gavinchu@sunrises-group.com +852-95143941
Do you know the following expertise in wind power bearings?

Do you know the following expertise in wind power bearings?

Dec 11, 2019

风电轴承专业知识讲解

Do you know the following expertise in wind power bearings?

 1 wind turbine bearing

近年来,全球新兴市场的风电发展迅速。在国家政策支持和能源供应紧张的背景下,中国风电设备制造业迅速崛起,风电设备的市场需求增势迅猛,其中也带动了风电机组轴承的发展。

In recent years, wind power in emerging markets around the world has developed rapidly. Against the backdrop of national policy support and tight energy supply, China's wind power equipment manufacturing industry has risen rapidly, and the market demand for wind power equipment has grown rapidly, which has also driven the development of wind turbine bearing.


(Freely contact with Mr Gavin Chu(gavinchu@sunrises-group.com) if any wind power bearings demand or other industrial bearings have requirement)

 

轴承属于风电机组的核心零部件。风电轴承的范围涉及从叶片、主轴和偏航所用的轴承、到齿轮箱和发电机中所用的高速轴承。下面就一起了解风电轴承的那些事吧!

Bearings are the core components of wind turbines. Wind power bearings range from blade bearing, shafts bearing, yaw bearing to high-speed bearings used in gearboxes and generators. Let ’s takes a look at wind power bearings together!

 

每台风力发电机设备用偏航轴承(回转支承)1套,变桨轴承(回转支承)3套(部分兆瓦级以下的风力发电机为不可调桨叶,可不用变桨轴承),发电机轴承(深沟球轴承、圆柱滚子轴承)3套,主轴轴承(调心滚子轴承)2套,共计9套。

Each set wind power equipment require 1 set of yaw bearing (slewing bearing) and 3 sets of pitch bearing (slewing bearing) for each wind turbine equipment 3 sets of machine bearings (deep groove ball bearings, cylindrical roller bearings), 2 sets of main shaft bearings (spherical roller bearings), a total of 9 sets.

此外还有变速箱轴承,而变速箱有三种结构形式,第一种形式需装用轴承15套,第二种形式需装用轴承18套,第三种形式需装用轴承23套。这样,风力发电机组轴承数量平均值为27套。

In addition, there are gearbox bearings, and gearboxes have three structural forms. The first form requires 15 sets of bearings, the second form requires 18 sets of bearings, and the third form requires 23 sets of bearings. In this way, the average number of wind turbine bearings is 27 sets.

风力发电机用轴承的结构形式主要有四点接触球轴承、交叉滚子轴承、圆柱滚子轴承、调心滚子轴承、深沟球轴承等。偏航轴承安装在塔架与座舱的连接部,变桨轴承安装在每个叶片的根部与轮毂连接部位。

The structural forms of bearings for wind turbine generators mainly include four-point contact ball bearings, cross roller bearings, cylindrical roller bearings, spherical roller bearings, deep groove ball bearings, and so on. The yaw bearing is installed at the connection between the tower and the cockpit, and the pitch bearing is installed at the connection between the root of each blade and the hub.

 

1风电轴承的主要特点

Features of wind power bearings

 

1、使用环境恶劣;Harsh working environment

2、高维修成本;  High maintenance cost   

3、要求高寿命;  Require long usage life

 

2 风电轴承的分类

Classification of wind power bearing

 

风力发电机用轴承主要包括:偏航轴承、变桨轴承、发电机轴承、传动系统轴承(主轴和变速箱轴承)

The bearings for wind generators mainly include: yaw bearings, pitch bearings, spindle bearings, generator bearings,transmission system bearing (spindle and gearbox bearing)

 

2.1发电机轴承(Generator bearing)

 

轴承类型:深沟球轴承、角接触轴承等。

Bearing type: deep groove ball bearings, angular contact bearings, etc.

 

工况特点:高转速(1000-1500rpm)、高温(90-120℃)重载。

Working condition characteristics: high speed (1000-1500rpm), high temperature (90-120 ° C) and heavy load.

 

对润滑脂的要求:优异的剪切安定性、良好的氧化安定性、良好的抗磨性能、优异的低温启动性能等。

Requirements for grease: excellent shear stability, good oxidative stability, good anti-wear performance, excellent low-temperature starting performance, etc.

 2 generator bearing

2.2主轴轴承 spindle bearing

 

轴承类型:圆锥滚子轴承、球面滚子轴承等。

Bearing type: tapered roller bearing, spherical roller bearing, etc.

 

工况特点:低转速(<25rpm)、宽温、重载且变化大、振动、高湿度。

Characteristics of working conditions: low speed (<25rpm), wide temperature range, heavy load and large change, vibration, high humidity.

 

对润滑脂的要求:优异的抗磨性能、良好的氧化安定性、优异的低温启动性能、良好的抗水淋性等

Requirements for grease: excellent anti-wear performance, good oxidative stability, excellent low-temperature starting performance, good water resistance, etc.

 3 spindle bearing

2.3 变桨/偏航轴承(pitch/yaw bearing)

 

轴承类型:四点接触球轴承等。

Bearing type: Four-point contact ball bearings, etc.

 

工况特点:停多于转、宽温、重载、振动、高湿度。

Characteristics of working conditions: stop more than rotation, wide temperature range, heavy load, vibration, high humidity.

 

对润滑脂的要求:优异的防腐和抗微动磨损性能、优异的低温启动性能、良好的抗水淋性、良好的氧化安定性等。

Requirements for grease: excellent anti-corrosion and anti-fretting wear performance, excellent low-temperature startup performance, good water resistance, good oxidation stability, etc.

 4 pitch bearing yaw bearing

3 风电轴承的生产工艺要求

Production process requirements for wind power bearings

 

1、 要控制好锻造温度,不要晶粒粗大;

It is necessary to control the forging temperature and avoid large grains;

 

2、 要控制好调制质工艺,保证其心部的调质组织,从而保证其力学性能;

It is necessary to control the modulation process and ensure the tempering organization of the heart, thereby ensuring its mechanical properties;

 

3、 表面的中频淬火硬化层深度的控制;

Control of the depth of the surface IF hardened layer;

 

4、 避免表面产生微细裂纹。

Avoid fine cracks on the surface.

 5 Production control of wind power bearing

 

4 风电轴承的润滑分析

Lubrication analysis of wind power bearings

 

风电齿轮箱输入轴的转速一般在10-20转/分钟,由于转速比较低,导致输入轴轴承(也就是行星架支撑轴承)的油膜较难形成。

The speed of the input shaft of the wind power gearbox is generally 10-20 rpm. Due to the relatively low speed, it is difficult to form an oil film on the input shaft bearing (that is, the planet carrier support bearing).

 

油膜的作用是在轴承运转时分开两个金属接触面,避免金属与金属直接发生接触。

The role of the oil film is to separate the two metal contact surfaces when the bearing is running to avoid direct metal-to-metal contact.

 

我们可以引入一个参数λ来表征轴承的润滑效果。

We can introduce a parameter λ to characterize the lubrication effect of the bearing.

(λ定义为油膜厚度与两接触表面粗糙度之和的比值)

(λ is defined as the ratio of the thickness of the oil film to the sum of the roughness of the two contact surfaces)

如果λ>1,说明油膜的厚度足够分开两个金属表面,润滑效果良好;

If λ> 1, it means that the thickness of the oil film is sufficient to separate the two metal surfaces, and the lubrication effect is good;

而如果λ<1,则说明油膜的厚度不足以完全分开两个金属表面,润滑效果不理想。

If λ <1, it means that the thickness of the oil film is not enough to completely separate the two metal surfaces, and the lubrication effect is not ideal.

 

在润滑不良的情况下运转,轴承有可能会发生损伤。由于风电齿轮箱一般都采用ISOVG320粘度的循环润滑油,因此如果发现λ小于1,我们一般只能通过降低轴承滚道及滚子的粗糙度来改善润滑效果。

Bearings may be damaged due to poor lubrication conditions. Because wind power gearboxes generally use circulating oil of ISOVG320 viscosity, if we find that λ is less than 1, we can only improve the lubrication effect by reducing the roughness of the bearing raceways and rollers.

 

另外,在齿轮箱设计时,行星架支撑轴承要尽量避免一端轴承的尺寸太小,在实际的应用分析中我们发现即使寿命满足条件,这种设计也会导致小轴承的线速度非常低,油膜更加无法形成。

In addition, in the design of the gearbox, the planetary support bearing should try to avoid that the size of the bearing at one end is too small. In actual application analysis, we found that even if the life meets the conditions, this design will cause the linear velocity of the small bearing too low to form the oil film.

6 installation of wind power equipment

 

5 风电轴承的承载区分析

Analysis of load bearing area of wind power bearings

 

在运转的滚子中通常只有一部分承受载荷,而这部分滚子所在的区域我们称之为轴承的承载区。

Only a part of the running rollers bears the load, and the area where these rollers are located is called the bearing area of the bearing.

 

轴承承受的载荷大小,运行游隙的大小都会对承载区产生影响。如果承载区范围太小,滚子在实际的运转中则容易发生打滑现象。

The magnitude of the load and the running clearance of the bearing will affect the bearing area. If the range of the load area is too small, the rollers are prone to slippage in actual operation.

 

对于风电齿轮箱而言,如果主轴的设计采用双轴承支撑的方案,那么理论上只有扭矩传递到齿轮箱。在这种情况下,经过简单的受力分析,我们不难发现行星架支撑轴承承受的载荷是比较小的,因此轴承的承载区往往也比较小,滚子容易发生打滑。在风电齿轮箱设计中行星架支撑轴承一般采用两个单列圆锥轴承或者两个满滚圆柱轴承的方案。

For wind power gearboxes, if the design of the main shaft adopts a double bearing support scheme, then theoretically only torque is transmitted to the gearbox. In this case, after a simple force analysis, it is not difficult to find that the load on the planetary support bearing is relatively small, so the bearing area of the bearing is often relatively small, and the roller is prone to slip. In the design of the wind power gearbox, the planet carrier support bearing generally adopts the scheme of two single-row tapered bearings or two full-compliment cylindrical bearings.

 

我们可以通过适当预紧圆锥滚子轴承或者减小圆柱滚子轴承游隙的方法来提高承载区。

We can increase the load zone by properly preloading tapered roller bearings or reducing the clearance of cylindrical roller bearings.

7 wind power bearing installation

6 风电轴承的使用技术

Technology of winder power bearing

 

设计与分析:仍以经验类比设计为主,受力分析与载荷谱的研究几近空白。其中的难点技术是针对主轴轴承的要求无故障运转达13*104h以上,并具有95%以上的可靠度;针对齿轮箱轴承的高损坏率的高载荷容量设计等。

Design and analysis: mainly depends on the empirical analog design at present, and the study of the force analysis and load spectrum is almost blank. The difficult technology is the failure-free operation of the main shaft bearing for more than 13 * 104h, and has a reliability of more than 95%; the high load capacity design of the gear box bearing with high damage rate.

 

材料:不同部位的轴承采用不同的材料及热处理,如提高偏航和变桨轴承用40CrMo钢的低温(环境温度-40℃∽-30℃,轴承工作温度在-20℃左右)冲击功等力学性能的热处理方法,表面感应淬火的淬硬层深度、表面硬度、软带宽度和表面裂纹的控制;增速器轴承用相当于国外STF、HTF钢的研制及控制其残余奥氏体最佳含量的研究;主轴轴承在国产真空脱气钢质量尚存在一定差距的情况下,采用电渣重熔渗碳钢ZG20Cr2Ni4A制造等。

Material: Different parts of the bearing are made of different materials and heat treatments, such as improving the low temperature (environment temperature -40 ℃ ∽-30 ℃, bearing working temperature around -20 ℃) impact performance of 40CrMo steel for yaw and pitch bearings. Heat treatment method, surface induction hardening depth of the hardened layer, surface hardness, soft band width and control of surface cracks; gearbox bearings equivalent to the development of foreign STF, HTF steel and control of the optimal content of residual austenite Research; In the case where there is still a certain gap in the quality of domestic vacuum degassed steel, the spindle bearing is manufactured by electroslag remelting and carburizing steel ZG20Cr2Ni4A, etc.

8 Bearing of wind turbines