Lubrication knowledge

Hazard of poor quality or improper use of engine oil 

The quality of lubricating oil will directly affect the working state of the engine. High quality lubricating oil can reduce engine wear, prolong service life and reduce fuel consumption. On the contrary, if the use of poor quality lubricating oil or improper use method, it will bring some problems to the engine: 

1. Burn the bearing bush

If the quality of the lubricating oil is not good, or the viscosity chosen of the lubricating oil is not right, the lubrication effect will be not good.Too low oil pressure, engine oil shortage, cooling system failure and so on can cause engine overheating. In this case, high-speed operation can burn the bearing easily, commonly known as "burning tile". In addition, if using inferior oil filter element or not replace the oil filter element on time, it will have impurities in it, resulting in "burning tile".

2. Clasp

If the clean dispersity of lubricating oil is not good, it will produce carbon deposits around the piston ring after long-term using time, and carbon deposits can cause the piston ring to be stuck or broken under the serious deposits situation.

3. Too large oil consumption

If the anti-wear performance of the lubricating oil is not good, it will aggravate the wear between the piston ring and the cylinder, weaken the scraping effect of the oil ring, make the oil enter the combustion chamber to participate in the combustion, and produce the phenomenon of blue smoke from the exhaust pipe. If the engine seal is not good, valve oil ring failure will also cause oil leakage,it will also speed up oil consumption.

4. Oil lamp alarm

Once this phenomenon occurs, it is mainly found in the following aspects: insufficient lubricating oil (add); Oil induction plug damage (replacement); Filter screen of oil pump is blocked (cleaning); Insufficient lubricating oil viscosity (replace lubricating oil or check whether there is fuel dilution and engine overheating phenomenon); Oil limiting valve spring failure (clean and replace). 

How are the viscosity index, flash point, pour point and oxidation stability of lubricating oil defined?

Viscosity index: indicates that the viscosity of an oil changes with temperature. A high viscosity index indicates that the viscosity of an oil changes less with temperature, and vice versa. 

Flash point: under specified conditions, the lower temperature at which the mixture of steam and air escaping from the heating oil comes into contact with the flame is called the flash point, expressed by ℃. Flash point measurement methods are divided into open cup method and closed cup method. Open cup method is used to determine the flash point of heavy lubricating oil. The closed-mouth cup method is used to determine the flash point of fuels and light lubricants.

Pour point: refers to the lower temperature at which the test oil can flow after cooling under specified conditions, expressed in ℃. Pour point and condensing point are both used to indicate the low-temperature flow performance of petroleum products. 

Oxidative stability: The ability of petroleum products to resist the action of air (or oxygen) and maintain their properties without long-term changes is called the oxidative stabili

What is the lubrication principle of lubricating oil?

The lubrication principle of lubricating oil is to reduce friction, the so-called friction, refers to a relative displacement created, is generated through two surfaces in relative motion move relative to each other under the action of external forces, called the friction surface.There are many kinds of friction phenomena, including external friction, internal friction, sliding friction, rolling friction, dry friction, boundary lubrication friction, fluid lubrication friction, mixed lubrication friction and so on. The apparent phenomena brought by friction include high temperature, high pressure, noise, wear and so on. Among them, wear is more harmful. Wear includes adhesive wear, abrasive wear, corrosion wear, surface fatigue wear and other types. It directly affects the normal operation or even failure of mechanical equipment. 

The role of lubricating oil is to form a protective film between the two friction pairs, to avoid direct contact between metal and metal, so as to buffer the effect of friction, lubrication, reduce wear, protect the normal operation of machinery. The protective film can be physical adsorption film, chemical adsorption film or oxidation film, the thickness and strength of the film can directly affect the lubrication.

The lubrication function of ordinary lubricating oil is mainly to form a layer of oil film between the friction surface for protection. The lubrication theory of lubricating oil relies on the additive forming adsorption film on the friction surface for protection. The base oil itself only plays a sealing role between the additive carrier and the friction surface, and the lubrication function of oil film has been relegated to a secondary position  of petroleum products.

发动机润滑油品质差或使用不当的危害

润滑油的品质好坏将直接影响发动机的工作状态，高品质润滑油可以减少发动机磨损， 延长使用寿命，并降低燃油消耗。相反，如果使用品质不好的润滑油或使用方法不当，就会给发动机带来一些问题：

1、烧轴瓦

如果选用的润滑油质量不好，或者选用的润滑油黏度不对，润滑效果就不好。而油压过低、发动机缺油、冷却系统故障等又可以引起发动机过热。在这种情况下高速运转，就容易将轴承烧坏，俗称“烧瓦”。另外，如果使用了劣质机油滤芯或者没有按时更换机油滤芯，还会使杂质夹在其间，造成“烧瓦”。

2、卡环

如果润滑油的清洁分散性不好，长期使用后就会在活塞环周 围产生积碳，而积碳严重时就可以造成活塞环卡死或者折断。

3、机油消耗过大

如果润滑油的抗磨损性能不好，就会使活塞环和气缸之间的磨损加剧，油环刮油作用减弱，使机油进入燃烧室参加燃烧，产生排气管冒蓝烟的现象。如果发动机的密封不好、气门挡油环失效等也会造成机油渗漏，同样会加快机油的消耗。

4、机油灯报警

一旦发生这种现象主要在以下几方面找原因： 润滑油不足 ( 添加) ； 机油感应塞损坏(更换) ；机油泵过滤网堵塞(清洗)；润滑油黏度不足(更换润滑油或检查有无燃油稀释及发动机过热现象)；机油限压阀弹簧失效(清洗更换)。

润滑油的粘度指数、闪点、倾点和氧化安定性是如何定义的?

粘度指数：表示油品粘度随温度变化这个特性的一个约定量值，粘度指数高表示油品的粘度随温度变化较小，反之亦然。

闪点：在规定条件下，加热油品所逸出的蒸汽和空气组成的混合物与火焰接触发生瞬间火时的较 低温度称为闪点，以℃表示。闪点的测定方法分为开口杯法和闭口杯法，开口杯法用以测定重质润滑油的闪点；闭口杯法用以测定燃料和轻质润滑油的闪点。

倾点：指在规定条件下被冷却了的试油能流动时的较 低温度，以℃表示，倾点和凝点一样都是用来表示石油产品低温流动性能的指标。

氧化安定性：石油产品抵抗空气（或氧气）的作用而保持其性质不发生长期性变化的能力叫做油品的氧化安定性。

润滑油的润滑原理?

润滑油的润滑原理是减少摩擦，所谓摩擦，是指当两个相对运动表面，在外力作用下发生相对位移时，存在一个相对的接触面，叫摩擦面。摩擦现象的种类很多，有外摩擦、内摩擦、滑动摩擦、滚动摩擦、干摩擦、边界润滑摩擦、流体润滑摩擦、混合润滑摩擦等。摩擦带来的表观现象如高温、高压、噪音、磨损等。其中危害较 大的是磨损，磨损有粘着磨损，磨料磨损，腐蚀磨损、表面疲劳磨损等类型,它直接影响机械设备的正常运转甚至失效。

润滑油的作用就是在两摩擦副之间形成一种保护膜，避免金属与金属之间直接接触，从而缓冲了摩擦力作用，起到润滑作用，减少磨损，博爱户机械正常运转。这种保护膜可以是物理吸附膜，或化学吸附膜或氧化膜，膜的厚度及强度直接影响到润滑作用。

普通润滑油的润滑作用主要是在摩擦面间形成一层油膜作保护，润滑油的润滑理论是依靠添加剂在摩擦面形成吸附膜起保护作用，基础油本身仅起到添加剂载体和摩擦面间密封作用，油膜的润滑作用已退到次要地位

润滑油的润滑原理

润滑油的润滑原理是减少摩擦，所谓摩擦，是指当两个相对运动表面，在外力作用下发生相对位移时，存在一个相对的接触面，叫摩擦面。摩擦现象的种类很多，有外摩擦、内摩擦、滑动摩擦、滚动摩擦、干摩擦、边界润滑摩擦、流体润滑摩擦、混合润滑摩擦等。摩擦带来的表观现象如高温、高压、噪音、磨损等。其中危害较 大的是磨损，磨损有粘着磨损，磨料磨损，腐蚀磨损、表面疲劳磨损等类型,它直接影响机械设备的正常运转甚至失效。

润滑油的作用就是在两摩擦副之间形成一种保护膜，避免金属与金属之间直接接触，从而缓冲了摩擦力作用，起到润滑作用，减少磨损，博爱户机械正常运转。这种保护膜可以是物理吸附膜，或化学吸附膜或氧化膜，膜的厚度及强度直接影响到润滑作用。

普通润滑油的润滑作用主要是在摩擦面间形成一层油膜作保护，润滑油的润滑理论是依靠添加剂在摩擦面形成吸附膜起保护作用，基础油本身仅起到添加剂载体和摩擦面间密封作用，油膜的润滑作用已退到次要地位。