What is viscoseal? (Regarding gear pumps)
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The VisiSeal is a grooved-type seal that prevents leakage of the pumping medium from the drive shaft(s). Each VisiSeal features multiple helical grooves on its inner diameter; as the shaft rotates, these grooves guide the medium that is flowing outward back into the pump. (The emphasis is on the sentence highlighted in red.) For more information, please visit http://www.maag.com/application/polyrex.pdf. This post was last edited by echommm on 2009-2-12 at 16:10
The inner diameter surface of each viscoseal is provided with multi-start threaded grooves.
Multi-start helical groove---Great! The origin of “viscoseal” for “adhesive sealing” cannot be found.
Viscoseal refers to viscous sealing. By viscosity here, it is not meant that the seal is made of a viscous material, but rather a dynamic-viscosity type of seal. Spiral seal: Spiral seal: also known as dynamic viscosity type seal. A type of non-contact seal, belonging to the dynamic type of dynamic seals. Its structural features and working principle are as follows: Spiral grooves are machined on the shaft or hole wall at the location where sealing is required, as shown in figure (a); alternatively, composite spiral grooves with opposite rotation directions can be machined on both the shaft and the hole, as shown in figure (b). The spiral grooves are filled with a viscous liquid. When the shaft rotates, these spiral grooves act as a screw pump to move the viscous liquid. When the pumping pressure balances the pressure of the medium to be sealed, a sealing effect is achieved, thereby preventing leakage of the medium. Its advantages are: contactless sealing, no friction, tolerance for larger sealing gaps, long service life, easy maintenance, and good sealing performance; it is particularly suitable for gas sealing ； Under low-pressure conditions (pressure less than 1–2 MPa), the gas seal leakage is minimal; the sealing viscous fluid does not require circulating cooling, and the structure is very simple. The disadvantage is: it is not suitable for gas sealing under high-pressure conditions ； It is also not suitable for sealing under high-speed conditions, as the air flow emulsification effect is likely to occur ； Cannot be sealed when parked ； The temperature should not be too high, otherwise the viscosity of the viscous liquid is likely to be affected. It is widely used in dust-proof sealing applications where there is dust and sand in the external environment. There is also an explanation for exceptions at http://www.freepatentsonline.com/4114059.html. This post was last edited by niuky on 2009-2-12 at 10:24.]
I don’t know that word either; it doesn’t appear in my mechanical dictionary, so I’ve written down the original term.
For Viscoseal, use the treatment method from Floor 2.