 亂DO!BOOK丒儁乕僕儕儞僋亃 bearing丂丂丂329 / 392 BOOK傪傒傞 10昩屻偵BOOK偺儁乕僕偵堏摦偟傑偡 嘇 Calculating driving force F=乮兪1A亄兪2B亄兪3C亄兪4D亄nFs亄nMs乯亊俽 Find the driving force from the use conditions using the above formula. F = driving force S = safety factor (2 in this example) 兪1, 兪2, 兪3, 兪4 = coefficient of friction of each table 兪1 = 0.15 (erecting) 兪2 = 0.30 (hanging) 兪3 = 0.15 (erecting) 兪4 = 0.15 (erecting) A, B, C and D = load applied to each table A = 25 kgf B = -75 kgf C = 25 kgf D = 125 kgf n = number of tables = 4 Fs = seal friction = 1.2 kgf The value of F is obtained as shown below: F = (0.15 亊 25 亄 0.3 亊 75 亄 0.15 亊 25 亄 0.15 亊 125 亄 4 亊 1.2) 亊 2 佮 107 kgf 嘊 Calculating service life N = a亊K亊乮1/2S乯亊乮Wa/Wi乯亊fc/乮fw亊fv亊fe亊f.乯 Find the service life from the use conditions using the above formula. N = service life = required service life (1 million cycles) a = allowable wear amount = 0.1 mm K = coefficient of friction = 5 x 106 S = stroke = 0.25 m Wa = allowable load = 130 kgf (Hanging STF28) Wi = applied load = 75 kgf (Value closest to the allowable load: Select the severest one among the loads found with the load calculating formula.) fc = contact factor = 0.75 (Two single-axis units) fw = load factor = 1.0 (No impact load) fv = velocity factor = 1.0 (0.05 m/s) fe = environmental factor=1.0 (60亱C or less, no foreign matter) fl = lubrication factor = 1.0 (No lubrication) The value of N is found as shown below: N = 0.1 亊 5 亊 106 亊 (1/2 亊 0.25) 亊 (130/75) 亊 0.75/ (1.0 亊 1.0 亊 1.0 亊 1.0) = 1,300,000 The required service life of 1 million cycles is satisfied. Type S Type 仸Do not use the STC20 in the lateral or hanging condition. Installation condition Coefficient of friction 兪 Erecting 0.15 Lateral 0.17 Hanging 0.30 Technical Information of Slide Shifters 328 Selection Guide Product Information Plastic Bearing Multi-layer Bearing Metallic Bearing Air Bearings Technical Slide Shifter Information Corporate Profi le