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.

The scroll compressor includes a fixed scroll (8) having a fixed end plate (11) and a fixed spiral wrap (12) extending from the fixed end plate (11); an orbiting scroll (9) having an orbiting base plate (14) and an orbiting spiral wrap (15) extending from a first face of the orbiting base plate (14), the orbiting spiral wrap (15) of the orbiting scroll (9) meshing with the fixed spiral wrap (12) of the fixed scroll (8) to form compression chambers (18), the orbiting base plate (14) having a flange portion (16) radially extending on at least part of the circumference of the orbiting base plate (14) and beyond an outer wall surface of the orbiting spiral wrap (15); and a first and a second axial stabilizing arrangement (29, 31) configured to axially stabilize the orbiting scroll (9), the first axial stabilizing arrangement (29) being formed between the flange portion (16) of the orbiting base plate (14) and the fixed scroll (8), and the second axial stabilizing arrangement (31) being formed between a portion of the orbiting spiral wrap (15) of the orbiting scroll (9) and the fixed end plate (11) of the fixed scroll (8).

A centrifugal compressor includes: a scroll housing including a scroll flow path; a shroud piece attached to the scroll housing at a position radially inside the scroll flow path and including a shroud portion that faces a compressor impeller in a radial direction; and a throttling portion arranged in a gap formed between the scroll housing and the shroud piece.

A scroll type gas machine that can suppress wear of tip seals is provided. The scroll type compressor includes: a fixed scroll 11 having a helical wrap 16; an orbiting scroll 12 having a helical wrap 21; a drive shaft 13 that causes the orbiting scroll 12 to orbit relative to the fixed scroll 11; and a helical tip seal 29A inserted into a seal groove 28A of the wrap 21. The tip seal 29A has: a groove 36A that has an opening at a central portion of a sliding surface 30 in the seal width direction; and a communication groove 37A that establishes communication between the inside of the groove 36A and a working chamber S.sub.H on the inner side in the wrap width direction. The groove 36A is provided in a range where the differential pressure (P.sub.H−P.sub.L) is equal to or higher than 0.1 Mpa between the working chamber S.sub.H on the inner side in the wrap width direction and a working chamber S.sub.L on the outer side in the wrap width direction. The communication groove 37A is shorter than the groove 36A in the seal extension direction.

A scroll pump includes a first scroll member having a first involute, a second scroll member scroll member having a second involute, and a camshaft rotatably connected to the first scroll member and to the second scroll member. A link is pivotably connected to the first scroll member and the second scroll member. The first and second scroll members cooperate to define a working volume wherein a working fluid is pressurized during operation of the scroll pump. The second scroll member is configured to equalize pressure across first and second opposed surfaces of an end plate thereof. The second scroll member includes a piston and cavity configured to bias the second scroll member toward the first scroll member in response to pressure across the first and second opposed surfaces of the end plate of the second scroll member.

A scroll compressor to compress fluid in a compression chamber formed by combining a scroll wrap of a fixed scroll and a scroll wrap of an orbiting scroll, the scroll wrap of the fixed scroll and the scroll wrap of the orbiting scroll each having a scroll inner end part having a bulb shape defined by an outer surface involute curve, an inner surface involute curve, and a plurality of arcs connecting an end of the outer surface involute curve and an end of the inner surface involute curve, at least one of the scroll inner end parts being formed in an n-tier stair-like shape in which n (n≧3) number of bulb shapes are stacked on top of one another in an upright direction of the scroll wrap, the scroll compressor being configured to satisfy φos (0)>φos (1)>φos (2)> . . . >φos (n−1) where involute roll angles of the outer surface involute curve in tiers of the stair-like shape of the scroll inner end part are φos (0), φos (1), φos (2), . . . , φos (n−1), respectively, from a wrap tip side to a wrap root side.

A scroll pump has a tip seal between an axial end of the scroll blade of one of stationary and orbiting plate scrolls of the pump and the plate of the other of the stationary plate and orbiting plate scrolls. The scroll pump may have a ballast gas supply system and use the operation of the ballast gas supply system to assess the condition of the tip seal. Alternatively, the scroll pump may have two pressure sensors that sense pressure at two locations spaced along a compression mechanism of the pump to assess the condition of the tip seal.

A compression device includes at least: two interleaved scrolls each of which is made of an aluminum alloy, one of the scrolls, being a fixed scroll (3), and is fixed and the other scroll, which is an orbiting scroll and moves eccentrically without rotating. Also included are anti-rotation means made of an aluminum alloy and configured to allow anti-rotation of the orbiting scroll. The compression device also includes one flat thrust bearing configured to axially contain the orbiting scroll and is made of aluminum alloys or grades of cast iron. The compression device also includes coatings for promoting friction between the fixed scroll, the orbiting scroll, the anti-rotation means and the flat thrust bearing.

Disclosed are a sealing structure and a scroll air compressor having the same. The sealing structure includes: an orbiting scroll including an orbiting scroll spiral tooth (11), the orbiting scroll spiral tooth (11) being provided with an orbiting scroll spiral tooth groove (12), an orbiting scroll wear-resistant sealing strip (30) being provided in the orbiting scroll spiral tooth groove (12); a stationary scroll including a stationary scroll spiral tooth (21) matched with the orbiting scroll spiral tooth (11), the stationary scroll spiral tooth (21) being provided with a stationary scroll spiral tooth groove (22), a stationary scroll wear-resistant sealing strip (40) is provided in the stationary scroll spiral tooth groove (22), the wear-resistant sealing strip (30) is divided into sections including a high-temperature and high-pressure section (30a) and a medium-temperature and medium-pressure section (30b). The sealing structure reduces costs of use and maintenance of the sealing strip; a buffer contact surface of the wear-resistant sealing strip (30) in contact with a scroll surface is flat, which improves performances of sealing and noise-reduction; a bottom surface of the wear-resistant sealing strip (30) is equipped with a sealing ring having a cross section in a shape of a circle or a circular tube, which improves the damping and buffering performances; thereby the performance of the air compressor is improved, and the use cost of the air compressor is also reduced.

In a stepped scroll compressor, inclined surfaces (28, 29) of which heights are gradually reduced toward stepped portions are formed in a range W of at least 2ρ to 3ρ (here, ρ denotes a turning radius of a turning scroll) at (1) any one or both of inner peripheral end portions of high top lands (14H, 15H) of both scrolls and inner peripheral end portions of low bottom lands (14J, 15J) of the opposite scrolls corresponding to the inner peripheral end portions and (2) any one or both of outer peripheral end portions of high bottom lands (14K, 15K) of both the scrolls and outer peripheral end portions of low top lands (14I, 15I) of the opposite scrolls corresponding to the outer peripheral end portions, on the stepped portions (14F, 15F and 14G, 15G) of the top and bottom lands.