What is Slew Drive?

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What is Slew Drive?

A slew drive, also known as a slewing drive, is a gearbox designed to handle radial and axial forces simultaneously while allowing for rotational motion. The device typically consists of a slewing bearing, a drive gear (often a worm gear), and other components such as seals and lubrication systems, all housed within a compact, robust assembly. The primary function of a slew drive is to facilitate controlled, precise rotational motion and to transmit torque effectively.

Features of Slew Drive

High Load Capacity: Slew drives are designed to handle significant loads both axially and radially, making them suitable for heavy-duty applications.

Precision: They allow for precise control over movement, which is critical in applications requiring exact positioning.

Compact Design: The integration of bearings and gearing into a single unit allows for a more compact installation footprint.

Ease of Installation: The self-contained unit is generally easier and quicker to install than separate components.

Versatility: They can be customized with different motors (hydraulic, electric, etc.) and can be designed to suit various environmental conditions and loads.

Sealed Unit: Provides protection against dust, dirt, and water, which helps in maintaining performance in harsh environments.

Applications of Slew Drive

Solar Trackers: Used extensively in solar energy systems to rotate solar panels towards the sun throughout the day to maximize energy capture.

Wind Turbines: Helps in the yaw and pitch adjustment of wind turbine blades to optimize the wind capture.

Cranes and Manlifts: Facilitates the rotation of the crane boom and the basket of manlifts, providing movement and positioning.

Slewing Drive for Excavators: Used in the rotation of the cab and the attachment for better maneuverability and operation.

Medical Equipment: In devices such as CT scanners and MRI machines, slew drives help in the precise movement of machinery around the patient.

Robotic Arms and Automation Systems: Provides rotational movement that is precise and reliable for various automated and robotic systems.

Slewing Drive for Machinery

In general machinery, slew drives are used to enhance the functionality of moving parts, allowing for rotational movement that can support significant loads. This is particularly useful in automation, where precise and reliable movement is critical.

Slew Drive for Excavator

In excavators, the slew drive enables the upper structure (including the cab and engine) to rotate independently of the undercarriage. This is crucial for tasks such as digging and loading, where the operator needs to pivot the machine to access different areas without relocating the entire vehicle.

Slew Drive for Crane

For cranes, the slew drive is critical in the rotation of the crane’s boom. It allows the boom to turn horizontally, enabling the crane to lift and move loads over different parts of a construction site or other locations without needing to move the base of the crane. This capability is essential for the efficient operation of both mobile and stationary cranes.

Slew drives are integral components in many types of heavy machinery, offering enhanced load capacity, precision, and operational efficiency. Their robust design tailored to withstand harsh environments makes them indispensable in both industrial applications and infrastructure development projects.

Suppliers of Slewing Drive

Luoyang Longda Bearing Co., Ltd., with registered trademark LDB, is an enterprise specializing in the design, development, manufacture and sales of precision slewing bearings (slewing rings) and precision slewing drives. If you are looking for slewing drives for your project, feel free to contact us.

The structure and function of the slewing drive of the truck-mounted crane

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Slew Drive

The structure and function of the slewing drive of the truck-mounted crane

Slew Drive Structure

The slewing drive device of the truck-mounted crane includes a hydraulic motor, a brake and a reducer.

Function:

1.Hydraulic Motor

Convert the pressure of hydraulic oil into rotational mechanical energy and transmit the rotational motion to the reducer.

2.Brake

The brake is inside the hydraulic motor and brakes the output shaft of the hydraulic motor.

3.Reducer

The reducer of truck-mounted crane is composed of a two-stage reduction planetary gear transmission. It is decelerated through the gear transmission device and transmitted to the output shaft of the reducer.

Slewing Bearing

Abnormal noise problem of excavator slewing bearing

It is normal for the new slewing bearing to make a uniform sound of rolling steel balls when it is idling. It will disappear after a period of running-in after installation. If there is a loud sound or special noise, you should pay attention.

1. The mounting surface is uneven and the mounting bolts are loose

2. There is a foreign body in the slewing bearing

3. Abnormal noise caused by a problem with the grease

4. Raceway and rolling body are severely worn

Conclusion: you should not be careless when there is abnormal noise in the excavator slewing bearing, you must check and solve the fault in time.

Slewing Gear Ring Bearing Drive

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Slewing Gear Ring Bearing & Slewing Gear  Drive

Rotary gears are usually divided into two types, one is the rotary gear support bearing, the other is the rotary gear drive
Slewing gear support bearings are composed of an inner ring and an outer ring, usually one of which contains the gear. Together with the connecting holes on the two rings, they are easily and quickly wired through the adjacent link components for optimized power transmission. Slewing gear bearing raceways combined with rolling elements and cages are designed to withstand loads acting individually or in combination in any direction.
Rotary gears can be used in various industries such as aerospace, heavy equipment, industrial machinery, medical systems, mining, oil and gas, etc., and are the key to many industries and play a vital role.
The slewing gear support bearing is different from ordinary bearings, the difference is that it has a gear that can adjust the rotation. The machine transmits and adjusts the direction of the mechanical products fixed on the slewing bearing through the dynamic sensing system installed on the slewing gear bearing. and take advantage of special constructs:

It maintains the overall balance, effectively guarantees the radial force generated in the work, and ensures the balance.

The rotary gear drive is a kind of turntable fixed in the gear box, which can safely bear the radial and axial load force, and drives the rotation of the turntable through the rotation of the turbine. Rotary gear drive is a gearbox composed of gears, bearings, seals, casings and motors.
The rotary gear drive is a modification of the worm drive mechanism. It dates back to the Renaissance period, when the Greek mathematician Pappus devised a worm drive. Da Vinci also used the slewing gear drive trim in many of its machines.


The driving force of the rotary gear drive comes from the rotational force given by the motor to the worm, and the gear on the worm is adjusted by the gear on the electric turntable. This combination mode reduces the rotation speed of the turntable, increases the torque, and can drive heavier objects.
Slewing gear drives can be applied to solar trackers, wind turbines, elevators, hydraulic machinery, telescopic arms, cranes and other equipment.

Slewing Bearing Installation Surface

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Mechanical machining of the bearing connection surfaces on the connecting structure is required . The mounting position of slewing bearings must correspond to that shown in the drawing. If a transporting cross was delivered, it has to be removed before installation.

The corrosion protection can be removed with an alkaline cleaner. Cleaner must be prevented from coming into contact with the seals or the raceway. Remove the protective coating from the upper and the lower mounting surfaces of the slewing bearing as well as from the gear.

The corrosion protection can easily be removed, for example, using a biodegradable alkaline cleaner.

Rapid removal of the corrosion protection and low environmental impact.

The unhardened zone between the beginning and the end of the hardened region of the raceway is marked with an “S” on the inner or outer diameter of each bearing ring. On the gear ring, the hardness gap is marked on the axial surface. Wherever possible, the hardness gap “S” must be positioned outside the main load-carrying areas. If the main working area for the application is known, then the hardness gap of the ring loaded on the circum-ference must also be positioned outside the main load-carrying area.

The bearing must be completely screwed on for commissionings and test runs. Sufficient load / moment loan must be applied to avoid a slip-stick effect on the anti-friction bearing bodies.

Gearing

Entanglement hazard due to exposed gear

  • Keep hands away from moving parts

The backlash is adjusted relative to the three gear teeth marked in green and should be 0.03 – 0.04 x module.After the final tightening of the bearing,the backlash should be rechecked over the entire circumference. A tip edge radius and a tip relief must be provided on the pinion.

Marine Propeller orientation device (POD)

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Marine Propeller orientation device (POD)

LDB has a long history of providing a full range of slewing bearings for the azimuth positions of marine applications.

These highly tailored solutions cover outside diameters from 50 to 7 900 mm.

Our wide range of engineering expertise in bearings, seals, mechatronics, services and lubrication systems all contribute to the high quality of our marine solutions.

As proof, every bearing designed and produced for marine applications is subject to approval by certifying authorities.

Slewing Driver Application

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Slewing reducer -Slewing driver can be applied to the host of the circular motion, such as the crane rotation platform and the rotation machinery, etc. The turbine and worm mechanisms are often used for two -axis intertwined, large transmission ratio, small transmission power, or intermittent work. This product can be widely used in the field of engineering machinery represented by high -altitude operating vehicles, car cranes, new energy fields represented by solar photovoltaic power generation, wind power generation, and other fields of automation, machine tool manufacturing, aerospace communications and other fields. Therefore, the product’s market potential is huge.

Slewing drive
Slewing reducer –Slewing driver Subjective list

Rotate machine with a dual snail turn drive drive

Driver driver with a car

Heavy tablet transport vehicle turning driver

High -altitude operating vehicle turning driver

Railway turning driver Driven driver

Slewing claws with rotation driver

Bridge detection vehicle rotation driver device

China Railway Liangji Slewing Driver Device

Solar turning driver

What are the sealing methods of the slewing bearing? Sealing function and method

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We know that the slewing bearing has a very important role in some production, and in order to ensure these functions, we need to perform a lot of operations on the slewing bearing during the use of the slewing bearing. The sealing of the more common bearings, then why should the slewing bearing be used? to seal? What are the common sealing methods of slewing bearings?

The role of sealed slewing bearing

Slewing Bearings

1. Isolate foreign objects from outside

Protect the bearing to prevent external dust, dirt, metal particles, moisture, acid gas and other debris from invading the inside of the bearing. If the bearing is poorly sealed and external debris invades, the working condition of the bearing will be significantly deteriorated, and the service life of the bearing will be significantly reduced.

2. Prevent grease leakage

If the oil leaks, it will quickly destroy the normal lubrication of the bearing, causing the bearing to burn out due to heat. In addition, the poor sealing device not only causes waste of oil leakage, but also contaminates mechanical equipment and processed products. Therefore, to make the machine work properly, the bearing must have a good sealing device.

The way of sealing the slewing bearing

Slewing Bearings

Generally, the sealing methods of bearings include contact sealing and non-contact sealing, but these two sealing methods are suitable for different situations. Contact sealing is suitable for bearings operating in medium and low-speed working environments, while non-contact sealing Bearings that are suitable for high-speed and high-temperature working environments, as slewing bearings, generally operate at low speeds, but there are also high-temperature operations. The analysis shows that the methods of sealing slewing bearings are as follows:

1. Felt ring seal

A trapezoidal groove is opened on the bearing cover, and the fine felt on the rectangular surface is placed in the trapezoidal groove to contact the shaft, or the gland is pressed axially, so that the felt ring is compressed to generate radial pressure and hug the shaft, thereby achieve the purpose of sealing. The sealing structure is simple and the cost is low, but the sealing effect is poor, it cannot be adjusted, and the wear is serious.

2. The leather bowl is sealed

Place a sealing cup in the bearing cover (the cup is made of rubber and other materials) and press it directly on the shaft. In order to enhance the sealing effect, a ring-shaped coil spring is used to press the inner ring of the leather cup, so that the inner ring of the leather cup and the shaft have a tighter fit, and the sealing effect is better than that of the felt ring. /s of grease lubrication or lubricating oil lubrication.

3. Sealing ring seal

The sealing ring is usually made of leather, plastic or oil-resistant rubber, and can be made into different cross-sectional forms as required. The 0-shaped sealing ring has a circular section and is pressed on the shaft by its own elastic force. It has a simple structure and is easy to assemble and disassemble. Also commonly used are J-shaped and U-shaped profile seals, which all have a lip-shaped structure. The direction of the sealing lip is towards the sealing part, which is similar to the direction of the flange in the cup seal. When the temperature is high and the rotational speed is high, it is recommended that the sealing lip also be installed away from the bearing. The sealing effect of the sealing ring is better than that of the felt ring, and it can be used for the sealing of grease and oil.

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4. Skeleton seal

The skeleton seal we often say is the improvement of the leather cup seal. In order to improve the overall strength of the leather cup seal, a metal lining with an L-shaped cross-section and an overall annular shape is installed in the oil-resistant rubber, so that the leather cup seal is not easily deformed and improves the use of This kind of seal is easy to install and has good performance. It is generally suitable for occasions where the peripheral speed of the journal is 7m/s.

5. Sealing ring seal

This is an annular seal with a gap, which is placed in the ring groove of the sleeve, the sleeve rotates with the shaft, and the seal ring is pressed against the static part by the elasticity of the gap after being compressed. On the inner hole wall, it can play a sealing role, and this kind of sealing is more complicated.

6. Labyrinth seal

The basic principle of this kind of seal is to form a section of flow channel with great flow resistance at the seal. Structurally, a small tortuous gap is formed between the stationary part and the rotating part, forming a “labyrinth”. If the “labyrinth” is radial, the axial dimension is compact, but the radial dimension is larger. If the “labyrinth” is axial, the radial dimension is compact, but the bearing cover should be divided, and the axial clearance should be larger, so as not to be stuck due to thermal deformation of the shaft. Labyrinth seals are quite reliable for both lubricating oil and bone grease, and the higher the speed, the better the effect.

The above is the summary of the sealing methods of the slewing bearing, and the whole content of the sealing function and method. We have learned that the slewing bearing has the functions of isolating foreign objects and preventing grease leakage. The common methods are felt ring sealing, leather cup Seal, seal ring seal, skeleton seal, seal ring seal, labyrinth seal, etc., you can choose according to the specific situation of your bearing

What are the application fields of slewing drive

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The slewing drive can be applied to the main engine that does circular motion, such as crane turntable, rotating machinery, and other machines that perform circular work.

Slewing drive can be widely used in the field of construction machinery represented by aerial work vehicles and truck cranes, as well as in the field of new energy represented by solar photovoltaic power generation and wind power generation, as well as other fields of automation, machine tool manufacturing, aerospace communications, etc. It can be said that this product The market potential is huge.

1. The field of beam transport vehicles

The core components of the traditional beam-carrying slewing assembly mostly use traditional slewing bearing products. Since the slewing bearing does not have an outer casing, the corrosion resistance is not ideal. For the steering system that relies on hydraulic cylinders to push the tires, the The range of rotation angles is also greatly limited.

VE Series Slewing Drive

2. Field of aerial work vehicles

Aerial work vehicles are an important application area of ​​slewing drive. Usually, aerial work vehicles require the main engine to have a high safety factor. The high safety of slewing drive (self-locking of worm gears) is the choice of the majority of users as accessories for aerial work platforms. An important factor; on the other hand, the worm gear transmission has a larger transmission speed ratio, which improves the safety factor of the main engine and also omits a set of worm gear reducers for the main engine, thereby reducing the manufacturing cost of the main engine.

3. Photovoltaic power generation field

Photovoltaic power generation is an important application field of rotary drive. The use of solar photovoltaic modules with rotary drive as a rotating component can accurately adjust the rotation angle and elevation angle of the host according to the different positions of the sun during the day. the receiving angle.

SE Series Slewing Drive

4. Wind power generation

Similar to the photovoltaic discovery, the slewing drive can be applied to the yaw part of the wind turbine to realize the horizontal 360 rotation of the mechanism, so as to better adjust the receiving angle.

5. The field of construction machinery claws

Auxiliary equipment for construction machinery is a brand-new application field of slewing drive.

The above is all about the application field of slewing drive. If you have any questions during use, please feel free to communicate with us in depth.

Will the slewing drive raceway be damaged? Causes of raceway damage and preventive measures

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The main structure of the slewing reducer is a structure in which the slewing bearing is used as a transmission follower and a mechanism attachment, and the slewing bearing itself is used to cooperate with the driving power source and the main transmission parts to complete the rotation, deceleration and driving. The slewing bearing is still one of the more critical components, so will the raceway of the slewing drive be damaged? Below, Xiaobian will give you a detailed introduction.

Will the raceway of the slewing drive be damaged?

Will be damaged. As an important component used by many construction machinery, the slewing reducer will inevitably have problems such as wear and fatigue damage during daily use. Because of its slewing structure, it is inevitable that the raceway will be damaged during work. . In addition to the insufficient rigidity of the raw materials in the manufacturing process, the reasons for the damage to the raceway may include unreasonable structural design and insufficient manufacturing accuracy of the reducer. Let’s take a look at it in detail:

VE Series Slewing Drive

Causes of damage to the slewing drive raceway

1. Heat treatment process

The processing quality of the rotary reducer itself is related to the manufacturing accuracy, heat treatment state, and axial clearance. What we usually ignore is the influence of the heat treatment state. In addition to the external force, the most important thing for the damage of the raceway is the depression and cracks on the surface of the raceway during its production. This is related to the hardness of the raceway surface and the hardness of the hardened layer and the core, and these factors are determined in the heat treatment process. For this reason, the depth of the hardened layer on the raceway surface is insufficient and the hardness of the core is low. A more critical factor in its raceway damage.

2. Structural rigidity of turntable

The key component that transmits various loads between the turntable and the chassis when driven by gears. The rigidity of the turntable itself is not large. It mainly depends on the rigidity of the chassis and the structure of the turntable that supports it. When the structural rigidity of the turntable is not enough, the turntable under large eccentric loads The deformation of the bottom plate connected to the slewing mechanism is more serious, which in turn causes the equipment load to concentrate on a small part of the rollers, thereby increasing the pressure on a single roller, resulting in the contacting raceway also bearing a large contact stress, which It is also one of the reasons for the damage to the raceway.

SE Series Slewing Drive

Preventive measures for rotary drive raceway

1. Pay attention to the rated load: the rotary drive should not be overloaded;

2. Correct model selection: Select the appropriate slewing drive according to your needs. When purchasing the slewing drive, you must strictly calculate the various parameters of the slewing drive, and select the turntable bearing that suits the actual needs. road damage;

3. Pay attention to maintenance: maintain regular maintenance, and regularly add lubricating oil to the rotary drive. Only through reasonable maintenance and maintenance can we ensure that the slewing drive raceway is not easily damaged and prolong the service life of the slewing drive.
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The above is the answer to the question about whether the raceway of the slewing drive will be damaged. It includes the reasons for the damage of the raceway and preventive measures. In fact, whether it is the drive device or the bearing itself, as mechanical parts, there is a certain fatigue limit, which should be based on Use the guide reasonably and maintain it properly, so as to better play the role and value of the equipment.

How to judge the operating status of the slewing drive? Common faults and solutions

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Slewing drives are widely used due to their modular installation convenience, operational stability, load-bearing capacity and strong environmental adaptability, etc., to improve industrial production efficiency and accelerate the realization of industrial automation. Then, once a failure occurs during the operation of the equipment, it may affect the normal production plan. For this reason, we should pay attention to the operation of the equipment and make timely judgments.

Judgment method of slewing drive operating state

SE Series Slewing Drive

1. Pay attention to the backhaul gap

During the operation of the equipment, observe the clearance of the rotary reducer during the return stroke, and judge the return clearance of the drive by the instant forward and reverse operation mode during operation. Refer to the theory of the type of rotary reducer corresponding to the instruction manual provided when the drive is purchased. The return gap can be used to judge whether the running state is normal.

2. Listen to the running sound

Normal equipment operating sounds are different from abnormal sounds. How to determine the operating status of the slewing drive can start from identifying the abnormal sounds. For abnormal noises or irregular sounds during operation, it is necessary to judge whether the reducer is in normal operation. If there are abnormal sounds, it should be repaired in time to determine the damage location and repair it.

3. Observe the operating temperature

If the slewing drive has abnormal temperature, there may be problems with overload operation or bearing wear and abnormal voltage, but these are usually not directly reflected from the operating state when the equipment is running, so we can judge by the temperature of the drive during operation. If the temperature is too high, it needs to be overhauled in time.

If all the above conditions are normal after running for more than 30 minutes, it means that the rotary reducer is in good working condition and can be used with confidence. So, the following editor introduces some common faults of rotary reducers for reference only.

Common faults and solutions of slewing drive

S Series Slewing Drive

1. The motor does not rotate: the motor does not rotate. Eliminate power failure and poor switch contact. There may be problems such as abnormal voltage, gear damage, overload operation, coil breakage, etc. You need to check the power supply, wiring, voltage, capacitor or directly contact the manufacturer for repair.

2. Abnormal heating: Abnormal heating of the drive may be caused by overload operation, abnormal voltage, bearing wear, etc. It is necessary to reduce the load and frequency of use, confirm whether the voltage is normal and perform maintenance.

3. Noise: The noise of the rotary reducer may have bearing damage, gear wear, or foreign matter jamming, and it needs to be disassembled and repaired by the manufacturer’s service personnel. Or there is lubricating oil contaminated or lack of lubricating oil, it should be supplemented or replaced in time.

4. Abnormal vibration: abnormal vibration caused by loose screws or wear of gears and bearings requires screw progress or replacement and maintenance of gear bearings.

5. Oil leakage: There are reasons such as loose screws or damage to the sealing ring, and the screws should be replaced or tightened in time.

The above are several judgment methods of Lunda editor on how to judge the running status of the slewing drive, as well as the common faults and solutions of the equipment. I hope it will be helpful to everyone. In the daily use of the reducer, you should pay attention to the running status of the equipment and find the problem in time. Repairs to prevent the deterioration of the problem from affecting production.