| 摘要 |
The invention relates to drive units for the motive operation of horizontally displaceable doors, so-called all-round doors. According to the invention, it is proposed to fasten to the door (3), displaced along a guide rail (7), a drive unit (2) in which in addition to the motor transmission unit (1) there are, among other things the limit switches (8) for cutting off the door (3) in the end positions. The output shaft (50) of the motor transmission unit (2) projects outwards through the base plate (5) of the housing (4) and there carries a pinion (70) which engages into a toothing (77) along the guide rail (7) and which thereby moves the door during the rotation of the output shaft (50). A metal bush (18) is attached on the output shaft (50), for example by means of a conical multi-toothed profile (13). In contrast, the pinion (70) itself can consist, for example, of plastic and is in turn connected fixedly in terms of rotation to the metal bush (18). To compensate the lower strength of the plastic of the pinion (70) in relation to the metal of the toothing, in the toothing form selected there are extremely narrow tooth necks of the metal toothing and wide tooth cross-sections on the pinion (70). Furthermore, a bush (12), for example likewise made of plastic, is pushed onto the metal bush (18) in such a way that it projects back just into the housing (4) axially relative to the output shaft (50) and at this end carries a bevel gear (13). A bevel pinion (14) engages into this and is connected fixedly in terms of rotation to the end of a threaded rod (9), on which nuts (10) are screwed. However, because of an angle piece (16) fastened in parallel, these cannot rotate with the threaded rod (9), but during the rotation of the output shaft (50) are displaced axially on the then likewise rotating threaded rod (9). Thus, these nuts (10) of variable basic position serve as actuating elements for limit switches (8) fastened parallel and next to the threaded rod (9) for cutting off the door (3). <IMAGE> |
