Ebara Corporation

Ebara Densan Ltd.

Minoru Iwata

Toshio Nakamura

Yoshimi Soeda

Toshifumi Miyasaka

Kozo Matake

Tomoyuki Shibata

Hiroyuki Chino

Nobuyuki Kuji

Kiyohiko Sano

Toshiya Akasaka

Yukio Murata

The improved thermotropic LCP composition comprises 10-13 wt. % of a thermotropic liquid crystal polymer resin and 90-87 wt. % of zircon and is useful as an electrical insulator. The composition is a good electrical insulator, permits good heat conduction and experiences small thermal expansion, thus insuring high reliability. The composition may be injection molded to form an electrically insulated housing of a stator for electric machines or appliances that includes a coil and terminals thereof.

Thermotropic liquid crystal polymer composition and insulator

A DC motor apparatus which can be started with a power supply having a small current capacity and which provides a large driving force. The DC motor apparatus comprises a permanent magnet in a rotor of the DC motor, a plurality of coils provided at a stator of the DC motor, a distributor for controlling the switching of current paths to the coils and a position detector for detecting a rotational position of the rotor of the motor to output switching signal to the distributor. A pulsating unit is further provided for pulsating currents supplied to the coils whereby a current flowing from the distributor to any one of the coils can be pulsated when the DC motor is activated, resulting in easy starting the DC motor.

Easily started DC motor apparatus

The improved thermotropic LCP composition comprises 10-13 wt % of a thermotropic liquid crystal polymer resin and 90-87 wt % of zircon and is useful as an electrical insulator. The composition is a good electrical insulator, permits good heat conduction and experiences small thermal expansion, thus insuring high reliability. The composition may be injection molded to form an electrically insulated housing of a stator for electric machines or appliances that includes a coil and terminals thereof.

A submersible motor having a primary winding made of a water-tight wire has an improved life characteristic. The water-tight wire is made of a conductor and three layers formed on the conductor. The three layers are a heat-resistant enamel layer, a main insulating layer and an outer protective layer. The main insulating layer is composed of crosslinked polyethylene or a polypropylene. The outer protective layer is composed of a polyvinyl chloride composition having as a base material a polyvinyl chloride having a number average polymerization degree of 2000 or higher.

Submersible motor using a water-tight wire as the primary winding

A submersible electric motor for use in submersible pump or the like, in which an upright motor shaft is supported by upper and lower thrust bearings for supporting upward and downward thrust loads, respectively, and thrust pads of the upper and the lower thrust bearings receive upper and lower slide contact members secured to the motor shaft in its upper and lower portions, and in which resilient means such as coil springs or rubber bushings bias the thrust pads of the upper thrust bearing, suspension mounted to the motor frame, towards the upper thrust contact member secured to the motor shaft. This thrust bearing for supporting an upward thrust given to the motor shaft may be applicable to various electric motors.

Submersible electric motor having floating bearings

A submersible motor is given a relatively short axial length by arranging a member, at the portion which is on the lower end during use, to serve for transmitting radial torque as well as for transmitting thrust load. By such arrangement, the axial length normally required for the thrust bearing and radial bearing is made shorter.

Submersible motor

A submersible pump adapted to pump out the liquid in a reservoir has a built-in control unit for alternate pump operation. The control unit includes step memory means which provides a signal to permit the starting of pump operation every other time a high liquid level sensor senses the liquid. Once started, the pump continues its operation until the liquid level drops below a low liquid level sensor. The submersible pump can be combined with an additional pump having a conventional control unit in which case the two pumps are alternately operated.

Growing community of inventors

Kanagawa, Japan

Minoru Iwata