Damage to Rotor Components Caused by Diesel Generator Shaft Current

Today, the professional diesel generator manufacturer, Dingbo Electric, combined years of experience to explain in detail the damage of shaft current to rotor components during the production process of diesel generators.

The rotating shaft must be lubricated using a certain method to prevent direct contact between the rotor and the bearing, that is, there is an oil film insulation between the entire rotor and static electrons during high-speed rotation. Due to the resistance of the rotor to the ground, once charged, a voltage will be established to the ground. When the voltage rises to a certain value, it will break through the area with the lowest resistance and generate electric spark discharge. The main consequences of this discharge are as follows:

1. Metal particles melt in the discharge zone, forming tiny electrical corrosion pits on the metal surface.

2. The accumulation of pits makes the surface rough and lose its luster. If it is subjected to bearing shells, pure mechanical wear will occur.

3. Molten metal particles enter the lubrication system, contaminating the lubricant and deteriorating the lubrication performance of the entire lubrication system. In addition, lubricants containing a large amount of metal particles can reduce the oil film resistance and accelerate the progress of spark erosion.

4. Local high temperature is generated in the bearing bearing bearing area, which damages the oil film, burns out the metal, increases wear, and causes serious friction damage.

In the rotor system of rotating machinery, the most vulnerable parts to electric spark discharge are the bearing surfaces of radial bearings and thrust bearings. The working tooth surface and floating ring sealing surface of the gear coupling. Due to changes in various conditions during operation, such as load, temperature, lubrication conditions, and rotor vibration, these components may reduce oil film and gap resistance, leading to electric spark discharge.

For radial sliding bearings, the development of corrosion pits in the bearing will seriously corrode the alloy surface, not only changing the original clearance of the bearing, but also causing scratches and scratches on the bearing surface. Local high temperature and burns. The wear on the surface of high-speed light load bearings can cause some bearing shells to lose the preload of the rotor journal, which is particularly prone to inducing oil film vortices and leading to instability of the rotor system. On the contrary, an unstable oil film can cause a sharp decrease in the resistance of the bearing oil film, causing more shaft current to pass through the area and exacerbate electric sparks, which excite each other and damage the bearing or rotor system.

Guangxi Dingbo Generator Set Manufacturing Co.,Ltd is an early professional manufacturer of generators and diesel generator sets in China. The company has first-class national-level large-scale production and load testing equipment. Provide users with long-term diesel generator set sales, leasing, technical consultation, commissioning, maintenance, training services and generator set trusteeship business. If you would like to get more information welcome to contact us via sales@dieselgeneratortech.com.