Abstract: A pump includes a housing that contains a liquid, and a rotor including a plurality of blades extending radially from a shaft, and defining a conical space. A port member is disposed within the conical space. The port member defines an inlet port in communication with a low pressure region, a discharge port in communication with a high pressure region, and an anti-cavitation port in communication with a fluid supply having a pressure between the low and the high pressure regions. Each pair of adjacent blades cooperates with the liquid and the port member to enclose a variable volume bucket, wherein rotation of the rotor selectively positions a bucket in an inlet position adjacent the inlet port to draw in fluid, in an anti-cavitation position wherein the bucket is adjacent the anti-cavitation port and fluid is admitted into the bucket, and a discharge position wherein the bucket is positioned adjacent the discharge port to discharge fluid.

Abstract: A liquid ring pump includes a stationary housing that defines an inner space, and a drive shaft rotatably mounted within the stationary housing. The drive shaft defines a rotational axis. An impeller includes a plurality of blades extending radially outward with respect to the rotational axis, and each blade includes a root and a tip, wherein a continuous curve extends from the tip of each blade through the root of the blade and intersects with the rotational axis.

Abstract: A pump includes a housing that contains a liquid, and a rotor including a plurality of blades extending radially from a shaft, and defining a conical space. A port member is disposed within the conical space. The port member defines an inlet port in communication with a low pressure region, a discharge port in communication with a high pressure region, and an anti-cavitation port in communication with a fluid supply having a pressure between the low and the high pressure regions. Each pair of adjacent blades cooperates with the liquid and the port member to enclose a variable volume bucket, wherein rotation of the rotor selectively positions a bucket in an inlet position adjacent the inlet port to draw in fluid, in an anti-cavitation position wherein the bucket is adjacent the anti-cavitation port and fluid is admitted into the bucket, and a discharge position wherein the bucket is positioned adjacent the discharge port to discharge fluid.