The Dilemma of Servo Motor Precision and Service Life —— The

I. Customer Background and Core Issues

A large-scale automation equipment enterprise offers a diverse range of products including electronic manufacturing equipment (e.g., PCB drilling machines), machine tools for auto parts processing, and logistics warehousing robots. Its core drive component is independently developed servo motors with a power range of 0.75kW-22kW. The enterprise’s servo motors suffer from three critical issues:

Rapid precision degradation: Bearing clearance increases from the initial 0.005mm to 0.015mm after 3 months of operation, leading to a decline in motor rotation precision and a 5% scrap rate of processed workpieces.

Short service life and high maintenance costs: Frequent start-stop cycles and high loads (axial load of 12kN) result in an average bearing service life of only 6 months. A single bearing replacement requires an 8-hour machine shutdown, with annual maintenance costs exceeding RMB 300,000.

Severe heating at high speeds: At a high rotational speed of 10,000rpm, the bearing temperature rise reaches 75℃, triggering the motor overheat protection and causing frequent production line interruptions.

II. SKL Customized Solution

SKL has tailored an ultra-precision single-row angular contact ball bearing solution for the customer, with the core configuration as follows:

Bearing Model: SKL 7012-C-T-P4S (Ultra-precision single-row angular contact ball bearing, pairing mode: back-to-back DB)

Core Technical Highlights

Material Upgrade: The inner and outer rings are made of SUS440C martensitic stainless steel, treated with vacuum quenching + low-temperature tempering, achieving a hardness of HRC60-62 and a 15% improvement in toughness. The rolling elements are made of silicon nitride (Si₃N₄) ceramic material with a density of only 3.2g/cm³ (40% of steel balls), reducing centrifugal force by 60% and effectively minimizing high-speed friction.

Structural Optimization: A 15° contact angle is designed to adapt to the axial load requirements of servo motors; the raceway curvature radius coefficient is optimized to 0.52, reducing contact stress by 18%. A laminated phenolic resin window-type cage is adopted, featuring light weight and high wear resistance, which guides the even distribution of rolling elements.

Precision and Lubrication Control: Dimensional tolerance meets P4 grade, rotational precision reaches P2 grade, and radial runout is ≤1μm. An oil-air lubrication system is equipped, realizing precise lubrication of the raceway contact area through circumferential lubrication grooves and radial oil holes on the bearing outer ring, reducing temperature rise by 25%.

III. Application Effects and Data Verification

Since January 2025, the automation equipment enterprise has adopted SKL ultra-precision bearings in 200 sets of its servo motors (mainly applied in PCB drilling machines and auto parts processing machine tools), achieving a significant improvement in equipment performance and production efficiency. The core data is shown in the table below:

IV. Core Value of SKL Bearings in Motor Applications

As evidenced by the above case, SKL bearings address the core pain points of motor operation such as precision loss, short service life and overheating through a systematic solution integrating material innovation + structural optimization + lubrication adaptation. Its core value is reflected in three aspects:

Technological Breakthrough: Through technologies such as electrical insulation coating, ceramic rolling elements and ultra-precision machining, SKL breaks the physical limits of traditional bearings and adapts to the high-frequency, high-speed and high-load working conditions of motors.

Cost Optimization: Extending bearing service life, reducing machine shutdowns, lowering maintenance costs and production capacity losses, and creating direct economic benefits for customers.

Efficiency Improvement: Enhancing motor precision and energy efficiency, helping customers improve product quality and seize the high-end market, and achieving the dual goals of cost reduction and efficiency enhancement.

In the future, as motors develop towards the direction of higher speed, higher precision and lower carbon consumption, SKL will continue to take technological innovation as the core, provide more competitive bearing solutions for the global motor industry, and boost the upgrading of industrial equipment and the transformation to green manufacturing.