JP2003099997A - Capstan motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capstan motor which can be made further thin and miniaturized, while maintaining motor characteristics. SOLUTION: The capstan motor is provided with a plurality of coils arranged on a plane, a rotor unit equipped with a permanent magnet face polarized by a plurality of poles facing with the coil keeping a fixed intervals, a means for detecting a number of magnetic flux equivalent to the driving phase, and a power transmission means between the above coil and the above rotor unit to transfer the power of the motor to the outside. In the capstan motor, the coil arrangement is made up by eliminating the number of coils equivalent to the number of driving phase from a plurality of coils arranged concentrically to the capstan shaft at equal angles, arranging the above magnetic flux detection means to the eliminated part, and arranging the power transmission means to the gaps of the above magnetic flux detection means, or the gaps of the above coil and the magnetic flux detection means. The shapes protrusion parts at a caulking part of a housing supporting a capstan shaft which sends out a tape is made to be a shape having no interference with the above power transfer means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capstan motor such as a video tape recorder.

[0002]

2. Description of the Related Art Recent video tape recorders (hereinafter referred to as V
The capstan motor used for TR) is required to be further miniaturized, and how to make it thinner and reduce its diameter while maintaining its characteristics is a particularly problem to be solved. .

A conventional capstan motor will be described below.

FIG. 4 is a side sectional view of a conventional capstan motor in which power transmission is arranged in a gap between a rotor unit and a stator coil, and FIG. 5 shows a coil and a hall element, a housing, a timing belt and a pulley of the conventional capstan motor. FIG. 6 is a front view of a caulking portion of a housing of a conventional capstan motor, and FIG. 7 is a conventional capstan in which power transmission when the housing is fixed by screwing is arranged in a gap between a rotor unit and a stator coil. It is a side sectional view of a motor.

In FIG. 4, the shaft 1 is a housing 1.
It is rotatably supported by metal bearings 11 fitted to both ends of 0. The lower end of the shaft 1 is fixed to the rotor yoke 2 by a fixing means such as press fitting, and the FG magnet 4 for detecting the number of rotations, which is magnetized in multiple poles, is fixed to the outer peripheral portion of the rotor yoke 2 by injection molding or the like. A drive magnet 3 magnetized to have several poles is fixed in the rotor yoke 2. A pulley 5 fitted to the shaft 1 is fixed to the magnet side of the rotor yoke 2, and a timing belt 16 is wound around the first pulley 5 so that the power of the motor can be transmitted to the outside. It has become.

The housing 10 is fixed to a stator yoke 7 made of a silicon steel plate or the like, which is a material having excellent magnetic characteristics, by a fixing means such as caulking.
A flexible printed circuit board 6 (hereinafter referred to as FPC) is attached to the stator yoke 7.
As shown in FIG. 5, six drive coils 8 are arranged via the FPC 6 close to each other about the rotation axis of the shaft 1 every 40 degrees, and fixed to the drive magnet 3 with a predetermined gap. . At this time, the area occupied by the coil is 40
Degrees × 6 = 240 degrees, and the remaining 120 degrees has no coil. This area corresponds to three coils and is equal to the number of motor phases. Hall elements 24, the number of which is equal to the number of motor drive phases, are attached to the portion where the drive coil 8 does not exist by soldering at the same angle as the arrangement angle of the drive coil 8.

Although the electrical angle per coil is smaller than that of the conventional coil, the number of turns of all coils can be increased to the inner diameter side of the coil because the Hall element is not arranged inside the coil. It is possible to maintain the torque characteristics.

The stator yoke 7 is a magnetoresistive sensor M arranged at a predetermined distance from the FG magnet.
The R element 9 is attached. A thrust plate 14 is fixed to the upper portion of the housing 10 by a thrust plate stopper screw 15, and the shaft 1 is disposed below the thrust plate 14 and is attached to a thrust receiver 13 made of a material having high slidability. It is abutted by point contact. Here, the distance between the drive magnet 3 and the shaft 1 and the distance from the drive coil 8 to the thrust receiver 13 allow the drive magnet 3 and the drive coil 8 to have a desired distance.

An oil washer 12 is provided below the upper metal bearing and above the lower metal bearing.
It prevents the oil of the metal bearing from leaking to the center of the shaft.

A second pulley 18 is attached to the stator yoke 7 via a pulley support pin 17,
The power can be taken out by hanging the timing belt 16 on the second pulley 18. Here, a washer 19 is attached to the pin 17 and plays a role of preventing the counterpart pulley 18 from coming off.

The operation of the capstan motor configured as described above will be described below.

When the Hall element 21 detects the magnetic flux emitted from the drive magnet 3, a current corresponding to the detected magnetic flux is applied to the drive coil 8. At this time, a rotational force is generated in the drive magnet 3 according to Fleming's left-hand rule,
Shaft 1, rotor yoke 2, drive magnet 3 and F
The rotor unit constituted by the G magnet 4 rotates in a predetermined direction. By sequentially repeating this operation according to the rotation, the rotor unit can continuously rotate in a fixed direction to obtain a driving force.

The driving force of the capstan motor causes the shaft 1 to rotate to generate the power for feeding the tape, and the rotation of the pulley 5 causes the timing belt 16 to rotate to generate the power to wind the tape.

As shown in FIG. 6, the caulking portion of the housing of the capstan motor having such a structure is provided with a convex portion 20 concentrically with the shaft 1, and the convex portion 20 is provided at several places. Housing 10 by just crushing
Can be fixed to the chassis 7.

On the other hand, as a method of fixing the housing 10, in addition to the above-described caulking and fixing, a method of fixing with a housing mounting screw 23 as shown in FIG. 7 is also considered.

[0016]

However, in the crimping and fixing method as shown in FIG. 4 among the above-mentioned conventional examples, the timing belt 16 interferes with the convex portion 20 of the caulking portion, so that a predetermined clearance must be provided. However, it was difficult to reduce the thickness.

Further, as shown in FIG. 7, in the screw fixing type, since it is not possible to newly provide a screw fixing portion, it is difficult to miniaturize the mechanical chassis and the number of working steps is increased. Had been one cause.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a capstan motor which can be further thinned and downsized while maintaining the motor characteristics. is there.

[0019]

In order to achieve the above object, the present invention is directed to a plurality of coils arranged on a plane and a plurality of poles facing each other with a certain distance from the coils. A rotor unit having a magnetized permanent magnet; magnetic flux detection means equal in number to the number of drive phases; and power transmission means for transmitting the power of the motor to the outside between the coil and the rotor unit. Of the plurality of coils arranged concentrically with the capstan shaft at an equal angle, the coils are deleted by the number of drive phases, and the magnetic flux detecting means is arranged in the deleted part. In a capstan motor having power transmission means arranged so as to pass through the gap between the magnetic flux detecting means or the gap between the coil and the magnetic flux detecting means, the housing for supporting the capstan shaft for feeding the tape is crimped. The Butotsu section shape characterized in that the interference-free shape to said power transmission means.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side sectional view of a three-phase full-wave drive capstan motor according to the present invention, FIG. 2 is a layout view of coils and hall elements, a housing, a timing belt and a pulley of the same capstan motor, and FIG. It is a front view of the housing crimping part of the same capstan motor.

In FIG. 1, the shaft 1 is a housing 1.
It is rotatably supported by metal bearings 11 fitted to both ends of 0. The lower end of the shaft 1 is fixed to the rotor yoke 2 by fixing means such as press-fitting, and the multi-pole magnetized FG magnet 4 for detecting the rotational speed is fixed to the outer peripheral portion of the rotor yoke 2 by injection molding or the like. A drive magnet 3 magnetized to have several poles is fixed in the rotor yoke 2. A pulley 5 fitted to the shaft 1 is fixed to the magnet side of the rotor yoke 2, and a timing belt 16 is wound around the pulley 5 so that the power of the motor can be transmitted to the outside.

The housing 10 is fixed to a stator yoke 7 made of a silicon steel plate or the like, which is a material having excellent magnetic characteristics, by a caulking fixing means. Here, as shown in FIG. 5, a part of the caulking portion convex portion 20 is crushed and fixed like a caulking portion 22 at several places.

An FPC 6 is attached to the stator yoke 7, and as shown in FIG. 2, six drive coils 8 are arranged around the rotation axis of the shaft 1 via the FPC 6.
They are arranged close to each other at an angle of 0 degree, and are fixedly adhered to the drive magnet 3 with a predetermined space. At this time, the area occupied by the coil is 40 ° × 6 = 240 °,
No coil is present in the remaining 120 ° area. This area corresponds to three coils and is equal to the number of motor phases. In the portion where the drive coil 8 does not exist, a number of Hall elements 21 equal to the number of motor drive phases are attached by soldering at an angle equal to the arrangement angle of the drive coil 8.

Although the electrical angle per coil is smaller than that of the conventional coil, the number of turns of all the coils can be increased to the inner diameter side of the coil because the Hall element is not arranged inside the coil. It is possible to maintain the torque characteristic.

The stator yoke 7 is a magnetoresistive sensor M arranged at a predetermined distance from the FG magnet.
The R element 9 is attached. A thrust plate 14 is fixed to the upper portion of the housing 10 by a thrust plate stopper screw 15, and the shaft 1 is disposed below the thrust plate 14 and is attached to a thrust receiver 13 made of a material having high slidability. It is abutted by point contact. Here, the distance between the drive magnet 3 and the shaft 1 and the distance from the drive coil 8 to the thrust receiver 13 allow the drive magnet 3 and the drive coil 8 to have a desired distance.

An oil washer 12 is disposed below the upper metal bearing and above the lower metal bearing.
It prevents the oil of the metal bearing from leaking to the center of the shaft.

A mating pulley 18 is attached to the stator yoke 7 via a pulley supporting pin 17,
The power can be taken out by hanging the timing belt 16 on the counterpart pulley 18. A washer 19 is attached to the pulley support pin 17 to prevent the counterpart pulley 18 from coming off.

The operation of the capstan motor constructed as above will be described below.

When the Hall element 21 detects the magnetic flux emitted from the drive magnet 3, a current corresponding to the detected magnetic flux is applied to the drive coil 8. At this time, a rotational force is generated in the drive magnet 3 according to Fleming's left-hand rule,
Shaft 1, rotor yoke 2, drive magnet 3 and F
The rotor unit constituted by the G magnet 4 rotates in a predetermined direction. By sequentially repeating this operation according to the rotation, the rotor unit can continuously rotate in a fixed direction to obtain a driving force. The drive force of the capstan motor causes the shaft 1 to rotate to generate the power for feeding the tape, and the rotation of the pulley 5 causes the timing belt 16 to rotate to generate the power to wind the tape.

As shown in FIG. 3, the shape of the caulking portion of the housing of the capstan motor having such a structure is arranged at a position facing the second pulley 18, and the timing belt 16 has the same shape. The first caulking portion convex portion 24 provided with a predetermined space from the timing belt 16 so as not to interfere with each other.
And a second caulking portion convex portion 25 which is disposed in the gap between the shaft 1 and the hall element 21 and is provided with a predetermined gap from the timing belt 16 so as not to interfere with the timing belt 16.

With the above structure, the power transmission means including the power take-off pulley and the timing belt can be arranged between the rotor and the stator yoke.
It is possible to make the capstan motor as thin as possible, and it is possible to easily realize a small diameter capstan motor without extra protrusion.

As described above, according to the present invention, among the coils arranged at an equal angle with respect to the center of rotation of the rotor, as many coils as the number of phases are deleted, and the coil arrangement angle is set in the part where the coils are deleted. The hall element 21 is disposed at an equal angle to the second pulley 1 and the timing belt 16 for extracting power is disposed between the hall elements 21 adjacent to each other.
8, a first caulking portion convex portion 24 provided at a position facing the timing belt 16 and having a predetermined distance from the timing belt 16 so as not to interfere with the timing belt 16, the shaft 1 and the hall element 21. The second caulking portion convex portion 25, which is disposed in the gap and is provided at a predetermined distance from the timing belt 16 so as not to interfere with the timing belt 16, efficiently drives the stator yoke and the drive magnet. Since the transmission means can be arranged, there is no extra protrusion from the motor, the outer diameter of the rotor can be reduced, and a small capstan motor can be easily obtained while maintaining the characteristics of the motor. .

[0034]

As is apparent from the above description, according to the present invention, a plurality of coils arranged on a plane and a plurality of poles facing each other with a constant distance from the coils. A rotor unit having a magnetized permanent magnet; magnetic flux detection means equal in number to the number of drive phases; and power transmission means for transmitting the power of the motor to the outside between the coil and the rotor unit. Of the plurality of coils arranged concentrically with the capstan shaft at an equal angle, the coils are deleted by the number of drive phases, and the magnetic flux detecting means is arranged in the deleted part. In a capstan motor comprising power transmission means arranged so as to pass through the gap between the magnetic flux detecting means or the gap between the coil and the magnetic flux detecting means
Since the convex shape of the caulking portion of the housing that supports the capstan shaft that feeds out the tape has a shape that does not interfere with the power transmission means, the characteristics of the capstan motor are maintained and the motor is made thinner and smaller. The effect that can be achieved is obtained.

[Brief description of drawings]

FIG. 1 is a side sectional view of a capstan motor according to the present invention.

FIG. 2 is a layout view of a coil, a hall element, a housing, a pulley and a timing belt of the capstan motor according to the present invention.

FIG. 3 is a front view of the housing of the capstan motor according to the present invention as viewed from the convex portion of the caulking portion.

FIG. 4 is a side sectional view of a conventional capstan motor in which power transmission is arranged in a gap between a rotary unit and a stator coil.

FIG. 5 is a layout view of a coil, a hall element, a housing, a timing belt and a pulley of a conventional capstan motor.

FIG. 6 is a front view of a conventional capstan motor as seen from a housing caulking portion convex portion.

FIG. 7 is a side view of a conventional capstan motor in which a housing is fixed to a chassis by screwing.

[Explanation of symbols]

1 shaft 2 rotor yoke 3 drive magnet 4 FG magnet 5 pulleys 6 Flexible printed circuit board 7 Stator yoke 8 drive coil 9 MR element 10 housing 11 Metal bearing 16 Timing belt 20 Crimping part convex part 21 Hall element 22 Crimping section 23 Housing fixing screw 24 Housing caulking part convex part 25 Housing caulking section convex section

Claims (2)

[Claims] 1. A rotor unit comprising a plurality of coils arranged on a plane, permanent magnets which are face-magnetized to a plurality of poles which are opposed to each other at a constant interval, and the number of drive phases. And a power transmission means for transmitting the power of the motor to the outside between the coil and the rotor unit, and disposing the coils concentrically with the capstan shaft at equal angles. Of the plurality of coils arranged, the number of coils corresponding to the number of driving phases is deleted, and the magnetic flux detecting means is arranged in the deleted portion, and the gap between the magnetic flux detecting means or the gap between the coil and the magnetic flux detecting means is eliminated. In a capstan motor having power transmission means arranged so as to pass through, the convex shape of the caulking portion of the housing supporting the capstan shaft for feeding the tape is changed to a shape that does not interfere with the power transmission means. Capstan motor, characterized in that the. 2. A first fixed to a capstan shaft.
Through the pulley means, the second pulley means outside the motor for transmitting the power of the capstan by the belt means for transmitting power, and the gap between the plurality of magnetic flux detecting means or the gap between the coil and the magnetic flux detecting means. The belt means arranged, the first caulking portion convex portion of the housing, which is arranged at a position opposed to the second pulley means and has a predetermined distance from the belt means, the capstan shaft, and the 2. The capstan motor according to claim 1, further comprising a second caulking portion convex portion of the housing which is arranged between the belt means and the magnetic flux detecting means and has a predetermined distance from the belt means.