Tesla, Inc.
Passive air bleed for improved cooling systems

Abstract:

An electric vehicle drive unit includes an inverter, a gear box, an electric motor coupled to the inverter and to the gear box, a cooling jacket, and coupled to the gear box, a main coolant inlet, a coolant outlet, and an external passive air bleed device. The cooling jacket has a cooling chamber and surrounds at least a portion of the electric motor. The main coolant inlet couples to the cooling jacket. The coolant outlet is located at a lower portion of the gear box. The external passive air bleed device runs between an upper portion of the cooling jacket and the coolant outlet. The inverter may couple to a first side of the gear box and the electric motor may couple to a second side of the gear box such that the inverter and the electric motor reside on opposite sides of the gear box.