A composite drive shaft includes a web-based body defining a longitudinal axis. The web-based body has a first composite layup end section, a second composite layup end section that is opposite to the first composite layup end section, a first spiral composite element extending between the first composite end section and the second composite layup end section, and a second spiral composite element extending between the first composite end section and the second composite layup end section. The first spiral composite element and the second composite spiral element are embedded into the first composite layup end section, and the second composite layup end section. The first composite spiral element and the second composite spiral element are arranged in a bi-directional orientation relative to the longitudinal axis. The first spiral composite element and the second spiral composite element are arranged at pre-determined angles and possess a uni-directional fiber-reinforced polymer-matrix composite structure.

A rolling device includes: an inner member that has a raceway face; an outer member that has a raceway face facing the raceway face; and rolling elements that are disposed between both raceway faces in a rollable manner, wherein at least one of the inner member and the outer member has a space formed therein. Further, a method for manufacturing a rolling device including an inner member that has a raceway face, an outer member that has a raceway face facing the raceway face, rolling elements that are disposed between both raceway faces in a rollable manner, and a space that is formed inside at least one of the inner member and the outer member by a 3D printer.

A raceway surface (3a) of an outer ring (3) of a tapered roller bearing (1) includes a composite crowning surface. The composite crowning surface includes a center curve (3a1), which is formed at a center portion in a generating-line direction, and end portion curves (3a2 and 3a3), which are formed on both sides of the center curve (3a1) in the generating-line direction. The raceway surface (3a) of the outer ring (3) is entirely subjected to superfinishing. Each of a ratio (R.sub.2/R.sub.1) of a curvature radius (R.sub.2) of the end portion curve (3a2) to a curvature radius (R.sub.1) of the center curve (3a1) and a ratio (R.sub.3/R.sub.1) of a curvature radius (R.sub.3) of the end portion curve (3a3) to the curvature radius (R.sub.1) is set to 0.02 or more. Each of drop amounts of the end portion curves (3a2 and 3a3) is set to 0.07 mm or less.

Downhole tools for use in downhole operations and electrical submersible pumping systems having an additively manufactured first part including a first layer having a first predetermined material property and a second layer having a second predetermined material property, wherein the first and second layers are layers of an integral piece and the first predetermined material property is different from the second predetermined material property and a second part configured to rotationally engage with the additively manufactured first part. One of the first part and the second part is rotated relative to the other of the first part and the second part in operation.

A method of forming a bearing ring having improved hardness is disclosed herein. The method generally includes a duplex hardening process in which the bearing ring is first subjected to a heat treatment. After the heat treatment process, the bearing ring undergoes a nitriding treatment in predetermined portions, including at least a raceway and a cage pilot surface.

An improved design and method is disclosed that uses a novel nesting linear slide which incorporates machine tool slides or ways into a structural member. The design simplifies the fabrication and assembly of components requiring accurate sliding alignment, such as milling machine bases, saddles, tables and columns. Due to the use of the single piece, which replaces multiple pieces in the prior art, fabrication and assembly costs are also significantly lower. The invention also enables a method of construction utilizing the novel single shape component which simplifies the assembly of machines requiring sliding surfaces with accurate alignment. The invention essentially comprises a single structural element that includes both male and female sliding members. By nesting two of the single structural elements it is possible to create sliding joints for machine tool bases, saddles, tables, and columns, as well as a wide variety of other sliding joints, in an extremely cost-effective manner. The linear slide includes a deformable element that allows for accurate alignment with no play and creates a strongly supported sliding joint.

A raceway surface (3a) of an outer ring (3) of a tapered roller bearing (1) includes a composite crowning surface. The composite crowning surface includes a center curve (3a1), which is formed at a center portion in a generating-line direction, and end portion curves (3a2 and 3a3), which are formed on both sides of the center curve (3a1) in the generating-line direction. The raceway surface (3a) of the outer ring (3) is entirely subjected to superfinishing. Each of a ratio (R.sub.2/R.sub.1) of a curvature radius (R.sub.2) of the end portion curve (3a2) to a curvature radius (R.sub.1) of the center curve (3a1) and a ratio (R.sub.3/R.sub.1) of a curvature radius (R.sub.3) of the end portion curve (3a3) to the curvature radius (R.sub.1) is set to 0.02 or more. Each of drop amounts of the end portion curves (3a2 and 3a3) is set to 0.07 mm or less.

A bearing ring with integrated cooling channels and a method for producing a bearing ring with integrated cooling channels are provided.

Downhole tools for use in downhole operations and electrical submersible pumping systems having an additively manufactured first part including a first layer having a first predetermined material property and a second layer having a second predetermined material property, wherein the first and second layers are layers of an integral piece and the first predetermined material property is different from the second predetermined material property and a second part configured to rotationally engage with the additively manufactured first part. One of the first part and the second part is rotated relative to the other of the first part and the second part in operation.

Downhole tools for use in downhole operations and electrical submersible pumping systems having an additively manufactured first part including a first layer having a first predetermined material property and a second layer having a second predetermined material property, wherein the first and second layers are layers of an integral piece and the first predetermined material property is different from the second predetermined material property and a second part configured to rotationally engage with the additively manufactured first part. One of the first part and the second part is rotated relative to the other of the first part and the second part in operation.