Woodward has filed a patent for seal arrangements in a hydraulic device. The seal arrangement includes a seal channel with a loop, and a coolant flow passage that provides hydraulic fluid to the seal channel in opposite directions. The patent aims to improve the efficiency and functionality of hydraulic devices. GlobalData’s report on Woodward gives a 360-degree view of the company including its patenting strategy. Buy the report here.

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According to GlobalData’s company profile on Woodward, photovoltaic drones was a key innovation area identified from patents. Woodward's grant share as of September 2023 was 60%. Grant share is based on the ratio of number of grants to total number of patents.

Seal arrangement in a hydraulic device with coolant flow passage

Source: United States Patent and Trademark Office (USPTO). Credit: Woodward Inc

A recently filed patent (Publication Number: US20230296117A1) describes a seal arrangement in a hydraulic device. The arrangement includes a first seal channel with a first width and a first seal with a second width that is smaller than the first width. A first coolant flow passage intersects with the first seal channel at two points, allowing hydraulic fluid to flow in opposite directions around a circular loop formed by the first seal channel. At one of the points, the hydraulic fluid flows into a second part of the first coolant flow passage.

The patent also describes a linear actuator that incorporates the seal arrangement. The actuator includes a housing with an interior cavity, a piston head that divides the cavity into two sections, and a piston cover at one end of the cavity. The piston cover has a first aperture through which a piston shaft extends, and a position sensor is disposed within the piston shaft. The actuator also includes at least one seal arrangement between various components, such as the housing and the piston cover, the interior aperture surface and the piston shaft, or the position sensor head and the second aperture. Hydraulic fluid flows between two ports into the interior cavity and is provided to the at least one seal channel to cool the seal. The seal arrangement includes a first seal arrangement with a first coolant flow passage that allows hydraulic fluid to flow in opposite directions around a circular loop formed by the seal channel.

The patent claims that the seal arrangement is designed to keep the temperature of the seal below 1000° F for at least 5 minutes when tested according to SAE AS4273 or RTCA DO-160 - Section 26.0. The seal can be made of elastomer or PTFE.

In summary, the patent describes a seal arrangement for a hydraulic device and a linear actuator that incorporates this arrangement. The seal arrangement allows hydraulic fluid to flow in opposite directions around a circular loop, providing cooling to the seal. The design aims to keep the seal temperature below 1000° F for a specified duration.

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GlobalData, the leading provider of industry intelligence, provided the underlying data, research, and analysis used to produce this article.

GlobalData Patent Analytics tracks bibliographic data, legal events data, point in time patent ownerships, and backward and forward citations from global patenting offices. Textual analysis and official patent classifications are used to group patents into key thematic areas and link them to specific companies across the world’s largest industries.