JPH0424947B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] This invention relates to a step motor.

[Background technology]

Conventionally, a step motor with 100 to 200 poles generally had a structure as shown in FIG. That is, the stator poles are salient poles 50, and each salient pole 50 is wound with a coil 51. However, since the space in which the coil 51 is wound is the groove 52 between the salient poles 50, it is very difficult to wind the coil 51 and the processing cost is high. Even if the coil 51 is fitted with a separately wound coil, in the example of FIG.
It had the disadvantage of requiring 1.

[Purpose of the invention]

An object of the present invention is to provide a step motor which has a number of poles of 100 or more, reduces the number of parts such as coils, and is simple and inexpensive in structure and assembly.

[Disclosure of the invention]

The step motor of the present invention, as a first invention, includes first and second coils coaxially arranged in parallel, and a second coil interposed between the first and second coils. an intermediate plate having a predetermined number of magnetic pole pieces extending in both axial directions on the inner peripheral side and further having a predetermined number of magnetic pole teeth formed on its surface;
A magnetic pole piece is provided on the outer side of the first and second coils in the axial direction, extends toward the intermediate plate side in the axial direction on the inner peripheral side of each coil, and is located between the magnetic pole pieces of the intermediate plate. a pair of yokes having a predetermined number of magnetic pole teeth formed on the surface thereof; and a rotor disposed on the central axis of the coil and having magnetic poles opposite to the magnetic pole teeth formed on the outer periphery;
a set of magnetic pole teeth of the intermediate plate and yoke and magnetic poles of a rotor opposing these in the coil;
The magnetic pole teeth of the intermediate plate and yoke in the second coil and the set of magnetic poles of the rotor opposing these are deviated from each other in the direction of rotation by a predetermined electrical angle. Further, as a second invention, first and second coils are coaxially arranged in parallel, and an axis is interposed between the first and second coils and is arranged on the inner peripheral side of the first and second coils. an intermediate plate having a predetermined number of magnetic pole pieces extending in both directions, and further having a predetermined number of magnetic pole teeth formed on its surface;
Pole electrons are provided on the outer sides of the first and second coils in the axial direction, extend toward the intermediate plate in the axial direction on the inner peripheral side of each coil, and are positioned between the magnetic pole pieces of the intermediate plate. a pair of yokes having a predetermined number of magnetic pole teeth formed on their surfaces; and a pair of yokes disposed on the central axis of the coil and magnetized in the radial direction, and having magnetic pole teeth opposite to the magnetic pole teeth formed on the outer periphery. a rotor having a permanent magnet;
a set of magnetic pole teeth of the intermediate plate and yoke and magnetic pole teeth of the rotor opposing these in the coil; and a set of magnetic pole teeth of the intermediate plate and yoke and magnetic pole teeth of the rotor opposing these in the second coil. The sets are shifted from each other in the direction of rotation by a predetermined electrical angle. That is, in the first invention, since the magnetic pole teeth are formed on the magnetic pole pieces of the intermediate plate and the yoke, it is possible to achieve an extremely large number of poles of more than 100 poles, and in addition, the number of parts is reduced and the structure and assembly are simplified compared to the conventional method. It is possible to reduce the size and cost. In the second invention,
Since the permanent magnet is magnetized in the radial direction and magnetic pole teeth are formed on the outer surface, the structure of the permanent magnet is further simplified.

An embodiment of the present invention will be described based on FIGS. 1 to 9. In the figure, a stator 1 consists of a cup-shaped stator yoke 2, 3 that also serves as a case, coils 6, 7 held in a pair of coil frames 4, 5, an intermediate plate 8, and a bearing 9. magnet 1
1a, 11b, a shaft 12, and a magnet holder 13. The stator yokes 2 and 3 of the stator 1 are formed in substantially the same shape, and both have a plurality of cylindrical magnetic pole pieces 14 and 15 raised in the center of the bottom plate, and magnetic pole teeth 14a and 15a on the inner circumferential side. Forming and evenness of the opening edge 4
A locking notch 16 is formed at each location at a predetermined depth, and a bearing fixing hole 17 is formed in the center of the yoke 3. The intermediate plate 8 is formed of a magnetic material into a disc shape, and has locking protrusions 18 formed at four equal locations on the outer periphery as shown in FIGS. 3 and 4, and the magnetic pole piece 14,
The same number of magnetic pole pieces 19 and 20 as 15 are arranged at equal intervals on the front and back sides.
The magnetic pole teeth 19a and 20a, which are the same as the magnetic pole teeth 14a and 15a, are formed on the inner peripheral surface thereof. When each coil frame 4, 5 is housed in each stator yoke 2, 3, each magnetic pole piece 14, 15 is located on the inner periphery of the coil frame 4, 5. Also, bearing fixing hole 1
Attach a bearing 9 made of oil-impregnated sintered alloy to 7,
Covering the opening of one stator yoke 3 with the intermediate plate 8,
The projection 18 is engaged with the notch 16. The depth of the notch 16 is half the thickness of the protrusion 18, so place the other stator yoke 2 on it and insert the notch 16 into the protrusion 18.
It is engaged with the protruding part that is half the thickness of the plate and assembled into one body. At this time, the magnetic pole pieces 14 of the stator yokes 2 and 3,
15 and these magnetic pole pieces 14, 15 and the intermediate plate 8
The relationship between the magnetic pole pieces 19 and 20 is made so that they cross each other as shown in FIG. Try to shift it by just that.

In the rotor 10, a holder 13 is attached to a shaft 12 by press fitting, and permanent magnets 11a, 1 are attached to the holder 13.
1b is attached. In this case, the collar (non-magnetic material) 13a of the holder 13 is used to magnetize the permanent magnets 11a and 11b.
is in charge. These permanent magnets 11a, 11
For example, b is formed by molding a plastic magnet or the like to form 100 magnetic pole teeth 21a, 21b on the outer periphery, which are the same as the magnetic pole teeth 19a, etc. (by setting the width of the magnetic pole teeth 19a, etc., 100 poles (each magnet 11
Permanent magnets 11a and 11b are both radially magnetized, but the outer surface of permanent magnet 11a is, for example, the N pole, and the outer surface of permanent magnet 11b is radially magnetized. are made different so that they become S poles. Also, permanent magnet 11
The mutual magnetic pole teeth 21a and 21b of a and 11b are shifted by half a pitch (one tooth) in the rotational direction by 180 degrees in the electrical angle as shown in Fig. 7a and b (in the figure, the black parts are the teeth, and the white parts are the tooth groove).

Magnetic pole teeth 14a, 19 facing each other for each coil 6, 7
The set a and the set of magnetic pole teeth 15a and 20a have different magnetic poles facing each other by energizing the coils 6 and 7, respectively. Therefore, the operation of this step motor is based on the magnetic pole teeth 14a, 19a, 15a, 20a.
Since the correspondence between the magnetic pole teeth 21a and 21b is the same as that of a conventionally known two-phase coil system, the step operation is the same as the conventional one. In other words, to summarize:
For example, when the magnetic pole teeth 21a of the rotor 10 face the magnetic pole teeth 14a, 19a on the coil 6 side as shown in FIG. 8, the magnetic pole teeth 15a, 19a on the other coil 7 side,
20a is the ninth magnetic pole tooth 21b of the rotor 10.
As shown in the figure, the relationship is shifted by 90 degrees, and when the opposite occurs, the relationship is reversed, so step motion can be obtained by sequentially exciting the shifted side. The excitation currents are 90 degrees out of phase with each other in the coils.

With this configuration, only two coils 6 and 7 are required compared to the conventional case, which reduces the number of parts and simplifies the structure. Moreover, donut-shaped coils 6, 7
As a result, processing costs are extremely low, and assembly is extremely simple as the parts are stacked one on top of the other. Furthermore, since one side of each of the magnetic pole teeth 19a and 20a for each of the coils 6 and 7 is formed simultaneously on a single intermediate plate 8, the length in the axial direction is shortened and the work of expressing the positional relationship of the magnetic pole teeth of the coils is simplified. becomes unnecessary. Also, the intermediate plate 8 and its magnetic pole pieces 19, 20
The precision is good because it can be pressed using a mold.

Note that the magnetic pole pieces 14, 15, 19, and 20 may be separately attached to the yokes 2, 3 and the intermediate plate 8. Further, in the embodiment, the magnetic pole teeth 21a, 21b of the rotor 10 are shifted in the rotation direction in order to obtain rotation, but they may be shifted together with the magnetic pole teeth 19, 20 of the intermediate plate 8 or the magnetic pole teeth 19, 20 thereof. . This is because if there is a relative shift as a whole, the operation is the same. Although the embodiment uses a two-phase coil, the same effect can also be obtained by using a plurality of coils of two or more phases and applying the structure of the present invention to the relationship between the first and second coils.

〔Effect of the invention〕

According to the present invention, the number of parts can be reduced compared to the prior art, the structure and assembly can be significantly simplified, the size can be reduced, and the cost can be reduced.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of an embodiment of the present invention, Fig. 2 is a sectional view thereof, Fig. 3 is a sectional view of the intermediate plate, Fig. 4 is a plan view thereof, and Fig. 5 is an enlarged perspective view of the magnetic pole piece. , Fig. 6 is a developed view of the magnetic pole piece, Fig. 7 is a developed view of the magnetic pole teeth of the rotor, Fig. 8 is an explanatory view showing the relationship between the stator on the coil side and the magnetic pole teeth of the rotor, and Fig. 9 is a developed view of the magnetic pole teeth of the rotor. FIG. 10, an explanatory diagram showing the relationship between the magnetic pole teeth of the stator and rotor on the coil side, is a side view of a conventional example. 1... Stator, 2, 3... Yoke, 6, 7...
Coil, 8...Intermediate plate, 10...Rotor, 11
a, 11b...Permanent magnet, 14, 15, 19, 2
0...Magnetic pole piece, 14a, 15a, 19a, 20a
...Magnetic pole teeth, 21a, 21b...Rotor magnetic pole teeth.

Claims (1)

[Scope of Claims] 1. First and second coils coaxially arranged in parallel; an intermediate plate having a predetermined number of magnetic pole pieces extending in both directions, and further having a predetermined number of magnetic pole teeth formed on its surface;
A magnetic pole piece is provided on the outer side of the first and second coils in the axial direction, extends toward the intermediate plate side in the axial direction on the inner peripheral side of each coil, and is located between the magnetic pole pieces of the intermediate plate. a pair of yokes having a predetermined number of magnetic pole teeth formed on the surface thereof; and a rotor disposed on the central axis of the coil and having magnetic poles opposite to the magnetic pole teeth formed on the outer periphery;
a set of magnetic pole teeth of the intermediate plate and yoke and magnetic poles of a rotor opposing these in the coil;
A step motor in which the magnetic pole teeth of the intermediate plate and yoke in the second coil and a set of magnetic poles of the rotor opposing these are mutually shifted by a predetermined electrical angle in the rotational direction. 2 first and second coils that are coaxially arranged in parallel; and a coil that is interposed between the first and second coils and extends in both axial directions on the inner peripheral side of the first and second coils. an intermediate plate having a predetermined number of magnetic pole pieces and further having a predetermined number of magnetic pole teeth formed on its surface;
A magnetic pole piece is provided on the outer side of the first and second coils in the axial direction, extends toward the intermediate plate side in the axial direction on the inner peripheral side of each coil, and is located between the magnetic pole pieces of the intermediate plate. a pair of yokes having a predetermined number of magnetic pole teeth formed on their surfaces; and a pair of yokes disposed on the central axis of the coil and magnetized in the radial direction, and having magnetic pole teeth opposite to the magnetic pole teeth formed on the outer periphery. a rotor having a permanent magnet;
a set of magnetic pole teeth of the intermediate plate and yoke and magnetic pole teeth of the rotor opposing these in the coil; and a set of magnetic pole teeth of the intermediate plate and yoke and magnetic pole teeth of the rotor opposing these in the second coil. A step motor in which the sets are offset from each other by a predetermined electrical angle in the direction of rotation.