Method and apparatus for lapping gears which includes an active torque system to substantially improve the lapping process with respect to run-out and other longer-term motion transmission errors without compromising tooth-to-tooth performance. Motion transmission error measurements provide the basis for calculating a corrective active torque component which is combined with conventional process torque to reduce or eliminate part run-out.

A hard finishing machine for machining workpieces with at least one gearing, in particular a gear grinding machine, including a spindle rotated by a motor, wherein the spindle has, at a first axial position, a first sensor system for detecting rotation of the spindle at the first axial position, wherein the first sensor system is connected to a control unit for controlling rotation of the spindle. A second sensor system is arranged at a second axial position of the spindle, which is designed to detect rotation of the spindle at the second axial position, wherein the second sensor system is connected to a measuring device, wherein a further sensor system is arranged at the first axial position of the spindle, which is designed to detect rotation of the spindle at the first axial position and is also connected to the measuring device.

A hard finishing machine for machining workpieces with at least one gearing, in particular a gear grinding machine, including a spindle rotated by a motor, wherein the spindle has, at a first axial position, a first sensor system for detecting rotation of the spindle at the first axial position, wherein the first sensor system is connected to a control unit for controlling rotation of the spindle. A second sensor system is arranged at a second axial position of the spindle, which is designed to detect rotation of the spindle at the second axial position, wherein the second sensor system is connected to a measuring device, wherein a further sensor system is arranged at the first axial position of the spindle, which is designed to detect rotation of the spindle at the first axial position and is also connected to the measuring device.

The present invention provides a film lapping device capable of detecting meshing between a gear-shaped workpiece and a gear-shaped backup tool, thereby reducing the burden on the operator and improving work efficiency. The configuration of the film lapping device according to the present invention includes the gear-shaped backup tool that meshes with the workpiece, the slide motor that moves the slide table toward or away from the workpiece holder, the tension sensor that detects the tension in the lapping film, and the controller including circuitry that operates the slide motor to move the slide table toward the workpiece holder and determines that the backup tool and the workpiece are meshed when the tension sensor detects an increase in the tension of the lapping film.

The present invention provides a film lapping device capable of detecting meshing between a gear-shaped workpiece and a gear-shaped backup tool, thereby reducing the burden on the operator and improving work efficiency. The configuration of the film lapping device according to the present invention includes the gear-shaped backup tool that meshes with the workpiece, the slide motor that moves the slide table toward or away from the workpiece holder, the tension sensor that detects the tension in the lapping film, and the controller including circuitry that operates the slide motor to move the slide table toward the workpiece holder and determines that the backup tool and the workpiece are meshed when the tension sensor detects an increase in the tension of the lapping film.