A. Bertarelli

1
CERN European Organization for Nuclear Research
Actuating system of the LHC Collimators (Phase
1) Main Features Alessandro Bertarelli TS dept.
- MME Group May, 12 2005
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TECHNICAL DESIGN Mechanical Assembly
Vacuum Tank
Beam axis
Actuating system
External adjustment motor
Overall length 1480mm Tank width 260mm
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TECHNICAL DESIGN Collimator Cross-section
Jaw (25x80x1200 mm)
Support Bar
Cooling Pipes
Clamping springs
Bellow
Return Spring
Stepper Motor
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TECHNICAL DESIGN Actuating System
1
1
Each jaw is supported by two pivoting steel
axles, allowing rotational adjustment and axial
expansion.
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TECHNICAL DESIGN Actuating System
2
1
2
1
Each jaw is actuated by 2 stepper-motors (200
steps/rev) Each motor drives a specially coated
steel roller screw (2 mm lead, i.e. 10 mm/step)
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TECHNICAL DESIGN Actuating System
Support fixed plate
Sliding table
Linear guideways (schematic)
Sliding table
The axle is connected to a sliding table The
table can slide on a support fixed plate via
linear guideways
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TECHNICAL DESIGN Actuating System
1
1
A return spring (with adequate spring rate) per
each axle allows play suppression and ensures jaw
retraction in case of motor failure
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TECHNICAL DESIGN Actuating System
Grooves on this pinion allow angular play
Rack
Pinion
A rack and pinion system links the two axles. A
play on one of the pinions allows a maximum
relative gap of /- 3 mm