Gears are one of the most important basic components in mechanical products. Gear transmission is a form of mechanical movement and power transmission. Gears have the characteristics of large transmission force, accurate rotation ratio, wide range of use, safety and reliability. Gears need lubricating oil, and gear transmission is developing in the direction of high speed, heavy load, high and low temperature. Improper lubrication can lead to gear failure and mechanical damage. Therefore, reasonable selection of gear lubricants has become more and more important.
What are the factors that affect gear lubrication?
1. Temperature factor:
The lubricating oil thickens when the temperature drops, and becomes thinner when the temperature rises. Therefore, low-viscosity grease is required in a low-temperature environment, and thicker grease is required in order to prevent friction between metals under high-temperature conditions.
2. Speed factor:
The main reason for the speed is that when the speed is fast, there is less lubricant between the gears, and the lubricant is easy to solidify when running at high speed. Therefore, high-viscosity grease can be used at low speeds, and low-viscosity grease can be used at high speeds.
3. Load factor:
High-viscosity lubricants are more resistant to heavy loads than thin oils and prevent metal-to-metal collisions. Therefore, low-viscosity lubricants are required for light loads, and high-viscosity lubricants are required for high loads to prevent gears from colliding with each other.
4. Gear types and structural elements:
There are spur gears, helical gears, switch gears, hyperbolic gears, worms, etc., sliding and rotating form an effective oil film, slow down the direct contact between the gears, and extend the life of the gears. In unequal bearing transmission devices such as worm gears and hyperboloid gears, the direction of relative sliding motion is not conducive to maintaining the oil film, and boundary lubrication often occurs. Therefore, transmissions of worms and hypoid gears require thicker grease. When these rotating devices are subjected to heavy loads and high pressures, greases with high oil film characteristics and high viscosity are selected.
5. Material elements:
The material of the gear is different, and the choice and choice of grease are also different.
① Between plastics and plastics: First consider compatibility. If the compatibility is poor, the plastic will harden and expand and contract softly. Some plastics have poor affinity with grease, leading to poor lubrication.
②For the lubrication of plastics and metals, first consider the strength and affinity of plastics, and there is a tendency to choose grease. The selected lubricating grease provides lubrication, vibration reduction, noise reduction, and extended life for the parts. It has good compatibility with plastic parts and will not age the plastic. The metal parts have good protective properties.
③The metal gear reacts with part of the lubricating material to form a lubricating film on the metal surface. For all-metal gears, we can choose a grease with a high viscosity, the thickness of the oil film becomes thicker, and the appropriate viscosity can be fully utilized.
6. Working environment factors:
Working environment such as dust environment, strong acid and alkali, ozone pure oxygen environment, high temperature and humidity, high pressure and so on.
①The grease corresponding to each environment is different. In special environments, due to the wrong choice of grease, the life is shortened, reacting with environmental substances, lubricating the contact position, material embrittlement, oxidation, and losing the lubricating effect.
②The poor water-wetting resistance of grease in a high-temperature and high-humidity environment will lead to emulsification and loss of grease.
③Considering the anti-rust properties of lubricants for metal materials.
