Nok Corporation

Denso Corporation

Nobuyuki Eguchi

Kyohei Umetsu

Hiroshi Inoue

Junichi Nakayama

Shinya Nakaoka

Kokichi Hamamoto

Tamio Inamura

Takaaki Yasudomi

Naohiro Jotaki

A sealing device in which damage on a resin seal by a plate spring can be suppressed is provided. The sealing device includes a metal ring, a resin sealwhich is deformed on the radially inward side to be curved toward a sealed-region side and, in this state, slidably in close contact with an outer surface of a shaft, and a plate springwhich presses a radially inward side of the resin sealradially inward, wherein, a bent portionin which a part of a distal end of the plate springon the radially inward side is bent in advance so that the distal end of the plate springon the radially inward side is separated from the outer surface of the resin sealin a state where the shaftis inserted.

Sealing device

A sealing device includes a metal ringwith a cylindrical sectionand an inward flange sectiondisposed at one end of the cylindrical section. A resin sealhas an outer circumference side fixed to the metal ringand an inner circumference side configured to slidably and closely come into contact with an outer circumference surface of the rotary shaft in a state deformed to curve toward a sealing target region. A flat springincludes a plate-shaped annular metal member and has an outer circumference side fixed to the metal ringand an inner circumference side configured to deform to curve along the resin sealand press the inner circumference side of the resin sealradially inward. A metal slide bearing, is sandwiched between the resin sealand the inward flange sectionand configured to slide on the outer circumference surface of the rotary shaft.

Sandwiching of a foreign matter between a seal ring and a housing is suppressed, and abrasion of the housing and the seal ring is suppressed. The size of the diameter of a second seal portionis set to be larger than the size dof the diameter of an inner peripheral faceso that the difference in diameter size between the second seal portionand an inner peripheral faceof a housingbecomes 1.0 mm or less in a state before the ring body is provided in the annular gap.

Seal ring

To cope with severe use conditions, a high-pressure fuel pump has a seal system () for separating/sealing fuel and lubricating oil, in an annular space between an axle reciprocating within the pump and a housing having the axle passing therethrough, wherein the seal system () consists of a combination of a fuel-side seal () for sealing fuel and lubricating-oil-side seal () for sealing lubricating oil, the fuel-side seal () is composed of a plastic-made seal ring () and a rubbery-elastomer-made O ring () for backup of the seal ring (), the lubricating-oil-side seal () consists of a single body of single-lip-type oil seal () having a rubbery-elastomer-made seal lip () fitted to a metal ring () and arranged toward the lubricating oil side, and a distance between the fuel-side seal () and the lubricating-oil-side seal () is set to be larger than the reciprocating distance of the axle.

High-pressure fuel pump and seal system for high-pressure fuel pump

A resin lip type seal has first and second inner peripheral seal lips and an outer peripheral seal lip slidably contacting an operation member and a fixed member. The second inner peripheral seal lip is formed in a plate-shape to extend obliquely in an inner peripheral direction toward a second sealed fluid side so that an inner peripheral side end portion slidably contacts with a shaft and an outer peripheral side end portion contacts with a tapered surface formed on a housing or an installation member of the housing, whereby contact surface pressure in the inner peripheral direction acts on the inner peripheral side end portion.

Lip type seal

A seal ring for sealing an annular clearance between two members, which are made rotatable relative to each other. The seal ring is provided with a reliefthroughout the circumference of a sliding face side to confront the side wall faceof an annular groove. This reliefis set to have a radially smaller width in the vicinity of a separate portionand a radially larger width at a position apart from the separate portion, and the portion of the reliefto transit from the narrower portion to the wider portion is set to have a gradually changing width.

A seal ring which maintains a stable sealing performance over a long term is provided. In a first seal portion, linear contact portions which come into linear contact with the sidewall surface of an annular groove on the unsealed fluid side are continuously extended over the whole circumference of the seal ring from one side of a separation portion to the other side thereof, and the linear contact part provided at the convex part of the separation portion, and the linear contact part provided at the concave part of the separation portion are located at a distance in the radial direction of the seal ring.

Growing community of inventors

Nihonmatsu, Japan

Nobuyuki Eguchi