PATENTS

March 2013 Sealing Technology13

Patent number: WO/2012/154056 Inventors: N. Newlands, O. Säfvenberg,

Publication date: 15 November 2012

Dual-tip seals for a rotary engine

Applicant: Power Source Technologies Inc, USAThis patent describes a biased dual-tip seal arrangement for the rotor (106) of a rotary engine (102). The dual-tip seals (100-T, 100-L) are located on opposite corners of the tip (130) of a planetary rotor (106). The rotor orbits within a cut-out (126) in a main rotor (108). The seals are biased away from the corners in order to make sealing contact with the (sealing) surfaces of the asymmetrical lobe (112) and the cut-out (126) of the main rotor (108). Biasing is implemented with springs and conduits that pressurise the area under the seals. An asym-metrical lobe includes a transition zone. In this area, at least one seal on the tip (130) maintains contact with the surface while alternating con-tact from one seal (100-T, 100-L) to the other.Patent number: WO/2012/151423 Inventor: B.W. WatkinsPublication date: 15 November 2012

Method for affixing a seal sheet to a valve rotorApplicant: UOP Llc, USAThis invention is associated with the manner in which the seal sheet of a rotary valve may be affixed to the rotor plate in order to maintain good attachment, even under varying operat-ing conditions (for example, different pressures and temperatures). Various aspects of this invention focus on the potential improvements that are offered compared with conventional rotary valves – in which a hold-down element,

such as a washer, is embedded in the seal-sheet material, without directly contacting the rotor plate. In rotary valve operations in which the approach described here is adopted, the sus-ceptibility to failure of the seal-sheet anchoring assemblies, and particularly the loss (or ‘‘back-ing out’’) of screws or other rotor-plate engag-ing members (designed to ‘‘stake’’, or affix, the seal sheet to the rotor plate), is significantly reduced. Therefore, this invention addresses commercially significant issues associated with the strict operating tolerances of the seal sheet, in sealing pressurised fluids as they are con-tinuously routed to different rotary valve inlet and outlet ports as the valve indexes or rotates from one position to the next. The diminished likelihood of seal-sheet failure, caused by loos-ening or complete disengagement of seal-sheet anchoring assemblies, or their components (such as a screw and button washer), leads to increased on-stream operating time.Patent number: WO/2012/154485 Inventor: S.J. KoskiPublication date: 15 November 2012

Texturised seal

Applicant: Aktiebolaget SKF, SwedenThis patent provides details of an elastomeric sealing element and a method of manufacturing it, so that its contact surface has a textured finish. According to the inventors, the contact surface is provided with a wear-resistant coating and the surface texture is introduced into this coating. Patent number: WO/2012/152808Inventors: B. Stellario, G. Popovici and B.X. ZhouPublication date: 15 November 2012

Seal that acts as a sterile barrier

Applicant: Sartorius Stedim Biotech GmbH, Germany

This invention relates to a seal that acts as a sterile barrier, between a first part (2) and a second part (3), which are designed to move with respect to one another. A contact adhesive (11) is disposed as a peripheral expandable seal (4) between these parts. It further relates to a method for producing this seal. In a first step, a peripheral strand of contact adhesive is applied to the outer surface of the first part in a prede-termined position, while in a second step, the second part is positioned on the first part such that the contact adhesive adheres to the end face (13) of the second part. This patent also describes the use of a contact adhesive as a seal.Patent number: WO/2012/156001 Inventors: S. Fatherazi, H. Hennig and O.-W. ReifPublication date: 22 November 2012

Stiff seal for imaging component surfaces

Applicant: Lexmark International Inc, USAThis patent describes an end-seal for use in an image-forming apparatus. It is designed to provide increased contact pressure by using projecting ribs at nip locations formed between the end of a roll and the ends of other components such as a doc-tor blade or flap seal, and lower contact pressure along the end of the roll. The contact pressure may be changed by varying the thickness along portions of the projecting ribs or through the use of transverse ribs between each of the projecting ribs and the second surface of the end-seal.Patent number: WO/2012/158761Inventors: S.A. Brown and N.F. GibsonPublication date: 22 November 2012

Sintered metal oil seal

Applicant: NTN Corp, JapanAn oil seal member that consists of sintered metal has been developed. According to its inventors, the member, designed for use with bearings, is capable of effectively preventing the passage of oil, and can be mass-produced without a particular increase in cost. The mem-ber defines a liquid-tight hydraulic chamber formed between a rotor and a housing. The seal comprises a pair of side surfaces, which face each other in the direction of rotation of the rotor and are parallel to each other, and a sur-rounding surface composed of areas that extend between both the side surfaces, one of which slides on the inner diameter surface of the housing. The surrounding surface is composed of an upper surface that has an irregular shape; a lower surface, sliding on the housing; a pair of end-surfaces; and a pair of sloped surfaces.

Patent WO/2012/151423 describes a biased dual-tip seal arrangement for the rotor (106) of a rotary engine (102).

This invention – detailed by patent WO/2012/156001 – relates to a seal that acts as a sterile barrier between two parts (2 & 3) that are designed to move with respect to one another. A contact adhesive (11) is disposed as a peripheral expandable seal (4) between these parts.