Precision four-point contact ball slewing bearing for AGV equipment

I. What is a four-point contact ball slewing bearing?

The four-point contact ball slewing bearing—also known as a single-row ball slewing bearing—is one of the most widely used types of slewing bearings.

These bearings feature a Gothic arch raceway design, allowing a single row of rolling elements to establish four points of contact simultaneously with both the inner and outer raceways. This unique structure enables a single bearing to withstand combined loads—axial, radial, and tilting moments—thereby saving valuable installation space within AGVs, reducing the overall weight of the unit, and controlling manufacturing costs.

A four-point contact ball slewing bearing primarily consists of six components: the inner ring, outer ring, steel balls, spacers, seals, and grease nipples. Based on the drive configuration, they are categorized into three types: non-geared, externally geared, and internally geared.

Precision slewing bearings are developed based on standard four-point contact ball bearings. Through processes such as precision raceway grinding, strict clearance control, rigorous management of geometric tolerances, and the use of upgraded raw materials, these bearings offer enhanced rotational accuracy, reduced rotational clearance, and minimized fluctuations in starting torque, thereby meeting the high-precision positioning requirements of AGV.

LTZC manufactures precision four-point contact ball slewing bearings for AGVs across accuracy classes P0, P6, P5, and P4, allowing for the selection of the appropriate precision grade to match the specific positioning accuracy requirements of a customer's AGV project.

II. Technical Requirements for Four-Point Contact Ball Slewing Bearings in AGV Equipment

2.1 Low starting torque; smooth rotation without sticking

AGVs operate at low speeds with frequent start-stop cycles. Under these conditions, if the machining precision of the slewing bearing raceway is insufficient, the rotation may stick or stutter. LTZC’s AGV-specific four-point contact ball slewing bearings utilize high-precision steel balls and precision-ground raceways to ensure uniform and stable rotational resistance.

2.2 Strict control of rotational clearance for high-precision positioning

AGVs require precise delivery of goods to designated locations, necessitating that the rotational clearance of the slewing bearing be kept within a very tight range. LTZC’s high-precision four-point contact ball slewing bearings enable repeatable, high-precision positioning, thereby enhancing the operational efficiency of the customer's equipment.

2.3 Compact structure and lightweight design

AGV equipment often has strict installation space constraints and limited height allowances. LTZC manufactures thin-walled four-point contact ball slewing bearings that reduce cross-sectional height—lowering equipment weight and energy consumption—without compromising load capacity or performance.

2.4 Resilience against frequent start-stop cycles and long fatigue life

AGVs often operate with continuous rotation, making them susceptible to fatigue pitting and abnormal noise. For its AGV slewing bearings, LTZC uses 42CrMo steel for the inner and outer rings, maintains raceway hardness within the HRC 55–62 range, and ensures adequate hardening depth. This results in excellent resistance to fatigue wear and meets the requirement for a service life of one million rotation cycles.

2.5 Reliable sealing against dust and particulate contamination

Smart warehouse floors generate dust and debris; if these enter the slewing bearing raceway, they can cause wear on the raceway and rolling elements. LTZC’s precision four-point contact ball slewing bearings come standard with double-lip rubber seals that effectively block contaminants from entering the raceway, thereby extending maintenance intervals and reducing equipment failures.

III. Detailed Case Study: LTZC Precision Four-Point Contact Ball Slewing Bearing for AGV Project

3.1 Project Background

LTZC recently undertook an AGV project for a company specializing in intelligent warehousing automation integration. The AGV, designed for large-scale unmanned warehouse operations, features a load capacity of 800 kg and requires its top-mounted pallet-lifting mechanism to perform independent 360° rotation.

3.2 LTZC Four-Point Contact Ball Slewing Bearing Solution

Following technical consultations with the client, LTZC’s technical team determined the optimal product solution: a non-geared four-point contact ball slewing bearing. Key specifications include a P5 precision grade, customized minimal internal clearance, double-lip rubber dust seals, and factory-applied long-life grease.

3.3 Sample Testing and Batch Delivery

Upon completion of the initial batch of samples, LTZC’s quality control department conducted comprehensive inspections covering dimensions, rotational torque, and internal clearance. The samples were subsequently sent to the client’s laboratory for durability rotation testing. After undergoing 100,000 rotation cycles, the bearings operated smoothly without binding; pallet positioning accuracy met all requirements, and no abnormal noises associated with wear were detected. These precision slewing bearings for AGV are now being supplied in stable batches for intelligent warehousing projects across Southeast Asia and Europe, with excellent operational feedback.

IV. LTZC AGV Precision Slewing Bearing Manufacturing Capabilities

As a renowned hub for the bearing industry in China, LTZC operates a factory in the Bearing Industrial Park of Yiyang County, Luoyang City, Henan Province. With over 30 years of experience in R&D and production, LTZC is an integrated manufacturer covering R&D, heat treatment, precision machining, raceway grinding, gear processing, assembly, finished product inspection, sales, and after-sales service. We possess comprehensive, end-to-end production capabilities, ensuring quality control from the very source of production.

4.1 Comprehensive Advanced Production Equipment

The LTZC factory is equipped with vertical CNC lathes, specialized large-scale slewing bearing raceway grinders, high-precision gear hobbing machines, gear shaping equipment, and gantry drilling/milling machines. We are capable of manufacturing slewing bearings with outer diameters ranging from 100mm to 15,000mm. Specifically for small, precision four-point contact ball slewing bearings used in AGVs, we operate a dedicated precision machining workshop to guarantee the rotational accuracy of every unit.

4.2 State-of-the-Art Finished Product Inspection Laboratory

LTZC’s quality inspection department is equipped with advanced testing instruments, including Coordinate Measuring Machines (CMM), roundness testers, and ultrasonic flaw detectors. Every AGV four-point contact ball slewing bearing undergoes full-dimensional inspection before shipment, and a detailed inspection report is provided.

4.3 Authoritative Quality Certification Systems

The LTZC factory holds certifications such as ISO, ABS, BV, and CCS. Our slewing bearings are exported to markets across Europe, Southeast Asia, the Middle East, India, and Russia, backed by extensive experience in fulfilling international orders.

4.4 Robust Custom Development and Delivery Capabilities

The LTZC team can utilize customer-provided 3D drawings and equipment specifications to develop precision slewing bearings tailored to specific needs, offering comprehensive, one-stop solutions.

V. FAQ: Precision Slewing Bearings for AGV Equipment

Q1: Which type of slewing bearing is best suited for AGV rotating platforms?

A: For AGV load-carrying rotating platforms, non-geared four-point contact ball slewing bearings are the preferred choice. These bearings offer a high cost-performance ratio, a lightweight design, and ease of installation.

Q2: What is the difference between using four-point contact ball slewing bearings and crossed roller slewing bearings on AGV?

A: Four-point contact ball slewing bearings utilize point contact, resulting in lower rotational resistance, smooth and agile rotation, and high cost-effectiveness; they are suitable for most standard AGV operating conditions. Crossed roller slewing bearings utilize line contact, offering higher rigidity and superior resistance to overturning moments; they are ideal for high-precision, heavy-load AGV projects. LTZC supplies both product lines and can compare the two options to recommend the most suitable product for the customer.

Q3: Can LTZC provide custom, non-standard slewing bearings for AGV?

A: Absolutely. LTZC possesses strong capabilities for non-standard customization, allowing us to tailor precision four-point contact ball slewing bearings to specific requirements regarding mounting flanges, height constraints, and precision levels.

Q4: What is the typical service life of an AGV slewing bearing?

A: Service life depends heavily on factors such as load, eccentric loading, cycle frequency, lubrication and maintenance, and the operating environment. Provided that the bearing is correctly selected, properly maintained, and operated in a clean environment, LTZC’s precision four-point contact ball slewing bearings designed for AGV can achieve a service life exceeding one million rotation cycles.

Contact LTZC to learn more about our solutions.