Actuators are widely used across industrial applications, but each use case comes with its own set of requirements. The considerations below will help you choose the right actuator for heavy-duty packaging systems or case sealing machines.

Selecting, sizing, and applying a linear actuator is not a simple task. It requires careful evaluation of multiple factors such as stroke length, duty cycle, accuracy, and repeatability. In other words, choosing the right actuator means balancing technical specifications with performance expectations, project timelines, and budget constraints.

1. Accuracy and Repeatability

In most end-of-line packaging applications, a positioning repeatability of around 50 μm is generally sufficient.

For example, a SCARA robot equipped with a vacuum gripper or mechanical gripper may be mounted on a linear actuator. The actuator moves the robot along a linear axis to pick cartons and place them onto pallets. In this scenario, the motion needs to be stable, consistent, and repeatable—accurate enough for efficient operation, but not necessarily ultra-precise. However, for applications requiring higher positioning accuracy, integrating a linear encoder is recommended.

2. Load Capacity

You need to clearly define the load, moment, and forces the actuator must handle in heavy-duty packaging applications. Special attention should be paid to performance under high speeds and accelerations. Key parameters to evaluate include thrust force, dynamic load, and bending moments.

Load capacity depends heavily on the actuator’s internal design. While many actuators may look similar externally, some are engineered for high loads at high speeds, while others are only suitable for lighter-duty tasks.

Note: Always check the units when comparing products. Some manufacturers use SI (metric) units, while others use imperial units. Converting to a common system is essential for accurate comparison.

3. Stroke Length and Installation Space

Define the required working stroke as well as the total installation space available.

For example: how far does the robot need to travel? Will you use multiple actuators to build a Cartesian robot system?

4. Duty Cycle

Các ứng dụng như xếp pallet hay đóng thùng thường yêu cầu cơ cấu truyền động hoạt động gần như liên tục, di chuyển qua lại giữa các vị trí.

Maintenance and lubrication schedules should also be considered. Some actuators require re-lubrication only after 20,000 km of operation, while others need more frequent servicing.

5. Operating Environment

Environmental conditions directly impact actuator lifespan and stability.

Will the system operate in dusty, humid, or contaminated environments? If so, protective components such as seals or bellows may be necessary to protect moving parts.

6. Mounting Orientation

In many packaging applications, actuators are mounted horizontally. However, in multi-axis systems or processes like shrink wrapping, vertical installation is also common.

For multi-axis setups, proper alignment between actuators is critical. Poor connections can lead to misalignment, vibration, reduced accuracy, and even system failure.

7. Speed and Acceleration

As mentioned earlier, many actuators look similar on the outside. Most use anodized aluminum profiles for a lightweight yet rigid structure. However, the real difference lies in the internal design.

In some cases, the actuator must synchronize quickly with a moving conveyor to pick products at the right moment. In others, a robot may only need to move into position for a few seconds to complete a pick-and-place operation before returning rapidly to its starting point.

These are critical inputs that actuator suppliers need in order to recommend the right solution. Some heavy-duty actuators can handle large loads while reaching speeds of up to 5 m/s, while others are limited in either speed or load capacity.

8. Actuator Design and Internal Structure

Như đã đề cập, nhìn bên ngoài nhiều cơ cấu truyền động khá giống nhau. Phần lớn đều sử dụng thân nhôm định hình anod hóa để vừa nhẹ vừa cứng. Tuy nhiên, điểm khác biệt thực sự nằm ở cấu tạo bên trong.

For heavy-duty packaging applications, it is essential to evaluate internal components in detail.

One key factor is the guiding system. Linear guide systems with preload are highly recommended, as they improve rigidity, accuracy, and repeatability. In contrast, wheel-based guides with rubber or plastic coatings may perform well initially but cannot match the durability and stiffness of preloaded linear guides.

Bearings are another critical component. Preloaded linear bearings made from machine-grade steel significantly enhance system rigidity and precision.

A robust actuator design is not only suitable for end-of-line packaging but also performs well in applications such as case packing, boxing, and heavy-load transfer on parallel axes.

For belt-driven actuators, additional attention should be given to shaft and pulley design:

• Use steel pulleys for better durability and longer service life
• Prefer one-piece machined shaft assemblies to eliminate slippage between the pulley and shaft (compared to multi-part press-fit designs
• Choose pulleys with securely bolted flanges rather than thin, stamped, or press-formed designs
• Opt for preloaded radial ball bearings instead of plastic or bronze bushings

These design details collectively define a truly heavy-duty actuator capable of operating reliably in demanding packaging environments.

9. Gearbox and Motor Selection

For high-speed belt-driven actuators in packaging applications, more than 95% of cases require a gearbox or speed reducer to match inertia and increase torque.

You should also request motor sizing data from the supplier. A reliable supplier can provide complete technical data to support accurate motor selection, ensuring optimal system performance. Some manufacturers even include this data directly in their quotations.

As an authorized distributor of THK products in Vietnam, Temas offers a comprehensive portfolio—from linear motion guides, ball screws, slide tables, and cross roller guides to electric actuators—along with complete solution support for customers.

If you are looking for the right THK linear motion guide for your application, Temas is ready to assist with analysis and recommend the most suitable solution. Contact us today for expert consultation.

Credit: Linear Motion Tips