How Can O Rings in Collaborative Robot Grippers Balance Lightweight Design and Sealing Reliability?

Number of hits：302026-01-13 11:39:56　

In the design of collaborative robot end‑effectors, achieving a balance between lightweight construction and sealing reliability is a recurring challenge. This is especially true when o rings are used as sealing elements. Reducing weight while maintaining sealing performance often appears contradictory. In reality, the o ring itself offers very limited potential for weight reduction. The true engineering task is to optimize surrounding structural components while preserving the stability of the sealing zone.

Maintain Standardized Sealing Components

The dimensions of the o ring should not be modified arbitrarily. Using internationally standardized sizes such as ISO 3601 or AS568 is the most reliable approach. These standards have been validated over decades and ensure consistent sealing performance, ease of manufacturing, and simplified maintenance.

Likewise, the material properties of the o ring should not be compromised. Materials such as NBR or FKM, and hardness levels typically between 70 and 80 Shore A, must be selected based on the application. Altering hardness or elasticity solely for the purpose of weight reduction can directly affect sealing performance and service life. Preserving the o ring’s original performance characteristics is fundamental to sealing reliability.

Lightweight Structural Components Without Affecting Sealing Performance

Meaningful weight reduction should focus on structural components rather than the sealing element itself. Several strategies can be applied:

Thin‑wall design and lightweight materials

Aluminum alloys and engineering plastics such as POM or PA+GF can replace steel components to reduce mass. Properly designed thin‑wall structures can lower weight while maintaining the rigidity required around the sealing zone.

Use of composite materials

Composite materials offer low density and high strength, enabling significant weight reduction without compromising stiffness or stability in the end‑effector.

Proper Control of Groove Design

The groove design directly determines o ring sealing performance. During lightweight optimization, the following aspects must be carefully controlled:

Optimized groove geometry

Groove width, depth, and overall dimensions must provide adequate compression while maintaining wall stiffness. Reducing material in the wrong areas can weaken the sealing zone and increase leakage risk.

Balanced compression and stretch

Compression should typically remain within 10–30 percent, and stretch should not exceed 5 percent. Proper balance prevents premature wear or sealing failure.

Simplified Air Channels and Component Layout

Lightweight design also involves optimizing pneumatic paths and accessory components:

Streamlined air passages

Combining small chambers and reducing unnecessary sealing surfaces lowers weight and minimizes potential leakage points.

Integrated structural design

Integrating multiple functions into a single component reduces the number of flanges, gaskets, and fasteners. This not only reduces weight but also simplifies assembly and maintenance.

Durability and Reliability Testing

While lightweight construction is desirable, sealing durability must remain the top priority. Materials such as FKM, which perform well in high‑temperature or oil‑rich environments, should be prioritized. Simulation and real‑world testing of different lightweight configurations help ensure that sealing performance is not compromised.

Lightweight design and sealing reliability are not mutually exclusive in collaborative robot end‑effectors. The key is to focus weight‑reduction efforts on structural components rather than altering the o ring itself. By maintaining standardized sealing elements, optimizing structural design, and ensuring sufficient rigidity in the sealing zone, engineers can achieve meaningful weight reduction without sacrificing performance. This approach enhances the robot’s agility and efficiency while extending the overall service life of the equipment.