Daimler Chrysler Ag

Mercedes-benz Aktiengesellschaft

Klaus Brandes

Henning Bloecker

Martin Kruessmann

Gottfried Schremmer

Joachim Kieserling

Hanno Lox

Andreas Barth

Frank Rohwer

Ruediger Unfug

Uwe Affolderbach

Henning Bl&ouml;cker

A process and system for manufacturing a built-up camshaft by which the operational safety of the camshaft is ensured in a simple manner in any engine operation and the camshaft can arbitrarily be adapted to abutments which have different positions because of the individual engine construction. At least one cam is pushed onto a hollow shaft, after which the hollow shaft is expanded between the two faces of the cam which extend transversely with respect to the longitudinal course of the hollow shaft and at the respective bearing point by means of a highly pressurized pressure fluid. This fluid is delivered by a lance-shaped probe introduced into the hollow space of the shaft. On the one hand, a press fit occurs between the cam and the hollow shaft and, on the other hand, a bulging of the bearing point of the hollow shaft occurs which bridges the distance between the hollow shaft and the abutment. The hollow shaft is sealed off between the expanded points by a sealing arrangement on the probe with respect to the expanding internal high pressure.

System for manufacturing built-up camshafts

A process is provided for the production of a cam to be joined to a hollow shaft to form a camshaft. In order to make the cam suitable for stable long-term operation on the camshaft, the internal compressive stresses achieved in the cam track before the joining of the cam to the camshaft being so high that the tensile stresses resulting from joining are permanently overcompensated, it is provided that the material selected for the cam is a steel in which the carbon can be dissolved easily as cementite in the pearlite and martensite or is in the form of a fine composite carbide. The cam, which is composed of a hardenable steel, should be fully hardened and, during tempering in the hardening operation, the basic hardness should be set in a range of between 25 and 40 HRC. The cam should then be edge-zone-hardened in a two-stage heating process by induction hardening at a medium frequency of 10-35 kHz, after the preheating stage of the heating process, the introduction of heat being interrupted for 0.3-1.5 seconds. After the action of the preheat, the cam track should then be heated in such a way by means of medium frequency that an edge-zone hardening depth of between at least 0.5 mm and at most 2.0 mm relative to the cam base circle and the cam flanks and at most 2.2 mm relative to the cam tip is obtained in the middle of the track, after which the cam is sprayed with a quenching medium immediately, within a matter of milliseconds of the end of the heating process.

Method for producing a cam that can be placed on a hollow shaft to form a camshaft

A process for manufacturing a built-up camshaft by which the operational safety of the camshaft is ensured in a simple manner in any engine operation and the camshaft can arbitrarily be adapted to abutments which have different positions because of the individual engine construction. At least one cam is pushed onto a hollow shaft, after which the hollow shaft is expanded between the two faces of the cam which extend transversely with respect to the longitudinal course of the hollow shaft and at the respective bearing point by means of a highly pressurized pressure fluid. This fluid is delivered by a lance-shaped probe introduced into the hollow space of the shaft. On the one hand, a press fit occurs between the cam and the hollow shaft and, on the other hand, a bulging of the bearing point of the hollow shaft occurs which bridges the distance between the hollow shaft and the abutment. The hollow shaft is sealed off between the expanded points by a sealing arrangement on the probe with respect to the expanding internal high pressure.

Process for manufacturing built-up camshafts

A steering spindle for a motor vehicle has a plug-in connection in which a splined shaft profile extends axially and is arranged at the end of a shaft, and a receiving tube which receives the splined shaft profile and is provided along its inner circumference with a corresponding splined hub profile. Furthermore, the steering spindle has, in the region of the plug-in connection, a plastic layer which extends at least along certain axial regions and fills clearances between the inner wall of the receiving tube and the splined shaft profile. The splines of the one part, arranged in the region of the receiving tube, are formed uninterruptedly in the axial direction and are an undersized portion in the circumferential direction with respect to the grooves of the other part. The splines of the one part are provided with the plastic layer of elastomeric plastic bridging this undersize portion. The plastic layer has an axial portion which is greater than the amount of maximum relative movement between the shaft and the receiving tube.

Motor vehicle steering spindle with plug-in connection

Growing community of inventors

Asendorf, Germany

Klaus Brandes