Patent Application
20190245312
The invention relates to sliprings and parts thereof. It specifically relates to slipring modules that include a plurality of individually prefabricated sliding tracks and a method of assembling slipring modules from plurality of individually prefabricated sliding tracks. Sliprings are used for transferring electrical signals or power between parts rotating relative to each other. Sliprings generally have circular tracks of an electrically-conductive material at a first part and brushes of an electrically conductive material at a second part. The brushes are sliding at the electrically-conductive tracks.
A slipring disclosed in U.S. Pat. No. 6,283,638 B1 comprises a cylindrical slipring module having cylindrical sliding tracks of a conductive material and brush blocks that include brushes configured to slide on the sliding tracks. The brush blocks (and therefore the brushes) are made rotatable against the module. The embodiment disclosed in this document specifically has wire brushes made of a comparatively thin metal wire. The sliding tracks of the module contain V-shaped grooves to guide the wire(s) at a predetermined position.
The embodiments are providing a slipring module, which can be manufactured with a simple and straight forward manufacturing process, and which allows a large variety of module designs with different sliding track geometries.
In one embodiment, a sliding track component includes at least one sliding track and, preferably, a connector configured to electrically connect the sliding track made of (as) one piece. Accordingly, the sliding track component has a monolithic structure. This means at least that the sliding track component is formed as a single piece of the same material. This monolithic structure of the sliding track component is preferably made with a 3D printing process carried out with the use of a 3D printer. Such a 3D printing process may be a process that involves dissipating multiple layers of a material to generate a predetermined three-dimensional structure. Such processes may include the Electron Beam Melting (EBM), Laser-engineered Net Shaping (LEMS), Selective Laser Melting (SLM), and Selective Laser Sintering (SLS). The method of Electron Beam Melting includes a selective melting process, by which the 3D structure is built-up layer by layer using an electron beam in vacuum. A precursor material in this case is a metal powder. The positioning of the electron beam is controlled with software according to the desired design (such software control based on 3D CAD design data is an intrinsic property of all modern additive manufacturing processes).
For Laser-engineered Net Shaping, a high-power laser beam is applied to the target material. The metallic powder (made of pure metal or alloy(s)) is deposited by using a nozzle locally at a desired location that is determined according to the 3D structure, and subsequently melted by the laser beam. The elements of deposited material are formed in lines, in form of a raster process for each layer. This method can be used as an additive manufacturing process to generate new parts as well as for various repair actions.
In selective laser sintering, a laser used to generate heat at specific positions within a powder material. The heat generation then leads to sintering of the material at a given specific position and, hence, solidification and formation of a spatially-continuous complex structure.
For selective laser melting process, a laser is used to achieve complex 3D designs. However, in this case the laser energy is used to cause melting of the metal powder (rather than just sintering). In the majority of cases, a single laser output is utilized, although a double-beam technology exists that combines the output of a lower- and higher-power laser outputs to generate complex spatial patterns.
Preferably, a 3D printed structure of an embodiment is a structure comprising a plurality of thin material layers that are molded, sintered, and/or processed with any other electrical thermal or chemical process to form a monolithic body from these thin material layers. Preferably, the used material is a metal, an electrically conductive material, or a metallic material that possesses good electrical characteristics and that is able to guide electrical current. The material of choice may additionally be defined to possess good contacting and/or good mechanical/frictional and/or good wear characteristics, in order to ensure that a fabricated from this material sliding surface (on which a sliding brush may slide) has a long lifetime and good contact characteristics (such as, for example, low contact noise and low contact resistance).
The connector may be a connector for plug and/or socket connection, soldering connection, or screw connection. The connector may further have a connecting line section, defined between the sliding track and an external connecting point for external electrical connection.
In a related embodiment, a sliding track component may include at least two sliding tracks. The sliding track may further include at least one connector.
Preferably, a sliding track of an embodiment is structured as a hollow cylindrical or ring-shaped body defining an outer side, an inner side, and a center axis about which the slipring may later be rotated.
A sliding track preferably has a contact surface configured to be contacted by a sliding brush (such as a wire brush or a carbon brush, for example). The sliding track is further formatted to have a surface opposite to the contact surface (an opposite surface) and two side surfaces. There exist two basic slipring geometries. The first is a drum-type geometry, and the second is a platter or disk-type geometry. When the slipring is of a drum type, the sliding tracks are preferably arranged co-axially with the rotation axis, while the slipring module has a cylindrical or drum-like shape with the sliding tracks having their contact surfaces or sliding surfaces at the outside of the cylindrical drum. When the slipring is of a disk type, the sliding tracks are arranged radially with respect to an axis of rotation, and the sliding surfaces of all sliding tracks are preferably pointing in the same direction.
Preferably, at least one connector is connected at a side that is opposing the contact surface. In a drum-type configuration of the sliding track, the connector preferably protrudes from the inner side of the ring-shaped sliding track in a direction parallel to the center axis, but outside of the center axis. In a disk-type sliding track, the connector preferably protrudes from the inner side of the ring in a radial direction. Preferably the connector has an elongated shape, most preferably a shape of a rod.
Preferably, each sliding track has at least one connector. There may be two or more connectors at a single sliding track to improve the electrical connection and to lower the ohmic resistance. In a related embodiment, it may also be possible to employ a single connector to contact multiple sliding tracks, but this may not be desirable in most applications, as such arrangement may cause a short circuit between the sliding tracks.
Another embodiment includes a sliding track component having a plurality of sliding tracks and, preferably, connectors that are further interconnected with at least one strut. Preferably, the struts are at the inner side of the sliding tracks. The struts preferably are interconnected with each other and with the sliding tracks. The ring-shaped sliding tracks, the connectors, and the struts form a monolithic piece, which includes a 3D printed structure and which preferably has been made with the use of a 3D printer. Basically, a strut forms a mechanical connection between two parts (for example, between sliding tracks).
Preferably, fracture points/locations are provided between the struts and the sliding tracks and/or the connectors, such that the struts may be removed at a later time.
In yet another embodiment, the sliding track component includes at least one sliding track and at least one connector that form one single piece of a 3D printed material. In such embodiment, the use of at least two different 3D printing materials are required. A first 3D printing material possesses metallic conductive characteristics and is used for transmitting the electrical current. This material is used for manufacturing the sliding tracks and the connectors. A second 3D material is used for making the insulating material parts and, therefore, is chosen to have electrically-insulating properties. (Here, a plastic material may be used. Such a plastic material may be epoxy, polyurethane or any other suitable material, as well as combination of such materials with fillers or other materials.) As a result of printing the whole, complete slipring module in a single printing process, the need to provide the above-mentioned struts for forming a stiff monolithic structure is no longer present.
In one embodiment, at least one sliding track has a holding structure which may later provide a form-fit with an insulating body to increase the mechanical stability and to firmly hold the sliding track and the insulating body together. The holding structure may include protrusions and/or recesses. In one embodiment, there may be present at least one protrusion and/or recess at opposing sides of the sliding track and distant from the sliding surface. In a related embodiment, there may be present at least one holding protrusion extending from a side that is distant with respect to the contact side of the sliding track.
In a further embodiment, at least one sliding track may have at least one V-groove or a plurality of V-grooves, or any other appropriately structured profile form that facilitates the guidance of contact brushes and/or reduces wear and friction of the brushes upon the sliding. In a further embodiment, at least one sliding surface has a microstructure configured to increase contacting performance. Preferably, such a microstructure is manufactured with a 3D printing process.
A further embodiment relates to a method of manufacturing a slipring module. The method includes the steps of
A further embodiment includes the steps of:
Although the embodiment explained above relates to the cylindrical or drum-shaped slipring modules, disk-shaped or platter modules may be manufactured in the same way, by using a 3D printing process on a 3D printer.
There may be a finishing process of the module, which process may include the step(s) of coating or plating at least one sliding surface and/or machining at least one sliding surface to form a specific bare-surface structure such as V-grooves, or to generate a specific surface roughness. Coating or plating of such initially bare (that is, lacking any coating) surface may be additionally carried out with galvanic deposition, PVD or CVD, or any other suitable fabrication methodology.
The embodiments disclosed below provide significant improvements over the prior art. Now, slipring modules can be manufactured easily by using a monolithic sliding track component and at least partially embedding the same into an insulating material (such as a plastic material). This results in a mechanically robust slipring module structure, because the monolithic sliding track component is present in only one, single piece that contains multiple sliding tracks together with their corresponding electrical connectors and a holding structure (comprising at least one strut and preferably comprising a main support unit that may be configured to hold or connect the struts). Such a monolithic sliding track component may easily be manufactured via 3D printing, as has been already mentioned above, resulting in a simple and straightforward manufacturing methodology that includes 3D printing the monolithic sliding track component, inserting the monolithic sliding track component into a mold, filling insulating material into the mold, and curing the insulating material to form the insulating body. After at least one partial curing of the insulating material, the mold may be removed. Finally, the struts and/or the main support are removed to procure the finished slipring module.
Yet another embodiment relates to monolithic brush holder, which preferably is made by a 3D printing process by a 3D printer as mentioned above. The brush holder preferably includes a brush holder body that has at least one brush contact. There may be present at least a second brush contact. The brush contacts establish a contact with and/or hold at least one brush wire. Generally, any number of brush contacts and/or brush wires may be present. Preferably, the brush contacts are oriented such that the brush wire extends from the brush holder body at a certain angle that is different from 90°, to apply the desired pressure to a sliding track. Electrical contact(s) between the brush wires and the brush holder body may be established by crimping, soldiering, welding, or any other suitable method. There may be a threaded hole or any other appropriate means for mounting and/or electrically contacting the brush holder. Multiple brush holders may be assembled into a brush block. This embodiment may be operably combined or cooperated with at least one of the embodiments mentioned above.
In the following, the invention is described with the use of non-limiting examples of embodiments and with reference to the drawings, of which:
Embodiments of the invention can be variously modified and assume alternative forms. It should be understood that the drawings and the corresponding detailed description are not intended to limit the invention to the any particular disclosed forms but to the contrary, the scope of the intention is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
In
In
In
In
In
In
Before removing the struts and the main support from the mold, any tests or modification may be done which require an electrical connection of the sliding tracks. For example, a common electrical test may be performed, or the sliding tracks may be galvanized or anodized, for which the main support may be a common electrode connection.
In
In
In
In
In
In
It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to provide slipring modules. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be re-versed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16195609.9 | Oct 2016 | EP | regional |
This application is a continuation of the pending International Application No. PCT/EP2017/077346 filed on 25 Oct. 2017, which designates the United States and claims priority from the European Application No. 16195609.9 filed on 25 Oct. 2016. The disclosure of each of the above-identified patent applications is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2017/077346 | Oct 2017 | US |
| Child | 16385986 | US |
