| 摘要 |
A multistage spur-type gearing for small and miniature electric motors having a gearing housing and at least two gear shafts or axles held in the gearing housing, with spur gears of different diameters arranged on the gear shafts or axles. To achieve an extremely small construction at maximum reduction ratios in comparison with conventional spur-type gearings, at least two spur gears are fixedly connected to one another and combined to form a dual gear set, with the dual gear set rotatably supported on a gear axle made from a hard material, such as ceramics. At least one of the gear shafts should fixedly be held as a gear axle in the housing. An input shaft opening through which a motor shaft projects into the gearings is arranged to be substantially coaxial to the center axis of the gearing housing with which the gear shafts also extend in parallel and at some distance. Such a gearing makes it possible to arrange several reduction stages on one gear axle. Preferably, only two gear shafts or axles are used. Thus, in constructional terms, the present gearing is the smallest one among all conceivable variants of the gearing. |
