Effects Of Oil Groove On Hydro-viscous Transmission Characteristics With Variable Rotate Speed

Hydro-viscous transmission is a new type of fluid transmission,it uses the discoid oil film between friction disks to transmit power and realize speed regulation by changing oil film thickness.Hydro-viscous transmission is widely researched for its excellent performance in the field of speed regulation and energy-saving of high-power equippment.There have already been a lot of research on hydro-viscous transmission mechanism,but still no research on influence of friction disk rotate speed and oil groove structure on hydro-viscous transmission characteristics.According to the existing problems,following aspects are throughly researched in the dissertation:Basic mathematic model of hydro-viscous transmission and numerical calculation model of the oil film between friction disks are built.Grid independence test and verification are done with structural grid and unstructural grid both in consideration.Finally,the most suitable meshing schemene was achieved.Theoretical analysis and numerical calculation are done to research the impact of passive disk rotate speed on hydro-viscous transmission characteristics,while the rotate speed difference between active disk and passive is the same.Results show that,while passive disk rotate speed increases,oil film coverage rate decreases,torque transmitted decreases and fluid temperature rises.According to numerical calculation results,the influence of oil groove structure on torque transmission is analysized.The scheme,decreasing oil groove width or depth with the rise of radius and effective area constant,was raised to increase torque transmitted.Under the condition of the same rotate speed difference and variable passive disk rotate speed,impact of oil groove width and depth on hydro-viscous transmission characteristics are then researched.Research show that: with decrease of outter oil groove width,torque transmitted rises.When2?=0.5?,the torque transmitted is almost 200% of that of2?=4.5?.With decrease of outter oil groove depth,torque transmitted rises.The torque transmitted with2h=0.05 mm is almost 150% of that with2h=0.2mm.According to the experiment scheme,hydro-viscous clutch experiment bench was built.Experiment results show that,while rotate speed difference is constant,torque transmitted decrease with increase of passive disk rotate speed.Under the condition of constant relative rotate speed and variable passive disk rotate speed,torque transmitted increases with decrease of outter oil groove depth while fluid temperature is almost unchanged.