What Type of Pump is a Car Power Steering Pump?
3 Answers
Car power steering pumps are part of mechanical hydraulic power steering systems, electro-hydraulic power steering systems, or electric power steering systems. The power steering pump can reduce the driver's effort in turning the steering wheel and also plays a role in the safety and fuel efficiency of the vehicle. Mechanical Hydraulic Power Steering System: This power steering system is generally composed of components such as a hydraulic pump, oil pipes, pressure and flow control valve body, V-type drive belt, and oil reservoir. Electro-Hydraulic Power Steering System: The main components of the electro-hydraulic power steering system include an oil reservoir, power steering control unit, electric pump, steering gear, and power steering sensor, with the power steering control unit and electric pump forming an integrated structure. Its working principle is that the electro-hydraulic power steering system overcomes the shortcomings of traditional hydraulic power steering systems. The hydraulic pump it uses is no longer directly driven by the engine belt but instead employs an electric pump, with all its operating states calculated by the electronic control unit based on signals such as vehicle speed and steering angle to achieve the most optimal state. Electric Power Steering System (EPS): The full English name of the electric power steering system is Electronic Power Steering, abbreviated as EPS. It utilizes the power generated by an electric motor to assist the driver in steering. Main working principle: When the car is turning, the torque (steering) sensor "feels" the steering wheel's torque and intended direction of rotation. These signals are sent via the data bus to the electronic control unit, which then issues action commands to the motor controller based on data signals such as the transmitted torque and intended direction. The motor then outputs the corresponding amount of torque as needed, thereby providing power steering assistance.
The automotive power steering pump is primarily a type of hydraulic pump, with vane pumps or gear pumps being particularly common. Having driven for many years, I've noticed it's located next to the engine, driven by the engine's rotation to pressurize the steering fluid, which then powers the assistance system, making the steering wheel lighter. Modern vehicles mostly use vane pumps due to their simple structure, high efficiency, and reliability. Some older or economy cars use gear pumps, which are cheaper but noisier. The design of this pump is aimed at providing stable pressure output; otherwise, turning the wheel would tire your arms. During maintenance checks, I always pay attention to the fluid level and signs of leakage, as leaks or aging in the power steering pump can lead to unusual noises or complete failure. If the power assistance fails, steering becomes heavy, making high-speed driving dangerous, so regular maintenance is crucial.
I've experienced the importance of the power steering pump multiple times. When it's working, even a slight turn of the steering wheel makes the car change direction effortlessly. Most power steering pumps in cars are hydraulic types, such as vane pumps or gear pumps. The engine drives them to rotate via a belt, compressing the steering fluid to generate pressure and assist with steering. Once the pump fails, you'll feel the steering become stiff, and driving in congested city traffic for long periods can make your arms sore. Common failures include oil leaks due to aging seals or reduced pressure caused by vane wear. I recommend checking the fluid condition and the pump's operating sound every two years. Cars with vane pumps tend to be quieter, while gear pumps are more economical but less durable. Nowadays, many cars are switching to electric power steering systems. When power assist fails, it's best to drive at low speed and find a repair shop.
