Ntn Corporation

Takashi Yamamoto

Kazumasa Seko

Michio Hori

Yasuyuki Inoue

Masaki Nakanishi

Seiichi Takada

Masaaki Honda

Chikara Katagiri

Naoya Hasegawa

Weida Yan

Provided is a self-aligning roller bearing for supporting a main shaft of a wind power generator, the self-aligning roller bearing including an inner ring, an outer ring, two rows of rollers, and retainers. Each of the rollers has an outer peripheral surface formed with a DLC coating having a multilayer structure. The DLC coating has a film thickness of 2.0 &#x3bc;m or larger. A base material of each of the rollers has an external surface having a surface roughness of Ra&#x2264;0.3 and R&#x394;q&#x2264;0.05. The DLC coating having the multilayer structure includes layers having stepwisely increasing film hardnesses such that a layer situated closer to outside has a higher hardness.

Self-aligning roller bearing

Provided is a double-row self-aligning roller bearing including: an inner ring; an outer ring having a spherical raceway surface; and rollers arranged in two rows and interposed between the inner ring and the outer ring, wherein a ratio of a contact angle &#x3b8;in one row to a contact angle &#x3b8;in the other row falls within a range of 0.25&#x2264;&#x3b8;&#x2264;0.5, and a ratio of distance Bin a bearing width direction from an end face of the bearing on a side of the one of the rows to an intersection of two lines of action defining the contact angles of the two rows, relative to a distance Bin the bearing width direction from an end face of the bearing on a side of the other of the rows to the intersection falls within a range of 0.5&#x2264;B/B&#x2264;0.6.

Double-row self-aligning roller bearing

The double-row self-aligning roller bearing includes an outer ring having a spherical raceway surface, and each of rollers in two rows has an outer peripheral surface whose cross-sectional shape corresponds to the raceway surface of the outer ring. The rollers in the two rows have different lengths from each other, and the length of the longer rollers is equal to or greater than 36% of a bearing width. A ratio of a contact angle of the shorter rollers relative to a contact angle of the longer rollers is within a range of 1:4 to 1:2. The contact angle of the shorter rollers has a range of 3&#xb0; to 5&#xb0;, and the contact angle of the longer rollers has a range of 11&#xb0; to 14&#xb0;.

A double-row self-aligning roller bearing has rollers interposed, in two rows aligned in a bearing width direction, between an inner ring and an outer ring. The outer ring has a spherical raceway surface. Each of the rollers has an outer circumferential surface having a cross-sectional shape that matches the raceway surface of the outer ring. Either or both of shapes and contact angles of the rollers are different from each other. An attachment hole to which a protrusion prevention jig is attachable is provided in an end surface of at least either one of the inner ring and the outer ring. The protrusion prevention jig prevents protrusion of the end surface of the inner ring in the bearing width direction with respect to the end surface of the outer ring.

Double-row self-aligning roller bearing and protrusion prevention jig

A rolling bearing includes an inner ring, an outer ring, and rolling elements interposed between the inner ring and the outer ring. A surface layer portion, beneath a raceway surface (), of a base material of a raceway ring () which is the inner ring or the outer ring, is a wear-resistant layer () which has a higher hardness than a residual portion (), beneath the surface layer portion, of the base material, and includes a minute-recess-and-projection surface. An oxide film () is provided which has such a film thickness (t) as to fill recesses of the minute-recess-and-projection surface of the wear-resistant layer (), and includes recesses and projections existing along the minute-recess-and-projection surface, and the oxide film () coats the surface of the wear-resistant layer (). The oxide film () is made from a material more fragile than the wear-resistant layer () of the base material.

Rolling bearing, and abrasion resistance treatment method for bearing raceway surface

A double-row self-aligning roller bearing has rollers interposed, in two rows aligned in a bearing width direction, between an inner ring and an outer ring. The outer ring has a spherical raceway surface. Each of the rollers has an outer circumferential surface having a cross-sectional shape that matches the raceway surface of the outer ring. The rollers have lengths equal to each other and maximum diameters equal to each other, and have different distances from centers of the roller lengths to positions at which the maximum diameters are obtained.

A double-row self-aligning roller bearing, which is suitable for receiving an axial load and a radial load, and loads having different magnitudes acting on rollers in two rows, and achieves sufficient load capacity for the rollers that receive axial load within the constraint of dimensional standards, is provided. The double-row self-aligning roller bearing includes inner and outer rings; and rollers in two rows arranged in a bearing width direction interposed between the inner and outer rings and having lengths different from each other. The roller has an outer peripheral surface of a cross-sectional shape along a raceway surface of the outer ring having a spherical shape. Length of the longer rollers is equal to or greater than 39% of the bearing width. A ratio of contact angle of the shorter rollers and contact angle of the longer rollers is within a range of 1:4 to 1:2.

In a spring type torque limiter, it is proposed to prevent cut end portions of a coil spring fitted on an inner ring from causing chatter of the torque limiter, even if the cut end portions of the coil spring are separated from a radially outer surface of the inner ring in order to prevent burrs remaining on the cut end portions of the coil spring from contacting the radially outer surface of the inner ring. The first cut end portion of the coil spring fitted on the inner ring is inserted in a recess of a first spring receiving protrusion formed on the radially inner surface of the outer annular member. The second cut end portion is inserted in a recess of a second spring receiving protrusion formed on the inner surface of the lid member, thereby restraining the first and second cut end portions with the recesses.

Torque limiter

A torque limiter comprising an inner ring fitted inside an outer member; and a torque transmission member interposed between said inner ring and said outer member. A predetermined torque is generated by a friction generated between said inner ring and said torque transmission member, when said inner ring and said outer member rotate relatively to each other. The members are impregnated with lubricating oil to slide said members on each other. The lubricating oil contains a base oil consisting of synthetic saturated hydrocarbon oil having a kinematic viscosity of 500 to 1200 mm/s at 40&#xb0; C. and an emulsifier added to said base oil. The lubricating grease contains the base oil consisting of the synthetic saturated hydrocarbon oil having a kinematic viscosity of 500 to 1200 mm/s at 40&#xb0; C. and an emulsifier and a thickener both added to said base oil.

Growing community of inventors

Kuwana, Japan

Takashi Yamamoto