Positive displacement machine such as a compressor, expander, pump or the like, for displacing a gaseous or liquid medium, the machine containing an element with at least one inlet and at least one outlet for the medium and at least two cooperating driven moving parts. The mutual periodic movement of the moving parts displaces the medium from the inlet to the outlet. Each of the at least two driven cooperating moving parts is provided with its own individual drive. The element is provided with a kinematic synchronisation coupling between the at least two cooperating moving parts for the mutual kinematic synchronisation of their movements.

The present invention provides a method of replacing a failed pump seal of a pump having a pump housing and a rotating pump shaft. As part of the method, there is provided a specially configured rescue seal. The rescue seal is placed on the pump shaft above the failed seal so that the pump shaft extends through both the failed seal and the rescue seal. In order to affix the rescue seal to the pump shaft and above the failed seal, a plurality of studs are first attached to the pump housing after removing some of the bolts that fasten the failed seal to the pump housing. The failed seal is then secured to the studs with nuts. Nuts are then placed on the studs to secure the rescue seal to the studs above the failed seal.

A supercharger includes a rotor housing defining a pair of cylindrical chambers. A driving shaft bearing is to support a driving rotor shaft for rotation in the rotor housing. A driven shaft bearing is to support a driven rotor shaft for rotation in the rotor housing. An oil sump housing is to enclose a timing gear end of the rotor housing. A shaft seal is disposed between the rotor housing and each respective rotor shaft. The oil sump housing, the rotor housing and driving and driven shaft seals define a closed container for oil to lubricate the driving shaft bearing, the driven shaft bearing, a driving timing gear and a driven timing gear. The oil pools in the closed container and a top surface of the oil is spaced below the timing gears when the driving rotor shaft is in a vertical orientation.

The present disclosure relates to an electric compressor capable of fixing a shaft seal without a retainer for fixing the shaft seal, and includes a shaft which is rotatably coupled inside a main housing, and a shaft seal which is press-fitted between the shaft and the main housing, seals between the shaft and the main housing by an elastic structure, prevents deformation in the elastic structure with a rigid structure formed integrally with the elastic structure, and maintains the coupled position by a frictional force of the elastic structure.

A method of priming a pump includes supplying lubricant, via a priming flow path, into an interface defined between a first part of a shaft of the pump and a second part of the shaft coaxially engaged with the first part of the shaft to define the pump, the first part of the shaft rotatable about a rotation axis relative to the second part of the shaft, and supplying lubricant into the interface via a lubrication flow path that is different from the priming flow path. A method of lubricating an aircraft motor of an aircraft engine, and a machine for an aircraft engine are also described.

An oil-free water-injected screw air compressor comprises a housing that encloses two rotors for generating compressed air, and an air water separator for separating the water from the compressed air. Water injection can effectively cool a compressor, and some embodiments provide a sealing system for isolation of compressor bearing lubricant from water used for cooling.

A scroll vacuum pump has an axially extending drive shaft with an eccentric shaft portion, such that rotation of the drive shaft imparts an orbiting motion to an orbiting scroll relative to a fixed scroll. An axial adjustment mechanism has a plurality of adjustment members angularly spaced around the drive shaft and extending through the pump housing towards the orbiting scroll, the plurality of adjustment members each being configured to provide an independently adjustable axial position of the orbiting scroll. A plurality of sealing means isolate the plurality of adjustment members from a pump chamber, the plurality of sealing means extending around each of the plurality of adjustment members and comprising at least one flexible portion such that one end of the sealing means may orbit relative to a fixed other end of the sealing means.

A squeeze film damper assembly for a compressor includes a damper sleeve configured to be disposed about a rotor shaft of the compressor. The damper sleeve includes a pressure dam pocket formed in an inner circumference of the damper sleeve. The pressure dam pocket is configured to receive a flow of lubricant and to pressurize the flow of lubricant via rotation of the rotor shaft. The damper sleeve includes an outlet passage extending from the pressure dam pocket to an outer circumference of the damper sleeve. The squeeze film damper assembly also includes a bearing housing disposed about the damper sleeve to form a damper gap extending between the outer circumference of the damper sleeve and the bearing housing. The damper gap is fluidly coupled to the outlet passage and is configured to receive the flow of lubricant from the pressure dam pocket.

A sectional sealing system for water-spray type screw rotor compressor that is configured to prevent the intermixing of coolant and working fluid from a compression chamber with lubricant used to lubricate at least a bearing system of a rotor. The sealing system may include suction side and discharge side sealing portions that are positioned about first and second shafts, respectively, of the rotor. The suction side sealing portion may include a first seal, a first labyrinth seal, and a second labyrinth seal, the first seal being in proximity to a suction side of the compression chamber. The discharge side sealing portion may include a plurality of first seals, a second seal, a first labyrinth seal, and a second labyrinth seal, the plurality of first seals of the discharge side sealing portion being in proximity to a discharge side of the compression chamber.

An oil-free screw compressor includes: a casing having a rotor chamber; a bearing supporting rotary shafts of the screw rotors; a shaft seal device including an oil seal portion and an air seal portion; an atmosphere open hole formed in the shaft seal device; at least one communication hole formed in the rotary shaft; and an annular space communicating the atmosphere open hole with the at least one communication hole communicate with each other. The annular space includes an inner peripheral annular space formed on an inner peripheral side of the casing. Assuming an open cross-sectional area of the inner peripheral annular space as S1, a total open cross-sectional area of the communication holes as S2, an open cross-sectional area of the i-th communication hole out of the communication holes as S2i, and the number of communication holes as n (n being a natural number of 1 or more), a following relationship is satisfied.

[00001]$S.Math..Math.1\geqq S.Math..Math.2=\underset{i=1}{\overset{n}{.Math.}}.Math..Math.S.Math..Math.2.Math.i$