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Model selection guide of slewing drive

Views:11     Author:Linda Ren     Publish Time: 2017-08-09      Origin:Site

It will determine the slewing drive model according to its working conditions and load characteristics. Following three steps help to complete the selection of slewing drive.


When installing slewing drive, the bolt strength grade shall not be less than 10.9.


A.1 Step 1: Primary selection of slewing drive


The selection of slewing drive is a process of repeated calculations. First, it will conduct primary selection of slewing drive according to the load parameters, then calculate if its operating point is under the limit load curve.


When the operating point is under its limit load curve, this model of slewing drive is able to withstand the load, then can move to next step of selection; when the operating point is above the limit load curve, the slewing drive cannot bear the load, the need to conduct re-selection, until it can meet the requirement of limit load curve.


The limit load curve needs to meet the requirement of formulaA.1andA.2.


              图片1.jpg………………………A.1


              图片2.jpg………………………………………………A.2


In the formula图片3.jpg——equivalent axial loadunit is kN;


      图片4.jpg——total axial loadunit is kN;


      图片5.jpg——total radial load on acting surface, unit is kN;


      图片6.jpg——safety factor of static loadsee table A.1);


      图片7.jpg——equivalent tilting momentunit is kN·m;


      图片8.jpg——total tilting momentunit is kN·m.

 

         A.1   Safety factor of slewing ring under static condition

Application

Safety factor

Note

Solar power generation

1.20

Normal operation

                    Construction machinery

1.25

Normal operation

Forestry machinery

1.50

Severe operation

                      Steel-casting foundry

1.75

Severe operation

working platform

1.30

Normal operation

                    Engineering equipment

1.25

Normal operation

Measurement technology

2.00

Accurate operation

Rail car

1.50

Normal operation

Special vehicle

1.50

Normal operation

Deep mining

1.75

Normal operation

 

 

A.2  Step 2:Torque reliability verification


The following conditions must meet formula A.3):

 

                      图片9.jpg………………………A.3

图片12.jpg

Where图片10.jpg——Working torqueunit is kN·m;


          图片11.jpg——rated output torque of slewing drive (See drawing),The unit iskN·m

 

Note 1: The maximum output speed of slewing drive is not more than 3r / min (for some models, output speed is not more than 2r / min); Corresponding relationship between output speed and output torque shown in Figure 1.


Note 2: The starting torque of slewing drive is not more than 2 times rated torque.


Note 3: The mechanical efficiency of slewing drive is 33% -40%.

 


Figure 1   Corresponding relationship between output speed and output torque

 

A.3  Step3Verify  Max working time radio per minute 图片13.jpg


When conduct verification, the requirements of formula (A.4) must be met:

Load working time ratio    图片14.jpg…………………………A.4

Where

图片15.jpg——Under load conditions, slewing drive working time ratio per minute %/min);

图片16.jpg——maximum working time ratio per minute%/min)。

Maximum working time ratio per minute  图片16.jpgcan be used to calculate 图片17.jpg by formula (A.5) , then refer to Figure 2:         图片18.jpg………………………………A.5

Where图片19.jpg——proportional coefficient of working torque and slewing drive maximum output torque

           图片20.jpg——allowable maximum output torque of slewing drive.

 

图片21.jpg 

Figure 2  Max working time radio per minute

 

ReferencesJB/T 11993-2014


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