Radial-piston pump
AssigneeElasis Sistema Ricerca Fiat Nel Mezzogiorno
InventorsEgon Eisenbacher, Franz Pawellek, Bernhard Arnold
Life of this patent
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Abstract
A pump comprising a number of radial cylinders arranged a given angular distance apart about a drive shaft and each housing including a piston resting radially on a respective pad by virtue of the action of a return spring. The connection between the piston and pad comprises a retainer for preventing in-service detachment of the pad, which rests on a respective flat portion of a cam mounted for rotation on an eccentric portion of the shaft. The force on the pad produced by sliding friction between the pad and the flat portion of the cam and directed perpendicular to the axis of the cylinder is absorbed by the piston.
Claims16
A radial-piston pump comprising:
- a number of cylinders (12) respectively arranged a given angular distance apart about a drive shaft (18);
- a number of pistons (140, 240) respectively having inner radial ends (180) and sliding inside said cylinders respectively (12);
- a cam (228) rotating on an eccentric portion (24) of said drive shaft (18);
- a number of pads (162, 262) respectively connected to said pistons (140, 240) so that said inner radial ends (180) thereof respectively rest on said pads (162, 262) by action of a return Spring (166, 266) and said pads (162, 262) rest on a flat portion (232) of said cam (228) so that sliding friction (Q) between said pads (162, 262) and said flat portion (232) is directed perpendicular to said drive shaft (18);
- retaining means (186, 286) for preventing in-service detachment of said pads (162, 262) from said pistons (140, 240);
- and
- seats (185, 285) respectively in said pads (162, 262) for housing said inner radial ends (180, 280) of said pistons (140, 240);
- wherein said pads (162,262) are circular in shape and respectively provided with shoulders (198, 298), and said retaining means comprises a retaining disk (186, 286) fitted to said pads (162, 262) and axially connected to said pistons (140, 240), said retaining disk (186, 286) comprising at least one clamping portion (188, 288) engaging said shoulders (198, 298) with a central opening (192, 292) for connection to said pistons (140, 240).
A radial-piston pump comprising a number of cylinders (12) arranged a given angular distance apart about a drive shaft (18);
- a number of pistons (40), each having an inner radial end (80), and each sliding inside a respective said cylinder (12);
- a cam (28) rotating on an eccentric portion (24) of said shaft (18);
- a number of pads (62), each connected to one of said pistons (40) so that said inner radial end (80) rests on each of said respective pads (62) by virtue of the action of a return spring (66), said pad (62) resting on a respective flat portions (32) of said cam (28) so that the sliding friction (Q) between said pads (62) and said flat portion (32) is directed perpendicular to said shaft (18);
- and a guide disk (74) connected to by each of said pistons (40) and forming a shoulder for supporting said return spring (66), said pad (62) being cup shaped and including a sleeve portion (72) housing said disk (74), said portion having such a length as to prevent in-service detachment of said pad (62) from said disk (74);
- wherein said cylinder (12) includes a cylindrical wall (64) fitted with a cylindrical insert 36, said insert (36) having a hole (38) inside which said respective piston (40) is slidably guided, said pad (62) having a cross section with a diameter smaller than the inside diameter (W) of a said cylindrical wall 64, whereby said sliding friction (Q) is absorbed solely said piston (40) against said insert (36).
Dependencies are inferred from the claim text.