JPH0442761A - Motor - Google Patents

Abstract

PURPOSE:To thin a magnetic recorder by forming a recess lacking coils at one part of the periphery of the yoke of a stator. CONSTITUTION:Coils 6 are wound on consecutive fifteen iron core teeth, which are gotten by equally dividing the inside periphery of a yoke 3a, and the inner part of the yoke 3a corresponding to consecutive three iron core teeth is made as a bridging part 3b. That is, the outside periphery of the part laking in coils 6 of the yoke 3a is made as a recess 3c retreated inward. Magnetic heads 14 and 15 are provided capably in linear motion by sliding members on the supporting shaft being fixed through an attaching member 1 to the motor frame 4. At this time, the shifting lines of the magnetic heads 14 and 15 are aligned to the recess 3c of the yoke 3a, and the rotor 9, the stator 3, and the magnetic heads 14 and 15 are arranged on approximately the same level. Hereby, the thinning of the magnetic recorder can be attained easily.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an electric motor, particularly an electric motor that rotates a recording medium of a magnetic recording device having a magnetic head for reading and writing magnetic recording signals on a recording medium such as a disc-shaped magnetic disk. Regarding.

"Prior art" The above-mentioned conventional electric motor of this type is, for example, the Utility Model No. 6C1-1
The configuration is as disclosed in Japanese Patent No. 35863.

That is, as shown in FIG. 7113 and FIG. 8, a rotating shaft 31 to which a hub 30 for rotating the magnetic TiSF is fitted and fixed is fixed to a frame 32 via two bearings on the hub side and the opposite side. It is rotatably held by a bearing holter 33 having a shape. A stator 34 having a doughnut-shaped core is fixed to the outside of the bearing holder 33 with a frame 32 interposed therebetween by screws, and a coil 35 is wound around the core. Rotating shaft 31
A rotor 38 is constituted by a yoke 37 having a driving permanent magnet 36 fixed to its inner circumferential surface facing the stator 34 on the opposite end of the hub. The driving permanent magnet 36 generates magnetic force in the radial direction, and generates rotational torque by a current applied to a coil 35 wound around the iron core of the stator 34 . In the figure, reference numeral 39 is an index detection element constituting the index detection mechanism, and 40 is an index detection magnet also constituting the index detection mechanism.The index detection mechanism generates a -pulse signal in one rotation. Further, reference numerals 41 and 42 denote magnetic heads, which are attached to the frame 32 through a member and are fixed to a support shaft, and are configured to be capable of linear movement by a sliding member.

This type of electric motor has a rotor 38 disposed outside the stator 34.
is called an outer rotor type in which the index detecting magnet 40 is located, and the magnetic flux of the index detecting magnet 40 is transferred to the index detecting element 3.
Based on this detection, the energization of the coil 35 wound around the iron core of the stator 34 is controlled and driven to rotate.

[Problems to be Solved by the Invention] The conventional electric motor described above has a rotor 38 located outside and a magnetic head 14 that moves linearly in the radial direction with respect to the recording medium.
15 cannot be placed in the plane position of the rotor 38,
This includes issues such as the difficulty of making magnetic recording devices thinner.

The present invention was made to solve these conventional problems, and an object of the present invention is to obtain an inner rotor type electric motor that can contribute to making a magnetic recording device thinner.

[Means for Solving the Problems] An electric motor according to the present invention has a rotatably supported rotary shaft and a ring-shaped driving permanent magnet that generates magnetic force in the radial direction, and is integrated with the rotary shaft. The stator is equipped with a rotor that rotates by a rotor, and a stator that has a plurality of coils wound around an iron core and is disposed outside the rotor to generate rotational force in the rotor through magnetic action with a driving permanent magnet. A recessed portion lacking a coil is formed in a part of the outer periphery of the iron core.

Another electric motor of the present invention includes a rotatably supported rotary shaft, a ring-shaped driving permanent magnet that generates magnetic force in the radial direction, and a rotor that rotates integrally with the rotary shaft. A stator is provided with a plurality of coils wound around an iron core, and a stator is placed outside the rotor, which generates rotational force in the rotor through magnetic interaction with a driving permanent magnet. It is constructed in an almost C-shape.

[Function] In this invention, the stator is located on the outside,
Since a part of the stator core is retreated or opened in the radial direction, by aligning the movement line of the magnetic head with the recess or open part of the core, members such as the magnetic head can be moved within the plane of the rotor and stator. This makes it possible to reduce the thickness of the magnetic recording device.

[Example] Figures 1 to 3 show examples of the present invention.
This is an electric motor called an inner rotor type, which is located inside the rotor or stator and rotates with the rotating shaft. In FIGS. 1 to 3, a bearing body 2 that rotatably supports the rotating shaft 1 is vertically fitted and fixed to a flat motor frame 4 on which a stator 3 is attached. . The stator 3 is screwed onto the motor frame 4 at a concentric position with the bearing body 2 via a spacer 5, and a plurality of coils 6 are wound inside the iron core 3a. The coil 6 is wound around 15 consecutive core teeth obtained by dividing the inner circumference of the core 3a into 18 equal parts, and the inner diameter portion of the core 3a corresponding to three consecutive core teeth is a bridge. It is formed as a connecting portion 3b.

That is, the outer periphery of the portion of the iron core 3a where the coil 6 is missing is formed as a recessed portion 3C that recedes toward the inner periphery. The number of coils 6 is 3xm (m is a positive integer of 2 or more), and the number of missing coils is 3xn (a positive integer of 1 or more). Inside the stator 3, a rotor 9 is disposed, in which a ring-shaped rotor yoke 7 made of ferromagnetic metal is integrated with a hub 8 press-fitted into the rotating shaft 1, and the rotor 9 is fixed to the rotor 9. A ring-shaped driving permanent magnet 10 is mounted on the outer circumferential surface of the child 3 opposite to the inner circumferential surface. In the figure, reference numeral 11 indicates a thrust stopper attached to the side opposite to the hub of the rotating shaft 1, and reference numeral 12 indicates a drive bin provided on the hub 8.

In FIG. 4, the conditions for the number of coils 6 are the same as described above, and the iron core 3a corresponding to the missing coil is opened,
The iron core 3a has an approximately C-shaped planar shape with an open portion 3d, and FIG. 5 shows the stator 3 having its upper part and outer circumference covered with a magnetic shielding member 13. In any of the above-described embodiments, by forming a part of the iron core 3a into a recessed portion 3c or an open portion 3d, a significant unbalanced force is generated in the magnetic force acting in the radial direction with respect to the driving permanent magnet 10 of the rotor 9. Therefore, a force in a certain direction acts as a preload at all times on the bearing portion, and axial wobbling of the rotating shaft 1 is prevented.

In application to a magnetic recording device, as shown in FIG. 6, a magnetic head 14, 15 is provided so as to be linearly movable by a sliding member on a support shaft fixed to a motor frame 4 via a member. At this time, the movement line of the magnetic head 14, 15 is set to the iron core 3.
The rotor 9.a is aligned with the recess 3c or opening 3d of the rotor 9.a. The stator 3 and the magnetic heads 14, 15 are arranged substantially in the same plane. Thereby, the magnetic recording device can be easily made thinner.

[Effects of the Invention] As is clear from the above description of the embodiments, according to the present invention, the stator is located on the outside, and a part of the iron core of the stator is retreated or opened in the radial direction. Therefore, by aligning the movement line of the magnetic head with the recess or open portion of the core, members such as the magnetic head can be placed within the plane of the rotor and stator, contributing to thinning of the magnetic recording device.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an electric motor as an embodiment of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is an exploded perspective view of the electric motor, and Fig. 4 is an electric motor showing another embodiment. A plan view, FIG. 5 is a sectional view of a motor showing another embodiment, FIG. 6 is a sectional view of a motor applied to a magnetic recording device, and FIGS. 7 and 8 are sectional views of conventional motors. Figure and side view. In the figure, 1 is the rotating shaft, 3 is the stator,
3a is the iron core, 3C is the recessed part, 3d is the open part, 6 is the coil,
7 is a rotor yoke, 9 is a rotor, 10 is a driving permanent magnet, and 14.15 is a magnetic head. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa (and 2 others) Figure R415 Go to 1J Figure 1 Ward 1 Town Voluntary> 5. Column for detailed explanation of the invention in the specification to be amended. 6. “Magnetic head 14°15” on page 4, line 8 of the statement of contents.
The description of ``magnetic head 41, 42'' is corrected. 3. Relationship with the case of the person making the amendment Patent Applicant Address 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Mitsubishi Electric Corporation Representative Moriya Shiki 4 Proxy address Chiyoda-ku, Tokyo Marunouchi 2-2-3

Claims (2)

[Claims] (1) A rotor that has a rotatably supported rotary shaft, a ring-shaped driving permanent magnet that generates magnetic force in the radial direction, and rotates integrally with the rotary shaft, and a plurality of rotors on an iron core. In an electric motor equipped with a stator arranged outside the rotor, the stator is wound with a coil and generates a rotational force in the rotor through magnetic action with the driving permanent magnet. An electric motor characterized in that a part of the stator is retreated toward the inner periphery to form a recess, and a portion of the stator corresponding to the recess does not have the coil. (2) A rotor that has a rotatably supported rotary shaft, a ring-shaped driving permanent magnet that generates magnetic force in the radial direction, and rotates integrally with the rotary shaft, and a plurality of coils. In an electric motor including a stator disposed outside the rotor that generates rotational force in the rotor by magnetic action with the permanent driving magnet that is wound, a part of the iron core of the stator is opened. 1. An electric motor characterized in that the stator is formed into a substantially C-shape in plan view, and the stator in a portion corresponding to the open portion does not have the above-mentioned coil.