REPORT (14.12.1999)
MDT-wheel Assembling at the End (Vertical) Wall in the Cavern
Three holes ( see pos.12 Fig.1) will be made in each assembly unit of
the MDT-wheel (see pos.1,2…9, Fig.1) for pins (see pos.14, Fig.1)
Pins with the same nominal location of centers as for test horizontal
assembling, but of less diameter (that allows to compensate deviations from
nominal location of holes and pins as well as to move assembly units while
assembling within the hole limits), are placed at the end wall (at CERN) where
the MDT-wheel will be assembled.
The option of pin design at the end wall is shown in Fig.2. Pin is
threaded. Originally the thread is dressed with cone tip (see pos.9, Fig.2),
intended for getting into the holes of MDT-wheel plate of 30mm thickness.
Then the thread is used for sector fixing at the end wall. In this case cone
bushing, nut and washer are used (see pos.7 and 8, Fig.2). The cone bushing
(see pos.7, Fig.2) is intended for uniform distribution of sector weight among
the pins (since after sector suspension some pins may be unloaded).
Prior to lowering down into the cavern in hall SX 15 horizontal
assembling of eight sectors and inner ring is expected. For lifting preassembled sectors from assembly fixture, their lowering down into the cavern,
reloading from one crane to another and assembling at the end wall special
fixtures – two stiff steel frames and stand (see Fig.3) are used. To protect
from collisions with shaft walls projecting parts of the sectors are dressed with
protective caps. Because of adequate strength and stiffness of the inner ring
its transportation doesn’t assume significant difficulties.
The sequence of MDT-wheel assembling into the cavern at the end wall (see
Fig.1) is as follows:
1. Installation of inner ring (see pos.1, Fig.1) on three pins.
2. Two bottom sectors (see pos.2 and 3, Fig.1) are consistently
hanged on pins and connected with each other with flange joint.
3. Next two sectors (see pos.4 and 5, Fig.1) are consistently hanged
on pins and connected with two bottom sectors with flange joints.
4. Four top sectors (see pos.6,7,8 and 9, Fig.1) are consistently and
from the bottom to top are placed on pins and connected with
previously installed sectors and with each other. When sector pos.4
(Fig.1) is hanged and connected with sector pos.2 (Fig.1) it (and all
the following sectors –pos.5,6,7,8,9) are fixed at the wall with the
help of cone bushings pos.7(Fig.2). It allows more uniform
distribution of sectors weight among the pins.
5. Sector spokes are fixed with each other and with the inner ring.
6. Connection of locking devices of the first and middle rings (in the
direction from the center to outer frame).
7. Connection of two top flanges with half-axles (see pos.10, Fig.1),
with the help of which MDT-wheel is placed on movement
mechanisms.
8. MDT-wheel removal from the pins at the end wall (see pos.2) and
its placement on movement mechanisms, deployed on guiding rails.
The wheels are expected to be removed from the pins at the end wall with the
help of screw jacks (see pos.15, Fig.1).
Fig.1. Schematic diagram of MDT-wheel at the end wall (vertical)
1- inner ring; 2,3 …9 –sectors; 10- flanges with half-axles; 11-bottom element
for connection with mechanism for setting inclination angle; 12-holes in plates
of MDT-wheel assembly units; 13-plate of MDT-wheel assembly units; 14-pin
at the end wall; 15-screw jacks.
Digits in rectangles indicate the sequence of MDT-wheel assembling
operations.
Fig.2. Schematic diagram of installation of MDT-wheel assembly units on
pins.
1- assembly unit of MDT-wheel; 2-MDT-wheel plate of 30mm thickness; 3-end
wall (vertical); 4-pin; 5-pin fixing screw; 6-pin fixing dowel; 7-cone bushing; 8nut and plane washer; 9-cone tip; 10-casing of fixture for forced removal of
pins from MDT-wheel
1
2
3
Fig.3. Schematic diagram of stiff steel frame and stand, intended for sectors
lifting from assembly fixture, their lowering down into the cavern, reloading in
the cavern from one crane to another and assembling at the end wall
1- top sector of MDT-wheel; 2-stiff steel frame (red), links spokes and top
frame into stiff package – to reduce deformations while transportation; 3-stiff
steel stand (violet), intended for sectors lifting from assembly fixture, their
lowering down into the cavern, reloading in the cavern from one crane to
another and assembling at the end wall
TGC M1 Wheel Assembling at the End Wall in the Cavern
For the moment the wheel is expected to be transported by truck. For
these purposes the wheel will be disassembled into fragments freely placed in
a truck body. These fragments will be fixed at a transport frame generating a
single package. Perhaps, several packages will be required if not all
fragments can be put into one body.
At CERN for less work time to be spent in hall UX15 the fragments
should be assembled into as large parts as possible that can be lowered
down into the shaft. This partial assembling would be accomplished in hall
SX15.
It is expected that assembled fragment will be 1/6 of TGC M1 wheel.
For assembling 1/6 part and its lowering down into the cavern through 12,6m
shaft special fixture will be required – frame which design enables changing of
suspension and support places.
1. In hall SX15 1/6 part of the wheel will be assembled in horizontal position
on the frame. Then the frame with fixed first fragment of the wheel (I) will
be lifted into vertical position. Total weight of the wheel fragment and the
frame is less 6 tons.
The frame with fixed fragment will be lowered down with a crane from hall
SX15 to hall UX15. The frame will be put on the cavern bottom for reloading
to another crane operating inside the cavern. The frame will be moved to end
wall with the crane and the fragment will be hanged on pins, located at the
cavern end wall. This wheel fragment is hanged on three pins.
The diagram in AutoCAD v.14 format is presented (see STEP 1_TGC).
2. In parallel assembling of another 1/6 part of the wheel is possible. The
second wheel fragment (II) – is adjacent part, located to the right from the one
placed into the cavern. Similar operations described above will be conducted
with the second fragment.
The diagram in AutoCAD v.14 format is presented (see STEP 2_TGC).
Thus, to reduce time for wheel assembling two frames are required (or more
depending upon a number of groups of operating personnel). With the help of
one frame a group of operating personnel fixes fragment to end wall in hall
SX15, on another frame second group of operating personnel assembles next
fragment in UX15. Then the frames exchange their places.
The second fragment is hanged on pins and joint with the first
fragment. Probably pins design will enable their advance into the fragment
holes or these pins will have different length (to be discussed)
3. Third fragment (III) –is adjacent left part for the first part of the wheel,
already placed into the cavern. Similar above described operations will be
conducted.
4. Fourth fragment (IV) – is right top 1/6 part of the wheel with a part of main
beam.
5. Fifth fragment (V) – is left top 1/6 part of the wheel with a part of main
beam.
The diagram in AutoCAD v.14 format is presented (see STEP 5_TGC).
6. Sixth fragment (VI) –is top 1/6 part of the wheel with a part of main frame.
The diagram in AutoCAD v.14 format is presented (see STEP 6_TGC).
When the wheel assembling at the end wall is completed the Big wheel must
be put on end carriages in the cavern. Jacks are expected to be used for
these purposes. They lift the wheel through the main beam. Freed pins are
removed under small value of the wheel lifting. Then the Big Wheel is lowered
and fixed in hinges on the end carriages.
Notes
TGC M1 wheel assembling at the end wall in the cavern is under
discussion.
Please provide the information about time limits for partial assembling in hall
SX15 and final assembling in hall UX15.
Is it possible to avoid partial assembling and increase time for a final
assembling? Place a package with the wheel fragments into hall UX15 at
once. The Big wheel will be assembled at the end wall of light fragments at
once by two groups of operating personnel.
FEA calculations
We studied the possibility to model joint elasticity by coupling certain
degrees of freedom set. FEA calculations of MDT-octant for combination ofshell-and-beam finite-element models with account of such joints are
conducted. We are comparing the obtained results with previous calculations.
Specified shell finite-element model of the MDT-octant which will be
used for reference FEA-calculation is under work
Summarizing and analysis of the calculations results of the bolted and
welded joints as well as other design elements for new values of the member
forces is done.