JB/T 12477-2018Foot mounted gearboxes for cranes (English PDF)

National Standard of the People's Republic of China

Replacing

JB/T 8905.2-1999

Issued by: Ministry of Industry and Information Technology of the People's Republic of China

Contents

• 1 Scope
• 2 Normative references
• 3 Type
• 3.1 Structural type
• 3.2 Assembly type
• 3.3 Shaft end type
• 3.4 Method of indicating the model
• 4 Basic parameters and dimensions
• 4.1 Centre distance
• 4.2 Transmission ratio
• 4.3 Basic profile of the gears
• 4.4 Module and helix angle of the gears
• 4.5 Overall dimensions and mounting dimensions
• 4.6 Load carrying capacity of the speed reducer and maximum radial load allowed on the output shaft end
• 5 Technical requirements
• 5.1 Working environment conditions
• 5.2 Main parts and components
• 5.3 Assembly requirements
• 5.4 Lubrication
• 5.5 Noise
• 5.6 Efficiency
• 5.7 Painting and appearance
• 6 Test methods
• 6.1 Visual inspection
• 6.2 No-load, load and overload tests
• 6.3 Contact spots
• 6.4 Cleanliness and tightness
• 6.5 Noise
• 6.6 Adhesion of the paint film
• 7 Inspection rules
• 7.1 Classification of inspection
• 7.2 Factory inspection
• 7.3 Type inspection
• 8 Marking, packaging, transport and storage
• 8.1 Marking
• 8.2 Packaging
• 8.3 Storage
• Annex A (informative) Instructions for the selection of the speed reducer
• A.1 Conversion of the power of the speed reducer
• A.2 Basic load for the fatigue calculation of the crane mechanisms
• A.3 Calculation of the power value
• Annex B (informative) Noise limits of the speed reducers with a nominal centre distance greater than 500 mm
• Figure 1 Assembly types of the speed reducer
• Figure 2 Types of output shaft end
• Figure 3 Speed reducer of type QJR-D
• Figure 4 Speed reducer of type QJS-D
• Figure 5 Speed reducer of type QJRS-D
• Figure B.1 Noise values of the speed reducer
• Table 1 Dimensions of the output shaft end
• Table 2 Nominal centre distance
• Table 3 Transmission ratio
• Table 4 Normal module of the gears
• Table 5 Overall and mounting dimensions of the speed reducer of type QJR-D
• Table 6 Overall and mounting dimensions of the speed reducer of type QJS-D
• Table 7 Overall and mounting dimensions of the speed reducer of type QJRS-D
• Table 8 Load carrying capacity of the speed reducer of type QJR-D for mechanism working class M5
• Table 9 Load carrying capacity of the speed reducers of type QJS-D and QJRS-D for mechanism working class M5
• Table 10 Load carrying capacity of the speed reducer of type QJR-D for continuous duty
• Table 11 Load carrying capacity of the speed reducers of type QJS-D and QJRS-D for continuous duty
• Table 12 Maximum radial load allowed on the output shaft end
• Table 13 Allowable misalignment and contact tightness
• Table 14 Dimensional tolerance zone, geometrical tolerances and surface roughness of the bearing bores
• Table 15 Parallelism tolerance of the axes of the bearing bores
• Table 16 Machining dimensional tolerance zone, positional tolerances and surface roughness of the reference bore and reference end face of the gears
• Table 17 Machining dimensional tolerance zone, positional tolerances and surface roughness of the reference journal and shoulder
• Table 18 Machining dimensional tolerance zone, positional tolerances and surface roughness of the shaft extension diameter and shoulder
• Table 19 Fit tolerances of the gear shaft, of the shaft and of the gear bore
• Table 20 Machining dimensional tolerance zone, positional tolerances and surface roughness of the keyway
• Table 21 Surface roughness of the working surfaces of the gears
• Table 22 Minimum limit backlash of the gear pair
• Table 23 Tightening torque of the bolts
• Table 24 Noise values
• Table 25 Inspection items