There are significant differences between gearless traction machines and geared traction machines in terms of working principles, structural features, application scenarios, and performance. The following is a detailed comparison of the two:

1. Working Principles

Gearless traction machine: It connects the traction sheave directly to the motor without the need for a mechanical reducer. It utilizes the rotational torque of the motor to drive the traction sheave, achieving the traction function. This direct-drive method reduces energy loss and improves transmission efficiency.

Geared traction machine: It achieves traction through mechanical gear transmission. The traction motor is connected to a worm gear via a coupling, and the worm gear is coaxially mounted with the traction sheave. When the traction rope sheave rotates, it drives the relevant devices through the friction between the traction rope and the traction sheave.

1. Structural Features

Gearless traction machine:

The structure is relatively simple, mainly consisting of a motor, traction sheave, brake, and other components.
Due to the absence of a gearbox, the overall size is smaller, and the weight is lighter, facilitating installation and maintenance.
Geared traction machine:
The structure is relatively complex, composed of multiple gears, shafts, worm gears, worm wheels, and other components.
The presence of a gearbox increases the overall size and weight, and also increases the difficulty of maintenance and upkeep.

1. Application Scenarios

Gearless traction machine:

Widely used in medium to high-speed elevators, especially in elevator systems of modern high-rise buildings.
Also suitable for applications with strict space requirements or the need for high energy efficiency.
Geared traction machine:
Primarily used in low-speed or heavy-load traction scenarios, such as the traction of engineering materials on construction sites (e.g., steel beams, concrete bridges, etc.).
Still applied in some old elevators or specific scenarios.

1. Performance

Gearless traction machine:

Has high transmission efficiency, typically reaching 90%-95%.
Operates smoothly with low noise and vibration, enhancing riding comfort.
Energy-saving and environmentally friendly, often utilizing permanent magnet synchronous motors with high energy efficiency.
Long service life, as the absence of a gearbox reduces wear and the occurrence of failures.
Geared traction machine:
Relatively low transmission efficiency, and as operating time increases, gear wear leads to further efficiency reduction.
May generate significant noise and vibration during operation, affecting riding comfort.
Relatively high energy consumption, and requires regular replacement of lubricating oil and maintenance of the gearbox.
Service life is affected by gear wear and failures, relatively shorter.

In summary, gearless traction machines and geared traction machines exhibit significant differences in multiple aspects. When selecting a traction machine, comprehensive consideration should be given to factors such as specific application scenarios, performance requirements, and cost budgets.

Working principle of gearless traction machine

The working principle of gearless traction machine is as follows:

Basic Components

The gearless traction machine mainly consists of a permanent magnet synchronous motor, braking system, and traction wheel. The traction wheel and brake wheel are coaxially fixed and connected, and are directly installed on the motor shaft extension. The braking system is composed of the brake body, brake wheel, brake arm, and brake shoe, etc.

Working Principle

1. Starting Stage

When the elevator control system issues a start command, the inverter provides three-phase variable frequency and variable voltage power according to the feedback from the encoder, generating a rotating magnetic field. This causes the motor rotor, made of rare earth permanent magnetic materials, etc., to rotate at synchronous speed, directly driving the traction wheel.

The traction wheel drives the steel wire rope through friction, thus realizing the up and down movement of the elevator car. For example, when the traction wheel rotates clockwise, the steel wire rope on the car side is driven upward by the traction wheel, and the steel wire rope on the counterweight side moves downward, making the car rise.

1. Running Stage

During the operation of the elevator, the permanent magnet synchronous motor continuously provides stable torque, driving the car and counterweight to run smoothly through the friction between the traction wheel and the steel wire rope. The inverter adjusts the operating parameters of the motor in real time according to the running speed, load and other factors of the elevator, ensuring the smooth operation of the elevator.

Due to the characteristics of linear and constant torque and adjustable speed of the permanent magnet synchronous motor, the traction wheel can run smoothly, with low noise and low energy consumption.

1. Stopping Stage

When the elevator reaches the target floor, the control system issues a stop command. The motor is powered off and stops rotating, and at the same time, the brake electromagnet is powered off. The brake loses magnetic suction, and the spring pushes the armature to press the friction disc tightly, generating a braking torque to quickly stop the traction wheel, making the car stop at the corresponding position.

The braking process of the brake should be quick and smooth to avoid excessive impact and vibration of the elevator. The brake armature is divided into two parts, left and right, and two sets of springs act on the armature and friction disc respectively, in accordance with the double braking requirement of the elevator brake.

Advantages

1. High Efficiency and Energy Saving: There is no power loss of gear transmission, and the mechanical efficiency is high.
2. Low Noise: Low-speed direct drive, low bearing noise, no fan and gear transmission noise, noise can generally be reduced by 5 - 10 dB.
3. Small Size: Simple structure, gear reducer is cancelled, small size, convenient for installation and maintenance.
4. Smooth Operation: The permanent magnet synchronous motor has the characteristics of constant torque and adjustable speed, making the traction wheel run smoothly.
5. Maintenance-free: Using high-performance permanent magnetic materials and special motor structure, basically no maintenance is required.

Application Range

Gearless traction machines are suitable for driving various passenger elevators, medical elevators and passenger and freight elevators controlled by frequency conversion devices.

Working principle of gearless traction machine

The working principle of gearless traction machine is as follows:

Basic Components

The gearless traction machine mainly consists of a permanent magnet synchronous motor, braking system, and traction wheel. The traction wheel and brake wheel are coaxially fixed and connected, and are directly installed on the motor shaft extension. The braking system is composed of the brake body, brake wheel, brake arm, and brake shoe, etc.

Working Principle

1. Starting Stage

When the elevator control system issues a start command, the inverter provides three-phase variable frequency and variable voltage power according to the feedback from the encoder, generating a rotating magnetic field. This causes the motor rotor, made of rare earth permanent magnetic materials, etc., to rotate at synchronous speed, directly driving the traction wheel.

The traction wheel drives the steel wire rope through friction, thus realizing the up and down movement of the elevator car. For example, when the traction wheel rotates clockwise, the steel wire rope on the car side is driven upward by the traction wheel, and the steel wire rope on the counterweight side moves downward, making the car rise.

1. Running Stage

During the operation of the elevator, the permanent magnet synchronous motor continuously provides stable torque, driving the car and counterweight to run smoothly through the friction between the traction wheel and the steel wire rope. The inverter adjusts the operating parameters of the motor in real time according to the running speed, load and other factors of the elevator, ensuring the smooth operation of the elevator.

Due to the characteristics of linear and constant torque and adjustable speed of the permanent magnet synchronous motor, the traction wheel can run smoothly, with low noise and low energy consumption.

1. Stopping Stage

When the elevator reaches the target floor, the control system issues a stop command. The motor is powered off and stops rotating, and at the same time, the brake electromagnet is powered off. The brake loses magnetic suction, and the spring pushes the armature to press the friction disc tightly, generating a braking torque to quickly stop the traction wheel, making the car stop at the corresponding position.

The braking process of the brake should be quick and smooth to avoid excessive impact and vibration of the elevator. The brake armature is divided into two parts, left and right, and two sets of springs act on the armature and friction disc respectively, in accordance with the double braking requirement of the elevator brake.

Advantages

1. High Efficiency and Energy Saving: There is no power loss of gear transmission, and the mechanical efficiency is high.
2. Low Noise: Low-speed direct drive, low bearing noise, no fan and gear transmission noise, noise can generally be reduced by 5 - 10 dB.
3. Small Size: Simple structure, gear reducer is cancelled, small size, convenient for installation and maintenance.
4. Smooth Operation: The permanent magnet synchronous motor has the characteristics of constant torque and adjustable speed, making the traction wheel run smoothly.
5. Maintenance-free: Using high-performance permanent magnetic materials and special motor structure, basically no maintenance is required.

Application Range

Gearless traction machines are suitable for driving various passenger elevators, medical elevators and passenger and freight elevators controlled by frequency conversion devices.