柴油发电机组使用常见问题（润滑油相关知识） Common problems in using diesel generator sets (knowledge related to lubricating oil)

柴油发电机组的润滑油相关知识

（1）润滑油的主要作用

A、润滑及减低摩擦阻力润滑油的作用，就是润滑发动机内的各种机件，并在两者表面之间形成一层油膜，以减低摩擦阻力，使运作更加顺畅。
  B、密封性作用润滑油必须能在活塞环与汽缸之间形成有效的密封性，以防汽体的泄漏和外界的污染物侵入。
  C、冷却作用在运转过程中，机件与机件的相互摩擦产生很大的热量或高温，润滑油的作用就是冷却及减低发动机的温度。
  D、清洁性把机件中的有害杂质和未及燃烧的不溶性物质带走，使这些污染物远离润滑表面及避免油泥的形成。

E、防腐蚀功能润滑油如能提供接触部件完全分离的油膜，会减少机件接触及磨损的机会，避免金属表面受到腐蚀。

（2）润滑油的等级 

  美国汽车工程师协会对润滑油粘度等级规定简称SAE，有0W5W10W15W20W25W，为多级油在寒冷地区使用，数字越小，其低温性能越好SAE20304050为粘度等级，它表示100的粘度数，数字越大，粘度越大如15W40表示此油在低温下符合15W的要求和100的粘度符合SAE40的要求。  
  美国石油协会对机油品质等级评定标准简称为API汽油机油的级别以S打头，字母越往后，级别越高：SA  SB  SC  SD  SE  SF  SG  SH  SJ  柴油机油，以C打头CA  CB  CC  CD  CE  CF  CF4  CG  CG4例SAE  15W40  API  SG/CD表示冬夏通用南北适用的多级油，具有汽油，柴油两性能通用的机油。

Knowledge related to lubricating oil for diesel generator sets

(1) The main function of lubricating oil

A、 The function of lubricating oil is to lubricate various components inside the engine and form an oil film between their surfaces to reduce frictional resistance and make operation smoother.

B、 The sealing effect of lubricating oil must be able to form an effective seal between the piston ring and the cylinder to prevent leakage of the steam body and invasion of external pollutants.

C、 Cooling effect: During operation, the friction between components generates a large amount of heat or high temperature. The function of lubricating oil is to cool and reduce the temperature of the engine.

D、 Cleanliness removes harmful impurities and unburned insoluble substances from the components, keeping these pollutants away from the lubricating surface and avoiding the formation of sludge.

E、 If the anti-corrosion lubricating oil can provide a completely separated oil film for the contact parts, it will reduce the chance of mechanical contact and wear, and prevent metal surfaces from being corroded.

(2) Grade of lubricating oil

The Society of Automotive Engineers (SAE), abbreviated as 0W5W10W15W20W25W, specifies the viscosity grade of lubricating oil. It is a multi-stage oil used in cold regions, and the smaller the number, the better its low-temperature performance. SAE20304050 is the viscosity grade, which represents the viscosity number of 100. The larger the number, the higher the viscosity. For example, 15W40 indicates that this oil meets the requirements of 15W at low temperatures and 100 viscosity meets the requirements of SAE40.

The American Petroleum Institute's standard for evaluating the quality level of engine oil, abbreviated as API gasoline engine oil, starts with S and the later the letter, the higher the level: SA SB  SC  SD  SE  SF  SG  SH  SJ   Diesel engine oil, starting with C, CA CB CC CD CE CF CF4 CG CG4, SAE 15W40 API SG/CD represents a multi-stage oil suitable for both winter and summer use, suitable for both gasoline and diesel use.