6 Ball screw selection calculation
6.1 Determination of the axial load of the ball screw
1, the basic static load Co definition
That is, the axially static load of the lead screw means that the total amount of permanent deformation of the screw receiving the contact point between the screw groove and the steel ball (ie, the nut and the screw shaft) and the permanent deformation of the steel ball itself is 0.01% of the diameter of the steel ball. The maximum axial force. This load value is the basic static load rating.
2, force analysis
When there is no external force, the axial load is 30KG, which is 30kgf
When an external force is applied, the axial load is 1 ton, that is, 1000 kgf
Considering the actual working condition of the equipment, the ball screw is only affected by the gravity of the load platform when it is in motion (ie, adjusting the gap size), and the weight is very small and can be ignored. When an external force is applied, it is important to consider the external force. At this time, the lead screw is at a standstill state, so we can refer to the rated static load value of the ball screw.
3, the selection of the nut form
Corresponding to the application of 1000kgf external force conditions, referring to the ball screw sample, the corresponding diameter of 25mm, the lead 5mm, the number of ball recirculations 4, and the rated static load value of the ball screw are 4100kgf. As shown in the data in Figure 1.
Chart 1
Co=4100kgf Cj=1000kgf
Co>Cj
Therefore, the R25-5T4 series ball screw can be selected initially.
6.2 Ball screw safety factor
Since the ball screw is only stressed when it is static, as long as the force is given a certain safety margin, the safety margin S is recommended to be more than 3 times. Calculated according to the following formula:
S=Co/Cj
Bring the corresponding data, there are:
S=Co/Cj=4100/1000=4.1>3
Therefore, the R25-5T4 series ball screw meets the expected use requirements.
| Previous page | 1 | 2 | 3 | Next page |
Steel Plate,Steel Sheet,Steel Coil
Comat Metal Products Co., Ltd. , http://www.china-tinplate.com