Vane-type camshaft adjuster

#The invention relates to a camshaft adjuster for an internal combustion engine comprising a housing with two side sections, a center section and a rotor mounted in the housing. The invention further relates to a method for manufacturing a housing for a camshaft adjuster for an internal combustion engine.

#A camshaft adjuster of the generic type and a corresponding method for manufacturing the housing thereof are disclosed in DE 101 48 687 A1. Herein, the housing and/or the rotor are produced by the extrusion of an aluminum alloy.

#Extrusion, however, is a relatively expensive method, which also has the disadvantage that it can be used with only a relatively limited number of materials.

#FIG. 1 is a side view of the camshaft adjuster according to the invention;

#FIG. 2 is a sectional view taken along the line II-II in FIG. 1; and

#FIG. 3 shows a step in a method for manufacturing a housing for the camshaft adjuster according to the invention.

#FIG. 1 shows a schematically a camshaft adjuster 1, which is intended for adjustment of the angle of rotation of a camshaft 2 in relation to a crankshaft (not shown) of an internal combustion engine (likewise not shown). The camshaft adjuster 1 may be embodied, for example, in a form such as is described in DE 199 55 507 A1 or DE 198 17 319 C2, and will therefore not be explained in any further detail. The camshaft adjuster 1 may be mounted to the camshaft 2 by means of a central bolt (not shown).

#The camshaft adjuster 1 has a housing 3 with two side cover sections 4 and 5 and a middle jacket section 6 arranged between the side sections 4 and 5. The side section 4 facing the camshaft 2 is provided with a sprocket wheel 7, which allows the camshaft adjuster 1 to be incorporated into a chain drive of the internal combustion engine. The two side sections 4 and 5 are connected together by means of multiple fastening elements 8, here in the form of bolts, extending outside the jacket section 6, in order to seal the housing 3 tightly. The fastening elements 8 however might also extend inside the jacket section 6.

#As will be clear from the representation according to FIG. 2, the jacket section 6 is of profiled cross section and in this case has three salient projections 9, making it suitable for the accommodation of a rotor 10 with three vanes 11 formed as a sintered or forged part, for example. The rotor 10 could also possibly have a different number of vanes 11, for example two or four. The jacket section 6 would then have to be provided with a corresponding number of salient projections 9. It can further be seen from FIG. 2 that at least one of the salient projections 9, in this case two, is formed in such a way that together with one of the vanes 11 of the rotor 10 it forms a chamber 12 for hydraulic fluid. Owing to the method for manufacturing the jacket section 6 described below, its wall in this area extends obliquely, that is to say at an angle in relation to the vane 11. In order to achieve the best possible sealing of the housing 3, the fastening elements 8 are in each case arranged immediately adjacent to the salient projections 9, two fastening elements 8 being associated with each salient projection 9.