A Rankine cycle circuit is formed by an expander (72) that forms part of a fluid machine (34), a condenser, a gear pump (67) that forms part of the fluid machine (34), and a boiler. A discharge path (47) is connected to a discharge chamber of a pump chamber (64). A branch path (48) branches off from the discharge path (47), and a restriction path (49) is provided at an end of the branch path (48). The restriction path (49) opens into an inner space (K) of a generator housing (37). An outflow path (50) is provided passing through a barrier wall (361) of a center housing (36) and a side plate (62). The inner space (K) in which an alternator (43) is disposed communicates with an exhaust chamber (80) through the outflow path (50).