In oil seal automation production lines—especially during injection molding and post-processing—gripping is a deceptively simple but highly challenging step. In this case, two specifications are involved: outer diameters Φ43 and Φ44, with a requirement of gripping ≥30 pieces per cycle, which places higher demands on stability and consistency.
. Existing Process Challenges
After demolding, oil seals are typically transferred or arranged in batches at high speed. The original solution used pneumatic grippers and injection-based gripping methods, but several issues emerged in real production:1. Frequent part dropping
- Freshly demolded parts have surface adhesion and vacuum suction effects
- Pneumatic grippers tend to loosen momentarily during high-speed operation
- Batch gripping of ≥30 pieces significantly increases drop rate
2. Visible surface marking on rubber
- Oil seals consist of rubber combined with a metal skeleton
- Rigid contact from pneumatic grippers concentrates pressure on small areas
- Permanent marks appear on sealing lips or outer surfaces, affecting performance and appearance
3. Injection-based gripping also causes damage
- High-temperature demolding state (incomplete cooling)
- Hard contact surfaces with concentrated pressure
- Irreversible indentation on rubber surfaces
2. Core Engineering Challenges
This application involves three key contradictions:
- Insufficient gripping force → part dropping
- Excessive or concentrated force → surface damage
- High temperature + vacuum adhesion → unstable release behavior
Additional requirements:
- Compatible with Φ43 / Φ44 variants
- ≥30 pcs per cycle high-throughput gripping
- Stable operation under high-temperature conditions
3. Design Approach: From Rigid Clamping to Conformal Contact
Traditional pneumatic grippers rely on rigid clamping: “grip—hold—transfer.”However, for oil seals made of rubber under high-temperature, adhesive demolding conditions, a more suitable approach is:
Stable handling through large-area contact and distributed force, rather than point-based clamping.
4. Advantages of Soft Gripper Solution
After introducing a soft gripper in this application, the improvements are mainly reflected in the following areas:
1. Distributed force prevents surface marking
Soft grippers provide larger contact areas through compliant structures:
- Eliminates concentrated stress points
- Conformal contact with rubber surfaces
- Significantly reduces indentation and clamping marks
2. Improved stability against demolding suction forces
To address vacuum adhesion during demolding:
- Flexible structure provides micro-deformation buffering
- Enables smooth transition between contact and release
- Reduces instantaneous slipping and part dropping
3. Stable batch gripping of ≥30 pieces
Through optimized structure and balanced force distribution:
- Simultaneous stable gripping of multiple parts
- Prevents edge-piece slipping
- Improves overall cycle stability
4. High-temperature adaptability
In post-molding high-temperature environments:
- Elastic structures better tolerate thermal expansion and variation
- Reduced risk of grip failure due to temperature changes
- Suitable for continuous production cycles
5. Compatibility: Φ43 / Φ44 Dual Specifications
Although the two sizes are similar, adaptability is still required:
- Flexible deformation automatically accommodates dimensional differences
- No frequent fixture change required
- Reduced changeover time and improved line flexibility
6. Overall Performance Improvement
With the soft gripper solution, the oil seal handling process achieves:
- Significant reduction in part dropping rate
- No visible rubber surface marks
- Stable gripping of ≥30 pieces per cycle
- Compatibility with Φ43 / Φ44 variants
- Better suitability for continuous high-temperature production
The challenge of oil seal automation gripping is not simply “whether the part can be held,” but rather:How to achieve stable, high-speed, and high-volume handling without damaging the product.
The value of soft grippers lies exactly in solving this contradiction between stability and delicacy.If your production line is facing similar issues—such as part dropping, surface marking, or high-temperature gripping instability—they all belong to the same category of challenges: flexible materials combined with high-throughput handling requirements.