Determining The Required Clamping Force Of A Power Chuck - Rohm Norm RN 1391 Informaciones Y Directivas Generales Para El Empleo De Instalaciones De Sujeción Accionadas Por Fuer

2 | Reference Speed and Clamping Force Calculation
▪ Welded jaws should not be used. If required, the welding seams must be
checked as to their centrifugal and clamping force capacity.
▪ The mounting screws must be arranged in such a way that the highest
possible useful moment is reached.
2.1.2

Determining the Required Clamping Force of a Power Chuck

Determining the required clamping force of a power chuck and the cor-
responding actuating force to machine workpieces
a) Determining the required clamping force F
fects of speed) based on the machining task (process).
b) Determining the initial clamping force F
(taking into account the centrifugal forces of the jaws).
c) Determining the actuating force required for the initial clamping force F
Definition of clamping force
For reasons of occupational safety, progress in machining technology has
made it necessary not only to determine the necessary clamping force but
also to know and consider its changes with increasing speeds.
The forces and moments generated by the machining operation must be prop-
erly absorbed and transmitted by the chuck. The chuck accomplishes this task
mainly by producing a clamping force:
This clamping force is the arithmetic sum of the radial forces exerted on the
workpiece by the jaws. The initial clamping force F
chuck is stationary can be measured at any time and is therefore controllable
(denoted "total clamping force" in the clamping force actuating diagrams). The
figures given in the catalogue refer only to chucks that are fully and correctly
lubricated and in a properly serviced condition.
Many factors act on the clamping point during any machining operation. A
precise specification of these factors in the form of universally applicable
tables is not possible in this context.
In most cases it is sufficient in practice to use a simplified formula containing
the fundamental determining factors (approximate calculation).
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(without considering the ef-
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of the chuck at spindle standstill
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produced when the
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RN-1391