LTZC mining slewing bearing technology achieves breakthrough

Against the backdrop of the global trend towards larger, more intelligent, and heavier-duty mining equipment, an increasing number of heavy-duty machines are needed to support the development of the mining industry. These mining machines, such as excavators, cranes, and stacker-reclaimers, all rely heavily on slewing bearings as core rotating components. In these heavy-duty machines, slewing bearings bear axial loads, radial loads, and overturning moments, while also rotating 360 degrees. Their performance directly determines the safety and service life of the entire machine. As a key load-bearing component, the performance of mining slewing bearings not only affects the stable operation of equipment but also the production efficiency and operating costs of mining companies.

In recent years, LTZC, as a professional slewing bearing manufacturer, has completed a series of structural innovations and process upgrades to meet the demands of high impact loads, complex working conditions, and ultra-long service life in mining. This has resulted in a breakthrough in mining slewing bearing technology, providing more reliable solutions for mining equipment, crane slewing rings, and excavator slewing bearings. Recently, a Chilean client, a mining company, contacted us. They are currently working on a new project, designing a new type of excavator, and needed us to share our experience in manufacturing slewing bearings for the mining industry. We held a detailed experience exchange meeting.

I. The Extreme Challenges of Mining Conditions to Slewing Bearings

Mining equipment differs from ordinary construction machinery in that its working environment has the following significant characteristics:

Long-term continuous heavy-load operation

High dust, high humidity, and even corrosive environments

Strong impact loads and frequent start-stop cycles

Low-speed, high-torque operating conditions

In open-pit mines, underground mines, and mineral processing plants, mining slewing bearings are typically used in critical components of large excavators, stacker-reclaimers, mobile crushing plants, and crawler cranes. These machines, operating in such environments, require slewing bearings to possess high performance in lubrication, sealing, load capacity, and lifespan. The core requirements for slewing bearings include:

Extremely high axial load capacity

Excellent overturning moment withstand capability

Stable rotational accuracy

Ultra-long fatigue life

Good sealing and dustproof capabilities

Traditional designs often balance load capacity and lifespan, but with the trend towards larger and heavier mining equipment, this balance is no longer sufficient to meet the needs of the new generation of equipment. The LTZC technical team, based on this real challenge, has undertaken systematic technical research and development, especially in extending the service life of bearings while increasing their load capacity.

II. Mining Slewing Bearing Structural Optimization and Upgrade

In this technological breakthrough, LTZC has systematically optimized the structure of heavy-duty mining slewing bearings. The core upgrades focus on the following aspects:

1. Raceway Geometry Optimization

Through finite element analysis and multibody dynamics simulation, LTZC redesigned the raceway curvature radius and contact angle, resulting in a more uniform load distribution and reduced localized stress concentration. The optimized structure features: higher contact area, lower unit contact stress, and superior rolling stability. In actual fatigue life tests, the theoretical life of the new mining slewing bearing is increased by approximately 25%-35%, significantly better than traditional structures.

2. Enhanced Double-Row Ball and Three-Row Roller Combination Structure

For ultra-large mining equipment, most use three-row cylindrical roller slewing bearings and double-row ball slewing bearings capable of bearing extremely high loads. LTZC employs an improved three-row roller distribution structure, separating the axial force, radial force, and overturning moment for load bearing, thereby achieving a higher safety factor.

This structure performs particularly well in large crane slewing ring applications, especially suitable for heavy-duty crawler cranes and bulk material handling equipment in mining areas. LTZC has supplied several sets of three-row cylindrical roller slewing bearings with a diameter of up to 5000mm to a European excavator manufacturer. Customer feedback indicates that the slewing bearings are performing well and have not experienced any malfunctions. This customer feedback affirms LTZC's bearing manufacturing technology.

III. Load-Bearing Upgrades of Cranes Slewing Rings in Mining Equipment

Extreme Load Adaptation Technology for Cranes Slewing Rings

Large-scale lifting equipment in mining areas generates enormous instantaneous impact loads and overturning moments when hoisting ore crushing modules, conveying structures, and large steel structures.

To address this issue, the LTZC technical team focused on strengthening the design of the cranes slewing ring: prioritizing quality during forging procurement, controlling the quenching process and grinding precision of the gear ring during manufacturing, and significantly reducing stress concentration at the tooth root by optimizing the tooth root transition radius design. Simultaneously, CNC tooth profile modification technology was employed to ensure smoother meshing and reduce impact and vibration.

In mining project application cases, the cranes slewing rings provided by LTZC have operated continuously for over 18 months without any abnormal wear records, demonstrating greater stability compared to previously imported products.

IV. Breakthrough in Impact Resistance Technology of Excavator Slewing Bearing

Performance of Excavator Slewing Bearing in High-Impact Environments in Mining Areas

Large mining excavators generate high-frequency impact loads when loading hard ore, especially when working with broken rock strata or metal-bearing ores. Under impact, debris can be ejected into the equipment's interior, potentially affecting gear meshing and causing jamming and shutdown. This places extremely high demands on the hardness and sealing of the slewing bearing.

LTZC has made the following improvements to the excavator slewing bearing:

Increasing the quenching depth of the raceway surface

Enhancing the hardness gradient transition of the raceway

Improving the strength of the cage material

Multiple sealing structure design

Optimizing the contact surface between the roller and the raceway

Especially in terms of sealing, LTZC has developed a dual dustproof sealing system, effectively preventing dust from entering the raceway area and significantly reducing the risk of grease contamination.

Comparative field tests in mining areas have shown that the maintenance cycle of the new excavator slewing bearing is extended by more than 30%, and the frequency of grease replacement is significantly reduced.

After in-depth communication with the customer, the customer reported that the manufacturing of the new excavator requires a significant improvement in load capacity and lifespan. The mining industry has stringent requirements for slewing bearings, which means that when purchasing from suppliers in the mining industry, it is important to focus on the supplier's manufacturing capabilities and slewing bearing solutions.