What Are the Functions of an Elevator Traction Sheave?
In an elevator system, the traction sheave is one of the most essential components for both drive and safety.It connects the motor to the wire ropes (or steel belts) and uses friction to move the elevator car and counterweight up and down.Without the traction sheave, an elevator simply could not operate.
Today, the technical team from A-FLY Elevator & Escalator Parts Supplier explains the key functions and types of elevator traction sheaves and why they matter.
1. Core Functions of the Elevator Traction Sheave
The elevator traction sheave is a grooved metal wheel installed on the traction machine.
When the motor rotates, the sheave drives the wire rope (or steel belt) through friction, enabling the elevator car to ascend or descend smoothly.
Main functions include:
Power Transmission
The sheave converts the motor’s torque into traction force, driving the wire ropes and enabling vertical movement.
It acts as the “power core” of the elevator, directly influencing acceleration smoothness and operational efficiency.
Friction and Speed Control
The elevator relies on the friction between the sheave and the wire rope.
Too little friction can cause slippage, while too much increases wear.
Therefore, traction sheaves are made with special alloys or anti-slip grooves to maintain optimal friction.
Load Balancing and Safety
Positioned between the car and the counterweight, the sheave ensures that both sides remain balanced.
Its precision design and weight distribution guarantee smooth and safe operation, even at high speeds.
Vibration and Noise Reduction
High-quality sheaves are dynamically balanced to minimize vibration and noise, providing passengers with a more comfortable ride.
2. Main Types of Traction Sheaves
Based on material, structure, and application, traction sheaves can be classified as follows:
Cast Iron Sheave
The most common type—durable, wear-resistant, and ideal for low- to medium-speed elevators.
Steel Sheave
Higher strength and tensile capacity, suitable for heavy-duty or high-speed elevators.
Polyurethane-Coated Sheave
The surface is covered with a wear-resistant PU layer, which reduces rope wear and noise.
Commonly used in premium passenger or panoramic elevators.
Maintenance-Free Sheave
Made from high-performance alloy with specialized grooves, designed for long-term use without frequent adjustment or lubrication.
A-FLY’s elevator traction sheave series includes cast iron, steel, and PU-coated options, compatible with all major elevator brands and systems.
3. Maintenance and Replacement Recommendations
Although simple in structure, traction sheaves are subject to constant friction and mechanical stress.
Over time, they may develop groove wear, deformation, or imbalance.
Common issues include:
Slippage due to worn grooves
Reduced friction and unstable starts
Uneven wear between rope and groove causing abnormal noise
Maintenance tip:
Inspect the traction system every 12 months.
If the groove depth exceeds the wear limit or surface damage occurs, replace the sheave immediately.
A-FLY provides complete traction sheave + wire rope matching solutions to ensure long-lasting stability and reduced maintenance frequency.
4. A-FLY — Professional Elevator Traction System Parts Supplier
As a leading elevator & escalator parts supplier, A-FLY specializes in developing and providing core mechanical and control system components, including:
Elevator Wire Ropes & Steel Belts
Door Operator Systems & Control Boards
Escalator Drive Wheels & Guide Components
All A-FLY sheaves are manufactured with high-strength materials and precision machining, passing dynamic balance and wear-resistance tests to ensure reliable, long-term operation.
We support global shipping and OEM/ODM customization to meet diverse project needs.
5. Conclusion: The Power Core of Safe Operation
Though small, the traction sheave determines the elevator’s smoothness, stability, and safety.Choosing the right sheave not only extends the lifespan of your elevator system but also ensures a quieter, more comfortable ride.
Choose A-FLY — making every lift smoother, every ascent safer.
A-FLY — delivering high-quality elevator & escalator parts worldwide for reliable traction and long-lasting safety.
