JPH0449832A - 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. Furthermore, the small vibration motor of the present invention can be used in place of a pager, such as a vibration-transmitting pager that does not disturb the surroundings, a pine surge device that transmits vibrations to the human body, or a signal receiver for the blind.

[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,
The 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 coil 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 is a brushless motor that eliminates the 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.

Then, by detecting the position of the rotor magnet (not shown), the coil segments 41, 42...
Currents with different phases are supplied to the rotor, and a rotating magnetic field is sequentially generated to generate rotational force in the rotor.

Furthermore, although not shown, there is a flat plate type brushless motor 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. Furthermore, in a flat type motor consisting of a brushless motor, a device that generates rotational vibrations was obtained by making the rotor magnet eccentric.

[Problem to be solved by the invention]

BACKGROUND ART In recent years, electronic devices have become lighter, thinner, and smaller, and 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 1010 x 10 in the space for incorporating into an electronic device, the length in the shaft direction x the length in the radial direction with respect to the shaft direction, 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 portion.

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. That is, since the coil segments 41, 42, etc. are separated from each other, the insert resin 4 is used to hold them.
3. Or a printed wiring board for printing is required. Further, when the coil segment is made to have concentrated winding, the mechanical dimensions of the coil become thicker, so the operating point on the magnetic circuit becomes lower and the torque performance decreases. 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. Therefore, it would be possible to attach a flywheel to a flat plate motor, but 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 a flat motor and the rotor magnet is 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]

In order to achieve the above object, the cylindrical brushless motor of the present invention is a cylindrical brushless motor having a control circuit that sequentially generates a rotating magnetic field in a stator coil by detecting the position of a rotor magnet, the motor having a shaft, A cylindrical rotor yoke with a bottom fixed to the shaft at the bottom, a cylindrical rotor magnet fixed to the inner peripheral surface of the cylindrical rotor yoke with a bottom, and a rotor vector attached concentrically apart from the rotor magnet. A rotor consisting of a yoke; conductive wires are wound diagonally with respect to the armature axis in alignment with the wire diameter pitch, and when unfolded, a plurality of isosceles triangular winding areas are formed that are sequentially connected in opposite directions. and a bearing house in which a bearing for mounting the stator coil and the shaft is provided. The stator coil is loosely inserted between the rotor magnet and the rotor back yoke, and the shaft is mounted on a bearing.

2. A small vibration motor using a cylindrical brushless motor according to claim 1, wherein at least one of the rotor magnet and the rotor yoke is partially cut out in the radial direction to make it eccentric.

[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 coil 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 so that the wire diameter pitch of the conductor wires is shifted and the wires are aligned diagonally. 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 molded into a thin cylindrical shape with uniform thickness without using a molding resin such as a bobbin or a printed wiring board, thereby increasing the space factor. Since the stator coil formed thin in this way can narrow the gap with the rotor magnet, the operating point on the magnetic circuit becomes high, and the performance of the motor increases. 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. Furthermore, since the air gap magnetic flux density increases when a thin stator coil is used, the rotor back yoke and rotor yoke prevent energy loss due to eddy current loss and the like.

In addition, the cylindrical brushless motor of the present invention rotates a heavier rotor magnet, rotor yoke, and rotor back yoke than a stator coil formed in a thin cylindrical shape, so the moment of inertia is higher and power fluctuations occur. However, there is little rotational unevenness.

Furthermore, the 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. Obtained.

〔Example〕

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

In FIG. 1, the rotor yoke 1 has a bottom portion 3, for example.
It consists of a cylindrical body with a The rotor magnet 2 is attached to the inner peripheral surface of the rotor yoke 1. Also,
A rotor back yoke 9 is attached to the bottom portion 3 of the cylindrical rotor yoke 1 and is formed concentrically with the inner peripheral surface of the rotor magnet 2. The rotor yoke 1 and the rotor back yoke 9, and the rotor yoke 1 and the rotor magnet 2 can be fixed together using, for example, an adhesive or the like. Further, the cylindrical rotor yoke 1 including the bottom portion 3 is manufactured integrally by a multi-stage press, but after the bottom portion 3 is manufactured separately, the rotor yoke 1 is
It is also possible to attach a rotor back yoke 9. Further, a cylindrical rotor yoke 1 having a bottom portion 3
In this case, the shaft 4 is connected to the bottom part 3 through the rotor bush 4'.
is fixed. The rotor yoke 1, rotor magnet 2, shaft 4, rotor bush 4', and rotor back yoke 9 constitute a rotor of the motor.

Next, the stator coil of the present invention will be explained with reference to FIGS. 2(a) and 2(d). FIGS. 2(A) and 2(B) are developed views of stator coils having different numbers of poles, and are developed so that the center imaginary axis direction of the stator coil is above and below the illustration. FIG. 2(c) is (b) a plan view of the illustrated stator coil, and (d) is a sectional view of the stator coil. The stator coils are arranged sequentially in diagonal alignment with respect to their axis. (In this specification, "alignment j" in the stator coil winding method is
This includes cases in which the wires are wound in alignment at the wire diameter pitch, cases in which the wires are wound while being compressed so as to slightly overlap the wire diameter, and cases in which the wires are wound with a slight gap formed in the wire diameter. ) That is, the conductor runs obliquely to the direction of the central imaginary axis, with winding sections 21 and 22 forming an isosceles triangle, and winding section 23 forming an isosceles triangle in the same opposite direction. 24
are wound in 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 shifted by the wire diameter pitch of the windings, then aligned and winding is continued. Therefore, 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. The stator coil wound in this way is
Can be molded to a uniform thickness using two wire diameters. Furthermore, all the windings transition from one layer to the other on both sides of these isosceles triangles having the winding ends as their bases.

The number of pole pairs can be determined by counting the number of transition points.

The stator coil may be wound using a conventional winding machine, or the conducting wire used in the stator coil of the present invention may be formed into 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. When the adhesive layer of the conductive wire is applied to a winding machine, it is either dried or, after winding, a solvent or heat is applied to bond the wires together to form a stator coil.

The stator coil 5 molded as described above is attached to the cylindrical first stage portion 7 formed in the hollow cylindrical stator bearing house 6 without the need for resin molding or printed wiring boards. . Furthermore, a cylindrical second stage part 8 having a smaller diameter and longer than the cylindrical first stage part 7 is formed in the stator pairing tooth 1 6, and a bearing house equipped with a bearing 10, 10' therein. 6'. A stator is constituted by the stator coil 5, the stator bearing house 6, and the bearing 1O110'.

When assembling the motor, the stator coil 5 is loosely inserted between the rotor magnet 2 and the rotor back yoke 9, and the shaft 4 of the rotor is mounted on the bearing 10.10'.

The stator coil 5 is connected to a control circuit, also not shown, via a lead wire, not shown.

The control circuit sequentially supplies currents out of phase to the stator coil 5 by detecting the position of the rotor magnet 2 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 5, 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. be.

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 fill can be formed thinly, we have adopted 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. Then it is advantageous.

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, so 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 at least one of the rotor magnet 2 and the rotor yoke 1 is partially cut out in the radial direction to make it eccentric. The rotor magnet 2 and rotor yoke l are cut out as shown in the figure.
It reaches Tacoil 5. Furthermore, the cutout for eccentricity can be made halfway through the rotor magnet 2 or only in the rotor yoke 1. In addition to this, various modifications can be made to make it eccentric. In addition, in the claims, the expression "J is partially 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 or rotor yoke 1 having the shape shown in FIG. 3 rotates without vibrating due to these eccentricities.

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 without causing any inconvenience. Moreover, a small vibrating device can be similarly provided in a pine surge 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, a rotor magnet and a shaft are respectively rotated around a cylindrical stator bearing house that is formed thin and uniformly and has a stator coil with a good space factor, and within the bearing of the stator bearing house. Since it was inserted freely, it became 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 rotor magnet is narrowed, the operating point of the magnetic circuit can be raised, improving the performance of the motor. On the other hand, the eddy current loss caused by the narrowing of the gap is solved by providing a rotor yoke and a rotor back yoke.

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, by using the rotor yoke, rotor magnet, and rotor back yoke as a rotor, it is possible to create a motor with high inertia without attaching a flywheel, and even if there are power fluctuations, the rotation is stable and reliable. It is possible to provide an ultra-small cylindrical brushless motor with a large size.

A small vibration motor using a cylindrical brushless motor according to the present invention can generate large eccentric force by simply cutting out a portion of at least one of the rotor magnet and rotor yoke in the radial direction, and can generate large vibrations despite its small size. Can you get it?

5　・・ 6 ・・ 6′・ 7・・・ 8・・・ 9　・・ 10, stator coil stator bearing house ・Bearing house Cylindrical first stage part Cylindrical second stage part rotor back yoke 0′...Bearing

[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 fill according to the present invention, and Figs. FIG. 4 is an explanatory diagram of a stator coil in a conventional brushless motor. l...Rotor yoke 2...Rotor magnet 3...Bottom 4...Shaft 4'...Rotor pusher W1 Pushing circular part c) (d)

Claims (2)

[Claims] (1) In a cylindrical brushless motor having a control circuit that sequentially generates a rotating magnetic field in the stator coil 5 by detecting the position of the rotor magnet 2, the motor has a shaft 4 and a bottom that is fixed to the shaft 4 at the bottom 3. It is composed of a cylindrical rotor yoke 1, a cylindrical rotor magnet 2 fixed to the inner peripheral surface of the bottomed cylindrical rotor yoke 1, and a rotor back yoke 9 attached concentrically apart from the rotor magnet 2. The rotor; conductive wires are wound obliquely with respect to the armature axis in alignment at a wire diameter pitch, and when unfolded, a plurality of isosceles triangular winding areas are formed that are successively connected in opposite directions; A stator coil 5 formed to have the same length as each base of an equilateral triangle or the pitch of the magnetic pole pair, and a bearing house 6 provided with bearings 10 and 10' to which the stator coil 5 and the shaft 4 are mounted. a stator composed of; and the stator coil 5 is connected to the rotor magnet 2.
and a rotor back yoke 9, and the shaft 4 is mounted on bearings 10, 10'. (2) A small-sized vibration using a cylindrical brushless motor according to claim (1), characterized in that at least one of the rotor magnet 2 and the rotor yoke 1 is made eccentric by notching a part in the radial direction. motor.