A driving unit that comprises a hydraulic motor and a reduction gear

摘要

A driving unit (1a) comprises a multiple-stage planetary gear type reducer (2) used to reduce rotation speed of a hydraulic motor (3) and output the reduced rotation speed, which is used as a driving device for a traveling apparatus. The driving unit (1a) is so structured that a trunnion boss (25) for rotatably supporting a planetary gear train (26) of a final state is supported at opposite ends thereof. This structure enables the load applied to the trunnion boss (25) to be dispersed to the both ends, and as such can allow the trunnion boss (25) to be reduced in diameter or can allow the fixed casing (11) to be reduced in circumferential dimension. This can produce a downsized driving unit (1a). The driving unit (1a) has additional features, such as the feature that an output shaft (16) of the hydraulic motor (3) and an input shaft (16) of the reducer (2) are formed in the form of a single rotating shaft (16). This can provide a driving unit (1a) structurally optimized for every principal part, to provide downsizing and improved durability.