Stator assembly, motor and heat pump unit

The invention provides a stator assembly, a motor and a heat pump unit, the stator assembly comprises a stator body and a rain-proof structure arranged on the outer surface of the stator body, the rain-proof structure is internally provided with a buffer cavity, and the cavity wall of the buffer cavity is provided with a lead channel for leading out a power line in the stator body. A wire outlet hole is formed in the bottom of the rainproof structure, the power line is in clearance fit with the wire outlet hole, and the power line is led out from the lead channel, the buffer cavity and the wire outlet hole in sequence. According to the invention, when the motor is in thermal stable operation, if the motor is rapidly cooled, the internal pressure of the motor is reduced and rainwater is sucked back at the wire outlet hole due to external rain, the rainwater sucked back can be temporarily gathered in the buffer cavity and cannot enter the motor because the buffer cavity is arranged in the rain-proof structure;