HYDROK
Use and limits of use
52
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the clamping force diagram [see »Clamping force diagram«
chapter].
When full axial force is exerted on the clamping head chuck
with
𝐹
𝑎𝑥 𝑚𝑎𝑥
= 45𝑘𝑁
, nominal radial
120𝑘𝑁
forces are being
applied to the workpiece.
In the example calculated here, an axial force of at least
𝐹
𝑎𝑥
= 37𝑘𝑁
must be applied, resulting in a radial clamping
force of
𝐹
𝑟𝑎𝑑
= 98𝑘𝑁
.
This satisfies condition
𝐹
𝑟𝑎𝑑
≥ 𝐹
𝑟𝑎𝑑 𝑒𝑟𝑓
.
Machining can then be performed.
The value is close to the limit value. This ensures that the
clamping head chuck is in good condition in terms of the level
of contamination.
It is advisable to conduct a check on radial clamping force
using an appropriate clamping force meter before the ma-
chining operation. The values established must lie within an
appropriate range for the rotational speed [see »Clamping
force diagram« chapter].
5.3 Aid to selection of the hydraulic unit
The clamping and release times can be relevant to the se-
lection of an appropriate hydraulic unit. The clamping and
release time depends on the volume involved.
5.3.1 Nomenclature
Brief des-
ignation
Unit
Explanation
𝐴
𝑐𝑚
2
Piston surface area
𝐹
𝑎𝑥 𝑚𝑎𝑥
𝑘𝑁
Maximum axial actuating force
𝑝
𝑚𝑎𝑥
𝑏𝑎𝑟
Maximum supply pressure
𝐻
𝑚𝑚
Stroke
𝑡
𝑠
Time
𝑉
𝑐𝑚
3
Volume
𝜗
𝑙
𝑚𝑖𝑛
Volumetric flow rate
Table 16: Nomenclature for selection of hydraulic unit
