Fanuc Corporation

Shinpei Uemura

Kosei Nakamura

Yukio Katsuzawa

Michi Masuya

Hisashi Maeda

Yoshinobu Maeda

Kazuki Yoshimura

A compact terminal unit for an electric motor capable of switching over windings with ease and improving automation of assembling and inspection process of the electric motor. A terminal base is fixed at a position of a through hole formed on a housing of the electric motor. Leads of the windings of a rotor are connected with cylindrical presser portions of lead connectors by caulking. A conducting portions of the lead connectors are inserted into mounting portions of the terminal base. The power cables are connected with conducting portions with screws engaged with the conducting portions so that the power cables are electrically connected with leads of the windings. Since the leads are connected to the lead connectors with their orientations vertically under the power cable connection terminals not to be present in a space in a terminal box, an ample space for attachment of the power cables to the power cable connection terminals is secured. The switchover of windings from a delta connection to star connection and vice versa can be easily performed. Since positions and orientation of the leads are fixed at mounting portions of the terminal base, the inspection of the windings can be easily performed.

Terminal unit for electric motor

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

Growing community of inventors

Yamanashi, Japan

Shinpei Uemura