PROBLEM TO BE SOLVED: To provide a hydraulic circuit for achieving a combine-harvester at reduced manufacturing cost, the combine-harvester including a hydraulic non-stage transmission for driving a cooling fan and a hydraulic non-stage transmission for driving a feed chain, both being stably operated with a gear change of the feed chain in particular conducted accurately to thereby allowing an excellent threshing performance.SOLUTION: A combine-harvester is provided with a feed chain hydraulic non-stage transmission 1 for driving a feed chain and a cooling fan hydraulic non-stage transmission 2 for driving a cooling fan which cools down a mover part. A hydraulic circuit for a combine-harvester is characterized in that the combine-harvester is provided with non-stage transmission charge pumps 1a, 2b for respectively supplying a pressure oil to the feed chain hydraulic non-stage transmission 1 and the cooling fan hydraulic non-stage transmission 2 directly from an oil tank 11 separately from a main hydraulic circuit 13 and a travel non-stage transmission hydraulic circuit 3 for controlling postures of a travel clutch and for controlling a lifting operation of reaping and auger.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】本発明は、コンバインに冷却ファンを駆動する油圧無段変速機とフィードチェンを駆動する油圧無段変速機を設けた構成で、両油圧無段変速機が安定して作動し、特にフィードチェンの変速が正確に行われて脱穀性能が良く、また、コンバインの製造コストを抑えた油圧回路を提供することを課題とする。【解決手段】フィードチェンを駆動するフィードチェン油圧無段変速機1と原動部の冷却を行う冷却ファンを駆動する冷却ファン油圧無段変速機2を設けたコンバインにおいて、走行クラッチと機体姿勢制御および刈取・オーガ昇降制御を行なうメイン油圧回路13と走行無段変速油圧回路3とは別に直接オイルタンク11からフィードチェン油圧無段変速機1と冷却ファン油圧無段変速機2に圧油を供給する無段変速機チャージポンプ1a,1bを設けたことを特徴とするコンバインの油圧回路とする。【選択図】図1
