Astra G
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Function (EHPS) The EHPS system is an electro-hydraulic steering system that operates independently of the engine. With the exception of the electro-hydraulic supply unit, all components of the EHPS are the same as those in conventional power steering systems. A brushless electric motor (4) with minimal idle current consumption and a high degree of efficiency powers the external gear supply pump (3). A resonator (2) connected to the pump unit and specially adapted high pressure lines are used to prevent any pressure pulsation. The electro-hydraulic supply unit is connected to the steering gear by a pressure line and a return line. The EHPS has integrated control electronics (6) in the motor housing (5). The control electronics are divided into motor management and control management. The motor management regulates the voltage supply for the electric motor, the rotational speed and monitors the temperature. The system management governs the logic for the switchover between the "standby" mode with reduced electric motor rotational speed and the "operational" mode, when the electro-hydraulic power steering operates according to its defined steering assistance characteristics. The switchover between the "standby" mode and the "operational" mode is dependent on the power consumption of the electric motor, which varies according to the system pressure.
5.1.1 Function (EHPS) (continued) |
