JPH0449830A - Cylindrical type brushless motor and small-sized vibrating motor using same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a cylindrical brushless motor that is ultra-compact yet has high reliability and long life, and a small vibration motor using the cylindrical brushless motor. be. In particular, the cylindrical brushless motor of the present invention is used in small electronic devices that require a short shaft and radial length and a uniform rotational speed. In addition, the small vibration motor of the present invention can be used as a vibration transmission type pager that can be used as a pager and does not disturb the surroundings.
It is used in pine surge devices that transmit vibrations to the human body, signal receivers for blind people, etc.

[Conventional technology]

Although the rotor coil of the commutator motor in the conventional example is not shown, one end thereof is attached to the flange part,
A shaft is fixed at the center of the flange. Further, a plurality of commutator pieces are attached to the end of the shaft, and the lead wire of the rotor coil and the commutator pieces are electrically connected.

In a commutator motor equipped with such a rotor coil, when current is supplied from the brushes to the rotor coil through the commutator pieces, rotational force is obtained by the current flowing through the rotor filter and the magnetic force of the stator magnet.

However, such a commutator motor as described above has poor reliability and service life due to mechanical contact between the brushes and the commutator pieces.

On the other hand, there are brushless motors that eliminate mechanical contact between the brushes and the commutator pieces, thereby improving the reliability and life of the motor. The stator coil of a brushless motor is composed of a plurality of centrally wound coil segments 41, 42, . . . as shown in FIG. By detecting the position of the rotor magnet (not shown), the coil segments 41, 42...
- Supply currents with different phases to sequentially generate rotating magnetic fields to generate rotational force in the rotor.

Furthermore, there is also a flat plate type brushless motor, which is not shown, in which a plurality of coil segments are printed on a flat plate. A flat brushless motor also obtains rotational force in the same manner as above by sequentially passing currents of different phases through a control circuit.

When a rotary vibration device is obtained using a small motor as described above, an eccentric weight having a heavy specific gravity such as tungsten is attached to the rotating shaft of the small motor to generate vibrations. In addition, a flat type motor consisting of a brushless motor has been obtained as a device that generates rotational vibration by eccentrically centering the rotor magnet.

[Problem to be solved by the invention]

In recent years, as electronic devices have become lighter, thinner, and smaller, motors have been required to be shortened in the radial direction or shaft direction to match the structure of the electronic devices. For example, if there is only a margin of IOXIO mm for the length in the shaft direction x the length in the radial direction with respect to the shaft direction to be incorporated into an electronic device, a motor of a smaller size is required.

However, since commutator motors require commutator pieces,
The length of the motor in the axial direction increases by the length of this part.

Brushless motors without commutator strips reduce the axial length of the motor by the length of the commutator, but require multiple centrally wound coil segments. and,
Providing multiple concentrically wound coil segments presents many manufacturing problems. In other words, since the coil segments 41, 42, etc. are separate coils, the insert resin 4 is used to hold them.
3 or a printed wiring board for printing is required. In addition, when the coil segment is wound in a concentrated manner, the mechanical dimensions of the coil become thicker, which lowers the operating point on the magnetic circuit and reduces torque performance. Furthermore, a tap must be provided for each coil segment.

Furthermore, if it is desired to stabilize the rotational speed of the motor, a flywheel or the like is attached to the shaft of the motor to provide inertia to the rotation. However, the length in the shaft direction increases by the amount that the flywheel is attached to the motor shaft. So, is it okay to attach a flywheel to a flat plate motor? In order to obtain the specified torque with a flat plate motor, not only does the length of the shaft in the radial direction become long, but also there are manufacturing problems in providing coil segments. Also comes out.

Furthermore, in order to obtain a small vibration motor, an eccentric weight must be attached to the rotating shaft. However, it is more efficient to use a member with a higher specific gravity for an eccentric weight;
Not only is it more expensive, but the axial length of the small vibration motor becomes longer. If the small vibration motor is made into a flat motor and the rotor magnet is made eccentric, the length in the axial direction becomes shorter, but not only does it become larger in the radial direction, but the rotational vibration cannot be increased.

The present invention is intended to solve the above problems.
To provide a cylindrical brushless motor that eliminates uneven rotation without attaching anything special to the motor shaft, and has a thin stator coil to shorten the length of the motor in the shaft direction and radial direction.

Another object of the present invention is to provide a small-sized vibration motor that can generate large rotational vibrations without attaching an eccentric weight to the motor shaft.

[Means to solve the problem]

To achieve the above object, the cylindrical brushless motor of the present invention has a control circuit that sequentially generates a rotating magnetic field in a stator coil by detecting the position of a rotor magnet. a rotor composed of a bottomed cylindrical rotor yoke for forming and fixed to the shaft at the bottom, and a cylindrical rotor magnet fixed to the inner peripheral surface of the rotor yoke; rotating the shaft; A stator bearing house consisting of a bearing fixed to support and a yoke body for forming a magnetic path, and a stator coil installed around the stator bearing house, have a conductor line diagonally with respect to the axis of the stator coil. A plurality of isosceles triangular winding sections are formed in a row in opposite directions when the wires are wound in alignment at a radial pitch, and each base of the isosceles triangle has the same length as the magnetic pole pair pitch. and a stator constituted by a stator coil formed in the rotor, and the rotor and the stator are arranged through an air gap.

Further, the small vibration motor of the present invention is configured such that at least one of the rotor magnet and the rotor yoke is eccentrically centered by cutting out a portion in the radial direction.

[For production]

By detecting the position of the rotor magnet, currents of different phases generated by a control circuit (not shown) are applied to the stator coils via lead wires. The rotor is rotated by the rotating magnetic field caused by the current applied to the stator coil and the magnetic force of the rotor magnet.

The stator coil is wound by a normal winding machine in diagonal alignment while shifting the wire diameter pitch of the conductors. Also, when the stator coil is cut in the axial direction and expanded,
A plurality of isosceles triangular winding sections are formed which are successively arranged in opposite directions.

The base of this isosceles triangle is formed to have the same length as the magnetic pole pair pitch.

Therefore, the stator coil can be made into a thin cylindrical shape without using a molded resin such as a bobbin or a printed wiring board, so that the space factor can be increased. Since the stator coil formed thin in this manner can narrow the gap with the rotor magnet, the operating point on the magnetic circuit becomes higher, and the performance of the motor improves. In addition, not only is the coil itself mechanically held in the stator bearing house, but the number of taps is smaller than that of coil segments that are wound centrally, and terminal processing is easier.

In addition, the cylindrical brushless motor of the present invention has a higher moment of inertia and less uneven rotation than a stator coil formed in a thin cylindrical shape because it is an outer rotor type that rotates a heavy rotor magnet and rotor yoke. .

Furthermore, a small vibration motor using the above-mentioned cylindrical brushless motor can increase eccentricity by cutting out a portion of at least one of the rotor magnet and rotor yoke in the radial direction, so it can generate large vibrations despite its small size. was gotten.

〔Example〕

An embodiment of the present invention will be described with reference to FIG. 1 and FIGS. 2(a) to 2).

In FIG. 1, a rotor yoke I is comprised of a cylindrical body having a bottom portion 3, and a stator coil 2, which will be described later, is concentrically attached to the inner circumferential surface of the rotor yoke I, for example, with an adhesive or the like. Further, the cylindrical rotor yoke 1 having the bottom portion 3 is manufactured integrally using a plate made of iron material such as a cold-rolled steel plate or a silicon steel plate by multistage pressing, but after manufacturing the bottom portion 3 separately, the rotor yoke 1 It is also possible to attach it to Further, a rotor bush 5' is fixed to the bottom 3 of the cylindrical rotor yoke 1. The rotor yoke 1, rotor magnet 6, rotor bush 5', and shaft 5 constitute a rotor.

Further, the opposite side of the rotor yoke 1 from the bottom 3 is open, and a stator bearing house 8 to which bearings 4 and 4' are attached is fixed to this part. A stator coil 2, which will be described later, is fixed around the stator bearing house 8 in which the bearings 4 and 4' are located, for example, with an adhesive or the like. Therefore, stator coil 2,
The stator bearing house 8 and the bearing 4.4' constitute the stator.

Next, the stator coil in the present invention will be explained with reference to FIGS. 2(a) to 2).

FIGS. 2(A) and 2(B) are developed views of stator coils having different numbers of poles, and are developed so that the central imaginary axis direction of the stator coil is at the top and bottom as shown. Second
Figure (c) is a plan view of the stator coil shown in (b).
D) is a sectional view of the stator coil. The stator coils are sequentially arranged diagonally with respect to the axis.
This includes cases in which the wire is compressed and wound so as to slightly overlap the wire diameter, and cases in which the wire is wound with a slight gap formed in the wire diameter. ) That is, the conductor runs obliquely to the direction of the central imaginary axis, and the winding sections 21 and 22 form an isosceles triangle.
The winding sections 23 and 24, which also form opposite isosceles triangles, are wound in mutually different directions. That is, the winding starting from the winding section 21 proceeds diagonally downward, turns back at the lower part of the winding section 21, and ascends through the winding section 23 to reach the upper part. Similarly, it passes through winding section 22 and winding section 24 and returns to winding section 21 . These are aligned while being shifted by the wire diameter pitch of the winding, and winding is continued. Thus, in such a winding type, isosceles triangular winding sections are formed on the inner and outer circumferential surfaces, the number of these winding sections being equal to the number of pole pairs.

On both sides of these isosceles triangles with the winding ends as their bases, all the windings transition from one layer to the other. The number of pole pairs can be determined by counting the number of transition points.

The stator coil is wound by a normal winding machine, but the conducting wire used in the stator coil of the present invention has a three-layer structure. That is, at least one insulating layer is provided around the conductive wire, and an adhesive layer is further formed thereon. The adhesive layer of the conductive wire is dry when it is applied to a winding machine, but after winding, a solvent or heat is applied to bond the wires together to form a stator coil.

A rotor shaft 5 is rotatably attached to a stator bearing 4,4' having the stator coil 2 as described above.

The stator coil 2 is connected to a control circuit, also not shown, via a lead wire, not shown.

The control circuit sequentially supplies out-of-phase currents to the stator coil 2 by detecting the position of the rotor magnet 6 using a sensor such as a Hall element. By supplying the above-mentioned current, a rotating magnetic field is sequentially generated in the stator coil 2, giving rotational force to the rotor.

However, when using a sensor such as a Hall element to detect the position of the rotor magnet, it is necessary to make the sensor into a thin film that is sufficiently thinner than the diameter of the conductor in the stator coil and attach it to the surface of the stator coil. .

Furthermore, if the sensor cannot be attached to the surface of the stator coil, it cannot pick up the main magnetic flux from the rotor magnet, and needs to be attached at a position where leakage magnetic flux can be picked up, for example, near the end surface of the stator coil.

Therefore, the air gap formed between the rotor magnet and the stator coil is determined not by the original thickness of the stator coil but by the thickness of the sensor element. Furthermore, in order to pick up the leakage magnetic flux, it is necessary to deform a part of the end face of the stator coil and attach a sensor to that part, which may result in a deviation in position detection or a decrease in efficiency.

In the case of a stator coil wound in alignment as in the present invention, in the case of a two-layer lamination, the thickness of the coil is less than twice that of the winding conductor. Taking advantage of the fact that this stator coil can be formed thinly, we have created a sensorless control circuit that energizes the coil at a conduction angle of 120 degrees or 180 degrees by combining the voltage (back electromotive force) induced by the stator coil between phases. It is advantageous to adopt it.

That is, by employing the stator coil wound in alignment and the sensorless type control circuit of the present invention, the following effects can be obtained.

■ The thickness of the stator coil is determined by the diameter of the winding conductor and the number of laminated layers.Since it is possible to form an air gap, it is possible to obtain a high magnetic flux density and provide a highly efficient ultra-compact motor.

■ Since the stator coil is energized according to the voltage induced, there is no torque unevenness based on the position where the sensor is installed, so it is possible to provide an ultra-compact motor with stable rotation.

FIGS. 3A and 3B are explanatory diagrams of a small vibration motor according to the present invention, and are sectional views in the shaft direction and in the radial direction with respect to the shaft, respectively.

Since the small vibration motor of the present invention uses the cylindrical brushless motor shown in FIG. 1, the same parts corresponding to those shown in FIG. 1 are given the same reference numerals. The only difference is that the rotor magnet 6 and the rotor yoke 1 are both partially cut out in the radial direction to make them eccentric. As shown in the figure, the cutout reaches the stator coil 2.In addition, the cutout for eccentricity can be made in the middle of the rotor magnet 6 or only in the rotor yoke 1.In addition, various modifications can be made to make the eccentricity. Note that, in the claims, "a portion is cut out in the radial direction to make it eccentric" includes the various modifications described above.

A small vibration motor equipped with a rotor magnet 6 and a rotor yoke 1 shaped as shown in FIG. 3 rotates while vibrating due to the eccentricity of these components. Therefore, when this small vibration motor is used as a pager, if the pager consisting of a receiver (not shown) and the above-mentioned small vibration motor is placed in a shirt pocket, etc., it will emit a sound to the surrounding area like a pager. You can feel the caller's call on your skin without causing any inconvenience. Further, a small vibrating device can be similarly provided in a massage device or a signal receiver for blind people.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments. Various design changes can be made without departing from the scope of the invention as set forth in the claims.

For example, it is possible to arbitrarily select to make the cylindrical brushless motor of the present invention single-phase or multi-phase, or to perform half-wave or full-wave control. Furthermore, any known control circuits can be used for the stator coil position detection method, rotating magnetic field generation method, etc.

〔Effect of the invention〕

According to the present invention, the stator coil and shaft of the rotor are disposed around a cylindrical stator bearing house having a stator coil formed thinly and uniformly and having a good space factor, and within the bearing of the stator bearing house. Since they are inserted freely and rotatably, it is possible to reduce the dimensions in both the shaft direction and the radial direction. Furthermore, since the stator coil is formed thin and the gap between the stator coil and the rotor magnet is narrowed, the operating point of the magnetic circuit can be set high, and the performance of the motor is improved.

Since the stator coil according to the present invention is molded to have a uniform thickness, it can be directly attached to the stator yoke without requiring a bobbin or a substrate such as a resin mold. In addition, the stator coil is wound continuously, has a small number of taps, and is gathered on the end face of the coil, so wiring is easy and terminal processing is easy.

According to the present invention, since the rotor magnet and the rotor yoke are used as the rotor, it is possible to create a motor with high inertia without attaching a flywheel, and even when the power source fluctuates, it is possible to create an ultra-compact motor with stable rotation and reliability. Cylindrical brushless motors can be provided.

A small chamber vibration motor using a cylindrical brushless motor according to the present invention can be obtained by simply cutting out a portion of at least one of the rotor magnet and the rotor yoke in the radial direction.
A large eccentric force can be obtained, and a large vibration can be obtained despite its small size.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a cylindrical brushless motor according to the present invention, Fig. 2 (a) or 2) is an explanatory diagram of a stator coil according to the present invention, and Figs. 3 (a) and (b) are explanatory diagrams of a small vibration motor according to the present invention. FIG. 4 is an explanatory diagram of a stator coil in a conventional brushless motor. 1... Rotor yoke 2... Stator coil 3... Bottom 4.4'... Bearing 5... Shaft 5'... Rotor bush 6... Rotor magnet 8... Stator bearing house (rotor ) (C) (D) Circular type planless motor in the middle of the day Diagram 1 Diagram 1 of the zero-fired motor Stator Koino 4φ
Misfortune figure 4

Claims (2)

[Claims] (1) In a cylindrical brushless motor having a control circuit that sequentially generates a rotating magnetic field in the stator coil 2 by detecting the position of the rotor magnet 6, the shaft 5 is connected to the shaft 5 at the bottom 3 for forming a magnetic path. A rotor composed of a fixed bottomed cylindrical rotor yoke 1 and a cylindrical rotor magnet 6 fixed to the inner peripheral surface of the bottomed cylindrical rotor yoke 1; fixed so as to rotationally support the shaft 5. bearing 4,
4' and a yoke body for forming a magnetic path, and a stator coil 2 provided around the stator bearing house 8, the conductive wire is arranged diagonally with respect to the axis of the stator coil 2. A plurality of isosceles triangular winding sections are formed which are wound in alignment at a radial pitch and are sequentially connected in opposite directions when unfolded, and each base of the isosceles triangle has the same length as the magnetic pole pair pitch. A cylindrical brushless motor, characterized in that the rotor and the stator are arranged through an air gap. (2) A small vibration motor using a cylindrical brushless motor according to claim (1), characterized in that at least one of the rotor magnet 6 and the rotor yoke 1 is partially cut out in the radial direction to make it eccentric. .