Nok Corporation

Nippon Oil Seal Industry Co., Ltd.

Noboru Matsushima

Satoshi Yamanaka

Noriyuki Wada

A method of manufacturing a sealing device by preparing a mold for molding both a rubber-like elastic material and a resin material, the resin material having a flat washer shape, inserting an outer diameter portion of the resin material into a mold cavity of the mold, and adhesively baking the rubber-like elastic material to the outer diameter portion of the resin material together with the molding of the rubber-like elastic material. An inner diameter portion of the flat washer shape resin material is pressed by a mold part adjacent to the mold cavity in utilization of a mold clamping pressure, the pressed inner diameter portion of the resin material is bent at an elevated temperature by a mold part to form a resin lip, arranged so as to not interfere with the rubber seal lip, and the sealing device produced is separated from the mold.

Method of manufacturing a sealing device

A method of manufacturing a sealing apparatus has an annular sealing lip formed of a resin material, a reinforcing ring having a bent section for nipping the peripheral; end portion of the annular sealing lip, and a sealing portion formed of a rubber-like elastic material and vulcanization formed integrally with the reinforcing ring and the annular sealing lip. Metal rings and a PTFE sealing member which are integrally assembled in such a manner that the inside surface of he peripheral portion of the metal ring is fitted to the outside surface of the peripheral portion of the metal ring to nip the sealing member having a sealing lip portion between the flange portion of the metal ring and the flange portion of the metal ring are integrally held by a rubber formed covering portion composed of an axial end portion, a peripheral fitting portion, a wall portion, a sealing lip portion, and a bonding airtight portion which are continuously formed.

Method of manufacturing a sealing apparatus

The follow-up performance to the operation of a shaft is improved by forming an annular space between a rubber seal lip formed of a rubber-like elastic material and a resin seal lip so as to prevent the resin seal lip from interfering with the rubber seal lip. The follow-up performance to the shaft is further improved by increasing the flexibility of the resin seal lip by forming a plurality of annular grooves parallel to one another to the side surface of the annular gap side of the resin seal lip. A PTFE sheet is inserted as in the form of a flat washer shape into a mold, it is adhesively baked to a first seal member formed of rubber together with the vulcanization formation, a plurality of annular grooves and a helical groove are formed to the PTFE sheet by utilizing a mold clamping pressure, and the PTFE sheet is bent at the mold separation time after the molding process.

Sealing device having an annular space between sealing lips

A sealing structure for use in an automobile engine includes a retainer 1, a plurality of lips 2a, 2b, 2c, 2d and a metal ring 3. The retainer 1 has a main annular body made of a resin material. The lips 2a, 2b 2c, 2d are formed on the metal ring 3. After that, the metal ring 3 and the lips together are inserted in a die so as to produce the retainer 1 by an injection molding method. Thus, the retainer 1, the lips and the metal ring 3 are formed as an integral unit. Two inner lips 2a, 2d are positioned at an inner periphery of the ring 3 and contact a shaft 6 for the engine, while the other two outer lips 2b, 2c are made of a resilient or elastic material and positioned at an outer periphery of the ring 3 so that the main body of the retainer 1 supports the ring 3 and the inner lips 2a, 2d in a floating manner. (FIG. 2 A)

Crankshaft seal having resilient portion embedded in rigid retainer

A sealing device in accordance with the present invention includes a projected portion having a rubber-like elastic member on the outer periphery of a seal member, and an outer cylindrical portion extending toward the seal member on a flange portion of a sleeve member. This outer cylindrical portion covers an opening formed between the seal member and the flange portion, thereby preventing entry of dust. The outer cylindrical portion is further provided on the tip thereof with a bend portion which can be engaged with the projected portion. The projected portion, the outer cylindrical portion, and the bend portion form a small clearance which serves as a labyrinth seal. The projected portion is fixedly fitted with a protection ring for covering the opening formed between the seal member and the flange portion of the sleeve member so that the free end portion of the protection ring can be engaged with the flange. This free end portion of the protection ring and the flange portion form a small clearance, and this small clearance serves as a labyrinth seal.

Sealing device

A sealing device comprising a projected portion having a rubber-like elastic member on the outer periphery of a seal member, an outer cylindrical portion extending toward the seal member on a flange portion of a sleeve member. This outer cylindrical portion covers an opening formed between the seal member and the flange portion, thereby preventing entry of dust. The outer cylindrical portion is further provided on the tip thereof with a bend portion which can be engaged with the projected portion. The projected portion, the outer cylindrical portion, and the bend portion form a small clearance which serves as a labyrinth seal. The projected portion is fixedly fitted with a protection ring for covering the opening formed between the seal member and the flange portion of the sleeve member so that the free end portion of the projection ring can be engaged with the flange. This free end portion of the protection ring and the flange portion form a small clearance, and this small clearance serves as a labyrinth seal.

A unitized seal (A) for sealing between a stationary shaft (16) and the bore of a rotating housing is comprised of a rotary member (1) having an outer cylindrical portion (1a), a flange portion (4) extending radially inwardly from one end of the cylindrical portion (1a), and a curved or tapered portion (5) at the radially innermost portion of the flange portion (4), a stationary member (10) having at least a main seal lip (14), and at least an auxiliary dust lip (6). The seal lip (14) contacts the inside surface (3) of the flange portion (4) of the rotary member and the dust lip (6) contacts against the curved or tapered portion (5) of the rotary member.

Sealing unit

A lip-type oil seal for use with a rotary shaft is manufactured by a method wherein different elastomeric materials for forming respectively the sealed liquid side and the atmospheric side of a tip portion of a sealing lip of the oil seal have different moduli of elasticity or hardnesses and are placed in a superposed condition within a mold prepared for vulcanization molding the oil seal. The mold is then clamped and the materials are heated and compressed so that an elastomeric material is fluidized and is vulcanization molded together with the other material to form an integral structure while a surplus portion is allowed to remain on the atmospheric side, thereby forming a sealed liquid side surface of the sealing lip. After the fluidized material has been hardened, the mold is opened and the surplus portion is then cut off, thereby forming an atmospheric side surface of the sealing lip.

Method for manufacturing oil seal

An oil seal disposed between a housing and a rotating shaft received in the hollow inside of the housing so as to prevent a liquid in the housing from leaking to the outside. The oil seal has a first metal ring and a second metal ring. The first metal ring is secured at the outer peripheral portion thereof to the housing and is provided at the inner peripheral portion thereof with an annular seal lip which is in slide contact with the outer peripheral surface of the rotating shaft thereby to seal the liquid in the housing. The second metal ring is connected at the outer peripheral portion thereof to the outer peripheral portion of the first metal ring and is separated at the inner peripheral portion thereof from the inner peripheral portion of the first metal ring in the axial direction of the rotating shaft so as to form an annular space in cooperation with the first metal ring. The second metal ring further has a dust lip which is in slide contact with the outer peripheral surface of the rotating shaft. The seal lip is constituted by a main lip located on the side thereof which is closer to the liquid to be sealed and a subsidiary lip located on the side thereof which is closer to the dust lip. Further, the dust lip is provided in its slide contact surface for slide contact with the rotating shaft with a circumferentially continuous groove.

Growing community of inventors

Fukushima, Japan

Noboru Matsushima