Lightweight-construction roller tappet
This disclosure relates to a roller tappet, in particular for a high-pressure fuel pump. The roller tappet is guided in a direction of a longitudinal axis thereof in a housing receptacle and is driven in the longitudinal direction by cams of a camshaft. The roller tappet has a tappet body. The tappet body has a tappet skirt, a pump piston contact seat, and a rotatably mounted roller, by means of which the roller tappet is supported on the camshaft. The tappet body has a guide cylinder, which is mounted in the housing receptacle and on which the roller is mounted, and a cup-shaped sleeve having the pump piston contact point, which cup-shaped sleeve is supported axially and radially in the guide cylinder.
1. A multi-part roller tappet for a high-pressure fuel pump, the roller tappet comprising:
a tappet body including:
a guide cylinder configured to rotatably support a roller, the guide cylinder having a cylindrical constriction groove; and,
a cup-shaped sleeve arranged at least partially within the guide cylinder, the cup-shaped sleeve having:
a pump piston contact seat;
a radially outward-facing radial ring arranged between axial ends of the cup-shaped sleeve, the radial ring secured on an inner lateral surface of the constriction groove; and,
an end ring with a radially projecting bead, the end ring located in a region of an axial end of the guide cylinder which is close to the roller.
2. The roller tappet as claimed in claim 1 , wherein the guide cylinder is configured with a continuous opening.
3. The roller tappet as claimed in claim 1 , wherein an equalizing opening is arranged in the cup-shaped sleeve.
4. The roller tappet as claimed in claim 1 , wherein the cup-shaped sleeve has a dome-shaped support at the pump piston contact seat.
5. The roller tappet as claimed in claim 1 , wherein the guide cylinder extends beyond the constriction groove at an end of the guide cylinder remote from the roller.
6. The roller tappet as claimed in claim 1 , wherein the inner lateral surface of the constriction groove projects radially inward.
7. The multi-part roller tappet as claimed in claim 1 , wherein the radial ring is secured on the inner lateral surface of the constriction groove by one of either a press-fit, adhesive bond, or a weld.
8. The multi-part roller tappet as claimed in claim 1 , wherein the radially projecting bead rests axially against two supports arranged within the guide cylinder.
9. A multi-part roller tappet for a high-pressure fuel pump, the roller tappet comprising:
a tappet body including:
a guide cylinder configured to rotatably support a roller, the guide cylinder having a cylindrical constriction groove; and,
a cup-shaped sleeve arranged at least partially within the guide cylinder, the cup-shaped sleeve having:
a pump piston contact seat, the pump piston contact seat and the roller located at opposite ends of the roller tappet; and,
a radially outward-facing radial ring arranged between axial ends of the cup-shaped sleeve, the radial ring secured on an inner lateral surface of the constriction groove.
10. The multi-part roller tappet as claimed in claim 9 , wherein the guide cylinder further comprises two supports, each of the two supports having a hole that receives a pin which rotatably supports the roller.
11. The multi-part roller tappet as claimed in claim 9 , wherein a lateral surface region of the guide cylinder extends beyond the constriction groove at an end remote from the roller.
12. The multi-part roller tappet as claimed in claim 11 , wherein the lateral surface region of the guide cylinder extends beyond the pump piston contact seat.
13. A multi-part roller tappet for a high-pressure fuel pump, the roller tappet comprising:
a tappet body including:
a guide cylinder configured to rotatably support a roller, the guide cylinder having a cylindrical constriction groove; and,
a cup-shaped sleeve arranged at least partially within the guide cylinder, the cup-shaped sleeve having:
a pump piston contract seat;
a radially outward-facing radial ring arranged between axial end of the cup-shaped sleeve, the radial ring secured on an inner lateral surface of the constriction groove; and,
an equalizing opening arranged between the pump piston contact seat and the radial ring.
14. The multi-part roller tappet as claimed in claim 13 , wherein the inner lateral surface of the constriction groove projects radially inward.