| 摘要 |
A gear pump having a pair of intermeshing gears which operate in a housing and which are supported by a pair of bearing blocks which are biased towards the side faces of the gears for effecting a seal. There is interposed, between each bearing block and the adjacent side faces of the gears, a flexible plate which on its outer side is pressure-loaded by pump-delivery pressure admitted to an area of the plate confined by a linear seal element that includes part-circular portions extending around the gear axes at a radial distance appreciably smaller than the radius of the root circle of the gear teeth. The leakage flow from the intermeshing gear teeth to the bearing bores between the adjacent surfaces of the flexible plate and a continuous surface of each gear inside its gear root circle produces, in the area between the root circle and the circular portions of the seal element, a pressure difference which deflects the plate to minimize the width of the gap through which the leakage flow passes, thus preventing the access to that area of any but the smallest contaminating particles.
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