How to increase the bearing preload

How to increase the bearing preload - 2019 07 - 14 preload: when it comes to reducing the noise of bearing, we will often said to be a concept, called preload. Impose certain preload on deep groove ball bearing can reduce noise. But, the preload should be how to exert? Said a thing in a lot of information, to the exerted load bearing internal, if it is 5 - 10 times of preload bearing diameter is so big, can effectively reduce the noise of the deep groove ball bearings. Increase the preload failure case: in daily work, will encounter a variety of situations. Such as a motor factory, motor bearing noise, by increasing the preload solution, but there are noise, when unwrapped motor bearing and found the back of the spring washer has been pressure without flexibility, such cases, the preload applied is failure. Another case, a customer of a very small motor, have noise, using the add preload, still have the noise, gently shake with a small motor, can hear the sound of the spring washer in the shaking, so the preload is failure. So how to add to the bearing preload? How to determine the preload is added to the bearing? The numerical calculation of preload value should be equal to a coefficient multiplied by the bearing inside diameter: F = k * dF - - Load strength ( Unit: N) k - - Is a factor. d - - Is the bearing inner diameter ( Unit: mm) If it is to reduce the motor noise: coefficient should be 5 - 10 times; If in order to avoid the creasing: coefficient should be 20 times. For the said noise, so the coefficient of 5 - Between 10 times. Increase the preload method usually use spring, generally use column spring or spring washer. Anyway, the spring of the elastic is you calculate the preload value. Spring elasticity and equal to spring coefficient multiplied by the deformation of the spring, spring elasticity equal to spring coefficient multiplied by the deformation of the spring: F = K * & Delta; L　　F- - Spring spring, Is N) load, unit K - - Spring coefficient & Delta; L - - Spring deformation coefficient of the deformation of the spring can be found from the components in the parameters of manufacturer of spring, the spring deformation refers to the amount minus the spring in the spring of the initial length length: & Delta; L = L - L 'by the formula above, the spring deformation & Delta; L can be calculated, the spring of the initial length is known, to the amount of the spring length L '. Bearing medium length: medium length of bearing in motor drawings as is the face of the bearing installed after bearing preload and residual length between bearing end face, and the length is controlled in motor design drawings, so for applying the normal bearing preload on the drawings, in fact is to design a reasonable bearing end face and the distance between the cap, so often say adding a suitable preload is to add the surface in the process of the load and the end of the bearing distance to design a drawing. Choose a suitable elastic coefficient, of course, to make the preload reasonable on the bearing. So by checking the drawings of spring numerical of medium length, well preload is applied to. Extreme conditions of the above two cases, one is the bearing slice completely flattened, spring has lost its elasticity, and there's a spring has no deformation, so there will be no corresponding elastic. So the spring deformation in 0. 5 to 0. 25 initial length, and the deformation can be. Spring quantity whether to add more to the more practical application always meet other conditions, such as bearing face increased 4 with spring, and increase the eight spring bring what are the differences? , of course, add 8 spring preload is applied evenly, add 4 root spring preload may not bring eight so evenly, but have the remaining space problem, the remaining space for motor is the cumulative of the dimension chain all tolerances, if there is a mm error, if there are four spring, then 4 root spring the overall error of the space is 4 mm, 4 mm from the deviation of the force is so much, so easy bad the perspective of the spring is not the more the better. （ Source: industrial solutions center)