Omron R6YXG500, Installation Manual

Page: 102 / 330

2
Installa
tion
2-44
6.2 Equation for moment of inertia calculation
Usually the R axis load is not a simple form, and the calculation of the moment of inertia is not easy. As a method, the
load is replaced with several factors that resemble a simple form for which the moment of inertia can be calculated.
The total of the moment of inertia for these factors is then obtained.
The objects and equations often used for the calculation of the moment of inertia are shown below. Incidentally, there
is the following relation: J (kgfcmsec
2
) = I (kgm
2
) × 10.2.
1) moment of inertia for material particle
The equation for the moment of inertia for a material particle that has a rotation center such as shown in the Fig. below is as
follows:
This is used as an approximate equation when x is larger than the object size.
Moment of inertia for material particle
x
J=
Wx
2
g
(kgfcmsec
2
)
g : Gravitational acceleration (cm/sec
2
)
m : Mass of material particle (kg)
... (1)
I= mx
2
(kgm
2
)
W : Weight of material particle (kgf)
2) moment of inertia for cylinder (part 1)
The equation for the moment of inertia for a cylinder that has a rotation center such as shown in the Fig. below is given as
follows.
Moment of inertia for cylinder (part 1)
D
h
J=
rpD
4
h
32g
WD 2
8g
= (kgfcmsec 2 )
... (2)
I=
rpD
4
h
32
mD
2
8
= (kgm
2
)
r : Density (kg/m 3 , kg/cm 3 )
g : Gravitational acceleration (cm/sec
2
)
m : Mass of cylinder (kg)
W : Weight of cylinder (kgf)