After The Paper Machine Has Been Installed And Operated For A Period Of Time, Various Meshing Points Of The Gearbox Have Leaked To Varying Degrees, Forming An Oil Accumulation Area At The Base Plate Of The Paper Machine. The Following Reasons Are Analyzed And Summarized:

(1) Due To The Uneven Distribution Of The Mass Center Of Gravity Of The Drying Cylinder (the Weight Of A Single Drying Cylinder Is About 5 Tons), And The Drying Cylinder Is Heated By Steam, During The Operation Of The Equipment, The High-pressure Steam Forms Condensate In The Drying Cylinder, Which Causes Unfavorable Drainage Of Condensate During High-speed Operation, And Forms A Centrifugal Force In The Drying Cylinder. To Release This Force, The Drying Cylinder Can Only Move Towards Both Ends Of The Drying Cylinder, Causing Vibration Of A Certain Frequency At The Gear Mesh. Generally, Modern Multi Cylinder Paper Machine Is Composed Of 55-80 Cylinders, Which Produce Such Vibration Together During Operation, Resulting In Leakage At Each Meshing Position, Which Is Mainly Caused By Leakage;

(2) As The Drying Cylinder Is Heated By Saturated Steam, The Steam Temperature Is 120 ℃ - 130 ℃. The Self Absorption Heat Of The Metal Frame In The Closed Steam Hood Can Reach 150 ℃, And The Thermal Expansion And Cold Contraction Make The Clearance At The Fitting Position Of Individual Parts Too Large (such As The Junction Between The Drying Cylinder And The Gearbox), Causing Leakage;

(3) Sealant Is Applied Between The Mating Surfaces Of Various Parts Of The Gearbox, Which Causes Long-term High-temperature Vibration, Leading To Seal Failure And Leakage;

(4) The Gear Box Is A Casting, Which Shall Undergo Aging Treatment During Production. If The Aging Time Is Short And The Internal Stress Of The Gearbox Is Not Completely Eliminated, The Installed Gearbox Will Continue To Deform During Operation, Resulting In Leakage;

(5) During Installation Or Maintenance, Different Materials Of Bearing Gland, Gear Gland And Gear Shaft Will Lead To Different Coefficient Of Thermal Expansion During Operation. Therefore, The Expansion Clearance Is Required To Be Greater Than A Certain Standard During Installation. In The Actual Operation And Installation Process Of The Gearbox, Due To Improper Maintenance And Installation Process, The Expansion Clearance Is Less Than The Standard Value, Which Will Cause The Gearbox To Bear The Strong Expansion Force Of The Components In The Gearbox During Operation, Resulting In Deformation And Leakage;

(6) In Order To Ensure The Sealing Effect Of The Junction Surface Of The Gearbox, The Elongation Of Each Cold Tightened And Hot Tightened Bolt Is Also Clearly Specified. However, In The Actual Maintenance Work, If The Bolts Are Not Tightened As Required, The Joint Surface Will Deform And Leak.