Abstract: A rotating electric machine system includes a rotor having a rotor plane. The rotor includes magnetic salient poles in a circumferential direction on the rotor plane. Adjacent magnetic salient poles are magnetized in different polarities from each other by a permanent magnet. A control magnet is arranged in an inside part of the adjacent magnetic salient poles. An excitation coil is placed so as to make an excitation flux collectively in the rotor. The magnetization state of the control magnet where the magnetic flux by the armature coils and the excitation flux flow in a same direction is changed irreversibly. An amount of the magnetic flux flowing through the armature coils is controlled by changing the magnetization state of the control magnet in accordance with an output of the rotating electric machine system so that the output is optimized.

Abstract: A rotor surface has magnetic salient poles and island-shaped magnetic poles alternately in circumferential direction, and the island-shaped magnetic pole is constituted so that a magnetic flux coming from an external source does not flow through. A magnetic excitation part magnetizes the island-shaped magnetic poles and the magnetic salient poles collectively in the same direction, and then control a flux amount flowing through an armature. The armature has armature coils that face the magnetic salient pole and the island-shaped magnetic pole simultaneously so that driving torque fluctuation or power generation voltage waveform distortion is controlled. The magnetic excitation part changes magnetization state of a field magnet irreversibly, or changes an excitation current to an excitation coil to control a flux flowing through the armature.

Abstract: In a magnet-exciting rotating electric machine system, a rotor surface has magnetic salient poles and island-shaped magnetic poles alternately in circumferential direction, and the island-shaped magnetic poles are constituted so that magnetic flux coming from an external source does not flow through. A magnetic excitation part magnetizes the island-shaped magnetic poles and the magnetic salient poles collectively in the same direction, and then control a flux amount flowing through an armature. The armature has armature coils that face the magnetic salient pole and the island-shaped magnetic pole simultaneously so that driving torque fluctuation or power generation voltage waveform distortion is controlled. The magnetic excitation part changes magnetization state of a field magnet irreversibly, or changes an excitation current to an excitation coil to control a flux crossing the armature.

Abstract: In a magnet-exciting rotating electric machine system, every magnetic salient pole group to be magnetized in a same polarity is collectively magnetized by a magnetic excitation part. In the magnetic excitation part, a main magnetic flux path in which a magnetic flux circulates through the armature and a bypass magnetic flux path are connected to the field magnet in parallel. Magnetic flux amount in each path is controlled by mechanical displacement. Thereby, the rotating electric machine system and the magnetic flux amount control method in which magnetic field control is easy are provided. Also, means and method are provided so that a power required for the displacement may be made small by adjusting magnetic resistance of the above magnetic flux path.

Abstract: A rotating electric machine system includes a rotor having a rotor plane. The rotor includes magnetic salient poles of more than one in a circumferential direction on the rotor plane. Adjacent magnetic salient poles are magnetized in different polarities from each other by a permanent magnet. A control magnet is arranged in an inside part of the adjacent magnetic salient poles. An excitation coil is placed so as to make an excitation flux collectively in the rotor. The magnetization state of the control magnet where the magnetic flux by the armature coils and the excitation flux flow in a same direction is changed irreversibly. An amount of the magnetic flux flowing through the armature coils is controlled by changing the magnetization state of the control magnet in accordance with an output of the rotating electric machine system so that the output is optimized.

Abstract: In a magnet-exciting rotating electric machine system, a rotor surface has magnetic salient poles and island-shaped magnetic poles alternately in circumferential direction, and the island-shaped magnetic poles are constituted so that magnetic flux coming from an external source does not flow through. A magnetic excitation part magnetizes the island-shaped magnetic poles and the magnetic salient poles collectively in the same direction, and then control a flux amount flowing through an armature. The armature has armature coils that face the magnetic salient pole and the island-shaped magnetic pole simultaneously so that driving torque fluctuation or power generation voltage waveform distortion is controlled. The magnetic excitation part changes magnetization state of a field magnet irreversibly, or changes an excitation current to an excitation coil to control a flux crossing the armature.

Abstract: A rotor surface has magnetic salient poles and island-shaped magnetic poles alternately in circumferential direction, and the island-shaped magnetic pole is constituted so that a magnetic flux coming from an external source does not flow through. A magnetic excitation part magnetizes the island-shaped magnetic poles and the magnetic salient poles collectively in the same direction, and then control a flux amount flowing through an armature. The armature has armature coils that face the magnetic salient pole and the island-shaped magnetic pole simultaneously so that driving torque fluctuation or power generation voltage waveform distortion is controlled. The magnetic excitation part changes magnetization state of a field magnet irreversibly, or changes an excitation current to an excitation coil to control a flux flowing through the armature.

Abstract: In a magnet-exciting rotating electric machine, a magnetic field pole part opposing an armature is composed to be divided into a surface magnetic pole part and a magnetic excitation part so as to be capable of being relatively displaced. The magnetic excitation part supplies a magnetic flux to a magnetic salient pole. The magnetic flux from the field magnet is divided into a main magnetic flux pathway that circulates through the armature side and a bypass magnetic flux pathway that does not pass through the armature, and thereby, the magnetic flux of the main magnetic flux pathway is changed. The magnetic resistances of the main magnetic flux pathway and the bypass magnetic flux pathway are composed so that total magnetic flux amount from the field magnet is maintained constant, and then a magnetic force preventing the relative displacement is maintained small.

Abstract: In a magnet-exciting rotating electric machine, a magnetic excitation part for supplying a magnetic flux between a magnetic salient pole and an armature is composed to be divided into two so as to be capable of being relatively displaced. In this structure, the magnetic flux from the field magnet is divided into a main magnetic flux pathway that passes through the armature side and a bypass magnetic flux pathway that does not pass through the armature, and thereby, the magnetic flux of the main magnetic flux pathway is changed. The magnetic resistances of the main magnetic flux pathway and the bypass magnetic flux pathway are composed to be approximately equal, and then a magnetic force preventing the relative displacement is suppressed small. Thereby, the rotating electric machine system and the magnetic field control method in which magnetic field control is easy are provided.

Abstract: In a magnet-exciting rotating electric machine system, every magnetic salient pole group to be magnetized in a same polarity is collectively magnetized by a magnetic excitation part. In the magnetic excitation part, a main magnetic flux path in which a magnetic flux circulates through the armature and a bypass magnetic flux path are connected to the field magnet in parallel. Magnetic flux amount in each path is controlled by mechanical displacement. Thereby, the rotating electric machine system and the magnetic flux amount control method in which magnetic field control is easy are provided. Also, means and method are provided so that a power required for the displacement may be made small by adjusting magnetic resistance of the above magnetic flux path.

Abstract: In a magnet-exciting rotating electric machine, a magnetic field pole part opposing an armature is composed to be divided into a surface magnetic pole part and a magnetic excitation part so as to be capable of being relatively displaced. The magnetic excitation part supplies a magnetic flux to a magnetic salient pole. The magnetic flux from the field magnet is divided into a main magnetic flux pathway that circulates through the armature side and a bypass magnetic flux pathway that does not pass through the armature, and thereby, the magnetic flux of the main magnetic flux pathway is changed. The magnetic resistances of the main magnetic flux pathway and the bypass magnetic flux pathway are composed so that total magnetic flux amount from the field magnet is maintained constant, and then a magnetic force preventing the relative displacement is maintained small.

Abstract: A fixed shaft type fluid dynamic bearing motor having two interfaces of a lubricant at least, in which a channel leading from near the outer region of a rotating sleeve top end to near the periphery of the bottom of the sleeve is formed in the sleeve. The lubricant near the outer region of a rotating sleeve top end is thrown out into the channel by centrifugal force, and further conveyed to near the periphery of the bottom of the sleeve by centrifugal force and/or by slanted channel in circumferential direction. A dynamic-pressure generating groove for pumping the lubricant toward the top end of the sleeve is formed between the fixed shaft and the sleeve. The dynamic-pressure generating groove and the centrifugal force cause the circulation of the lubricant, thereby sealing the lubricant. According to the invention, axial space smaller than that of tapered seals can be utilized to achieve a low-profile recording disk drive.

Abstract: A fixed shaft type fluid dynamic bearing motor having two interfaces of a lubricant at least, in which a channel leading from near the outer region of a rotating sleeve top end to near the periphery of the bottom of the sleeve is formed in the sleeve. The lubricant near the outer region of a rotating sleeve top end is thrown out into the channel by centrifugal force, and further conveyed to near the periphery of the bottom of the sleeve by centrifugal force and/or by slanted channel in circumferential direction. A dynamic-pressure generating groove for pumping the lubricant toward the top end of the sleeve is formed between the fixed shaft and the sleeve. The dynamic-pressure generating groove and the centrifugal force cause the circulation of the lubricant, thereby sealing the lubricant. According to the invention, axial space smaller than that of tapered seals can be utilized to achieve a low-profile recording disk drive.

Abstract: A fixed shaft type fluid dynamic bearing motor having two interfaces of a lubricating fluid, in which a channel leading from near the top end of the inner periphery of a rotating sleeve to near the periphery of the bottom of the sleeve is formed in the sleeve. The lubricating fluid near the top end of the inner periphery of the sleeve is thrown out into the channel by centrifugal force, and further conveyed to near the periphery of the bottom of the sleeve by centrifugal force and/or by slanted channel in circumferential direction. A dynamic-pressure generating groove for pumping the lubricating fluid toward the top end of the sleeve is formed between the fixed shaft and the sleeve. The dynamic-pressure generating groove and the centrifugal force cause the circulation of the lubricating fluid, thereby sealing the lubricating fluid. For bearing configuration, a cone bearing or a cylindrical bearing can be used to achieve a low profile.

Abstract: A single cone fluid dynamic bearing motor, including a shaft having a diminishing conical taper surface, a sleeve having a concavity opposite the shaft, lubricant filled in a clearance between the shaft and the sleeve, and magnetic members to generate magnetic attraction between the shaft and the sleeve. Grooves are formed on the conical taper surface of the shaft or the sleeve so as to create load capacity when the motor rotates, whereby rotating parts of the motor are supported by the axial components of the load capacity balanced with the magnetic attraction. The motor thereby achieves reduction in thickness, current, and cost, and inhibits non-repeatable runout.

Abstract: A single cone fluid dynamic bearing motor, including a shaft having a diminishing conical taper surface, a sleeve having a concavity opposite the shaft, lubricant filled in a clearance between the shaft and the sleeve, and magnetic members to generate magnetic attraction between one end of the shaft and a cone apex of the sleeve. Grooves are formed on the conical taper surface of the shaft or the sleeve so as to create load capacity when the motor rotates, whereby rotating parts of the motor are supported by the axial components of the load capacity balanced with the magnetic attraction. The motor thereby achieves reduction in thickness, current, and cost, and inhibits non-repeatable runout.

Abstract: A single cone air dynamic bearing motor, including a shaft having a diminishing conical taper surface, a sleeve having a concavity opposite the shaft, and magnetic members to generate magnetic attraction between the shaft end and the sleeve. Grooves are formed on the conical taper surface of the shaft or the sleeve so as to create load capacity when the motor rotates, whereby rotating parts of the motor are supported by the axial components of the load capacity balanced with the magnetic attraction. The motor thereby achieves reduction in thickness, current, and cost, and inhibits non-repeatable runout.

Abstract: A magnetic fluid bearing motor provided with a bearing assembly, the bearing assembly comprising a shaft, a substantially solid porous sleeve, magnetic fluid oil, and the like, wherein the shaft or the sleeve is formed of a ferromagnetic substance, and the surface of the shaft or the sleeve is locally magnetized such that the magnetization-varying portion is so arranged as to correspond to the bearing portion. Inside the porous sleeve is formed magnetic flux density gradient which is set at the maximum on the bearing surface, and thereby oil diluted with air bubbles is divided into dense and rarefied portions so as to retain a proper amount of oil with sufficiently high viscosity in the bearing portion. With the above stated structure, an inexpensive and long-wearing motor can be attained.