HYDRAULIC/MECHANICAL STEPLESS GEAR SHIFT DEVICE

To provide a hydraulic/mechanical stepless gear shift device capable of small-sizing a case in which an HST and a planetary gear mechanism accommodated in a housing are stored.SOLUTION: A hydraulic/mechanical stepless gear shift device comprises: an HST 10 in which a hydraulic pump 21 and a hydraulic motor 22 are stored in an HST case 23 and which includes a center section 35 mounted on the HST case 23 and fluidically connecting the hydraulic pump 21 with the hydraulic motor 22; and a planetary gear mechanism 11 which is combined with the HST 10 and outputs a stepless gear shift to a travel power transmission mechanism 89. The planetary gear mechanism 11 constituted an HMT unit 100 by being stored in a planetary gear support case 71 mounted on a surface of the center section 35 at an opposite side of the side where the HST case 23 is mounted. In the HMT unit 100, a housing mount surface 35d to be fixed to a housing 91 of the travel power transmission mechanism 89 is further provided in an outer periphery of a planetary gear support case mount surface 71a in the center section 35.SELECTED DRAWING: Figure 1 【課題】ハウジング内に収容されるＨＳＴおよび遊星歯車機構を収容するケースのサイズを小型化することができる油圧・機械式無段変速装置を提供する。【解決手段】ＨＳＴケース２３に油圧ポンプ２１と油圧モータ２２とを収容し、ＨＳＴケース２３に装着して油圧ポンプ２１と油圧モータ２２とを流体的に接続するセンタセクション３５を備えたＨＳＴ１０と、ＨＳＴ１０と組み合わせて無段階的な変速を走行動力伝達機構８９へ出力する遊星歯車機構１１と、を備え、遊星歯車機構１１は、ＨＳＴケース２３を装着した側とは反対側のセンタセクション３５の面に装着した遊星歯車支持ケース７１に収容してＨＭＴユニット１００を構成し、ＨＭＴユニット１００はさらに、走行動力伝達機構８９のハウジング９１に固定するためのハウジング装着面３５ｄをセンタセクション３５における遊星歯車支持ケース装着面７１ａの外周囲に設けた。【選択図】図１