Bridge bearings bearing materials used by classification: 1) steel bearing: flat seat, curved seat, rocking shaft bearings, roller bearings. 2) PTFE bearings: sliding bearings. 3) rubber bearings: laminated rubber bearing, rubber bearing basin, PW laminated rubber bearings. 4) bearing concrete: Concrete relatively bearing 5) lead-bearing structure in the form of bridge bearings according to classification: 1) curved seat 2) rocking shaft support 3) roller bearing 4) laminated rubber bearing 5) tetrafluoroethylene layout rubber bearings 6) basin rubber bearing 7) spherical bearings and so on. The traditional bridge bearings used are: cushion seat, flat seat, curved seat, rocking shaft bearings, hinges and hinge-mounted bearing roller bearing and so on. Many types of bridge bearings, mainly based on the support reaction force, span, building height, and is expected to select the amount of displacement. The main performance of bridge bearings. A, bearing vertical bearing capacity of the series is divided into 21: 1500,2000,2500,3000,3500,4000,4500,5000,6000,7000,8000,9000,10000,12500,15000,17500,20000,22500, 25000,27500,30000KN. B, bearing activities (bidirectional and unidirectional) structure along the main displacement direction and displacement graded 5: ± 50, ± 100, ± 150, ± 200, and ± 250mm, bi-lateral displacement bearing activities for ± 40. The amount of displacement can be adjusted according to actual needs. C, bearing angle into three 0.02,0.04 and 0.06rad. D, ball bearings Temperature range -40 ℃ ~ + 60 ℃. When E, bearing friction coefficient of PTFE plate design has grease lubrication under conditions of stress is about 30MPa, values ??are as follows: room temperature (-25 ℃ ~ + 60 ℃) 0.03; low temperature (-40 ℃ ~ + 60 ℃) 0.05. F, bearings can withstand the horizontal forces: the role of vertical design load, bearing vertical compression shall not exceed 1% of the total height of the seat; bridge bearing fixed bearing and the one-way bearing activities bound to to withstand the horizontal force for bearing vertical design load of 10%. Bridge bearings from Theravada board, Xiazuo plate, ball cap and two Teflon liner board composed of different shapes. Middle Xiazuo board for a concave spherical, ibid base plate (GD) or ball cap liner (refer to DX or SX) on the convex spherical cap, corresponding to a spherical PTFE plate lining between the two, and by the spherical The slide to meet the beam end rotation; the DX and SX-type bearings, attendance plate and stainless steel plate with another PTFE plate spherical liner on the composition of the second sliding surface, complete displacement i telescopic beam generated due to temperature factors . Bridge bearings ball bearings reliable power transmission, each identical to the rotational behavior, not only with pot rubber bearing load capacity, the horizontal displacement of large features, and can meet the needs of a large corner for wide bridge, curved bridge. Because of pressure parts do not use rubber parts, rubber low temperature brittleness and other effects do not exist, it is particularly suitable for low-temperature region. 

palabras clave: Ball bearings, ball bearings earthquake, earthquake-way ball bearing,