Este documento detalla el sello anular de la trituradora de cono, un componente de sellado crítico instalado entre el anillo de ajuste y el bastidor, o en los conjuntos de cono móvil y fijo. Su función es prevenir la contaminación, retener lubricantes y mantener el equilibrio de presión. Se describe su composición, incluyendo el cuerpo del sello (caucho con anillo de refuerzo metálico integrado), los labios/bordes de sellado, el anillo de refuerzo metálico, las características de montaje y los orificios de ventilación (en algunos diseños), junto con sus características estructurales. Se detalla el proceso de fabricación, que abarca la preparación del material, el moldeo (por compresión o inyección), la vulcanización y el recorte. También se describe el mecanizado del anillo de refuerzo metálico, la preparación del conjunto del sello y los pasos de instalación. Además, se especifican las medidas de control de calidad, como las pruebas de materiales, las verificaciones de precisión dimensional, las pruebas de rendimiento del sellado, las pruebas ambientales y de durabilidad, y la inspección visual y de defectos. Estos procesos garantizan que el sello anular proporcione un sellado confiable, protegiendo los componentes internos y prolongando la vida útil de la trituradora en entornos hostiles.
Detailed Introduction to the Cone Crusher Ring Seal Component
1. Function and Role of the Ring Seal
The ring seal (also called the dust seal or oil seal ring) is a critical sealing component in cone crushers, primarily installed between the adjustment ring and the frame, or between the moving cone and the fixed cone assembly. Its core functions include:
Preventing Contamination: Blocking dust, rock particles, and moisture from entering the internal transmission system (e.g., eccentric shaft, bearings, and lubrication channels) to avoid abrasive wear and corrosion.
Retaining Lubricants: Sealing the lubricating oil or grease within the bearing chambers and transmission components, ensuring continuous lubrication and reducing friction-induced damage.
Maintaining Pressure Balance: Assisting in regulating internal pressure differences between the crushing chamber and the transmission system, preventing oil leakage caused by pressure fluctuations.
2. Composition and Structure of the Ring Seal
The ring seal is a composite annular component designed for high wear resistance and flexibility, consisting of the following key parts:
Seal Body: The main annular structure, typically made of nitrile rubber (NBR), polyurethane (PU), or fluororubber (FKM), with a metal reinforcement ring (carbon steel or stainless steel) embedded to enhance structural rigidity. The rubber material is selected based on operating temperature (NBR for -40°C to 120°C; FKM for high-temperature environments above 150°C).
Lips or Sealing Edges: One or multiple flexible lips on the inner and outer diameters of the seal body, which form a tight contact with mating surfaces (e.g., adjustment ring outer wall or frame inner wall). These lips are often designed with a spring-loaded structure (garter spring) to maintain constant pressure against the mating surface, ensuring a reliable seal even with minor wear.
Metal Reinforcement Ring: A thin, annular steel ring (SPCC or 304 stainless steel) embedded in the rubber body during molding. It provides dimensional stability, preventing deformation under radial pressure and ensuring the seal maintains its shape during assembly and operation.
Mounting Groove or Flange: A recessed or protruding structure on the seal’s outer edge that fits into a corresponding groove on the crusher frame or adjustment ring, securing the seal in place and preventing axial displacement during vibration.
Vent Holes (in some designs): Small holes drilled through the metal reinforcement ring to equalize pressure between the seal’s inner and outer sides, reducing the risk of lip deformation due to pressure differentials.
3. Manufacturing Process for the Ring Seal
Unlike metal components, ring seals are primarily produced through rubber molding rather than casting, due to their flexible and composite nature. The key steps are as follows:
Material Preparation:
Rubber Compound: Raw rubber (e.g., NBR) is mixed with additives (carbon black for reinforcement, sulfur for vulcanization, antioxidants, and lubricants) in a Banbury mixer. The mixture is kneaded at 80–100°C to form a homogeneous rubber compound with a Mooney viscosity of 60–80 (ML 1+4 at 100°C).
Metal Reinforcement Ring: Carbon steel strips are cut into rings, deburred, and treated with a bonding agent (e.g., Chemlok 205) to ensure strong adhesion between the metal and rubber.
Molding (Compression or Injection Molding):
Compression Molding: The rubber compound is pre-formed into a ring shape and placed in a heated mold (160–180°C) alongside the metal reinforcement ring. The mold is closed, applying pressure (10–20 MPa) for 5–15 minutes to vulcanize the rubber, which bonds to the metal ring and forms the seal’s shape (including lips and grooves).
Injection Molding: For high-volume production, molten rubber compound is injected into a heated mold containing the metal ring. This method ensures tighter dimensional control and uniform material distribution, with cycle times reduced to 2–5 minutes.
Vulcanization:
The mold is maintained at 160–180°C to complete the vulcanization reaction, cross-linking the rubber molecules to achieve elasticity and mechanical strength. Post-vulcanization (2–4 hours at 100–120°C) may be performed for FKM seals to improve chemical resistance.
Trimming and Finishing:
Flash (excess rubber) is removed from the seal edges using trimming machines (rotary knives or cryogenic trimming with liquid nitrogen) to ensure smooth, burr-free sealing lips.
The sealing lips are polished with abrasive pads to achieve a surface roughness of Ra0.8–1.6 μm, enhancing contact with mating surfaces.
4. Machining and Assembly Processes
While rubber components require minimal machining, the metal reinforcement ring and mating parts undergo precision processing:
Metal Reinforcement Ring Machining:
The steel ring is blanked from strips using a stamping press, with outer and inner diameters rough-turned to within ±0.1 mm.
The ring’s surface is cleaned and coated with a bonding agent, dried at 80–100°C for 30 minutes to activate adhesion.
Seal Assembly Preparation:
Mating grooves on the crusher frame or adjustment ring are machined to precise dimensions (width ±0.05 mm, depth ±0.02 mm) using CNC lathes, ensuring the seal fits snugly without distortion.
The mating surfaces (contacting the seal lips) are ground to a surface roughness of Ra0.8–1.6 μm and polished to remove burrs or scratches that could damage the seal.
Installation Features:
The ring seal is press-fitted into the mounting groove using a hydraulic press, with a guiding tool to prevent lip deformation during installation.
Garter springs (if equipped) are stretched and positioned in the spring groove of the sealing lip to maintain radial pressure against the mating surface.
5. Quality Control Processes
Material Testing:
Rubber compound testing: Tensile strength (≥15 MPa for NBR), elongation at break (≥300%), and hardness (60–70 Shore A) are verified using ASTM D412 standards.
Metal ring testing: Adhesion strength between rubber and metal is tested via a peel test (≥5 N/mm) to ensure no delamination.
Dimensional Accuracy Checks:
Outer and inner diameters of the seal are measured using a coordinate measuring machine (CMM) to ensure compliance with tolerances (±0.1 mm for critical dimensions).
Lip thickness and angle are inspected using a profile projector, with deviations ≤0.05 mm to guarantee proper contact with mating surfaces.
Sealing Performance Testing:
Pressure testing: The seal is installed in a test fixture and subjected to internal pressure (0.5–1 MPa) with oil or air. No leakage is allowed for 30 minutes, verified via visual inspection or pressure drop monitoring.
Dust resistance testing: The seal is exposed to ISO 12103-1 A2 fine dust under simulated operating conditions for 100 hours. Post-test inspection confirms no dust ingress into the sealed cavity.
Environmental and Durability Testing:
Temperature resistance: Seals are aged in an oven at 120°C (NBR) or 200°C (FKM) for 168 hours, with post-aging tests confirming minimal changes in hardness (≤5 Shore A) and tensile strength (≤20% reduction).
Flex fatigue testing: The seal undergoes 100,000 cycles of radial compression (±0.5 mm) to simulate vibration, with no cracks or lip deformation allowed.
Visual and Defect Inspection:
Surface checks: Rubber surfaces are inspected for bubbles, cracks, or uneven curing using a magnifying glass (10x). Metal rings are checked for rust or burrs.
Adhesion inspection: A knife test is performed to ensure no separation between rubber and metal, with any delamination resulting in rejection.
By adhering to these manufacturing and quality control processes, the ring seal achieves reliable sealing performance, effectively protecting the cone crusher’s internal components from contamination and lubricant loss, thereby extending the equipment’s service life in harsh mining and aggregate environments
