1.1 Application scope
This standard is applicable to important turbine gearing system adopted for turbine generator unit, turbine compressor, blower and centrifugal pump, etc.. The structure is closed and parallel to the fixed shaft, including helical tooth or double helical tooth, single-stage or two-stage involute cylindrical gear drive.
High-speed gearing system similar to the above scope may also refer to this standard.
Basic tooth profile of involute cylindrical gear shall meet "Basic Tooth Profile for Involute Cylindrical Gear" (GB 1356-78), other involute tooth profile agreed through joint negotiation of the Buyer and the Seller may also be adopted. Corresponding standard for gear accuracy is "Accuracy of Involute Cylindrical Gears" (JB 179-83). Load bearing capacity of gear is calculated according to "Methods for the Calculation of Load Capacity of Involute Cylindrical Gears" (GB 3480-83), while the bonding strength of gear is calculated according to "Calculation of Scuffing Load Capacity for Involute Cylindrical Gears" (GB 6413-86).
This standard is not applicable to gearing systems being integrated with other equipment.
This standard includes the technical requirements of relevant lubricating system, control device, instrument and other auxiliary equipment.
1.2 Special requirements
Where there is any special requirement from the Buyer or the Seller, the requirements in Oder Contract shall prevail.
1.3 Terms and definitions
The Buyer: the subscriber of gearing.
The Seller: the manufacturer of gearing.
Rated power of gear: the power specified by the Buyer in the Oder Contract, namely on the nameplate of gearing system.
Rated input speed of gearing: the specified rated speed of driver indicated by the Buyer in the Oder Contract.
Rated output speed of gearing: the specified rated speed of driver indicated by the Buyer in the Oder Contract.
Maximum continuous speed: the upper limit of speed of gearing system operated continuously. Such speed of variable unit shall at least equal to 105% the rated speed of small gear. Such speed of constant-speed unit is the rated speed of small gear.
Tripping speed: the act-speed of overspeed trip gear of prime motor (the tripping speed of steam turbine is 110% of the maximum continuous speed while that of steam turbine is at least 105% of the maximum continuous speed).
2 Technical Requirements
2.1 General
2.1.1 The design and manufacturing of gearing must follow the criteria of capable of operating normally for 3 years under the specified operating conditions.
2.1.2 Assessment of noise level of gearing: assess with sound power level according to "Determination of Sound Power Level for Noise Emitted by Gear Units" (GB 6404-86) while with sound-pressure level according to Appendix A.
2.1.3 The gearing shall be safely operated within the set tripping speed of the connected unit.
