PATENTS

February 2013 Sealing Technology13

PATENTSMetal chevron axial seal

Applicant: Parker-Hannifin Corp, USAThis invention provides an annular seal assembly for a subterranean system that has cylindri-cal inner and outer concentric surfaces, and an annular space between these surfaces. The assembly may be part of well-bore unit. The seal assembly includes at least one chevron seal which includes an annular central body and two annu-lar wings extending radially and axially from the central body. One of these wings extends radi-ally inwards from the body to a distal annular end and is arranged so as to make contact with the cylindrical inner surface, creating a seal. Similarly, the other wing extends radially out-wards from the body to another distal annular end and is arranged so as to make contact with the cylindrical outer surface. The chevron seal is made from metal or a metal alloy.Patent number: WO/2012/121745Inventors: G. Rowe and K. BierutPublication date: 13 September 2012

Tapered channel macro/micro feature for mechanical face seals

Applicant: Flowserve Management Co, USAThis invention relates to a tapered channel macro-feature (or micro-feature) for mechani-cal face seals, and a mechanical seal or seal ring that incorporates this feature. The mechanical seal generally has a pair of coaxially aligned seal rings that are able to rotate while the shaft is rotating. These rings have opposing faces that define a sealing region between them, which prevents leakage of a fluid along the shaft. The tapered channels serve to generate hydrodynamic lift which results in stable separation of the seal faces, permitting the formation of a fluid film between the seal faces. Rather than the film being generated solely by the static pressure of the fluid being sealed, the hydrodynamic lift fea-tures generate lift dynamically during shaft rota-tion to provide a lift load that is stable. Testing of this unique macro/micro feature shows that it is possible to achieve a reduction in friction of 65% and significantly lower face temperature. It also exhibits debris resistance, shows low-to-zero measurable leakage, and low-to-zero wear, com-pared with a non-textured seal face.Patent number: WO/2012/125714Inventors: L.A. Young, J.K. Benedict and J. DavisPublication date: 20 September 2012

Low-torque radial shaft seal assembly

Applicant: Federal-Mogul Corp, USAThe shaft seal that is described by this patent addresses the need to accomplish both a reliable seal and minimise friction, while also being easy to install on a shaft in an air-side installation without concern of inadvertent seal-lip inver-sion. The shaft seal assembly includes a metal case that has an annular leg extending radially inwards to a free end, with opposite oil and air sides of the leg facing respective oil and air sides of the assembly. An elastomeric material, bonded to the leg, forms a main body adjacent to the free end and a primary seal lip, oriented radially inwards from the main body. The pri-mary seal lip has a surface that extends between the air-side end and the free-oil-side end. The former is attached to an annular bridge via a first hinge and the bridge is attached to the main body via a second hinge. These hinges each have a thickness that is less than that of the bridge, and the thickness of the first hinge is less than that of the primary seal lip.Patent number: WO/2012/125992Inventors: B.R. Sedlar and D.M. TothPublication date: 20 September 2012

Sealing system incorporates sensor technology

Applicant: Aktiebolaget SKF, SwedenThis patent provides details of a sealing system that consists of a seal which retains a liquid in a space between two concentrically mounted components that are able to rotate relative to each other. More specifically, this invention

relates to a sealing system that uses one or more sensors to measure a parameter (or parameters) of interest associated with the liquid that is being sealed. The accompanying figure shows the seal-ing system (100) – containing the seal (110) that retains a liquid (105) in a space between two concentrically mounted components (120 & 130). According to the inventors, the system includes at least one magneto-elastic reso-nance sensor (140 & 180) for measuring at least one parameter of interest associated with the liquid that is being sealed, based on a detected resonant frequency of the at least one sensor.Patent number: WO/2012/122999Inventor: S. ZieglerPublication date: 20 September 2012

Seal ring with integrated filter

Applicant: NTN Corp, JapanA way of ensuring that foreign matter is cap-tured even if a seal ring thermally expands has been developed. The bearing system described by this patent includes a filter. As can be seen from the accompanying figure, a rolling ele-ment (13) is incorporated between an outer bearing ring (11) and an inner bearing ring (12). A seal ring (20) covers the opening of at least one end of the bearing space, and a filter (23), covering an oil hole (22) that is formed in the seal ring, captures foreign matter present in the lubrication oil. The seal ring is formed from resin, and together with the filter (23) is integrated through insert moulding. The filter and ring are formed from the same material. A lip part (41), formed from a circular member (40), which is separate from the seal ring (20), is in contact with the outer bearing ring (11). An engagement part (21) – provided on the inner radial side of the seal ring (20) – enters a recessed part provided on the inner bearing ring (12), such that during thermal expansion of the seal ring it is engaged so as to enable movement of the seal ring in the radial direction with respect to the inner bearing ring (12).

The sealing system described by patent WO/2012/122999 includes at least one sensor (140 & 180) for measuring a parameter of interest associated with the liquid that is being sealed.

A way of ensuring that foreign matter is captured even if a seal ring thermally expands has been developed. Patent WO/2012/128316 explains how this is achieved.