A method for producing a rotor of a screw compressor or a workpiece with a helical profile, the rotor or the workpiece with a helical profile having a number of profiles in the form of groove-shaped recesses running in a spiral manner on the outer periphery thereof, the groove-shaped recesses being fine-machined using a grinding tool for the purpose of generating a precise profile. To be able to produce rotors and workpieces having variable pitch along the axial extent of the rotor or the workpiece as precisely as possible, the groove-shaped recesses are fine-machined with a grinding tool which only touches the surface of the groove-shaped recess at one point during the grinding process. The entire surface to be machined is machined by the grinding tool through line-by-line traversing of the surface to be machined.

A method of machining, with a formed tool, a first rotor and a second rotor with mutually complementary meshing threads involves rotating a first workpiece about a longitudinal axis of the workpiece. The tool makes one or more passes along the longitudinal axis of the workpiece as the workpiece rotates so as to remove material, thereby forming the flanks of each helix of the first rotor's thread. The value of at least one of the parameters that collectively define the relative position and relative movement of the workpiece and formed tool is varied during each pass so as to vary the lead of the thread. The above steps are repeated for a second workpiece, thereby forming the second rotor. Adjustments are made to at least one of said parameters during one or more of the passes in order to maintain mutually complementary shapes of the threads of the rotors.

A puncture needle includes a needle tube 1 provided with a spiral groove 3 and wall surfaces 3a and 3b of the spiral groove 3 serve as a surface for reflecting ultrasonic waves. The spiral groove is formed on the peripheral surface of the needle tube such that a grinding stone 2 is brought into contact with the peripheral surface of the needle tube while the needle tube 1 is being moved in its axial direction and rotated. The wall surfaces of the spiral groove formed on the needle tube serve as a reflection surface to change the orientation of the reflection surface in the axial direction of the needle tube according to change in position of the spiral. Therefore, even if a direction in which an ultrasonic wave is applied to the puncture needle is fixed, any portion of the reflection surface changing in orientation can become a surface for reflecting well ultrasonic waves, so that good ultrasonic waves can be obtained. The slant angles of the reflection surfaces in the axial direction of the needle tube can be changed by adjusting the moving speed in the axial direction of the needle tube or the rotation speed.

The invention describes an additional manufacturing method to improve the metallurgical properties of an endodontic file, which method customizes torsional and cyclic fatigue resistance behavior performance for separate files sizes. A heat-treatment file size tailored method accomplished after grinding the blank is disclosed aiming to improve the elasticity behavior of the specific file size based on its application during instrumentation protocol, also generating a colored oxidation layer on the working part surface of the file. The colored coded customized heat-treatment process will help the operator to identify the improved metallurgical properties behavior of each file, and decide the best use of such files.

A grinding device for raised joints of rivets on sheet metal is provided, including a lateral plate, legs, a moving plate, first springs, a first bearing seat, a sleeve, a grinding wheel, a moving bar, a 7-shaped plate, a vertical bar, a second spring, an oscillating plate, etc. The legs are fixedly connected, in a symmetric manner, to left and right sides of the bottom of the lateral plate. A through hole, which has a function of guiding, is formed on a left side of the lateral plate. The moving bar is located in the through hole. In the present disclosure, a driving motor is started to rotate the grinding wheel, the grinding device is moved to enable the grinding wheel to be located above a raised joint, and then the oscillating plate is pulled so that the grinding wheel can move downward to grind the raised joint.

A drilling tool, in particular a twist drill, has a substantially cylindrical main body formed with a shank portion, a cutting-edge portion having a drill diameter, and a drill end. The drilling tool is rotatable in a direction of rotation about a drill longitudinal axis. At least two flutes extend in a twisted manner along the drill longitudinal axis and are inclined with at least one helix angle. The flutes form a chip space. Webs are formed between the flutes with a web width. The chip space is formed with a chip space extension that enlarges the chip space in at least part of at least one of the flutes. The web width is reduced in the region of the chip space extension.

A method for manufacturing a rotor includes the following operations: the clamping of a workpiece in a grinding machine; the performance of one or more cylindrical grinding operations whereby a rotor shaft section is ground to the desired diameter with a cylindrical grinding disk; the performance of one more profile grinding operations whereby a rotor body is profiled with a profile grinding disk. During the manufacture of the rotor in the grinding machine, the workpiece is not undamped and the cylindrical grinding operations and the profile grinding operations are done with the same grinding machine.

A method for manufacturing a rotor includes the following operations: the clamping of a workpiece in a grinding machine; the performance of one or more cylindrical grinding operations whereby a rotor shaft section is ground to the desired diameter with a cylindrical grinding disk; the performance of one more profile grinding operations whereby a rotor body is profiled with a profile grinding disk. During the manufacture of the rotor in the grinding machine, the workpiece is not undamped and the cylindrical grinding operations and the profile grinding operations are done with the same grinding machine.

A method and a system for producing nanoparticles. The method includes obtaining a foil covered screw by wrapping a foil around an externally threaded section of an outer surface of a screw, placing the foil between an internally threaded section of an inner surface of a nut and the externally threaded section of the outer surface of the screw by screwing the foil covered screw into the nut, and grinding the foil between the internally threaded section of the inner surface of the nut and the externally threaded section of the outer surface of the screw by vibrating one of the nut and the foil covered screw along a first axis. The system includes a foil covered screw, a nut with an internally threaded section, and an ultrasound transducer. The nut and the screw are configured to grind the foil between the internally threaded section of the nut and the externally threaded section of the screw responsive to one of the nut and the screw vibrating along the first axis.

A cylindrical workpiece with a helical axial groove allowing for centerless grinding which has an angular overlap around the outer circumference on the body of the workpiece. The angular overlap ensures continuous tangential contact with the grinding wheels as the workpiece is rotated.