LTZC's four-point contact ball slewing bearing technology achieves a new breakthrough.

Recently, LTZC Bearings successfully completed the assembly and multiple rounds of continuous operation testing of its newly developed generation of four-point contact ball slewing bearings. The test results showed that the product operates smoothly, with controllable temperature rise and reliable structure under high load and medium-to-high speed conditions, fully meeting and in some aspects exceeding design expectations. This achievement not only marks a new milestone in LTZC's technological advancements in the field of slewing bearings but also lays a solid foundation for subsequent larger diameter slewing bearing, higher-precision bearing, and higher-speed series products.

The product validated in this test is an externally geared four-point contact ball slewing bearing with a slewing center diameter of 2480mm, employing a segmented copper cage structure design. During the testing process, even with significant deviations between some raceway parameters and theoretical values, the bearing still demonstrated excellent operational stability and reliability, fully reflecting LTZC's comprehensive capabilities in design redundancy, manufacturing control, and engineering verification.

What is a four-point contact ball slewing bearing?

A four-point contact ball slewing bearing is a type of bearing structure where the rolling elements and raceways form four points of contact.  It is a combined bearing structure that can simultaneously withstand axial force, radial force, and overturning moment. This type of bearing has a compact structure, high load capacity, and relatively low friction resistance, and is widely used in engineering machinery, lifting equipment, port machinery, metallurgical equipment, energy equipment, and high-end industrial equipment.

In slewing ring equipment, the bearing not only bears the structural weight but also directly affects the operating accuracy, service life, and safety of the entire machine. Therefore, extremely high demands are placed on materials, heat treatment, machining accuracy, tooth profile quality, and assembly consistency.

Why choose an external helical gear structure?

Compared with straight gears, helical gears have a higher degree of overlap during meshing, resulting in smoother transmission, less noise, and less impact. This is particularly suitable for medium-to-high speed, large-diameter slewing bearing applications. For large slewing bearings with a rotation center diameter of up to 2480mm, the external helical gear design helps reduce meshing vibration and improve the overall operating comfort and reliability of the machine.

New Product Structural Design Highlights

1. Large Slewing Center Design: 2480mm

The slewing center of the bearing tested reached 2480mm, falling into the category of large-diameter slewing bearings. This large size structure places higher demands on material consistency, ring forming precision, heat treatment uniformity, and subsequent precision machining. LTZC has developed a mature process system in ring forging, turning, raceway machining, and overall assembly, ensuring the stable manufacturing of this specification product.

2. Segmented Copper Cage Structure

The cage is one of the key components in four-point contact ball bearings. Its structure and material directly affect the uniformity of steel ball movement, friction characteristics, and bearing life. This product adopts a segmented copper cage design:

It has good self-lubricating properties and wear resistance;

It maintains structural stability under high load conditions;

It helps reduce mutual interference between steel balls and improves overall smooth operation.

In the initial experiment, the cage performed stably under high speed and high load conditions, providing reliable basic data for subsequent optimization.

3. Engineering Redundancy in Four-Point Contact Raceway Design

It is worth noting that in this test, even with some deviations between the raceway parameters and theoretical calculated values, the bearing still operated stably. This phenomenon verifies, from an engineering perspective, LTZC's reasonable redundancy and safety factor control capabilities in raceway design, and also demonstrates the important support that manufacturing consistency provides for actual operating performance.

 Initial Assembly and Testing: Stable Performance Under High Load

Test Condition Overview

In the initial experiment, the four-point contact ball slewing bearing was tested under the following conditions:

Rotational speed: 47 rpm

Axial equivalent load: 11 tons

Operating mode:

Continuous operation for 8 hours (twice)

Continuous operation for 12 hours (once)

Temperature Rise and Operating Status Analysis

Throughout the entire test process, the maximum bearing temperature was 61.8°C, and the temperature rise curve was stable with no sudden changes. After multiple rounds of continuous operation, the overall condition of the bearing was good, with no abnormal noise, jamming, or torque loss.

From an engineering testing perspective, this result is of great significance:

It verifies the reliability of the structural design under medium-high speed and high load conditions;

It demonstrates the adaptability of the segmented copper cage in actual working conditions;

It provides benchmark data for subsequent long-term durability testing.

 Second Round of Optimization Testing: 72-Hour Continuous Operation Verification

Targeted Optimization Measures

After summarizing the data from the first test, the LTZC engineering and technical team implemented targeted optimizations on the bearings:

The sharp edges of the copper cage were finely polished to further reduce friction and localized stress concentration;

New steel balls were installed to ensure better consistency in rolling element size and surface quality.

Long-Term Continuous Operation Conditions

Under the same load and speed conditions, the bearings underwent a continuous 72-hour uninterrupted operation test. This test more closely simulates the long-term use scenarios of actual industrial equipment, placing higher demands on the bearing's thermal stability, running-in characteristics, and structural reliability.

Test Results and Data Performance

Final stable temperature: Approximately 56°C

Maximum temperature throughout the test: Did not exceed 60°C

First day of running-in phase: Slight fluctuations in temperature and torque were observed, which is a normal running-in phenomenon.

As the operating time increased: The temperature rise curve gradually stabilized, and the torque variation became stable.

These results fully demonstrate that the optimized bearings possess excellent thermal balance capabilities and stable friction characteristics under long-term continuous operation conditions.

Engineering Significance of the Test Results

1. Verification of Product Reliability

From assembly testing to 72-hour continuous operation verification, this four-point contact ball slewing bearing performed excellently under high load and medium-to-high speed conditions, providing sufficient basis for its application in actual equipment.

2. Verification of Design and Bearing Manufacturing

The test results represent not only the success of a single product but also a comprehensive reflection of LTZC's overall design methodology, manufacturing process, and quality control system.

3. Laying the Foundation for Serialized Product Development

Through the successful verification of the 2480mm specification product, LTZC has accumulated valuable design and testing data, providing solid support for the subsequent development of products with larger outer diameters, higher precision, and higher rotational speeds.

Conclusion: Crafted with Expertise, Driving Reliable Rotation

The successful testing of the four-point contact ball slewing bearing marks a significant step for LTZC Bearings in the field of high-end slewing bearings. In the future, LTZC will continue to be guided by customer needs, based on engineering validation, and centered on lean manufacturing, constantly introducing more reliable and higher-performance bearing products.

LTZC, as a leading rotary bearing manufacturer in China, boasts over 20 years of experience in bearing research and development.With a spirit of craftsmanship, LTZC Bearings will continue to provide trustworthy bearing solutions and professional services to global customers, supporting every safe, stable, and precise rotation.

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