JP2528123Y2 - Linear DC motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a moving coil type linear DC motor used for transporting and accessing a recording / reproducing head for a magnetic disk, an optical disk, and a movable head card reader / writer. Things.

[Conventional technology]

FIG. 3 is a perspective view of a conventional linear DC motor, and FIG. 4 is a sectional view. In the figure, 1 is a drive coil, 2 and 2 'are permanent magnet plates, 3 is a center yoke, 4 and 4' are outer yokes, 5 is a coil holder, and 6 is a linear sliding system. The permanent magnet plates 2 and 2 ′ are magnetized in the thickness direction, and the magnetic poles are arranged so that the same poles face each other with the center yoke 3 interposed therebetween.

Here, when a current is applied to the coil 1, a left and right driving force is generated along the center yoke 3 according to the direction of the current according to Fleming's left-hand rule.

In the conventional linear DC motor, it is necessary to separately provide a linear sliding system 6 (for example, a linear bearing) in order to efficiently and highly accurately transmit the driving force generated in the coil 1 to the outside. For this reason, the coil 1 must be connected to the linear sliding system 6 via the coil holder 5, and there is a problem that the rigidity of the sliding system is reduced, reliability is reduced due to an increase in man-hours, and cost is increased. .

[Purpose of the invention]

The purpose of the present invention is to provide a separate linear sliding system externally by using the outer yoke, which is a part of the magnetic circuit of the linear DC motor, as a linear guide and allowing the movable table connected to the drive coil to slide. An object of the present invention is to provide a compact, high-precision, and inexpensive linear DC motor by reducing the number of components and reducing man-hours.

[Structure of device]

According to the present invention, at least one or more plate-shaped permanent magnets 2, 2 'magnetized in the thickness direction are arranged to face the plate-shaped center yoke 3 at a certain interval so that the same poles face each other. Yoke plates 4 and 4 'are provided outside the permanent magnets 2 and 2', and are magnetically short-circuited with the center yoke 3 to form a magnetic circuit. In a voice-coil type linear DC motor which is arranged and utilizes a reciprocating motion driving force generated when an electric current flows through the coil 1, at least one or more guide grooves 41, 41 are provided in the motor stroke length direction of the outer yokes 4, 4 '. '
Guide grooves 71, 71 'are formed in the movable table 7, which is linked to the drive coil 1, so that the guide grooves are formed in the outer yokes 4, 4'.
A plurality of steel balls 9 provided so as to face the same number as 41, 41 'and held at equal intervals by a retainer 8 are used to guide the guide grooves 41, 41' and 71, 71 on both the outer yoke side and the movable table side. ′
Is a linear DC motor inserted in the gap.

[Action]

When a direct current is applied to the drive coil 1, the movable table 7 reciprocates linearly with the outer yokes 4, 4 'as guides.

〔Example〕

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

FIG. 1 is a perspective view of the linear DC motor according to the present invention, and FIG. 2 is a sectional view.

1 and 2, 1 is a drive coil, 2 and 2 'are permanent magnets, 3 is a center yoke, 4 and 4' are outer yokes, 7 is a movable table, 41, 41 ', 71 and 71' are guides. The groove, 8 is a retainer, and 9 is a steel ball.

In the figure, a drive coil 1 surrounds a center yoke 3 and is arranged so as to be able to reciprocate. permanent magnet
2, 2 'are magnetized in the thickness direction, and are arranged at a constant interval so that the same pole faces the center yoke 3. The outer yokes 4, 4 'are provided on the outer side of the permanent magnet toward the center yoke 3, and are arranged so as to be magnetically short-circuited at the end with the center yoke 3 to constitute a magnetic circuit. The movable table 7 is connected to the drive coil 1 so as to be interlocked therewith, and is configured to be able to reciprocate at the same time when the drive coil 1 is energized. The outer yokes 4, 4 'and the movable table 7 are provided with guide grooves 41, 41' and 71, 71 ', respectively, so as to face each other, and retainers are provided in gaps between 41 and 71, 41' and 71 ', respectively. A plurality of steel balls 9 held at equal intervals by 8
The linear motor itself is configured as a compact and high-accuracy linear sliding system by using a part of the magnetic circuit for a linear guide.

[Effect of the invention]

As described above, in the linear DC motor according to the present invention, the movable table interlocking with the drive coil is configured to be slidable by using the outer yoke, so that, for example, a linear bearing is separately provided outside as a linear sliding system. This eliminates the necessity and reduces the number of components as a device using the linear DC motor, thereby reducing man-hours and providing a compact, high-accuracy, and inexpensive linear DC motor.

[Brief description of the drawings]

FIG. 1 is a perspective view of a linear DC motor according to the present invention. FIG. 2 is a sectional view of the linear DC motor according to the present invention. FIG. 3 is a perspective view of a conventional linear DC motor. FIG. 4 is a sectional view of a conventional linear DC motor. In the figure, 1: drive coil, 2, 2 ': permanent magnet, 3: center yoke, 4, 4': outer yoke, 5: coil holder, 6: linear sliding system, 7: movable table, 8: retainer, 9 : Steel ball, 41, 41 ': Guide groove (fixed side), 71, 71': Guide groove (movable side).

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-167669 (JP, A) JP-A-60-16335 (JP, A) Jpn.

Claims (1)

(57) [Scope of request for utility model registration] At least one plate-shaped permanent magnet magnetized in a thickness direction is opposed to a plate-shaped center yoke at a predetermined interval so that the same poles of the permanent magnets face each other. An external yoke is fixed outside the permanent magnet, the center yoke is magnetically short-circuited to form a magnetic circuit, a drive coil is arranged so as to surround the center yoke, and a current flows through the coil. A linear DC motor utilizing a reciprocating driving force generated when the motor is driven, wherein at least one or more guide grooves are provided in a motor stroke length direction of the outer yoke, and a guide is provided on a movable table connected so as to interlock with the drive coil. A plurality of grooves are provided so as to face the same number of guide grooves as the outer yoke, and a plurality of grooves held by retainers in the guide grooves provided in the outer yoke and the movable table. Linear direct current motor comprising placing a rigid sphere.