Provided is a high-pressure fuel pump that ensures oil tightness even at high fuel pressure and has a small and lightweight inexpensive discharge valve structure. Therefore, a high-pressure fuel pump according to the present invention includes: a discharge valve arranged on a discharge side of a pressurizing chamber; a discharge valve seat on which the discharge valve is seated; and a facing member configured independently as a separate member from the discharge valve seat and located on an opposite side of the discharge valve seat with the discharge valve interposed therebetween, in which a stroke direction regulating portion that regulates displacement of the discharge valve in a stroke direction is formed on a tapered surface of the facing member.

A driveshaft assembly, for example in an Electronic Unit Injector, Unit Injector or Electronic Unit Pump testing machine, wherein an indexing arrangement, such as complementary external and internal splines, enables a cam to be mounted on a shaft at a number of discreet positions, each providing a different offset of a central axis of the base cylinder section from a central axis of the shaft, each position providing a different maximum lift value of a plunger in contact with the cam, directly or via a rocker arm.

A tappet assembly for use in translating force between a camshaft lobe and a fuel pump assembly via reciprocal movement within a tappet cylinder having a guide slot. The tappet assembly comprises a tappet body having inner and outer surface and defining a pair of apertures, and a follower assembly. The follower assembly has a shaft and a first bearing and a second bearing each supported on the shaft for engaging the camshaft lobe. A beam is further supported on the shaft between the first and second bearings and has a platform for engaging the fuel pump assembly. The shaft is disposed in the pair of apertures of the tappet body and the beam is arranged in the tappet body.

A coil component of an electromagnetic valve is made compact to achieve both low cost and improvement in sound vibration performance. Therefore, a high-pressure fuel pump of the present invention includes: a coil 3g; a magnetic core 3e that is arranged on a side opposite to a pressurizing chamber 11 with respect to a movable core 3h and attracts the movable core 3h when the coil 3g is energized; a yoke 3q arranged on a radially outer side of the coil 3g; a cover portion 3r that covers the coil 3g from an axially outer side; and a molded portion 17 that covers a radially outer side of the yoke 3q and an axially outer side of the cover portion 3r.

A metal diaphragm damper which is resistant to breakage even if repeated stress is applied is provided. The metal diaphragm damper includes a diaphragm that is disk shaped and has a gas enclosed therein the diaphragm has a deforming action part in a center and an outer periphery fixing part on an outer periphery, the deforming action part is formed into a shape curved toward an exterior of the diaphragm, a folded part is formed in a connecting portion of the deforming action part and the outer periphery fixing part and is opened to an inner diameter side, and the folded part is movable in a radial direction.

The damper mechanism used for a high-pressure fuel supply pump is configured so that an outer circumferential surface of a cover in regard to the thickness direction of the base material of the cover engages with the inner circumference of an open end part of a bottomed tubular concave part formed in a damper housing or in a pump housing of the high-pressure fuel supply pump. The total height of the damper as a low-pressure pulsation reducing mechanism can be reduced, and the dimensions of the damper in the radial directions can also be reduced. In cases where the damper mechanism is formed integrally with the high-pressure fuel supply pump, the total height of the high-pressure fuel supply pump can be reduced and the dimensions of the damper part in the radial directions can also be reduced.

The damper mechanism used for a high-pressure fuel supply pump is configured so that an outer circumferential surface of a cover in regard to the thickness direction of the base material of the cover engages with the inner circumference of an open end part of a bottomed tubular concave part formed in a damper housing or in a pump housing of the high-pressure fuel supply pump. The total height of the damper as a low-pressure pulsation reducing mechanism can be reduced, and the dimensions of the damper in the radial directions can also be reduced. In cases where the damper mechanism is formed integrally with the high-pressure fuel supply pump, the total height of the high-pressure fuel supply pump can be reduced and the dimensions of the damper part in the radial directions can also be reduced.

In at least some implementations, an adapter, for a fuel pump having a casing, has a base having an axis and an opening through which fluid may flow, and multiple tabs connected to the base. The tabs are circumferentially spaced apart with a void between at least part of the tabs, and at least two tabs have a contact portion that extends radially inwardly to define a minimum diameter opening between the tabs. Each contact portion extends along a portion less than all of the surface areas of the radially inner surface of the tabs.

A fuel pump includes a plunger that reciprocates, a retainer having a mounting portion attached to a lower end portion of the plunger, and a spring that biases the plunger via the retainer. The mounting portion has an engagement portion that is engaged with a constricted portion formed at the lower end portion of the plunger. A diameter of a circle formed by a corner portion of the engagement portion and an inner peripheral wall of the spring is smaller than a diameter of the lower end portion of the plunger.

A fuel pump includes a plunger that reciprocates, a retainer having a mounting portion attached to a lower end portion of the plunger, and a spring that biases the plunger via the retainer. The mounting portion has an engagement portion that is engaged with a constricted portion formed at the lower end portion of the plunger. A diameter of a circle formed by a corner portion of the engagement portion and an inner peripheral wall of the spring is smaller than a diameter of the lower end portion of the plunger.