The Research Of The Friction Coupling On Hydro-viscous Drive

The Hydro-Viscous Drive(HVD) is a new type of power transmission device,utilizing the shear of oil film between two sets of discs. It is widely used for speed regulation and energy saving in large fans and pumps.With the development of HVD, using the friction pair of damp clutch indiscriminately can't meet HVD's physical application now. According to the special work condition on HVD, this thesis introduce the research and experiment of the friction coupling on Hydro-Viscous drive.Chapter 1 mainly introduces the background and significance of the research theme, including the performance of the Hydro-Viscous drive and the advantage of the application of Hydro-Viscous drive. It also introduce of the development of the hydro-viscous at home and abroad.In chapter 2, we explore the fundamental theories of the mechanism of oil film drive, which is the basis of HVD. Specifically, we derive the practical analytic solutions to the pressure distribution of the oil film and the parameters of the oil flow in the viscous drive for typical frication disks with radial grooves, based on analyzing the oil film between two sets of smooth discs. We also obtain the close-form solution to the load carrying capacity of the oil film. In our analysis we use a unique superposition-by-steps method of boundary conditions, which is based on the dynamical lubrication theory of the sector-thrust-step bearing. All the theoretical solutions by experiments are validated by experiments.Chapter 3 is mainly about the materials of friction coupling .In this chapter we study two kinds of friction material(copper-based firction material and paper-based friction material) which are wide-ranging applied in friction coupling. Further,we draw a selection principle of friction material for friction coupling of HVD,Chapter 4 we investigate the distortion of the friction discs in HVD devices. Specifically, we build the model of the thermodynamics and heat conduction, based on which we use numerical computations to derive the thermal loading distribution on the friction discs of a hydro-viscous drive, and to plot the curves of the instantaneous asymmetric temperature field along the radial direction of the discs as well as the instantaneous asymmetric thermal stress field. Our analysis unveils the main cause of the distortion of the discs and suggests methods for effectively preventing the distortion phenomena.Chapter 5 is the summary of the paper's study work and the prospect of the next step's work.