A stator assembly for a downhole-type well tool includes a stator housing including an internal chamber, an electric stator, a flow channel in the stator housing, and a heat exchanger. The electrical stator is disposed within the stator housing and in contact with the heat exchanger, the electrical stator to drive a rotor. The flow channel in the stator housing includes an inlet and an outlet, and the heat exchanger includes a first heat exchanger portion in contact with the electric stator in the internal chamber and a second heat exchanger portion at least partially disposed in the flow channel. The flow channel flows coolant fluid along the second heat exchanger portion to transmit heat across the heat exchanger from the electric stator to the coolant fluid.