JP2008136270A - Feeder system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a feeder system where heat generation is little when it transfers electricity between a fixed part and a rotating part. <P>SOLUTION: In the feeder system 1 which transfers electricity from the side of the fixed part 5 to the side of the rotating part 3, with its current feeder and current collector contacting with each other between the inner fixed part 5 and the outer rotating part 3 and taking rotary slide motion, the contact faces 7 of the current collectors 45, 47, 49 and 51 an current feeders 69, 71, 73 and 75 are made spherical to secure large contact area. Therefore, the contact resistance becomes small, and heat generation lessens. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power supply apparatus that transfers electricity between a fixed part and a rotating part of a machine tool, a transport machine, a construction machine, a robot, and other industrial machines.

  A slip ring is a device that exchanges electric power and electrical signals between a fixed part and a rotating part. In a general slip ring, a cylindrical or prismatic brush (power supply) is pressed from the radial direction against the outer peripheral surface of the rotor, and is energized by sliding contact between the rotor and the brush. Further, Patent Document 1 discloses a slip ring in which a contact surface between a ring-shaped power supply and a ring-shaped current collector is formed as a conical surface. This is because the contact surface is formed as a conical surface, so that the contact area is larger than when the contact surface is formed as a cylindrical surface. Further, Patent Document 2 discloses a slip ring in which an arc-shaped brush whose one end is fixed to a rotating portion contacts an inner wall of a cylindrical fixing portion. This is because the arc-shaped brush is deformed by the centrifugal force of the rotating part, and the contact area is increased. Further, Patent Document 3 discloses a rotary electrical connector in which a roller made of a conductive metal material is interposed between a rotary side electrode and a fixed side electrode. This prevents frictional heat generation and wear, and can reduce the rotational torque.

JP 2003-45600 A JP 58-85287 A Japanese Patent Laid-Open No. 10-223346

  In a machine tool, a transport machine, a construction machine, a robot, and other industrial machines, the present invention incorporates an electric motor for driving the electric motor from the outside through the rotating structure when the electric motor is provided inside the rotating structure. Mainly uses power supply devices. Therefore, the supplied voltage is 100 volts or more, and the current is a single-phase alternating current, three-phase alternating current or direct current of several tens of amperes or more. As an application example of such a high-power feeding device, there is a 5-axis machine tool in which a spindle head has an A-axis and a C-axis rotary feed shaft. A spindle base that can rotate C-axis is provided on the headstock that moves up and down in the column, and a spindle head that can rotate A-axis is provided on the A-shaft base, and a spindle with a built-in motor is rotatably provided in the spindle head. This is a well-known machine tool for machining a workpiece by performing relative motion in the X, Y, Z, A, and C axis directions with a tool mounted on 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 a first power feeding device provided in the C-axis rotating structure. And the electric power to a built-in motor is further supplied with the 2nd electric power feeder provided in the A-axis rotation structure part. The power passing through the first and second power feeding devices is, for example, 400 volts, 200 amperes of three-phase AC power having U-phase, V-phase, W-phase, and ground polar lines. Then, the total number of poles is 8 poles, and the second power supply device requires a total of 4 poles. In addition, the rotational speed of the rotation part of the 1st, 2nd electric power feeder is 20-30 rotations / min.

  Applying the above-described general slip ring technical idea of the above-described prior art to such a high-power, multi-pole power supply device, in order to energize the high power, the contact resistance must be reduced, As a result, it is necessary to increase the contact area between the current collector and the current collector, resulting in a problem that the apparatus becomes larger. In addition, since the brush is cylindrical or prismatic, the edge portion of the brush always exists at the sliding contact portion with the rotor, and the edge portion easily breaks, resulting in a problem that the life of the brush is short. Next, when the technical idea of Patent Document 1 is applied, if the axis of the ring-shaped power supply or the ring-shaped current collector is tilted due to an assembly error or processing error, the contact portion between the power supply and the current collector becomes a line contact. In other words, the contact area is greatly reduced, which causes a problem that heat generation during power feeding increases. Next, when the technical idea of Patent Document 2 is applied, a large contact area can be secured when a sufficient centrifugal force is working, but there is a problem that a sufficient contact area cannot be secured when the centrifugal force is reduced. Next, when the technical idea of Patent Document 3 is applied, a third member called a roller is interposed between the fixed ring member and the rotating ring member, and the contact area is small because each contact portion is a line contact, Since the contact resistance increases, heat generation at the time of power supply increases, and the number of components of the power supply unit increases, resulting in a problem that the structure becomes complicated.

  Therefore, the present invention has a technical problem to solve such a problem, and even if there is an assembly error or a processing error, a predetermined contact area is secured between the power supply and the current collector, heat generation is small, An object of the present invention is to provide a power supply device having a long life. It is another object of the present invention to provide a compact multipolar power supply device that can collect wear powder generated by sliding contact between a power supply and a current collector, and that can conduct high power.

  In order to achieve the above-described object, according to the present invention, in a power feeding device that transmits and receives electricity between a fixed portion and a rotating portion, a power supply and a current collector are supported so as to be relatively rotatable, The current collector has a sliding contact surface that contacts each other, and the sliding contact surface is formed as a concave spherical surface or a convex spherical surface having the same rotation axis. Since the sliding contact surface between the power supply and the current collector is a spherical surface, the surface contact can be maintained even when the axis of the power supply or current collection is inclined with respect to the center of the sphere forming the sliding contact surface due to a processing error or assembly error.

  In addition, according to the present invention, there is provided a power feeding device in which a plurality of power supplies are insulated from each other and arranged in the rotation axis direction, and a plurality of current collectors are insulated from each other and arranged in the rotation axis direction. For example, when power is supplied to a motor driven by three-phase alternating current, each of U, V, and W phases and ground are required, and therefore, it is sufficient to arrange four power supply and four current collectors.

  In addition, according to the present invention, there is provided a power feeding device further provided with a biasing means provided in the fixed part or the rotating part and biasing in a direction in which a pressing force is applied to the sliding contact surface between the power supply and the current collector. Even if the power supply and the current collector are worn, the surface contact is maintained with an appropriate contact pressure by the biasing means.

  In addition, according to the present invention, there is provided a power feeding device that further includes an insulating member that is provided in the fixed portion and the rotating portion and insulates the power supply and current collection from surrounding members. In addition, a power feeding device is provided in which the insulating member is formed of an inorganic resin laminate. The insulating member appropriately insulates the portion that needs to be insulated.

  Further, according to the present invention, in the power feeding device that the power supply and the current collector are supported so as to be relatively rotatable, and electricity is exchanged between the fixed portion and the rotating portion by sliding contact between the power supply and the current collector, A plurality of feeders that are insulated from each other and arranged in the direction of the rotation axis in a fixed part, and a sliding contact surface is formed in a convex spherical surface, and a plurality of sliding contacts that are insulated from each other and arranged in the direction of the rotation axis. A current collector formed on a concave spherical surface that is in surface contact with the sliding contact surface of the power supply, an insulating member that is provided on the fixed portion and the rotation portion, and that insulates the power supply and current collection from surrounding members, and is provided on the rotation portion. There is provided a power supply apparatus comprising: an urging means for urging the current collector toward the power supply electron in the direction of the rotation axis; and a pressure fluid flow path for supplying and discharging pressure fluid to and around the power supply and current collector. The

  In addition, according to the present invention, there is provided a power feeding device in which a groove for discharging wear powder is formed on at least one of the sliding contact surfaces of the power supply and the current collector. By this groove, wear powder that causes poor conduction and heat generation is discharged, and the power supply state can be kept good.

  According to the present invention, the sliding contact between the fixed portion and the rotating portion is performed on the spherical surface formed on the power supply and the current collector, so that the power supply or the current collector forms a sliding contact surface due to a processing error or an assembly error. Surface contact can be maintained even when tilted about the center of the fulcrum, and a larger contact area can be ensured than when the contact surface is formed on a cylindrical surface or a conical surface. Accordingly, the contact resistance is reduced, heat generation is small, and high power can be energized. Therefore, even if one power feeding device has a multipolar structure, the power feeding device can be made compact. Since the contact area is large, the contact surface pressure is relatively small, which is advantageous in terms of heat generation and wear. Further, by providing a groove for discharging the wear powder on the contact surface and supplying and collecting a fluid around the contact surface, a cooling action and a wear powder discharge action are generated, heat generation is reduced, and the frequency of maintenance is reduced. If an inorganic resin laminate is used for the insulating member, the insulating and heat resistance are excellent, and there is an effect that it is easy to mold.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Referring to FIGS. 1 to 4, the power feeding device 1 performs a rotational sliding motion on four contact surfaces 7 between an outer rotating portion 3 supported by a bearing (not shown) and an inner fixing portion 5. In addition, power is supplied from the fixed portion 5 side to the rotating portion 3 side. The rotating part 3 incorporates disc springs 17, 19, 21, 23, copper cups 25, 27, 29, 31 and spacers 33, 35, 37, 39 inside annular housings 9, 11, 13, 15 respectively. The holding plate 41 and the bolt / nut 43 are integrated. The ring-shaped current collectors 45, 47, 49, 51 are fixed to the inner sides of the copper cups 25, 27, 29, 31 with a conductive adhesive. Two 53 protrude outward in two circumferential directions of the copper cup, and the core wire of the electric wire 55 is welded to the 53. Two electric wires from each of the four current collectors 45, 47, 49, 51 are taken out to the outside with different phases. The housings 9, 11, 13, 15 and the presser plate 41 may be made of a material having insulating properties, heat resistance, and strength such as glass epoxy and ceramics. A material that has both insulating properties and heat resistance, such as IG), and is easy to mold is preferable. The ring-shaped current collectors 45, 47, 49, and 51 are preferably made of a conductive material having a solid lubricating property such as a composite material of copper and carbon or graphite.

  On the other hand, the fixing part 5 inserts ring-shaped insulating spacers 59, 61, 63, 65, 67 and ring-shaped supply electrons 69, 71, 73, 75 alternately on the columnar shaft 57 from the right side (see FIG. 1) The lid member 77 is pressed and fixed to the shaft 57 with a bolt (not shown). The lid member 77 covers the outer periphery of the pressing plate 41 and seals the gap between the rotating portion 3 and the fixed portion 5 with a seal member 79. Four electrode rods 81 are respectively screwed into electrode rod insertion holes 97 of the power supply 69, 71, 73, 75, taken out to the outside by changing the phase, and a power line 85 is connected by a nut 83 provided at the outer end. Has been. The shaft 57 and the lid member 77 may be made of a material having insulation, heat resistance, and strength, such as glass epoxy and ceramics. However, the shaft 57 and the lid member 77 have insulation and heat resistance like an inorganic resin laminate, and are further molded. Easy materials are preferred. The power supply 69, 71, 73, 75 is a conductor and is preferably a sliding bearing material or wear-resistant copper or copper alloy (brass, phosphor bronze, etc.).

  The contact surface 7 is formed into a spherical surface that is in close contact with each other, the contact surface 7a for collecting current is formed into a concave spherical surface, and the contact surface 7b for supplying electrons is formed into a convex spherical surface. The contact surface 7a and the contact surface 7b have a configuration in which the contact area is made as large as possible with respect to the dimensions of the current collector and the power supply. Further, the contact surface 7a for collecting current and the contact surface 7b for supplying electrons are arranged to have the same rotation axis. In order to apply a pressing force to the contact surface 7, the rotating portion 3 may be supported by a bearing (not shown) at a position where the rotating portion 3 is pressed to the right side in the axial direction (see FIG. 1) with respect to the fixed portion 5. After that, the pressing force is maintained at a predetermined value by the elastic biasing action of the disc springs 17, 19, 21, 23. Instead of the disc spring, a wave washer (wave 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 spherical surface and the contact area is made as large as possible, it is possible to supply power without increasing the pressing force, which is advantageous in terms of heat generation and wear.

  Further, a spiral groove 93 is provided on the contact surface 7 a of the current collectors 45, 47, 49, 51, and a groove 95 is provided on the contact surface 7 b of the power supply electrons 69, 71, 73, 75. The abrasion powder generated on the surface 7 is effectively discharged.

  Further, a fluid supply channel 87 and a fluid recovery channel 89 are provided in the shaft 57 in the radial direction so as to communicate with the gap in the vicinity of the disc springs. When pressurized air is supplied to the inside from the fluid supply channel 87, the air passes through the periphery of each contact surface 7, passes through the fluid recovery channel 89, and is discharged to the outside. At this time, the pressurized air cools each part and has an action of collecting the abrasion powder generated by the sliding of the contact surface 7. A cover 91 is attached to the left side of the rotating unit 3.

  The power supply device according to the present embodiment is configured as described above. The current collector and the power supply are brought into contact with each other, the contact surface is made a spherical surface, and the power supply or the current collector has a sliding contact surface due to a processing error or an assembly error. Since the surface contact can be maintained even when the center of the formed sphere is inclined with respect to the fulcrum, the contact resistance can be reduced and high power can be transferred with little heat generation. As a result, an effect of applying to a machine that power can be stably supplied to the rotating part of the above-described 5-axis machine tool is exhibited. Further, by flowing the pressurized fluid through the gap around the contact surface 7, a cooling action is generated, the wear powder can be collected, and an effect of preventing an accident in which the phases are short-circuited by the accumulated wear powder is also produced. The present invention also includes a case where a current collector is provided in the fixed part and a power supply is provided in the rotating part. The present invention also includes a case where the outer ring side is a fixed part and the inner ring side is a rotating part. The present invention also includes the case where the contact surface of the power supply is formed as a concave spherical surface and the contact surface of the current collector is formed as a convex spherical surface. The present invention also includes a case where an electrical signal is exchanged between the fixed portion and the rotating portion. Needless to say, the fixing unit can be applied to a case where the fixing unit is fixed to a moving body of a machine that uses the power feeding device of the present invention, or to a rotating body.

It is sectional drawing which shows embodiment of the electric power feeder of this invention. It is the perspective view which made the cross section the electric power feeder shown in FIG. (A) It is the front view which looked at current collection from the contact surface side, (b) It is sectional drawing of current collection. (A) It is the front view which looked at the electric supply from the contact surface side, (b) It is sectional drawing of an electric supply.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Feeding 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 Electric wire 57 Shaft 69, 71, 73, 75 Supply Electron 81 Electrode rod 85 Power line 87 Fluid supply channel 89 Fluid recovery channel

Claims (7)

In a power feeding device that exchanges electricity between a fixed part and a rotating part,
The power supply and the current collector are supported so as to be relatively rotatable, and the power supply and the current collector have sliding contact surfaces that are in contact with each other, and the sliding contact surface is formed as a concave or convex spherical surface having the same rotation axis. A power supply device characterized by   2. The power feeding device according to claim 1, wherein a plurality of the supplied electrons are insulated from each other and arranged in the rotation axis direction, and a plurality of the current collectors are insulated from each other and arranged in the rotation axis direction.   3. The power feeding device according to claim 1, further comprising a biasing unit that is provided in the fixed portion or the rotating portion and biases in a direction in which a pressing force is applied to a sliding contact surface between the power supply and the current collector.   4. The power feeding device according to claim 1, further comprising an insulating member that is provided in the fixed portion and the rotating portion and insulates the power supply and the current collector from surrounding members. 5.   The power feeding device according to claim 4, wherein the insulating member is formed of an inorganic resin laminate. In the power supply device, in which the power supply and the current collector are supported so as to be relatively rotatable, and electricity is transferred between the fixed portion and the rotating portion by sliding contact between the power supply and the current collector,
A plurality of electrons that are insulated from each other in the fixed portion and arranged in the direction of the rotation axis, and a sliding contact surface formed on a convex spherical surface,
A plurality of current collectors that are insulated from each other and arranged in the direction of the rotation axis, and a sliding contact surface formed on a concave spherical surface that is in surface contact with the sliding contact surface of the power supply,
An insulating member that is provided in the fixed portion and the rotating portion and insulates the power supply and the current collector from surrounding members;
An urging unit provided in the rotating unit and urging the current collector toward the power supply in a rotation axis direction;
A pressure fluid passage for supplying and discharging a pressure fluid to and from the periphery of the power supply and the current collector;
A power supply apparatus comprising:   The power feeding device according to any one of claims 1 to 6, wherein a groove for discharging wear powder is formed on at least one of the sliding contact surface of the power supply and the sliding contact surface of the current collector.

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