Research on the thrust force reduction effect of balance holes on a turbine hub in a hydrodynamic torque converter

To reduce the thrust force in a hydrodynamic torque converter, the influence of balance holes on the thrust force that is set on a turbine hub was investigated. A full-flow-passage computational model was built to analyze the relationship between the thrust force reduction effect and the number of balance holes with different design parameters by flow-field analysis and design of experimental techniques. The results indicated that at a low speed ratio, the thrust force of the pump and the turbine decreased with a larger distribution radius and a larger hole diameter, and a total of 6 to 10 balance holes were set to optimally reduce the thrust force of the pump and the turbine, while at a high speed ratio, these parameters affected the thrust force slightly. The parameter sensitivity analysis also showed that the distribution radius plays more important roles than the number of balance holes and the hole diameter. The reasonable measure to reduce the thrust forces from the viewpoint of balance hole design in a torque converter is to increase the distribution radius and hole diameter as much as possible and set the number of balance holes in the range of 6 to 10.