In the field of heavy-duty logistics automation, 120-ton AGVs are pushing the engineering limits of wheeled mobile robots. At this load level, every additional ton of payload capacity and every improvement in reliability requires deep integration between the drive wheel system, suspension, shock absorption, and chassis structure.

Based on real-world engineering requirements, this article focuses on one key question: why the Yikong TEC550 heavy-duty differential drive wheel is a strong candidate for the core drive unit of a 120-ton AGV, and how it can work together with the chassis suspension and auxiliary load-bearing system.

1. Real Requirements for Drive Wheel Systems on 120-Ton AGVs

Many solutions appear reasonable on paper, but their limitations often become apparent only after the AGV enters actual factory operation.

For a 120-ton AGV, the drive wheel system needs to meet five major requirements.

Single-wheel-unit load capacity determines chassis layout flexibility.

Chassis space is limited, and the number of drive wheel units cannot be increased indefinitely. If each drive wheel unit can only carry 10 or 15 tons, a 120-ton AGV may require eight or more drive units. This significantly increases chassis complexity, control difficulty, and overall cost.

A higher load capacity per drive wheel unit provides greater freedom in chassis design and layout.

The drive wheels must deliver stable torque under heavy vertical loads.

During starting and climbing, a heavy-duty AGV must generate substantial driving torque while the drive wheels are subjected to extremely high vertical loads.

The gears, bearings, wheel structure, and other internal components must withstand combined radial and torsional loads. Standard industrial casters and light-duty AGV drive wheels are not designed for these conditions.

The drive system should provide differential steering capability.

Four differential drive wheel units are one of the established drive configurations for heavy-duty AGVs. This configuration does not require a separate steering mechanism. Instead, steering is achieved through the speed difference between the left and right drive wheels.

However, each drive wheel must maintain accurate speed control, sufficient lateral stiffness, and reliable traction under heavy loads.

Vertical adjustment capability is highly desirable.

A 120-ton AGV may need to compensate for height differences during docking, unloaded and loaded operation, and uneven wheel loading.

If the drive wheel does not provide hydraulic lifting or vertical adjustment, an additional suspension or lifting mechanism may have to be installed between the chassis and the drive wheel. This increases both structural complexity and vertical space requirements.

Long-term reliability directly affects maintenance costs.

When a heavy-duty AGV stops unexpectedly, the resulting production downtime can be much more costly than the equipment itself.

Bearing service life, gearbox sealing, wheel wear resistance, and overall structural durability directly affect maintenance intervals, failure rates, and spare-parts consumption.

These five factors provide a practical benchmark for selecting drive wheels for heavy-duty AGVs. The Yikong TEC550 is designed around these requirements and provides several advantages for high-load applications.

2. Key Parameters and Engineering Value of the Yikong TEC550

The TEC550 is a heavy-duty differential drive wheel developed by Yikong for heavy-load AGV applications. It has a rated load capacity of 27 tons per drive wheel unit.

This high load capacity allows the TEC550 to provide a high load density within the drive system, making it suitable for demanding heavy-duty AGV chassis configurations.

What Does a 27-Ton Load Capacity per Unit Mean?

For a 120-ton AGV, four TEC550 drive wheel units provide a combined static rated load capacity of 108 tons.

When an appropriate operating load factor is considered, four TEC550 units can be used to carry approximately 86 to 97 tons of the actual vehicle load, with the remaining load distributed through a small number of auxiliary load-bearing wheels.

This means a practical 120-ton AGV chassis can be configured with:

• 4 sets of TEC550 differential drive wheels
• 4 to 6 auxiliary load-bearing wheels
• A mechanical suspension system
• An integrated hydraulic vertical adjustment system

This configuration avoids the need for eight or ten independent drive units and can significantly simplify the chassis structure and motion-control system.

The direct benefit of high load density is a more compact chassis, fewer drive units, reduced control complexity, and potentially lower system cost.

Integrated Hydraulic Lifting and Vertical Adjustment

The TEC550 integrates a hydraulic lifting mechanism that provides vertical adjustment between the drive wheel and the vehicle chassis.

It is important to clarify that this hydraulic mechanism is used for drive-wheel suspension and height adjustment, rather than material lifting.

Material lifting is handled by an independent lifting platform or tooling installed on the vehicle chassis. The hydraulic mechanism integrated into the TEC550 controls the relative position between the drive wheel and the chassis.

This provides several engineering benefits.

Improved docking accuracy

When a 120-ton AGV docks with a conveyor or workstation, the vehicle height may need to be controlled within a millimeter-level range.

The hydraulic adjustment function of the TEC550 can provide fine vertical adjustment without requiring an additional complex lifting structure on the chassis.

Compensation between unloaded and loaded conditions

Vehicle height can change significantly between unloaded and fully loaded conditions.

A mechanical spring alone cannot maintain the same chassis height under both conditions. Hydraulic adjustment can compensate for these changes and help maintain a consistent docking height.

Active wheel-load balancing

If the load distribution causes insufficient contact pressure on one drive wheel, hydraulic adjustment can modify the position of the corresponding wheel unit and redistribute the load.

This can help reduce traction loss, wheel slip, and uneven loading.

Simplified chassis suspension design

With vertical adjustment integrated into the drive wheel, the mechanical suspension system on the chassis can focus primarily on absorbing high-frequency shocks and maintaining wheel contact.

This creates a clearer division of functions between the mechanical suspension and hydraulic adjustment system.

Reliability Design for Heavy-Duty Applications

A 27-ton load capacity per drive wheel unit cannot be achieved simply by making the structure larger and thicker.

The TEC550 is designed specifically for heavy-duty AGV applications, including the selection of bearings, gearbox sealing, wheel materials, and hydraulic integration.

The drive wheel is designed to operate under high wheel loads, frequent starts and stops, and differential steering conditions.

The wear life of the wheel and maintenance requirements of the gearbox are evaluated according to heavy-duty operating conditions rather than light-duty AGV standards.

This is one reason why a high-capacity drive wheel unit can be preferable to simply increasing the number of medium-capacity drive units.

A system with fewer critical drive units can reduce the number of potential failure points and simplify maintenance and troubleshooting.

3. 120-Ton AGV Chassis Architecture: TEC550 + Auxiliary Wheels + Mechanical Suspension

Using only four TEC550 units to support the entire 120-ton vehicle is not recommended.

As discussed above, four TEC550 units provide a combined static rated capacity of 108 tons. Under dynamic loading, uneven load distribution, and impact conditions, relying on these four drive units alone would leave insufficient load margin.

A more practical system architecture is therefore:

TEC550 drive wheels for traction and major load support + auxiliary wheels for additional load distribution + mechanical suspension for shock absorption and wheel contact.

Recommended Chassis Configuration

Why Is Mechanical Suspension Essential?

Even though the TEC550 provides hydraulic vertical adjustment, mechanical suspension remains an important part of a 120-ton AGV chassis.

The reason is straightforward: hydraulic adjustment cannot replace a mechanical spring and damping system for continuous high-frequency impact absorption.

When the AGV passes over floor joints, steel-plate transitions, or other uneven surfaces, the drive wheels need to respond rapidly to changes in the road surface.

A mechanical suspension system provides passive response without requiring active control commands. This makes it particularly suitable for absorbing frequent impacts during vehicle operation.

The two systems therefore serve different purposes:

Mechanical suspension: handles high-frequency impacts and maintains wheel contact during driving.

TEC550 hydraulic adjustment: handles low-speed docking, chassis height compensation, and load distribution adjustment.

For 120-ton AGVs, articulated swing-arm and four-link suspension designs are generally preferable.

A vertical guide-post suspension may be more susceptible to sticking or uneven loading under extremely high loads and is therefore less suitable as the primary suspension structure for heavy-duty drive wheels.

Comparison of Mechanical Suspension Structures

4. Operating Conditions Where the TEC550 Is Most Suitable

Based on the above analysis, the TEC550 can provide particular value in the following heavy-duty AGV applications.

Heavy steel plate and foundry operations

Factory floors may contain joints or steps exceeding 5 mm. Combined with an articulated swing-arm suspension, the TEC550 can maintain wheel contact and provide sufficient wheel floating travel to reduce traction loss.

Heavy-load docking stations

When a 120-ton AGV needs to dock precisely with a conveyor or workstation, the hydraulic adjustment function of the TEC550 can provide fine vertical height adjustment and reduce the need for a separate chassis lifting system.

Frequent unloaded and loaded operation

Large differences in vehicle load can result in significant changes in chassis height. Hydraulic compensation can help maintain a consistent chassis height while the mechanical suspension handles impact absorption.

Space-constrained chassis designs

When vertical chassis space is limited and the design cannot accommodate a large number of drive units, the TEC550's 27-ton rated load capacity per unit allows a higher load capacity to be achieved with fewer drive units.

5. Engineering Conclusion for the TEC550

Selecting a drive wheel system for a 120-ton heavy-duty AGV is essentially a decision based on load density, system integration, and long-term reliability.

With its 27-ton rated load capacity per drive wheel unit, integrated hydraulic vertical adjustment, and heavy-duty design, the Yikong TEC550 provides a strong engineering option for high-load AGV chassis applications.

For heavy-duty AGV developers evaluating a 120-ton chassis platform, the TEC550 is worth considering as an early-stage evaluation unit because:

1. It can support a high-load chassis architecture with a relatively small number of drive units, helping simplify the chassis and motion-control system.
2. Its integrated hydraulic adjustment function can reduce the need for additional vertical adjustment mechanisms in the chassis suspension.
3. Its design is focused on real heavy-duty operating conditions, including high wheel loads, frequent starts and stops, differential steering, and long-term mechanical durability.

For 120-ton AGVs, the chassis architecture is where the TEC550 can demonstrate its greatest value.

When the drive wheel system is selected correctly, the mechanical suspension, auxiliary wheels, and hydraulic adjustment system can be designed with clearer and more independent functions, resulting in a more integrated and maintainable heavy-duty AGV platform.