JPH09149602A - Dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dynamo-electric machine from which the harmful influence of a magneto-electrical noise is eliminated. SOLUTION: A dynamo-electric machine has a stator core 2 which has salient poles 2a on which coils 1 are applied, a board 3 which holds the stator core 2 and a rotor which has driving magnets 5 which are so provided as to face the stator core 2. The board 3 has a conductor pattern 7 which is connected to the ground potential. The stator core 2 is fixed to the board 3 by conductive tightening members 4 which are electrically connected to the conductor pattern 7. Further, the one of the ends of the conductor pattern 7 is connected to the part of a connector terminal 8 which is connected to the ground potential.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine applicable to rotary cylinder heads used in various VTRs and the like.

[0002]

2. Description of the Related Art For example, a rotary cylinder head shown in FIG. 6 is known as a rotary cylinder head used in various VTRs. In FIG. 6, a boss member 42 is fixed to the outer peripheral surface on the upper side of the fixed shaft 39. A board 33 made of phenolic resin or the like is formed on the upper end surface of the boss member 42 by using screws or the like.
Is attached. The substrate 33 has a hole in the center, and the upper end of the fixed shaft 39 projects from this hole.

On the lower surface side of the substrate 33, and moreover, the boss member 4
A core holder 41 is attached on the outer peripheral side of the position 2. A stator core 32 is attached to the lower end surface of the core holder 41. The stator core 32 is configured by laminating a plurality of magnetic plates, and is provided with a plurality of salient poles outward in the radial direction. Also,
A coil 31 is wound around each salient pole.

A screw 46 is inserted from the upper surface side of the substrate 33. The screw 46 penetrates the core holder 41, and its tip is screwed into the stator core 32. The stator core 32 and the core holder 42 are fixed to the substrate 33 by using the screws 46. The substrate 33, the stator core 32, and the core holder 41 constitute a motor stator.

An inner ring of a ball bearing 43 is fitted and fixed to the outer peripheral surface of the fixed shaft 39 below the stator. An upper drum 44 is attached to the outer ring of the ball bearing 43. The ball bearing 43 allows the upper drum 44 to rotate with respect to the stator. The upper drum 44 has a peripheral wall 44b on the upper side and a peripheral wall 44c on the lower side with the plane portion 44a as the center in the axial direction, and the peripheral wall 44b is configured to cover the lower side portion of the stator core 32. The bottom surface of the rotor case 40 is attached to the end surface of the upper drum 44 inside the peripheral wall 44b. Rotor case 40
Has a cup-like shape and has a peripheral wall on the outer periphery, and the peripheral wall covers the stator core 32 from below.
A drive magnet 35 is attached to the inner surface of the peripheral wall, and the inner peripheral surface of the drive magnet 35 faces the salient poles of the stator core 32 with a constant gap. Therefore, by controlling the energization of the coil 31 wound around the salient pole of the stator core 31, the driving magnet 3
5 is urged, and as a result, the upper drum 44 is rotationally driven. Further, the rotor case 4 which is such a rotating member
0, the upper drum 44, the drive magnet 35, and the like constitute a rotor of the motor.

Heads 46 are attached at a plurality of locations on the lower end surface of the peripheral wall 44c of the upper drum 44. A rotary rotary transformer 47 is attached to a lower end surface of the upper drum 44 inside the peripheral wall 44c so as to surround the fixed shaft 39.

Further, a lower drum 45 is fitted and fixed to the outer peripheral surface of the fixed shaft 39 below the upper drum 44. A peripheral wall 45 a protruding toward the upper drum 44 is formed on the outer periphery of the lower drum 45. A fixed rotary transformer 47 is attached to the upper surface inside the peripheral wall 45a so as to surround the fixed shaft 39. The upper end surface of the fixed rotary transformer 48 faces the lower end surface of the rotary rotary transformer 47 located above,
The rotary transformer 47 on the rotation side and the rotary transformer 48 on the fixed side constitute a rotary transformer 50. The rotary transformer 50 is configured so that signals can be magnetically exchanged between the rotary rotary transformer 47 and the fixed rotary transformer 48. That is, the signal recorded on the magnetic tape (not shown) is read by the head 46, and is rotated from the rotary rotary transformer 47 to the fixed rotary transformer 48.
Is configured to be transmitted to. Further, when a signal is transmitted from the fixed rotary transformer 48 to the rotary rotary transformer 47, the head 46 records the signal on the magnetic tape.

[0008]

The signal obtained by the cylinder device configured as described above is amplified outside the cylinder device. The signal level in the cylinder system is very low and sensitive to noise. However, electromagnetic noise is likely to occur at the stator core 32 portion of the cylinder device,
The electromagnetic noise generated in the stator core 32 portion jumps into the rotary transformer 50 and the head 46, becomes noise, and is an image signal obtained from a magnetic tape (not shown).
Also, the S / N ratio of the signal written to the magnetic tape is adversely affected. In particular, in the cylinder device, since the signal level is small, the degree of adverse effect is large. Therefore, in order to eliminate the above electromagnetic noise, conventionally, an additional component such as a shield plate has to be provided, and the manufacturing cost has risen.

There is also a method of electrically connecting the stator core 32 and the fixed shaft 39 and grounding the fixed shaft 39 so that electromagnetic noise generated in the stator core 32 is released from the fixed shaft 39 to the outside. Is close to the rotary transformer 50, the magnetoelectric noise flowing through the rotary shaft 36 reaches the rotary transformer 50 and the head 46, so that the magnetoelectric noise cannot be eliminated.

The present invention has been made in order to solve the above problems of the prior art, and an object of the present invention is to provide a rotating electric machine in which the adverse effects of magnetoelectric noise are eliminated.

[0011]

According to the first aspect of the present invention,
A rotating electrical machine comprising a stator core having a coil wound around a salient pole, a substrate holding the stator core, and a rotor having a driving magnet arranged to face the stator core, wherein the substrate has a conductor pattern connected to a ground potential. Have,
The stator core is fixed to the substrate with a conductive fastening member, and the fastening member and the conductor pattern are electrically connected.

The invention according to claim 2 is characterized in that one end of the conductor pattern is connected to a part of the connector terminal, and the connector terminal is connected to the ground potential.

Magnetoelectric noise generated in the stator core is caused by a fastening member used for mounting the stator core,
It escapes to the conductor pattern formed on the substrate and connected to the ground potential.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a rotating electric machine according to the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, a boss member 12 is fixed to the outer peripheral surface on the upper side of the fixed shaft 9. A substrate 3 made of an insulating material such as phenol resin is attached to the upper end surface of the boss member 12 by using a screw 16. The substrate 3 has a hole in the center, and the upper end of the fixed shaft 9 projects from this hole.

At the lower end side of the substrate 3, and further, the boss member 12
The core holder 11 is attached to the outer peripheral side, and the stator core 2 is attached to the lower end surface of the core holder 11. The stator core 2 is configured by laminating a plurality of magnetic plates, and is provided with a plurality of salient poles 2a toward the outer side in the radial direction. Also,
The coil 1 is wound around each salient pole 2a.

A screw 4, which is a conductive fastening member, is inserted from the upper surface side of the substrate 3. The screw 4 penetrates the core holder 11, and the tip end is screwed into the stator core 2. For this reason, the stator core 2
The core holder 12 is fixed to the substrate 3. In addition, the substrate 3, the stator core 2, and the
Each member of the core holder 11 constitutes a motor stator.

In FIG. 1, the screw 4 is provided on the substrate 3.
The hole into which is inserted is 3 on a concentric circle centered on the fixed shaft 9.
One is formed. Land portions 7b, 7b ', 7b "made of thin film conductors are formed on the outer peripheral edge of each hole. Of the land portions 7b, 7b', 7b", the land portion 7 is formed.
b is electrically connected to the land portion 7b ″ by a pattern 7c made of a thin film conductor, and the land portion 7b ′ is electrically connected to the land portion 7b ″ by a pattern 7d made of a thin film conductor. A pattern 7e made of a thin-film conductor foil is drawn out from the land 7b ", and the end of the drawn pattern 7e is a square land 7a. This land 7a is formed. ,
It is connected to a part of the connector terminals 8 mounted on the substrate 3 by soldering or the like. The terminal of the connector terminal 8 to which the land portion 7a is connected is connected to a ground potential (not shown). Such a land portion 7a,
7b, 7b ', 7b "and patterns 7c, 7d, 7
The conductor pattern 7 is composed of e and the like. By inserting the screw 4 on the board 3 and attaching the core holder 11 and the stator core 2 to the board 3, the land portions 7b, 7b ′, 7b ″ on the board 3 come into contact with the head of the screw 4, and the screw 4 And the pattern 7 are electrically connected.

In FIG. 2, the inner ring of the ball bearing 13 is fitted and fixed to the outer peripheral surface of the fixed shaft 9 below the stator. The ball bearing 13 allows the upper drum 14 to rotate with respect to the stator. An upper drum 14 is attached to the outer ring of the ball bearing 13. The upper drum 14 has a boss portion 14a at the center, and the inner peripheral surface of the boss portion 14a is attached to the outer ring of the ball bearing 13. Further, a portion of the upper drum 14 outside the boss portion 14a is a step portion 14b.
The rotor case 10 is attached to b with screws 15.

The rotor case 10 is cup-shaped and has a hole 10a at the center of the bottom surface.
The four bosses 14a are inserted. Further, the lower end surface of the rotor case 10 has a step portion 14b of the upper drum 14a.
Is placed on top. Further, the rotor case 10 has a peripheral wall on the outer periphery, and the drive magnet 5 is attached to the inner surface of the peripheral wall. The drive magnet 5 faces the laminated surface of the salient poles 2a of the stator core 2 described above with a constant gap. Therefore, the drive magnet 5 is biased by controlling the energization of the coil 11 wound around the salient pole 2a, and the rotor case 10 and the upper drum 1 are urged.
4 is driven to rotate. A rotor of the motor is composed of the rotor case 10, which is a rotating member, the upper drum 14, the driving magnet 5, and the like.

On the lower end surface of the upper drum 14, a head (not shown) used for reading a signal recorded on a magnetic tape or writing a signal on the magnetic tape is attached. Also, the upper drum 14
A rotary rotary transformer (not shown) is attached to the lower end surface of the. Further, the upper drum 14 of the fixed shaft 9
A lower drum is attached to the lower outer peripheral surface. The lower drum has a peripheral wall protruding toward the upper drum 14,
A fixed-side rotary transformer is attached inside the peripheral wall. A rotary transformer is composed of the rotary rotary transformer and the fixed rotary transformer.

In the rotating electric machine having the above-mentioned structure, the screw 4 is a conductive member, and therefore the stator core 2 is formed by using the screw 4.
Is fixed to the substrate 3, the stator core 2 and the substrate 3 are electrically connected. Further, since the screw 4 is electrically connected to the conductor pattern 7, the stator core 2 and the conductor pattern 7 are also electrically connected via the screw 4 therebetween. Therefore, electromagnetic noise generated in the stator core 2 can be made to flow from the screw 4 to the conductor pattern 7, and can be released from the end of the conductor pattern 7 to the ground potential via the connector terminal 8.
In this way, by releasing the electromagnetic noise generated in the stator core 2 to the ground potential, it is possible to prevent the electromagnetic noise from flying to the rotary transformer and the head, and it is possible to largely eliminate the noise. Further, the electromagnetic noise generated in the stator core 2 is escaped by the conductor pattern 7 formed on the substrate 3 by the screw 4, and does not approach the rotary transformer or the head which is easily affected by the noise. Therefore, this can also prevent electromagnetic noise from flying to the rotary transformer and head,
The S / N ratio of the signal is greatly improved. Further, in order to eliminate electromagnetic noise, it is not necessary to newly provide a shield plate as an additional component, and moreover, the conductor pattern 7 can be formed in the same manner as other patterns formed on the substrate 3, The assembly cost can be kept low.

In the above embodiment, the three screws 4
And the land portions 7b, 7b ′, 7b ″ of the conductor pattern 7 are directly connected. However, as shown in FIG. 3, the head of the screw 4 and the land portions 7b, 7 of the conductor pattern 7 are
A washer 20 may be interposed between b ′ and 7b ″. Even with such a configuration, the same effect as in the above-described embodiment can be obtained. In this case, the screw 4 and the washer 2 are provided.
0 is the fastening member.

In the above embodiment, the substrate 3 is made of an insulating material such as phenol resin. However, the substrate 3 is not limited to this, and a conductive material such as iron may be used for the substrate 3. However, when the substrate 3 is made of a conductive material such as iron, the surface of the substrate 3 is covered with an insulating layer, so that the substrate 3
It is difficult to ground itself and release magnetoelectric noise.
Therefore, when the substrate 3 is made of a conductive material, the conductor pattern 7 connected to the ground potential is formed on the insulating layer,
It is preferable that the conductor pattern 7 has a structure that allows electromagnetic noise to escape.

Further, in the above embodiment, the conductor pattern 7 was formed on the upper surface of the substrate 3, but as shown in FIG. 4, the conductor pattern 7 is formed on the lower surface of the substrate 3, that is, the surface on the side of the stator core 2. 7 may be formed. In FIG. 4, a core holder 11 is arranged on the lower surface of the substrate 3 where the conductor pattern 7 is formed, and a stator core 2 is arranged on the lower end surface of the core holder 11. The core holder 3 and the stator core 2 are It is inserted from the second side, and the front end is fixed to the substrate 3 by a screw 4 which is a conductive fastening member screwed into the substrate 3. When the screw 4 penetrates the conductor pattern 7 between the substrate 3 and the core holder 11, the screw 4 and the pattern 7 are electrically connected, and the stator core 2 and the conductor pattern 7 are electrically connected. Therefore, even with such a configuration, the electromagnetic noise generated in the stator core 2 can be released to the conductor pattern 7 connected to the ground potential, and the same effect as that of the above-described embodiment can be obtained.

In the embodiment shown in FIG. 4, the screw 4
The contact area between the conductor pattern 7 and the conductor pattern 7 is small. Therefore, when the conductor pattern 7 is formed on the lower surface side of the substrate 3 as shown in FIG. 4, a large contact area between the conductor pattern 7 and the screw 4 may be secured as follows.

As shown in FIG. 5A, the screw 4 of the substrate 3
A hole 3a having a diameter larger than the diameter of the screw 4 is formed at a portion into which the tip of is screwed, and a nut 21 is embedded in the hole 3a. Further, the conductor pattern 7 is formed on the lower surface side of the substrate 3. The land portion, which is the end portion of the conductor pattern 7, extends to the lower end surface of the nut 21, and the nut 21 and the conductor pattern 7 are electrically connected. For such a screw hole at the center of the nut 21,
By screwing the ends of the screws 4 penetrating the stator core 2 and the core holder 11 (not shown), the stator core 2 and the conductor pattern 7 (not shown) can be electrically connected, and a screw is provided via a nut 21 between them. A large contact area between 4 and the conductor pattern 7 can be secured.

Further, without using the nut 21, as shown in FIG.
As shown in FIG. 3, when the hole 3b into which the screw 4 is screwed is formed in the substrate 3 and the conductor pattern 7 is formed on the substrate 3, the land portion which is the end portion of the conductor pattern 7 has the hole 3b.
It may be extended to the inside of. By doing so, when the screw 4 is screwed into the hole 3b, a large contact area between the screw 4 and the conductor pattern 7 can be secured. The screw 4 may be a self-tapping screw.

Further, in the above embodiment, the screw 4 and the washer 20 used together with the screw 4 are used as the fastening member, but the present invention is not limited to this. A core holder made of a conductive material may be used as the fastening member. The stator core is fixed to the core holder by rivet caulking or the like, the core holder to which the stator core is fixed is fixed to the substrate, and the core holder is connected to the conductor pattern connected to the ground potential of the substrate. You can do it like this. Even with such a configuration, electromagnetic noise generated in the stator core can be released from the core holder to the conductor pattern, and the fastening member can be the screw 4 or the washer 20.
Has the same effect as the case.

[0029]

According to the present invention, the substrate has the conductor pattern connected to the ground potential, the stator core is fixed to the substrate by the conductive fastening member, and the fastening member and the conductor pattern are electrically connected. Therefore, the electromagnetic noise generated in the stator core can be released to the conductor pattern connected to the ground potential via the fastening member, the magnetic noise is prevented from flying, and the signal S / N ratio is greatly improved. can do. Further, since the magnetic pattern is escaped by the conductor pattern at a location away from the components such as the rotary transformer and the head which are easily affected by the magnetic pattern, the S / N ratio of the image or video signal can be greatly improved. It will be possible. Furthermore, since it is not necessary to newly provide a shield plate or the like as an additional component, it is possible to suppress the cost increase.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a rotary electric machine according to the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is a step view showing another embodiment of the rotating electric machine according to the present invention by enlarging a main part.

FIG. 4 is a step view showing another embodiment of the rotating electric machine according to the present invention in an enlarged manner of essential parts.

FIG. 5 is a cross-sectional view showing a connection between a conductor pattern and a fastening member used in the rotating electric machine.

FIG. 6 is a sectional view showing an example of a conventional rotating electric machine.

[Explanation of symbols]

 1 coil 2 stator core 2a salient pole 3 substrate 4 fastening member 5 driving magnet 6 rotor 7 conductor pattern

Claims (2)

[Claims] 1. A rotating electrical machine comprising: a stator core having a coil wound around a salient pole; a substrate holding the stator core; and a rotor having a driving magnet arranged to face the stator core, wherein the substrate is grounded. A rotating electrical machine having a conductor pattern connected to a potential, wherein the stator core is fixed to the substrate by a conductive fastening member, and the fastening member and the conductor pattern are electrically connected. 2. The rotating electric machine according to claim 1, wherein one end of the conductor pattern is connected to a part of a connector terminal, and the connector terminal is connected to a ground potential.