A magnetic bearing retains a rotatable shaft in a selected position by magnetic coupling between two circularmagnetic assemblies, one of which is connected to the shaft. Each magnetic coupling completes a magnetic circuit. Shaft rotation does not affect the magnetic circuit, but radial displacement of the shaft disrupts the magnetic circuit and increases magnetic reluctance. Increasing magnetic reluctance inhibits radial displacement. The shaft thereby supports a load while rotating freely, constrained to a selected position by forces of magnetic reluctance. A bearing may be employed to maintain gap distance between the magnetic assemblies.

A vacuum pump for rotary driving a rotor by a motor to perform vacuum pumping, wherein a motor rotor of the motor includes a yoke fixed to a shaft of the rotor, and a permanent magnet held at the yoke, and the yoke includes a holding portion provided apart from the shaft and configured to hold the permanent magnet, and a pair of fitting portions provided respectively at both ends of the holding portion in an axial direction and bonded to the shaft by fitting, and a radial thickness dimension of each fitting portion is set less than that of the holding portion.

A hard disk drive includes a base deck that is coupled to a cover, a motor assembly that is coupled to the base deck, and magnetic recording media that is coupled to the motor assembly. The motor assembly includes a magnetic bearing with a horizontal magnetic bearing component and a vertical magnetic bearing component.

A timepiece sub-assembly including a mobile timepiece element including first and second annular and opposite peripheral surfaces of revolution about a same pivot axis, and a device for guiding pivoting about a theoretical axis of a timepiece mechanism. The first surface is magnetically or electrically charged, and the device includes at least three first surfaces regularly arranged around the theoretical axis, oppositely magnetically or respectively electrically charged to the first surface to repulse it at a first interface. In a watch, the second surface is magnetically or electrically charged, and the device includes at least three second surfaces regularly arranged around the theoretical axis, oppositely magnetically or electrically charged to the second surface to repulse it at a second interface.

A bearingless hub assembly comprising a rim hollowed to receive a tube magnet, and magnets embedded around the circumference of the rim on both ends. The rim is capped by front and rear rim plates configured to hold the embedded magnets in place and fitted to receive respective circular magnets. Similar magnets in corresponding front or rear drive plate maintain space (i.e., levitation) vis-à-vis the front and rear rim caps by repelling each other, thus allowing the rim (and, as applied, a mechanically-attached tire assembly) to move freely with no friction. The front and rear drive plate carry forward and reverse electromagnetic actuators as well as forward and reverse levitation control units, power generators and speed sensors. These components mount 360 degrees around the circumference of the drive plates while the embedded magnets of the rim spin through when in motion.

In certain embodiments, apparatus for self-aligning elements of coupled platforms includes a radially repulsive magnetic bearing. The radially repulsive magnetic bearing includes a first axially polarized magnet and a second axially polarized magnet that is concentrically disposed around the first axially polarized magnet and radially repulsive to the first axially polarized magnet. The radially repulsive magnetic bearing is configured to align a first element of a first platform with a second element of a second platform when the first and second platforms are coupled together.

A flywheel device includes a base, a cantilever mounted on the base, a bearing seat mounted on the base, first magnetic members mounted on the base, a rotation shaft arranged between the cantilever and the bearing seat, a magnetically floating seat mounted on the rotation shaft, second magnetic members mounted on the magnetically floating seat and corresponding to the first magnetic members, third magnetic members mounted on the magnetically floating seat, a repulsion driver locked on the base and surrounding the magnetically floating seat, fourth magnetic members mounted on the repulsion driver and corresponding to the third magnetic members, and a flywheel unit mounted on the rotation shaft. The second magnetic members have a polarity the same as that of the first magnetic members. The fourth magnetic members have a polarity the same as that of the third magnetic members.

A bearingless hub assembly comprising a rim hollowed to receive a tube magnet, and magnets embedded around the circumference of the rim on both ends. The rim is capped by front and rear rim plates configured to hold the embedded magnets in place and fitted to receive respective circular magnets. Similar magnets in corresponding front or rear drive plate maintain space (i.e., levitation) vis-à-vis the front and rear rim caps by repelling each other, thus allowing the rim (and, as applied, a mechanically-attached tire assembly) to move freely with no friction. The front and rear drive plate carry forward and reverse electromagnetic actuators as well as forward and reverse levitation control units, power generators and speed sensors. These components mount 360 degrees around the circumference of the drive plates while the embedded magnets of the rim spin through when in motion.

A hard disk drive includes a base deck that is coupled to a cover, a motor assembly that is coupled to the base deck, and magnetic recording media that is coupled to the motor assembly. The motor assembly includes a magnetic bearing with a horizontal magnetic bearing component and a vertical magnetic bearing component.

A self-adjusting bushing bearing receivable within a housing to control movement of a shaft therein. Shaft magnet segments are configured to receive the shaft therein, where each shaft magnet segment has an inner portion having an inner polarity and an outer portion of the shaft magnet segments has an outer polarity that is opposite the inner polarity. Bearing magnet segments are configured to receive the shaft magnet segments therein, where each of the bearing magnet segments has an inner portion having an inner polarity and an outer portion of the bearing magnet segments has an outer polarity that is opposite the inner polarity. A springy element is disposed between the housing and the bearing magnet segments to bias the bearing magnet segments radially inwardly relative to the shaft magnet segments. The outer polarity of the shaft magnet segments is the same as the inner polarity of the bearing magnet segments so as to repel each other.