Selecting a Compact Electric Cylinder: Tentative Selection of DRS2 Series

Selection Method

(1) Confirming the Required Specifications

Confirm the required specifications for the equipment.

Drive Direction: Vertical
Load Mass
m = 10 [kg]
Positioning Distance
L = 20 [mm]
Positioning Time
T = Within 1 [s]
Drive Direction
Vertical
Stopping Accuracy
± 0.01 mm

(2) Tentative Selection of Electric Actuators

The following electric actuator is tentatively selected based on the required specifications.

Product Name
DRSM42RG-04A2AZMK
Lead
2 mm
Types of Ball Screws
Rolled Ball Screw
Resolution
0.001 mm
Power Supply Input
24 VDC

(3) Confirming the Positioning Time

Check whether the actuator can perform the necessary positioning within the specified time. This can be done by obtaining a rough positioning time from the graph or by obtaining a fairly accurate positioning time by calculation. Each of the confirmation procedures is explained below.
The actual operating time is subject to a small margin of error, so use the calculation only as a reference.

Obtaining From a Graph

①

Use the graph to confirm the positioning time necessary for a positioning distance of 20 mm.

Positioning Time: 0.59 s

The requested positioning time of 1 second or less is satisfied, so it can be used.

②

If the positioning time requirement is satisfied, check the operating speed and acceleration.

Operating Speed: 43 mm/s
Acceleration: 0.33 m/s2 (0.15 G)

③
If the positioning time requirement is not satisfied, select a different model.
Positioning distance - positioning time, positioning distance - operating speed, and positioning distance - acceleration for vertical direction installation

Using Formula Calculations

①
Confirm operation conditions
Check the following conditions:
Positioning distance, starting speed, acceleration, and operating speed
②

From the operation conditions above, confirm whether the drive pattern is a triangular drive or trapezoidal drive
Calculate the maximum speed of triangular drive from the positioning distance, starting speed, acceleration and operating speed. If the calculated maximum speed is equal to or below the operating speed, the operation is considered a triangular drive. If the maximum speed exceeds the operating speed, the operation is considered a trapezoidal drive.

\(\begin{align} V_{Rmax} &= \sqrt{ \frac{2 \cdot a_1 \cdot a_2 \cdot L}{a_1 + a_2} \cdot 10^3 + V_{S^2}} \\[5pt] V_{Rmax} & \leqq V_R \rightarrow \text{Triangular Drive} \\[5pt] V_{Rmax} & \gt V_R \rightarrow \text{Trapezoidal Drive}\end{align}\)
③

Calculate the positioning time
[In the case of trapezoidal drive]

\(\begin{align}T &= T_1 + T_2 + T_3 \\[5pt] & = \frac{V_R - V_S}{a_1 \times 10^3} + \frac{V_R - V_S}{a_2 \times 10^3} + \frac{L}{V_R} - \frac{\left(a_1 + a_2 \right) \times \left(V_{R^2} - V_{S^2} \right)}{2 \times a_1 \times a_2 \times V_R \times 10^3} \end{align}\)

[In the case of triangular drive]

\(\begin{align}T &= T_1 + T_2 \\[5pt] & = \frac{V_{Rmax} - V_S}{a_1 \times 10^3} + \frac{V_{Rmax} - V_S}{a_2 \times 10^3} \end{align}\)
In the case of triangular drive
VRmax
Maximum Speed Calculated for Triangular Drive [mm/s]
VR
Operating Speed [mm/s]
Vs
Starting Speed [mm/s]
L
Positioning Distance [mm]
a1
Acceleration [m/s²]
a2
Deceleration［m/s²］
T
Positioning Time [s]
T1
Acceleration Time [s]
T2
Deceleration Time [s]
T3
Constant Speed Time [s]

Selection Procedure and Calculation Formula