304 TECHNICAL INFORMATION Life Span For the LX actuator, calculate the life span of the rail, ball screw and support bearing. The actuator life span is determined to be the smallest value from among these results. Load mass Stroke Acceleration Maximum speed Gravity acceleration Speed diagram Operating conditions : W kg : Ls mm : a mm/s2 : v mm/s : g=9.81m/s2 : Horizontal : (Fig. 1) : (Fig. 2) Examination Select the temporary model number based on the load mass W (kg) and the maximum speed V (mm/s). Then prepare a speed diagram based on the acceleration, maximum speed and travel. The conditions that can develop this speed diagram will serve as the basis for the selection calculation. Selection Calculation Examine the status of the load applied (Fig. 2) to the rail of the LX actuator. Put each load in the formula below (formula (1) for single nut block specifications and formula (2) for double nut block specifications), and obtain the equivalent load Fe. Lifetime Calculation Example Equivalent Load t*O UIF DBTF PG TJOHMF CMPDL Fe=YHFH+YVFV+YpKpMa+YyKyMb+YrKrMc − t*O UIF DBTF PG EPVCMF CMPDL Fe=YHFH/2+YVFV/2+YRKRMa+YPKPMb+YYKYMc − Fe : Equivalent Load FH : Horizontal load acting on blocks FV : Vertical load applied to the block Ma : Pitching direction moment applied to the block Mb : Yawing direction moment applied to the block Mc : Rolling direction moment applied to the block Kp : Equivalent coefficient for pitching direction moment Ky : Equivalent coefficient for yawing direction moment Kr : Equivalent coefficient for rolling direction moment YH,YV,Yp,YY,YR: 1.0 or 0.5 When using with moment loads applied, multiply by Table 3 Rail Section Moment Equivalent coefficient to calculate the Load. In formulas and , in order to obtain the equivalent load Fe, the maximum value among FH, Fv, KpMa, KyMb and KrMc is regarded to be 1.0, and the remaining values are regarded to be 0.5. Average Load As Ma and Mb for the LX actuator vary with acceleration and deceleration, obtain the average load Fm from formula (3). 3 1 Fm= (Fe13· L1+Fe23·L2+Fe33·L3··Fen3·Ln) LS − Fm: Average load for fluctuating loads (N) L: Total travel distance (km) Rail Life Span Obtain the rail life span for the LX actuator from formula . C 3 L=La× fw·Fm − L: Rail lifetime (km) La: Travel distance (km) fw: Load coefficient C: Basic dynamic load rating (N) When the travel length and the number of reciprocal motions per minute are constant, the number of life span hours can be calculated from formula . L×106 Lh= 2·ℓs·n1×60 − Lh: Life span hours (h) ℓs: Travel (mm) n1: Reciprocal motions per minute Life span of ball screw and support areas Obtain the average load from the load applied in the axial direction. Calculate life span for both ball screws and bearings from formula . Obtain the average load from formula . Ca 3 Lr= · ℓ×106 fw·Fm − Lr: Life span of ball screw (km) ℓ: Ball screw lead (mm)) fw: Load coefficient Ca: Basic dynamic load rating of screw and support (N) ( ) ( ) V(mm/s) Ls (mm)=ℓ1+ℓ2+ℓ3 ℓ1(mm) ℓ2(mm) ℓ3(mm) t1(s) t2(s) t3(s) T(s)=t1+t2+t3 Speed diagram (Fig. 1) Status of load applied (Fig. 2) W W
RkJQdWJsaXNoZXIy MTc2MTk0OA==