| 摘要 |
A shield 56 for a gas management pintle valve 10, such as an exhaust gas recirculation valve for an internal combustion engine, for mitigating leakage of gas and moisture along the valve pintle 22 into the actuator 30, to prevent corrosion and failure of the actuator. The shield 56 is a tubular member 58,60 having an equatorial radial flange 62 and is slidably mounted on the pintle 22 in an annular chamber 54 between the valve body and the actuator. The inner diameter of the tube is selected to be as close-fitting to the pintle as possible while still being slidable thereupon to be adapted to either of two operating positions. During engine shutdowns, the shield is drawn by gravity toward the valve body 12 to form a first seal with the flange 62 against the pintle bearing 26 or a bearing splash shield 38, preventing or minimizing the escape of moist, hot gases under low pressure from the valve along the pintle. During engine running, high-pressure exhaust gases within the valve may be forced along the pintle through the bearing bore 24 and bearing splash shield 38 toward the actuator 30. The gases force the shield 56 to slide along the pintle 22, opening the first seal and forming a second seal with the flange 62 against the actuator 30, allowing the leaked gases to escape radially from the pintle without invading the actuator. |
