What Is a Dust Seal?
Dust Seal is used to protect packing and bearings by preventing harmful particles from entering. As the name “dust seal” implies, it seals up, or prevent internal intrusion. It is also sometimes referred to as “packing”.
Dust Seals are used in a variety of fields, from industrial machinery to automotive parts, where they are attached to moving parts.
Specifically, they are attached to shafts that rotate and cylinders that move in a linear motion.
Smooth operation, long life, and reliability are important for the moving parts of various machines. For this reason, Dust Seals are available in a variety of materials and shapes, depending on the operating temperature, anticipated harmful substances, and mechanical strength.
In addition, Dust Seals are used to protect the interior at the outermost part of the equipment and must be replaced on a regular basis.
Uses of Dust Seals
Dust Seals are important components used in a wide range of applications, from industrial machinery and automobiles to the aerospace industry.
The reason for this is to prevent the ingress of foreign matter through gaps in operating components and to ensure the longevity, performance, and reliability of systems.
This reduces costs for maintenance and improves the efficiency of the entire machinery system.
Typical examples in the field of industrial machinery are motors represented by pumps, gearboxes, and electric actuators.
Exposure to contaminants such as dust and dirt, especially in components containing rotating shafts, accelerates wear and causes reduced efficiency. In addition, in processing machines such as CNC machines, it leads to a decrease in machining accuracy.
In the automotive field, this includes axle bearings, suspensions, and drive trains. All of these parts are susceptible to dust, dirt, and moisture. Protecting them ensures their function and vehicle safety.
In the aerospace industry, sealing is critical.
Actuators that operate under hydraulic and pneumatic pressure require a contaminant-free environment to ensure seamless function.
Dust Seals are used to prevent the entry of harmful substances from the outside, but they also play an important role in ensuring the longevity, performance, and reliability of a wide variety of mechanical systems.
Principle of Dust Seals
The basic principle behind the construction of Dust Seals is based on the idea that they effectively seal (protect) machine parts from external substances such as particles, dust, dirt, moisture, and contaminants.
Since these seals are attached to moving parts, they must also be designed with friction in mind.
Both sealing and low-friction properties must be established in a well-balanced manner to ensure functionality.
To ensure this balance, Dust Seals are available with a “lip” cross-sectional shape or a “labyrinth” shape with an internal structure that resembles a labyrinth.
A typical oil seal has a lip shape.
The construction is simple: a flexible lip contacts a rotating shaft or component, and the lip repels intrusion from the outside, thereby ensuring sealing performance.
Since the lip is subject to sliding, lubrication may be required to reduce the friction and heat generated by this.
Materials vary and must be selected for durability, flexibility, and resistance to environmental factors.
Labyrinth seals are used on machines that are subjected to high speeds and harsher environments.
Labyrinth seals have an internal labyrinth-like barrier that prevents harmful substances from passing through the seal.
Compared to lip seals, labyrinth seals have a higher initial cost but offer superior sealing and durability.
Most Dust Seals are press-fit, so care must be taken to ensure that they are installed in the correct direction.
Other Information on Dust Seals
Dust Seal Materials
Dust Seals are mainly made of rubber-based materials.
Typical materials are molded from nitrile rubber, urethane rubber, and fluoro rubber.
Nitrile rubber is characterized by its low cost and high versatility. On the other hand, it has limitations in weather resistance and temperature conditions. A disadvantage is that it is particularly vulnerable to direct sunlight and easily deteriorates when used in areas exposed to sunlight.
Urethane rubber is characterized by the best abrasion resistance among synthetic rubbers. It tends to be used for industrial goods that involve intense movement due to its high mechanical strength, high elasticity, and high energy absorption capacity.
Fluoroelastomers are used in hydraulic cylinders and outdoor applications because of their resistance to chemicals and heat.
Manufacturing Dust Seals
Dust Seals are manufactured by press molding. Rubber raw materials and hardeners or compounding agents are kneaded together to create a rubber material called compound. The rubber material is poured into the mold and subjected to heat and pressure, which causes a sulfur cross-linking reaction, vulcanization, and molding at the same time. The molded Dust Seal is removed from the mold and deburred. The dust seal is further heated for secondary vulcanization.