DE2510597A1 - ROTATIONAL SYMMETRIC ELECTRIC CONTACT ARRANGEMENT AND METHOD OF MANUFACTURING IT - Google Patents

Description

9570-75 / Dr.ν.B / S

GB-PA 10984/74

S ¹ IIed: March 12, 1974

Geo. L. Scott & Colita., Cromwell Road, Elle ame re Port . Cheshire

L65 4DT, England

Rotationally symmetrical electrical contact arrangement and process for their manufacture

The present invention relates to rotationally symmetrical, In particular, cylindrical electrical contact arrangements, such as slip rings, commutators and the like., With at least one Contact piece made of electrically conductive material, as used to establish an electrical connection between two in with respect to each other rotatable components is required. The invention also relates to a method for producing a such contact arrangement.

The present invention is based on the object of providing an electrical contact arrangement of the type specified above create, which requires less electrical conductor material than corresponding known contact arrangements, which are also can be easily produced and which can also be designed so that heat can be easily dissipated from it.

This object is achieved by the invention specified in claim 1.

The subclaims relate to further developments and advantageous ones Embodiments of the invention and preferred methods for producing the subject matter of the invention.

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Embodiments of the invention and preferred processes for producing the subject matter of the invention are described below explained in more detail with reference to the drawing; show it:

Figure 1 is a schematic end view of part of a commutator;

Figure 2 is a simplified cross section of the commutator according to Figure 1;

Figure 3 is a plan view of part of a contact arrangement}

FIG. 4 shows a cross section through part of another Commutators and

FIG. 5 shows a cross section through yet another embodiment of a commutator.

The one in Figures 1 and 2 as an embodiment of the invention Commutator shown contains copper segments 1, the are arranged at a distance from one another and connected to a flexible tape 2, which in turn is attached to a core 3 which is made from an aluminum alloy by an impact extrusion or cold pressing process. That Flexible tape contains a phenolic-based adhesive, but other adhesives or other means of attachment can also be used of the tape on the core. The tape can be made of nylon, fiberglass or some other material, for example, which ensures adequate electrical insulation of the copper segments 1 from one another and from the core 3.

The core 3 is rotatable about its longitudinal axis 20 and shaped so that it has a relatively large inner surface 14, which strongly promotes the dissipation of heat to the surrounding air. The re-entrant shape of the core 3 is also only a minimum of material is required. Instead of the core 3 of this special embodiment made of metal, it is of course also possible to have a core made of a other material, e.g. made of pressed or injected plastic

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fabric can be used. Before being applied to the core 3, the segments 1 are in the correct relative position with respect to one another attached to a flexible strip 4 which is provided with a pressure-sensitive adhesive. In Pigur 1 it is indicated that the strip 4 is removed from the segments 1, after they have been attached to the core 3.

A hook-shaped tab 9 projects from each segment 1, which is used to connect the relevant segment to a corresponding one The end of an anchor winding adjacent to the core is used.

Pigur 3 shows a strip-shaped building 5 made of sheet copper, made by punching from a copper strip. The structure 5 consists of commutator segments 6, the are connected by tabs 7 with strip-shaped parts 8 The punched strip-shaped structure 5 is on the intended Cut to length and according to a further method for manufacturing a contact arrangement according to the invention an adhesive tape arranged on a core is wound without the aid of an adhesive tape such as the adhesive tape 4 in Figure 1 is required. The segments 6 are in this way in the correct mutual position on the belt (corresponding to the band 2 in Figure 1) arranged and then connected to this; then the strip-shaped parts 8, which extend beyond the band 2, as well as at least the tabs 7 protruding from one side of the segments 6 cut off. The protruding from the other end of the segments 6 the tabs 7 can be left on the segments and hook-shaped be bent open so that connections for the armature winding are available, as above in connection with the tabs was mentioned.

In Figure 4 is a core with a rib or a flange 12 shown, which connects a sleeve-like property located on the inside with an inclined outer edge. With the oblique

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frustoconical outer edge are segments 10, which are in Taper cross-section, fastened by means of a band 13. The inside 15 of the inclined outer edge is used for delivery, in particular Radiation of heat similar to the inner surface 14 of the embodiment according to Figure 1. The outer side 11 of the Segments IO is parallel to the axis of rotation of the core and serves as a Support surface for a carbon or brush that is connected to an external circuit. The connection of the segments 10 with an associated winding takes place via hooks 10a. Since the cross section of the segments 10 increases in the direction of the hook 10a, stands for the electric current that flows from a brush resting on the segment surface 11 to the hook 10a, an increasing conductor cross-section is available.

In the embodiment shown in Figure 5, the core has a web or flange 17, which has an inner hub part connects with an outer cylindrical (axially parallel) hand 19, which is covered with a layer 18 of insulating material, for example by dipping the tape in liquid Nylon can be made. Around the edges of the coated Commutator segments 16 are bent around the outer edge and thereby mechanically on the layer 18 of insulating material attached to the edge. At one end of the segments 16 flags (not shown) for connecting an armature winding stop. Such a commutator is easy to assemble, since the cores can be manufactured in batches and none Waiting time for the hardening of adhesives is required. The segments 16 can to facilitate assembly on a Adhesive strips (corresponding to the adhesive strip 4 in Figure 1) arranged or by strip-shaped parts (such as the parts 8 in Figure 3) are supported.

The embodiments described all have a core which is designed to give off heat easily can. Of course, other constructions are also possible, e.g. constructions with ribs, spokes or webs;

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If desired, a solid core can also be used.

You can come along with the described contact details a minimum of copper from; manufacture is simple and does not require complicated machinery.

The exemplary embodiments described can be modified in the most varied of ways without leaving the scope of the invention To exceed. For example, the segments 16 shown in Figure 5 on a strip according to the Strip 4 must be attached in ligur 1 before being attached to the flange-like The outer edge of the core is clamped; the retaining strip is then after clamping the commutator segments replaced.

The segments can of course also consist of an electrically conductive material other than copper. In all of the described embodiments of the invention, only a minimum of the expensive electrical conductor material for the attachment and the connection of the segments 1 or 10 required, while one is much less expensive for the grain Material such as plastic or a cheaper metal can be used, so that is essential for the contact arrangement result in lower total costs than in the known commutator arrangements and the like.

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Claims (7)

Claims ί 1, / Rotationally symmetrical electrical contact arrangement with at least one contact piece made of electrically conductive material, characterized in that that the contact piece '1, 10) is attached to a core (3) which consists of a material which is less expensive than the contact piece material. 2. Contact arrangement according to claim 1, characterized in that the core (3) consists of one there is electrically conductive material and that between him and a layer (2, 13, 18) made of electrically insulating material is arranged on the contact pieces (1, 10). 3. Contact arrangement according to claim 2, characterized in that the core (3) has a rim-like Edge (19) and that the contact pieces (1) by bending their bands around the hand (19) of the core on this are attached, 4. Contact arrangement according to claim 1, 2 or 3, characterized in that the core (3) has an inclined, rim-like outer edge and that the contact pieces (10) attached to this outer edge run in such a way are designed that their outer surfaces (11) run parallel or concentrically to the axis of rotation of the core. 5. A method for producing a contact arrangement according to any one of claims 1 to 4, characterized in that that the core (3) is manufactured by, in particular, cold drop forging or pressing. 6. Method for producing a contact arrangement according to one of claims 1 to 4, characterized 509838/0300 draw.net that the contact pieces (1) before their attachment attached to the core (3) on a flexible strip (4). 7. Method for producing a contact arrangement according to one of claims 1 to 4 »characterized in that that the contact pieces (6) before being attached to the core of strip-shaped parts (8) from the the same material as they are attached and that the strip-shaped parts (8) after attaching the contact pieces be removed at the core. 509838/0300 Blank page