A large gear involute artifact assembled with mandrel used as physical datum of precision traceability and measurement transmission for large gear involute is proposed. The artifact comprises a large gear involute artifact stripe, a mandrel, a backing plate, a counterweight shaft, an adjustable counterweight ring, the adjustable screws of counterweight, the connecting screws for backing plate, the connecting screws for artifact and an eccentric multi-ball bearing. The structure and the rolled length of the large gear involute artifact assembled with mandrel fit the basic requirements of class-1 accuracy in the national standard of gear involute artifact GB/T 6467-2010 in China. It has advantages of long rolled length, adjustable center of mass, uniform datum, compact structure, and portability. It adopts lightweight design, which can be installed and transported by one person manually, and is suitable for the structural design of large gear involute artifact with base-circle diameter greater than 500 mm.

In the straightening of radial run-out faults or linearity faults on elongate workpieces having at least one toothed region having peaks and troughs of the teeth of said toothed region, such as on toothed shafts or toothed racks, for ascertaining deviations from the ideally straight workpiece, the locations of the surfaces of the not yet straightened workpiece that form a reference plane are scanned at least at points or in portions on or in the region on the active reference circle or pitch circle, respectively, of the toothing that lies between the peaks and troughs of the teeth. The resulting measured items of data are utilized by the straightening machine such that a workpiece that is as ideally straight as possible at least in the toothed region is achieved by the straightening. The elevated locations of the tooth heads of the toothed region that form the peaks of the teeth and the elevated locations of neighboring tooth surfaces that lie in the reference plane are detected, and the height differentials of the elevated locations of the tooth heads in relation to the elevated locations of neighboring tooth surfaces that lie in the reference plane are ascertained. The height differentials are utilized by the straightening machine as corrective measured items of data such that said height differentials are considered when straightening the workpiece so as to form a workpiece that is as ideally straight as possible in the reference plane.

The present application discloses a method for calibrating a measuring probe in a gear cutting machine by using a workpiece received in a workpiece holder of the gear cutting machine, wherein the measuring probe includes a measuring probe tip which is movably arranged on a measuring probe base, wherein the deflection of the measuring probe tip relative the measuring probe base can be determined via at least one sensor of the measuring probe, and wherein the measuring probe is traversable relative to the workpiece holder via at least two axes of movement of the gear cutting machine. The method comprises rotating the workpiece via an axis of rotation of the workpiece holder and traversing the measuring probe via the at least two axes of movement of the gear cutting machine such that in the case of a perfect calibration the touch point of the measuring probe tip on the tooth flank would remain unchanged.

A reference-level gear helix artifact for transferring gear helix value. The invention provides a reference-level gear helix artifact with a global symmetrical structure that can be easily obtained by generating method. The centroid point of the artifact passes through the geometric center of the artifact mandrel. The cylinder of the reference-level gear helix artifact is provided with the straight tooth groove, the left-hand tooth groove and the right-hand tooth groove, axial reference torus and radial reference cylinder, fine tooth threads and center holes. Among them, the straight tooth groove includes a pair of involute cylindrical surfaces with opposite 0° helix angle, the left-handed tooth groove includes a involute helicoidal surface with 15° and a involute helicoidal surface with 30°, and the right-hand tooth groove includes a involute helicoidal surface with 15° and a involute helicoidal surface with 30°.

A method and machine whereby utilizing both tactile (46) and non-contact (50) sensors or probes for workpiece (56) inspection and/or measurement results in significant cycle time savings while accuracy is maintained.

A gear inspection apparatus includes: a measurement unit which has a probe installed to be movable forward and rearward relative to a work gear rotatably mounted on a frame, and measures a dimension of the work gear, which rotates, by a measurement ball provided at a tip of the probe; a drive unit which is installed on the frame so as to be connected to the measurement unit and moves the probe forward and rearward; and a controller which receives a displacement measurement value related to a position of the probe which is measured by the measurement unit, and converts the displacement measurement value into a digital value.

A profile measuring machine is for measuring a profile of a workpiece having a plurality of known-profile portions and a plurality of unknown-profile portions, the known-profile portions being cyclically arranged via the respective unknown-profile portions. The profile measuring machine includes: a scanning probe having a contact piece capable of being in contact with the workpiece; a drive mechanism for moving the scanning probe; an autonomous scanning measurement unit for controlling the drive mechanism to perform the autonomous scanning measurement; a measurement-path calculator for calculating a movement path of the scanning probe; and a nominal-value scanning measurement unit for controlling the drive mechanism to move the scanning probe along the movement path to perform a nominal-value scanning measurement. The measurement-path calculator calculates the movement path for the workpiece based on measurement results of the unknown-profile portions measured by the autonomous scanning measurement unit and design data of the known-profile portions.

A check method of worm gears includes the following steps: identification of a real profile (PR) of a worm gear to be checked; scanning of the real profile (PR) in such a way to obtain a measured profile (PM), filtering of the measured profile (PM) with a low pass filter in such a way to obtain a primary profile (PP), filtering of the primary profile (PP) with a high pass filter in such a way to obtain a surface analysis profile (SA), calculation of three parameters (SA.sub.a; SA.sub.q; SA.sub.p) from said surface analysis profile (SA) and comparison of the three parameters (SA.sub.a; SA.sub.q; SA.sub.p) with preset threshold values (TSa; TSq; TSp) in such a way to reject the worm gear when at least one of the parameters exceeds the corresponding threshold value.

A method of determining the minimum radius and the mounting distance of a worm gear member (6) of a worm drive (2). The root portion (26) of a tooth slot (24) is probed at a plurality of points along the length of the root and the locations of the points are utilized as the basis for determining the minimum radius and the mounting distance.

An apparatus including an NC controller, a tactile system controlled by the NC controller and movable along a measurement axis, a workpiece receptacle for receiving a workpiece, a rotational drive for rotating the workpiece receptacle with the workpiece about an axis of rotation, and a contactlessly operating sensor device arranged on the tactile system and transferable from a first position into a second position by displacement relative to the tactile system.