JPH0722764Y2 - motor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a motor.

<Prior Art and Its Deficiencies> A motor for rotating a recording member such as an optical disc includes a housing, a hub member that is relatively rotatable with respect to the housing, a yoke member attached to the hub member, A permanent magnet fixed to the yoke member is provided. The recording member is located above the hub member and is held on the end surface of the hub member by the magnetic attraction of the permanent magnet.

However, in the conventional motor, there are the following problems related to the sticking of the permanent magnets. That is, when an adhesive (cyano-based adhesive) having a relatively short solidification time is used for fixing the permanent magnet, the work efficiency at the time of manufacturing the motor is improved, but the permanent magnet is removed from the yoke member due to vibration, shock, or the like. Easy to peel off. On the other hand, when an adhesive (acrylate-based adhesive) having a relatively long solidification time is used for fixing, the permanent magnet can be fixed to the yoke member with sufficient strength. Work efficiency decreases.

<Purpose of Invention> The present invention has been made in view of the above facts, and its main purpose is to provide an excellent motor capable of securely fixing a permanent magnet to a yoke member without impairing work efficiency. It is to be.

<Summary of Invention> According to the present invention, a housing, a hub member rotatable relative to the housing, a yoke member attached to the hub member, and a recording member fixed to the yoke member are provided. In a motor including a permanent magnet for magnetically holding the yoke member, the yoke member has a circular shape, and an annular protrusion is provided on the outer peripheral edge of the yoke member. The lower surface of the permanent magnet and the upper surface of the yoke member are housed in a defined space, and are fixed to each other by a first adhesive having a relatively short solidification time. Provided is a motor characterized in that the peripheral surface is fixed by filling a second adhesive having a relatively long solidification time and a large adhesive strength in a space defined between the both surfaces.

In such a motor, the first adhesive is interposed between the lower surface of the permanent magnet and the upper surface of the yoke member. The first adhesive has a relatively short solidification time, and therefore the permanent magnet and the yoke member are temporarily fixed in a short time by this first adhesive. The space defined by the outer peripheral surface of the permanent magnet and the inner peripheral surface of the annular protrusion of the yoke member is filled with the second adhesive. The second adhesive has a sufficient solidification time, but has a sufficient adhesive strength, so that the permanent magnet and the yoke member are firmly fixed by the second adhesive in a temporarily fixed state. Therefore, by using two kinds of adhesives having different properties, the permanent magnet can be fixed as required without impairing work efficiency.

<Specific Example of Device> A specific example of the motor according to the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, the illustrated motor includes a housing 2 having a hollow cylindrical shape. At one end (upper end) of the housing 2, a bracket portion 4 extending outward in the radial direction is attached to a device frame (not shown).

A shaft member 6 is rotatably disposed in the housing 2 via a pair of bearing members 8. The pair of bearing members 8 are maintained at a predetermined interval by the sleeve member 10 fitted on the shaft member 6. A hub member 12 having a substantially short cylindrical shape is fixed to one end (upper end) of the shaft member 6 by means such as press fitting.
The illustrated hub member 12 is a fixed boss portion fixed to the shaft member 6.
14 and an annular support portion 16 arranged outside the fixed boss portion 14.
And a circular connection portion 18 that connects the fixed boss portion 14 and the annular support portion 16, and the fixed boss portion 14, the annular support portion 16 and the connection portion 18 define an annular accommodation space having an open upper surface. . Then, the yoke member 20 and the holding permanent magnet 22 are arranged in the accommodation space thus defined. The yoke member 20 has a substantially circular shape, and an annular protrusion 24 is provided on the outer peripheral edge thereof.
Are provided integrally. The yoke member 20 is fixed to the fixed boss portion 14 of the hub member 12 by means such as press fitting. The permanent magnet 22 is fixed to the yoke member 20 (specifically, the inner portion of the annular protrusion 24) by an adhesive as described later, and is housed in the space defined by the annular protrusion 24 as required. A substantially cylindrical rotor 26 is fixed to the other end (lower end) of the shaft member 6. The rotor 26 includes a rotor yoke member 28 and the rotor yoke member 28.
The rotor magnet 30 fixed to the inner peripheral surface of the rotor yoke 30 is provided, and the inner peripheral end portion of the rotor yoke member 28 is fixed to the shaft member 6 by means such as press fitting.

A stator 32 is attached to the other end of the housing 2. The stator 32 is composed of a stator core 34 mounted on the outer peripheral surface of the housing 2 and an amateur coil 36 wound around the stator core 34.

A recording member 40 such as an optical disk is held by the hub member 12 as shown by the chain line. That is, the recording member 40 is located above the annular support portion 16 of the hub member 12, and is biased downward by the magnetic attraction action of the permanent magnet 22, and thus magnetically retained on the upper end surface of the annular support portion 16 of the hub member 12. To be done. Therefore,
When the rotor 32 rotates, the recording member 40 also integrally rotates via the shaft member 6 and the hub member 12.

Next, with reference to FIG. 2 as well as FIG. 1, a manner of fixing the permanent magnet 22 will be described.

In the motor according to the present invention, the permanent magnet 22 is fixed by two kinds of adhesives having different properties. That is, first, it is temporarily fixed by the first adhesive having a relatively short solidification time, and then securely fixed by the second adhesive having a strong adhesive strength. The first adhesive may be, for example, a cyano-based adhesive, and a commercially available product under the trade name “Loctite 405” can be used as an example. Such first
The adhesive is applied to one surface 22a (lower surface) of the permanent magnet 22 and placed on the yoke member 18, so that the lower surface of the permanent magnet 22 is temporarily fixed to the upper surface of the yoke member. When the cyano-based adhesive "Loctite 405" is used, the adhesive is solidified in 1 to 2 seconds, and therefore the permanent magnet 22 can be temporarily fixed quickly. The second adhesive may be, for example, an acrylate-based adhesive and has a trade name of “Hard Rock C-
323-03 "or" Loctite 648UV "commercially available can be used as an example. The second adhesive is a ring of the permanent magnet 22 and the yoke member 12 after the permanent magnet 22 is temporarily fixed. The space 42 existing between the protrusion 24 and the protrusion 24 is filled, and the filled adhesive is solidified, so that the outer peripheral surface of the permanent magnet 22 is inside the annular protrusion 24 of the yoke member 12, as shown in FIG. The acrylate adhesive "Hard Rock C-323-03" requires about 4 to 5 minutes for the adhesive to solidify, and therefore work only when such an adhesive is used. On the other hand, when the temporary fixing is performed with the cyano-based adhesive as in this example, the above-mentioned problem is completely solved, and the permanent magnet 22 has a sufficient strength without impairing the working efficiency. Can be glued with.

<Advantage of the Invention> According to the present invention, the permanent magnet 22 is securely fixed to the yoke member 20 by the second adhesive having sufficient adhesive strength after being temporarily fixed by the first adhesive having a relatively short solidification time. Therefore, the characteristics of the first adhesive and the second adhesive can be effectively used to securely fix the permanent magnet 22 without impairing the work efficiency in manufacturing the motor. it can.

[Brief description of drawings]

FIG. 1 is a sectional view showing a specific example of a motor according to the present invention. FIG. 2 is a partially enlarged cross-sectional view showing a hub member and its vicinity in the motor of FIG. 1 in an enlarged manner. 2 …… Housing 6 …… Shaft member 12 …… Hub member 20 …… Yoke member 22 …… Permanent magnet 26 …… Rotor 32 …… Stator

Claims (1)

[Scope of utility model registration request] 1. A housing, a hub member rotatable relative to the housing, a yoke member attached to the hub member, and a recording member fixed to the yoke member magnetically held. And a permanent magnet for operating the yoke member, wherein the yoke member has a circular shape, and an annular projection is provided on an outer peripheral circular portion of the yoke member, and the permanent magnet is formed by the annular projection of the yoke member. The permanent magnet is housed in a defined space, the lower surface of the permanent magnet and the upper surface of the yoke member are fixed by a first adhesive having a relatively short solidification time, and the outer peripheral surface of the permanent magnet and the yoke member are fixed. The motor is characterized in that the inner peripheral surface of the annular protrusion is fixed by filling a second adhesive having a relatively long solidification time and a large adhesive strength into a space defined between the two surfaces. .