A machine tool includes a workpiece spindle unit (15) including a workpiece spindle (17) and a workpiece spindle motor (20) and includes a tool spindle unit (25) including a tool spindle (27) and a tool spindle motor. The machine tool further includes a first-axis movement mechanism (6) and a second-axis movement mechanism (9) relatively moving, in a plane including an axis of the workpiece spindle (17) and an axis of the tool spindle (27), the workpiece spindle unit (15) and the tool spindle unit (25) in a first axis direction and a second axis direction intersecting the first axis direction, respectively, and further includes a controller. The tool spindle unit (25) is arranged such that the axis of the tool spindle (27) intersects the axis of the workpiece spindle (17). The controller relatively moves the workpiece spindle unit (15) and the tool spindle unit (25) along the axis of the tool spindle (27) through combined operation of the first-axis movement mechanism (6) and second-axis movement mechanism (9), thereby grinding a workpiece (W) with a cup grindstone (T).

A machine tool includes a workpiece spindle unit (15) including a workpiece spindle (17) and a workpiece spindle motor (20) and includes a tool spindle unit (25) including a tool spindle (27) and a tool spindle motor. The machine tool further includes a first-axis movement mechanism (6) and a second-axis movement mechanism (9) relatively moving, in a plane including an axis of the workpiece spindle (17) and an axis of the tool spindle (27), the workpiece spindle unit (15) and the tool spindle unit (25) in a first axis direction and a second axis direction intersecting the first axis direction, respectively, and further includes a controller. The tool spindle unit (25) is arranged such that the axis of the tool spindle (27) intersects the axis of the workpiece spindle (17). The controller relatively moves the workpiece spindle unit (15) and the tool spindle unit (25) along the axis of the tool spindle (27) through combined operation of the first-axis movement mechanism (6) and second-axis movement mechanism (9), thereby grinding a workpiece (W) with a cup grindstone (T).

A double-disc straight groove cylindrical-component surface grinding disc, includes a first grinding disc and a second grinding disc, rotating relative to each other; the the first grinding disc's working face is planar; the second grinding disc's surface, opposite the first grinding disc, includes a set of radial straight grooves, with groove faces of the straight grooves are the working face of the second grinding disc; the cross-sectional outline of the working face of the second grinding disc is arcuate or V-shaped or is a V-shape having an arc; during grinding, a workpiece spins inside the straight grooves, while under the effect of an advancing apparatus, the workpiece slides in translational motion along the straight grooves. The described grinding disc device has high-volume production capabilities, and the shape accuracy and size consistency of the cylindrical roller's cylindrical surface and the efficiency in machining are improved, and machining cost is reduced.

A double-disc straight groove cylindrical-component surface grinding disc, includes a first grinding disc and a second grinding disc, rotating relative to each other; the the first grinding disc's working face is planar; the second grinding disc's surface, opposite the first grinding disc, includes a set of radial straight grooves, with groove faces of the straight grooves are the working face of the second grinding disc; the cross-sectional outline of the working face of the second grinding disc is arcuate or V-shaped or is a V-shape having an arc; during grinding, a workpiece spins inside the straight grooves, while under the effect of an advancing apparatus, the workpiece slides in translational motion along the straight grooves. The described grinding disc device has high-volume production capabilities, and the shape accuracy and size consistency of the cylindrical roller's cylindrical surface and the efficiency in machining are improved, and machining cost is reduced.

A downhole tool or component, such as a hydraulic fracturing ball, may have a base body having an outer surface. The outer surface of the base body may have a lapped coating thereon. The downhole tool or component may be made by lapping the outer surface of the base body with a lapping slurry. The downhole tool or component may be used in downhole applications, such as hydraulic fracturing, and may resist degradation upon exposure to fluids, such as production fluids.

A downhole tool or component, such as a hydraulic fracturing ball, may have a base body having an outer surface. The outer surface of the base body may have a lapped coating thereon. The downhole tool or component may be made by lapping the outer surface of the base body with a lapping slurry. The downhole tool or component may be used in downhole applications, such as hydraulic fracturing, and may resist degradation upon exposure to fluids, such as production fluids.

The invention relates to a milling bowl, in particular for vertical mills, and to the production of such a milling bowl. Milling bowls of this type have hitherto typically been produced from a cast material as a single piece. Due to the increasing size of said milling bowls, said milling bowls can generally only be transported to the destinations by means of special transport. Therefore, the invention creates a milling bowl consisting of assemblies, wherein a double-walled center part formed from two housing shells is provided between a head flange and a base flange. Said center part forms a cavity, which is filled with a curable casting compound such that a rotationally rigid milling bowl is present after the casting compound has been cured.

The invention relates to a milling bowl, in particular for vertical mills, and to the production of such a milling bowl. Milling bowls of this type have hitherto typically been produced from a cast material as a single piece. Due to the increasing size of said milling bowls, said milling bowls can generally only be transported to the destinations by means of special transport. Therefore, the invention creates a milling bowl consisting of assemblies, wherein a double-walled center part formed from two housing shells is provided between a head flange and a base flange. Said center part forms a cavity, which is filled with a curable casting compound such that a rotationally rigid milling bowl is present after the casting compound has been cured.

A method of forming a fracking tool, such as a frac ball or a frac plug mandrel, may include: applying a resin to wet a filament; winding the wetted filament to form a cylinder; placing the cylinder in a cylindrical mold; increasing a pressure in the cylindrical mold to at least 3,000 psi; curing the resin at the pressure and a temperature of at least 250° F.; and extracting the cylinder from the mold. In some instances, the method may further include adding the resin and/or another resin into the cylindrical mold.

A method of forming a fracking tool, such as a frac ball or a frac plug mandrel, may include: applying a resin to wet a filament; winding the wetted filament to form a cylinder; placing the cylinder in a cylindrical mold; increasing a pressure in the cylindrical mold to at least 3,000 psi; curing the resin at the pressure and a temperature of at least 250° F.; and extracting the cylinder from the mold. In some instances, the method may further include adding the resin and/or another resin into the cylindrical mold.