As well known, a self-propelled walking mower has as its machine frame a deck which mounts at its upper side an engine fixedly and supports at its lower side a mowing cutter rotatably. Such deck further supports at its front end portion freely rotatable left and right front wheels. Left and right rear wheels are used as drive wheels and are associated with a wheel axle which extends leftward and rightward from a transaxle-type transmission casing.
Such transmission casing is, in general, fixedly supported by a rear end portion of the deck, as shown in, for example, JP, A(U) No. 61-135057.
According to such prior art, a transmission mechanism is put into a transmission casing firstly and then the transmission casing is attached to the deck.
A primary object of the present invention is to provide a novel drive system for walking mowers in which structure and assemblage for a transmission casing are much simplified so as to enhance economy.