Nok Corporation

Hideharu Hyakutake

Hiroki Matsui

Takehiro Nakagawa

Akira Yamaguchi

Kei Sasaki

Masayuki Tanida

Satoshi Yamanaka

Go Kanzaki

Hideyuki Furuyama

Tomoaki Nishimura

Makoto Kamemura

Shinya Takeda

Yuya Sakano

Yoshihisa Yamaguchi

Yuki Sato

Yoshimi Imamoto

Masaaki Yagi

In a sealing device having a combination of a seal lip and a seal flange which slidably come into contact with each other, and having a thread groove in an axial end face of the seal flange, the seal lip installed to a not-rotating housing side slidably comes into contact with an axial end face of the seal flange in a rotating shaft side, and the thread groove achieves a fluid pumping action at the rotating time in an axial end face of the seal flange. The thread groove has an inner peripheral side inclined surface as a part of an inner surface thereof, and an angle formed between an inner peripheral surface of a leading end portion of the seal lip and the inner peripheral side inclined surface is set to a range of 0 degree&#xb1;3 degrees. The sealing device can suppress generation of a static leakage.

Sealing device

The invention provides a sealing device which can suppress occurrence of static leakage and has a seal lip and a seal flange which are slidably in contact with each other, and a screw groove arranged in an end face, in an axial direction, of the seal flange. In the sealing device, the seal lip attached to a non-rotational housing side is slidably in contact with the end face, in the axial direction, of the seal flange on the rotational axis side, and which has the screw groove arranged in the end face, in the axial direction, of the seal flange so as to exert a fluid pumping action during rotation, is characterized in that the screw groove has an inner-circumferential-side inclined surface and an outer-circumferential-side inclined surface as the internal surfaces, and has a groove bottom part in a circular arc cross-sectional shape that interconnects both of the inclined surfaces.

The purpose of the present invention is to provide a sealing device which has forward and reverse screw threads exhibiting a fluid-pumping action provided on a sliding portion of a seal lip, such that the pumping action is less susceptible to deterioration even with increasing wear on the screw threads and such that leakage of droplets from the screw threads is minimized. To achieve this, the forward and reverse screw threads which exhibit a pumping action on sealing fluid are arranged in a circle on the air-side lateral surface of the sliding portion of the seal lip. The forward and reverse screw threads each have a shape gradually increasing in thread height from the leading end of the lip to the air side. The forward screw threads and/or reverse screw threads are provided with seal protrusions for preventing leakage of droplets.

A sealing device is provided with a seal lip which extends toward a sealing space side, a lip edge and an opposite sealing space side conical surface are formed in an inner peripheral surface of the seal lip, the lip edge being slidably brought into close contact with an outer peripheral surface of a rotating body, and the opposite sealing space side conical surface being larger in diameter from the lip edge toward an external space side, a plurality of screw protrusions are formed in the opposite sealing space side conical surface, the screw protrusions generating a screw pump action toward the lip edge side on the basis of rotation of the rotating body in a fixed direction, and a desired number of dust capture portions are formed in a hem portion of each of the screw protrusions, thereby preventing dusts from being bitten into the lip edge sliding portion.

The invention provides a sealing device which can inhibit an external dust in an atmospheric side from intruding into a lip end, thereby inhibiting a sealing fluid leakage by trapped dust. In a sealing device inhibiting leakage of a sealing fluid in an inboard side to an atmospheric side, coming into contact with a shaft by a seal lip end and circumferentially having in an atmospheric side inclined surface of the seal lip with a plurality of screws exerting a pumping action to the sealing fluid, a three-dimensional shape for preventing the dust intrusion is provided between the screws so as to inhibit the external dust intrusion in the atmospheric side toward the lip end. The three-dimensional shape is constructed by a projection or a groove extending in a parallel direction to the lip end. The projection or the groove is connected to the screws longitudinally in both end portions.

To improve durability of a seal lip () of an oil seal () in slidably contact with the peripheral surface of a shaft (), a lubricating oil supply section () for collecting adhered oil and dropping it on the shaft () is provided at a forward end portion of an installation section (), the lubricating oil supply section () has projections () formed on the inner peripheral surface of the installation section () to collect oil on the surface thereof, the surface of each projection () has a recess () for temporarily accumulating oil, guidance projections, or a slope for collecting the oil, and dams are formed on a forward end face () of the installation section () to block the oil flowing down along the circumferential direction on the forward end face () and guides the oil toward each projection ().

Oil seal

A sealing device in which oil (O) is supplied by ejection to a sealing device body (). In the sealing device, an increase in friction of a seal lip () caused by the pressure of the oil (O) is prevented, and effective lubrication by the oil (O) is promoted. The sealing device has the sealing device body () having the seal lip () slidably in intimate contact with the outer peripheral surface of a rotating shaft (), an oil ejection opening () for ejecting the oil (O) toward a position on the outer peripheral side of the seal lip () of the sealing device body (), and oil splashing means () for splashing the oil (O), ejected from the ejection opening (), back to a portion near a sliding portion (S) of the seal lip ().

A seal lip of an oil seal is in slidable contact with a peripheral surface of a shaft. A lubricating oil supply section for collecting adhered oil and dropping it on the shaft is provided at a forward end portion of an installation section. The lubricating oil supply section has projections formed on the inner peripheral surface of the installation section to collect oil on the surface thereof. The surface of each projection has a recess for temporarily accumulating oil. Guidance projections, or a slope for collecting the oil, and dams are formed on a forward end face of the installation section to block the oil flowing down along the circumferential direction on the forward end face and guides the oil toward each projection.

Growing community of inventors

Fukushima, Japan

Hideharu Hyakutake