Abstract: A turbo fan, formed by ultrasonic welding, a first component including: a flat portion; and plate-shaped blade portions standing from the flat portion, and a second component having recessed groove portions in each of which an end portion of the respective blade portion fits. The groove portions have a groove width greater than a thickness of the end portions of the blade portions. The turbo fan includes a group of positioning ribs partially burying two clearances created on two sides of the end portion in a thickness direction thereof, respectively, in a pre-welding state. The group of positioning ribs protrude in the thickness direction from the end portion of at least one of the blade portions, or from side surfaces of at least one of the groove portions, and are in contact with side surfaces of the groove portion, or in contact with the end portion of the blade portion.

Abstract: A turbo fan, formed by ultrasonic welding, a first component including: a flat portion; and plate-shaped blade portions standing from the flat portion, and a second component having recessed groove portions in each of which an end portion of the respective blade portion fits. The groove portions have a groove width greater than a thickness of the end portions of the blade portions. The turbo fan includes a group of positioning ribs partially burying two clearances created on two sides of the end portion in a thickness direction thereof, respectively, in a pre-welding state. The group of positioning ribs protrude in the thickness direction from the end portion of at least one of the blade portions, or from side surfaces of at least one of the groove portions, and are in contact with side surfaces of the groove portion, or in contact with the end portion of the blade portion.

Abstract: A holding structure includes a bearing holder including a cylindrical holder portion into which a ball bearing is internally fitted from one side in an axial direction of a shaft, and a positioning portion on another side in the axial direction of the holder portion and abutting on the ball bearing; and a mounting plate having a cylindrical mounting portion in which a portion of the holder portion is press-fitted. An inner surface of the holder portion includes an adhesion surface bonded to an outer peripheral surface of the ball bearing, a relief surface having an inner diameter larger than an inner diameter of the adhesion surface, and a step surface connecting the adhesion surface and the relief surface. An axial position of the step surface overlaps the ball bearing engaged to the bearing holder.

Abstract: A rotor applied to an inner rotor brushless motor includes: a rotor core having a laminate of a plurality of annular thin plate-shaped core pieces, the rotor core being configured to rotate together with a shaft in an integrated manner; a cylindrical resin magnet mounted on an outer peripheral surface of the rotor core via a gap; a groove-shaped adhesive admission portion in a straight line along the entire length of the rotor core in an axial direction thereof, the adhesive admission portion being recessed into the outer peripheral surface of the rotor core; and an adhesive configured to bond and fix the rotor core and the magnet. The adhesive is filled in an entire adhesive allowance having both of the gap and the adhesive admission portion between the outer peripheral surface of the rotor core and an inner peripheral surface of the magnet.

Abstract: To provide a brushless motor with a simple configuration, which has accomplished size reduction. An inner rotor brushless motor having a rotor in a center of a cylindrical stator includes: three bus bars on one end side of the stator in an axial direction thereof, the bus bars connecting three phase coils provided to the stator on a phase-by-phase basis; a bottomed tubular connector portion adjacent to a housing that houses the stator and the rotor; a plurality of connector terminals fixed, penetrating a bottom portion of the connector portion, the plurality of connector terminals being exposed to an internal space of the connector portion; and a board stretching from the one end side of the stator in the axial direction to the bottom portion side of the connector portion, the board being configured to electrically connect an end of each of the bus bars and the penetrating connector terminal.

Abstract: To provide a brushless motor with a simple configuration, which has accomplished size reduction. An inner rotor brushless motor having a rotor in a center of a cylindrical stator includes: three bus bars on one end side of the stator in an axial direction thereof, the bus bars connecting three phase coils provided to the stator on a phase-by-phase basis; a bottomed tubular connector portion adjacent to a housing that houses the stator and the rotor; a plurality of connector terminals fixed, penetrating a bottom portion of the connector portion, the plurality of connector terminals being exposed to an internal space of the connector portion; and a board stretching from the one end side of the stator in the axial direction to the bottom portion side of the connector portion, the board being configured to electrically connect an end of each of the bus bars and the penetrating connector terminal.

Abstract: Even in a case of a rotor having a thick laminate, avoidance of nonuniform adhesive application and an increase in quality is achieved with a simple configuration. A rotor applied to an inner rotor brushless motor includes: a rotor core having a laminate of a plurality of annular thin plate-shaped core pieces, the rotor core being configured to rotate together with a shaft in an integrated manner; a cylindrical resin magnet mounted on an outer peripheral surface of the rotor core via a gap; a groove-shaped adhesive admission portion in a straight line along the entire length of the rotor core in an axial direction thereof, the adhesive admission portion being recessed into the outer peripheral surface of the rotor core; and an adhesive configured to bond and fix the rotor core and the magnet. The adhesive is filled in an entire adhesive allowance having both of the gap and the adhesive admission portion between the outer peripheral surface of the rotor core and an inner peripheral surface of the magnet.

Abstract: A miniature motor includes a closed-bottomed cylindrical motor casing having a cylindrical bearing support portion projecting from a central portion of the bottom of the motor casing, a motor-casing-side bearing accommodated in the bearing support portion, a casing cover fitted to an open end portion of the motor casing, a casing-cover-side bearing accommodated in a central portion of the casing cover, and a rotor rotatably supported by means of the motor-casing-side bearing and the casing-cover-side bearing. The end face of the motor-casing-side bearing is concentrically polished at at least a portion which, when the rotor is urged toward the motor casing, abuts a washer provided on a shaft of the rotor. The above structure reduces sliding loss on the end face of an oil-impregnated bearing which receives a thrust load of the rotor generated due to rotation of the motor.

Abstract: A miniature motor includes a closed-bottomed cylindrical motor casing having a cylindrical bearing support portion projecting from a central portion of the bottom of the motor casing, a motor-casing-side bearing accommodated in the bearing support portion, a casing cover fitted to an open end portion of the motor casing, a casing-cover-side bearing accommodated in a central portion of the casing cover, and a rotor rotatably supported by means of the motor-casing-side bearing and the casing-cover-side bearing. The end face of the motor-casing-side bearing is concentrically polished at at least a portion which, when the rotor is urged toward the motor casing, abuts a washer provided on a shaft of the rotor. The above structure reduces sliding loss on the end face of an oil-impregnated bearing which receives a thrust load of the rotor generated due to rotation of the motor.

Abstract: A miniature electric motor comprises a housing, a cover plate fitted in an opening portion of the housing, a stator fixed to an inner circumferential surface of the housing, a rotor supported rotatably to one and the other bearing portions mounted on the housing and the cover plate, respectively, the rotor being disposed in the housing, and a brush holder holding brushes slidingly engaging with a commutator of the rotor, the brush holder being mounted on the cover plate. A first projection is formed in the vicinity of a center of the brush holder, and the first projection is forcibly pressed at a predetermined pressure against the cover plate. According to the present invention, without using any vibration proof elastic member, it is possible to reduce a noise of the miniature motor and keep the motor quiet. This motor is used for driving an air conditioner of an automobile, or the like.

Abstract: A miniature electric motor comprises a housing, a cover plate fitted in an opening portion of the housing, a stator fixed to an inner circumferential surface of the housing, a rotor supported rotatably to one and the other bearing portions mounted on the housing and the cover plate, respectively, the rotor being disposed in the housing, and a brush holder holding brushes slidingly engaging with a commutator of the rotor, the brush holder being mounted on the cover plate. A first projection is formed in the vicinity of a center of the brush holder, and the first projection is forcibly pressed at a predetermined pressure against the cover plate. According to the present invention, without using any vibration proof elastic member, it is possible to reduce a noise of the miniature motor and keep the motor quiet. This motor is used for driving an air conditioner of an automobile, or the like.

Abstract: An object of the present invention is to provide a material for a sliding contact whose alloy composition does not contain an environmentally detrimental substance such as Cd, which exhibits excellent contact resistance, whose electrical functions are good and free of time-course variation, and which further exhibits excellent wear resistance. The material for a sliding contact assumes the form of an Ag—Zn—Pd, Ag—Zn—Pd—Cu, Ag—Zn—Pd—Ni, or Ag—Zn—Pd—Cu—Ni alloy. In the compositions of these alloys, the Zn content is 0.1-3.0% by weight, the Pd content is 0.1-1.5% by weight, and the balance is Ag. When Cu is contained, the Cu content is 0.1-3.0% by weight. When Ni is contained, the Ni content is 0.01-0.5% by weight. Zn, Pd, and Cu are present in the Ag &agr; phase in the form of solid solution. Ni particles are finely dispersed in the alloys. A composite clad material is formed through use of the material for a sliding contact.

Abstract: A digital to analog converter having an improved conversion linearity is disclosed.The digital to analog converter comprises means for receiving an input digital signal (1), means for dividing the first digital signal to a plurality of digital signals (2, 3), a plurality of conversion means (8, 9) for converting the divided digital signals to analog signals, respectively, and means (10) for summing the analog signals to produce a summed analog signal corresponding to the input digital signal.