Mitsuba Corporation

Mitsuba Electric Manufacturing Co., Ltd.

Hirohiko Maekawa

Masashi Fukui

Hidetake Ota

Masaei Sato

Takayoshi Sakamoto

Yuichi Katayama

Yasuaki Nakazawa

A cooling fan of the present invention includes: a bottomed cylindrical boss portion; and a plurality of blades provided on an outer circumferential surface of the boss portion, the blades radiating in a radial direction, in which a ring member for connecting the blades with each other is provided on a side radially inner from tips of the blades. According to the present invention, it is possible to provide a cooling fan capable of preventing the worsening of the noise characteristic and also of enhancing the versatility even if the blades are made thinner.

Cooling fan

A drain structure for a fan motor prevents water from entering a discharge hole in the casing of the fan motor. A guiding passage is in opposed relation to the discharge hole and includes a front end portion covered by a fan boss section and an outer rib to prevent water from entering through the discharge hole into the casing. The guiding passage receives water discharged from the discharge hole. The discharge hole is formed in a lower portion of a casing cylindrical section. The casing cylindrical section is mounted on a fitting bracket for securement to a radiator.

Drainage structure of fan motor

A casing of a motor is rendered light and also capable of forming a magnetic circuit in cooperation with a permanent magnet. The casing consists of an outer cylinder and an end bracket each being made of aluminum. An inner cylinder, made of iron and carrying a permanent magnet fixed to the inner peripheral surface thereof, is integrally fitted on the inner peripheral surface of a cylindrical portion of the outer cylinder which is sealed by the end bracket.

Casing structure for motor

A waterproof structure for a fan motor comprising a vertical motor shaft projecting from the lower surface of a motor yoke and a fan boss portion which has a bottomed cylindrical shape formed by a bottom opposite to the lower surface of the motor yoke, an outer cylinder opposite to the outer periphery of the motor yoke and which is mounted on the motor shaft at the center thereof. The bottom of the fan boss portion, opposite to the lower surface of the motor yoke is partitioned by concentric circular ribs to form a plurality of enclosed rooms having floors which are successively lower in the direction toward the outer periphery and notches for allowing the adjacent enclosed rooms to communicate with each other are formed in the ribs in such a manner that the notches of the adjacent ribs are offset from one another so as to be placed on different radial lines. The structure produces a maze-like water guide passage for guiding water, which may enter the fan boss portion, from the inner to the outer enclosed rooms where drainage holes are formed in the floors of the enclosed rooms in the outermost periphery for the purpose of discharging the water guided thereto to outside of the fan boss portion. The waterproof structure thus provides excellent waterproofing capability that results in increased reliability of the fan motor.

Growing community of inventors

Kiryu, Japan

Hirohiko Maekawa