JP3138627B2 - Driving method of hybrid type step motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving method of a hybrid step motor, and more particularly, to a method of driving a coil with a high efficiency and low cost by facilitating winding and mounting of a coil and improving coil mounting density. The present invention relates to a novel improvement for preventing a torque difference in rotation.

[0002]

2. Description of the Related Art As a hybrid step motor of this type which has been conventionally used, a pair of bearings 2, 3 provided at both ends of a casing 4 as shown in FIG.
Is provided with a rotating shaft 1 rotatably. An inner surface 4a of the stator case 4 is provided with a stator yoke 6 having an annular shape and having a stator coil 5, and a plurality of stator teeth 7 are formed circumferentially at predetermined intervals on the inner surface of the stator yoke 6. ing. Ring-shaped first and second rotor yokes 9 and 10 are provided integrally with each other between the bearings 2 and 3 in the axial direction with a magnet plate 8 interposed therebetween. A plurality of rotor teeth 9a and 10a are formed on the surface, and the rotor yokes 9 and 10 have different polarities. Therefore, by supplying a drive pulse to the stator coil 5 via a drive circuit (not shown), step rotation of the rotor yokes 9 and 10 can be obtained.

[0003]

Since the conventional hybrid type stepping motor is configured as described above,
The following issues existed. That is, in the case of a step motor having a hybrid structure in which the above-described magnet plate is sandwiched between the rotor yokes, the stator coil wound around each tooth of the stator yoke is located inside the casing, so that each tooth is Coil winding is difficult,
Also, it has been difficult to improve the coil winding density.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and in particular, in a highly efficient and inexpensive configuration which facilitates winding and mounting of a coil and improves coil mounting density, An object of the present invention is to provide a driving method of a hybrid type step motor that prevents a torque difference within one pitch rotation.

[0005]

According to the present invention, there is provided a method of driving a hybrid step motor, comprising: a pair of bearings provided on a fixed shaft at a distance from each other; and a rotor rotatably provided via the bearings. A case, a ring-shaped rotor yoke provided on an inner surface of the rotor case and having a plurality of rotor teeth, a magnet cylinder provided on an outer periphery of the fixed shaft, and a magnet fitting provided on an outer periphery of the magnet cylinder.
A pair of stators comprising a pair of first and second annular stator yokes, a plurality of stator teeth formed on the outer periphery of each annular stator yoke, and a central position and an outer peripheral position in the axial direction of each annular stator yoke; The formed first and second coil receiving grooves, and the first and second coil receiving grooves provided in the respective coil receiving grooves.
A second coil, wherein each of said ring-shaped stator yokes is a hybrid type step motor in which N hybrid step motor units having different polarities are arranged in series at intervals from each other; The pitch between the pair of stators in the portion is shifted from each other, the magnetic path pattern formed simultaneously for each pair of stators is different, and the annular rotor yokes corresponding to each pair of stators have different torques from each other. This is a method for preventing a torque difference within one 360 ° rotation of the annular rotor yoke by combining torque and weak torque.

More specifically, the pitch is shifted by ず れ.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method for driving a hybrid type stepping motor according to the present invention will be described below in detail with reference to the drawings. The same or equivalent parts as those in the conventional example will be described using the same reference numerals. First, before describing a multiple hybrid step motor according to the present invention, a single hybrid step motor before forming a multiple hybrid will be described. In FIG.
Is a fixed shaft made of a magnetic material. A pair of bearings 2 and 3 provided on the fixed shaft 1 at a distance from each other is rotatably provided with a rotor case 4 having a substantially annular shape as a whole. Is provided. On the inner surface of the rotor case 4,
An annular rotor yoke 6 having an annular shape and having a plurality of rotor teeth 7 is provided.

[0008] First and second annular stator yokes 9 and 10 arranged in the axial direction are provided in a magnet cylinder 8 provided on the outer periphery of the fixed shaft 1 with a gap 1A therebetween.
The magnet 8 is integrally formed with the outer circumference of the magnet cylinder 8 in a fitted state. First and second coil receiving grooves 20a and 21a are formed at the center position and the outer peripheral position in the axial direction of each of the stator yokes 9 and 10, respectively. Each of the coil receiving grooves 20a and 21a has a first coil 22 and a second coil 23 formed by a bobbin wound in a well-known bobbin shape.
Is provided by automatic winding by a winding machine or the like. The first coil 2 is provided on the outer periphery of the first annular stator yoke 9.
First and second N-poles N1 and N2 are formed so as to sandwich the second coil 23. The first and second annular N-poles N1 and N2 are formed on the outer periphery of the second annular stator yoke 10 so as to sandwich the second coil 23.
S poles S1, S2 are formed, and each pole N1, N2, S1, S
2 corresponds to the rotor teeth 7 and each of the poles N1,
A plurality of stator teeth 9a, 10a having the same pitch as the pitch of the rotor teeth 7 are formed on the outer periphery of N2, S1, S2. As shown in the operation diagram of FIG. 5, each of the poles N1 and N2 is formed with stator teeth 9a and 10a with a half pitch and S1 and S2 also shifted by a half pitch.
1, N2 and S poles S1, S2, each stator tooth 9a and 10a
Are formed so as to be shifted by 1/4 pitch. Therefore,
The first and second stator yokes 9 and 10 form one 1
A pair of stators 50 is configured, and one hybrid step motor unit 100 is configured by the rotor case 4, the annular rotor yoke 6, and one pair of stators 50 of FIG. 1. In the case of a multiple unit shown in FIG. 6, which will be described later, this one pair of stators 50 is used, and N hybrid step motor units 100 are connected in series and used.

Next, the operation in the above-mentioned single type configuration will be described. 3 shows the flow of the magnetic flux formed by the magnet cylinder 8, and FIG. 4 shows the magnetic flux generated by the first coil 22 and the second coil 23. The direction of the flow of the magnetic flux is determined by the current flowing through each of the coils 22, 23. Depends on the orientation. FIG. 5 shows the first and second coils 2 provided via the magnet cylinder 8.
When currents in the directions indicated by A and B are passed from a drive circuit (not shown) to the rotors 2 and 23, the rotor yoke 6 rotates from the state 0 to the state 1 by a well-known magnetic action. By flowing a current from the drive circuit in the directions indicated by A and B bars opposite to the directions of A and B, the rotor yoke 6 rotates as shown in states II and III, Thereafter, the position becomes the above-mentioned state 0, and the step rotation of each rotor tooth 7 is performed by one pitch. Therefore, a weak torque and a strong torque are generated in the annular rotor yoke 6 by changing the magnetic path patterns R and S from the state 0 to the state III in FIG. Although the above-described coils 22 and 23 have been described in the case of the well-known bipolar winding, the same operation can be obtained in the case of the well-known unipolar winding. In the above description, one-phase excitation is used, but driving can be performed by two-phase excitation or 1-2-phase excitation. In addition, the above-described pitch shift between the teeth 7, 9a, and 10a is relative, and the same operation as described above can be obtained even if any of the sides is shifted. Also,
Although the outer rotor type has been described above as an example, the inner rotor type can be similarly configured.

Next, in the configuration shown in FIG. 6, the single hybrid type step motor shown in FIG. 1 is connected in series (two in this case, but any number of N) can be connected in series. Two pairs of stators 50 are used, and there is a gap between each pair of stators 50. However, a non-magnetic plate (not shown) may be provided on the fixed shaft 1 instead of the gap. FIG. 7 shows another embodiment of FIG. 6, in which the annular rotor yoke 6 is
Each of the ring-shaped rotor yokes 6 corresponds to each pair of the stators 50.

Next, the operation will be described. FIG. 8 shows the step operation of the multiple hybrid step motor shown in FIG. 6, but when only a single pair of stators 50 is used as shown in FIG. Since the generated torque is weak and the generated torque is strong when flowing inside, a torque difference is generated at each step when the same current is applied as in FIG. 5, and gogging due to the torque difference occurs within one rotation of 360 °. Will be. Therefore, as shown in FIG. 8, in the new state 0, the states 0 and II in FIG.
In state 1, state I and III in FIG. 5 are combined, in state 2, state II and 0 in FIG. 5 are combined, and in state 3, state III in FIG.
By using the combination of I and I, the magnetic path patterns R and S different from each other are formed in each pair of stators 50 and 50 for each step rotation, and the combination of strong torque and weak torque different from each other is 360 °. No torque difference is generated within one rotation of the motor, and smooth rotation is obtained.

[0012]

Since the outer rotor type stepping motor driving method according to the present invention is configured as described above, the following effects can be obtained. That is, in the case of the configuration shown in FIGS. 1 and 6, the coil can be provided on the outer periphery of the stator yoke, so that the winding work is extremely easy, and the cost of this type of hybrid outer rotor type step motor is greatly reduced. be able to. Also, a plurality of hybrid step motor units are connected in series,
Because the torque within one rotation of ° is driven in a combination of strong and weak, rotation without a torque difference can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an outer rotor type step motor having one pair of stators applied to the present invention.

FIG. 2 is a cross-sectional view of FIG.

FIG. 3 is an explanatory diagram showing a flow of a magnetic flux created by the magnet plate of FIG. 1 for one pair of stators.

FIG. 4 is an explanatory diagram showing the flow of magnetic flux created by the coil of FIG. 1 for one pair of stators.

FIG. 5 is an explanatory diagram showing a combined magnetic flux and a step rotation of a rotor yoke when a current is applied to the magnet plate and each coil of FIG. 1;

FIG. 6 is a half sectional view of a multi-unit configuration using two step motors each having one pair of stators shown in FIG. 1;

FIG. 7 is a sectional view showing another form of the main part of FIG. 6;

FIG. 8 is an explanatory diagram showing a rotation state of the multiple step motor of FIG. 6;

FIG. 9 is a cross-sectional view showing a conventional hybrid type step motor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fixed shaft 1A air gap 2,3 bearing 4 rotor case 6,6A annular rotor yoke 7,7a rotor teeth 8 magnet cylindrical body 9,10 annular stator yoke 9a, 10a stator teeth 20a, 21a coil receiving groove 22,23 coil 50 one pair Stator 100 Hybrid step motor

Claims (2)

(57) [Claims] A pair of bearings (2, 3) provided separately from each other on a fixed shaft (1), and a rotor case (4) rotatably provided via the bearings (2, 3). ) And the rotor case (4)
A ring-shaped rotor yoke (6) having a plurality of rotor teeth (7) provided on the inner surface thereof; a magnet cylinder (8) provided on the outer periphery of the fixed shaft (1); and an outer periphery of the magnet cylinder (8) A pair of first and second annular stator yokes provided to be fitted with each other
(9, 10) and a plurality of stator teeth (9, 10) formed on the outer periphery of each of the annular stator yokes (9, 10).
a, 10a), and a first and a second formed at an axially central position and an outer peripheral position of each of said annular stator yokes (9, 10).
A coil receiving groove (20a, 21a), and first and second coils (22, 23) provided in each of the coil receiving grooves (20a, 21a), and each of the annular stator yokes (9, 10) is Using a hybrid type step motor in which N hybrid step motor units (100) having different polarities are arranged in series at an interval from each other, each of the paired stators (100) in the hybrid step motor unit (100) is used. The pitch between the pair of stators (50) is different from each other, the magnetic path patterns (R, S) formed simultaneously for each pair of stators (50) are different, and the ring-shaped rotor yoke (6) corresponding to each pair of stators (50) is different. )
The combination of the strong torque and the weak torque, which are different from each other, enables the 360-degree rotation of the annular rotor yoke (6).
A method for driving a hybrid type step motor, comprising: preventing a torque difference within one rotation of °. 2. The method according to claim 1, wherein the pitch is shifted by ２.