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 (10a), of a base material of a raceway ring (10) which is the inner ring or the outer ring, is a wear-resistant layer (13) which has a higher hardness than a residual portion (12), beneath the surface layer portion, of the base material, and includes a minute-recess-and-projection surface. An oxide film (14) 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 (13), and includes recesses and projections existing along the minute-recess-and-projection surface, and the oxide film (14) coats the surface of the wear-resistant layer (13). The oxide film (14) is made from a material more fragile than the wear-resistant layer (13) of the base material.

A gear mechanism (1), in particular coaxial gear mechanism, having a housing with a fixedly arranged toothing (3), a tooth carrier (5) rotatable about a gear mechanism axis relative to the housing and guides (7), teeth (9), which are received in the guides (7) for engagement with the toothing (3), wherein the teeth (9) are mounted in the guides (7) so as to be displaceable in the direction of their longitudinal axis relative to the tooth carrier (5), a cam disk (13) rotatable about the gear mechanism axis (11) and intended to drive the teeth (9) along the respective longitudinal axis of the teeth (9), and a bearing row (35, 37) between the tooth carrier (5) and the housing for mounting the tooth carrier in the housing, wherein the bearing row (35, 37) includes axial rolling bodies, the axes of rotation of which are aligned perpendicularly in relation to the gear mechanism axis (11), and radial rolling bodies, the axes of rotation of which are aligned parallel to the gear mechanism axis (11).

A rolling bearing 1 includes an outer ring 1A, an inner ring 1B, and a plurality of rolling elements. The outer ring IA includes a first outer ring 10 and a second outer ring 20. The inner ring 1B includes a first inner ring 30 and a second inner ring 40. In a cross section including a central axis R, grain flows 111 in the steel constituting the first outer ring 10 extend along a first rolling surface 511, grain flows 211 in the steel constituting the second outer ring 20 extend along a second rolling surface 512, grain flows 311 in the steel constituting the first inner ring 30 extend along a third rolling surface 513, and grain flows 411 in the steel constituting the second inner ring 40 extend along a fourth rolling surface 514.

An improved bearing assembly is disclosed. Ring-shaped rolling elements in an alternating staggered formation, which allows maintenance of the bearing assembly geometry with fewer structural elements than prior bearings. The rolling elements can create a constant elastic tension, or pre-load, which maintains the bearing assembly geometry under various loads and rotational speeds, and reduces wear on the rolling elements and the raceways. The rolling elements can also comprise energy-dampening members and/or instrumentation which can monitor the functioning of the bearing assembly. An alternate embodiment in which the rolling elements are interlocked allows the use of more rolling elements in the same volume. An improved cage assembly, highly suitable for use with the improved bearing assembly, is also disclosed. The improved cage assembly comprises individual cage segments, which each retain one rolling element. The cage assembly can flex at every joint in a way not allowed by prior cage assemblies.

In a cross roller bearing, an outer ring and an inner ring have respective mounting portions formed thereon in such a manner as to reduce the radial thickness of the bearing to thereby reduce weight. The cross roller bearing has rollers and separators disposed in a load-carrying race formed between the outer ring and the inner ring. The outer ring and the inner ring have the respective mounting portions located axially away from respective raceway surfaces. The outer circumferential surface of the outer ring and the inner circumferential surface of the inner ring are flat. The mounting portion of the outer ring does not radially protrude from the inner circumferential surface of the inner ring, and the mounting portion of the inner ring does not radially protrude from the outer circumferential surface of the outer ring.

The roller insertion groove of the inner ring of a crossed roller bearing is provided with an outer circumferential surface-side groove opening that is exposed to an inner rings-side V-groove. The groove opening is defined by circumferential direction opening edge that extends in the circumferential direction along the inner ring-side V-groove and side opening edges that extend from both ends of the circumferential direction opening to the ring-shaped end face of the inner ring. Concentration of stress occurs in the corners between the circumferential direction opening edges and the side opening edges. The circumferential direction opening edge is formed so as not to coincide with the minimum outer diameter section of the inner ring-side V-groove.

The rotary table device includes a base, a motor, a rotary drive shaft and a cross-roller bearing. An outer ring is rotationally driven through engagement of a pinion gear formed at a shaft end of the rotary rive shaft with a rack gear formed on the outer ring and transmission of a rotary drive force from the rotary drive shaft to the outer ring. The outer ring is formed in a hollow cylindrical shape covering a side of an inner ring, includes a table capable of mounting an external member on one side of the hollow cylindrical shape, and is integrated with the rack gear formed over an entire circumference of the other side thereof. With such a configuration, a rotary table device that can realize reduction in height, size and weight can be provided.

A wave plug of a wave generator of a wave gear device includes: a metallic outer hollow body with an elliptical wave plug outer circumferential surface formed thereon; a metallic inner hollow body with a wave plug inner circumferential surface formed thereon; and an intermediate hollow body sandwiched between the outer hollow body and the inner hollow body. The intermediate hollow body includes CFRP layers. It is possible to implement a light wave plug in which a big hollow portion can be formed while assuring a required rigidity. Using the wave plug makes it possible to implement a light wave gear device which allows jumping to occur at a high load torque and which includes a big hollow portion.

A universal coupling is provided which can have a wide range of motion of a second member with respect to a first member. The universal coupling is provided with a bearing having an outer ring and an inner ring relatively rotatable about a center line with respect to the outer ring. A shaft that is square to the center line of the bearing is fixed to the inner ring of the bearing. The shaft supports an arm in such a manner as to be rotatable about the shaft. The bearing is connected to the first member. The arm is connected to the second member.

Provided is a torque sensor that includes: a bearing that is provided with an inner ring and an outer ring that are supported so as to be relatively movable only in the direction of rotation about a predetermined axis; a connecting member that is provided with fixing sections that are respectively fixed to the inner ring and the outer ring and a strain generation section that connects between the fixing sections; and a strain sensor that is disposed on the connecting member so as to be capable of detecting a strain at least in the circumferential direction.