JPS58207861A - Motor - Google Patents

Abstract

PURPOSE:To strengthen the rotary force of the second rotor in a motor as required by releasably connecting the first rotor which generates a synchronous rotation torque to the second rotor which individually generates a torque from the first rotor. CONSTITUTION:When a drive current is supplied by a control circuit to a coil 5, the first rotor 9 rotates at the desired rotating speed. When a rotor magnet 9b rotates in this manner, a torque added with eddy current torque or hysteresis torque is gererated in the second rotor 11, and a rotary torque of the same direction as the rotation of a rotor magnet 9b is generated at the second rotor 11. Simultaneously, therotary force of the first rotor 9 is added to the rotary torque of the second rotor 11 by frictional force generated at the stepped end 7a by the attracting force of the stepped end surface 7a of a shaft 7 to the second rotor 11. In this manner, the resultant torque produced at the second rotor 11 can be extracted by a pinion 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a first rotor that takes out synchronous rotational torque and a second rotor that takes out asynchronous rotational torque with respect to a rotating magnetic field generated by a coil. The present invention relates to an electric motor equipped with the following.

Conventionally, when using an electric motor to drive a cassette tape recorder, for example, the capstan shaft was made to correspond to the output shaft of a synchronous electric WJ machine, and the reel shaft that wound the tape was provided with a separate motor to provide the drive source. Alternatively, the driving force was obtained from a synchronous motor via an idler or a synchronous motor. However, the former example requires two or more electric motors. In addition, in the latter example, the rotational speed of the capstan shaft and the rotational speed of the reel shaft do not always have a constant proportional relationship, so a mechanical sliding mechanism was required to rotate the reel shaft.

However, these sliding mechanisms have a problem in that their characteristics change over time.

In view of the above points, this invention has been made to be suitable for this type of use, and has a single electric motor with two output shafts, and a mechanical movement mechanism. The object of the present invention is to provide an electric motor that does not require a reel shaft, has stable drive characteristics of the reel shaft, and can change the drive torque to the Lee and /l/axes as necessary. DESCRIPTION OF THE PREFERRED EMBODIMENTS An electric motor according to an embodiment of the present invention will be explained below using the drawings.

1 to 4 are plan views of a cassette tape recorder as an example of a magnetic recording and reproducing device to which an embodiment of the present invention is applied, which provides the background of the present invention, and FIG. 1 shows the normal direction. Steady running (playback or recording) to (FP)
The state of time, Figure 2 is fast forwarding in the normal direction, ? (FF) state, Figure 3 shows steady running in the rewinding direction (playback or recording)
The state at (R, P,), Figure 4 is fast forwarding in the rewinding direction! 0 (RW) state. Further, FIGS. 5 to 9 show an electric wJ according to an embodiment of the present invention.
FIG. 5 is a longitudinal side view of the machine, and FIG.
The figure is a sectional view taken along the line ■-■ in Figure 5, and Figure 7 is a cross-sectional view taken along the line ■-■ in Figure 5.
FIG. 8 is a sectional view of the linking means, and FIG. 9 is a side view of essential parts showing the capstan and idler portion of the device shown in FIGS. 1 to 4.

In Figures 5 to 8, the coil housing (3) of the electric motor* (1) is fixed integrally with the board (2).
) is made of an insulator such as plastic, and a bearing (4) is formed in the center, and a coil TV (5) and a magnetic flux detection element (6) are held integrally. A pulley (8) for transmitting rotational force to the capstan is integrally fixed to one end of the shaft (7), and this shaft (7) is fixed to the bearing (4). It is fitted so that it can rotate freely. A rotor disc (9a) having a rotor magnet (9b) is coaxially fixed to the pulley (8) to form a first rotor (9). Here, the rotor magnet (9b) has a mechanical angle of 4 as shown in FIG.
It is alternately magnetized to N, S, and poles every 5 degrees, and
The rotor disc (9a) also serves as the magnetic circuit of the rotor magnet (9b). (b) is the second rotor, which is disc-shaped and is made of a material with eddy current characteristics such as an electromagnetic soft iron plate and a material with hysteresis characteristics such as a hard magnetic material, and the rotor magnet ) (9b
) also serves as a magnetic circuit for the spatial magnetic flux from. That is,
The second rotor (6) is fitted to the shaft (7) so as to rotate freely, and the pinion (6) is integrated with the second rotor (b). is fixed to. Therefore, an attractive force due to magnetic force acts between the rotor magnet (9b) and the second rotor (b), and this attractive force is applied to the end surface (7a) of the stepped portion provided on the shaft (7).
At the contact portion with the end face of the second rotor (b) facing
t-force. Therefore, the rotational force of the first rotor (9) contributes to the rotational force of the second rotor (6) via the frictional force.

In the above configuration, the magnetic flux of the rotor magnet (9b) is detected by the magnetic flux detection element (6), and the control circuit (
If a drive current is supplied to the rotor A/ (5) (not shown), it becomes a two-phase eight-pole synchronous motor and the first rotor (9) rotates. Therefore, the external synchronization signal and the first rotor (9
) to control the input to the coil (5) by comparing the control signal (detected by a known electromagnetic or optical method; the generator is not shown) generated in accordance with the rotation of the coil (5). , the rotation of the first rotor (9) can be controlled to a desired rotation speed. In this way the rotor magnet) (
9'b), that is, synchronous rotational torque can be obtained at the pulley (8). Note that when it is necessary to reverse the rotation direction, it is possible to do so by a known method such as reversing the polarity of the magnetic flux detection element (6). Further, as described above, a magnetic circuit is formed by the spatial magnetic flux of the rotor magnet (9b) passing through the second rotor (b). When the rotor magnet (91)) rotates, the second rotor (b) receives an eddy current torque or a hysteresis characteristic, or both (depending on the material of the disk constituting the second rotor). Different types. ) is generated and the rotor magnet () is generated in the second rotor (6).
(91)) The revolving door yaw occurs in the same direction as the rotation. At the same time, the rotation from the first rotor (9) is caused by the frictional force generated at the part (7a) due to the suction force between the stepped part end face (7a) of the shaft (7) and the second rotor (B). Power is also second
Adds to the rotating torque of the rotor. In this way the second
The resultant torque generated in the second rotor (6) is transferred to the second rotor (6).
It is possible to take it outside by means of a pinion (6) that is integrated with the shaft.

The torque generated in the second rotor (B) increases as the difference between the rotation speed of the shaft (7) (synchronous rotation speed) and the rotation speed of the second rotor (6) increases. FIG. 10 shows the relationship between the resultant torque generated in this way and the relative rotational speed (difference between the rotational speeds of the first rotor and the second rotor). In the figure (
Part a) is a torque component based on frictional force, and shows that torque is generated regardless of the relative rotational speed. (b)
is a component of the torque electromagnetically generated in the second rotor (6), and indicates that the generated torque increases in proportion to the relative rotational speed.

The torque that can be extracted from the second rotor (6) in this way is not utilized for rotational force as electromagnetic and mechanical losses in conventional electric motors of this type. Since the rotational force obtained by the second rotor (6) can obtain a nearly constant torque regardless of the rotation speed, if it is adopted for the rotational drive of the magnetic chiapuri Tμ, it will be possible to wind the tape at a constant rate. Torque can be obtained, and stable long-life characteristics can be obtained without the need for a mechanical sliding mechanism.

Next, as shown in FIG.
A metal bearing (to) is provided at the center of the case a4, and disk-shaped permanent magnets Qaa) and Qab) are respectively fixed to the inner surfaces of the pair of flanges so as to face each other. In this case, the pair of permanent magnets Q6b) are arranged so that their N and S poles face each other, as shown in the figure, and the case (B) is made of a highly permeable material such as an electromagnetic soft iron plate. one magnetic circuit is closed and each permanent magnet Q6a)
Q6b) Spatial magnetic flux is formed between the open ends. Such a linking means (Ll is 6), and a supporting shaft (10) fixedly protruding from the arm at the protruding end of the arm in the above-mentioned moving means (young) is rotatably mounted. It is attached.

That is, the metal bearing (a) of the linking means (+, l) is externally fitted onto the support shaft α so that it can only rotate freely.

On the other hand, the arm (g) is, for example,
As shown in the figure, its base end is pin-coupled to a plunger (E) of an electromagnetic solenoid (E) installed on a fixed side [for example, the board (2)], so as to be relatively swingable, and , the intermediate portion of which is a pin), for example, is swingably supported on the substrate (2), and furthermore, the substrate (2)
) is always biased in the direction of protruding the plunger by a return spring tensioned between the plunger and the plunger. The means of transportation (b) is composed of each of the elements (goods) to) explained above.

Here, the linking means (13 is connected to its permanent magnet 0 by deenergizing and energizing the electromagnetic solenoid (4)) 0
A first position where the spatial magnetic flux generated between the two rotors (6°C) is linked to the first rotor (9) and the second rotor (b), and a second position where this link is released. It is designed to be moved when it opens. Specifically, in the first position, the linking means (13 is its permanent magnet Q6a)
Qa'b) in a non-contact state between the first rotor (9)
and a part of the second rotor (b), and in the second position, the above-mentioned spatial magnetic flux is applied to the first rotor, (9) and the second rotor.
It becomes a state of being cut off from the rotor distributor 6.
In order to ensure the above-mentioned first position, as shown in FIG. 6, a notch ( 3
a) is formed (see Figures 6 and 8).

Next, a magnetic recording and reproducing apparatus employing the above-mentioned electric motor (1) will be explained with reference to FIGS. 1 to 4 and FIG. 9.

In Figures 1 to 4, (3) is a normal direction capstan, (Rotation) is a rewind direction capstan, and as shown in Figure 9, the cap is attached to the board (2). The pulley part (8
)@b). In Figure 1, electric motor (1)
The shaft (7) is mounted to rotate in the A direction, the pulley (8) also rotates synchronously in the A direction, and the rubber belt () is hung to rotate the normal direction capstan (3) in the B direction. , the magnetic tape (7) is held between normal direction pinch rollers (), and the magnetic tape (7) is run at a constant speed in the C direction. In addition, the pinch roller in the rewinding direction @b
) is not pressed against the unwinding capstan (8) in FIG. 1, and the pinion (6) rotates in the same direction as the shaft (7), ie in six directions. ma) is a normal direction reel gear, and as shown in its cross-sectional view in FIG. ,
It is made to rotate freely by a fixed shaft (E) provided on the substrate (2). On the other hand, a rewinding direction υ゛-reel gear 1b is provided with the same structure on the part of the substrate (2) facing the normal direction reel gear 01a).
) is attached. That is, 02b) is that'
J-/'7 section, 03b) is a fixed shaft.

Next, ``■'' is an idler gear, which is arranged so as to transmit rotational force between the gear, the pinion (6), the normal direction reel gear (31a), and the rewinding direction reel gear (31b). In other words, the idler gear rotates the arm (not shown) so that the center of the shaft (7) is the same center of rotation.
It is placed on top and constantly meshes with the pinion (6),
It moves according to the rotational direction of the pinion (2), and the normal direction reel gear cIm> and the rewinding direction V-V gear 1: (lb
) is selectively engaged with and locked with one of the above rotational directions, and transmits the rotational force of the pinion (2) to the reel gear C(la)t or 01b);
In FIG. 1, the pinion (6) is rotating in the A direction.

Therefore, the idler gear rotates in the D direction and the normal direction reel gear 01a) rotates in the E direction to wind up the magnetic tape. In this case, due to the action of the electric motor (1) mentioned above, winding can be performed with almost constant tension regardless of the number of rotations of the 1μ gear Cl1a) in the normal direction, thereby providing a magnetic tape running system with good performance. Obtainable.

FIG. 2 shows a state of rapid forwarding in the normal direction. At this time, it is necessary to transmit a strong rotational force to the reel part of the normal direction reel gear.

Therefore, in this case, by energizing the electromagnetic solenoid member, the arm is swung in the G direction against the energizing force of the return spring (2), and this linkage is established.
The means (la) is moved to the first position. When this is done, the spatial magnetic flux generated between the permanent magnets 06a) α (to) is transferred to the first rotor (9), the shaft (7) and the second Since a closed magnetic path is formed by the rotor (B), the rotor magnet (
9b) (in the electric motor of this example, the torque generated at
The torque of the first rotor (9) also increases the torque of the second rotor (b). ) is transmitted to the second rotor (6) via the linkage means (to). That is, permanent magnet Q6a)
Q61)) The magnetic flux generated between the first rotor (
9) and the second rotor east, an electromagnetic coupling (forced by eddy current torque or hysteresis torque) is established between the first rotor (9) and the linking means (to). ) is configured,
The linking means also rotates in the direction G in FIG. Similarly, an electromagnetic coupling is configured between the linking means (9) and the second rotor (B), and the torque of the first rotor (9) is combined with the torque of the second rotor (9). Then, the normal direction lead/
Since the signal is transmitted to the L' gear la), the reel part 02a)
A strong torque is transmitted to the hub portion of the audio cassette (to) through the cassette, which generates a rotational force in the E direction, and the magnetic tape (2) is rapidly forwarded in the normal direction. At this time, naturally, the normal direction capstan (3) and the normal direction pinch roller (2) are not in contact with each other.

FIG. 3 shows a state of steady running (playback or recording) in the rewinding direction. During rewinding, the first rotor (9) and second rotor (6) rotate in the H direction (opposite direction to Figures 1 and 2), so the capstan in the unwinding direction rotates in the unwinding direction. In addition, the magnetic tape) is held between pinch roller sails in the unwinding direction and is run at a constant speed in the J direction. Then, the pinion (6) that transmits the winding torque of the tape (2) also rotates in the H direction, the idler gear rotates in the crooked direction, and the unwinding reel gear (1lb) rotates in the L direction. (on magnetic tape). In this case, the electromagnetic solenoid (4) is deenergized and the linking means (branch) is returned to the second position by the biasing force of the return spring (4).

As described above, according to this embodiment, the switching operation from steady running in the normal direction (the state shown in FIG. 1) to steady running in the rewinding direction (the state shown in FIG. 3) is performed simply by switching the electric motor (1). Since it is only necessary to reverse the rotation direction and at the same time selectively switch the pressing of )@b) on the pinch roller, an automatic reversing type audio cassette mechanism can be easily constructed.

Next, FIG. 4 shows a state of rapid forwarding (RW) in the rewinding direction. At this time, the first rotor (9) and the second
The rotor (6) rotates in the H direction and the electromagnetic solenoid (4
) is energized and energized, the linking means (to) operates and the torque from the first rotor (9) is also transmitted to the rewinding direction v - /L' gear 01b), and the Rotational torque sufficient for the rewinding operation is supplied to the rewinding operation. In this case as well, switching from fast forwarding (the state shown in FIG. 2) to rewinding (the state shown in FIG. 4) requires only reversing the direction of rotation of the electric motor, and a simple mechanism can be realized.

As described above, according to the present invention, in the electric motor,
The rotation of a first rotor that generates a synchronous rotational torque and the rotation of a second rotor that obtains a driving force by the rotation of this first rotor and rotates independently from the first rotor are releasably linked. Since the linkage means is provided, if the rotational force extracted from the second rotor is insufficient only by the low torque produced by the second rotor, the rotational force is extracted from the first rotor via the linkage means. By transmitting the synchronous rotational torque from the rotor to the second rotor, there is an effect that the rotational force extracted from the second rotor can be strengthened as necessary.

[Brief explanation of the drawing]

1 to 4 are plan views of a cassette tape recorder equipped with an electric motor according to an embodiment of the present invention. 3 shows a steady running state in the rewinding direction, FIG. 4 shows a fast forwarding state in the rewinding direction, and FIG. 5 shows a part of the electric motor according to an embodiment of the present invention. 6 is a sectional view taken along the line M-VI in FIG. 5, and FIG.
8 is a vertical sectional view of the linking means that is a part of the electric motor, and FIG. 9 is a main part showing the capstan and idler of the device shown in FIGS. 1 to 4. The side view, FIG. 10, is a diagram showing the characteristics of the electric motor. (1)...Electric motor, (3)...Coil housing,
(5)... Carp A/, (7)... Axis, (9)...
First rotor, (9~... rotor disk, (9b)...
・Rotor magnet, (6)...Second rotor, (1
3...Coordination means, (b)...Case, Qaa) Q
gb)...Permanent magnet, (B)...Transportation means, (G)
...Arm, wing...support shaft, (4)...electromagnetic solenoid, (4)...return spring. In addition, in the figures, the same reference numerals indicate the same or similar parts. Agent Makoto Kuzuno - (11 people in the evening) -: v5 gu Chiku 6 = ¥7γ Kure 8 = 9th ward j 10! −> /? ,? M

Claims (2)

[Claims] (1) A rotatable first rotor comprising a coil that generates a rotating magnetic field and a magnet facing the filter, and a rotational driving force is obtained from the first rotor and applied to the first rotor. A second rotor that is individually rotatable, a linking means that rotatably supports a pair of disk-shaped permanent magnets that are opposed to each other and have opposing surfaces magnetized with different polarities, and this linking means, An electric motor comprising a moving means for moving the first rotor and the second rotor between a position where the first rotor and the second rotor are linked by a spatial magnetic flux between a pair of disc-shaped permanent magnets and a position where the link is released. (2) The electric motor according to claim 1, wherein a highly permeable material is provided on each non-opposed surface of the pair of disc-shaped permanent magnets.