A gear pump that selectively directs lubrication to certain components within the pump. A system and method of retrofitting existing pumps to improve their longevity in the field. The system and method provides a clean, simple, efficient, and elegant improvement to current gear pump fuel delivery systems.

A rotary compressor is provided that may include a rotational shaft, first and second bearings configured to support the rotational shaft in a radial direction, a cylinder disposed between the first and second bearings to form a compression space, a rotor disposed in the compression space and coupled to the rotational shaft to compress a refrigerant as the rotor rotates, and at least one vane slidably inserted into the rotor, the at least one vane coming into contact with an inner peripheral surface of the cylinder to separate the compression space into a plurality of regions. At least one of the first bearing and the second bearing may include first and second pockets formed on a surface facing the rotor, and at least one of the first pocket and the second pocket may be formed in an asymmetrical shape.

Provided is a sliding component capable of reducing the frictional resistance of a sliding surface entailing eccentric rotation. A sliding component is formed in an annular shape and has a sliding surface relatively sliding with eccentric rotation. A plurality of grooves not communicating with spaces on the inner and outer diameter sides of the sliding component are circumferentially provided in the sliding surface.

A variable displacement lubricant pump includes a housing, a control ring arranged in the housing, an inlet chamber and an outlet chamber, and a lateral slide bearing. The control ring is shiftable, radially confines a pumping chamber, and comprises a drainage channel. The outlet chamber and the inlet chamber are arranged at opposite lateral sides of the control ring. The lateral slide bearing is arranged at the lateral side of the control ring where the outlet chamber is arranged and comprises a first lateral slide bearing surface defined by the static housing, a second lateral slide bearing surface arranged opposite to the first lateral slide bearing surface which is defined by the control ring, and a lateral slide bearing gap defined between the first and second lateral slide bearing surfaces. The drainage channel of the control ring fluidically connects the lateral slide bearing gap with the inlet chamber.

A system for an unmanned aerial vehicle can include an altitude control system, which further includes a compressor assembly, a valve assembly, and an electronics assembly. The compressor assembly may include a driveshaft and a bearing assembly configured to rotate the driveshaft. The driveshaft may be formed from a first material and a compressor housing may be formed from a second material. The first and second materials may have different rates of thermal expansion. A dynamic preloading mechanism, such as a flexible plate, may be provided within the compressor assembly to exert a preloading force on the bearing assembly. Throughout the duration of the flight of the unmanned aerial vehicle, the preloading mechanism can continually compensate for differences in rates of thermal expansion between the first and second materials throughout.

A hermetic compressor according to the present disclosure may include an oil guide disposed on a rotating shaft between a driving motor and a main frame, the oil guide may include an oil block surrounding a main bearing surface between the main frame and the rotating shaft, and one end of the oil block may radially overlap a shaft support protrusion of the main frame. This can suppress oil returned after lubricating a compression unit from being scattered, thereby reducing a leakage of the oil to outside of a casing through a refrigerant discharge pipe.

A twin-shaft pump comprising: a pumping chamber; two rotatable shafts each mounted on bearings is disclosed. Each of the two rotatable shafts comprises at least one rotor element, the rotor elements being within the pumping chamber and the two rotatable shafts extending beyond the pumping chamber to a support member. The support member comprises mounting means for mounting the bearings at a predetermined distance from each other, the predetermined distance defining a distance between the two shafts. A thermal break between the pumping chamber and the support member is provided for impeding thermal conductivity between the pumping chamber and the support member, such that the pumping chamber and support member can be maintained at different temperatures. The support member and the rotor elements are formed of different materials, a coefficient of thermal expansion of a material forming the support member being higher than a coefficient of thermal expansion of a material forming the rotor elements.

A scroll device includes a fixed scroll with an idler shaft bearing, an orbiting scroll with another idler shaft bearing; and an eccentric idler shaft having first and second arms extending in opposite directions and ending at first and second ends, the first and second arms supported by the fixed scroll idler shaft bearing and the orbiting scroll idler shaft bearing, respectively. The eccentric idler shaft has a hollow core extending from the first end to the second end, with at least one channel extending through the first arm and enabling fluid communication between the hollow core and the at least one first bearing, and at least one second channel extending through the second arm and enabling fluid communication between the hollow core and the least one second bearing.

A rotary compressor may include a rotational shaft, a first bearing and a second bearing each supporting the rotational shaft in a radial direction, a cylinder disposed between the first bearing and the second bearing and forming a compression space, a roller disposed in the compression space to form a contact point spaced at a predetermined interval from the cylinder and coupled to the rotational shaft to compress a refrigerant in response to rotation of the roller, and at least one vane slidably inserted into the roller and in contact with an inner circumferential surface of the cylinder and dividing the compression space into a plurality of compression chambers.

A screw compressor includes a housing, a first rotor rotatable about a first axis relative to the housing, and a second rotor rotatable about a second axis relative to the housing. The second rotor is enmeshed with the first rotor. A motor is embedded within the first rotor such that the motor is coaxial with the first axis.