How to choose the bearing and the use of attention to matters

Along with society's progress and developed, and the mechanization in consumption and widely applied in the life. Bearing as a local machinery is short of, the scope of its use will be more and more widely, because of the need to have in the center of rotation to use bearing. A support and bearing mainly in machinery to reduce the effect of friction, so the precision of the bearing, the noise is directly related to the use of machinery and the life. But business people always will often encounter some customers even with the best bearing or imports bearing its efficiency is not high, it is related to the use of the bearing and selection problem. May be some people say that 'the use of the bearing and the choice that is the user, I though I sell what the user wants'. But as a qualified procurement staff in addition to the knowledge of product knowledge itself but also familiar with the use of products, namely the doctor sales, on the basis of the users of products performance, supporting bearing conditions to choose the best. This is now the world each big company of professional manufacture and sale, this way since in humanistic group shall also obtained the good effect. Because the type of bearing is much broader, the following will mainly to use the most widely use and selection of deep groove ball bearings. Hope to shaft for those who know less can deepen the understanding of the bearing. Bearing selection 1, bearing types of options: bearing is common, that is by the user's technical personnel according to the using conditions supporting products and accept load on bearing stop selection. Business people can understand the practice of the user load and corresponds to the selected bearing, if bearing short of using request, should be initiative customer reorganization model as soon as possible, but unless special product general won't have any problems in selecting type. 2, the selection of the bearing clearance: users in the purchase of bearing general will only inform in what type, grade and rarely, at the request of the clearance of bearing the use of business people must ask bearing conditions, which the bearing rotating speed, temperature, tolerance is directly related to the selection of the bearing clearance. Ordinary under 3500 RPM speed motor mostly adopts CM clearance, such as high temperature and high speed motor request adopt relatively large clearance. Bearing clearance after assembly will rise as a result of the inner hole and the decrease of cylindrical and incur reduced, the reduction of clearance = interference quantity x 60% ( Except the bearing chamber is aluminum) 。 For bearing clearance is zero before assembly. 01 mm, interference when assembling the quantity to zero. 01 mm, bearing assembly after the clearance of 0. 004mm。 In theory when zero clearance noise and bearing life all reach the best state, but in the practical operation thinking to problems such as temperature, bearing clearance to 0 after assembly. 002mm- 0. 004 mm is better. 3, the choice of grease: the choice of grease ordinary is depending on the speed of the bearing, heat resistance, noise, request and the starting torque stop choosing, request the business personnel to understand the performance of all kinds of grease. 4, the choice of bearing seal type: smooth bearing can be divided into smooth smooth oil and fat. Smooth bearing common way is to choose bearing oil, fat and smooth bearing common choose dust cover or rubber seals seal. Dust cover suitable for high temperature or using the good environment, seal two points contact seal and non-contact seal and contact seal dustproof performance is good but the starting torque, the sealing type starting torque is small, but there is no contact sealing performance is good. Bearing when using, should pay attention to item 1, selection of shaft and the bearing chamber tolerance and control: after the bearing pressure into the bearing should be sensitive rotation without block. If there are any apparent rotation not sensitive, indicates the size of the shaft is too big, tolerance to downgrade. Such as bearing pressure into the shaft by hand after the rotation has obvious 'sasha vujacic' feeling, may be the shaft or shaft roundness tolerance is too big. When control the shaft and the bearing chamber tolerance so also want to control the roundness, at present many domestic manufacturers to control the tolerance to stop, only without the roundness stop control. 2, bearing assembly way: since the bearing is high precision products, such as improper assembly on bearing channel formation damage easily, cause damage of bearing. When bearing assembly shall have a dedicated mold, not casually, only small circle of stress when pressure into the shaft, pressure can force the circle circle. Assembly request when using pneumatic or hydraulic, lower die when being connected to outside the state, if have tilted bearing channel will incur due to mechanical damage, and make the bearing guide ring. 3, the assembly to avoid foreign bodies: bearing dynamic equilibrium in loaded on the rotor will easily generated when the dynamic equilibrium of internal iron into bearing, so it is best to install bearing before do dynamic balance. There are some manufacturers in order to assemble bento, assemble indoor apply some oil or grease in the bearing when the smooth effect, but often operators good amount of it is hard to control, if oil or grease in the bearing indoor storing up more, in the bearing rotates along axis to the bearing inside easily. Bearing chamber it is best not to apply oil or grease, if must apply to control shall not be storing up in bearing interior. 4, paint, rust prevention: paint rust is characterized by multiple in sealing type motor, the motor sound is very good, when it is assembled but put some time in the warehouse, the motor sound is very big, remove the bearing has serious rust phenomenon. Many manufacturer would think that is the problem of bearing before, after our propaganda from time to time, motor factory now has realized mainly is a question of insulating varnish. The problem is mainly due to the insulating paint volatilizes the acid under certain temperature and humidity of corrosive substances, the damage of bearing channel after the corrosion cause bearing. Asked the title can be to choose good insulating paint, before and after drying ventilation assembly after a period of time. The life of the bearing is manufacturing, assembly and use are closely related, must do in each link, talent make the bearings in optimum operation state, thus increasing the using life of the bearing.