JPH01138993A - Disc driving gear - Google Patents

Abstract

PURPOSE:To prevent a device from being enlarged and reliability from being lowered even if the phase number of a synchronous motor is increased, by interrupting or shortcircuiting the DC output sides of a full-wave rectifier circuit respectively, synchronized with the energizing or energy-extinction of armature windings. CONSTITUTION:A switch 5 is closed, and the exciting coil 16e of a relay 16 is energized, and a change-over contact 16a is connected to a fixed contact 16u. When a variable frequency converter 3 is also energized and the alternating current of starting frequency is fed to the armature windings 1a, 1b, 1c of a synchronous motor 1, then a rotor comes to a previously set rotational speed. When the rotation of the synchronous motor 1 is stopped, then the switch 5 is opened, and the variable frequency converter 3 is energy-extinguished, and the feed of the alternating current to the armature windings 1a, 1b, 1c is stopped, and the exciting coil 16e of the relay 16 is energy- extinguished, and the change-over contact 16a is connected to a fixed contact 16x, and the DC output sides of a three-phase full-wave rectifier circuit 17 are short- circuited. Then, all the armature windings 1a, 1b, 1c are short-circuited via the three- phase full-wave rectifier circuit 17, and power generation braking is to be applied to.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disk drive device that is rotationally driven by a rotating field type synchronous motor using permanent magnets.

[Conventional technology]

FIG. 2 is a circuit diagram showing the configuration of a rotary drive portion of a conventional disk drive device similar to that shown in Japanese Patent Application No. 61-48939. In FIG. 0, (1) is a rotating field type 0 (la) (lb) (10) is a non-commutator type synchronous motor with a permanent magnet in the outer rotor and an armature winding in the inner stator. 1) is the three-phase armature winding; (2) is the rotor field of the synchronous motor (1) and the stator armature winding (1a);
) (from) A rotor position detector C3) detects a position signal corresponding to the phase relationship of (la) using a Hall element, and a rotor position detector C3) detects the position signal of the synchronous motor (1) based on the position signal detected by this rotor position detector. A variable frequency converter that outputs an alternating current with a rotational frequency and a frequency that is always periodic, (4) is a direct current vt,
m, (5) is a switch, (6) is a relay, (6a) (6
b) is the switching contact of this relay, (6・) is the excitation coil of the relay (6), (au) (6v) (ax) (6y
) is a fixed contact of the relay (6).

In the disk drive configured as described above, the switch (5) is first closed and the excitation coil (6) of the relay (6) is closed.
6 is energized to connect the switching contacts (aa) and (ab) to the fixed contacts (6u) and (6v), respectively, and the variable frequency converter (3) is also energized to convert the alternating current at the starting frequency into a synchronous electric @
When supplied to the armature windings (la), (lb), and (1o) of (1), the rotor using permanent magnets starts rotating and accelerates to reach a preset rotational speed. The field of the rotor of the synchronous motor (1) and the electrical prewinding of the stator 11 (1 &) (11)) (
The rotor position detector (2) detects a position signal corresponding to the phase relationship of 1G) and feeds it to the variable frequency converter (3).
The alternating current at a frequency that is always synchronized with the rotational frequency of the rotor is transmitted from the variable frequency converter (3) to the armature winding (1&).
(11)) (lo) and operate. Synchronous motor (1
) To stop the rotation of the armature windings (la) (l), open the switch (5), de-energize the variable frequency converter (3), and
b) Stop the supply of alternating current to (1,) and switch on the relay (
6), the excitation coil (6e) is deenergized and the switching contact (6a)
(ab) are connected to fixed contacts (ax) and (ay), respectively, and the three-phase armature windings (1m), (1b), and (lo) are all short-circuited to apply dynamic braking.

[Problem that the invention seeks to solve]

Conventional disk drives like the ones mentioned above use synchronous motors (
When the number of phases of 1) increases, the switching contacts (6&) (6b) and fixed contacts (6u) (6v) of the relay (6) increase accordingly.
Xat) (6y) must also increase and relay (6)
However, there were problems such as increased size, increased mounting space, and decreased reliability.

This invention was developed to solve the above-mentioned problems, and even if the number of phases of the synchronous motor increases, it also becomes larger.
Another object of the present invention is to obtain a disk drive device that does not reduce reliability. [Means for solving the problem] The disk drive device according to the present invention has a magnetic field generated by a permanent magnet of a rotor and a magnetic field generated by a permanent magnet of a rotor. A synchronous motor with multiple phases that converts direct current into alternating current with a frequency synchronized with the rotational frequency of the rotor based on a position signal corresponding to the phase relationship with the armature winding, and supplies the alternating current to the armature winding. A full-wave rectifier circuit with the same number of phases is provided, and the DC output side of the full-wave rectifier circuit is cut off and short-circuited in synchronization with energization and deenergization of the armature winding, respectively.

[Effect]

In this invention, the full-wave rectifier circuit energizes and energizes the armature winding.
In synchronization with de-energization, the DC output side is cut off and short-circuited, respectively.

[Embodiments of the invention]

FIG. 1 is a circuit diagram showing one embodiment of the present invention. In the figure (iL(la) t (it)) t (10)
, -(5) are completely the same as the above-mentioned conventional device. (to) is the relay, (16&) is the switching contact of this relay, (16・) is the excitation coil of the above relay ω, (16
u) (16 is a fixed contact of the above-mentioned relay (2), αη is a three-phase aftereffect rectifier circuit, and (17&) is a diode that constitutes this three-phase full-wave rectifier circuit.

In the disk drive configured as described above, first the switch (5) is closed and the excitation coil (2) of the relay (2) is closed.
166) to change the switching contact (16a) to the fixed contact (
1611) and also energizes the variable frequency converter (3) to supply alternating current at the starting frequency to the armature winding (xaXlb) (10) of the synchronous motor (1), the rotor using permanent magnets It starts rotating and accelerates to reach a preset rotation speed. A rotor position detector (2) detects a position signal corresponding to the phase relationship between the rotor field of the synchronous motor (1) and the stator armature winding (from 1&X) (lo), and a variable frequency converter (3) is fed back to the variable frequency converter (
3) to the armature windings (la), (lb), and (la) for operation. When stopping the rotation of the synchronous motor (1), the switch (5) is opened and the variable frequency converter (3) is deenergized to supply alternating current to the armature windings (la), (lb), and (io). At the same time, the excitation coil (16.) of the relay ω is deenergized, the switching contact (laa) is connected to the fixed contact (16x), and the DC output side of the three-phase aftereffect rectifier circuit αη is short-circuited. At this time, the armature windings (la), (lb), and (lo) are all short-circuited via the three-phase full-wave rectifier circuit α, and dynamic braking is applied.

〔Effect of the invention〕

As explained above, the present invention provides a full-wave rectifier circuit which is connected in parallel with the armature winding of a synchronous motor having a plurality of phases and has the same number of phases as the synchronous motor, and which energizes and deenergizes the armature winding. Since the DC output side of the full-wave rectifier circuit is synchronously cut off and short-circuited, there is an effect that even if the number of phases of the synchronous motor increases, there is no increase in size or deterioration in reliability.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing the configuration of a rotary drive portion of a conventional disk drive device. In the figure, (1) is a synchronous motor, (la) (lbXl
G) is armature winding, (2) is rotor position detector, (3)
is a variable frequency converter, (4) is a DC power supply, (5) is a switch, (to) is a relay, (16a) is a switching contact, (1
6-) is an excitation coil, (16u) and (16x) are fixed contacts, α is a three-phase full-wave rectifier circuit, and (1a) is a diode. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] Direct current is converted into alternating current at a frequency synchronized with the rotational frequency of the rotor based on a position signal corresponding to the phase relationship between the field generated by the permanent magnet of the rotor and the armature winding of the stator. A full-wave rectifier circuit connected in parallel with the armature winding and having the same number of phases as the synchronous motor is provided to rotate the armature winding. A disk drive device characterized in that the direct current output side of the full-wave rectifier circuit is cut off and short-circuited in synchronization with the energization and deenergization of the full-wave rectifier circuit.