Steering column

Core Structural Components

1. Main Force Transmission Components

Steering Shaft (Upper/Lower Shaft): Made of 40Cr alloy steel with quenching treatment (HRC 50–55), spline/cross shaft connection, torsional stiffness ≥100N·m/rad, radial runout ≤0.05mm, ensuring zero-backlash and zero-hysteresis torque transmission.

Universal Joint (Cross Shaft/Cage Type): Double universal joint structure, compensating for relative displacement and angular deviation between the cab and chassis (maximum included angle ≤30°), ensuring continuous and smooth steering action, compatible with BZZ steering gear input shaft connection.

Column Housing: High-strength steel/aluminum alloy integral molding, with built-in reinforcing ribs, protecting the internal shaft system, providing mounting reference and rigid support.

2. Adjustment and Locking Mechanism

Height/Tilt Adjustment: Manual/Electric stepless adjustment, adjustment range: Height **±50mm**, Tilt **±15°, unlocking force 15–30N**, locking torque ≥15N·m, adaptable to different driver seating positions.

Mechanical Locking/Electronic Steering Lock (ESCL): Integrated anti-theft locking solenoid valve (12VDC), automatically locks the steering shaft after engine shutdown to prevent vehicle theft.

3. Safety Energy Absorption Module

Collapseable Structure: Shear bolts + honeycomb energy-absorbing box + collapsible bracket, axial collapse of 50–150mm and collapse force of 500–800N during a collision, absorbing impact energy and reducing the risk of secondary injury to the driver.

Vibration Isolation Bushings: Double-layer rubber vibration isolation design, attenuates engine and road vibrations, steering wheel idle vibration acceleration ≤0.5m/s², improving handling comfort.

4. Electronic Integrated Components

Steering Angle Sensor: 0.1° resolution, real-time output of steering wheel angle/speed signals, compatible with vehicle electronic control systems (e.g., EPS, ESP), supports CAN bus communication.

Rotary Coupler (Swiss Spring): Connects steering wheel control switches (horn, cruise control, multimedia) to the vehicle wiring harness, ensuring continuous circuit conduction during steering.

Working Principle (in conjunction with BZZ Steering System)

Steering Operation: When the driver turns the steering wheel, the steering column precisely transmits torque and angle to the input shaft of the BZZ load-sensing steering system via a universal joint.

Signal Feedback: The steering angle sensor synchronously acquires the steering angle signal. The LS port of the BZZ steering system outputs a load pressure signal to the YXL priority valve, achieving priority flow distribution.

Non-Steering Condition: When the steering wheel returns to the center position, the steering shaft locking mechanism is ready. The YXL priority valve supplies all flow to the working system; the steering column consumes no additional energy.

Safety Protection: In the event of a collision, the steering column collapses along a preset path to absorb energy, while the BZZ steering system provides emergency steering capability, ensuring driving safety.

Core Performance Advantages

Precise and Backlash-Free Force Transmission: High-rigidity shaft system + precision universal joint, zero-lag steering response, high compatibility with BZZ steering systems, and excellent handling consistency.

Comfortable and User-Friendly Adjustment: Multi-dimensional adjustment + low unlocking force, adaptable to drivers of different sizes, reducing fatigue during long-term operation.

Safe and Reliable: Multi-stage collapsible energy absorption + anti-theft lock, passed 500,000 dynamic fatigue tests, adaptable to harsh working conditions and continuous operation.

High Integration: Integrates force transmission, adjustment, safety, and electronic signals into one unit, facilitating installation and reducing the overall vehicle piping and wiring layout.

Strong Adaptability: Standardized interface, directly compatible with the entire BZZ series of static/dynamic steering systems, and compatible with YXL-80/160/250 priority valve systems.

Key Technical Parameters (General for Engineering Vehicles)

Input Torque: ≤80 N·m

Torsive Stiffness: ≥100 N·m/rad

Adjustment Range: Height **±50 mm**, Tilt Angle **±15°**

Collapse: 50–150 mm

Operating Temperature: -40℃～85℃

Protection Rating: IP54

Compatible Steering Gear: BZZ Series Fully Hydraulic Load Sensing Steering Gear

Compatible Priority Valve: YXL Series Static/Dynamic Priority Valve

Typical Applications

Widely used in hydraulic steering systems of forklifts, loaders, bulldozers, tractors, combine harvesters, heavy trucks, construction machinery, and special-purpose vehicles. Especially suitable for medium and large-sized engineering and agricultural vehicles with stringent requirements for steering precision, handling comfort, and safety reliability.