A travel transmission apparatus has a transmission case 29. A variable speed changer device 38 is attached to the transmission case 29, and a travel clutch and a brake are built therein. The variable speed change device is controlled by a travel control rod 125 which is driven by a control motor 122. The control motor 122 is controlled on the basis of a rotation of a shift pedal 57. A clutch operation shaft 153 and a brake operation shaft 151 are protruded from the transmission case 29. If the shift pedal 57 is fully turned back, an interlocking shaft 157 moves backward on the basis of a return rotation of a sensor bracket 103 by the control motor 122, and the travel clutch is disconnected and the brake lightly works while working with this.本發明之行駛變速裝置包含變速箱29。於變速箱29上安裝有無段變速器38,並且內置有行駛離合器或剎車件。無段變速器係藉由利用控制馬達122驅動之行駛控制桿125而控制。控制馬達122係藉由變速踏板57之旋動而控制。於變速箱29突出有離合器操作軸153及剎車件操作軸151。當使變速踏板57倒退完畢時,感測器托架103藉由控制馬達122而倒轉,此時連動軸157後退,與其連動而切斷行駛離合器,並且剎車輕微作用。18‧‧‧側架19‧‧‧前架21‧‧‧枝架29‧‧‧變速箱29a、29b‧‧‧凸部31‧‧‧傳送帶38‧‧‧HST(靜油壓式無段變速器)39‧‧‧輸入軸40‧‧‧驅動軸41‧‧‧動力轉向單元43‧‧‧轉向油壓馬達44‧‧‧轉向齒輪箱45‧‧‧前托架51‧‧‧變速桿、縱向桿56‧‧‧輸出控制軸57‧‧‧變速踏板80‧‧‧作業動力輸出部81‧‧‧作業動力輸出軸88‧‧‧剎車踏板89‧‧‧絞鏈90‧‧‧第1軸承筒91‧‧‧中間軸96‧‧‧管托架97‧‧‧步行操作用線100‧‧‧凸輪(周面凸輪)101‧‧‧第2軸承筒102‧‧‧控制軸103‧‧‧感測器托架104‧‧‧踏板感測器105‧‧‧開關軸106b‧‧‧第2開關臂116‧‧‧前支撐部119‧‧‧支持板120‧‧‧分隔棒122‧‧‧傳動馬達(致動器)125‧‧‧行駛控制桿126‧‧‧輸出控制臂126a‧‧‧第1臂部126b‧‧‧第2臂部129‧‧‧第1彈簧130‧‧‧油門線134‧‧‧曲柄桿135‧‧‧曲柄軸136‧‧‧中間托架137‧‧‧中間撐桿139‧‧‧上部輔助托架141‧‧‧支持筒143‧‧‧剎車托架145‧‧‧側操作桿150‧‧‧接頭桿153‧‧‧離合器操作軸154‧‧‧離合器臂154a‧‧‧背板157‧‧‧連動軸158‧‧‧螺母
