双列角接触球轴承的设计基本上与单列角接触球轴承相同，但只占用更小的轴向

The design of double-row angular contact ball bearings is basically the same as that of single-row angular contact ball bearings, but it only takes up less axial space. Double-row angular contact ball bearings can bear radial loads and axial loads acting in two directions. It can limit the axial displacement of the shaft or the housing in two directions. The contact angle is 30 degrees. Can provide high rigidity bearing configuration, and can withstand overturning moment. <br><br>Design Features <br>Double-row angular contact ball bearings can withstand large radial loads, mainly radial and axial combined loads and moment loads, limiting axial displacement in both sides of the shaft. Mainly used in components that limit the axial displacement of the shaft and the housing in both directions. <br>For example: SKF double row angular contact ball bearings are similar in design to two single row contact ball bearings arranged back to back, but the width is slightly narrower than the two single row bearings. Compared with single-row bearings, it has better rigidity. <br><br>Structural classification <br>(1) Standard design of A-type bearings with an outer diameter less than or equal to 90mm. There is no ball gap, so it can bear equal bidirectional axial load. The use of lightweight glass fiber reinforced nylon 66 cage, the bearing temperature rise is very small. <br>(2) Standard design for B-type bearings with an outer diameter greater than 90mm. There is a ball loading notch on one side, equipped with steel stamping cage or brass solid cage. <br>(3) Type C is a reinforced structure, with a ball loading notch on one side, which can hold more steel balls, so the load carrying capacity is higher. <br>(4) Double-row angular contact ball bearings with dust cover on both sides and seal ring on both sides, A-type design and C-type design can be equipped with dust cover (non-contact) or sealing ring (contact type) on both sides ). Sealed bearings are filled with anti-rust lithium-based grease, the operating temperature is generally -30 ~ +110 ℃. No relubrication is required during use, and it should not be heated or cleaned before installation. <br><br>Range of applications <br>as compared with the single row angular contact ball bearings, double row angular contact ball bearing having better rigidity and can withstand the overturning moment. The bearings are non-detachable. Especially suitable for applications with high rigidity requirements. Widely used in the front wheel hub of cars (some models also use double-row tapered roller bearings of the same size). <br><br>Performance characteristics<br>The tiltability between the inner and outer rings of double row angular contact ball bearings is limited. The allowable tilt angle depends on the internal clearance of the bearing, the bearing size, the internal design, and the forces and moments acting on the bearing. The maximum allowable tilt angle should be guaranteed There will be no excessively high additional stress in the bearing. <br>If there is an inclination angle between the inner and outer rings of the bearing, it will affect the life of the bearing, and at the same time cause the bearing's running accuracy to decrease and the running noise to increase. Double row angular contact ball bearings generally use nylon cage or brass solid cage. When installing double-row angular contact ball bearings, it should be noted that although the bearings can withstand two-way axial loads, if there is a ball loading gap on one side, care should be taken not to let the main axial load pass through the groove side of the gap. When using bearings, care should be taken to make the one side raceway without the ball notch bear the main load. <br><br>Double-row angular contact ball bearing installation method The installation of <br><br>double-row angular contact ball bearings is more complicated than deep groove ball bearings, mostly in pairs, and Pre-loading is required. Good installation can greatly improve the working accuracy and bearing life of the host; otherwise, not only the accuracy can not meet the requirements, but also the life will be affected. <br>There are three types of installation for double row angular contact ball bearings: back-to-back, face-to-face and tandem arrangement. So what are the characteristics and benefits of each of these three installation forms? ? <br>-Back (wide face two opposite bearing) is mounted, the bearing contact angle lines in the pivot axis direction of the diffuser, which can increase the angle of radial and axial bearing rigidity, the maximum resistance to deformation;? <br>Face (bearing two narrow end During relative installation, the contact angle of the bearing converges towards the axis of rotation, and its ground bearing angle is less rigid. Because the inner ring of the bearing protrudes from the outer ring, when the outer rings of the two bearings are pressed together, the original clearance of the outer ring is eliminated, which can increase the preload of the bearing; when the <br>series is arranged (the wide end faces of the two bearings are in one direction) , The contact angle line of the bearing is the same and parallel, so that the two bearings can share the working load in the same direction. However, when using this type of installation, in order to ensure the axial stability of the installation, two pairs of bearings arranged in series must be installed opposite the two ends of the shaft. <br>In addition, pay attention to a parameter during the installation process to obtain the preload. The preload can be achieved by grinding the end face of a ring in the bearing, or using two spacers of different thickness between the inner and outer rings of a pair of bearings to clamp the bearings together so that the steel ball and the raceway Obtained in close contact.<br>The size of the preload has a great influence on the service life of the bearing. According to relevant information, the service life is reduced by 380 when the bearing is equipped with an interference of 0.012mm, and the service life is reduced by 501 when there is an interference of 0.016mm; when the bearing is assembled With a 0.004mm gap, the service life is significantly reduced, and with a 0.008mm gap, the service life is reduced by 705. <br>Therefore, it is very important to choose the size of the preload. Generally, a small preload should be used for high speed, and a large preload should be used for low speed. At the same time, the preload should be slightly greater than or equal to the axial working load. ? After the <br>double-row angular contact ball bearings pass the assembly inspection, they should be run at the working speed for a dry run test, the time is not less than 2h, and the temperature rise should not exceed 15 ℃

双列角接触球轴承的设计基本上与单列角接触球轴承相同，但只占用更小的轴向空间。双列角接触球轴承可以承受径向负荷和作用在两个方向的轴向负荷，它能限制轴或外壳双向轴向位移，接触角为30度。可以提供刚性较高的轴承配置，并能承受倾覆力矩。<br><br>设计特点<br>双列角接触球轴承能承受较大的径向负荷为主的径向和轴向联合负荷和力矩负荷，限制轴的两方面的轴向位移。主要用于限制轴和外壳双向轴向位移的部件中。<br>比如：SKF双列角接触球轴承在设计上与二个背靠背排列的单列接触球轴承相似，但宽度比二个单列轴承稍窄。与单列轴承相比有更好的刚性 。<br><br>结构分类<br>(1)A型外径小于或等于90mm轴承的标准设计。无装球缺口，因此能承受相等的双向轴向载荷。采用轻型玻璃纤维增强尼龙66保持架，轴承温升很小。<br>(2)B型外径大于90mm轴承的标准设计。一侧有装球缺口，配备钢板冲压保持架或黄铜实体保持架。<br>(3)C型属加强型结构，一侧带装球缺口，可以装更多的钢球，因此承载能力较高。<br>(4)两面带防尘盖型和两面带密封圈型A型设计和C型设计的双列角接触球轴承都可以两侧带防尘盖(非接触式)或密封圈(接触式)。密封轴承的内部都填有防锈锂基润滑脂，运行温度一般在-30～+110℃。在使用期间不需再润滑，安装前不应加热，也不应清洗。<br><br>应用范围<br>与单列角接触球轴承相比，双列角接触球轴承具有更好的刚性，能承受倾覆力矩。轴承为非分离式。特别适用于有高刚性要求的应用场合。广泛用于小汽车的前轮轮毂中（有的车型也用同尺寸的双列圆锥滚子轴承） 。<br><br>性能特点<br>双列角接触球轴承内、外圈之间的可倾斜性有限，允许倾斜角取决于轴承的内部间隙、轴承尺寸、内部设计及作用于轴承上的力和力矩，而最大允许倾斜角应保证轴承内不会产生过高的附加应力。<br>若轴承内、外圈之间存在倾斜角，将影响轴承的寿命，同时造成轴承运转精度下降，运转噪声增大。双列角接触球轴承一般采用尼龙保持架或黄铜实体保持架。双列角接触球轴承安装时应注意，虽然轴承可承受双向轴向载荷，但若一侧有装球缺口时，则应注意不要让主要轴向载荷通过有缺口的一侧沟边。在轴承使用时应注意使不带装球缺口的一侧滚道承受主要载荷<br><br>双列角接触球轴承安装方法<br><br>双列角接触球轴承的安装比深沟球轴承复杂，多为成对安装，并需采用预加载荷。安装得好，可使主机的工作精度、轴承寿命大大提高；否则，不仅精度达不到要求，寿命也会受到影响。<br>双列角接触球轴承的安装形式有三种，分别是：背对背、面对面和串联排列三种。那么这三种安装形式各有什么特点与好处呢？?<br>背对背（两轴承的宽端面相对）安装时，轴承的接触角线沿回转轴线方向扩散，可增加其径向和轴向的支承角度刚性，抗变形能力最大；?<br>面对面（两轴承的窄端面相对）安装时，轴承的接触角线朝回转轴线方向收敛，其地承角度刚性较小。由于轴承的内圈伸出外圈，当两轴承的外圈压紧到一起时，外圈的原始间隙消除，可以增加轴承的预加载荷；<br>串联排列（两轴承的宽端面在一个方向）安装时，轴承的接触角线同向且平行，可使两轴承分担同一方向的工作载荷。但使用这种安装形式时，为了保证安装的轴向稳定性，两对串联排列的轴承必须在轴的两端对置安装。<br>此外，在安装的过程中要注意一个参数，预加载荷的获得。预加载荷可通过修磨轴承中一个套圈的端面，或用两个不同厚度的隔圈放在一对轴承的内、外圈之间，把轴承夹紧在一起，使钢球与滚道紧密接触而得到。<br>预加载荷的大小对轴承使用寿命影响很大，据有关资料介绍，当轴承装配有0.012mm过盈量时，使用寿命降低380，有0.016mm过盈量时，使用寿命降低501；当轴承装配有0.004mm间隙时，使用寿命显着下降，有0.008mm间隙时，使用寿命下降705。<br>因此，对预加载荷的大小进行合理选择十分重要。一般高转速宜选用小的预加载荷，低转速宜选用大的预加载荷。同时，预加载荷应稍大于或等于轴向工作载荷。?<br>双列角接触球轴承经装配检验合格后，要以工作转速作空运转试验，时间不少于2h，温升应不超过15℃

The design of double row angular contact ball bearing is basically the same as that of single row angular contact ball bearing, but it only takes up less axial space. Double row angular contact ball bearing can bear radial load and axial load acting in two directions. It can limit axial displacement of shaft or shell in two directions, and the contact angle is 30 degrees. It can provide high rigidity bearing configuration and can withstand overturning moment.<br>Design features<br>The double row angular contact ball bearing can bear the combined radial and axial load and moment load which are mainly radial load, and limit the axial displacement of the two sides of the shaft. It is mainly used in the parts that limit the two-way axial displacement of the shaft and the shell.<br>For example, SKF double row angular contact ball bearing is similar to two back-to-back single row contact ball bearings in design, but its width is slightly narrower than two single row bearings. It has better rigidity than single row bearing.<br>Structure classification<br>(1) Standard design for type a bearings with OD less than or equal to 90mm. There is no loading gap, so it can bear equal bi-directional axial load. Using light glass fiber reinforced nylon 66 cage, the temperature rise of bearing is very small.<br>(2) Standard design for bearings with an outside diameter greater than 90mm. There is a ball loading gap on one side, equipped with a steel plate stamping cage or a brass solid cage.<br>(3) Type C is a reinforced structure with a ball loading gap on one side, which can hold more steel balls, so it has a high bearing capacity.<br>(4) Double row angular contact ball bearings with dust cover on both sides and seal ring on both sides can have dust cover (non-contact type) or seal ring (contact type) on both sides. The inside of sealed bearing is filled with anti rust lithium base grease, and the operating temperature is generally - 30 ～ + 110 ℃. During use, it is not necessary to re lubricate, and it shall not be heated or cleaned before installation.<br>Application scope<br>Compared with single row angular contact ball bearing, double row angular contact ball bearing has better rigidity and can bear overturning moment. The bearing is non separating type. It is especially suitable for applications with high rigidity requirements. It is widely used in the front wheel hub of cars (some models also use double row tapered roller bearings of the same size).<br>Performance characteristics<br>The tilting between the inner and outer rings of double row angular contact ball bearings is limited. The allowable tilting angle depends on the internal clearance, bearing size, internal design and the force and moment acting on the bearing. The maximum allowable tilting angle shall ensure that no excessive additional stress will be generated in the bearing.<br>If there is an inclination angle between the inner and outer rings of the bearing, the service life of the bearing will be affected, and the running accuracy of the bearing will be reduced and the running noise will be increased. Generally, double row angular contact ball bearing adopts nylon cage or brass solid cage. During the installation of double row angular contact ball bearing, it should be noted that although the bearing can bear two-way axial load, if there is a ball mounting gap on one side, it should be noted that the main axial load should not pass through the groove edge of the notched side. When using the bearing, pay attention to make the side raceway without ball loading notch bear the main load<br>Installation method of double row angular contact ball bearing<br>The installation of double row angular contact ball bearing is more complex than that of deep groove ball bearing, which is usually installed in pairs and requires preloading. Good installation can greatly improve the working accuracy and bearing life of the main engine; otherwise, not only the accuracy fails to meet the requirements, but also the life will be affected.<br>There are three kinds of installation forms of double row angular contact ball bearings: back-to-back, face-to-face and series arrangement. So what are the characteristics and benefits of each of these three types of installation? ?<br>When the back-to-back (the wide end faces of the two bearings are opposite) is installed, the contact angle line of the bearing spreads along the direction of the rotation axis, which can increase the rigidity of the radial and axial bearing angles, and the maximum deformation resistance;?<br>When face-to-face (the narrow end faces of two bearings are opposite), the contact angle line of the bearing converges towards the rotation axis direction, and the rigidity of the bearing angle is small. As the inner ring of the bearing extends out of the outer ring, when the outer rings of the two bearings are pressed together, the original clearance of the outer ring is eliminated, which can increase the preload of the bearing;<br>When the two bearings are installed in series (the wide end faces of the two bearings are in one direction), the contact angle lines of the bearings are in the same direction and parallel, so that the two bearings share the working load in the same direction. However, in order to ensure the axial stability of the installation, two pairs of bearings arranged in series must be installed at both ends of the shaft.<br>In addition, in the process of installation, pay attention to a parameter, the acquisition of preload. The preload can be obtained by grinding the end face of a ferrule in the bearing, or by placing two spacer rings of different thickness between the inner and outer rings of a pair of bearings to clamp the bearings together so that the steel ball and the raceway are in close contact.<br>The preload has a great influence on the service life of the bearing. According to relevant data, when the bearing is equipped with 0.012mm interference, the service life will be reduced by 380, when there is 0.016mm interference, the service life will be reduced by 501; when the bearing is equipped with 0.004mm clearance, the service life will be significantly reduced, when there is 0.008mm clearance, the service life will be reduced by 705.<br>Therefore, it is very important to choose the appropriate preload. Generally, small preload should be selected for high speed and large preload should be selected for low speed. At the same time, the preload shall be slightly greater than or equal to the axial working load. ?<br>After the double row angular contact ball bearing passes the assembly inspection, it is required to conduct the no-load running test at the working speed for at least 2h, and the temperature rise shall not exceed 15 ℃<br>