JPH0449831A - Cylindrical type brushless motor and small-sized vibrating motor using same - Google Patents

Abstract

PURPOSE:To reduce size both in the shaft direction and the radial direction by loosely inserting a rotor magnet and a shaft rotatably around a cylindrical type stator bearing house with a stator coil being molded thinly uniformly and having an excellent space factor and into the bearing of said stator bearing house respectively. CONSTITUTION:A rotor magnet 2 is installed to a rotor yoke 9 concentrically formed while being separated from the inner circumferential surface of a rotor back yoke 1 in the cylindrical type rotor back yoke 1 with a bottom 3. Conductors are made to obliquely travel in the central virtual axial direction in a stator coil 5, and conductors are wound in the mutually different directions in isosceles triangular winding ranges 21 and 22 and isosceles triangular winding ranges 23 and 24 in the opposite direction. The stator coil 5 is mounted to a cylindrical type first stage section 7 formed to a hollow cylindrical type stator bearing house 6, and inserted loosely between the rotor back yoke 1 and the rotor magnet 2. The shaft of a rotor is set up to bearings 10, 10'.

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 a long life, and a small-chamber 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,
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 plate type brushless motor also obtains rotational force in the same manner as above by sequentially passing currents of different phases through the 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-bottom motor consisting of a brushless motor, a device that generates rotational vibration was obtained by eccentrically centering the rotor magnet.

[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 space for incorporating the electronic device into 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 part.

A brushless morada C without commutator strips either reduces the axial length of the motor by the length of the commutator, or requires multiple centrally wound coil segments. And, providing multiple concentrically wound coil segments presents many manufacturing problems. That is, since the coil segments 41142 are separated from each other, the insert resin 43 or a printed wiring board is required to hold them. Also,
Concentrated winding of a coil segment increases the mechanical dimensions of the coil, lowering the operating point on the magnetic circuit and reducing 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. 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 this expensive, but the axial length of the small-volume vibration motor is also long. If the small-volume vibration motor is a flat motor and the rotor magnet is made eccentric, the length in the axial direction will be shortened, but not only will it become larger in the radial direction, but it will not be possible to take large rotational vibrations.

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 rotor comprising a bottomed cylindrical rotor back yoke fixed to the shaft at the bottom, and a cylindrical rotor magnet concentrically attached to the rotor yoke apart from the inner peripheral surface of the bottomed cylindrical rotor back yoke. and:
The conductor 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 the isosceles triangular winding areas are A stator consisting of a stator coil, each base of which is formed to have the same length as the magnetic pole pair pitch, and a stator bearing house that has a bearing house that includes an attachment part for the stator fill and a bearing for mounting the shaft. The stator coil is configured to be loosely inserted between a bottom-cone-shaped rotor back yoke of the rotor and a rotor magnet.

A small vibration motor using a cylindrical brushless motor according to the present invention is configured such that at least one of the rotor magnet and the rotor back yoke is eccentrically cut out 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 in a series of sequentially 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, so that the space factor can be increased. Since the stator coil formed thin in this manner narrows the gap with the rotor magnet, the operating point on the magnetic circuit becomes high, and the performance as a 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. 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 the violet rotor magnet, rotor yoke, and rotor back yoke compared to a stator coil formed in a thin cylindrical shape, so the moment of inertia is higher and power fluctuation is reduced. Even if there is, 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 the rotor back yoke in the radial direction. A large vibration was 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 back yoke 1 includes, for example,
It consists of a Maruzaki body with a bottom 3. The rotor magnet 2 is made of a cylindrical body, and is attached to a rotor yoke 9 that is formed concentrically with the inner peripheral surface of the rotor back yoke 1 inside a cylindrical rotor back yoke l having the bottom portion 3. The fixation between the rotor back yoke 1 and the rotor yoke 9, and between the rotor yoke 9 and the rotor magnet 2 is as follows.
For example, this can be done with an adhesive or the like. Further, the cylindrical rotor back yoke l having the bottom portion 3 is manufactured integrally using a multi-stage press, but it is also possible to manufacture the bottom portion 3 separately and then attach the rotor back yoke 1 and the rotor yoke 9. . Further, a shaft 4 is fixed to the cylindrical rotor back yoke 1 having a bottom portion 3 via a rotor bush 4'.

The rotor back yoke 1, rotor magnet 2, shaft 4, rotor bush 4', and rotor 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 central imaginary axis direction of the stator coil is at the top and bottom as shown. 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" in the stator coil winding method means
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, 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.

The stator coil wound in this manner can be formed into a uniform thickness using the two wire diameters. Furthermore, all of 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 fill may be wound using a conventional winding machine, or the conducting wire used in the stator coil of the present invention may have 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. . Further, the stator bearing house 6 is formed with a round-shaped second stage part 8 which is smaller in diameter and longer than the cylindrical first stage part 7, and has a bearing house 6' equipped with a bearing 10, 10' inside. It consists of The stator is constituted by the stator coil 5, the stator bearing house 6, and the bearings 10 and 10'.

When assembling the motor, the stator coil 5 is loosely inserted between the rotor back yoke 1 and the rotor magnet 2, and the rotor shaft 4 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 only 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 the stator coil 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 Ikuri.

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 the small chamber vibration motor in 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 back yoke 1 is partially cut out in the radial direction to make it eccentric. Furthermore, the cutout for eccentricity can be made halfway through the rotor magnet 2 or only in the rotor back yoke l.

In addition to this, various modifications can be made to make it eccentric.

In addition, in the claims, "a part is notched in the radial direction to make it eccentric" includes the various modifications described above.

A small vibration motor equipped with a rotor magnet 2 and a rotor back yoke 1 shaped as shown in FIG. 3 rotates without vibrating due to the eccentricity of these motors.

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 like a pager and disturb the surroundings. You can feel the caller's call without having to call. Furthermore, a compact 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, 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 the rotor magnet is narrowed, the operating point of the magnetic circuit can be set high, and the performance of the motor is improved. On the other hand, the eddy current loss due to the narrowing of the gap is solved by providing a rotor back yoke and a rotor 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, a rotor yoke, a rotor magnet, and a rotor back yoke are used as a rotor, so a motor with high inertia can be made without installing a flywheel.
It is possible to provide an ultra-compact cylindrical brushless motor with stable rotation and reliability even when power supply fluctuations occur.

The small vibration motor using the cylindrical brushless motor according to the present invention can obtain a large eccentric force by simply cutting out a part of at least one of the rotor magnet and the rotor back yoke in the radial direction. You can get vibrations.

6 ・・ 6′・ 7・・・ 8・・・ 9　・・ 10, stator bearing house ・Bearing house Cylindrical first stage part Cylindrical second stage part rotor 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 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. l...Rotor back yoke 2...Rotor magnet 3...Bottom 4...Shaft 4'...Rotor bush 5...Stator coil Figure (B) (C) (D) Figure 2

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, there is a shaft 4 and a bottomed part fixed to the shaft 4 at the bottom 3. A cylindrical rotor back yoke 1 and a rotor yoke 9 separated from the inner peripheral surface of the bottomed cylindrical rotor back yoke 1.
A rotor consisting of a cylindrical rotor magnet 2 concentrically attached to the armature; a plurality of conductive wires are wound diagonally with respect to the armature axis in alignment at a wire diameter pitch, and when unfolded, a plurality of conductive wires are sequentially connected in opposite directions. A stator coil 5 is formed with an isosceles triangular winding area, and each base of the isosceles triangle is formed to have the same length as the magnetic pole pair pitch; a stator comprising a stator bearing house 6' having bearings 10, 10' on which the shaft 4 is mounted; and a rotor magnet 2. (2) The cylindrical brushless motor according to claim (1), wherein at least one of the rotor magnet 2 and the rotor back yoke 1 is partially cut out in the radial direction to make it eccentric. Small vibration motor.