JP2959166B2 - Brushless motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor which is effective for driving a rotary head cylinder device such as a magnetic recording / reproducing device.

[0002]

2. Description of the Related Art In recent years, brushless motors have been desired to be smaller and lighter.

A conventional brushless motor will be described below. FIG. 3 is a sectional view showing a structure of an example in which a conventional brushless motor is used in a rotary head cylinder device.

In FIG. 3, reference numeral 10 denotes a lower drum, which has two ball bearings 12 rotatably supporting a rotating shaft 14 and corresponds to a motor housing. A magnet 16 constituting a rotor 20 of the motor is adhered to the back yoke 17 on the rotating shaft, and a sub rotor 18 made of a magnetic material for constituting a magnetic circuit with the magnet 16.
Are opposed to each other with a predetermined gap by a collar 19.

[0005] A stator 22 is supported between the magnet 16 of the rotor 20 and the sub rotor 18 with a predetermined gap.

The stator 22 is formed by forming a coil (not shown) by chemical treatment such as etching or plating, is connected to a flexible rotary board 24 having a portion having the same shape as the stator 22, and is drawn out to a drive circuit.

When the stator 22 and the flexible circuit board 24 are fixed to the lower drum 10 with screws 28, a resin ring-shaped pressing member 30 is narrowed so that the stator 28 is not deformed by the screws 28.

The rotor 20 is fixed to the boss 32 via the spacer 26 by screws 34 so that the axial position of the stator 22 is substantially equidistant from the magnet 16 and the sub rotor 18 of the rotor 20.

Several kinds of spacers 26 having different thicknesses are prepared, the heights of the stator 22 and the boss 32 are measured, and the thickness is selected and adjusted according to the height variation. .

[0010]

However, the above-mentioned conventional configuration has the following problems.

It is necessary to make more spacers 26 than necessary, and there are many wasteful numbers.

At the time of assembling, the height of the stator 22 and the height of the boss 32 must be measured for each unit.

When the stator 22 is fixed to the lower drum 10, the holding member 30 is also fixed at the same time.
2 and the holding member 30 must be simultaneously positioned.

In order to prevent the surface of the stator 22 from oscillating, the flexible circuit board 24 must be attached to the entire surface of the stator 22, which increases the cost. Had many disadvantages.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a brushless motor having a stator unit having excellent assemblability.

[0016]

In order to achieve this object, a brushless motor according to the present invention comprises a housing for rotatably supporting a rotor of a motor having a permanent magnet, and a plurality of coils formed by chemical means such as plating or etching. in configuration
Is and the flat plate-shaped stator having a plurality of holes, comprising a conductive terminal for drawing the wires of the coils of the stator, a first surface in contact with the stator, the opposite surface of the first surface And a second side which is in contact with the housing.
A ring-shaped terminal means made of an insulating material having a plurality of protrusions on a surface of the first surface and a third surface opposite to the terminal means of the stator, and at least one recess on the third surface; Ring-shaped holding means made of an insulating material having
And a stay provided on a first surface of the terminal means and
Positioning protrusion penetrating through the holes provided in the holding means and the holding means.
It has a configuration with an opening.

[0017]

According to this structure, the parts constituting the stator are unitized, and not only the handling is excellent, but also the runout accuracy and gap accuracy of the rotor and the stator can be improved.

[0018]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing the structure of an example in which a brushless motor according to an embodiment of the present invention is used in a rotary head cylinder device, and FIG.

In FIG. 1 and FIG. 2, reference numeral 50 denotes a lower drum, and two ball bearings 5 rotatably supporting a rotating shaft 54.
2 and corresponds to a motor housing.

A disk 56 is fixed to the rotating shaft 54, and an upper drum 58 having a magnetic head 60 is fixed to the disk 56.

On the lower surface 62 of the upper drum 58, the upper drum 5
The rotor 64 for driving the rotation of the rotor 8 is fixed.

The rotor 64 has a magnet 66, a back yoke 68 for forming a magnetic circuit, and a resin yoke for maintaining a constant height of the magnet 66 in the axial direction. And a sub-rotor 72 configured to face with a predetermined gap.

The sub rotor 72 has an end surface of a spacer 76 formed by outsert molding on an iron plate 74 so that the back yoke 6
8 and a predetermined gap is obtained, and at the same time, the inner periphery of the spacer portion is aligned with the outer periphery of the rotary rotary transformer 78 for transmitting the signal from the magnetic head 60 in a non-contact manner and is centered. .

On the other hand, the rotor 64
A stator unit 82 is configured to support the stator 80 in a magnetic circuit including the magnet 66 and the iron plate 74 of the sub rotor 72.

The stator unit 82 has the structure shown in FIG. The stator 80 in which a plurality of coils (not shown) are formed by a chemical treatment such as etching or plating,
A resin terminal 86 having a terminal 84 for pulling out the wiring of the coil to the outside of the lower drum 50 is adhered to the lower surface, and the terminal 84 penetrating through the terminal hole 88 of the stator 80 is connected by means such as solder. .

On the upper surface of the stator 80, a resin holding ring 92 having a clearance 90 at a position facing the terminal 84 soldered through the terminal hole 88 of the stator 80,
Further, a shield ring 94 for blocking magnetic flux leakage from the magnet 66 is superimposed on the upper surface of the holding ring 92, and the positioning protrusion 9 provided on the terminal 86 is provided.
6 is heat-sealed through holes 98 provided in the stator 80, the holding ring 92, and the shield ring 94. As a result, the stator 80, the terminal 86, the press ring 92, and the shield ring 94 can be completely handled as a single stator unit 82.

The size of the stator unit 82 is T based on the upper surface 100 of the stator 80 in order to remove the runout of the stator 80, eliminate assembly errors, and keep the gap from the magnet 66 constant. Then, the seating surface 102 of the terminal 86 is processed. The seating surface 102 is partially provided at a plurality of locations (three locations in the present example), thereby obtaining the following effects.

The processing area is small. Even if the terminal 84 protrudes, it can be processed by using a milling cutter or the like.

[0030]

As described above, according to the present invention, the stator, the terminal, the holding ring, and the shield ring are provided by providing the terminal positioning projections and heat-sealing through the holes provided in the stator, the holding ring, and the shield ring. Can be treated as a stator unit, which is completely one part.

Further, by assembling the seating surface provided on the terminal with reference to the upper surface of the stator, the surface vibration of the stator is eliminated, the assembly error is eliminated, and the gap from the magnet becomes constant.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a rotary head cylinder device to which a brushless motor according to an embodiment of the present invention is applied.

FIG. 2 is a perspective view of a main part showing a brushless motor according to one embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional brushless motor.

[Explanation of symbols]

 Reference Signs List 80 Stator 82 Stator unit 86 Terminal 92 Pressing ring 94 Shield plate 96 Positioning protrusion 98 Hole

Claims (1)

(57) [Claims] 1. A housing for rotatably supporting the rotor of the motor having a permanent magnet, configured done and having a plurality of holes a plurality of coils by chemical means such as plating or etching
A flat plate-shaped stator having, comprising a conductive terminal for drawing the wires of the coils of the stator, a first surface in contact with the stator, a surface opposite the first surface,
A ring-shaped terminal means made of an insulating material having a plurality of projections on a second surface which is in contact with the housing, and a third surface which is opposite to the terminal means of the stator, Ring-shaped pressing means made of an insulating material having at least one concave portion on the surface of the third terminal;
The stator and the holding means provided on the first surface of
And positioning projections penetrating the holes provided in the
A brushless motor.