Patent Application
20110140568
This application claims the benefit of DE 10 2009 058 259.2, filed Dec. 14, 2009.
The present embodiments relate to a device for establishing an electrical contact between two device elements moving relative to each other.
Arrangements for establishing a sliding contact between two moving components are used in various areas of technology. Arrangements of this kind are used, for example, in computer tomographs, which have a stationary structure and elements rotating around the patient (e.g., radiation sources and detectors). The transmission of data or energy between the moving part (e.g., a rotor) and the stationary part (e.g., a stator) is achieved, for example, by sliding contacts (e.g., a slip ring).
Arrangements of this kind may have a lubricant (e.g., a liquid lubricant) between components moved relative to each other. The operation of a sliding contact arrangement also develops abrasion. Abrasion may include small particles that are ground off during operation.
Lubricants and abrasion may have a negative impact on the contact element used. For example, the operational capability of brushes in conventional brush-type contact pickoffs becomes impaired over time. The lubricant or the mixture of abrasion and lubricant impairs the elasticity of the brushes over time. As a result, the entire system reacts much more sensitively to unevennesses in the slideway, and the signal quality deteriorates. For this reason, the brushes used for the currents and voltages may be overdimensioned. The overdimensioning (e.g., increasing the wire diameter of wires from which the brushes are formed) has certain drawbacks such as, for example, a deterioration of the dynamic properties due to the greater weight of the brush.
Comparable problems are addressed in DE 195 43 383 B4, DE 198 17 796 C2 and DE 102 007 054 675 A1. These publications describe possibilities for avoiding the negative consequences of abrasion (e.g., with the aid of a collecting device (DE 195 43 383 B4 and DE 102 007 054 675 A1) or by design measures (DE 198 17 796 C2)).
The present embodiments may obviate one or more of the drawbacks or limitations in the related art. For example, in one embodiment, a brush design for a brush contact system with better durability than conventional brush contact systems may be provided. In another embodiment, a brush contact system that withstands the negative influences of lubricants and abrasion for longer and thus has a longer service life may be provided.
The present embodiments are based on a device for establishing an electrical contact between two device elements moving relative to each other (e.g., a rotor and a stator). The contact is established by a plurality of brushes arranged on one of the device elements or held by the one device element. The plurality of brushes establishes contact on the relative movement of the device elements along a slideway provided on the other device element (i.e., the plurality of brushes slide along the other device element and thereby establish a contact). The plurality of brushes may be arranged staggered one behind the other relative to a direction of movement determined by the relative movement. In one embodiment, the offset is up to 50% of the brush diameter (e.g., 20%-30% of the brush diameter). This arrangement may be effected, such that during the course of the movement executed by the plurality of brushes, a substance (e.g., lubricant, abrasion) provided between the device elements may be pushed or guided out of the way. For example, the plurality of brushes may be arranged in an arrow shape relative to the direction of movement, such that the substance is pushed or guided out of the way. According to another embodiment, the plurality of brushes is arranged in the form of an inclined line relative to the direction of movement.
The arrangement of the plurality of brushes according to the present embodiments pushes dirt or oil mixtures to the side so that the individual brushes have less contact with the dirt or oil mixtures. This, therefore, reduces the impairment of the brushes, and the brushes remain elastic for longer and have a longer service life. In addition, an arrangement with a plurality of small brushes has greater elasticity than one big brush with a corresponding number of contact wires. This enables unevennesses and faulty points on the track to be better compensated. The plurality of brushes according to the present embodiments may have a much smaller diameter than the brushes of the prior art. For example, each brush of the plurality may include 25-100 fibers.
In one embodiment, the plurality of brushes is arranged on a carrier (e.g., brush holder or spring holder). The carrier may be, for example, a parallel rocker arm so that the angle of the plurality of brushes relative to the contacted element (e.g., the other element) remains substantially constant.
In another embodiment, solid lubricant is used for the brushes and/or for the slideway. The solid lubricant may, for example, be incorporated in each brush of the plurality as individual fibers, which wear uniformly with the plurality of brushes. This, at least partially, eliminates problems incurred by oil lubrication.
This brush contact arrangement in the form of thin elastic contact bundles increases tolerance toward slideway unevenesses. The slideway 2 may not be machined. The influence of oil or dirt and mixtures on the track decreases. The signal quality remains constant despite lower voltages and currents.
The present embodiments may be used, for example, for computer tomographs. However, the present embodiments are not restricted to this field of application but may be used for any technical application establishing a contact between two parts or components moving relative to other (e.g., automation).
While the present invention has been described above by reference to various embodiments, it should be understood that many changes and modifications can be made to the described embodiments. It is therefore intended that the foregoing description be regarded as illustrative rather than limiting, and that it be understood that all equivalents and/or combinations of embodiments are intended to be included in this description.
| Number | Date | Country | Kind |
|---|---|---|---|
| DE 102009058259.2 | Dec 2009 | DE | national |
