Lubrication has been a major area of interest in engineering. Especially in
vehicle transmissions, lubrication plays a very crucial role because gears and
bearings are constantly subjected to heavy loads. Proper lubrication is
essential for maintaining system performance and ensuring endurance life.
Insufficient lubrication can lead to excessive wear, increased friction, and
eventually, failures in the transmission components. However, excess lubrication
can result in power losses due to the resistance offered by the excessive
lubricant. Therefore, achieving effective lubrication using optimized
lubrication system design is vital for ensuring the longevity and efficiency of
the transmission system.
Majorly, two types of lubrication methods are used in transmissions: splash
lubrication and forced lubrication. This article focuses on forced lubrication,
where the lubrication system actively delivers the required flow of lubricant to
specific locations within the transmission. Pump outflow, orifice diameters, and
channel dimensions are a few of the critical design parameters of the forced
lubrication system. This article presents two design optimization methods: one
using ANSYS DX (3D) and the other using GT-Suite (1D) tool. In the 3D method,
ANSYS Fluent is used for CFD (computational fluid dynamics) simulations and
subsequently ANSYS DesignXplorer (DX) is leveraged for design optimization.
Predictions from CFD simulations are validated against physical test data and
show good agreement (>90% match for flow rate). GT-SUITE is used in the 1D
method, which is validated with predictions from 3D CFD method. The optimized
designs obtained from both methods are effective in achieving the desired flow
rate distribution, demonstrating their reliability. The ANSYS DX method provides
an advantage in terms of reduced overall turnaround time (50% less) for the
optimization. On the other hand, co-simulation (CFD+1D) approach can prove
beneficial if it is required to perform minor routing changes on the lube system
layout.
