A tip seal 1 for a scroll compressor capable of reducing a frictional force between scroll members and the tip seal where the tip seal 1 has a spiral shape for sealing a compression chamber formed between a fixed scroll and a movable scroll in a scroll compressor provided with the fixed scroll. The movable scroll having a plurality of concave parts 4 being formed by partially notching a sliding surface 5 on the scroll members, the concave parts 4 being arranged on at least one of a spiral inner peripheral surface 1b or a spiral outer peripheral surface 1a. Each of the concave parts 4 being open to the inner peripheral surface 1b or the outer peripheral surface 1a.

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.

The invention relates to the rotary piston machines, namely, to the working volume sealing systems of the said machines and can be used in the gas (air)’ and refrigerating compressors, heat’ and vacuum pumps and in the internal-combustion engines. The rotary piston compressor sealing system comprises the radial and butt sealing bars configured in the rotor slots, tightened towards the working surfaces by expanders and interacting with the sealing cylinders wherein the radial and butt sealing bars are made from antifriction composite material and each of the sealing cylinders is configured conjointly with one of the ends of one butt sealing bar. Also, a second embodiment of the rotor piston compressor sealing system is disclosed. The technical result consists in the increasing of the efficiency of the sealing system’ and the whole compressor operation, simplification of the system production process, simplification and labor intensity reduction of the system assembly and maintenance process, increasing of the working chambers leakage tightness, increasing of the system reliability and durability and improvement of the compressor performance related to the bleeding and the dynamic pneumatic process as a whole.

A variable diffuser for a centrifugal compressor comprises a passage between opposing disc faces and a plurality of vanes extending therethrough with a fixed angle relative to the engine centerline. Axial displacement between the opposing disc faces is variable. The vanes extend through one of the opposing disc faces as that disc face is axially translated.

Provided is a tip seal for a scroll compressor capable of reducing a frictional force between scroll members and the tip seal and contributing to energy saving of the scroll compressor while maintaining the sealing performance. A tip seal 1 in a spiral shape for sealing a compression chamber formed between a fixed scroll and a movable scroll in a scroll compressor provided with the fixed scroll and the movable scroll serving as the scroll members has a plurality of concave parts 4 formed by partially notching a sliding surface 5 on the sliding surface 5 for the scroll members, the concave parts 4 are arranged on at least one of a spiral inner peripheral surface 1b and a spiral outer peripheral surface 1a, and each of the concave parts 4 opens to the inner peripheral surface 1b or the outer peripheral surface 1a and also does not penetrate through the inner peripheral surface 1b or the outer peripheral surface 1a.

Rotary piston machines working volume sealing systems thereof are disclosed. They can be used in gas (air) and refrigerating compressors, heat and vacuum pumps, and internal-combustion engines. The rotary piston compressor sealing system includes radial and butt sealing bars in the rotor slots, tightened towards the working surfaces by expanders and interacting with the sealing cylinders. The radial and butt sealing bars are made from an antifriction composite material. Each sealing cylinder is configured conjointly with one end of one butt sealing bar. Variations also are disclosed. The technical result involves increasing efficiency of the sealing system and the whole compressor operation, simplification of the system production process, simplification and labor intensity reduction of the system assembly and maintenance, increasing of the working chambers leakage tightness, increasing of system reliability and durability, and improvement of compressor performance related to bleeding and the dynamic pneumatic process as a whole.

A roots pump includes a housing, a rotor chamber, a pair of rotary shafts, and a pair of rotors. The rotor chamber includes a rotor chamber peripheral surface facing a pair of distal end portions of each of the rotors. Each of the pair of the distal end portions includes: a pair of rotor peripheral surfaces facing the rotor chamber peripheral surface with a first radial clearance; and a distal end peripheral surface that is formed between the pair of the rotor peripheral surfaces in the rotational direction and faces the rotor chamber peripheral surface with a second radial clearance greater than the first radial clearance. A width of the rotor chamber peripheral surface facing the distal end peripheral surface in the rotational direction is greater than a sum of a pair of predetermined widths of the rotor chamber peripheral surface facing the pair of the rotor peripheral surfaces.

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 variable diffuser for a centrifugal compressor comprises a passage between opposing disc faces and a plurality of vanes extending therethrough with a fixed angle relative to the engine centerline. Axial displacement between the opposing disc faces is variable. The vanes extend through one of the opposing disc faces as that disc face is axially translated.

A refrigerant scroll compressor for a motor vehicle air conditioning system having a fixed scroll, a orbiting scroll engaging with the fixed scroll, wherein the fixed scroll and the orbiting scroll cooperate to compress a refrigerant gas. An intermediate pressure chamber is disposed adjacent the orbiting scroll, an oil return duct provides fluid communication between the intermediate pressure chamber and a high pressure area of the refrigerant scroll compressor, and at least one intermediate pressure duct is formed in one of the orbiting scroll and fixed scroll and is in fluid communication with the intermediate pressure chamber.