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.

PATENTS

14Sealing Technology February 2013

Patent number: WO/2012/128316 Inventors: K. Sone, N. Yamamoto, H. Ito, K. Yamauchi, H. Miyazaki and T. ItoPublication date: 27 September 2012

Abrasion monitoring device

Applicant: Ebara Corp, JapanDetails are provided of an abrasion monitoring device for a mechanical seal. According to the inventors, it is capable of monitoring abrasion of a seal ring (used in a mechanical seal) and forecasting the service life of the seal ring. A multi-stage mechanical seal is described. It has a control bleed-off mechanism for adjusting the pressure difference between stages, and a seal leak passage for discharging fluid that passes between surfaces where sliding occurs – between the rotating seal rings and stationary seal rings in each stage. The abrasion monitoring device for this seal uses an instrument for continuously measuring the concentration of abrasive particles in the liquid that is discharged from the control bleed-off mechanism, and a processing device for estimating the amount of abrasion that occurs, based on the concentration of abrasive particles measured by the instrument.Patent number: WO/2012/128164Inventors: K. Sugiyama, K. Nishiyama, C. Takatoh and H. KatoPublication date: 27 September 2012

Sealing mechanism for use in systems based on the Organic Rankine cycleApplicant: Nuovo Pignone Spa, ItalyMethods and systems for controlling the infiltra-tion of ambient air into, and ‘‘ex-filtration’’ of process gas out of, an Organic Rankine cycle (ORC) system are described by this patent. A first sealing mechanism – for example, a double, dry gas seal – can be used to prevent ex-filtration of process gas when the system is operating. A second sealing mechanism, such as an inflatable static ring seal, can be used to prevent infiltra-tion of ambient air when the system is stationary. One or more pressure sensors are incorporated into the ORC system in order to determine if, for example, infiltration of ambient air has occurred and if a system purge is required.Patent number: WO/2012/130935Inventors: A. Asti, P. Susini, M. Martini, D. Sabella and G. LandiPublication date: 4 October 2012

Sealing device

Applicant: Eagle Industry Co Ltd, JapanThe purpose of this invention is to provide

a way of reducing the amount of leakage of sealed fluid and to align the axes of a floating ring and a rotating shaft. According to this patent, a seal device is provided with a floating ring between the outer periphery of a rotat-ing shaft and the inner periphery of the cas-ing. This device is characterised by including dynamic, pressure-generating grooves arranged in the circumferential direction and extend-ing in opposite directions. These grooves cause sealed fluid that attempts to leak to the inner peripheral surface of the floating ring to be pushed back to the upstream side.Patent number: WO/2012/132832Inventor: H. InouePublication date: 4 October 2012

Flat gasket with

filter elementsApplicant: Reinz-Dichtungs GmbH, GermanyIn order to fulfil requirements for cleanliness, filter elements are being integrated into flat gaskets. This patent relates to a flat gasket with a mesh material which forms the filter element for passage openings. A flat gasket, composed of at least two metallic layers, is described. Each of these layers may be a metal sheet. They have passage openings which, upon assembly of the gasket layers, correspond to each other and are arranged adjacent to each other in a direc-tion perpendicular to the planes of the gasket layers. (Here, adjacent means that the passage openings can be arranged directly one upon the other, or indirectly, at a distance from each other, separated by at least one intermediate layer.) These gaskets enable fluids – for exam-ple, hydraulic oil in a transmission or air in a pneumatic transmission actuator – to pass from one side of the passage opening to the opposite one. Apart from that, they usually also include passage openings for fasteners, especially for bolts and/or screws. In both metallic layers, several passage openings are said to be arranged ‘‘vicinal’’ to each other in the respective plane of the gasket layer, with respective passage openings in the different layers preferably being flush with each other, or at least being continu-ous in the passage direction. These passage openings may be provided with a filter or may be designed in such a way that they allow for the passage of non-filtered media. According to the patent, a third layer is arranged between the two metallic layers. This does not create its own passage opening (in the area of the passage openings) but, instead, spans them. In order to allow for the passage of fluids, this third layer takes the form of a sieve, which consists of a mesh material.Patent number: WO/2012/136384

Inventors: G. Egloff, O. Claus, H. Waldvogel and A. HelfenbeinPublication date: 11 October 2012

Shaft seal arrangement for a turbo-machine

Applicant: Siemens Aktiengesellschaft, SwedenThis invention relates to a shaft seal arrange-ment for turbo-machinery. It has a high-pres-sure side, at one axial end and a low-pressure side at the other axial end, and comprises a rotor part, a fixed stator part and at least one dry gas seal. A further additional shaft seal is provided at the end of the high-pressure side, in a serial configuration with the dry gas seal, in order to seal the intermediate space. The aim of this invention is to prevent damage from occur-ring, because of changes in thrust, should the dry gas seal not function properly.Patent number: WO/2012/136497Inventor: G. MatemanPublication date: 11 October 2012

Metal gasket with primary stopper layer

Applicant: Federal-Mogul Corp, USAA multi-layer metal gasket has been developed for establishing a seal between two mating members, such as a cylinder head and an engine block. The gasket assembly includes a primary functional layer that has an embossed primary sealing bead. A primary ‘‘stopper layer’’ bridges the convex embossed portion of the primary sealing bead and is fixed relative to the primary functional layer by welding or clinching. A secondary functional layer is paired with the pri-mary functional layer, but is inverted relative to it so that its secondary sealing bead aligns with the primary sealing bead, and respective concave depressions open towards one another, with the primary stopper layer sandwiched between them. A compression limiter may be carried on the functional layer or, alternatively, a distance layer. The assembly may also include another functional layer that has a tertiary sealing bead inverted relative to, and aligned directly with, the primary sealing bead. The primary stopper layer functions to limit full or over-compression of the primary and secondary sealing beads and thereby prevents the formation of premature fatigue cracks and other undesirable effects. The primary stopper layer balances loading between the primary and secondary sealing beads and thereby enhances the sealing characteristics of the gasket assembly.Patent number: WO/2012/142350Inventor: J. HennePublication date: 18 October 2012