Ⅰ. Supporting Load of Slewing Ring

　　During the use of slewing ring, it is usually endure axial force, radial force and overturning moment together. For different application situation, due to the vary of working manner and structure form, the fuction combined condition also different of the above three loads. Sometimes may be the combination of two loads, sometimes may be only one load. Generally speaking, installation of slewing ring have two kinds of mode: compressive installation and suspended installation. The load of the bearing of this two kinds of installation see as follows: 

　　If the slewing ring is compressive installation, the customer could select and calculate as follows; if the slewing ring is suspended installation, please contact our Engineering 　　Department for assistance.

 

　　1. Selection of Structure

　　Common structure of slewing ring have four kinds: single row ball slewing ring, cross-roller slewing ring, double-row different diameter ball slewing ring, three-row roller slewing ring.

Based our experience and calculation, we have follow conclution:

　　·Do ≤2000, single row ball slewing ring first; Do＞2000,three-row roller slewing ring first.

　　·For the slewing ring have the same figure size, the load capacity of single row ball slewing ring is more than the cross roller and double-row different diameter slewing ring.

　　·Single row ball slewing ring of Q-series have higher compact structure, less weight and more economically. They are the first chose of single row ball slewing ring.

 

　　2. Select Product Type by Calculation

　　（1）Calculation of single-row ball slewing ring

　　① Calculation of rated static capacity

　　Co = 0.6×Do×do0.5

　　Co ─── kN      Rated static capacity

　　Do ─── mm    Diameter of track center

　　Do ───  mm    Diameter of ball

　　② Equivalent load calculation according outside compound load      

　　Cp = Fa + 4370M/Do + 3.44Fr 

　　Cp─── kN          Equivalent axial load

　　M  ─── kN·m    Overturning moment 

　　Fa ─── kN          Axial force

　　Fr ─── kN          Radial force

　　③ Safety factor

　　fs = Co / Cp≥fo

　　fo  See the following table

 

　　（2）Calculation of 3-row roller slewing ring

　　① Calculation of rated static capacity        

　　Co= 0.534×Do×do0.75

　　Co───  kN         Rated static capacity        

　　Do───  mm        Diameter of track center

　　Do ───  mm        Upper row roller diameter

　　②  Equivalent load calculation according outside compound load

　　Cp = Fa + 4500M/Do

　　Cp───  kN           Equivalent axial load

　　M  ───  kN•m      Overturning moment 

　　Fa ───  kN          Axial force

　　③ Safety factor

　　fs = Co / Cp≥fo

　　fo See the following table

　　3. Select Product Type Use Static Load Curve

　　① Static load curve show the maximum load of slewing ring when in the static state. Each type of the slewing ring in this specimen has a corresponding load capacity curve. Load capacity curve can help customer to make an elementary chose of slewing ring. Draw the static load curve. Customer draw the static load curve based on the type which wanted to be selected. See as follows:

　　P1=Co         

　　M1=Co*Do/4370（ M1=Co*Do/4500） 

　　②The point which total axial force Fa and total overturning moment M multiply the safety factor respectively should located below the static load curve.  

　　③ Example:Draw the static load curve of QUA1000.32          P1=Co=0.108*1000*32=3456kN
M1=Co * Do/4370=3456*1000/4370=790 kN•m 
Static load curve see as following:

　　4、Technical Parameter of Slewing

　　Ring Selection After making an elementary chose of slewing ring, customer could confirm the selecting result together with our Engineering Department or provide some informations about slewing ring to our company. When the selection is made by our company, please filling ‘Technical References Concerned for Selection of Slewing Ring of Maanshan Tongli Slewing Ring CO.,LTD’ in detail, so as to provide you economical and suitable selection of the slewing ring as soon as we can.

Maanshan Tongli Slewing Ring CO.,LTD          Technical References Concerned for Selection of Slewing Ring
Name of company：                                     Address： Contactor：                                            Department： Telephone：                                            Fax：
Using condition (Model of Main Machine)			Installing type (Compression or suspension)
Requirement of gear shape: (inner teeth,outer teeth,no teeth or no restrict)			Application character   Only positioning   Intermittent rotation   Continuous rotation			Revolution per minute   Normal   Maximum
Value of Load
Type of Load		Maximum Working Load			Maximum Testing Load			Destroy Load
Axial Load（kN）
Radial Load（kN）
Overturning Moment(kNm)
Load driving torque:Normal           Maximum          No. of Drive Pinion:
Special requirement:special situation,temperature,fit size,figure size limit etc.
Deatailed load condition	Axial load（kN）		Radial load     (kN)	Overturning moment       (kNm)			Revolution per minute (rpm)		Working time (%)
1)
2)
3)
4)
。。。
									100%
Continue working condition Life:Under the mean speed of     rpm,work at least    hours
Intermittent working condition Required life:Under angular of +/-       degree,work at least    hours
Please fill this table thoroughly so as to provide you economical and suitable selection of the slewing ring as soon as we can. Signature：                                                   Date：

　

　Appendix:Confirmation of the Load Outside the Slewing Ring When selecting the slewing ring, customer first to confirm the outside load of the slewing ring. The outside load of single row ball slewing ring is the total load after combination which include:      

　　a.overturning moment M, N•mm      

　　b.total axial force Fa, N      

　　c.total radial force Fr of the fuctional surface of total overturning moment M  When the outside mechanical force composing the outside load, customer should put working condition factor K into consideration which based on the working type of the machine. The following are examples of crane and excavator which explain the confirmation of outside load.(The listed calculational position not always represent the abominable condition of working condition, customer should calculate according to the maximum working condition.

　　1.  Crane(see figure 1)

Figure 1  Crane Calculation