Device for connecting two parts

This application is a USC 371 application of PCT/DE 99/01527 filed on May 21, 1999.

The invention is based on a device for connecting two parts.

A known device for positionally secure connection of two structural parts, which have retaining edges, spaced apart from one another, on surfaces located in the same plane (German Patent Disclosure DE 30 47 133 A1), includes two connecting elements, which are inserted into the retaining edges of the structural parts and overlap one another. The connecting elements have detent and counterpart detent means, in the form of serrations and detent tongues, that rest on one another in the overlapping region and that enable a detent engagement at different mutual spacings of the two structural parts.

In an electric motor with a housing cylinder and at least one cover on the face end for closing an end opening of the housing cylinder (German Patent Disclosure DE 33 05 645 A1), it is known to secure the cover by means of a detent connection. For that purpose, the detent connection has two rows of teeth, extending axially to the housing cylinder and capable of detent engagement with one another, of which a first row of teeth is disposed on the cover, and a second row of teeth is disposed on the housing cylinder.

The connection device according to the invention has the advantage that the connection of the two parts can be made with a defined positioning of the axial position of the two parts to one another, and thus where the two parts are embodied as a housing and an end cover of an electric motor, the longitudinal armature play of the armature or rotor of the electric motor, the armature or rotor being received in a bearing toward the cover, can be fixedly set. The provision of two connection pairs with opposed inward pivoting directions of the tabs into the assigned notches enables sensitive adjustment and a reliably secure, final fixation of the two parts in a desired relation to one another.

The invention is described in further detail in the ensuing description in terms of an exemplary embodiment shown in the drawing. Shown are:

FIG. 1, a plan view of a housing and an end cover of an electric motor before they are connected to one another by means of a connection device;

FIG. 2, a view identical to that of FIG. 1 after the housing and end cover have been connected;

FIG. 3, a detail of a section taken along the line III—III of FIG. 2;

FIG. 4, an enlarged view of detail IV in FIG. 2 .

With the device, shown in FIGS. 1-4, for connecting two parts, a caplike end cover 11 is secured to a cylindrical housing 12 of an electric motor; the housing 12 fits over the end cover 11 in the region of its cap edge, as seen from FIG. 2 . Beyond this special exemplary embodiment, however, the connection device can also be used for connecting any two arbitrary parts.

The connection device, which in this special case of connecting the housing 12 and the end cover 11 at diametrically opposed points of the housing 12 and end cover 11 , is present at least twice, includes two connection pairs 13 , 14 , each comprising one wedgelike tab 15 and 16 , assigned to the first part and extending in the connection direction, and one wedge-shaped notch 17 and 18 , assigned to the second part and extending in the connection direction and having a course of the wedge that is contrary to the tab 15 . In this special exemplary embodiment, the two tabs 15 , 16 of the connection pairs 13 , 14 are assigned to the housing 12 , and the two wedge-shaped notches 17 , 18 are assigned to the end cover 11 , specifically in such a way that in the overlapping region of the end cover 11 and housing 12 and the tabs 15 , 16 are located above the notches 17 , 18 . The notches 17 , 18 are embodied in the cap edge of the caplike end cover 11 parallel to one another with opposite courses of the wedges, so that on the circular-annular face end, oriented toward the housing 12 , of the caplike end cover 11 , the wedge-shaped notch 17 has its smallest wedge width, while the wedge-shaped notch 18 has its greatest wedge width. The two wedgelike tabs 15 , 16 are relief-stamped in the housing jacket, spaced apart somewhat from the circular-annular face end of the housing 12 oriented toward the end cover 11 , in such a way that the respective wedgelike tapers, originating at the roots of the tabs, on the two tabs 15 , 16 extend oppositely. The two tabs 15 , 16 are also disposed parallel to one another with an extension direction opposite the connection direction; the tabs 15 , 16 each taper opposite one another from the root of the tab to the free end of the tab. The opening 19 that remains in the housing jacket after the two wedgelike tabs 15 , 16 have been relief-stamped is used as a vent hole for the electric motor. As seen from FIG. 4, the tabs 15 , 16 and the notches 17 , 18 can be provided along their outer contours with a microscopic serration 20 , to improve the mutual engagement of the tabs 15 , 16 and notches 17 , 18 .

Now, for establishing the connection, after the end cover 11 has been inserted into the face end of the housing 12 , the two wedgelike tabs 15 , 16 are pressed into the assigned notches 17 , 18 , causing deformation of the tabs 15 , 16 , as seen from FIG. 3 . Since in the process the inward pivoting directions of the tabs 15 , 16 into the assigned notches 17 , 18 are opposite one another, seen in terms of the connection direction, at the end of the process of pressing the tabs 15 , 16 in, the end cover 11 is reliably fixed to the housing 12 in an axially correct association. The wedge shape of the tabs 15 , 16 and of the notches 17 , 18 makes it possible to vary the relative location of the end cover 11 and housing 12 to one another, in terms of the axial direction, and thus to establish the axial play of an armature or rotor of the electric motor, the armature or rotor being received in the manner of a bearing in the end cover 11 , in a highly sensitive and fixed way.

In addition, the free ends of the tabs 15 , 16 , which after the end cover 11 has been fixed in the housing 12 protrude through the wedge-shaped notches 17 , 18 , can be used to secure further components inside the housing 12 as well.

The invention is not limited to the described exemplary embodiment of a connection of an end cover 11 to a housing 12 . On the contrary, arbitrary parts can be fixed in precise positions to one another with the connection device described. Nor is it necessary that the tabs and notches be made in the two parts themselves. On the contrary, these tabs and notches can be machined into separate connecting elements that are fixed in a suitable way to the two parts to be connected, for instance by being suspended in the two parts, as described in DE 30 47 133 A1, or by embodying such connecting elements integrally in the two parts.

The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.