If you are in the process of screening elevators for your building, then you should have heard of traction elevators. Traction refers to the way the elevator is driven, where a winch generates the power and a steel belt or wire rope pulls the elevator car to run. Compared with screw and hydraulic elevators, traction elevators are the most common, the most widely used, and the most popular type of elevator, which is the most popular in the market.

Nevertheless, in the face of a wide range of elevator products on the market, you may still find it difficult, as each elevator manufacturer presents its brand side of each argument, so you do not know how to choose. In this article, we will bring you a comprehensive understanding of the traction elevator, all the information, so that you have a clearer perception of the traction elevator.

What Is a Traction Elevator?

The core principle of a traction elevator is to drive the traction machine through the electric motor and transfer the power to the wire rope, so as to make the elevator car rise or fall.

Generally, traction elevators are equipped with counterweights to balance the weight, which reduces the burden on the electric motor, thus making traction elevators more energy-efficient than other types of elevators.

The design of a traction elevator is very suitable for medium and high-rise buildings, especially those over 10 floors. Compared with hydraulic elevators, traction elevators are faster, can carry more weight, and operate stably.

Also, the machine room of a traction elevator is usually located at the top of the building, which is a space-saving, quieter, and more efficient design. This makes traction elevators the preferred choice of many contractors, consultants, building owners, and property managers.

Structure And Working Principle Of Traction Elevator

Structure Of a Traction Elevator

Before we look at how a traction elevator works, let’s take a look at the structure of a traction elevator.

There are two common types of traction elevator structures: the gantry traction elevator and the backpack traction elevator. Below are the drawings and characteristics of these two types of elevator structures.

Gantry Traction Elevator
Gantry traction elevator structures are typically used in buildings that require greater load capacity and stability.

Its core feature is the use of a fixed metal frame structure, or gantry, made of high-strength materials, such as steel, to support the entire elevator’s components to ensure the elevator’s stability and safety.

Gantry Traction Elevator System Of Structure Includes:

• Traction Machine: Located at the top or bottom of the gantry, it is responsible for driving the steel ropes to drive the car and counterweight up and down.

• Ropes and Cables: Driven by the traction sheave of the traction machine, connecting the car and counterweight to ensure up and down movement.

• Guide Rail System: The guide rails of the elevator are usually installed on the two sides or four corners of the gantry to ensure that the car stays smooth during the lifting and lowering process.

• Counterweight System: The counterweight is usually located on the other side of the elevator to reduce the burden of the traction machine by balancing the weight of the car.

The design advantage of a gantry traction elevator is its strong structure and stability, which is suitable for places requiring large loads and long-term operation.

Backpack-type Traction Elevator
The backpack traction elevator is a more compact elevator design in which the traction machine and other mechanical components of the elevator are usually mounted on top or behind the top of the car, just like a backpack.

This structure effectively reduces the area occupied by the equipment and is more space-efficient, making it ideal for shopping malls or places with space constraints.

Key Features Of Backpack Elevators Include:

• Compact Design: Since the traction machine is installed at the back of the car, it saves space by avoiding the requirement for a large machine room for traditional elevators.

• Simplified Installation: This design allows for more flexible installation of the elevator, making it suitable for old buildings or remodeling projects where the elevator can be installed in a limited space.

• Safety and Stability: Although the backpack design is compact, it is also equipped with advanced safety devices, such as a speed limiter and door locking system, to ensure the safety and stability of the elevator.

Working Principle Of Traction Elevator

The core working principle of a traction elevator is to drive the traction machine by an electric motor and pull the car upward or downward by wire rope or steel cable. The power of the electric motor is transferred to the traction sheave through the reducer to push the wire rope to connect with the car and complete the vertical movement. A counterweight block is connected to the other end of the elevator, which ensures the balance of the elevator and reduces the burden on the motor.

Key Components Of a Traction Elevator

The traction elevator consists of several core components, each of which has its own unique role and works together to ensure the smooth operation of the elevator:

• Electric Motor: Provides power to propel the elevator’s movement. The motor is usually used in conjunction with a speed reducer to reduce the speed and ensure smooth operation of the elevator.

• Traction Machine: The traction machine is one of the core components of the traction elevator, which controls the movement of the wire rope by driving the traction sheave to drive the car up and down.

• Wire Rope: The wire rope transmits power to the car through friction, which is an important transmission part of the traction elevator.

• Traction Sheave: The traction sheave is used to drive the movement of the wire rope, which is the key part of the traction elevator drive system.

• Counterweight: A counterweight is used to balance the weight of the elevator car, reduce the burden of the motor, and improve the energy efficiency of the elevator.

• Guide Rail: The guide rail ensures the stable operation of the elevator car in the shaft and prevents the car from tilting or shifting.

Working in tandem, these components are the key to an efficient and smooth traction elevator.

Safety Features Of Traction Elevators

Traction elevators transport a large number of passengers every day, so ensuring safety is a crucial point. Modern traction elevators are generally equipped with multiple safety systems to ensure the safety of passengers. Take the BDFUJI elevator as an example, it is equipped with its traction elevator:

• Overload Protection: The traction elevator has a built-in load detection system. When the elevator is overloaded, the system will automatically stop running to prevent damage to the elevator equipment.

• Counterweight Safety System: The counterweight system ensures that the elevator car can be balanced under any circumstances, effectively avoiding elevator failure caused by gravity imbalance.

• Power Interruption Protection: Modern traction elevators are usually equipped with a backup power system. When a power interruption occurs, the elevator will automatically stop at the nearest floor to ensure that passengers can leave safely.

• Fall Protection: Elevators are equipped with a fall protection mechanism that prevents the elevator car from falling rapidly through the emergency braking system, even in extreme situations.

These safety protection designs make traction elevators more widely used in high-rise buildings.

Advantages And Disadvantages Of Traction Elevator

What Are The Advantages Of a Traction Elevator?

• High Performance: Traction elevators can transmit power efficiently through the transmission system of wire rope and traction machine, which is suitable for long-term and efficient operation.

• Stability: The counterweight design of the traction elevator makes the elevator run more smoothly, especially suitable for high-rise buildings.

• Wide Range of Applications: The traction elevator can adjust the speed and loading capacity according to the demand, which is suitable for all kinds of places, from residential buildings to super high-rise buildings.

• Energy-Saving: The elevator with a gearless traction system can greatly reduce energy consumption, which is outstanding in energy-saving.

• Long Service Life: Traction elevators have a long service life due to the durability of their mechanical structure and motor design.

Disadvantages Of A Traction Elevator

• Occupying a Large Space: A traction elevator needs a special machine room, which requires a large building space.

• Higher Installation Cost: A traction elevator has a higher installation cost due to complex wiring and machine room setup.

• Maintenance Cost: The wire rope and traction machine of the traction elevator need regular inspection and maintenance, especially the wear and tear of the wire rope and the inspection of the traction sheave.

• Noise: Although the noise of modern traction elevators has been controlled, compared with hydraulic elevators, traction elevators still have certain noise. Of course, BDFUJI’s permanent magnet synchronous traction machine has solved this problem.

What Are The Different Types Of Traction Elevators?

There are three types of traction elevators, each with a unique operating principle, advantages, and disadvantages, and application scenarios. Below are the three common types of traction elevators, their respective characteristics, and applications:

Geared Traction Elevator

Overview:
Geared traction elevators drive the up and down movement of the elevator car through the cooperation of gears and traction wheels. The power of the electric motor is transmitted to the traction sheave through the gear, and then the traction sheave drives the wire rope to run, so that the elevator car moves up and down.

Advantages:

• High Efficiency: Due to the combination of gears and traction sheaves, the elevator is able to generate strong power, which is suitable for high-rise buildings that require fast transportation.

• Suitable for High-Rise Buildings: This type of elevator is suitable for buildings of greater height and can effectively cope with higher transportation needs.

Disadvantages:

• Noisy: The noise generated by the operation of the gear system is more noticeable, especially at high speeds, and may affect the comfort of the building.

• Higher Maintenance Costs: Due to the contact friction between the gears and the traction sheave, long-term operation may require more frequent maintenance, increasing maintenance costs.

Gearless Traction Elevator

Overview:
Gearless traction elevators adopt a gearless drive, where the electric motor directly drives the traction sheave and drives the wire rope through friction to run the car up and down. Unlike gear traction elevators, it does not require a gear system, making the entire running process smoother.

Advantages:

• Low Noise: Since there is no gear friction, the elevator operates at a very low noise level, making it suitable for buildings that require a quiet environment.

• Energy Saving: Gearless drive system is more energy-efficient and can effectively reduce energy consumption, especially suitable for medium and high-rise buildings.

• Smooth: Due to its simple structure, the elevator runs more smoothly, providing a more comfortable riding experience.

Disadvantages:

• Requires Precise Installation and Maintenance: Since the elevator has no gears, all components must fit together more precisely, which requires more installation and maintenance.

• Higher Cost: Gearless traction elevators are technically more complex, so installation and maintenance costs are typically higher.

MMR Elevator (Machine Room Reduced)

 

Overview:
MMR elevators are an innovative type of elevator developed in recent years that centrally installs the elevator’s drive system at the top of the shaft, eliminating the need for a traditional separate machine room. This design allows the elevator to operate without the need for additional space, thus saving space resources in the building.

Advantages:

• Space Saving: The biggest advantage of the MMR elevator is the machine room-less design, which can save building space, especially for environments with limited space.

• Adaptable: Suitable for small apartments, hotels, etc., without the need for additional machine rooms and complex installation structures, ideal for space-constrained buildings.

• Short Installation Cycle: Due to the elimination of the machine room, the installation process is easier and the construction cycle is shorter, which can significantly reduce the installation time and cost.

Disadvantages:

• Higher Technical Requirements for Installation: Due to the elimination of the machine room, the system must be centralized at the top of the shaft, which requires higher precision and technical requirements for installation.

• Limited Load Capacity: Due to the space savings, MMR elevators typically have a lower load capacity and are suitable for locations with low load requirements.

Differences Between Traction Elevators and Hydraulic Elevators

The main difference between a traction elevator and a hydraulic elevator lies in the working principle and application scenarios.

• Traction Elevator: Driven by wire rope and traction machine, suitable for high-rise buildings, with higher transportation efficiency and better energy efficiency.

• Hydraulic Elevator: Driven by a hydraulic system, suitable for low-rise buildings, lower cost, but slower running speed, and higher energy consumption.

Traction elevators are suitable for buildings that require fast transportation and high load capacity, especially for high-rise buildings over 20 floors, while hydraulic elevators are more suitable for low-rise residential and small commercial buildings.

How Much Does It Cost to Buy a Traction Elevator?

The cost of purchasing and installing a traction elevator is mainly affected by the following factors:

• Purchase Cost: The purchase cost of a traction elevator typically ranges from $25,000 – $70,000, depending on the model, configuration, and features of the elevator.

• Installation Costs: Due to the need to install a machine room and complex electrical systems, traction elevator installation costs are high and typically range from $8,000 – $15,000.

• Maintenance Costs: Traction elevators have relatively high maintenance costs, typically ranging from $1,500 – $3,000 per year.

Traction Elevator Shaft Size

Traction elevators are not a standardized product, so the shaft size of a traction elevator depends on the car size, load capacity, and operating speed. The following are common shaft size recommendations for traction elevators:

1. Shaft Width:
The shaft width is the horizontal width of the elevator shaft, which needs to be wide enough to accommodate the car and leave space for the elevator equipment to function properly.
Standard Width: 1500mm – 1800mm

2. Shaft Depth:
The depth of the shaft is the vertical depth of the elevator shaft. The elevator shaft needs to be deep enough to ensure that the elevator car and other components can run freely and have enough buffer space.
Standard Depth: 1800mm – 2200mm

3. Pit Depth:
The pit is the space at the bottom of the elevator installation. The pit depth mainly depends on the type of elevator and the installation requirements, and usually needs to provide enough buffer space for the elevator to ensure its smooth operation.
Standard Pit Depth: 1000mm – 1400mm

4. Top Space:
The headroom needs to be left sufficient to accommodate the elevator machine room or other elevator drive systems to ensure that the elevator can function properly.
Standard Headroom: 2500mm – 3000mm

At the same time, the shafts of elevators with too small locations need to be constructed with steel structures to save location dimensions as much as possible.

Traction elevators are the preferred choice for high-rise buildings due to their stability, efficiency, and long service life when faced with the choice of hydraulic elevators and other types of elevators. BDFUJI, as a high-quality traction elevator manufacturer, can provide you with standard or customized traction elevator solutions. Contact us and we will provide you with an elevator solution that meets your needs without sacrificing performance at a great price.