Electro-Hydraulic Transmission Start-Up for Low-Speed Motor Overheating

The patent applies preliminary action by establishing a minimum rotation speed threshold before the electric motor is engaged. The controller monitors the rotation speed of the electric motor and prevents engagement below this threshold, thereby avoiding the harmful condition of low-speed high-torque operation that causes overheating. This proactive control ensures the motor operates in an efficient temperature range while still meeting torque requirements through alternative means.

The patent employs multi-functionality by integrating both an electric motor and a hydraulic pump within the same drive system. The hydraulic pump serves as a complementary power source that can deliver high torque when the electric motor operates at higher speeds for efficiency. The controller coordinates both power sources, allowing the system to achieve both motor efficiency and adequate torque delivery by distributing the load between the two components based on their optimal operating ranges.

The patent applies periodic action by implementing a control strategy that selectively engages and disengages the hydraulic motor based on real-time operating conditions. The controller monitors parameters such as vehicle speed, load requirements, and temperature, and only activates the hydraulic assistance when genuinely needed. This intermittent operation pattern maintains vehicle performance during critical moments while minimizing overall energy consumption and heat generation compared to continuous engagement.