JPH06132060A - Brush structure for electrical connection of rotating body - Google Patents

Abstract

PURPOSE:To provide a brush structure wherein a stable contact condition can be held without adjusting a contact pressure of a brush against a slip ring. CONSTITUTION:In a brush structure 10 for electrical connection of a rotating body, holding each brush parallelly to each other by a tightening member 16 in the vicinity of a root, including the brush 15, consisting of elastic material, fixedly arranged so that respective point end part is brought into contact from a side surface, relating to a plurality of annular slip rings 12 mounted with a predetermined space along the lengthwise direction in a rotary shaft of a rotary unit, each brush is supported in its both ends and further brought into contact relating to the slip ring 12 in the vicinity of the center.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, for example, in a VTR rotary drum or the like, in order to supply electric power or input / output an electric signal to / from a substrate mounted on the rotary portion of the rotary drum, The present invention relates to a structure of a brush which is brought into contact with a slip ring provided on a rotating shaft of the rotating portion when electrically connected.

[0002]

2. Description of the Related Art Conventionally, a rotary drum of a VTR is constructed as shown in FIG. In the figure, the rotating drum 1
Is composed of a fixed lower drum 2 and an upper drum 3 arranged above the lower drum 2 so as to be rotatable around a rotary shaft 3a. In the upper drum 3, a rotary head 3b for recording and reproducing video and audio signals is built in, and a printed circuit board 3c on which a circuit for driving and controlling the rotary head is mounted is mounted. There is. The rotary head 3b and the printed circuit board 3c are adapted to rotate integrally with the upper drum 3. Therefore, in order to supply electric power for drive control or input / output various electric signals such as control signals to the rotary head 3b and the printed circuit board 3c, it is necessary to make electrical connection from the outside. .

This electrical connection is generally made to a contact portion 4 attached to a portion exposed to the outside of a rotary shaft 3a that rotatably supports the upper drum 3, that is, near the lower end in the case shown in the figure. Be done. That is, as shown in FIG. 4, the contact portion 4 has a plurality of annular shapes arranged at predetermined intervals along the longitudinal direction of the slip ring holder 5 attached to the rotary shaft 3a. A brush 8 mounted on a gold slip ring 6 and a brush holder 7 fixedly arranged on the lower drum 2, for example, and rotatably supported on the slip ring holder 5.
It is composed of

The brush portion 8 is shown in FIGS. 4 (A) and 4 (B).
As shown in detail in FIG. 3, each of the slip rings 6 is composed of a plurality of brushes 9 made of an elastic material, the tips of which are in contact with the side surfaces. Here, each of the brushes 9 is held in parallel with each other by a fastening member 9a near the root thereof.

According to the electrical connection having such a structure, each brush 9 is deformed at its tip by δ as shown in FIG. 5, and the corresponding slip ring 6 fixed to the rotating shaft 3a is fixed. The load W is pressed against the side surface. Here, when the upper drum 3 and the rotating shaft 3a rotate, each brush 9 can be held in a state of always abutting on the side surface of the rotating slip ring 6. Therefore,
Each brush 9 can be electrically connected to a predetermined terminal or the like of a printed circuit board mounted in the upper drum 2 via a slip ring 6, respectively.

[0006]

However, in the electrical connection having such a structure, each brush 9 is connected to the brush shown in FIG.
As shown in (B), the root portion has a so-called “cantilevered beam” structure, which is fixedly held by the fastening member 9a. Therefore, the brush 9 itself is easily bent. Therefore, when the slip ring 6 is rotating, the brush 9 may vibrate and float up from the surface of the slip ring 6. Thus, there is a problem that contact noise is intermittently caused and contact noise is generated.

Further, the adjustment of the contact pressure of the brush 9 with respect to the slip ring 6 needs to be accurately performed, and the assembling work is troublesome.

Further, when the slip ring 6 is worn, the brush 9 will bite into the flip ring 6. Therefore, when the slip ring 6 is normally or reversely rotated, the brush 9 is deformed, and it is impossible to maintain a stable contact state of the brush 9 with the slip ring 6.

In view of the above points, the present invention has an object to provide a structure of a brush capable of maintaining a stable contact state without adjusting the contact pressure of the brush with respect to the slip ring.

[0010]

According to the present invention, the above-mentioned object is fixed so that a plurality of conductive parts mounted at predetermined intervals along the longitudinal direction of the rotating body are abutted from the respective side surfaces. In a brush structure for electrically connecting a rotating body including a plurality of brushes, each of the brushes is supported at both ends thereof, and is configured to abut against a slip ring near the center thereof. This is achieved by the structure of the brush for the electrical connection of.

[0011]

According to the above construction, since both ends of each brush are supported, the vibration at the contact portion with the conductive portion, such as a slip ring, is reduced and the brush slips. The contact pressure on the ring can be kept almost constant.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to FIGS. The examples described below are preferred specific examples of the present invention, and therefore, various technically preferable limitations are given, but the scope of the present invention particularly limits the present invention in the following description. Unless otherwise stated, the present invention is not limited to these modes.

FIG. 1 shows an embodiment of a contact portion constructed according to the present invention. In FIG. 1, the contact portion 10 is V
In the vicinity of the end exposed to the outside of the rotary shaft of the rotary body such as the rotary head of the TR, the slip ring holder 11 attached to the rotary shaft (not shown) is attached in the longitudinal direction. A plurality of annular gold slip rings 12 arranged at predetermined intervals along with the slip ring holder 1 fixedly arranged, for example, with respect to the lower drum.
Brush holder 1 rotatably supported with respect to 1
3 and the brush 14 part attached to it.

The brush portion 14 is composed of a plurality of brushes 15 made of an elastic material, the tips of which contact the side surfaces of the slip rings 12.

Further, both ends of the brush 15 are
The fastening members 16 bind and hold them in parallel with each other.

The present embodiment is configured as described above, and in the contact portion 10, each brush 15 is slightly deformed in the vicinity of its center, while the corresponding slip ring 1 is deformed.
It will be pressed against the side surface of 2. Therefore, when the slip ring 12 rotates, each brush 15 can be kept in a state of constantly abutting on the side surface of the rotating slip ring 12. Thus, each brush 15 can be electrically connected to a predetermined terminal or the like of a printed circuit board or the like mounted in the rotating body via the slip ring 12, respectively.

Here, the slip ring 12 is, for example, Δδ.
If worn only, slip ring 1 of brush 15
The deformation amount at the contact position with respect to 2 is reduced. The ratio of this deformation amount to the entire length of the brush 15 along the bent shape is relatively small. Therefore, the brush pressure of the brush 15 against the slip ring 12 does not decrease so much. Thereby, even if the slip ring 12 is worn, a sufficient brush pressure can be obtained. It will be. Thus, with the rotation of the slip ring 12, the brush 15 does not float up from the surface of the slip ring 12, and stable contact with less contact noise can be achieved.

For example, the deformation amount (deflection) δ _{1 of} the brush 15
Is

[Equation 1] Is represented by Where E is Young's modulus and Iz is
The second moment of area, W is a load. On the other hand, in the case of the conventional contact portion 4 shown in FIG.
Is a cantilever type, the deformation amount δ ₂ is

[Equation 2] It is represented by. Here, if L = 2 · l,

[Equation 3] Becomes As a result, by fixing and holding both ends of the brush 15, the deformation amount δ ₁ of the central portion of the brush 15 is halved as compared with the case of the conventional cantilever type brush 9. Therefore, the brush 15 is brought into contact with the surface of the slip ring 12 in a stable state in the vicinity of the center thereof. Thus, the slip ring 12
The center portion of the brush 15 does not float up from the surface of the slip ring 12 when rotating, and contact noise can be reduced.

Further, even if the mounting position of the brush with respect to the slip ring 12 deviates to some extent, the brush pressure does not fluctuate so much that the mounting tolerance of the brush 15 can be designed to be large, and the contact pressure can be adjusted in most cases. Since it is unnecessary, the assembly cost can be reduced and the yield can be improved.

Further, since both ends of the brush 15 are supported, even if the slip ring 12 is worn and the brush 15 bites into the slip ring 12, for example, the slip ring 12 is not supported. The brush 15 is not deformed by the normal rotation and the reverse rotation.

[0021]

As described above, according to the present invention, since each brush is supported at both ends, it can be fixedly held in a stable state. Therefore, when the slip ring rotates, the contact noise can be reduced without being lifted from the surface of the slip ring due to vibration. Further, even if the brush mounting position with respect to the slip ring deviates slightly, the brush pressure does not fluctuate much, so it is possible to design a large brush mounting tolerance, making contact pressure adjustment unnecessary and reducing assembly costs. It can be reduced and the yield will be improved.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a contact portion including a brush according to the present invention.

FIG. 2 is a schematic diagram showing a relationship between the brush and the slip ring of FIG.

FIG. 3 is a schematic sectional view showing an example of a conventional rotary head device.

4 (A) of a contact portion in the rotary head device of FIG.
It is a top view and (B) side view.

5 is a schematic diagram showing a relationship between a brush and a slip ring in the contact portion of FIG.

[Explanation of symbols]

 10 Contact part 11 Slip ring holder 12 Slip ring 13 Brush holder 14 Brush part 15 Brush 16 Fastening member

Claims (1)

[Claims] 1. An electrical connection of a rotating body including a plurality of brushes fixed so as to abut from side surfaces of a plurality of conductive portions mounted at predetermined intervals along the longitudinal direction of the rotating body. The brush structure for electrical connection of a rotating body, wherein each of the brushes is supported at both ends thereof, and is configured to abut against a slip ring in the vicinity of the center. Structure.