Abstract: A heat exchanger includes a plurality of fins and a plurality of tubes that are inserted into the fins and that allow refrigerant to flow in the tubes. The tubes include first heat transfer tubes and second heat transfer tubes. Each of the first heat transfer tubes includes grooves formed in an inner surface of the first heat transfer tube, and has an inside diameter Da and a groove depth Ta. Each of the second heat transfer tubes has an inner surface smoothed, has an inside diameter Db, and is connected to an associated one of the first heat transfer tubes. Da?2×Ta?Db is satisfied.

Abstract: According to one embodiment, a first permanent magnet and a second permanent magnet are disposed in each magnetic pole of a rotor core. When angular coordinates of intersections of a flux line in a d-axial direction passing an outer end A1 of the first permanent magnet, a flux line in the d-axial direction passing through an inner end A2 of the first permanent magnet, a flux line in the d-axial direction passing an outer end B1 of the second permanent magnet, a flux line in the d-axial direction passing an inner end B2 of the second permanent magnet and a circumscribing circle of the rotor core are respectively defined as ?dA1, ?dA2, ?dB1 and ?dB2, the ?dA1, ?dA2, ?dB1 and ?dB2 satisfy a formula (?34/p<(?dB1-?dA1)<22/p, ?34/p<(?dB2??dA2)<22/p).

Abstract: A permanent magnet rotor includes: a rotor shaft; a rotor core having, in each magnetic pole, a first and second outer through holes to make a pair and a first and second inner through holes to make a pair; and a first and second outer magnets, a first and second inner magnets housed in these respectively. An outer opening angle ?a between the first outer through hole and the second outer through hole is larger than an inner opening angle ?b between the first inner through hole and the second inner through hole. An inter-inner through hole length between the first inner through hole and the second inner through hole is larger than that between the first outer through hole and the second outer through hole.

Abstract: According to one embodiment, a rotor includes a rotor core which includes magnetic poles, magnet holding slots for each of the magnetic poles, and permanent magnets arranged in the magnet holding slots, respectively. The magnet holding slot includes a magnet loading area, a magnetic cavity, and an opening which opens to the magnetic cavity and an outer circumference of the rotor core. The rotor core includes a protruding portion having an outer surface which extends to the opening continuously with the outer circumferential surface of the rotor core, an end surface which intersects the outer surface at angle 90±10° to face the opening, and an inner surface which intersects the end surface to form an edge of the magnetic cavity.

Abstract: According to one embodiment, a rotor includes a rotor core including magnetic poles arranged in a circumferential direction around a central axis, each magnetic pole including magnet holder slots each of which includes an opening end opened to an outer circumference of the rotor core, a first core portion between adjacent magnet holder slots, a second core portion between the magnet holder slots and the central axis, and a bridge connecting the first core portion and the second core portion, permanent magnets within the respective magnet holder slots, and a non-magnetic filling material filled into a cavity between the permanent magnet and the opening end in the magnet holder slot and joined to the permanent magnet and an inner wall of the magnet holder slot.

Abstract: According to one embodiment, a stator includes a stator core with slots, and multi-phase segment coils each including coil segments each including a first linear part and a second linear part arranged in different slots and a bridge part, the coil segment formed of a rectangular conductor. An innermost coil segment in the slot is structured with divided segments adhered together. Each divided segment includes a first linear part and a second linear part, and a bridge part, and is formed of a rectangular conductor cross-sectional area of which is smaller than the rectangular conductor of other coil segments. The bridge parts of the divided segments are arranged to cross each other in the radial direction.

Abstract: In a refrigeration and air-conditioning apparatus, an inner diameter of an upward-flow pipe is defined as an inner pipe diameter, where a spherical droplet of refrigerating machine oil with a diameter equal to the inner pipe diameter is defined as a spherical refrigerating machine oil droplet, and where a force received by the spherical refrigerating machine oil droplet from refrigerant in liquid form flowing upward through the upward-flow pipe is defined as a fluid force, the refrigerant in liquid form flows upward through the upward-flow pipe at such a speed that the fluid force is greater than a gravitational force applied to the spherical refrigerating machine oil droplet.

Abstract: An air-conditioning apparatus includes a refrigerant circuit that is formed of an outdoor unit and an indoor unit connected through indoor/outdoor connection pipes. The outdoor unit includes a compressor, an outdoor heat exchanger, and an expansion valve. The indoor unit includes an indoor heat exchanger. Combustible refrigerant is used as refrigerant flowing through the refrigerant circuit. The outdoor unit includes a refrigerant filling-dedicated connection port to fill the refrigerant and an evacuation-dedicated connection port to evacuate the refrigerant inside the refrigerant circuit. The refrigerant filling-dedicated connection port is provided inside a machine chamber that accommodates the compressor and the expansion valve, and the evacuation-dedicated connection port is provided outside the machine chamber.

Abstract: In an air conditioning apparatus, heat exchange is conducted between refrigerant passing through a first high-temperature-side flow path and refrigerant passing through a first low-temperature-side flow path of a cooler, and between refrigerant passing through a second high-temperature-side flow path and refrigerant passing through a second low-temperature-side flow path of the cooler. A switching device switches between first/second refrigerant circuits. In the first circuit, an inlet of the first high-temperature-side flow path is formed downstream of the first low-temperature-side flow path with respect to an outlet of the first high-temperature-side flow path, and in the second refrigerant circuit, an inlet of the second high-temperature-side flow path is formed downstream of the second low-temperature-side flow path with respect to an outlet of the second high-temperature-side flow path.

Abstract: An outdoor unit includes a casing including an air passage, an outdoor fan disposed in the air passage, a compressor disposed in the casing, an outdoor heat exchanger disposed in the casing and including fins and a heat transfer tube connected to the fins, a control board disposed in the casing and including a control unit that controls the compressor, and a heat sink disposed in the air passage in the casing and being in contact with the control board. The heat transfer tube of the outdoor heat exchanger includes a first region in which gas refrigerant or two-phase gas-liquid refrigerant flows when the outdoor heat exchanger is used as a condenser and a second region that is located downstream of the first region in a refrigerant flow direction and in which single-phase liquid refrigerant flows.

Abstract: According to one embodiment, a rotor includes a rotor core including magnetic poles arranged in a circumferential direction around a central axis, each magnetic pole including at least two magnet holding slots opposed to each other at intervals in the circumferential direction, a first core portion between the two magnet holding slots, a second core portion between the two magnet holding slots and the central axis, and a bridge connecting the first core portion and the second core portion, and permanent magnets each arranged in the magnet holding slot. The bridge includes first center bridges located between the two magnet holding slots and separated from each other in the circumferential direction, and a coupling element that connects the first center bridges to each other.

Abstract: A heat exchanger includes a plurality of fins and a plurality of tubes that are inserted into the fins and that allow refrigerant to flow in the tubes. The tubes include first heat transfer tubes and second heat transfer tubes. Each of the first heat transfer tubes includes grooves formed in an inner surface of the first heat transfer tube, and has an inside diameter Da and a groove depth Ta. Each of the second heat transfer tubes has an inner surface smoothed, has an inside diameter Db, and is connected to an associated one of the first heat transfer tubes. Da?2×Ta?Db is satisfied.

Abstract: A heat exchanger includes a plurality of plate-shaped fins disposed at intervals, and a plurality of heat transfer tubes disposed to be inserted into through holes of the fins in a direction perpendicular to the fins. In each of the fins, a starting hole is formed between adjacent through holes, and the starting hole serves as a start point of bending of the fins and has a vertex portion at a bending portion of each fin which is close to an edge thereof. In each of the fins, a cut is made to connect the other edge of the fin and a side of the starting hole which is located opposite to the vertex portion of the starting hole. The above each fin is bent at the vertex portion of the starting hole, by opening the cut from the starting hole.

Abstract: According to one embodiment, a first permanent magnet and a second permanent magnet are disposed in each magnetic pole of a rotor core. When angular coordinates of intersections of a flux line in a d-axial direction passing an outer end A1 of the first permanent magnet, a flux line in the d-axial direction passing through an inner end A2 of the first permanent magnet, a flux line in the d-axial direction passing an outer end B1 of the second permanent magnet, a flux line in the d-axial direction passing an inner end B2 of the second permanent magnet and a circumscribing circle of the rotor core are respectively defined as ?dA1, ?dA2, ?dB1 and ?dB2, the ?dA1, ?dA2, ?dB1 and ?dB2 satisfy a conditional formula (?34/p<(?dB1-?dA1)<22/p, ?34/p<(?dB2??dA2)<22/p).

Abstract: According to one embodiment, a rotor core of a rotor includes, in each magnetic pole, two embedding holes on sides of a d-axis, in which respective permanent magnets are loaded, respectively, and grooves formed in an outer circumferential surface in positions each including respective q-axes. When A represents a pole arc degree of the grooves along the outer circumferential surface, B represents a depth of the grooves, C represents a pole arc degree, and R represents a circumradius tangent to an outer circumference of the rotor core, each grooves is formed to satisfy relationships: 0.05<A<0.075 and 0.005<B/R<0.027.

Abstract: An air-conditioning apparatus includes a refrigerant circuit that is formed of an outdoor unit and an indoor unit connected through indoor/outdoor connection pipes. The outdoor unit includes a compressor, an outdoor heat exchanger, and an expansion valve. The indoor unit includes an indoor heat exchanger. Combustible refrigerant is used as refrigerant flowing through the refrigerant circuit. The outdoor unit includes a refrigerant filling-dedicated connection port to fill the refrigerant and an evacuation-dedicated connection port to evacuate the refrigerant inside the refrigerant circuit. The refrigerant filling-dedicated connection port is provided inside a machine chamber that accommodates the compressor and the expansion valve, and the evacuation-dedicated connection port is provided outside the machine chamber.

Abstract: In an axial flow fan according to the present invention, a plurality of blades rotate about a rotation axis of the blades to convey a fluid. In the axial flow fan, the plurality of blades each have a leading edge at a leading side in a rotational direction, a trailing edge at a trailing side in the rotational direction, and an outer peripheral edge connecting the leading edge and the trailing edge. The leading edge of one of the plurality of blades and the trailing edge of another blade adjacent to the leading edge of the blade in the rotational direction are connected by a plate-shaped connection portion. The plurality of blades each have at least one plate-shaped reinforcement rib extending from a periphery of the rotation axis toward the outer peripheral edge of the blade.

Abstract: In an indoor unit of an air-conditioning apparatus, an air inlet for room air is provided at a position lower than a height position of a drain pan. A partition plate is provided to partition a space below a height position of the drain pan in a housing. A pipe connecting portion connected to a refrigerant pipe of an outdoor unit is provided in one part of the partitioned space and a heat exchanger and a fan are placed in the other part of the partitioned space. At least one communicating path is formed in the partition plate to communicate the two parts of the partitioned space with each other. The indoor unit can include a controller for activating a fan when leakage of refrigerant is detected or for closing the communicating path when leakage of refrigerant is detected.

Abstract: Provided is an air-conditioning apparatus configured so that a decrease in a refrigeration capacity can be suppressed without increasing the amount of refrigerant with which a refrigerant circuit is filled and that refrigerant can be suitably stored during a pump down operation. The air-conditioning apparatus includes a first on-off valve provided at a pipe between an expansion valve and a use side heat exchanger, a bypass branching from a pipe between the expansion valve and the first on-off valve and connected to a pipe at a suction-side of a compressor, and a refrigerant storage unit configured to store the refrigerant having passed through the bypass. In a pump down operation in which the compressor operates with the first on-off valve being in a closed state, the refrigerant having flowed out from the heat source side heat exchanger flows into the bypass, and then, is stored in the refrigerant storage unit.

Abstract: An outdoor unit includes a casing including an air passage, an outdoor fan disposed in the air passage, a compressor disposed in the casing, an outdoor heat exchanger disposed in the casing and including fins and a heat transfer tube connected to the fins, a control board disposed in the casing and including a control unit that controls the compressor, and a heat sink disposed in the air passage in the casing and being in contact with the control board. The heat transfer tube of the outdoor heat exchanger includes a first region in which gas refrigerant or two-phase gas-liquid refrigerant flows when the outdoor heat exchanger is used as a condenser and a second region that is located downstream of the first region in a refrigerant flow direction and in which single-phase liquid refrigerant flows.