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 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.

Rotary internal combustion engine includes a body made of four parts, each of which is an L-shaped fragment, and, when connected, forming two mutually perpendicular ring-shaped walls in plan view with ribs on the outer surface and an annular groove inside, which form two passages, each of which contain a torus-shaped rotor, which can move along the groove. Each torus-shaped rotor has longitudinal notches located outside or inside the rotor forming cavities between the rotor and groove surface, connected to chambers located outside the walls. The intake and exhaust windows are made in the walls communicating with the cavities between the rotor and groove surface. The rotors are interconnected by the kinematic chain of rotation synchronization made of successively engaged gears, one of which is engaged with one torus-shaped rotor, and the last of the gears is engaged with the output shaft, rigidly connected with another torus-shaped rotor.

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 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 rotating cutting tool to cut asymmetrical teeth in a gearwheel in which each tooth (21) has an active flank (A) with a convex profile meshing with the profile of a tooth of an opposing gearwheel meshing with the gearwheel and a secondary concave flank (S), provided with teeth (11) on a generally helical path which extends from one side to the other with respect to a median cross-section (M-M) of the tool which is intended to be intersected by the radius Rp of the gearwheel which is at right angles to the axis of rotation of the tool working on the gearwheel to cut its teeth. The helical teeth have a first flank (CA) which is intended to cut the said active flank (A) of the gearwheel teeth and a second flank (CS) intended to cut the secondary flank (S), the pitch (P1) between the first flank (CA) of the helical teeth being constant and the pitch (P2) of the second flank of the teeth being smaller than the pitch (P1).

A rotating cutting tool to cut asymmetrical teeth in a gearwheel in which each tooth (21) has an active flank (A) with a convex profile meshing with the profile of a tooth of an opposing gearwheel meshing with the gearwheel and a secondary concave flank (S), provided with teeth (11) on a generally helical path which extends from one side to the other with respect to a median cross-section (M-M) of the tool which is intended to be intersected by the radius Rp of the gearwheel which is at right angles to the axis of rotation of the tool working on the gearwheel to cut its teeth. The helical teeth have a first flank (CA) which is intended to cut the said active flank (A) of the gearwheel teeth and a second flank (CS) intended to cut the secondary flank (S), the pitch (P1) between the first flank (CA) of the helical teeth being constant and the pitch (P2) of the second flank of the teeth being smaller than the pitch (P1).

A gear wheel (10) for a hydraulic apparatus is rotatable about an axis of rotation (H-H) and comprises a plurality of teeth (11) having a sectional profile (P) and being adapted to mesh with respective teeth of another gear wheel during a rotational motion about the axis of rotation (H-H), wherein at least one tooth (11) is shaped so as to have at least one cutting edge (12) configured to remove material, in particular chips, from a body which is contacted by said cutting edge during the rotation of the gear wheel (10). Suitably, the cutting edge (12) is defined by at least one groove (14) which is lowered by amount from 0.2% to 5% of the height (H′) of the tooth (11), said groove (14) decreasing away from the cutting edge (12) along the profile (P).

A gear wheel (10) for a hydraulic apparatus is rotatable about an axis of rotation (H-H) and comprises a plurality of teeth (11) having a sectional profile (P) and being adapted to mesh with respective teeth of another gear wheel during a rotational motion about the axis of rotation (H-H), wherein at least one tooth (11) is shaped so as to have at least one cutting edge (12) configured to remove material, in particular chips, from a body which is contacted by said cutting edge during the rotation of the gear wheel (10). Suitably, the cutting edge (12) is defined by at least one groove (14) which is lowered by amount from 0.2% to 5% of the height (H′) of the tooth (11), said groove (14) decreasing away from the cutting edge (12) along the profile (P).

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.