A dry rotary pump for recirculating an at least partially gaseous composition containing hydrogen. The dry rotary pump comprising a first rotating shaft and a second rotating shaft. The first rotating shaft and the second rotating shaft are driven in rotation by a drive system in a gear chamber. The dry rotary pump comprises a first pair of seals and a second pair of seals, each comprising a first shaft seal and a second shaft seal. The dry rotary pump comprises a pressure equalization chamber in fluid connection with a gap between the first shaft seal and the second shaft seal to regulate pressure in the gap. The gear chamber is in fluid connection with the gap, and the pumping chamber is in fluid connection with the first shaft seal and the first shaft seal by a pulsation attenuation chamber.

A compression system is disclosed having a compressor and a seal package including a non-contact seal and one or more radial shaft seals. In one form the non-contact seal is placed in proximity to a high pressure portion of the compressor. The offset of the non-contact seal from a shaft used to drive the compressor allows some amount of pressure reduced leakage air to pass. A radial shaft seal is coupled to the shaft axial aft of the non-contact seal on the other side of the compressor and oriented to discourage further passage of the leakage air past the radial shaft seal. A vent conveys leakage air to return to the compressor. A backup radial shaft seal can be used axially aft of the first radial shaft seal. A further radial shaft seal is disposed adjacent to the backup seal and oriented in the other direction to seal lubricant for a bearing.

A compressor includes a non-orbiting scroll, an orbiting scroll, a driveshaft, a bearing housing and a bushing. The non-orbiting scroll includes a first spiral wrap. The orbiting scroll includes an end plate having a first side and a second side. The first side has a second spiral wrap that extends therefrom and meshingly engages with the first spiral wrap of the non-orbiting scroll. The second side has a hub extending therefrom. The driveshaft has a crankpin that is received in the hub and that drives the orbiting scroll. The bushing includes a first member and a second member. The first member is disposed within the hub of the orbiting scroll between the hub and the crankpin of the driveshaft. The second member extends radially from the first member and is disposed between the hub and the bearing housing.

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.

A rotary pump, preferably a vacuum. pump, featuring: a delivery space including an inlet on a low-pressure side and an outlet on a high-pressure side of the pump; a rotor which is arranged in the delivery space and delivers a fluid from the inlet into the delivery space to the outlet from the delivery space; at least one housing part which delineates the delivery space at least axially; and a drive shaft which is connected in drive terms to the rotor; including at least one sealing element which is connected, secured against shifting and/or rotating, to the drive shaft and/or rotor and forms a radial sealing gap with the housing part.

An oil-free screw compressor has a screw rotor including a screw and a shaft, a bearing supporting the shaft, a first shaft seal device disposed between the screw and the bearing and including a first seal opposite to the shaft, and a first communication portion communicating the inner periphery face and the outer peripheral face of the first shaft seal device, a second shaft seal device disposed between the first shaft seal device and the bearing and including a second seal opposite to the shaft, and a second communication portion communicating an inner periphery face and the outer peripheral face of the second shaft seal device, and a casing including an atmosphere communication portion connected to both of the first communication portion and the second communication portion on the inner peripheral face of a shaft accommodation space.

A high suction pressure thrust load balance assembly configured for use with a single screw compressor includes comprises a sealing baffle that is keyed to, so as to be rotatable along with, a main rotor drive shaft of the single screw compressor. The sealing baffle is configured to create a force or load to counteract the axial force of the main rotor drive shaft created during rotation of the main rotor drive shaft using the pressurized oil used to lubricate the mechanical shaft seal of the compressor.

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. $S1S2=\underset{i=1}{\overset{n}{.Math.}}S2i$

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 seal for a rotary machine may include an end cap configured to be coupled to the rotary machine. The end cap may define an end face and a bore. The seal may also include a sleeve received through the bore of the end cap and configured to receive a shaft associated with the rotary machine. The seal may also include a collar coupled to the sleeve and configured to couple the sleeve to the shaft associated with the rotary machine. The seal may further include a spacer coupled to the end face of the end cap, in a first position, such that at least a portion the spacer is between the collar and the end face of the end cap, and, in a second position, such that the portion of the spacer is not between the collar and the end face of the end cap.