| · Static selection 1) Selection calculation flow chart ![]() 2) Calculation method of static reference loads Fa'' and M'': · Single row four point contact ball type: The selection calculation of the single-row four-point contact ball type slewing bearing is carried out according to the bearing angles of 45 ° and 60 °, respectively. I, a=45° II, a=60° Fa''=(1.225*Fa+2.676*Fr)*fs Fa''=(Fa+5.046*Fr)*fs M''=1.225*M*fs M''=M*fs Then find the above two points on the graph, one of which is below the curve. ·Single row cross roller type Fa''=(Fa+2.05Fr)*fs M''=M*fs ·Double row reducer ball For the calculation of the double-row reducer ball slewing type, but Fr ≦ 10%Fa, Fr is ignored. When Fr ≧ 10% Fa, the change of the pressure angle inside the orbit must be considered. Please calculate with us. Fa''=Fa*fs M''=M*fs ·Three rows of rollers When selecting three rows of roller slewing bearings, only the effects of axial raceway load and overturning moment are calculated. Fa''=Fa*fs M''=M*fs ·Dynamic selection For continuous operation, high-speed rotation and other applications that have specific requirements for the life of the slewing ring, please contact us. ·Check the bearing capacity of the bolt: • Use the large zoi load (without the static safety factor fs) that the slewing bearing is subjected to as the load for selecting the bolt. · Check if the load is below the required level bolt limit load curve; · If the bolt bearing capacity is not enough, you can re-select the slewing ring, or with our company. · Selection calculation distance - door seated crane (grab) ![]()
Table I ![]() Note: fl is the dynamic safety factor and must be used in conjunction with the dynamic load curve (the dynamic load curve does not include the secondary sample). It comes from experience and experimentation. It is a reference value based on the large work load of zui. When using the load capacity curve selection, the calculation method of Zui heavy load is recommended as follows: Before selecting the slewing bearing, first determine the static safety factor fs that should be considered for the mainframe, which can be found in Table 1. Door-seat crane (grab): fs=1.45 It is known that the large static load of zui occurs when the amplitude ziu is large, and the load calculation formula is as follows: · Zui large working load of eight winds Axial force Fa=Q+A+O+G Overturning moment: M=Q*lmax+A*amax+W*rO*oG*g 2) Considering the wind, consider the load of 25% of the experimental load Axial force: Fa=1.25Q+A+O+G Overturning force: M=1.25Q*lmax+A*amax-O*oG*g Example: It is known that the workload and amplitude of a grab port hang is large: Q=260KN lmax=23m A=75KN amax=11m O=450KN o=0.75m G=900KN g=3m W=27KN r=6.5m · Zui large working load when eight winds: Fa=Q+A+O+G=260+75+450+900=1685KN M=Q*lmax+A*amax+W*rO*oG*g=260*23+75*11+27*6.5-450*0.75-900*3=3943KNm 2) Regardless of the wind, consider the Zui large working load at 25% test load Fa=1.25Q+A+O+G=325+75+450+900=1750KN M=1.25Q*lmax+A*amax-O*oG*g=325*23+75*11-45*0.75-900*3=5566.3KNm · Zui large working load regardless of wind power Fa=1685KN M=Q*lmax+A*amax-O*oG*g=260*23+75*11-450*0.75-900*3=3767.5KNm Use case 2 as the static calculation of the working load. The slewing bearing static reference load is: Fa''=1750KN*1.45=2537.5KN M''=5566.3KNm*1.45=8071.1KNm The calculated load of the bolt is: Fa=1750KN M=5566.3KNM According to the above calculation results, the selection of the load capacity curve can be determined to select the 13*.45.2000.002 slewing ring. ![]() ? l Line is the static load capacity curve 8.8 and 10.9 are bolt bearing curves 1''- Static load point 2''- bolt load point 1'' point re-tracking static load bearing curve 1 below, thus meeting the requirements The 2'' point is below the 10.9 bolt load curve, so a 0.9 grade bolt is available. | 
