A rotary compressor may include a rotary shaft; a plurality of plates that supports the rotary shaft; a cylinder provided between the plurality of plates to define a compression space, and provided with a vane slot; a roller slidably coupled to the rotary shaft inside of the cylinder, and having a hinge groove on an outer circumferential surface thereof; and a vane, a first end which is slidably coupled to the vane slot of the cylinder, and a second end of which is rotatably coupled to the hinge groove of the roller. At least one of axial end surfaces of the roller facing the plurality of plates is provided with a wear avoiding portion having a predetermined depth. Contact surfaces between the roller and the plate may be suppressed from being in close contact with each other to suppress the roller or the plate from being damaged or a performance of the compressor due to friction loss from being deteriorated, thereby improving reliability and performance of the compressor.

A vane pump includes: a casing forming a pump chamber therein; a rotor arranged inside the casing to rotate eccentrically with respect to the casing; and a plurality of vanes configured to rotate with the rotor and slide on an inner side surface of the casing. At least one of Formula (1): l≤(b/a)×k and Formula (2): l≤(c/a)×j is satisfied, where “a” represents a height of the pump chamber, “b” represents a height of the rotor, “c” represents a height of the vane in a rotation axis direction of the rotor, and where “l” represents a linear expansion coefficient of the casing in the rotation axis direction, “k” represents a linear expansion coefficient of the rotor in the rotation axis direction, and “j” represents a linear expansion coefficient of the vane in the rotation axis direction.

A vane pump includes: a casing forming a pump chamber therein; a rotor arranged inside the casing to rotate eccentrically with respect to the casing; and a plurality of vanes configured to rotate with the rotor and slide on an inner side surface of the casing. At least one of Formula (1): l≤(b/a)×k and Formula (2): l≤(c/a)×j is satisfied, where “a” represents a height of the pump chamber, “b” represents a height of the rotor, “c” represents a height of the vane in a rotation axis direction of the rotor, and where “l” represents a linear expansion coefficient of the casing in the rotation axis direction, “k” represents a linear expansion coefficient of the rotor in the rotation axis direction, and “j” represents a linear expansion coefficient of the vane in the rotation axis direction.

A screw compressor includes a screw rotor including a rotor shaft, a radial bearing, a thrust plate, a balance mechanism, which is a slide bearing, a lubrication oil supply flow passage for supplying a lubrication oil, and a working fluid supply flow passage for supplying a working fluid for pressing the balance mechanism toward the thrust plate so that a reverse thrust load acts on the thrust plate.

A scroll compressor is provided that may include an orbiting scroll having an orbiting wrap, and which performs an orbiting motion; and a fixed scroll having a fixed wrap to form a compression chamber including a suction chamber, an intermediate pressure chamber, and a discharge chamber, by being engaged with the orbiting wrap. A wrap thickness of the fixed wrap may be greater than a wrap thickness of the orbiting wrap within a range which forms the suction chamber. With such a configuration, even if the fixed scroll or the orbiting scroll is thermally-expanded, a transformation of the fixed wrap at a suction side may be prevented. This may prevent a gap between the fixed wrap and the orbiting wrap at an opposite side to the suction side, thereby enhancing compression efficiency.

A rotary compressor may include a rotary shaft; a plurality of plates that supports the rotary shaft; a cylinder provided between the plurality of plates to define a compression space, and provided with a vane slot; a roller slidably coupled to the rotary shaft inside of the cylinder, and having a hinge groove on an outer circumferential surface of the roller; and a vane, a first end of which is slidably coupled to the vane slot of the cylinder, and a second end of which is rotatably coupled to the hinge groove of the roller. When an imaginary line passing through an axial center of the rotary shaft and a hinge center of the vane is a first center line, and a radial center line of the vane slot passing through the hinge center of the vane is a second center line, the vane slot is disposed such that the second center line is intersected by a predetermined tilting angle with respect to the first center line. With this structure, a roller reaction force is canceled to suppress an increase in side pressure or side wear between a vane and a vane slot into which the vane is inserted.

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. The at least one vane may include a pin that extends in an axial direction, and at least one of the first bearing and the second bearing may include a rail groove into which the pin may be inserted.

The invention relates to a dual-spindle helical spindle pump with a single-entry design, comprising a pump housing (11) which has a pump portion (12), a bearing portion (13) and a gear portion (14) with a gear chamber, wherein the bearing portion (13) and the pump portion (12) are designed separately from one another, comprising a feed housing part (50) as a component of the pump portion (12) in which two feed screws (17, 18) are provided, said feed screws having flanks (46) and being arranged on shafts (15, 16) in a feed space (51), wherein the shafts (15, 16) are mounted in the bearing portion (13) (external bearing system) and extend into the gear portion (14), and wherein the feed housing part (50) has at least one feed portion (52) with an inner wall (58) which faces the outer face (59) of the feed screws (17, 18). The invention provides that at least one separating element (60), which is in contact with at least one portion of the outer face (59) of the feed screws (17, 18), is between the inner wall (58) of the feed portion (52) and the outer face (59) of the feed screws (17, 18), at least in the region (57) of the feed screws (17, 18), and in that the separating element (60) is floatingly mounted in the feed housing part (50) relative to the inner wall (58) of the feed portion (52).

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. The at least one vane may include a pin that extends in an axial direction, and at least one of the first bearing and the second bearing may include a rail groove into which the pin may be inserted.

A rotary compressor may include a rotary shaft; a plurality of plates that supports the rotary shaft; a cylinder provided between the plurality of plates to define a compression space, and provided with a vane slot; a roller slidably coupled to the rotary shaft inside of the cylinder, and having a hinge groove on an outer circumferential surface thereof; and a vane, a first end of which is slidably coupled to the vane slot of the cylinder, and a second end of which is rotatably coupled to the hinge groove of the roller. At least one of first and second axial end surfaces of the roller facing the plurality of plates is provided with a dimple portion having a predetermined depth. With this structure, contact surfaces between the roller and the plate may be prevented from being in close contact with each other.