Piston pump and method of manufacturing the same

A piston pump comprising:

• a pump housing having
• a crankshaft chamber,
• a pumping chamber, and
• one or more piston passages, each piston passage extending from the crankshaft chamber to the pumping chamber;
• a crankshaft rotatably mounted in the crankshaft chamber, the crankshaft having
• a longitudinally extending crankshaft rotation axis, and
• one or more cams distributed along the crankshaft axis, each cam having
• a plurality of cam noses and a plurality of cam heels, the cam noses circumferentially alternating with the cam heels around the crankshaft axis, the cam noses all having a nose radius, the cam heels all having a heel radius, the nose radius being greater than the heel radius,
• a cam stroke length that is a difference between the nose radius and the heel radius, and
• a cam material abrasion resistance;
• one or more pistons, each piston corresponding to a cam of the one or more cams, each piston slidably mounted in a corresponding piston passage of the one or more piston passages between a nose position and a heel position, each piston having
• a piston shaft extending within the corresponding piston passage, the piston shaft having a first shaft end positioned in the crankshaft chamber and a second shaft end, and
• a sacrificial piston crown having threads that provide a removable connection to the first shaft end, the piston crown having a cam engagement side in contact with the corresponding cam, the cam engagement side having a piston crown material abrasion resistance that is less than the cam material abrasion resistance;
• and
• one or more resiliently compressible piston biases, each piston bias biasing a corresponding piston of the one or more pistons toward the crankshaft and maintaining constant contact between the cam engagement side of the piston crown and the corresponding cam of the piston as the crankshaft rotates, the piston being in the nose position when the cam engagement side is in contact with the nose of the cam, and the piston being in the heel position when the cam engagement side is in contact with the heel of the cam.

A piston pump comprising:

• a pump housing having
• a crankshaft chamber,
• a pumping chamber, and
• one or more piston passages, each piston passage extending from the crankshaft chamber to the pumping chamber;
• a crankshaft rotatably mounted in the crankshaft chamber, the crankshaft having
• a longitudinally extending crankshaft rotation axis, and
• one or more cams distributed along the crankshaft axis, each cam having
• a plurality of cam noses and a plurality of cam heels, the cam noses circumferentially alternating with the cam heels around the crankshaft axis, the cam noses all having a nose radius, the cam heels all having a heel radius, the nose radius being greater than the heel radius,
• a cam stroke length that is a difference between the nose radius and the heel radius, and
• a cam material abrasion resistance;
• one or more pistons, each piston corresponding to a cam of the one or more cams, each piston slidably mounted in a corresponding piston passage of the one or more piston passages between a nose position and a heel position, each piston having
• a piston shaft extending within the corresponding piston passage, the piston shaft having a first shaft end positioned in the crankshaft chamber and a second shaft end, and
• a sacrificial piston crown threadably connected to the first shaft end, the piston crown having a cam engagement side in contact with the corresponding cam, the cam engagement side having a piston crown material abrasion resistance that is less than the cam material abrasion resistance;
• and
• a one or more resiliently compressible piston biases, each piston bias biasing a corresponding piston of the one or more pistons toward the crankshaft and maintaining constant contact between the cam engagement side of the piston crown and the corresponding cam of the piston as the crankshaft rotates, the piston being in the nose position when the cam engagement side is in contact with the nose of the cam, and the piston being in the heel position when the cam engagement side is in contact with the heel of the cam.