many instances. Grooving of
Vesconite bearings is highly recommended as the improvement in performance and
reduction in wear more than compensates for the additional machining required.
Grooves are advantageous because they help:
-
Achieve an extra long life.
-
Achieve additional lubrication when operating with an elevated PV (load and speed combination).
-
Provide traps to catch and eliminate environmental dust and contaminants.
-
Promote water flow.
Groove
shape
Grooves
for marine bearings
Grooves
for pump bearings
Examples of grooving designs:
Through
or axial grooves
These are used for
continuous water lubrication in pumps, marine and hydro-electric
applications. These grooves can be either the UV design or a round
design. Make sure that sufficient water flow is provided to achieve
cooling of the bearing surface.
Where bearings are water cooled, do not grease the grooves as this will block the water flow through the grooves resulting in overheating.
Through grooves are also valuable for providing dirt traps which allow dirt to be removed from the bearing surface/shaft interface.
Blind
radial groove or round grooves
This is useful when
operating in dirty conditions. A felt washer or seal can be inserted
into the groove, alternatively the lubrication grease fills the
cavity and acts as an effective dust trap.
Ideally, the round grooves should be linked with blind through grooves, which facilitate greasing and grease storage, and act as dirt traps.
Internal
spiral groove
Has the advantage of
spreading the lubrication well even when there is not a full rotation
within the bearing. With modern numerically controlled
NC lathes, these are relatively easy to machine.
Lantern
ring
A lantern ring allows a
good distribution of the water from an external feed. This can be
used as an effective seal in slurry pumps or together with a grooved
bush to distribute water to the longitudinal grooves.
A combination of grooves can be used to
achieve optimal results, in particular radial grooves combined with axial
(through) grooves.
Groove
shape
| Rectangular. These are most often used in industrial applications and
in marine bearings. The UV design allows a better lubrication film on
the bearing especially when considering rotational shafts on stern
tube bearings. |
|
| Round. This design is most typical in pump applications. | |
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Although Vesconite rudder bearings generally do not need water circulation grooves, they are highly recommended to enhance the life of rudder bearings, provided there is sufficient wall thickness to accommodate axial grooves. The same number of grooves and dimensions can be used for rudder bearings as for stern tube bearings (see below).
Vesconite
stern tube bearings should be grooved as follows:
| Shaft diameter |
No. of grooves |
Groove width | Groove depth | Waterflow rate | ||||
| mm |
inches |
mm |
inches |
mm |
inches |
liter/ minute |
gallon/ minute |
|
|
60-79 |
2-3 |
7 |
7 |
0.25 |
4 |
0.15 |
12 | 3.0 |
|
80-119 |
3-5 |
7 |
9 |
0.3 |
5 |
0.2 |
18 | 4.5 |
|
120-159 |
5-6 |
7 |
10 |
0.35 |
6 |
0.25 |
24 | 6.0 |
|
160-199 |
6-8 |
7 |
12 |
0.4 |
7 |
0.3 |
30 | 8.0 |
|
200-249 |
8-10 |
7 |
12 |
0.4 |
8 |
0.3 |
38 | 10.0 |
|
250-299 |
10-12 |
7 |
14 |
0.5 |
8 |
0.3 |
45 | 12.0 |
|
300-349 |
12-14 |
8 |
15 |
0.5 |
8 |
0.3 |
58 | 14.0 |
|
350-399 |
14-16 |
8 |
15 |
0.5 |
8 |
0.3 |
60 | 16.0 |
|
400-499 |
16-20 |
9 |
15 |
0.5 |
9 |
0.35 |
75 | 20.0 |
|
500-599 |
20-24 |
10 |
18 |
0.5 |
9 |
0.35 |
90 | 24.0 |
|
600-699 |
24-28 |
11 |
18 |
0.5 |
9 |
0.35 |
105 | 28.0 |
|
700-800 |
28-32 |
12 |
18 |
0.5 |
9 |
0.35 |
120 | 32.0 |
The groove depth should
not be deeper than half of the wall thickness.
Grooves for pump bearings
Water or medium
lubricated pump bearings require a lubrication film to ensure
sufficient cooling of the bearing. This is especially required with
inline shaft bearings.
|
Shaft diameter |
No. of grooves |
Groove radius |
Groove depth |
|||
|
mm |
inches |
mm |
inches |
mm |
inches |
|
|
23-30 |
1-1.5 |
3 |
3 |
0.125 |
2.5 |
0.1 |
|
31-50 |
1.5-2 |
4 |
4 |
0.125 |
3 |
0.125 |
|
51-80 |
2-3 |
6 |
4 |
0.125 |
3 |
0.125 |
|
81-120 |
3-5 |
6 |
5 |
0.25 |
3.5 |
0.125 |
|
121-160 |
5-7 |
8 |
6 |
0.25 |
4 |
0.125 |
|
161-200 |
7-9 |
10 |
6 |
0.25 |
4 |
0.125 |
The groove depth should not be deeper than half of the wall thickness.
Updated Jul 28 2003
