This article explores various types of drive wheels, including solid rubber drive wheels, polyurethane drive wheels (such as Vulkollan wheels), heavy-duty wheels, flanged wheels, and guide rollers. We highlight their applications in AGVs, forklifts, construction machinery, and transport systems, providing engineers, buyers, and maintenance technicians with essential insights for optimal selection and usage.
Drive wheels are the powered wheels that move a vehicle or machine by converting motor torque into motion. Unlike free-rolling swivel and fixed castors, drive wheels provide traction and forward movement across various surfaces. Their performance depends on key factors including friction (rolling resistance, slip, and grip), torque transmission, heat build-up, surface characteristics, and machine type. This knowledge article provides an in-depth exploration of these aspects. We also cover slope behaviour, surface tread variations, and compare materials such as solid rubber drive wheels and polyurethane drive wheels (including Vulkollan wheels), alongside specialised designs like flanged wheels and guide rollers.
Friction: Rolling Resistance, Slip, and Grip
Rolling resistance is the force opposing a wheel’s motion. Lower rolling resistance requires less energy to move the wheel, influenced by material, hardness, load, diameter, and surface. Harder tread materials like polyurethane typically offer lower rolling resistance than softer materials like rubber, which deform more and convert energy into heat. Larger wheels generally reduce resistance by bridging surface irregularities better.
Slip and grip are critical for effective torque transfer. Sufficient grip between the drive wheel and the ground prevents slippage. Solid rubber drive wheels often provide higher friction coefficients than polyurethane, offering superior traction on smooth or wet surfaces. Polyurethane wheels, although slightly less grippy, offer reduced rolling resistance and superior wear resistance on clean, flat floors.
Torque Transmission and Drive Force
Torque (rotational force) must be effectively transmitted from the motor to the drive wheels to propel the machine. Smaller wheels generate more tractive force for the same torque but rotate faster, requiring careful sizing to balance speed and power. Slip prevention depends on sufficient normal force on the drive wheel, often achieved by optimal weight distribution (e.g., battery placement near drive wheels).
High torque applications, such as electric forklifts, require heavy-duty drive wheels with reinforced cores and durable tread materials like polyurethane or rubber to prevent structural failure. Choosing the right drive wheel directly affects performance, acceleration, and wheel life.
Heat Build-up During Heavy or Prolonged Use
Repeated tread deformation generates internal heat through hysteresis. Prolonged or high-load operation can cause excessive heat build-up, leading to material softening, accelerated wear, or even tread separation. Polyurethane typically generates less heat than rubber but must still be monitored under heavy duty conditions.
Vulkollan drive wheels are engineered to handle higher dynamic loads and temperatures without premature failure. Proper wheel sizing, material choice, and operational practices (such as cooling intervals for AGVs) can help manage heat build-up effectively.
Surface Conditions and Floor Types
The operating surface significantly influences drive wheel selection. On smooth concrete floors, polyurethane drive wheels with smooth treads offer minimal resistance and maximum efficiency. Rough, uneven, or outdoor surfaces may require softer solid rubber drive wheels or profiled treads for better shock absorption and grip.
Special environments, such as cleanrooms, demand non-marking polyurethane wheels. Rail-bound systems benefit from flanged drive wheels for guided motion, often supported by guide rollers to manage lateral forces.
Machine Types: Specific Requirements
- AGVs (Automated Guided Vehicles): Require low-resistance, high-precision wheels like polyurethane or Vulkollan to maximise battery life and ensure accurate navigation.
- Warehouse Trucks: Electric pallet trucks and stackers favour polyurethane wheels for durability and floor protection; solid rubber may be used on uneven surfaces.
- Forklifts: Electric forklifts commonly use Vulkollan drive wheels for heavy loads and high torque; mixed-use forklifts may employ solid rubber for outdoor resilience.
- Construction Machinery: Heavy-duty vehicles like wheel loaders and dumpers use massive pneumatic or solid rubber drive wheels with aggressive tread patterns for rough terrain traction.
Incline Handling: Behaviour on Slopes
Drive wheels must generate sufficient torque and grip to ascend slopes and provide controlled descent. Proper load distribution ensures adequate pressure on the drive wheels. Material choice and tread design play key roles: softer compounds or profiled treads offer better climbing performance on slick surfaces, while descent demands stable, high-traction contact to avoid uncontrolled sliding.
Tread Surfaces and Profiles
Tread design significantly impacts traction and wear. Smooth treads maximise contact area and are ideal for clean, flat floors. However, in contaminated or wet environments, profiled treads help disperse liquids and debris, improving grip.
While profiled treads increase traction in adverse conditions, they may accelerate wear on rough floors and slightly increase rolling noise. Maintaining wheel condition—free from embedded debris and excessive wear—is essential for safe and efficient operation.
Conclusion
Drive wheels are essential for machine mobility and performance. Understanding factors such as friction, torque transmission, heat management, surface compatibility, machine-specific requirements, slope handling, and tread design enables optimal drive wheel selection. Whether choosing silent polyurethane drive wheels for an AGV, rugged solid rubber drive wheels for outdoor transport, or durable Vulkollan wheels for forklifts, selecting the right drive wheel enhances operational efficiency, safety, and durability. Specialised solutions like flanged wheels and guide rollers further expand possibilities for precise motion in guided systems.