A flap device for a motor vehicle comprises a flap housing that can be flowed through by a gas flow; and a flap shaft that is rotatably supported about an axis of rotation in the flap housing by means of at least a first and a second bearing element, which are held at the flap housing, and that carries a flap for selectively blocking or throttling the gas flow. The flap shaft is supported at the first bearing element in a first axial direction via a fixed abutment element that is axially fixedly arranged with respect to the flap shaft. The flap shaft is supported at the second bearing element in a second axial direction, which is oriented opposite the first axial direction, via a movable abutment element that is axially displaceably seated on the flap shaft, with the movable abutment element being preloaded in a direction toward the second bearing element by means of a spring device, and with the spring device in this respect being supported at a support surface fixed to the shaft and thus pressing the fixed abutment element against the first bearing element.

A throttle valve device includes a shaft in a cylindrical passage, a slit passing through the shaft from one lateral side to another lateral side of the shaft, a pair of bearings on both sides of the cylindrical passage and rotatably supporting one end part and another end part of the shaft, and a circular-plate valve inserted into the slit of the shaft and rotatable to open and close the cylindrical passage. A length of the slit on the one lateral side of the shaft is, in an axial direction of the shaft, longer than a length of the slit on the other lateral side of the shaft. A round end hole is formed at an end of the slit in the one end part of the shaft on the one lateral side of the shaft.

A valve disk of a double eccentric butterfly valve having boss sections (3, 4) for accommodating a stem (8) and rib sections (6, 7) each extending toward outer edge portions of the valve disk in a direction intersecting a stem (8) from the boss sections are provided on a surface on one side of a disc (2), and each of the ribs respectively excluding the boss sections is provided such that a height from a surface (2a) of the disc on the side on which a distance to an end on the edge portion side of the valve disk is longer than that on the side on which a distance to an end on the edge portion side of the valve disk is short when the heights are respectively compared at positions spaced an equal distance apart from a stem center axis (20), and the butterfly valve.

A centric butterfly valve (1) in which top and bottom boss surfaces (19, 29) are formed to be spherical, an outer peripheral end of the blade portion of the valve disk (24) is formed to be an M-shaped section part (29) with round-shaped apex parts (27) and a round-shaped valley part (28) smoothly linked, and the centric butterfly valve has a valve disk (3) having an extended part (41) obtained by successively and slightly extending the spherical surface of each of the top and bottom boss surfaces (19, 20) to a blade portion (40) side.

Pre-insulated valves (102, 144) for a fluid system, comprising valve body (104, 146) having lugs (128, 168). The valves (102, 144) comprises first insulating layer (134, 172) comprising an inner surface (136, 174) being adapted to cover an entire outer surface (132, 176) of the plurality of lugs (128, 168) and an entire outer surface (130, 170) of the valve body (104, 146) such that the first insulating layer (134, 172) is in close physical contact with the outer surface (130, 170) of the valve body (104, 146) including an outer surface (132, 176) of the plurality of lugs (128, 168). The valves (102, 144) comprises second insulating layer (138, 178) comprising an inner surface (140, 180) being adapted to be in close physical contact with an entire outer surface (137, 182) of the first insulating layer (134, 172).

Pre-insulated valves (102, 144) for a fluid system, comprising valve body (104, 146) having lugs (128, 168). The valves (102, 144) comprises first insulating layer (134, 172) comprising an inner surface (136, 174) being adapted to cover an entire outer surface (132, 176) of the plurality of lugs (128, 168) and an entire outer surface (130, 170) of the valve body (104, 146) such that the first insulating layer (134, 172) is in close physical contact with the outer surface (130, 170) of the valve body (104, 146) including an outer surface (132, 176) of the plurality of lugs (128, 168). The valves (102, 144) comprises second insulating layer (138, 178) comprising an inner surface (140, 180) being adapted to be in close physical contact with an entire outer surface (137, 182) of the first insulating layer (134, 172).

A throttle valve device includes a shaft in a cylindrical passage, a slit passing through the shaft from one lateral side to another lateral side of the shaft, a pair of bearings on both sides of the cylindrical passage and rotatably supporting one end part and another end part of the shaft, and a circular-plate valve inserted into the slit of the shaft and rotatable to open and close the cylindrical passage. A length of the slit on the one lateral side of the shaft is, in an axial direction of the shaft, longer than a length of the slit on the other lateral side of the shaft. A round end hole is formed at an end of the slit in the one end part of the shaft on the one lateral side of the shaft.

A method and system for controlling a fluid valve are described that avoid the effects of hysteresis. In hysteresis, the power signals associated with a valve position are different on the upstroke and downstroke. As a result, predicting the valve position can be difficult if you only know the current power signal. Instead of using upstrokes and downstrokes, a valve can momentarily be set to zero power, or a rest position when receiving a new command signal. This way the command signal is applied from a zero power or rest position, making the valve position more predictable and accurate.

The valve includes a valve case; an annular valve body, an outer peripheral end of which is a free end movable to both sides in an axial direction with respect to the valve case; a facing portion provided in the valve case, the facing portion including an annular facing surface which is located on an outer peripheral side of the valve body and is configured to face the free end with a gap; and first and second valve stoppers which are located on both sides respectively in the axial direction of the valve body. The first and second valve stoppers, respectively, have a plurality of support portions that are configured to support different positions of the valve body in a radial direction at different heights when the valve body deflects.

A valve assembly for an active clearance control (ACC) system in a gas turbine engine. The assembly comprises a first valve disc positioned within a first outlet duct, a second valve disc positioned within the second outlet duct, and a shaft coupled to the first and second valve discs such that rotation of the shaft rotates both the first and second valve discs within the first and second outlet ducts, respectively. A flow control member in the second outlet duct surrounds the second valve disc, and is configured to restrict fluid flow passing through the second outlet duct to a greater extent than the fluid flow passing through the first outlet duct for a given degree of rotation of the first and second valve discs. A corresponding ACC system, gas turbine and method is also provided.