JPH0797896B2 - 2-phase step motor - Google Patents

Description

Description: TECHNICAL FIELD The present invention is used for OA equipment, FA equipment and the like, and has a rotor having a permanent magnet disc and a magnetic pole tooth of a stator displaced by π / 2 in electrical angle. The present invention relates to a two-phase stepping motor of a type opposed to each other.

[Background Art] In this type of two-phase stepping motor, a terminal plate as shown in Fig. 4 is generally used in order to easily draw out the terminal wire of the coil. In the figure, A is a rotor composed of a permanent magnet disc B and a rotor shaft C, D is an upper stator, E is a lower stator, F is a coil for each phase, G is a terminal plate, and H is an external lead wire. Is. The terminal board G is made of a printed wiring board in which conductive parts are printed and wired. The terminal board G has a ring plate shape, the coil F is placed on the terminal board G, and a protruding portion that partially projects from the upper stator D. G1 is formed. The conductive portion is formed to extend from a position where the terminal wire of the coil F can be connected to the protruding portion G1, and the external lead wire H is connected thereto.

With this structure, although the terminal wire of the coil F can be easily drawn out, the space of the coil F is restricted by the thickness of the terminal plate G, which is an obstacle to the thinning of the motor. It was

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a two-phase stepping motor capable of increasing the space of the coil and making it possible to reduce the thickness. .

DISCLOSURE OF THE INVENTION A two-phase step motor according to the present invention includes a rotor, an upper and lower stators, and a coil, in which an upper stator has a cylindrical shape with a bottom and a lower stator has a disk shape. In a two-phase step motor that is coupled so as to close the opening of the upper stator, a wire that holds the external lead wire and the terminal wire of the coil by providing a protruding portion that protrudes from the outer periphery of the upper stator on a part of the lower stator. A holding member is attached to the protruding portion.

According to the present invention, since the coil and the terminal plate do not overlap with each other as in the conventional case, the space of the coil can be increased, and accordingly, the reduction in the thickness can be dealt with.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

Reference numeral 1 denotes a rotor, which comprises a permanent magnet disc 2 and a rotor shaft 3.
This permanent magnet disc 2 has different poles (N pole, S pole) at equal intervals in the circumferential direction.
Poles) are alternately magnetized, and in this embodiment, two poles are formed in the thickness direction, that is, different poles (N pole, S pole) in the thickness direction.
Is magnetized to exist. The permanent magnet disc 2 is attached to the rotor shaft 3 via the bush 4.

Reference numeral 5 denotes an upper stator made of a magnetic material, which has a cylindrical shape with a bottom as a whole, and a center of a bottom portion 5a is slightly projected for bearing mounting, and an insertion hole 5b through which the rotor shaft 3 is inserted. Is provided. Further, the bottom portion 5a has four magnetic pole tooth group forming portions 5c and 5d which are squeezed inward substantially symmetrically in the circumferential direction. The magnetic pole tooth group forming portions 5c and 5d are squeezed out to a position where a predetermined gap is present with respect to the permanent magnet disc 2, and a large number of magnetic pole teeth 5e corresponding to the poles of the permanent magnet disc 2 are formed at the tips thereof. Therefore, the magnetic pole tooth group forming portions 5c and 5d constitute magnetic pole tooth groups 5g and 5h. The formation of the magnetic pole teeth 5e is specifically obtained by cutting off between the adjacent magnetic pole teeth 5e. The magnetic pole tooth groups 5g and 5h are positioned so as to be deviated from each other by an electrical angle of π / 2. 5j is a notch for joining, and 5k is a notch for inserting a wire holding member described later.

Reference numeral 6 denotes a lower stator made of a magnetic material, which is generally disc-shaped, and has a peripheral wall 6a for mounting a bearing at its inner center and an insertion hole 6b at the center for inserting the rotor shaft 3 therein. It is provided. The lower stator 6 has a magnetic pole tooth group forming portion of the upper stator 5.
The magnetic pole tooth group forming portions 6c, 6d corresponding to 5c, 5d are similarly squeezed out, and a large number of magnetic pole teeth 6e are formed in the same manner.Therefore, the magnetic pole tooth group forming portions 6c, 6d are provided with the magnetic pole tooth groups 6g, 6h. Constitute. The magnetic pole tooth group formation portions 6c and 6d are squeezed deeper than those of the upper stator 5 because of the coil winding described later. Further, a part of the outer periphery of the lower stator 6 has a protrusion 6j protruding from the outer periphery of the upper stator 5.
Is provided. 6k is a coupling protrusion.

7 and 8 are bearings mounted on the upper and lower stators 5 and 6, and 9 and 10 are magnetic pole tooth groups.
It is a coil of each phase wound around 6g and 6h.

The upper and lower stators 5 and 6 are joined together so that the lower stator 6 closes the opening of the upper stator 5, thereby supporting the rotor shaft 3 and mutually providing an electrical angle of π / 2. The displaced magnetic pole tooth groups are arranged so as to face each other with the permanent magnet disc 2 interposed therebetween. Reference numeral 11 is a washer for adjusting the gap between the permanent magnet disc 2 and each magnetic pole tooth 5e, 6e.

A wire holding member 12 made of plastic includes a fitting portion 12a for fitting with the protruding portion 6j of the lower stator 6, a holding slit 12b for the external lead wire 13, and a slit 12c for holding the terminal wires of the coils 9 and 10. ,
Recess 12 for connecting the external lead wire 13 and the terminal wires of the coils 9 and 10
consists of d. In this embodiment, each of the slits 12b and 12c holds four lines, that is, two lines of each phase. Therefore, the terminal wires of the coils 9 and 10 are internally branched and connected. When the wire holding member 12 is attached to the projecting portion 6j by press fitting or bonding, the inner end thereof is located near the inner peripheral surface of the cylindrical portion of the upper stator 5.

Such a two-phase stepping motor is driven according to a general two-phase coil excitation type driving principle.

In this embodiment, the permanent magnet disk of the rotor has been described as being magnetized in two stages in the axial direction, but it may be magnetized in one stage and the upper and lower magnetic pole tooth groups are displaced by a predetermined angle.

[Effects of the Invention] A two-phase step motor of the present invention comprises a rotor, upper and lower stators, and a coil, wherein the upper stator has a bottomed cylindrical shape and the lower stator has a disk shape. In a two-phase step motor that is coupled so as to close the opening of the upper stator, a wire that holds the external lead wire and the terminal wire of the coil by providing a protruding portion that protrudes from the outer periphery of the upper stator on a part of the lower stator. Since the holding member is attached to the projecting portion, the coil and the terminal plate do not overlap with each other as in the conventional case, so that the space of the coil can be increased, and the thinning can be realized. .

[Brief description of drawings]

1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is an exploded perspective view thereof, FIG. 3 is a perspective view of a line holding member thereof, and FIG. 4 is a vertical section showing a conventional example. It is a side view. 1 ... Rotor, 2 ... Permanent magnet disk, 3 ... Rotor shaft,
5 ... Upper stator, 5e ... Magnetic pole teeth, 5g, 5h ... Magnetic pole tooth group,
6 ... Lower stator, 6e ... Magnetic pole teeth, 6g, 6h ... Magnetic pole tooth group, 6
j …… Projection part, 9,10 …… Coil, 12 …… Line holding member, 13
...... External lead wire.

Claims (1)

[Claims] Claim: What is claimed is: 1. A rotor comprising permanent magnet disks having different poles magnetized at equal intervals in the circumferential direction, the rotor shaft being attached to the rotor shaft, and the rotor shaft supporting the rotor shaft and having an electrical angle of π / 2. An upper and lower stator in which magnetic pole tooth groups displaced from each other are disposed so as to face each other with the permanent magnet disc sandwiched therebetween; and a coil wound around the magnetic pole tooth group of any one of the stators, In a two-phase step motor in which the upper stator has a cylindrical shape with a bottom and the lower stator has a disk shape and is coupled so as to close an opening of the upper stator, the upper stator is partially attached to the lower stator. A two-phase step motor having a projecting portion projecting from the outer periphery of a child, and a wire holding member for holding an external lead wire and a terminal wire of the coil is attached to the projecting portion.