A camera module includes a housing, a carrier, a frame, a lens holder, an autofocusing (AF) ball bearing, and an optical image stabilization (OIS) ball bearing. The carrier is coupled to the housing and configured to move in an optical axis direction. The frame is coupled to the carrier and configured to move in a first axis direction, perpendicular to the optical axis direction. The lens holder is coupled to the frame and configured to move in a second axis direction, perpendicular to the optical axis and the first axis. The AF ball bearing is disposed between the housing and the carrier. The OIS ball bearing is disposed on either one or both of the carrier and the frame, and the frame and the lens holder. Either one or both of the AF ball bearing and the OIS ball bearing have an elastic modulus of 20 GPa or less.

Described herein are methods and system for welding, for example, girders. The method may include activating a homopolar generator. The method may include applying a force to two metal girders at a desired coupling joint. The method may include generating an electrical pulse using the homopolar generator and conducting the electrical pulse to the desired coupling joint to increase a temperature of the girders. The method may include forming a weld at the desired coupling joint attaching the two metal girders at the desired coupling joint. In some embodiments, the homopolar generator may include a radial bearing rotor including a rotatable shaft and a bearing assembly. The bearing assembly may include nonmagnetic bearings. The homopolar generator may include a field coil. The homopolar generator may include a brush actuation mechanism which when activated engages a plurality of brush devices to the radial bearing rotor.

Described herein are methods and system for welding, for example, girders. The method may include activating a homopolar generator. The method may include applying a force to two metal girders at a desired coupling joint. The method may include generating an electrical pulse using the homopolar generator and conducting the electrical pulse to the desired coupling joint to increase a temperature of the girders. The method may include forming a weld at the desired coupling joint attaching the two metal girders at the desired coupling joint. In some embodiments, the homopolar generator may include a radial bearing rotor including a rotatable shaft and a bearing assembly. The bearing assembly may include nonmagnetic bearings. The homopolar generator may include a field coil. The homopolar generator may include a brush actuation mechanism which when activated engages a plurality of brush devices to the radial bearing rotor.

In a bearing for vertical axis windmill configured to rotatably support a vertical axis of a vertical axis windmill, the bearing includes a ball (7), a diameter of the ball and a curvature of a rolling groove of the bearing are set to satisfy a predetermined starting torque and a load rating. For example, the curvature of the rolling groove of the bearing is 54% or more and 100% or less, and the diameter of the ball has a ratio of 20% or less with respect to a vertical shaft (2).

In a bearing for vertical axis windmill configured to rotatably support a vertical axis of a vertical axis windmill, the bearing includes a ball (7), a diameter of the ball and a curvature of a rolling groove of the bearing are set to satisfy a predetermined starting torque and a load rating. For example, the curvature of the rolling groove of the bearing is 54% or more and 100% or less, and the diameter of the ball has a ratio of 20% or less with respect to a vertical shaft (2).

A wheel bearing arrangement for a vehicle, comprising at least one roller bearing, wherein at least one of the roller bearings is a ball bearing, which includes an inner ring and an outer ring, wherein both rings have raceways for balls being located between the rings. To ensure a sufficient lifetime of the roller bearings and to minimize the friction in the bearing, the at least one of the rings of the bearing arrangement is made from a ball bearing steel produced by a powder metallurgical process using a powder metallurgy component including 0.5 to 2.0 weight-% C, a maximum of 0.035 weight-% S, 3.0 to 5.0 weight-% Cr, 1.0 to 4.0 weight-% V, 1.0 to 12.0 weight-% W and 2.0 to 12.0 weight-% Mo, wherein at least one raceway has a radius and the balls have a diameter which fulfills the equation: radius/diameter>0.53.

A method of treating bearing rolling elements or bearing rings after a hardening and temper heat treatment is disclosed. The method may include treating the bearing rolling elements in a tumbling treatment and then in a duplex hardening treatment. The method may include treating the bearing rings in a peening treatment and then in a duplex hardening treatment. The duplex hardening treatment may also include at least one sequential process segment consisting of subjecting the bearing rolling element & rings to a nitriding process to increase the surface hardness and compressive residual stress. The combined two-step process produces a deep surface/sub-surface residual stress greater than the depth of the maximum operating von-Mises shear stress along with an ultra-hard surface with high magnitude of compressive residual stress. In so doing, the bearing ring and rolling elements will have significantly enhanced rolling contact fatigue resistance and resistance to surface imperfections and debris.

A method of treating bearing rolling elements or bearing rings after a hardening and temper heat treatment is disclosed. The method may include treating the bearing rolling elements in a tumbling treatment and then in a duplex hardening treatment. The method may include treating the bearing rings in a peening treatment and then in a duplex hardening treatment. The duplex hardening treatment may also include at least one sequential process segment consisting of subjecting the bearing rolling element & rings to a nitriding process to increase the surface hardness and compressive residual stress. The combined two-step process produces a deep surface/sub-surface residual stress greater than the depth of the maximum operating von-Mises shear stress along with an ultra-hard surface with high magnitude of compressive residual stress. In so doing, the bearing ring and rolling elements will have significantly enhanced rolling contact fatigue resistance and resistance to surface imperfections and debris.

In order to make a bearing, such as a roller bearing, insensitive to a lack of maintenance lubrication or irregular maintenance lubrication while at the same time retaining its mechanical performance, at least one bearing part of the bearing is provided at least partially with an oleophilic adhesion promoter layer. The adhesion promoter layer binds a lubricant layer of the bearing to the bearing part provided with the adhesion promoter layer. The adhesion promoter layer is bonded to an elemental-iron-free surface of a bearing part body. The removal of free iron from the bearing part body surface is carried out with nitric acid, chromate solution and/or citric acid. The treated bearing part has an oleophilic anti-corrosion adhesion promoter layer. The bearing may be used in pressure-operated devices, in particular in turbine handpieces used by dentists, because the loss of the lubricant layer during operation of the device was particularly high.

In order to make a bearing, such as a roller bearing, insensitive to a lack of maintenance lubrication or irregular maintenance lubrication while at the same time retaining its mechanical performance, at least one bearing part of the bearing is provided at least partially with an oleophilic adhesion promoter layer. The adhesion promoter layer binds a lubricant layer of the bearing to the bearing part provided with the adhesion promoter layer. The adhesion promoter layer is bonded to an elemental-iron-free surface of a bearing part body. The removal of free iron from the bearing part body surface is carried out with nitric acid, chromate solution and/or citric acid. The treated bearing part has an oleophilic anti-corrosion adhesion promoter layer. The bearing may be used in pressure-operated devices, in particular in turbine handpieces used by dentists, because the loss of the lubricant layer during operation of the device was particularly high.