1. Classification by Structure
Based on their mechanical structure, palletizing robots fall into three categories: Cartesian, articulated (rotary joint), and gantry-style.
① Cartesian Palletizing Robots: These consist primarily of four components: a vertical column, an X-axis arm, a Y-axis arm, and a gripper. They utilize four degrees of freedom (comprising three linear joints and one rotary joint) to perform palletizing tasks. This type features a simple structure, high structural rigidity, and a high load-bearing capacity, making it suitable for palletizing heavier materials.
② Articulated (Rotary Joint) Robots: These robots rotate around their base and feature four rotary joints: waist, shoulder, elbow, and wrist. Programming is achieved through a "teach" method: an operator uses a handheld teach pendant to guide the robot through specific movements, which are then stored in memory for automatic reproduction during subsequent operations. These robots combine a compact body with a large operating range; they can palletize onto one or multiple pallets simultaneously and offer the flexibility to handle tasks across diverse product lines.
③ Gantry-style Robots: These consist of a robot arm mounted on a gantry frame. This configuration offers a large working envelope and the capability to handle heavier materials.
2. Classification by Stacking Requirements
① Single-layer Palletizing Robots
Single-layer palletizing robots represent a basic configuration. Materials are delivered via a conveyor belt to a turning mechanism, where they are oriented according to specifications before moving onto the layering mechanism. Products are tightly arranged in a preset pattern at this stage, and conveyor rollers then transfer the arranged products to the next workstation, completing the robot's stacking operation.
② Multi-layer Palletizing Robots
As the counterpart to single-layer systems, multi-layer palletizing robots are inherently more complex. In these systems, the transfer platform is positioned beneath the conveyor belt and is capable of lateral movement. During the stacking process, materials are neatly arranged on a transfer plate, which is initially positioned at its leftmost limit. When materials on the conveyor belt are halted by a stop, they form a single, aligned row. The transfer plate then shifts to the right, and the process repeats to form another row. This cycle continues; as each new layer of material is added, the palletizing robot's lifting platform descends by one layer height, stopping only when the stack reaches the desired total height.
③ Row-Arrangement Palletizing Robot
This type of palletizing robot conveys materials arranged in rows; a pusher plate transfers the incoming materials onto an accumulation platform. The mechanism then moves to the left and pushes upward to stack three layers of material together. An inclined plane mechanism ensures the process proceeds smoothly, while the specific design of the accumulation platform further facilitates the stacking operation. These are merely a few examples of common palletizing robots.