Worm Gear Reducer Maintenance Guide and Common Issues: Causes and Solutions to Prevent Worm Shaft Bearing Wear and Damage
2025
Common Problems and Their Causes
1. Overheating and Oil Leakage
To balance strength and efficiency, worm gears are usually made of non-ferrous metals, while the worm shaft is hardened steel. Since the transmission relies on sliding friction, significant heat is generated during operation, which can cause thermal expansion differences between components and seals, leading to gaps. At the same time, lubricants thin as temperature rises, making leakage more likely.
The main causes include:
- Whether the material pairing is appropriate
- Surface quality of the meshing friction faces
- Selection and quantity of lubricant
- Assembly precision and operating environment
2. Worm Gear Wear
Worm gears are commonly made of non-ferrous metals such as tin bronze, while the mating worm shaft is typically 45# steel that has been hardened. During normal operation, the harder worm acts like a “file” against the softer worm gear, gradually causing wear. This wear usually progresses slowly, and many gearboxes can operate for over ten years. However, if wear occurs rapidly, factors such as improper gearbox selection, overloading, inferior materials, poor assembly quality, or harsh environments should be checked.
3. Wear of Small Helical Transmission Gears
This issue often appears in vertically installed gearboxes and is closely related to the type and amount of lubricant. In vertical setups, oil levels can become insufficient. When the machine stops, lubricant drains away from the small transmission gear between the motor and gearbox, leaving gear teeth uncoated. As a result, during cold starts or operation, the gears may run without proper lubrication, leading to accelerated wear or even failure.
4. Worm Shaft Bearing Damage
In some failure cases, even when the gearbox seal remains intact, the lubricating oil may become emulsified, and bearings may rust, corrode, or fail. This often results from condensation as the oil heats up and cools down, releasing moisture inside the housing. Additionally, the bearing’s own quality and assembly workmanship have a direct impact on service life.
Common Solutions for Worm Gear Reducer Failures
1. Ensure Assembly Quality
To guarantee installation accuracy, it is recommended to use dedicated tools and avoid hammering or forceful impacts when disassembling or assembling worm gears, worms, bearings, and other components. Pay close attention to tolerance fits for the output shaft according to the manufacturer’s manual. In addition, applying anti-seize compound or red lead oil can protect hollow shafts from wear, corrosion, and scaling on mating surfaces, making future maintenance and disassembly easier.
2. Selection of Lubricants and Additives
Based on long-term operating experience, ISO VG 220–460 oils are generally recommended, depending on design specifications. For heavy loads, frequent starts, or harsh environments, synthetic gear oils are preferred. Since different synthetic oils provide varying effects on worm gear performance, selection should be made carefully. A proper lubricant film remains on gear surfaces even after shutdown, forming a protective layer that prevents direct metal-to-metal contact during heavy loads, low speeds, high torque, or startup conditions.
3. Choose Installation Position Wisely
Whenever possible, avoid vertical installation. Vertical gearboxes require more lubricant, which increases the risk of overheating and leakage, as well as accelerated gear wear. For example, on an acid pickling line in a steel plant, some vertically installed gearboxes experienced severe small-gear wear and even failures after a period of operation. Once the installation was adjusted, conditions significantly improved.
4. Establish a Comprehensive Lubrication and Maintenance System
Daily maintenance should follow the “Five Fixed” lubrication principles, with designated personnel responsible for routine checks. If oil temperature rises significantly (temperature rise >40 °C or oil temperature >80 °C), oil quality deteriorates, copper particles increase, or abnormal noise occurs, the gearbox should be stopped immediately for inspection. Faults must be corrected, and the lubricant replaced before resuming operation. Always maintain the correct oil quantity and level consistent with the installation position to ensure proper lubrication.
Fully Synthetic Lubricants for Worm Gear Reducers
| Application | Product | ISO VG | Food Grade Certification | Features |
|---|---|---|---|---|
| Worm Gear Oil | BESLUX GEAR ET RED | 220, 320 | N.A. | Semi-synthetic red gear oil with adhesiveness and water-repellent properties |
| Worm Gear Oil | BESLUX GEARSYNT XP | 220, 320, 460 | N.A. | PAO fully synthetic gear oil, outstanding protection for gearboxes |
| Worm Gear Oil | BESLUX SINCART | 220, 320, 460 | N.A. | Special fully synthetic gear oil, long-lasting protection to prevent copper wear |
| Worm Gear Oil | BESLUX GEARSYNT ATOX | 220, 320, 460 | NSF H1 | Food-grade synthetic gear oil, ensuring no secondary contamination in food production lines |
Brugarolas Lubricants
Founded in 1885 and headquartered in Barcelona, Brugarolas Lubricants (Eagle Brand, Spain) is dedicated to innovation in lubricant applications. All products comply with the RoHS directive, ensuring worry-free import and export without concerns over restricted substance testing. Our solutions extend equipment lifetime and reduce operating costs.
With a complete product line covering diverse industries—cement, mining, food processing, paper, aerospace, and advanced electronics—Brugarolas provides reliable lubrication for a wide range of applications. If you require specialized products beyond those listed, our engineers are ready to assist with tailored solutions.
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