초록 ▼

A balanced vane type hydraulic pump has a thrust plate and a pressure plate which cooperate with a cam ring, rotor and vanes to provide a plurality of pump chambers. During pump operation, fluid trapped under the vanes flows from under the vanes at the discharge port, as the vane recedes, to under t

A balanced vane type hydraulic pump has a thrust plate and a pressure plate which cooperate with a cam ring, rotor and vanes to provide a plurality of pump chambers. During pump operation, fluid trapped under the vanes flows from under the vanes at the discharge port, as the vane recedes, to under the vanes at the inlet port to assist vane extension and improve pump priming. The undervane fluid passes through grooves in both plates with the groove in the pressure plate being in communication with the discharge flow of the pump. The grooves incorporate restrictions to the undervane fluid flow between the discharge and inlet positions of the vanes with the restriction in the thrust plate permitting more fluid flow than the restriction in the pressure plate to ensure that most of the fluid will pass through the rotor under the vanes in the inlet position to assist in vane extension.

대표청구항 ▼

An improvement in self-priming, pressure balanced sliding vane pumps having a ported pressure plate and a ported thrust plate with passage means in each plate being axially aligned with the undervane cavities formed in the pump rotor, wherein the improvement comprises; said passage means in the thru

An improvement in self-priming, pressure balanced sliding vane pumps having a ported pressure plate and a ported thrust plate with passage means in each plate being axially aligned with the undervane cavities formed in the pump rotor, wherein the improvement comprises; said passage means in the thrust plate comprising two kidney-shaped passage means each of which extend the arcuate distance of adjacent ports and said kidney-shaped passage means being joined by a pair of restricted passages of predetermined flow area for accommodating undervane flow; and said passage means in said pressure plate comprising four kidney-shaped passages each aligned with respective ports and a pair of restricted passages joining adjacent kidney-shaped passages for flow from under the outlet port to under the inlet port in the direction of pump rotation and said restricted passages having a flow area of 15 to 23% of the restricted passages in said thrust plate to permit a small amount of fluid flow to bypass the passage means in said thrust plate.