Heads With Square Tables, Types 4811, 4812, 4813; Flexure System - BRUEL & KJAER System V Instruction Manual

6. DESCRIPTlON OF EXCITER HEADS
6.1. H EADS WITH SQUAR E TABLES: TYPES 4811, 4812, 4813
Figs.6.1, 6.2 and 6.3 show the Types 4811, 4812 and 4813 respectively with their
rubber boots and protective cans removed. A description of their major features follows.
~ _ _ _ Table & mounting surface
...........- -
" ' - - - - -
Aeplaceable insert
Upper radial flexure
Magnetic shield
Mounting hales for protective can
Frame
Overtravei stop
Moving element skeleton-rib edge
Flexure mounting block
Lower radial flexure
Tangential flexure
Split hub
_ _ _ _ _ Moving element skeleton-gusset
Driver coli
- - - - - - ­..... Drive connector to amplifier
2"054
Fig.6. 1. Head 4811 with rubber boot and protective can re­
moved
6.1.1. Table and Mounting Surface
All three of these Heads have square tables with dimensions as shown in Table 3.2. The
mounting surface is hardened and anodized. At the center of the table and at the four
corners are threaded holes. The threads are NOT to be used to mount fixtures directly.
They are intended for the special inserts supplied with the Head. See Section 3.4.
6.1.2. Flexure System
Eight radial flexures, four upper and four lower, and four tangential flexures form a
strong guidance system for the moving element. The moving element moves easily along
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