A scroll compressor in which a winding angle of a first lap is larger than a winding angle of a second lap, a plurality of compression chambers are formed between the first lap and the second lap, the compression chambers include at least a first compression chamber and a second compression chamber that has a volume smaller than the first compression chamber, a first base plate is provided with a first injection port 16a for injection of refrigerant into the first compression chamber and a second injection port for injection of refrigerant into the second compression chamber, and an injection flow rate of the second injection port is higher than an injection flow rate of the first injection port.

An insulating material that tends not to hydrolyze is used to thereby provide a heat pump apparatus having long-term reliability. An electric motor of a compressor is fixed to a sealed container and includes a stator around which a winding wire is wound through intermediation of an insulating material, and a rotor surrounded by the stator. The insulating material is a wholly aromatic liquid crystal polyester (LCP) having a molecular main chain constituted by a monomer including p-hydroxybenzoic acid (PHB) as an essential monomer and a monomer solely including benzene-ring as another monomer via an ester bond. The refrigerating machine oil has a saturated water content of 2% or less at 40 degrees C., a relative humidity of 80%, for 24 Hr. To suppress the explosive decomposition reaction of ethylene-based fluorohydrocarbon, a flame retardant is used to generate chemical species that complement active radicals that cause the decomposition reaction.

An end of each of slits of a rotor on a magnet insertion hole side has a triangular shape. A slit inner-side line of each of the slits includes an apex and a pair of side ends. An interval between each of the pair of side ends and the magnet insertion hole is larger than an interval between the apex and the magnet insertion hole, and an interval between the apex and the magnet insertion hole is larger than a plate thickness of each of steel plates forming a rotor core.

A fluid compressor includes a closed container having an inlet, a compression mechanism including a compression chamber in which fluid flowing into the closed container through the inlet is compressed, a discharge port through which the fluid compressed in the compression chamber is allowed to flow, a discharge valve opening and closing the discharge port, and a valve retainer limiting an amount of lift of the discharge valve. The discharge valve includes a curved portion whose shape is defined by one or more curvatures. When the discharge port is closed by the discharge valve, the valve retainer and the discharge valve are spaced apart from each other.

Provided is an interior permanent magnet motor, including: a rotor including a plurality of permanent magnets; and a stator. The rotor further includes a rotor core. The rotor core has a plurality of magnet insertion holes. A plurality of slits are formed in a region of the rotor core, which is located on a radially outer side of the magnet insertion holes. At least two of the slits are formed so that a core region sandwiched between the two slits has a portion increased toward the radially outer side.