A Simple Introduction to Slewing Ring Bearings

Slewing ring bearings help move heavy things easily. You can find these bearings in big machines. They are in construction equipment, wind turbines, and medical devices. If you like machines or engineering, learning about slewing bearings helps you. These bearings are used in almost 88% of important industries. Here is their global market value:

You will see slewing bearings where big machines need to move well.

Key Takeaways

• Slewing ring bearings help machines move heavy things easily. They let parts turn all the way around. They can hold different kinds of weight at the same time.
• These bearings have a special design. There are inner and outer rings. They have rolling parts, gear teeth, and seals. This makes them strong and last a long time. They also work very well.
• There are different slewing bearings for different jobs. Some types are ball, crossed roller, and maintenance-free. They fit many machines, like cranes and medical tools.
• Slewing ring bearings save space in machines. They also make machines lighter. They can hold a lot of weight. They last a long time if you take care of them.
• Picking the right bearing is important. You need to match the weight, size, and gear choices. You also need to think about where the machine will be used. Regular care keeps machines safe and working well.

What Are Slewing Ring Bearings?

Slewing ring bearings help you move and support big, heavy parts in machines. You often see these bearings in cranes, wind turbines, and even medical equipment. They make it possible for large objects to rotate smoothly and safely. If you work with machinery or enjoy engineering, you will find that slewing bearings are a key part of many designs.

Structure

Let’s break down what makes up slewing ring bearings. You will notice that their structure is different from regular bearings. Here’s what you’ll find inside:

• Inner and Outer Rings: These rings form the main body. They hold everything together and provide the surfaces for the rolling elements.
• Rolling Elements: You might see balls or rollers inside. These parts carry the loads and let the rings spin smoothly.
• Gear Teeth: Many slewing bearings have gear teeth on either the inner or outer ring. These gears help connect the bearing to motors or other moving parts, making rotation easy.
• Attachment Holes: You will spot holes around the rings. These let you bolt the bearing securely to your machine.
• Seals and Lubrication: Seals keep dirt out and grease in. Good lubrication helps the bearing last longer and work better.

Tip: Always make sure the mounting surface is flat and strong. If the base is weak or uneven, the bearing will wear out faster and may not work well. Using a thicker, well-supported mounting plate helps spread the load and keeps everything running smoothly.

The design of slewing ring bearings allows them to handle more than just one type of force. They can take on heavy loads from different directions at the same time. This means you don’t need several separate bearings for each type of load. One slewing bearing can do the job of many.

Key Features

Slewing ring bearings stand out because they do things regular bearings can’t. Here are some features you should know:

• You get 360-degree movement. The bearing lets your machine turn all the way around.
• The shaftless design gives you more space inside your machine. You can fit extra parts or cables through the middle.
• These bearings handle heavy loads with ease. They support weight from above (axial loads), from the side (radial loads), and even twisting forces (moment loads).
• You will notice low friction. This means less energy is wasted, and your machine runs more efficiently.
• Slewing bearings are durable. With good care, they can last from 10,000 up to 192,000 hours, depending on how you use and maintain them.
• They offer high precision. Even when spinning fast or carrying big loads, they keep everything steady and accurate.
• You can find different types, like single-row ball, cross roller, or three-row roller slewing bearings. Each type fits a special job or load.

Here’s a quick look at how slewing ring bearings compare to traditional bearings:

Slewing bearings make your design simpler. You don’t need extra gears or supports. The built-in gear teeth and strong rings do the work for you. If you want a bearing that can handle complex loads and last a long time, slewing ring bearings are a smart choice.

How Slewing Bearings Work

Operating Principle

You might wonder how slewing bearings make heavy machines move so smoothly. The secret is in their clever design. Slewing ring bearings use rolling elements, like balls or rollers, placed between two rings. When you turn the bearing, these rolling elements move along raceways. This rolling action cuts down friction, so the bearing spins easily. You get smooth, controlled rotation even when the load is huge.

Lubrication helps a lot here. Grease or oil keeps everything moving without too much heat or wear. The rolling elements turn instead of sliding, which means less resistance and longer life for your bearings. Slewing bearings also use gear teeth on the rings. These gears connect to motors or other drive parts, helping you start and stop rotation with precision.

Note: Slewing bearings work best when you keep them clean and well-lubricated. Dirt or old grease can make them wear out faster.

Main Components

Let’s look at how the main parts of slewing bearings work together:

1. The inner ring and outer ring form the main structure. You bolt these rings to your machine.
2. Rolling elements, like balls or rollers, sit between the rings. They roll along raceways, carrying the weight and letting the rings turn.
3. The raceways have a special shape. This shape spreads out the load, so no single spot gets too much stress.
4. Gear teeth on one ring let you connect the bearing to a motor or drive system. You get controlled rotation for your equipment.
5. Seals keep out dirt and hold in lubrication. This helps your bearings last longer.
6. As the bearing turns, the rolling elements keep moving. They spread the load and keep everything stable.
7. Good materials and smart design mean slewing bearings can handle heavy loads without bending or breaking.
8. Lubrication keeps friction low, so your bearing runs smoothly and doesn’t get too hot.

• Slewing ring bearings combine all these parts to support big loads and allow precise, controlled rotation. You get reliable movement for cranes, wind turbines, and other heavy machines.

Slewing bearings give you the power to move heavy parts with ease. You get smooth, accurate motion and long-lasting performance. If you want your machines to work better and last longer, slewing ring bearings are a smart choice.

Types of Slewing Ring Bearings

Slewing bearings come in different types. Each type has a special design for certain jobs. Let’s look at the main types you might see.

Ball Slewing Bearings

Ball slewing bearings use balls to help them turn. These bearings are good for machines that need smooth movement. The balls roll between two rings. This makes turning easy and reduces friction. Ball slewing bearings work well for light and medium loads.

You can pick single-row or double-row ball slewing bearings. Single-row types have one row of balls. They handle forces from many directions. Double-row types have two rows of balls. They are stronger and can carry heavier loads. You will find these bearings in cranes, small excavators, and medical equipment.

Tip: Ball slewing bearings let your machine turn all the way around. They also save space inside. You can run cables or pipes through the middle.

Crossed Roller Slewing Bearings

Crossed roller slewing bearings use rollers instead of balls. The rollers are placed in a crisscross pattern. Each roller sits at a right angle to the next. This design helps the bearing carry heavy loads from any direction. You get strong support and high precision.

You will see crossed roller slewing bearings in robots and medical scanners. These bearings help machines move very accurately. The cross pattern increases the contact area. This makes the bearing stronger and keeps it stable. You also get less vibration and smoother motion.

• Crossed roller slewing bearings give you:
  • High stiffness for steady movement.
  • Low friction for easy turning.
  • Small size for tight spaces.
  • Simple installation with mounting holes.
  • Long life because of strong materials and good seals.

If you need precise movement and strong support, crossed roller slewing bearings are a good choice.

Turntable and Plain Bearings

Turntable and plain slewing bearings have special features. Turntable bearings use balls or rollers. They may have gear teeth for easy turning. Plain slewing bearings use sliding surfaces instead of rolling parts. This makes them simple and dependable.

You will find turntable bearings in welding tables and radar systems. They can carry light or heavy loads. Plain bearings are good when you want less maintenance and quiet operation.

Turntable and plain slewing bearings give you choices. You can pick the best design for your machine.

Sliding and Maintenance-Free Types

Sliding and maintenance-free slewing bearings use special materials that slide easily. They do not have rolling elements. You may see polymer pads or solid lubricants inside. This means you do not need to add grease or oil.

These bearings resist rust and work well in wet or dirty places. You get less noise and less shaking. The design lets you change sliding pads without replacing the whole bearing.

• Benefits of sliding and maintenance-free slewing bearings:
  • No need to add grease often.
  • Less chance of problems from dirt or water.
  • Cleaner use with no grease leaks.
  • Lighter and cheaper.
  • Longer life and less downtime.

Maintenance-free slewing bearings help you save money and keep machines working well. You can use them in clean rooms, food factories, or places where you want less mess.

If you need a rectangular standard capacity slewing ring, you can get it with balls or rollers. This type gives you strength, saves space, and is easy to install.

Slewing bearings come in many shapes and sizes. You can always find one that fits your project. Some are for high precision, some for heavy loads, and some for easy, maintenance-free use.

Custom Slewing Ring Bearings

Custom slewing ring bearings help you get the right fit. You can talk to engineers about your machine’s needs. They help you pick the best design for your project.

Segmental and Non-Segmental Designs

You can choose segmental or non-segmental designs. Segmental bearings have separate pieces joined together. This makes them easier to install in small spaces. Non-segmental bearings are one solid ring. They give strong support and are easy to mount.

Here are ways you can change the design:

• Pick single-row or double-row ball or roller bearings for different loads.
• Choose the raceway diameter and material, like stainless steel or aluminum alloy.
• Add custom mounting holes and grease zerk spots for easy care.
• Use induction hardening to make the metal stronger for heavy loads.
• Pick rectangular or low-profile cross sections to save space.
• Upgrade seals for longer life in tough places.

Tip: If you want your bearing to last longer, ask for special seals and surface protection. This helps in places with lots of dust or moisture.

You can also get help from engineers. They look at CAD designs and run tests. They check how the bearing works with your machine. This makes sure your bearing fits your needs.

Gear Options

You can add gears to your slewing ring bearing. Gears can be cut into the inner or outer ring, or both. This lets you connect motors or drive systems directly. It saves space and lowers costs.

Common gear choices include:

• Spur gears made to DIN 3967 standards.
• Toothed belt profiles like T10 or AT10.
• Molded plastic or 3D-printed gears for special shapes.
• Worm gear joints for direct motor coupling.

These gear choices help you balance torque and speed. You can change the gear ratio to fit your design. Built-in gears make your system work better and easier to care for. You can add encoders, brakes, or sensors for closed-loop control.

Precision-cut gears help move power better. This is important in wind turbines and other machines that need strong, steady power. With the right gear design, you get better energy use and longer equipment life.

If you want a bearing that fits your project exactly, custom slewing ring bearings let you pick the design, gear options, and features you need.

Benefits

Load Capacity

You want your machines to lift heavy things without breaking. Slewing ring bearings are strong and can carry big loads. There are different types for different jobs. Some have balls inside, and some have rollers. You can choose single, double, or triple row designs for better strength.

Here’s a simple look at how the bearing series compare:

Slewing bearings are used in cranes, wind turbines, and mining machines. They can handle strong forces from every direction. Your machines will work well, even when the job is hard.

Tip: Always check how much weight the bearing can hold. This keeps your machines safe and working longer.

Space and Weight Savings

You might think big bearings are hard to fit in small spaces. Slewing ring bearings fix this problem. They are small and light because of their smart design. Some use aluminum rings and plastic parts, so they weigh less than steel ones. For example, a 50 mm ID slewing ring can weigh only 2.5 kg.

One slewing bearing can take the place of many regular bearings. This makes your machine shorter and easier to build. The gear teeth are built in, so you do not need extra gears. You get better performance and it is easier to put together.

Slewing bearings help you make lighter, smaller machines that are still strong.

Versatility

Slewing ring bearings work in many different machines. You can use them in heavy equipment, wind turbines, mining, robots, and medical devices. They support axial, radial, and moment loads at the same time. You get smooth turning, high accuracy, and strong performance.

Here are some ways to use slewing bearings:

• Cranes, excavators, and earthmovers for turning and lifting
• Wind turbines and solar trackers for energy systems
• Robots and automation for careful movement
• Marine and offshore machines for tough jobs
• Medical scanners for smooth and quiet motion

They work well even in dirty or wet places. Special seals keep out dirt and water. You get long life and strong load support, no matter where you use them.

Slewing ring bearings let you design better machines for almost any job.

Applications

Slewing ring bearings are used in many places. You see them at construction sites, wind farms, factories, and hospitals. These bearings help move, lift, and position heavy things easily. Let’s look at some important ways they are used.

Construction Equipment

Big machines on job sites use slewing ring bearings. Cranes need them to turn and lift things. Excavators use them to pivot arms for digging. Aerial lifts move smoothly because of these bearings. They help machines handle heavy loads and stay safe.

You get strong support and smooth turning for tough jobs. TFL bearings help machines work hard every day.

Wind Turbines

Wind turbines need slewing ring bearings to work well. They help the yaw system turn the nacelle. They also help the pitch system change blade angles. These bearings must hold big loads and work in bad weather.

Check the mounting surface and look for wear often. Keep the bearings greased so your wind turbine works longer and better.

Cranes and Material Handling

Cranes and material handling machines use slewing ring bearings. These bearings let cranes turn all the way around. They help lift and move heavy things safely. Tower cranes use them to lift and place loads. Excavators use them to move arms for digging.

• Slewing bearings help cranes move and lift safely.
• You get smooth turning and good control.
• Keep bearings greased and check bolts often.

Stackers and ship loaders also use slewing bearings. They help load and unload things quickly in ports and factories. These bearings make work easier and keep machines running well.

Tip: Take care of your bearings to keep cranes and loaders safe.

Medical and Industrial Uses

Hospitals and factories use slewing ring bearings too. In hospitals, they help machines like CT scanners and X-ray tables move quietly and smoothly. Patients feel safe, and doctors get better results.

• Medical bearings are light, quiet, and last a long time.
• You get smooth movement for patient safety.

Factories use slewing bearings in robots and CNC machines. They help machines turn and work with heavy loads. TFL can make special bearings for your needs. This helps your machines work better and saves money.

Slewing ring bearings help medical and industrial machines work well and last longer.

Selection Factors

When you choose slewing ring bearings, you want to make sure they fit your machine and job. Picking the right bearing helps you get the best capacity, long life, and smooth operation. Let’s look at what matters most.

Load and Size

You need to match the bearing’s capacity to your machine’s needs. Start by checking the weight your bearing must support. Think about radial, axial, and moment loads. These loads come from different directions and can change as your machine moves. The size of the bearing matters too. You want a bearing that fits your space but still handles the stress.

Here’s a simple checklist for load and size selection:

1. Check the maximum load your machine will put on the bearing.
2. Look at both static and moving loads.
3. Make sure the bearing fits your space and mounting area.
4. Pick materials that resist wear and corrosion.
5. Ask about custom options if you need special shapes or sizes.
6. Review the bearing’s limit and utilization curves to avoid overload.
7. Balance load capacity and stiffness for safe, stable support.
8. Talk to engineers for help with optimization.

Tip: Never exceed the bearing’s rated capacity. This keeps your machine safe and helps it last longer.

Gear Integration

Some slewing ring bearings come with built-in gears. These gears help your machine turn smoothly and handle heavy loads. If you need precise rotation, gear integration is a smart choice. You get better performance and easier control.

• Integrated gears let you connect motors and drive systems directly.
• You can pick external or internal gears based on your design.
• Gear integration boosts load handling and rotation accuracy.
• These bearings work well in cranes, wind turbines, and robots.
• Always match gear type to your speed and torque needs for optimization.

If your job needs stable, continuous rotation, gear integration makes your system stronger and more reliable.

Environment and Maintenance

Your bearing must survive in tough places. Dust, water, and chemicals can damage it. Good seals keep out dirt and hold in grease. You need heavy-duty lubrication to prevent wear. Routine checks help you spot problems early.

• Use seals made for your temperature and chemical needs.
• Clean and inspect seals often.
• Check grease levels and keep everything clean.
• Make sure mounting surfaces are flat and strong.
• Replace seals if you see leaks or damage.
• Never overload your bearing. This prevents early failure.
• Regular maintenance means longer life and better performance.

More than 96% of bearing failures come from poor lubrication, contamination, or bad installation. Take care of your bearings for the best results.

Slewing ring bearings have a clever design with inner and outer rings. They also have rolling elements and a cage inside. You can choose from different types for your needs. Some types are four-point contact ball or crossed roller. These bearings can hold heavy loads. They work in many machines, like cranes and medical equipment. If you need help picking the right slewing ring bearings, TFL Bearings can help you. We are here to give advice and support you at every step.

FAQ

What is the main job of a slewing ring bearing?

A slewing ring bearing helps your machine turn or rotate heavy parts. You get smooth movement and strong support. These bearings work in cranes, wind turbines, and robots.

How do I know which slewing ring bearing to choose?

You should check your machine’s load, space, and speed needs. Look at the type of force—axial, radial, or moment. If you need help, you can ask TFL for advice.

Do slewing ring bearings need a lot of maintenance?

You do not need much maintenance if you keep the bearing clean and greased. Check seals and bolts often. If you use maintenance-free types, you save even more time.

Can I use slewing ring bearings outdoors?

Yes, you can use them outside. Good seals and strong materials protect the bearing from rain, dust, and dirt. You get long life even in tough weather.

Where can I get help with slewing ring bearings?

You can contact TFL Bearings for expert help. TFL offers advice, custom designs, and support for your project. You get answers fast and friendly service.