Given: The linear guide bears a load of 40kg, the servo motor has a power rating of 400W, a rated speed of 3000rpm, and a maximum speed of 5000rpm. The lead screw shaft has an outer diameter of 16mm, a lead of 16mm, and a stroke of 350mm. The servo motor acceleration time is 0.1s, and the slider connection plate is 210mm. Determine the linear guide model.
1. Four-Step Method for Linear Guide rail System Selection Calculation
Considering the limit case, maximum operating speed V = N × Pb = 5000 × 0.016 = 80 rpm = 1.33 m/s (rounded to 1.5 m/s)
a = v/t = 1.5/0.1 = 15 m/s
F = ma = 40 × 15 = 600 N
2. Calculate the overturning moment of the load
Distance R from center of gravity to “slider center point” = 0.1 m
Overturning moment T acting on load = FR = 600 × 0.1 = 60 Nm
3. Calculate the force borne by a single slider
Considering an extreme case where only two sliders move under gravity while the other two fail, the roll moment borne by the slider equals the load’s roll moment: T = 2F₁L = 60 Nm
(If the center of gravity is not on the centerline connecting the two sliders, L is directly taken as the shortest distance from the center of gravity to either slider. For example, if the horizontal distance from the center of gravity to the left slider is 300mm and to the right slider is 200mm, L is directly taken as 200mm.)
Below is the formula for calculating the force on a single slider. To expedite selection, we directly consider the extreme case rather than performing lengthy calculations per the formula.
The slider connection plate is 210mm, so the distance between the two sliders is taken as 200mm, L=100mm=0.1m
Force acting on a single slider: F1=T/2L=300N
After calculation, considering other external factors or for future modification convenience, apply a safety factor of 2
Force acting on a single slider F2=2F1=600N
Calculation Summary: When R = L, the force on a single slider F2 = 2F1 = 600N equals the load force.
Can I then conclude: F (single slider) L = F (load) R to quickly calculate the force on a single slider?
You can verify this conclusion during actual use.
4. Linear Guide Model Selection
For linear guides, we typically choose the HGH series. For limited space, use the MGN series. Here, we select the HGH series high-profile heavy-duty linear guide.
Consulting the table shows: The basic dynamic rated load of HGH15CA is 14.7kN > 600N
This indicates that the actual force a single slider can withstand is quite substantial.
Therefore, the HGH15CA series linear guide is selected.
Finally, based on the required guide length, the final linear guide model is determined:
Linear Guide HGH15CA2R580Z0C HIWIN
Linear Guide Selection Summary:
1. Calculate the total load force on the slider
2. Calculate the rolling moment of the load
3. Calculate the force acting on each individual slide block
4. Determine the linear guide rail system model
