Field of the Invention
The invention relates to a method and a configuration for supplying a large number of actuators with electrical power without the use of wires, to an actuator and a primary winding for this purpose, and to a system for a machine having a large number of actuators. The invention may be used, for example, for supplying electrical power to micromechanical, piezoelectric, electrochemical, magnetostrictive, electrostricktive, electrostatic or electromagnetic actuators, such as those that are used in actuator systems or machines, for example, in open-loop/closed-loop control systems, in remote control systems, in robot technology, in automatic production machines and automated production machines, as display elements, and in protection and safety systems (for example in outdoor or indoor switchgear assemblies).
A method and a configuration for supplying an electrical load with an electrical supply voltage or with an electrical supply current is known from Published German Patent Application DE 44 42 677 A1, in which radio waves are transmitted from a radio transmitter to a radio receiver that is electrically connected to the load, and are converted by the radio receiver to the electrical supply voltage or the electrical supply current, respectively. The radio waves may be in the electromagnetic radio-frequency range (radio waves) or in the microwave range (radio link).
A disadvantageous factor in this case is that the high frequencies and correspondingly small antennas, and the maximum permissible transmission power, which is restricted by EMC (Electromagnetic Compatibility) regulations and rules for health and safety at work when exposed to electrical, magnetic or electromagnetic fields, mean that only very inadequately short distances can be achieved between the radio transmitter and the radio receiver. The same applies to the achievable power levels, which are in the region of a few microwatts, which is generally inadequate for actuators.
It is accordingly an object of the invention to provide a system for supplying a large number of actuators with electrical power, which overcomes the above-mentioned disadvantages of the prior art apparatus of this general type.
In particular, it is an object of the invention to provide a cost-effective and reliable way to supply electrical power to a large number of actuators without using wires. Furthermore, a cost-effective and reliable configuration is intended to be specified for carrying out this method. In addition, an actuator which is suitable for this purpose is intended to be proposed. Furthermore a primary winding which is suitable for this purpose is intended to be proposed.
With the foregoing and other objects in view there is provided, in accordance with the invention, a system for a machine having a large number of actuators. The system includes: a machine having a large number of actuators; a medium-frequency oscillator; a process computer for the machine; a central transmission device for transmitting radio signals, the transmission device connected to the process computer; and at least one primary winding for producing a medium-frequency magnetic field for supplying the actuators with electrical power without using wires. The primary winding is fed from the medium-frequency oscillator. Each one of the actuators has a plurality of orthogonal secondary windings that are suitable for drawing power from the medium-frequency magnetic field. Each one of the actuators is equipped with a receiving device for receiving the radio signals from the central transmission device.
In accordance with an added feature of the invention, there is only a single primary winding that globally surrounds the secondary windings of the actuators.
In accordance with an additional feature of the invention, there are at least two primary windings that are configured parallel to each another and between the secondary windings of the actuators.
In accordance with another feature of the invention, two primary windings are configured at right angles to one another.
In accordance with a further feature of the invention, there are three primary windings that are configured at right angles to one another.
In accordance with a further added feature of the invention, the primary winding locally influences at least one of the secondary windings of one of the actuators.
In accordance with a further additional feature of the invention, the primary winding is formed as a two lines; and the secondary windings of the actuators are configured between the double lines.
In accordance with yet an added feature of the invention, the primary winding is provided with a ferrite core.
In accordance with yet an additional feature of the invention, a compensation capacitor is connected to the primary winding.
In accordance with yet another feature of the invention, a central receiving device is connected to the process computer. The actuators are provided with transmission devices for emitting radio signals, containing actuator information, to the central receiving device so that bi-directional information interchange is possible between the process computer and the actuators.
In accordance with yet a further feature of the invention, a compensation capacitor is connected to the secondary windings of one of the actuators.
In accordance with yet a further added feature of the invention, an energy storage device is provided; and an AC/DC controller is provided for charging the energy storage device. The secondary windings of one of the actuators is connected to the AC/DC controller.
In accordance with yet another feature of the invention, the machine is an automated production machine.
With regard to the method according to the invention, this object is achieved by a method for supplying a large number of actuators with electrical power without the use of wires, with a medium-frequency magnetic field which is emitted from at least one primary winding being transmitted to each actuator which has at least one secondary winding, where it is converted into electrical power.
The medium-frequency oscillations that are of interest in this context are intended to mean the range from about 15 kHz to about 15 MHz.
With regard to the inventive apparatus, the object of the invention is achieved by a configuration for supplying a large number of actuators with electrical power without using wires. The configuration includes at least one primary winding which is fed from a medium-frequency oscillator, with each actuator having at least one secondary winding that is suitable for drawing power from a medium-frequency magnetic field.
With regard to the actuator, the object is achieved by an actuator having a number of orthogonal secondary windings that are suitable for drawing power from a medium-frequency magnetic field.
With regard to the primary winding, the object of the invention is achieved by providing a primary winding that includes a number of separate winding sections that are each formed from a number of parallel conductors. The individual winding sections are mechanically and electrically connected to one another via connecting elements. Two winding sections are electrically connected to one another, in an offset manner with respect to one another, when there is one connecting element, thus resulting in two free winding ends that are suitable for the connection of connecting lines to a generator or oscillator.
Alternatively, with regard to the primary winding, the object is achieved by a primary winding consisting of a flexible cable formed from a number of parallel conductors. A connecting element electrically and mechanically connects the two cable ends to one another, in an offset manner with respect to one another, thus resulting in two free winding ends which are suitable for the connection of connecting lines to a generator or oscillator.
With regard to the system, the object is achieved by providing a system for a machine having a large number of actuators, in particular an automated production machine, in which each actuator has at least one secondary winding that is suitable for drawing power from a medium-frequency magnetic field. The system includes at least one primary winding that is fed from a medium-frequency oscillator. The primary winding is provided for supplying the actuators with electrical power without using wires. Each actuator is equipped with a receiving device that receives radio signals from a central transmission device that is connected to a process computer for the machine.
The advantages that an be achieved by the invention are, in particular, in comparison to conventional solutions with a cable connection for supplying the actuators with electrical power, that there is no need for the relatively high cost factor involved with a cable connection for planning, material, installation, documentation and maintenance. No failures can occur as a result of cable breaks or poor for example corroded, contacts.
In comparison to using batteries for supplying power to the actuators, there is no maintenance penalty or cost penalty resulting from the necessity to replace batteriesxe2x80x94often at points where access is difficult.
In the stated medium-frequency range from about 15 kHz to about 15 MHz, the disadvantages that result from skin effects, for example, the losses that occur are still manageable. Since the primary windings are too small, in comparison to the wavelengths that occur, to act as antennas, electromagnetic waves are not emitted, thus allowing the configurations to be of simple construction. There is no need for EMC (Electromagnetic Compatibility) measurement of radiated interference. Another advantageous factor is that medium-frequency magnetic fields are shielded only to a minor extent by metallic machine components, so that a magnetic field that is sufficiently strong to supply power advantageously also occurs at inaccessible points in an actuator system or machine.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method and configuration for supplying a large number of actuators with electrical power without the use of wires, and actuator and a primary winding for this purpose, as well as a system for machine having a large number of actuators, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.