A method of machining a workpiece using a machine tool, the machine tool comprising a tool mount carrying a tool, a workpiece mount carrying a workpiece, a drive mechanism for moving at least one of the tool mount and the workpiece mount relative to the other, and a control arrangement for controlling the drive mechanism. The method comprises moving at least one of the tool mount and the workpiece mount with the drive mechanism under the control of the control arrangement so that the tool contacts a portion of the workpiece to commence a machining operation, and the tool then removes material from the portion of the workpiece until completion of the machining operation, the movement being such that the relative velocity between the tool and the workpiece decreases continuously during the majority of the time that the tool and the workpiece are in contact with each other during the machining operation.

A workpiece centering gauge for a grinding machine includes a link having a first pivot configured to couple with the grinding machine; a first encoder that measures an angle of the link at the first pivot; a second pivot included with the link; a measuring fork configured to releasably contact an outer surface of an elongated workpiece; a surface feeler, having a transducer, included with the measuring fork that measures a workpiece diameter a second encoder that measures an angular position of the link relative to the measuring fork; the angular position measured by the first encoder, the angular position measured by the second encoder, and a measured workpiece diameter are used to determine a deviation of the elongated workpiece from a centerline.

A grinding machine including one or more grinding wheels has a workpiece holder that releasably holds a crankshaft and is configured to rotate the crankshaft about a longitudinal axis; a spindle assembly, that is moveable in at least two directions, including a spindle shaft and a grinding wheel attached to the spindle shaft; and an acoustic emission sensor coupled to the grinding machine, such that the grinding machine is configured to monitor an output signal from the acoustic emission sensor, move the grinding wheel into contact with the crankshaft at a first angular position, detect contact between the grinding wheel and the crankshaft based on the output signal, determine a position of the grinding wheel based on the detected contact between the grinding wheel and the crankshaft, move the grinding wheel away from the crankshaft, rotate the crankshaft a defined angular amount, move the grinding wheel into contact with the crankshaft at a second angular position, determine a position of the grinding wheel based on the detected contact between the grinding wheel and the crankshaft, and determine a position of a crankshaft surface.

A grinding machine including one or more grinding wheels has a workpiece holder that releasably holds a crankshaft and is configured to rotate the crankshaft about a longitudinal axis; a spindle assembly, that is moveable in at least two directions, including a spindle shaft and a grinding wheel attached to the spindle shaft; and an acoustic emission sensor coupled to the grinding machine, such that the grinding machine is configured to monitor an output signal from the acoustic emission sensor, move the grinding wheel into contact with the crankshaft at a first angular position, detect contact between the grinding wheel and the crankshaft based on the output signal, determine a position of the grinding wheel based on the detected contact between the grinding wheel and the crankshaft, move the grinding wheel away from the crankshaft, rotate the crankshaft a defined angular amount, move the grinding wheel into contact with the crankshaft at a second angular position, determine a position of the grinding wheel based on the detected contact between the grinding wheel and the crankshaft, and determine a position of a crankshaft surface.

A grinding machine and a method for grinding large crankshafts are disclosed. During pre-grinding, steady-rest seats are ground, and a plurality of steady rests are placed against them. Synchronous electric drives drive the crankshaft at both ends. A desired shape is produced by interpolating motion of a first grinding disk about CNC-controlled X and Z axes and about a WK pivot axis. The grinding disk is a CBN grinding disk with a width less than the axial length of the main journals and crankpins of the crankshaft. Diameters are measured along the axial length of the main journals and/or crankpins by an in-process device. The drives for the X1, Z1, and WK axes are controlled in an interpolating manner on the basis of the measurements to achieve the desired shape.

A grinding machine and a method for grinding large crankshafts are disclosed. During pre-grinding, steady-rest seats are ground, and a plurality of steady rests are placed against them. Synchronous electric drives drive the crankshaft at both ends. A desired shape is produced by interpolating motion of a first grinding disk about CNC-controlled X and Z axes and about a WK pivot axis. The grinding disk is a CBN grinding disk with a width less than the axial length of the main journals and crankpins of the crankshaft. Diameters are measured along the axial length of the main journals and/or crankpins by an in-process device. The drives for the X1, Z1, and WK axes are controlled in an interpolating manner on the basis of the measurements to achieve the desired shape.

The present invention relates to a measuring steady rest which has a device for supporting central workpiece regions, in particular, bearing points on shaft parts, in particular crankshafts, and a measurement device integrated therein for directly adjusting the measurement of the workpiece regions before and/or during machining of the shaft parts. The measuring steady rest is preferably designed in the form of a prism, the measurement device being arranged on the bottom of the prism between the lateral flanks of the prism. The present invention further relates to a grinding machine comprising such a measuring steady rest, and to a method for supporting and measuring central workpiece regions on such a grinding machine comprising such a measuring steady rest.

A grinding machine and a method for measuring and producing a target outer contour is disclosed, particularly for a pin-bearing journal of a crankshaft. First, a measurement device acquires measurement values for the dimensions and shape of a workpiece in at least two measurement planes that are spaced apart and extend transversely to a longitudinal extension of a workpiece region. The measurement planes are produced by a relative movement of the workpiece region and the measurement device in a Z axis direction, relative to the movement of a grinding disc in the direction of the Z-axis thereof. These measurement values are transmitted to a CNC system for advancing a grinding disc, such that any deviations from the target contour that may be present are corrected, and the target contour of the workpiece region in question is ground adaptively on the basis of the measurement values.

A grinding machine and a method for measuring and producing a target outer contour is disclosed, particularly for a pin-bearing journal of a crankshaft. First, a measurement device acquires measurement values for the dimensions and shape of a workpiece in at least two measurement planes that are spaced apart and extend transversely to a longitudinal extension of a workpiece region. The measurement planes are produced by a relative movement of the workpiece region and the measurement device in a Z axis direction, relative to the movement of a grinding disc in the direction of the Z-axis thereof. These measurement values are transmitted to a CNC system for advancing a grinding disc, such that any deviations from the target contour that may be present are corrected, and the target contour of the workpiece region in question is ground adaptively on the basis of the measurement values.

A self-centering grinding wheel assembly that includes a spindle shaft including a conical-shaped end, a grinding wheel, and a grinding wheel adapter. The grinding wheel adapter affixed to the grinding wheel. A plurality of alignment members disposed radially within the grinding wheel adapter. Each of the plurality of alignment members include a tapered surface that conforms to a conical end of the spindle shaft. The plurality of alignment members slide radially with the grinding wheel adapter. The plurality of alignment members self-center the grinding wheel adapter on the spindle shaft in response to the grinding wheel adapter being assembled to the conical end of the conical shaft.