A camshaft (24), in particular for a pump (10), is proposed. The camshaft (24) has at least two cams (26, 28) which are arranged next to one another in the direction of the longitudinal axis (25) of the camshaft (24) and the cam elevations of which are arranged offset with respect to one another around the longitudinal axis (25) of the camshaft (24). An intermediate region (30) is provided between two adjacent cams (26, 28), and at least one bearing region (32) is arranged next to the cams (26, 28) in the direction of the longitudinal axis (25) of the camshaft (24). The intermediate region (30) runs in axial longitudinal sections which contain the longitudinal axis (25) of the camshaft (24), at a radial spacing (r1, r2) from the longitudinal axis (25) of the camshaft (24), which radial spacing (r1, r2), starting from the adjacent cam (26) with the smaller cam elevation (h1) in the respective axial longitudinal section, increases towards the adjacent cam (28) with the greater cam elevation (h2) in the respective axial longitudinal section.

A pump unit for feeding fuel, in particular diesel fuel, to an internal-combustion engine; the pump unit comprising a head (2) inside which a cylinder (3) is formed along an axis; a pumping piston (4) housed inside the cylinder and comprising a head portion (24) inside the cylinder and an opposite foot portion (23) projecting outside the cylinder; wherein the piston is slidable inside the cylinder in a reciprocating manner between a first position and a second position where the foot projects from the cylinder by a greater or smaller amount respectively; and wherein the outer surface of the piston comprises a portion (16) with a surface finish so as to have less friction and a greater lubricant-retaining capacity than the remainder of the outer surface of the piston; the portion extending along the axis between the head of the piston and a first intermediate point (17) in the first position of the piston, the first intermediate point being inside the cylinder.

In a high-pressure pump, a center of load in a virtual plane including an end face of a coil spring facing a pressurizing chamber in an axial direction is defined as an upper load center, and a center of load in a virtual plane including an end face of the coil spring facing a cam in the axial direction is defined as a lower load center. The coil spring is configured such that, when viewed in the axial direction, during motion of a plunger toward the pressurizing chamber by rotation of the cam, the upper load center moves in one direction along a circumference of the coil spring while the lower load center moves in an opposite direction along the circumference of the coil spring, and the lower load center substantially coincides with the upper load center and subsequently further moves in the opposite direction.

A piston pump, in particular a high-pressure fuel pump for an internal combustion engine, includes a pump housing, a pump piston, and a delivery chamber that is delimited at least by the pump housing and the pump piston. The piston pump further includes a seal configured to seal the delivery chamber and a separate guide element configured to guide the pump piston. The seal and the guide element are arranged between the pump piston and the pump housing. The seal is formed as a plastic ring with a substantially sleeve-shaped base portion.

An axial piston pump has a fluid inlet, a fluid outlet, and a rotatable, one-piece piston housing carrying one or more pistons movable within one or more respective sleeves formed by the housing. A circumferential row of fixed field members is mounted to the housing at a mounting location formed by the housing, the mounting location being radially outward of the sleeve(s). The pump further has a stator surrounding the piston housing and including a circumferential row of armature windings such that the piston housing and the stator form an electro-magnetic motor operable to rotate the piston housing, and a swashplate engaged with the piston(s) such that rotation of the piston housing relative to the swashplate around an axis of rotation produces reciprocating movement of the piston(s) for the pressurisation of fluid received into the sleeve(s) from the fluid inlet and then discharged from the sleeve(s) to the fluid outlet.

A high-pressure fuel pump includes a housing, at least one piston, and a sealing device. The device is positioned on the piston so as to surround the piston, and includes a seal carrier. The carrier is connected, at least in sections, to the housing, and includes at least one radially peripheral portion that is materially bonded to the housing via a capacitor discharge weld connection. Such a pump enables improved cycle times and reduced error rates during production.

An object of the present invention is to obtain a high pressure fuel supply pump capable of reducing pressure pulsation that occurs in a low pressure pipe, preventing damage to the low pressure pipe, or reducing noise due to vibrations of the low pressure pipe. The present invention provides a high pressure fuel supply pump of a type in which, from a fuel suction port connected to a low pressure pipe provided upstream of a fuel, a low pressure passage, an electromagnetic suction valve driven by an electromagnetic force, a pressurizing chamber in which the volume thereof is increased or reduced by a plunger that is reciprocatingly moved by being guided by a cylinder, and a discharge valve provided at an outlet of the pressurizing chamber are sequentially arranged, a fuel is sucked to the pressurizing chamber through the electromagnetic suction valve, the amount of a part of the fuel, which is sucked to the pressurizing chamber, to be returned to the low pressure passage side is adjusted so that the amount of the fuel to be discharged through the discharge valve is controlled, and the high pressure fuel supply pump includes a backflow suppression mechanism for suppressing backflow of fuel from the fuel from the fuel suction portion to the low pressure pipe side.

An engine comprising: a fuel injection device including a rack and an actuator, the rack being configured to regulate the amount of fuel injected to a combustion chamber, the actuator being configured to control the position of the rack; and a control device that controls fuel injection performed by the fuel injection device based on an instructed revolution number, and that performs a dither control on the actuator, wherein the control device has information of a revolution number variation region that is based on the relationship between a dither frequency in the dither control and an engine revolution number, and upon determining that the instructed revolution number is within the revolution number variation region, changes at least one of the dither frequency and the instructed revolution number. Thus, an engine capable of reducing a periodic variation in engine speed which may be caused by a dither control is provided.

When a condition for reducing a noise caused in the high-pressure pump is satisfied, a reduction control unit implements a noise reduction control to supply a smaller power to reduce a moving speed of a movable portion in a close acting direction to put a valve body into a closed state for a predetermined time after an energization start timing of a solenoid in a plunger rising period. A closing control unit causes a closing current, which is a constant current for surely putting the valve body into the closed state, to flow the closing current in the solenoid when the noise reduction control is completed in the plunger rising period. The predetermined time is shorter than an energization period in which a current flows in the solenoid.

A pump actuator for use between a cam and a pump includes an outer body, an inner body, an axle and a bearing. The outer body has an outer body inner surface. The inner body is received by the outer body. The inner body has an inner body outer surface. The axle is supported by the inner body. The bearing is supported on the axle. The inner body includes at least one stamped feature protruding outwardly from the inner body outer surface. The at least one stamped feature is configured to form an interference fit with the outer body inner surface.