JP2003045600A - Feeder system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact multipolar feeder system, which can transmit and receive high-voltage current between a stationary part and a rotating part. SOLUTION: This feeder system 1 transmits and receives power from a stationary part 5 side to a rotating part 3 side, while rotating and sliding on four contact faces 7 between the outside rotating part 3 and the inside stationary part 5. In this feeder system, the contact faces 7 between ring-like current collectors 45, 47, 49, 51 and ring-like feeders 69, 71, 73, 75 are formed into a conical shape, to obtain a large contact area. Thereby, the electrical resistance at the contact part becomes small and heat generation becomes lower, and the entire device compact can be made compact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for transmitting and receiving electric power by sliding contact between a fixed part and a rotating part of machine tools, transportation machines, construction machines, robots and other industrial machines.

[0002]

2. Description of the Related Art A slip ring is a device for transmitting and receiving electric power and electric signals between a fixed portion and a rotating portion. In a general slip ring, a cylindrical or prismatic brush (electron supply) is pressed against the outer peripheral surface of the rotor from the radial direction, and electricity is applied by sliding contact between the rotor and the brush. The contact between the rotor and the brush is line contact, or when the contact surface of the brush is formed in a shape that conforms to the circumferential surface of the rotor, the contact is substantially surface contact that is integral with the cross section of the brush.

A rotating conductor (slip ring) for transmitting a low power signal with low noise is disclosed in Japanese Patent Laid-Open No. 56-1624.
No. 84 publication. In FIG. 1 of this publication, the facing surfaces of the fixed ring member 12 and the rotating ring member 10 are formed as conical surfaces (S1, S2) that are opposite to each other, and between them, a frustoconical solid carbon graphite ring 20 is provided. A structure is shown in which it is pressed and inserted in the direction. The present invention is characterized in that the fixed ring member 12 and the rotating ring member 10 are not brought into direct contact with each other, but the solid carbon graphite ring 20 is interposed therebetween, so that a low power signal can be transmitted with low noise. Is what you are doing.

[0004]

SUMMARY OF THE INVENTION The present invention is a machine tool,
In a transportation machine, a construction machine, a robot, and other industrial machines, when an electric motor is provided inside the rotating structure, a power supply device incorporated in the rotating structure for supplying electric power for driving the electric motor from the outside through the rotating structure is mainly used. ing.
Therefore, the voltage to be supplied is 100 V or more, and the current is tens of amperes or more for single-phase AC, three-phase AC or DC. As an application example of such a high power feeding device, there is a 5-axis machine tool having a spindle head having rotary feed axes of an A axis and a C axis. A spindle head that moves up and down in the column is provided with an A spindle that can rotate the C axis, an A spindle that is rotatable with the A spindle, and a spindle that has a built-in motor in the spindle spindle is rotatably provided. Is a well-known machine tool that processes a workpiece by performing relative movement in the X, Y, Z, A, and C axis directions between a tool attached to the tip of the spindle and a workpiece provided on the table.

First, power is supplied to the built-in motor and the A-axis motor from the outside by the first power feeding device provided in the C-axis rotating structure portion. Then, the second power supply device provided in the A-axis rotating structure portion further supplies electric power to the built-in motor. Electric power passing through the first and second power supply devices is U-phase, V-phase,
For example, 400 V with each phase wire of W phase and ground, 2
It is a three-phase AC power of 00 amperes, and requires a total of 8 poles in the first power feeding device and a total of 4 poles in the second power feeding device. The rotation speed of the rotating portion of the first and second power supply devices is 20 to 30 rotations / minute.

When the above-mentioned general slip ring technical idea of the prior art is applied to such a high-power, multi-pole power supply device, the contact resistance must be reduced in order to apply high power, and the rotation is reduced. Since it is necessary to increase the contact area between the child and the brush, the size of the device becomes large. Further, since the brush is columnar or prismatic, the edge portion of the brush is always present at the sliding contact portion with the rotor, and the edge portion is easily chipped, which causes a problem that the life of the brush is short. Next, when the technical idea of the invention of JP-A-56-162484 is applied, the third member, which is a solid carbon graphite ring, is interposed between the fixed ring member and the rotating ring member, and the contact surface increases. However, there is a problem in that the electric resistance at the time of passing a high electric power increases, which causes heat generation, and the number of slip points increases, so that the structure becomes complicated and abrasion powder increases.

[0007] Therefore, the present invention has a technical problem to solve such a problem, and an object thereof is to provide a compact multi-pole power supply device capable of conducting high power. Another object of the present invention is to provide a power supply device that has a long life, generates little heat, and can collect wear particles.

[0008]

A power feeding device of the present invention is a power feeding device for transmitting and receiving electric power by sliding contact between a fixed part and a rotating part, the sliding contact surface being provided on the fixed part or the rotating part. A plurality of ring-shaped power supply terminals formed on the conical surface are insulated from each other and are arranged in the rotation axis direction, and are provided in the rotating part or the fixed part so as to face the power supply electrons in the radial direction, and the power supply slips. A ring-shaped current collector having a conical surface that is in close contact with the contact surface is insulated from each other and a plurality of current collectors are arranged in the direction of the rotation axis so that the current collector and the current collector can directly make a sliding contact with a predetermined pressing force. An elastic urging means for constantly urging the power supply or current collector in the axial direction is provided, and an electric wire is connected to each of the power supply and current collector from the direction of the rotation axis line to transfer electric power between the fixed part and the rotating part. Is configured to do. Since the ring-shaped current collector and the ring-shaped current collector make a sliding contact directly on the conical surface, they are compact, but the contact area is large, the electrical resistance does not increase, and the heat generation is small. Since the contact area is large, it is not necessary to increase the contact surface pressure and wear is small. Further, the power supply device of the present invention may be configured such that air is supplied to a gap around a contact portion between the power supply and the current collector, and the air flowing through the gap is recovered. As a result, the heat generating portion is air-cooled, and the abrasion powder is recovered by the air flow. Further, in the power supply device of the present invention, it is preferable that one of the power supply and the current collector is made of a conductive material having solid lubricity such as a composite material of copper and carbon and graphite, and the other is made of copper or a copper alloy. . As a result, the conductivity between the power supply and the current collector is improved, and the lubricity is improved to suppress the generation of frictional heat and wear.

[0009]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of an embodiment of the power feeding device of the present invention, and FIG. 2 is a perspective view of the power feeding device of FIG. The power supply device 1 of the present embodiment is
Electric power is supplied from the fixed part 5 side to the rotary part 3 side while performing a rotational sliding motion on the four contact surfaces 7 between the outer rotary part 3 supported by a bearing (not shown) and the inner fixed part 5. ing. The rotating part 3 includes annular housings 9, 11, 13, 1
5, the disc springs 17, 19, 21, 23, the copper cups 25, 27, 29, 31 and the ring-shaped spacer 33,
35, 37, and 39 are incorporated, respectively, and are integrated by a holding plate 41 and a bolt / nut 43. Ring-shaped current collectors 45, 47, 49, 51 are copper cups 25, 2 respectively.
It is fixed to the inside of 7, 29, 31 with a conductive adhesive. Two 53 are projected to the outside at two positions in the circumferential direction of the copper cup, and the core of the electric wire 55 is welded to the three 53. Two electric wires are taken out from each of the four brushes 45, 47, 49, 51 while changing their phases. Housing 9, 11, 13, 15 and holding plate 41
Is preferably a material having insulating properties, heat resistance, and strength such as glass epoxy and ceramics. Current collectors 45, 47,
49 and 51 are preferably a conductive material having solid lubricity such as a composite material of copper and carbon or graphite.

On the other hand, in the fixed portion 5, the ring-shaped insulating spacers 59, 61, 63, 65, 67 and the ring-shaped power supply terminals 69, 71, 73, 75 are alternately inserted into the columnar shaft 57, and the right side is provided. (See FIG. 1), the lid member 77 is pressed against and fixed to the shaft 57 with a bolt (not shown). The lid member 77 covers the outer peripheral portion of the pressing plate 41, and seals the gap between the rotating portion 3 and the fixed portion 5 with a seal member 79. Power supply 6
Four electrode rods 81 are respectively screwed into 9, 71, 73, and 75, the phases are changed and taken out to the outside, and a power line 85 is connected by a nut 83 provided at the outer end. The shaft 57 and the lid member 77 are preferably made of a material having insulating properties, heat resistance, and strength, such as glass epoxy and ceramics. The electrode rings 69, 71, 73, 75 are preferably conductors, and are preferably copper or copper alloys (brass, phosphor bronze, etc.) which are slide bearing materials and have wear resistance.

The contact surface 7 is formed as a conical surface that is in close contact with each other, and has a structure in which the contact area is as large as possible with respect to the size of the current collector and the power supply. The contact pressure of the contact surface 7 may be supported by a bearing (not shown) at a position where the rotating portion 7 is pressed rightward in the axial direction (see FIG. 1) with respect to the fixed portion 5. After that, the contact surface pressure is maintained at a substantially predetermined value by the elastic biasing action of the disc springs 17, 19, 21, 23. Instead of the disc spring, a wave washer (corrugated washer), a spring washer, or the like having an elastic biasing action in the axial direction can be used.
In the present invention, since the contact surface 7 is formed as a conical surface and the contact area is made as large as possible, power can be supplied without increasing the contact surface pressure, which is advantageous in terms of heat generation and wear. The low heat generation does not require a large gap between the power supply collector and the current collector to be cooled unlike the conventional technique, which is also the reason why the power supply device can be made compact.

Inside the shaft 57, the air supply passage 8 is provided.
7 and the air recovery passage 89 are provided in the radial direction so as to communicate with the axial direction and the gaps near the disc springs. When pressurized air is supplied to the inside from the air supply flow path 87, the air passes through the vicinity of each contact surface 7 and passes through the air recovery flow path 89,
It has a structure to be collected outside. At this time, the pressurized air has an action of air-cooling each place and collecting the abrasion powder of the current collector which is slightly generated due to the slip of the contact surface 7. The rotating unit 3
A cover 91 is attached to the left side of the.

The power feeding device of the present embodiment is configured as described above, and the ring-shaped current collector and the ring-shaped current collector are directly brought into contact with each other, and the contact surface is made into a conical surface so that the contact area is as large as possible. By making use of this, electric resistance can be reduced, high power can be transmitted and received with less heat generation, and the whole can be made compact. As a result, the effect of application to an actual machine, such as miniaturization of the spindle head of the 5-axis machine tool described above, is exhibited. Further, since the ring-shaped power supply and current collector are used to eliminate the edge portion, the power supply or current collector is less likely to be chipped, and the life of the power supply or current collector is extended. By flowing the pressurized air into the gap in the vicinity of the contact surface 7, an air-cooling action is created and the abrasion powder can be collected. Furthermore, the C-axis of a normal 5-axis machine tool does not use a power supply device ±
Although only a rotation angle of 180 ° can be obtained, a compact and infinitely rotatable C-axis can be obtained by applying the power supply device of the present invention to the C-axis portion.

[0014]

As described above, according to the present invention, the sliding contact between the fixed portion and the rotating portion is directly performed by the conical surface formed on the ring-shaped current collector and the ring-shaped current collector. A large contact area can be secured. Therefore, the electrical resistance of the contact portion is reduced, heat generation is small, and high-power energization can be performed. Therefore, the power feeding device can be made compact even with a multi-pole structure. Since the contact area is large, the contact surface pressure can be relatively small, which is advantageous in terms of heat generation and wear. Further, by supplying and collecting air in the gap near the contact surface, an air-cooling action and an abrasion powder collecting action occur, heat generation is small, and maintenance frequency is reduced. Furthermore, by using a composite material of copper and carbon, which is a conductive material having solid lubricity, or graphite for power supply and current collection, or by using copper or a copper alloy, which is a wear-resistant conductor, Generation of heat and abrasion powder can be suppressed, and the life of the power supply and current collector can be extended.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of a power feeding device of the present invention.

FIG. 2 is a perspective view of the power supply device shown in FIG. 1 with a partial cross section.

[Explanation of symbols]

1 ... Power supply device 3 ... Rotating part 5: Fixed part 7 ... Contact surface 9, 11, 13, 15 ... Housing 17, 19, 21, 23 ... Disc spring 45, 47, 49, 51 ... Current collector 55 ... Power supply 57 ... Axis 69, 71, 73, 75 ... Power supply 81 ... Electrode rod 85 ... Power line 87 ... Air supply flow path 89 ... Air recovery channel

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shingen Suzuki             4023 Nakatsu, Aikawa-cho, Aiko-gun, Kanagawa Stock             Makino Milling Co., Ltd. F term (reference) 5H613 AA03 BB01 BB05 BB15 BB31                       GA02 GB01 GB12 GB14

Claims (3)

[Claims] 1. A power supply device for transmitting and receiving electric power by sliding contact between a fixed part and a rotating part, wherein the ring-shaped power supply device is provided in the fixed part or the rotating part and has a sliding contact surface formed in a conical surface. A ring having a conical surface which is insulated from each other and is arranged in the direction of the rotation axis, and which is provided in the rotating portion or the fixed portion so as to face the power supply terminal in the radial direction and is in close contact with the sliding contact surface of the power supply terminal. -Shaped current collectors are insulated from each other and arranged in a plurality in the direction of the rotation axis, so that the current collectors and current collectors can be directly and slidingly contacted with a predetermined pressing force, and the current collectors or current collectors are always attached in the axial direction. A power supply device comprising elastic urging means for urging, connecting an electric wire to each of the power supply and the current collector in a direction of a rotation axis line to transfer electric power between the fixed part and the rotating part. 2. The power supply device according to claim 1, wherein air is supplied to a gap around a contact portion between the power supply and the current collector, and the air flowing through the gap is recovered. 3. One of the power supply and the current collector is made of a conductive material having solid lubricity such as a composite material of copper and carbon or graphite, and the other is made of copper or a copper alloy.
Alternatively, the power feeding device according to item 2.