摘要:
A linear actuator for e.g. a disk drive has a fixed member and a movable member. One of those members carries at least one track of permanent magnets extending in the direction in which the movable member is to move, with adjacent permanent magnets having alternate magnetic polarity. The other member has first and second drive parts, each having at least one pair of opposing sets of teeth. The moveable member or each track passes between those teeth. Each pair of teeth is associated with a corresponding drive coil giving the teeth a magnetic polarity so that there is a magnetic alignment between a polarity of the teeth and the permanent magnets. The drive parts are arranged so that, for any given relative position of the first and second members, the magnetic alignment of the teeth of one drive part is out of phase with the magnetic alignment of the teeth of the other part. In order to ensure that the magnetic alignments are out of phase, there may be a physical displacement between the teeth of the two drive parts. This displacement may be (m.+-.1/2).multidot.T.sub.p, where m is an integer and T.sub.p is the teeth pitch. This gives a phase displacement of 180.degree.. Alternatively, the drive parts may be aligned, and two tracks of permanent magnets be provided with the magnets thereof having opposite polarity for a given track position, or the drive current to the drive coils may be controlled to be out of phase.
摘要:
A portable-type disk apparatus for a 3.5-inch or less optical disk implemented in a thin, light-weight and miniaturized structure having a vibration-withstanding capability. An optical head assembly is disposed stationarily while an optical disk and a spindle motor for rotating the optical disk are disposed movably in a diametrical direction of the optical disk. The spindle motor is constituted by a brushless motor of a substantially semi-circular form in cross section and having a laterally truncated portion. The optical head assembly including an optical head and a laser circuit is disposed at the side of the laterally truncated portion.
摘要:
A motor has a stator and a rotor, the stator having cores and drive coils which generate magnetic fields for rotating the rotor. The stator also has a yoke surrounding the rotor and the rotor is positioned such that it is closer to one part of the outer periphery of the yoke than another part of the outer periphery of the yoke. Such a motor is particularly suitable for use in a disk drive unit as a spindle motor for rotating the disk. Then an actuator for moving a head may be located adjacent the part of the outer periphery of the yoke which is closest to the rotor. This permits the head to approach closely the axis of rotation of the disk without the spindle motor interferring with the movement of the head. The continuous yoke prevents magnetic flux leakage from the spindle motor interferring with the actuator. The actuator may itself have a yoke integral with the yoke of the spindle motor, and/or other components in common.
摘要:
An electrostatic actuator includes a stationary element and a movable element. The stationary element has a surface which faces a surface of the moving element. Both the surface of the stationary element and the surface of the moving element have electrode lines disposed thereon, including a first set of parallel electrode lines and a second set of parallel electrode lines which are perpendicular to the lines in the first set. By facing the stationary surface and the movable surface towards each other such that the electrode lines of such surfaces are aligned, the movable element can be moved along either of two perpendicular axes when a voltage is applied to the electrode lines.
摘要:
The present invention comprises a stator, and a rotor which is disposed oppositely to the stator with a gap interposed. The stator comprises a stator core, and a distributed stator winding mounted to the stator core. The stator core comprises a ring-like yoke core, and a plurality of teeth cores which protrude from the yoke core in the radial direction. The rotor comprises a rotor core, and a plurality of permanent magnets embedded in the rotor core. A pair of non-magnetic portions is created inside the rotor core and on both sides of the circumferential width of a permanent magnet for one magnetic pole. In the rotor core located on the stator side of the pair of non-magnetic portions, a pair of magnetic paths is created as the result of the creation of the pair of non-magnetic portions. Furthermore, a groove or hole is created on the outer circumferential portion of the rotor core and between the adjacent magnetic poles.
摘要:
An object of the present invention is to provide an air cell which is capable of detecting that the upper end side and the lower end side of the air bag are nearer than a predetermined distance. This air cell has an air bag, a base member to which the lower end portion of the air bag is attached, an air chamber AR configured by the air bag and the upper surface of the base member, a thin film portion which forms the bottom surface of the air chamber and capable of deforming elastically in the up-and-down direction, an extending member configured to extend upwardly from the upper surface of the thin film portion, detecting means which is provided under the thin film portion and which detects downward deformation of the thin film portion.
摘要:
A wheel information-acquiring system (10) sends wheel information, such as a tire inner pressure, together with preset identification information from a transmitter provided on a wheel installed on a motor vehicle and causes a receiver to receive the transmitted information. In the wheel information-acquiring system, a setting device (60) transmits by wireless an ID, which the setting device is causing a transmitter (16a) to set, to the transmitter (16a) and causes the transmitter (16a) to set the ID. The setting device then transmits by wireless this ID and wheel installation position information, which is separately set and input, to the receiver, causing the receiver to map the ID and the wheel installation position information and then set and register the result of the mapping. The setting device also can acquire an ID unique to the transmitter (16a) and transmit the ID and wheel installation position information to the receiver. The structure makes it possible that the installation position of a wheel having wheel information received by the receiver is reliably specified. Thus the system with excellent durability and the wheel installation position information-setting device that realizes the system are provided.
摘要:
An air cellular cushion according to one aspect of the present disclosure includes: a plurality of air cells; a sensor configured to detect an air cell collapsing to a bottom; a parameter measuring unit configured to measure a parameter indicating a collapse state of the air cell collapsing to the bottom; an indicator configured to output an indication; and a control unit configured to change the indication output from the indicator based on a parameter value measured by the parameter measuring unit.
摘要:
When the torque command value is zero, a set point of DC current for an inverter is calculated to obtain a difference between the set point and a detected DC current so that an error in magnetic pole position may be estimated and corrected. By correcting the magnetic pole position, unwanted power running and regenerative torque of the motor can be avoided and unnecessary charge or discharge to or from a battery can be prevented.
摘要:
The A phase stator and the A phase stator are opposed each other winding same phase coil thereat. The B phase stator and the B phase stator are opposed each other winding same phase coil thereat. The A phase stator and the A phase stator, and the B phase stator and the B phase stator sandwich the mover, respectively. The mover fixes the permanent magnets having small magnetized pitch on the both surfaces thereof. The permanent magnets on both surfaces of the mover comprises the first permanent magnets and the second permanent magnets. The first permanent magnets having one polarity and a predetermined interval each other along the longitudinal direction of the mover are fixed previously on the mover. The second permanent magnets are inserted to the intervals on the mover.