Abstract: A control device for safely controlling an electrical motor during decelerating and stopping operations of the motor. The control device includes a control part for controlling the decelerating and stopping operations; a monitoring part for monitoring the operations of the electric motor; and a judging part for judging whether the velocity of the electric motor monitored by the monitoring part is abnormal while the control part controls the motor so as to decelerate and stop the motor. The judging part forcibly cuts off power to the electric motor, via a circuit breaker, when the judging part judges that the velocity of the motor is abnormal.

Abstract: A control device for safely controlling an electrical motor during decelerating and stopping operations of the motor. The control device includes a control part for controlling the decelerating and stopping operations; a monitoring part for monitoring the operations of the electric motor; and a judging part for judging whether the velocity of the electric motor monitored by the monitoring part is abnormal while the control part controls the motor so as to decelerate and stop the motor. The judging part forcibly cuts off power to the electric motor, via a circuit breaker, when the judging part judges that the velocity of the motor is abnormal.

Abstract: A brake apparatus provided in an operating system including an electric motor as a driving source. The brake apparatus includes a brake unit section attached to an operating part in the operating system; a brake control section controlling an operation of the brake unit section; a braking condition monitoring section monitoring a braking condition of the brake unit section; and a feedback signal outputting section outputting a feedback signal representing a working condition of the electric motor. When the brake control section issues a braking command to the brake unit section, the braking condition monitoring section obtains the feedback signal, output from the feedback signal outputting section, and judges the braking condition on the basis of the feedback signal.

Abstract: The invention relates to a reference-point return method for returning a movable element of a machine to a reference point using solely a linear scale, without relying upon a limit switch. The method includes providing the linear scale (1) with a second scale portion (2) for stipulating a deceleration starting position and a reference-point position, in addition to first scale portion (3, 4) for generating two-phase signals for position detection, generating signals (S.sub.1, S.sub.2) indicative of the deceleration starting position (D) and reference-point position (O) from the second scale portion (2) of the linear scale, slowing a reference point return rapid-traverse velocity (Va) to a reference-point return rapid-traverse velocity (Vb) using the deceleration starting signal (S.sub.1), and effecting return to the reference point by stopping movement in response to the reference-point signal (S.sub.2).

Abstract: A magnetic-type absolute position encoder includes a magnetic drum having a magnetic material magnetized on a circumferential surface thereof is rotated and absolute position in one revolution is calculated based on sinusoidal and cosinusaoidal signals outputted by a magnetic reluctance element arranged to oppose the circumferential surface. The polarities of a magnetic material (2) magnetized on the circumferential surface of a magnetic drum (1) are aligned in the direction of the rotational axis of the magnetic drum to form a magnetization track (3). In a case where a sinusoidal signal having n cycles per revolution is to be generated, the magnetization track is made to undulate n cycles per revolution in the direction of the rotational axis. A sinusoidal signal and a cosinusoidal signal having a phase difference of 90.degree.

Abstract: When a pulse encoder is attached to a motor, first a stationary coded plate (20) is temporarily held on one end (18) of a motor housing (12) to modify a deviation thereof during a rotation of the motor housing (12) around an output shaft (14) of the motor, then a gauge (50) is interposed between said stationary coded plate (20) and a rotary coded plate (48) to separate them from the other by a prescribed distance, and next the output shaft (14) is rotated relative to the motor housing (12) to modify a deviation of the rotary coded plate (48) temporarily fixed to the sleeve member (42). According to the above method, the pulse encoder is accurately and efficiently attached to the motor.

Abstract: A motor equipped with a pulse encoder, the motor equipped with a pulse encoder being characterized in that: the rear housing portion of the motor is formed of an insulator; the pulse encoder comprises a light emitting unit, a light receiving element unit for receiving light from the light emitting unit, a rotary encoder disc and a fixed encoder disc having signal patterns which pass or interrupt light sent from the light emitting unit to the light receiving element unit, a fixed slit plate to which the fixed encoder disc and the light receiving element unit are affixed, and a printed circuit board on which is formed the signal processing circuit to which the signal output from the light receiving element unit is input through connection lines, the fixed slit plate being affixed to the rear housing portion of the motor; the fixed slit plate is electrically connected to the 0.sub.

Abstract: Disclosed is an optical rotary encoder having a fixing base having a cylinder concentric with the axis of a rotating shaft and adapted to be fixed to a flange surrounding the shaft. The encoder includes a light receiving element plate having a hole of a size to be engaged with the cylinder of the fixing base and be rotatable relative thereto during assembly and a light receiving element precisely aligned from the center of the hole in the radial direction thereof, and a fixed encoding plate, in which an encoding portion is formed so that an emitted light is radiated on the light receiving element of the light receiving element plate. The plate is fixed to the fixing base so as to be adjacent to the light receiving element plate at a predetermined distance therefrom.Also disclosed is a method for assembling the optical rotary encoder.

Abstract: A permanent-magnet field rotor (20) for use in a synchronous motor such as an AC servo motor comprises a shaft (21), a pair of end plates (22, 23) fixed on the shaft (21) and axially spaced from each other, a plurality of permanent magnets (24) extending outwardly in the radial direction of the shaft (21) and axially extending between the end plates (22, 23), and a plurality of yokes (25) disposed between successive permanent magnets (24) and axially extending between the end plates (22, 23) to hold the permanent magnets (24). Each of said yokes (25) has an axial protrusion (34, 35) at either end thereof, and the end plates (22, 23) have provided therein engagement holes (26, 37) which serve, when engaged on the axial protrusions (34, 35) to prevent the yokes from moving circumferentially and radially.

Abstract: An optical absolute endoder, provided with a rotary code plate and fixed plate, for detecting the angle of rotation and the position of rotation of a motor, etc. The rotary code plate has a plurality of concentric code patterns with light passage portions and light blocking portions alternately arranged and a reference pattern comprised of just a light passage portion sandwiched between adjoining code patterns and arranged concentrically with the code patterns. The fixed plate is provided with first and second code pattern slit groups arranged in the radial direction of the rotary code plate at first predetermined intervals and corresponding to the code patterns and with reference pattern light passage portions provided at positions corresponding to the reference pattern at positions separated by exactly second predetermined intervals from the center line of the code pattern light groups. By this, fluctuations in the voltage level of the reference signals due to light leakage are prevented.

Abstract: A pulse encoder having a circuit for diagnosing abnormalities such as the breaking of wire in LEDs or lowering of a power supply voltage, the pulse encoder comprising LEDs, a rotary lattice plate, a stationary lattice plate, light-receiving elements, and a driving unit for driving the electric signals from the light-receiving elements, the driving unit having a control terminal for controlling the output signal of the driving unit, wherein the anode of one of the LEDs connected to the ground is connected to the control terminal so that when the potential of the control terminal is lowered to a level lower than a predetermined value an alarm signal is output from the driving unit.

Abstract: A pulse coder comprises a rotating member (1) on which first and second magnetic patterns (221, 222; 221', 222') are formed and a fixed member (3) on which first and second magnetoresistance patterns (MR5, MR6) are formed. When the first and second magnetic patterns of the rotating member directly face the first and second magnetoresistance patterns, respectively, of the fixed member, the first and second magnetoresistance patterns have a minimum resistance value and a maximum resistance value, respectively. The first and second magnetic patterns are constructed by alternately and irregularly arranging strong magnetic field generating areas and weak magnetic field generating areas.