TRANSMISSION UNIT

PROBLEM TO BE SOLVED: To provide a simply structured transmission unit which can effectively keep a lubricity of gear transmission mechanism while effectively preventing a transmission efficiency of the transmission mechanism from decreasing, and preventing temperature rise of oil stored in a gear casing in a transmission unit in which the gear transmission mechanism is housed inside the gear casing which can store oil. SOLUTION: When each transmission gear 231, 232, 233 of a gear transmission mechanism 230 rotates with accompanying rotation of an input shaft 210 by power of a drive source 2, oil Q stored in the gear housing part 240a is mixed with accompanying that. On the other hand, the gear housing part 240a and the oil storage part 245a are partitioned by a rib 244 provided in the gear casing 240. Consequently, mixing action of the oil Q in the oil storage part 245a partitioned by the rib 244 is weakened as compared with mixing action of the oil Q in the gear housing part 240a (less influence of mixing) when the oil Q stored in the gear housing part 240a is mixed by the gear transmission mechanism 230. COPYRIGHT: (C)2008,JPO&INPIT