阅读说明：本技术 用于滑环刷的架 (Frame for slip ring brush ) 是由 J·卡茨 P·海因布赫 C·霍尔茨阿普费尔 M·多尔 于 2019-08-06 设计创作，主要内容包括：一种用于滑环刷的刷架,包括由杆保持在基座处的刷支架。杆通过基座枢轴连接至基座并且能够在与刷支架枢转轴线和/或滑环旋转轴线正交的平面内枢转。弹簧设置在基座和杆之间。刷支架通过能够在所述平面中枢转的刷支架枢轴连接至杆。刷支架保持第一刷和第二刷,其中刷支架枢轴位于第一刷和第二刷之间。(A brush holder for a slip ring brush includes a brush holder retained at a base by a rod. The rod is pivotally connected to the base by the base and is pivotable in a plane orthogonal to the brush holder pivot axis and/or the slip ring rotation axis. A spring is disposed between the base and the stem. The brush holder is pivotally connected to the rod by a brush holder that is pivotable in said plane. A brush holder holds the first brush and the second brush, wherein the brush holder is pivotally positioned between the first brush and the second brush.)

1. A brush holder (200) comprising a brush holder (240) held at a base (210) by a rod (220), wherein

The lever (220) is pivotably connected to the base (210) by a base pivot (221) having a base pivot axis (222), and

a spring (230) is disposed between the base (210) and the lever (220),

it is characterized in that the preparation method is characterized in that,

the movement of the lever (220) is restricted within a first plane (400) orthogonal to the base pivot axis (222),

the brush holder (240) is connected to the lever (220) by a brush holder pivot (223) having only a first pivot axis parallel to the base pivot axis (222).

2. A brush holder (200) comprising a brush holder (240) held at a base (210) by a rod (220), wherein

The lever (220) is pivotably connected to the base (210) by a base pivot (221) having a base pivot axis, and

a spring (230) is disposed between the base (210) and the lever (220),

it is characterized in that the preparation method is characterized in that,

the brush holder (240) comprises at least a first brush holder (241) and a second brush holder (242), wherein the brush holder pivot (223) is located between the first brush holder (241) and the second brush holder (242), and

the distance between the first brush attachment means (241) and the brush holder pivot (223) is greater than the distance between the second brush attachment means (242) and the brush holder pivot (223).

3. The brush holder (200) according to claim 2,

it is characterized in that the preparation method is characterized in that,

the distance between the first brush holding means (241) and the brush holder pivot (223) is at least 10%, preferably 20% to 50%, greater than the distance between the second brush holding means (242) and the brush holder pivot (223).

4. The brush holder (200) according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

movement of the brush holder (240) is restricted to the first plane (400).

5. The brush holder (200) according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the brush holder (240) is free to pivot about an axis parallel to the base pivot axis within an angular range of 30 °, preferably 20 °, and most preferably 10 °.

6. The brush holder (200) according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

an effective brush contact area on a first side of the brush holder pivot (223) is at least 10%, preferably 20% to 50%, greater than an effective brush contact area on a second side of the brush holder pivot (223).

7. A brush holder (200) comprising a brush holder (240) held at a base (210) by a rod (220), wherein

The lever (220) is pivotably connected to the base (210) by a base pivot (221) having a base pivot axis, and

a spring (230) is disposed between the base (210) and the lever (220),

it is characterized in that the preparation method is characterized in that,

the rod (220) includes a plurality of sealed hollow spaces (620) to reduce the weight of the rod.

8. The brush holder (200) according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the pole comprises at least one of foam, a mesh structure, a honeycomb structure, a truss frame (fackwerk) or a lightweight structure with structure along the force line or a similar 3D printed structure.

9. The brush holder (200) according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the spring (230) is an extension spring, and preferably a helical spring, and/or

The spring (230) is arranged parallel to the base, and/or

The spring (230) is longer than the lever (220).

10. The brush holder (200) according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the shaft includes a first shaft section (226) and a second shaft section (227), the first shaft section (226) holding the brush holder (240), the spring (230) attached to the second shaft section (227), wherein the base pivot (221) is located between the first shaft section (226) and the second shaft section (227), and

preferably, the angle between a first line between the brush holder pivot axis 224 and the base pivot axis 222 and a second line between the spring attachment point and the base pivot axis 222 is in the range between 80 ° and 120 °, and

preferably, the second rod section (227) is shorter than the first rod section (226), and

the rod (220) may be a rigid rod.

11. The brush holder (200) according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the brush holder (240) is pulled by the spring (230) in a direction away from the base (210), and/or

The brush holder (240) has a second pivot axis orthogonal to the first pivot axis.

12. A brush holder (200) comprising a brush holder (240) held at a base (210) by a rod (220), wherein

The rod (220) is a resilient rod which is only bendable in a movement plane (400), the movement plane (400) being orthogonal to a slip ring rotation axis of a cylindrical slip ring and/or orthogonal to a track surface of a disc shaped slip ring,

and the rod (220) is firmly connected to the base,

it is characterized in that the preparation method is characterized in that,

the brush holder (240) is connected to the lever (220) by a brush holder pivot (223) which is pivotable in the movement plane (400).

13. The brush holder (200) according to the preceding claim,

it is characterized in that the preparation method is characterized in that,

the rod (220) comprises two parallel wires.

14. The brush holder (200) according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

litz wires (250) are arranged between the brush holder (240) and the base (210), the litz wires (250) preferably being guided within the coil springs (230) if coil springs are provided.

15. The brush holder (200) according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the brush holder (240) holds at least one sliding brush comprising at least one of sintered carbon material, metal foam, or bundled wires.

Technical Field

The present invention relates to a slip ring brush and a holder for a slip ring brush, and particularly to a slip ring brush and a holder for a slip ring brush for applications requiring a long life and a high current load. Such slip ring brushes are preferably used together with slip rings for energy or signal transmission and current collectors of a generator or motor.

Background

In U.S. patent application publication US 2005/0029896 a1, a brush holder for holding a carbon brush on a commutator of a dc motor is disclosed. The brush is slidably held in the housing and pressed against the commutator by a spring. As the wear of the brush increases, the brush slides downward through the housing, which causes the spring to reduce its length and reduce the force applied to the brush. Therefore, the pressure of the slip ring brush is reduced with time, which results in a change in the electrical contact characteristics.

German patent DE 967293 discloses a brush for an electric machine, in which a piece of carbon brush material is pressed against a slip ring by means of a spring-loaded rod. To achieve a constant pressure, a long spring and a long rod are required, which makes the brush holder large.

A pivotable ball-mounted brush holder with brushes is disclosed in GB 146,828. The ball-type mounting enables the brush to tilt in two axes and enables the brush to rotate. This requires a female slip ring and a male brush that fits into the female slip ring.

Further brush holders are disclosed in DE 7100971U, CN 105470766 a and FR 530801 a. RO 92696 a2 discloses a slip ring brush holder in which the brush is pivotable about two axes which are neither parallel nor orthogonal.

EP 3364508 a1 discloses a holder for a slip ring brush.

Disclosure of Invention

The problem to be solved by the present invention is to provide a holder for a slip ring brush, which holder is relatively compact in size and provides a substantially constant pressure over the life of the brush, irrespective of the wear of the brush.

The solution to the problem is described in the independent claims. The dependent claims relate to further developments of the invention.

The brush holder includes a base, a rod, and a brush holder. The base is a body that can be used to mount the brush holder to the brush holder assembly and can also support electrical contacts or connectors for electrical connection. The base may be a conductive or non-conductive material depending on the particular application. In the case of high current brushes, it may be desirable to make a metal base that has high stability and enables simple contact and current guiding through the base. Alternatively, it may be desirable to have high insulation. Thus, the base may be made of an insulating material. Furthermore, insulating materials such as plastic materials are lighter in weight than required for metal bodies. In any case, the primary function of the base is a mechanical function to support and retain other components of the brush holder.

The brush holder is a member for holding at least one brush and preferably two brushes. Such a brush may be any brush known in the art, such as sintered graphite or silver-graphite material. The brush may also comprise bundles of wires or other suitable material or sintered carbon material. It is also possible that only one brush or a plurality of such brushes, for example a foamed metal brush, is present. Preferably, the brush holder comprises an electrically conductive material to improve the conduction of current to the brush. Insulating materials may also be used here if desired. In a typical application, multiple brushes on a single brush holder travel on the same sliding track. Therefore, they should be electrically connected, which is preferably accomplished by using the conductive material of the brush holder. The brush holder itself or the brush at the brush holder may be electrically contacted by litz wires or any other flexible wires that can lead an electric current to and through the brush.

A rod is provided to mechanically connect the brush holder to the base. There is a base pivot to connect the rod to the base. The base pivot has a base pivot axis. When such a brush holder is mounted to a slip ring comprising a sliding track, also referred to as slip ring module, the base pivot axis is preferably parallel to the axis of rotation of the cylindrical slip ring and in the case of a disc slip ring to the track plane.

The lever may also be pivotally connected to the brush carriage by a brush carriage pivot having a first pivot axis parallel to the base pivot axis and preferably having a second pivot axis orthogonal to the first pivot axis. The second pivot axis may be orthogonal to a plane passing through the axis of rotation of the cylindrical slip ring. Preferably, the second pivot axis is not orthogonal to the axis of rotation of the cylindrical slip ring. Therefore, it is preferable that the brush holder is capable of tilting relative to the surface of the slide rail but is not capable of rotating away from the moving direction of the slide rail. Preferably, such rotation is prevented. According to a preferred embodiment, the brush holder pivot is only pivotable about an axis parallel to the base pivot axis. According to another embodiment, the brush holder pivot is further pivotable about an axis parallel to the plane of the sliding track, as will be defined in detail below.

A spring, preferably a tension spring and most preferably a coil spring, is connected between the base and the rod such that the brush holder pivot increases the distance of the brush holder pivot from the base under the force of the spring. Thus, the brush holder and thus the brush holder pivot may be pulled by the spring in a direction away from the base, and if properly mounted with respect to the slip ring, the brush holder and thus the brush holder pivot exerts a force on the sliding track of the slip ring. The spring may be arranged parallel to the base. In any operating condition, the spring may be longer than the lever.

The rod may include a first rod section that holds the brush holder and a second rod section to which the spring is attached. The other side of the spring is attached to the base. The base pivot is located between the first rod section and the second rod section. Preferably, the angle between a first line between the spring attachment point and the base pivot axis and a second line between the brush holder pivot axis and the base pivot axis is in the range between 90 ° and 120 °, preferably in the range between 80 ° and 120 °. With this configuration, the direction of force can be changed and the overall size can be reduced. The magnitude of the force can also be modified by the difference in length of the rod sections. Preferably, the second rod section is shorter than the first rod section.

In a preferred embodiment in which the brush holder comprises at least two brush fixtures and the brush holder pivot is arranged between the brush fixtures, the brush holder will be pivoted into a position such that both brushes are pressed against the sliding track. Thus, such tiltable double brush holder is automatically aligned with the position of the sliding rail, and variations in height and even relative position between the brush holder and the sliding rail can be easily compensated for. The tiltable double brush holder may even compensate for lateral offsets in the surface of the sliding rail.

The brush fixing means may comprise a sleeve or rivet or hole or thread for mounting the brush to the brush holder. The fixture may also include a fixture that glues, solders, or welds the brush to the brush holder. Further, the brush may be clamped or press fitted to the brush holder. In another embodiment, the brush may comprise a metal foam, which may also comprise silver, gold, copper, brass or any other electrically conductive material with good contact properties. Preferably, an open cell foam may be used, but a closed cell foam is also suitable for this embodiment. Preferably, such foam may be soldered to a thin sheet of copper or any other electrically conductive material.

Preferably, the distance between the first brush attachment means and the brush holder pivot is at least 10%, preferably 20% to 50%, greater than the distance between the second brush attachment means and the brush holder pivot.

In another embodiment, litz wires are disposed between the brush holder and the base. Litz wire may be used to contact the brush and to direct current to the brush. Preferably, the litz wire is guided in a helical spring. This may give additional damping to the spring, which may improve the mechanical properties. The litz wire may be formed as a strip wire, which may be bare or insulated.

It is further preferred that the rod is a rigid rod. A rigid or stiff rod may allow high pressure to be applied to the brush without deforming the rod.

In another embodiment, the rod includes a plurality of sealed hollow spaces to reduce the weight of the rod. The rod may include at least one of foam, a mesh structure, a honeycomb structure, a truss frame (fackwerk), or a lightweight structure with structure along the force line, or a similar 3D printed structure. There should be a closed or sealed hollow space to avoid a large surface area of the rod to which dust and debris may adhere. Furthermore, if high insulation is required, hollow spaces that can collect dust and debris within the rod can be avoided, as the conductive dust collected therein can reduce electrical insulation and add weight (due to the dust material) to the rod. The sealed hollow space reduces the weight and inertia of the rod while preventing the accumulation of conductive debris. There may be a structure closed on at least one side.

In an alternative embodiment, the rod may be a resilient rod, which is preferably only able to bend orthogonally to the brush holder pivot axis and/or to the slip ring rotation axis of the cylindrical slip ring and/or to the track surface of the disc shaped slip ring. Furthermore, preferably, the rod is firmly connected to the base. Preferably, the spring constant of the lever is designed such that the lever produces a desired force on the brush. Furthermore, it is preferred that the brush holder is pivotally connected to the lever by a brush holder pivot axis which is parallel to the base pivot axis, as already described above. Therefore, this embodiment also has the same advantages as the above-described embodiment. Preferably, the rod comprises a resilient material and preferably a spring-loaded resilient material. This may be a spring, steel or brass material. It is also preferred that the rod is capable of conducting electrical current, which will simplify the electrical connection of the brush.

In a preferred embodiment, the rod comprises two parallel wires. Preferably, the line is parallel to a plane through the brush holder pivot axis and/or a plane through the slip ring rotation axis of the cylindrical slip ring. These parallel lines allow the rod to move only in a plane orthogonal to the brush holder pivot axis and/or the slip ring rotation axis and not out of plane, thus providing a stable support of the brush. The wire may be elastic and may provide a spring characteristic that may be used to press the one or more brushes to the sliding track. Wires may also be used to electrically contact the brushes.

In the following, further embodiments are explained, which can be combined with different embodiments of the bar as described above.

In another embodiment, the brush holder is pivotable about an axis parallel to the base pivot axis and/or in a plane orthogonal to the brush holder pivot axis and/or the slip ring rotation axis of the cylindrical slip ring and/or the orbital surface of the disc shaped slip ring. It is further preferred that the angle of movement is limited to a range of 30 degrees, preferably 20 degrees and most preferably 10 degrees.

The first brush fixture and the second brush fixture may define a sliding track plane. This is simply a defined matter and not an actual plane. The sliding track plane may tangentially contact a surface of the sliding track.

It is further preferred that the brush holder pivot is further pivotable about an axis parallel to the plane of the sliding track. This may allow compensating for lateral tilting of the sliding rail. In another embodiment, a rotation prevention device is provided to prevent rotation of the brush holder pivot about an axis orthogonal to the plane of the sliding track. This may further increase the stability and guidance of the brush.

In another embodiment, the front brushes or brush segments may be positioned further away from the brush holder pivot than the rear brushes or brush segments. The front brush is the brush that a certain section of the sliding track passes first. This section of the sliding track then passes over the rear brush.

Drawings

Hereinafter, without limiting the general inventive concept, the present invention will be described by way of example in examples of embodiments with reference to the accompanying drawings.

Figure 1 shows an embodiment of a brush holder.

Figure 2 shows a front view of the brush holder.

Figure 3 shows the basic function of the lever.

Fig. 4 shows an embodiment with inclined planes.

Fig. 5 shows an embodiment with a skewed sliding track plane.

Fig. 6 shows a side view of an embodiment with a wire rod.

Fig. 7 shows a perspective view of an embodiment with a wire rod.

Fig. 8 shows an embodiment with a metal foam brush.

Fig. 9 shows a portion of an embodiment of a lever.

Fig. 10 shows the different forces at the brush holder.

Detailed Description

In fig. 1, an embodiment of a brush holder is shown. Further details of the force are shown in fig. 10. The brush holder 200 includes a base 210, a lever 220, and a brush holder 240. The base is preferably mounted to the slip ring housing and is preferably mounted in a fixed spatial relationship with respect to the rotational axis 130 of the slip ring. The lever may have an extension from the first side to the second side and is preferably mechanically connected to the base with the first side by a base pivot 221, the base pivot 221 preferably having a single base pivot axis 222 (shown in fig. 3). The base pivot axis may be parallel to the rotation axis 130. The brush holder 240 may be coupled to the second side of the lever 220 by a brush holder pivot 223, which brush holder pivot 223 may have a single brush holder pivot axis 224. The brush holder pivot axis 224 may be parallel to the base pivot axis 222.

A spring, which may be a helical spring 230, may be arranged between the base 210 and the rod 220, such that the spring may pull the rod such that the brush holder is pushed away from the base, which pushing away may be in the direction of the sliding rail 110, which sliding rail 110 is part of the slip ring 100. The slip ring may further include an insulating support 120 that holds the sliding track. The slip ring may rotate about its axis of rotation 130.

In one embodiment, in order to achieve a constant force even in the case of a brush that shortens due to wear, it is advantageous to have a long spring, so that the spring force is almost constant in all operating states and even in the case of a brush that is worn. This configuration is shown herein in fig. 1, where the springs are parallel to the base to achieve a low height for the brush holder 200.

The brush holder 240 may include at least a first brush fixture 241 and may also include a second brush fixture 242. The brush fixture may hold the first brush 310 and the second brush 320. One litz wire 250 or a plurality of such litz wires may be in contact with the brush for electrical connection of the brush. The litz wire may be arranged inside a helical spring.

The movement of the lever 220 may be limited to within a first plane 400 orthogonal to the base pivot axis 222. The brush holder 240 may only be movable in a first plane 400, which first plane 400 is orthogonal to the brush holder pivot axis 224, and/or orthogonal to the base pivot axis 222 and/or orthogonal to the slip ring rotation axis 130. The first plane 400 is in the figure parallel to and/or in the plane of the drawing. It may be beneficial that the brush holder cannot move away from the first plane 400. This avoids vibration and oscillation. Because the brush holder and the brush cannot move laterally of the slide rail (e.g., out of a plane orthogonal to the base pivot axis 222), the side walls of the slide rail may not be needed. Wear due to sliding of the sliding brush along such a rail side wall can thus no longer occur. The brush holder 240 may also be prevented from tilting or rotating away from the first plane 400 such that the first brush moves in a direction above the first plane and the second brush moves in a direction below the first plane or such that the first brush moves in a direction below the first plane and the second brush moves in a direction above the first plane. This may ensure that the first brush 310 and the second brush 320 run on the same track without lateral displacement.

The only possible movement of the brushes may be in a parallel direction away from the first plane such that both brushes move in a direction above the first plane at the same time or in a direction below the first plane at the same time, as shown in fig. 5.

The embodiments described herein having a first brush 310 and a second brush 320 may also be applied to a single elongated brush, which may have a first brush segment 310 and a second brush segment 320 opposite the first brush segment. This configuration is shown in fig. 8.

Now, further reference is made to fig. 10. When the slip ring rotates, the first brush 310 and the second brush 320 induce a torque in the brush holder pivot through their friction forces 710, 720. In this figure, the direction of rotation may be clockwise. To provide at least partial torque compensation, the front first brush 310 may be positioned a greater distance 712 from the brush holder pivot 223 than the distance 722 from the brush holder pivot as shown in FIG. 1 for the rear second brush 320. Thus creating a torque and additional force component for each brush. When the slip ring rotates clockwise, the front first brushes are additionally loaded with a force caused by the brush friction torque, and the rear brushes are less loaded because the force caused by the spring is now reduced due to the friction momentum of the brushes. Because the brush support pivot 223 is asymmetrically positioned relative to the first brush 310 and the second brush 320, a greater force is applied to the second brush 320 than to the first brush 310. This may compensate for the different forces generated by friction.

In summary, to improve torque compensation, the front brushes may be positioned further away from the brush holder pivot than the rear brushes. This may be combined with all embodiments described herein.

If the slip ring is rotated in the opposite direction (counterclockwise) as shown, the brush holder pivot 223 may be disposed closer to the first brush 310, which first brush 310 may then be the rear brush.

The brush holder pivot 223 may be symmetrically located between the first brush 310 and the second brush 320 in the case of changing the direction of rotation.

In fig. 2, a front view of the brush holder of fig. 1 is shown. Here, the relationship with the slip ring and its sliding track can also be clearly seen. Now, the plane 400 orthogonal to the brush holder pivot axis and/or to the slip ring rotation axis is preferably orthogonal to the drawing plane and also orthogonal to the slip ring rotation axis 130. Preferably, blocking means are provided to prevent rotation of the brush holder about an axis 225 in a plane 420 orthogonal to the brush holder pivot axis and/or the slip ring rotation axis and orthogonal to the slip ring rotation axis 130. Obviously, if the brush holder rotates about the axis 225, the brush may move laterally away from the sliding track, which would result in damage to the slip ring and cause the electrical contact to be interrupted. Such a prevention means may be an overlapping region of the brush holder 240 and the rod 220.

In fig. 3, the basic function of the lever is shown. The spring 230 may pull and may generate a force in a direction 232 that results in a force 228 on the brush holder 240 that is perpendicular to the sliding track. Preferably, the distance between the brush holder pivot axis 224 and the first brush holder 241 is the same as the distance between the brush holder pivot axis 224 and the second brush holder 242, such that if the brushes have the same length, the force applied to the brushes is the same. Although it is clear that the sliding track is circular and has a certain radius, as shown in fig. 1 and 2, in the following description, for the sake of simplicity, it is assumed that the radius is infinite, which may result in a plane, which is referred to herein as the sliding track plane. In addition to applying the brush holder in a slip ring arrangement, the brush holder may also be used for a linear sliding track, which is also represented by a sliding track plane.

A preferred embodiment of a lever 220 is shown herein. The spring 230 is attached to the lever 220 outside of the section of the lever between the base pivot 221 and the brush holder pivot 223. The spring may provide the pulling force. The rod may include a first rod section 226 and a second rod section 227, the first rod section 226 holding a brush holder 240, and a spring 230 attached to the second rod section 227. The other side of the spring is attached to the base 210. The base pivot 221 is located between the first rod section 226 and the second rod section 227. Preferably, the angle between the second line between the spring attachment point and the base pivot axis 222 and the first line between the brush holder pivot axis 224 and the base pivot axis 222 is in the range between 80 ° and 120 °. With this configuration, the direction of force can be changed and the overall size can be reduced. The magnitude of the force can also be modified by the difference in length of the rod sections. Preferably, the second rod section 227 is shorter than the first rod section 226.

In this figure, an ideal configuration is shown, wherein the sliding track plane 420 is a horizontal configuration. Basically, the horizontal configuration can be freely chosen as long as there is a main force component 228 perpendicular to the sliding rail plane 420.

In fig. 4, an embodiment with inclined planes is shown. Here, the sliding track plane 420 is inclined, as indicated with reference numeral 421. This can easily be compensated for by the brush holder pivoting about its first pivot axis accordingly, so that the two brushes are again in contact with the plane. Thus, there is again a force 228 perpendicular to the inclined sliding rail plane 421.

In fig. 5, an embodiment with a skewed sliding track plane is shown. Here, the sliding track plane 420 is in a deflected configuration, as indicated by reference numeral 422. This may occur if the axis of rotation of the slip ring is not exactly parallel to the base pivot axis. There may be a brush holder having a second pivot axis orthogonal to the first pivot axis to allow adaptation to the deflection plane 422 so that at the sliding track the brush runs smoothly all the way with its full contact surface and thus provides the best possible contact. Otherwise, the brush may only run with the edge at the sliding track. This may be acceptable in some circumstances if the axis of the slip ring is at a constant position that is not parallel to the pivot axis of the base. In this case, as the wear of the brush increases, the brush will increase its contact surface with the sliding rail, since the edge will be worn. For the case where the slip ring is not eccentric or otherwise moving, there will be continuous movement and the angle of the plane of deflection may vary continuously, which will not provide constant brush wear, and a common slip ring brush will have multiple varying contact characteristics. For the above described embodiment of the brush holder, this can also be compensated dynamically, since the brush can easily follow the movement of the sliding track. Preferably, there is only a first pivot axis and a second pivot axis at the brush holder. Preferably, other degrees of movement of the brush holder relative to the rod are undesirable, as these degrees of movement can lead to instability and oscillation, thereby increasing brush wear.

In fig. 6, a side view of an embodiment of a brush holder 500 having a resilient rod 520 is shown, the resilient rod 520 comprising a wire. The rod 520 comprises two parallel wires fixed together at their ends and parallel to the brush holder pivot axis and/or parallel to the slip ring rotation axis of the cylindrical slip ring and/or parallel to the track surface of the disc shaped slip ring. Two parallel wires may be injection molded or otherwise fixedly held within the base 510. The wire may be a one-piece member connected at the end of the brush holder. Since the wires are connected together at both ends, the wires cannot twist and can only bend in one plane (the plane orthogonal to the brush holder pivot axis and/or the slip ring rotation axis). Preferably, the spring constant of the lever is designed such that the lever produces a desired force on the brush. Further, it is preferred that the brush holder is connected to the rod by a brush holder pivot 524, which brush holder pivot 524 is pivotable in a plane orthogonal to the brush holder pivot axis and/or the slip ring rotation axis, as already described above. Therefore, this embodiment also has the same advantages as the above-described embodiment. The material of the spring may be a spring, steel or brass material. It is also preferred that the rod is capable of conducting electrical current, which will simplify the electrical connection of the brush. A shim 529 may be present at the wire to further stabilize the wire.

Fig. 7 shows a perspective view of an embodiment with a wire rod. It further shows a brush holder 540 having a first brush holder 541 and a second brush holder 542. These brush holders may hold brushes or hold sleeves for holding brushes.

Fig. 8 shows an embodiment with a metal foam brush 350. The base and stem are substantially the same as shown in figure 1. There are exceptions, such as foam brushes mounted (preferably soldered or welded) to foam brush carrier 352, and foam brush carrier 352 may be a sheet of copper or any other electrically conductive material. Preferably, the foam brush carrier is connected to litz wire, which may be the wire shown or the wire as shown in any other figure. The brush holder is also modified to hold the foam brush carrier and/or the foam brush. For this purpose, the brush holder preferably has a flat surface which can be matched to at least one of the foam brush (width, length, radius) and/or the sliding track (width, radius). The foam brush carrier may be part of a brush holder. Here a flat sliding track section is shown. The flat sliding track section may be part of a linear sliding track or a disc-type flat sliding ring.

The same asymmetric position of the pivot axis as described in fig. 1 is advantageous when a single brush is mounted with contact areas between the brush and the slip ring extending to both sides of the brush holder pivot. Here, the front brush segment may be located further away from the brush holder pivot than the rear brush segment.

For a reel slip ring module, the bottom side of the foam brush carrier may be curved to the radius of the sliding track.

Fig. 9 shows a portion of an embodiment of a lever. A plurality of sealed hollow spaces 620 are included between the 3D printed sidewalls 610. There are also parallel layers, for example, covering layers parallel to the drawing plane to enclose the hollow space.

Fig. 10 shows the different forces at the brush holder and is explained in further detail in the section describing fig. 1.

List of reference numerals

100 slip ring

110 sliding rail

120 insulating support

130 slip ring axis of rotation

200 brush holder

210 base

212 set screw

220 rod

221 base pivot

222 base pivot axis

223 brush holder pivot

224 brush carrier pivot axis

225 axis orthogonal to the axis of rotation of the slip ring

226 first rod segment

227 second rod segment

228 to the sliding track

230 spring

Direction of 232 spring force

240 brush support

241 first brush fixing device

242 second brush attachment

250 litz wire

310 first brush

320 second brush

350 metal foam brush

352 Metal foam Brush Carrier

400 first plane

410 pass through the plane of the brush holder

420 sliding rail plane

421 inclined plane

422 skew plane

500 brush holder

510 base

520 bar

524 Brush support pivot

529 gasket

540 brush support

541 first brush fixing device

542 second brush fixing device

600 sections of rods

610 side wall

620 sealed hollow space

710 friction of first brush

712 distance of first brush

720 second brush friction force

722 distance of second brush