Industrial shaft seals
Industrial shaft seals
Industrial shaft seals
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gab.ru<br />
Radial<br />
Берг<br />
<strong>shaft</strong>АБ <strong>seals</strong><br />
bergab@ya.ru Тел. (495)-228-06-21, факс (495) 22<br />
60<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
0,8<br />
Temperature rise, C<br />
Conventional lip<br />
1000 2000 3000 4000 5000<br />
Diagram 4. Temperature rise at sealing lip/counterface<br />
contact for conventional and Waveseal lips as a function<br />
of rotational speed for a 76 mm diameter <strong>shaft</strong> with SAE<br />
30 engine oil<br />
Frictional moment, Nm<br />
Conventional lip<br />
Waveseal lip<br />
Speed, r/min<br />
As a consequence, Wave<strong>seals</strong> produce up to<br />
20% less friction and up to 30% lower<br />
temperatures than conventional <strong>seals</strong>; see also<br />
Diagram 4 and Diagram 5. These advantages<br />
prevent the formation of deep tracks in the<br />
counter surface and provide much longer<br />
service lives.<br />
Wave<strong>seals</strong> are available for <strong>shaft</strong> diameters<br />
of 6 to 310 mm. Their use is specially<br />
recommended where demands for operational<br />
reliability and long service life for machines<br />
and equipment are high.<br />
SKF <strong>seals</strong> with conventional spring-loaded<br />
lip meet normal demands and provide efficient<br />
sealing even under unfavorable operating<br />
conditions.<br />
To strengthen the sealing effect, some SKF<br />
radial <strong>shaft</strong> <strong>seals</strong> are provided with hydrodynamic<br />
aids on the contact surface of the<br />
sealing lip. These have either a right-hand<br />
twist for a clockwise direction of rotation of the<br />
<strong>shaft</strong>, or a left-hand twist for anti-clockwise<br />
<strong>shaft</strong> rotation, seen from the lip contact. The<br />
degree of improvement depends not only on<br />
the form of the spiral flutes but also on the<br />
circumferential speed, the pressure conditions<br />
and the media being sealed.<br />
0,6<br />
0,4<br />
0,2<br />
0<br />
Waveseal lip<br />
1000 2000 3000 4000 5000<br />
Speed, r/min<br />
Secondary (dust) lips<br />
SKF radial <strong>shaft</strong> <strong>seals</strong> with conventional and<br />
Waveseal lips can also be supplied as standard<br />
with an additional lip as shown in fig 38,<br />
page 54. On Wave<strong>seals</strong>, the secondary lip<br />
forms a narrow gap to the counter surface and<br />
there is practically no contact. Because of this,<br />
the <strong>seals</strong> can be operated at the same speeds<br />
as single-lip radial <strong>shaft</strong> <strong>seals</strong> without causing<br />
higher temperatures; they provide enhanced<br />
sealing.<br />
Diagram 5. Frictional moment at sealing lip/counterface<br />
contact for conventional and Waveseal lips as a function<br />
of rotational speed for a 76 mm diameter <strong>shaft</strong> with<br />
SAE 30 engine oil<br />
gab.ru 60 Берг АБ bergab@ya.ru Тел. (495)-228-06-21, факс (495) 22
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