NSK EDD Megatorque Motor, Руководство пользователя

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3. Unpacking, Installation and Wiring
— 3-4 —
3.2.1.4. Confirmation of Use Conditions

The load moment of inertia is generally much bigger than the rotor moment of inertia in the Megatorque
Motor System. Recommended load moment of inertia of each Motor size is shown in the “Table 3-4:
Recommended load moment of inertia of Megatorque Motor”.
Table 3-4: Recommended load moment of inertia of Megatorque Motor
Motor type Rotor moment of inertia [kg
･
m
2
]
Recommended load moment of
inertia [kg
･
m
2
]
PS1004 0.0023 0.15 to 0.23
PS1006 0.0024 0.015 to 0.24
PS1012 0.0031 0.03 to 0.31
PS1018 0.0038 0.03 to 0.38
PS3015 0.011 0 to 1.1
PS3030 0.014 0 to 1.4
PS3060 0.019 0.12 to 1.9
PS3090 0.024 0.12 to 2.4
PN2012 0.0024 0.02 to 0.24
PN3045 0.011 0.11 to 0.77
PN4135 0.057 0.57 to 3.99
PN4180 0.065 0.65 to 4.55
PX3050 0.0028 0.0028 to 0.28
！
Warning : Check if the use conditions exceed the allowable axial load and the
allowable moment load of the Motor.

Refer to “2.5. Motor Specifications” for the allowable axial load, allowable radial
load and the allowable moment load.
3.2.1.5. Dummy Inertia

For the full use of the benefits of the direct drive motor system, it is essential to maximize the resonance
frequency of the whole mechanism by increasing the rigidity of the load, as well as securely fastening the
Motor to a highly rigid mechanical system. Therefore, adding some dummy load to the rotor directly may
help in the following cases.
(1) A key is used to fix the load to the rotor because the load cannot be directly attached to the rotor.
(2) The load is directly fixed to the rotor. However, vibration occurs due to torsional deflection on the
rotary axis of the load.
(3) Inertia of the whole mechanism is very low when a thin shaft such as a ball screw shaft is attached.
(4) There exists play because a sprocket chain or a gear train is used.

Inertia of a dummy load shall be approximately 20% of the load moment of inertia.
When a speed reducer mechanism is used, it shall be
GD
2
1
/(r
2
× GD
2
d
) ≤ 5
Where GD
2
1
= inertia of indirectly connected load, GD
2
d
= inertia of directly attached load, and
r = reduction ratio.)
Fig 3-4: Example of dummy load
Dummy load
Megatorque
Motor
Load