Yanmar Co., Ltd.

Bunei Katagiri

Tatsuo Yamaguchi

Keiichi Hayashi

The present invention aims at making a transmission casing compact. In the present invention, in the inside of a transmission casing, a traveling-system power transmission mechanism which is interposed between an engine and an axel, a PTO-system power transmission mechanism which is interposed between the engine and a PTO shaft, and a changeover mechanism which is interposed between both power transmission mechanisms are provided, wherein the power transmission of the PTO-system power transmission mechanism is interrupted at a middle portion thereof by the changeover mechanism and, at the same time, the changeover mechanism is allowed to perform a changeover manipulation to connect a downstream side portion of the PTO-system power transmission mechanism and a downstream side portion of the traveling-system power transmission mechanism. In this manner, it is possible to transmit the rotational speed proportional to the rotational speed of the engine to the PTO-shaft (first PTO-system power transmission) with the use of the PTO-system power transmission mechanism, while with the use of the changeover mechanism, it is possible to perform the changeover manipulation which interrupts the power transmission of the PTO-system power transmission mechanism in the middle portion thereof and, at the same time, connects the downstream-side portion of the PTO-system power transmission mechanism and the downstream-side portion of the traveling-system power transmission mechanism so as to transmit the rotational speed proportional to a vehicle speed to the PTO shaft (second PTO-system power transmission).

Tractor

The present invention aims at a tractor which can easily perform an assembling operation and a maintenance operation of a PTO transmission mechanism. According to the present invention, a PTO casing which incorporates a PTO transmission mechanism therein is detachably mounted on a rear portion of a transmission casing and, at the same time, the PTO casing is mounted in a state that a front portion thereof is housed in the inside of the transmission casing. By mounting the PTO casing which incorporates the PTO transmission mechanism therein on the rear portion of the transmission casing in this manner, it is possible to easily perform the assembling operation and the maintenance operation of the PTO transmission mechanism. Further, by mounting the PTO casing in a state that the front portion thereof is housed in the inside of the transmission casing, it is possible to miniaturize the transmission casing (make the transmission casing compact).

Growing community of inventors

Osaka, Japan

Bunei Katagiri