Abstract: Column which includes a first column with an upper layer of H2SO4 silica gel and a lower layer AgNO3 silica gel and a second column packed with alumina, connected detachably to a lower end of the first column. An oily liquid containing polychlorinated biphenyls, is added to the upper layer and heated. An aliphatic hydrocarbon solvent is supplied to the upper layer, whereby polychlorinated biphenyls captured by the first column are dissolved in the aliphatic hydrocarbon and then flow to the second column. The polychlorinated biphenyls are captured by the alumina which is located near the inlet of the second column, which is then detached from the first column. A hydrophobic solvent is passed through the second column in a direction opposite to the direction in which the aliphatic hydrocarbon was passed, providing an extract containing the polychlorinated biphenyls dissolved in a small amount of the hydrophobic solvent.

Abstract: A rotary shaft of a rotor including a magnet with a plurality of magnetic poles arranged at equal intervals on an outer circumference is supported at both ends by bearings. By externally fitting the inner ring of one bearing to the rotary shaft and holding it to be immovable in an axial direction and loosely fitting the outer ring of the bearing into the support hole and positioning it with belleville springs which are in contact resiliently with both sides, the rotary shaft and the rotor are supported so that they are movable in an axial direction within a movement amount of not greater than 2 mm according to a movement of the bearing caused against spring forces of the belleville springs.

Abstract: A column 1 is formed which includes a first column 10 in which an upper layer 14 made of sulfuric acid silica gel and a lower layer 15 made of silver nitrate silica gel are stacked and packed and a second column 20 packed with an alumina layer 23 and connected detachably to the lower end part of the first column 10. An oily liquid containing polychlorinated biphenyls, such as an electric insulating oil, is added to the upper layer 14 and then kept for a predetermined time in a state heated to at least 35° C. An aliphatic hydrocarbon solvent such as n-hexane is supplied to the upper layer 14 having been cooled to ordinary temperature. As a result, polychlorinated biphenyls captured by the first column 10 are dissolved in the aliphatic hydrocarbon solvent and then flows to the second column 20. The polychlorinated biphenyls are captured by that part of the alumina layer 23 which is located near the inlet of the second column 20. The second column 20 is then detached from the first column 10.

Abstract: A rotary shaft of a rotor including a magnet with a plurality of magnetic poles arranged at equal intervals on an outer circumference is supported at both ends by bearings. By externally fitting the inner ring of one bearing to the rotary shaft and holding it to be immovable in an axial direction and loosely fitting the outer ring of the bearing into the support hole and positioning it with belleville springs which are in contact resiliently with both sides, the rotary shaft and the rotor are supported so that they are movable in an axial direction within a movement amount of not greater than 2 mm according to a movement of the bearing caused against spring forces of the belleville springs.

Abstract: To treat an organotin compound in a liquid at low cost. Addition of iron oxide into a liquid containing an organotin compound allows trapping of the organotin compound in the liquid by the iron oxide, and reduction of the organotin compound concentration in the liquid. Various iron oxides such as FeO, Fe2O3(iron sesquioxide), and Fe3O4 (iron oxide black) may be used, but iron oxide black is preferred. Such the method of treating a liquid may be applied to polluted seawater at a harbor to allow reduction of the organotin compound concentration in the seawater and purification of the harbor.

Abstract: A bridge (8) in conformity with a tooth opening angle of the stator (1) is provided between a permanent magnet (5) and a permanent magnet (5) in a rotor (4), so that a magnetic flux for a reluctance torque is made to pass an inner side of the permanent magnet (5). An opening angle of each of ribs (7) on both sides of the permanent magnet (5) is set to be equal to or smaller than the teeth interval opening angle and equal to or larger than a half thereof. Thereby, reluctance of the rib (7) against a magnetic flux in a circumferential direction is increased and leakage of the magnetic flux of the permanent magnet (5) is prevented.

Abstract: To treat an organotin compound in a liquid at low cost. Addition of iron oxide into a liquid containing an organotin compound allows trapping of the organotin compound in the liquid by the iron oxide, and reduction of the organotin compound concentration in the liquid. Various iron oxides such as FeO, Fe2O3(iron sesquioxide), and Fe3O4 (iron oxide black) may be used, but iron oxide black is preferred. Such the method of treating a liquid may be applied to polluted seawater at a harbor to allow reduction of the organotin compound concentration in the seawater and purification of the harbor.

Abstract: A bridge (8) in conformity with a tooth opening angle of the stator (1) is provided between a permanent magnet (5) and a permanent magnet (5) in a rotor (4), so that a magnetic flux for a reluctance torque is made to pass an inner side of the permanent magnet (5). An opening angle of each of ribs (7) on both sides of the permanent magnet (5) is set to be equal to or smaller than the teeth interval opening angle and equal to or larger than a half thereof. Thereby, reluctance of the rib (7) against a magnetic flux in a circumferential direction is increased and leakage of the magnetic flux of the permanent magnet (5) is prevented.

Abstract: A brushless DC motor including a stator having plural slots; and a rotor which has plural permanent magnets and is divided into three rotor blocks in a rotation axis direction, the three rotor blocks being layered so that the arrangement angles of the rotor blocks differ from each other by an amount of a mechanical angle in a rotary direction that is equivalent to one third of a pulsation period of cogging torque generated by the rotor and stator. A brushless DC motor including a rotor having plural magnetic poles provided at an equal pitch in a circumferential direction by mounting permanent magnets in magnet mounting holes; and a stator having plural slots arranged at an equal pitch in a circumferential direction.

Abstract: A brushless DC motor including a stator having plural slots; and a rotor which has plural permanent magnets and is divided into three rotor blocks in a rotation axis direction, the three rotor blocks being layered so that the arrangement angles of the rotor blocks differ from each other by an amount of a mechanical angle in a rotary direction that is equivalent to one third of a pulsation period of cogging torque generated by the rotor and stator. A brushless DC motor including a rotor having plural magnetic poles provided at an equal pitch in a circumferential direction by mounting permanent magnets in magnet mounting holes; and a stator having plural slots arranged at an equal pitch in a circumferential direction.

Abstract: A bridge (8) in conformity with a tooth opening angle of the stator (1) is provided between a permanent magnet (5) and a permanent magnet (5) in a rotor (4), so that a magnetic flux for a reluctance torque is made to pass an inner side of the permanent magnet (5). An opening angle of each of ribs (7) on both sides of the permanent magnet (5) is set to be equal to or smaller than the teeth interval opening angle and equal to or larger than a half thereof. Thereby, reluctance of the rib (7) against a magnetic flux in a circumferential direction is increased and leakage of the magnetic flux of the permanent magnet (5) is prevented.

Abstract: A bridge (8) in conformity with a tooth opening angle of the stator (1) is provided between a permanent magnet (5) and a permanent magnet (5) in a rotor (4), so that a magnetic flux for a reluctance torque is made to pass an inner side of the permanent magnet (5). An opening angle of each of ribs (7) on both sides of the permanent magnet (5) is set to be equal to or smaller than the teeth interval opening angle and equal to or larger than a half thereof. Thereby, reluctance of the rib (7) against a magnetic flux in a circumferential direction is increased and leakage of the magnetic flux of the permanent magnet (5) is prevented.

Abstract: A brushless DC motor including a stator having plural slots; and a rotor which has plural permanent magnets and is divided into three rotor blocks in a rotation axis direction, the three rotor blocks being layered so that the arrangement angles of the rotor blocks differ from each other by an amount of a mechanical angle in a rotary direction that is equivalent to one third of a pulsation period of cogging torque generated by the rotor and stator. A brushless DC motor including a rotor having plural magnetic poles provided at an equal pitch in a circumferential direction by mounting permanent magnets in magnet mounting holes; and a stator having plural slots arranged at an equal pitch in a circumferential direction.

Abstract: A bridge (8) in conformity with a tooth opening angle of the stator (1) is provided between a permanent magnet (5) and a permanent magnet (5) in a rotor (4), so that a magnetic flux for a reluctance torque is made to pass an inner side of the permanent magnet (5). An opening angle of each of ribs (7) on both sides of the permanent magnet (5) is set to be equal to or smaller than the teeth interval opening angle and equal to or larger than a half thereof. Thereby, reluctance of the rib (7) against a magnetic flux in a circumferential direction is increased and leakage of the magnetic flux of the permanent magnet (5) is prevented.

Abstract: A brushless DC motor including a stator having plural slots; and a rotor which has plural permanent magnets and is divided into three rotor blocks in a rotation axis direction, the three rotor blocks being layered so that the arrangement angles of the rotor blocks differ from each other by an amount of a mechanical angle in a rotary direction that is equivalent to one third of a pulsation period of cogging torque generated by the rotor and stator. A brushless DC motor including a rotor having plural magnetic poles provided at an equal pitch in a circumferential direction by mounting permanent magnets in magnet mounting holes; and a stator having plural slots arranged at an equal pitch in a circumferential direction.

Abstract: A brushless DC motor including a stator having plural slots; and a rotor which has plural permanent magnets and is divided into three rotor blocks in a rotation axis direction, the three rotor blocks being layered so that the arrangement angles of the rotor blocks differ from each other by an amount of a mechanical angle in a rotary direction that is equivalent to one third of a pulsation period of cogging torque generated by the rotor and stator. A brushless DC motor including a rotor having plural magnetic poles provided at an equal pitch in a circumferential direction by mounting permanent magnets in magnet mounting holes; and a stator having plural slots arranged at an equal pitch in a circumferential direction.

Abstract: In a brushless DC motor constructed by a rotor 2 to which a permanent magnet 3 is attached; and a stator 1 having a plurality of slots, when an effective opening angle of magnetic pole of the rotor 2 that was set to a predetermined opening angle whose base is the rotation axis of the rotor 2 is &thgr;2 and a salient area opening angle of magnetic pole formed within the effective opening angle &thgr;2 of magnetic pole is &thgr;3, the opening angles &thgr;2 and &thgr;3 are set so that cogging torque generated by the effective opening angle &thgr;2 of magnetic pole and cogging torque generated by the salient area opening angle &thgr;3 of magnetic pole are mutually in antiphase. Accordingly, a brushless DC motor capable of reducing cogging torque is realized.

Abstract: A driving and controlling system for driving a shredding mechanism by a motor to shred paper sheets increases shredding capacity represented by the number of paper sheets that can be simultaneously shredded while limiting input current in an allowable range and reduces time necessary for shredding a predetermined number of paper sheets. The driving and controlling system comprises a motor (4) for driving a shredding mechanism (5) for shredding paper sheets (10), and a controller (1) interposed between the motor and a commercial power supply system (13) to control power to be supplied to the motor. The motor has a characteristic to reduce motor torque substantially linearly with the increase of operating speed for voltage applied thereto as a parameter.

Abstract: A bridge (8) in conformity with a tooth opening angle of the stator (1) is provided between a permanent magnet (5) and a permanent magnet (5) in a rotor (4), so that a magnetic flux for a reluctance torque is made to pass an inner side of the permanent magnet (5). An opening angle of each of ribs (7) on both sides of the permanent magnet (5) is set to be equal to or smaller than the teeth interval opening angle and equal to or larger than a half thereof. Thereby, reluctance of the rib (7) against a magnetic flux in a circumferential direction is increased and leakage of the magnetic flux of the permanent magnet (5) is prevented.

Abstract: In a brushless DC motor constructed by a rotor 2 to which a permanent magnet 3 is attached; and a stator 1 having a plurality of slots, when an effective opening angle of magnetic pole of the rotor 2 that was set to a predetermined opening angle whose base is the rotation axis of the rotor 2 is &thgr;2 and a salient area opening angle of magnetic pole formed within the effective opening angle &thgr;2 of magnetic pole is &thgr;3, the opening angles &thgr;2 and &thgr;3 are set so that cogging torque generated by the effective opening angle &thgr;2 of magnetic pole and cogging torque generated by the salient area opening angle &thgr;3 of magnetic pole are mutually in antiphase. Accordingly, a brushless DC motor capable of reducing cogging torque is realized.