Conductive Film, Paint for Downhole Tool Wiring
Publication Date: 2015-Aug-11
The IP.com Prior Art Database
This invention describes a method of securing an electrical conductor along a shaft while maintaining the structural integrity of the shaft.
Purpose of Invention
The purpose of this invention is to provide a method of securing an electrical conductor along a driveshaft while maintaining a circular cross-section without a wireway groove.
The Transmission of electrical power and signals between one or more components is often accomplished by running one or more insulated conductors along the axis of a shaft. These conductors are typically recessed into a groove which is cut into the shaft as shown in Figure 1. The recessed conductors also allow the driveshaft to maintain its uniform cross-section which would be required for bearing and bushing surfaces.
As a consequence, machining a groove into a shaft reduces the torque carrying capacity of the shaft. The groove also introduces stress concentrations which may reduce the fatigue life of the shaft.
This invention uses a conductive film or paint which is applied to a smooth (no groove) shaft. A film or conductive paint would have a much thinner cross-section than a circular wire with the same current carrying capacity. This would allow for a higher torque carrying capacity than a grooved shaft with the same outside and inside diameters. Applying the conductor to a smooth shaft allows it to maintain its structural integrity for transmitting torsional, axial and bending loads.
Description of Invention
In In this invention, a Conductor  would be sandwiched between an Inner Insulator  and Outer Insulator  and applied to a smooth Shaft  as shown in Figure 2 to form a conductor path along the Shaft.
The Inner Insulator (2) is an electrical insulation material which may be painted onto the shaft or is an adhesive film or tape or a heat shrink sleeve. The insulation material must be at least as wide as the conductor (3). The purpose of the Inner Insulator is to electrically...