Ntn Corporation

Makoto Seki

Tomoko Baba

Takayuki Kawamura

Tomoya Sakaguchi

Shinsuke Hirano

Yasuhiro Aritake

Tadashi Mitsuishi

Ryouta Kondou

Hisanori Kobayashi

Naoto Shibuya

Susumu Yamaji

Tomoki Baba

A hub bearingincluding an outer ringthat serves as a stationary side raceway ring, a hub wheeland an inner ringserving as a rotatable side raceway ring, ballsserving as a plurality of rolling elements disposed between a raceway surface of the stationary side raceway ring and a raceway surface of the rotatable side raceway ring, and grease that lubricates a rolling contact part between each of the raceway surfaces and the rolling elements. The surface roughness of at least one raceway surface selected from the raceway surface of the stationary side raceway ring and the raceway surface of the rotatable side raceway ring in the rolling contact part is 0.03 μm Ra or less.

Hub bearing

To provide an axle bearing having a low torque property and superior bearing lifetime. A hub bearingis configured to rotatably support a wheel of a vehicle, and has a grease compositionsealed in an inner space thereof. The grease compositioncontains a base oil and a thickener. The shear stress of the grease composition at the shear rate of 1,000-10,000 sat 25° C. is 3,000 Pa or less. The viscosity of the grease composition is 1 Pas or less. The yield stress of the grease composition at 25° C. measured by a dynamic viscoelasticity analysis method using a rheometer is 1,300-3,000 Pa.

Axle bearing, grease composition and rolling ball bearing

A sealing member of a bearing device for vehicle wheel including: a sealing plate having a sealing plate fitting section () fitted to an inner circumferential surface of an outer ring, an annular support section () extending radially inwardly from the sealing plate fitting section, and sealing lips provided on one side surface of the support section; and a slinger () having a slinger fitting section () fitted to the outer circumferential surface of an inner ring () and an annular upright plate section () extending radially outwardly from the slinger fitting section and facing the support section. The plurality of sealing lips are in contact with one side surface of the upright plate section or with the slinger fitting section, the support section is bent to form an annular groove section, and the outer peripheral portion of the upright plate section is bent to form a cylindrical wall section.

Sealing member, and bearing device for vehicle wheel comprising same

A bearing device for vehicle wheel includes a sealing ring () that includes: a core bar () and sealing rubber (). The sealing rubber () includes: a first sealing lip () that is formed to the radial-direction outside of the fitting part () and has a tip end part that is in sliding contact with a sealing plane part (); and a second sealing lip () that is formed to the radial-direction inside of the fitting part () and has a tip end part that is in sliding contact with the sealing plane part (). A flat surface () that can be contacted by a press-fitting tool (P) and by the tip end part of the fitting part () of another bearing device for vehicle wheel is formed between the first sealing lip () and the second sealing lip ().

Bearing device for vehicle wheel

This bearing device () for vehicle wheels comprises: an inner undercut part () provided in a portion at which an inner rolling surface () formed on the inner side of an inner member () and an inner flange surface () of the inner rolling surface () intersect; an outer undercut part () provided in a portion at which an inner rolling surface () formed on the outer side of the inner member () and an outer flange surface () of the inner rolling surface () intersect; and a vehicle wheel installation flange () provided at a portion adjacent to the inner rolling surface () formed on the outer side of the inner member (), wherein, when the radius of curvature of the inner undercut part () is Ri, and the radius of curvature of the outer undercut part () is Ro, the relationship of Ri&#x3c;Ro is satisfied.

A wheel bearing apparatus has a double row rolling bearing detachably united with a constant velocity universal joint. The double row rolling bearing has an outer member, an inner member, and double row rolling elements rollably disposed between the double row raceway surfaces of the outer member and inner member. The constant velocity universal joint has an outer joint member, a shoulder portion, and a shaft portion. A female thread is formed on the shaft portion. End faces of the shoulder portion and the caulked portion are formed with face splines, respectively. The face spline of the caulked portion has a portion where a tooth height of a tooth space of a portion radially outside the pitch circle diameter is set lower than that of other portions of the tooth space.

Wheel bearing apparatus

A wheel bearing has a seal device formed as a pack seal with an annular sealing plate and slinger. The sealing plate has a metal core and an integrally adhered sealing member. The sealing member has a base portion, side lip and radial lip. The base portion covers an inner circumferential surface of the metal core. The radial lip slidingly contacts the cylindrical portion of the slinger. A garter spring is mounted on the radial lip. A tightening force of the garter spring is set to 50% or more of a total tightening force of the radial lip. The tightening force of the radial lip without the garter spring is set to 3N or more.

Seal device for a wheel bearing

A wheel bearing apparatus has a protecting cover formed from non-magnetic steel sheet with a cup-shaped configuration. The protective cover has a cylindrical fitting portion, a disk-shaped shield portion, a radially reducing portion, a stepped portion and a bottom portion. The cylindrical fitting portion is press-fit into the inner circumference of the inner-side end of the outer member. The disk-shaped shielding portion extends radially inward from the fitting portion, via the radially reducing portion. The inner-side surface of the shielding portion is arranged close to or in contact with a rotation speed detecting sensor. The bottom portion is continuous with the shielding portion, via the stepped portion to close the inner-side end of the inner member. A full deflection of the side surface of the shielding portion that is caused by a load the same as that applied to the protecting cover when it is press-fit into the outer member is limited to a predetermined value or less.

A wheel bearing apparatus has a protecting cover formed from non-magnetic material with a substantially dish-shaped configuration. A cylindrical fitting portion is adapted to be press-fit onto the inner circumference of the inner-side end of the outer member. A disc-shaped shielding portion extends radially inward from the fitting portion, via a radially tapered portion. A bottom portion extends from the shielding portion, via a stepped portion. A flat relief portion is formed between the radially tapered portion and the shielding portion. The relief portion is parallel with the shielding portion. The relief portion is set slightly back from the shielding portion toward the radially tapered portion. An elastic member is integrally adhered to the outer circumference of the radially tapered portion. The elastic member elastically contacts with the inner circumference of the inner-side end of the outer member.

Growing community of inventors

Iwata, Japan

Makoto Seki