Murata Manufacturing Co., Ltd.

Osamu Naito

Atsushi Yamamoto

Yuko Fujita

Akihiro Nakamura

Tomoyuki Ankyu

Hiroki Kowada

Miyuki Furuya

Yoichiro Ito

A coil conductor of each of a U-phase, a V-phase, and a W-phase is provided with a configuration in which a terminal wiring conductor, a first tooth conductor wound around a first tooth, a bridging line conductor, a second tooth conductor wound around a second tooth, and a neutral-point connection conductor are connected in this order. The terminal wiring conductor is connected to the first tooth conductor at an upper side of an insulator. The bridging line conductor is disposed on an upper side of the insulator disposed on a stator core and along an outer side portion of a tooth of another phase. The neutral-point connection conductor is connected to the second tooth conductor at a lower side of the insulator.

Stator assembly and method of assembling stator assembly

A brushless motor is provided that includes a rotor, a stator, a bearing member, an attraction magnet, and a yoke. The rotor includes a shaft, a rotor yoke that holds the shaft and covers a peripheral surface of the shaft, and a magnet disposed around an outer periphery of the rotor yoke. The stator is disposed around an outer periphery of the rotor. An inner wall of a housing serving as a bearing member rotatably holds the shaft with a bearing. The attraction magnet is disposed at an end portion of the inner wall at which the rotor yoke holds the shaft, and produces an attraction force to attract the rotor yoke. The yoke supplements and enhances the attraction force produced by the attraction magnet.

Brushless motor

A laminated coil component includes a magnetic body part made of a Ni&#x2014;Zn-based ferrite material and a coil conductor containing Cu as a main component, which is wound into a coil shape, and the coil conductor is embedded in the magnetic body part to form a component base. The component base is divided into a first region near the coil conductor and a second region other than the first region. The grain size ratio of the average crystal grain size of the magnetic body part in the first region to the average crystal grain size of the magnetic body part in the second region is 0.85 or less. The molar content of CuO in the ferrite raw material is set to 6 mol % or less, and firing is performed in a reducing atmosphere in which the oxygen partial pressure is an equilibrium oxygen partial pressure of Cu&#x2014;CuO or less.

Laminated coil component

A laminated coil component that has DC superimposition characteristics improved without causing an increase in direct-current resistance, and reduces stress which can be generated in a magnetic body. A laminated coil component includes a magnetic section of magnetic layers stacked and a conductor section which has a plurality of conductor pattern layers arranged between the magnetic layers, and interconnected in a coiled shape to pass through the magnetic layers, and which is buried in the magnetic section. The conductor section is composed of a conductor containing silver. The magnetic section is of a sintered ferrite material containing FeO, NiO, ZnO, and CuO. The ratio of the Cu content (in terms of CuO) in a near-conductor section region of the magnetic section to the Cu content (in terms of CuO) in a central region of the magnetic section is 0.2 to 0.5.

Laminated coil component and method for manufacturing same

A laminated coil component includes a magnetic body part made of a ferrite material and a coil conductor wound into a coil shape and embedded in the magnetic body part to form a component base. The component base is divided into a first region near the coil conductor and a second region other than the first region. The grain size ratio of the average crystal grain size of the magnetic body part in the first region to the average crystal grain size of the magnetic body part in the second region is 0.9 or less. The molar content of CuO in the ferrite raw material is set to 0.2 to 4 mol %. In a method laminated coil component, the coil is formed from a conductive paste including Ag, and firing the laminated body is performed by setting the oxygen concentration is 0.1 volume % or less as a firing atmosphere.

Laminated coil component, and method of manufacturing the laminated coil component

A layered coil component includes a coil that is constructed by layering coil conductor patterns and ceramic sheets. The ceramic sheets include a first ceramic sheet and a third ceramic sheet having a permeability lower than the permeability of the first ceramic sheet. The third ceramic sheet has an arrangement that is astride at least two of the coil conductor patterns adjacent to each other in a layering direction, in a section including a coil axis of the coil. As a result, DC bias characteristics of the open magnetic circuit type layered coil component are improved.

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Kyoto, Japan

Osamu Naito