Abstract: The cooling means of the linear motor is formed of an assembly of plate parts adapted to dimensions of linear motor stator element plates on which magnets are disposed, piping, and bonding material for securing the plate parts and the piping to each other. Opposite ends of the plate parts are bent to form piping housing portions. The stator element plates and the plate parts are mounted to the machine while overlaid on each other. The piping is passed through the piping housing portions at the opposite ends of the plate parts. Thus, mounting of the cooling means is completed.

Abstract: An electric motor (10) comprising a stator core (11) in which slots (12) are formed, and a coil (20) is inserted in the slots. The slots are filled with an insulating resin (3), and the surface of the coil is coated with a coating layer, such as a phenol type epoxy powdery coating material or a phenol type varnish material. This prevents the insulating layer of the coil from being corroded by a strong alkaline liquid. The coating layer may have a thickness nearly equal to the thickness of an insulating paper. Further, the coating layer may have a thickness nearly equal to, or larger than, the thickness of the insulating paper.

Abstract: A motor driver capable of detecting the insulation deterioration of a motor easily and inexpensively is disclosed. The voltage supplied from an AC power supply (1) is rectified by a first rectifying circuit (D1 to D6) and smoothed by a capacitor (C) in a power supply unit (6). The output voltage of the power supply unit (6) is converted into an AC voltage of a frequency and a motor (M) is driven by a motor drive amplifier (8). Elements (R1, C2, R11, C21) are connected between at least one of the positive electrode (4) and the negative electrode (5) of the output line (4, 5) of the power supply unit (6) and the ground (G2, G4). An insulation deterioration circuit (10, 11, 12) detects at least one of the voltage between the elements and the current flowing through the elements.

Abstract: A motor driver capable of detecting the insulation deterioration of a motor easily and inexpensively is disclosed. The voltage supplied from an AC power supply (1) is rectified by a first rectifying circuit (D1 to D6) and smoothed by a capacitor (C) in a power supply unit (6). The output voltage of the power supply unit (6) is converted into an AC voltage of a frequency and a motor (M) is driven by a motor drive amplifier (8). Elements (R1, C2, R11, C21) are connected between at least one of the positive electrode (4) and the negative electrode (5) of the output line (4, 5) of the power supply unit (6) and the ground (G2, G4). An insulation deterioration circuit (10, 11, 12) detects at least one of the voltage between the elements and the current flowing through the elements.

Abstract: An electric motor (1) is driven by an inverter amplifier (2) through a cable (5). An absorber (3) is built in the electric motor (1) to suppress and absorb a surge voltage generated due to the surge impedance mismatch between the cable (5) and the electric motor (1) as well as a high-frequency noise generated due to the switching operation of a switching element in the inverter amplifier. The absorber (3) is made up of a plurality of conductors, each of which has a predetermined length and is covered with an insulating material. The conductors are connected to the input terminals (4a, 4b, 4c) of the electric motor (1), respectively. The forward end of each conductor of the absorber (3) is either open or connected to one or more other conductors through a member of a high impedance. The surge voltage and the high-frequency noise are suppressed and absorbed by the absorber.

Abstract: Semiconductor surge absorbing devices are connected individually between power lines for the U, V and W phases, which connect an inverter and a motor, and between the ground and the power lines. The absorbing devices are adapted to be energized to clamp voltages between opposite terminals thereof when the voltages are higher than a given value.

Abstract: A reflective surge suppressing cable is provided wherein surge is suppressed by canceling a specific frequency component of the surge by reflection. A main wire is constituted by an insulated core wire comprising a conductor covered with for plating for increasing resistance, and provided thereon with an insulator of high permittivity. An auxiliary wire is constituted by an insulating core provided with shielding on top of a construction identical with that of the main wire. The reflection is deliberately generated by adjusting the length of the auxiliary wire when winding the auxiliary wire in the longitudinal direction around the periphery of the main wire.

Abstract: An electric motor in which ends of lead wires of stator winding can be easily connected to a connector and the time for assembling the motor becomes shorter. The motor includes a stator winding having a plurality of lead wires, a plurality of conductors or conductive parts each electrically connected to each end of the lead wires, and a junction member having an insulator for integrally holding the conductive parts. The conductive parts and the ends of the lead wires of the stator winding may be connected to each other, respectively, by fusing members. As each of the conductive parts is configured to be disposed along a shape of a coil end of the motor, the conductive parts do not protrude to the inside of the stator winding or the outside of the coil end, and the insulator is held at a predetermined position.

Abstract: A method of producing a squirrel-cage rotor for an induction motor, which includes a plurality of secondary conductors arranged respectively in through holes (16) of a laminated core (14), and a pair of end rings connecting the secondary conductors with one another at both axial ends of the laminated core (14). Each of a pair of reinforcing members (22) includes a cylindrical wall (26), an annular multi-aperture wall (28) provided with apertures (32) and extending in a radial inward direction from one edge of the cylindrical wall (26), and an annular end wall (30) extending generally parallel to the multi-aperture wall (28) in a radial inward direction from another edge of the cylindrical wall (26). Each reinforcing member (22) is arranged in a manner in which the multi-aperture wall (28) is brought into contact with one of the axial end faces of the laminated core (14) while the apertures (32) communicate with the through holes (16).

Abstract: A squirrel-cage rotor (10) includes a laminated core (14) fixed to a rotor shaft (12), a plurality of secondary conductors (18) arranged respectively in a plurality of through holes (16) formed through the laminated core (14), a pair of end rings (20) connected to the secondary conductors (18) at axial ends of the laminated core (14), and a pair of reinforcing members (22, 23) respectively covering the end rings (20). The secondary conductors (18) and the end rings (20) are integrally formed through a casting process, and are connected with the laminated core (14) and the reinforcing members (22, 23).

Abstract: A spindle motor for a machine tool is required to operate at a low rotational speed and to deliver a high output in a machining mode, and is required to operate at a high rotational speed and to deliver a high output in another machining mode. An AC motor employing a winding arrangement of the present invention meets those operating conditions for different machining modes, in that the coils (X1, X2; X1', X2') of each winding for a phase are divided into a plurality of sets of coils, and the plurality of sets of coils are held in a slot (SL). The connection of terminals (U1, U2; V1, V2; W1, W2) for phase dividing the coils into the sets is changed selectively by switching unit (SW, SW') such as an electromagnetic relay, to thereby supply power selectively to the coils for the output regulation.

Abstract: The stator of a built-in motor must be firmly and accurately mounted on the spindle head housing or the like of a machine tool. A stator core (10), i.e., a principal component of the stator is welded partially at the circumference (14) thereof, and then the circumference of the stator core (10) held by a mandrel is finished to an accurate outside diameter by grinding. The stator core (10) thus constructed is subjected to a deformation with a lapse of time after the mandrel has been removed. To solve this problem, each lamination (12) of the stator core (10) is coated with a thermosetting adhesive, to be thereby joined together, and each lamination (12) is provided with a plurality of pressed projections (22) to be joined together by weld portions (20) on the circumference of the stator core (10), or each lamination (12) is joined together by pressing a serrated bar (26) into a bore (24) thereof, without a pressed projection (22).

Abstract: The stator of a built-in motor must be firmly and accurately mounted on the spindle head housing or the like of a machine tool. A stator core (10), i.e., a principal component of the stator is welded partially at the circumference (14) thereof, and then the circumference of the stator core (10) held by a mandrel is finished to an accurate outside diameter by grinding. The stator core (10) thus constructed is subjected to a deformation with a lapse of time after the mandrel has been removed. To solve this problem, each lamination (12) of the stator core (10) is coated with a thermosetting adhesive, to be thereby joined together, and each lamination (12) is provided with a plurality of pressed projections (22) to be joined together by weld portions (20) on the circumference of the stator core (10), or each lamination (12) is joined together by pressing a serrated bar (26) into a bore (24) thereof, without a pressed projection (22).

Abstract: An ac spindle motor (10) for driving a spindle motor of a machine tool provided with a rotor (14) having an output shaft (12) connected to the spindle, and a stator (16) surrounding the rotor and having a laminated core (20) serving as a yoke, and stator winding assemblies of three phases (U-phase, V-phase, W-phase). The stator winding assembly of each phase (18u, 18v, 18w) has: windings (C.sub.2, C.sub.4) of a first group which are energized for a rotation of the spindle in both a low-speed range not higher than a given speed, and a high-speed range above the given speed; windings (C.sub.1, C.sub.3) of a second group energized only for a rotation of the spindle in the low-speed range; and electrical contact means (S1, S2, S3, S4) controlled so that the windings (C.sub.1, C.sub.2, C.sub.3, C.sub.4) of the first and second groups are energized to generate a first multipolar revolving magnetic field for the rotation of the spindle in the low-speed range, and so that only the windings (C.sub.2, C.sub.

Abstract: When a spindle (10) of a machine tool is rotated and moved relative to a workpiece linearly along an axis (Z) thereof during a machining process such as screw cutting, a spindle servomotor (12) and a feed servomotor (22), each of which is the primary drive, must be rotated synchronously. In general, the spindle servomotor directly drives the spindle without a reduction gear, and the feed servomotor feeds a spindle head (18) through reduction gears (26, 28). Therefore, in general, the synchronous work is controlled in accordance with an acceleration and deceleration capacity of the spindle servomotor. Consequently, the spindle servomotor is rotated along the torque limit curve line (L1, L2) to drive the spindle, to thereby effect the synchronous work at a high efficiency.