Seal type deep groove ball bearings

Many deep groove ball bearing sealing problems mainly ineffective drain grease and dust, etc., in a nutshell is poor sealing performance; non-contact seals no big problem, the main problem is multi-contact seals. What are the causes it?
Main bearing seal structure is relatively backward. Seal structure lies in the rotary member of the seal groove and the sealing cap sealing lips. Sealed general there are three forms, one does not actually slot; second is a small inner diameter, there is a step; third is a complete seal groove.
Sealing lip with a single and double lip of the points, to improve the sealing effect, we believe that the sealing lips should be developed and groove seal structure, because this form of contact seals and labyrinth seals combined sealing effect is better, but the process is complicated, higher cost.
In the modern enterprise in the pursuit of cost-premise, as far as possible the pursuit of double lip seal and groove seal structure deep groove ball bearings, but conditions were not under seal structure can only produce a general, after all, is now a large domestic use part of the sealing structure in general, and the sealing structure by many users.