The calculation for heat dissipation in a gear unit

Standard:ISO/TC 60/WG 6

1.Heat dissipation through the housing:

Overall height of gear unit housing : h ca = [m]
Temperature of housing wall : T wall = [K]
Temperatura okolice: Too = K
Kinematic viscosity of air : NIair = [m2/s]
Impingement velocity : vair = [m/s]
Flow length : Ix = [m]
Cooling air temperature : T air = [K]
Overall housing area (external) : Aca = [m2]
Ventilated housing area : Aair = [m2]
Emission ratio of gear unit ratio : EPSILON = [-]
Oil side heat transfer : ALFAoil = [W/m2K]
Overall housing area (internal): Aoil = [m2]
Mean housing wall thickness : DELTAwall = [m]
Thermal conductivity of housing : LAMBDAwall = [W/mK]
Oil temperature : THETA oil = [C]

Choose the tipe of hiusing(with/without thermal fining):

- Housing without thermal fining
- Housing with thermal fining



-Specification for housing with thermal fining :

Projected fin area : Apro = [m2]
Total fin area (housing external): Afin = [m2]
Thickness of one fin : DELTAfin = [m]
Thermal conductivity of the fin : LAMBDAfin = [W/mK]
Depth of one fin : Ifin = [m]
-Choose the tipe of fin convection:

 -For free convection(Aair=0)
-For free convection and ventilated fin surface(Afin=Aair)
-For free and forced convection(Aair>Aca)

2.Heat dissipaton via the foundaton:

Footprint of gear unit : Afoot = [m2]
Gear unit bottom area : Abot = [m2]
Thermal conductivity of foundation : LAMBDAfun = [W/mK]
Heat transfer coefficient at gear unit foundation : ALFAfun = [W/m2K]

Insert only needed Aq data for foundation of gear unit (foundation is devided in many parts wich compose the whole foundation of gear unit)!

-Insert data for Aq successively (the Aq data wich is not inserted must be 0 and will not be included in the calculation).

Chose the direction of heat dissipation :

 -Upwards and downwards
-Only in upward direction(insulated underneath)

3.Heat dissipation via shaft and couplings:

-INSERT THE DATA FOR INPUT SHAFT:

Speed: n = [1/min]
Shaft diameter : Dsh = [m]
Kinematic viscosity : NIL = [m2/s]
Temperature of the shaft T sh = [K]
Thermal conductivity : LAMBDAL = [W/mK]
Thermal conductivity of shaft : LAMBDAsh = [W/mK]
Thermal conductivity of coupling : LAMBDAfl = [W/mK]
Temprature of coupling : T fl = [K]
Equivalent flange diameter : Dfl = [m]
Cross-sectional area of shaft : Aq,sh = [m2]
Cross-sectional area of coupling: Aq,fl = [m2]
Equivalent length of coupling flange : lfl = [m]
Leght of free shaft end :lsh = [m]

-INSERT THE DATA FOR OUTPUT SHAFT:

Speed: n2 = [1/min]
Shaft diameter : Dsh2 = [m]
Temperature of the shaft : T sh2 = [K]
Thermal conductivity of shaft : LAMBDAsh2 = [W/mK]
Thermal conductivity of coupling : LAMBDAfl2 = [W/mK]
Temprature of coupling : T fl2 = [K]
Equivalent flange diameter : Dfl2 = [m]
Cross-sectional area of shaft : Aq,sh2 = [m2]
Cross-sectional area of coupling : Aq,fl2 = [m2]
Equivalent length of coupling flange :lfl2 = [m]
Leght of free shaft end :lsh2 = [m]

4.Heat dissipation via an external cooler:

Oil injection rate : Voil = [l/min]
Density of oil at operating temperature : ROoil = [kg/dm3]

-Withowt cooler(only lines and pump outside the housing)
-Withhout cooler on large gear units, continuous operation at rated power
-With cooler on small gear units, periodic duty usually 70% rated power

After you insert all needed data press the button to calculte the results:
To calculate press :