A - 25
Appendices A Technical Information
High-function General-purpose Inverter RX2 Series User’s Manual
A-
3 Overview
o
f In
verter Select
ion
A
A-3
Overview of Inverter Selection
Simplified Selection Method (Required Output Calculation)
For linear motion: Steady power P0 [kW]
M
Motor
: Friction coefficient
: Mass of linear motion part [kg]
: Acceleration of gravity (g≈9.8 [m/s
2
])
: Speed of linear motion part [m/min]
: Efficiency of transfer part (
1)
: Load torque (Load shaft) [N·m]
: Rotation speed of load shaft [r/min]
: Efficiency of transfer part (
1)
For rotation motion: Steady power P0 [kW]
* The same calculating formula is applicable to belt conveyors.
J
W
J
1
J
2
M
1
M
2
D
: Shaft conversion inertia [kg·m
2
]
: Inertia of cylinder (Shaft conversion) [kg·m
2
]
: Inertia of workpiece (Shaft conversion) [k·m
2
]
: Mass of cylinder [kg]
: Mass of workpiece [kg]
: Diameter of cylinder [mm]
J
W
[kg·m
2
]
=J
1
+ J
2
Motor
Detailed Selection Method (RMS Calculation)
Motor Capacity Selection
D
M
2
J
W
M
1
=
M
1
· D
2
8
+
M
2
· D
2
4
• Example in hoist application
• Example in conveyor application
× 10
–6
: Shaft conversion inertia (Cylinder-1-shaft conversion) [kg·m
2
]
: Inertia of cylinder 1 (Cylinder-1-shaft conversion) [kg·m
2
]
: Inertia of cylinder 2 (Cylinder-1-shaft conversion) [kg·m
2
]
: Inertia of workpiece (Cylinder-1-shaft conversion) [kg·m
2
]
: Inertia of belt (Cylinder-1-shaft conversion) [kg·m
2
]
: Mass of cylinder 1 [kg]
: Mass of cylinder 2 [kg]
: Mass of workpiece [kg]
: Mass of belt [kg]
: Diameter of cylinder 1 [mm]
: Diameter of cylinder 2 [mm]
J
W
J
1
J
2
J
3
J
4
M
1
M
2
M
3
M
4
D
1
D
2
: Shaft conversion inertia (Roller-1-shaft conversion) [kg·m
2
]
: Inertia of roller 1 (Roller-1-shaft conversion) [kg·m
2
]
: Inertia of roller 2 (Roller-2-shaft conversion) [kg·m
2
]
: Mass of workpiece [kg]
: Diameter of roller 1 [mm]
: Diameter of roller 2 [mm]
J
W
J
1
J
2
M
D
1
D
2
J
W
[kg·m
2
]
=J
1
+J
2
+J
3
+J
4
=
M
1
·D
1
2
8
+
M
2
·D
2
2
8
× 10
–6
J
W
D
1
M
1
D
2
M
2
M
3
M
4
·
D
1
2
D
2
2
+
M
3
·D
1
2
4
+
M
4
·D
1
2
4
• Example in roller application
• Example of conversion into motor-shaft inertia
J
W
[kg·m
2
]
D
1
D
2
M
J
W
J
1
J
2
=J
1
+
D
1
2
D
2
2
J
2
+
M·D
1
2
4
× 10
–6
Motor
Load J
W
Load-side gear J
2
J
L
Motor-side gear
J
1
J
L
: [kg·m
2
]=J
1
+G
2
(J
2
+J
W
)
J
L
J
W
J
1
J
2
Z
1
Z
2
G
: Motor-shaft conversion inertia [kg·m
2
]
: Load inertia (Load-side gear-shaft conversion) [kg·m
2
]
: Inertia of motor-side gear [kg·m
2
]
: Inertia of load-side gear [kg·m
2
]
: Number of motor-side gear teeth
: Number of load-side gear teeth
: Gear ratio (Speed reduction ratio) = Z1 / Z2
Before selecting an inverter, first the motor should be chosen. In
selecting the motor, calculate the load inertia appropriate to the
application, and then calculate the required capacity and torque.
This method of calculation helps you select a motor by
calculating the output (kW) required by the motor to maintain
its steady rotations. To use this method for motor selection,
make allowance for the calculated result because it does not
include acceleration/deceleration and other transient state
calculations. The simplified selection method is suitable for
fan, conveyor, mixer, and other applications where a constant
state continues for a while.
* The simplified selection method cannot be used for the
following applications. For these applications, use the
detailed selection method.
• Those requiring rapid startup (acceleration).
• Those that frequently repeat run and stop.
• Those that have a large inertia at the power transfer part.
• Those that have an inefficient power transfer part.
This method helps you select a motor by calculating the
effective torque and maximum torque values required to
achieve a certain pattern of operation for the application. It
selects a motor that is optimal for a particular operation
pattern.
Calculation of load inertia and motor-shaft conversion inertia
Depending on the type of the motor transfer system, calculate
the inertia for all parts and convert it into the motor-shaft
inertia.
× 10
–3
× 10
–3
Summary of Contents for RX - 2
Page 1: ...High function General purpose Inverter RX2 Series User s Manual I620 E1 01 3G3RX2...
Page 54: ...1 Overview 1 22 High function General purpose Inverter RX2 Series User s Manual...
Page 136: ...2 Design 2 82 High function General purpose Inverter RX2 Series User s Manual...
Page 592: ...8 Applied Settings 8 192 High function General purpose Inverter RX2 Series User s Manual...
Page 754: ...11 Options 11 56 High function General purpose Inverter RX2 Series User s Manual...
Page 794: ...12 Troubleshooting 12 40 High function General purpose Inverter RX2 Series User s Manual...
Page 919: ......
