초록 ▼

A pump includes a piston rod and precision bearings that eliminate radial movement of the piston rod while permitting reciprocal axial translation. A piston extends axially from the piston rod, and is received in a cylinder in a pump head. A static seal assembly includes an annular ring received abo

A pump includes a piston rod and precision bearings that eliminate radial movement of the piston rod while permitting reciprocal axial translation. A piston extends axially from the piston rod, and is received in a cylinder in a pump head. A static seal assembly includes an annular ring received about the piston in a leakproof sliding engagement, the ring being formed of a soft polymer material. The annular ring is encapsulated in an outer ring formed of a stiff plastic material, defining a self-contained seal cartridge. The outer ring is dimensioned to be received in the pump head in a cylindrical recess that permits radial freedom relative to the axis of the cylinder. To assemble the pump, the seal cartridge is first assembled to the piston, thus assuring that the seal is aligned with the piston. Thereafter, the head is assembled to the pump body, the piston being inserted in the cylinder and the seal cartridge being received with clearance in the recess. Subsequently, the head is tightened, immobilizing the seal cartridge in the aligned relationship with the piston.

대표청구항 ▼

1. In a pump having a piston mounted in a pump body and a cylinder formed in a pump head, the improvement comprising:a seal assembly adapted to be secured about the piston prior to assembly of the pump head to the pump body; a recess formed in the pump head, said recess disposed generally concentric

1. In a pump having a piston mounted in a pump body and a cylinder formed in a pump head, the improvement comprising:a seal assembly adapted to be secured about the piston prior to assembly of the pump head to the pump body; a recess formed in the pump head, said recess disposed generally concentrically to the cylinder, said recess dimensioned to receive said seal assembly with free play in a radial direction, said recess having a depth such that assembly of the pump head to the pump body compresses said seal assembly axially and immobilizes said seal assembly in said recess.