Mitsubishi Denki Kabushiki Kaisha

Hiroshi Inao

Mitsuhiro Nishida

Sakuei Yamamoto

Kiyonori Tokumitsu

Shigekazu Sakabe

Kiyoshi Hani

Noboru Tashiro

Takatoshi Ishikawa

Hidemi Komoda

Matao Matsushita

Sadahiro Kumamoto

A motor of the submersible type drives a pump immersible in liquids. The motor is provided with guide grooves formed on the motor bracket for guiding undesirable small particles falling by gravity onto the bracket away from the area near the motor shaft so that before an overabundance of undesirable small particles accumulates on a collar mounted on the motor shaft, the accumulated particles gravity fall into the guide grooves. By this arrangement the undersirable wear of the motor shaft and oil seals located between the motor shaft and the motor bracket is eliminated.

Submersible motor and pump assembly

A submerged electric motor has a molded bracket fitted into a hollow cylindrical molded member for a canned stator to cause an annular sealing member to abut against a radial front end surface connected to a cylindrical surface abutting against that of the molded member and another cylindrical surface connected to the front end surface on the bracket side and against an axial extension of the abutting cylindrical surface and a radial bottom surface connected to each other on the molded member side while a can disposed on the inner surface of the molded member has an extension radially outward bent so as to be sandwiched between the sealing member and the bottom surface.

Submerged electric motor

A submergible motor for use in a well of water, for example, comprises a motor winding, an insulated power supply conductor for connection to a power supply, an insulated motor conductor connected to the motor winding, and a circuit element electrically connected between the power supply and motor conductors, the circuit element being encased in a molded material in a water-resistant manner and connected to the power supply and/or motor conductors.

Submergible motor including circuit element encased in molded plug

A submerged electric motor comprises an outer hollow cylinder formed of a stainless steel, a stator iron core fixed on the inside of the outer cylinder, an annular end plate of a general structural rolled steel welded to an annular end portion formed between the outer hollow cylinder and an inner hollow cylinder coaxial with it by using a welding wire of the stainless steel. A combined deposit metal and fused portion underlaid with the end plate is machined to have an end surface flush with that of the end plate. A bracket is fixed to those end surfaces through bolts. Also a sheet-shaped soft sealing member may be interposed between the bracket and the machined end plate.

In an encased electric motor within a casing, an electrically insulating varnish is applied by vacuum impregnation to the inside surfaces of the casing and to the outer surface of the stator of the motor. The remaining empty space within the casing is filled with a heat conducting gas mixture comprising approximately 60-90% by volume of helium, with the remaining percentage being an electrically insulating gas having better electrically insulating properties than helium, such as sulphur hexafluoride. This encased motor is much lighter than conventional encased motors in which the stator enclosure is filled with a heat conducting resin potting compound and avoids warping damage which frequently occurs in conventional encased motors due to thermal expansion of the heat conducting resin potting compound.

Encased electric motor employing gas as heat dissipating means

A shaft seal device for a submersible motor, comprising a seal box which is provided at an end part of a case of the motor; a pair of lip type shaft sealing members which are disposed between an inner surface of said seal box and a rotary shaft of the motor and whose lips are arranged so as to inwardly face each other with a spacing therebetween; a lubricant which is stored in an interspace defined between said shaft sealing member; an auxiliary refuse remover which adjoins an outer side of one of said shaft sealing members and which is snugly inserted between the inner surface of an end part of said seal box and the rotary shaft of the motor, said auxiliary refuse remover being composed of a fitting and a soft material member which is received in said fitting and which is snugly positioned on the rotary shaft of the motor; and another refuse remover which is disposed so as to adjoin an outer side of said auxiliary refuse remover.

Growing community of inventors

Fukuoka, Japan

Hiroshi Inao