Abstract: The present invention provides a method and system for controlling the temperature of an electric motor by adjusting the electric losses in the motor. In an embodiment, the required load on the motor is determined and a first motor voltage is provided to meet the required load. A predetermined temperature set point for the motor is compared against the temperature of the motor and based on the temperature of the motor and the predetermined temperature set point, a secondary motor voltage is determined. The motor voltage may then be adjusted based on the calculated voltage and the motor load measurement adjusted based on the measured motor speed and actual motor voltage.

Abstract: The present invention provides a method and system for controlling the temperature of an electric motor by adjusting the electric losses in the motor. In an embodiment, the required load on the motor is determined and a first motor voltage is provided to meet the required load. A predetermined temperature set point for the motor is compared against the temperature of the motor and based on the temperature of the motor and the predetermined temperature set point, a secondary motor voltage is determined. The motor voltage may then be adjusted based on the calculated voltage and the motor load measurement adjusted based on the measured motor speed and actual motor voltage.

Abstract: The present invention provides a method and system for controlling the temperature of an electric motor by adjusting the electric losses in the motor. In an embodiment, the required load on the motor is determined and a first motor voltage is provided to meet the required load. A predetermined temperature set point for the motor is compared against the temperature of the motor and based on the temperature of the motor and the predetermined temperature set point, a secondary motor voltage is determined. The motor voltage may then be adjusted based on the calculated voltage and the motor load measurement adjusted based on the measured motor speed and actual motor voltage.

Abstract: A method of detecting the state of a gap between an electrode and a workpiece in electrical discharge machining (EDM) equipment, the method including the steps of: prior to generating an electrical discharge to remove material from the workpiece, applying a low energy checking pulse across the gap during a checking phase period (Tc); and inferring a short circuit gap state when the gap current exceeds a current threshold (IT).

Abstract: A tool gripping arrangement for loading an elongate tool having a lengthwise axis into a collet. The tool gripping arrangement includes a tool clamp comprising a pair of tool clamp grippers for clamping the tool along a clamping axis. The tool gripping arrangement further includes a mounting arrangement for mounting the gripping arrangement to a robot arm, the tool clamp being mounted for free rotation relative to the mounting arrangement.

Abstract: A collet adaptor (10) including a body (11, 12) having forward and rear ends and an axial bore (17) extending through the forward and rear ends. A drawbar (13) disposed at least partly within the bore (17) for connection to a collet (14). The drawbar (13) is secured within the bore (17) and a biasing arrangement (42) acts on the drawbar (13) in a direction tending to shift the drawbar (13) rearwardly within the bore (17). The drawbar (13) is displaceable within the bore (17) against the biasing influence of the biasing arrangement (42) to shift forwardly within the bore (17).

Abstract: A collet adaptor 20 including a work piece clamp mechanism 29. The collet adaptor 20 is rotatable about a first axis A and the work piece clamp mechanism 29 is mounted within the collet adaptor 20 for rotation with the collect adaptor 20. The clamp mechanism 29 is also mounted for movement laterally to the first axis A during rotation of the collet adaptor 29. The clamp mechanism 29 can also be mounted within the collect adaptor 20 for rotational movement lateral to the first axis A during rotation of the collect adaptor 20.

Abstract: A method of sensing contact between a first member (606, 908) and a second (608, 910) member in a computer numerical control machine, wherein the position of at least one of the first member and the second member is controlled by one or more servo mechanisms, the method including the steps of: causing at least one of the first member and the second member to be driven towards the other; monitoring an error signal in one of the servo mechanisms; and detecting when the error signal exceeds a predetermined threshold.

Abstract: A method of computing imbalance in a motion control system is disclosed. The motion control system includes an object mounting mechanism for holding and rotating the object about a first axis; an object positioning mechanism for displacing the object mounting mechanism; an object positioning drive for driving the object positioning mechanism; and one or more rotation detection devices for generating an output signal indicative of the rotation of the object about the first axis. The method includes the steps of computing an object rotation signal indicative of the speed and phase of the object about the first axis from the rotation detection devices' output signal; demodulating an output signal from the drive with the object rotation signal to derive a demodulated output signal that is synchronous with rotation of the object about the first axis; and computing the magnitude and phase of the object imbalance from the demodulated output signal.

Abstract: A CNC tool grinding machine has at least one rotatable grinding wheel (1) movable relative to a workpiece (2) for grinding a flute surface (3) of a blade in the workpiece (2). The machine is programmed with a path for the grinding wheel (1) calculated to grind a smooth cutting edge (5) for the blade, and programmed with perturbations to the path which vary the movement of the grinding wheel (1) to grind a wavy cutting edge (6) in the workpiece. With such a machine, it is possible to grind all surfaces of a wavy cutting edge in a single set up rather than requiring two more grinding and milling operations to form the wavy cutting edge.

Abstract: A collet adaptor and method is provided for adjusting a collet (2) in a machine tool. The collet adaptor has a body or arbor (10) with a cylindrical bore (14) for receiving a cylindrical portion (20) of the collet (2) and a tapered surface (18) at its front end for engagement with a tapered split head (21) portion of the collet (2). An anti-rotation screw (40) prevents rotation of the collet (2) relative to the collet arbor (10). The collet arbor (10) has an accurately ground planar rear surface (5) which is bolted to a planar front face (6) of the headstock (4) of a rotatable spindle so as to correct for errors in concentricity.

Abstract: A computer numerically controlled (CNC) machine has a chuck (2) rotatable about a first axis (A) and a V-block clamp (#) for clamping a workpiece (4) with its central longitudinal axis (C) extending parallel to the first axis (A). The offset (d) between the axes (A) and (C) is known or calculated and the CNC machine is programmed to compensate for the offset (d) during operation of a cutting tool (5) upon the workpiece (4). The V-block clamp (3) can accommodate workpieces of different diameters without having to align the central longitudinal axis (C) of each workpiece to coincide with the axis of rotation of the chuck (2), resulting in a reduction in set up time and an increased concentricity of a ground workpiece compared with conventional CNC grinding machines.

Abstract: A simulation system (20) for a CNC machine tool includes a swept surface calculation engine (21) for processing workpiece data and grinding wheel data representing information about the grinding wheel (12) and its programmed path to generate a set of geometric envelopes representing the solid volume occupied by the grinding wheel (12) as it moves along its programmed path. The envelopes, workpiece data and grinding wheel data are processed by a 3-D rendering engine (22) to produce a three-dimensional perspective image of the workpiece (11) as it would appear after being ground by the grinding wheel (12). The simulation system (20) also includes a manipulation and control interface 923) which may be used for a wide variety of purposes to enhance the three-dimensional image, such as position, orientation and zoom control, control of simulated illuminated light sources, control of texture maps and color maps and overlay grids which may be superimposed on the surface of the simulated workpiece image.

Abstract: A computer numerically controlled (CNC) machine tool is provided in which a cutting tool is movable along a programmed path determined by a part program in a programmable control unit (PCU). A trajectory interpolator receives high level motion commands and a feedrate specification from the PCU to produce interpolated position commands. A position controller controls movement of the cutting tool in response to the interpolated position commands. The machine tool further includes a handwheel and a manual pulse generator (MPG) which can be used in MPG feed mode to control movement of the cutting tool incrementally along the programmed path in either the forward or reverse direction. In MPG feed mode, an MPG feed specification from an MPG position counter is superimposed onto the feedrate specification in the trajectory interpolator.

Abstract: A multi-axis computer numerically controlled machine tool is provided in which a cutting tool is movable relative to a workpiece by a number of linear and rotary joints under the control of a programmable control unit. The machine is programmed with a plurality of principal programmable axes, called "hard" axes, and with at least one synthesised additional programmable axis or "soft" axis which enables the cutting tool to be moved linearly in the direction of the soft axis without requiring a specific joint for that purpose. The synthesised "soft" axis is a non-collinear, partially redundant axis which increases the number of programmable degrees of freedom to a greater number than the machine degrees of freedom, i.e., the number of non-collinear joints. The principle of synthesising "soft" axes may be extended to CNC machine tools having four or more principal hard axes, for instance, to produce a 5-joint CNC machine tool which has the flexibility of a conventional 7- or 8-joint machine tool.

Abstract: A multi-axis computer numerically controlled (CNC) machine tool is provided in which a cutting tool (7) is movable relative to a workpiece (6) by means of a number of linear and rotary joints (J.sup.1 to J.sup.3) under the control of a programmable control unit (1). The machine is programmed with a plurality of principal programmable axes, called "hard" axes (X, Z and B), and with at least one synthesized additional programmable axis or "soft" axis (V) which enables the cutting tool (7) to be moved linearly in the direction of the soft axis (V) without requiring a specific joint for that purpose. The synthesized "soft" axis is a non-collinear, partially redundant axis which increases the number of programmable degrees of freedom to a greater number than the machine degrees of freedom ie: the number of non-collinear joints.