About Rotary Shaft Seal For Linear Motion Shaft
Rotary shaft seal for linear motion shaft can provide reliable sealing performance, reduce shaft wear and friction, extend shaft life, and ensure normal operation of the system. These seals are usually made of elastic materials such as rubber or polyurethane. They usually have an annular or U-shaped cross-sectional shape and can fit tightly between the shaft and the bearing or guide rail to form a sealing interface. This sealing interface blocks the ingress of liquids, solid particles and contaminants and maintains the presence of lubricant on the shaft.
Rotary shaft sealing performance
1. The rotary shaft seal adopts a spring-free wide lip dynamic structure with a contact surface width of 3-5mm, which can maintain a sufficient oil film and is insensitive to the eccentricity of the shaft. It can still work normally under the condition of radial runout of 0.4mm.
2. Rotary shaft seal has excellent anti-friction properties, especially suitable for working in a state of no or little oil. Even if it is started again after a long period of shutdown, it can immediately have low friction properties. Rubber oil seal is only suitable for working in a state of oil.
3. A rotary shaft seal is especially suitable for high-speed rotating applications, with a linear speed of up to 30m/s, and a butadiene rubber oil seal with a higher speed of 10m/s than the breaking line.
4. Rotary shaft sealing can seal water, acid, alkali, solvent, gas, etc.
Special Features
The special feature of Rotary shaft seal for linear motion shaft is that it needs to adapt to the requirements of linear motion and specific working conditions. The following are some special features related to linear motion axes:
■ High-speed motion: Linear motion shafts usually have high motion speeds, so the rotary shaft seal needs to be able to adapt to the requirements of high-speed rotation. The sealing structure must have good friction and wear resistance to reduce frictional heat and wear while maintaining effective sealing performance.
■ High Loads: Linear motion shafts may be subject to large loads, so rotating shaft seals need to be strong and durable enough to withstand the pressures and forces under high load conditions. The sealing structure must be able to maintain stable sealing performance regardless of load.
■ Long stroke: Linear motion axes usually have a long stroke, and the sealing structure needs to be able to maintain effective sealing performance over a long stroke. It must be able to adapt to changes in the shaft’s different positions and movement ranges, and maintain a stable sealing effect.
■ Selection of sealing materials: Since the linear motion axis may be exposed to different working media during movement, the selection of sealing materials is very important. The sealing material must have good corrosion resistance and chemical resistance to avoid damage to the sealing performance by the medium.
■ Accuracy requirements: Linear motion shafts usually require high-precision motion and position control, so rotary shaft seals need to have good sealing accuracy and dimensional stability. It must be able to maintain stable sealing performance without negatively affecting the movement and position control of the shaft.
Sealing Principle
1. Sealing lip contact: The core of the rotating shaft seal is the contact between the sealing lip and the shaft surface. Sealing lips are usually made of elastic materials such as rubber or elastic polymers. When the linear motion shaft moves, a certain contact pressure is formed between the sealing lip and the shaft surface, thereby achieving a sealing effect. The sealing lip should have sufficient elasticity to ensure the tightness and reliability of the sealing contact.
2. Friction seal: The contact between the sealing lip and the shaft surface forms a friction seal. Friction seals use friction to stop lubricant leakage and prevent external impurities from entering the bearing or mechanical system. The elasticity of the sealing lip and the contact pressure with the shaft surface, as well as the friction characteristics between the sealing lip and the shaft surface, jointly determine the effectiveness of the friction seal.
3. Sealing lip design: The design of the sealing lip is crucial to the sealing effect. It usually has a specific shape and cross-section to suit the requirements of the linear motion axis. For example, sealing lips may have special geometries, such as designs with bevels or rounded corners, to reduce friction and wear. In addition, the material selection and hardness of the sealing lip are also key factors affecting sealing performance.
4. Lubricant management: On linear motion axes, lubricant management is very important. Rotating shaft seals need to ensure that the lubricant forms an effective lubricating film inside the shaft seal to reduce friction and wear. Therefore, the seal structure may include lubrication grooves or oil grooves to store lubricant and form a lubricating film between the seal lip and the shaft surface.
Application Scenarios
1. Mechanical engineering: Rotary shaft seals for linear motion shafts are widely used in various mechanical equipment and systems, such as linear drives, linear guides, sliders, guide devices, etc. They are used to protect bearings and transmission components in mechanical systems, prevent lubricant leakage and external impurities from entering the system, and ensure the normal operation of the system.
2. Automobile industry: Rotating shaft seals are widely used in automobile manufacturing and auto parts. They are used to protect the vehicle’s drive shaft, engine crankshaft and bearings and sealing surfaces in the transmission system, reduce friction and wear, maintain normal circulation of lubricants, and improve vehicle performance and life.
3. Aerospace industry: In the aerospace field, rotating shaft seals are used for linear motion axes in aircraft, rockets, satellites and other equipment. They provide effective sealing during high-speed flight and extreme environmental conditions and ensure system reliability and safety.
4. Medical equipment: Rotating shaft seals are also widely used in medical equipment, such as medical robots, scanners and surgical equipment. They are used to protect the moving shafts and transmission components in the equipment, prevent contamination and bacterial infection, and ensure the normal operation and hygiene requirements of the equipment.
5. Manufacturing: In the manufacturing industry, rotating shaft seals are used for linear motion shafts in various production equipment and mechanical systems. They play an important role in conveyor systems, machine tools, handling equipment, etc. on production lines, protecting bearings and transmission devices, reducing losses and downtime, and improving production efficiency.
To help meet customers’ specific requirements, Linde Polymers produces a range of rotary shaft seals made from a variety of rubber materials. We can satisfy bulk orders from dozens to hundreds to thousands. To learn more about the rotary shaft seal products and services we offer, please feel free to contact us. You can also request a quote, contact our professionals and discuss your individual needs.
