Patent ID: 6192844
Filing Date: 2001-02-27
Classification: F01L

Abstract:
Device for varying the control times of gas-exchange valves of an internal combustion engine, in particular a camshaft adjusting device with an impeller, having the following features:the device (1) comprises a drive wheel (2) which is constructed as an outer rotor and is connected in driving terms to a crankshaft of the internal combustion engine via a driving means,the drive wheel (2) has a cavity (6) formed by a hollow cylindrical peripheral wall (3) and two side walls (4, 5), a tooth system (7) for the driving means being arranged on one of the side walls (4 or 5) or on the peripheral wall (3),the device (1) further comprises an impeller (8) which is constructed as an inner rotor, is connected in a rotationally fixed fashion to the camshaft of the internal combustion engine, is inserted into the cavity (6) of the drive wheel (2), and has at least one radially arranged blade (11) on the peripheral surface (9) of its wheel hub (10),extending from an inner lateral surface (12) of the peripheral wall (3) of the drive wheel (2) into the cavity (6) of the drive wheel (2) are at least two radial bounding walls (13) which are directed toward the longitudinal center axis of the drive wheel (2) and are operationally connected to the wheel hub (10) of the impeller (8),at least one hydraulic operating chamber (17) is formed inside the device (1) by lateral surfaces (15, 16) of the bounding walls (13) and by the inner lateral surface (12) of the peripheral wall (3) of the drive wheel (2) together with a peripheral surface (9) of the wheel hub (10) of the impeller (8),at least one operating chamber (17) of the device (1) is subdivided in turn into in each case two hydraulic pressure chambers (18, 19) acting against one another by in each case one blade (11) of the impeller (8) extending into this operating chamber (17),given an optional or simultaneous application of pressure by a hydraulic pressure fluid within a maximum pivoting angle, the pressure chambers (18, 19) effect a pivoting movement or fixing of the impeller (8) with respect to the drive wheel (2), and thus of the camshaft with respect to the crankshaft,characterized in thatthe device (1) has between the impeller (8) and the drive wheel (2) an additional angle-limiting device (26) with the aid of which the maximum pivoting angle of the impeller (8), which is limited per se by the lateral surfaces (15, 16) of the bounding walls (13) in the drive wheel (2), can be reduced with respect to the drive wheel (2) to a smaller pivoting angle,virtually stepless reduction in the pivoting angle being possible merely by exchanging a component of the device (1) or an element of this angle-limiting device (26) for another component, which likewise reduces the pivoting angle, of the device (1) or an element of the angle-limiting device (26), andthe device (1) can be used while retaining all the remaining components on all internal combustion engines for which the possible relative angle of rotation between their camshaft and their crankshaft is smaller than or equal to the maximum pivoting angle, limited by the lateral surfaces (15, 16) of the bounding walls (13) in the drive wheel (2), of the impeller (8) with respect to the drive wheel (2).