5.4　Tilting Device

5.4.1　The gear of secondary speed reducer should be assembled via cold shrinking method，which shall also meet the following requirements:

1　The gear，trunnion and key shall be cleaned up and free of dirt and burr.

2　As for assembly of gear and trunnion，in case that the gear's axle hole and the trunnion shaft are cylindrical，the gear's end face and the trunnion's shaft shoulder shall be tightly contacted and inspected with feeler gauge with the local clearance of not larger than 0.05mm；in case that the gear's axle hole and the trunnion shaft are cone，the backing ring shall be tightly contacted with the gear's end face and the end face of the trunnion's groove with the local clearance of not larger than 0.05mm.

3　The actual dimensions of keyway and key shall be inspected and conform to the requirements of the design technical document.

4　The contact area between the key and its mesh slope and the working face of keyway shall be larger than 70%，and the grinding of their contact face shall not result in the change in the geometric tolerance and size tolerance of key.

5　The assembly depth of key shall be calculated and determined according to the actually-measured dimensions of key and keyway as well as the design interference value of key，and marked on it.The keys shall be numbered and tagged.

6　The keyways and keys shall be cleaned again.

7　Firstly place the key into the cooling tank in which the cooling medium should be liquid nitrogen，then slowly inject the cooling medium into the tank until the key is completely immersed into it，and finally kept the temperature to cool the key as required.After the cooled key meets the requirement for assembly，two pairs of keys shall be assembled to the marked depth at the same time.

8　During the temperature of key returning to the room temperature，the applicable displacement measure shall be taken and any tilting device shall not be installed.After returning to the room temperature，the assembly of key shall be checked and comply with the requirement of the design technical document.

9　The operators shall be protected against being frosted by liquid nitrogen.

5.4.2　The pinion and shell of secondary speed reducer should be installed in accordance with the following requirements:

1　The pinions shall be installed and positioned based on the gears.The mesh clearance and contact surface of pinions shall be adjusted according to the requirement of the design technical document，or related requirements of current national standard General Code for Construction and Acceptance of Mechanical Equipment Installation Engineering GB 50231 in case of no requirement in the design technical document.

2　The shell shall be adjusted and positioned based on the trunnions during installation.Its levelness shall be inspected on its subdivision surface according to the requirement of the design technical document.The subdivision surface shall be applied with heat-and-oil-resistant sealant and assembled and free of leakage.

5.4.3　The primary speed reducer shall be positioned based on the secondary speed reducer.The shaft seal with the shell shall conform to the requirement of the design technical document.

5.4.4　For the installation of lubricating device，the piping and elements shall be cleaned up and assembled according to the design drawings.

5.4.5　The torsion bar installations shall be installed in accordance with the following requirements:

1　The torsion bar support shall be installed in accordance with the following requirements:

1）The distance from the longitudinal center line of the torsion bar support to the axis of the trunnion shall be adjusted，and the measurement by plumb wire should be carried out，with the allowable deviation of±1.0mm.

2）The distance from the horizontal center line to the center line of the bearing pedestal at the fixed end shall be adjusted，and the measurement by plumb wire should be carried out，with the allowable deviation of±0.5mm.

3）The distance from the axle hole center of the torsion bar support to the axis of trunnion shall be adjusted，and the measurement by plumb wire should be carried out，with the allowable deviation of 1.0mm.

4）The levelness of the torsion bar support shall be adjusted，and the measurement by leveler should be carried out，with the allowable deviation of 0.2/1000.

2　The retaining support shall be installed in accordance with the following requirements:

1）The distance from the longitudinal center line of the retaining support to the axis of the trunnion shall be adjusted，and the measurement by ruler should be carried out，with the allowable deviation of±2.0mm.

2）The distance from the horizontal center line to the center line of the bearing pedestal at the fixed end shall be adjusted，and the measurement by ruler should be carried out，with the allowable deviation of±2.0mm.

3）The clearance between the top surface of retaining support and the bottom of shell of secondary speed reducer shall be adjusted in accordance with the requirement of the design document，and the measurement by ruler or feeler gauge should be carried out，with the allowable deviation of±1.0mm.

4）The levelness of retaining support shall be adjusted，and the measurement by leveler should be carried out，with the allowable deviation of 0.2/1000.

3　The shell，tie（compression）bar，torsion arm and torsion bar shall be connected.The levelness of torsion bar shall be adjusted，and the measurement by leveler should be carried out，with the allowable deviation of 1.0/1000.