A flywheel apparatus that magnetically unloads a top rotor bearing is described. The apparatus includes a flywheel housing, a rotor with a vertical axis of rotation that includes a magnetic material, a magnet configured to apply a desired upward off-loading force along the vertical axis of rotation, an upper bearing connected to an upper shaft of the rotor, and a bearing housing disposed between the upper bearing and the flywheel housing that substantially prevents downward axial motion of the upper bearing. The magnet includes an electromagnet. A force sensor is used to measure a force on the upper bearing which is provided as input to a controller that updates the current to the electromagnet. The rotor is maintained in a fixed axial position and a spring disposed below a lower bearing absorbs axial dimension growth of the rotor.

A flywheel system comprises a flywheel rotor comprising a rotor disc and a rotor shaft and has a longitudinal axis extending centrally through the rotor disc and the rotor shaft. The system further comprises a journal assembly configured to facilitate rotation of the flywheel rotor. The journal assembly comprises a sleeve having an aperture extending therethrough from a first end to a second, opposite end, a rod at least partially disposed within the aperture of the sleeve, and a nut coupled to a portion of the rod. The rod has a length greater than the sleeve such that a portion the rod extends axially beyond the first end of the sleeve. A method of forming the flywheel comprises coupling the rod to the rotor shaft and pulling the second end of the rod to tension the rod. The nut maintains the tension in the rod when coupled thereto.

A flywheel system comprises a flywheel rotor comprising a rotor disc and a rotor shaft and has a longitudinal axis extending centrally through the rotor disc and the rotor shaft. The system further comprises a journal assembly configured to facilitate rotation of the flywheel rotor. The journal assembly comprises a sleeve having an aperture extending therethrough from a first end to a second, opposite end, a rod at least partially disposed within the aperture of the sleeve, and a nut coupled to a portion of the rod. The rod has a length greater than the sleeve such that a portion of the rod extends axially beyond the first end of the sleeve. A method of forming the flywheel comprises coupling the rod to the rotor shaft and pulling the second end of the rod to tension the rod. The nut maintains the tension in the rod when coupled thereto.

In an electric motor, a magnetic bearing generates an electromagnetic force between multiple permanent magnets and a coil and rotatably supports an other side of a rotation shaft in an axis line direction. The rotation shaft is configured to be capable of being inclined with a rotation center line using a bearing side of the rotation shaft as a fulcrum. An electronic control device controls a current that flows to the coil such that an axis line of the rotation shaft approaches the rotation center line due to a supporting force which is the electromagnetic force between the multiple permanent magnets and the coil. Accordingly, the rotation shaft is rotatably supported to be freely rotatable by a magnetic bearing and the bearing.

In an electric motor, a magnetic bearing generates an electromagnetic force between multiple permanent magnets and a coil and rotatably supports an other side of a rotation shaft in an axis line direction. The rotation shaft is configured to be capable of being inclined with a rotation center line using a bearing side of the rotation shaft as a fulcrum. An electronic control device controls a current that flows to the coil such that an axis line of the rotation shaft approaches the rotation center line due to a supporting force which is the electromagnetic force between the multiple permanent magnets and the coil. Accordingly, the rotation shaft is rotatably supported to be freely rotatable by a magnetic bearing and the bearing.

A magnetic bearing system for controlling magnetic coupling between a mobile carriage and a guideway and a method for controlling the magnetic bearing system. The magnetic bearing system includes at least one engine, which includes at least two poles, at least one permanent magnet and at least one coil. The engine is configured to be magnetically coupled to the guideway through at least one air gap.

A magnetic phonograph record stabilizer is configured to hold a phonograph record in a biased contact against a turntable. The stabilizer features a base which is engaged with a magnetic housing which is moveable from a first position where magnetic attraction biases the base toward the turntable. The magnetic housing is slidable to a second position eliminating the biasing from the magnetic flux so the stabilizer can be removed from the turntable.

A control method for a magnetic bearing includes following steps: acquiring a suspension stopping instruction for the magnetic bearing, and respectively applying a control current to one or more control coils of the magnetic bearing to subject a rotor to a vertically or obliquely upwards electromagnetic force, a vertical component of the electromagnetic force is less than the gravity of the rotor. A control device for a magnetic bearing is also disclosed, including a suspension stopping instruction acquiring unit and a control current applying unit. The control method and control device for a magnetic bearing can control a falling velocity of the rotor to be lower than that of the rotor being subjected only to the gravity, and have higher control efficiency.

A control method for a magnetic bearing includes following steps: acquiring a suspension stopping instruction for the magnetic bearing, and respectively applying a control current to one or more control coils of the magnetic bearing to subject a rotor to a vertically or obliquely upwards electromagnetic force, a vertical component of the electromagnetic force is less than the gravity of the rotor. A control device for a magnetic bearing is also disclosed, including a suspension stopping instruction acquiring unit and a control current applying unit. The control method and control device for a magnetic bearing can control a falling velocity of the rotor to be lower than that of the rotor being subjected only to the gravity, and have higher control efficiency.

In a substrate stage, when a Y coarse movement stage moves in the Y-axis direction, an X coarse movement stage, a weight cancellation device, and an X guide move integrally in the Y-axis direction with the Y coarse movement stage, and when the X coarse movement stage moves in the X-axis direction on the Y coarse movement stage, the weight cancellation device move on the X guide in the X-axis direction integrally with the X coarse movement stage. Because the X guide is provided extending in the X-axis direction while covering the movement range of the weight cancellation device in the X-axis direction, the weight cancellation device is constantly supported by the X guide, regardless of its position. Accordingly, a substrate can be guided along the XY plane with good accuracy.