Provided is a thermal energy recovery device in which poor lubrication of a bearing can be inhibited when an expander is driven. The thermal energy recovery device includes an evaporator (10), an expander (20), a power recovery machine (30), a condenser (40), a pump (50), a circulation flow path (60), a cooling flow path (70) for supplying working fluid from the pump (50) partially to the power recovery machine (30), an on-off valve (V1) provided in the cooling flow path (70), and a control unit (80), in which the expander (20) has a rotor (21), a bearing (22), and a primary casing (23), and in which the power recovery machine (30) has a power recovery unit (31) and a secondary casing (35), and in which upon reception of a stop signal for stopping power recovery by the power recovery machine (30), the control unit (80) closes the on-off valve (V1).

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have an elongate first island disposed thereon. The first island can have a body with a volume generally defined between front and rear surfaces that are spaced apart. The front and rear surfaces can lie in a plane parallel to a radial axis R. The perimeters of the front and rear surfaces can define a curved perimeter surface therebetween. The disclosure further provides embodiments having stationary islands and casings that rotate about the island.

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have an elongate first island disposed thereon. The first island can have a body with a volume generally defined between front and rear surfaces that are spaced apart. The front and rear surfaces can lie in a plane parallel to a radial axis R. The perimeters of the front and rear surfaces can define a curved perimeter surface therebetween. The disclosure further provides embodiments having stationary islands and casings that rotate about the island.