Abstract: An interior permanent magnet rotor restrains demagnetization of permanent magnets embedded in a core. Each permanent magnet is formed by joining a first portion and a second portion at a connection. The first and second portions extend from the outer side toward the inner side in the radial direction of the core. The outer end faces of the first and second portions in the radial direction of the core extend in an orientation direction as viewed in section perpendicular to the axial direction. The outside diameter of the core gradually increases from the boundaries between a single magnetic pole and magnetic poles adjoining the single magnetic pole toward the middle of the single magnetic pole in the circumferential direction of the core.

Abstract: A pump housing, a fixing member and a holding member are assembled in the axis direction of an oil pump to fix a stator and a rotor of a brushless motor. The holding member is made of metal material and has a cylindrical shape that extends from its bottom portion toward one side in the axial direction. The fixing member is a cylindrical metal member. Stepped portions, extending in the circumferential direction, are formed in the outer periphery of the holding member and the inner periphery of the fixing member, and contact each other. The outer periphery of the holding member engages with the inner periphery of the fixing member. The outer periphery of the other end portion of the fixing member is fitted to the inner periphery of a flange portion projecting from the end face of the pump housing, which is adjacent to the brushless motor.

Abstract: A radial magnetizing part including permanent magnets is disposed so as to face a rotor unit in a radial direction of the rotor unit. Axial magnetizing parts are disposed on both end faces in an axial direction of the rotor unit. The axial magnetizing parts include low magnetic permeability portions and high magnetic permeability portions. The low magnetic permeability portions are disposed so as to face magnet materials. Magnetic flux from the N pole of the permanent magnet of the radial magnetizing part enters a core in the radial direction, crosses the magnet material, and returns to the S pole of the permanent magnet. The magnetic flux from the N pole of the permanent magnet of the radial magnetizing part also enters the core through the high magnetic permeability portions of the axial magnetizing parts, crosses the magnet material, and returns to the S pole of the permanent magnet.

Abstract: A stator is fixedly fastened at its outer periphery by a cylindrical and thin metal collar. One end of the collar is engaged with a pump housing. Multiple metal nuts are embedded in insulators fitted to stator cores through insert molding. The stator of a brushless motor is fixed by screwing bolts passed through the pump housing from a pump plate, to nuts embedded in the insulators.

Abstract: In an internal gear pump that includes an inner gear having outer teeth and an outer gear having inner teeth, either the inner or outer teeth have a shape based on a tooth shape that is respectively formed by a generating curve of the outer or inner teeth. The inner teeth are arc-shaped, the outer teeth are curved-shaped, and both end sections of the curved shape are arc-shaped. If a radius of the arc shape of the inner teeth is set as ro, a radius of the arc shape of each of the corner sections is set as ri, a diameter of a pitch circle of the inner teeth is set as dp, and the number of the inner teeth is set as z, the inner gear and the outer gear each has a shape that satisfies a relationship established by following equations: 1.6>ro/(dp/z)>1.0; and ro/(dp/z)>ri/(dp/z)?0.13.

Abstract: The multi-stage reducer includes a first-stage reduction part to which the rotation from a motor is input and a second-stage reduction part to which the rotation having undergone speed reduction by the first-stage reduction part is input. The second-stage reduction part is disposed on an outer circumference of the first-stage reduction part.

Abstract: The multi-stage reducer includes a first-stage reduction part to which the rotation from a motor is input and a second-stage reduction part to which the rotation having undergone speed reduction by the first-stage reduction part is input. The second-stage reduction part is disposed on an outer circumference of the first-stage reduction part.

Abstract: The super finishing stone has such a shape that a width of an abrasive surface in a direction perpendicular to a radial direction becomes gradually narrower from outside to inside in the radial direction, when the raceway surface and the abrasive surface in contact with the raceway surface are seen at a plurality of sections perpendicular to the radial direction of the object to be worked, so that the abrasive surface and the raceway surface in contact with the raceway surface may intersect with each other at a constant angle at opposite side edges of the abrasive surface.

Abstract: The super finishing stone has such a shape that a width of an abrasive surface in a direction perpendicular to a radial direction becomes gradually narrower from outside to inside in the radial direction, when the raceway surface and the abrasive surface in contact with the raceway surface are seen at a plurality of sections perpendicular to the radial direction of the object to be worked, so that the abrasive surface and the raceway surface in contact with the raceway surface may intersect with each other at a constant angle at opposite side edges of the abrasive surface.

Abstract: When obtaining microcapusles by covering a hydrophobic material with an aminoaldehyde polycondensation product as a wall-forming material in an acidic aqueous medium containing an anionic water-soluble polymer, a microcapsule slurry having a high solid content and low viscosity can be obtained by using as the anionic water-soluble polymer a multi-component copolymer consisting as essential monomer components thereof of at least three types of acrylic monomers selected respectively from (A) acrylic acid and/or methacrylic acid, (B) acrylonitrile and/or methacrylonitrile and (C) an acrylamidoalkylsulfonic acid and/or sulfoalkyl acrylate. Over a wide pH range, the microcapsule slurry obtained in accordance with this invention undergoes little viscosity changes and exhibits neither destruction of its dispersed state nor coagulating tendency. Resulting microcapsules have a sharp particle size distribution and are equipped with dense wall films.

Abstract: When obtaining microcapsules by covering a hydrophobic material with an aminoaldehyde polycondensation product as a wall-forming material in an acidic aqueous medium containing an anionic water-soluble polymer, a microcapsule slurry having a high solid content and low viscosity can be obtained by using as the anionic water-soluble polymer a multi-component copolymer consisting as essential monomer components thereof of at least three types of acrylic monomers selected respectively from (A) acrylic acid and/or methacrylic acid, (B) acrylonitrile and/or methacrylonitrile and (C) an acrylamidoalkylsulfonic acid and/or sulfoalkyl acrylate. Over a wide pH range, the microcapsule slurry obtained in accordance with this invention undergoes little viscosity changes and exhibits neither destruction of its dispersed state nor coagulating tendency. Resulting microcapsules have a sharp particle size distribution and are equipped with dense wall films.