A scroll expander includes a driving scroll body having a first axis line a driven scroll body having a second axis line shifted with respect to the first axis line, a bearing plate including two plates coupled to the driven scroll body and having the second axis line a cylindrical driving pin attached to the driving scroll body, and a cylindrical guide ring attached to the bearing plate and having an inner diameter larger than an outer diameter of the driving pin. The driving pin includes an outer circumferential surface in contact with an inner circumferential surface of the guide ring. A hard film including diamond-like carbon is formed on the outer circumferential surface of the driving pin. The inner circumferential surface of the guide ring includes a polymer resin material with self-lubricity.

A scroll expander includes a driving scroll body having a first axis line a driven scroll body having a second axis line shifted with respect to the first axis line, a bearing plate including two plates coupled to the driven scroll body and having the second axis line a cylindrical driving pin attached to the driving scroll body, and a cylindrical guide ring attached to the bearing plate and having an inner diameter larger than an outer diameter of the driving pin. The driving pin includes an outer circumferential surface in contact with an inner circumferential surface of the guide ring. A hard film including diamond-like carbon is formed on the outer circumferential surface of the driving pin. The inner circumferential surface of the guide ring includes a polymer resin material with self-lubricity.

A compressor provided with an oil stabilizing member capable of preventing oil stored in an oil storage space from being scattered is provided. A compressor may include a closed container provided with an inlet port and an outlet port, a compression unit configured to compress refrigerant introduced into an inside the closed container through the inlet port, a driving unit configured to provide a driving force to drive the compression unit, a rotating shaft configured to deliver the driving force to the compression unit, an oil storage space formed at a lower portion of an inside the closed container and configured to store a predetermined oil to come into contact with one end portion of the rotating shaft, and an oil stabilizing member installed so as to move along a surface of oil formed at the oil storage space, thereby preventing the oil from being scattered and thus released through the outlet port, wherein the oil stabilizing member floating on the surface of the oil prevents oil from being scattered upward according to operation of the compressor.

A compressor includes a discharge housing member, which includes a discharge chamber and an oil separation chamber. The discharge housing member includes a cylindrical wall defining the discharge chamber and the oil separation chamber. The discharge chamber includes a partition that is continuous with and protrudes from the cylindrical wall. The cylindrical wall extends from an upper section of the discharge chamber toward a lower section of the discharge chamber. The cylindrical wall includes a communication hole connecting the discharge chamber to the oil separation chamber. The partition extends from the upper section of the discharge chamber toward the lower section of the discharge chamber and defines a first space and a second space in the discharge chamber. The first space and the second space are connected to each other at least at the lower section of the discharge chamber through a clearance between the partition and the circumferential wall.

A longer-lasting, lower cost, more powerful, all metal, mud motor than the presently available progressing cavity type mud motors for drilling boreholes into the earth. A mud motor apparatus possessing one single drive shaft that turns a rotary drill bit, which apparatus is attached to a drill pipe which provides high pressure mud to the mud motor, wherein the drive shaft receives at least a first portion of its rotational torque from any high pressure mud flowing through a first hydraulic chamber within the apparatus, and receives at least a second portion of its rotational torque from any high pressure mud flowing through a second hydraulic chamber within the apparatus. A typical mud motor apparatus possesses two or more hydraulic chambers, each having its own power stroke, and return stroke, which act together in a controlled fashion to provide continuous power to a rotary drill bit.

A compressor includes a casing, a motor fixed to the casing, a vertically extending drive shaft coupled to the motor, and a compression mechanism driven by the drive shaft to compress a fluid. A shaft-inside oil supply path is provided in the drive shaft. Oil at a bottom of the casing is supplied through the shaft-inside oil supply path to a sliding portion of the drive shaft above the motor. The compressor includes a shaft-inside oil discharge path provided in the drive shaft, and an oil discharge coupled to a lower end of the drive shaft. The shaft-inside oil discharge path extends from an upper portion to a lower portion of the motor. The oil discharge pump discharges the oil that has been supplied to the sliding portion of the drive shaft to the bottom of the casing through the shaft-inside oil discharge path.

A longer-lasting, lower cost, more powerful, all metal, mud motor than the presently available progressing cavity type mud motors for drilling boreholes into the earth. A mud motor apparatus possessing one single drive shaft that turns a rotary drill bit, which apparatus is attached to a drill pipe which provides high pressure mud to the mud motor, wherein the drive shaft receives at least a first portion of its rotational torque from any high pressure mud flowing through a first hydraulic chamber within the apparatus, and receives at least a second portion of its rotational torque from any high pressure mud flowing through a second hydraulic chamber within the apparatus. The mud motor apparatus possesses two hydraulic chambers, each having its own power stroke, and return stroke, and acting together in a controlled fashion, provide continuous power to a rotary drill bit.

A longer-lasting, lower cost, more powerful, all metal, mud motor than the presently available progressing cavity type mud motors for drilling boreholes into the earth. A mud motor apparatus possessing one single drive shaft that turns a rotary drill bit, which apparatus is attached to a drill pipe which provides high pressure mud to the mud motor, wherein the drive shaft receives at least a first portion of its rotational torque from any high pressure mud flowing through a first hydraulic chamber within the apparatus, and receives at least a second portion of its rotational torque from any high pressure mud flowing through a second hydraulic chamber within the apparatus. The mud motor apparatus possesses two hydraulic chambers, each having its own power stroke, and return stroke, and acting together in a controlled fashion, provide continuous power to a rotary drill bit.

A hydraulic device comprises a rotary toroidal piston chamber having a rectangular space with a bottom, two sidewalls, and an open top. Four stationary pistons and two retractable gates for each piston are within the toroidal chamber mounted on a chamber wheel fixed to an axle on which it rotates, wherein the pistons and the gates are evenly spaced around the toroidal chamber separating the chamber into four partitions. A piston support for each piston is configured to hold the piston stationary while the piston chamber rotates. A stationary cover encircles and seals the open top of the piston chamber wherein openings through the stationary cover allow each of the piston supports to pass through and be sealed. An input port opening and an output port opening are in the stationary cover for each partition. The piston chamber rotates by reacting directly to continuous hydraulic force on the stationary pistons.