JPH09515A - Slip ring device - Google Patents

Abstract

PURPOSE: To provide a slip ring device by which the service life of the device can be lengthened by reducing a generating quantity of friction powder when brushes and a ring-shaped electrode slidingly move and maintenance work can be simplfied and a generating quantity of a slidingly moving sound at slidingly moving time can be reduced. CONSTITUTION: A brush part 3 is composed of plural brush blocks BO and Bl. One brush block is composed of a brush holder and plural brushes arranged in this brush holder. In the brush block BO, brushes bO are fixed to a stand fixing part so that both can slidingly move 6 by always contacting with a ring-shaped electrode 5 by constant pressing force, and the brush block Bl has a mechanism to drive a brush holder hl so that pressing force of brushes bl to the ring shaped electrode 5 changes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slip ring device in which a rotating part is rotatably held by a fixed part, and the rotating part and the fixed part are electrically connected via a ring-shaped electrode and a brush. .

[0002]

2. Description of the Related Art Conventionally, this type of slip ring device is
The rotating part is rotatably held by the fixed part, and the brush provided on the fixed part and the ring-shaped electrode that is provided on the rotating part and rotates together with the rotating part are always in contact with each other.
Like the relationship between the pantograph and the overhead wire of a train, the brush and the ring-shaped electrode slide while intermediating the supply of electric power and signals from the fixed part to the rotating part (or vice versa) to realize continuous rotation of the rotating part. To do.

In recent years, an X-ray computed tomography apparatus (hereinafter abbreviated as X-ray CT apparatus), which applies this slip ring apparatus to perform high-speed continuous scanning, has become popular. In such an X-ray CT apparatus, electrical connection between the X-ray tube provided in the gantry rotating part and the high voltage generator provided in the gantry fixed part, and a detector provided in the gantry rotating part The electrical connection between the signal processing circuit and the signal processing circuit (for example, the image reconstructing device) provided in the pedestal fixing part can be realized by the slip ring device, and high-speed continuous scanning can be performed.

However, such a conventional slip ring device has the following problems. That is,
The brush and the ring-shaped electrode are in constant contact with each other,
When sliding on the surface of the ring-shaped electrode, a large amount of friction powder is generated from the brush, which shortens the life. In addition, the maintenance work for removing and cleaning the generated friction powder is a heavy labor and takes a lot of time. Also,
There is also a problem that when the brush slides on the surface of the ring-shaped electrode, an unpleasant sliding sound is generated.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to address the above-mentioned circumstances, and an object thereof is to reduce the amount of friction powder generated when a brush and a ring-shaped electrode slide to reduce the amount of frictional particles. An object of the present invention is to provide a slip ring device which has a long life, simplifies maintenance work, and reduces the amount of sliding noise generated during the sliding.

[0006]

In a slip ring device according to the present invention, a rotating portion is rotatably held by a fixed portion, and the rotating portion and the fixed portion are electrically connected via a ring-shaped electrode and a brush. The slip ring device described above is characterized by comprising means for varying the pressing force of the brush against the ring-shaped electrode.

[0007]

According to the slip ring device of the present invention, the pressing force of the brush against the ring-shaped electrode can be made smaller than the pressing force in the other period during a certain period while the rotating portion is rotating. Becomes

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a slip ring device according to the present invention will be described below with reference to the drawings. FIG. 1 is an external view schematically showing a slip ring device of the present embodiment, and FIG. 2 is a diagram schematically showing a configuration of a medical X-ray CT device to which the slip ring device is applied. As shown in FIG. 2, the X-ray CT apparatus according to this embodiment has a gantry fixing unit 1 and a gantry rotating unit 4 rotatably held by the gantry fixing unit 1. The gantry fixing part 1 is provided with a high voltage generator 2 and a brush part 3, and the gantry rotating part 4 is provided with a ring-shaped electrode 5,
An X-ray tube 6 and a detector 7 are provided. In particular,
The ring-shaped electrode 5 is fixed to the outside of the gantry rotating part 4 having a cylindrical shape, and the X-ray tube 6 and the detector 7 are fixed to the inside of the gantry rotating part 4, and the ring-shaped electrode 5, the X-ray tube 6 and the detector are detected. The container 7 rotates as the gantry rotating unit 4 rotates. The brush portion 3 is fixed to the pedestal fixing portion 1 so as to come into contact with the ring-shaped electrode 5 on the outer side of the rotation track thereof.

The slip ring device is constituted by such a brush portion 3 and the ring-shaped electrode 5, and is provided in the gantry rotating portion 4 for supplying high voltage power from the high voltage generator 2 to the X-ray tube 6, for example. Supply of power to devices other than the X-ray tube 6, transmission of control signals to these devices, transmission of X-ray transmission information from a DAS (data acquisition system, not shown) based on detection signals of the detector 7, Used for.

The X-ray tube 6 irradiates the subject P with a fan-shaped X-ray beam by the high voltage power supplied via the slip ring device. Further, the detector 7 detects the transmitted X-rays that have passed through the subject P and outputs the detection signal to the DAS.
The DAS transmits X-ray transmission information based on the detection signal from the detector 7 to the image reconstruction device 8 via the slip ring device. The image reconstruction device 8 reconstructs a tomographic image of the subject P based on the transmitted X-ray transmission information, and the CRT 9 displays the reconstructed image.

As shown in FIG. 1, the brush portion 3 is composed of a plurality (two in this embodiment) of brush blocks B0 and B1. One brush block B includes a brush holder h and a plurality (or a single number) of brushes b arranged in the brush holder h. Further, in this embodiment, the brush block B0 is fixed to the pedestal fixing part 1 so that the brush b0 always contacts the ring-shaped electrode 5 with a constant pressing force and both slide, and the brush block B1 is ring-shaped. A mechanism is provided for driving the brush holder h1 so that the pressing force of the brush b1 against the electrode 5 changes.

By the way, the X-ray CT apparatus according to the present embodiment has two operation modes including a fluoroscopic mode and an imaging mode. The fluoroscopic mode irradiates the subject P with weak X-rays for a long time, and the imaging mode irradiates the subject P with strong X-rays for a short time. Normally, the amount of electricity supplied to the X-ray tube 6 is maximum in the photographing mode. Accordingly, a predetermined number of brushes (brush blocks) are provided so that the maximum energization amount can be allowed.

In the present embodiment, both the brush blocks B0 and B1 are brought into contact with the ring-shaped electrode 5 in the photographing mode, while the brush blocks are used in the transparent mode which does not require a large current as compared with the photographing mode. B0
Only the (brush b0) is brought into contact with the ring-shaped electrode 5 and the brush holder h1 of the brush block B1 is driven to separate the brush b1 from the ring-shaped electrode 5. In the fluoroscopy mode, the minimum electric power for fluoroscopy is supplied to the X-ray tube 6 only through the brush block B0 (in addition, the equipment other than the X-ray tube 6 provided in the gantry rotating section 4 is operated. The power for supplying the X-ray transmission information from the DAS based on the control signal to the equipment other than the X-ray tube 6 provided in the gantry rotating part 4 and the detection signal of the detector 7 is transmitted only to the brush block B0. Is transmitted through.

FIG. 1A shows brush blocks B0 and B1.
Shows the state where both are in contact with the ring-shaped electrode 5, and FIG. 7B shows the state where the brush block B0 is in contact with the ring-shaped electrode 5 and the brush block B1 is separated from the ring-shaped electrode 5. ing.

As a result, when the gantry rotating part 4 is rotationally driven in the perspective mode, the brush b1 of the brush block B1 is separated from the ring-shaped electrode 5, and only the brush b0 of the brush block B0 is ring-shaped electrode 5. Will come into contact with and slide. Therefore, the amount of generated friction powder can be reduced, and the brush b1 does not easily deteriorate. Further, since the amount of generated friction powder is reduced, maintenance work of the device for removing and cleaning the friction powder is facilitated. Also, the brush b
Since 1 is separated from the ring-shaped electrode 5, the amount of sliding noise generated is reduced. Therefore, the noise in the fluoroscopic mode is reduced, the patient is not anxious or uncomfortable, and the habitability in the CT room is improved.

The brush block B1 is not detached from the ring-shaped electrode 5, in other words, the brush holder h1 of the brush block B1 is not driven so that the pressing force of the brush b1 against the ring-shaped electrode 5 becomes zero. The brush holder h1 may be driven so that the block B1 is not completely separated from the ring-shaped electrode 5, in other words, the pressing force of the brush b1 against the ring-shaped electrode 5 is weakened. Even with this structure, the same effects as described above can be obtained, and there is an advantage that no electrical noise is generated when the brush b1 and the ring-shaped electrode 5 come into contact with or separate from each other.

In the above description, the brush holder h1 is driven to change the pressing force of the brush b1 for each brush block, but a plurality of brushes b1 may be individually driven. Good.

Here, the brush b for the ring-shaped electrode 5
A specific configuration for changing the pressing force of 1 will be described with various examples. (Structural Example 1) As shown in FIG. 3, a brush block 34 is supported by a linear motion guide 31 and a rack 33 that engages with a motor 32 having a pinion gear, and a brush 35 is attached by rotation of the motor 32. The pressing force is changed by driving the brush block 35 in the direction of the arrow 3a. (Structural Example 2) As shown in FIG. 4, the link mechanism 42 connected to the motor 41 drives the brush block 44, on which the brush 43 is mounted, in the direction of the arrow 4a to change the pressing force. (Structural Example 3) As shown in FIG. 5, the pressing force is changed by driving the brush block 53 to which the brush 52 is attached in the direction of the arrow 5a by the solenoid mechanism 51. (Structural Example 4) As shown in FIG. 6, a leaf spring 62 having a brush 61 mounted thereon is attached to the shaft 6 with respect to the brush block 60.
5, the shaft 65 is connected to the belt 63 and the motor 64, and the rotation of the motor 64 drives the belt 63 in the direction of the arrow 6a so that the leaf spring 62 uses the shaft 65 as a fulcrum. Drive in the direction and change the pressing force. (Structure example 5) As shown in FIG. 7, the electromagnet 72 provided on the brush 71 is energized to press the brush 71 against the ring-shaped electrode 73 by its electromagnetic force (electromagnetic force in the direction of arrow 7a). By stopping the energization of the electromagnet 72, the pressing force on the ring-shaped electrode 73 can be weakened or the brush 71 can be detached from the ring-shaped electrode 73. It should be noted that, although this configuration example is driven in brush units, as shown in FIG. 8, an electromagnet 82 may be provided in the brush block 81 to change the pressing force in brush block units. (Structural Example 6) As shown in FIG. 9, a brush 92 is provided on the pressure-transforming element 91 that bends in a predetermined direction when a voltage is applied, and the pressing force is changed by driving in the arrow 9a direction.

The present invention is not limited to the above-mentioned embodiments, but can be implemented with various modifications. For example, in this embodiment, the ring-shaped electrode is attached to the gantry rotating part, and the brush block (brush) is attached to the gantry fixed part, and the ring-shaped electrode rotating with the gantry rotating part and the gantry fixed part are stationary. I explained the case of sliding with the brush to be installed, but attach the brush block (brush) to the gantry rotating part,
A ring-shaped electrode may be attached to the gantry fixing portion.

In this embodiment, the brush pressing force is changed in the fluoroscopic mode.
For example, the pressing force may be changed as described above during the idling period until the rotor of the X-ray tube reaches a desired rotation speed while the gantry rotating unit is rotating.

Further, the slip ring device of the present invention is not limited to the above-mentioned X-ray computed tomography apparatus, but other medical equipment such as nuclear medicine diagnosis and treatment equipment, or not only medical equipment but also industrial robots and other rotating parts. The present invention can be applied to various devices that make an electrical connection for transmission of a signal or electric power between a stationary part and a fixed part.

[0022]

As described above, according to the present invention, it is possible to reduce the amount of friction powder generated when the brush and the ring-shaped electrode slide, thereby extending the life of the apparatus and simplifying maintenance work. It is possible to provide a slip ring device that reduces the amount of sliding noise generated during the sliding.

[Brief description of drawings]

FIG. 1 is an external view schematically showing a slip ring device according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing the configuration of a medical X-ray CT apparatus to which the slip ring device of the present invention is applied.

FIG. 3 is a diagram schematically showing a configuration example 1 of a pressing force variable mechanism.

FIG. 4 is a diagram schematically showing a configuration example 2 of a pressing force variable mechanism.

FIG. 5 is a diagram schematically showing a configuration example 3 of a pressing force variable mechanism.

FIG. 6 is a diagram schematically showing a configuration example 4 of a pressing force variable mechanism.

FIG. 7 is a diagram schematically showing a configuration example 5 of a pressing force variable mechanism.

FIG. 8 is a diagram schematically showing a configuration example 6 of a pressing force variable mechanism.

FIG. 9 is a diagram schematically showing a configuration example 7 of a pressing force variable mechanism.

[Explanation of symbols]

3 ... Brush part, B0, B1 ... Brush block, h0, h
1 ... Brush holder, b0, b1 ... Brush, 5 ... Ring-shaped electrode.

Claims (1)

[Claims] 1. A rotating portion is rotatably held by a fixed portion,
A slip ring device in which the rotating portion and the fixed portion are electrically connected via a ring-shaped electrode and a brush, comprising means for varying the pressing force of the brush against the ring-shaped electrode. Slip ring device.