Yamaha YP-X Series, Owner'S Manual

Page: 101 / 110

CHAPTER 6 Specifications
6-19
2-2 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 is obtained.
The objects and calculation methods often used for the calculation of the moment
of inertia are shown below.
1. Moment of inertia for cylinder
The equation for the moment of inertia for a cylinder that has a rotation center
such as shown in Fig. 6-18 is given below.
D
h
ρ π
D
4
h
32g
WD
2
8g
= J = (kg · cm · sec
2
)
...(6.1)
: Density (kg/cm
3
)
: Gravitational acceration (cm/sec
2
)
: Weight of the cylinder (kg)
ρ
g
W
Fig. 6-18
2. Moment of inertia for rectangular parallelopiped
The equation for the moment of inertia for a rectangular parallelopiped that
has a rotation center as shown in Fig. 6-19 is given below.
a
c
b
1/2a
ρ
abc (a
2
+b
2
)
12g
W (a
2
+b
2
)
12g
= J =
...(6.2)
: Density (kg/cm
2
)
: Gravitational acceration (cm/sec
2
)
: Weight of the rectangular parallelepiped (kg)
ρ
g
W
Fig. 6-19