Electric Motors for Electric Scissor Lifts: The Key Driving Force for Efficient Lifting and Precision Control

Due to the high demand for aerial work platforms in industries like warehousing, electrical maintenance, and construction, electric scissor lifts have become vital tools due to their compact layout, vertical stability, and safety. The electric motor is at the heart of these machines and it is vital to define lifting performance, work efficiency, and overall system reliability.

1. Structures, features, and power demands

Electric scissor lifts raise the platforms in a vertical direction using a 'scissor' like mechanism. The scissor lift has several key components that make up the system design: 1. Drive mechanisms (platform, emergency stop, and steering), 2. Scissor arm length, hinge positions, and capabilities, 3. Hydraulic system working in conjunction with the drive motors, 4. Electric motors, 5. Batteries, and 6. Controllers (telemetry, sensors, etc...). The motor drive assemblies are usually classified into 2 main electric motor types:

Drive Motor: Provides forward/reverse motions and steering. The drive motor requires high torque in low speed ranges, and associated braking feature.

Pump Motor (lifting motor): Provides the hydraulic pump to raise and lower the platform. The pump usually requires high starting torque and continuous duty.

2. Motor Types

AC induction motor

Most popular motor type used for drive system due to robust performance, lower cost, and a better effort to adapt to changing load conditions. Motors are rated for low-speed, heavy-duty use in varied terrain.

Permanent magnet DC motor

Generally used in the hydraulic pump system. They tend to offer small form factors and high efficiency, along with fast response speeds for frequent short-burst lift cycles. Some higher-end scissor lifts have begun using PMSM (Permanent Magnet Synchronous Motor) designed motors and controllers that have energy savings and performance advantages.

3. Looking at technical demands placed on motors

-High-starting torque is needed for raising weights and incline drive operations

-High thermal resistance for greater duration of continuous use

-Low noise and vibration for enhanced operator comfort

-Ability to program precise control and braking to provide speed regulation and safe stopping with controllers

-Low profiles for installations in confined spaces and easier maintenance access to all motor system components

4. Trends of intelligence and energy efficiency

More scissor lifts are including CAN-bus communications that integrate the electric motor with other systems in the overall control system. Each lift has BMS (Battery Management System) that provides monitoring of motor parameters such as temperature, voltage, and current so that problems can be flagged and fixed before the components fail. Some manufacturers have introduced energy-recovery motors in some of their models to improve battery life and to ultimately reduce energy consumption.