A fuel injection pump pressurizes and injects fuel. A cam rotates about a rotational axis of the cam. A housing includes a cam chamber that houses the cam and a sliding chamber communicated to the cam chamber. A roller rotates while being in contact with a surface of the cam. A shoe reciprocates in the sliding chamber by rotation of the cam and is in contact with and slides on a surface of the roller. A plunger reciprocates with the shoe. A cylinder houses the plunger and includes a pump chamber to pressurize and feed the fuel by reciprocation of the plunger. A deformed section is a groove or a protrusion which extends in a direction of a rotational axis of the cam, on a part of a surface of the cam, and has a shape different from a cam profile of the cam.

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 guide ring of a pump portion is fixed in a cylinder containing hole in such a manner that a distal end of a first end portion thereof is positioned in a cam containing hole on an upper side with respect to an opening edge of the cylinder containing hole.

A cam follower roller device having a tappet body extending along a longitudinal axis and defining a tappet bore, a pin centered on a transverse axis and providing two opposite ends arranged in through-holes transversally facing one another on tappet body, and a roller rotatably mounted on the pin around said transverse axis. The tappet body is a machined metal tube or bar and is provided with a radial plate that is securely fixed within tappet bore, said radial plate being dedicated to support a longitudinally movable piston.

A cam follower roller device having a tappet body extending along a longitudinal axis and defining a tappet bore, a pin centered on a transverse axis and providing two opposite ends arranged in through-holes transversally facing one another on tappet body, and a roller rotatably mounted on the pin around said transverse axis. The tappet body is a machined metal tube or bar and is provided with a radial plate that is securely fixed within tappet bore, said radial plate being dedicated to support a longitudinally movable piston.

A fuel injection pump pressurizes and injects fuel. A cam rotates about a rotational axis of the cam. A housing includes a cam chamber that houses the cam and a sliding chamber communicated to the cam chamber. A roller rotates while being in contact with a surface of the cam. A shoe reciprocates in the sliding chamber by rotation of the cam and is in contact with and slides on a surface of the roller. A plunger reciprocates with the shoe. A cylinder houses the plunger and includes a pump chamber to pressurize and feed the fuel by reciprocation of the plunger. A deformed section is a groove or a protrusion which extends in a direction of a rotational axis of the cam, on a part of a surface of the cam, and has a shape different from a cam profile of the cam.

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.

Presented is a piston pump comprising: a frame, a control element mounted in a rotatable manner about a central axis with at least one control surface, a plurality of cylinders having pistons displaceable therein, a suction connection for inflow of a fluid into the cylinders, a pressure connection for outflow of the fluid out of the cylinders. The cylinders are connected by lines to the suction and pressure connection. The cylinders, the pistons, and the control element are configured such that the position of the pistons in the cylinders can change by movement of the control element. The cylinders and the pistons are mounted so that they do not rotate completely about the central axis when the control element rotates. So that the piston pump can be operated with low maintenance, it is proposed that the cylinders or the pistons are connected respectively to a rotatably mounted roller.

A mechanical system forming one of a cam follower or a rocker arm, the mechanical system comprising: a support element, a pin extending between two opposite ends along a first axis and supported by the support element, and a roller mounted on pin, movable in rotation relative to the pin around the first axis and adapted to roll on a cam. The support element includes a bearing body adapted to receive pin, and an additional retaining member blocking the translation of pin back and forth, along first axis.

A guide ring of a pump portion is fixed in a cylinder containing hole in such a manner that a distal end of a first end portion thereof is positioned in a cam containing hole on an upper side with respect to an opening edge of the cylinder containing hole.