Fastech Ezi-Speed ST, Manual, Page: 47 / 111

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6.3.7 Permissible overhung load and permissible thrust load
Overhung load is a load on the gearhead shaft in the vertical direction.
• When using transmission device like chain, gear and belt, etc., overhung load on the gearhead
shaft.
• Overhung load acts direct load on gearhead shaft. It affects the life time of the gearhead.
• Overhung load can be calculated by following formula.
W =
𝐾 × 𝑇 × 𝑓
𝑟
[Kg]
W : Overhung load [kg]
K : Weight factor by operation method
T : Delivery force to the gearhead shaft[kg - cm]
f : Service factor
r : Effectiveness radius of pully and gear, etc.[cm]
• If the calculated overhung load value is used in excess of the permissible limit below data sheet,
the bearing will be damaged within a short period of time, causing the output shaft to warp
and cause fatigue damage due to repeated load.
• In this case, install in a structure that can withstand the overhung load shown in the right
picture.
• Also, if a load should be directly imposed on the output shaft, please place the load as near to
the gearhead as possible to avoid the one-sided load.
• When using a helical gear or a worm gear in transmission devices, make sure not to exceed
both the overhung load and the thrust load simultaneously.
Attention
• Maximum permissible torque is different by gear ratio.
• Use within the permissible torque for each gear ratio.