This disclosure relates to electrical connectors, and more particularly to a system and method to provide underwater electrical mating connections utilizing self-passivating transition metals.
To avoid water contamination of electrical contacts, conventional receptacle and female plug electrical connectors may be sealed by o-rings or gaskets. These designs may work well in generally dry environments however electrical connectors in some applications may be exposed to non-dry air environments, such as humid air, rain, or seawater. Further still, a connector may be submerged in water, for example, ships, submarines, or underwater equipment, for example. Thus, it may be desirable to exclude water from the electrically live portions of the connectors as, among other things, water may create electricity leakage paths. Water can damage the electrically conducting connector contacts by corrosion or by deposition of insulating salts or impurities onto the connectors. In certain applications and environments, it is desirable to not only exclude water after being mated, but also to exclude water during mating—even when mating under water.
Conventional connectors addressing underwater mating or mating in a wet environment may be complex. Such connectors may be filled with oil and may have many small parts, such as dynamic seals and springs, for example. Due, at least in part, to their complexity, conventional connectors may be difficult to build and repair. Such connectors may also be expensive to produce and replace. Dielectric gel containing connectors can also be designed to allow underwater mating of connectors with water exclusion, for example. However, repeated connection and disconnection of these gel-containing connectors may lead to contamination, leakage of the gel, or other problems.
This disclosure relates to a system and method to provide underwater electrical mating connections utilizing self-passivating transition metals. In one aspect, a system includes a first mating component formed from a self-passivating transition metal to supply power. The self-passivating transition metal has a property of forming a non-conductive passivation layer when immersed in water. A second mating component formed from a self-passivating transition metal provides a return path for the power and prevents a leakage path from forming due to the formation of the non-conductive passivation layer when the power is applied to the first mating component in the water.
In another aspect, a system includes a first mating pin formed from a self-passivating transition metal to supply power. The self-passivating transition metal has a property of forming a non-conductive passivation layer upon immersion in water. A first mating receptor is formed from a self-passivating transition metal to receive power from the first mating pin in the water. A portion of the non-conductive passivation layer is removed upon mating the first mating pin to the first mating receptor. A communication source communicates data across a conductive connection formed by mating the first mating pin and the first mating receptor.
In yet another aspect, an underwater system includes a first mating pin formed from a self-passivating transition metal to supply power. The self-passivating transition metal has a property of forming a non-conductive passivation layer upon immersion in water. A second mating pin is formed from a self-passivating transition metal to provide a return path for the power and to supply a leakage path to form the non-conductive passivation layer when the power is applied to the first mating pin in the water. A first mating receptor is formed from a self-passivating transition metal to receive power from the first mating pin in the water. A portion of the non-conductive passivation layer is removed upon mating of the first mating pin and the first mating receptor to form a conductive connection. A second mating receptor is formed from a self-passivating transition metal to receive the return path for the power from the second mating pin.
This disclosure relates to a system to provide underwater electrical mating connections utilizing self-passivating transition metals. A self-insulating underwater electrical connector (SUEC), in one example, is provided for direct current (DC) power transfers and data exchanges (e.g., between devices, systems, a pair of electrical conductors, and so forth). The SUEC includes connector pins and a socket interface configured with mating receptors for accepting the connector pins, or any pair of contacting surfaces including flat plates. The mating receptors and the connector pins can be fabricated out of self-passivating transition metals such as niobium (Nb) or Tantalum (Ta) metal, for example. Due to the electrochemical properties of the transition metals, a passivation layer can be formed when they are exposed to water. Thus, when the mating receptors and/or the connector pins interact with water, a non-conductive passivation layer forms on a surface of the connector pins and/or the receiving ports to provide insulation from the water.
The connector pins can be mated with the mating receptors by positioning (configuring) each connector pin or surface with a respective receptor. The positioning of the connector pins within the mating receptor causes each connector pin to contact a physical port. Since the receptor and the connector pin are fabricated out of transition metals, the physical contact causes a disruption in their respective passivation layers to form a low resistance connection. The low resistance connection provides an electrical connection (electrical medium) through which power and/or data can be exchanged. The connector pin can also be un-mated (disconnected) from the receptor of the SUEC. Disconnecting the connector pin from the receptor exposes the connector pin and the receiving port to the water. This exposure causes the connector pin and the receiving port to re-grow the passivation layer to provide the insulation from the water, and thus, prevent current leakage from the exposed contacts into the water.
The system 100 includes a second housing connector (H2) that includes at least two mating components shown as receptors R1 and R2 in this example to form a load circuit to a load 130 via the first mating component P1 and the second mating component P2 of the first housing connector H1. As will be illustrated and described below with respect to
In one specific example, the system 100 provides a self-insulating underwater electrical connector (SUEC) for alternating current (AC) or direct current (DC) power transfers and data exchanges (e.g., between devices, systems, a pair of electrical conductors, and so forth). The SUEC includes connector pins P1 and P2 and a socket interface configured with mating receptors R1 and R2 for accepting the connector pins. The mating receptors and the connector pins can be fabricated out of self-passivating transition metals such as niobium (Nb) or Tantalum (Ta) metal, for example. Due to the physical properties of the transition metals, a passivation layer can be formed when the transition metals are exposed to water 120. As used herein the term water can include any type of water (e.g., salt water, well water, lake water, river water) that includes enough mineral content to support leakage current flows such as IL described herein. When the mating receptors R1 and R2 and/or the connector pins P1 or P2 interact with water 120, a non-conductive passivation layer forms on a surface of the connector pins and/or the receiving ports by providing insulation from the water.
The connector pins P1 and P2 can be mated with the mating receptors R1 and R2 by positioning (configuring) each connector pin with a respective receptor. The positioning of the connector pins within the mating receptor causes each connector pin to be within physical contact with a physical port. Since the receptor and the connector pin are fabricated out of transition metals, the physical contact causes a disruption in their respective passivation layers to form a low resistance connection. The low resistance connection provides an electrical connection (electrical medium) through which power and/or data can be exchanged. The connector pins P1 and P2 can also be un-mated (disconnected) from the receptor of the SUEC. Disconnecting the connector pin from the receptor exposes the connector pin and the receiving port to the water. This exposure causes the connector pin and the receiving port to re-grow the passivation layer to provide the insulation from the water, and thus, prevent current leakage from the exposed contacts into the water.
In one specific example, contacts for both the male pins P1 and female receptors R1 can be made out of a transition metal such as niobium metal, for example. Niobium is a transition metal and is in the same group as tantalum in the periodic table, for example. Using oxide growth principles connector 200 grows the passivation layer 230 on its contacts P1 and R1 which provides a durable insulating layer which prevents the flow of electricity through water after contact is made. When a mating contact also made of niobium (or other transition metal) interfaces with the connector 200, it locally disrupts the passivation layer 230 on the pin and receptor and allows for a low resistance connection between the two while still preventing short circuiting through the water to the complementary electrode. The connector 200 effectively “grows” its own insulation in any area of the connector which is exposed to water. Rather than trying to rely on complex seals and oil to exclude water as in a conventional wet-mate connector, the connector 200 utilizes water being in contact with the contacts P1 and R2 to form the insulation.
In one specific example of forming the passivation layer 230, 50VDC (or other potential) can be applied to contacts in the housing 210 and/or 220 before and after immersion in sea water, for example. The contacts can be separated by about 50 mm where all metal surfaces of the contacts exposed to the water are a transition metal such as niobium metal. When power is applied, initial leakage current (IL) through the water with the exposed metal contacts is about 5 mA and rapidly decreases after the passivation layer 230 is formed. If this were a common electrode material such as copper, there would be a short circuit through the water causing rapid corrosion of the metal and generation of hydrogen and chlorine gasses. In this example, a drop of about 180 mV may be measured across both contacts and the wiring to the connectors indicating a resistance of less than 1 ohm through the wiring and contacts. This can be improved by tailoring the contact pressure and pin/socket interface to enhance conductivity when P1 and R1 are mated.
A COM SIGNAL employed for communications is shown riding on top of a DC voltage. Thus, in addition to being able to efficiently transfer power, the system 500 can be used for high speed data transfer by superimposing a low level RF signal on top of the voltage used to provide power to the receiver 530. This can include RF data transfer techniques such as 802.11, for example, that can be used with the system 500. This allows a two contact connector (or more contacts (See e.g.,
A COM SIGNAL employed for communications is shown riding on top of an AC voltage. Thus, in addition to being able to efficiently transfer power, the system 600 can be used for high speed data transfer by superimposing a low level RF signal on top of the voltage used to provide power to the receiver 630. This can include RF data transfer techniques such as 802.11, for example, that can be used with the system 500. This allows a two contact connector (or more contacts (See e.g.,
What has been described above are examples. It is, of course, not possible to describe every conceivable combination of components or methodologies, but one of ordinary skill in the art will recognize that many further combinations and permutations are possible. Accordingly, the disclosure is intended to embrace all such alterations, modifications, and variations that fall within the scope of this application, including the appended claims. As used herein, the term “includes” means includes but not limited to, the term “including” means including but not limited to. The term “based on” means based at least in part on. Additionally, where the disclosure or claims recite “a,” “an,” “a first,” or “another” element, or the equivalent thereof, it should be interpreted to include one or more than one such element, neither requiring nor excluding two or more such elements.