Abstract: A cup-type hollow strain wave gearing of a hollow actuator has a seal part assembled inside a cup-shaped externally toothed gear. The seal part seals between a boss of the externally toothed gear and a plug of the wave generator so as to prevent lubricant from leaking from the side of the externally toothed gear into a hollow part. Since the seal part employs an oil seal and an O-ring, it is able to be constituted inexpensively and to surely prevent leakage of low-viscosity lubricant.

Abstract: A linear DC motor having first and second drive coils and first and second drive magnets arranged in a symmetrical state in relation to a motor central axis that passes through a sliding member in which a lens is mounted. The first and second coils on a moveable side are positioned to both the left and right sides of the sliding member. The first and second drive coils are designed to be independent without being affected by the shape, size, arrangement position, and the like of the sliding member, a linear guide, and a detection part. The first and second drive coils have high rigidity and do not deform when the sliding member slides. Accordingly, it is possible to obtain a linear DC motor that has a highly rigid moveable part and performs positioning action with high responsiveness and high precision.

Abstract: A magnetic absolute encoder includes: a board-holding assembly mounted to a motor case assembly side; and a flexible printed wiring board which is held, by the board-holding assembly, in the shape of a loop surrounding multipolar and bipolar ring magnets. On the flexible printed wiring board, multipolar-side hall elements and bipolar-side hall elements are mounted and a wiring pattern relating to the hall elements are printed. The assembling work and wiring work of the magnetic absolute encoder provided with a multipolar magnetic encoder and a bipolar magnetic encoder can be performed simply in a short time.

Abstract: First to fourth magnetic detection units (22-25) are arranged in opposition to a multipole magnetized surface (21a) of a multipole magnet (21) of a magnetic encoder (17). The first and second magnetic detection units (22, 23) are placed on positions separated from each other by 180 degrees on the periphery of the center of the multipole magnet and output an A-phase signal and a B-phase signal. The third and fourth magnetic detection units (24, 25) are placed on positions separated from each other by nearly 180 degrees on the periphery of the center of the multipole magnet and output an A-phase reverse signal and a B-phase reverse signal. Detection signals of the same phase are synthesized and averaged, and consequently a detection error generated by an outer magnetic flux extending in the diameter direction of the multipole magnet can be removed.

Abstract: A magnetic absolute encoder includes: a board-holding assembly mounted to a motor case assembly side; and a flexible printed wiring board which is held, by the board-holding assembly, in the shape of a loop surrounding multipolar and bipolar ring magnets. On the flexible printed wiring board, multipolar-side hall elements and bipolar-side hall elements are mounted and a wiring pattern relating to the hall elements are printed. The assembling work and wiring work of the magnetic absolute encoder provided with a multipolar magnetic encoder and a bipolar magnetic encoder can be performed simply in a short time.

Abstract: First to fourth magnetic detection units (22-25) are arranged in opposition to a multipole magnetized surface (21a) of a multipole magnet (21) of a magnetic encoder (17). The first and second magnetic detection units (22, 23) are placed on positions separated from each other by 180 degrees on the periphery of the center of the multipole magnet and output an A-phase signal and a B-phase signal. The third and fourth magnetic detection units (24, 25) are placed on positions separated from each other by nearly 180 degrees on the periphery of the center of the multipole magnet and output an A-phase reverse signal and a B-phase reverse signal. Detection signals of the same phase are synthesized and averaged, and consequently a detection error generated by an outer magnetic flux extending in the diameter direction of the multipole magnet can be removed.

Abstract: A multiple-rotation absolute encoder attached to an actuator provided with a motor and a reduction gear comprises a multiple-rotation value counter for counting a multiple-rotation value representing a number of rotations of a rotating shaft of the motor from a predetermined origin; a memory part for storing a reduction ratio R of the reduction gear; and a counter-controlling part for setting a range of the count value of the multiple-rotation value counter from zero rotations to (R?1) rotations on the basis of the reduction ratio R stored and maintained in the memory part, resetting the count value to zero when the rotating shaft makes a single rotation in a forward direction from a state in which the count value is (R?1), and setting the count value to (R?1) when the rotating shaft makes a single rotation in a reverse direction from a state in which the count value is zero.

Abstract: In an actuator (1) in which an angle detector (13) of a magnetic encoder for detecting the rotational position of a motor (3) is incorporated inside a wave reduction gear (5), detection signals from Hall elements (11a, 11b) of the angle detector (13) are transmitted via sensor lead wires (17) that have been brought out through wiring holes (36a, 33a, 35a, 37a) formed inside the motor (3) to a sensor signal converter board (14) disposed on the rear end side of the motor. Since the wiring is not required to be brought out to the exterior, indirectly routed along the exterior of the motor (3), and brought out to the rear side thereof, the wiring is not mechanically damaged and can be brought out with the shortest possible wiring distance, and the effect of electromagnetic noise can be reduced.

Abstract: A multiple-rotation absolute encoder attached to an actuator provided with a motor and a reduction gear comprises a multiple-rotation value counter for counting a multiple-rotation value representing a number of rotations of a rotating shaft of the motor from a predetermined origin; a memory part for storing a reduction ratio R of the reduction gear; and a counter-controlling part for setting a range of the count value of the multiple-rotation value counter from zero rotations to (R?1) rotations on the basis of the reduction ratio R stored and maintained in the memory part, resetting the count value to zero when the rotating shaft makes a single rotation in a forward direction from a state in which the count value is (R?1), and setting the count value to (R?1) when the rotating shaft makes a single rotation in a reverse direction from a state in which the count value is zero.

Abstract: In the magnetic absolute encoder, an ordinary operating circuit and an ordinary/backup operating circuit are actuated during ordinary operation in which power is supplied from the ordinary operating power supply; the single-rotation absolute value (1) and single-rotation absolute value (2) detected by these circuits are compared by the abnormality diagnosis circuit, and the presence or absence of an abnormality is automatically judged During backup in which the ordinary operating power supply is interrupted, only the low-power-consumption ordinary/backup operating circuit is actuated, and the multiple-rotation value (2) is detected At the point in time at which the system is returned to ordinary operation, the multiple-rotation value setting circuit sets the multiple-rotation value (2) as the multiple-rotation value (1) of the ordinary operating circuit. As a result, the calculation operation of the multiple-rotation value (1) can be restarted.

Abstract: A flat, hollow brushless servomotor (1) has a motor housing (2), housing through holes (22a, 23a) formed in a center of both end plate portions (22, 23), a rotor shaft (41) of which a portion of both ends is exposed from the through holes, a tool-mounting hole (43) that extends through a center thereof, and workpiece insertion recesses (24, 25) formed in an external surface of both end plate portions (22, 23) of the motor housing (2) by reducing the thickness thereof. A workpiece with a shape that has facing portions facing each other across a narrow space can be introduced from an outside to a center of the motor (1) along the workpiece insertion recesses, and the facing portions of the workpiece can be machined by a tool mounted in the center of the motor.

Abstract: In the magnetic absolute encoder, an ordinary operating circuit and an ordinary/backup operating circuit are actuated during ordinary operation in which power is supplied from the ordinary operating power supply; the single-rotation absolute value (1) and single-rotation absolute value (2) detected by these circuits are compared by the abnormality diagnosis circuit, and the presence or absence of an abnormality is automatically judged During backup in which the ordinary operating power supply is interrupted, only the low-power-consumption ordinary/backup operating circuit is actuated, and the multiple-rotation value (2) is detected At the point in time at which the system is returned to ordinary operation, the multiple-rotation value setting circuit sets the multiple-rotation value (2) as the multiple-rotation value (1) of the ordinary operating circuit. As a result, the calculation operation of the multiple-rotation value (1) can be restarted.

Abstract: In an actuator (1) in which an angle detector (13) of a magnetic encoder for detecting the rotational position of a motor (3) is incorporated inside a wave reduction gear (5), detection signals from Hall elements (11a, 11b) of the angle detector (13) are transmitted via sensor lead wires (17) that have been brought out through wiring holes (36a, 33a, 35a, 37a) formed inside the motor (3) to a sensor signal converter board (14) disposed on the rear end side of the motor. Since the wiring is not required to be brought out to the exterior, indirectly routed along the exterior of the motor (3), and brought out to the rear side thereof, the wiring is not mechanically damaged and can be brought out with the shortest possible wiring distance, and the effect of electromagnetic noise can be reduced.

Abstract: A flat, hollow brushless servomotor (1) has a motor housing (2), housing through holes (22a, 23a) formed in a center of both end plate portions (22, 23), a rotor shaft (41) of which a portion of both ends is exposed from the through holes, a tool-mounting hole (43) that extends through a center thereof, and workpiece insertion recesses (24, 25) formed in an external surface of both end plate portions (22, 23) of the motor housing (2) by reducing the thickness thereof. A workpiece with a shape that has facing portions facing each other across a narrow space can be introduced from an outside to a center of the motor (1) along the workpiece insertion recesses, and the facing portions of the workpiece can be machined by a tool mounted in the center of the motor.

Abstract: An actuator has a housing, a motor and a wave gear reduction drive arranged axially in the housing, and a rotational shaft extending through the centers of these portions. The rotational shaft is supported at its rear side by a first bearing and at its front side by a boss of a flexible external gear of the wave gear reduction drive via a second bearing. The rotational shaft is formed integrally on its outer peripheral portion with a cam plate of a wave generator of the wave gear reduction drive. The actuator thus configured does not require a coupling mechanism between the motor and the wave gear reduction drive and needs fewer bearings to support the rotational shaft, making it possible to reduce the axial length of the actuator.

Abstract: A DC motor of a galvanometer-type scanner has four poles, and compared to a conventional DC motor with a bipolar construction, the armature inductance L can be reduced to half or less for a case where the external diameter of the rotor and the induced voltage constant KE are the same. Since KE/L, which is the index for the rise of torque of the motor, is increased by a factor of two or more, the responsiveness of the motor can be improved without increasing the exciting current of the winding. Accordingly, it is possible to provide a galvanometer-type scanner that can set minute angles of around one degree within several hundred microseconds.

Abstract: A DC motor of a galvanometer-type scanner has four poles, and compared to a conventional DC motor with a bipolar construction, the armature inductance L can be reduced to half or less for a case where the external diameter of the rotor and the induced voltage constant KE are the same. Since KE/L, which is the index for the rise of torque of the motor, is increased by a factor of two or more, the responsiveness of the motor can be improved without increasing the exciting current of the winding. Accordingly, it is possible to provide a galvanometer-type scanner that can set minute angles of around one degree within several hundred microseconds.

Abstract: An actuator has a housing, a motor and a wave gear reduction drive arranged axially in the housing, and a rotational shaft extending through the centers of these portions. The rotational shaft is supported at its rear side by a first bearing and at its front side by a boss of a flexible external gear of the wave gear reduction drive via a second bearing. The rotational shaft is formed integrally on its outer peripheral portion with a cam plate of a wave generator of the wave gear reduction drive. The actuator thus configured does not require a coupling mechanism between the motor and the wave gear reduction drive and needs fewer bearings to support the rotational shaft, making it possible to reduce the axial length of the actuator.

Abstract: An optical position sensor comprises a linearity correction circuit 20 having ROM 22 in which a corresponding table between compensation values and respective rotational angular position of a rotational disk 51. The compensation values are obtained such that an actual relationship is measured between the rotational angular positions of the rotational disk 51 and the output B of a semiconductor position sensing device 54, deviation of the output B of the device 54 from a predetermined linearity relationship (A) is calculated, and compensation values are determined for eliminating the deviation of the output B of the device 54 at respective rotational angular positions of the rotational disk 51. The linearity correction circuit 20 retrieves a compensation value E from ROM 22 based on the output B of the device 54, and compensates the output A so as to produce the sensing output E which has a linearity relationship to the rotational angle of the rotational disk 51.

Abstract: An electromagnetic motor of the finite rotational type has an improved rotor-returning mechanism for exerting a magnetic force to return its rotor to the initial angular position in a non-excited condition. The rotor-returning mechanism is comprised of a permanent magnet fixedly mounted on a stator and a permanent magnet mounted around the rotor. The permanent magnets are arranged such that, a magnetic attractive force generated between the permanent magnets functions to return the rotor to the initial angular position. The rotor-returning mechanism can be constitued by first and second ring-shaped permanent magnets mounted on the rotor. The N and S poles of the first magnet are offset in a the circumferential direction from those of the second magnet so as to generate a magnetic torque for returning the rotor to the initial angular position.