Shaft contacting device and system

Abstract

The invention relates to a shaft contacting device (10) having a carbon brush (14), which is held in a brush guide (16) so as to be movable along a working direction (18) in order to bring a contact side (20) of the carbon brush (14) into contact with the motor shaft, and a spring (22). The brush guide (16) has a holding protrusion (24), and the carbon brush (14) has a holding recess (30) which corresponds to the holding protrusion (24), wherein an engagement of the holding protrusion (24) into the holding recess (30) blocks a movement of the carbon brush (14) in the working direction (18) in an installed position. The brush guide (16) is designed such that a force (F) exerted onto the carbon brush (14) from the release side (26) of the brush guide (16) can raise the holding recess (30) over the holding protrusion (24), thus allowing a movement of the carbon brush (14) in the working direction (18). The invention additionally relates to a system (1) comprising a housing (2) and a shaft contacting device (10).

Description

Wave contact device and system

[0001] Electric motors have a rotating motor shaft. To ensure that the electric motor's commutation is performed correctly, it is possible, for example, in a two-pole design, to install at least two conductive contact surfaces on the motor shaft. These contact surfaces are connected to the electric motor's coils.

[0002] To apply operating voltage to these contact surfaces, at least two shaft contact devices are used, which are arranged in a fixed position relative to the motor shaft. Since the rotation of the motor shaft does not allow a fixed connection to the motor shaft, a sliding connection is used. For this purpose, a shaft contact device typically uses a carbon brush, which is pressed toward the motor shaft by a spring in a brush guide. If only a single-pole connection is required, e.g., for grounding the motor shaft, a single shaft contact device is sufficient.

[0003] Although this functionality has proven itself, the manufacturing process is not trivial. As long as the shaft contactor is not in mechanical contact with the motor shaft, the spring pushes the carbon brush out of the brush guide, making installation of the shaft contactor difficult.

[0004] It is therefore an object of the present invention to provide an improved shaft contacting device and an improved shaft contacting system which enable easier assembly without impairing the known functionality.

[0005] According to a first aspect of the invention, the object is achieved by a shaft contacting device for electrically contacting a conductor with a motor shaft, the shaft contacting device comprising a carbon brush which is held displaceably in a brush guide along a working direction in order to contact the motor shaft with a contact side of the carbon brush, and a spring which is designed to apply a compressive force to the carbon brush in the direction of the working direction, wherein the brush guide has a holding projection, and wherein the carbon brush has a holding recess corresponding to the holding projection, and an engagement of the holding projection in the holding recess blocks a displacement of the carbon brush in the working direction in an assembly position, wherein the brush guide is designed such that a force acting on the carbon brush from the release side of the brush guidethe retaining recess can be lifted over the retaining projection and thus allow the carbon brush to be moved in the working direction.

[0006] A special feature of this shaft contact device is that the carbon brush is held in the brush guide almost until assembly is completed and is only released in the final step by the assembly process itself. Specifically, the carbon brush only shifts in the working direction when it is actually positioned against the motor shaft. The shaft contact device locks the carbon brush without the need for any additional components. No additional or separate release process is required, as the release can be achieved simply during assembly.

[0007] Another special feature of some designs is that the force acting on the carbon brush is generated during the assembly process. This prevents accidental release or triggering of the carbon brush, which could occur, for example, if a locking device were accidentally removed.

[0008] Another special feature is that the effectively usable length of the carbon brush remains large. The retaining projection can easily be located in the distal half of the carbon brush, i.e., the half that does not have the contact side, or even at the distal end, i.e., the end opposite the proximal contact side. The retaining projection extends, in particular, from a release side of the brush guide transversely to the working direction toward the carbon brush.

[0009] Thus the task is completely solved.

[0010] In a preferred embodiment, the brush guide has an opening on its release side which is designed to allow the passage of a trigger projection which exerts the force on the carbon brush.

[0011] This design provides a defined opening through which the release projection can exert its force on the carbon brush. If the opening is selected to be small, accidental release of the carbon brush can be effectively prevented. The opening can, in particular, be circular.

[0012] In a preferred embodiment, the force acting on the carbon brush is parallel to a normal vector of the mounting surface.

[0013] This design allows for a simple construction. A suitable trigger projection can also be easily implemented. This leads to lower manufacturing costs for the shaft contact device.

[0014] In a preferred embodiment, the force acting on the carbon brush is at an angle to a normal vector of the mounting surface, in particular at an angle of at least approximately 90°.

[0015] This design allows for good adaptation to the specific installation situation. The first force vector generated during the assembly process is not the same as the second force vector acting on the carbon brush, even if the first force vector is the cause of the second force vector. The force vectors can differ in direction and / or magnitude.

[0016] In a preferred embodiment, a force emanating from the mounting surface is converted into the force acting on the carbon brush via a force conversion element.

[0017] The force emanating from the mounting surface is described as a first force vector, and the force acting on the carbon brush as a second force vector. The force vectors can differ in direction and / or magnitude. The force conversion element can be designed, in particular, as a deflection element, rocker, lever, or pivoting element.

[0018] In a preferred embodiment, the brush guide has a spring side opposite the release side, which is designed to be freely resilient in a rear region opposite the retaining projection.

[0019] This design allows the carbon brush to fit well in both the mounting position and the release position.

[0020] In a preferred embodiment, the brush guide has a slot-shaped recess on a spring side opposite the release side, through which an electrical conductor contacted to the carbon brush is guided to the outside.

[0021] This design allows for easy contact between the carbon brush and an electrical component of the electric motor. The slot-shaped recess allows that the carbon brush can move freely, even if the conductor is led outwards.

[0022] In a preferred embodiment, the brush guide has a second holding projection in addition to the said first holding projection and the carbon brush has a second holding recess in addition to the said first holding recess.

[0023] This design allows for the carbon brush to be securely held in the mounting position. Furthermore, each of the two retaining projections can be designed somewhat smaller, particularly in terms of its height, while still providing the same secure hold as a single, larger retaining projection. Finally, a particularly symmetrical arrangement of the two retaining projections, relative to a longitudinal axis of the carbon brush in the working direction, can enable a well-controlled transition from the mounting position to the release position.

[0024] In a preferred embodiment, the carbon brush has an inclined surface which is arranged in such a way that the force acts on the inclined surface and there develops a first force component in the working direction and a second force component perpendicular to the working direction.

[0025] This configuration allows the carbon brush to be lifted out of the retaining recess due to the second force component and simultaneously pushed in the working direction by the first force component. This can ensure that, even with higher friction of the carbon brush in the brush guide during the release process, the carbon brush is pushed in the working direction, even if the force of the spring is insufficient for this during the release process. The inclined surface is arranged, in particular, between two retaining recesses. The inclined surface has an inclination of between 10° and 70°, preferably between 15° and 50°, and particularly preferably between 25° and 35°, relative to the working direction.

[0026] In a preferred embodiment, the brush guide forms a U-shape in side view.

[0027] This design is structurally simple to implement. The side view shows the side of the brush guide, with the viewing direction in the side view perpendicular to the viewing direction in the top view. The upper leg of the II, i.e., the leg remote from the release side, is particularly spring-loaded.

[0028] In a preferred embodiment, the brush guide forms a U-shape in plan view. The spring side of the brush guide is visible in the plan view, with the viewing direction in the plan view being perpendicular to the viewing direction in the side view.

[0029] This design is simple to implement. The side view shows the side of the brush guide.

[0030] In a preferred embodiment, the brush guide has a mounting side which is designed to be fixed on a mounting surface.

[0031] Depending on the design, the mounting side may coincide with the release side. However, the mounting side may also be at an angle to the release side, in particular at an angle of at least approximately 90°.

[0032] According to a second aspect of the invention, the object is achieved in that the brush guide has a flexible tongue on the release side, which in the mounting position projects outwards beyond the release side and has a trigger projection at its free end, wherein the trigger projection is designed to exert the force acting on the carbon brush when the trigger projection is pressed in a triggering direction in the direction of the carbon brush by fixing the brush guide on the mounting surface.

[0033] In this variant, the mechanism for releasing the carbon brush is combined with the shaft contact device. The force exerted by the release side of the The force acting on the carbon brush from the brush guide is transferred to the carbon brush via the release projection. Since the flexible tongue protrudes outwards beyond the release side in the mounted position, but is pressed into the plane of the release side when placed on the mounting surface, the tongue presses the release projection against the carbon brush. The resulting force lifts the holding recess above the holding projection and thus releases the carbon brush to move in the working direction. Depending on the design, only the release projection of the tongue can protrude outwards beyond the release side and / or at least part of the tongue. The release projection extends in particular transversely to the working direction of the carbon brush.

[0034] According to a third aspect of the invention, the object is achieved by a system with a housing and a previously described shaft contacting device, wherein the housing has a mounting surface on which the shaft contacting device can be mounted or is mounted, wherein the housing has a release projection in the region of the mounting surface, where a mounting side of the brush guide comes to rest, which is designed such that when the shaft contacting device is fixed on the mounting surface, the release projection presses against the carbon brush, lifts the holding recess above the holding projection and thus releases the displacement of the carbon brush in the working direction.

[0035] This variant uses a mounting surface on which a release projection is arranged. This release projection interacts with the shaft contact device in such a way that, when the shaft contact device is correctly installed, the release projection exerts the force on the carbon brush. This variant provides additional safety during the assembly process, since if the shaft contact device is incorrectly positioned, the release projection cannot release the carbon brush. This is especially true if the brush guide has an opening on its release side that is designed to allow the release projection to penetrate, and only in the area of ​​the opening.

[0036] According to a fourth aspect of the invention, the object is achieved by a system comprising a housing and a previously described wave contacting device with flexible tongue, wherein the housing has a mounting surface on which the shaft contacting device is or can be mounted.

[0037] This variant does not require a housing with a trigger projection. It is sufficient to provide a mounting surface that, when the shaft contact device is mounted on the mounting surface, presses the tongue, particularly the trigger projection, so that the force is exerted against the carbon brush.

[0038] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0039] An embodiment of the invention is illustrated in the drawings and explained in more detail in the following description. They show: Fig. 1 shows a first embodiment of the wave contacting device in perspective view; Fig. 2 shows the first embodiment of the shaft contacting device in plan view; Fig. 3 shows the first embodiment of the shaft contacting device in sections AA and BB from Fig. 2; Fig. 4 shows a second embodiment of the wave contacting device in perspective view; Fig. 5 shows the second embodiment of the shaft contacting device in plan view; Fig. 6 shows the second embodiment of the shaft contacting device in sections AA and BB from Fig. 5; Fig. 7 shows a third embodiment of the wave contacting device in perspective view; Fig. 8 shows the third embodiment of the shaft contacting device in a view from the front; Fig. 9 shows the third embodiment of the shaft contacting device in sections AA and BB from Fig. 8; Fig. 10 shows a fourth embodiment of the wave contacting device in perspective view; Fig. 11 shows the fourth embodiment of the wave contacting device in a view from the front; Fig. 12 shows the fourth embodiment of the shaft contacting device in a side view; and Fig. 13 shows the fourth embodiment of the shaft contacting device in sections AA and BB from Fig. 12;

[0040] Fig. 1, together with Fig. 2 and Fig. 3, shows a first embodiment of a shaft contacting device 10 for electrically contacting a conductor 12 with a motor shaft (not shown). The motor shaft, not shown here, is located in this embodiment on the rear side of the shaft contacting device 10, facing away from the viewer. Together with the housing 2, the shaft contacting device 10 forms a system 1.

[0041] The shaft contacting device 10 has a carbon brush 14, which is held displaceably in a brush guide 16 along a working direction 18 in order to contact the motor shaft with a contact side 20 of the carbon brush 14. The shaft contacting device 10 also has a spring 22, which is symbolically referred to here as Roller spring is shown and is designed to apply a compressive force to the carbon brush 14 in the direction of the working direction 18.

[0042] The brush guide 16 has a retaining projection 24 which extends from a release side 26 of the brush guide 16 transversely to the working direction 18 to the carbon brush 14. To clarify the orientation of the extension of the retaining projection 24, a release direction 28 is shown, along which the retaining projection 24 extends from the release side 26 transversely to the working direction 18.

[0043] The carbon brush 14 has a retaining recess 30 corresponding to the retaining projection 24. Interlocking of the retaining projection 24 with the retaining recess 30 prevents displacement of the carbon brush 14 in the working direction 18 in an assembly position. This assembly position is shown here.

[0044] The brush guide 16 is designed such that a force F acting on the carbon brush 14 from a release side 26 of the brush guide 16 can lift the holding recess 30 above the holding projection 24 and thus release the displacement of the carbon brush 14 in the working direction 18.

[0045] The brush guide 16 has an opening 31 on the release side 26, which is designed to allow the passage of a trigger projection 32, which exerts the force F on the carbon brush 14. The force F acting on the carbon brush 14 is parallel to a normal vector 34 of a mounting surface 36 of the shaft contacting device 10. A mounting side 52 of the brush guide 16 or of the shaft contacting device 10 lies at least substantially flat on the mounting surface 36, so that the normal vector 34 of the mounting surface 36 is at least substantially parallel to a normal vector of the mounting side 52.

[0046] On the release side 26, the brush guide 16 has a flexible tongue 38 which, in the illustrated assembly position, projects outwardly beyond the release side 26 and which has the release projection 32 at its free end, which extends transversely to the working direction 18 of the carbon brush 14. The release projection 32 is designed to Carbon brush 14 acting force F when the trigger projection 32 is pressed in the direction of the carbon brush 14 in a triggering direction, which here corresponds at least approximately to the triggering direction 28, by fixing the brush guide 16 or the shaft contacting device 10 on the mounting surface 36.

[0047] In addition, the brush guide 16 has a spring side 42 opposite the release side 26, which is freely resilient in a rear region opposite the retaining projection 24. The resilient property is achieved here by a longitudinal slot 44 on each of the two sides of the brush guide 16, with each longitudinal slot 44 extending completely into the rear region opposite the retaining projection 24. Similar to the brush guide 16 having a U-shape when viewed from the spring side 42, the two sides of the brush guide 16 have a U-shape. As an alternative to the longitudinal slot 44, the brush guide 16 can have an elastic upper side or spring side 42 made of an elastic material. It is also possible for there to be some air between the upper side of the brush guide 16 and the carbon brush 14, so that the carbon brush 14 can be lifted within the brush guide 16 towards the upper side.

[0048] The U-shape just described on the upper side of the brush guide 16 or on the spring side 42 is achieved by a slot-shaped recess 46 through which an electrical conductor 12 contacted to the carbon brush 14 is led outwards.

[0049] In the embodiment shown here, the brush guide 16 has a second retaining projection (hidden here) in addition to the aforementioned first retaining projection 24. Accordingly, the carbon brush 14 has a second retaining recess (hidden here) in addition to the aforementioned first retaining recess 28.

[0050] The shaft contacting device 10 functions as follows. The shaft contacting device 10 is placed with the release side 26 onto the mounting surface 36. This creates a force F, which in turn acts on the release projection 32, which is resiliently held on the flexible tongue 38.

[0051] The trigger projection 32 is in contact or comes into contact with the carbon brush 14, so that the force F now acts on the carbon brush 14 approximately in the direction of the trigger direction 28. This, in turn, causes the carbon brush 14 to now shift approximately in the direction of the trigger direction 28. This leads to the holding recess 30 being lifted above the holding projection 24.

[0052] When the retaining recess 30 is raised above the retaining projection 24, the carbon brush 14 is no longer blocked in the working direction 18. Therefore, the compressive force of the spring 22, which presses against the carbon brush 14 in the working direction 18, now causes the carbon brush 14 to shift in the working direction 18. Specifically, the carbon brush 14 will now shift in the working direction 18 until it encounters a target object, in particular the motor shaft. Since the carbon brush 14 is conductive, an electrical contact is established between the conductor 12 and the motor shaft.

[0053] In the embodiment shown here, a further design feature is provided for this release or triggering process. The carbon brush 14 has an inclined surface 50, which is arranged such that the force F acts on the inclined surface, where it develops a first force component in the working direction 18 and a second force component perpendicular to the working direction 18, i.e., along the triggering direction 28.

[0054] The second force component lifts the retaining recess 30 above the retaining projection 24. The first force component acts in the working direction 18 and thus supports the spring 18 during the release or triggering process. This can be particularly helpful when, since the carbon brush 14 is pressed against the spring side 42, the frictional resistance increases due to the increased surface pressure between the carbon brush 14 and the spring side 42, and therefore a force greater than the force intended to be provided by the spring 22 during normal operation may be required.

[0055] Fig. 4 shows, together with Fig. 5 and Fig. 6, a second embodiment of a wave contacting device 10 for electrically contacting a conductor 12 with a motor shaft (not shown). Apart from a modification in the actuation of the carbon brush 14, the second embodiment is similar to the first embodiment except for the differences described below. The details described for the first embodiment are therefore not repeated here. The reference numerals already introduced are retained for identical or functionally similar components, even if they are not shown again.

[0056] In the system 1 formed here, the housing 2 again has the mounting surface 36 on which the shaft contacting device 10 is mounted. In the region of the mounting surface 36, where the mounting side 52 of the brush guide 16 lies, the housing 2 has the release projection 32, which is designed so that when the shaft contacting device 10 is fixed to the mounting surface 36, the release projection 32 presses against the carbon brush 14, lifts the holding recess 30 above the holding projection 24, and thus releases the displacement of the carbon brush 14 in the working direction 18.

[0057] Fig. 7, together with Fig. 8 and Fig. 9, shows a third embodiment of a shaft contacting device 10 for electrically contacting a conductor 12 with a motor shaft (not shown). Apart from a modification in the triggering of the carbon brush 14 and the use of a helical spring as the spring 22, the third embodiment is similar to the first embodiment except for the differences described below. The details described for the first embodiment will therefore not be repeated here. The reference numerals already introduced are retained for identical or functionally similar components, even if they are not shown again.

[0058] The carbon brush 14 is triggered here from the side, specifically from the release side 26. After the shaft contact device 10 has been mounted, the flexible tongue 38 is actuated by applying a force F using a finger or a tool. In certain embodiments, it is also possible to trigger the triggering by subsequently installing another component that presses against the flexible tongue 38. The force F acting on the carbon brush 14 is at an angle to a normal vector of the mounting side 52, here in particular at an angle of at least approximately 90°.

[0059] Fig. 10, together with Fig. 11, Fig. 12 and Fig. 13, shows a fourth embodiment of a shaft contacting device 10 for electrically contacting a conductor 12 with a motor shaft (not shown). Apart from a modification in the triggering of the carbon brush 14, the fourth embodiment is similar to the third embodiment except for the differences described below. The details described for the first embodiment and the third embodiment will therefore not be repeated here. The reference numerals already introduced are retained for identical or functionally similar components, even if they are not shown again.

[0060] In the system 1 formed here, the housing 2 again has the mounting surface 36 on which the shaft contacting device 10 is or will be mounted. A force emanating from the mounting surface 36 is converted via a force conversion element 54 into the force F acting on the carbon brush. For this purpose, the force conversion element 54 has an inclined run-up surface 56 that is inclined to the normal vector 34 of the mounting surface 36.

[0061] When the shaft contacting device 10 is placed on the mounting surface 36, it first assumes a defined position relative to the force conversion element 54 through an opening 58 in a base plate 60 of the shaft contacting device 10. Such a defined position can also be achieved in other ways, e.g., by projections on the shaft contacting device 10 that engage in recesses in the mounting surface 36; positioning elements independent of the force conversion element 54 can also be used.

[0062] In a further step, the inclined run-up surface 56 strikes the flexible tongue 38 and presses it successively in the release direction 28 until the holding recess 30 is lifted over the holding projection 24 and thus the displacement of the carbon brush 14 in the working direction 18 is released.

Claims

Claims 1. Shaft contacting device (10) for electrically contacting a conductor (12) with a motor shaft, the shaft contacting device (10) comprising a carbon brush (14) which is held displaceably in a brush guide (16) along a working direction (18) in order to contact the motor shaft with a contact side (20) of the carbon brush (14), and a spring (22) which is designed to apply a compressive force to the carbon brush (14) in the direction of the working direction (18), wherein the brush guide (16) has a holding projection (24), and wherein the carbon brush (14) has a holding recess (30) corresponding to the holding projection (24), and an engagement of the holding projection (24) in the holding recess (30) blocks a displacement of the carbon brush (14) in the working direction (18) in an assembly position, wherein the brush guide (16) is designed such that a force (F),which acts from the release side (26) of the brush guide (16) onto the carbon brush (14), can lift the retaining recess (30) over the retaining projection (24) and thus release the displacement of the carbon brush (14) in the working direction (18).

2. Shaft contacting device (10) according to claim 1, wherein the brush guide (16) has an opening (32) on the release side (26) which is designed to allow the passage of a trigger projection (32) which exerts the force (F) on the carbon brush (14).

3. Shaft contacting device (10) according to one of the preceding claims, wherein the force (F) acting on the carbon brush (14) is parallel to a normal vector (34) of a mounting surface (36).

4. Shaft contacting device (10) according to one of the preceding claims, wherein the force (F) acting on the carbon brush (14) is at an angle to a normal vector (34) of a mounting surface (36), in particular at an angle of at least approximately 90°.

5. Shaft contacting device (10) according to claim 4, wherein a force emanating from the mounting surface (36) is converted into the force acting on the carbon brush via a force conversion element.

6. Shaft contacting device (10) according to one of the preceding claims, wherein the brush guide (16) has a spring side (42) opposite the release side (26) which is freely resilient in a rear region opposite the holding projection (24).

7. Shaft contacting device (10) according to one of the preceding claims, wherein the brush guide (16) has a slot-shaped recess (46) on a spring side (42) opposite the release side (26), through which an electrical conductor (12) contacted to the carbon brush (14) is guided outwards.

8. Shaft contacting device (10) according to one of the preceding claims, wherein the brush guide (16) has a second holding projection in addition to said first holding projection (24) and the carbon brush (14) has a second holding recess in addition to said first holding recess (30).

9. Shaft contacting device (10) according to one of the preceding claims, wherein the carbon brush (14) has an inclined surface (50) which is arranged such that the force (F) acts on the inclined surface (50) and there develops a first force component in the working direction (18) and a second force component perpendicular to the working direction (18).

10. Shaft contacting device (10) according to one of the preceding claims, wherein the brush guide (16) forms a U-shape in side view.

11. Shaft contacting device (10) according to one of the preceding claims, wherein the brush guide (16) forms a U-shape in plan view 12. Shaft contacting device (10) according to one of the preceding claims, wherein the brush guide (16) has a mounting side (52) which is designed to be fixed on a mounting surface (36).

13. Shaft contacting device (10) according to one of the preceding claims, wherein the brush guide (16) has a flexible tongue (38) on the release side (26), which in the mounted position projects outwards beyond the release side (26) and which has a trigger projection (32) at its free end, wherein the trigger projection (32) is designed to exert the force (F) acting on the carbon brush (14) when the trigger projection (32) is pressed in a triggering direction (28) in the direction of the carbon brush (14) by fixing the brush guide (16) on a mounting surface (36).

14. System (1) with a housing (2) and a shaft contacting device (10) according to one of claims 1 to 12, wherein the housing (2) has a mounting surface (36) on which the shaft contacting device (10) can be mounted or is mounted, wherein the housing (2) has a release projection (32) in the region of the mounting surface (36), where the mounting side (52) of the brush guide (16) comes to rest, which is designed such that when the shaft contacting device (10) is fixed on the mounting surface (36), the release projection (32) presses against the carbon brush (14), lifts the holding recess (30) above the holding projection (24) and thus releases the displacement of the carbon brush (14) in the working direction (18).

15. System (1) with a housing (2) and a shaft contacting device (10) according to claim 13, wherein the housing (2) has a mounting surface (36) on which the shaft contacting device (10) can be mounted or is mounted.

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