Oil pump dual-motor drive device with electric-hydraulic power steering function

Abstract

The invention provides an oil pump dual-motor drive device with an electric-hydraulic power steering function. A main drive motor (brushless DC motor) directly drives an oil pump to rotate, and a secondary drive motor (brush DC motor) works in due time. The rotation speed, torque and other working states of the double motors can be adjusted in the manner that an electronic control unit collects steering wheel rotation speed signals, car speed signals, current signals of the double motors and the like, and dynamic coupling of the main drive motor and the secondary drive motor can be achieved through a synchronous belt and a belt wheel by means of a one-way clutch. The double motors, a power transmission and coupling mechanism, the steering oil pump and a steering controller are of an integrated structure, and the integrated design of the dual-motor electric oil pump can be achieved. According to the oil pump dual-motor drive device, a dual-motor distributed type control scheme is adopted, the degree of freedom of system control is improved; low-speed steering is convenient, and high-speed road feel is good; the motors work at high speed only when power assistance is needed, and rotate at low speed on the condition of no steering, and the energy consumption of a system is low; when one motor breaks down, the other motor can still provide a certain steering power, so safety of the system is improved.

Description

Technical field [0001] The invention belongs to the technical field of automobile parts, and in particular relates to an oil pump dual-motor drive device of an electric hydraulic power steering system for a vehicle. Background technique [0002] With the rapid development of new energy vehicle technologies including pure electric vehicles, hybrid vehicles, and fuel cell vehicles, the bottlenecks in the industrialization of electric vehicles such as power battery life, cost, and driving range have not been completely resolved. Electric vehicle steering, braking, air conditioning and other electrified components are designed and controlled for energy saving, so as to reduce the power consumption of the power battery by each component, increase the mileage of the electric vehicle, and improve the service life of the power battery. [0003] Although gasoline-electric hybrid vehicles are also equipped with engines, in order to reduce energy consumption, such vehicles have engine ...

AI Technical Summary

Problems solved by technology

[0006] ①The steering oil pump of an electric vehicle is driven by a single AC asynchronous motor, and the electric energy of the power battery must undergo multiple energy conversions (battery—DC / AC inverter—AC asynchronous motor—oil pump) before it can be converted into hydraulic energy for steering assist. The efficiency is lower than 70%, and the energy loss is large;

[0007] ②When parking in place and driving straight at high speed, power steering is not needed, but the steering oil pump of the electric vehicle keeps working after the car is started. Valuable electric energy wastes about 60% of the energy consumption of the hydraulic power steering system;

[0008] ③The steering oil pump used in electric vehicles is still the steering oil pump of traditional vehicles. After the oil pump speed is above 600r / min-800r / min, the flow characteristics of the oil pump remain basically unchanged. Even if the control system introduces the vehicle speed signal, the flow rate that changes with the vehicle speed cannot be obtained characteristics to improve the handling stability of the car at high speed;

[0009] ④When the vehicle fails and the high-voltage power is cut off, the steering oil pump stops working, and the hydraulic power steering fails. Therefore, the high-voltage power cut has an impact on the steering power, and there are potential safety hazards

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