A piston pump and a piston motor are provided. The piston pump includes a cylinder body, a piston, a main shaft, an end cover, and an oil dispensing mechanism. The oil dispensing mechanism includes an oil suction mechanism and an oil discharging mechanism. A roller is mounted on the piston, and the roller is rotatablely connected to the piston. A driving wheel is arranged on the main shaft, and the driving wheel is mounted in cooperation with the main shaft or is integrally formed with the main shaft. A driving groove is formed on the driving wheel, and a roller-path surface of the driving groove is a curved surface. The size of the driving groove is adapted to the size of an outer circle of the roller. The main shaft rotates to drive the driving wheel to rotate to further drive the piston to move along the cylinder bore.

A cam follower, comprising: a tappet which includes two flanges provided with opposite holes centered on a transverse axis; a pin extending along the transverse axis between two opposite ends received in the opposite holes; and a roller movable in rotation relative to the pin around the transverse axis and adapted to roll on a cam. Each of the opposite holes is provided with: an open portion for mounting the pin by translation in a first direction perpendicular to the transverse axis, a cylindrical portion for supporting the pin along the first direction and a plane portion for retaining the pin along the transverse axis during transport and mounting of the cam follower. A method includes steps for manufacturing such a cam follower.

A roller for a mechanical fuel pump assembly includes an elongate body extending from a first axial end to a second axial end of the elongate body over an overall length of the elongate body. The elongate body defines an effective length that is less than the overall length. The elongate body defines a uniform circular cross section over a second length of the elongate body. The second length is 75 to 90 percent of the effective length and the second length extends between a first plane and a second plane. A first area of reduced cross section extends axially outward from the first plane to a third plane located axially inward of the first axial end; and a second area of reduced cross section extends axially outward from the second plane to a fourth plane located axially inward of the second axial end.

Disclosed is a pump, in particular a high-pressure fuel pump, comprising at least one pump element (10) that has a roller tappet (20) inside which a roller (42) is rotatably mounted on a bearing bolt (44) by means of a bearing sleeve (46), said roller (42) rolling off a cam (22) of an input shaft (24). The bearing sleeve (46) is made of a plastic material, especially polyether ether ketone (PEEK) or polyphthalamide (PPA).

The invention relates to a reciprocating pump (1) comprising a roller tappet (2) and a pump plunger (10) that is operatively connected to the roller tappet (2). The roller tappet (2) has a roller support (3), a roller (4) and a pin (5). A first bearing eye (6) and a second bearing eye (7) are formed in the roller support (3), the pin (5) being supported in the first bearing eye (6) and in the second bearing eye (7). The roller (4) is rotatably mounted on the pin (5). The pin (5) is mounted more resiliently in the first bearing eye (6) than in the second bearing eye (7).

A pumping assembly includes at least one removable unit barrel pumping assembly coupled to a housing of the pumping assembly. The pumping assembly further includes a drive member having a roller configured to engage a portion of the unit barrel pumping assembly during operation of the pumping assembly. The roller is configured to include a plurality of geometric shapes to distribute load forces during operation of the pumping assembly.

A pumping assembly includes at least one removable unit barrel pumping assembly coupled to a housing of the pumping assembly. The pumping assembly further includes a drive member having a roller configured to engage a portion of the unit barrel pumping assembly during operation of the pumping assembly. The roller is configured to include a plurality of geometric shapes to distribute load forces during operation of the pumping assembly.

A roller tappet for a fuel pump includes an integral and hollow-walled guide housing, which has a drive-side edge that encloses a roller mounted on a pin. The ends of the pin are seated in openings in arranged in indented flat surfaces that originate from the drive-side edge and are diametrically opposite each other. An output-side edge of the guide housing has a bridge piece that extends continuously from an inner wall of the one of the flat surfaces to an inner wall of the other flat surface. The bridge piece projects beyond the inner wall towards the outer wall of the particular flat surface, and the output-side outer face of the bridge piece has a contact surface for a pump piston. The flat surfaces are completely continuous from the drive-side edge to the output-side edge of the guide housing.

A roller tappet for a fuel pump includes an integral and hollow-walled guide housing, which has a drive-side edge that encloses a roller mounted on a pin. The ends of the pin are seated in openings in arranged in indented flat surfaces that originate from the drive-side edge and are diametrically opposite each other. An output-side edge of the guide housing has a bridge piece that extends continuously from an inner wall of the one of the flat surfaces to an inner wall of the other flat surface. The bridge piece projects beyond the inner wall towards the outer wall of the particular flat surface, and the output-side outer face of the bridge piece has a contact surface for a pump piston. The flat surfaces are completely continuous from the drive-side edge to the output-side edge of the guide housing.

A roller tappet for a high-pressure fuel pump or for a valve drive of an internal combustion engine is provided. The tappet can be guided in a direction of a longitudinal axis thereof in a housing receptacle and can be driven displaceably by a cam shaft of the internal combustion engine. The tappet includes a tappet body which has a guide cylinder, and a cup-shaped sleeve supported axially and radially on the guide cylinder. The sleeve includes a bearing surface for the pump piston or a valve drive element, and the guide cylinder includes a rotatable roller mounted on support flanks, by means of which roller the roller tappet can be supported on the internal combustion engine camshaft. The sleeve has, at its end region facing away from the bearing surface, a ring-shaped shoulder for radial support and an end ring for axial support on the guide cylinder.