Fanuc Corporation

Fujitsu Fanuc Limited

Kosei Nakamura

Yoshiyuki Hayashi

Kazuhisa Numai

Yukio Katsuzawa

Masami Kimijima

Michi Masuya

Hisashi Maeda

Yasuyuki Nakazawa

Yohei Arimatsu

Shinichi Kono

Shigeaki Oyama

Shigeru Koyoshida

Yoshikazu Takano

Junichi Nagai

Yoshiki Fujioka

Tatsuo Shinohara

Hideki Oka

Yoshinobu Maeda

Katsuo Kohari

Shinpei Uemura

Takashi Yoshida

Akio Sadatsuki

Minoru Kasama

An induction motor capable of obtaining a high power characteristic in a wide range without producing induced voltage. A winding for each phase is composed of a plurality of winding components having the same number of turns. When high torque is needed with low speed rotation, a Y-connection in which winding components for each phase are connected in series is formed as shown in FIG.,. For medium low speed rotation, a &Dgr;-connection in which winding components for each phase are connected in series is formed as shown in FIG.,. For medium high speed rotation, a Y-connection in which winding components for each phase are connected in parallel is formed as shown in FIG.,. For high speed rotation, a &agr;-connection in which winding components for each phase are connected in parallel is formed as shown in FIG.,. Using the entire winding for each phase, the number of turns is decreased stage by stage to switch from low speed rotation to high speed rotation. Since there is no unused part of windings, there is no problem of induced voltage. A fall in power at the time of switching the winding formation can be restrained, so that a high power characteristic can be obtained in a wide range.

Induction motor

A reactor (,) and a switch (,) are interposed in parallel between U-phase, V-phase and W-phase on a power source side (,) and U, V and W terminals on a motor side (,). A changeover switch ),) is interposed between Z, X and Y terminals on the motor side (,) and the U, V and W terminals on the motor side (,). When the switch (,) is set to OFF, the changeover switch (,) is set to ON, and the switch (,) is set up so as to interconnect Z, X and Y terminals, windings of the motor are set up in the form of Y-connection, so that the motor and a power source are connected directly to each other. On the other hand, when the changeover switch (,) is switched over to OFF, and the switch (,) is set up so as to interconnect Z, X and Y terminals to the U, V and W terminals, the windings of the motor are set up in the form of &Dgr;-connection, so that the motor and the power source are connected together through the reactor (,).

AC motor with reactor interposed between AC motor and power source

Cage rotor having reinforcing members that prevent deformation of end

Method for casting conductor of a cage rotor of an induction motor and

Method of machining motor frame body and motor machined by the method

Conductor casting apparatus for a squirrel-cage rotor of an induction

An air-cooled type electric motor (20) includes a rotor, a stator includes a stator core (28), and a front support member (32) and a rear support member (34) arranged at both axial ends of the stator core (28). A plurality of air passages (42), extending continuously in an axial direction, are provided in the stator core (28), the front support member (32), and the rear support member (34). A centrifugal blower unit (50) is placed at further rear side of the rear support member (34). Because the centrifugal blower unit (50) has a large pressure rise, air, surrounding the motor and sufficient to cause an effective cooling, can be made to flow into the air passages (42) with a smaller diameter. A drive section (56) of the blower unit (50) is fixed directly to the rear support member (34) by bolts (72). Consequently, an electric wire (74) for the drive section (56) extends through the interior space of the motor (20), and is connected to a terminal box (48). In this manner, the blowing capacity, and the moisture-proofing of the terminal box, can be improved.

Air-cooled type electric motor

Induced voltage reduction method and an induced voltage reduction

An electric motor includes a covering member for covering the outer periphery of a stator core, to improve the cooling efficiency of an air-cooling system of the motor. The covering member is fixed to a stator while defining a cavity therebetween in fluidic communication with air passages formed directly in the stator core. When an blower unit mounted on the motor operates, an ambient air surrounding the motor is introduced into the cavity, and then flows from the cavity into the air passages, so as to actively absorb heat generated in the stator from the outer peripheral surface of the stator core and the tubular wall surfaces of the air passages. Thereafter, the air is discharged from the air passages out of the motor.

Electric motor with an air-cooling system

A multi-function machine tool provided with a motor-driven spindle on which each of a plurality of sub-motor units having individual drive motors and tools, respectively, can be removably mounted to perform a plurality of machining operations in order to comply with a change in the machining conditions and a change in the material of workpieces to be machined. The drive motors of the sub-motor units exert different output performances, i.e., different rated rotating speeds and different output torques, and can be electrically connected to the electric powers lines and control signal lines provided for the spindle head.

Multi-function machine tool

A terminal box for a motor is made of a thick plastic plate and includes a plurality of closed windows provided on the terminal box. Each of the closed windows is made of a thin plastic plate. The plurality of closed windows are each surrounded by a groove which is one of a plurality of concentric circular grooves. The terminal box is also provided with a plurality of radial linear grooves passing through a center of the concentric circular grooves to produce an open window for positioning a conduit therein when one of the plurality of closed windows is broken.

Terminal box for motor and method of positioning a conduit therein

An improved supporting arrangement for a bearing in an electric motor is provided for preventing the development of fretting corrosion. The electric motor comprises a housing, the housing including a longitudinal axis and bores at either end thereof so that the bores are aligned to the longitudinal axis, a rotating shaft extending along the longitudinal axis through the bores, and bearings for rotationally supporting the rotating shaft at either end thereof, the bearings being provided within the respective bores. The supporting arrangement comprises a support in the form of a ring for supporting the one of the bearings into which the bearing is fitted, the support being fitted into one of the bores and slidable along the longitudinal axis, a pair of O-rings provided between the outer surface of the support and the inner surface of the bore into which the support is fitted, the O-rings being separated from each other by an interval along the longitudinal axis, a lubricant receiving receptacle provided between the pair of O-rings, and lubricant material applied on the outer surface of the support, on the inner surface of the bore, and in the lubricant receiving receptacle.

Supporting arrangement for a bearing in an electric motor

Squirrel-cage rotor for induction motor

An air-cooled motor having cooling-air passages each formed by a plurality of small ventilation passages extending through a front housing, a stator, and a rear housing, constructed in one piece. Cuttings are prevented from being accumulated at inlets of cooling-air passages. For example, the cooling-air passages are formed of ten small ventilation passages, each defined between adjacent ones of eleven ribs each forming part of the stator. All the eleven ribs are provided with respective front housing ribs. End faces of the front housing ribs on the cooling-air inlet side are uniform in height, and positioned in an identical plane. Cooling air flows into the small ventilation passages in the direction of an arrow. In this case, the end faces of the small ventilation passages on the cooling-air inlet side are aligned, so that cuttings contained in cooling air are accumulated only on the end faces of ribs defining the small ventilation passages on the cooling-air inlet side, forming accumulation layers thereon, which prevents the small ventilation passages from being clogged with accumulations of cuttings.

Air-cooled motor

Method and device of producing a squirrel-cage rotor for an induction

Growing community of inventors

Yamanashi, Japan

Kosei Nakamura