Iso Tr 14179-2 Pdf [2021]

ISO Technical Report (TR) – not a full International Standard, but a supporting document providing explanatory or application guidance.

The document presents methods for determining the thermal load-carrying capacity of gear units, primarily through:

Rates gear drives based on a fixed thermal equilibrium at an artificial limit of 95 °C oil sump temperature.

The technical report is a critical international standard that establishes analytical methods and practical measurements for determining the thermal load-carrying capacity of mechanical gear drives . In high-performance machinery design, managing the thermal equilibrium—the balance between power losses generated as heat and the system's ability to dissipate that heat—is vital to prevent premature component failure and lubricant degradation. iso tr 14179-2 pdf

The thermal capacity calculation in ISO/TR 14179-2 revolves around modifying a baseline thermal rating ( Pt0cap P sub t 0 end-sub ) to find the permissible thermal power ( Ptgcap P sub t g end-sub ) for a specific application. 1. Baseline Thermal Capacity ( Pt0cap P sub t 0 end-sub

For splash-lubricated gear units—those where gears dip into an oil bath to distribute lubricant—the standard prescribes a method for determining the . This approach is particularly relevant for industrial gearboxes where oil temperature serves as a key indicator of thermal health.

: Measured via torque differentials or input/output energy monitoring. ISO Technical Report (TR) – not a full

(Duty Cycle / Intermittent Operation Factor): Gearboxes that run intermittently can cool down during periods of rest. This factor allows for higher peak power limits compared to continuous 24/7 duty. Why Managing Thermal Capacity Matters

: Specifically for splash-lubricated gear units, it provides methods to determine the quasi-stationary temperature in the oil sump. Key Components of Thermal Balance

: It offers analytical methods to calculate individual parts of power loss—such as gear mesh friction, bearing losses, and shaft seal friction—as well as heat dissipation through the housing and foundation. Baseline Thermal Capacity ( Pt0cap P sub t

The document utilizes an iterative calculation method to determine the expected oil sump temperature for a given load, or conversely, the maximum power allowable for a specific temperature limit. 1. Power Loss Components

Inadequate oil film thickness causes scuffing, bearing wear, and seal failures.