Device for altering the control timing of gas exchange valves of an internal combustion engine, especially an apparatus for hydraulic rotational angle adjustment of a camshaft relative to a crankshaft

US6619248B1 · kind B1 · utility

Assignee

• Ina Schaeffler KG · DE

Inventors

• Thomas Bertelshofer · Ebermannstadt, DE
• Gerd Wiessner · Neustadt an der Aisch, DE
• Jurgen Schwab · Ketsch, DE
• Thomas Kleiber · Herzogenaurach, DE

Key dates

• Filing date: Jul 12, 2002
• Grant date: Sep 16, 2003
• Expiry date: Jul 12, 2022

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F01L2301/00
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A device (1) for hydraulic rotational angle adjustment of a camshaft relative to a crankshaft of an internal combustion engine including a drive unit (4) connected with the crankshaft and an output unit (5) non-rotatably connected with the camshaft. The drive unit (4) stands in power transmitting connection with the output unit (5) through at least two pressure chambers (6, 7) formed inside the device (1) which bring about, under action by pressure under continuous compensation for external pressure leakages, a relative rotation or a hydraulic clamping of the output unit (5) in relation to the drive unit (4). In addition, the device (1) has a coil spring (8) arranged outside the device which is provided for adaptation of its adjustment speeds in both adjustment directions. The coil spring (8) is arranged via enclosure in an additional housing (11) in a closed annular space which is completely fillable with the external pressure medium leakages of the device (1), whereby the hydraulic pressure medium acts at the same time as a damping agent against sympathetic resonant vibrations of the spring turns (13) of the coil spring (8) resulting from vibrations of the internal combustion eng…