371results about How to "Reduce magnetism" patented technology

A stator includes a bracket having a shaft bearing portion at a center, a stator base including a flexible printed wiring board outwardly attached to the shaft bearing portion, single-phase air-armature coils disposed on the stator base, and a drive circuit member disposed on the stator base so as not to overlap with the single-phase air-core armature coils. The bracket has a through hole at the section corresponding to the bottom of the drive circuit member. The stator base is embedded at least partly in the thickness direction in the through hole and fixed using a resin, and a detent torque generation member is contained in, and is no thicker than, the stator base.

A method comprising: a first process of placing a laminated rotor core (13) in a preheating device (18) to preheat the laminated core (13); a second process of removing the preheated laminated core (13) from the preheating device (18) and disposing the laminated core (13) between upper and lower dies (14, 15) of a resin sealing apparatus (29); a third process of pressing the laminated core (13) by the upper and lower dies (14, 15) and liquefying resin material (17) in resin reservoir pots (16) by heating; and a fourth process of ejecting the liquefied resin material (17) from the pots (16) into the magnet insertion holes (12) by plungers (32) inserted and moving vertically in the pots (16) and thermally curing the resin material (17). The method improves efficiency of resin sealing the permanent magnets (11) in the laminated core (13).

The invention discloses a manufacturing method for a neodymium iron boron lanthanon permanent magnet device with a composite plated film. The manufacturing method includes the steps that an alloy is firstly smelted, and the alloy in a molten state is cast on a rotary copper roller with water cooling to form alloy sheets through cooling; hydrogen decrepitation is then performed, material is mixed after the hydrogen decrepitation, airflow grinding is performed after material mixing, the material is mixed through a mixing machine under the protection of nitrogen and then conveyed to a magnetic field orientation pressing machine protected by nitrogen to be formed, the formed material is encapsuled in a protection box and then taken out to be subjected to isostatic pressing, and then the pressed material is conveyed to sintering equipment for sintering to manufacture a neodymium iron boron lanthanon permanent magnet in a timeliness mode; the neodymium iron boron lanthanon permanent magnet is machined to obtain the neodymium iron boron lanthanon permanent magnet device, then the neodymium iron boron lanthanon permanent magnet device is plated with films, the plated films comprise the first magnetron sputtering plated layer with the thickness of 0.02 micrometer-5 micrometers, the second magnetron sputtering and ion plating mixed plated layer with the thickness of 1 micrometer-10 micrometers and the third magnetron sputtering plated layer with the thickness of 0.1 micrometer-5 micrometers. The composite plated films are adopted in the surface treatment process of the lanthanon permanent magnet device, not only corrosion resistance but also magnetic performance of the lanthanon permanent magnet device are improved.

A magnetic head for use in a perpendicular recording system having a novel shield structure that provides exceptional magnetic shielding from extraneous magnetic fields such as from a write coil, shaping layer or return pole of the write head. The magnetic head includes a write pole, a return pole and a magnetic shield that is magnetically connected with the return pole near the ABS and extends toward the write pole. The shield is formed with a notch at its edge closest to the write pole. The notch assures adequate physical, magnetic, and electrical separation between the write pole and the shield, while allowing un-notched portions of the shield to provide additional magnetic shielding.