In-Depth Knowledge of Motors Used in Electric Stackers

In recent times, electric stackers are the kind of material handling equipment that are proving more important than ever in our automated warehouses as they offer speed, maneuverability, and a potentially lower environmental footprint. Plus more than anything else in the material handling space, stackers can have an considerably varying level of sophistication surrounding the motor technology. In this article we will take a look at electric motors used in stackers; how they work, types, performance specifications and the trends to look out for.

1. Main Purpose of Motors in Stackers

Electric stackers contain a drive system, hydraulic lift system, control electronics, battery pack and an interface to the operator. Electric motors are limited to two examples:

Drive Motor: This supplies mechanical power to stacker's wheels, allowing it to move forward, reverse or steer. It must have a flat torque curve over its whole range of operation, as well as smooth operation at low-speed.

Hydraulic Pump Motor:This operates the hydraulic pump that lifts and lowers the forks. It must show quick dynamic response to the drive system and have sustained torque output when exposed to heavy or intermittent loads.

Determining stacker safety, productivity, and overall ownership cost can be influenced by the electric motor used in stackers.

2. Motor Types Typically Found in Stackers

AC Induction Motor

Generally used, durable, cost effective and low-maintenance;

Equipment may use VFD's (Variable Frequency Drives), allowing for variable speeds;

It is more than appropriate for the routine picking and storing applications of average loads in the warehouse duty cycle.

Permanent Magnet Synchronous Motor (PMSM)

Has better performance and energy efficiently with greater power density as it contains rare-earth permanent magnets;

Has very good dynamic response and low-speed torque, has a small form factor;

A PMSM is an appropriate example of a drive motor for the higher value stackers requiring greater performance, low-noise and energy efficiency;

Look at the comparison of PMSM vs AC motors, the PMS