Abstract: A fluid machine includes a fluidization portion for compressing or expanding a working fluid which is heated to be brought into a vapor phase state after circulating in a cycle, an oil storage portion for storing therein lubricant oil for lubricating a sliding surface of the fluidization portion, a lubricant oil feed passage for guiding the lubricant oil stored in the oil storage portion to a sliding portion of the fluidization portion by a flow of the working fluid, and a sliding surface pressure adjustment portion that is controlled to adjust a sliding surface pressure of the sliding portion. The working fluid flows inside the machine with the sliding surface pressure of the sliding portion decreased as compared with that in a normal operation of the fluidization portion by the sliding surface pressure adjustment portion, and thereafter the decreasing of the sliding surface pressure by the sliding surface pressure adjustment portion is released.

Abstract: A hydraulic pump includes a cylinder block having a cylinder, a rotor rotatable in the cylinder, and a vane movable in a radial direction of the rotor and biased to the rotor. The vane, the cylinder, and the rotor thereamong define an operation chamber. The rotor draws fluid into the operation chamber and sends the fluid outside the operation chamber. The vane is urged to the rotor according to differential pressure between pressure of fluid at high-pressure in the operation chamber and pressure of fluid at low-pressure in the operation chamber. The vane and the rotor define a hardness ratio being calculated by dividing hardness of the vane by hardness of the rotor, and the hardness ratio is greater than or equal to 1.6.

Abstract: A fluid machine includes a fluidization portion for compressing or expanding a working fluid which is heated to be brought into a vapor phase state after circulating in a cycle, an oil storage portion for storing therein lubricant oil for lubricating a sliding surface of the fluidization portion, a lubricant oil feed passage for guiding the lubricant oil stored in the oil storage portion to a sliding portion of the fluidization portion by a flow of the working fluid, and a sliding surface pressure adjustment portion that is controlled to adjust a sliding surface pressure of the sliding portion. The working fluid flows inside the machine with the sliding surface pressure of the sliding portion decreased as compared with that in a normal operation of the fluidization portion by the sliding surface pressure adjustment portion, and thereafter the decreasing of the sliding surface pressure by the sliding surface pressure adjustment portion is released.

Abstract: An object of the invention is to provide a waste heat collecting system having an expansion device, in which an over expansion of refrigerant is prevented so that a loss to be caused by the over expansion is eliminated. A volume ratio of expansion for the expansion device is selected at a value, at which proper expansion of the refrigerant is achieved when the pressure difference between the high pressure and the low pressure is minimum.