Heat pump apparatus

A heat pump apparatus, comprising:

• a compressor;
• a condenser;
• an expansion mechanism;
• and
• an evaporator,
• the compressor, the condenser, the expansion mechanism, and the evaporator being configured to perform a refrigeration cycle,
• the heat pump apparatus being configured to perform heat transfer in the condenser or the evaporator,
• wherein the compressor includes
• a sealed container,
• a compression mechanism mounted inside the sealed container, and
• an electric motor configured to rotate and drive the compression mechanism,
• the compression mechanism being configured to compress refrigerant, and to be lubricated by a refrigerating machine oil,
• wherein the electric motor includes
• a stator fixed to the sealed container with a winding being wound around the stator through intermediation of an insulating material, and
• a rotator surrounded by the stator,
• wherein the insulating material includes a liquid crystal polymer having a main chain of a molecule obtained by ester bonding, the liquid crystal polymer being obtained by polycondensation of a total of two or more kinds of monomers, the monomers containing, as an essential component, p-hydroxybenzoic acid (PHB) as a monomer component having an ester bond and containing, as an additive component, one or more kinds of a following five kinds:
• 4,4′-biphenol (BP), hydroquinone (HQ), terephthalic acid (TPA), isophthalic acid (IPA), and 6-hydroxy-2-naphthoic acid (BON6), and
• wherein a saturated water amount of the refrigerating machine oil is 0.5% or more and 1% or less at 40 degrees Celsius and a relative humidity of 80%.