JP2008099351A - Stepping motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stepping motor employing a pancake type structure in which two stators of phases A, B integrated with a housing are disposed in a radius direction on the outer circumference of a rotor, and capable of being satisfactorily miniaturized while reducing the width of a terminal portion in the outer diameter of a motor and widening a terminal pitch as much as possible. <P>SOLUTION: The stepping motor has a structure in which the two stators Sa, Sb of phases A, B are disposed in a radius direction on the outer circumference of the rotor, constituents for the phases are housed in cylindrical housing 1a, 1b respectively, and opening portions 5a, 5b extending in an axial direction of the rotor from one end edge to the other end edge are provided on the outer circumference of the housing to form end edge portions 6a, 6b as predetermined portions fitting and protruding. A coil is formed by winding a wire around a bobbin, a winding end is drawn to the protruding portion of the flange of the bobbin to form a terminal portion of a doubly arranged terminal array, and it is positioned on an opening portion and disposed to be overlapped viewed from the axial direction of the rotor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a claw pole type stepping motor. More specifically, each component of an A-phase stator and a B-phase stator is radially arranged on the outer periphery of a rotor, and two excitation phases including a yoke and a coil are provided. In the arranged pancake structure, the present invention relates to an improvement in the arrangement of terminals provided protruding from a housing.

  One well known type of stepping motor is the claw pole type. This is a structure in which a large number of magnetic poles are arranged on the outer periphery of the rotor, and there are comb-like inductors (pole teeth) on the stator side so that the pole teeth are engaged with each other in the A phase and the B phase. Take. This type of motor is preferred because of its relatively good resolution and reduced manufacturing costs.

In a claw pole type stepping motor, as seen in Patent Document 1 and the like, a pair of a yoke integrated with a cylindrical housing concentrically on the outer periphery of a rotor and a coil provided with a terminal block are paired. There is known a stepping motor having a structure in which two excitation phases (A phase and B phase) are arranged (hereinafter referred to as “pancake structure”). FIG. 1 shows an example of a conventional stepping motor having a two-phase pancake structure, where (a) is a side view and (b) is a front view. Here, the coil is formed by winding a wire around a bobbin, and the winding end is drawn out to a protruding part of the flange of the bobbin to form terminal parts 100a and 100b. The phase components of the A phase and the B phase are housed in cylindrical housings 101a and 101b, respectively, and are connected to each other. The terminal portions 100a and 100b are provided on the outer periphery of the housings 101a and 101b. It is located in the notch portions 102a and 102b and protrudes somewhat from the outer diameter of the housing.
JP-A-8-322231

  The stepping motor has a use as a drive source of a drive mechanism such as a shutter or a lens in a digital still camera or a small camera of a mobile phone. In such applications, it is required to further reduce the motor outer diameter to make it ultra-small. In that regard, in the conventional configuration as described above, the terminal portions 100a and 100b of the coil are formed so as to protrude from the outer diameter of the housings 101a and 101b, and generally four terminals of A phase and B phase are provided in a row in the circumferential direction. Therefore, the array of terminals requires a predetermined wide width, which hinders miniaturization.

  That is, in recent years, the motor outer diameter has been reduced, but the terminal portion has not been made so small, and there is a problem that the proportion of the terminal portion in the motor outer diameter is relatively large. For this reason, in the application of the motor, there is an interference with a nearby component, and the arrangement of the components can be restricted, and the main body of the application apparatus becomes large.

  In addition, in the configuration in which four terminals of A phase and B phase are provided in a row in the circumferential direction, the terminal pitch is inevitably narrowed when the size is reduced, and the workability is reduced because the terminal pitch is narrow when soldering the lead wires. However, a short circuit in which the solder bridges between the terminals is likely to occur.

  The present invention solves the above-mentioned problems, and its purpose is to adopt a configuration of a pancake structure motor that is preferable for reducing the diameter, to reduce the width of the terminal portion occupying the outer diameter of the motor, and to make the terminal pitch as wide as possible. Therefore, it is an object of the present invention to provide a stepping motor that can be downsized well.

  In order to achieve the above-described object, a stepping motor according to the present invention includes: (1) a stator composed of a permanent magnet magnetized in multiple poles in the circumferential direction, a yoke and a coil integrated with a cylindrical housing; The stator has two components, A phase and B phase, arranged concentrically on the outer periphery of the rotor, and in each stator, a yoke having pole teeth inside the cylinder surrounds the coil. In the claw pole type stepping motor configured as described above, the terminals of the coil are arranged in a row having a predetermined width in each phase, and the terminal rows are arranged so as to overlap each other when viewed from the axial direction of the rotor.

  (2) Each phase component is housed in a cylindrical housing, and an opening is provided on the outer periphery of the housing extending in the axial direction of the rotor from one end edge to the other end to fit the terminals. It is good to set it as the predetermined site | part which protrudes.

  With this configuration, in the present invention, the terminals of the coil are arranged in a predetermined width in each phase, and the terminal rows are arranged so as to overlap when viewed from the axial direction of the rotor. The width of the terminal part can be made narrower than that. That is, two terminals of the coil are arranged in each phase, so that the entire width of the terminal portion can be reduced even if the terminal pitch is set wider than that of the conventional four arranged terminal row.

  Moreover, since the opening part which extends in the axial direction of a rotor and extends from one end edge to the other end edge is provided on the outer periphery of the housing, and the terminal is a predetermined part that fits and protrudes, the position of the terminal part can be easily changed.

  As described above, in the stepping motor according to the present invention, the terminals of the coil are arranged so as to superimpose the row of each phase when viewed from the axial direction of the rotor, so that the terminal portion is compared to the conventional four row of terminal rows. The width of the terminal portion can be narrowed even if the terminal pitch of each two-phase terminal row is set wider than that of the conventional four-row terminal row. Therefore, the width of the terminal portion occupying the motor outer diameter can be reduced, and the terminal pitch can be increased as much as possible. As a result, the diameter can be reduced and the size can be reduced. And since a terminal pitch can be made wide, soldering becomes easy and a short circuit defect can be prevented.

  And since the projection area in the axial direction of a rotor can be made small, a mounting space can be reduced and the freedom degree about arrangement | positioning of components can be increased. As a result, the application device can be reduced in size.

  Moreover, since the opening part which extends in the axial direction of a rotor and extends from one end edge to the other end edge is provided on the outer periphery of the housing, the position of the terminal part can be easily changed and the degree of freedom in design is high.

  2 and 3 show a preferred embodiment of the present invention. In this embodiment, the stepping motor has a rotor made of permanent magnets and two stators Sa and Sb of A phase and B phase, and the stators Sa and Sb have respective components of the A phase and B phase in the axial direction of the rotor. In each stator Sa and Sb, the stator teeth Sa and Sb are arranged in a comb shape in the circumferential direction and surrounded by the outer periphery of the rotor, and the coil is concentrically outside the array of pole teeth. A two-phase structure to be arranged is adopted and a so-called pancake structure motor is configured.

  The rotor has a rotating shaft 10 at the center of a cylindrical permanent magnet, and the surface of the permanent magnet is divided into n parts in the circumferential direction so as to be magnetized into alternating poles of N and S poles. The two stators are configured so that the two A-phase and B-phase components are concentrically arranged on the outer periphery of the rotor, and in each stator, a yoke having pole teeth inside the cylinder surrounds the coil. ing.

  Each phase component of the A phase and the B phase is accommodated in cylindrical housings 1a and 1b, respectively, and both housings 1a and 1b are accommodated with the rotor at the center, and the bracket plates 2 and 3 are fitted in front and back. The rotor shaft 10 is rotatably supported by the bearing portion.

  The housings 1a and 1b are configured in a so-called pancake type in which one end of the cylindrical body is a bottom surface. As shown in FIG. 3, a bottom plate is integrally formed at one end of the cylinder, and the bottom plate is provided with an array of pole teeth by punching at the center to form outer yoke plates 4a and 4b. . Therefore, the cylindrical body forming the housings 1a and 1b also functions as a yoke.

  Opening portions 5a and 5b extending in the axial direction of the rotor and extending from one end edge to the other end edge are provided on the outer periphery of the housings 1a and 1b. The opening portions 5a and 5b are predetermined portions where terminal portions 6a and 6b, which will be described later, are fitted and protruded. That is, the coil is formed by winding a wire around a bobbin, and the winding end is drawn out to a protruding part of the bobbin flange to form terminal parts 6a and 6b. The phase components such as coils and bobbins are housed in the housings 1a and 1b, respectively, but the terminal portions 6a and 6b are positioned at the opening portions 5a and 5b provided on the outer periphery of the housings 1a and 1b. It is a form that protrudes somewhat from the outer diameter.

  The coil terminals are arranged in rows with a predetermined width for each phase. That is, the terminals of the coil are arranged in two rows for each of the A phase and the B phase, and the terminal rows are arranged so as to overlap each other when viewed from the axial direction of the rotor. The widths of the terminal portions 6a and 6b can be set to about ¾ of the width of the conventional four-row terminal row. As a result, two terminals are arranged in a row width corresponding to the conventional four terminals, and the terminal pitch can be made sufficiently wide as compared with the conventional case.

  In the present invention, openings 5a and 5b extending in the axial direction of the rotor from the one end edge to the other end edge are provided on the outer circumferences of the housings 1a and 1b so that the coil terminals are fitted and protruded. The positions of the terminal portions 6a and 6b can be easily changed, and can be set as appropriate according to the specifications of the application device.

  That is, as shown in FIG. 2, the positions of the A-phase terminal part 6a and the B-phase terminal part 6b can be respectively arranged on the motor rear end side, or conversely, as shown in FIG. It is also possible to adopt an arrangement in which the positions of the A-phase terminal part 6a and the B-phase terminal part 6b are respectively located on the motor front end side. Further, as shown in FIG. 5, it is possible to easily adopt an arrangement in which the A phase terminal portion 6a is on the motor front end side and the B phase terminal portion 6b is on the motor rear end side. Further, as shown in FIG. 6, the A phase terminal portion 6a may be located on the rear side of the motor, and the B phase terminal portion 6b may be located on the front side of the motor so that they are back-to-back at the central portion.

  As for the position of the coil terminal, as shown in FIGS. 7 and 8, terminal portions are provided on both sides of the bobbin flange so that the terminal interval is set longer in the axial direction of the rotor. The phase side coil terminals can be arranged side by side in the circumferential direction. In these cases, the coil terminals are arranged at three positions in the axial direction of the rotor, and the terminal pitch is remarkably wide when viewed in each phase.

  As described above, since the coil terminals are arranged so that the row of each phase overlaps when viewed from the axial direction of the rotor, the width of the terminal portions 6a and 6b is made narrower than that of the conventional four-row terminal row. The width of the terminal portions 6a and 6b can be narrowed even if the terminal pitch is set wider than that of the conventional four-row terminal row in the two-row terminal row in each phase. Therefore, the width of the terminal portions 6a and 6b occupying the outer diameter of the motor can be reduced, and the terminal pitch can be increased as much as possible. Thereby, size reduction can be performed satisfactorily. And since a terminal pitch can be made wide, soldering becomes easy and a short circuit defect can be prevented.

  And since the projection area in the axial direction of a rotor can be made small, a mounting space can be reduced and the freedom degree about arrangement | positioning of components can be increased. As a result, the application device can be reduced in size.

  In addition, opening portions 5a and 5b extending in the axial direction of the rotor and extending from one end edge to the other end edge are provided on the outer periphery of the housings 1a and 1b so that the terminals are fitted and protruded, so that the terminal portions 6a and 6b are provided. The position can be easily changed, and the degree of freedom in design is high.

An example of a conventional stepping motor having a two-phase vertically stacked structure is shown, in which (a) is a side view and (b) is a front view as seen from the rear end. 1 shows a preferred embodiment of a stepping motor according to the present invention, wherein (a) is a side view and (b) is a front view as seen from the rear end. It is a perspective view which shows the housing which concerns on this invention. The other example 1 of the coil terminal which concerns on this invention is shown, (a) is a side view, (b) is the front view seen from the rear end. The other example 2 of the coil terminal which concerns on this invention is shown, (a) is a side view, (b) is the front view seen from the rear end. The other example 3 of the coil terminal which concerns on this invention is shown, (a) is a side view, (b) is the front view seen from the rear end. The other example 4 of the coil terminal which concerns on this invention is shown, (a) is a side view, (b) is the front view seen from the rear end. The other example 5 of the coil terminal which concerns on this invention is shown, (a) is a side view, (b) is the front view seen from the rear end.

Explanation of symbols

1a, 1b Housing 2, 3 Bracket plate 4a, 4b Outer yoke plate 5a, 5b Opening portion 6a, 6b Terminal portion 10 Rotating shaft Sa, Sb Stator

Claims (2)

The rotor includes a permanent magnet magnetized in multiple poles in the circumferential direction, and a stator including a yoke and a coil integrated with a cylindrical housing, and the stator includes two components of A phase and B phase. In a claw pole type stepping motor in which a yoke having pole teeth inside a cylinder surrounds a coil in each stator, concentrically arranged on the outer periphery of the rotor,
The stepping motor is characterized in that the terminals of the coil are arranged in a row having a predetermined width in each phase, and the terminal rows are arranged so as to overlap each other when viewed from the axial direction of the rotor.   Each of the phase components is housed in a cylindrical housing, and an opening is provided on the outer periphery of the housing extending in the axial direction of the rotor from the one end edge to the other end so that the terminal fits and protrudes. The stepping motor according to claim 1, wherein the stepping motor is a part.

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