Skeleton oil seal machine: the guardian of oil seal products

1. Basic structure and composition of skeleton oil seal machine
Skeleton oil seal is the most common type of mechanical sealing device. Its typical structure consists of three main parts: metal skeleton, elastomer and spring. This structural design makes it an ideal choice for isolating the lubrication parts of the transmission system from the external environment, effectively preventing lubricating oil leakage and external pollutants from invading.
The metal skeleton, as the supporting structure of the oil seal, is usually made of high-quality cold-rolled steel plate or stainless steel material, and is formed by precision stamping. The skeleton provides structural strength and installation stability to ensure that the oil seal maintains its shape in harsh working environments. According to application requirements, the skeleton can be designed as an internal skeleton type, an external skeleton type, or an internal and external composite skeleton type.

Elastomer materials are the key part of the oil seal to achieve the sealing function. Common materials include:
Nitrile rubber (NBR): suitable for most mineral oils and lubricants, operating temperature range -40℃~120℃
Fluororubber (FKM): resistant to high temperature and chemical corrosion, operating temperature can reach 250℃
Acrylic rubber (ACM): excellent extreme pressure resistance
Silicone rubber (VMQ): outstanding high and low temperature resistance
The spring element (usually a spiral spring or spring ring) continuously applies radial pressure to the sealing lip to compensate for the pressure loss caused by wear and ensure long-term effective sealing performance. The spring material is mostly stainless steel, which has good elasticity and corrosion resistance.

2. Working principle and sealing mechanism
The sealing principle of the skeleton oil seal is based on the synergistic effect of three key mechanisms:

Interface sealing: The elastomer sealing lip fits tightly with the surface of the rotating shaft to form a microscopic sealing interface. When the shaft rotates, an extremely thin oil film (about 1-2μm) is generated between the sealing lip and the shaft surface, which not only achieves sealing but also provides necessary lubrication.

Pumping effect: The oil seal lip is designed with special spiral patterns or bevels, which produce a directional pumping effect when the shaft rotates, redirecting the leaked lubricating oil back into the seal cavity. This self-tightening design significantly improves the sealing reliability.

Spring pressure: The built-in spring provides continuous radial pressure to compensate for the drop in contact pressure caused by shaft eccentricity, vibration or lip wear, ensuring the long-term stability of sealing performance.

3. Equipment composition and functional modules
The skeleton oil seal machine is usually composed of the following core modules:

Metal skeleton processing unit——
Precision stamping system: complete skeleton unloading and molding
Surface treatment device: including pretreatment processes such as degreasing, phosphating or sandblasting
Skeleton positioning and conveying mechanism: high-precision transmission and positioning system

Rubber molding system——
Precision metering and injection device: control rubber dosage accuracy up to ±0.5%
High temperature vulcanization unit: multi-temperature zone precise control, temperature fluctuation ±1℃
Mold quick change system: realize multi-variety rapid switching production

Spring assembly unit——
Spring automatic feeding mechanism
Precision assembly manipulator
Spring tension detection system

Post-processing and detection system——
Trimming and deburring device
Laser marking unit
Automatic optical inspection (AOI) system
Sealing performance test bench