JPH0226461B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to the structure of a step motor in which stator magnetic pole portions of each phase are arranged in a certain relationship on the circumference, and in particular, This is an improved arrangement structure of the drive coil.

[Conventional technology]

In the structure of the conventional distributed step motor,
In the stator part formed by lamination or sintering,
A magnetic pole section and a winding pole section were formed for each phase, and each phase coil was directly wound around the winding pole section using a special winding machine.

In order to explain the features of the present invention in an easy-to-understand manner, the structure of a conventional hybrid step motor will be explained with reference to FIGS. 7 and 8. Any type of step motor, such as a VR type or a hybrid type, may be used, but for the sake of explanation, a hybrid type step motor will be described below as an example. FIG. 7 is a sectional view showing a conventional hybrid stepping motor, and FIG. 8 is a plan view taken along line DD in FIG. 101 is a rotor, and the phase of the teeth provided on the circumference of the rotor 101 is shifted by 180 degrees between the left and right rotors, and is fixed to the rotor shaft 108. Moreover, between the left and right rotors 101, there is a permanent magnet 1 magnetized in the axial direction.
04 is fixed. 102 is a stator, and as shown in FIG. 6, it is provided with a winding pole part (B) around which a drive coil 103 is wound, and a stator magnetic pole part (A) having stator teeth provided at the tip thereof in accordance with each phase. . Figure 8 uses a four-phase motor as an example, so 103-a, 103-b, 103-c, 1
The stator teeth of 03-d are varied in a certain relationship to each other. g is the gap between the teeth of the rotor 101 and the stator teeth of the stator magnetic pole part A; z is the gap through which the nozzle provided between the stator magnetic pole part A passes when winding is performed on the winding pole part B using a special winding machine, etc. It is. 105, 106 are brackets, 109
is a bearing.

[Problems to be Solved by the Invention] Looking at the drawbacks of this conventional step motor, first, the drive coil 103 is connected to the stator 10.
It is directly wound on the winding pole part B of No. 2. Therefore, a gap z must be provided between the stator poles for the winding, through which the nozzle of the special winding machine passes. Sometimes this requires reducing the effective number of teeth on the stator. In addition, the winding is complicated, which makes the work difficult and causes high costs. Also, as a factor in the size of the outer diameter of the motor, the rotor 10
1. Gap between rotor teeth and stator teeth g, stator magnetic pole part a, winding pole part b (drive coil 10
3) Since the motor is arranged in series with the outer periphery of the stator 102 in the radial direction, it has the disadvantage that it is difficult to reduce the outer diameter of the motor.

The present invention has been made in an attempt to improve these drawbacks.

A first object of the present invention is to provide a structure in which winding work is easy to perform regardless of the factors of the stator yoke, and winding costs are low.

A second object of the present invention is to make it possible to realize a motor with a small diameter, a large number of divisions, and high precision.

Furthermore, a third object of the present invention is to make it possible to easily change the coil specifications.

[Means to solve the problem]

The present invention has a structure for exciting stator magnetic poles,
A hybrid stepping motor includes a stator magnetic pole divided into magnetic poles, a non-magnetic fixing member that fixes the stator magnetic pole in a cylindrical shape, and a coil core that comes into contact with an exposed portion of the end surface of the stator magnetic pole in the rotor axial direction. It consists of a coil unit with a

〔Example〕

Next, one embodiment of the present invention will be described. 1st
The figure is a sectional view showing one embodiment of the present invention.
This figure is a plan view showing the drive coil unit section, and FIG. 3 is a view taken from BB in FIG. 1. Reference numeral 1 denotes a rotor, which is fixed to a rotor shaft 12 with the teeth of the left and right rotors having a phase shift of 180 degrees. Left and right rotor 1
Permanent magnets magnetized in the axial direction are fixed between them, and these constitute a rotor body. 2 is a stator pole part made of magnetic material, and support body 4 is made of non-magnetic material.
The stator body is fixed to the stator body. In this embodiment, a four-phase motor is used as an example, so the stator teeth provided in the stator magnetic pole portion (teeth of the stator magnetic pole portions 2a, 2b, 2c, and 2d) are shown in FIG.
has been modified in a certain way. Reference numeral 5 denotes a drive coil, which has a coil core 6 at its center, and is disposed on the coil unit frame 7 so as to correspond to the stator magnetic pole part 2 in FIG. This constitutes the drive coil unit shown in FIG. 8 is a holding frame, and 9 and 10 are bearing supports A and B made of non-magnetic material. FIG. 4 shows a plan view of the bearing support 9. A step adjustment member 11 made of a magnetic material that connects the stator magnetic pole part 2 and the coil core 6 is embedded so as to correspond to each phase stator magnetic pole part 2. This step adjustment member 11 allows the drive coil 5 to be placed inside, making it possible to reduce the diameter of the motor. However, the function of this step adjustment function section remains the same even if the coil core 6 is deformed or a part of the stator magnetic pole section is deformed. Moreover, it may naturally be unnecessary for motors that do not require the drive coil 5 to be disposed inside. In addition, the bearing supports A and B are provided with a stator inner diameter part (in this embodiment, the stator inner diameter part is used, but the side surface of the stator body, etc. The shaft center positioning guides 9G and 10G, which engage with the shaft center positioning guides 9G and 10G (which may be provided with a positioning pin or the like), are designed to facilitate accurate center positioning.
Furthermore, the stator body, rotor body, bearing support body, and bearing described above constitute a driven body unit that can be separated from the drive coil part (unit part) and subassembled independently as shown in FIG. are doing. In this structure, if it is desired to eliminate leakage of magnetic flux, a magnetic cover 14 can be provided.

A description of the operating principle of the present invention will be omitted since it is the same as that of a conventional hybrid step motor.

The most significant feature of the present invention is that it is separated into a drive coil unit and a stator body.
With this structure, the drive coil 5 is not arranged in series in the radial direction like the conventional motor described above, so the outer diameter can be reduced by that size (the rotor diameter is the same). in the case of). If the outer diameter is left unchanged, the diameter of the rotor can be increased, and a motor with higher positioning accuracy can be expected. Naturally, the number of teeth on the rotor can be increased, making it possible to create a motor with a large number of divisions. Furthermore, if the output torque of the motor is made the same by increasing the diameter of the rotor, the dimension of the rotor in the thickness direction can be reduced, and a thin motor can be realized.

Regarding the number of stator teeth provided on the stator magnetic poles, since the drive coil 5 is separated from the stator body, the nozzle shown in Fig. 8, which required a conventional motor for winding. There is no need to take a large gap dimension z for this purpose, and the number of teeth can be set accordingly without being restricted, and the gap can be used effectively.

Regarding the drive coil section 5, since it is separated from the driven unit (stator section), winding can be performed regardless of the factors of the driven section. A special winding machine is not required, a structure such as bobbin winding can be used, and an inexpensive motor with good workability can be realized. Furthermore, in the case of step motors, even if the required number of divisions, size, etc. of the motor are the same, different coil specifications are frequently required due to differences in usage conditions. Conversely, even if the coil specifications are the same, there may be a request to change the number of divisions, etc. According to the structure of the present invention, as mentioned above, since the driving coil unit and the driven unit are separated, the great advantage is that the requirements can be easily met by combining and assembling units that meet the requirements. From an industrial perspective, it can be said that the structure is suitable for mass production.

Furthermore, in terms of the size of the drive coil, in conventional motors, the cross-sectional area of the coil core is determined by the winding pole portion of the stator, which is formed by lamination or integral sintering. According to the structure of the present invention, since the drive coil section is separated from the stator section, the dimensions of the coil core can be arbitrarily set to optimal dimensions in terms of the magnetic circuit. Therefore, the cross-sectional area of the coil core can be made much smaller compared to conventional motors, and the effective volume of the coil can be increased. As a result, the overall dimensions of the coil can be reduced, and a step motor that is small as a whole and has good volumetric efficiency can be realized.

An experimental example is shown below. As a result of experiments to achieve performance almost equivalent to that of a conventional hybrid step motor with dimensions of 39 x 32 mm, we found that when the rotor diameter is the same, the outer diameter is approximately 32 mm. By increasing the outer diameter of the rotor while keeping the diameter the same, the thickness of the motor was reduced to about 2/3, making it possible to achieve almost the same performance with a very small motor.

Further, in the embodiment shown in FIG. 1, an example was shown in which the drive coil unit section was provided only on the left side, but it is also possible to provide it on both sides. In Figure 3,
Although the structure of 4-phase 8-pole (stator magnetic pole part) was taken as an example, according to the structure of the present invention, 4-phase 16-pole, 4-phase
20 poles per phase...etc. The number of poles can be increased without being as limited by the windings as with conventional motors. Therefore, a more uniform force can be generated on the circumference of the rotor, and a highly efficient motor with less vibration can be realized. Similarly, by increasing the number of phases of the step motor, a multi-phase step motor capable of smooth rotation with little torque fluctuation can be easily realized. Therefore, the arrangement of the stator magnetic pole parts divided into integral multiples of the plurality of phases arranged on the circumference of the stator body can be arranged with some degree of arbitrariness as required. Incidentally, in order to increase the number of phases and the number of poles mentioned above, it is possible to arrange the drive coils more efficiently by arranging the drive coil units on both sides.

Needless to say, the present invention is effective not only for the hybrid type step motor described above but also for VR type step motors and the like.

〔Effect of the invention〕

In the structure of the step motor according to the present invention, since the stator body can be separated from the drive coil unit having the coil core, the coil core can be wound in a separated state, and the winding work can be easily performed. There is no winding cost, and since the coil core contacts the axial end of the stator magnetic pole part of the stator body to form a magnetic circuit, a motor with a small outer diameter can be realized, and the specifications of the coil core can be reduced. It has the remarkable effect of being able to be set optimally on the magnetic circuit without being subject to too many restrictions on the outer diameter.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention, FIG. 2 is a plan view showing a drive coil unit section, and FIG. 3 is a view taken from BB in FIG. 1. FIG. 4 is a plan view of the bearing support A. FIG. 5 is a sectional view of the drive coil unit, and FIG. 6 is a sectional view of the driven body unit. FIG. 7 is a sectional view showing the structure of a conventional hybrid step motor, and FIG. 8 is a plan view taken along line DD in FIG. 7. 1 is a rotor, 2 is a stator magnetic pole part, 3 is a permanent magnet, 4 is a support body, 5 is a drive coil, 6 is a coil core, 7 is a coil unit frame, 8 is a holding frame, 9 is a bearing support body A, 10 is a bearing Support B,
11 is a step adjustment member, 12 is a rotor shaft, 13 is a bearing, and 14 is a cover. 101 is a rotor, 102 is a stator, 103 is a drive coil, 104 is a permanent magnet, 105 and 106 are brackets, 108 is a rotor shaft, and 109 is a bearing.

Claims (1)

[Scope of Claims] 1. In a hybrid stepping motor, a stator magnetic pole divided into magnetic poles, a non-magnetic fixing member that fixes the stator magnetic pole in a cylindrical shape, and an exposed end face of the stator magnetic pole in the rotor axial direction A hybrid stepping motor is characterized in that it consists of a coil unit having a coil core that comes into contact with a part of the stepping motor. 2. The hybrid stepping motor according to claim 1, wherein the coil unit is disposed on one side of the stator magnetic pole in the rotor axial direction. 3. The hybrid stepping motor according to claim 1, wherein the coil units are arranged on both sides of the stator magnetic poles in the rotor axial direction.