JPH0437668B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a variable air type motor suitable for use, for example, in driving the arm of an industrial robot, and in particular reduces vibration and noise accompanying this vibration. The present invention relates to a variable gap type motor that aims to increase output torque while increasing output torque.

[Prior Art] Conventionally, variable air type motors as shown in FIGS. 3A, 3B, and 3C have been known as motors whose operating principle is completely different from that of general motors. In these figures, 1 is a stator, which includes a cylindrical core 1a having eight pole teeth (not shown) formed on its inner periphery;
It is composed of a coil (not shown) wound around each pole tooth. As a result, as shown in FIG. 3B, eight magnetic poles a to
h is provided. Then, by sequentially supplying excitation current to each coil of the stator 1, the magnetic pole a
~h are sequentially excited. The stator 1 is housed in a frame 2 as shown in FIG.
Two output shafts 3, 3 disposed on the central axis C of the stator 1 are rotatably supported via bearings 4, 4, respectively. One end of each crank plate 5, 5 is fixed to each inner end of the two output shafts 3, 3, and both ends of a support shaft 7 are fixed to each other end of each of these crank plates 5, 5. Fixed. This support shaft 7
A cylindrical rotor 6 made of a magnetic material is rotatably supported via a bearing 8 .
In this case, the distance l between each axis of the output shaft 3 and the support shaft 7 is slightly smaller than the length obtained by subtracting the radius R of the rotor 6 from the radius R ₁ of the inner circumference of the core 1a.

With the above configuration, the rotor 6 is able to rotate around the support shaft 7 while revolving around the axis of the output shaft 3, as shown in FIG. A part of the outer circumference is able to revolve in a state close to the inner circumference of the stator 1. For example, when the rotor 6 is positioned as shown in FIG. 3B, when the magnetic pole b is excited, a magnetic attraction force is generated between the magnetic pole b and the rotor 6. As a result, the rotor 6 is attracted in the direction of narrowing the gap G between the rotor 6 and the magnetic pole b, that is, in the direction of the arrow F. As a result, the rotor 6 starts to revolve around the axis of the output shaft 3 in the direction of arrow _A1 , and along with this revolution, starts to rotate around the support shaft 7 in the direction of arrow B. Thereafter, when the magnetic poles c, d, e... are sequentially excited, the rotor 6 is attracted to the magnetic poles c, d, e... one after another, and the rotor 6 moves in the direction indicated by the arrow A.
It continues to revolve continuously in the direction, and this revolution movement is outputted to the outside by the output shaft 3.

The variable air type motor described above has a structure in which the air space between the magnetic poles a, b, c... and the rotor 6 changes as the rotor 6 revolves, and the magnetic attraction force (variable Air force) is applied directly to the rotor 6 to cause the rotor 6 to revolve, and rotational output is obtained by this revolving force. On the other hand, the space between the rotor and stator
A general motor, a so-called fixed air type motor, in which the magnetic flux is always constant, does not use the above-mentioned magnetic attraction force, but uses only the tangential force (fixed air force) orthogonal to the field magnetic flux generated from the magnetic poles. ing. Here, it is generally known that the variable air force is extremely large compared to the fixed air force, and for this reason, the variable air force is larger than the fixed air force. It can be used as a drive source that requires high torque, such as the arm drive of an industrial robot.

[Problems to be Solved by the Invention] By the way, in the above-mentioned conventional variable air type motor, the center of gravity of the rotor 6 is on the support shaft 7 separated by a distance l from the axis of the output shaft 3. Rotation with the center of gravity eccentric, that is, eccentric load rotation. As a result, as the rotor 6 revolves, vibrations occur in the entire rotating system, and this vibration also causes noise.

In order to solve such problems, it is conceivable to arrange a plurality of rotors 6 symmetrically about the central axis C of the stator 1 so that the center of gravity of the rotating system coincides with the central axis C.

However, for example, when there are four rotors 6a as shown in FIG. 4, a certain amount of space must be secured between the rotors 6a, 6a, . . . in order to prevent adjacent rotors from coming into contact with each other. Must be. That is, in FIG. 4, when the inner diameter of the stator 1 is R ₁ and the diameter of the rotor 6a is R ₂ , as is clear from the figure, the following equation holds true.

R ₁ = R ₂ /2 + √2・R ₂ +R ₂ /2 = R ₂ +√2・R ₂ = (1+√2・R ₂ ) ... (1) From the above formula (1), the rotor 6a's The diameter R ₂ is R ₂ =R ₁ /(1+√2) (2).

Therefore, in order to secure a certain amount of space between the rotors 6a, 6a, . . . , the following equation must be satisfied.

R ₂ <R ₁ /(1+√2) ...(3) In this way, when four rotors 6a are arranged on the inner circumference of the stator 1, the diameter R ₂ of the rotor 6a is
As shown in equation (3), it must be smaller than R ₁ /(1+√2).

By the way, in the above-mentioned variable air type motor, its output torque is determined by the diameter of the rotor. In other words, if the diameter of the rotor is large, the opposing area between the rotor and the magnetic poles will be large, and as a result,
The magnetic attraction force acting on the rotor increases, and as a result, the output torque also increases. However, when multiple rotors are arranged as shown in Figure 4, the diameter of the rotor cannot be made larger than a certain value as shown in equation (3) above, and therefore the output torque could not be increased beyond a certain point.

In addition, in the conventional variable air type motor, 2
Since the rotor 6 is supported through the output shafts 3, 3 and the crank plates 5, 5, the assembly process is complicated.

This invention was made in view of the above circumstances, and its purpose is to reduce vibration and noise, and to increase output torque by creating a structure that allows the rotor to have a large diameter. It is an object of the present invention to provide a variable pneumatic type motor which is designed to improve the overall performance of the motor and which also simplifies the assembly process.

[Means for Solving the Problems] The present invention includes a cylindrical stator that generates a rotating magnetic field along an inner circumferential surface, and a stator that is disposed penetratingly on the central axis of the stator and that is rotatable. a supported output shaft; a plurality of rotors arranged parallel to the output shaft and revolving around the output shaft in close proximity to the inner peripheral surface of the stator; and each rotor rotatable on its own axis. and supporting means for transmitting the revolution of each of the rotors to the output shaft, and each of the rotors is arranged in a plurality of stages in the axial direction of the output shaft, and each rotor is arranged in a plurality of stages in the axial direction of the output shaft, and They are characterized in that they are arranged at equal intervals on a virtual circumference centered on the output shaft.

[Operation] According to the present invention, a plurality of rotors are arranged in a plurality of stages in the axial direction of the output shaft, so that the size of each rotor in each stage is determined by the radius of the inner circumference of the stator. It can be formed sufficiently large within the range obtained by subtracting the radius of the output shaft from
The magnetic attraction force acting on each rotor becomes large. As a result, high torque is obtained on the output shaft via the support means. Also, the axis of each rotor is parallel to the output shaft,
In addition, each stage is arranged at equal intervals on a virtual circumference centered on the output shaft, so the center of gravity of the entire rotating system and the axis of the output shaft coincide, and therefore the revolution of each rotor The vibrations caused by this vibration and the noise caused by these vibrations can be completely prevented. Further, since the structure is such that one output shaft passes through the central axis of the stator, manufacturing is easy.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. In FIGS. 1A, 1B, and 1C, 20 is a stator, which includes a cylindrical core 20a with 12 pole teeth (not shown) formed at equal intervals on the inner periphery, and each pole tooth (not shown). and a coil (not shown) wound around each of the coils. As a result, along the inner circumferential surface of the stator 1, magnetic poles a ₁ to a ₄ , b ₁
~ _b4 , _c1 ~ _c4 are provided, respectively. An output shaft 21 is disposed to pass through the center axis C of the stator 1, and the output shaft 21 is rotatably supported by the frame 2 via bearings 4, 4. Also,
This output shaft 21 has a revolution plate 2 formed in a cross shape.
The central part of 2 is fixed. A support shaft 23 disposed parallel to the output shaft 21 is located at a distance m from the center of one surface 22a of the revolution plate 22.
a, 23c are respectively attached, and similarly the revolution plate 2
Support shafts 23b and 23d, which are arranged parallel to the output shaft 21, are respectively attached at positions spaced apart from the center of the other surface 22b of the output shaft 21 by a distance m. That is, support shafts 23a to 2 are arranged alternately on both sides of the revolution plate 22.
3d is placed. These support shafts 23a-2
The rotor 2 is connected to the rotor 3d via each bearing 24a to 24d.
5a to 25d are each supported rotatably.
These rotors 25a to 25d are each made of a cylindrical magnetic body, and the radius r thereof is equal to the stator 2.
Output shaft 21 and support shaft 23 from inner radius R ₁ of 0
The length is slightly smaller than the length obtained by subtracting the distance m between the axes a to 23d. With such a configuration, the rotors 25a and 25c are arranged on one side of the revolution plate 22, and the rotors 25b and 25d are arranged on the other side of the revolution plate 22, respectively. i.e. 4
The rotors 25a to 25d are arranged parallel to the output shaft 21 and divided into two stages in the axial direction of the output shaft 21. Furthermore, in each stage, regarding the output shaft 21, a rotor 25a and a rotor 25c are
The rotor 26b and the rotor 25d are located symmetrically. And these rotors 25a-2
A part of the outer periphery of the stator 5d always revolves around the axis of the output shaft 21 in a state close to the inner peripheral surface of the stator 20, and is rotatable around the support shafts 23a to 23d.

In the above configuration, for example, the rotors 25a to
_{25d is} positioned as _{shown in FIG .} Magnetic attractive forces are generated between the rotor 25b, between the magnetic pole _a3 and the rotor 25c, and between the magnetic pole _a4 and the rotor 25d, and the rotors 25a to 25d each generate the magnetic attraction force between the magnetic pole a3 and the rotor _25c.
~ _a4 , that is, the rotor 25a moves in the direction of the arrow Fa.
b is attracted in the direction of arrow Fb, the rotor 25c is attracted in the direction of arrow Fc, and the rotor 25d is attracted in the direction of arrow Fd. As a result, the rotors 25a to 25d begin to revolve around the axis of the output shaft 21 in the direction of arrow _Q1 ,
Along with this revolution, the rotors 25a to 25d start rotating in the direction of arrow P around the support shafts 23a to 23d. Below, magnetic poles b ₁ to b ₄ , then magnetic poles c ₁ to _{c 4} ,
Again, by sequentially exciting the magnetic poles _a1 to _a4 and the magnetic poles whose central angles are shifted by 90 degrees, the rotors 25a to 2
5d is the same as above, magnetic poles b ₁ to b ₄ , then magnetic poles c ₁ to
c ₄ is again attracted to magnetic poles a ₁ to a ₄ respectively. As a result, the rotors 25a to 25d are moved by the arrow Q in the same manner as above.
It continues to revolve in the direction, and this revolving force is applied to the bearings 24a to 2.
4d, the support shafts 23a to 23d, and the revolution plate 22 are transmitted to the output shaft 21, and as a result, the output shaft 21 rotates.

According to the embodiment described above, the four rotors 25a to 25d are arranged in two directions in the axial direction of the output shaft 21.
Since they are arranged in stages and each rotor has two rotors, the diameter 2r of each rotor 25a to 25d is calculated by subtracting the radius of the output shaft 21 from the radius _R1 of the inner circumference of the stator 20. It can be formed sufficiently large within this range. In other words, each rotor 25a to 25
d is larger than the radius R ₂ /2 of the rotor 6a when four rotors 6a, 6a... are arranged on the same plane inside the stator 1 as shown in FIG. be able to. As a result, each rotor 25a~
25d and each of the magnetic poles a to h can be fully utilized.
Higher torque can be obtained than in the case shown in the figure. In addition, since the rotors in each stage are arranged at equal intervals on a virtual circumference centered on the output shaft 21, the center of gravity of the entire rotating system coincides with the axis of the output shaft 21, and as a result, vibration And the noise accompanying this vibration is prevented. In addition, since the structure is such that one output shaft 21 passes through the center axis of the stator 20,
It is not necessary to align the axes of the two output shafts 3, 3 (see Fig. 3A) as in the conventional case, which facilitates manufacturing.

Next, FIGS. 2A, 2B and 2C are diagrams showing the configuration of another embodiment of the present invention. In these figures, the difference from the above-mentioned embodiment is that three rotors 30 are provided on one side of a revolution plate 31 formed in a disk shape.
a, 30c, and 30e are arranged, and three rotors 30b, 30d, and 30f are arranged on the other side of the revolution plate 31. That is, the rotor 30a
The support shaft 32a of the rotor 30c, the support shaft 32c of the rotor 30c,
One end of each of the support shafts 32e of the rotor 30e is
They are each attached to one surface 31a of the revolution plate 31 at a center angle of 120 degrees, and one end of each of the support shaft 32b of the rotor 30b, the support shaft 32d of the rotor 30d, and the support shaft 32f of the rotor 30f is , are attached to the other surface 31b of the revolution plate 31 with a center angle of 120 degrees. As a result, the rotors 30a to 30f are parallel to the output shaft 21, and
They are arranged in two stages in the axial direction of the output shaft 21. Furthermore, 18 magnetic poles are formed on the stator 1, and six of these magnetic poles whose center angles are shifted by 60 degrees are simultaneously excited.

In this embodiment as well, the diameter of each of the rotors 30a to 30f can be made sufficiently large as in the above-mentioned embodiment, so that high torque can be obtained.

Note that in each of the embodiments described above, the stator 2
The explanation has been given using an example in which a magnetic pole is formed by winding a coil around each of the zero pole teeth. A coil is continuously wound around the core 20, and an alternating current is passed through the coil.
A rotating magnetic field may be continuously generated along the inner circumferential surface of a, thereby magnetically attracting the rotor.

[Effects of the Invention] As explained above, according to the present invention, there is provided a cylindrical stator that generates a rotating magnetic field along the inner circumferential surface, a cylindrical stator that is disposed penetratingly on the central axis of the stator,
and a rotatably supported output shaft; a plurality of rotors arranged parallel to the output shaft and revolving around the output shaft in close proximity to the inner circumferential surface of the stator; and each of the rotors. support means for supporting the rotor rotatably and transmitting the revolution of each rotor to the output shaft; each of the rotors is arranged in a plurality of stages in the axial direction of the output shaft; Since each stage is arranged at equal intervals on a virtual circumference centered on the output shaft, the diameter of each rotor is within the range obtained by subtracting the radius of the output shaft from the radius of the inner circumference of the stator. can be made sufficiently large, thereby making it possible to fully utilize the magnetic attraction force generated between the stator and the stator, and thus obtaining high torque. In addition, the center of gravity of the entire rotating system is aligned with the axis of the output shaft, which completely prevents vibration and noise.Furthermore, one output shaft passes through the center axis of the stator. Because the structure is
Manufacturing becomes easy.

[Brief explanation of drawings]

Figure 1 A, B and C are exploded perspective views, front views and side sectional views showing the configuration of one embodiment of the present invention, and Figure 2 A, B and C are the configuration of another embodiment of the present invention. The exploded perspective view, front view and side sectional view showing the conventional variable air
An exploded perspective view, a front view, and a side sectional view showing the configuration of the type motor, and FIG. 4 shows the radius of the inner circumference of the stator 1 when four rotors 6a are arranged inside the stator 1.
It is a figure which shows the relationship between _R1 and diameter _R2 of the rotor 6a. 20... Stator, C... Central axis, 21... Output shaft, 22, 31... Revolution plate, 23a to 23d, 3
2a to 32f...Support shaft, 24a to 24d...Bearing, 25a to 25d, 30a to 30f...Rotor.

Claims (1)

[Claims] 1. A cylindrical stator that generates a rotating magnetic field along an inner circumferential surface, an output shaft that is disposed penetratingly on the central axis of the stator and is rotatably supported, and a stator that is parallel to the output shaft. A plurality of rotors are arranged and revolve around the output shaft in close proximity to the inner circumferential surface of the stator, and each of the rotors is supported so as to be freely rotatable, and the revolution of each of the rotors is controlled by the rotation of the rotor. and a support means for transmitting power to the output shaft, each rotor is arranged in a plurality of stages in the axial direction of the output shaft, and each stage is arranged equally on a virtual circumference centered on the output shaft. A variable air type motor characterized by being arranged at intervals.