JPH04178158A - Electric motor - Google Patents

Abstract

PURPOSE:To regulate the quantity of shifting of a driving pin within the specified range and besides, prevent it for interfering with a rotary yoke at the time of shifting of the driving pin by supporting, in the condition that it can shift, the driving pin capable of engagement with the window of the rotary plate of a magnetic disk. CONSTITUTION:This is equipped with a rotor 11, which has a rotary shaft 21 being releasably supported by a sintered oil-containing bearing 42 freely in rotation and rotates integrally with the rotary shaft 21 and on the outer periphery of which a ring-shaped driving magnet 25 to generate a magnetic field in radial direction are arranged, and a stator, which is positioned outside the rotor and on the iron cores 31 of which a plurality of coils 32 are wound, a driving pin 26, which can engage with the rotary plate of a magnetic disk, a plate spring 29, which consists of the elastic member supporting the driving pin 26 capable in shifting on the side opposite to the disk mounting face of the rotor, and a rotor yoke 24, which is incorporated in the rotor and has notch part 24a at the part opposed to the elastic deformed part of the plate spring 29.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric motor, and in particular to a recording device used in a device having a magnetic head for reading and writing magnetic recording signals on a magnetic disk, which is a disc-shaped recording medium. The present invention relates to an electric motor for driving rotation of a medium.

[Prior art] As a conventional electric motor of this type, Utility Model Application No. 60-13586
The technology published in Publication No. 3 can be mentioned.

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

In the figure, (1) is the rotating shaft of the electric motor, (2) is a rotating body that has a magnetic disk holding function;
) rotates integrally with the rotating shaft (1). (3) is the rotor of the electric motor, (4) is the yoke of the rotor (3), (
5) is a permanent magnet arranged on the outer periphery of the yoke (4), (
6) is the screw fixing the rotor (3) and the rotating shaft (1), (7) is the stator of the motor, and (8) is the stator (
7) is the iron core, (9) is the coil wound around the iron core (8),
(10) is a bearing mounting member, and (11) and (12) are bearings that are mounted on the bearing mounting member (11) and rotatably support the rotating shaft (1). (13) is the frame of the electric motor, (
14) is a screw fixing the stator (7) and the bearing mounting member (10), and (15) is a drive pin attached to the rotating body (2), and this drive pin (15) is a screw that fixes the stator (7) and the bearing mounting member (10). It engages with a window hole (not shown) in a rotary plate fixed to the rotary plate.

(16) is an index detection element disposed on the frame (13), (17) is an index detection magnet disposed on the rotor (3), and this index detection element (
16) and the index detection magnet (17) generate one pulse per rotation.

The electric motor with the above configuration has a rotor (3) on the outside of the stator (7).
The permanent magnet (5) of the rotor (3) generates a magnetic field in the radial direction of rotation.

[Problems to be Solved by the Invention] The conventional outer rotor type electric motor as described above requires a certain amount of space between the rotor (3) and the stator (7). Further, a frame (13) or a bearing mounting member (10) was interposed between the stator (7) and rotor (3) and the magnetic disk and magnetic head (not shown). Therefore, there is a limit to how thin the electric motor can be made. For this reason, it has been considered to create a thin inner rotor type electric motor in which the stator (7) is located outside the rotor (3).

However, in this type of electric motor, a drive pin is engaged with a window hole in a rotary plate fixed to the magnetic disk to drive the magnetic disk. Therefore, in order for the drive pin to engage with the window hole of the rotating plate of the magnetic disk, a special support mechanism is required to give the drive pin a certain degree of freedom and to attach it in a somewhat movable state. there was. However, if the amount of movement of this drive pin is too large, there is a problem that the drive pin cannot reliably engage with the window hole of the rotating plate of the magnetic disk. Adding a special support mechanism had the disadvantage of increasing the thickness of the electric motor.

Further, in this type of electric motor, a rotor yoke and a rotor made of a ferromagnetic material are integrally constructed in order to increase the magnetic flux density of the driving magnet.

However, depending on the shape of this rotor yoke, it interferes with the movement of the drive pin, so a predetermined interval is required, and there is also the problem that the thickness of the electric motor cannot be made very thin.

Therefore, this invention can regulate the amount of movement of the drive pin within a predetermined range, ensure the engagement of the drive pin with the window hole of the rotating plate of the magnetic disk, and have a thin structure that does not interfere with the rotor yoke when the drive pin moves. The objective is to provide a thin electric motor.

[Means for Solving the Problems] The electric motor according to the present invention includes a rotating shaft (21) that is rotatably supported, and a ring-shaped drive that rotates with the rotating shaft (21) and generates a magnetic field. a rotor on which a magnet (25) is disposed, a stator located outside the rotor and having a plurality of coils (32) wound around a stator core (31), and a rotating plate of a magnetic disk. a plate-like member made of an elastic material that supports the drive pin (26) in a movable state on the side of the rotor opposite to the disk mounting surface; A notch (24a
) and a rotor yoke (24).

[Function] In the present invention, the drive pin (26) capable of engaging with the window hole of the rotating plate of the magnetic disk is movably supported by a plate-like member made of an elastic material, and the drive pin (26) is movably supported by a plate-like member made of an elastic material. Since the rotor yoke (24) having the notch (24a) in the part facing the elastic deformation part is incorporated into the rotor, the drive pin (26) can be moved without having a special support mechanism. It can be elastically supported by the drive pin (2
6), the drive pin (26) and the plate-like member do not interfere with the rotor yoke (24), and the drive pin (26) and the plate-like member can be positioned very close to the rotor yoke (24).

[Example] Examples of each invention will be described below.

FIG. 1 is a sectional view showing an electric motor according to an embodiment of the present invention, and FIG. 2 is a plan view of a rotor of the electric motor according to an embodiment of the invention, viewed from the frame side.

In the figure, (21) is a rotating shaft of an electric motor, and (22) is a rotating body having a magnetic disk holding function, and this rotating body (22) rotates integrally with the rotating shaft (21). (2
3) is a disk mounting surface formed on the rotating body (22), (
24) is a rotor yoke embedded in the rotating body (22), (
25) is a driving magnet consisting of a permanent magnet arranged on the outer periphery of the rotor yoke (24), and (26) is a rotating body (
This drive pin is attached to the drive pin (22).
6) engages with a window hole (not shown) in a rotary plate fixed to the magnetic disk. (27) is a rotation speed detection surface that emits a magnetic field for rotation speed detection, and (28) is an index detection surface that emits a magnetic field for index detection. Note that the disk mounting surface (23), rotation speed detection surface (27), and index detection surface (28) are integrally molded with the rotating body (22). (29) is a plate made of an elastic material, and the tip (29a) of this plate spring (29) has a drive pin (26).
) is attached, and a notch (29b) is provided so that the drive pin (26) can be easily moved. Note that this leaf spring (29) is supported by a sliding portion (29c) interposed between the rotor (3) and the thrust surface of the bearing. This sliding part (29c) is connected to the leaf spring (29).
A through hole (29d) for inserting the rotating shaft (21) is bored in the center shaft. Further, the rotor yoke (24) is provided with a notch (24a) in order to avoid interference (54) with the rotor yoke (24) when the leaf spring (29) is elastically deformed. (31) is a stator core, (32) is a coil wound around the stator core (31), and the stator core (31) and coil (32) constitute the stator of the motor. . (40) is a steel plate frame that also serves as a circuit board, (41) is a frame (40
The bearing mounting member (42) installed in the rotor mounting hole (40c) of ) is a sintered oil-impregnated bearing that rotatably supports the rotating shaft (21). (47) is an index detection element disposed on the frame (40), which outputs an index detection signal by facing the index detection surface (28). (50) is a magnetic shielding plate made of a ferromagnetic electromagnetic shielding material such as an iron plate, and the stator core (31
) and covers the exposed portion of the rotor drive magnet (25) on the disk mounting surface (23) side.

The electric motor of this embodiment is constructed as described above, and the stator core (31) is capable of passing magnetic flux in the direction of the rotation radius of the electric motor. Iron core teeth are formed at 15 angles, and 15 coils (32) are wound around the iron core teeth. A concave portion is formed from the outer peripheral surface of the core to the inner peripheral surface at locations corresponding to the three core teeth, and the inner peripheral surface is connected by the core. This concave portion allows the magnetic head (not shown) to move without interfering with the stator. Further, the rotor driving magnet (25) located on the inner circumferential side of the stator has, for example, 24 equally divided N and S poles magnetized in the rotation radius direction of the rotor. 15 coils (32
) are wound in three phases every second, and are energized 120 degrees in accordance with the rotation angle of the rotor, generating rotational torque in a fixed direction.

As described above, the electric motor of this embodiment is an inner rotor type in which the stator is located outside the rotor, and the stator is formed with a concave portion for moving the magnetic head, unlike the conventional outer rotor type. Since the gap for avoiding interference between the stator and rotor and the magnetic disk and magnetic head can be omitted, as in the case of the electric motor, the thickness of the entire electric motor can be reduced.

Moreover, in this embodiment, the drive pin (26) that can engage with the window hole of the rotating plate of the magnetic disk is a leaf spring (26) made of an elastic material.
29), and a drive pin (26) attached to the tip (29a) of this leaf spring (29).
) is securely engaged with a window hole (not shown) in the rotating plate of the magnetic disk. Therefore, there is no need to add a special mechanism for movably supporting the drive pin (26).
The thickness of the electric motor does not become particularly thick. In addition, a notch (2
A rotor yoke (24) with 4a) is integrated into the rotor. Therefore, when moving the drive pin (26),
Drive pin (26), leaf spring (29) and rotor yoke (
24), and the drive pin (26) and leaf spring (29) can be positioned extremely close to the rotor yoke (24).

As mentioned above, the electric motor of this example has a sintered oil-impregnated bearing (
a rotating shaft (21) rotatably supported by 42);
A ring-shaped driving magnet (2) rotates integrally with the rotating shaft (21) and generates a magnetic field in the rotational radial direction on its outer circumference.
5), a stator located outside the rotor and having a plurality of coils (32) wound around a stator core (31), and a window hole in a rotating plate of a magnetic disk. a drive pin (26) that can be engaged with the drive pin (26), and a plate spring (29) made of an elastic material that supports the drive pin (26) in a movable state on the side of the rotor opposite to the disk mounting surface (plate-shaped member). and,
The rotor yoke (24) is incorporated into the rotor and has a notch (24a) at a portion facing the elastic deformation portion of the leaf spring (29) (plate-like member).

That is, in the electric motor of this embodiment, the drive pin (26), which can engage with the window hole of the rotating plate of the magnetic disk, is made movable by the plate spring (29') (plate-like member) made of an elastic material. A rotor yoke (24) that supports the rotor and has a notch (24a) at a portion facing the elastically deformable portion of the leaf spring (29) (plate-like member) is incorporated into the rotor.

Therefore, in this embodiment, the drive pin (26) can be moved appropriately by elastically supporting the drive pin (26) in a movable state without having a special support mechanism, and the leaf spring ( 29) has resilience, so
There is no error in the position of the drive pin (26), and the engagement between the drive pin (26) and the window hole (not shown) in the rotating plate of the magnetic disk can be ensured. In addition, the drive pin (26)
The drive pin (26) and leaf spring (29) do not interfere with the rotor yoke (24) during movement when the rotor yoke (24) sinks or sinks.
Since the motors can be located extremely close to each other, the thickness of the electric motor can be reduced.

As a result, a highly reliable and thin electric motor is obtained.

[Effects of the Invention] As described above, the electric motor of the present invention includes a rotatably supported rotating shaft, a rotor that rotates integrally with the rotating shaft,
a stator located outside the rotor; a drive pin that can engage with a window hole in a rotary plate of a magnetic disk; a plate-like member made of an elastic material that supports the drive pin; The rotor yoke is equipped with a rotor yoke, the drive pin is movably supported by a plate-like member on the side of the rotor opposite to the disk mounting surface, and the rotor yoke has a notch at a portion facing the elastic deformation part of the plate-like member. By incorporating the drive pin into the magnetic disk, the drive pin can be elastically supported in a movable state without the need for a special support mechanism, and the engagement between the drive pin and the window hole (not shown) in the rotary plate of the magnetic disk is facilitated. This can be done reliably, reliability is improved, and the drive pin and plate-like member do not interfere with the rotor yoke when the drive pin moves, and the drive pin and plate-like member can be positioned extremely close to the rotor yoke. The thickness of the electric motor can be reduced, resulting in a thin and thin electric motor.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an electric motor which is an embodiment of the present invention, Fig. 2 is a plan view of the rotor of the electric motor which is an embodiment of the invention as seen from the frame side, and Fig. 3 is a conventional electric motor. FIG. In the figure, 21: Rotating shaft 22: Rotating body 23: Disk mounting surface 24: Rotor yoke 24a: Notch 25: Drive magnet 26: Drive pin 29: Leaf spring 29a: Tip 29b: Notch 29c: Sliding part 2
9d: Through hole 31: Stator core 32 coils. In the drawings, the same reference numerals and the same symbols indicate the same or equivalent parts. Agent: Patent attorney Masuo Ohone and 2 others 24a: Notch 29c: Sliding portion 29d: Through hole

Claims (1)

[Scope of Claims] A rotary shaft rotatably supported; a rotor that rotates integrally with the rotary shaft and is provided with a ring-shaped driving magnet; and a rotor located outside the rotor and fixed thereto. a stator having a plurality of coils wound around a child core; a drive pin capable of engaging with a window hole in a rotating plate of a magnetic disk; and a drive pin movable on a side of the rotor opposite to the disk mounting surface. An electric motor comprising: a supporting plate-like member made of an elastic material; and a rotor yoke that is incorporated into the rotor and has a notch at a portion facing the elastically deformable portion of the plate-like member.